Journals >Spectroscopy and Spectral Analysis
Contents
2016
Volume: 36 Issue 11
62 Article(s)
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Research Article
Review on the Methodology for Optical Parameter Extraction with Terahertz Time-Domain Spectroscopy
HAN Xiao-hui, ZHANG Jin, YANG Ye, MA Yu-ting, CHANG Tian-ying, and CUI Hong-liang
Optical parameters which macroscopically characterize optical properties of materials indirectly reflect microscopic peculiarities of materials. Accurate extractions of optical parameters are significant for the research of microscopic behavior and macroscopic responses of materials. In recent years, as a new spectral Optical parameters which macroscopically characterize optical properties of materials indirectly reflect microscopic peculiarities of materials. Accurate extractions of optical parameters are significant for the research of microscopic behavior and macroscopic responses of materials. In recent years, as a new spectral analysis method, terahertz time-domain spectroscopy (THz-TDS) technology has become a research hotspot. Due to the low THz radiation energy and narrow pulse width (picosecond range), THz-TDS technology is nondestructive with high-temporal-resolution when being used to extract optical parameters of samples. This paper summarizes optical parameters extraction methods by using THz transmission and reflection spectroscopy technology, emphatically introduces several classic methods and analyses, along with their respective merits and demerits, and finally discusses the challenges of THz-TDS technology in optical parameters extraction. In conclusion, the transmission methods are adaptive for measuring substances which slightly absorb terahertz radiation, whereas the reflection methods are suitable for measuring materials with strong absorption capacity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3449 (2016)
Study on the Turning Effect of the Energy Gap of π Electron on Atomic Vibration in Conjugated Linear Polymer
HE Xin, SUN Mei-jiao, LI Shuo, GAO Shu-qin, SUN Cheng-lin, LI Zuo-wei, HE Zhi, and SONG Wen-zhi
The Visible absorption and Raman spectra of β-carotene were measured in dimethyl sulfoxide in temperature ranging from 81 to 25 ℃ and in carbon disulfide in pressure range from 0.04 to 0.60 GPa, respectively. The results indicated that the visible absorption and Raman spectra are both red-shifted, Raman scattering crosThe Visible absorption and Raman spectra of β-carotene were measured in dimethyl sulfoxide in temperature ranging from 81 to 25 ℃ and in carbon disulfide in pressure range from 0.04 to 0.60 GPa, respectively. The results indicated that the visible absorption and Raman spectra are both red-shifted, Raman scattering cross section increase with the temperature decreasing. And with the pressure increasing, the visible absorption spectra are red-shifted, but the frequency shift towards higher frequencies in the Raman spectra, the Raman scattering cross section decrease unexpectedly. The latter can’t be explained by the model of “effective conjugation length” and “coherent weakly damped electron-lattice vibrations”. In this paper, we combined electron-vibration coupling rule with theoretical calculations and found that the electron-phonon coupling constant had a certain changing trend with the temperature and pressure variation, which Indicate that the interaction between π-electron and CC bond vibration was essential for this experiment result. Thus, the turning effect of energy gap of the π on CC vibration mode is responsible for such phenomenon..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3455 (2016)
Application Progress of Holographic Lithgraphy in Fabrication of Micro-Nano Photonic Structures
WANG Xia, L Hao, ZHAO Qiu-ling, ZHANG Shuai-yi, and TAM Wing-yim
Micro-nano photonic structures are developing vigorously based on the progress of photonics, semiconductor physics and microfabrication technology. A series of results are achieved in structure characterization, theory, and fabrication of them. Most high quality photonic structures are man-made ones; however, there areMicro-nano photonic structures are developing vigorously based on the progress of photonics, semiconductor physics and microfabrication technology. A series of results are achieved in structure characterization, theory, and fabrication of them. Most high quality photonic structures are man-made ones; however, there are still some challenges in fabricating artificial large-area and high-quality photon materials. With the advantages of photonic structure processing technology, holographic lithography, a low-cost, time-saving and high-efficiency microfabrication method, performs superior application potentials in making metamaterials as well as photonic crystal templates. In this article, we introduced the principles of holographic lithography and described the applications in fabricating various micro-nano photonic structures, such as three dimensional face-center-cubic, wood-pile, diamond-like photonic crystals, as well as quasi-crystalline structure, chiral metamaterials and periodic defect-mode structures. Moreover, the applications of some structures in solar cell and optical fiber sensing are discussed. The success of fabricating micro-nano photonic structures by holographic lithography would pave the way for more applications of these structures in wide fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3461 (2016)
Optical Properties of Ag-Al Nanosphere Heterodimer
CHENG Long, JIANG Yong-gang, HUANG Li-qing, ZHANG Yu, WU Ji, SUN Hao, LIU Qi, and WANG Jun
Metal nanostructure material has attracted great attention due to its surface plasmon resonance. The optical properties of heterodimer metallic nanostructure materials are different compared with that of homogeneous nanostructure materials because their symmetry structure is broken. The symmetry of the original structuMetal nanostructure material has attracted great attention due to its surface plasmon resonance. The optical properties of heterodimer metallic nanostructure materials are different compared with that of homogeneous nanostructure materials because their symmetry structure is broken. The symmetry of the original structures will be changed, and the interaction between the two particles will produce Fano resonance. The Fano resonances are the result of the double or more surface plasmon resonances coupling, and be controlled by properly controlling the nanostructures. The electric field enhancement and the radiation characteristics of the nanostructure are further optimized for the Fano resonance controlled. Aluminum nanostructure materials have become the best choice of the surface plasmon resonance in the UV region, because gold, silver and other noble metals have inter-band transition effects. In this work, we study the local field and absorption spectra of heterodimer composed of a silver nanosphere and an aluminum nanosphere by the Finite-Difference Time-Domain (FDTD) theory. Firstly, the effects of the incident polarization, the geometric like, nanospheres separation, nanosphere radius and physical dielectric media on the optical response of silver-aluminum nanospheres heterodimer are analyzed. Secondly, the near field distributions of heterodimer are given in-depth discussion. Due to the destruction of the symmetry of dimer material, heterodimeric optical character is significantly different from homodimer. Fano resonances are produced in UV and visible light in the heterodimer respectively when silver-aluminum nanospheres heterodimer is illuminated by the Y-polarized light. More favorable Fano resonance effects can be obtained by regulating the spacing and size of heterodimer in the given dielectric environment which is also an effect factor certainly. Finally, the absorption of the heterodimer contributed from each nanosphere structure is also analyzed. In this way, the result which is a general and complete description of the optical properties of silver-aluminum nanospheres heterodimer nanostructure in the paper, leads to the suppression and enhancement of the surface plasmon resonance in different frequency bands and may be valuable for the design and development of plasmonic devices and optical tools in UV-visible light and could serve as the basis of the future experimental analysis of surface enhanced spectroscopy, molecular detection and biosensor etc..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3470 (2016)
The Acceleration of Monte Carlo Simulation for Optical Transmission in Large Space Biological Tissue
YANG Xue, LI Gang, LIU Yan, ZHAO Jing, and LIN Ling
Typically, it is time-consuming to use Monte Carlo simulation to model light propagation in turbid media, such as breasts, mainly because of the thick simulated tissue and the large number of photons required by the stochastic nature of MC simulations. In this paper, in view of the light source and the receiver in a stTypically, it is time-consuming to use Monte Carlo simulation to model light propagation in turbid media, such as breasts, mainly because of the thick simulated tissue and the large number of photons required by the stochastic nature of MC simulations. In this paper, in view of the light source and the receiver in a straight line, the transmitted light received by optical fiber model is analyzed; in terms of the optical properties of biological tissue itself, implementation of boundary constraint conditions and restriction of the number of backscatter events have been developed to reduce the simulation time. It is verified that the calculation is relatively simple by many experiments, when the position after two scattering is regarded as the demarcation and the boundary constraint conditions are efficiently solved by optical parameters of tissue respectively. At the same time, considering the actual situation in incident and emergent position, the boundary constraint conditions are expanded. The number of backscatter of every photon that received by optical fiber in the same position are recorded and tissues are selected different thickness and the similar optical parameters in the simulations. Additionally, it is found that the number of backscatter would increase as the depth of tissue or scattering coefficient increases, or as absorption coefficient or anisotropic factor decreases. Therefore, the time is saved further through limiting the number of backscatter. The simulation results show the combination of those new methods reduces the operation time of the MC simulation by 50% on a typical desktop computer. Those new methods are especially suitable for MC simulations of the thick tissue or the scatterer with a complex boundary. This acceleration method is applicablewhen light source and receiver are in a straight line the biological tissue is thicker and scattering coefficient is large. It can effectively save needed time and be beneficial to analyze the transmission imaging..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3476 (2016)
Measurement of Soot Yield from the Pyrolysis of Toluene at High Temperatures by Laser Extinction Method
XIAN Lei-yong, LI You-liang, HE Jiu-ning, ZHANG Chang-hua, LI Ping, and LI Xiang-yuan
The measurement system for the detection of soot production as high-temperature pyrolysis of hydrocarbon fuels behind the reflected shock wave was established. By using the laser extinction method, the soot yields of toluene/argon mixtures were measured at high temperatures. The mole fractions of toluene were 0.25% andThe measurement system for the detection of soot production as high-temperature pyrolysis of hydrocarbon fuels behind the reflected shock wave was established. By using the laser extinction method, the soot yields of toluene/argon mixtures were measured at high temperatures. The mole fractions of toluene were 0.25% and 0.5% while the pressures were approximate 2 and 4 atm. The temperatures ranged from 1 630 to 2 273 K. The dependence of soot yield on the temperature, pressure and fuel concentration was obtained. With the changes of temperature, the soot yield is a Gauss distribution. The soot yield increases as the pressure or fuel concentration increases. The maximum of soot yield was as high as 55%. The peak temperature of soot yield was not changed dramatically with the pressure. However, it changed from 1 852 to 1 921 K as the concentration of toluene increase from 0.25% to 0.5%. Moreover, we compared the soot yield between toluene and methylcyclohexane at pressure of 4 atm with fuel concertation of 0.5%. During the pyrolysis of methylcyclohexane, the peak temperature of soot yield was 2 045 K, which is about 135 K higher than that of toluene. However, the maximum soot yield of methylcyclohexane is only 1/8 of toluene. This work provides experimental reference for the research of soot particle emission in the engines and the mechanism of soot formation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3481 (2016)
Research on the Distribution of Gas Concentration of Two-Dimensional Reconstruction Based on Tunable Diode Laser Absorption Spectroscopy with Multispectral Absorption
ZHANG Li-fang, WANG Fei, ZHANG Hai-dan, WU Qi, YAN Jian-hua, and CEN Ke-fa
The two-dimensional concentration distribution was reconstructed by using algebraic iterative reconstruction algorithm. This paper mainly focused on the effects of multispectral H2O absorptions on condition that the laser beam was less and the temperature was known, i.e. the influence of temperature on spectral line-stThe two-dimensional concentration distribution was reconstructed by using algebraic iterative reconstruction algorithm. This paper mainly focused on the effects of multispectral H2O absorptions on condition that the laser beam was less and the temperature was known, i.e. the influence of temperature on spectral line-strength was not considered as to this concentration distribution. Based on ART algorithm, increased spectral lines and increased laser beam were compared under the same concentration model. Three H2O lines were selected to reconstruct two-dimensional distribution of non-uniform gas concentration, and these three transitions were selected within the external cavity diode laser turning range in the simulated system. The interested region was discretized to 10×10 grid points, and the temperature and concentration of the reconstruction model were not evenly distributed, so the unimodal distribution and bimodal distribution were used to describe the concentration distribution. The simulated system also calculated the effective utilization of laser beams and absorption lines. The results showed that the reconstruction quality quickly increased with increasing H2O absorption lines when the laser beams were very few, the increased absorption lines could get more spectral information related to the concentration. The increased laser beam is also effective to improve the accuracy of reconstruction results, but increasing the absorption lines can better reconstruct a two-dimensional concentration distribution. Improving the absorption lines can also effectively reduce the costs of the hardware and the complexity of the measurement system, which shows that the multispectral absorption lines are applicable to in-situ measurements..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3485 (2016)
Research on Radiation Spectrum of Pulverized Coal Combustion Flame
GUI Xin-yang, Aymeric Alliot, YANG Bin, ZHOU Wu, PING Li, and CAI Xiao-shu
In order to study on radiation spectrum of pulverized coal flame, radiation spectrums of pulverized coal flame on flat flame burner were measured with fiber optic spectrometer and the radiation characteristic was analyzed in detail. Distribution curves of radiation intensity of flame with wavelength were obtained basedIn order to study on radiation spectrum of pulverized coal flame, radiation spectrums of pulverized coal flame on flat flame burner were measured with fiber optic spectrometer and the radiation characteristic was analyzed in detail. Distribution curves of radiation intensity of flame with wavelength were obtained based on Planck’s Law and calibration by using blackbody furnace. Then, combustion parameters such as temperature and emissivity were calculated by using least square method. Therefore, the measurement method based on radiation spectrum of pulverized coal flame was proposed. And the experimental investigations on pulverized coal flame under different conditions were carried out with this method. The result shows that the radiation spectrum of pulverized coal flame is significant and continuous in the wavelength ranging from 200 to 1 100 nm.The temperature and emissivity of flame can be determined by using Planck’s Law and least square method. Meanwhile, emission peaks of alkali metal such as sodium and potassium appear on the radiation spectrum of pulverized coal combustion flame near 590, 766, 769 and 779 nm, and the appearance of these emission lines is related with temperature. When the concentration of pulverized coal is increasing, the temperature of pulverized coal flame has a little change but the emissivity changes obviously. The intensity of radiation is increasing greatly with emissivity. It can provide important reference for combustion optimization of boiler..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3492 (2016)
Laser Induced Time-Resolved Fluorescence Spectroscopy Characteristics of Fluoranthene in Ethanol with Eanosecond Laser of 355 nm
XIAO Xue, ZHAO Nan-jing, YU Shao-hui, MA Ming-jun, and YANG Rui-fang
Polycyclic Aromatic Hydrocarbons (PAHs) have been widely investigated in environmental field, for most of them are mutagenic (carcinogenic, teratogenic, mutagenic). The influence of delay time and gate width on the time-resolved fluorescence spectroscopy of fluoranthene in ethanol was studied in this paper. FurthermorePolycyclic Aromatic Hydrocarbons (PAHs) have been widely investigated in environmental field, for most of them are mutagenic (carcinogenic, teratogenic, mutagenic). The influence of delay time and gate width on the time-resolved fluorescence spectroscopy of fluoranthene in ethanol was studied in this paper. Furthermore, laser induced time-resolved fluorescence spectroscopy of fluoranthene with different concentration were also researched. According to the results, fluorescence kinetics decay curves and fluorescence lifetime of fluoranthene matched. The research results showed that there was closely relationship between the fluorescence spectrum of fluoranthene and the delay time and gate width of detector. When the delay time was fixed, the fluorescence intensity of fluoranthene grew increased as the gate width increased. When the gate width was fixed, the fluorescence intensity of fluoranthene increased first and then decreased with the delay time increases. The process of the attenuation of fluorescence intensity of fluoranthene with time delay conformed to the exponential decay process. The stepwise dilution of fluoranthene ethanol solution was also studied. With increasing dilution, the fitting of fluoranthene fluorescence lifetime increased. The results of this paper can provide a technical basis for the detection of PAHs in the environment, due to the different characteristics of the fluorescent substance having fluorescence lifetime..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3497 (2016)
Online Detection System on Acetylene with Tunable Diode Laser Absorption Spectroscopy Method
HE Qi-xin, LIU Hui-fang, LI Bin, PAN Jiao-qing, WANG Li-jun, ZHENG Chuan-tao, and WANG Yi-ding
Based on tunable diode laser absorption spectroscopy (TDLAS) technique, an acetylene (C2H2) online detection system was developed by using the absorption band at the wavelength of 1.534 μm of C2H2 molecule. The sensing system consists of four modules including a distributed feedback (DFB) laser, a DFB laser driver, a gBased on tunable diode laser absorption spectroscopy (TDLAS) technique, an acetylene (C2H2) online detection system was developed by using the absorption band at the wavelength of 1.534 μm of C2H2 molecule. The sensing system consists of four modules including a distributed feedback (DFB) laser, a DFB laser driver, a gas cell with single optical path and a data processing module. With the prepared standard C2H2 gas sample, detailed measurements were carried out to study the detection performance of the system. Experimental results reveal that, the limit of the system (LOD) is about 0.02%; a good linear relationship is observed between C2H2 gas concentration and the amplitude of the 2f signal is within the range of 0.02%~1%. A long-term measurement lasting for 20 h on a 0.5% C2H2 gas sample was carried out to test the stability of the system. Compared with the C2H2 detection systems utilizing quantum cascaded lasers (QCLs) and wideband incandescence, this system has great advantage due to the capability of using long-distance and low-loss optical fiber for remote monitoring. With self-developed DFB laser driver and lock-in amplifier, the system has good prospects in industrial field because of its simple structure, low price and capability of easy to be integrated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3501 (2016)
Study on the Design of Explosive (HNS) Content Analysis System Based on THz Spectrum Monomer
LI Jing, LU Xu-tao, L Hai-feng, and SUN Yun-qiang
HNS quantitative spectral analysis can not be achieved with the existing infrared Fourier transform spectrometer. As a common monomer explosive concerned, quick identification and quantitative analysis of the substance is important, so it is necessary to research and design a HNS detection system based on THz spectroscHNS quantitative spectral analysis can not be achieved with the existing infrared Fourier transform spectrometer. As a common monomer explosive concerned, quick identification and quantitative analysis of the substance is important, so it is necessary to research and design a HNS detection system based on THz spectroscopy. Transmissive mode was used in the system to calculate the content of HNS. Electro-optic modulator module was introduced in the system, in order to achieve steady and rapid static scanning optical path. In the experiments HNS characteristic absorption peak positions were acquired. With this basis, combined air absorption characteristics of the wavelength band and spectrum data correlation expression was obtained, thus more characteristic wavelengths selected were determined. According to Beer-Lambert law, the function expression of HNS content and coefficient formula were presented. In the experiment different content of HNS sample powder was obtained with chemical configuration method with the content at the standard level. It made HNS sample powder into HNS Sample slice for all HNS samples, and it carried out HNS content testing with MINI-Z Terahertz spectroscopy and the system. Experimental results show that the results of the two methods are similar in the range of 0.10% to 50.00% for HNS content. Their error is less than 5.0% compared to the standard value, and the system has better linearity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3506 (2016)
Infrared Spectroscopy Combined with Chemometrics for Rapid Discrimination on Species of Bolete Mushrooms and an Analysis of Total Mercury
YANG Tian-wei, ZHANG Ji, LI Tao, WANG Yuan-zhong, and LIU Hong-gao
Fourier transform infrared spectroscopy combined with chemometrics was used to establish a method for rapid identification of different species of bolete mushrooms and determination of total mercury (Hg). In this study, 15 species of bolete mushrooms were used and the information of infrared spectra of 48 samples was cFourier transform infrared spectroscopy combined with chemometrics was used to establish a method for rapid identification of different species of bolete mushrooms and determination of total mercury (Hg). In this study, 15 species of bolete mushrooms were used and the information of infrared spectra of 48 samples was collected. Meanwhile, the total Hg was determined with cold-vapour atomic absorption spectroscopy and direct mercury analyzer. The food safety of bolete mushrooms was evaluated according to provisional tolerable weekly intake (PTWI) for Hg recommended by the United Nations food and agriculture organization and the World Health Organization (FAO/WHO). The original infrared spectra were optimized with Norris smooth, multiplicative signal correction (MSC), second derivative, orthogonal signal correction and wavelet compression (OSCW). The spectra data were analyzed with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) after the optimal pretreatment. Then the discrimination model for different species of bolete mushrooms and prediction model of Hg content were established, respectively. The results showed that: (1) The cumulative contribution of first three principal components of PCA was 77.1%. Different species of boletes can be obviously distinguished in principal component score plot. It indicated that the chemical composition or contents were different in these species of boletes. (2) There were significant differences in total Hg contents in different samples and the total Hg content in the boletes were 0.17～15.2 mg·kg-1 dry weight (dw). If adults (60 kg) ate 300 g fresh bolete mushrooms a week, Hg intakes in a few samples were higher than the PTWI standard with potential risks. (3) The infrared spectra data in combination with the total Hg content was performed by partial least squares discriminant analysis. The mushroom samples with low (≤1.95 mg·kg-1 dw), medium (2.05～3.9 mg·kg-1 dw) and high (≥4.1 mg·kg-1 dw) total Hg content could be discriminated. Moreover, the more different the Hg content was, the more easily to distinguish. In addition, the prediction model of total Hg content of boletes was established. The R2 and RMSEE of the training set were 0.911 4 and 1.09, respectively while R2 and RMSEP of validation set were 0.949 7 and 0.669 5, respectively. The predictive values of total Hg content in boletes were approximate to the measured values which showed that the model has good predictive effect. Infrared spectroscopy combined with chemometrics can be used for rapid identification of bolete species and discrimination of bolete samples with different contents of total Hg. Furthermore, the total Hg content could also be predicted, accurately. This study may provide a rapid and simple method for quality control and edible safety assessment of wild-grown bolete mushrooms..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3510 (2016)
Structural Analysis of Organic Matter Composition in Piggery Wastewater during the Process of Organic Degradation Based on FTIR Spectroscopy
LI Lei, LI Zhong-pei, LIU Ming, WU Meng, MA Xiao-yan, and TANG Xiao-xue
More and more attentions were paid on the environmental pollutions of wastewater discharged from scale pig farms, and it could provide scientific bases for formulating reasonable pollution control measures to study the structural changes of organic matter composition in piggery wastewater. In the present study, a laborMore and more attentions were paid on the environmental pollutions of wastewater discharged from scale pig farms, and it could provide scientific bases for formulating reasonable pollution control measures to study the structural changes of organic matter composition in piggery wastewater. In the present study, a laboratory-scale incubation experiment was carried out with piggery wastewater collected from different scale pig farms, and a continuous sampling was conducted at a certain interval during the process of incubation experiment. The main purpose of this study was to elucidate the change of structural composition of dissolved organic matter (DOM) in piggery wastewater during the process of organic degradation. All dried and solid DOM samples were achieved using filtration and freeze-drying methods. Spectral analysis of all DOM samples was completed with the application of Fourier transform infrared (FTIR) spectrometer. Results of spectral analysis showed a similar DOM structural composition was observed in the wastewater derived from different scale pig farms, and was mainly comprised of lipids, proteins, fulvic acids, polysaccharides, and phenolic compounds. With the increase in the incubation days, the percent of functional groups, related to proteins, phenolic acids, and lipids, decreased gradually and kept stable eventually, while these functional groups, linked with fulvic acids and polysaccharides, showed a significant increase and leveled off at the end. Compared with primary samples, fulvic acids and polysaccharides were the predominant fractions of DOM at 20 days after organic degradation, indicating a higher aromatic degree of DOM. Meanwhile, the degradation rate of OH bonded by intermolecular H-bond of cellulose was faster than OH bonded by intra-molecular H-bond of cellulose, whereas the latter was more sensitive to microbial degradation. The degradation rate of phenolic hydroxyl C—O was the fastest, followed by aromatic COOH, carbohydrate C—O, and amide CO.Furthermore, the carbohydrate C—O was apt to be utilized preferentially by microorganisms. In sum, the structural change of various DOM in piggery wastewater was different during the process of organic degradation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3517 (2016)
Study on Outliers Influence in NIR Quantitative Analysis Model
ZHENG Feng, LIU Li-ying, LIU Xiao-xi, LI Ye, SHI Xiao-guang, ZHANG Guo-yu, and HUAN Ke-wei
As a secondary analysis method, reproducibility and reliability of near-infrared spectroscopy (NIRS) quantitative analysis are quite dependent on modelling process. In this paper, it is focused on outlier analysis for protein quantitative model of wheat based on NIRS. The purpose is to discuss the outlier effect in modAs a secondary analysis method, reproducibility and reliability of near-infrared spectroscopy (NIRS) quantitative analysis are quite dependent on modelling process. In this paper, it is focused on outlier analysis for protein quantitative model of wheat based on NIRS. The purpose is to discuss the outlier effect in modelling process of complex sample set. The indicator of outliers is the deviation between two interpretative percentage curves in partial least squares regression (PLSR) modelling, when two percentage curves have significant deviation or departure point, the sample set should include the outliers. The innovative research work is the analysis and treatment of outliers. On the basis of sub-model ergodic calculation method, outliers can be gradually identified and picked-up. The standard deviation of model’s prediction residual is used as the reference graduation to distinguish the degree of deviation. According to the degree of deviation from sample population, outliers can also be divided into significant outliers, relative outliers and potential outliers. In this paper, the significant outliers of the sample set are about 7.8%, and the relative outliers are about 15.6%. The outliers will pull normal samples apart from the ideal fitting line and make the dispersity increase. No matter modelling with removed outliers or weighted samples, the purpose is to make the fitting results of quantitative analysis modelling more inclined to majority samples, while reducing or eliminating the impact of outliers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3523 (2016)
Study on Identification of PBDEs and Characteristic Information Extraction of Biological Toxicity Based on Infrared Spectrum Partition
JIANG Long, and LI Yu
In this paper, 9 most abundant PBDE congeners in environment and 14 congeners with high/medium biological toxicity were selected as target compounds. Firstly, IR spectra of 23 compounds were divided into 6 spectrum regions based on known vibrational assignment, and their identification abilities for PBDEs were evaluateIn this paper, 9 most abundant PBDE congeners in environment and 14 congeners with high/medium biological toxicity were selected as target compounds. Firstly, IR spectra of 23 compounds were divided into 6 spectrum regions based on known vibrational assignment, and their identification abilities for PBDEs were evaluated by using similarity analysis. Then, the spectrum regions with high identification ability relatively have been analyzed to search identification method on the basis of each spectrum characteristic. At last, the principal component analysis and discriminant analysis method were used to extract characteristic spectrum information of congeners with high/medium biological toxicity and establish biological toxicity discriminant model. The triangle breathing vibration region (961～1 153 cm-1) and C—O stretching vibration region (1 153～1 346 cm-1) has been filtered as characteristic IR spectrum regions because of smaller similarity among PBDEs relatively. For the former, the information of vibration peaks distribution can be taken as tool to identification, with the smallest frequency difference of 3.19 cm-1 among 23 congeners and bad ability to distinguish PBDEs from dioxin-similar compounds. For the later, the frequency and shape of main peak is as mark and the smallest frequency difference among PBDEs and between PBDEs with dioxin-similar compounds are 0.74 and 0.67 cm-1 separately, both larger than the common minimum resolution of IR spectrum 0.5 cm-1, depicting good ability for both inner and outer identification of PBDEs. The established biological toxicity discriminant model via discriminant analysis also have shown well ability to biological toxicity prediction, with accuracy of 100% and 88.9% for high/medium and low biological toxicity relatively, representing the extracted IR spectrum information from congeners with high/medium toxicity can realize the accurate classification of biological toxicity for PBDEs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3530 (2016)
Discrimination of Varieties of Cabbage with Near Infrared Spectra Based on Principal Component Analysis and Successive Projections Algorithm
LUO Wei, DU Yan-zhe, and ZHANG Hai-liang
The varieties of cabbage seeds directly affect the yield and quality of cabbage, in order to rapidly and nondestructively identify the varieties of cabbage seeds, near infrared spectra technique were applied in this study and reflectance spectrum of the cabbage seeds was obtained. Firstly, to excavate the effective infThe varieties of cabbage seeds directly affect the yield and quality of cabbage, in order to rapidly and nondestructively identify the varieties of cabbage seeds, near infrared spectra technique were applied in this study and reflectance spectrum of the cabbage seeds was obtained. Firstly, to excavate the effective information in the spectral data and improve signal to noise ratio, the raw spectra was pre-processed with the method of standard normal variate (SNV) and multiplicative scatter correction (MSC). Secondly, principal component analysis (PCA) was used to analyze the clustering of cabbage samples, then the characteristic differentia of three cabbage varieties was obtained through qualitative analysis. Six Effective wavelengths were selected by successive projections algorithm (SPA). Finally, the full spectra variable, the first three principal components (PCs) using PCA and selected effective wavelengths using SPA were respectively set as inputs of the partial least squares discriminant analysis (PLS-DA) and least-squares support vector machine (LS-SVM) models for the classification of cabbage seeds. As can be seen from the two dimensional plot drawn with the scores of PC1 and PC2 (the first two principle components), PC1 and PC2 had a good clustering effect for different kinds of cabbage seeds. LS-SVM models performed better than PLS-DA models, the correct rates of discrimination were 100% achieved with LS-SVM models. PLS-DA and LS-SVM models built based on the selected wavelengths performed better than the models built based on the first three principal components, moreover, the SPA-LS-SVM model obtained the best results among all models, with 100% discrimination accuracy for both the calibration set and the prediction set. The overall results show that SPA can extract wavelengths, and the LS-SVM model combined with SPA can obtain optimal classification results. So the present paper could offer an alternate approach for the rapid discrimination of cabbage seeds variety..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3536 (2016)
Effects of Freezing and Thawing Treatments on Beef Protein Secondary Structure Analyzed with ATR-FTIR
SUN Zhen, YANG Fang-wei, LI Xia, ZHANG Chun-hui, and XIE Xiao-lei
In order to further clarify the influence mechanism of different freezing temperature on meat quality in meat industry. The effects of freezing at -18, -23 and -38 ℃ on the stability of protein secondary structures of beef were studied. The attenuated total reflectance Fourier transfer infrared spectroscopy（ATR-FTIR）teIn order to further clarify the influence mechanism of different freezing temperature on meat quality in meat industry. The effects of freezing at -18, -23 and -38 ℃ on the stability of protein secondary structures of beef were studied. The attenuated total reflectance Fourier transfer infrared spectroscopy（ATR-FTIR）technique and automatic deconvolution, curve fitting and other calculation and analysis methods were used to analyze the changes of beef myofibrillar protein infrared spectra and secondary structures during -18, -23 and -38 ℃ freezing-thawing processes. ATR-FTIR results showed that the peak high and peak area of infrared spectra of beef myofibrillar protein in the freezing-thawing processes were changed, and the red shift or blue shift of wavenumbers occurred. The intensities of the absorption peak of 3 500~3 300 cm-1 in the infrared spectra of the frozen-thawed beef were reduced or even disappeared. This indicated that the intramolecular and intermolecular hydrogen bonding interactions, which formed by the bound water O—H group and the amino acid CO group, in thawed beef myofibrillar protein were broken. In other words, freezing can result in the destruction of beef myofibrillar protein secondary structures and protein advanced structures unfolded. Once the beef is thawed, the unfolded protein would reaggregation, and protein renaturation. Freezing could affect the stability of beef myofibrillar protein, the relative content of α-helix, β-sheet, and β-turn of beef myofibrillar protein were decreased, and the α-helix and ordered structures changed to the randon coil and disordered structures. After thawing, the increase of β-sheet relative content of beef myofibrillar protein at -38 ℃ was greater than that of -23 and -18 ℃. The stability of -38 ℃ frozen beef myofibrillar protein was the best, and the protein renaturation was also the best after thawing. That is, the lower the freezing temperature, the lower the measure of freezing denaturation of beef myofibrillar protein, and the better the secondary structures stability of beef myofibrillar protein. The experimental study based on the actual production condition of the meat industry. And the effect of freezing temperatures on beef protein denaturation and the possible mechanism were revealed at the micro-aspect. It can be seen that the ATR-FTIR technology can reflect the changes of protein secondary structures in the process of freezing-thawing of beef, and reveal the regularity of beef protein denaturation, which can be used to identify and evaluate the quality of frozen meat. The experimental results provide a reference for the freezing preservation process and a method for the quality evaluation of meat..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3542 (2016)
Determination of Wine Varieties with NIR and Fusion of Multiple Classifiers
LI Kai, LI Xue-ying, LUAN Li-li, HU Wen-yan, WANG Yu-heng, LI Jing-ming, LI Jun-hui, LAO Cai-lian, and ZHAO Long-lian
The conventional qualitative analysis of near infrared spectroscopy (NIR) commonly uses one single classification model. This paper focused on the fusion of multiple classifiers based on different single classifiers by using the fused classifier to determine different varieties of red-wines. NIR spectra of 170 red-wineThe conventional qualitative analysis of near infrared spectroscopy (NIR) commonly uses one single classification model. This paper focused on the fusion of multiple classifiers based on different single classifiers by using the fused classifier to determine different varieties of red-wines. NIR spectra of 170 red-wine samples were collected by using Fourier transform near-infrared spectrometer. Red-wine classification models were established respectively, based on PLS-DA, SVM, Fisher and AdaBoost. Then these models were selected to obtain some different base classifiers according to Diversity Measure Feature Selective (DMFS). The highest accuracy rate of determining different varieties of red-wine test samples of four single base classifiers was up to 88.24%, and at the same time the lowest discriminant accuracy rate was 81.18%. At last, we got the fused classifier, which combined four base classifiers with weighted voting principle, and determined its test set again by using the fused classifier. The final classification accuracy rate for red-wine varieties increased to 92.94%, In contrast with one single classifier, the lowest misjudged number of fused classifiers decreased from 9 to 6.These results suggested that the performance of fused classifier is superior to one single classifier. It is feasible to use fused classifier combined with near infrared spectroscopy to determine different varieties of red-wines..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3547 (2016)
Recognition of Three Types of Plantation Wood Species with Near Infrared Spectra Coupled with Back-Propagation Network
PANG Xiao-yu, YANG Zhong, L Bin, and JIA Dong-yu
In this study, the near infrared spectroscopy coupled with Back-Propagation (BP) network was used for the recognition of three kinds of plantation wood (Eucalyptus urophylla, Pinus massoniana, Populus×euramericana (Dode) Guineir cv. “San Martino” (1-72/58)). The study considered the effects of hidden layer neuronsIn this study, the near infrared spectroscopy coupled with Back-Propagation (BP) network was used for the recognition of three kinds of plantation wood (Eucalyptus urophylla, Pinus massoniana, Populus×euramericana (Dode) Guineir cv. “San Martino” (1-72/58)). The study considered the effects of hidden layer neurons number, spectral pretreatment method and spectral regions on BP model, which are compared with SIMCA model simultaneously. The results showed that, (1) the recognition rate was 97.78% achieved by BP network model with hidden layer neurons number 13 and the spectral region of 780～2 500 nm. (2) BP model with spectral region of 780～2 500 nm was more robust than the other two BP models with spectral regions of 780～1 100 and 1 100～2 500 nm, of which recognition rates were 97.78%, 95.56% and 96.67%, respectively. After the full spectra was pretreated with the first derivative and the second derivative methods, the recognition rates of BP models fell down to 93.33% and 71.11%. However, the recognition rate of BP model rose to 98.89% with the full spectra being pretreated by the multiplicative scatter correction (MSC). (3) Compared with SIMCA models that recognition rates of three spectral regions (780～2 500, 780～1 100 nm, and 1 100～2 500 nm) were 76.67%, 81.11% and 82.22% respectively, BP network work models had higher recognition rates..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3552 (2016)
The Chemical Composition of Bamboo after Heat Pretreatment with Fourier Infrared Spectrum Analysis
CHU Jie, MA Li, and ZHANG Jun-hua
Thermochemical pretreatment of lignocellulosic biomass is a critical step in obtaining high yields of cellulose and hemicellulose-derived sugars to realize effective utilization of cellulose in renewable biofuels. The pretreatment process can quickly remove hard dissolving lignin and the physical separation of hemicellThermochemical pretreatment of lignocellulosic biomass is a critical step in obtaining high yields of cellulose and hemicellulose-derived sugars to realize effective utilization of cellulose in renewable biofuels. The pretreatment process can quickly remove hard dissolving lignin and the physical separation of hemicelluloses in the cell wall while changing the chemical composition in plant cell wall, so as to increase the production of lignocellulose. Research with medium of sulfuric acid (H2SO4), dilute alkali (NaOH) and glycerin,and at different pretreatment temperature (117 and 135 ℃ in sulfuric acid (H2SO4)and dilute alkali (NaOH) , 117 ℃ in glycerin) analyzed and compared the main changes of chemical composition before and after the bamboo processing, and further confirmed that the mechanism of the chemical conversion after chemical pretreatment of bamboo through the Fourier infrared spectrum. The results showed that the output cellulose increased significantly after the thermochemical pretreatment. The change rules for yield of cellulose and the removal rate of lignin under the different pretreatment condition had been indicated dilute alkali (NaOH) treatment effect is better than that of dilute acid (H2SO4) and glycerin. In addition, the effect is more remarkable under the condition of 135 ℃ than 117 ℃ in the same medium. The changes of degradation degree of hemicellulose with different processing conditions were the same. The infrared spectrum analysis provided that C—O—C asymmetric stretching vibration peak appeared in cellulose decomposition after heat treatment, and it is the obvious steep fall in hemicelluloses infrared absorption characteristic peaks, benzene ring characteristic absorption peak of lignin has been abated. It is prove that yield of cellulose increased significantly, degradation trend of hemicelluloses is obviously, removal effect of lignin has also been better. The analysis results of Fourier infrared spectrum are consistent with the standard measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3557 (2016)
Design and Fabrication of Silver Nanoparticles/Graphen Complex Substrate and Its Application for Detecting Uranium (Ⅵ)
JIANG Jiao-lai, ZHANG Jing, JIA Jian-ping, WANG Shao-fei, WU Hao-xi, YUN Wen, WANG Xiao-lin, and LIAO Jun-sheng
Uranium is one of the important nuclear materials to nuclear industry. Because of the direct disposal of spent fuel, there is still a huge possibility that uranium migrates into the groundwater, causing water contamination. It is of great importance to understand the concentration and their species distribution in aqueUranium is one of the important nuclear materials to nuclear industry. Because of the direct disposal of spent fuel, there is still a huge possibility that uranium migrates into the groundwater, causing water contamination. It is of great importance to understand the concentration and their species distribution in aqueous solutions. Surface-Enhanced Raman Scattering (SERS) technique has been widely used for the detection of uranium (Ⅵ). However, the interactions between uranium (Ⅵ) and SERS substrate cause the symmetric stretching vibration peak of uranium (Ⅵ) shift to low wave number direction, which is unfavorable for confirming the species of uranium (Ⅵ) in aqueous solution. For instance, the normal Raman bands of uranyl in nitric acid solution are 871 cm-1, which belongs to the symmetric stretching mode of UO2+2. However, it moves to 710 cm-1 on the surface of silver nanorods SERS substrtate. What’s more, different SERS substrate causes different number of shift. Graphene has advantages of inertness and integrity as well as 2-dimensional thickness. In this paper, graphene-isolated SERS substrate which is silver nanoparticles (AgNPs)/graphene complex substrate, was designed to prevent the interaction between SERS substrate and it was analyzed by using the inert graphene layer. First of all, according to our previous work, AgNPs SERS substrate was fabricated on silicon wafer by using an ascorbic acid-actived self-assembly method. Then, AgNPs/graphene complex substrate was prepared by transfering monolayer graphene onto the self-assembly AgNPs substrate. The morphology of complex substrate was obtained by SEM. Some AgNPs link together closely to form nanochain structures. Nanochain structures were distributed evenly on the surface of silicon wafer. The 2-dimensional thickness of graphene did not affect the morphology of AgNPs. When using the complex substrate to detect uranyl nitrate (5×10－4 mol·L-1), the Raman peak that appeared around 771 cm-1 is considered to be the symmetric stretching mode of UO2+2, shifting back about 52 cm-1 to high wave number direction when compared with AgNPs substrate, which was about ~719 cm-1. The result indicates that graphene layer isolates the interaction between AgNPs substrate and uranyl in some degree..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3563 (2016)
Raman Spectra Study on the Structure and Thermal Stability of Vacuum Annealed Cr-DLC Films Prepared with UBMS
LU Bao-qi, XU Yao-xian, SHEN Guang-yao, JI Jiang-hua, and WANG Lin-jun
Chromium doped amorphous hydrogenated carbon a-C∶H(Cr) films (2.23 μm in thickness)have been successfully prepared with unbalanced magnetron sputtering technology(UBMS) in this paper. Raman spectrum and X-ray photoelectron spectroscopy (XPS) have been used to study the structure and thermal stability of the Chromium doChromium doped amorphous hydrogenated carbon a-C∶H(Cr) films (2.23 μm in thickness)have been successfully prepared with unbalanced magnetron sputtering technology(UBMS) in this paper. Raman spectrum and X-ray photoelectron spectroscopy (XPS) have been used to study the structure and thermal stability of the Chromium doped diamond-like carbon films (Cr-DLC). The results indicate that, at the room temperature, the Raman absorption peak “G” near 1 580 cm-1was assigned to C—C stretching vibration mode (E2g) in the Cr-DLC films, while the peak “D” near 1 350 cm-1was assigned to sp2 breathing vibration mode (A1g). The relative concentration of sp3 bond in the film is at 48%. When heated till 300 ℃, the Raman pattern of sample is similar to that of the sample at room temperature, indicating the structure of Cr-DLC film is stable. At 400 ℃, the ratio of ID/IG and the concentration of sp2 bond clearly increase, indicating the change of the structure in the Cr-DLC and the appearance of graphitization. With temperature going up, the rise of ID/IG ratio and the shift of the peak “G” to high wavenumber show that the rise of sp2/sp3 ratio, the intensity of graphitization, and the decline of the disorder of sp2 in the Cr-DLC films lead to the increase of the friction coefficient and wearing rate and the decline of the Cr-DLC thermal stability. When the it is up to 600 ℃, the ratio of ID/IG and the concentration of sp2 bond reach the max value while the Cr-DLC film loses its efficacy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3568 (2016)
Study on Non-Detective Determination of β-Carotene Content in Loquats with Raman Spectroscopy
WANG Tao, QIU Zheng-jun, ZHANG Wei-zheng, ZHAO Yan-ru, and HE Yong
In china, researches on Raman spectroscopy in terms of foodstuff mainly focus on carbohydrates, fatty acids, proteins and vitamins. Conventional methods for determining the carotenoids content require the extraction of the samples as well as other cleanup steps. In this work, Raman spectroscopy is applied to get the meIn china, researches on Raman spectroscopy in terms of foodstuff mainly focus on carbohydrates, fatty acids, proteins and vitamins. Conventional methods for determining the carotenoids content require the extraction of the samples as well as other cleanup steps. In this work, Raman spectroscopy is applied to get the measured value form loquats with different mature stage which are compared with the reference value get from High Performance Liquid Chromatography （HPLC）, in order to find new, fast, and nondestructive calibration methods for quantification of β-carotene content in loquat fruits. Least Squares Support Vector Machine and Partial least squares data processing methods are used to analyze the Raman spectra while PLS model has a prediction quality with the correlation coefficient of 0.845; the root-mean-square error of 0.022 μg·g-1 and LS-SVM model has a better prediction quality with the correlation coefficient of 0.910 with the root-mean-square error of 0.058 μg·g-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3572 (2016)
In Situ Research on Ginger Oil Cell with Raman
SI Min-zhen, ZHANG De-qing, LI Lun, and ZHANG Chuan-yun
This article presents a novel and original approach to analyze the main components of the essential oils in ginger oil cell by means of Raman spectroscopy. Fresh ginger sample was prepareed with free-hand section. Under the DXR Laser confocal micro Raman spectrometer, the oil cell has 20 objective lens. As to the gingeThis article presents a novel and original approach to analyze the main components of the essential oils in ginger oil cell by means of Raman spectroscopy. Fresh ginger sample was prepareed with free-hand section. Under the DXR Laser confocal micro Raman spectrometer, the oil cell has 20 objective lens. As to the ginger oil cell, the Raman spectrum, all together 21 spectroscopic bands, was obtained. It has been found that the obtained Raman spectrums at different oil cells are very similar. The Raman spectrum of the commercial essential oils of ginger, together 37 spectroscopic bands, was obtained. It has been found that the 19 presented spectroscopic bands of ginger oil cell correlate very well with those obtained by the commercial essential oils. Density Functional Theory (DFT) of zingiberene calculations were performed in order to interpret the spectra of the essential oils of the ginger oil cell and essential oils of ginger. There are 31 spectroscopic bands of the essential oils of ginger, and 19 spectroscopic bands of ginger oil cell correlate very well with calculations. All these investigations are helpful tools to generate a fast and easy method to control the quality of the essential oils with Raman spectroscopic techniques in combination with DFT calculations..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3578 (2016)
A Quercetin-Based Fluorescent Probe for the Recognition of Fluorid Ions
YANG Shi-long, JIANG Wei-na, YIN Bin, XU Li, ZHAO Feng-yi, GAO Bu-hong, SUN Hai-jun, DU Li-ting, TANG Ying, and CAO Fu-liang
Quercetin (Q) is one of the most common flavonoids present in roots, stems, leaves, flowers and fruits of most plants. In this study, a quercetin-based fluorescent probe for detecting fluorid ions had been proposed. With good selectivity and sensitivity for fluorid ions, Q-based fluorescent probe was easier to prepare,Quercetin (Q) is one of the most common flavonoids present in roots, stems, leaves, flowers and fruits of most plants. In this study, a quercetin-based fluorescent probe for detecting fluorid ions had been proposed. With good selectivity and sensitivity for fluorid ions, Q-based fluorescent probe was easier to prepare, more eco-friendly and more innoxious compared with traditional fluorescent probe obtained by organic chemistry synthesis operation. There was a major fluorescence emission peak at 500 nm for Q in dimethyl sulfoxide (DMSO) when the excitation wavelength was 390 nm. The changes of fluorescence spectra were investigated before and after adding different anions into Q solution. The fluorescence emission intensity of Q even had no change when adding Cl－, Br－, I－, ClO－4, H2PO－4, respectively. While adding fluorid ions, the fluorescence emission intensity of Q was decreased obviously, which suggested fluorid ions could induce fluorescence quenching of Q in DMSO. And the fluorescence emission intensity of Q-F－ system had almost no significant change when adding other anions (Cl－, Br－, I－, ClO－4, H2PO－4), which meant the progress for detecting fluorid ions didn’t be affected by other anions, and Q showed a good selectivity for fluorid ions. The fluorescence titration spectra showed that the fluorescence emission intensity of Q was decreased with the increase of concentration of fluorid ions, and they were in concentration-dependent manner. The fluorescence titration curve exhibited that the Q as fluorescent probe can be applied to the quantification of fluorid ions with a good linearity (R2=0.991), linear range of 1.0～8.0×10-6 mol·L-1 and the detection limit of 1.0×10－7 mol·L-1. Not only the changes appeared in fluorescence spectra, but also the changes appeared in UV-visible spectra, compared with Q absorption spectrum, the location of band at 375 nm had no change after adding Cl－, Br－, I－, ClO－4, H2PO－4, respectively. However, when adding fluorid ions, the band at 375 nm was shifted to 394 nm, and the color of the solution was changed into dark yellow, which revealed the interactions between Q and fluorid ions. The probable mechanism of fluorid ions inducing fluorescence quenching of Q was obtained with 1H NMR spectrum and the changes of fluorescence emission intensity of Q-F- system in different polar solvents (DMSO containing different concentration of water). The interaction mode about Q and fluorid ions in DMSO was related with hydrogen bond. Both experiments suggested that the possible recognition mechanism on fluorid ions was: fluorid ions were destroyed or weakened by original hydrogen bonds, and were promoted charge transfer within quercetin molecule, which resulted in fluorescence intensity decreasing of quercetin. This method was successfully applied in detecting fluorid ions of samples in DMSO with good recovery..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3582 (2016)
Research on Spectrum Matching Method for PbSe Quantum Dots Luminescence Spectrum and Gas Absorption Spectrum
XING Xiao-xue, QIN Hong-wu, and SHANG Wei-wei
As typical nano metarials in near infrared waveband, PbSe Quantum Dots have a very large exciton Bohr radius of 46 nm and a small band gap of 0.28 eV at room temperature. PbSe QDs have very unique properties, such as the quantum confined optical property, and which possess high photoluminescence (PL) quantum yield (QY)As typical nano metarials in near infrared waveband, PbSe Quantum Dots have a very large exciton Bohr radius of 46 nm and a small band gap of 0.28 eV at room temperature. PbSe QDs have very unique properties, such as the quantum confined optical property, and which possess high photoluminescence (PL) quantum yield (QY) with size dependent tunable wavelength emissions. By analyzing the luminescence spectrum of PbSe Quantum Dots, a method through adjusting the particle size of PbSe Quantum Dots (QDs) to match gas absorption spectrum was presented in this paper. 4.6 and 6.1 nm PbSe QDs were synthesized and deposited on the GaN chip to fabricate the NIR QDs light sources. The PbSe QDs-UV glue composites thickness was determined to be 48.0 and 671.5 μm for 6.1 and 4.6 nm PbSe QDs. The NIR QDs were used to detect the C2H2 and NH3 gas. The experiments show that the PL spectrum of 4.6 nm NIR QDs can cover the entire absorption spectrum of C2H2 gas (from 1 500 to 1 550 nm) and the PL spectrum of 6.1 nm NIR QDs can cover the entire absorption spectrum of NH3 gas (from 1 900 to 2 060 nm). By changing the quantum size of QDs, the PL peak of the NIR QDS light source can be adjusted to cover the absorption peak of different gases. The matching method presented in this paper is efficient and feasible, which has great application potential in gas detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3588 (2016)
Research on Water Quality Analysis Model with PCA Method and UV Absorption Spectra
ZHAO You-quan, LI Xia, LIU Xiao, DONG Peng-fei, WANG Ling-li, and WANG Xian-quan
Using the UV absorption spectrum to detect Organic pollutants content in water has become one of the most important methods for real-time online monitoring in the field of water quality inspection, however, the water complex and unstable components often bring much uncertain offset to the standard test. In this paper, Using the UV absorption spectrum to detect Organic pollutants content in water has become one of the most important methods for real-time online monitoring in the field of water quality inspection, however, the water complex and unstable components often bring much uncertain offset to the standard test. In this paper, water samples were classified firstly by analyzing UV absorption spectrum ranging from 200 nm to 400 μm including the organic substances, through the way of combining principal component analysis (PCA) with Euclidean distance. In this paper, we compared the Principal component analysis combined with partial least squares regression (PCA-PLSR) and the direct multi-wavelength absorption models combined with partial least squares regression (MWA-PLSR), not only for the real water sample but also for the analysis of different concentrations of COD standard solution. The result indicates that the measurement errors of the PCA is less than 5%, it is the smallest by using the first and second principal components as regression parameters for PLSR. Using the methods above can simultaneously achieve to classify of water samples and to measure the concentration of water quality parameters more accurately..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3592 (2016)
Characterization of the Effect of Anion on the Complex of Oat β-Glucan and Congo Red with UV-Vis Absorption Spectroscopy
WU Xiao-yan, ZHAO Lan, LI Lin-lin, LI Jian, WANG Han-yuan, and WU Jia
The effects of concentration and type of anions on aggregation of Congo red in solution were studied with UV-Visible spectroscopy. And the influence of anions on the complex of Congo red and oat β-glucan was further studied. The results showed that the maximum absorption wavelength of Congo red in aqueous solution shifThe effects of concentration and type of anions on aggregation of Congo red in solution were studied with UV-Visible spectroscopy. And the influence of anions on the complex of Congo red and oat β-glucan was further studied. The results showed that the maximum absorption wavelength of Congo red in aqueous solution shifted toward the shorter wavelength, and the absorbency lowered considerably with increasing ionic concentration. There was a significant linear correlation between logarithm of anion concentration and the maximum absorption wavelength, with the peak absorbance, and the absorbance at 499 nm. The influence of anions on aggregation of Congo red was in accordance with Hofmeister series, indicating that hydrophobic interaction is an important driving force for Congo red molecules to assemble into micelles. As for the complexation of Congo red and oat β-glucan, when the concentration of anions exceeded the first critical concentration, the micelle of Congo red began to form and then combined to β-glucan. The absorption peak of the complex presented at 556 nm. When the concentration of anions exceeded the second critical concentration, the complex was developed into supramolecular structure through aggregation of Congo red micelles on Congo red/β-glucan complex, which resulted in the shift of absorption peak toward 583 nm. And the presence of Mie scattering effects at the longer wavelength indicated the formation of larger supramolecular structure. The effect of anions on the above supramolecular structures also followed the order of Hofmeister series, showing that the aggregation of Congo red/β-glucan complex into supramolecular structure was mainly driven through hydrophobic interactions between Congo red micelles on the complex. The research indicated that ions had an important effect on the aggregation of Congo red and the interaction between biopolymers and Congo red..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3597 (2016)
Fingerprint Properties of Semi Synthetic Penicillin Pharmaceutical Wastewater
TANG Jiu-kai, WU Jing, CHENG Cheng, LI Zhong-hua, ZHAO Yu-fei, WANG Shi-feng, and WANG Yong-jun
High-concentration antibiotics are detected in surface water from time to time. There has been an increasing demand for strengthening the supervision of the antibiotic pharmaceutical wastewater. Three-dimensional fluorescence technique is known as a rapid, simple and high-sensitivity method. The three-dimensional fluorHigh-concentration antibiotics are detected in surface water from time to time. There has been an increasing demand for strengthening the supervision of the antibiotic pharmaceutical wastewater. Three-dimensional fluorescence technique is known as a rapid, simple and high-sensitivity method. The three-dimensional fluorescence spectrum can display organic components and it was named as aqueous fingerprint. In this paper, three-dimensional fluorescence characteristics of a typical semi synthetic penicillin pharmaceutical wastewater were studied. There were totally four fluorescence peaks in the aqueous fingerprint of this wastewater, locating in excitation wavelength/emission wavelength of 360/445, 255/445, 275/305 and 230/300 nm respectively. Fluorescence peak’s intensity within certain range related linearly to the relative concentration. The possible fluorescent pollutants related to Peak C and Peak D might be the mixture of D-(-)-A-4-Hydroxyphenylglycine Dane Salt Methyl Potassium (pharmaceutical intermediates), Amoxicillin (pharmaceutical product) and D(-)-4-Hydroxyphenylglycine (pharmaceutical hydrolysate). PH played an important role in the fluorescence characteristics of this wastewater. This indicated that the fluorescent organic pollutants in this wastewater might contain acid or base groups. The aqueous fingerprint technique could be used to monitor the discharge of semi synthetic penicillin pharmaceutical wastewater as a novel tool..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3602 (2016)
Compositional Characteristics of Sediment Dissolved Organic Nitrogen in Typical Lakes and Its Relationship on Water Trophic Status
QIAN Wei-bin, ZHANG Li, WANG Sheng-rui, CAO Chang-chun, LI Yan-ping, CHENG Jie, YANG Jia-chun, and LI Wen-zhang
UV-Vis absorbance, fluorescence, and Gas Chromatography Mass Spectrometry (GC-MS) were applied to the comparative study on sediment dissolved organic nitrogen (DON) in five typical lakes (Erhai lake, Dianchilake, Poyang lake, Wuhan Dong lake, and Taihu lake) in different lake regions with different nutrition status, reUV-Vis absorbance, fluorescence, and Gas Chromatography Mass Spectrometry (GC-MS) were applied to the comparative study on sediment dissolved organic nitrogen (DON) in five typical lakes (Erhai lake, Dianchilake, Poyang lake, Wuhan Dong lake, and Taihu lake) in different lake regions with different nutrition status, revealing the relationship between structural and compositional characteristics of sediment DON and trophic level of lakes. The obtained results showed that: ①Structure of lake sediment DON in Yungui Plateau region is more stable, compared with those in Eastern Plain region, indicating its lower bioavailability. ②In Yungui Plateau region, the source and compositional characteristics of sediment DON weremore complex in Dianchi lake (a seriously polluted lake), and its sediment DON bioavailabilitywas relatively higher. While, with respect to the less polluted Erhai lake, the source of sediment DON is more simple with a higher stability in DON structure and composition, which is beneficial for maintaining its good water quality. ③In Eastern Plain region, nutrition status of Taihu lake was similer to Donghu lake. The structure and composition of sediment DON was complex. But the lower aromaticityand fewer Aromatic ring substituents abundance made their relatively weak nutrient retention ability, posing risk to water quality. With regard to Poyang Lake, the structure and composition of sediment DON was relatively simple, but nutrient retention ability was relatively strong, which played a positive role in maintaining good water quality. ④P(Ⅲ+Ⅴ, n)/P(Ⅰ+Ⅱ, n) values(the content ratio of humic-like substanceto protein-like substances)were in sequence of Dianchi Lake (33.14)>Erhai Lake(21.49)>Taihu Lake(9.06)>Donghu Lake(7.04)>Poyang Lake(4.83), while E4/E6 values (the ratio of UV-Vis absorbance at 465 and 665 nm) were in sequence of Dianchi Lake (27.00)>Donghu Lake(6.65)>Poyang Lake(5.47)>Taihu(3.50)>Erhai Lake(2.31). In addition, P(Ⅲ+Ⅴ, n)/P(Ⅰ+Ⅱ, n) and E4/E6 valueswere positively correlated with thecontents of the different nitrogen (N) forms in the sediments. The above information suggested that P(Ⅲ+Ⅴ, n)/P(Ⅰ+Ⅱ, n) and E4/E6 values exhibited good discrimination degree among different trophic status lakes, and they were considered to indirectly indicate the nutrition levels of lakes to a certain extent..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3608 (2016)
Estimating Soil Iron Content Based on Reflectance Spectra
XIONG Jun-feng, ZHENG Guang-hui, and LIN Chen
In recent decades, the application of spectral technology in soil science is getting more and more attention. Soil information can be obtained quickly by using soil reflectance spectra to understand the physical and chemical properties of soil and to estimate soil iron content. In previous studies, the surface soil alwIn recent decades, the application of spectral technology in soil science is getting more and more attention. Soil information can be obtained quickly by using soil reflectance spectra to understand the physical and chemical properties of soil and to estimate soil iron content. In previous studies, the surface soil always is selected for the estimation of soil iron content by using spectroscopy. It needs to estimate total iron and, the different forms of soil iron is ignored, therefore, the estimation result is not ideal. In order to gets a different form of soil iron processing method of optimal model to evaluate the accuracy of models, as well as discuss the organic matter content and soil depth on the influence of different forms of soil iron estimation accuracy. A total of 160 soil samples were collected from 20 sites in Dongtai city, Jiangsu province. These samples were ground to 10 meshes and 100 meshes. In the use of 8 different methods for the pretreatment of the same time each method will be selected by a variety of parameters, using partial least squares regression method to model the total reflection band and the total iron, free iron, amorphous iron content in the soil respectively, then evaluation model precision. The results showed that: (1) the optimal model of three kinds of soil iron was all ground to 100 meshes and the best pretreatment method was MSC. The prediction accuracy of total iron was acceptable and R2 was less than 0.6. The results of free iron and amorphous iron inversion were better and the R2 was 0.77 and 0.69, respectively. The errors were small and the models were stable. (2) Because the ferric metasilicate in total iron is easily affected by external environment, the organic matter and soil depth are of great influence on the estimate precision of total iron the most. But the estimation accuracy of free iron is the least affected. Because of the low content of amorphous iron, the estimated model is also susceptible to the influence of organic matter and soil depth..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3615 (2016)
The Application of the L-Curve Method in the Retrieval of Temperature Profiles Using Ground-Based Hyper-Spectral Infrared Radiance
HUANG Wei, LIU Lei, GAO Tai-chang, LI Shu-lei, and HU Shuai
The thermodynamic profiles of Planetary Boundary Layer could be retrieved by using ground-based hyper-spectral infrared radiance. The AERIoe algorithm has a better performance at the dependency of initial profiles than the “onion peeling” method which was originally applied in the Atmospheric Emitted Radiance InterferoThe thermodynamic profiles of Planetary Boundary Layer could be retrieved by using ground-based hyper-spectral infrared radiance. The AERIoe algorithm has a better performance at the dependency of initial profiles than the “onion peeling” method which was originally applied in the Atmospheric Emitted Radiance Interferometer. The regularization parameter is the key to the AERIoe algorithm, and the strategy for choosing the regularization parameter in the retrieval algorithm is based on the empirical method, which requires too much time for computation while the empirical method needs many iteration steps. A L-curve criterion is proposed to calculate the regularization parameter in AERIoe algorithm. The L-curve criterion is based on a log-log plot of corresponding values of the residual and solution norms, and the optimal regularization parameter corresponds to a point on the curve near the “corner” of the L-shaped region. Therefore, the L-curve criterion has better theoretical basis than the traditional empirical method. The result of retrieval experiment using the observed data collected at the SGP site of the year 2011 shows that, the L-curve method has a good performance in terms of stability, convergence and accuracy of the retrieval. Compared with empirical method, L-curve algorithm converges more quickly which saves much computation time when retrieving the temperature profiles. When considering the retrieval accuracy, the L-curve method has a better behavior at the middle and top of the boundary layer, with an improvement of 0.2 K of RMSE at the altitude of 1～3 km than the empirical method. Therefore, the L-curve algorithm has a better performance compared with the empirical method when choosing the regularization parameter in the retrieval of temperature profiles using the ground-based hyper-spectral infrared radiance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3620 (2016)
Research on the Noise Reduction with Hyper-Resolution Infrared Spectrum Based on Improved PCV Method
HUANG Wei, GAO Tai-chang, LIU Lei, and LI Shu-lei
The noise reduction with observed high resolution infrared radiance is crucial to improve the accuracy and stability of the retrieval of thermodynamic profiles. When applying the principal component analysis noise filter algorithm to the observed radiance, the optimal number k of principal components that used in the aThe noise reduction with observed high resolution infrared radiance is crucial to improve the accuracy and stability of the retrieval of thermodynamic profiles. When applying the principal component analysis noise filter algorithm to the observed radiance, the optimal number k of principal components that used in the algorithm was mostly calculated with the statistical and empirical method. The percent cumulative variance method is one of the statistical methods that have been commonly used to calculate k, however, the threshold of the percent cumulative variance was determined subjectively and arbitrarily, which limits the application of this method. While the empirical method need the real-time Noise-Equivalent Spectral Radiance (NESR) to normalize non uniform noise in the observed data, but the real-time NESR needs the raw data of complex spectrum which is not easy to obtain in most cases. Aiming at the solving the problems above, a PCA noise filter based on the Improved PCV algorithm is proposed, of which the threshold is determined by iteratively calculating the difference between the simulated and reconstructed spectrum using different principal components, whereby k is determined such that the PCV is larger than the threshold. The new method solves the problem of arbitrary of the determination of k, and at the same time it doesn’t need the real-time NESR to normalize the observed radiance. First, the impact of normalization on the noise reduction is analyzed using physical retrieval of temperature profiles; the result shows that the impact is very small, which less than the impact of calculation error of k is caused by normalization on the retrieval of temperature profiles. Then, the noise reduction of the representative radiance data which covers four quarters of 2011 shows that, the RMSE of the retrieved temperature profile using the Improved PCV method is improved by 0.1 K compared to the factor indicator function method when the real-time NESR is not available, and it is almost the same with the latter when the normalization is done. Under the condition that the NESR is not available, the method proposed in this article could objectively and reasonably reduce the noise level of the ground-based high resolution infrared radiance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3625 (2016)
Hyperspectral Analysis and Electrolyte Leakage Inversion of Creeping Bentgrass under Salt Stress
XIAO Guo-zeng, WU Xue-lian, TENG Ke, CHAO Yue-hui, LI Wei-tao, and HAN Lie-bao
Leaf electrolyte leakage is an important index of the plant cell permeability which plays an important role in the study of turfgrass salt stress. Traditional methods of measuring leaf electrolyte leakage have many disadvantages such as time-consuming, destroying the plants and being unable to monitor salt stress in laLeaf electrolyte leakage is an important index of the plant cell permeability which plays an important role in the study of turfgrass salt stress. Traditional methods of measuring leaf electrolyte leakage have many disadvantages such as time-consuming, destroying the plants and being unable to monitor salt stress in large area. The aim of this study is to build a hyperspectral inversion model for leaf electrolyte leakage of creeping bentgrass under different salt concentration stresses thus to promote the application of the hyperspectral techniques in turfgrass salt stress monitoring. Creeping bentgrass was used in this study, and it was grown in water for two weeks before salt treatments. Leaves were collected at 7, 14 and 21 d under 0(CK), 100 and 200 mmol·L-1 NaCl respectively. The spectral values were gathered using Unispec-SC Spectral Analysis System (PP SYSTEMS, USA）before collecting grass leaves. Leaf electrolyte leakage was measured with electrical conductivity method. The relation and differences between salt treatments and spectral reflectance values were analyzed with EXCEL. Normalized difference vegetation index (NDVI) and difference vegetation index (DVI) were calculated using the spectral reflectance values. The first-order differential was calculated with difference method. The trilateral parameters of the blue, green and red rays were calculated at the meantime. The correlation analysis of the Leaf electrolyte leakage, spectral reflectance value, DVI and trilateral parameters was achieved by using EXCEL and Matlab software. Electrolyte leakage inversion model of the calibration set consisted of 48 high correlational samples, was built using unary linear regression, multivariate linear regression and partial least-squares regression methods. The prediction set inspection inversion model was established using the other 24 samples. The results showed that there is a positive correlation between salt stresses and 450～700 nm wave band. The leaf electrolyte leakage was positively associated with 450～732 nm band region at 0.01. The green edge amplitude and area of green edge were correlated with the foliar electrolyte leakage positively. Models based on partial least squares regression could inversion the foliar electrolyte leakage optimally. The calibration R2 reached to 0.681, and the validation R2 reached to 0.758. The calibration RMSE was 7.124, and the validation RMSE reached to 7.079. The inversion model made it possible to detect creeping bentgrass leaf electrolyte leakage under salt stress rapidly. This study also provided theoretical reference for monitoring the damage of other creeping bentgrass related plant species resulted by salt stress..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3630 (2016)
Spectral Response and Inversion Models for Prediction of Total Copper Content in Soil of Xifanping Mining Area
TENG Jing, HE Zheng-wei, NI Zhong-yun, ZHAO Yin-quan, and ZHANG Zhi
In order to solve the problem of high cost and low efficiency by using the traditional soil geochemical survey methods, this paper studied the simple detection method of soil heavy metal content with visible and near-infrared reflectance spectroscopy. The study collected visible and near-infrared reflectance spectroscoIn order to solve the problem of high cost and low efficiency by using the traditional soil geochemical survey methods, this paper studied the simple detection method of soil heavy metal content with visible and near-infrared reflectance spectroscopy. The study collected visible and near-infrared reflectance spectroscopy of soil samples in Xifanping mining area; then treated the reflectance spectroscopy with six mathematic changes such as differentials and continuum removal in advance; the next step was to select characteristic wavelengths that were sensitive to soil copper content by using stepwise regression method and Pearson correlation coefficient as set of comprehensive characteristic variables; finally, utilized different methods and parameters of characteristic variable selection to build the soil total copper content models and tested them. Results showed that: to extract the information of copper content in soil, the performance of different spectral transform methods varied, and each spectrum transform method corresponded to its certain sensitive spectral ranges; the inversion models based on the integrated spectrum transform information were better than that based on only one kind of spectrum transform information; as for establishing the prediction model of soil copper content by using the integrated spectrum transform information, backward elimination was better than forward selection and stepwise selection, and when the Removal is 0.20, the optimum model was obtained, its coefficients of determination（R2）and determination coefficients of prediction（R2pre）reached 0.851 and 0.830, root mean square error of calibration（RMSEC）and root mean square error of prediction（RMSEP）were 0.349 and 0.468 mg·kg-1. The model has a good precision, and it provides a train of thought for the detection of other soil heavy metal elements with visible and near-infrared reflectance spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3637 (2016)
Research Process on Hyperspectral Imaging Detection Technology for the Quality and Safety of Grain and Oils
YU Hong-wei, WANG Qiang, LIU Li, SHI Ai-min, HU Hui, and LIU Hong-zhi
The quality and safety of grain and oils are related to the national nutrition and health safety of the public. Owing to the difficulties in operation, destruction, high cost, reagent pollution and other shortcomings, conventional detection method cannot meet the fast, non-destructive, efficient and pollution-free requThe quality and safety of grain and oils are related to the national nutrition and health safety of the public. Owing to the difficulties in operation, destruction, high cost, reagent pollution and other shortcomings, conventional detection method cannot meet the fast, non-destructive, efficient and pollution-free requirements, which pose great difficulties in integrating with Industry 4.0. With the development of chemometrics, hyperspectral imaging (HSI) technology integrates the advantages of spectroscopy and image technology to overcome the defects of conventional detection method, which has become the developingt trend of grain and oils quality testing technology. Based on many interrelated research papers, this paper reviews the principles of HSI and the existing research in quality (component determination, germination test, variety classification) and safety (fungal detection, pest detection) of grain and oils. Meanwhile, in order to promote the application and development of hyperspectral imaging technology in the field of grain and oils, we specially analyze the aspect of HSI including spectral range, chemometrics, equipment and the accuracy of model, pointing out the current problems and prospecting the direction and priority..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3643 (2016)
Comparison of Predicting Blueberry Firmness and Elastic Modulus with Hyperspectral Reflectance, Transmittance and Interactance Imaging Modes
HU Meng-han, DONG Qing-li, and LIU Bao-lin
In this study, a imaging system with hyperspectral reflectance, transmittance and interactance was constructed for estimate the firmness and elastic modulus of blueberry. The comparisons of these three imaging modes were carried out. This hyperspectral system could also be applied for scattering modewhile this mode wasIn this study, a imaging system with hyperspectral reflectance, transmittance and interactance was constructed for estimate the firmness and elastic modulus of blueberry. The comparisons of these three imaging modes were carried out. This hyperspectral system could also be applied for scattering modewhile this mode was not suitable for small fruit such as blueberry. The reflectance hypercubes were segmented with the algorithm based on the Otsu method, and the transmittance and interactance hypercubes were processed with the algorithms based on region growing approach. Subsequently, the extracted spectra were pretreated with the Standard Normal Variate (SNV) and Savitzky-Golay of the first derivative (Der), and least squares-support vector machine was applied for the establishment of the corresponding prediction models. The obtained results demonstrated that -reflectance-SNV model could predict blueberry firmness with correlation coefficient of prediction sample set (Rp) of 0.80 and the ratio of percent deviation (RPD) of 1.76 among the models using full spectra. The elastic modulus of blueberry was better estimated by the full transmittance spectra subjected to SNV pretreatment with Rp (RPD) of 0.78 (1.74) than the other models. Furthermore, Random Frog selection approach could to some extent reduce the uninformative wavelengths while increasing the prediction accuracy of the established models. Random Frog-Interactance-Der model achieved Rp (RPD) of 0.80 (1.83) for blueberry firmness, but the number of wavelength was 140. In the case of blueberry elastic modulus, random frog-transmittance-SNV showed the relatively superior performance compared to the other models, with Rp (RPD) of 0.82 (1.83) and fewer wavelength number of 20..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3651 (2016)
Multifractal Analysis of Rapeseed Spectrum for Chlorophyll Diagnosis Modeling
WANG Xiao-qiao, WANG Fang, LIAO Gui-ping, and GUAN Chun-yun
One of the most important topics in crop information science is how to make use of the crop’s information for non-destructive nutrient diagnosiswhich can be solved with spectrum analysis. The canopy’s spectrum feature is a key indicator to describe the nutritional status for the rapeseeds. The original spectrum is to bOne of the most important topics in crop information science is how to make use of the crop’s information for non-destructive nutrient diagnosiswhich can be solved with spectrum analysis. The canopy’s spectrum feature is a key indicator to describe the nutritional status for the rapeseeds. The original spectrum is to be disturbed with external factors such as environment and climate; however, it is difficult to be directly used for rapeseed biomass diagnosis due to its huge fluctuation. However, the multifractal feature of the spectra remains stable relatively. In order to study the relationship between the canopy’s spectrum of the rapeseed and its chlorophyll, based on the multifractal theory, a quantitative model of chlorophyll prediction and a qualitative model of planting pattern identification were proposed in this paper to study the high oleic acid rapeseed samples in 24 transplanting regions and 24 direct planting regions. At first, the generalized Hurst exponent and mass exponents together with other relevant multifractal parameters of the spectra were extracted with popular multifractal detrended fluctuation analysis (MF-DFA) in different six considered wavelength ranges. It shows that all of them possess representative multifractal nature. However, there are some differences of the multifractal characteristics between the two kinds of regions with different planting pattern in some bands. In addition, by correlation analysis and detection between the multifractal parameters of the spectra and the SPAD values in six considered ranges of bands, it demonstrates that there is some difference of the effective information content in the different ranges of bands. In the quantitative model of chlorophyll prediction, for each groups of samples in transplanting regions and direct planting regions and mixed together in each significant bands, a selected multifractal parameter was used to establish the univariate model for predicting the rapeseed leaf’s SPAD values, respectively. The results of all the relative root mean square errors are small than 5%. Finally, the qualitative model was proposed to distinguish the samples by the two planting pattern. Youden index, as the identification accuracy was calculated for the six considered ranges of bands by the Fisher’s linear discriminant analysis. The best Youden index is 0.902 5 and the corresponding band range is 350~1 350 nm. The significant work provides a theoretical and practical method for predicting rapeseed leaf’s SPAD and also provides effective way to find the sensitive bands of the spectra for identification diagnosis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3657 (2016)
Influence of Light Source and Paper Color on the Exhibiting Preference of Traditional Calligraphy
LIU Qiang, and TANG Mei-hua
The Chinese calligraphy is a unique art of traditional Chinese culture. The core of color preference for Chinese calligraphy is figural preference, which is a special kind of color combination preference. Currently, the exhibition of calligraphy is always lack of scientific basis in the aspect of color science. In thisThe Chinese calligraphy is a unique art of traditional Chinese culture. The core of color preference for Chinese calligraphy is figural preference, which is a special kind of color combination preference. Currently, the exhibition of calligraphy is always lack of scientific basis in the aspect of color science. In this research, the influence of light sources and paper color on the preference of traditional calligraphy was analyzed based on subjective and objective experiments. The relative spectral power distribution of 5 typical light sources (correlated color temperature: 2 500, 3 500, 4 500, 5 500 and 6 500 K) and spectral reflectance of 5 typical Chinese rice papers (white, orange, light white, red, yellow-white) were firstly measured and then transformed into CIEXYZ and CIECAM02 color space, respectively. Subsequently, the correlation between those colors attributes and 1 000 series of psychophysical experiment data from 40 observers on calligraphy exhibiting preference was analyzed. At last, the influence factors of the correlation were discussed form a multiple statistical point of view, such as normal distribution, correlation analysis and multiple regression. The experimental results indicated that the exhibiting preference of Chinese calligraphy is obviously different with that of ordinary color preference cases, for it is mainly affected by the attributes of lighting sources instead of the contrast of hue and lightness. The authors believe that the finding of the research will provided effective support for the development of calligraphy exhibiting in near future for museums and gallaries..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3664 (2016)
Quantitative Detection of Iron in Soybean Oils with Laser Induced Breakdown Spectroscopy and Simple Regression Methods
WU Yi-qing, LIU Xiu-hong, SUN Tong, MO Xin-xin, and LIU Mu-hua
LIBS (laser-induced breakdown spectroscopy) was used to detect Fe element content in soybean oil quantitatively. In this experiment, a series of soybean oil samples with different concentrations of Fe were used; LIBS spectra were collected with a two-channel high precision spectrometer. According to the LIBS spectrum oLIBS (laser-induced breakdown spectroscopy) was used to detect Fe element content in soybean oil quantitatively. In this experiment, a series of soybean oil samples with different concentrations of Fe were used; LIBS spectra were collected with a two-channel high precision spectrometer. According to the LIBS spectrum of samples, two characteristic wavelength of Fe (404.58 and 406.36 nm) were determined, and different simple regression methods (exponential regression, linear regression and quadratic regression) were used to establish the quantitative analysis models of Fe content using each characteristic spectral line. The results indicate that the average relative error of Fe Ⅰ 404.58 and Fe Ⅰ 406.36 in simple exponential regression, linear regression and quadratic regression models were 29.49%, 8.93%, 8.70% and 28.95%, 8.63%, 8.44%, respectively. The results of Fe Ⅰ 406.36 regression models is better than that of Fe Ⅰ 404.58, and the quadratic regression model is optimal among the three regression models. According to these results, LIBS technology has certain feasibility for detecting Fe in soybean oil; the quadratic linear regression model can improve the prediction accuracy of Fe element effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3671 (2016)
Determination of 20 Trace Elements in the Blood Collection Tubes with ICP-MS
XIONG Chan, JIANG Xue-hui, TIAN Ya-ping, MA Qing-wei, LIU Li-peng, and GUO Guang-hong
To investigate the contamination of blood collection tubes, 20 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Ba, W, Hg, Tl, Pb) in 13 different types of blood collection tube were studied with ICP-MS method. The lixivium of H2O and 10% HNO3 were measured with ICP-MS, and then the contaminatTo investigate the contamination of blood collection tubes, 20 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Ba, W, Hg, Tl, Pb) in 13 different types of blood collection tube were studied with ICP-MS method. The lixivium of H2O and 10% HNO3 were measured with ICP-MS, and then the contamination coming from the blood collection tube is specified. According to the concentration range of human blood, plasma and serum from recently published literature, this report presents a detailed analysis of capable trace elements for each blood collection tube. The results showed that, tube No.1 is capable to analyze 18 trace elements in the human serum; tube No.6 is capable to analyze 15 trace elements in the human plasma; tube No. 13 is capable to analyze 17 trace elements in the human blood. But we still should be aware that, the elements Sb and W in tube No.1, the elements V, Cr, Ni, and Sb in tube No.6, and the elements Al, Sb and W in tube No.13, are in the same magnitude of the normal trace element concentration range in the human serum, plasma and blood. They might affect the testing results. The serum collected from the same volunteer by tube No.1 and tube No.3 were compared here, the results show that, almost each trace element concentration of human serum from tube No.1 is lower than from tube No.3, especially for elements Al, V, Cr, Mn, As, Sn, and Sb. The results indicate that the blood collection tubes show great impact on determination of trace element..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3676 (2016)
A New Sample Fusion Technique for Quantitative Analysis of Major and Minor Elements in Sulfides with X-Ray Fluorescence Spectrometry and Laser Ablation Inductively Coupled Plasma Mass Spectrometry
XU Juan, YANG Shou-ye, HU Zhao-chu, LUO Tao, and HUANG Xiang-tong
A new sample fusion method for sulfides has been developed in this study. HNO3 was used as a short pre-oxidation reagent instead of the traditional solid oxidant (e.g., NaNO3, KNO3), which avoid the erosion of the platinum crucible. GeO2 was also added in samples to avoid the break of glass beads. The good analytical pA new sample fusion method for sulfides has been developed in this study. HNO3 was used as a short pre-oxidation reagent instead of the traditional solid oxidant (e.g., NaNO3, KNO3), which avoid the erosion of the platinum crucible. GeO2 was also added in samples to avoid the break of glass beads. The good analytical precisions of X-ray fluorescence spectrometry (RSD<5.6%, 1σ) and laser ablation inductivity coupled plasma mass spectrometry (RSD<3%, 1σ) demonstrated that the major elements were homogeneously distributed in the fused beads of sulfides. The determined major and minor elements (Si, Al, Fe, Mg, K, Ca, Na, Mn, Cu and Zn) values by using XRF and LA-ICP-MS are in excellent agreement with published values in three reference sulfide standards(reference values for Ti were absent). These results clearly demonstrate that the present fusion technique is well suitable for routine sulfide sample preparation for both XRF and LA-ICP-MS analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3683 (2016)
A Hydride Generation-Catalytic Resonance Rayleigh Scattering Method for Detection of Trace Arsenic
LIANG Ai-hui, YANG Duo, WEN Gui-qing, LIU Qing-ye, and JIANG Zhi-liang
Arsenic is a toxic metal element and the establishment of a highly sensitive and selective method for As has great significance to human health and environment protection. In sulfuric acid medium, As(Ⅲ) was reduced by NaBH4 to form AsH3 gas that was trapped by the Ce(Ⅳ)-I－ catalytic absorption solution to cause Ce(Ⅳ) cArsenic is a toxic metal element and the establishment of a highly sensitive and selective method for As has great significance to human health and environment protection. In sulfuric acid medium, As(Ⅲ) was reduced by NaBH4 to form AsH3 gas that was trapped by the Ce(Ⅳ)-I－ catalytic absorption solution to cause Ce(Ⅳ) concentration decreased and As particle increased, which resulted in the resonance Rayleigh scattering (RRS) and fluorescence increased at 370 and 351 nm respectively. The increased RRS and fluorescence intensities were linear to As(Ⅲ) concentration in the range of 0.006~0.76 and 0.006~0.28 mg·L-1 respectively, with a detection of As of 3.0 μg·L-1 . The new hydride generation-catalytic RRS method was applied for detection of trace As(Ⅲ) in milk samples, and the results were in agreement with that of hydride generation-atomic absorption spectrometry..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3689 (2016)
Spectra and Mineralogy Study on Black Tianhuang and Kengtou Stone from Shoushan, Fujian Province
CHEN Tao, LIU Yun-gui, WU Di, and XU Wen-jing
Shoushan Stone is one of the national stones of our country which is also the most famous stone of the four outstanding seal stones in China. As to Shoushan stones, black Tianhuang stone is a kind of black colored stone. It is one of the most special species in Tianhuang stones which comes from fields beside the ShoushShoushan Stone is one of the national stones of our country which is also the most famous stone of the four outstanding seal stones in China. As to Shoushan stones, black Tianhuang stone is a kind of black colored stone. It is one of the most special species in Tianhuang stones which comes from fields beside the Shoushan Brook. The black Kengtou stone comes from Kengtou Zhan, its original place. In this study, black Tianhuang stone is studied and compared with black Kengtou stone by using X-ray powder diffraction spectrometer (XRD), infrared spectrometer (IR), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and scanning electron microscopy (SEM) in order to analyze the mineral composition, characteristic of infrared spectra, color genesis, and characteristic of micro- morphology of these stones. The results of the study indicate that the mineral compositions are different between these stones. The analysis of IR and XRD studies indicate that the black Kengtou stone is mainly composed of dickite. On the other hand, XRD analysis indicates that it can contain a small amount of pyrophyllite, illite, pyrite, and quartz. However, the analysis of IR and XRD studies indicate that black Tianhuang stone is mainly composed of dickite or nacrite. On the other hand, XRD analysis indicates that the minor mineral composition in the black Kengtou stone can be svanbergite and tochilinite. Their characteristics of micro-morphology of black Tianhuang stone and black Kengtou stone are also different. The crystal size of dickite in black Tianhuang stone is inconformity, and the margin of lamellae crystals is smoothed. It indicates that such kind of stone had undergone corrosion effect due to water-rock reaction. On the other hand, the black Kengtou stone are well crystalized. The lamellae has sharp margin, and the size of the lamellae is relatively uniform. It indicates that the black Kengtou stone is original ore. According to the trace chemical composition analysis of LA-ICP-MS, it preliminary suggests that black color of both black Tianhuang and Kengtou stones have relationship with Fe element. The final conclusion of color genesis needs more experiments to prove..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3693 (2016)
Spectroscopy Characterization of Anthracite Oxide
HUANG Du-bin, CHUAN Xiu-yun, and CAO Xi
With high degree of metamorphism and carbon content, anthracite is commonly used for activated carbon. The structural properties of anthracite play a decisive role in its materialization, while with chemical oxidation, anthracite structure can be purposefully improved. The anthracite oxide was prepared via acid leachinWith high degree of metamorphism and carbon content, anthracite is commonly used for activated carbon. The structural properties of anthracite play a decisive role in its materialization, while with chemical oxidation, anthracite structure can be purposefully improved. The anthracite oxide was prepared via acid leaching and oxidizing, using high carbon content and low ash content anthracite from Zhaotong, Yunnan Province, China. The structural and spectroscopy characteristics of anthracite and anthracite oxide were acquired with X-ray diffraction (XRD), Raman spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The results show that crystallites in anthracite have intermediate structures between graphite and amorphous. Compared with bitumite and lignite, its structure order degree lies between graphite and low metamorphic coals with relatively high average diameter of coal crystallites(La) and average height of coal crystallites (Lc）. The process of anthracite oxidation can be modeled in two steps, the edge of crystal was curled and destroyed with strong oxidation, with the generation of CO group and intercalation of HNO3/H2SO4 into the edge layers, leading to the reducing of lateral sizes; HNO3/H2SO4 were continually intercalated into crystals, resulted in the increase of interlayer spacing (d(002)) from 0.351 to 0.361 nm, and the number of stacked layers dropped to 4.5 from 6 due to exfoliate. ID1/IG in Raman spectroscopy increased from 1.9 to 2.0, with full width at half maximum (FWHM) of G bond and intensity of D2 bond increasing from 63 to 68 and 10.26 to 13.78. Numbers of new —C—O—, CO, —NO2 groups generated, leading to the decrease of oxygen-containing functional groups content from 0.11 to 0.42. After HNO3/H2SO4 oxidation, the aromaticity (fa) of anthracite oxide increases, with the decrease of structure order degree and more-over a lot of active reaction sites generates in the process. The oxidation of anthracite enables anthracite has great potential in the application of porous carbon preparation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3698 (2016)
Study on the Crystal Structure of Cellulose in Bamboo with Synchrotron Radiation Wide Angle X-Ray Scattering
AN Xin, YANG Shu-min, LIU Rong, WEI Peng-lian, YANG Chun-ming, and +++++++++++++++FEI Ben-hua
The crystal structure of cellulose will directly affect the properties of bamboo fiber -reinforced composite, but the unit cell of native cellulose in bamboo has never been investigated. The most accepted model for the structure of native cellulose is Meyer-Misch model which provides a reference to understand the unit The crystal structure of cellulose will directly affect the properties of bamboo fiber -reinforced composite, but the unit cell of native cellulose in bamboo has never been investigated. The most accepted model for the structure of native cellulose is Meyer-Misch model which provides a reference to understand the unit cell of native cellulose in bamboo. The native cellulose consists of two different crystal structures (Ⅰα and Ⅰβ) which exist in different plants with different proportions. Because of this situation, the crystal structure of bamboo cellulose should have a unique model. The moso bamboo （Phyllostachys edulis (Carr. ) H. de Lehaie）was selected. The crystal structure of cellulose of bamboo was investigated with two dimensional synchrotron radiation wide angle X-ray scattering (SR-WAXS). The values of the interplanar spacings of each peak were obtained from SR-WAXS patterns, and then crystal structure parameters were calculated according to monoclinic crystal system. The results show that the fibre axis of a bamboo cellulose unit cell with a monoclinic unit cell of a=8.35 , b (fiber axis)=10.38 , c=8.02 , β=84.99°. This model has a two antiparallel arrangement for the chains in unit cell, with four glucose residues. Thus, the model may be used to provide a theoretical basis for high value-added bamboo fiber -reinforced composite..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3704 (2016)
Effect of Raw Materials and Preparing Process on the Composition of Lime-Ash
WU Jun-ming, LUO Ting, XIONG Chun-hua, YU Hui-qing, and FAN Zhi-wei
As the saying goes that “no ash, no glaze”, lime-ash has been the core material widely used to prepare glaze in ancient China. Among all the lime-ashes, those made in Jingdezhen are the most influential and representative ones. Not only did lime-ash contribute greatly to the prosperity of porcelain making of JingdezhenAs the saying goes that “no ash, no glaze”, lime-ash has been the core material widely used to prepare glaze in ancient China. Among all the lime-ashes, those made in Jingdezhen are the most influential and representative ones. Not only did lime-ash contribute greatly to the prosperity of porcelain making of Jingdezhen in Song, Yuan, Ming and Qing Dynasty, but also it has a complicated, rigorous and a touch of “mysterious” in its preparation process, technical principle and glaze mechanism. Therefore, the research of the lime-ash has been an important subject in exploring the “secret” of ancient Chinese porcelain production by Chinese and foreign researchers. In this paper, four representative firewood and two lime stones as the raw materials were collected for the comparative studies, and three kinds of lime-ash with different smolder times were collected from one of the only two traditional lime-ash workshops in Shou’an town nearby Jingdezhen urban area. The chemical composition and phase composition of the raw materials and lime-ash with different smolder times made in Jingdezhen were discussed by testing with the Energy Dispersive X Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD). The results showed that Fe2O3, MnO contents reaches 1.41% and 1.52% respectively, but the P2O5 content is just 0.54% of Langqi grass which is lower than other firewood that is not only benefited to form the characteristic of “Green in the white” in Jingdezhen traditional glaze, but also is favor to enhance the transparency of glaze and promote the coloration of traditional under-glazed color painted porcelain, such as the blue and white porcelain. The CaO content of grey lime stone is lower than that of the black lime stone with MgO content of 35.79%.This could be the main reason why the craftsmen prefer to use black lime stone to prepare lime-ash. In addition, the EDXRF results show that the K2O, P2O5, MnO and Fe2O3 contents have increased as the time of smoldering increases. In the meanwhile, the calcium carbonate (CaCO3) phase has also increased, but the calcium hydroxide (Ca(OH)2) phase has decreased. The study helps Jingdezhen porcelain “look like jade” and is also good to avoid the “thickness” of glaze when there is a certain amount of Ca(OH)2 in glaze. So it could be concluded that the unique raw materials and smolder technology of the lime-ash which have provided the technical support for the development of lime-ash glaze are the unique features of ancient Jingdezhen ash glaze..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3709 (2016)
The Analysis of Element and Measure Analysis of NMR Spectrum and XRD Spectrum for High Purity 3,4,9,10 Perylenetetracarboxylic Dianhydride-PTCDA
ZHANG Xu, ZHANG Jie, YAN Zhao-wen, SHAO Yu-bo, and ZHANG Fu-jia
vacuum sublimation method was used to purify the homegrown 3,4,9,10 perylenetetracarboxylic dianhydride（PTCDA）powder with a purity of 98% in its sublimation point of 450 ℃. With Bill’s law and ultraviolet-visible spectrophotometer testing analysis, its purity reached to 99.8%. Meanwhile, the contents of C and H elementvacuum sublimation method was used to purify the homegrown 3,4,9,10 perylenetetracarboxylic dianhydride（PTCDA）powder with a purity of 98% in its sublimation point of 450 ℃. With Bill’s law and ultraviolet-visible spectrophotometer testing analysis, its purity reached to 99.8%. Meanwhile, the contents of C and H elements in the pre-and post-purified molecules were also measured by using elemental analyzer. The measured results indicate that the contents of C and H elements in the post-purified the molecules are very close to the theoretical value. H element in the molecular structure was investigated with nuclear magnetic resonance (NMR) spectroscopy and the results demonstrated that there are an equal number of H atoms in two different chemical environments and it can only be located on the aromatic ring. By discussing the chemical bond formation of PTCDA molecules, the C, H and O atoms in high purity PTCDA molecules are mainly covalent bonds. The crystalline state and crystal structure of this organic material were tested and analyzed by X-ray diffractometer. The results suggest that the post-purified PTCDA power existed α-PTCDA and β-PTCDA two phases, in which α-PTCDA phase is major component while β-PTCDA phase accounts for about one five of the total ingredients. Besides, the crystal cell belonged to bottom-centered monoclinal structure. Meanwhile, the crystal state, grain size and band structure of PTCDA single crystal thin films formed on the surface of p-type silicon in its sublimation point are investigated in detail. During the high-purity α-PTCDA forming organic single thin film on the surface of p-type single silicon, the π-electron cloud covered on the top, bottom and two sides of its thin film’s molecular layer plane. Due to the formation of delocalized bond that attributed to the overlap of the outermost valence electron orbital of C, H, O atom, the valence electrons generate co-movement and the energy level splitting for the band. The energy difference between valence band and the first tight binding is 2.2 eV which lead to this organic material possessing the properties of semiconductor conduction. In addition, this organic material with the intrinsic carrier concentration for 1014 cm-3 belong to weak p-type organic semiconductor material. This organic material combines with the surface of p-type silicon to form hetehomo-type heterojunction which is provided with excellent response for visible light to near infrared wavelengths of light..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3714 (2016)
A Research on Filed-of-View (FOV) Widening and Thermal-Phase-Drift (TPD) Compensating Technology Applied in a Polarized Interference Imaging Spectrometer (PIIS)
ZHAI Yang, XIAO Dong, LI Bo, and ZHU Ri-hong
The Polarized Interference Imaging Spectrometer (PIIS), which is based on the theory of Fourier Transform Spectroscopy, is consisted of a series of birefringent crystals such as polarizers, a beam splitter as well as various lengths of birefringent crystals required to achieve large delays. The PIIS, compared with a trThe Polarized Interference Imaging Spectrometer (PIIS), which is based on the theory of Fourier Transform Spectroscopy, is consisted of a series of birefringent crystals such as polarizers, a beam splitter as well as various lengths of birefringent crystals required to achieve large delays. The PIIS, compared with a traditional grating-based dispersion spectrometer, has various advantages of multiple-channel measurements, simultaneous information acquisition of both original images and fringes containing spectral details, large light flux, better light signal-to-noise ratio (SNR) as well as anti-vibration etc. Therefore, the PIIS has also been developed in a range of astronomy and astrophysics areas such as remote sensing, extrasolar planet radial velocity measurements, spacecraft design, lunar exploration etc. However, by reviewing of former works and references, two major drawbacks still remain in PIIS and need to be fixed. For one thing, the classic PIIS has a very limited field-of-view (FOV) around ±2°, which means the acquired fringes on the image plane will show quite strong non-linear distortion and hence degrade the accuracy of spectral reconstruction via Fourier transform. For another, the random thermal-phase-drift (TPD), given rise from both thermal expansion and birefringence variation caused by the environmental temperature fluctuation, has barely been studied before and will inevitably result in extra radial velocity error based on Doppler Spectroscopy. In this paper, a noble polarization interference imaging spectrometer with the emphasis on the FOV widening technology is introduced. This technology, using a compensated Savart plate containing a half-wave plate sandwiched between two orthogonally placed displacer plates as a compensated Savart plate, produces an angle-dependent phase shear to create parallel spatial interference fringes with a FOV around ±10°. This improvement not only enhances the accuracy of Fourier Transform algorithm but also increases input luminous flux and therefore even weak input spectrum detection and calibration results with high SNR can be fully accomplished. Also, a secondary set of birefringent plates (α-BBO and LiNbO3) with opposite thermal properties is proposed to passively diminish TPD caused by temperature fluctuation. The experiment shows that thermal-drift-phase error is perfectly restricted within 0.02 rad in the laboratory environment. As a consequence, this advanced PIIS is eligible to realize the fast and accurate measurement and calibration application in the field of large astronomical spectral instruments with ultra-high spectral resolution occasions such as Astronomical Frequency Comb..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3720 (2016)
Refractive Index Insensitive Temperature Sensor Based on Cascading Single Mode Fiber with Few Mode Fiber
FU Xing-hu, ZHANG Shun-yang, LIU Qiang, XIE Hai-yang, HAN Xue-wen, YANG Chuan-qing, FU Guang-wei, and BI Wei-hong
A refractive index insensitive temperature sensor is proposed base on cascading single mode fiber with few mode fiber(FMF). During the sensor preparation, the splicing current is set to 100 mA, and a section of FMF is no core-offset splicing between two single-mode fibers. Therefore, it can motivate the transmission moA refractive index insensitive temperature sensor is proposed base on cascading single mode fiber with few mode fiber(FMF). During the sensor preparation, the splicing current is set to 100 mA, and a section of FMF is no core-offset splicing between two single-mode fibers. Therefore, it can motivate the transmission mode preferably and form optical fiber Mach-Zehnder interferometer. The mode phase difference in FMF will be changed according to the outside environment. It will cause interference fringe shift. The parameter to be measured can be achieved by detecting the amount shift of interference spectrum. The FMF can transmit four modes with LP01, LP11, LP21, LP02. The transmission spectrum is also analyzed, which shows that they have two modes of LP01 and LP11 in sensor with the length of 81.5 mm. In the refractive index and temperature sensing experiment, the cascading FMF sensor with the length of 81.5 mm is used. The results show that the transmission spectrum of sensor appears obvious blue shift as temperature is increasing, the temperature sensitivity can be up to -85.9 pm·℃-1 within the range of 27.6~93.8 ℃ with good linearity. The refractive index sensitivity is 3.697 34 nm·RIU-1 within the range of 1.347 1~1.443 9. There is no obvious shift phenomenon in the transmission spectrum with the feature of refractive index insensitive. Therefore, compared with the traditional cladding mode and multimode interferometric fiber-optic sensor, the proposed sensor based on FMF is easier to control and analyze transmission mode has the advantages of simple structure, easy process and high sensitivity. It can avoid cross-sensitivity between temperature and refractive index measurement. Thus, it can be used for temperature detection of power system, biomedicine, aerospace and other fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3726 (2016)
Combined Transmission Laser Spectrum of Core-Offset Fiber and BP Neural Network for Temperature Sensing Research
WANG Fang, ZHU Han, LI Yun-peng, and LIU Yu-fang
When studying the wavelength response to the temperature of the single mode fiber interference laser spectrum, a three layer BP neural network model is built to solve the problem of high complexity and low accuracy of temperature measurement system. With the Discussion of the parameters of network model, we obtain the When studying the wavelength response to the temperature of the single mode fiber interference laser spectrum, a three layer BP neural network model is built to solve the problem of high complexity and low accuracy of temperature measurement system. With the Discussion of the parameters of network model, we obtain the optimal network structure by comparing the data acquisition which is the laser wavelength corresponding to its temperature trained by BP neural network. With network training completed and the wavelength of input laser reached the specified value, the corresponding temperature prediction can be obtained from the output layer. In conclusion, it shows a clear correlation between the predictive value and the actual value, i.e. the former is approximately equal to the latter. The correlation coefficients of the calibration and prediction are 0.999 61 and 0.979 27, respectively; while the standard errors of the calibration and prediction are 0.017 5 and 0.144 0, respectively, and the average relative error of prediction set is 0.17%. The residual predictive deviation (RPD), obtained theoretically, is 5.258 3. RPD>3. It indicates that the calibration effect is good, and the model can be used for practical testing. In addition, the algorithm is also applied to the system of double coupled structure with single-mode core-offset fiber and correction for the temperature measurement. The results show that BP neural network method can deal with the nonlinear relationship between the laser spectral data and the temperature in the optical fiber temperature measurement system. The correlation and the average relative error between the predicted temperature and the true temperature are 0.996 58 and 0.63%, respectively. The precision and stability of the fiber optic temperature sensor are significantly improved. At the same time, the feasibility of the proposed algorithm is verified in the fiber optical sensor system. It also provides a new way for the accurate measurement of pressure, curvature and other physical quantities of the core-offset fiber..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3732 (2016)
The Intramolecular Spin-Spin Interactions in Ruthenium Complexes of Pyrazole Derivatives
Peter A. Ajibade
The spin-spin coupling can provide useful information for analysing the structure of a system and the extent of non-covalent bonds interactions. In this study, we present the isotropic NMR properties and spin-spin coupling involving ruthenium-ligand (Ru-L) bonds and other spin-spin interactions obtained from DFT calculThe spin-spin coupling can provide useful information for analysing the structure of a system and the extent of non-covalent bonds interactions. In this study, we present the isotropic NMR properties and spin-spin coupling involving ruthenium-ligand (Ru-L) bonds and other spin-spin interactions obtained from DFT calculations. The proton shift which in close proximity with the Ru and Cl (or O) atoms are characterised with lower and higher chemical shift respectively. Though Ru-Cl bond has longer bond length than all other Ru-L bonds, yet its spin-spin coupling is higher than others because of a very high contribution of PSO which is far higher than the contribution from FC terms. In all other Ru-L bonds, FC is the most significant Ramsey terms that define their spin-spin coupling. Both the isotropic and anisotropic shielding of the Hz of the pyrazole is lower than Hc of the cymene and the spin-spin coupling 3J(Hz…Hz) of the pyrazole are less than half of the 3J(Hc…Hc) of the cymene unit in the complexes. There is a little increase in both the 3J(Hc…Hc) and 3J(Hz…Hz) spin-spin coupling in the hydrolysed complexes compare to the non-hydrolysed complexes. The isotropic and anisotropic shielding tensor of Ru atoms increases in magnitude as the complexes get hydrolysed that could be ascribed to a more deshielding chemical environments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3737 (2016)
Distinguishing the Rare Spectra with the Unbalanced Classification Method Based on Mutual Information
LIU Zhong-bao, REN Juan-juan, and KONG Xiao
Distinguishing the rare spectra from the majority of stellar spectra is one of quite important issues in astronomy. As the size of the rare spectra is much smaller than the majority of the spectra, many traditional classifiers can’t work effectively because they only focus on the classification accuracy and have not paDistinguishing the rare spectra from the majority of stellar spectra is one of quite important issues in astronomy. As the size of the rare spectra is much smaller than the majority of the spectra, many traditional classifiers can’t work effectively because they only focus on the classification accuracy and have not paid enough attentions on the rare spectra. In view of this, the relationship between the decision tree and mutual information is discussed on the basis of summarizing the traditional classifiers, and the cost-free decision tree based on mutual information is proposed in this paper to improve the performance of distinguishing the rare spectra. In the experiment, we investigate the performance of the proposed method on the K-type, F-type, G-type, M-type datasets from Sloan Digital Sky Survey (SDSS), Data Release 8. It can be concluded that the proposed method can complete the rare spectra distinguishing task compared with several traditional classifiers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3746 (2016)
The Application of THz Spectroscopy and GA-BP in Methanol Concentration Detection
TAN Hong-ying, ZHENG De-zhong, LI Xue, and XU Zheng-xia
At ambient temperature and atmospheric pressure, making use of a photoconductive-antenna terahertz time-domain spectrograph and a self-designed air chamber, the terahertz time-domain spectroscopy (THz-TDS) technique test of methanol gas in the range of 0.1~3.0 THz shows that the methanol gas has no obvious absorption pAt ambient temperature and atmospheric pressure, making use of a photoconductive-antenna terahertz time-domain spectrograph and a self-designed air chamber, the terahertz time-domain spectroscopy (THz-TDS) technique test of methanol gas in the range of 0.1~3.0 THz shows that the methanol gas has no obvious absorption peaks in the range of 0.1~3.0 THz and has obvious absorption peaks in the range of 0.1~1.0 THz. In order to improve the determination accuracy of the concentration of the methanol gas, the author detected 15 groups of methanol gas with different concentrations on the basis of the relationship between the strengths of 15 characteristic absorption peaks of different locations and the concentration of the methanol gas, and obtained the difference curve of the of the characteristic absorption peaks. Based on the function approximation of BP neural network, the author optimized the initial weights and biases of the BP neural network by using the GA the genetic algorithm, which has higher rate of convergence to prevent from getting into local optimum easily, and constructed the mathematical model with the purpose of predicting the methanol gas concentration. The test results show that the neural network is applicable to predict methanol gas in the volume concentration range of 0.028 3~0.424 6 m3·L-1, the average relative standard deviation of the 2 sets of samples is 1.7%, the average recovery rate is 98%, the error precision of the neural network is 10-1, and correlation coefficient of the measured values and the predicted values is 0.996 77. The test basically achieved ideal predicted results. The research results obtained experimental data of methanol gas in the terahertz frequency band and found that the method of combining terahertz time-domain spectroscopy with GA-BP neural network can effectively detect the volume concentration of methanol gas, and provided a new method for the detection of concentration of methanol gas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3752 (2016)
Research on the Preparation and Chromaticity Coordinates Shift Mechanism of Organic White Light Top-Emitting Devices
WANG Guang-hua, ZHAO Hui-qiong, DENG Rong-bin, DUAN Yu, SUN Hao, ZHANG Xiao-dan, ZHOU Qin, QIAN Jin-mei, WAN Rui-min, JI Hua-xia, and JI Rong-bin
The top emission organic light-emitting devices were fabricated on the multi-layers metal anode with co-doping method in single host system. In experiment, the multilayer Al/Mo/MoO3 anode on silicon are deposited, systematically analyzed the effect MoO3 thickness on the reflectance and found the mechanism of the MoO3 tThe top emission organic light-emitting devices were fabricated on the multi-layers metal anode with co-doping method in single host system. In experiment, the multilayer Al/Mo/MoO3 anode on silicon are deposited, systematically analyzed the effect MoO3 thickness on the reflectance and found the mechanism of the MoO3 thickness variation to the reflectivity of Al/Mo/MoO3 on silicon. Experimental results showed that the luminous intensity of blue, green and red appear to change according to the current density increase, and compared with the red intensity, the luminous intensity of blue and green gradually increased. The emission in this host-guest co-doping system is considered to usually involve two emission mechanisms, energy transfer and carrier trapping, and the energy transfer and carrier trapping between the host-guest should be responsible for chromaticity coordinates shift of organic white emitting light devices. In addition, through further study, it is proved the electroluminescence intensity of dopant linearly decrease with the driving voltage applied to the device by theoretical and experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3758 (2016)
Identification of Plant-Pathogenic Fungi Using Fourier Transform Infrared Spectroscopy Combined with Chemometric Analyses
CHAI A-li, WANG Yi-kai, ZHU Fa-di, SHI Yan-xia, XIE Xue-wen, and LI Bao-ju
Identification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic examination and can be influenced by the interpretation of the micro-morphological characters observed. The present investigation aimed to create a simple but sophisticated method for the identification of plant-pathogenic funIdentification of plant-pathogenic fungi is time-consuming due to cultivation and microscopic examination and can be influenced by the interpretation of the micro-morphological characters observed. The present investigation aimed to create a simple but sophisticated method for the identification of plant-pathogenic fungi by Fourier transform infrared (FTIR) spectroscopy. In this study, FTIR-attenuated total reflectance (ATR) spectroscopy was used in combination with chemometric analysis for identification of important pathogenic fungi of horticultural plants. Mixtures of mycelia and spores from 27 fungal strains belonging to nine different families were collected from liquid PD or solid PDA media cultures and subjected to FTIR-ATR spectroscopy measurements. The FTIR-ATR spectra ranging from 4 000 to 400 cm-1 were obtained. To classify the FTIR-ATR spectra, cluster analysis was compared with canonical vitiate analysis (CVA) in the spectral regions of 3 050～2 800 and 1 800～900 cm-1. Results showed that the identification accuracies achieved 97.53% and 99.18% for the cluster analysis and CVA analysis, respectively, demonstrating the high potential of this technique for fungal strain identification..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3764 (2016)
Analysis of Thermal Field Distribution in Winter over Beijing from 1985 to 2015 Using Landsat Thermal Data
ZHOU Xue-ying, SUN Lin, WEI Jing, JIA Shang-feng, TIAN Xin-peng, and WU Tong
Heat supply, automobile exhaust, industrial production and decrease of thermal inertia in winter caused by the decrease of vegetation coverage leads to an obvious difference in the distribution of the land thermal field in the winter compared with other seasons. The Urban thermal field distribution in the winter directHeat supply, automobile exhaust, industrial production and decrease of thermal inertia in winter caused by the decrease of vegetation coverage leads to an obvious difference in the distribution of the land thermal field in the winter compared with other seasons. The Urban thermal field distribution in the winter directly affects the spread of air pollutants, which has important implications for analyzing the contribution of the thermal field to particulate air pollution. Atmospheric transmissivity and atmospheric upwelling/downwelling radiance in simulations are first calculated using the moderate spectral resolution atmospheric transmittance algorithm and computer model (MODTRAN). Then, we solve the radiative transfer model of the thermal infrared band by constructing a look-up table. In addition, the accuracy estimation is performed using the simulated data, showing that when the error range of emissivity and water vapor content are confined to ±0.005 and ±0.6, respectively, the temperature retrieval error are less than 0.348 and 2.117 K, respectively indicating the high retrieval accuracy of the method. In addition, the long-term sequenced Landsat TM and ETM+ data were selected to retrieve land surface temperature (LST) during 1985-2015. The analysis of the temporal and spatial distribution of thermal fields in Beijing show that the spatial and temporal variations are observable. The spatial variation covers four levels: high temperature is distributed within the second ring, low temperature loops are distributed between the second and the fifth ring, high temperature is distributed in the outer suburb areas and the lowest temperature is distributed in the western mountainous areas. Meanwhile, the temporal variation of thermal field distribution changed a great deal during the rapid development in the past 3 decades: the low temperature loop expanded from the third to the sixth ring; the intensity and scope of the heat island effect within the second ring increased gradually..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3772 (2016)
Trace Element Analysis by PIYE and ICP-AES of Raw Material and Ancient Serpentine Artifacts from China
DONG Jun-qing, WANG Yong-ya, GAN Fu-xi, and LI Qing-hui
This work mainly talks about serpentine mineral with the aim to explore the possible raw materials sources of ancient serpentine artifacts by trace element content analysis. The major and trace elements of serpentine samples from several typical deposits in China were nondestructively determined by external-beam protonThis work mainly talks about serpentine mineral with the aim to explore the possible raw materials sources of ancient serpentine artifacts by trace element content analysis. The major and trace elements of serpentine samples from several typical deposits in China were nondestructively determined by external-beam proton-induced X-ray emission (PIXE). For comparison, trace element concentrations were destructively measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results showed the trend of the trace element contents of serpentine jade obtained by the two methods have preferably coherence, which indicate that the nondestructive technique of PIXE can be applied to trace element analysis of serpentine. The relationship between trace element contents and serpentine formation mechanism was discussed. The difference of the trace elements contents in these serpentine minerals is obvious. It can be used to distinguish the different kinds of serpentine formed by different mechanisms. A low amount of Ni and almost no Cr and Co were found in type I serpentine group mineral, whereas significant amounts of Cr, Co and Ni were found in Type II serpentine group mineral. The chemical composition of 18 ancient serpentine artifacts were analyzed by PIXE, they were unearthed from 14 sites and tombs in provinces of Zhejing, Jiangsu, Henan, Anhui and Hubei and dated from Neolithic Age to the Warring States Period (4585 BC—231 BC). By comparing the trace element contents between ancient serpentine artifacts and two kinds of serpentine samples, the provenance of ancient serpentine artifacts were preliminarily inferred. It is beneficial to try to explore the possible raw material of ancient serpentine artifacts based on the relationship between the trace element contents and serpentine formation mechanism in this article..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3780 (2016)
Spectroscopic and Molecular Docking Study on Specific Binding and Inhibition of Isoniazid to Human Serum Albumin and Catalase
WANG Yi-run, FANG Qing, HU Tao-ying, and LIU Ying
Isonicotinic acid hydrazide (Isoniazid, INH) is one of the most commonly used first-line anti-tuberculosis drugs, which has been reported that the high concentration of INH in human body can lead to epilepsy, liver function failure, and even death. Therefore, studying the potential binding effects of INH on the structuIsonicotinic acid hydrazide (Isoniazid, INH) is one of the most commonly used first-line anti-tuberculosis drugs, which has been reported that the high concentration of INH in human body can lead to epilepsy, liver function failure, and even death. Therefore, studying the potential binding effects of INH on the structure and activity of human serum albumin (HSA) and catalase (CAT) is very essential for evaluating its toxicity and side effect. In this paper, multi-spectroscopic and molecular docking methods were used to elucidate the patterns of INH to HSA and CAT under imitated physiological conditions. The inner filter effect of all fluorescence data in the paper was eliminated to get accurate binding parameters. The Stern-Volmer quenching constants (KSV) of both HSA-INH system and CAT-INH system inversely correlated with temperatures, demonstrating that INH quench the intrinsic fluorescence of HSA and CAT via static quenching. The conformational investigation of HSA and CAT through UV-visible absorption spectroscopy, synchronous fluorescence and circular dichroism (CD) showed that INH could change the micro-environment of tryptophan residues and reduced the α-helix content of protein. These results demonstrated that the binding of INH may lead to the loosening of protein skeleton, which which may affect its physiological function. The results of molecular docking revealed that the INH was located in Sudlow’s site I of HSA. And INH bound to CAT at a cavity among the wrapping domain helical domain and β-barrel, which resulted in the inhibition of CAT activity. In addition, Levofloxacin (LVFX) is a new effective and safe second-line anti-tuberculosis drugs and can improve the curative effect on anti-TB by using with other anti-TB drugs, the result of Hill’s coefficients (nH) about synergy between INH and proved that LVFX promoted the interaction of HSA with INH. Moreover, according to the CD spectra, synergy between INH and LVFX changed the conformation of HSA and the amount of α-helix decreased about 7.9%. This work will provide important insights into the binding and toxicity mechanism of INH to HSA and CAT in vivo and is expected to be helpful in evaluating the essential information for using the INH safely..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3789 (2016)
Structural Effect on Absorption and Emission Properties of 1,8-Naphthalimide Derivatives: a DFT Study
QI Qi, WANG Yu-qiao, and SUN Yue-ming
Using B3LYP/6-31G(d) model, time depended(TD)-B3LYP/6-31+G(d) method and Conductor-like Polarizable Continuum Model (C-PCM)-TD-B3LYP/6-31+G(d) method, we calculated the structure and the absorption and emission spectra of a series of N-substituted 1,8-naphthalimides in both gas-phase and dichloromethane. The influence Using B3LYP/6-31G(d) model, time depended(TD)-B3LYP/6-31+G(d) method and Conductor-like Polarizable Continuum Model (C-PCM)-TD-B3LYP/6-31+G(d) method, we calculated the structure and the absorption and emission spectra of a series of N-substituted 1,8-naphthalimides in both gas-phase and dichloromethane. The influence of the substituents on the electronic absorption spectra and their emission spectra has been discussed on their calculated frontier molecular orbitals contour and their energy levels. Results show that their rings extension from CN group and the substituents on their naphthalimic ring play an important role in the absorption spectra and the emission spectra properties. Modification of OCNCO group and the substituents in their naphthalimic rings breaks the structural symmetry. The Mulliken atomic charges values of NO2 groups from S0 to S1 in 4 positions are a little greater than the 5-positions, which also mean that the 5 position provide more electrons. For MACs of N(Ph)2 and N(Me)2, the 4 position substituents provide more charges than that of 5 position. They not only lead to bigger dipole moments, but also extend frontier orbital contour. Frontier orbitals also show that the modification of OCNCN and the introduction N(Me)2, N(Ph)2 and NO2 groups extends their π—π* excitation scope and decreases their energy gap accordingly. Besides, those kinds of molecular design enhance intra molecular charge transfer between substituent and naphthalimic ring. Therefore, redshift are shown in their absorption and emission spectra, which is also verified by calculated results. Their absorption and emission spectra in solvent redshift compared with their gas spectra. For the NO2 derivatives, the charge transfer state is in the 5 position substituent compounds. For donor substituents, charge transfer state lies in their 4 position compounds. When the CO group is in the same side with the NO2 group, and the N(Me)2 and the N(Ph)2 are in the different side with the CO group, compounds have better conduction properties. From compound 1 to compound 4, the redshift of the absorption spectra in dichloromethane is about 139 nm. The more intramolecular charge transfer, the bigger absorption maximum those compounds shown. Above result is in good agreement with the 5-position NO2 derivatives and the 4-position N(Me)2, N(Ph)2 derivatives. Above OCNCO structural change and their charge transfer mechanism provide design basis for further 1,8-naphthalmic derivatives..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3796 (2016)
Research on Assessment Methods of Spectral Reflectance Data Quality for Computer Color Matching
HE Cheng-dong, WAN Xiao-xia, HUANG Xin-guo, CHEN Hua-pei, OU Li-guo, and ZHAO De-fang
Spectral reflectance data quality is important for computer color matching. There are two existing methods for evaluating the quality—spectral reflectance method and K/S method, which are too complex to apply. In this paper, 45°/0° and d/8° geometric conditions are used in the measurement of spectral refSpectral reflectance data quality is important for computer color matching. There are two existing methods for evaluating the quality—spectral reflectance method and K/S method, which are too complex to apply. In this paper, 45°/0° and d/8° geometric conditions are used in the measurement of spectral reflectance of the offset ink samples printed on coated paper and silver-foiled paper while improvement on the geometric condition is made on the basis of the spectral reflectance method. Moreover, a new evaluation method—lightness and chromaticity comparative method is put forward, and comparison is made among the three methods. The results show that both 45°/0° and d/8° are feasible in the measurement of spectral reflectance of coated paper; however the former one cannot meet the requirement of spectral reflectance measurement of silver-foiled paper. In addition, as to d/8° Specular Component Included (SCI), when the silver-foiled paper is taken as the substrate, the reflectance of transparent white ink samples are smaller than that of other primary inks; and abnormal intersections appear in the curves of cyan and magenta ink respectively at the concentration of 60%, resulting in a poor spectra quality at high ink concentration; In the figure of lightness and chromaticity curves, there is significant divergence of the cyan and magenta ink curves from the referenced coated paper. In conclusion, the spectral reflectance of the transparent ink should be greater than or at least equal to other primary inks, and the maximum concentration of cyan and magenta should be limited; when the coated paper with good diffusion performance is taken as the reference, the comparative analysis is more intuitive than the two existing methods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 3805 (2016)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 11, 1 (2016)
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