Journals >Spectroscopy and Spectral Analysis
Contents
2017
Volume: 37 Issue 1
61 Article(s)
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Recent Progress at Atomic Spectrum Field for DBD Research and Development
LI Ming, YANG Meng, HUANG Xiu, FENG Lu, FAN Bo-wen, and XING Zhi
Because of its small volume, simple structure, low energy consumption, low working temperature, strong ability of sample dissociation/excitation and other significant characteristics, the dielectric barrier discharge is especially suitable for the miniaturization and portable analytical instruments. By now, atomizer orBecause of its small volume, simple structure, low energy consumption, low working temperature, strong ability of sample dissociation/excitation and other significant characteristics, the dielectric barrier discharge is especially suitable for the miniaturization and portable analytical instruments. By now, atomizer or excitation source based on dielectric barrier discharge has applied in atomic absorption spectrometer, atomic fluorescence spectrometer and atomic emission spectrometer successfully, which promoted the development of miniaturization atomic spectrum instrument. This paper reviews DBD’s recent progress in atomic spectrum field, emphatically introduces the applications of the DBD-AFS system in different sampling modes and analyses, along with their respective merits and demerits. This paper also introduces the new applications of DBD in vapor generation and direct solid sampling. Due to the DBD’s reaction mechanism is still unclear; the study of its subsequent development may be restricted..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 1 (2017)
Preparation of Au Nanoparticles with Different Morphologies and Study of Their Property as Surface Enhanced Raman Scattering Substrates
SU Xiao-yue, CHEN Xiao-yan, SUN Cheng-bin, ZHAO Bing, and RUAN Wei-dong
Different shapes of gold nanoparticles (NPs) have different enhancement effect in Surface Enhanced Raman Scattering (SERS). The polyhedral Au NPs have multiple angular structures, which show stronger enhancement effect than Au nanoplatelets. In recent years, the research on synthesis and properties of polyhedral Au NPsDifferent shapes of gold nanoparticles (NPs) have different enhancement effect in Surface Enhanced Raman Scattering (SERS). The polyhedral Au NPs have multiple angular structures, which show stronger enhancement effect than Au nanoplatelets. In recent years, the research on synthesis and properties of polyhedral Au NPs has attracted much attention. In this study the enhancement effect of the Au NPs in SERS was observed in Au NPs with the shape of dodecahedron, icosahedron, triangular plate and spherosome. Triangular Au NP films were prepared through a chemical reduction method using sodium borohydride as the reductant. As for synthesizing icosahedral Au NPs, Poly (vinyl pyrrolidone) is used as a capping agent and diethylene glycol is used as a reducing agent. Dodecahedral Au NPs were synthesized using icosahedral Au NPs as seeds. SERS spectra were detected for these three Au NPs as well as the traditional colloidal Au by using 4-mercaptopyridine and 4-mercaptobenzoic as probing molecules. Triangular Au NP films, icosahedral Au NPs and dodecahedral Au NPs were with average diameters of about 130, 100 and 120 nm. UV/Vis spectroscopy indicated that these three Au NPs had typical absorbance bands at 589, 598 and 544 nm. The results show that the Au polyhedron has better enhancement ability than the Triangular NPs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 7 (2017)
Fluorescence Anisotropy and Applications Based on Functional Nucleic Acid Recognition
WU Xi, PEI Xiao-jing, LIN Ruo-yun, LIU Feng, and LI Na
Based on the difference of the depolarization of the emitted light before and after the interaction of molecules, fluorescence anisotropy, also known as fluorescence polarization, can be beneficial for the study of interactions and the detection of the targets. In 1950s, Gregorio Weber first studied the interactions beBased on the difference of the depolarization of the emitted light before and after the interaction of molecules, fluorescence anisotropy, also known as fluorescence polarization, can be beneficial for the study of interactions and the detection of the targets. In 1950s, Gregorio Weber first studied the interactions between dansyl chloride and bovine serum albumin or ovalbumin with fluorescence anisotropy method, which paved the way for fluorescence anisotropy in biochemical applications. Since the early 1990s, functional nucleic acids (FNAs, including aptamers, and nucleic acid enzymes) were discovered and synthesized, which have been widely used in functional nucleic acid-based sensing. Aptamers are oligonucleotides that can recognize and bind specifically to various molecular targets. The fluorescence anisotropy methods which are based on aptamer recognition have the advantages of high selectivity, sensitivity and through-put. They play an important role in the study of interaction with protein, nucleic acids and small molecules. However, the way of enhancing the fluorescence anisotropy change of small molecules associated with the binding events is challenging. This paper reviews the basic principles and designs of fluorescence anisotropy methods bases on functional nucleic acid recognition for study and detection of proteins, nucleic acids and small molecules that play an important role in the life activity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 13 (2017)
Progress in the Analysis and Conservation of Cultural Relics and Artworks with Fiber Optic Reflectance Spectroscopy
ZHAO Xing, and WANG Li-qin
Cultural relics are non-renewable precious heritages, while artworks are limited cultural fortune. Therefore, it cannot afford any damage when cultural relics and artworks are analyzed. Fiber optic reflectance spectroscopy (FORS) has features of non-destructive testing, direct measurement and remote analysis and has itCultural relics are non-renewable precious heritages, while artworks are limited cultural fortune. Therefore, it cannot afford any damage when cultural relics and artworks are analyzed. Fiber optic reflectance spectroscopy (FORS) has features of non-destructive testing, direct measurement and remote analysis and has its unique advantages in the research of cultural relics and artworks. This paper introduced the application of FORS in the identification pigments and dyes, the analysis of binders and the research of conservation results and preservation environments. Detection limits, reproducibility and signal characterization method were discussed. The future development of FORS in the research of cultural relics and artworks was summarized..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 21 (2017)
Study on Pressure Characteristics of Photoacoustic Spectroscopy and TDLAS
CHEN Yi-kang, JU Yu, and HAN Li
Based on priciples of PAS and TDLAS, relevance between them was dicussed, while the relationships of PAS and TDLAS signal with pressure were derived. A contrast device for making PAS and TDLAS gas detection simultaneously was designed and constructed to test different pressure and provide a reference for the gas measurBased on priciples of PAS and TDLAS, relevance between them was dicussed, while the relationships of PAS and TDLAS signal with pressure were derived. A contrast device for making PAS and TDLAS gas detection simultaneously was designed and constructed to test different pressure and provide a reference for the gas measurement technology selection under different pressure conditions. Experimental studies show that: as the pressure rises, PAS and TDLAS signals become larger, and limit detection sensitivity are improved; with the rising pressure, conversion efficiency from energy absorbed by gas to PAS signals becomes low; at low pressure condiction, PAS is a better choice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 27 (2017)
Synthesis and Fluorescence Properties of Rare Earth Ions Co-Doped CaMoO4
WU Wen, XUAN Ya-wen, XIAO Li-na, YANG Zhi-guang, ZHU Can-can, and XIE Jian-ping
In this paper, a series of CaMoO4 phosphor co-doped rare earth ions were prepared with chemistry co-precipitation method．The concentration of Pr3+/Tb3+ and temperature had obvious influence on the luminescent properties. The crystal structures and spectrum characteristics of the samples were identified with X-ray powdeIn this paper, a series of CaMoO4 phosphor co-doped rare earth ions were prepared with chemistry co-precipitation method．The concentration of Pr3+/Tb3+ and temperature had obvious influence on the luminescent properties. The crystal structures and spectrum characteristics of the samples were identified with X-ray powder diffraction (XRD) and fluorescence spectrophotometer (PL). According to XRD analysis, the main diffraction peaks of samples are consistent with the standard card (JCPDS 29-0351) of the diffraction peak data. This showed doped rare earth ions did not change matrix lattice structure. The emission spectrum excited by 275 nm exhibit sharp lines peaking at 488, 560, 621 and 560 nm assigned to the 3P0—3H4, 3P0—3H5, 1D2—3H4 and 3P0—3F2 transitions of the Pr3+ ions. The intensity of fluorescence reached the strongest when the concentration of the doping amount was 3%. The optimum calcination temperatures of CaMoO4∶0.03Pr3+ and CaMoO4∶0.05Tb3+ were 800 and 600 ℃. Furthermore, the intensity of excitation spectra and emission spectra are dependent on the concentration of the doping amount. The emission spectra intensities of CaMoO4∶Pr3+ phosphors decrease and CaMoO4∶Tb3+ phosphors firstly increase and then decrease because of concentration quenching effect with increasing Pr3+ and Tb3+ concentration. In addition, the luminescence properties of Pr3+ ion in CaMoO4∶0.03Pr3+, yTb3+ system could be evidently improved with co-doping of Tb3+ ions which was due to the efficient energy transfer process from Tb3+ to Pr3+ ions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 32 (2017)
Effect of Junction Temperature on EL Spectra of GaN-Based White High Voltage LEDs
LI Song-yu, GUO Wei-ling, SUN Jie, CHEN Yan-fang, and LEI Jun
High voltage light emitting diodes (HV-LEDs) have potential advantages on general lighting application for their special features. But as novel power LEDs, their optical, electrical and thermal characteristics still need to be further studied. In this paper, 6 and 9 V GaN-based HV-LEDs were packaged in the same packageHigh voltage light emitting diodes (HV-LEDs) have potential advantages on general lighting application for their special features. But as novel power LEDs, their optical, electrical and thermal characteristics still need to be further studied. In this paper, 6 and 9 V GaN-based HV-LEDs were packaged in the same package structure and process conditions. The optical characteristics of two samples were investigated under different temperatures range from 10 to 70 ℃ which were calibrated to junction temperatures using thermal impedance measurement. To ensure the same current density, working current was set to 150 mA for 6 V sample and 100 mA for 9 V sample respectively. Results show that the increasing junction temperature has a great effect on EL spectra of two samples, such as peak wavelength red-shifting, full width at half maximum (FWHM) broadening, luminous efficiency reducing and color rendering index (CRI) increasing. The junction temperature of 9V sample is lower than that of 6 V sample in the same platform temperature and injection power. With temperature increasing, the extended quantitative value of FWHM for 9 V sample is 1.3 nm less than that of 6 V sample, the reduced quantitative value of luminous efficiency is 1.13 lm·W-1 less than that of 6 V sample, while the increased quantitative value of CRI is 0.28 less than that of 6 V sample. Those data suggest that EL spectra of HV-LEDs is less affected by junction temperature than traditional LEDs. It is because HV-LEDs perform better in current spreading and generate less heat. This conclusion has reference value for study, development and applications of GaN-based HV-LEDs. In addition, peak wavelength still has a good linear relationship with junction temperature and it can be a temperature-sensitive parameter when the spectra measurement accuracy is enough..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 37 (2017)
Spectral Matching Algorithm Applied to Identify the Terahertz Spectrum of Caulis Spatholobi and Caulis Sargentodoxae
XU Zhe, HE Ming-xia, LI Peng-fei, and WANG Peng-fei
Caulis spatholobi and caulis sargentodoxae are two different kinds of traditional Chinese medicine, which are similar to each other in appearance, but they are from differ sources with different functions.. This paper presents their spectrum using terahertz time-domain spectroscopy technology combines spectral matchingCaulis spatholobi and caulis sargentodoxae are two different kinds of traditional Chinese medicine, which are similar to each other in appearance, but they are from differ sources with different functions.. This paper presents their spectrum using terahertz time-domain spectroscopy technology combines spectral matching algorithm to identify five different kinds of these samples. Due to the complex chemical composition of traditional Chinese medicine, different components of the characteristic absorption peak occurred easily mutually overlapping, therefore, it’s very difficult to find obvious characteristic absorption peak in terahertz range, caulis spatholobi and caulis like this. Every sample was measured 10 times in some position. These standard spectral data have been calculated in different frequency, data show good stability in range of 0.2~1.3 THz. The second order differential method is used to process the THz spectrum data from 0.2~1.3 THz. These tiny differences of absorption coefficient have been hemerged between caulis sargentodoxae and caulis spatholobi and compare with these data using the method of correlation coefficient block coding method, spectral angle method and information divergence method, respectively. The analysis results, the spectral angle method is the best algorithm, the discriminate accuracy of a total of 100 sets of data is 95%. It is a new way to distinguish difference of traditional Chinese medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 42 (2017)
Quality Optimization Method for Ambient CO2 Inversion of High Resolution Fourier Transform Infrared Spectrum
TIAN Yuan, SUN You-wen, XIE Pin-hua, LIU Cheng, LIU Wen-qing, LIU Jian-guo, LI Ang, HU Ren-zhi, WANG Wei, and ZENG Yi
CO2 retrievals with high quality facilitate resolving the sources and sinks of CO2 are helpful in predicting the trend in climate change and understanding the global carbon cycle. Based on a nonlinear least squares spectral fitting algorithm, we investigate the optimization method for CO2 products derived from ground-bCO2 retrievals with high quality facilitate resolving the sources and sinks of CO2 are helpful in predicting the trend in climate change and understanding the global carbon cycle. Based on a nonlinear least squares spectral fitting algorithm, we investigate the optimization method for CO2 products derived from ground-based high resolution Fourier transform infrared spectra. The CO2 vertical column densities (VCDs) are converted into column-averaged dry air mole fraction XCO2 by using the fitted O2 VCDs, and thus the system errors (e. g. pointing errors, ILS errors, zero-level offset) are corrected greatly. The virtual daily variation which is related to air mass factor is corrected with an empirical model. The spectra screening rule proposed in this paper can greatly improve the XCO2 quality. The CO2 retrievals before and after the optimized method are compared using a typical CO2 daily time series. After using the optimized method, the fitting error is reduced by 60%, and the two-hours-averaged precision is ~0.071% (equals to ~0.28 ppm), which is perfectly in line with the TCCON (the total carbon column observing network) threshold, i. e., less than 0.1%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 48 (2017)
The Research Development of FTIR in Analyzing Material Structures
ZHANG Ying, and YANG Shu-ming
Safety issues of animal derived food have been emerging one after another, and the using of the illegal addictives and abuse of high-risk chemicals bred for livestock have been increasingly serious from melamine, lean meat powder, Sudan Red, plasticizing agent, waste oils to leather milk．How to determine these chemicalSafety issues of animal derived food have been emerging one after another, and the using of the illegal addictives and abuse of high-risk chemicals bred for livestock have been increasingly serious from melamine, lean meat powder, Sudan Red, plasticizing agent, waste oils to leather milk．How to determine these chemicals faces severe challenges. Infrared spectroscopy is the same powerful for material structures as nuclear magnetic resonance spectroscopy, mass spectrometry and ultraviolet spectrum. There are few researches about quality and safety of livestocks products．In this article, some researches in analyzing structures has been reviewed, including studies of spectral features, molecular conformation, stability, homologous series, derivative and reaction products, inferring functional groups of macromolecular compounds and molecular structural formula and distinguishing complex biological samples．Forming the new thought screening contaminants maybe used for animals is expected to early warning addictives causing serious food safety problems that is to build the comprehensive analysis methods for these matters on the basis of creating spectrum or functional groups databases designed for animal products．.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 54 (2017)
Application of FTIR and Active Ingredients Quantitative Analysis on Quality Control of Dai Medicine Alstonia scholaris (L.) R. Br.
YANG Ni-na, YANG Chun-yong, WANG Yuan-zhong, and ZHAO Ying-hong
FTIR fingerprint of the leaves and immature stems of Alstonia scholaris (L.) R. Br. was established as a content determination method for the detection of picrinine, ursolic acid and oleanolic acid. Different medicinal parts were identified based on principal component analysis, while exploring the influence of immaturFTIR fingerprint of the leaves and immature stems of Alstonia scholaris (L.) R. Br. was established as a content determination method for the detection of picrinine, ursolic acid and oleanolic acid. Different medicinal parts were identified based on principal component analysis, while exploring the influence of immature stems for the leaves and the application of FTIR and HPLC in the Dai quality control in order to speed up the pace of Dai medicine modernization. Infrared spectroscopy of different batches samples were collected and the data was preprocessed as to automatic baseline correction, smooth, ordinate normalization, second order derivative, and then to PCA, all the datum in triplicate. For content determination of picrinine, mobile phase was acetonitrile (40) water (contain 0.1% ammonia water) (60) and the wavelength was set at 287 nm. For ursolic acid and oleanolic acid, the mobile phase was mixture (12∶88) of 0.1% formic acid in water (A) and methanol (B). Wavelength was 210 nm. As the results, the original spectrum difference was not obvious for leaves and stems. Pretreatment spectroscopy had a significant variation on absorption peak number and intensity in 3 000～2 800 and 1 800～500 cm-1. The results of PCA showed that, the leaves and stems were separated; in addition the difference of different batches leaves was bigger than the stems. The mean contents of picrinine, ursolic acid and oleanolic acid in leaves were 0.79, 8.47, 7.51 and 0.21, 1.78, 1.67 mg·g-1 in stems, respectively. The content of ursolic acid and oleanolic acid is higher than picrinine, but ursolic acid and oleanolic acid content had no obvious difference. Mean content of three ingredients in leaves is much higher than in stems. Picrinine content in leaves was 3.8 times of immature stems, ursolic acid and oleanolic acid content were 5.1 and 4.2 times of immature stems, respectively. The variety of picrinine content in different batches samples was biggest, ursolic acid and oleanolic acid content was relatively stable. The overall quality of leaves has an obvious difference compared with the immature stems, so the leaves of A. scholaris mix with immature stems could not be as Dai medicine in Dai clinic. Infrared spectroscopy combined with chromatography can quickly identify different medicinal parts and evaluate overall quality of Dai medicine, which can apply to quality control of Dai medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 58 (2017)
Study on the Release Process for Lavender Essential Oil Microcapsule by FTIR
GUAN Xue-li, FU Ji-hong, and TANG Jun
In order to find out the constitute forms of lavenderessential oil-β-cyclodextrin inclusion complex and the process of release of lavenderessential oilwith temperature changes, we used Fourier transform infrared spectroscopy (FTIR) method to compare and analyze lavender essential oil (LO), β- cyclodextrin (β-CD) and laIn order to find out the constitute forms of lavenderessential oil-β-cyclodextrin inclusion complex and the process of release of lavenderessential oilwith temperature changes, we used Fourier transform infrared spectroscopy (FTIR) method to compare and analyze lavender essential oil (LO), β- cyclodextrin (β-CD) and lavender essential oil microcapsule (LOM), while the infrared spectral changes of release process at different temperatures of the oil in microcapsulewas analyzed, andthe principal component method was further used to explore the physical and chemical stability and release process of LO after it was entrapped by β-CD. The results showed that comparative analysis by infrared spectroscopy, characteristic peaks of LO embedded had redshift peak and its peak shape became wider, which mainly affected by the formation of molecular hydrogen bonds , p-π conjugate phenomenon and the spatial structure of β-CD; in addition, we set temperature range from 25 to 95 ℃, the temperature interval of 10 ℃, and then determined LOM by IR spectrum to test and verify physical and chemical stability and release conditions of LO which was embedded by β-CD. The results demonstrated that, water molecule inLOM hydrate was easily lost and the essential oil component of LOM was in stable physical and chemical properties, and the amount of escaping for LO at 95 ℃ was less than 6.5 percent when the release was slow; through IR spectra data of variable temperature was analyzed under principal component analysis (PCA), We may find that the cumulative variance of the first two principal components was 99.3%. And PC1 ingredient could be considered as the characteristic variable of β-CD and PC2 component was the characteristic variable of LO by principal component load analysis. The result showed that the release of ester from LOM was faster than alcohol. It was simple and efficient by using infrared analysis method to have a comprehensive understanding on the physical and chemical stability and the release process of the embedded oil, and it will provide a new theoretical support for the study on the release process of lavender essential oil microcapsule..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 65 (2017)
Rapid Prediction Study of Total Flavonids Content in Panax notoginseng Using Infrared Spectroscopy Combined with Chemometrics
LI Yun, ZHANG Ji, XU Fu-rong, WANG Yuan-zhong, and ZHANG Jin-yu
The variation on origin and growth environment could make a holistic impact on the secondary metabolites and quality of traditional Chinese medicine. In recent years, the origin of Panax notoginseng is spread from the genuine producing area of Wenshan to surrounding cities. The content of three saponins, as an indicatoThe variation on origin and growth environment could make a holistic impact on the secondary metabolites and quality of traditional Chinese medicine. In recent years, the origin of Panax notoginseng is spread from the genuine producing area of Wenshan to surrounding cities. The content of three saponins, as an indicator, is to ensure the quality of Panax notoginseng in Chinese pharmacopoeia. However, a single indicator is limited to comprehensive quality evaluation of Panax notoginseng. In this study, the total flavonoids content of Panax notoginseng was determinated by ultraviolet-visible (UV-Vis) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy combined with chemometrics, as a rapid prediction model of total flavonoids content, was establish to provide some basic information for rapid and holistic quality assessment of Panax notoginseng. A total of 96 UV-Vis and FTIR spectra of Panax notoginseng originated from 12 regions were collected. The UV-Vis spectra of samples were recorded at 268 nm, and the content of total flavonoids was calculated based on standard linear equation of rutin. Pre-processing data were calculated with first (1D) and second derivative (2D), Savitsky-Golay smoothing with seven, nine, and eleven points. 2/3 of the 96 individuals were selected to form the training set by using Kennard-stone algorithm, and the rest were used as prediction set. Training set data were used to establish the orthogonal signal correction-partial least squares regression (OSC-PLSR) model and the 1/7 cross-validation method was used for screening optimal numbers of principal component, the prediction set was utilized to verify the accuracy and reliability of the OSC-PLSR model. Results showed that: (1) The correlation coefficient r of standard rutin was 0.9997, and the linear concentration range was from 5.6 to 72.0 μg·mL-1, namely, there were good correlation between the absorbance and concentration. (2) The Panax notoginseng contained higher content of total flavonoids (more than 7 mg·g-1) in three genuie producing areas of Wenshan, Luoping county and Shilin county. (3) After the same points of Savitsky-Golay smoothing, the model predictive ability of 2D is better than that of 1D, and the predictive ability of different processing model has an obvious difference. (4) In all prediction models, the 2D+SG 7+OSC-PLSR (R2pre=0.976 1, RMSEP=0.325 2) and 2D+SG 11+OSC-PLSR (R2pre=0.946 9, RMSEP=0.382 0) model showed an excellent predictive effect, the value of RMSEP was below 0.4, and the predicted values were close to the detection values. The result indicated that FTIR combined with OSC-PLSR could accurately predict the content of total flavonoids. It could provide a rapid, simple, and effective method for the holistic quality control of Panax notoginseng..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 70 (2017)
Detection of Camellia Oleifera Oil Adulterated with Sunflower Oil with Near Infrared (NIR) Spectroscopy and Characteristic Spectra
CHU Xuan, WANG Wei, ZHAO Xin, JIANG Hong-zhe, WANG Wei, and LIU Sheng-quan
Camellia oleifera oil has the reputation of “oriental olive oil”; it is important to detect the adulterated camellia oleifera oil. In this paper, NIR spectra were used to detect camellia oleifera oil adulterated with sunflower oil. Camellia oleifera oil adulterated with varying mass fraction of sunflower oil were prepaCamellia oleifera oil has the reputation of “oriental olive oil”; it is important to detect the adulterated camellia oleifera oil. In this paper, NIR spectra were used to detect camellia oleifera oil adulterated with sunflower oil. Camellia oleifera oil adulterated with varying mass fraction of sunflower oil were prepared, i. e., 11 samples in 0%～10% with the gradient of 1%, 6 samples in 15%～40% with the gradient of 5%, 6 samples in 50%～100% with the gradient of 10%, and all the samples were divided into four groups such as A(0%～5%), B(6%～10%), C(15%～40%) and D(50%～100%). A total of 207 absorbance spectra(1 000～2 500 nm) were acquired by sampling 9 times in each adulteration. Calibration set was consist of two-thirds of the spectra data in each group selected randomly, and the validation set was made up of the last spectral data. After removing the noise in both ends of the spectra, principal component analysis(PCA) was used to reduce the dimensionality, then the first four PCs were used to build the support vector machine (SVM) identification model, and the identification accuracies of 96.38% and 94.20% in calibration and validation set were obtained. Furthermore, five characteristic wavelengths (1 212, 1 705, 1 826, 1 905 and 2 148 nm) were selected based on the loading of the PCs, the peaks or troughs of the original spectra and the chemical functional groups they were corresponding to. A NIR simplified SVM identification model was built by them, and the identification accuracies were 94.20% and 92.75%. Overall, both NIR spectroscopy and NIR characteristic spectra can realize the identification of camellia oleifera oil adulterated with sunflower oil, and the characteristic wavelengths, selected in this study, provide a basis for the design of corresponding instrument..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 75 (2017)
Spectroscopy Identification of Untreated and Heated Corundum
HUANG Ruo-ran, and YIN Zuo-wei
Nowadays, a great quantity of heat treating corundums are emerging in our market. It is hard to distinguish them scientifically just by conventional methods. In order to accurately determine whether the corundums have been heated or not, we need to analyse their spectral characteristics. This paper describes the spectrNowadays, a great quantity of heat treating corundums are emerging in our market. It is hard to distinguish them scientifically just by conventional methods. In order to accurately determine whether the corundums have been heated or not, we need to analyse their spectral characteristics. This paper describes the spectroscopy identification of untreated and heated corundum. The experiment is conducted as follows: First, We observed the inclusions of corundum samples, then measured and recorded their infrared spectra, UV-Vis spectra by Fourier Transform Infrared Spectrometer and Ultraviolet-visible Spectrophotometer respectively. Next we chose a part of samples to heat, after the heat treatment, we recorded their spectra and made a comparison with that of untreated corundums. The results showed that we can detect the absorption peaks at 1 980 and 2 110 cm-1 which represent diaspore in untreated ruby. However, after heat treatment, the absorption peaks disappear which means the structure of AlO(OH) has been destroyed. The sapphires which grown in alkali basalt under reductive condition appear the absorption peak at 3 310 cm-1. However, this peak vanishes after 18 h heat treatment when the temperature is 1 600 ℃. For UV-Vis spectra of ruby, after heat treatment, the slight shift occurs in strong, wide absorption band at around 555 nm, and this band becomes more pointed. In addition, absorption intensity difference between wave crest and wave hollow increases. The absorption bands at 375, 387, 454 nm of heated sapphires are more pointed than that of the untreated sapphires, and absorption intensity difference rises. These changes in spectral characteristics can help us to distinguish untreated corundum from heat treating corundum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 80 (2017)
In-Vivo Noninvasive Measurement of Human Blood Glucose Levels by Mid-Infrared Spectrograph with External CO2 Laser Source
ZHANG Qian-qian, FAN Yu-ling, HE Xiu-quan, and SUN Yu-ming
Diabetes is a kind of diseases which does harm to people’s health, and the detection of human blood glucose levels utilizing blood samples will result in pain even infection for patients. Thus the in-vivo noninvasive measurement of human blood glucose levels has vital value in clinical diagnosis, detection and therapy,Diabetes is a kind of diseases which does harm to people’s health, and the detection of human blood glucose levels utilizing blood samples will result in pain even infection for patients. Thus the in-vivo noninvasive measurement of human blood glucose levels has vital value in clinical diagnosis, detection and therapy, and it also is a very hot research topic with challenging. At present, as to various noninvasive detection methods, the technology based on mid-infrared absorption spectrophotometry with ATR has been gaining increasing attention. However, when carrying out noninvasive measurement of human blood glucose levels by means of the spectrophotometry equipped with routine light sources, the penetration depth of probe light in human tissues is low and thus it is very difficult to reach the stromal layer containing body fluids and especially dermis layer containing blood for probe light, which resulting in low relativity between experimental data and real human blood glucose levels and thus limiting the clinical application. Generally, not only the mid-infrared laser with high strength and high purity can deeper penetrate the human tissues, but also the output wavelengths at 1 035 cm-1of CO2 laser very coincide with the fundamental frequency characteristic absorption at 1 029 cm-1of glucose. Thus, in this work, a novel noninvasive mid-infrared measurement system to detect human blood glucose levels has been successfully assembled, in which a CO2 laser was used a self-defined external light source of the new mid-infrared absorption spectrophotometry with ATR. In this system, the absorbance of human fingertip at 1 035 cm-1 has been measured when external CO2 laser source was used as probe light, at the same time, the mid-infrared absorption spectra of fingertip have been also obtained and absorbance at 1 492 cm-1 has been recorded. The human blood glucose levels were determined synchronously by means of the routine medical method. The experimental results showed that the ratio in fingertip between absorbance at 1 035 cm-1 from the laser source and one at 1 492 cm-1 from mid-infrared absorption spectrophotometry could synchronously change with the human blood glucose levels, and the ratio presents certain positive relativity with the real human blood glucose levels（R=0. 812 5）. Thus the measurement data could be used as a new index of blood glucose level in human body, which showed the potential in clinical diagnosis of the ATR mid-infrared absorption spectrophotometry with external CO2 laser source in noninvasive measurement of human blood glucose levels..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 85 (2017)
Research in Magnesite Grade Classification Based on Near Infrared Spectroscopy and ELM Algorithm
MAO Ya-chun, XIAO Dong, CHENG Jin-fu, JIANG Jin-hong, BA TUAN LE, and LIU Shan-jun
Due to the needs of industrial development, the different content and uncertain distribution of magnesite mineral lead to great difficulties in o determining its grade, therefore, we propose a combination of near-infrared spectroscopy and the ELM magnesite grade classification model. The model can achieve rapid classifDue to the needs of industrial development, the different content and uncertain distribution of magnesite mineral lead to great difficulties in o determining its grade, therefore, we propose a combination of near-infrared spectroscopy and the ELM magnesite grade classification model. The model can achieve rapid classification of magnesite grade. Near infrared spectroscopy, considering that different types of H group in magnesite have different absorption degrees to near-infrared spectroscopy, is used to determine the composition and content of magnesite. It is simple, fast, accurate and efficient without destroying the sample. In this paper, we take magnesite 30 group from Yingkou City, Liaoning Province Dashiqiao for the study, collecting their magnesite NIR data samples at 30×973, using principal component analysis (PCA) for data dimensionality reduction process. The main element contribution rate is greater than 99.99% obtained characteristic variables of 10, established quantitative analysis ELM algorithm mathematical model, take 20 groups of samples as the training samples (including 6 super group, 14 groups non), 10 groups of samples for testing samples (including super grade4 groups, 6 groups non), ELM algorithm model hidden layer nodes selection 20. In order to further improve the classification performance, two kinds improved ELM algorithm models are proposed: conduct optimization selection ELM for the traditional ELM input weights and threshold using the circulation patterns and integrate integration-Featured ELM based on Featured ELM. And compare to which use the artificial method, chemical method and BP neural network model approach. The results showed that magnesite grade classification with the near-infrared spectroscopy and ELM model have a distinct advantage regardless of cost or time, and the accuracy rate can reach over 90%, which provides a new way to classify magnesite grade..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 89 (2017)
Application of Intelligent Optimization Algorithms to Wavelength Selection of Near-Infrared Spectroscopy
BIN Jun, FAN Wei, ZHOU Ji-heng, LI Xin, and LIANG Yi-zeng
Near infrared spectroscopy (NIRS) is a kind of indirect analysis technology, whose application depends on the setting up of relevant calibration model. In order to improve interpretability, accuracy and modeling efficiency of the prediction model, wavelength selection becomes very important and it can minimize redundanNear infrared spectroscopy (NIRS) is a kind of indirect analysis technology, whose application depends on the setting up of relevant calibration model. In order to improve interpretability, accuracy and modeling efficiency of the prediction model, wavelength selection becomes very important and it can minimize redundant information of near infrared spectrum. Intelligent optimization algorithm is a sort of commonly wavelength selection method which establishes algorithm model by mathematical abstraction from the background of biological behavior or movement form of material, then iterative calculation to solve combinatorial optimization problems. Its core strategy is screening effective wavelength points in multivariate calibration modeling by using some objective functions as a standard with successive approximation method. In this work, five intelligent optimization algorithms, including ant colony optimization (ACO), genetic algorithm (GA), particle swarm optimization (PSO), random frog (RF) and simulated annealing (SA) algorithm, were used to select characteristic wavelength from NIR data of tobacco leaf for determination of total nitrogen and nicotine content and together with partial least squares (PLS) to construct multiple correction models. The comparative analysis results of these models showed that, the total nitrogen optimums models of dataset A and B were PSO-PLS and GA-PLS models. GA-PLS and SA-PLS models were the optimums for nicotine, respectively. Although not all predicting performance of these optimization models was superior to that of full spectrum PLS models, they were simplified greatly and their forecasting accuracy, precision, interpretability and stability were improved. Therefore, this research will have great significance and plays an important role for the practical application. Meanwhile, it could be concluded that the informative wavelength combination for total nitrogen were 4 587~4 878 and 6 700~7 200 cm-1, and that for tobacco nicotine were 4 500~4 700 and 5 800~6 000 cm-1. These selected wavelengths have actually physical significance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 95 (2017)
Research on Chemical Constituents of Bamboo Fiber Cell Wall Based on Nano-IR Technology
WEI Peng-lian, HUANG Yan-hui, LIU Rong, AN Xin, and FEI Ben-hua
Nano-IR technology was firstly employed on bamboo fiber research with purpose to further understand the fine structure of bamboo fiber cell wall. Chemical constituent distribution of bamboo fiber was studied, and the feasibility of the novel technology was discussed by comparing with other traditional methods. The resuNano-IR technology was firstly employed on bamboo fiber research with purpose to further understand the fine structure of bamboo fiber cell wall. Chemical constituent distribution of bamboo fiber was studied, and the feasibility of the novel technology was discussed by comparing with other traditional methods. The results showed that Nano-IR technology, which has made a breakthrough on diffraction limit of traditional infrared spectroscopy, can acquire nano-scale infrared spectrum of bamboo cell wall in situ condition. The characteristic peak positions of Nano-IR spectrum is basically the same with that of microscopic FTIR spectrum, indicating that Nano-IR spectrum can reveal the chemical information of bamboo cell wall. The results of the present work suggested that nano-IR technology could be an effective research tool in research of nano chemical composition distribution of bamboo cell wall..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 103 (2017)
Determination of Dibutyl Phthalate Based on Two-Dimensional Correlation Mid-Infrared Spectroscopy
ZHAO Li-jun, GAO Lei, YI Ling-xue, JIANG Chen, and ZHAO Kun
As a kind of Phthalate esters ( PEs ), Di-n-butyl phthalate ( DBP ) is widely employed as plasticizers in the production of polymeric materials. The concentration variation of DBP/n-hexane solution was studied by monitoring the chroma evolution of infrared absorption spectra in conjunction with spectral analysis by usiAs a kind of Phthalate esters ( PEs ), Di-n-butyl phthalate ( DBP ) is widely employed as plasticizers in the production of polymeric materials. The concentration variation of DBP/n-hexane solution was studied by monitoring the chroma evolution of infrared absorption spectra in conjunction with spectral analysis by using two-dimensional-correlation spectroscopy. Absorption peaks at 742, 1 078, 1 123, 1 281, 1 467, 1 728, 2 873, 2 933, 2 961 cm-1 was gained with Fourier transform infrared spectra. The IR spectra was divided into three bands: 400～1 200, 1 200～1 900 and 2 900～4 000 cm-1, correlation between the absorption peaks and the sequential order of the changes in spectral intensity extracted from synchronous and asynchronous plots indicated that some bong vibrations in 1 123 cm-1 (Benzene ring surface vibration and OCO bending vibration ), 1 728 cm-1 (CO bending vibration), 2 873, 2 961 cm-1 (CH3 concertina movement ) and 3 436 cm-1 (C—H bending vibration in plane of Benzene) is sensitive to the concentration of DBP. This result showed that the chroma evolution of infrared absorption spectra in conjunction with spectral analysis using two-dimensional-correlation spectroscopy can accurately analyze the concentration of DBP in n-hexane. This research provides a theoretical basis to the detection and analysis of DBP..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 109 (2017)
Research on Identification of Organic Gunshot Residue with Micro-Raman Spectroscopy
QIN Zhen-ke, YANG Fei-yu, LIU Wen-bin, ZOU Yun, YAN Yan, WANG Chang-liang, and CAI Neng-bin
A rapid approach for the nondestructive, accurate detection of organic gunshot residue was investigated. Raman microscopy was used to identify organic gunshot residue and the propellant in ammunition. The optimal excitation wavelength for the detection of organic particles using Raman spectroscopy was 473 nm. The RamanA rapid approach for the nondestructive, accurate detection of organic gunshot residue was investigated. Raman microscopy was used to identify organic gunshot residue and the propellant in ammunition. The optimal excitation wavelength for the detection of organic particles using Raman spectroscopy was 473 nm. The Raman spectra of organic gunshot residue obtained using 473 nm laser excitation can effectively avoid the interference of fluorescence. The results demonstrated that the organic particles were mainly from the partially burned propellant particles. Meanwhile it was proved that the main component was basically consistent with the propellant except somehow damage in chemical structure or degree of crystallization with Raman spectra. The surface color of organic particles was mainly brassiness, dark gray. A lot of craters were distributed on the surface of organic particles. Spherical inorganic particles with metallic luster attached to the surface of organic particles can be regarded as the typical characteristics of gunshot residue..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 114 (2017)
The Study of Methodology Validation in Multicomponent Quantitative Analysis of Raman Spectroscopy
XUE Jin-tao, LI Chun-yan, WU Chun-jie, and YE Li-ming
Raman spectroscopy with the help of sophisticated data analysis techniques based on multivariate analysis have made it possible to study the full information of Raman spectra and to draw conclusions about the chemical structure and composition of very complex systems. As Raman spectroscopy has the advantage to provide Raman spectroscopy with the help of sophisticated data analysis techniques based on multivariate analysis have made it possible to study the full information of Raman spectra and to draw conclusions about the chemical structure and composition of very complex systems. As Raman spectroscopy has the advantage to provide rich information of the sample, so it was first included in Chinese Pharmacopoeia (2010) as “Annex XIX L Guidelines of Raman spectroscopy”. However the validation method for multicomponent quantitative analysis of Raman spectroscopy was not discussed in this pharmacopoeia. The purpose of this study was to develop innovatively the validation method for the Raman model in multicomponent quantitative analysis. Two kinds of samples with different matrix background were used to study the self-performance test of the instrument, linearity, limit of quantitation, accuracy and precision, respectively. As the sample was complex composition in our study, so there is no need to provide sample blank and rupture test for specificity study which was carried out in the traditional method of experiments. As the result showed, we propose a validation method for Raman spectroscopy in multicomponent analysis for the further study and improvement of standards of the method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 120 (2017)
Application of Raman Spectroscopy and Pattern Recognition Methods for Determining the Authenticity and Detecting the Adulteration of Milk Powder
WANG Hai-yan, SONG Chao, LIU Jun, ZHANG Zheng-yong, XIE Wei-liang, LI Li-ping, and SHA Min
The authenticity and adulteration of dairy products are attracting broad attention in recent years. There is a need to develop rapid, simple and accurate analytical methods for the detection of authenticity and adulteration of dairy products. To discriminate between milk powder samples, Raman spectra of FIRMUS, Nestl&#The authenticity and adulteration of dairy products are attracting broad attention in recent years. There is a need to develop rapid, simple and accurate analytical methods for the detection of authenticity and adulteration of dairy products. To discriminate between milk powder samples, Raman spectra of FIRMUS, Nestlé and Being Mate milk powder were collected. The nearest neighbor algorithm (NN)combined with the characteristic peaks were employed for the design of a model. On the basis of 10 cross validation, the average recognition rate was 99.56%. In order to achieve the analysis of the adulteration of milk powder, FIRMUS milk powder was mixed with Nestlé milk powder according to the mass ratio 0∶1, 1∶3, 1∶1, 3∶1 and 1∶0 to get five kinds of the adulterated milk powder samples. Then, fat was extracted from the adulterated milk powder samples. Raman spectra of the fat were collected, then two methods were employed for the design of models. One was the nearest neighbor algorithm combined with the characteristic peaks, another was the kernel principal component analysis (KPCA) combined with NN. On the basis of 10 cross validation, the average recognition rate reached 93.33% and 98.89%, the average operation time was 0.085 and 0.104 s. The results of this work showed that the nearest neighbor algorithm combined with the characteristic peaks can be applied for the determination of the authenticity of milk powder while Raman-KPCA-NN model can provide a simple, accurate and rapid method to investigate the adulteration of milk power..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 124 (2017)
Fast Classification of Complex Sulphide Ore Based on Raman Spectroscopy
CAI Yao-yi, YANG Chun-hua, XU De-gang, LI Yuan-ying, and GUI Wei-hua
The regional features, metallogenitic regularities and mineral composition of the hydrothermal sulphide ore have been preliminarily studied. According to the different mineralization period, the patterns of valuable minerals disseminated in ore are complicated, which causes the large changes in the properties of the suThe regional features, metallogenitic regularities and mineral composition of the hydrothermal sulphide ore have been preliminarily studied. According to the different mineralization period, the patterns of valuable minerals disseminated in ore are complicated, which causes the large changes in the properties of the sulphide ore. The different properties of the sulphide ore may increase the difficulty of the mineral processing and reduce the recovery rate of valuable minerals. Therefore a simple method for rapidly classification of sulphide ore is required to optimize mineral processing flowsheet. Laser Raman spectrometry, as an effective method to analyze the structure of the material is used to identify the component and structure of minerals. The research on the Laser Raman spectra of the large number of sulphide ore samples can reveal the reasons for the difference of the Raman spectra. A new method for classifying the complex sulphide ore using Raman spectroscopy is proposed. The experiment results demonstrate that the properties of the sulphide ore in different mineralization period vary greatly and the fluorescent scattering is mainly produced by gangue minerals. The measured Raman spectral after quenching the fluorescence scattering show the peaks of Raman spectra at 201.62, 242.54, 288.38 and 309.77 cm-1 can be used to identify this kind of complex sulphide ore. The raw ore can be divided into three categories based on the difference of the intensity of fluorescence scattering and the ratio of fluorescence and Raman intensity. The accuracy of the classification method is further validated by the industrial tests. The findings demonstrate the close relationship between Raman spectra and the properties of sulphide ore. The proposed method, which can fast classify the sulphide ore, don’t need complex chemical pretreatment before spectra collection. Therefore, this method will have important application value for improving the efficiency of mineral processing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 129 (2017)
Density Functional Theory Calculation and Raman Spectroscopy Studies of Organophosphorus Pesticides
HUANG Shuang-gen, WU Yan, HU Jian-ping, and LIU Mu-hua
Organophosphorus pesticides were often used for prevention and control disease and insect of plant, and are acute toxic to human and livestock by anti-ache activity. The molecular geometry of three organophosphorus pesticides(dimethoate, trichlorfon and phosalone) were constructed on Gauss View3.07, and Density functioOrganophosphorus pesticides were often used for prevention and control disease and insect of plant, and are acute toxic to human and livestock by anti-ache activity. The molecular geometry of three organophosphorus pesticides(dimethoate, trichlorfon and phosalone) were constructed on Gauss View3.07, and Density functional theory (DFT) was used to optimize and calculate the vibrational wavenumbers of three organophosphorus pesticides by B3LYP hybrid functional and 6-31G(d,p) basis set. The experimental spectra of three organophosphorus pesticides were compared with the theoretically calculated spectra and Surface-enhanced Raman Scattering spectra (SERS). The results indicated that the experimental spectra and theoretically calculated spectra of three organophosphorus pesticides have a very good match. The Raman peaks of three organophosphorus pesticides were roundly assigned between the range of 400～1 800 cm-1, and the characteristics peaks of three organophosphorus pesticides were found. The Raman vibration peak of organophosphorus pesticide may appear similar characteristic peak. The pesticide contained PO is between 1 140 and 1 320 cm-1, the pesticide contained PS is in the range 535～750 cm-1, and the organophosphorus pesticide contained P—O—C is n the range 920～1 088 cm-1. The different characteristic peaks of three pesticides were found by the contrast of the surface enhanced Raman spectra. This shows that the SERS method can be used to identify the organophosphorus pesticide. The results can furnish a theoretical support for qualitative and quantitative analysis of organophosphorus pesticide..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 135 (2017)
The Study of Three-Dimensional Synchronous Fluorescence Spectral Characteristics of Liuwei Dihuang Pills
ZHU Chun, XIE Xin, ZHAO Jin-chen, DU Jia-meng, CHEN Guo-qing, and ZHU Tuo
Three-dimensional synchronous fluorescence of each component of Liuwei dihuang pills (Prepared rehmannia root, cornel, yam, alisma, poria cocos, and cortex moutan) is measured by using FLS920P fluorescence spectrometer. Feature parameters were extracted. It can be found that each component is fluorescent material and tThree-dimensional synchronous fluorescence of each component of Liuwei dihuang pills (Prepared rehmannia root, cornel, yam, alisma, poria cocos, and cortex moutan) is measured by using FLS920P fluorescence spectrometer. Feature parameters were extracted. It can be found that each component is fluorescent material and the lines are all different. Furthermore, Three-dimensional synchronous fluorescence of Liuwei dihuang pills boiling with standard water and non-standard water are all measured and there are significant differences between them. It can be applied in distinguishing different formula of Chinese medicine decoction. Experimental and Theoretical conclusion show that: the three-dimensional fluorescence spectrometry method and the combination of synchronous fluorescence spectroscopy method can further improve the sensitivity and selectivity of fluorescence spectroscopy, have a distinct advantage in a complex multi-component mixture of fluorescence spectroscopic analysis.The study can provide a convenient and reliable method for establishing a complete fingerprint of Chinese traditional medicine. It also can help identifying the component and the quality of Chinese patent medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 141 (2017)
Rapid Method for Determination of Furfural and 5-Hydroxymethyl Furfural of Ethanol-Water Hydrolysate of Biomass with UV Spectroscopy
PAN Meng-li, PING Qing-wei, ZHANG Jian, and LI Na
The soluble lignin and furan compounds in hydrolysate of lignocellulose biomass have absorbed peaks and inter-superimpose in UV spectroscopy. Therefore, this paper developed a method for the determination of furfural and 5-hydroxymethyl furfural in ethanol-water refining liquors of lignocellulose biomass based on UV spThe soluble lignin and furan compounds in hydrolysate of lignocellulose biomass have absorbed peaks and inter-superimpose in UV spectroscopy. Therefore, this paper developed a method for the determination of furfural and 5-hydroxymethyl furfural in ethanol-water refining liquors of lignocellulose biomass based on UV spectroscopy. The study showed that there is a good and linear relationship between maximum absorption (λmax) and the concentration percent of 5-HMF (W5-HMF) of M, the regression coefficient up to 0.998 4 (R2=0.998 4). Furthermore, a better linear relationship was also observed between the concentration of mixture (cM) and absorptivity (A) when the W5-HMF was constant, the R2 of 0.998 6～1.000 0 and reproducibility are desirable. The contents of F and 5-HMF could be calculated accurately according to the perfect liner relationship of A and cM, λmax and W5-HMF, and the relative deviation of F and 5-HMF of 5.6% and 3.7%, recovery of 89%～96%, RSD of 0.21%～0.85%, respectively. Overall, The simple rapid and precise method in this paper can be applied to the determination of the F and 5-HMF in the hydrolysate of ethanol-water refining lignocellulose biomass..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 146 (2017)
Visual Detection Study on Early Bruises of Korla Pear Based on Hyperspectral Imaging Technology
Chen Xinxin, Guo Chentong, Zhang Chu, Liu Ziyi, Jiang Hao, Lou Binggan, and He Yong
In this paper, hyperspectral imaging combined with chemometrics was applied for the detection of internal defects of Korla pear. The hyperspectral images covering the spectral range of 380～1 030 nm were acquired for 60 Korla pears before, and seven consecutive days after internal damages were induced by being dropped fIn this paper, hyperspectral imaging combined with chemometrics was applied for the detection of internal defects of Korla pear. The hyperspectral images covering the spectral range of 380～1 030 nm were acquired for 60 Korla pears before, and seven consecutive days after internal damages were induced by being dropped from a distance of 30 cm. The mean spectrum were computed from region of interests (ROI) of pear in each image, and was preprocessed with wavelet transform for eliminating system noise and external disturbances, and optimizing the spectral identification region (470～963 nm). Based on the preprocessed samples, the support vector machine models were built respectively through the full and feature wavebands selected by the second derivative. The results on testing set demonstrate that both of the two approaches achieved the discrimination accuracy of 93.75%. Furthermore, F-value based method was applied for image analysis to find out the optimal waveband ratio for the visual discrimination of bruises against normal surface. Based on the optimal waveband ratio images, the selective search algorithm was utilized for segmenting bruises from the pear surface, and shows the accurate identification results. Our research revealed that the hyperspectral imaging technique for detecting bruised features in pears is feasible, which could provide a theoretical reference and basis for designing classification system of fruits in further work..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 150 (2017)
Estimation Models for Jujube Leaf Pigment Concentration with Hyperspectrum Data at Canopy Scale
LIU Wei-yang, PENG Jie, DOU Zhong-jiang, CHEN Bing, WANG Jia-qiang, XIANG Hong-ying, DAI Xi-jun, WANG Qiong, and NIU Jian-long
Plant canopy pigment concentration is a critical variable for agricultural remote sensing due to its close relationship to leaf nitrogen content. The aims of this study were to: (1) compare the prediction performances on chlorophyll, chlorophyll-a and b, and carotenoid concentration in jujube leaf at canopy scale betwePlant canopy pigment concentration is a critical variable for agricultural remote sensing due to its close relationship to leaf nitrogen content. The aims of this study were to: (1) compare the prediction performances on chlorophyll, chlorophyll-a and b, and carotenoid concentration in jujube leaf at canopy scale between partial least squares regression (PLSR) and support vector machine (SVM), (2) develop quantitative models to estimate pigment concentration in jujube canopy using hyperspectral data and provide theoretical and technical support for rapidly, non-destructive, less expensive and eco-friendly measuring the concentration. Results from correlation analysis showed that jujube canopy pigment concentration correlated strongly with hyperspectral data. What’s more, the hyperspectral data was better correlated by chlorophyll and chlorophyll-a than chlorophyll-b and carotenoid. Results of independent samples tested in predicting performance indicated that both of the PLSR and SVM models could effectively estimate pigment concentration, however, with different prediction precisions. Additionally, the precision of SVM outperformed PLSR for predicting chlorophyll and carotenoid. Whereas chlorophyll-a and chlorophyll-b were better predicted using PLSR than SVM. Compared among all the pigments’ prediction precisions with corresponding optimal inversion models showed that prediction precisions on chlorophyll, chlorophyll-a and carotenoid were superior to chlorophyll-b. The determination coefficients and residual prediction deviation from predicting chlorophyll, chlorophyll-a and carotenoid were higher than 0.8 and 2.0, respectively, while the mean relative error values were lower than 13%. And the corresponding values from predicting chlorophyll-b were 0.60%, 20.79% and 1.79% respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 156 (2017)
Tongue Coat Information Extraction of the Traditional Chinese Medicine with Hyperspectral Image
LIU Ming, ZHAO Jing, LI Gang, ZHANG Hong-ming, and WU Tai-xia
Tongue coat information extraction plays an important role in disease diagnosis for the traditional Chinese medicine. For the purpose of quantifying the tongue coat properties in traditional Chinese medicine, most of the existing methods are based on computerized image analysis, carrying out RGB color space in a tongueTongue coat information extraction plays an important role in disease diagnosis for the traditional Chinese medicine. For the purpose of quantifying the tongue coat properties in traditional Chinese medicine, most of the existing methods are based on computerized image analysis, carrying out RGB color space in a tongue imaging captured with digital camera. However, those methods cannot meet the requirements of clinical medicine. To explore more information about the tongue objectively, a new approach to analyze tongue information based on hyperspectral images is presented. Hyperspectral images are acquired using the hyperspectral imaging system in the spectral range of 370.200 0 to 992.956 0 nm (343bands), and the traditional Chinese medicine clinical diagnosis information is recorded. The main region of interest (ROI) in the samples is extracted while the background is removed from the tongue image, then tongue information of ROI is analyzed. The largest different spectral characteristics between tongue proper and tongue coat are found in the wavelength range of about 525 to 600 nm. Nine wavelengths tongue spectral images from 382.108 0 to 963.668 0 nm are extracted, then comparing with the actual tongue situation, we find that the spectral image at 527.548 0 nm band can better reflect the actual tongue situation than others. The experiment results show that hyperspectral imaging technique is very helpful for tongue coat information extraction of the traditional Chinese medicine, and this new analysis approach can provide a fast and simple non-invasive detection method for tongue coat segmentation and tongue coat information extraction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 162 (2017)
Studies on the Interaction of Poly-L-lysine with Fibrinogen with Spectroscopic Methods
CAI Jian-zhou, and ZHANG Wu
Poly-L-lysine is an important polycation which has great prospect in the biomedical application. However, there are few reports on the blood compatibility of poly-L-lysine at present, especially the interaction between poly-L-lysine and some important proteins from the blood, which is studied with spectroscopic methodsPoly-L-lysine is an important polycation which has great prospect in the biomedical application. However, there are few reports on the blood compatibility of poly-L-lysine at present, especially the interaction between poly-L-lysine and some important proteins from the blood, which is studied with spectroscopic methods. Therefore, it is of certain innovation to further evaluate the blood compatibility of poly-L-lysine, which is studied by the interaction between poly-L-lysine and fibrinogen with many spectroscopic methods. In this study, the fluorescence, ultraviolet visible and circular dichroism spectroscopy were used to research the effects of poly-L-lysine on the structure of fibrinogen. Briefly, zeta potential experiment showed that positive potential of poly-L-lysine increased with increasing concentration. Complexation experiment showed that 0.01 mg·mL-1 poly-L-lysine had little effect on the function of fibrinogen, and the interaction strengthened with concentration increasing. Fluorescence spectra showed that the fluorescence of fibrinogen was quenched in a concentration dependent way when the emission wavelength was 341 nm (λem=341 nm). Ultraviolet visible spectra showed that the absorption intensity of fibrinogen at 200～240 and 278 nm, which was less affected by 0.025 mg·mL-1 poly-L-lysine, reduced with the concentration of poly-L-lysine increasing. Circular dichroism spectra showed when the concentration of poly-L-lysine increased, the effect of poly-L-lysine on the secondary structure of fibrinogen strengthened. Overall, as the concentration of poly-L-lysine increased, the α-helix content of fibrinogen decreased and the β-fold, β-turn and random coil content of fibrinogen increased. These results showed that the electrostatic interaction was occurred between poly-L-lysine and fibrinogen, which influenced the structure of fibrinogen by concentration dependence. While the effect of poly-L-lysine (0.01 and 0.025 mg·mL-1) on fibrinogen was little, poly-L-lysine of high concentration would damage the physiological function of fibrinogen. Therefore, it is necessary to consider the concentration factor in the development and application of poly-L-lysine. In this study, a simple, convenient and systematic method is utilized to study the interaction between materials and fibrinogen, which is helpful to evaluate the blood compatibility of materials sufficiently. Furthermore, the results of this study will provide important guiding information for the biomedical applications of poly-L-lysine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 166 (2017)
The Effect of Ambient Temperature on Human Head’s Surface Skin Temperature
YU Chun-yu, XIE Jia-le, FEI Bin, and ZHANG Jun-ju
It is important to understand heat loss from human head because human head produces much heat for its high metabolism, it also functions as a heat radiator to keep body heat balance. Heat loss from human head is closely related to its skin temperature. Therefore, skin surface temperature of human head changes with ambiIt is important to understand heat loss from human head because human head produces much heat for its high metabolism, it also functions as a heat radiator to keep body heat balance. Heat loss from human head is closely related to its skin temperature. Therefore, skin surface temperature of human head changes with ambient temperature is studied. In this research, several positions were sampled and the advanced infrared detectors (the infrared thermal imager and the infrared thermometer) were used as tools for measurement. For the sake of comparison, the young volunteers were grouped into the boys team and the girls team. Results showed that, firstly, between the groups, there was only a little difference in that girls’ head temperature was a little higher; secondly, head temperature of either girls or boys rises with air temperature till about 30 ℃; and thirdly, exercise has only a little effect on the head temperature variation. This research is practical for further investigation on head heat flow and referential for health diagnosing by comparing the data recorded in this experiment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 172 (2017)
Research on Visual Perception-Referenced Compression Method for Multi-Spectral Data with High-Fidelity
LIANG Jin-xing, WAN Xiao-xia, and LU Wei-peng
Aim In order to maintain the chromaticity precision in the process of linear compression of the multispectral data, a visual perception-referenced compression method (VPCM) based on the chroma gradient (refer to the partial derivative of chroma to wavelength) is proposed. Method The method firstly successfully developeAim In order to maintain the chromaticity precision in the process of linear compression of the multispectral data, a visual perception-referenced compression method (VPCM) based on the chroma gradient (refer to the partial derivative of chroma to wavelength) is proposed. Method The method firstly successfully developed the transfer functions which could synchronously fusion the spectral features and chromaticity characteristics of human visuals based on the nonlinear analytic feature of human visual system. For further improvement the transfer function, a modified optimizing function was developed to help find out the optimal transfer direction for different sample sets. If the transfer function was finally settled, it will be applied to transforming the spectral data of the sample set (Γ(S)=C). Then the transformed spectral data of the sample set will be compressed with high chromatic accuracy by the principle components analysis method. After that, the compressed data will be reconstructed through inverse transformation (Γ-1(C)=), while the reconstructed spectral data will be using to evaluate the effective of the proposed VPCM method. Result Four groups typical and representative sample sets were chosen to test the effective of the proposed method. The CIELab color difference in the D50/2° calculates condition and a proposed mean metamerism index (MMI) calculated with 75 groups typical light sources (including tungsten, fluorescent and LED lamp) was adopted as evaluating metrics. Eventually, the comparative experiment involving several existing methods Lab-PQR and 2-XYZ indicates that the proposed VPCM hold the best chromatic accuracy both for metric MMI and the average color difference ΔEab when compared with Lab-PQR and 2-XYZ, and the spectral accuracy was calculated between Lab-PQR and 2-XYZ with Lab-PQR maintained the highest spectral accuracy. Conclusion The proposed VPCM can preserve high compression chromatic precision at the price of small loss of spectral precision and possess good colorimetric stability under variable reference conditions. It is very applicable for some application fields which require compressing of the multi-spectral data with high chromatic accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 177 (2017)
Study on the Distinguishment of Camouflage Paints Based on Depolarization Characteristics
XU Jiang, QIAN Wei-xian, LU Dong-ming, ZHOU Xiao-jun, ZHANG Hai-yue, and LU Ying-cheng
As an important part in the modern warfare, camouflage technology plays a critical role in the battlefield, and the results of detection of camouflage target directly affect the results of war. However, there is little paper to detect camouflage paint by depolarization characteristics, so it is of great significance toAs an important part in the modern warfare, camouflage technology plays a critical role in the battlefield, and the results of detection of camouflage target directly affect the results of war. However, there is little paper to detect camouflage paint by depolarization characteristics, so it is of great significance to use the depolarization technology to study the distinguishment of camouflage paints. To address this issue, we studied the mechanism of the scattering of electromagnetic wave, and analysed the relationship between the characteristics of depolarization and mechanism of scattering. Jones Matrix and Mueller Matrix were used to set up the physical model, and the Mueller-Jones Matrix was decomposed with the characteristics of polarization, then the depolarization coefficients(ωd) of the surfaces of the samples was acquired. In this experiment, we measured soil and three kinds of camouflage yellow paints in seven different incident angles to analyze the characteristics of depolazation of the soil and three kinds of camouflage yellow paints’ surfaces. Finally, we applied the theory of Fresnel formulas to verify the theoretical model. The results showed that: the depolarization coefficients of the samples’ surfaces were related to the scattering, and with the increase of the incident angles, the depolarization coefficients were decline. But in the whole measurement process, the depolarization coefficients of the soil were far above the camouflage paints’. Research indicated that: this article was the first paper which used the depolarization coefficients as an important parameter to identify the camouflage targets, and could identify the camouflage yellow paints in the soil-background accurately and effectively. The processes of the experiments were simpler, and the time was shorter. In modern battlefield, it could identify the camouflage targets quickly and easily, and furnish the precious time for the victory of the war. Therefore, the depolarization technology had a great application value, and the paper had very important significance on the development of camouflage recognition technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 183 (2017)
Modeling and Predicting of MODIS Leaf Area Index Time Series Based on a Hybrid SARIMA and BP Neural Network Method
JIANG Chun-lei, ZHANG Shu-qing, ZHANG Ce, LI Hua-peng, and DING Xiao-hui
The modeling and predicting of vegetation Leaf area index (LAI) is an important component of land surface model and assimilation of remote sensing data. The MODIS LAI product (i.e. MOD15A2) is one of the most widely used LAI data sources. However, the time series of MODIS LAI contains some data of low quality. For examThe modeling and predicting of vegetation Leaf area index (LAI) is an important component of land surface model and assimilation of remote sensing data. The MODIS LAI product (i.e. MOD15A2) is one of the most widely used LAI data sources. However, the time series of MODIS LAI contains some data of low quality. For example, because of the influence of the cloud, aerosol, etc., the MODIS LAI presents the characteristics of the discontinuous in time and space. In fact, the time series of MODIS LAI include both linear and nonlinear components, which cannot be accurately modeled and predicted by either linear method or nonlinear method alone. In this paper, the original LAI time series data were first smoothed with Savitzky-Golay (SG) filtration and linear interpolation; SARIMA, BP neural network and a hybrid method of SARIMA-BP neural network were then used for modeling and predicting MODIS LAI time series. The SARIMA-BP neural network combined both SARIMA and BP neural network, which could model the linear and the nonlinear component of MODIS LAI time series respectively. That is, the final result of SARIMA-BP neural network was the sum of results of the two methods. Experiments showed that the time series of MODIS LAI that were smoothed with the SG filtration and linear interpolation were more smooth than original time series, with a determination coefficient up to 0.981, closer to 1 than that of SARIMA (0.941) and BP neural network (0.884); the correlation coefficient between SARIMA-BP neural network and the observation is 0.991, higher than that of between SARIMA (0.971) or BP neural network (0.942) SARIMA and the observation. Thus, it can be concluded that, the proposed SARIMA-BP neural network method can better adapt to the LAI time series, and it outperforms the SARIMA and BP neural network methods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 189 (2017)
Sensitive Bands Extraction and Prediction Model of Tomato Chlorophyll in Glass Greenhouse
DING Yong-jun, ZHANG Jing-jing, SUN Hong, and LI Xiu-hua
In order to predict the content of chlorophyll in tomato rapidly and accurately, this study, with spectrum technology, focused on the extraction of sensitive spectral bands of tomato chlorophyll in glass greenhouse environment and created an effective estimation model. During the period of cultivating tomatoes, leaf spIn order to predict the content of chlorophyll in tomato rapidly and accurately, this study, with spectrum technology, focused on the extraction of sensitive spectral bands of tomato chlorophyll in glass greenhouse environment and created an effective estimation model. During the period of cultivating tomatoes, leaf spectra were measured with an ASD FieldSpec HH spectrophotometer and chlorophyll content was measured with Type 752 UV-Vis spectrophotometer. Based on the original spectra, absorbance spectra, first derivative spectra and continuum removal spectra, spectral data was preprocessed, in which the effectiveness of spectral features of chlorophyll content of tomato was highlighted and spectral response characteristics of the absorbance spectra in the visible part was enhanced. It was shown that both the continuum removal spectra and the first derivative spectra have strong blue and red absorption valley and green reflection peak. In this paper, the original spectrum, absorbance spectrum, first derivative spectrum and continuum removal spectrum were analyzed and compared, and then optimal spectral feature parameters were extracted with methods of Inter-Correlation analysis and multivariate collinearity diagnosis. Sensitive bands from original spectrum are 639, 672, 696, 750 and 768 nm. Sensitive bands from absorbance spectrum are 638, 663, 750 and 763 nm. Sensitive bands from first derivative spectrum are 516, 559 and 778 nm. Sensitive bands from continuum removal spectrum are 436, 564, 591, 612, 635, 683 and 760 nm. The stepwise multiple regressions were used to develop the prediction models of the chlorophyll content of tomato leaf. The result showed that the prediction model, which used the values from continuum removal spectrum at 436, 564, 591, 612, 635, 683, 760 nm as input variables, had the best predictive ability. The calibration R-Square was 0.88 and the validation R-Square was 0.82..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 194 (2017)
Identification of Fertilized Chicken Eggs Based on Visible/Near-Infrared Spectrum During Early Stage of Incubation
QIN Wu-chang, TANG Xiu-ying, PENG Yan-kun, and ZHAO Xing-hua
In the process of chicken egg hatching, some eggs can not be hatched successfully due to the absence of fertilization. These eggs not only cause a lot of waste, but also infect other normal eggs with bacteria. In the study, the fertilized eggs and clear eggs is identified by using the visible/near-infrared spectrum. ItIn the process of chicken egg hatching, some eggs can not be hatched successfully due to the absence of fertilization. These eggs not only cause a lot of waste, but also infect other normal eggs with bacteria. In the study, the fertilized eggs and clear eggs is identified by using the visible/near-infrared spectrum. It is of great necessity to get the best time of identifying the clear eggs in the early of hatching, so the variation of eggs’ quality in the condition of hatching over time is studied. The results show that eggs are fresh after 24 hours’ hatching and eggs can not be eaten after 72 hours’ hatching while the best time of identification is within 36 hours. Static acquisition system is developed based on visible/near-infrared transmission spectrum for acquiring spectrum. Comparing the effect of the model of the different samples of same breed and samples of different breed, the different part of spectrum among fertilized eggs and clear eggs is deleted which caused by the color of eggshell and yolk, the effective spectral band are 355～590 and 670～1 025 nm. Adopting the pretreatment of PCA and comparing the accuracy of the various mathematical models with different time and the number of principal components decide the best number of principal components. Considering the production efficiency and comparing the different pretreatment methods of spectrum, for examples, SNV, MSC, Derivative correction and PCA, and various mathematical models are combined to establish the most efficient discriminant model. The result shows that the most efficient discriminant model is established with Fisher and based on the pretreatment of PCA after 24 hours’ hatching. And the precision rate is 87.18%. The study provides a new way for nondestructive and online identification of the fertilized eggs and clear eggs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 200 (2017)
New Algorithms to Separate the Contribution of Petroleum Substances and Suspended Particulate Matter on the Scattering Coefficient Spectrum from Mixed Water
HUANG Miao-fen, XING Xu-feng, SONG Qing-jun, and LIU Yuan
In the water with petroleum pollution, the petroleum will be adsorbed on the surface of suspended particulate matter and form a double-layer structure, which impacts on the spectrum characteristics to the scattering coefficient. It is a key to improve the accuracy of the scattering theory model that the contribution ofIn the water with petroleum pollution, the petroleum will be adsorbed on the surface of suspended particulate matter and form a double-layer structure, which impacts on the spectrum characteristics to the scattering coefficient. It is a key to improve the accuracy of the scattering theory model that the contribution of petroleum substances and suspended particulate matter on the scattering spectrum coefficient is be separated. A backward scattering coefficient spectrum measurement system was being built from linkage observation of three kinds of instruments, including DAWN HELEOS Ⅱ18 angle scattering measuring instrument (Wyatt company, American), LISST-100-xB size instrument(SEQUOIA SCIENTIFIC, INC, American), HydroScat-6 Sprctral Backscattering Sensor (HS6) ( Hobilabs company, American). Many parameters were measured such as voltage value of the scattering intensity, the particle size distribution, particle concentration and backward scattering coefficient in different water samples. Using the Mie scattering theory, a new algorithm to separate the scattering coefficient spectrum and new way of thinking to calculate volume scattering function β(λ, θ) of the unknown refractive index material were proposed. The matching experiments were done by selecting quartz sand as particles whose refractive index (m) is known and petroleum sewage collected from different oilfield area. On the basis of matching experiments different water samples with different properties were obtained and related data were determinated. Firstly, according to Mie scattering theory the water volume scattering function β(λ, θ) for each sample is calculated. Secondly, the equation was set up which can convert the scattering intensity corresponding to the voltage value V(θ) measured by DAWN HELEOS Ⅱ 18 Angle laser scattering instrument into volume scattering function β(λ, θ). Thirdly, according to the method of optimum the equivalent refractive index (mos) of the oil sands mixed and the refractive index (mo) of petroleum sewage were estimated; Finally, using β(λ, θ) and estimation of mos values and mo values to calculate the backscatter coefficient bb(λ) of all kinds samples, and new algorithms were set up which seperated quartz sand bb, s(λ) and petroleum sewage bb, o(λ) from mixed water with petroleum and sands respectively. The establishment of these separation algorithms improves the accuracy of the scattering theory model of the water petroleum pollution, on the other hand expands the Mie scattering theory in the application of ocean color remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 205 (2017)
Degradation Characteristics of Spectral Analysis of Straw Nursery Containers in Situ Soil Culture
SUN En-hui, WANG Ming-yan, WU Guo-feng, HUANG Hong-ying, CHANG Zhi-zhou, and XU Yue-ding
This paper aimed to reveal the degradation behavior of a new type of biodegradable containers. The biodegradable containers, which was made of modified soybean adhesive and straw, was processed in situ biodegradation under natural condition. The physicochemical property and microstructure of straw nursery containers trThis paper aimed to reveal the degradation behavior of a new type of biodegradable containers. The biodegradable containers, which was made of modified soybean adhesive and straw, was processed in situ biodegradation under natural condition. The physicochemical property and microstructure of straw nursery containers treated and untreated were characterized with Cellulose Tester, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope - Energy Dispersive X-ray Spectroscopy (SEM-EDS), and Thermo-gravimetry Analysis (TGA), respectively. The results indicated that the content of cellulose, hemicellulose and lignin of treated specimen decreased to 21.43%, 21.41% and 9.54% from 29.03%, 30.44% and 12.52%, respectively, comparing with those of untreated straw nursery container. FTIR analysis revealed that the ester and fat bond have been ruptured, and the aromatic characteristic peak became weakened. SEM-EDS spectrum showed the microfibril chain in the container has been fragmentation, and the soybean adhesive was also degradation. The surface of container appeared oxidization degradation. TGA analysis showed that a large number of small molecules have been produced in the process of degradation and the thermo-stability of treated samples improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 212 (2017)
Numerical Simulation on the Radiative Characteristics of the Particles in the Pulverized Coal Furnace
DU Jin-cai, ZHANG Hai-dan, WANG Fei, and YAN Jian-hua
The radiative characteristics of char and ash in the pulverized coal furnace at the wavelength of 560 nm are analyzed here. The particles’ radiative coefficients are calculated in the exit of the burner and in the upper part of the furnace separately according to the Mie theory. It can be inferred that in the exit of tThe radiative characteristics of char and ash in the pulverized coal furnace at the wavelength of 560 nm are analyzed here. The particles’ radiative coefficients are calculated in the exit of the burner and in the upper part of the furnace separately according to the Mie theory. It can be inferred that in the exit of the burner, char has a great effect on the particles’ radiative coefficient, which accounts for a percentage of 90%. While in the upper of the furnace, ash dominates the particles’ radiative coefficient. The scattering ratio of the ash is calculated to be 91.6 and the scattering ratio of the char is only 50%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 217 (2017)
Effects of Green Manures on Soil Dissolved Organic Matter in Moisture Soil in North China
CHANG Dan-na, CAO Wei-dong, BAI Jin-shun, GAO Song-juan, WANG Xue-cui, ZENG Nao-hua, and Shimizu Katsuyoshi
Soil dissolved organic matter (DOM) plays an important role in the biogeochemistry of carbon, nitrogen, and phosphorus and in the transport of heavy metals and pesticides in soil. In moisture soil, green manures and soils were sampled in situ at the ploughed stage of green manures. A 56-day laboratory incubation experiSoil dissolved organic matter (DOM) plays an important role in the biogeochemistry of carbon, nitrogen, and phosphorus and in the transport of heavy metals and pesticides in soil. In moisture soil, green manures and soils were sampled in situ at the ploughed stage of green manures. A 56-day laboratory incubation experiment was conducted to simulate the dynamic changes of soil DOM influenced by the decomposition of green manures, the green manures were Hairy vetch (Vicia villosa Roth.), February orchid (Orychophragmus Violaceus L.), Rye (Secale cereale L.), the soil without green manure was used as a control (CK). The composition and ultraviolet-visible spectrum parameters of soil DOM were investigated at different incubation stages. Results showed that green manures could increase the dissolved organic carbon (DOC), the total organic acids (TOAs) and total carbohydrate (TCs) contents, and all treatments were reached a peak on the 1st day and decreased later. Hairy vetch affected DOC and TOAs most and were increased by 114.01% and 109.10% higher than CK respectively at the 1st and 14th day. Rye influenced the total carbohydrate (TCs) most and was maximumly 323.18% higher than CK at the 42nd day. Green manures could increase the dissolved organic nitrogen (DON) content, DON in all green manure treatments increased on the 1st day, decreased several days later and increased again after 20～30 d. Hairy vetch effected DON best and was 305.83% higher than CK at the 42nd day. All green manures increased in SUVA254, SUVA260, SUVA272, SUVA280 and SAUC240-400, while decreasing in A250/A365 and A240/A420. The PCA analysis of ultraviolet-visible spectrum parameters showed that SUVA254, SUVA260, SUVA272, SUVA280 had a high positive correlation between each other, and the same situation was found between A250/A365 and A240/A420. Among them, SAUC240-400 was a key factor parameter featuring the characteristics of DOM. The results suggested that green manures could increase the contents of DOM and its aromaticity, hydrophobic percentage, humification degree and average molecular weight, and could be increased and the stability of DOM could be enhanced accordingly. The ultraviolet-visible spectrum parameters could indicate the changes of characteristics of DOM in this study..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 221 (2017)
Study on NIR Model Transfer between Similar Kinds of Fruits Based on Slope/Bias Algorithm
JI Na-yu, LI Ming, L Wen-bo, LIU Ran, ZHANG Yu-ying, and HAN Dong-hai
In order to expand the application range of the model for a single kind of fruits in the portable near infrared instrument, this paper comes up with a new method for the soluble solid content (SSC) model transfer between different kinds of fruits. This method is focusing on the idea of model transfer between different In order to expand the application range of the model for a single kind of fruits in the portable near infrared instrument, this paper comes up with a new method for the soluble solid content (SSC) model transfer between different kinds of fruits. This method is focusing on the idea of model transfer between different instruments. Based on the similar physical and chemical properties of apples, peaches and pears, such as the range of SSC content, fruit size and the thickness of peel, a simple Slope/Bias algorithm is applied to the transfer of apple SSC partial least square (PLS) model. After that, it can be used to predict pear & peach SSC value with very little extra samples. It’s more convenient and costs less by using this method. For pear samples, by using extra 35 standard samples to transfer apple SSC model, RMSEP reduced from 1.009 °Brix to 0.565 °Brix. For peaches, extra 40 standard samples led to a significant reduce of RMSEP from 1.726 °Brix to 0.677 °Brix after model transfer. To validate the feasibility of this model transfer method, both pear and peach SSC models were tested using the same Slope/Bias algorithm model transfer respectively. A pear SSC model was firstly set up and then transferred with Slope/Bias method. Taking 30 standard apples as samples, RMSEP value reached 0.597°Brix, while taking 40 standard peaches as samples, RMSEP value reached 0.689°Brix. The peach SSC model was transferred in the same way. For apples, using 35 standard samples, RMSEP value reached 0.654°Brix, and for pears, using 30 standard samples, RMSEP value reached 0.439°Brix. These results show that slope/bias algorithm can be used to transfer model between similar kinds of fruits such as apples, pears and peaches. The paper provides innovative ideas for the model transfer among similar kinds of materials, so that the portable near infrared instruments can be used more conveniently and widely..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 227 (2017)
Detection System for VOCs Concentration Based on Improved Photo-Elastic Modulator
YUE Bao-wang, and DING Wei-jie
Since the size of modulated crystal is limited with size in the conventional photo-elastic modulation system, it’s a low spectrum resolution, so detection accuracy of gas concentration is not high. In order to improve the spectrum resolution of the system, an improved photo-elastic modulation system was designed. This Since the size of modulated crystal is limited with size in the conventional photo-elastic modulation system, it’s a low spectrum resolution, so detection accuracy of gas concentration is not high. In order to improve the spectrum resolution of the system, an improved photo-elastic modulation system was designed. This method was carried out multiple reflection of incident light in the crystal. The optical path difference was increased by this method, so that a higher spectrum resolution was obtained. The entire system was constructed with the laser, photo-elastic modulator, polarizer, analyzer and photo-detector. Among them, a wedge angle (θ) was processed on modulation crystal. And a reflection film was plated on both sides; effective optical path length increase was implemented. Through the analysis the wedge angle (θ) was selected, and function on the optical path, the phase of modulation and the energy was calculated for the wedge angle. Ultimately, the appropriate wedge angle values were determined, and the corresponding optical path function expressions were given. In the experiments, the concentration of three common VOC gas was analyzed respectively. The concentration of sample gas was calibration by PTM400-VOC gas analyzer, and the results were compared with conventional photo-elastic modulation system. Experimental results show that gas concentration detection limit is reached to 0.010 mg·m-3 for improved photo-elastic modulation system, compared with conventional photo-elastic modulation system it’s an order of magnitude or more. The gas concentration detection error was 3.4%, and it’s also better than the traditional type. In summary, improved photo-elastic modulation system not only has the advantage of high static structural stability, but also a substantial increase in the spectrum resolution and detection accuracy of concentration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 232 (2017)
Elemental Analysis of Alloys with Picosecond Dual-Pulse LA-LIBS under Low Sample Destruction
WANG Fu-juan, LI Run-hua, WANG Zi-xin, ZENG Xue-ran, CAI Zhi-gang, and ZHOU Jian-ying
A study on elemental analysis of alloy samples under low sample destruction with dual-pulse laser-ablation laser induced breakdown spectroscopy (LA-LIBS) based on one picosecond Nd∶YAG laser is presented. In LA-LIBS, low pulse energy 532 nm laser was used for sample ablation and high pulse energy, time–delayed 1 064 nmA study on elemental analysis of alloy samples under low sample destruction with dual-pulse laser-ablation laser induced breakdown spectroscopy (LA-LIBS) based on one picosecond Nd∶YAG laser is presented. In LA-LIBS, low pulse energy 532 nm laser was used for sample ablation and high pulse energy, time–delayed 1 064 nm laser was used for re-excitation of the ablated samples to enhance atomic emissions of the laser-induced plasma and signal detection sensitivity. The influence of pulse energies of the ablation laser and excitation laser to the signal intensities was studied experimentally. I was observed that Cu 324.75 nm line intensity in LA-LIBS was enhanced 86 times in comparison with that obtained in SP-LIBS under 10 μJ pulse energy of the ablation laser and 2.5 mJ pulse energy of the excitation laser. The diameter of the crater generated in LA-LIBS was less than 10 μm. It is demonstrated the possibility of using dual-pulse LA-LIBS to realize elemental analysis of solid sample under low sample destruction. This technique is valuable for elemental analysis of precious samples and 2D elements mapping under high spatial resolution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 236 (2017)
Rapid Soil Classification with Laser Induced Breakdown Spectroscopy
MENG De-shuo, ZHAO Nan-jing, MA Ming-jun, GU Yan-hong, YU Yang, FANG Li, WANG Yuan-yuan, JIA Yao, LIU Wen-qing, and LIU Jian-guo
Soil classification is an important research content in soil science field. It is the basis of soil survey and resource evaluation which is important to agricultural production. There are many soil classification standards all over the world. China has two kinds of classifications including soil genetic classification Soil classification is an important research content in soil science field. It is the basis of soil survey and resource evaluation which is important to agricultural production. There are many soil classification standards all over the world. China has two kinds of classifications including soil genetic classification and soil system classification. There are great differences between different types of soil elements, so it is feasible for soil classification to use laser induced breakdown spectroscopy. Laser induced breakdown spectroscopy (LIBS) is a new element analysis technology which uses a laser pulse with high energy density to ablate samples. LIBS has been used in many fields including environmental protection and industrial production control. It can directly reflect the difference of element content in different soils. The experimental setup including an Nd: YAG laser, a spectrometer, a computer and a rotating platform. In the experiment 7 kinds of soil (red soil, brick red soil, lateritic red soil, paddy soil, cinnamon, alluvial soil and alpine meadow soil) including 25 samples were used. All soil samples were grinded and sieved before the experiment.Under the same experimental condition, the temperatures of the plasma created by the laser pulses on the surface of the different soil samples have great differences. The lateritic red soil had the highest temperature, and the alpine meadow soil had the lowest. But it was not enough to form the basis for classification. Therefore six constant elements including Si, Fe, Al, Mg, Ca and Ti were selected and their spectral line intensity were treated as classification index. Principal component analysis (PCA) was used to simplify the classification process. The PCA method could simplify the 6 indexes to few independent indexes which could also reflect the spectral information of the 6 elements. The original spectral data was processed by Matlab. The process consisted of spectral background removal, characteristic spectrum identify and extraction. The classification results showed a three--dimensional figure. Except alpine meadow soil which varied in element concentrations 6 kinds of soils achieved good classification. The brick red soil and lateritic red soil varied in PC1, but their PC2s and PC3s were the same. The two kinds of soil overlapped with each other and they couldn’t be separated. Back-propagation artificial network was also used to achieve soil classification. The classification results were the same with the PCA. Some brick red soil and lateritic red soil samples were identified inaccurately. When the PC1, 2, 3 were used as the input of the BP-neural network, the classification had much better accuracy because less input improved the performance of the BP-neural network. Only one alpine meadow soil sample was identified to cinnamon soil. When the plasma temperature was also taken into account, all the soil samples could be distinguished. The results showed that LIBS could be used to classify soils based on their element content differences. The PCA, soil plasma temperature and BP-neural network were useful tools to achieve soil classification. The LIBS provides a useful tool for general detailed soil survey and rational utilization of soil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 241 (2017)
Study on the Element Composition of Ancient Fossils and Meteorites
QI Li-jie, WANG Ying, MENG Qing-zhu, and ZHAO Zhen
The ancient fossils are formed by the ancient animals and plants after a long geological period and geological processes. They have witnessed the history of the earth and recorded the information of the evolution of the earth’s ecological environment; Meteorites traveling in the solar system for a long time with the abThe ancient fossils are formed by the ancient animals and plants after a long geological period and geological processes. They have witnessed the history of the earth and recorded the information of the evolution of the earth’s ecological environment; Meteorites traveling in the solar system for a long time with the abrasion of nuclear reactions and atmosphere of the universe, have formed a unique shape and texture. They recorded the original information about the formation and evolution of out space. The analysis of the ancient fossils composition is the scientific basis for the study of the origin and evolution of the earth; the meteorites as rock sample from outer space are gifts from nature. They are extremely valuable and rare; the analysis of the composition of meteorites can provide a better foundation for the development of the foreign planet exploration and the development of the celestial chemistry. In this paper, the method of sample dissolution was selected and optimized. The final choice of nitric acid, hydrofluoric acid and perchloric acid as the mixed reagent, a microwave digestion method was used in treatment of ancient fossil samples; The aqua regia, nitric acid, hydrofluoric acid and perchloric acid as the mixed reagent, both microwave digestion method and wet digestion method were used in treatment of meteorite samples. Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used to determine three different ancient fossil samples and three meteorite samples. And the content of same elements was compared. Analysis results show that the ancient fossils and meteorites contain Pb, Hg, Ge, Fe, Ni, Cu, Co, Mn and other heavy metal elements as well as part of the rare earth element. The standard addition recovery of the method was between 98.2%~106%, and the relative standard deviation was less than 2.12%. The method had high sensitivity, accuracy and precision..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 247 (2017)
Analysis of XPS in the Removal of Cr(Ⅵ) from Groundwater with rGO-nZⅥ
DONG Jun, REN Li-ming, CHI Zi-fang, and HU Wen-hua
Iron nanoparticles are widely used in heavy metal ions removal from water, but because of the characteristics of easily aggregation and transference in the groundwater, remediation effect was reduced. GO with a negative charge containing oxygen-containing functional groups on the surfaces of graphene, are widely used fIron nanoparticles are widely used in heavy metal ions removal from water, but because of the characteristics of easily aggregation and transference in the groundwater, remediation effect was reduced. GO with a negative charge containing oxygen-containing functional groups on the surfaces of graphene, are widely used for the removal of heavy metal ions from water, but it has little on remediating hexavalent chromium (Cr2O2-7, CrO2-4) with negatively charged electrons. Therefore, rGO-nZⅥ was synthesized via liquid phase reduction method to overcome the aggregation and transference of FeO, changing the negative charged Cr2O2-7 or CrO2-4 to positive charged Cr3+. The material behavior characteristics of Cr(Ⅵ) removal were discussed. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to test the prepared rGO-nZⅥ. Results indicated that nZⅥ was successfully loaded on the surface of GO, and the shape of the particles was approximate ball and the granular diameter ranged from 20 to 100 nm. Removal efficiency of Cr(Ⅵ) (40 mg·L-1) from water was nearly 100% within 24 h using rGO-nZⅥ. X-ray photoelectron spectroscopy (XPS) analyses using the XPSPEAK41 program indicated that FeO firstly reduced negatively charged Cr(Ⅵ) to positively charged Cr(Ⅲ) by providing electron, then the chromium in the solution can be removed as chromium hydroxide (Cr(OH)3) by a hydrolysis precipitation process. As the reaction progress, materials charges were changing, which benefited adsorpting Cr(Ⅵ). After 24 h reaction, the residual nZⅥ loading on rGO-nZⅥ remained, which showed the potential of sequentially remediating contamination. The results showed important theoretical value and practicability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 250 (2017)
Study of Crystallinity Performance of Pretreated Bamboo Fibers Based on X-Ray Diffraction and NMR
CHU Jie, ZHANG Jun-hua, MA Li, and LU Hai-dong
At present there are many methods to discuss the crystallinity of lignocellulose but scholars experts have different opinions about them. This study, with bamboo under the different pretreatment conditions, and with help of acid, alkali and glycerol uses X-ray diffraction and CP/MAS13NMR in order to make clear of the cAt present there are many methods to discuss the crystallinity of lignocellulose but scholars experts have different opinions about them. This study, with bamboo under the different pretreatment conditions, and with help of acid, alkali and glycerol uses X-ray diffraction and CP/MAS13NMR in order to make clear of the crystallinity of bamboo change characteristics, and measured the area length, spacing, crystal plane diffraction peak position, the crystallinity index and parameters and complete the comparison of crystalline cellulose and Gaussian function curve C - 4 area signal area. Results showed that crystalline overall increased significantly after pretreatment, 002 peak become sharp and offset to the direction of large angle for alkali pretreatment, 002 crystal width increases, crystalline spacing is smaller. CP/MAS13NMR is consisting with XRD, but calculated value is smaller. It proved that effective processing can effectively disrupted the recalcitrance of bamboo, and produce highly active cellulose in lignocelluloses’ biomass ethanol production, that provide guidance to realize the lignocellulose bioconversion and effective utilization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 256 (2017)
Study on Si-PIN and CdTe Detectors Used in Energy Dispersive X-Ray Fluorescence Measurements
HU Chuan-hao, ZENG Guo-qiang, GE Liang-quan, YU Ming-fu, WEI Shi-long, ZHANG Kai-qi, YANG Jian, and CHEN Chuan
Semiconductor detector is widely used in energy dispersive X-ray fluorescence measurementsdue to its excellent performance. In this paper, Si-PIN and CdTe semiconductor detectors were studied, performances of the two detectors were compared in material properties, detection efficiency, energy resolution and other aspecSemiconductor detector is widely used in energy dispersive X-ray fluorescence measurementsdue to its excellent performance. In this paper, Si-PIN and CdTe semiconductor detectors were studied, performances of the two detectors were compared in material properties, detection efficiency, energy resolution and other aspects. Focused on the performance of the detectors influenced by the thickness of detector sensitive area, energy of incident X-ray, shaping time of post-stage circuit, and analyzed the differences of energy spectrum caused by escape peaks and hole trailing. Aiming at the problem of incomplete hole collection in detector, a digital multi-channel analyzer (DMCA) based on FPGA with rise-time discriminator was designed, it could reduce the influence of hole trailing effectively and improve energy resolution. The experimentation results indicate that the detection efficiency of Si-PIN and CdTe is roughly equal when energy is below 15 keV while CdTe has much higher detection efficiency than Si-PIN when energy is above 15 keV. The optimum forming time of the Si-PIN detector is about 10 μs, and the CdTe detector is about 2.6 μs, so the CdTe detector is more suitable for the high count rate condition. Si-PIN detector has better energy resolution than CdTe detector for different energy incident X-ray. CdTe detector has obvious hole tailing effect and the energy resolution of CdTe detector is significantly improved by using DMCA with rise-time discrimination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 262 (2017)
On-Site Analysis of Heavy Metals in Water with Handheld X-Ray Fluorescence and Pre-Concentration Device without External Power Supply
JIAO Ju, ZHAN Xiu-chun, ZHAI Lei, FAN Xing-tao, WEN Hong-li, YUAN Ji-hai, LIU Xiao, and GUO Shu
Currently, increasing importance has been attached to heavy metal pollution of water environment. In order to help geologist and environmentalist to obtain on-site experimental data, there is an urgent need to develop portable analysis techniques of water quality, which can be used to give an timely and accurate assessCurrently, increasing importance has been attached to heavy metal pollution of water environment. In order to help geologist and environmentalist to obtain on-site experimental data, there is an urgent need to develop portable analysis techniques of water quality, which can be used to give an timely and accurate assessment of water quality of the contaminated area with low cost and to monitor water environment conveniently in daily preventing and controlling work of water pollution. Based on adsorption with Purolite S930 chelating resin at pH 4 and thin-film sample preparation technique, a rapid and simple on-site-oriented analysis method of heavy metal ions, namely Mn, Fe, Ni, Cu, Zn and Pb in aqueous solutions, was developed utilizing a handheld energy-dispersive X-ray fluorescence in this paper. The correlation coefficients of the calibration curves were greater than 0.992 for all six metal ions, the lower limits of detection were between 5.8 and 18.6 μg·L-1. Precision tests carried out on multi-element mixed solutions showed that the relative standard deviations (RSD, n=10) were better than 15%. The method has been used on-site to analysis 21 water samples collected from different river or well sites near a mining area northeast China. Out of the five underground water samples, one was found contaminated by Cu and Zn (Class Ⅲ), one by Zn and Fe (Class Ⅱ), and one by Fe(in between Class Ⅱ to Ⅲ). Surface water samples showed better qualities. But two out of the sixteen were found to be contaminated by Mn heavily (Class Ⅳ). Laboratory ICPMS was used to analyze the same samples. The results for Cu, Ni and Pb were coincident with the on-site data in general. But for Zn and Mn with higher concentrations, on-site data were lower than that by ICPMS. The reason for that might be the inclusion of the fine suspending particles in the samples by ICPMS. We conclude that the on-site data were effective. With the described method, an overall data acquisition time, including sampling, processing and measuring, can be within 12 hours for a batch of 10 samples. The pre-concentration device and the XRF instrument are both small, light, portable and can operate without external power supply. So, the method is suitable for on-site water sample analysis, especially in remote areas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 267 (2017)
The Automatic Recognition and Detection of Sky-Subtraction Residual Componentin the Stellar Spectra
AN Ran, PAN Jing-chang, YI Zhen-ping, and WEI Peng
The skylines, superimposing on the target spectrum as a main noise, will reduce the signal-to-noise ratio of the spectrum. If the spectrum still contains a large number of high strength skylight residuals after sky-subtraction processing, it will not be conducive to the follow-up analysis of the target spectrum. At preThe skylines, superimposing on the target spectrum as a main noise, will reduce the signal-to-noise ratio of the spectrum. If the spectrum still contains a large number of high strength skylight residuals after sky-subtraction processing, it will not be conducive to the follow-up analysis of the target spectrum. At present, the study on the automatic recognition of the abnormal sky-subtraction stellar spectra is limited in number. We can only find the abnormal sky-subtraction spectra by manual inspection, and this will reduce the speed of detection. This paper analyzes the influence factors of sky-subtraction results and finds the characteristics of the abnormal sky-subtraction spectra. A simple and effective method is proposed to automatic recognize the abnormal sky-subtraction stellar spectra which have been processed with the LAMOST Pipeline processing procedure and find the positions of the abnormal skylines. In this method, all the spectra are normalized first; the abnormal skyline is determined by detecting whether there exits any high strength skyline residuals which are similar to the emission line or absorption line. Finally, all the abnormal skyline positions in the spectra are obtained in this method. The experimental results with the LAMOST spectroscopic dataset show that this method can recognize the abnormal sky-subtraction spectra and find the abnormal skyline positions of different residual strength effectively. In addition, the method is simple and has high recognition efficiency, and can be applied to the automatic detection of abnormal sky-subtraction of large number of spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 273 (2017)
Stellar Alpha Element Abundance Estimation Using LASSO Algorithm
BU Yu-de, PAN Jing-chang, WANG Chun-yu, and CHEN Xiu-mei
In this paper, a new method based on LASSO algorithm is studied for the estimation of stellar alpha element abundance. The information of alpha elements (O, Mg, Ca, Si, and Ti) of massive stars will help us to better understand the evolution of the galaxy. Presently the main method of determining the alpha element abunIn this paper, a new method based on LASSO algorithm is studied for the estimation of stellar alpha element abundance. The information of alpha elements (O, Mg, Ca, Si, and Ti) of massive stars will help us to better understand the evolution of the galaxy. Presently the main method of determining the alpha element abundances from the low resolution spectra is the template matching method. However, it is difficult for us to optimize the algorithm parameters and the algorithm is sensitive to the noise. Thus, it is necessary to study the new method to determine the abundance. The experimental results show that the accuracy of LASSO algorithm on ELODIE spectra is 0.003 (0.078) dex. To explore the impact of the spectral resolution variation, we use ELODIE spectra to generate the spectral data sets with following resolutions: 42 000, 21 000, 10 500, 4 200 and 2 100 by using the Gaussian convolution. The results of the LASSO algorithm on these data sets are 0.003 3 (0.078) dex, -0.05 (0.059) dex, -0.007 (0.069) dex and -0.004 5 (0.067) dex, respectively. These results show that the LASSO algorithm is not sensitive to the change of the resolution. In order to verify the robustness of LASSO algorithm against the change of SNRs, we use ELODIE to generate the spectral data sets with following SNRs: 30, 25, 20, 15 and 5. The results of LASSO algorithm on the above data sets are: -0.002 (0.076) dex, -0.090 (0.073) dex, 0.003 6 (0.075) dex, 0.007 6 (0.078) dex and -0.009 (0.080) dex, respectively. Thus, LASSO algorithm is not sensitive to the change of SNR. Therefore, the LASSO algorithm is suitable for low resolution and low SNR spectra such as LAMOST and SDSS spectra. The accuracy of Lasso algorithm on the SDSS spectra is 0.003 7 (0.097) dex, and the results of LASSO on globular and open clusters show good agreement with literature values (within 1σ). Therefore, the LASSO algorithm can be used to estimate the alpha element abundances of stars..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 278 (2017)
FBG Self-Chirped Based on an Sine-Structure
FENG Shu-qing, XIONG Ke, BIAN Kan, and LU Ji-yun
Considerting that the uniform grating can be induced chirp effect under non-uniform strain, a method of making chirp grating by uniform grating with the use of sine structure is proposed. The sine structure was designed as basal material while the fiber Bragg and grating was pasted in the strain non-uniform area of basConsiderting that the uniform grating can be induced chirp effect under non-uniform strain, a method of making chirp grating by uniform grating with the use of sine structure is proposed. The sine structure was designed as basal material while the fiber Bragg and grating was pasted in the strain non-uniform area of basal material. the strain it produced was introducied into FBG gate area by applying tensile load to achieve FBG produce chirp effect. FBG was made with multiple peaks and wide bandwidth of the chirp grating. The finite element software was used to simulate the strain of sine-structure under tensile loading to get strain contours of the sinusoidal structure in different positions; The experimental results showd that the bandwidth has been increased five times when the displacement load wasup to 8 mm and the chirp grating reflection spectrum with multiple peaks; Thetransfer matrix method to reflection spectrum of chirp grating was combined for spectrum simulation reconstruction and the simulation spectrum spectrum trend was consistent with the experimental results. The chirp grating made in this method has an important application in complex strain field multiple parameters and achieving sense of temperature without compensation by the use of the bandwidth of the chirp grating at the same time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 283 (2017)
Influence of Dimethyl Sulfoxide as Processing Additive for Improving Efficiency of Polymer Solar Cells
YANG Bing-yang, HE Da-wei, ZHUO Zu-liang, and WANG Yong-sheng
The effect of dimethyl sulfoxide (DMSO) doping concentration on the performance of polymer solar cells (PSCs) based on poly(3-hexylthiophene) (P3HT)∶(6,6)-phenyl C60 butyric acid methyl ester (PCBM) as the active layer was investigated. The results suggest that the doping of DMSO can improve short-circuit current densiThe effect of dimethyl sulfoxide (DMSO) doping concentration on the performance of polymer solar cells (PSCs) based on poly(3-hexylthiophene) (P3HT)∶(6,6)-phenyl C60 butyric acid methyl ester (PCBM) as the active layer was investigated. The results suggest that the doping of DMSO can improve short-circuit current density (Jsc) and fill factor (FF) of the PSCs. The cell with 3% DMSO exhibits enhanced Jsc (7.88 mA·cm-2), and FF (55.5%). The optimized power conversion efficiency (PCE) arrived to 2.54%, which is 17% higher than that of the cell without DMSO doping. The Fourier Transform infrared spectroscopy (FTIR) is used to demonstrate the effect of DMSO doping into P3HT∶PCBM on chemical properties. The presence of FTIR suggests that the chemical properties of P3HT and PCBM have no changes. To investigate the causes of the PCE improvement after addition of DMSO, an enhanced light harvesting and charge carriers transport properties of electroluminescence devices were observed by UV-Visible spectra and J-V characteristics. The absorption peaks of P3HT∶PCBM∶DMSO thin film show a distinguished red shift and strong absorption compared to P3HT∶PCBM thin films in the visible light range. It was considered that the increase of the Jsc was supported by this phenomenon of UV-Visible absorption. The charge carrier mobility change of the P3HT∶DMSO films is studied by employing the donor-only devices. The increased performance should be attributed to the enhanced charge carrier mobility and widened absorption spectra of P3HT∶PCBM through doping DMSO..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 287 (2017)
Investigation of N Deficiency in Cherry Trees Using Visible and Near-Infrared Spectra Part of the Spectrum in Field Condition
Levent Basayiit, Mert Dedeolu, Hüseyin Akgül, Kadir Ugun, and Mesut Altndal
This objective of the study was to develop a model for the determination of N deficiency in cherry trees using a combination of visible near infrared methods and spectro-radiometric measurement. In our experimental design, cherry seedlings were grown under various N deficiency conditions in nutrient-controlled containeThis objective of the study was to develop a model for the determination of N deficiency in cherry trees using a combination of visible near infrared methods and spectro-radiometric measurement. In our experimental design, cherry seedlings were grown under various N deficiency conditions in nutrient-controlled containers. The reflectance values of plant leaves were measured using a spectro-radiometer. Plant leaves samples were simultaneously collected. Their nutrient contents were determined in the laboratory. Afterwards, we performed a statistical comparison of the reflectance values. Sample analysis results established the significant wavelengths. Moreover, we received accurate regression models for predicting N deficiency in cherry leaves that were grown in nutrient solutions. Next, we verified the model validity by measuring the reflectance of the leaves collected from cherry orchards at various locations using a spectroradiometer. Nutrient deficiencies were calculated using the developed model, and then, the predicted and measured data were compared to evaluate model validity. From these results, we determined the wavelengths that yielded the most accurate results for N prediction, selected from the blue and green regions of the spectrum. We established that for N prediction in cherry trees, the simplest model can be created using 560 and 570 nm wavelengths. However, the evaluated model can be applicable only under certain conditions. We concluded that in order to develop a prediction method with sufficient application capacity, as well as the ability to assess nutritional and physiological characteristics, the ecology condition of the plant should be properly considered based on the model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 293 (2017)
Novel Variable Selection Method Based on Uninformative Variable Elimination and Ridge Extreme Learning Machine:CO Gas Concentration Retrieval Trial
CHEN Yuan-yuan, WANG Zhi-bin, and WANG Zhao-ba
Variable selection is an essential part in spectroscopy analysis area. To overcome the problems of traditional interval selection methods, this paper proposed a novel variable selection and assessment method based on uninformative variable elimination (UVE) and ridge extreme learning machine (RELM) algorithms. Firstly,Variable selection is an essential part in spectroscopy analysis area. To overcome the problems of traditional interval selection methods, this paper proposed a novel variable selection and assessment method based on uninformative variable elimination (UVE) and ridge extreme learning machine (RELM) algorithms. Firstly, the UVE method was adopted to eliminate the uninformative wavelengths. Secondly, to solve the collinearity problem, RELM algorithm was adopted to replace the traditional modeling methods (PLS, BP neural network, etc.). Finally, the optimal combination of wavelength regions was selected by using feature selection path (FSP) plot and sparsity-error trade-off (SET) curve. The experiment results of CO gas concentration retrieval showed that (1) the UVE algorithm can select the most informative variables, which were the feature wavelengths of the CO gas transmittance spectrum; (2) the RELM algorithm has the advantage of rapid modeling, solving the collinearity problem, and high accuracy (the determined coefficient r of CO gas concentration retrieval can reach 0.995); (3) the FSP plot and SET curve were easy understanding, also intuitive to experts to find the best combination of wavelengths and extract useful domain knowledge..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 299 (2017)
A Comparative Study on Hemp (Cannabis sativa) Essential Oil Extraction Using Traditional and Advanced Techniques
Saima naz, Muhammad Asif Hanif, Tariq Mahmood Ansari, and Jamal Nasar Al-Sabahi
A comparative study of Cannabis sativa (Hemp) essential constituents obtained by using Supercritical Fluid Extraction (SCFE), Steam Distillation (SD) and Hydrodistillation (HD) is presented here. The optimized extraction temperatures were 130, 110 and 50 ℃ for hydrodistillation, steam distillation and supercritical fluA comparative study of Cannabis sativa (Hemp) essential constituents obtained by using Supercritical Fluid Extraction (SCFE), Steam Distillation (SD) and Hydrodistillation (HD) is presented here. The optimized extraction temperatures were 130, 110 and 50 ℃ for hydrodistillation, steam distillation and supercritical fluid extraction respectively. The essential oil of C. sativa was analyzed by using Gas chromatography mass spectrometry (GC-MS). A total of 33, 30 and 31 components have been identified in HD, SD and SCFE respectively. Yield of essential oil using SCFE (0.039%) was more than HD (0.025%) and SD (0.035%) extraction respectively. The main component of sesquiterpenes obtained by hydrodistillation at 130 ℃ with their percentages included caryophyllene (40.58%), trans-α-bergamotene (5.41%), humulene (10.97%), cis-β-farnesene (8.53%) and monoterpenes included α-pinene (2.13%), d-limonene (6.46%), p-cymol (0.65%) and cineole (2.58%) respectively. The main component of sesquiterpenes obtained by SD steam distillation at 110 ℃ including caryophyllene (38.60%) trans-α-bergamotene (4.22%), humulene (10.26%), cis-β-farnesene (6.67%) and monoterpenes included α-pinene (3.21%), d-limonene (7.07%), p-cymol (2.59%) and cineole (3.88%) whereas the more percentages of major components were obtained by SCFE at 50 ℃ included caryophyllene (44.31%), trans-α-bergamotene (6.79%), humulene (11.97%) cis-β-farnesene (9.71%) and monoterpenes included α-pinene (0.45%), d-limonene (2.13%) p-cymol (0.19%) and cineole (1.38 %) respectively. We found yield/efficiency, chemical composition, quality of the essential oils by supercritical fluid extraction superior in terms of modern, green, saving energy and a rapid approach as compared to traditional techniques..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 306 (2017)
The Antioxidant Inhibition of Clove Effective Fraction on Lipid, Protein and Spectra Variation of LDL
YANG Qiong-yu, WAN Yan, JIANG Shen-hua, HAO Shu, ZENG Jun-jie, ZHANG Hua-hao, MA Hai-le, QU Wen-juan, and SHEN Yong-gen
Oxidation of low density lipoprotein (LDL) has been considered as the critical factor which led to atherosclerosis (AS). Lipid and protein in LDL were oxidized to cause change of spectra during oxidation. Clove has been demonstrated to possess the strongest antioxidant capacity among 87 both medical and edible plants pOxidation of low density lipoprotein (LDL) has been considered as the critical factor which led to atherosclerosis (AS). Lipid and protein in LDL were oxidized to cause change of spectra during oxidation. Clove has been demonstrated to possess the strongest antioxidant capacity among 87 both medical and edible plants proclaimed by China. However, whether LDL oxidation is inhibited by clove? If so, whether it inhibits the oxidation of lipid and protein in LDL, and how does spectral characteristic of LDL change during oxidation when clove was added into LDL. Currently, these questions are still unclear. Therefore, the inhibition efficiency of the effective fraction from clove (EFC) on oxidation of LDL was studied by UV-Visible spectra and fluorescence spectra. The results indicated that EFC might effectively delay propagation of conjugated diene (CD) during LDL oxidation and postpone reaching maximum of its content. Likewise, it might inhibit cholesterol degradation, tryptophan (Trp) fluorescence quenching, lysine (Lys) residues from being modified, and lipofuscins from being generated in peroxidatic reaction among lipid and protein.Besides, EFC also might affect variation of UV-Visible spectra of LDL during oxidation. This study provides reference for future research and development of clove functional food inhibiting AS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 312 (2017)
Spectroscopic Study on the Interaction of Human Cytoglobin with Copper(Ⅱ) Ion
LI Jing-hong, BIAN Lin, TIAN Su-yan, KONG Jin-ming, and LI Lian-zhi
Cytoglobin (Cygb), a recently discovered member of the vertebrate globin family, exhibits a traditional globin fold with a three-over-three α-helical sandwich. The interaction between copper(Ⅱ) ion (Cu2+) and Cygb has been investigated by UV-Vis, fluorescence, synchronous fluorescence and circular dichroism (CD) spectrCytoglobin (Cygb), a recently discovered member of the vertebrate globin family, exhibits a traditional globin fold with a three-over-three α-helical sandwich. The interaction between copper(Ⅱ) ion (Cu2+) and Cygb has been investigated by UV-Vis, fluorescence, synchronous fluorescence and circular dichroism (CD) spectra. Results showed that the absorption intensity of Cygb at 280 nm increased and the intrinsic fluorescence of Cygb was quenched when Cu2+ was added. This fluorescence quenching of Cygb has been proven that it belongs to static quenching. The synchronous fluorescence spectra indicated that there were small changes about the microenvironment of tryptophan residues and tyrosine residues; furthermore, the binding site of Cu2+ is closer to tryptophan residues than tyrosine residues. No obvious change was observed about the secondary structure of Cygb with the addition of Cu2+ from the CD spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 321 (2017)
Spectroscopic and Molecular Modeling Studies on Binding of Fleroxacin with Human Serum Albumin
DONG Cheng-yu, XU Jia, ZHOU Shan-shan, and LIU Ying
Fleroxacin (FLRX) is a new member of the class of fluoroquinolones, its effects on human serum albumin (HSA) and the mechanism of action are poorly understood, Especially, the secondary structural alterations of HSA induced by FLRX and the inner filter effect, which resulted in a spurious decrease in the observed fluorFleroxacin (FLRX) is a new member of the class of fluoroquinolones, its effects on human serum albumin (HSA) and the mechanism of action are poorly understood, Especially, the secondary structural alterations of HSA induced by FLRX and the inner filter effect, which resulted in a spurious decrease in the observed fluorescence intensity and affected the binding parameters calculated from it are not considered. In this paper, binding of FLRX to HSA has been studied using multi-spectroscopy and molecular modeling methods. Fluorescence spectra revealed that the observed fluorescence quenching of HSA by FLRX was due to a 1∶1 complex formation by a static quenching process with a constant of 105 L·mol-1. The thermodynamic parameters (ΔH and ΔS) were calculated to be -107.99 kJ·mol-1 and -240.99 J·mol-1·K-1 via the Van’t Hoff equation, which indicated that hydrogen bond and van der Waals force were the dominant intermolecular force. From the synchronous fluorescence, FT-IR and three dimensional fluorescence spectra, it was evident that the binding of FLRX to HSA induced a conformational change in the protein, and the alterations of secondary structure were quantitatively calculated by the evidence from FTIR spectra with reductions of α-helices of about 18.3%, decreases of β-sheet structures of about 9.6%, and increases of β-turn structures of about 18.0%. Site marker competitive experiments showed that phenylbutazone and FLRX shared a common binding site Ⅰ corresponding to the subdomain ⅡA of HSA. The binding details between FLRX and HSA were further confirmed by molecular docking studies, which revealed that FLRX was bound at subdomain ⅡA through multiple interactions, such as hydrogen bond, hydrophobic and van der Waals, etc. The accurate and full basic data in the work is beneficial to clarify the binding mechanism of FLRX with HSA and is helpful for understanding its effect on protein function during the blood transportation process..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 327 (2017)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 1, 1 (2017)
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