Journals >Spectroscopy and Spectral Analysis
Contents
2015
Volume: 35 Issue 6
59 Article(s)
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Research Article
The Research of Spectral Dimension Reduction Method Based on Human Visual Characteristics
HE Song-hua, CHEN Qiao, and DUAN Jiang
The traditional spectral dimension reduction methods are usually carried out by matching the reconstructed spectra to the original spectra mathematically, which will often result in reconstructed spectra of small spectral reconstruction errors but very poor colorimetric accuracy when compared with the original one. In The traditional spectral dimension reduction methods are usually carried out by matching the reconstructed spectra to the original spectra mathematically, which will often result in reconstructed spectra of small spectral reconstruction errors but very poor colorimetric accuracy when compared with the original one. In order to minimize both the spectral and colorimetric errors more efficiently, we proposed three spectral dimension reduction methods by introducing the characteristics of human vision. The first method is VPCA, in which we apply spectral luminous efficiency function to the original spectra before reduction; The Second method (LMSPCA) uses a matrix derived from LMS cone sensitivity to weight the original spectra before reduction, and the matrix can be form by two methods, in which the L, M, S cones response offset is calculated by in two different ways: one is computed as the absolute value of each corresponding wave length offset, and the other is calculated as the square of each corresponding wave length offset. The third method is LMSPCAs, which is based on the second method LMSPCA by further applying PCA to the residual spectra. The result shows that the VPCA method produces the poorest perfomance. The two cones response weighted matrixes of LMSPCA method have similar performances by presenting better colorimetric accuracy and low spectral accuracy, while LMSPCAs method which compensates for the spectral loss of LMSPCA method can produce higher spectral and colorimetric reconstruction accuracy and color stability under different light source, and satisfies the requirements of spectral color reproduction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1459 (2015)
Research of Identify Spatial Object Using Spectrum Analysis Technique
SONG Wei, FENG Shi-qi, SHI Jing, XU Rong, WANG Gong-chang, LI Bin-yu, LIU Yu, LI Shuang, CAO Rui, CAI Hong-xing, ZHANG Xi-he, and TAN Yong
The high precision scattering spectrum of spatial fragment with the minimum brightness of 4.2 and the resolution of 0.5 nm has been observed using spectrum detection technology on the ground. The obvious differences for different types of objects are obtained by the normalizing and discrete rate analysis of the spectraThe high precision scattering spectrum of spatial fragment with the minimum brightness of 4.2 and the resolution of 0.5 nm has been observed using spectrum detection technology on the ground. The obvious differences for different types of objects are obtained by the normalizing and discrete rate analysis of the spectral data. Each of normalized multi-frame scattering spectral line shape for rocket debris is identical. However, that is different for lapsed satellites. The discrete rate of the single frame spectrum of normalized space debris for rocket debris ranges from 0.978% to 3.067%, and the difference of oscillation and average value is small. The discrete rate for lapsed satellites ranges from 3.118 4% to 19.472 7%, and the difference of oscillation and average value relatively large. The reason is that the composition of rocket debris is single, while that of the lapsed satellites is complex. Therefore, the spectrum detection technology on the ground can be used to the classification of the spatial fragment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1464 (2015)
Simulation Study of Dynamic Color Modulation Based on Tunable Micro/Nano-Structure Array
SHI Bin, ZHAO Xiang-dong, ZHU Nian, HU Xiao-lin, SUN Li-bin, WANG Xulongqi, and ZHANG Dong-xian
With the development of nanotechnology, it has been accessible to display colors by artificial micro/nano-structure, and then the study of structure coloring has become a hot subject, opening a new space for inkless printing. In this paper, a dynamic color modulation method based on tunable micro/nano-structure array iWith the development of nanotechnology, it has been accessible to display colors by artificial micro/nano-structure, and then the study of structure coloring has become a hot subject, opening a new space for inkless printing. In this paper, a dynamic color modulation method based on tunable micro/nano-structure array is proposed. To tune colors on the same device, a periodic micro/nano-structure array is designed with functional material inside, which could alter the height difference between up and bottom surface precisely by applying an external voltage. It is modeled, and simulated by the Finite Difference Time Domain (FDTD) method in this work. In simulations, perpendicular incident linearly polarized light source is applied, and parameters of surface height difference and period are swept. Series reflective spectra of the devices are obtained, and their corresponding colors are calculated and marked on the CIE 1931 chromaticity diagram. Simulation results demonstrate that when the period is in the range of 100~300 nm, full-color modulation could be realized by varying the height of functional material film via applied voltage, and the peak intensities of reflective spectra are at about 60%, having high energy efficiency. This method is innovative and provides a theoretical basis for the dynamic color modulation micro/nano device, which is quite promising in fields like inkless printing and display technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1469 (2015)
Evolution Characteristics of Electromagnetic Power Radiated in Lightning Discharge Processes
ZHAO Jin-cui, YUAN Ping, CEN Jian-yong, LI Ya-jun, and WANG Jie
Combining the spectra of could-to-ground lightning discharge processes obtained by a slit-less spectrograph with synchronous electric field information, the temperature, the conductivity, the current peak, electromagnetic power peak and the luminance of the discharge channel are calculated. The values are in a normal rCombining the spectra of could-to-ground lightning discharge processes obtained by a slit-less spectrograph with synchronous electric field information, the temperature, the conductivity, the current peak, electromagnetic power peak and the luminance of the discharge channel are calculated. The values are in a normal range reported by references. The correlation among cut-off time before a subsequent return stroke, the luminance and electromagnetic power peak of the channel is discussed. The change trends of the conductivity, the current peak and electromagnetic power peak are also investigated. The results show when cut-off time is long, neutralized charges will grow, the current will rise and electromagnetic power radiated from the channel will increase. When the conductivity and the peak of the electric field change increase simultaneously, the current in the channel will rise and electromagnetic power radiated from the channel will be greater. This work will provide some rferences for calculating optical and electromagnetic energy radiated by lightning discharge processes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1474 (2015)
An Improved DDV Method to Retrieve AOT for HJ CCD Image in Typical Mountainous Areas
ZHAO Zhi-qiang, LI Ai-nong, BIAN Jin-hu, and HUANG Cheng-quan
Domestic HJ CCD imaging applications in environment and disaster monitoring and prediction has great potential. But, HJ CCD image lack of Mid-Nir band can not directly retrieve Aerosol Optical Thickness (AOT) by the traditional Dark Dense Vegetation (DDV) method, and the mountain AOT changes in space-time dramatically Domestic HJ CCD imaging applications in environment and disaster monitoring and prediction has great potential. But, HJ CCD image lack of Mid-Nir band can not directly retrieve Aerosol Optical Thickness (AOT) by the traditional Dark Dense Vegetation (DDV) method, and the mountain AOT changes in space-time dramatically affected by the mountain environment, which reduces the accuracy of atmospheric correction. Based on wide distribution of mountainous dark dense forest, the red band histogram threshold method was introduced to identify the mountainous DDV pixels. Subsequently, the AOT of DDV pixels were retrieved by lookup table constructed by 6S radiative transfer model with assumption of constant ratio between surface reflectance in red and blue bands, and then were interpolated to whole image. MODIS aerosol product and the retrieved AOT by the proposed algorithm had very good consistency in spatial distribution, and HJ CCD image was more suitable for the remote sensing monitoring of aerosol in mountain areas, which had higher spatial resolution. Their fitting curve of scatterplot was y=0.828 6x-0.01 and R2 was 0.984 3 respectively. Which indicate the improved DDV method can effectively retrieve AOT, and its precision can satisfy the atmospheric correction and terrain radiation correction for HJ CCD image in mountainous areas. The improvement of traditional DDV method can effectively solve the insufficient information problem of the HJ CCD image which have only visible light and near infrared band, when solving radiative transfer equation. Meanwhile, the improved method fully considered the influence of mountainous terrain environment. It lays a solid foundation for the HJ CCD image atmospheric correction in the mountainous areas, and offers the possibility for its automated processing. In addition, the red band histogram threshold method was better than NDVI method to identify mountain DDV pixels. And, the lookup table and ratio between surface reflectance between red and blue bands were the important influence factor for AOT retrieval. These will be the important research directions to further improve algorithm and improve the retrieve accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1479 (2015)
Monitoring Water in Lubricating Oil with Min-Infrared LED
YU Liang-wu, TIAN Hong-xiang, MING Ting-feng, and YANG Kun
A method that could be used to quantify the water concentration in ship machinery lubricating oil based on Mid-infrared LED is discussed. A Mid-infrared LED with peak emission wavelength of 2 840 nm and FWHM of 400 nm is used as the light source, the emitting light is partly absorbed by the oil sample, the remaining isA method that could be used to quantify the water concentration in ship machinery lubricating oil based on Mid-infrared LED is discussed. A Mid-infrared LED with peak emission wavelength of 2 840 nm and FWHM of 400 nm is used as the light source, the emitting light is partly absorbed by the oil sample, the remaining is received by the infrared detector. The percentage of water is determined according to the absorbance. In the experiment, a optical configuration including the transmission, absorbing and receiving of infrared light is designed, calcium fluoride wafer is used as the window, a hard metal coil with circular section is selected as the washer to get the fixed thickness of oil film accurately, a photoelectric diode with detection wavelength of 2 500～4 800 nm and response time of 10～20 ns is used as the detector of light intensity. Matching with this, a system of signal preamplifier, microcontroller-based data acquisition, storage and communication is developed. Absorbance data of six oil samples with different water mass concentration: 0, 0.062 5%, 0.125%, 0.25%, 0.375% and 0.5% is acquired through experiment. Fitting the data by the method of least squares, a linear equation in terms of absorbance and water concentration is obtained, and the determination coefficient is 0.996. Finally, in order to test the accuracy of this measurement method, using oil sample with water concentration of 0.317 5% to validate the equation, measuring the absorbance by the experimental device, the water content is calculated through the linear equation, the results show that the relative error is 2.7% between the percentage calculated and the real sample, indicating that this method can accurately measure the water concentration in the oil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1488 (2015)
Study on A White-Eye Pattern in Dielectric Barrier Discharge by Optical Emission Spectrum
ZHU Ping, DONG Li-fang, YANG Jing, ZHANG Yu, and ZHANG Chao
The white-eye pattern was firstly observed and investigated in a dielectric barrier discharge system in the mixture of argon and air whose content can be varied whenever necessary, and the study shows that the white-eye cell is an interleaving of three different hexagonal sub-structures: the center spot, the halo, and The white-eye pattern was firstly observed and investigated in a dielectric barrier discharge system in the mixture of argon and air whose content can be varied whenever necessary, and the study shows that the white-eye cell is an interleaving of three different hexagonal sub-structures: the center spot, the halo, and the ambient spots. The white-eye pattern is observed at a lower applied voltage. In this experiment, the heat capacity of water is high so that the water in water electrode is good at absorbing heat. In the process of pattern discharging the gas gap didn’t increase its temperature, and the discharging phenomenon of this pattern has not changed. The temperature of the water electrodes almost keeps unchanged during the whole experiment, which is advantageous for the long term stable measurement. Pictures recorded by ordinary camera with long exposure time in the same argon content condition show that the center spot, the halo, and the ambient spots og the white-eye pattern have different brightness, which may prove that their plasma states are different. And, it is worth noting that there are obvious differences of brightness not only on the center spot, the halo, and the ambient spots at the same pressure but also at the different pressure, which shows that its plasma state also changed with the variation of the pressure. Given this, in this experiment plasma temperatures of the central spot, halo, and ambient spots in a white-eye pattern at different gas pressure were studied by using optical emission spectra. The molecular vibration temperature is investigated by the emission spectra of nitrogen band of second positive system (C3Πu→B3Πg). The electron excitation temperature is researched by the relative intensity ratio method of spectral lines of ArⅠ763.51 nm (2P6→1S5) and ArⅠ772.42 nm (2P2→1S3). The electronic density is investigated by the broadening of spectral line 696.5 nm. Through the analysis of experimental results, it is found that the molecular vibration temperature, electron excitation temperature and electronic density of the central spot are lowest, and the plasma parameters of the ambient spots are second, while the plasma parameters of the halo are highest at the same condition. The molecular vibration temperature and the electron excitation temperature of the three different parts of the pattern (central spot, halo, and ambient spots) decrease with the pressure increasing from 40 to 60 kPa, but the electronic density increases. These results are of great important to the formation mechanism of the patterns in dielectric barrier discharge..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1493 (2015)
The Research of Oxygen Measurement by TDLAS Based on Levenberg-Marquardt Nonlinear Fitting
YAN Jie, ZHAI Chang, WANG Xiao-niu, and HUANG Wen-ping
Oxygen concentration is an important monitoring parameter in industrial process. Wavelength modulation spectroscopy of tunable diode laser absorption spectroscopy (TDLAS)was used to measure concentration of oxygen gas in industrial process by online monitoring. In this paper, we use the characteristic absorption peak oOxygen concentration is an important monitoring parameter in industrial process. Wavelength modulation spectroscopy of tunable diode laser absorption spectroscopy (TDLAS)was used to measure concentration of oxygen gas in industrial process by online monitoring. In this paper, we use the characteristic absorption peak of Oxygen at 760 nm to measure the oxygen concentration. Because of the strong coherence of laser, the detection sensitivity of TDLAS is severely restricted by optical interference noise. Especially at low concentrations, there is larger error by extraction signal in the absorption peak waveform because of the background fluctuation caused by optical interference. In response to this situation, Levenberg-Marquardt nonlinear fitting algorithm was proposed, and the use of the absorption line-derivative form of Lorenz line to fit the second harmonic signal and to extract the peak amplitude. On the other hand, Levenberg-Marquardt nonlinear fitting method needs a large amount of calculation. In order to develop the TDLAS analyzer can achieve real-time monitoring of the site, we use the C28 series of DSQ for data processing which support floating-point arithmetic, and the instrument achieve real-time monitoring capabilities in industrial process. Experimental results show that the algorithm can effectively extract the absorption peak characteristic value of the 2nd harmonic signal and overcome the background noise, The ratio of calculated by algorithm to actual oxygen concentration is nearly 1.01, the linear error of the concentration measurement is 1.18%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1497 (2015)
Radiation Parameters of Some Potential Bioactive Compounds
Zeynep Gedik, Mehtap Tugrak, Aysenur Dastan, Halise Inci Gul, and Demet YIlmaz
In this study, we aimed to determine the radiation parameters of some potential bioactive compounds. 1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heating method. Aryl part was changed as phenyl (C6H5), 4-methylphenyl (4-CH3C6H4), 4-fluorophenyl (4-FC6HIn this study, we aimed to determine the radiation parameters of some potential bioactive compounds. 1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heating method. Aryl part was changed as phenyl (C6H5), 4-methylphenyl (4-CH3C6H4), 4-fluorophenyl (4-FC6H4), 4-nitrophenyl (4-NO2C6H4), 4-chlorophenyl (4-ClC6H4), 4-bromophenyl (4-BrC6H4), and 2-thienyl (C4H3S-2-yl). Mass attenuation coefficient (μｍ), effective atomic number (Ｚｅｆｆ) and effective electron density (Ｎｅｌ) of compounds were determined experimentally and theoretically for at 8.040, 8.910, 13.40, 14.96, 17.48, 19.61, 22.16, 24.94, 32.19, 36.38, 44.48, 50.38 and 59.54 keV photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. Radiation parameters of these compounds which can be anti-cancer drug candidate were given in the tables. The results show that phenyl ring behave like thiophene ring in terms of radiation absorption. It is thought that the results of study may drive allow the development of drug candidate new compounds in medical oncology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1501 (2015)
Natural Bond Orbital (NBO) Population Analysis, First Order Hyperpolarizabilities and Thermodynamic Properties of Cyclohexanone
Rubarani P. Gangadharan, and S. Sampath Krishnan
The molecular structure of cyclohexanone was calculated by the B3LYP density functional model with 6-31G(d,p) and 6-311++G(d,p) basis set by Gaussian program. The results from natural bond orbital (NBO) analysis have been analyzed in terms of the hybridization of atoms and the electronic structure of the title moleculeThe molecular structure of cyclohexanone was calculated by the B3LYP density functional model with 6-31G(d,p) and 6-311++G(d,p) basis set by Gaussian program. The results from natural bond orbital (NBO) analysis have been analyzed in terms of the hybridization of atoms and the electronic structure of the title molecule.The electron density based local reactivity descriptors such as Fukui functions were calculated. The dipole moment (μ) and polarizability (α), anisotropy polarizability (Δα) and first order hyperpolarizability (βtot) of the molecule have been reported. Thermodynamic properties of the title compound were calculated at different temperatures..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1506 (2015)
Applications of On-Line Near Infrared Spectroscopy Monitoring Technology in Polymer Processing
CHEN Ru-huang, WANG Xiao-lin, LIN Xiao-kai, HU Xin, and JIN Gang
Due to the significant impact of processing on the performance of polymer products, it is crucial to develop in-line monitoring methods on processing. Based on the feedback data from in-line monitoring the processing parameters can be adjusted, which will contribute to the stability of production, thereby ensuring prodDue to the significant impact of processing on the performance of polymer products, it is crucial to develop in-line monitoring methods on processing. Based on the feedback data from in-line monitoring the processing parameters can be adjusted, which will contribute to the stability of production, thereby ensuring product quality, reducing energy waste and improving production efficiency. Near infrared spectroscopy (NIR), a low-cost, real-time and accurately quantitative analysis technology, has been widely used in many areas but still under study in polymer processing. The applications of in-line NIR monitoring technology in measuring the content of component, melt index, melt density and dispersion of filler of polymer during processing were reviewed. The existing problems about in-line NIR monitoring technology were pointed out, as well as the suggestions for the corresponding problems. The future trends of in-line NIR monitoring technology were discussed. With the development of fiber optic spectrometer, computer science and chemometrics, it is foreseen that the in-line NIR monitoring technology will make considerable progress in the stability of raw data, methods of pretreatment and modeling, the robustness and accuracy of model. Therefore, in-line NIR monitoring technology will be applied to more areas generating the great economic and environmental value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1512 (2015)
Study on the Technology of the 4.4 μm Mid-Infrared Laser Heterodyne Spectrum
TAN Tu, CAO Zhen-song, WANG Gui-shi, WANG Lei, LIU Kun, HUANG Yin-bo, CHEN Wei-dong, and GAO Xiao-ming
In this paper, first time as our knowledge, we describe the development and performance evaluation of a 4.4 μm external cavity quantum cascade laser based laser heterodyne radiometer. Laser heterodyne spectroscopy is a high sensitive laser spectroscopy technique which offers the potential to develop a compact ground orIn this paper, first time as our knowledge, we describe the development and performance evaluation of a 4.4 μm external cavity quantum cascade laser based laser heterodyne radiometer. Laser heterodyne spectroscopy is a high sensitive laser spectroscopy technique which offers the potential to develop a compact ground or satellite based radiometer for Earth observation and astronomy. An external cavity quantum cascade laser operating at 4.4 μm, with output power up to 180 mW and narrow line width was used as a local oscillation. The external cavity quantum cascade laser offers wide spectral tuning range, it is tunable from 4.38 to 4.52 μm with model hop free and can be used for simultaneous detections of CO2, CO and N2O. A blackbody was used as a signal radiation source. Development and fundamental theory of Laser heterodyne spectroscopy was described. The performance of the developed Laser heterodyne radiometer was evaluated by measuring of CO2 spectral at different pressures. Analyses results showed that a signal-to-noise ratio of 86 was achieved which was less than the theoretical value of 287. The spectral resolution of the developed Laser heterodyne spectroscopy is about 0.007 8 cm-1 which could meet the requirement of high resolution spectroscopy measurement in the case of Doppler linewidth. The experiment showed that middle Infrared laser heterodyne spectroscopy system had high signal-to-noise ratio and spectral resolution, and had broad application prospect in high precision measurement of atmospheric greenhouse gas concentration and vertical profile..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1516 (2015)
Attenuated Total Reflection Infrared Spectroscopy for Degradation Profile of High Density Polyethylene after Weathering Aging
GUO Jun-jun, YAN Hua, BAO He-bin, WANG Xue-mei, HU Zhi-de, and YANG Jian-jian
High density polyethylene (HDPE) was widely used as rotational packaging case in the material reserve field. The chemical changes of HDPE, exposed to particular climatic conditions of tropic marine atmosphere for one year-long in Wanning Hainan, were elucidated by the attenuated total reflection infrared spectroscopy (High density polyethylene (HDPE) was widely used as rotational packaging case in the material reserve field. The chemical changes of HDPE, exposed to particular climatic conditions of tropic marine atmosphere for one year-long in Wanning Hainan, were elucidated by the attenuated total reflection infrared spectroscopy (ATR-FTIR). The structural changes were studied qualitatively, mainly from the polymeric chain breaking, branching and oxidation to distinguish the degradation profile. The variations of crystallinity & carbonyl index were also studied quantitatively according to the characteristic peaks intensity & area ratio. Finally, the relationships between structural changes and mechanical properties were investigated. The results showed that the polymeric chain breaking & branching play a leading role before 3 months in the aging progress. Then oxidation phenomena gradually takes place during 3~6 months. The chain branching & oxidation were predominant factors after 6 months. Nine months later, the oxidation was saturated gradually. Furthermore, the aging process is positively correlated to the temperature and irradiation. After 12 months aging, the carbonyl index increased by 112 times and crystallinity was 10% higher than before. The tensile/bending modulus deceased faster than tensile/bending strength of HDPE. The linear degree of tensile modulus and carbonyl index was 0.97. The degree of linearity of tensile strength and crystallinity calculated by feature bands (720~730 cm-1) was 0.96. It showed that the mechanical properties of HDPE can be speculated from the structural changes by ATR-FTIR..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1520 (2015)
The Study of Infrared Spectra of Acetophenone Molecule
Li Xiaoming, Zhang Laibin, Zhou Liuzhu, and Kong Xianghe
By implying the density functional theory method, the geometry of acetophenone molecular is fully optimized at the B3LYP/6-311++G(d,p) level and the frequency is also calculated at the same level. The infrared spectrum and complete vibrational modes of acetophenone molecular are attained. Meanwhile, the infrared spectrBy implying the density functional theory method, the geometry of acetophenone molecular is fully optimized at the B3LYP/6-311++G(d,p) level and the frequency is also calculated at the same level. The infrared spectrum and complete vibrational modes of acetophenone molecular are attained. Meanwhile, the infrared spectrum is obtained by experimental measurements. Through the comparison and analysis, it is found that the theoretical calculation results meet well with those of experiments. Finally, the vibrational modes of acetophenone molecule are assigned, and the strong vibration peaks in the experiment results belong to infrared characteristic peaks of acetophenone molecule..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1525 (2015)
Research on Analysis of Oil in Water Based on the Joint Optimization of Savitzky-Golay Smoothing and IBPLS Models
HOU Pei-guo, LI Ning, CHANG Jiang, WANG Shu-tao, and SONG Tao
Rapidly and accurately detection of the type and content of mineral oil in water pollution has important significance for the timely screening and control of pollution sources. The use of infrared spectral analysisi technology to detect mineral oil has advantanges of efficient, fast and pollution-free. Infrared spectruRapidly and accurately detection of the type and content of mineral oil in water pollution has important significance for the timely screening and control of pollution sources. The use of infrared spectral analysisi technology to detect mineral oil has advantanges of efficient, fast and pollution-free. Infrared spectrum technology is very for the detection of mineral oil in the water. In order to obtain a more reliable results, Fourier transforms attenuated total reflection infrared spectrometry (FITR-ATR) technology is used to get the spectral information of the mineral oil sample, and SPXY method is used to divide the sample set. The paper not only analyzed partial least squares (PLS) and iterative Bagging partial least squares (IBPLS) the two different methods to build regression model, also compared the difference of using the method of the combination of Savitzky-Golay (SG) smoothing and the method of a single iterative Bagging partial least squares (IBPLS) regression model. Based on the comparison of the predictive regression curve, we can get that the SG smooth has a better reflection on the results. And when the method of the combination of Savitzky-Golay (SG) smoothing and the method of a single iterative Bagging partial least squares (IBPLS) is used to build the regression model, the gasoline model parameters RMSEP is 0.001 125 g·mL-1, R is 0.992 5; diesel model parameters RMSEP is 0.001 384 g·mL-1, R is 0.989 3..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1529 (2015)
Study on the Micro-FTIR Spectra of the Euhedral Faceted Polycrystalline Diamonds (EFPCDs) from Western Yangtze Craton and Its Geological Significance
HU Piao-ye, ZENG Liang-liang, YANG Zhi-jun, FU Hai-fu, LIU Si-wei, SHEN Wen-jie, and PENG Zhuo-lun
The results of Micro-FTIR spectra analysis of the euhedral faceted polycrystalline diamonds(EFPCDs) from the Western Yangtze Craton show that the EFPCDs are mostly IaAB type, the concentration of nitrogen varies greatly from 25.70～358.35 μg·g-1. Different nitrogen content distributes in different diamond grains orThe results of Micro-FTIR spectra analysis of the euhedral faceted polycrystalline diamonds(EFPCDs) from the Western Yangtze Craton show that the EFPCDs are mostly IaAB type, the concentration of nitrogen varies greatly from 25.70～358.35 μg·g-1. Different nitrogen content distributes in different diamond grains or position in same sample. The C Center was not found in the samples and the conversion from A center to B center is incomplete, in the meanwhile, B% value concentrated in 40%. Thus, polycrystalline diamonds are not formed in the stage of nucleation but gathered together after formation of the individual diamond grains during the residence time in the mantle. And its formation environment is more complex than the euhedral faceted polycrystalline diamonds from Mengyin kimberlite, the Eastern of North China Craton. The diamonds extremely possibly originated in the deep mantle from 160 to 180 km, reaching the depth of the core of the Yangtze Craton, at the same time it is close to the bottom of the lithosphere. The C—H bond of sp2 hybridization are conducive to the formation of platelets in diamonds. Meanwhile, its concentrations are generally higher than the C—H bond of sp3 hybridization in the samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1534 (2015)
Qualitative-Quantitative Analysis of Rice Bran Oil Adulteration Based on Laser Near Infrared Spectroscopy
TU Bin, SONG Zhi-qiang, ZHENG Xiao, ZENG Lu-lu, YIN Cheng, HE Dong-ping, and QI Pei-shi
The purpose of this study is mainly to have qualitative-quantitative analysis on the adulteration in rice bran oil by near-infrared spectroscopy analytical technology combined with chemo metrics methods. The author configured 189 adulterated oil samples according to the different mass ratios by selecting rice bran oil The purpose of this study is mainly to have qualitative-quantitative analysis on the adulteration in rice bran oil by near-infrared spectroscopy analytical technology combined with chemo metrics methods. The author configured 189 adulterated oil samples according to the different mass ratios by selecting rice bran oil as base oil and choosing soybean oil, corn oil, colza oil, and waste oil of catering industry as adulterated oil. Then, the spectral data of samples was collected by using near-infrared spectrometer, and it was pre-processed through the following methods, including without processing, Multiplicative Scatter Correction(MSC), Orthogonal Signal Correction(OSC), Standard Normal Variate and Standard Normal Variate transformation De-Trending(SNV_DT). Furthermore, this article extracted characteristic wavelengths of the spectral datum from the pre-processed date by Successive Projections Algorithm(SPA), established qualitatively classified calibration methods of adulterated oil through classification method of Support Vector Machine(SVM), optimized model parameters(C, g) by Mesh Search Algorithm and determined the optimal process condition. In extracting characteristic wavelengths of the spectral datum from pretreatment by Backward interval Partial Least Squares(BiPLS) and SPA, quantitatively classified calibration models of adulterated oil through Partial Least Squares(PLS) and Support Vector Machine Regression(SVR) was established respectively. In the end, the author optimized the combination of model parameters(C, g) by Mesh Search Algorithm and determined the optimal parameter model. According to the analysis, the accuracy of prediction set and calibration set for SVC model reached 95% and 100% respectively. Compared with the prediction of the adulteration oil content of rice bran oil which was established by the PLS model, the SVR model is the better one, although both of them could implement the content prediction. Furthermore, the correlation coefficient R is above 0.99 and the Root Mean Square Error (MSE) is below 5.55×10-4. The results show that the near-infrared spectroscopy technology is effective in qualitative-quantitative analysis on the adulteration of rice bran oil. And the method is applicable to analyze adulteration in other oils..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1539 (2015)
Quantification of Wood Flour and Polypropylene in Chinese Fir/Polypropylene Composites by FTIR
LAO Wan-li, LI Gai-yun, ZHOU Qun, and QIN Te-fu
The ratio of wood and plastic in Wood Plastic Composites (WPCss) influences quality and price, but traditional thermochemical methods cannot rapidly and accurately quantify the ratio of wood/PP in WPCss. This paper was addressed to investigate the feasibility of quantifying the wood flour content and plastic content inThe ratio of wood and plastic in Wood Plastic Composites (WPCss) influences quality and price, but traditional thermochemical methods cannot rapidly and accurately quantify the ratio of wood/PP in WPCss. This paper was addressed to investigate the feasibility of quantifying the wood flour content and plastic content in WPCss by Fourier Transform Infrared (FTIR) spectroscopy. With Chinese fir, polypropylene (PP) and other additives as raw materials, 13 WPCs samples with different wood flour contents, ranging from 9.8% to 61.5%, were prepared by modifying wood flour, mixing materials and extrusion pelletizing. The samples were analyzed by FTIR with the KBr pellets technique. The absorption peaks of WPCss at 1059, 1 033 and 1 740 cm-1 are considered as characteristic of Chinese fir, and the absorption peaks at 1 377, 2 839 and 841 cm-1 are typical of PP by comparing the spectra of WPCss with that of Chinese fir, PP and other additives. The relationship between the wood flour content, PP content in WPCss and their characteristic IR peaks height ratio was established. The results show that there is a strong linear correlation between the wood flour content in WPCss and I1 059/I1 377, I1 033/I1 377, R2 are 0.992 and 0.993 respectively; there is a high linear correlation between the PP content in WPCss and I1 377/I1 740, I2 839/I1 740 R2 are 0.985 and 0.981, respectively. Quantitative methods of the wood flour content and PP content in WPCss by FTIR were developed, the predictive equations of the wood flour content in WPCss are y=53.297x-9.107 and y=55.922x-10.238, the predictive equations of the PP content in WPCss are y=6.828 5x+5.403 6 and y=8.719 7x+3.295 8. The results of the accuracy test and precision test show that the method has strong repeatability and high accuracy. The average prediction relative deviations of the wood flour content and PP content in WPCss are about 5%. The prediction accuracy has been improved remarkably, compared to thermochemical methods. More importantly, FTIR is more easy-handing. This experiment may provide a simple, rapid and accurate method for quantification of wood flour and PP in Chinese fir/PP composites..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1546 (2015)
Traceability of Wine Varieties Using Near Infrared Spectroscopy Combined with Cyclic Voltammetry
LI Meng-hua, LI Jing-ming, LI Jun-hui, ZHANG Lu-da, and ZHAO Long-lian
To achieve the traceability of wine varieties, a method was proposed to fuse Near-infrared (NIR) spectra and cyclic voltammograms (CV) which contain different information using D-S evidence theory. NIR spectra and CV curves of three different varieties of wines (cabernet sauvignon, merlot, cabernet gernischt) which comTo achieve the traceability of wine varieties, a method was proposed to fuse Near-infrared (NIR) spectra and cyclic voltammograms (CV) which contain different information using D-S evidence theory. NIR spectra and CV curves of three different varieties of wines (cabernet sauvignon, merlot, cabernet gernischt) which come from seven different geographical origins were collected separately. The discriminant models were built using PLS-DA method. Based on this, D-S evidence theory was then applied to achieve the integration of the two kinds of discrimination results. After integrated by D-S evidence theory, the accuracy rate of cross-validation is 95.69% and validation set is 94.12% for wine variety identification. When only considering the wine that come from Yantai, the accuracy rate of cross-validation is 99.46% and validation set is 100%. All the traceability models after fusion achieved better results on classification than individual method. These results suggest that the proposed method combining electrochemical information with spectral information using the D-S evidence combination formula is benefit to the improvement of model discrimination effect, and is a promising tool for discriminating different kinds of wines..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1551 (2015)
The SERS Detection of SudanⅠby Using AAO as Template to Prepare the Substrate
PAN Xiao-hui, ZHANG Qin, GUO Wei, and CHEN Fa-he
The large-scale controllable, ordered two-dimensional arrays of gold nanostructure with hot-spot were prepared together with chemical molecules were modified on the surface to concentrate SudanⅠwithin the zone of the SERS effect, which lead to analytical detection of SudanⅠin high resolution. The vapor of gold was depoThe large-scale controllable, ordered two-dimensional arrays of gold nanostructure with hot-spot were prepared together with chemical molecules were modified on the surface to concentrate SudanⅠwithin the zone of the SERS effect, which lead to analytical detection of SudanⅠin high resolution. The vapor of gold was deposed on anodic aluminum oxide(AAO)template by ～200 nm thickness to replicate its nanochannels, and the negative structure i.e. large-scale ordered gold nano-hemisphere array, was obtained after the removal of the template of AAO by NaOH solution. Au nano-hemisphere array was modified by 1-Dodecanethiol which can be self-assembled monolayer on the surface and concentrate SudanⅠwithin the zone of the SERS detection, which can facilitate the measurement of SudanⅠ. Due to the order and regularity of Au nano-hemisphere array, the signal of SudanⅠin the range of laser illumination is stable and uniform, and the quantitative analysis of SudanⅠwas realized. The SERS intensity of SudanⅠis logistic proportional to the concentration in the range of 10-7 to 5×10-4mol·L-1. The corresponding correlation coefficient of the liner equation is 0.99, the recoveries of SudanⅠare between 77%～117%. The limit of detection for SudanⅠis 4×10-8mol·L-1, comparable to that of HPLC of Chinese national standard method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1556 (2015)
DFT and Raman Scattering Studies of Benzimidazole
WANG Xiao-bin, WU Rui-mei, LIU Mu-hua, ZHANG Lu-ling, and LIN Lei
The Raman spectra of carbendazim, thiabendazole and benomyl were collected by laser Raman spectrometer. The molecules of the three pesticides were optimized and calculated by B3LYP hybrid functional and 6-31G(d,p) basis set. The results showed that the calculated value anastomosed preferably to measure value. VibrationThe Raman spectra of carbendazim, thiabendazole and benomyl were collected by laser Raman spectrometer. The molecules of the three pesticides were optimized and calculated by B3LYP hybrid functional and 6-31G(d,p) basis set. The results showed that the calculated value anastomosed preferably to measure value. Vibrational modes of pesticide molecules were assigned between 200 and 1 600 cm-1range, and found three characteristic peaks of benzimidazole about at 1 015, 1 265 and 1 595 cm-1. The comparative analysis on the differences of normal Raman spectra, found different characteristic peaks in three pesticide molecules. The results can provide theoretical for analysis Raman spectra of benzimidazole pesticide. This work will promote the research of benzimidazole pesticide residue in food and agricultural products based on Raman spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1562 (2015)
SERS Enhancement Factor Analysis and Experiment of Carbon Nanotube Arrays Coated by Ag Nanoparticles
ZHANG Xiao-lei, ZHANG Jie, REN Wen-jie, LAI Chun-hong, and ZHOU Hai-jun
To intuitive and accurate quantitatively analyze Raman enhancement of surface enhanced Raman scattering substrate structure, three-dimensional composite structure of silver nanoparticles modified vertically aligned carbon nanotube array is produced by magnetron sputtering and thermal annealing process; Relevant experimTo intuitive and accurate quantitatively analyze Raman enhancement of surface enhanced Raman scattering substrate structure, three-dimensional composite structure of silver nanoparticles modified vertically aligned carbon nanotube array is produced by magnetron sputtering and thermal annealing process; Relevant experiments using Rhodamine 6G (R6G) solution as the molecular probes are conducted to analyze surface enhanced Raman enhancement factor (EF), combining with confocal Raman microscopy systems. The result of scanning electron microscopy (SEM) shows that a large number of silver nanoparticles are attached onto the tips and sidewalls of the ordered carbon nanotubes array uniformly. EF of the sample which was produced 30 min annealing time and 450 ℃ annealing temperature evaluates to 2.2×103, and the reasons for the low EF are analyzed: on the one hand, thickness of silver film sputtered on vertically aligned carbon nanotube array is non-uniform, leading to distribution of silver nanoparticles is uneven after annealing, so that the value of sample roughness is too large, EF value is low; on the other hand, the excitation light source is not the advantage wavelength of silver nanoparticles in the experiments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1567 (2015)
Quantitative Analysis of Dimethoate Pesticide Residues in Honey by Surface-Enhanced Raman Spectroscopy
SUN Xu-dong, and DONG Xiao-ling
The feasibility of a combination method of surface-enhanced Raman spectroscopy (SERS) technology and linear regression algorithm was investigated for rapid quantitative analysis of pesticide residues in honey. The total of 30 samples was applied in the experiment with dimethoate pesticide residues range from 1 ppm to 1The feasibility of a combination method of surface-enhanced Raman spectroscopy (SERS) technology and linear regression algorithm was investigated for rapid quantitative analysis of pesticide residues in honey. The total of 30 samples was applied in the experiment with dimethoate pesticide residues range from 1 ppm to 10 ppm. The samples were divided into calibration set (20) and prediction set (10). The substrate of Klarite with an inverted pyramidal structure was adopted for improvement of the relative intensity of the majority of Raman shift peaks. The comparative analysis was carried out between SERS spectra of dimethoate pesticide residues in honey samples and conventional Raman spectra of dimethoate standard sample. And four characteristic Raman shift peaks at the wavenumbers of 867, 1 065, 1 317 and 1 453 cm-1 were found, which were related with the vibrational information of dimethoate molecule. The relationship was developed by linear regression algorithm between the intensity of Raman shift and the concentration of dimethoate pesticide residues. The 10 new samples in the prediction set were applied to evaluate the performance of the models. By comparison, the optimal model was obtained with the characteristic Raman shift peak of 867 cm-1. The higher correlation coefficient of prediction of 0.984 and lower root mean square error of prediction of 0.663 ppm were obtained. The detection limit of this method was 2 ppm, which was close to the maximum levels of pesticide residue detection limits. Experimental results showed that it was feasible to rapidly analyze quantitative of pesticide residues in honey with the combination method of SERS technology and linear regression algorithm. Compared with the conventional method coupled with the suitable pretreatment, the combination method of SERS technology and linear regression method could analyze the dimethoate pesticide residues in honey, and it also provided an optional method for rapid quantitative analysis pesticide residues in other agricultural products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1572 (2015)
Determination of Gasoline Composition Based on Raman Spectroscopy
ZHANG Bing, DENG Zhi-yin, ZHENG Jing-kui, and WANG Xiao-ping
For the purpose of the rapid prediction of every composition in gasoline, the Raman spectra of the gasoline brand 93 and 97, a batch of one-one mixtures with aromatic, olefin, ben, methanol and ethanol with different ratios are measured, 410 mixture samples were measured totally in this research. The obtained Raman speFor the purpose of the rapid prediction of every composition in gasoline, the Raman spectra of the gasoline brand 93 and 97, a batch of one-one mixtures with aromatic, olefin, ben, methanol and ethanol with different ratios are measured, 410 mixture samples were measured totally in this research. The obtained Raman spectra were preprocessed by a series of processing, they were data smoothing, baseline deduction and spectral normalized, etc. After that 33 characteristic peaks were extracted to be the eigenvalues for the whole Raman spectra. According to the current national standard test method, the values of every composition were measured by the gas chromatography. By using the eigenvalues as inputs, and actual contents of aromatic, olefin, ben, methanol and ethanol got from gas chromatography as outputs, two mathematical models of multi-output least squares support vector regression and partial least squares combination with multiple regression analysis were established to predict the values of the above compositions of a sample, respectively. The predicting results were compared with the values calculated from the gas chromatography measurement results and the mixture proportions, the multi-output least squares support vector regression has a better effects, and the obtained root mean square error of prediction for aromatic, olefin, ben, methanol and ethanol are 0.27%, 0.27%, 0.22%, 0.17%, 0.14%; the correlation coefficients are 0.999 3, 0.998 5, 0.998 6, 0.992 3, 0.993 5, respectively. This model is also applied to the detection of the unknown sample, the root mean square error of the prediction for the results does not exceed 0.5%, which can achieve the measurement requirements in the industry. Results show that the Raman spectra analysis technology based on multi-output least squares support vector regression can be a precise, fast and convenient new method for gasoline composition detection, and can be applied to the quality control of the gasoline production process, transportation, storage of the gasoline..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1577 (2015)
Characterization of Time-Resolved Laser-Induced Fluorescence from Crude Oil Samples
LIU De-qing, LUAN Xiao-ning, HAN Xiao-shuang, GUO Jin-jia, AN Ju-bai, and ZHENG Rong-er
To evaluate the feasibility of laser induced time-resolved fluorescence technique for in-situ detection of underwater suspended oil spill, extensive investigations have been carried out with different densities of crude oil samples from six different wells of Shengli Oilfield in this work. It was found that the fluoresTo evaluate the feasibility of laser induced time-resolved fluorescence technique for in-situ detection of underwater suspended oil spill, extensive investigations have been carried out with different densities of crude oil samples from six different wells of Shengli Oilfield in this work. It was found that the fluorescence emission durations of these crude oil samples were almost the same, the Gate Pulse Delay of DDG (Digital Delay Generator) in the ICCD started at 52ns and ended at 82ns with a width (FWHM) of 10 ns. It appears that the peak location and lifetime of fluorescence for different crude oil samples varied with their densities, and those with similar densities shared a similar lifespan with the closer peak locations of fluorescence. It is also observed that the peak of fluorescence remained the same location before reaching the maximum intensity, subsequently shift to longer wavelength as fluorescence attenuated from maximum intensity with a red shift among 17～30 nm varied with samples. This demonstrated that the decay rate of fluorescent components in the crude oils was different, and energy transfer between these components might exist. It is hoped that those obtained results and characteristics could be the useful information for identification of suspended spilled-oil underwater..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1582 (2015)
Spectral Analysis of Dissolved Organic Matter of Tannery Wastewater in the Treatment Process
FAN Chun-hui, ZHANG Ying-chao, DU Bo, SONG Juan, HUAI Cui-qian, and WANG Jia-hong
Tannery industry is one of the major traditional industries and important wastewater sources in China. The existing research mainly focus on the quality of inlet and outlet water, rather than the purification and transformation behavior of dissolved organic matter (DOM) in the treatment process of tannery wastewater. TTannery industry is one of the major traditional industries and important wastewater sources in China. The existing research mainly focus on the quality of inlet and outlet water, rather than the purification and transformation behavior of dissolved organic matter (DOM) in the treatment process of tannery wastewater. The UV spectra and fluorescence spectroscopy were used to detect the spectral characteristics of water samples in the treatment process, and it is analyzed that the formation process and the linear relationships between total fluorescence intensity and parameters. The results showed: the UV absorbance of DOM in wastewater increased firstly and then decreased with longer wavelength, and the wave peaks were found around the wavelength of 230 nm. The values of A253/A203 and SUVA254 increased firstly and then decreased, indicating the complex reaction process related to free substituent and aromatic rings. The fluorescence peaks appeared at the regions of λex/em=320～350/440～460 and λex/em=270～300/390～420, referred as visible humic-like and visible fulvic-like fluorescence, respectively. With the treatment process of tannery wastewater, the following fluorescence phenomenon were monitored, such as the blue-shift of humic-like fluorescence peak in the hydrolytic acidification tank, the appearance of tryptophan fluorescence peak in the second biochemical pond (λex/em=290/340), the weak fluorescence peak in the fourth biochemical pond (λex/em=350/520) and the stabilized fluorescence characteristics in the secondary sedimentation tank and water outlet. The achievements are helpful to investigate the degradation and formation behavior of water components, and significant for the fluorescence variation analysis in the treatment system. The removal rate of total fluorescence intensity of tannery wastewater fit better the removal rate of TOC with coefficient of r 0.835 5. The UV spectra and 3D-EEMs are effective to reveal the purification behavior and mechanism of tannery wastewater..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1587 (2015)
Laser Induced Fluorescence Spectroscopic Analysis of Aromatics from One Ring to Four Rings
ZHANG Peng, LIU Hai-feng, YUE Zong-yu, CHEN Bei-ling, and YAO Ming-fa
In order to distinguish small aromatics preferably, a Nd∶YAG Laser was used to supply an excitation laser, which was adjusted to 0.085 J·cm-2 at 266 nm. Benzene, toluene, naphthalene, phenanthrene, anthracene, pyrene and chrysene were used as the representative of different rings aromatics. The fluorescence emissiIn order to distinguish small aromatics preferably, a Nd∶YAG Laser was used to supply an excitation laser, which was adjusted to 0.085 J·cm-2 at 266 nm. Benzene, toluene, naphthalene, phenanthrene, anthracene, pyrene and chrysene were used as the representative of different rings aromatics. The fluorescence emission spectra were researched for each aromatic hydrocarbon and mixtures by Laser induced fluorescence (LIF). Results showed that the rings number determined the fluorescence emission spectra, and the structure with same rings number did not affect the emission fluorescence spectrum ranges. This was due to the fact that the absorption efficiency difference at 266 nm resulted in that the fluorescence intensities of each aromatic hydrocarbon with same rings number were different and the fluorescence intensities difference were more apparently with aromatic ring number increasing. When the absorption efficiency was similar at 266 nm and the concentrations of each aromatic hydrocarbon were same, the fluorescence intensities were increased with aromatic ring number increasing. With aromatic ring number increasing, the fluorescence spectrum and emission peak wavelength were all red-shifted from ultraviolet to visible and the fluorescence spectrum range was also wider as the absorption efficiency was similar. The fluorescence emission spectra from one to four rings could be discriminated in the following wavelengths, 275 to 320 nm, 320 to 375 nm, 375 to 425 nm, 425 to 556 nm, respectively. It can be used for distinguish the type of the polycyclic aromatic hydrocarbons (PAHs) as it exists in single type. As PAHs are usually exist in a variety of different rings number at the same time, the results for each aromatic hydrocarbon may not apply to the aromatic hydrocarbon mixtures. For the aromatic hydrocarbon mixtures, results showed that the one- or two-ring PAHs in mixtures could not be detected by fluorescence as three- or four-ring PAHs existed in mixture. This was caused by radiation energy transfer mechanism, in which the ultraviolet light was lost in mixtures but the fluorescence intensities were increased with the one- or two-ring PAHs adding. When the mixture only contained three- and four-ring PAHs, the fluorescence emission spectrum showed the both characteristics of three- and four-ring PAHs fluorescence. When three- and four-ring PAHs existed in mixtures at the same time, the fluorescence emission spectra were related to each concentration, so the rings number could be discriminated to a certain extent..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1592 (2015)
New Bipyridinium Salt: Synthesis and Application as a Fluorescence Enhancement Probe of Nitrate Ion
ZOU Shun-ying, SUN Wen-hao*, and GONG Wei-tao
Anions are ubiquitously distributed not only in biological systems but also in environment. Accordingly, anion recognition and sensing have attracted increasing attention due to the important roles anion plays in biological, chemical and environmental fields.Among various anionic species, NO-3 is a very important inorgAnions are ubiquitously distributed not only in biological systems but also in environment. Accordingly, anion recognition and sensing have attracted increasing attention due to the important roles anion plays in biological, chemical and environmental fields.Among various anionic species, NO-3 is a very important inorganic anions which has a great harm to the environment and human health. At present, methods for the determination of NO-3 mainly contained electrochemical method, ion chromatography and ion selective electrode method. Although all methods have their own advantages, but also has the obvious deficiency. Such as, the reproducibility of electrochemical method is not good, and ion chromatography and ion selective electrode method usually require expensive apparatus and lengthy analytical time. As a contrast, fluorescence spectroscopy become a hot research topic in anion recognition and detection because of its high sensitivity and easy operation and other advantages in recent years. New bipyridinium salt L was designed and synthesized using pyrylium as a starting material. The molecular structure was determined by 1H NMR, 13C NMR, and high resolution mass spectrometry. The molecular recognition properties of L have been investigated through fluorescence titration experiments. The results indicate that L has sensitive and selective fluorescent response to NO-3 among other different anions. Significant enhancements in the fluorescence intensity of L were observed when various concentrations of NO-3 were added, while other competing anions have a quenching effect towards the initial fluorescence of solution. The fluorescence titration spectra shows that the bonding stoichiometry between receptor L and NO-3 is 1∶1 as a supramolecular complexes (lgK=5±0.02). The chemosensing properties of L were evaluated through quantum chemical calculations and the variable temperature 1H NMR titration. These results suggested that L has strong binding affinity towards NO-3 with high selectivity, which may be ascribed to the specific hydrogen bonding between the L and active H atom of the bipyrydinium salts. The interaction between L and NO-3 made the complex more planar compared with L giving rise to enhanced fluorescence and specific selectivity towards NO-3..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1597 (2015)
Synthesis of YVO4∶Eu Fluorescent Nanomaterials and Their Applications in Development of Latent Fingerprints
WANG Meng
YVO4∶Eu fluorescent nanomaterials with small size and strong fluorescent intensity were synthesized via a hydrothermal method by using polyethylenimine (PEI) as the modifier, and the reaction mechanism of this synthesis was also discussed. The as-synthesized nanomaterials were characterized through transmission electroYVO4∶Eu fluorescent nanomaterials with small size and strong fluorescent intensity were synthesized via a hydrothermal method by using polyethylenimine (PEI) as the modifier, and the reaction mechanism of this synthesis was also discussed. The as-synthesized nanomaterials were characterized through transmission electron microscopy (TEM), X-ray diffraction (XRD) measurements, Fourier transform infrared (FT-IR) spectroscopy and fluorescence spectroscopy (FS). The as-prepared fluorescent nanomaterials were well-dispersed and spherical in shape with an average diameter of about 30 nm, which were modified with a layer of PEI on surfaces. The fluorescent nanomaterials were of pure tetragonal YVO4 structure. They could emit strong red fluorescence under the 254 nm ultraviolet excitation. The YVO4∶Eu fluorescent dry powders were then used as a novel fluorescent label for the development of latent fingerprints on various smooth substrates. Furthermore, the sensitivity and the resistance to background interference in fingerprint development were investigated in detail. The results showed that, use of YVO4∶Eu fluorescent nanomaterials to develop latent fingerprints resulted in clearly defined friction ridge details of fingerprints and eliminated background interference under 254 nm ultraviolet light. Compared with the traditionally used fluorescent developing powders, our YVO4∶Eu fluorescent nanomaterials were a novel agent for latent fingerprint development with high sensitivity, high contrast, and low background interference..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1601 (2015)
Determination of the Sodium Methylparaben Content Based on Spectrum Fluorescence Spectral Technology and GA-BP Neural Network
WANG Shu-tao, CHEN Dong-ying, HOU Pei-guo, WANG Xing-long, WANG Zhi-fang, and WEI Meng
Sodium methylparaben as one kind of preservatives is widely used in our life , but it will do harm to health if it is eaten too much. So there are strict rules on the dosage of sodium methylparaben in every country. The fluorescence spectral properties of sodium methylparaben in aqueous solution and orange juice solutiSodium methylparaben as one kind of preservatives is widely used in our life , but it will do harm to health if it is eaten too much. So there are strict rules on the dosage of sodium methylparaben in every country. The fluorescence spectral properties of sodium methylparaben in aqueous solution and orange juice solution are analyzed with FS920 fluorescence spectrometer. The research result shows that the fluorescence characteristic peak of sodium methylparaben solution is in λex/λem=380/510 nm, while sodium methylparaben orange juice solution has two fluorescence characteristic peaks which are in λex/λem=440/520 nm and 470/530 nm, and its best excitation wavelength is 440 nm. So it can be concluded from the result that there is a significant change between the characteristic peaks of sodium methylparaben in the two solution. Compared with the fluorescence characteristic peak of sodium methylparaben solution, thoses of sodium methylparaben orange juice solution are changed significantly, which are caused by the interference of orange juice fluorescence characteristics. In order to determine the content of sodium methylparaben in the fresh orange juice, a detection model of sodium methylparaben content in orange juice is built based on GA-BP neural network, according to the relationship between fluorescence intensity in λex=440 nm and the content of sodium methylparaben orange juice solution. When the accuracy of the mean square error in the process of network training reaches 10-3, the correlation coefficient of network output and that of the expected is 0.996. At the same time, a better prediction result can be obtained that the average recovery of the forecast samples is 98.67% and the average relative standard deviation is 0.86%. When the concentration ranges from 0.02 to 1.0 g·L-1, the results testify that detection method based on fluorescence spectroscopy and GA-BP neural network can accurately determine the content of sodium methylparaben in orange juice. This method has the features of novelty and simplicity and it is expected to be applied to the determination of sodium methylparaben in other kinds of drink..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1606 (2015)
The Implementation by PARAFAC Decompose Components Analysis in the Three-Dimensional Fluorescence Spectroscopy Data
ZHU Peng, LIU Cheng-lin, and ZHU Fei
The paper systematically analyzes the implementation process of the parallel factor analysis (PARAFAC) method decompose matrix data. As example, The three dimensional fluorescence spectra of the water samples taken from the lake were analyzed by PARAFAC. According to the distribution of the core matrix elements, the coThe paper systematically analyzes the implementation process of the parallel factor analysis (PARAFAC) method decompose matrix data. As example, The three dimensional fluorescence spectra of the water samples taken from the lake were analyzed by PARAFAC. According to the distribution of the core matrix elements, the core consistency, the degree of similarity between the model spectra and the original spectra, the physical meaning of the proposed decomposition components, the number of components was determined. Then the corresponding PARAFAC model was established. The components of the fluorescence material components dissolved in water samples can be decomposed by this PARAFAC model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1611 (2015)
Application of SDS Micellar Solution in Fluorescence Spectral Measurement of Petroleum Pollutant
YANG Li-li, WANG Yu-tian, and LU Xin-qiong
A new method of solubilizing, sensitizing and stabilizing petroleum substances by using sodium dodecyl sulfate (SDS) micellar solution as solvent was proposed. The variation relationship between fluorescence intensity of petroleum substances and SDS micellar solution concentration was studied, and the optimum concentraA new method of solubilizing, sensitizing and stabilizing petroleum substances by using sodium dodecyl sulfate (SDS) micellar solution as solvent was proposed. The variation relationship between fluorescence intensity of petroleum substances and SDS micellar solution concentration was studied, and the optimum concentration of SDS micelle solution as solvent was determined with 0.1 mol·L-1. Gasoline, diesel and kerosene SDS micellar solution of different diluted concentration were measured using FLS920 fluorescence spectrometer and fluorescence excitation-emission matrixes (EEMs) were obtained. After analyzing Rayleigh scattering, Raman scattering and instrument characteristics influence on measured spectrum, three-dimensional fluorescence spectra of three kinds of oil samples with excitation wavelength ranging from 250 to 400 nm and emission wavelength from 260 to 500 nm were established by spectral correction. The linear relationship between fluorescence intensity and concentration in certain concentration range was determined. By comparison with the spectra of gasoline, diesel, kerosene aqueous solution with the various concentrations under the same conditions and preparation method, the solubility and fluorescence intensity of petroleum pollutant in water was increased, and better stability was obtained. The measurement of petroleum substances without relying on some toxic solvent extraction was not only achieved, but its low solubility in water and difficult quantitative problems were solved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1618 (2015)
Outlier Detection of Time Series Three-Dimensional Fluorescence Spectroscopy
YU Shao-hui, ZHANG Yu-jun, and ZHAO Nan-jing
The qualitative and quantitative analysis are often interfered by the outliers in time series three-dimensional fluorescence spectroscopy. In this work, an efficient outlier detection method is proposed by taking advantage of the characteristics in time dimension and the spectral dimension. Firstly, the wavelength poinThe qualitative and quantitative analysis are often interfered by the outliers in time series three-dimensional fluorescence spectroscopy. In this work, an efficient outlier detection method is proposed by taking advantage of the characteristics in time dimension and the spectral dimension. Firstly, the wavelength points that are mostly the outliers are extracted by the variance in time dimension. Secondly, by the analysis of the existence styles of outliers and similarity score of any two samples, the cumulative similarity is introduced in spectral dimension. At last, fluorescence intensity at each wavelength of all samples is modified by the correction matrix in time dimension and the outlier detection is completed according the to cumulative similarity scores. The application of the correction matrix in time dimension not only improves the validity of the method but also reduces the computation by the choice of characteristics region in correction matrix. Numerical experiments show that the outliers can still be detected by the 50 percent of all points in spectral dimension..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1624 (2015)
Determination of Iodine and Iodate in Brine and Seafood Simultaneously by Ultraviolet Absorption Spectrometry
TAN Jun, ZHU Xia-ping, LIU Miao-miao, WEI Zhi-cheng, and SANG Shi-hua
The iodide in samples was oxidized to iodate by bromine water, which could be removed by formic acid, and iodate could be transformed to I-3 with excess of I- in phosphoric acid, the iodate in samples could be transformed directly to I-3 with excess of I- in phosphoric acid. The I-3 solution had strong absorption at 35The iodide in samples was oxidized to iodate by bromine water, which could be removed by formic acid, and iodate could be transformed to I-3 with excess of I- in phosphoric acid, the iodate in samples could be transformed directly to I-3 with excess of I- in phosphoric acid. The I-3 solution had strong absorption at 350 and 288 nm, and the absorbance had a linear relationship to the concentration of I-3 in a certain range. Total content of iodide and iodate had been detected after samples were oxidized by bromine water and the content of iodate had been detected directly, and the content of iodide was obtained by difference of the two results. Based on this, the method had been established to detect iodide and iodate in brine and seafood simultaneously by ultraviolet absorption spectrometry. The volumes of bromine water, formic acid, phosphoric acid and potassium iodide had been optimized. The effect of illumination, temperature and time also had been discussed. The optional reagents condition for iodide was: 2 drops of 3% bromine water, 0.5 mL of 10% formic acid, 4 mL of 20% phosphoric acid and 1 mL of 100 g·L-1 KI. The optional reagents condition for iodate was: 0.2 mL of 20% phosphoric acid and 1 mL of 100 g·L-1 KI. The absorbance were determined after reacting for 30 min at room temperature and natural light conditions. Under the optimized conditions, the concentration of iodide and iodate in the range of 0～1.2 and 0～1.5 mg·L-1 were well agreed with Lambert Beer law. The sample blank was detected for twelve times and the detection limit of iodide and iodate were 1.54 and 14.8 μg·L-1 respectively. The RSD of twelve times determination of 0.8 mg·L-1 of iodide and iodate were 0.097% and 0.067%, respectively. The iodide and iodate in Zhabuye brine, Hong Feng underground brine, kelp, seaweed and sea cabbage had been detected, the recovery experiments also had been conducted at the same time, the recovery of iodide and iodate were between 80%～120%. All the results met the requirement of analytical chemistry..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1628 (2015)
Study on Differential Optical Absorption Spectroscopy Data Processing Based on Chirp-Z Transformation
ZHENG Hai-ming, LI Guang-jie, and WU Hao
Differential optical absorption spectroscopy (DOAS) is a commonly used atmospheric pollution monitoring method. Denoising of monitoring spectral data will improve the inversion accuracy. Fourier transform filtering method is effectively capable of filtering out the noise in the spectral data. But the algorithm itself cDifferential optical absorption spectroscopy (DOAS) is a commonly used atmospheric pollution monitoring method. Denoising of monitoring spectral data will improve the inversion accuracy. Fourier transform filtering method is effectively capable of filtering out the noise in the spectral data. But the algorithm itself can introduce errors. In this paper, a chirp-z transform method is put forward. By means of the local thinning of Fourier transform spectrum, it can retain the denoising effect of Fourier transform and compensate the error of the algorithm, which will further improve the inversion accuracy. The paper study on the concentration retrieving of SO2 and NO2. The results show that simple division causes bigger error and is not very stable. Chirp-z transform is proved to be more accurate than Fourier transform. Results of the frequency spectrum analysis show that Fourier transform cannot solve the distortion and weakening problems of characteristic absorption spectrum. Chirp-z transform shows ability in fine refactoring of specific frequency spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1633 (2015)
The Research for Trace Ammonia Escape Monitoring System Based on Tunable Diode Laser Absorption Spectroscopy
ZHANG Li-fang, WANG Fei, YU Li-bin, YAN Jian-hua, and CEN Ke-fa
In order to on-line measure the trace ammonia slip of the commercial power plant in the future, this research seeks to measure the trace ammonia by using tunable diode laser absorption spectroscopy under ambient temperature and pressure, and at different temperatures, and the measuring temperature is about 650 K in theIn order to on-line measure the trace ammonia slip of the commercial power plant in the future, this research seeks to measure the trace ammonia by using tunable diode laser absorption spectroscopy under ambient temperature and pressure, and at different temperatures, and the measuring temperature is about 650 K in the power plant. In recent years lasers have become commercially available in the near-infrared where the transitions are much stronger, and ammonia’s spectroscopy is pretty complicated and the overlapping lines are difficult to resolve. A group of ammonia transitions near 4 433.5 cm-1 in the ν2+ν3 combination band have been thoroughly selected for detecting lower concentration by analyzing its absorption characteristic and considering other absorption interference in combustion gases where H2O and CO2 mole fraction are very large. To illustrate the potential for NH3 concentration measurements, predictions for NH3, H2O and CO2 are simultaneously simulated, NH3 absorption lines near 4 433.5 cm-1 wavelength meet weaker H2O absorption than the commercial NH3 lines, and there is almost no CO2 absorption, all the parameters are based on the HITRAN database, and an improved detection limit was obtained for interference-free NH3 monitoring, this 2.25 μm band has line strengths several times larger than absorption lines in the 1.53 μm band which was often used by NH3 sensors for emission monitoring and analyzing. The measurement system was developed with a new Herriott cell and a heated gas cell realizing fast absorption measurements of high resolution, and combined with direct absorption and wavelenguh modulation based on tunable diode laser absorption spectroscopy at different temperatures. The lorentzian line shape is dominant at ambient temperature and pressure, and the estimated detectivity is approximately 0.225×10-6 (SNR=1) for the directed absorption spectroscopy, assuming a noise-equivalent absorbance of 1×10-4. The heated cell experiments with controlled the temperature were performed to validate the sensing strategy. Here the Wavelength Modulation Spectroscopy (WMS) strategy was usually used to measure lower gas concentration for high noise immunity to the non-absorption transmission losses. The great agreement 2f signal with the calibrated concentration is within the uncertainty at different temperatures by using simple digital signal processing such as multiple averages, wavelet analysis and so on. The denoise processing has a great advantage in application and implementation over other noise suppression techniques. The result provided a good basis for trace ammonia escape detection based on tunable diode laser absorption spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1639 (2015)
Research on the Tomato Metacaspase Protein Interactions with Ca2+ by Spectroscopy and Molecular Probe
WEN Shuai, MA Ying-xuan, WU Kun-sheng, CUI Jin-tian, LUO Yun-bo, and QU Gui-qin
Metacaspases are cysteine-dependent proteases found in protozoa, fungi and plants and are distantly related to metazoan caspases. Most of MCPs activation are the calcium dependent, but the mechanisms are still unknown. Based on the techniques of CD spectroscopy, fluorescence spectroscopy, and Terbium Stains-all probe, Metacaspases are cysteine-dependent proteases found in protozoa, fungi and plants and are distantly related to metazoan caspases. Most of MCPs activation are the calcium dependent, but the mechanisms are still unknown. Based on the techniques of CD spectroscopy, fluorescence spectroscopy, and Terbium Stains-all probe, we selected three purified recombinant proteins from key residues mutated in tomato metacaspase (LeMCA1), including conserved catalytic site (C139A) mutant, N-sequenced cleaved site (K223G) mutant and the predicted Ca2+ binding sites (D116A/D117A) mutant, to explore the interaction mechanism of LeMCA1 and Ca2+. CD spectroscopy and Stains-all probe results suggested that the intense binding does not exist between LeMCA1 and Ca2+ as well as Ca2+ has little effect on the secondary structure of LeMCA1. However, fluorescence spectroscopy and Tb3+ probe results showed that Ca2+-induced the changes occur in the tertiary structure of LeMCA1, which contributes to the activation of zymogen. In addition, predicted Ca2+ binding residues, Asp-116 and Asp117, are the key sites responsible for the Ca2+ interaction with LeMCA1, and the loss of these two residues resulted in decreased interaction. Our data firstly provided insight on the mechanism of the interaction between Ca2+ and recombinant purified Solanaceae type Ⅱ metacaspase by spectroscopy and molecular probe techniques. Combined the results we got before from sequence-alignment and sites-mutation, the key residues Asp-116 and Asp117 affect the Ca2+-induced the changes of LeMCA1 tertiary structure. Our data provided information for the further biochemical and crystal assays of LeMCA1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1643 (2015)
Comparative Research on Estimating the Severity of Yellow Rust in Winter Wheat
WANG Jing, JING Yuan-shu, HUANG Wen-jiang, ZHANG Jing-cheng, ZHAO Juan, ZHANG Qing, and WANG Li
In order to improve the accuracy of wheat yellow rust disease severity using remote sensing and to find the optimum inversion model of wheat diseases, the canopy reflectance and disease index (DI) of winter wheat under different severity stripe rust were acquired. The three models of PLS (Partial Least Square), BP neurIn order to improve the accuracy of wheat yellow rust disease severity using remote sensing and to find the optimum inversion model of wheat diseases, the canopy reflectance and disease index (DI) of winter wheat under different severity stripe rust were acquired. The three models of PLS (Partial Least Square), BP neural network using seven hyperspectral vegetation indices which have significant relationship with the occurrence of disease and vegetation index (PRI) were adopted to build a feasible regression model for detecting the disease severity. The results showed that PLS performed much better. The inversion accuracy of PLS method is best than of the VI (PRI, Photochemical Reflectance Index) and BP neural network models. The coefficients of determination (R2) of three methods to estimate disease severity between predicted and measured values are 0.936, 0.918 and 0.767 respectively. Evaluation was made between the estimated DI and the measured DI, indicating that the model based on PLS is suitable for monitoring wheat disease. In addition, to explore the different contributions of diverse types of vegetation index to the models, the paper attempts to use NDVI, GNDVI and MSR which on behalf of vegetation greenness and NDWI and MSI that represents the moisture content to be input variables of PLS model. The results showed that, for the wheat yellow rust disease, changes in chlorophyll content is more sensitive to the disease severity than the changes in water content of the canopy . However, the accuracy of the two models are both lower than predicted when participating in all seven vegetation indices, namely using several species of vegetation indices tends to be more accurate than that using single category. It indicated that it has great potential for evaluating wheat disease severity by using hyper-spectral remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1649 (2015)
The Study of the Spectral Model for Estimating Pigment Contents of Tobacco Leaves in Field
REN Xiao, LAO Cai-lian, XU Zhao-li, JIN Yan, GUO Yan, LI Jun-hui, and YANG Yu-hong
Fast and non-destructive measurements of tobacco leaf pigment contents by spectroscopy in situ in the field has great significance in production guidance for nutrient diagnosis and growth monitoring of tobacco in vegetative growth stage, and it is also very important for the quality evaluation of tobacco leaves in matuFast and non-destructive measurements of tobacco leaf pigment contents by spectroscopy in situ in the field has great significance in production guidance for nutrient diagnosis and growth monitoring of tobacco in vegetative growth stage, and it is also very important for the quality evaluation of tobacco leaves in mature stage. The purpose of this study is to estimate the chlorophyll and carotenoid contents of tobacco leaves using tobacco leaf spectrum collected in the field. Reflectance spectrum of tobacco leaves in vegetative growth stage and mature stage were collected in situ in the field and the pigment contents of tobacco leaf samples were measured in this study, taking the tobacco leaf samples collected in each and both stages as modeling sets respectively, and using the methods of support vector machine (SVM) and spectral indice to establish the pigment content estimation models, and then compare the prediction performance of the models built by different methods. The study results indicated that the difference of estimation performance by each stage or mixed stages is not significant. For chlorophyll content, SVM and spectral indice modeling methods can both have a well estimation performance, while for carotenoid content, SVM modeling method has a better estimation performance than spectral indice. The coefficient of determination and the root mean square error of SVM model for estimating tobacco leaf chlorophyll content by each stage were 0.867 6 and 0.014 7, while the coefficient of determination and the root mean square error of SVM model for estimating tobacco leaf chlorophyll content by mixed stages were 0.898 6 and 0.012 3; The coefficient of determination and the root mean square error for estimating tobacco leaf carotenoid content by each stage were 0.861 4 and 0.002 5, while the coefficient of determination and the root mean square error of SVM model for estimating tobacco leaf carotenoid content by mixed stages were 0.839 9 and 0.002 5. The innovation point of this study is that on the basis of support vector machine and spectral indice, models established by each stage and mixed stages for estimating the pigment contents of tobacco leaf samples can provide scientific basis and technical support for quality control of tobacco leaf production in field and the ensurance of tobacco leaf recovery quality..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1654 (2015)
Preliminary Study on the Detection of Pork Tenderness by Three-Dimensional Diffuse Reflectance Spectroscopy
ZHANG Zhi-yong, ZUO Yue-ming, CHEN Jin-ming, LI Gang, CHEN Chen, and YANG Wei
Tenderness is an important index to evaluate the pork’s quality, in this paper a method called three-dimensional diffuse reflectance spectroscopy was proposed to detect pork tenderness. Because pork has a strong scattering impact on light, this method introduced more scattering information of pork samples into spectralTenderness is an important index to evaluate the pork’s quality, in this paper a method called three-dimensional diffuse reflectance spectroscopy was proposed to detect pork tenderness. Because pork has a strong scattering impact on light, this method introduced more scattering information of pork samples into spectral analysis of tenderness. Using the special data acquisition system, three-dimensional diffuse reflectance spectra of 64 pork samples were constructed by collecting the emergent light signals of different distances away from the light incident point. And n-way partial least squares (NPLS) regression was applied to establish the calibration model between the pork tenderness and three-dimensional diffuse reflectance spectra which were denoised by wavelet transform. The determination coefficient of model for the calibration set (R2Cal) is 0.883 1, and the root mean squared error of calibration (RMSEC) is 3.685 0N. The determination coefficient of model for the prediction set (R2Pred) is 0.874 7, and the root mean squared error of prediction (RMSEP) is 3.975 6N. The result indicates that the NPLS model of pork tenderness built by three-dimensional diffuse reflectance spectra has higher calibration accuracy and prediction stability than the traditional diffuse reflectance spectra. Three-dimensional diffuse reflectance spectroscopy can be expected to be a new method to quickly detect the tenderness and the other qualities of pork..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1660 (2015)
A Measurement Method for the Hepatic Functional Reserves Anti Oxygen Fluctuations
LIU Guang-da, CHEN Yong, and WANG Jing-jing
Hepatic functional reserves parameters are the key indictors to assess if the hepatic metabolic function is normal, they are also the important basis to a successful hepatectomy. Currently clinical hepatic functional reserves parameters are achieved through Indocyanine Green (ICG) concentration measurement in the methoHepatic functional reserves parameters are the key indictors to assess if the hepatic metabolic function is normal, they are also the important basis to a successful hepatectomy. Currently clinical hepatic functional reserves parameters are achieved through Indocyanine Green (ICG) concentration measurement in the method of pulse dye spectrophotometry, with the assumption that blood oxygen saturation is 100%, this hypothetical bias leads to an error in the calculated value of the hepatic functional reserves parameters. In order to solve this problem, hepatic functional reserves parameters measurement that resist fluctuation from blood is presented. The method is based on the modified Lambert Beer’s law and realize the correction of ICG concentration measurement in the method of pulse dye spectrophotometry. While the ICG is injected into the patient’s body by the cubital veins, using the data acquisition unit that developed by project team to collect 805 nm, 940 nm wavelengths of transmission signals and 730 nm, 805 nm and 890 nm wavelengths of reflected signals in the fingertip skin synchronously, and then upload 5 sets of data to the computer. Draw the ICG concentration curve according the collected data and blood oxygen saturation before injecting ICG to the human body and then calculate the characteristic parameters, according to the characteristic parameters calculate the hepatic reserves functional parameters. Taking the measurement of effective hepatic blood flow as an example, the relative error was obviously decreased when comparing this method and the pulse dye concentration method with the electromagnetic flowmeter (EMF) measurement which is the most accurate method to measure effective hepatic blood flow (EHBF) respectively. The results demonstrate that this method can improve the accuracy of hepatic reserves parameters, and it can also provide a more accurate detection method of hepatic functional reserves parameters for clinical application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1664 (2015)
Sophisticated Vegetation Classification Based on Feature Band Set Using Hyperspectral Image
SHANG Kun, ZHANG Xia, SUN Yan-li, ZHANG Li-fu, WANG Shu-dong, and ZHUANG Zhi
There are two major problems of sophisticated vegetation classification (SVC) using hyperspectral image. Classification results using only spectral information can hardly meet the application requirements with the needed vegetation type becoming more sophisticated. And applications of classification image are also limiThere are two major problems of sophisticated vegetation classification (SVC) using hyperspectral image. Classification results using only spectral information can hardly meet the application requirements with the needed vegetation type becoming more sophisticated. And applications of classification image are also limited due to salt and pepper noise. Therefore the SVC strategy based on construction and optimization of vegetation feature band set (FBS) is proposed. Besides spectral and texture features of original image, 30 spectral indices which are sensitive to biological parameters of vegetation are added into FBS in order to improve the separability between different kinds of vegetation. And to achieve the same goal a spectral-dimension optimization algorithm of FBS based on class-pair separability (CPS) is also proposed. A spatial-dimension optimization algorithm of FBS based on neighborhood pixels’ spectral angle distance (NPSAD) is proposed so that detailed information can be kept during the image smoothing process. The results of SVC experiments based on airborne hyperspectral image show that the proposed method can significantly improve the accuracy of SVC so that some widespread application prospects like identification of crop species, monitoring of invasive species and precision agriculture are expectable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1669 (2015)
Preparation and Photocatalytic Properties of Supported TiO2 Photocatalytic Material
GUO Yu, JIN Yu-jia, WU Hong-mei, and LI Dong-xin
Titanium dioxide (TiO2) supported on spherical alumina substrate was prepared by using sol-gel method combined with dip-coating process. The surface morphology and structure of the synthesized samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) pattern. The results show that theTitanium dioxide (TiO2) supported on spherical alumina substrate was prepared by using sol-gel method combined with dip-coating process. The surface morphology and structure of the synthesized samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) pattern. The results show that the morphology of the supported TiO2 composite material was obviously different from that of the original support. It reveals a layer formed by anatase TiO2 nanoparticles of 10～20 nm was deposited on the alumina substrate. Energy dispersive X-ray spectroscopy (EDX) analyses on the spherical alumina substrate and the resulting TiO2 composite catalyst were performed to determine the TiO2 loading content in the samples. It indicates that the TiO2 loading content on alumina substrate could be effectively increased by increasing the times of dip-coating alumina support in TiO2 sol. When dip-coating times increased to 5, the TiO2 loading content increased from 3.8 Wt.% to 15.7 Wt.%. In addition, the photocatalytic performances of the supported TiO2 materials prepared by different dip-coating times have been investigated by degrading methylene blue. It was found that the surface morphology of the supported TiO2 material was not only improved, but also the photocatalytic activity could be promoted significantly by increasing the dip-coating times. When the alumina substrate was dip-coated in TiO2 sol from 1 to 4 times, the degradation rate of methylene blue increased from 40% to 83.1%. However, after dip-coating the alumina support in TiO2 sol for 5 times, the degradation of methylene blue was only up to 85.6%. This indicates that the photocatalytic activity increased slowly when the TiO2 content in the supported catalyst was up to some extent. It is attributed to the continuous dip-coating resulted in less opportunities and weak intensity of illumination for the TiO2 nano-particles that under lower layer. The photocatalytic activity was relatively stable after repeated use of the supported TiO2 material for 5 times..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1677 (2015)
A Composition Analysis Method of Mixed Pigments Based on Spectrum Expression and Independent Component Analysis
WANG Gong-ming, and LIU Zhi-yong
Reflectance spectrometry is a common method in composition analysis of mixed pigments. In this method, similarity is used to determine the type of basic pigments that constitute the mixed pigments. But its result may be inaccurate because it is easily influenced by a variety of basic pigments. In this study, a compositReflectance spectrometry is a common method in composition analysis of mixed pigments. In this method, similarity is used to determine the type of basic pigments that constitute the mixed pigments. But its result may be inaccurate because it is easily influenced by a variety of basic pigments. In this study, a composition analysis method of mixed pigments based on spectrum expression and independent component analysis is proposed, and the composition of mixed pigments can be calculated accurately. First of all, the spectral information of mixed pigments is obtained with spectrometer, and is expressed as the discrete signal. After that, the spectral information of basic pigments is deduced with independent component analysis. Then, the types of basic pigments are determined by calculating the spectrum similarity between the basic pigments and known pigments. Finally, the ratios of basic pigments are obtained by solving the Kubelka-Munk equation system. In addition, the simulated spectrum data of Munsell color card is used to validate this method. The compositions of mixed pigments from three basic pigments are determined under the circumstance of normality and disturbance. And the compositions of mixture from several pigments within the set of eight basic pigments are deduced successfully. The curves of separated pigment spectrums are very similar to the curves of original pigment spectrums. The average similarity is 97.72%, and the maximum one can reach to 99.95%. The calculated ratios of basic pigments close to the original one. It can be seen that this method is suitable for composition analysis of mixed pigments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1682 (2015)
Simulation of Atmospheric Nitrous Oxide Profiles Retrieval from AIRS Observations
MA Peng-fei, CHEN Liang-fu, LI Qing, TAO Ming-hui, WANG Zi-feng, ZHANG Ying, WANG Zhong-ting, and ZHOU Chun-yan
Nitrous Oxide is a very important greenhouse gases and ozone-depleting substances. Due to the limited observations, there are still many uncertainties to quantitativelydescribe therole of nitrous oxide played in both cases. We can retrieve the methane and carbon dioxide gas using thermal infrared satellite data AIRS, bNitrous Oxide is a very important greenhouse gases and ozone-depleting substances. Due to the limited observations, there are still many uncertainties to quantitativelydescribe therole of nitrous oxide played in both cases. We can retrieve the methane and carbon dioxide gas using thermal infrared satellite data AIRS, but it is rarely for the nitrous oxide retrieval. Therefore, this paper retrieves nitrous oxideprofiles from the AIRS data with anOptimal Estimate Method for the first time in China. The issue of the a priori and channelselection is discussed. Comparison of the retrieved AIRS profiles with HIPPOprofiles show the retrieved profiles are in good agreement with the smoothed HIPPO profiles, and a notable improvementin this algorithmthan the eigenvector regression algorithm. For pressures between 300 and 900 hPa, we got the most accurate profiles and the relative erroris only 0.1%, which is consistent with the jacobian peaks of the selected channels..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1690 (2015)
Experimental Methods and Result Analysis of a Variety of Spectral Reflectance Properties of the Thin Oil Film
YE Zhou, LIU Li, WEI Chuan-xin, GU Qun, AN Ping-ao, ZHAO Yue-jiao, and YIN Da-yi
In order to analysis the oil spill situation based on the obtained data in airborne aerial work, it’s needed to get the spectral reflectance characteristics of the oil film of different oils and thickness as support and to select the appropriate operating band. An experiment is set up to measure the reflectance spectroIn order to analysis the oil spill situation based on the obtained data in airborne aerial work, it’s needed to get the spectral reflectance characteristics of the oil film of different oils and thickness as support and to select the appropriate operating band. An experiment is set up to measure the reflectance spectroscopy from ultraviolet to near-infrared for the film of five target samples, which means petrol, diesel, lubricating oil, kerosene and fossil, using spectral measurement device. The result is compared with the reflectance spectra of water in the same experimental environment, which shows that the spectral reflection characteristics of the oil film are related to the thickness and the type of the oil film. In case of the same thickness, the spectral reflectance curve of different types of film is far different, and for the same type of film, the spectral reflectance curve changes accordingly with the change of film thickness, therefore in terms of the single film, different film thickness can be distinguished by reflectance curves. It also shows that in terms of the same film thickness, the reflectance of diesel, kerosene, lubricants reaches peak around 380 nm wavelength, obviously different from the reflectance of water, and that the reflectance of crude oil is far less than that of water in more than 340 nm wavelength, and the obtained reflection spectrum can be used to distinguish between different types of oil film to some extent. The experiment covers main types of spilled oil, with data comprehensively covering commonly used detect spectral bands, and quantitative description of the spectral reflectance properties of film. It provides comprehensive theoretical and data supprot for the selection of airborne oilspill detection working band and the detection and analysis of water-surface oil spill..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1695 (2015)
A Method to Extract Content of Minerals Based on Measured Hyperspectral Data
WANG Ya-jun, WANG Qin-jun, CHEN Yu, HU Fang, XU Ru, and LIN Qi-zhong
To improve the accuracy of mineral content extraction by linear decomposition model, a method was established, which took rock spectra with wavelength from 350 to 2 500 nm as the data source, identified minerals based on spectral matching methods, applied Hapke model to transform spectral reflectance into single scatteTo improve the accuracy of mineral content extraction by linear decomposition model, a method was established, which took rock spectra with wavelength from 350 to 2 500 nm as the data source, identified minerals based on spectral matching methods, applied Hapke model to transform spectral reflectance into single scattering albedo and resolved single scattering albedo to get mineral content. In this method, sectional noise filtering and regional mineral spectra library were added to improve the identifying accuracy. Based on the analysis on the fifth Baogutu rock body, compared with XRD results, accuracies of quartz, feldspar class and altered minerals identification were 75%, 100% and 92.2% separately. Accuracy of the content extraction of feldspar class, hornblende and altered minerals were 80.5%, 64%, 92.36% separately. This method added mineralogy symbiotic relationship into mineral identification to ensure the reliability, proposed the idea of sectional noise filtering to avoid the influence of filtering algorithm, applied the single scattering albedo to avoid the complex nonlinearly calculations to improve the accuracy theoretically. This method has a certain guiding significance for the work such as rapid analysis of alteration information..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1700 (2015)
Transferability of Hyperspectral Model for Estimating Soil Organic Matter Concerned with Soil Moisture
CHEN Yi-yun, QI Kun, LIU Yao-lin, HE Jian-hua, and JIANG Qing-hu
Hyperspectral remote sensing, known as the state-of-the-art technology in the field of remote sensing, can be used to retrieve physical and chemical properties of surface objects based on the interactions between electromagnetic waves and the objects. Soil organic matter (SOM) is one of the most important parameters usHyperspectral remote sensing, known as the state-of-the-art technology in the field of remote sensing, can be used to retrieve physical and chemical properties of surface objects based on the interactions between electromagnetic waves and the objects. Soil organic matter (SOM) is one of the most important parameters used in the assessment of soil fertility. Quick estimation of SOM with hyperspectral remote sensing technique can provide essential soil data to support the development of precision agriculture. The presence of external parameters, however, may affect the modeling precision, and further handicap the transferability of existing model. With the aim to study the effects of soil moisture on the Vis/NIR estimation of soil organic matter, and the capacity of direct standardization(DS)algorithm in the calibration transfer, 95 soil samples collected in the Jianghan plain were rewetted and air-dried. Reflectance of these samplesat 13 moisture levels was measured. Results show that the model calibrated using air-dried samples has the highest prediction accuracy. This model, however, was not suitable for SOM prediction of the rewetted samples. Prediction bias and RPD improved from -8.34～3.32 g·kg-1 and 0.64～2.04 to 0 and 7.01, when DS algorithm was applied to the spectra of the rewetted samples. DS algorithm has been proven to be effective in removing the effects of soil moisture on the Vis/NIR estimation of SOM, ensuring a transferrable model for SOM prediction with soil samples at different moisture levels..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1705 (2015)
The Change Detection of High Spatial Resolution Remotely Sensed Imagery Based on OB-HMAD Algorithm and Spectral Features
CHEN Qiang, CHEN Yun-hao, and JIANG Wei-guo
The high spatial resolution remotely sensed imagery has abundant detailed information of earth surface, and the multi-temporal change detection for the high resolution remotely sensed imagery can realize the variations of geographical unit. In terms of the high spatial resolution remotely sensed imagery, the traditionaThe high spatial resolution remotely sensed imagery has abundant detailed information of earth surface, and the multi-temporal change detection for the high resolution remotely sensed imagery can realize the variations of geographical unit. In terms of the high spatial resolution remotely sensed imagery, the traditional remote sensing change detection algorithms have obvious defects. In this paper, learning from the object-based image analysis idea, we proposed a semi-automatic threshold selection algorithm named OB-HMAD (object-based-hybrid-MAD), on the basis of object-based image analysis and multivariate alternative detection algorithm (MAD). which used the spectral features of remotely sensed imagery into the field of object-based change detection. Additionally, OB-HMAD algorithm has been compared with other the threshold segmentation algorithms by the change detection experiment. Firstly, we obtained the image object by the multi-solution segmentation algorithm. Secondly, we got the object-based difference image object using MAD and minimum noise fraction rotation (MNF) for improving the SNR of the image object. Then, the change objects or area are classified using histogram curvature analysis (HCA) method for the semi-automatic threshold selection, which determined the threshold by calculated the maximum value of curvature of the histogram, so the HCA algorithm has better automation than other threshold segmentation algorithms. Finally, the change detection results are validated using confusion matrix with the field sample data. Worldview-2 imagery of 2012 and 2013 in case study of Beijing were used to validate the proposed OB-HMAD algorithm. The experiment results indicated that OB-HMAD algorithm which integrated the multi-channel spectral information could be effectively used in multi-temporal high resolution remotely sensed imagery change detection, and it has basically solved the “salt and pepper” problem which always exists in the pixel-based change detection, and has mitigated the impact of building shadows and geometric registration error, and has improved the overall accuracy and kappa coefficient than other change detection algorithm, but it has more undetected error. By compared with the SNR of image object, we know that the MNF transformation could effectively improve to concentrate the change information..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1709 (2015)
Quantitative Analysis of Mn in Soil Samples Using LIBS
ZHANG Bao-hua, JIANG Yong-cheng, ZHANG Xian-yan, and CUI Zhi-feng
The trace element of Manganese element in the agricultural farm (Anhui Huaiyuan Nongkang) soil was quantitatively analyzed by Laser-induced breakdown spectroscopy. The line of 403.1 nm was selected as the analysis line of Mn. The matrix element of Fe in soil was chosen as the internal calibration element and the analysThe trace element of Manganese element in the agricultural farm (Anhui Huaiyuan Nongkang) soil was quantitatively analyzed by Laser-induced breakdown spectroscopy. The line of 403.1 nm was selected as the analysis line of Mn. The matrix element of Fe in soil was chosen as the internal calibration element and the analysis line was 407.2 nm. Ten soil samples were used to construct calibration curves with traditional method and internal standard method, and four soil samples were selected as test samples. The experimental results showed that the fitting correlation coefficient (r) is 0.954 when using the traditional method, the maximum relative error of the measurement samples is 5.72%, and the detection limit of Mn in soil is 93 mg·kg-1. While using the internal standard method to construct the calibration curve, the fitting correlation coefficient (r) is 0.983, the relative error of measurement samples is reduced to 4.1%, and the detection limit of Mn in soil is 71 mg·kg-1. The result indicates that LIBS technique can be used to detect trace element Mn in soil. In a certain extent, the internal standard method can improve the accuracy of measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1715 (2015)
Influence of C-Fe Lines Interference Correction on Laser-Induced Breakdown Spectroscopy Measurement of Unburned Carbon in Fly Ash
YAO Shun-chun, CHEN Jian-chao, LU Ji-dong, SHEN Yue-liang, and PAN Gang
In coal-fired plants, Unburned carbon (UC) in fly ash is the major determinant of combustion efficiency in coal-fired boiler. The balance between unburned carbon and NOx emissions stresses the need for rapid and accurate methods for the measurement of unburned carbon. Laser-induced breakdown spectroscopy (LIBS) is emplIn coal-fired plants, Unburned carbon (UC) in fly ash is the major determinant of combustion efficiency in coal-fired boiler. The balance between unburned carbon and NOx emissions stresses the need for rapid and accurate methods for the measurement of unburned carbon. Laser-induced breakdown spectroscopy (LIBS) is employed to measure the unburned carbon content in fly ash. In this case, it is found that the C line interference with Fe line at about 248 nm. The interference leads to C could not be quantified independently from Fe. A correction approach for extracting C integrated intensity from the overlapping peak is proposed. The Fe 248.33 nm, Fe 254.60 nm and Fe 272.36 nm lines are used to correct the Fe 247.98 nm line which interference with C 247.86 nm, respectively. Then, the corrected C integrated intensity is compared with the uncorrected C integrated intensity for constructing calibration curves of unburned carbon, and also for the precision and accuracy of repeat measurements. The analysis results show that the regression coefficients of the calibration curves and the precision and accuracy of repeat measurements are improved by correcting C-Fe interference, especially for the fly ash samples with low level unburned carbon content. However, the choice of the Fe line need to avoid a over-correction for C line. Obviously, Fe 254.60 nm is the best choice for the correction of the C-Fe interference..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1719 (2015)
Application of ICP-MS and ICP-AES for Studying on Source Apportionment of PM2.5 during Haze Weather in Urban Beijing
CHEN Xi, DU Peng, GUAN Qing, FENG Xu, XU Dong-qun, and LIN Shao-bin
To investigate the characteristics of chemical constitute and pollution sources of aerosol fine particulate matter during haze-fog day in Beijing in winter 2013. The samples of PM2.5 were collected in Beijing from January to February, 2013. The technique of ICP-MS and ICP-AES coupled with procedure of bathing-ultrasoniTo investigate the characteristics of chemical constitute and pollution sources of aerosol fine particulate matter during haze-fog day in Beijing in winter 2013. The samples of PM2.5 were collected in Beijing from January to February, 2013. The technique of ICP-MS and ICP-AES coupled with procedure of bathing-ultrasonic extraction was applied to determine the concentration of 40 elements in the aerosol samples to analyze the characteristics of elements distribution statistically. The absolute principal factor method was used to apportion the pollution sources of PM2.5 during the haze weather in Beijing city in winter 2013. The results showed that during the period of sampling, the volume concentration of Li, Mn, Pb, S etc. obeyed normal distribution approximately, and according to National Ambient Air Quality Standard issued by Ministry of Environmental Protection of the People’s Republic of China, the geometric mean concentration of As was twice the annual limit of standard reference, while Pb of some aerosol samples beyond the annual limit of standard reference respectively. The mass fraction of Fe, Zn, Pb, Ti accounted for over 0.1%, while that of Mn, Cu, As, Se etc. 0.01%. These elements were primary inorganic pollutants, and especially the hazards and sources of As and Pb should be concerned. There were 6 main pollution sources were chosen by the factor analysis method, including industrial dust and human beings activities, biomass combustion and building dust, soil and sand dusts, fossil fuel, electronic waste and metal smelting, with the variance contribution rate of 40.3%, 27.0%, 9.1%, 4.9%, 4.8% and 4.6% respectively. ICP-MS and ICP-AES can be applied to analyzing multi-elements in PM2.5 accurately and quickly to facilitate source apportionment, and it indicated that the relevant pollution sources should be considered and the effect of regional transferring of haze pollution sources should be taken into account, and specific measures should be taken for control..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1724 (2015)
Metallic Elemental Analysis of Tibetan Herbal Medicines and Tibetan Medicine Preparations by Synchrotron Radiation X-Ray Fluorescence
YANG Hong-xia, LI Cen, DU Yu-zhi, and WEI Li-xin
To discuss the relationship between metallic element and disease through determine the elementals in Tibetan Herbal Medicines and Tibetan Medicine Preparations that have obvious effect on hepatobiliary diseases by Synchrotron Radiation X- ray Source, then to reveal the substance foundation of pharmacological action. ThTo discuss the relationship between metallic element and disease through determine the elementals in Tibetan Herbal Medicines and Tibetan Medicine Preparations that have obvious effect on hepatobiliary diseases by Synchrotron Radiation X- ray Source, then to reveal the substance foundation of pharmacological action. The results show that all the Tibetan Herbal Medicines used in the experiment have the 9 kinds of metallic elements of potassium(K), calcium(Ca), titanium(Ti), vanadium(V), chromium(Cr), manganese(Mn), ferrum(Fe), zinc(Zn) and lead(Pb), the content of the elements are in the ppb or ppm level though the element constitute and the content have obvious difference. Tibetan Medicine Preparations have another 6 kinds of metallic elements of nickel(Ni), copper(Cu), rubidium(Rb), mercury(Hg), cobalt(Co), gallium(Ga) and 1 kind of nonmetallic elements of arsenic(As) when compare with Herbal Medicines, and the element constitute and the content also have obvious difference. Take advantage of SR-XRF, the test gets the basic data of elements of Tibetan Herbal Medicines and Preparations, supply the scientific support to discuss the interaction of pharmacological mechanism and the metallic elements, and find the suitability of the technique for the metallic elements detection in Tibetan Medicines..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1730 (2015)
Fast Monitoring Soil Environmental Qualities of Heavy Metal by Portable X-Ray Fluorescence Spectrometer
WANG Bao, YU Jian-xin, HUANG Biao, HU Wen-you, and CHANG Qing
Portable X-ray fluorescence(PXRF) spectrometer as a new type of equipment for quick test has a prominent prospect, but there are also shortcomings of detection range and limition, therefore this paper studied the suitability of PXRF spectrometer in monitoring soil environmental qualities of heavy metals included Cr, NiPortable X-ray fluorescence(PXRF) spectrometer as a new type of equipment for quick test has a prominent prospect, but there are also shortcomings of detection range and limition, therefore this paper studied the suitability of PXRF spectrometer in monitoring soil environmental qualities of heavy metals included Cr, Ni, Cu, Zn, Pb, Cd, As and Hg, the aim of this paper is to screen elements which can be detected by this kind of instrument and evaluate the accuracy of test results. The research method is to test heavy metals contaminated soil samples by PXRF spectrometer, evaluate the accuracy of test results of PXRF compared with inductively coupled plasma mass(ICP-MS), then establish linear regression relationship between analysis results of PXRF and ICP-MS method. The results show that, (1) When measuring the soil environmental quality, PXRF spectrometer is appropriate to measure the content of Pb, Zn, Cr and Cu, except Ni, Cd, As and Hg. (2) Compared with the test value of ICP-MS, the test value of Pb and Zn is lower, the test value of Cu is higher, the test value of Cr is too high, all the results of PXRF spectrometer should be linear corrected according to standard analysis method. In conclusion, PXRF spectrometer is suitable for monitoring environmental quality of soil which is polluted by heavy metal such as Pb, Zn, Cr and Cu, it is an analysis means with characteristics of simple and rapid, accurate and reliable. The innovation of this article is that reasonable avoiding the shortcomings of PXRF spectrometer as using the instrument to monitor soil environmental quality, at last improved the application value of test results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1735 (2015)
Ultra-Fine Pressed Powder Pellet Sample Preparation XRF Determination of Multi-Elements and Carbon Dioxide in Carbonate
LI Xiao-li, AN Shu-qing, XU Tie-min, LIU Yi-bo, ZHANG Li-juan, ZENG Jiang-ping, and WANG Na
The main analysis error of pressed powder pellet of carbonate comes from particle-size effect and mineral effect. So in the article in order to eliminate the particle-size effect, the ultrafine pressed powder pellet sample preparation is used to the determination of multi-elements and carbon-dioxide in carbonate. To prThe main analysis error of pressed powder pellet of carbonate comes from particle-size effect and mineral effect. So in the article in order to eliminate the particle-size effect, the ultrafine pressed powder pellet sample preparation is used to the determination of multi-elements and carbon-dioxide in carbonate. To prepare the ultrafine powder the FRITSCH planetary Micro Mill machine and tungsten carbide media is utilized.To conquer the conglomeration during the process of grinding, the wet grinding is preferred. The surface morphology of the pellet is more smooth and neat, the Compton scatter effect is reduced with the decrease in particle size. The intensity of the spectral line is varied with the change of the particle size, generally the intensity of the spectral line is increased with the decrease in the particle size. But when the particle size of more than one component of the material is decreased, the intensity of the spectral line may increase for S, Si, Mg, or decrease for Ca, Al, Ti, K, which depend on the respective mass absorption coefficient . The change of the composition of the phase with milling is also researched. The incident depth of respective element is given from theoretical calculation. When the sample is grounded to the particle size of less than the penetration depth of all the analyte, the effect of the particle size on the intensity of the spectral line is much reduced. In the experiment, when grounded the sample to less than 8μm(d95), the particle-size effect is much eliminated, with the correction method of theoretical αcoefficient and the empirical coefficient , 14 major, minor and trace element in the carbonate can be determined accurately. And the precision of the method is much improved with RSD<2%, except Na2O. Carbon is ultra-light element, the fluorescence yield is low and the interference is serious. With the manual multi-layer crystal PX4, coarse collimator, empirical correction, X-ray spectrometer can be used to determine the carbon dioxide in the carbonate quantitatively. The intensity of the carbon is increase with the times of the measurement and the time delay even the pellet is stored in the dessicator. So employing the latest pressed powder pellet is suggested..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1741 (2015)
Study on Provenance of Kraak Porcelains from “Nan’ao Ⅰ” Shipwreck
DU Jing-nan, CHEN Yue, LI Nai-sheng, MING Chao-fang, ZHU Jian, and LUO Wu-gan
The “Kraak Porcelain” was a kind of Blue and White Porcelain which exported from China to Europe in Ming and Qing period. The study of Kraak Porcelain is a focus issue in international field of porcelain research. In 2007, the discovery of “Nan’ao Ⅰ” Shipwreck of Ming Dynasty and the porcelains loaded in it, provided pThe “Kraak Porcelain” was a kind of Blue and White Porcelain which exported from China to Europe in Ming and Qing period. The study of Kraak Porcelain is a focus issue in international field of porcelain research. In 2007, the discovery of “Nan’ao Ⅰ” Shipwreck of Ming Dynasty and the porcelains loaded in it, provided precious materials for the research on Kraak Porcelain. In this paper, we explored the provenance of 10 Kraak Porcelain samples from Nan’ao Ⅰ, using both traditional visual method and WDXRF..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1746 (2015)
Development of a High Spectral Resolution UV Flat-Field Spectrograph
DU Liang-liang, DU Xue-wei, LI Chao-yang, AN Ning, and WANG Qiu-ping
As an important optical splitting element, grating is used in many different spectrometers and spectrographs. Spherical varied-line-spacing grating (SVLSG) is easily combined with array detectors to get a wide wavelength range of spectrums in one time, because it can focus the spectrums in approximately a plane. TherefAs an important optical splitting element, grating is used in many different spectrometers and spectrographs. Spherical varied-line-spacing grating (SVLSG) is easily combined with array detectors to get a wide wavelength range of spectrums in one time, because it can focus the spectrums in approximately a plane. Therefore, it’s widely used in many spectral instruments. We usually only know the central groove density of a commercial grating and its mounting parameters, while its line spacing parameters are unknown. Moreover, the mounting parameters are optimized within the whole using wavelength range of the grating. However, in most circumstances only part of the wavelength range is used. Therefore, the mounting parameters are not optimized for the needed wavelength range. Under this condition, in this article we developed a method based on the focusing theory of the flat-field grating and the mounting parameters the manufacture provided to deduce the line spacing parameters of the grating. With these parameters, we can optimize the detector position according to the wavelength range we need and ray tracing can be done to test the optical system. In this article we developed a high spectral resolution ultraviolet spectrograph, covering a wavelength range of 230~280 nm. The grating used in this spectrograph has a central groove density of 1 200 lines·mm-1 and a designed wavelength range of 170~500 nm. We deduced the line spacing parameters of the grating and optimized the detector mounting parameters. Hollow cathode lamps of different elements were used to calibrate the spectrograph and test the spectral resolution of it. Wavelength calibration of the spectrograph has been done with the parameter fitting method, and the calibration accuracy is better than 0.01 nm. Results show the spectral resolution of the spectral graph is about 0.08 nm at 280.20 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1751 (2015)
Study on the Advanced Czerny-Turner Imaging Spectrometer with High Resolution in Broadband
YAN Ling-wei
This paper studies the Czerny-Turner optical structure which is used for the application in imaging spectrometers. To obtain the perfect astigmatism-corrected condition, the Czerny-Turner system has been analyzed and advanced. The basic structure of optical system is still as the traditional form which is composed by tThis paper studies the Czerny-Turner optical structure which is used for the application in imaging spectrometers. To obtain the perfect astigmatism-corrected condition, the Czerny-Turner system has been analyzed and advanced. The basic structure of optical system is still as the traditional form which is composed by the spherical collimating mirror, the plane grating and the spherical focusing mirror. However, an off-the-shelf cylindrical lens is added after the focusing mirror to remove astigmatism differences between the tangential direction and the sagittal direction. It makes the advanced optical system presents high resolution over the full bandwidth and decreases the cost. An example of the imaging spectrum system in the waveband of 380~760 nm has been designed to prove our theory. A system owns that NA equals to 0.05, and the modulation transfer functions (MTF) of all fields of view are more than 0.59 over the broadband under the required Nyquist frequency (20 lp·mm-1). It certificates that the optical system theory can be applied to the small scale imaging spectrometer with high resolution in spectral broadband..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1756 (2015)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 6, 1 (2015)
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