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2014 Vol. 34, No. 07 Published: 2014-07-01

光谱学与光谱分析

	1729	Retrieval and Analysis of Atmospheric XCO₂ Using Ground-Based Spectral Observation
		QIN Xiu-chun^1,2, LEI Li-ping^1*, Kawasaki Masahiro³, Masafumi Ohashi⁴, Takahiro Kuroki⁴, ZENG Zhao-cheng⁵, ZHANG Bing¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1729-07
		Atmospheric CO₂ column concentration (column-averaged dry air mole fractions of atmospheric carbon dioxide) data obtained by ground-based hyperspectral observation is an important source of data for the verification and improvement of the results of CO₂ retrieval based on satellite hyperspectral observation. However, few studies have been conducted on atmospheric CO₂ column concentration retrieval based on ground-based spectral hyperspectral observation in China. In the present study, we carried out the ground-based hyperspectral observation in Xilingol Grassland, Inner Mongolia of China by using an observation system which is consisted of an optical spectral analyzer, a sun tracker, and some other elements. The atmospheric CO₂ column concentration was retrieved using the observed hyperspectral data. The effect of a wavelength shift of the observation spectra and the meteorological parameters on the retrieval precision of the atmospheric CO₂ concentration was evaluated and analyzed. The results show that the mean value of atmospheric CO₂ concentration was 390.9 μg·mL^-1 in the study area during the observing period from July to September. The shift of wavelength in the range between -0.012 and 0.042 nm will generally lead to 1 μg·mL^-1 deviation in the CO₂ retrievals. This study also revealed that the spectral transmittance was sensitive to meteorological parameters in the wavelength range of 6 357~6 358, 6 360~6 361, and 6 363~6 364 cm^-1. By comparing the CO₂ retrievals derived from the meteorological parameters observed in synchronous and non-synchronous time, respectively, with the spectral observation, it was showed that the concentration deviation caused by using the non-synchronously observed meteorological parameters is ranged from 0.11 to 4 μg·mL^-1. These results can be used as references for the further improvement of retrieving CO₂ column concentration based on spectral observation.
		2014 Vol. 34 (07): 1729-1735 [Abstract] ( 585 ) PDF (3227 KB) ( 522 )

	1736	A Study of the Coupling Relationship Between Concrete Surface Temperature and Concrete Surface Emissivity in Natural Conditions
		TANG Lin-ling¹, CHEN Xiao-ling², WANG Jia-ning³, ZHAO Hong-mei^1*, HUANG Qi-ting⁴
		DOI: 10.3964/j.issn.1000-0593(2014)07-1736-06
		Land surface emissivity (LSE) has already been recognized as a crucial parameter for the determination of land surface temperature (LST). There is an ill-posed problem for the retrieval of LST and LSE. And laboratory-based emissivity is measured in natural constant conditions, which is limited in the application in thermal remote sensing. To solve the above problems, the coupling of LST and LSE is explored to eliminate temperature effects and improve the accuracy of LES. And then, the estimation accuracy of LST from passive remote sensing images will be improved. For different land surface materials, the coupling of land surface emissivity and land surface temperature is various. This paper focuses on studying concrete surface that is one of the typical man-made materials in urban. First the experiments of measuring concrete surface emissivity and concrete surface temperature in natural conditions are arranged reasonably and the suitable data are selected under ideal atmosphere conductions. Then to improve the determination accuracy of concrete surface emissivity, the algorithm worked on the computer of Fourier Transform Infrared Spectroradiometer (FTIR) has been improved by the most adapted temperature and emissivity separation algorithm. Finally the coupling of concrete surface temperature and concrete surface emissivity is analyzed and the coupling model of concrete surface temperature and concrete surface emissivity is established. The results show that there is a highest correlation coefficient between the second derivative of emissivity spectra and concrete surface temperature, and the correlation coefficient is -0.925 1. The best coupling model is the stepwise regression model, whose determination coefficient (R²) is 0.886. The determination coefficient (R²) is 0.905 and the root mean squares error (RMSE) is 0.292 1 in the validation of the model. The coupling model of concrete surface temperature and concrete surface emissivity under natural conditions provides a new approach for improving the estimation accuracy of LST from passive remote sensing images.
		2014 Vol. 34 (07): 1736-1741 [Abstract] ( 813 ) PDF (1862 KB) ( 452 )

	1742	Determination of Components of Mixed Color Solutions by Fluorescence Spectroscopy Combined with Calibration Algorithms
		ZHU Chun^1,2，LI Run¹, QUE Li-zhi¹, ZHU Tuo³, CHEN Guo-qing^1*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1742-05
		The three-dimensional spectra of mixed solutions of allure red, sunset yellow and brilliant blue were obtained. Then the three synthetic food colors were determined by parallel factor analysis (PARAFAC) and alternating trilinear decomposition (ATLD) algorithms, respectively. The component number of model is three by core-consistency diagnostic. The average recoveries of allure red, sunset yellow and brilliant blue obtained by PARAFAC were 98.75%±8.9%, 97.22%±2.9% and 99.00%±2.9% and those by ATLD algorithm were 99.78%±5.9%, 92.52%±5.5% and 97.23%±5.8%, respectively. Results show that both of the algorithms can be used in direct and rapid determination of multi-components of mixtures. From further comparison, the PARAFAC is more stable and advantageous.
		2014 Vol. 34 (07): 1742-1746 [Abstract] ( 556 ) PDF (1881 KB) ( 677 )

	1747	Raman Spectroscopic Quantitative Study of NaCl-CaCl₂-H₂O System at High Temperatures and Pressures
		LI Jing¹, MAO Shi-de^1*, ZHENG Hai-fei^2,3
		DOI: 10.3964/j.issn.1000-0593(2014)07-1747-07
		Raman spectra features of the ternary system NaCl-CaCl₂-H₂O under high temperatures and high pressures were systematically studied in the present work by using hydrothermal diamond anvil cell (HDAC) and Raman shifts of quartz to determine pressures, and it has been obtained for the quantitative relationship between Raman shifts of the O—H stretching band of water, mass fractions of solutes and pressures was obtained. The mass fractions of salts, where salinity of NaCl equal to that of CaCl₂, are 4.0 mass%, 8.0 mass%, and 12.0 mass%, respectively. Experimental results indicate that the standardized Raman frequency shift differences of the O—H stretching vibration (Δν_(O—H)) rise with the increasing temperatures when the mass fractions of salts and pressures of the NaCl-CaCl₂-H₂O system remain constant. Δν_(O—H) increases with the increase in mass fractions of salts in the system when the temperatures and pressures are constant. Linear relationship between Δν_(O—H) and pressure with similar slopes can be found for the NaCl-CaCl₂-H₂O system with different salinities. The quantitative relationship between Δν_(O—H), temperature (T), pressure (P), and mass fraction of solute (M) is P＝-31.892Δν_(O—H)+10.131T+222.816M-3 183.567, where the valid PTM range of the equation is 200 MPa≤P≤1 700 MPa, 273 K≤T≤539 K and M≤12 mass%. The equation can be used as a geobarometer in the studies of fluid inclusions of NaCl-CaCl₂-H₂O system with equal salinities. The method, as a direct geological detecting technique, has a potential application value.
		2014 Vol. 34 (07): 1747-1753 [Abstract] ( 643 ) PDF (2830 KB) ( 256 )

	1754	Intensity Loss of Two-Photon Excitation Fluorescence Microscopy Images of Mouse Oocyte Chromosomes
		ZHAO Feng-ying¹, WU Hong-xin², CHEN Die-yan¹, MA Wan-yun^1*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1754-04
		As an optical microscope with high resolution, two-photon excitation (TPE) fluorescence microscope is widely used in noninvasive 3D optical imaging of biological samples. Compared with confocal laser scanning microscope, TPE fluorescence microscope provides a deeper detecting depth. In spite of that, the image quality of sample always declines as the detecting depth increases when a noninvasive 3D optical imaging of thicker samples is performed. Mouse oocytes with a large diameter, which play an important role in clinical and biological fields, have obvious absorption and scattering effects. In the present paper, we performed compensation for two-photon fluorescence images of mouse oocyte chromosomes. Using volume as a parameter, the attenuation degree of these chromosomes was also studied. The result of our data suggested that there exists a severe axial intensity loss in two-photon microscopic images of mouse oocytes due to the absorption and scattering effects. It is necessary to make compensation for these images of mouse oocyte chromosomes obtained from two-photon microscopic system. It will be specially needed in studying the quantitative three-dimensional information of mouse oocytes.
		2014 Vol. 34 (07): 1754-1757 [Abstract] ( 544 ) PDF (1577 KB) ( 282 )

	1758	Time Resolved Distribution of Excitation Energy in Collisions of Vibrationally Excited KH with CO₂
		FENG Li, LIU Jing, WANG Shu-ying, ZHANG Wen-jun, LI Jia-ling, DAI Kang, SHEN Yi-fan
		DOI: 10.3964/j.issn.1000-0593(2014)07-1758-05
		The vibrational levels of KH(Х¹Σ⁺ ν″=0～3) were generated in the reaction of K(5P) with H₂. The vibrationally excited KH(ν″=17) was populated by an overtone pump-probe configuration. Different characteristics of collisional energy transfer in highly and lowly excited vibrational levels of KH and CO₂ were investigated through measuring the time-resolved distribution of vibrational energy in KH(ν″=17,3)+CO₂ collisions. For KH(ν″=17), there existed three principal regions of vibration temperature (T_ν) in this equilibration process. The initial phase consists of very rapid fall in T_ν within ~5 μs, and the vibrational energy of KH(ν″=17) is mainly transferred to the vibrational levels of CO₂(00⁰1) or high rotational levels of CO₂(00⁰0). The second phase (5～20 μs) has a slight decline in T_ν, and the process of energy transfer to vibrational levels or high rotational levels of CO₂ has already finished. The vibration temperature of the third phase has a slightly more rapid decline compared with the last phase. This phase shows that the process of transfer to lowly rotational levels and translation energy of CO₂ is accelerated. The equilibration of vibrationally excited KH (ν″=3) in CO₂ was also investigated. There are similarities to the behavior of KH (ν″=17) in CO₂ plot, but also are significant differences. Once the initial resonant V-R exchange has equalized vibrational temperatures, there is a very slow linear decline in T_ν with equilibrium attained within ~80 μs. This same point is reached within 15 μs for KH (ν″=17). The data demonstrate that single rate coefficient measurements are unlikely to capture the complex nature of processes that generally are multistaged with different relaxation rates characterizing each different stage. Examination of the quantum state distributions reveals that these distinct stages reflect the dominance of specific energy transfer mechanisms, some of which are inherently fast and others are much slower. The energy gain into CO₂ resulting from collisions with excited KH was probed using transient absorption techniques. Distributions of nascent CO₂ rotational populations in both ground (00⁰0) state and the vibrationally excited (00⁰1) state were determined. A kinetic model was developed to describe rate coefficients for appearance of CO₂ states resulting from collisions with excited KH. These experiments show that collisions resulting in CO₂ (00⁰0) are accompanied by substantial excitation in rotation while the vibrationally excited CO₂ (00⁰1) state has rotational energy distributions near the initial distributions.
		2014 Vol. 34 (07): 1758-1762 [Abstract] ( 613 ) PDF (1131 KB) ( 266 )

	1763	A Study on the Relationship between the Composition and Spectral Feature Parameters in Chlorite
		LIANG Shu-neng^{1, 2}, GAN Fu-ping^{1, 2*}, YAN Bo-kun^{1, 2}, WEI Hong-yan¹, XIAO Chen-chao¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1763-06
		In order to explore the intrinsic relationship of mineral spectral characteristics and its composition, and provide the basis for the detection of mineral micro information by using hyperspectral technology, based on the thinsection analysis, the authors identified the minerals characteristics and mineral assemblages in rock samples, delineated typical chlorite minerals and divided the occurrence characteristics of chlorite. The authors measured chemical composition of146 typical chlorite mineral particles by using electron probe micro analysis technology, and calculated the relevant chemical parameters of n(Al^Ⅳ), n(Al^Ⅵ), n(Fe), n(Mg), and n(Fe)/n(Fe+Mg) ratio. In addition we analysed the rock and mineral spectra, and extracted chlorite characteristic spectral parameters. Therelationship between the spectra feature parameters and the main crystal chemical parameters in chlorite was analyzed. The study indicated that the diagnostic spectral wavelength of chlorites moved to long wavelength. The results have important guiding significance for identifying the alteration and rock forming mineral species, composition and structure characteristics by usinghyperspectral remote sensing technology.
		2014 Vol. 34 (07): 1763-1768 [Abstract] ( 867 ) PDF (3456 KB) ( 381 )

	1769	Measurements of CO₂ Concentration at High Temperature and Pressure Environments Using Tunable Diode Laser Absorption Spectroscopy
		CAI Ting-dong^{1, 2}, GAO Guang-zhen¹, WANG Min-rui¹, WANG Gui-shi², GAO Xiao-ming²
		DOI: 10.3964/j.issn.1000-0593(2014)07-1769-05
		The present research was planned to develop a method for species concentration measurements under high temperature and pressure environments. The characteristics of CO₂ spectrum at high temperature and pressure were studied at first. Based on the research above, tunable diode-laser absorption of CO₂ near 2.0 μm incorporating fixed-wavelength modulation spectroscopy with second-harmonic detection was used to provide a method for sensitive and accurate measurements of gas temperature and CO₂ concentration at high temperature and pressure. Measurements were performed in a well-controlled high temperature and pressure static cell. The results show that the average error of the CO₂ concentration measurements at 5 atm, 500 K and 10 atm, 1000 K is 4.49%. All measurements show the accuracy and potential utility of the method for high temperature and pressure diagnostics.
		2014 Vol. 34 (07): 1769-1773 [Abstract] ( 661 ) PDF (2755 KB) ( 301 )

	1774	Research on Spectrum Technology Based on SG-DBR Laser
		SHAO Jie¹, HAN Ye-xing¹, GUO Jie¹, WANG Li-ming¹, HAN Ying¹, YING Chao-fu¹, WANG Yao²
		DOI: 10.3964/j.issn.1000-0593(2014)07-1774-06
		Tunable diode laser absorption spectroscopy (TDLAS) is a highly sensitive, highly selective, noninvasive and real-time trace gas detection technique, which has been widely used in atmospheric monitoring and industrial control. In the present research, a new type of widely tunable SG-DBR diode laser (WTDL) with a tunable range of about 1 520~1 570 nm was use as the light source for tunable diode laser absorption spectroscopy combined with the wavelength modulation (wm) to measure the spectrum of multi-gases. Also the structure, performance and other characteristics of WTDL were introduced. There were 18 channels compiled to the SG-DBR laser, which emitted central wavelength at the optimum absorption transitions of CO, CO₂ and H₂O by homemade program, of which 14 channels (corresponding to absorption lines of CO and CO₂) were investigated by second harmonic detection technique. Meanwhile, the detectabilities in these channel were analyzed which are about 10^-5 at the peak absorbance. The experiment results validate the feasibility of SG-DBR laser used as light source in multi-gases detection using wavelength modulation absorption spectroscopy technique in practical application. That could effectively reduce the cost and complexity of system in the field of TDLAS technique.
		2014 Vol. 34 (07): 1774-1779 [Abstract] ( 722 ) PDF (2693 KB) ( 300 )

	1780	Measurement of Path Transverse Wind Velocity Profile Using Light Forward Scattering Scintillation Correlation Method
		YUAN Ke-e, Lü Wei-yu, ZHENG Li-nan, HU Shun-xing, HUANG Jian, CAO Kai-fa, XU Zhi-hai
		DOI: 10.3964/j.issn.1000-0593(2014)07-1780-05
		A new method for path transverse wind velocity survey was introduced by analyzing time lagged covariance function of different separation sub-apertures of Hartmann wavefront sensor. A theoretical formula was logically deduced for the light propagation path transverse wind velocity profile. According to the difference of path weighting function for different sub apertures spacing, how to select reasonable path weighting functions was analyzed. Using a Hartmann wavefront sensor, the experiment for measuring path transverse velocity profile along 1 000 m horizontal propagating path was carried out for the first time to our knowledge. The experiment results were as follows. Path transverse averaged velocity from sensor had a good consistency with transverse velocity from the wind anemometer sited near the path receiving end. As the path was divided into two sections, the path transverse velocity of the first section had also a good consistency with that of the second one. Because of different specific underlaying surface of light path, the former was greater than the later over all experiment period. The averaged values were 1.273 and 0.952 m·s^-1 respectively. The path transverse velocity of second section and path transverse averaged velocity had the same trend of decrease and increase with time. The correlation coefficients reached 0.86.
		2014 Vol. 34 (07): 1780-1784 [Abstract] ( 534 ) PDF (2290 KB) ( 232 )

	1785	Analysis of Heavy Metals Distribution Characteristics and Pollution Assessment in Agricultural Region Soils of Huaihe Basin
		XIAO Xue¹, ZHAO Nan-jing^1*, YUAN Jing², MA Ming-jun¹, FANG Li¹, WANG Yin¹, MENG De-shuo¹, YU Yang¹, TANG Jie², ZHANG Xiao-ling¹, DAI Yuan², ZHANG Yu-jun¹, LIU Jian-guo¹, LIU Wen-qing¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1785-04
		By means of field sampling and laboratory analysis, the content distribution characteristics of Cd, Cr, Cu, Ni, Pb and Zn in agricultural region soils of Huaihe basin in Anhui province were analyzed. Assessment of heavy metal pollutions was conducted using enrichment factor, geoaccumulation index and potential ecological risk index. The results showed that the average mass fraction of Cd and Cu was 0.113 5 and 22.09 mg·kg^-1 respectively in the study area soil, which were above the background values 0.097 and 20.4 mg·kg^-1 in Anhui Province. The average mass fraction of other four heavy metals did not exceed the average values of Anhui Province. The results of the evaluations from geoaccumulation index and ecological risk assessment discovered that Cd is the strongest pollution metal among six heavy metals in the study area soil. For some samples of the study soil, Cd was slight risk for the ecosystem. The ecosystem risks caused by the other five heavy metals were not obviously for the sampling points. The entire study area soils were mid integrated potential ecological risk.
		2014 Vol. 34 (07): 1785-1788 [Abstract] ( 598 ) PDF (1172 KB) ( 319 )

	1789	Effects of Annealing Temperature on the Structure and Optical Properties of ZnMgO Films Prepared by Atom Layer Deposition
		SUN Dong-xiao¹, LI Jin-hua^1*, FANG Xuan^{1, 2}, CHEN Xin-ying¹, FANG Fang¹, CHU Xue-ying¹, WEI Zhi-peng^{1, 2}, WANG Xiao-hua¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1789-04
		In the present paper, we report the research on the effects of annealing temperature on the crystal quality and optical properties of ZnMgO films deposited by atom layer deposition(ALD). ZnMgO films were prepared on quartz substrates by ALD and then some of the samples were treated in air ambient at different annealing temperature. The effects of annealing temperature on the crystal quality and optical properties of ZnMgO films were characterized by X-ray diffraction (XRD), photoluminescence (PL) and ultraviolet-visible (UV-Vis) absorption spectra. The XRD results showed that the crystal quality of ZnMgO films was significantly improved when the annealing temperature was 600 ℃，meanwhile the intensity of(100)diffraction peak was the strongest. Combination of PL and UV-Vis absorption measurements showed that it can strongly promote the Mg content increasing in ZnMgO films and increase the band gap of films. So the results illustrate that suitable annealing temperature can effectively improve the crystal quality and optical properties of ZnMgO films.
		2014 Vol. 34 (07): 1789-1792 [Abstract] ( 626 ) PDF (1591 KB) ( 287 )

	1793	Research on Spectrum Correction Algorithm of Temperature Measurement System Based on FBG
		LIU Zhi-chao^1,2, YANG Jin-hua¹, WANG Gao³
		DOI: 10.3964/j.issn.1000-0593(2014)07-1793-04
		In order to solve the problem that temperature sensor laying is complex and maintenance cost is high in the large-scale, multi-point real-time temperature monitoring process, the temperature monitoring system based on Fiber Bragg Grating was designed and developed. Using wavelength selectivity by optical fiber diffraction grating,a function of temperature and wavelength was established. Temperature of the measured position was inversed by calculating the wavelength variation through the optical fiber Bragg grating. Due to environmental, materials and other factors, the spectral distribution and temperature changes do not satisfy linear relationship. Therefore, designed the spectrum correction algorithm was designed, and function curve fitting of wavelength and temperature was completed with a degree of fitting greater than 99.7%. Experiments used FB136L-IAC-proof oven, LPT-200 diode, and 1 550 nm optical fiber to detect 20 to 280 ℃ temperature range of multi-point in real-time. The results show that when the temperature is changed by 1 ℃, the corresponding center wavelength shifts about 0.04 nm to longer wavelengths. Compared with the test data from standard device, the error is less than ±0.3 ℃. Meanwhile, the spectral correction algorithm was applied to the system to further improve the uniformity and accuracy of the temperature detection. Because the system uses fiber-optic sensor network, it has a strong anti-electromagnetic interference capability. The diffraction grating can achieve precise measurements, so it has big dynamic range and high accuracy. The innovation of the system is to ensure high-precision measurements, while still satisfy large-scale, multi-point, high anti-jamming capability of rapid laying, and has a strong practical value.
		2014 Vol. 34 (07): 1793-1796 [Abstract] ( 562 ) PDF (1434 KB) ( 227 )

	1797	Design and Experiment of a Needle-to-Cylinder Electrode Structure Realizing the Negative DC Glow Discharge in Ambient Air
		LI Hua¹, WEI Chang-yan¹, LIU Chun-xia¹, SHEN Xian-hao², CHEN Zhen-cheng^1*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1797-04
		A new needle-to-cylinder electrode structure was designed to realize the stable glow discharge in ambient air. The stainless steel needle tip with diameter 56.4 μm and the copper cylinder with diameter 4mm were chosen as the cathode and the anode respectively, which were kept parallel by accurate mechanical structure. In the condition that the distance between the needle and the cylinder is 2 mm, the ballasting resistor is 10 MΩ, the discharge resistor is 10 MΩ, the testing resistor is 1 kΩ, and the discharge voltage is -2 740 V, without air flow in ambient air and at room temperature, the stable glow discharge between the needle and the cylinder was realized. Three different discharge modes can be observed: corona discharge, glow discharge and spark, which were verified by the discharge waveform stored in the oscilloscope, and the discharge pictures were recorded by digital camera. The needle-to-cylinder electrode structure is easy to fabricate by the MEMS technology, which can be used as the ion source of the portable analyzing instruments.
		2014 Vol. 34 (07): 1797-1800 [Abstract] ( 600 ) PDF (2264 KB) ( 288 )

	1801	Investigation of Plasma Parameters of the Square Pattern with Two Kinds of Spatiotemporal Symmetry in Dielectric Barrier Discharge
		WANG Yong-jie, DONG Li-fang^*, ZHAO Long-hu, LIU Wei-bo, ZHANG Xin-pu, ZHANG Chao
		DOI: 10.3964/j.issn.1000-0593(2014)07-1801-04
		Two kinds of square patterns with different spatiotemporal symmetry were observed in dielectric barrier discharge, and their plasma parameters were measured by using optical emission spectra. It was found that the spatiotemporal symmetry of the square pattern at lower gas pressure is different from the one at higher gas pressure. Six spectral lines in the emission spectrum of the N₂ second positive band were chosen to estimate the vibrational temperature, and the ratio of I_391.4/I_394.1 was used to represent the average electron energy. The excitation temperature was determined by the ratio of I_763.2/I_772.1. Furthermore, the width and shift of Ar Ⅰ 696.54 nm were used to estimate the electron density. The results show that the vibrational temperature, excitation temperature and electron energy of the square pattern at lower gas pressure are higher than those at higher gas pressure, while the electron density is lower than that at higher gas pressure.
		2014 Vol. 34 (07): 1801-1804 [Abstract] ( 648 ) PDF (2575 KB) ( 271 )

	1805	Theory Study of the Structures and IR of (C₅H₅N)_n(H₂O)_m(n=1～2, m=1～4) Clusters
		LI Xiao-ming, ZHANG Lai-bin, ZHOU Liu-zhu, KONG Xiang-he^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1805-06
		Using density functional theory, the possible geometrical structures of (C₅H₅N)_n(H₂O)_m(n=1～2, m=1～4) clusters were optimized at the B3LYP/6-311++G(d，p) level and the stable structures were attained. For the dimer formed between C₅H₅N and H₂O, the calculation result shows that there is only one stable structure and the configuration of cluster formed through π hydrogen bond (O—H…π) interaction was not found. In order to study the stability of the clusters, the total energies and binding energies of the clusters were calculated at the same level of theory, and the result shows that the four-membered ring structures of water molecules in (C₅H₅N)_n(H₂O)₄(n=1～2) clusters are more stable than structures of the triatomic ring of water molecules. The lowest energy structure of the C₅H₅N(H₂O)₄ cluster is more stable than the others and is probably a magic number structure by the analysis to the energy gap between HOMO and LUMO. At the end, the IR spectra of (C₅H₅N)_n(H₂O)_m(n=1～2, m=1～4) clusters were analysed and the stronger peaks appearing in infrared spectra were assigned.
		2014 Vol. 34 (07): 1805-1810 [Abstract] ( 658 ) PDF (2581 KB) ( 280 )

	1811	Hyperspectral Optimum Wavelengths and Fisher Discrimination Analysis to Distinguish Different Concentrations of Aflatoxin on Corn Kernel Surface
		CHU Xuan¹, WANG Wei^1*, ZHANG Lu-da², GUO Lang-hua¹, Peggy Feldner³, Gerald Heitschmidt³
		DOI: 10.3964/j.issn.1000-0593(2014)07-1811-05
		Aflatoxin is a toxic metabolite widely existing in corn. In the present paper, the feasibility of detecting aflatoxin on corn kernel surface by hyperspectral imaging technology was verified. The corn called pioneer with the same shape is provided by Toxicology and Mycotoxin Research Unit. With methanol configuration, four different concentrations of aflatoxin solutions were prepared and dripped on every 30 corn kernels. Also other clean 30 kernels without aflatoxin dripped were prepared to be the control samples. Among the 150 kernel samples, 103 training samples and 47 validation samples were prepared randomly. Firstly, hyperspectral image in the range of 400 to 1 000 nm was collected .For eliminating the deviations in original spectrum, standard normal variate transformation (SNV) was adopted as pretreatment method. And then several optimum wavelengths were selected by the principle of minimum misdiagnosis rate. After that the selected optimum wavelengths were taken as the input of the Fisher discrimination analysis to discriminate the different concentrations of aflatoxin on the corn. Finally, the discrimination model based on four optimum wavelengths (812.42, 873.00, 900.36 and 965.00 nm) was built and the accuracy of the model was tested. Results indicate that the classification accuracy of calibration and validation set was 87.4% and 80.9% respectively. This method provides basis for designing the corresponding portable instrument and distinguishing aflatoxin produced by naturally metabolism in corn.
		2014 Vol. 34 (07): 1811-1815 [Abstract] ( 910 ) PDF (1595 KB) ( 415 )

	1816	Spectral Scatter Correction of Coal Samples Based on Quasi-Linear Local Weighted Method
		LEI Meng, LI Ming^*, MA Xiao-ping, MIAO Yan-zi, WANG Jian-sheng
		DOI: 10.3964/j.issn.1000-0593(2014)07-1816-05
		The present paper puts forth a new spectral correction method based on quasi-linear expression and local weighted function. The first stage of the method is to search 3 quasi-linear expressions to replace the original linear expression in MSC method, such as quadratic, cubic and growth curve expression. Then the local weighted function is constructed by introducing 4 kernel functions, such as Gaussian, Epanechnikov, Biweight and Triweight kernel function. After adding the function in the basic estimation equation, the dependency between the original and ideal spectra is described more accurately and meticulously at each wavelength point. Furthermore, two analytical models were established respectively based on PLS and PCA-BP neural network method, which can be used for estimating the accuracy of corrected spectra. At last, the optimal correction mode was determined by the analytical results with different combination of quasi-linear expression and local weighted function. The spectra of the same coal sample have different noise ratios while the coal sample was prepared under different particle sizes. To validate the effectiveness of this method, the experiment analyzed the correction results of 3 spectral data sets with the particle sizes of 0.2, 1 and 3 mm. The results show that the proposed method can eliminate the scattering influence, and also can enhance the information of spectral peaks. This paper proves a more efficient way to enhance the correlation between corrected spectra and coal qualities significantly, and improve the accuracy and stability of the analytical model substantially.
		2014 Vol. 34 (07): 1816-1820 [Abstract] ( 595 ) PDF (3663 KB) ( 358 )

	1821	Rapid Quantitative Analysis of Hydrocarbon Composition of Furfural Extract Oils Using Attenuated Total Reflection Infrared Spectroscopy
		LI Na¹, YUAN Hong-fu^1*, HU Ai-qin¹, LIU Wei¹, SONG Chun-feng¹, LI Xiao-yu¹, SONG Yi-chang², HE Qi-jun², LIU Sha², XU Xiao-xuan³
		DOI: 10.3964/j.issn.1000-0593(2014)07-1821-05
		A set of rapid analysis system for hydrocarbon composition of heavy oils was designed using attenuated total reflection FTIR spectrometer and chemometrics to determine the hydrocarbon composition of furfural extract oils. Sixty two extract oil samples were collected and their saturates and aromatics content data were determined according to the standard NB/SH/T0509-2010，then the total contents of resins plus asphaltenes were calculated by the subtraction method in the percentage of weight. Based on the partial least squares(PLS), calibration models for saturates, aromatics, and resin+asphaltene contents were established using attenuated total reflection FTIR spectroscopy, with their SEC, 1.43%, 0.91% and 1.61%, SEP, 1.56%, 1.24% and 1.81%，respectively，meeting the accuracy and repeatability required for the standard. Compared to the present standard method，the efficiency of hydrocarbon composition analysis for furfural extract oils is significantly improved by the new method which is rapid and simple. The system could also be used for other heavy oil analysis, with excellent extension and application foreground.
		2014 Vol. 34 (07): 1821-1825 [Abstract] ( 659 ) PDF (2495 KB) ( 384 )

	1826	Application of Near-Infrared Spectroscopy to Distinguish Brands of Soy Milk Powder and Fake Soy Milk Powder
		ZHANG Chu, LIU Fei, KONG Wen-wen, HE Yong^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1826-05
		Near-infrared spectroscopy combined with chemometrics was used to investigate the feasibility of identifying different brands of soymilk powder and the counterfeit soymilk powder products. For this purpose, partial least squares-discriminant analysis (PLS-DA), linear discriminant analysis (LDA) and back-propagation neural network (BPNN) were employed as pattern recognition methods to class ify soymilk powder samples. The performances of different pretreatments of raw spectra were also compared by PLS-DA. PLS-DA models based on De-trending and multiplicative scatter correction (MSC)combined with De-trending(MSC+De-trending) spectra obtained best results with 100% prediction accuracy, respectively. Six and seven optimal wavenumbers selected by x-loading weights of the best two PLS-DA models were used to build LDA and BPNN models. Results showed that BPNN performed best and correctly classified 100% of the soymilk powder samples for both the calibration and the prediction set. The overall results indicated that NIR spectroscopy could accurately identify branded and counterfeit soymilk powder products.
		2014 Vol. 34 (07): 1826-1830 [Abstract] ( 473 ) PDF (1278 KB) ( 349 )

	1831	Study on Rapid Identification of Medicinal Plants of Paris Polyphylla from Different Origin Areas by NIR spectroscopy
		ZHAO Yan-li¹, ZHANG Ji¹, YUAN Tian-jun², SHEN Tao³, HOU Ying², YANG Shi-hua², LI Wei², WANG Yuan-zhong^1, JIN Hang^1
		DOI: 10.3964/j.issn.1000-0593(2014)07-1831-05
		Based on near infrared spectroscopy, seventy samples of wild medicinal plants of paris polyphylla from Guizhou, Guangxi and Yunnan Provinces were collected to identify their geographical origins. Multiplication signal correction (MSC), standard normal variate (SNV), first derivative (FD), second derivative (SD), savitzky-Golay filter (SG), and Norris derivative filter (ND) were conducted to optimize the original spectra of fifty samples of training set. The results showed that the method MSC combined with SD and ND presented the best results of spectra pretreatment. According to spectrum standard deviation, spectrum range (7 450～4 050 cm^-1) was chosen and principal component analysis-mahalanobis distance (PCA-MD) method was used to build the model. Its first three principal components, i.e. cumulative contribution, determination coefficient (R²), root-mean-square error of calibration (RMSEC) and root-mean-square error of prediction (RMSEP) were 89.44%, 97.58%, 0.179 6 and 0.266 4, respectively, and the prediction accuracy is 90%. Furthermore, according to variable importance plot (VIP), spectrum range (7 135.33～4 007.35 cm^-1) was chosen and partial least square discrimination analysis (PLS-DA) was applied to establish the model. Its first three principal components cumulative contribution, R², RMSEC and RMSEP were 89.28%, 95.88%, 0.234 8 and 0.348 2, respectively, and the prediction accuracy is 100%. Comparing the two methods, we found that spectrum range chosen by VIP and model built by PLS-DA could provide greater accuracy in identifying paris polyphylla from different origin areas. The method supplied foundation for authenticity and quality evaluation of traditional Chinese medicine.
		2014 Vol. 34 (07): 1831-1835 [Abstract] ( 644 ) PDF (2085 KB) ( 360 )

	1836	The Spectral Characteristic Wavelength Selection and Parameter Optimization Based on Tikhonov Regularization
		ZHAO An-xin^{1, 2}, TANG Xiao-jun^2*, ZHANG Zhong-hua^{2, 3}, LIU Jun-hua²
		DOI: 10.3964/j.issn.1000-0593(2014)07-1836-04
		In the multicomponent mixture hydrocarbon gases Fourier transform infrared (FTIR) quantitative analysis, especially for light alkane gases, it is not easy to establish the quantitative analysis model because their IR spectra absorption peaks are seriously overlapped. Aiming at this problem, the Tikhonov regularization algorithm was used to select the characteristic wavelengths for seven kinds of light alkane mixture gases FTIR which are composed with methane, ethane, propane, iso-butane, n-butane, iso-pentane and n-pentane. And then the wavelength selection was used to establish the quantitative analysis model. By comparing the analysis characteristics wavelength selection and TR parameters optimization of the mixed gases in the infrared all wave band, the first absorption peak band and the second peak band, the characteristic wavelength of 7 kinds of gases were selected by Tikhonov algorithm. The wavelength selection and Tikhonov regularization parameters were used to test the actual measured methane spectral data, and then we got that with other gas components the max cross sensitivity was 11.153 7%, the minimum cross sensitivity was 1.239 7%, and the root mean square prediction error was 0.004 8. The Tikhonov regularization algorithm effectively enhanced the accuracy in the light alkane mixed gas quantitative analysis. The feasibility of alkane gases mixture Fourier transform infrared spectrum wavelength selection was preliminarily verified by using the Tikhonov regularization algorithm.
		2014 Vol. 34 (07): 1836-1839 [Abstract] ( 552 ) PDF (2447 KB) ( 250 )

	1840	Identification of Chinese Herbal Medicines Based on Terahertz Spectroscopy Analysis
		ZHOU Yong-jun^1,2, LIU Jin-song¹, WANG Ke-jia¹, YANG Zhen-gang¹, ZHANG Hui²
		DOI: 10.3964/j.issn.1000-0593(2014)07-1840-04
		In order to study the feasibility of the identification of Chinese herbal medicines based on terahertz spectroscopy, the optical characteristic of astragalus, angelica, eucommia and three kinds of astragalus samples with different impurities in the frequency range 0.2~2.2 THz were researched by terahertz time-domain spectroscopy (THz-TDS), and their time-domain spectra, the frequency spectra and the absorption spectra were obtained at room temperature. The results indicated that the time-domain spectra, frequency-domain spectra and absorption spectra of astragalus, angelica, and eucommia have large differences in such a frequency range, the frequency-domain spectra and absorption spectra of three kinds of astragalus samples with different impurities are similar but there exists distinct difference. These researches proved that it is feasible to use terahertz time-domain spectroscopy to identify Chinese herbal medicine and provided a new method for Chinese herbal medicine quality control.
		2014 Vol. 34 (07): 1840-1843 [Abstract] ( 566 ) PDF (2078 KB) ( 794 )

	1844	Protein Content Determination of Shiitake Mushroom (Lentinus edodes) Using Mid-Infrared Spectroscopy and Chemometeics
		ZHU Zhe-yan^{1, 2}, LIU Fei^2, ZHANG Chu², KONG Wen-wen², HE Yong^2
		DOI: 10.3964/j.issn.1000-0593(2014)07-1844-05
		The feasibility of protein determination of shiitake mushroom (Lentinus edodes) using mid-infrared spectroscopy (MIR) was studied in the present paper. Wavenumbers 3 581～689 cm^-1 were used for quantitative analysis of protein content after removing of the part of obvious noises. Five points Savitzky-Golay smoothing was applied to pretreat the MIR spectra and partial least squares (PLS) model was built based on the pretreated spectra. The full spectra PLS model obtained poor performance with the ratio ofprediction to deviation (RPD) of only 1.77. Successive projections algorithm (SPA) was applied to select 7 sensitive wavenumbers from the full spectra, and PLS model, multiple linear regression (MLR), back-propagation neural network (BPNN) and extreme learning machine (ELM) model were built using the selected sensitive wavenumbers. SPA-PLS model and SPA-MLR model obtained relatively worse results than SPA-BPNN model and SPA-ELM model. SPA-ELM obtained the best results with correlation coefficient of prediction (R_p) of 0.899 5, root mean square error of prediction (RMSEP) of 1.431 3 and RPD of 2.18. The overall results indicated that MIR combined with chemometrics could be used for protein content determination of shiitake mushroom, and SPA could select sensitive wavenumbers to build more accurate models instead of the full spectra.
		2014 Vol. 34 (07): 1844-1848 [Abstract] ( 601 ) PDF (2434 KB) ( 441 )

	1849	*Study on Panax Notoginseng* and Its Processed Products by FTIR Spectroscopy**
		HUANG Dong-lan¹, CHEN Xiao-kang^1*, XU Yong-qun¹, SUN Su-qin², LU Wen-guan¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1849-04
		The chemical differences of panax notoginseng before and after processing were analyzed by Fourier transform Infrared spectroscopy (FTIR) combined with two-dimensionalcorrelation spectroscopy (2D-IR). Compared with conventional IR spectra of the samples, the FTIR spectra of panax notoginseng and its processed products were similar in the range of 1 200～400 cm^-1. The difference was that prepared panax notoginseng had strong and characteristic peaks at 2 925，2 855，1 746，1 460，1 376 and 1 158 cm^-1, which all arose from the characteristic vibration of peanut oil. This was because there was some peanut oil left in the panax notoginseng, when panax notoginseng after processing. Obvious differences were observed between 2D-IR spectra of them, in the range of 1 400～1 700 cm^-1, there was only one auto peaks at 1 650 cm^-1 in the spectra of panax notoginseng, but there were auto peaks at 1 469 and 1 640 cm^-1 in the spectra of prepared panax notoginseng. In the range of 1 400～1 700 cm^-1, the 2D-IR spectra of panax notoginseng and its processed product present characterstic peaks at 1 139(1 137)，1 194(1 196)，1 121(1 221)cm^-1 respectively, but the relative intensities of auto peaks were changed. For example, auto peak around 1 139 cm^-1 was enhanced, but auto peak around 1 194 cm^-1 was weakened. The results of 2D-IR correlation spectroscopy indicated the decomposition of flavonoids, saccharides and saponins. This method can track dynamically the processingprocedure of panax notoginseng and reveal the main tansformations, so it can explain the pharmacology of panax notoginseng and its processed product by FTIR and 2D-IR.
		2014 Vol. 34 (07): 1849-1852 [Abstract] ( 677 ) PDF (2423 KB) ( 359 )

	1853	*Detection of Puccinia striiformis* f. sp. tritici Latent Infections in Wheat Leaves Using Near Infrared Spectroscopy Technology**
		LI Xiao-long¹, MA Zhan-hong¹, ZHAO Long-lian², LI Jun-hui², WANG Hai-guang^1*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1853-06
		To realize the early detection of P. striiformis f. sp. tritici latent infections in wheat leaves while no disease symptoms appear, a qualitative model for identification of the wheat leaves in the incubation period of stripe rust was built using near infrared reflectance spectroscopy (NIRS) technology combined with qualitative partial least squares (DPLS). In this study, 30 leaf samples infected with P. striiformis f. sp. tritici were collected each day during the eleven-day incubation period. And 30 healthy leaf samples and 30 leaf samples showing disease symptoms infected with P. striiformis f. sp. tritici, were also collected as controls. In total, there were 390 leaf samples that were divided into thirteen categories. Near infrared spectra of 390 leaf samples were obtained using MPA spectrometer and then a model to identify the categories of wheat leaves was built using cross verification method. The effects of different spectral ranges, samples for building the model, preprocessing methods of spectra and number of principal components on NIRS prediction results for qualitative identification were investigated. The optimal identification results were obtained for the model built in the combined spectral region of 5 400～6 600 and 7 600～8 900 cm^-1 when the spectra were divided into the training set and the testing set with the ratio equal to 4∶1, “scatter correction” was used as the preprocessing method and the number of principal components was 14. Accuracy rate, misjudgment rate and confusion rate of the training set were 95.51%, 1.28% and 3.21%, respectively. And accuracy rate, misjudgment rate and confusion rate of the testing set were 100.00%, 0.00% and 0.00%, respectively. The result showed that using near infrared reflectance spectroscopy technology, P. striiformis f. sp. tritici latent infections in wheat leaves could be detected as early as one day after inoculation (or 11 days before symptoms appearing) and the number of days when the leaf has been infected could also be identified. The results indicated that the method using near infrared reflectance spectroscopy technology proposed in this study is feasible for the identification of wheat leaves latently infected by P. striiformis f. sp. tritici. A new method based on NIRS was provided for the early detection of wheat stripe rust in this study.
		2014 Vol. 34 (07): 1853-1858 [Abstract] ( 570 ) PDF (1472 KB) ( 355 )

	1859	Application of Surface-Enhanced Raman Spectroscopy to the Determination of Trace Chemical Hazards in Food Products
		FAN Yu-xia, LAI Ke-qiang, HUANG Yi-qun^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1859-06
		In the present review, we summarized the research progress in applying SERS for the determination of illegal food additives, residual pesticides, banned or restricted antibiotics and other drugs. The nanosubstrates used in these studies included, but were not limited to, gold and silver nanosphere colloids, solid surface gold coated nanosubstrates, bimetallic nanosubstrates and spherical magnetic-core gold-shell nanoparticles, and etc. Standard solutions of a targeted chemical were normally tested first before analysis of relevant food in which the targeted chemical was commonly detected, and the tested food products included dairy products, condiments (such as chili powder and spices), fish, fruits and vegetables. The intensity of surface-enhanced Raman scattering signal is affected by various factors, which makes it difficult to obtain reproducible spectra. In addition, interferences of non-targeted food components on the target molecules during SERS analyses further makes it difficult to apply SERS as a routine analytic technique, despite its high specificity and sensitivity. Nevertheless, SERS is a new tool with great potential for analysis of trace amounts of chemical hazards in various food products and other complex systems.
		2014 Vol. 34 (07): 1859-1864 [Abstract] ( 851 ) PDF (860 KB) ( 883 )

	1865	Rapid Detection of Chlorinated Organic Mixture by Laser Raman Spectroscopy
		MA Jing
		DOI: 10.3964/j.issn.1000-0593(2014)07-1865-04
		In order to realize the rapid, nondestructive detection of organic compounds, a two-dimensional analysis method based on technology of laser Raman spectroscopy was proposed. The results show that using 532 nm laser as excitation light source, the observation of 236.2, 348.9, 449.4 and 513.6 cm^-1, the four vibrational Raman spectra, and the intensity ratio of 6.4∶1.7∶9.4∶1.0 can determine the existence of tetrachloroethylene. The observation of 707.5，1 087.9，1 175.8 and 3 078.6 cm^-1, the four vibrational Raman spectra, and the intensity ratio of 9.6∶6.4∶1.0∶3.9 can determine the existence of chlorobenzene. In other words, that through the comprehensive study of spectral lines and intensity ratio of some spectral lines, the presence of organic compounds in the mixed solution can be determined quickly. In the aspect of quantitative analysis, using multi-spectral analysis combined with least square fitting method can improve the reliability of the measurement，The accuracy of sample concentration was 98.4%. This spectral measurement method is a potential tool for organic component identification and concentration analysis which has a prosperous application prospects.
		2014 Vol. 34 (07): 1865-1868 [Abstract] ( 593 ) PDF (1735 KB) ( 438 )

	1869	Effect of Temperature on the Structure of CaO-MgO-Al₂O₃-SiO₂ Nanocrystalline Glass-Ceramics Studied by Raman Spectroscopy
		LI Bao-wei¹, OUYANG Shun-li^1*, ZHANG Xue-feng¹, JIA Xiao-lin^1,2, DENG Lei-bo¹, LIU Fang¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1869-04
		In the present paper, nanocrystalline glass-ceramic of CaO-MgO-Al₂O₃-SiO₂ system was produced by melting method. The CaO-MgO-Al₂O₃-SiO₂ nanocrystalline glass-ceramic was measured by Raman spectroscopy in the temperature range from -190 to 310 ℃ in order to study the effect of temperature on the structure of this system nanocrystalline glass-ceramics. The results showed that different non-bridge oxygen bond silicon-oxygen tetrahedron structural unit changes are not consistent with rising temperature. Further analyses indicated that: the SiO₄ tetrahedron with 2 non-bridged oxygen (Q²), the SiO₄ tetrahedron with 3 non-bridged oxygen (Q¹), which are situated at the edge of the 3-D SiO₄ tetrahedrons network, and the SiO₄ tetrahedron with 4 non-bridged oxygen (Q⁰), which is situated outside the 3-D network all suffered a significant influence by the temperature change, which has been expressed as: shifts towards the high wave-number, increased bond force constants, and shortened bond lengths. This paper studied the influence of temperature on CMAS system nanocrystalline glass-ceramics using variable temperature Raman technology. It provides experiment basis to the research on external environment influence on CMAS system nanocrystalline glass-ceramics materials in terms of structure and performance. In addition, the research provides experimental basis for controlling the expansion coefficient of nanocrystalline glass-ceramic of CaO-MgO-Al₂O₃-SiO₂ system.
		2014 Vol. 34 (07): 1869-1872 [Abstract] ( 613 ) PDF (1363 KB) ( 235 )

	1873	A Review of Atmospheric Aerosol Research by Using Polarization Remote Sensing
		GUO Hong^{1, 2}, GU Xing-fa^1*, XIE Dong-hai³, YU Tao¹, MENG Qing-yan¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1873-08
		In the present paper, aerosol research by using polarization remote sensing in last two decades (1993—2013) was reviewed, including aerosol researches based on POLDER/PARASOL, APS(Aerosol Polarimetry Sensor), Polarized Airborne camera and Ground-based measurements. We emphasize the following three aspects: (1)The retrieval algorithms developed for land and marine aerosol by using POLDER/PARASOL; The validation and application of POLDER/PARASOL AOD, and cross-comparison with AOD of other satellites, such as MODIS AOD. (2) The retrieval algorithms developed for land and marine aerosolby using MICROPOL and RSP/APS.We also introduce the new progress in aerosol research based on The Directional Polarimetric Camera(DPC), which was produced by Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (CAS). (3)The aerosol retrieval algorithms by using measurements from ground-based instruments, such as CE318-2 and CE318-DP.The retrieval results from spaceborne sensors, airborne camera and ground-based measurements include total AOD, fine-mode AOD, coarse-mode AOD, size distribution, particle shape, complex refractive indices, single scattering albedo, scattering phase function, polarization phase function and AOD above cloud. Finally, based on the research, the authors present the problems and prospects of atmospheric aerosol research by using polarization remote sensing, and provide a valuable reference for the future studies of atmospheric aerosol.
		2014 Vol. 34 (07): 1873-1880 [Abstract] ( 922 ) PDF (2456 KB) ( 429 )

	1881	Determination of Chemical Rank of Three-Dimensional Fluorescence Spectra Using Mathematical Morphology Method
		YU Xiao-ya, ZHANG Yu-jun^*, YIN Gao-fang, XIAO Xue, ZHAO Nan-jing, LIU Wen-qing
		DOI: 10.3964/j.issn.1000-0593(2014)07-1881-05
		The present paper firstly denoises the signal with morphological method, selecting sine-shaped structure element, using the morphological difference in waveform between the three-dimensional fluorescence and noise signal, then singular value decomposition is applied to the denoised data, and finally the chemical rank is determinated jointing eigenvalues and eigenvectors form singular value decomposition. This paper principally discusses the theory basis of morphological filtering method, firstly simulated data is analysed by morphological filtering method to confirm the necessity and effectiveness of proposed method, then the feasibility and practicability of the proposed method is verified by the determination of components number of phenols mixture three-dimensional fluorescence spectra compared with traditional Monte Carlo method. The experiments demonstrate that the proposed method is able to estimate the chemical rank correctly.
		2014 Vol. 34 (07): 1881-1885 [Abstract] ( 730 ) PDF (4897 KB) ( 658 )

	1886	Quantitative Detection of Hydroxyl Radical Generated in Quartz Powder/Phosphate Buffer Solution System by Fluorescence Spectrophotometry
		LIU Li-zhu^{1, 2}, DONG Fa-qin^2*, SUN Shi-yong², HE Xiao-chun², WANG Ming-cui³
		DOI: 10.3964/j.issn.1000-0593(2014)07-1886-04
		Quartz powder would release radical hydroxyl in phosphate buffer solution. In order to detect the quantity of radical hydroxyl with a quite low concentration, the present paper established a fluorescence method. According to the relationship between the concentration of 2-hydroxyl of terephthalic acid (HOTP) and fluorescence intensity at the wavelength of EX_max/EM_max=316 nm/422 nm, a working standard curve was constructed. Then through the filtrated fluorescence intensity obtained from the powder and solution system, cumulative concentration of ·OH can be measured indirectly. By repeating tests and analysis of five different experimental conditions of ·OH cumulative concentration, the minimum detection limit of the method reached 1.59×10^-10 mol·L^-1, with a relative deviation of 1.20%~7.89%, standard deviation was 1.09×10^-9~2.17×10^-9 mol·L^-1 and the relative standard deviation was 3.5%~5.8%. The method features high accuracy and good repeatability performance. Compared to other quantitative studies, this method might be applied to test radical hydroxy produced in pH neutral solution systems. In addition, it has apparent advantages such as low detection limit, low cost, higher sensitivity, and better stability and reproducibility. That provides the means for the quantitative study of mixed systems consisting of quartz powder and phosphate buffered solution.
		2014 Vol. 34 (07): 1886-1889 [Abstract] ( 639 ) PDF (1270 KB) ( 379 )

	1890	Ultraviolet Spectroscopic Study on the Fine Structures in the Solar Polar Hole
		ZHANG Min^{1, 2}, WANG Dong¹, LIU Guo-hong¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1890-04
		Fine structures in the south solar polar coronal hole were observed by N Ⅳ line of SOHO/SUMER spectrograph. The scales of the fine structures range spatially range from 1 arcsec to several arcsecs, temporally from 1 min to several minutes, and parts of them are in strip shape along the slit direction. The line-of-sight velocity of them is up to tens of km·s^-1 with red and blue shift intercrossed occasionally, which appear periodically as long as 100 minutes in some regions. Part of the fine structures can be clearly observed at the Ne ⅤⅢ line with higher formation temperature in the same spectral window. The time and location of some fine structures with high velocity in the Ne ⅤⅢ spectrum are almost the same as that in N Ⅳ spectrum, but they are extended and diffused in the Ne ⅤⅢ spectrum. Some fine structures have non-Gaussian profiles with the line-of-sight Doppler velocities up to 150 km·s^-1 in the N Ⅳ blue/red wings, which is similar with the explosive events in the transition region. In the past, explosive events are small-scale dynamic phenomena often observed in the quiet-sun (QS) region, while their properties in coronal holes (CHs) remain unclear. Here, we find the EE-like events with strong dynamics in the south solar polar coronal hole by N Ⅳ line of SOHO/SUMER spectrograph.
		2014 Vol. 34 (07): 1890-1893 [Abstract] ( 543 ) PDF (2241 KB) ( 234 )

	1894	Simulation of Atmospheric Temperature and Moisture Profiles Retrieval from CrIS Observations
		MA Peng-fei^1,2, CHEN Liang-fu^1*, TAO Jin-hua¹, SU Lin¹, TAO Ming-hui¹, WANG Zi-feng¹, ZOU Ming-min¹, ZHANG Ying¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1894-04
		In order to get higher vertical resolution atmosphere profile information, the present paper retrieves atmospheric temperature and moisture profiles from the Cross-track Infrared Sounder (CrIS) on the newly-launched Suomi National Polar-orbiting Partnership (Suomi NPP) and future Joint Polar Satellite System (JPSS) with a nonlinear Newton iteration method by using the profiles retrieved via statical regression method as the first guess, and the issue of channel selection is discussed. The retrieved profiles are compared with radiosonde observations, and National Centers for Environmental Prediction (NCEP) Global Data Assimilation System (GDAS) analyses show that the physical retrievals of temperature and moisture are in good agreement with the distributions from GDAS analysis fields and radiosonde observations, and have a notable improvements of the atmospheric profile retrieval accuracy as compared with the eigenvector regression algorithm. For pressures between 200 and 700 hPa the accuracy is of the order of 1 K for the temperature profile, and 20% for the relative humidity profile is consistent with the jacobian peaks of the selected channels.
		2014 Vol. 34 (07): 1894-1897 [Abstract] ( 693 ) PDF (3168 KB) ( 652 )

	1898	Research on Monitoring Land Subsidence in Beijing Plain Area Using PS-InSAR Technology
		GU Zhao-qin¹, GONG Hui-li^1, ZHANG You-quan^1, LU Xue-hui^{1, 2}, WANG Sa¹, WANG Rong³, LIU Huan-huan¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1898-05
		In the present paper, the authors use permanent scatterers synthetic aperture radar interferometry (PS-InSAR) technique and 29 acquisitions by Envisat during 2003 to 2009 to monitor and analyze the spatial-temporal distribution and mechanism characterize of land subsidence in Beijing plain area. The results show that subsidence bowls have been bounded together in Beijing plain area, which covers Chaoyang, Changping, Shunyi and Tongzhou area, and the range of subsidence has an eastward trend. The most serious regional subsidence is mainly distributed by the quaternary depression in Beijing plain area. PS-Insar results also show a new subsidence bowl in Pinggu. What’s more, the spatial and temporal distribution of deformation is controlled mainly by faults, such as Liangxiang-Shunyi fault, Huangzhuang-Gaoliying fault, and Nankou-Sunhe fault. The subsidence and level of groundwater in study area shows a good correlation, and the subsidence shows seasonal ups trend during November to March and seasonal downs trend during March to June along with changes in groundwater levels. The contribution of land subsidence is also influenced by stress-strain behavior of aquitards. The compaction of aquitards shows an elastic, plastic, viscoelastic pattern.
		2014 Vol. 34 (07): 1898-1902 [Abstract] ( 512 ) PDF (3461 KB) ( 261 )

	1903	Observations of Spectral Data and Characteristics Analysis of Snow-Bare Soil Mixed Pixel Generated by Micro-Simulation
		LIU Yan, LI Yang
		DOI: 10.3964/j.issn.1000-0593(2014)07-1903-06
		To explore the differences of mixed-pixel in spectral mixing mechanism at micro-and macro -scale, the micro- simulation of snow-bare soil mixed pixel was taken as the object of study in an artificial test environment. Reflectance spectra of mixed pixel and snow, bare soil endmember with different area ratio were collected by full-band spectrometer with fixed probe distance. Qualitative and quantitative analysis of original reflectance spectra was done, and reflectance spectra form 350 to 2 500 nm and normalized reflectance spectral data of 350 to 1 815 nm excluding noise were normalized. At the same time, we collected EOS/MODIS and Environment and Disaster Monitoring Satellites data of the same period over the same area and analyzed the correlation of channels in visible, near-infrared and shortwave infrared wavelength range at different resolution scales and the relationship between spectrum of mixed snow-soil and endmember pixel in MODIS image was analyzed. The results showed that, (1) At the micro scale, non-linear relationship existed between mixed pixel and endmember within the scope of the full-wave and linear relationship existed in sub-band wavelength range; (2) At the macro scale, linear relationship existed between mixed pixel and endmember. (3) In statistics of spectral values, the correlation between snow-soil mixture and endmember is positive for snow-soil mixture and snow endmember, and is negative for snow-soil mixture and soil endmember.
		2014 Vol. 34 (07): 1903-1908 [Abstract] ( 649 ) PDF (5063 KB) ( 264 )

	1909	Real-Time Automatic Cloud Detection during the Process of Taking Aerial Photographs
		GAO Xian-jun, WAN You-chuan, ZHENG Shun-yi, YANG Yuan-wei
		DOI: 10.3964/j.issn.1000-0593(2014)07-1909-05
		The present paper adopted a method based on the spectrum signatures with thresholds to detect cloud. Through analyzing the characteristic in the aspect of spectrum signatures of cloud, two effective signatures were explored, one was brightness signature I and the other was normalized difference signature P. Combined with corresponding thresholds, each spectrum condition can detect some cloud pixels. By composing the union of two spectrum conditions together, cloud can be detected more completely. In addition, the threshold was also very important to the accuracy of the detection result. In order to detect cloud efficiently, correctly and automatically, this paper proposed a new strategy about the assignment of thresholds to acquire suitable thresholds. Firstly, the images should be classified into three kinds of types which were images with no cloud, with thin cloud and with thick cloud. Secondly, different assignment methods of automatic thresholds of signatures would be adopted according to different types of images. For images with thick cloud, they would be further classified into three kinds by another standard and assigned by different thresholds integrated by automatic thresholds from other spectrum signatures. The automatic thresholds were acquired by Otsu algorithm and an improved Otsu algorithm. For images with thin cloud, the cloud would be detected by score algorithm. Due to this flexible strategy, cloud in images can be detected rightly and if there isn’t cloud in images the detection will be null to show that there is no cloud. Compared to the detection results of other different methods, the contrast results show that the efficiency of the detection method proposed in this paper is high and the accuracy satisfies the demand of real-time evaluation and the application range is wider.
		2014 Vol. 34 (07): 1909-1913 [Abstract] ( 637 ) PDF (4239 KB) ( 285 )

	1914	Study on Transient Absorption Spectrum of Tungsten Nanoparticle with HepG2 Tumor Cell
		CAO Lin¹, SHU Xiao-ning¹, LIANG Dong¹, WANG Cong²
		DOI: 10.3964/j.issn.1000-0593(2014)07-1914-03
		Significance of this study lies in tungsten nano materials can be used as a preliminary innovative medicines applied basic research .This paper investigated the inhibition of tungsten nanoparticles which effected on human hepatoma HepG2 cells by MTT. The authors use transient absorption spectroscopy (TAS) technology absorption and emission spectra characterization of charge transfer between nanoparticles and tumor cell. The authors discussed the role of the tungsten nanoparticles in the tumor early detection of the disease and its anti-tumor properties. In the HepG2 experiments system,100～150 μg·mL^-1 is the best drug concentration of anti-tumor activity which recact violently within 6 hours and basically completed in 24 hours. The results showed that transient absorption spectroscopy can be used as tumor detection methods and characterization of charge transfer between nano-biosensors and tumor cells. Tungsten nanoparticles have potential applications as anticancer drugs.
		2014 Vol. 34 (07): 1914-1916 [Abstract] ( 596 ) PDF (2059 KB) ( 254 )

	1917	Winter Wheat GPC Estimation Based on Leaf and Canopy Chlorophyll Parameters
		SONG Xiao-yu^{1, 2}, WANG Ji-hua^{2, 3}, YANG Gui-jun^{1, 2}, CUI Bei⁴, CHANG Hong^{1, 2}
		DOI: 10.3964/j.issn.1000-0593(2014)07-1917-05
		The present study focused on the wheat harvest grain protein content (GPC) estimation based on wheat leaf and canopy chlorophyll parameters, SPAD and SFR, which were acquired by two hand-held instruments, SPAD and Multiplex 3. The wheat GPC estimate experiment was applied on a wheat field of the Scientific Observation and Experiment Field Station for Precision Agriculture at suburb of Beijing in 2012. The wheat leaf SPAD and canopy SFR value were measured in field for all 110 wheat sample points at five different wheat growth stages from April to June. The wheat plant sample for each point was then collected after the SPAD and SFR measurement and sent to lab for leaf nitrogen content (LNC) and canopy nitrogen density (CND) analysis. Analysis results showed that the correlation coefficients of wheat GPC with wheat CND were much higher than that from wheat tillering stage to early milking stage. They were similar at the wheat middle milking stage. While the wheat leaf SPAD value was highly correlated with wheat LNC at wheat tillering, heading and early milking stage. Wheat canopy chlorophyll parameters SFR were highly correlated with wheat CND at wheat tillering, jointing, heading and milking stage. It can be seen from the study that SFR is more sensitive to the wheat CND compared with wheat LNC. The analysis also indicated that leaf SPAD value at wheat tillering, heading and milking stage was highly correlated with wheat GPC and yield of grain protein (YGP). The wheat canopy parameters, SFR_G and SFR_R were significantly correlated with wheat GPC and YGP at wheat milking stage. Then the optimal GPC and YGP estimation model was established. The R² of GPC estimation models established by SPAD and SFR_R are 0.426 and 0.497, and the standard errors of the estimate are 0.060% and 0.055%, respectively. The R2 of YGP estimation models established by SPAD and SFR_R are 0.366 and 0.386 and the standard errors of the estimate are 125.367 and 123.454 kg·ha^-1, respectively. The study reveals that SPAD value is a good indicator of single plant activity while SFR_G and SFR_R are better indicators for the wheat group activity. Wheat leaf SPAD value and canopy chlorophyll fluorescence information SFR are all feasible and valuable for GPC estimation before wheat harvesting.
		2014 Vol. 34 (07): 1917-1921 [Abstract] ( 581 ) PDF (912 KB) ( 336 )

	1922	Estimation of Organic Matter Content of North Fluvo-Aquic Soil Based on the Coupling Model of Wavelet Transform and Partial Least Squares
		WANG Yan-cang^{1, 2, 3}, YANG Gui-jun^{2, 3}, ZHU Jin-shan¹, GU Xiao-he^{2, 3*}, XU Peng², LIAO Qin-hong²
		DOI: 10.3964/j.issn.1000-0593(2014)07-1922-05
		For improving the estimation accuracy of soil organic matter content of the north fluvo-aquic soil, wavelet transform technology is introduced. The soil samples were collected from Tongzhou district and Shunyi district in Beijing city. And the data source is from soil hyperspectral data obtained under laboratory condition. First, discrete wavelet transform efficiently decomposes hyperspectral into approximate coefficients and detail coefficients. Then, the correlation between approximate coefficients, detail coefficients and organic matter content was analyzed, and the sensitive bands of the organic matter were screened. Finally, models were established to estimate the soil organic content by using the partial least squares regression (PLSR). Results show that the NIR bands made more contributions than the visible band in estimating organic matter content models; the ability of approximate coefficients to estimate organic matter content is better than that of detail coefficients; The estimation precision of the detail coefficients fir soil organic matter content decreases with the spectral resolution being lower; Compared with the commonly used three types of soil spectral reflectance transforms, the wavelet transform can improve the estimation ability of soil spectral fir organic content; The accuracy of the best model established by the approximate coefficients or detail coefficients is higher, and the coefficient of determination (R²) and the root mean square error (RMSE) of the best model for approximate coefficients are 0.722 and 0.221, respectively. The R² and RMSE of the best model for detail coefficients are 0.670 and 0.255, respectively.
		2014 Vol. 34 (07): 1922-1926 [Abstract] ( 562 ) PDF (1547 KB) ( 280 )

	1927	Automatic Houses Detection with Color Aerial Images Based on Image Segmentation
		HE Pei-pei¹, WAN You-chuan¹, JIANG Peng-rui², GAO Xian-jun¹, QIN Jia-xin¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1927-06
		In order to achieve housing automatic detection from high-resolution aerial imagery, the present paper utilized the color information and spectral characteristics of the roofing material, with the image segmentation theory, to study the housing automatic detection method. Firstly, This method proposed in this paper converts the RGB color space to HIS color space, uses the characteristics of each component of the HIS color space and the spectral characteristics of the roofing material for image segmentation to isolate red tiled roofs and gray cement roof areas, and gets the initial segmentation housing areas by using the marked watershed algorithm. Then, region growing is conducted in the hue component with the seed segment sample by calculating the average hue in the marked region. Finally through the elimination of small spots and rectangular fitting process to obtain a clear outline of the housing area. Compared with the traditional pixel-based region segmentation algorithm, the improved method proposed in this paper based on segment growing is in a one-dimensional color space to reduce the computation without human intervention, and can cater to the geometry information of the neighborhood pixels so that the speed and accuracy of the algorithm has been significantly improved. A case study was conducted to apply the method proposed in this paper to high resolution aerial images, and the experimental results demonstrate that this method has a high precision and rational robustness.
		2014 Vol. 34 (07): 1927-1932 [Abstract] ( 602 ) PDF (3684 KB) ( 319 )

	1933	Quantitative Estimation of Glycyrrhizic Acid and Liquiritin Contents Using In-Situ Canopy Spectroscopy
		DING Ling^{1, 2}, LI Hong-yi^1*, ZHANG Xue-wen³
		DOI: 10.3964/j.issn.1000-0593(2014)07-1933-05
		The present study is the first to attempt to apply the in situ hyperspectral data of G. uralensis canopy in visible-shortwave infrared region (Vis-SWIR) to estimate quantification of GA and LQ contents of glycyrrhiza uralensis. After first derivative preprocessing and feature bands selection by Wilks’ lambda stepwise method , partial least squares(PLS) regression with high performance liquid chromatography (HPLC) as reference was constructed to predict the value of GA and LQ contents, respectively. With the nine selected bands and PLS regression model, GA regression accuracy of R² is 0.953, root mean square errors of calibration set (RMSEC) is 0.31, prediction accuracy R² is 0.875 and root mean square errors of validation set (RMSEP) is 0.39; LQ regression accuracy of R² is 0.932, RMSEC is 0.22, prediction accuracy R² is 0.883 and RMSEP is 0.27; The results showed that our methods provided acceptable results and implied the ability of determining GA and LQ contents from remotely sensed data. It is recommended that an advanced study be conducted in field condition using airborne and/or spaceborne hyperspectral sensors.
		2014 Vol. 34 (07): 1933-1937 [Abstract] ( 725 ) PDF (1774 KB) ( 403 )

	1938	Visualization of the Chilling Storage Time for Turbot Flesh Based on Hyperspectral Imaging Technique
		ZHU Feng-le, ZHANG Hai-liang, SHAO Yong-ni, HE Yong^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1938-05
		This study proposed a new method using visible and near infrared (Vis/NIR) hyperspectral imaging for the detection and visualization of the chilling storage time for turbot flesh rapid and nondestructively. A total of 160 fish samples with 8 different storage days were collected for hyperspectral image scanning, and mean spectra were extracted from the region of interest (ROI) inside each image. Partial least squares regression (PLSR) was applied as calibration method to correlate the spectral data and storage time for the 120 samples in calibration set. Then the PLSR model was used to predict the storage time for the 40 prediction samples, which achieved accurate results with determination coefficient (R²) of 0.966 2 and root mean square error of prediction (RMSEP) of 0.679 9 d. Finally, the storage time of each pixel in the hyperspectral images for all prediction samples was predicted and displayed in different colors for visualization based on pseudo-color images with the aid of an IDL program. The results indicated that hyperspectral imaging technique combined with chemometrics and image processing allows the determination and visualization of the chilling storage time for fish, displaying fish freshness status and distribution vividly and laying a foundation for the automatic processing of aquatic products.
		2014 Vol. 34 (07): 1938-1942 [Abstract] ( 576 ) PDF (1830 KB) ( 316 )

	1943	Comparative Investigation of Locust’s Phototactic Visual Spectrum Effect and Phototactic Response to Spectral Illumination
		LIU Qi-hang¹, ZHOU Qiang^2*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1943-05
		To provide theoretical support for determining locust’s phototactic spectrum, and explore locust’s phototactic mechanism stimulated by light, utilizing AvaSpec fiber-optic spectrometer system and AvaLight-DHS, the investigation of locust’s phototactic visual spectrum effect after light energy stimulated locst’s vision system was carried out and on this basis, utilizing the investigated device of locust’s phototactic response to spectral illumination, the discrepancy of locust’s phototactic response to spectral illumination was certificated comparatively. The results show that the degree of locust’s vision system absorbing the single spectrum photon of 430，545 and 610 nm is significant and there exists difference, and the behavioral response to orange, violet, green, and blue spectral light has the difference in selective sensitivity, with the intensity of response to violet light being the strongest. The degree of response to orange light is the maximum, simultaneously, locust’s vision system absorbing spectral photon energy has selective difference and requirement of illumination time, moreover, the sensitive degree of locust’s visual system to spectrum and the strength of the lighting energy, influencing locust’s phototactic response degree, and the micro-response of locust’s phototactic vision physiology, led by the photoelectric effect of locust absorbing sensitive photon and converting photon energy, is the reason for locust’s phototactic orientation response. In addition, locust’s phototactic visual spectrum effect, only when the biological photoelectric effect of locust’s visual system is stimulated by spectral illumination, can present the sensitivity of the spectral absorption effect, so, using the stronger ultraviolet stimulation characteristic of violet light, the different sensitive stimulation of orange, green, blue spectral light on locust’s phototactic vision, and combining orange, violet, green, blue spectral light field mechanism reasonably, can form the optical field trapping locusts effectively, while, the elaboration of locust’s phototactic mechanism lacks the quantification data, the comparative investigation of locust’s phototactic behavior, locust’s visual electric potential and locust’s visual spectrum effect has to be done, to improve and perfect the theory of locust’s phototactic mechanism.
		2014 Vol. 34 (07): 1943-1947 [Abstract] ( 818 ) PDF (2889 KB) ( 248 )

	1948	Study on the Soil Salinization Monitoring Based on Measured Hyperspectral and HSI Data
		LEI Lei^1,2, TIYIP Tashpolat^1,2, DING Jian-li^1,2*, JIANG Hong-nan^1,2, KELIMU Ardak^1,2
		DOI: 10.3964/j.issn.1000-0593(2014)07-1948-06
		The present paper selects the Kuqa Oasis as the study area, studies spectrum characteristics of soil salinity, and establishes soil spectrum library. Through transforming and analyzing varying degrees of soil salinization reflectance spectra data in the typical study area, and selecting the most sensitive spectral bands in response to salinization, we established the measured hyperspectral soil salinity monitoring model, and by correcting the soil salinity monitoring model established by HIS image through scale effect conversion improved the model accuracy under the conditions of a regional-scale monitoring of soil salinization. The results show that both measured hyperspectral soil salinity monitoring model and HSI image soil salinity inversion model have good accuracy, model determination coefficient (R²) is higher than 0.57 and the model stability is better. Compared with the corrected HSI image soil salinity inversion model and uncorrected HSI image soil salinity inversion model, the coefficient of determination has been greatly improved, which increased from 0.571 to 0.681, and through the 0.01 significance level, the root mean square error (RMSE) value is 0.277. The correction HIS image soil salinization monitoring model can better improve the model accuracy under the condition of regional scale soil salinization monitoring, and using this method to carry out the soil salinization quantitative remote sensing monitoring is feasible, and also can provide scientific reference for future research.
		2014 Vol. 34 (07): 1948-1953 [Abstract] ( 562 ) PDF (3648 KB) ( 406 )

	1954	Quantitative Analysis of Cu in Water by Collinear DP-LIBS
		ZHENG Mei-lan, YAO Ming-yin, CHEN Tian-bing, LIN Yong-zeng, LI Wen-bing, LIU Mu-hua^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1954-05
		The purpose of this research is to study the influence of double pulse laser induced breakdown spectroscopy (DP-LIBS) on the sensitivity of Cu in water. The water solution of Cu was tested by collinear DP-LIBS in this article. The results show that spectral intensity of Cu can be enhanced obviously by DP-LIBS, compared with single pulse laser induced breakdown spectroscopy (SP-LIBS). Besides, the experimental results were significantly impacted by delay time between laser pulse and spectrometer acquisition, delay time of double laser pulse and energy of laser pulse and so on. The paper determined the best conditions for DP-LIBS detecting Cu in water. The optimal acquisition delay time was 1 380 ns. The best laser pulse delay time was 25 ns. The most appropriate energy of double laser pulse was 100 mJ. Characteristic analysis of spectra of Cu at 324.7 and 327.4 nm was done for quantitative analysis. The detection limit was 3.5 μg·mL^-1 at 324.7 nm, and the detection limit was 4.84 μg·mL^-1 at 327.4 nm. The relative standard deviation of the two characteristic spectral lines was within 10%. The calibration curve of characteristic spectral line, established by 327.4 nm, was verified with 500 μg·mL^-1 sample. Concentration of the sample was 446 μg·mL^-1 calculated by the calibration curve. This research shows that the detection sensitivity of Cu in water can be improved by DP-LIBS. At the same time, it had high stability.
		2014 Vol. 34 (07): 1954-1958 [Abstract] ( 581 ) PDF (2064 KB) ( 223 )

	1959	Indirect Determination of Rare Earth Elements in Chinese Herbal Medicines by Hydride Generation-Atomic Fluorescence Spectrometry
		ZENG Chao¹, LU Jian-ping^2*, XUE Min-hua², TAN Fang-wei², WU Xiao-yan¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-1959-04
		Based on their similarity in chemical properties, rare earth elements were able to form stable coordinated compounds with arsenazo Ⅲ which were extractable into butanol in the presence of diphenylguanidine. The butanol was removed under reduced pressure distillation; the residue was dissolved with diluted hydrochloric acid. As was released with the assistance of KMnO₄ and determined by hydrogen generation-atomic fluorescence spectrometry in terms of rare earth elements. When cesium sulfate worked as standard solution, extraction conditions, KMnO₄ amount, distillation temperature, arsenazo Ⅲ amount, interfering ions, etc were optimized. The accuracy and precision of the method were validated using national standard certified materials, showing a good agreement. Under optimum condition, the linear relationship located in 0.2~25 μg·mL^-1 and detection limit was 0.44 μg·mL^-1. After the herbal samples were digested with nitric acid and hydrogen peroxide, the rare earth elements were determined by this method, showing satisfactory results with relative standard deviation of 1.3%~2.5%, and recoveries of 94.4%~106.0%. The method showed the merits of convenience and rapidness, simple instrumentation and high accuracy. With the rare earths enriched into organic phase, the separation of analytes from matrix was accomplished, which eliminated the interference. With the residue dissolved by diluted hydrochloric acid after the solvent was removed, aqueous sample introduction eliminated the impact of organic phase on the tubing connected to pneumatic pump.
		2014 Vol. 34 (07): 1959-1962 [Abstract] ( 561 ) PDF (1027 KB) ( 244 )

	1963	Analysis of XRD Spectral Characteristics of Soil Clay Mineral in Two Typical Cultivated Soils
		ZHANG Zhi-dan, LUO Xiang-li, JIANG Hai-chao, LI Qiao, SHEN Cong-ying, LIU Hang, ZHOU Ya-juan, ZHAO Lan-po^, WANG Ji-hong^
		DOI: 10.3964/j.issn.1000-0593(2014)07-1963-06
		The present paper took black soil and chernozem, the typical cultivated soil in major grain producing area of Northeast, as the study object, and determinated the soil particle composition characteristics of two cultivated soils under the same climate and location. Then XRD was used to study the composition and difference of clay mineral in two kinds of soil and the evolutionary mechanism was explored. The results showed that the two kinds of soil particles were composed mainly of the sand, followed by clay and silt. When the particle accumulation rate reached 50%, the central particle size was in the 15～130 μm interval. Except for black soil profile of Shengli Xiang, the content of clay showed converse sequence to the central particle in two soils. Clay accumulated under upper layer(18.82%)in black soil profile while under caliche layer(17.41%)in chernozem profile. Clay content was the least in parent material horizon except in black profile of Quanyanling. Analysis of clay XRD atlas showed that the difference lied in not only the strength of diffraction peak, but also in the mineral composition. The main contents of black soil and chernozem were both 2∶1 clay, the composition of black soil was smectite/illite mixed layer-illite-vermiculite and that of chernozem was S/I mixture-illite-montmorillonite, and both of them contained little kaolinite, chlorite, quartz and other primary mineral. This paper used XRD to determine the characteristics of clay minerals comprehensively, and analyzed two kinds of typical cultivated soil comparatively, and it was a new perspective of soil minerals study.
		2014 Vol. 34 (07): 1963-1968 [Abstract] ( 790 ) PDF (2017 KB) ( 740 )

	1969	An Automatic Peak Detection Method for LIBS Spectrum Based on Continuous Wavelet Transform
		CHEN Peng-fei, TIAN Di, QIAO Shu-jun, YANG Guang^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1969-04
		Spectrum peak detection in the laser-induced breakdown spectroscopy (LIBS) is an essential step, but the presence of background and noise seriously disturb the accuracy of peak position. The present paper proposed a method applied to automatic peak detection for LIBS spectrum in order to enhance the ability of overlapping peaks searching and adaptivity. We introduced the ridge peak detection method based on continuous wavelet transform to LIBS, and discussed the choice of the mother wavelet and optimized the scale factor and the shift factor. This method also improved the ridge peak detection method with a correcting ridge method. The experimental results show that compared with other peak detection methods(the direct comparison method, derivative method and ridge peak search method), our method had a significant advantage on the ability to distinguish overlapping peaks and the precision of peak detection, and could be be applied to data processing in LIBS.
		2014 Vol. 34 (07): 1969-1972 [Abstract] ( 895 ) PDF (1577 KB) ( 781 )

	1973	Compensation-Fitting Extraction of Dynamic Spectrum Based on Least Squares Method
		LIN Ling, WU Ruo-nan, LI Yong-cheng, ZHOU Mei, LI Gang^*
		DOI: 10.3964/j.issn.1000-0593(2014)07-1973-05
		Extraction method for dynamic spectrum (DS) with a high signal to noise ratio is a key to achieving high-precision noninvasive detection of blood components. In order to further improve the accuracy and speed of DS extraction, linear similarity between photoelectric plethysmographys (PPG) at each two different wavelengths was analyzed in principle, and an experimental verification was conducted. Based on this property, the method of compensation-fitting extraction was proposed. Firstly, the baseline of PPG at each wavelength is estimated and compensated using single-period sampling average, which would remove the effect of baseline drift caused by motion artifact. Secondly, the slope of least squares fitting between each single-wavelength PPG and full-wavelength averaged PPG is acquired to construct DS, which would significantly suppress random noise. Contrast experiments were conducted on 25 samples in NIR wave band and Vis wave band respectively. Flatness and processing time of DS using compensation-fitting extraction were compared with that using single-trial estimation. In NIR band, the average variance using compensation-fitting estimation was 69.0% of that using single-trial estimation, and in Vis band it was 57.4%, which shows that the flatness of DS is steadily improved. In NIR band, the data processing time using compensation-fitting extraction could be reduced to 10% of that using single-trial estimation, and in Vis band it was 20%, which shows that the time for data processing is significantly reduced. Experimental results show that, compared with single-trial estimation method, dynamic spectrum compensation-fitting extraction could steadily improve the signal to noise ratio of DS, significantly improve estimation quality, reduce data processing time, and simplify procedure. Therefore, this new method is expected to promote the development of noninvasive blood components measurement.
		2014 Vol. 34 (07): 1973-1977 [Abstract] ( 851 ) PDF (1486 KB) ( 380 )

	1978	Study on the Discharge Properties of Xeon Flash Lamp and Experimental Measurement
		ZHAO You-quan, MIAO Pei-liang, HE Feng, GU Jian, ZHAI Rui-wei
		DOI: 10.3964/j.issn.1000-0593(2014)07-1978-05
		The Xenon flash lamp is a new type of light source for analytical instrument. The present paper analyzed the discharge process of xenon flash lamp, presented the discharge test system, and conducted experimental measurement of the voltage, current and optical pulse signal in the process of discharge. The results show that in the preliminary discharge, the free electron concentration was at a low level, so the energy was at a low level, then following the gas discharge, numerous free electrons formed in the lamp, resultin in the increase in the concentration of free electrons, therefore discharge current rised rapidly and voltage reduced. The lamp released photons to generate light pulse in the moment of ionic recombination, The pulse xenon lamp light energy output and spectral characteristic is related to electron energy in recombination and combination level of xenon, if the input energy and the energy consumption of the xenon lamp is inconsistent, it will lead to repeated capacitor charging and discharging and produce oscillation waveform. This paper is very useful for understanding the process of xenon lamp discharge, optimizing the driver circuit and the production of xenon flash lamp.
		2014 Vol. 34 (07): 1978-1982 [Abstract] ( 593 ) PDF (2634 KB) ( 397 )

	1983	The Hyperspectral Camera Side-Scan Geometric Imaging in Any Direction Considering the Spectral Mixing
		WANG Shu-min^{1, 2}, ZHANG Ai-wu^1*, HU Shao-xing³, SUN Wei-dong⁴
		DOI: 10.3964/j.issn.1000-0593(2014)07-1983-07
		In order to correct the image distortion in the hyperspectral camera side-scan geometric Imaging, the image pixel geo-referenced algorithm was deduced in detail in the present paper, which is suitable to the linear push-broom camera side-scan imaging on the ground in any direction. It takes the orientation of objects in the navigation coordinates system into account. Combined with the ground sampling distance of geo-referenced image and the area of push broom imaging, the general process of geo-referenced image divided into grids is also presented. The new image rows and columns will be got through the geo-referenced image area dividing the ground sampling distance. Considering the error produced by round rule in the pixel grids generated progress, and the spectral mixing problem caused by traditional direct spectral sampling method in the process of image correction, the improved spectral sampling method based on the weighted fusion method was proposed. It takes the area proportion of adjacent pixels in the new generated pixel as coefficient and then the coefficients are normalized to avoid the spectral overflow. So the new generated pixel is combined with the geo-referenced adjacent pixels spectral. Finally the amounts of push-broom imaging experiments were taken on the ground, and the distortion images were corrected according to the algorithm proposed above. The results show that the linear image distortion correction algorithm is valid and robust. At the same time, multiple samples were selected in the corrected images to verify the spectral data. The results indicate that the improved spectral sampling method is better than the direct spectral sampling algorithm. It provides reference for the application of similar productions on the ground.
		2014 Vol. 34 (07): 1983-1989 [Abstract] ( 617 ) PDF (2954 KB) ( 639 )

	1990	A Method for Smear Removal of Push-Broom Imaging Spectrometers
		CUI Yi^1,2, WEI Jun¹, TANG Yu-yu¹, MA Liang^1,2
		DOI: 10.3964/j.issn.1000-0593(2014)07-1990-05
		Smear is an inherent problem of area CCD and there have been many researches on how to deduct it. However, the imaging model of push-broom imaging spectrometer is very special, in which the usual methods are no longer applicable. To develop a new method that is suitable for the application of imaging spectrometer, a more detailed model was built. The problem of distortion of usual method was also analyzed and simulated. The original image of each channel was used to estimate the spectral distribution of the target, by which the contribution of smear of the black optical channel to each channel is quantified. Both simulation and restoration result of the remote sensing image showed that the new method worked well for the CCD smear deduction of push-broom imaging spectrometer.
		2014 Vol. 34 (07): 1990-1994 [Abstract] ( 670 ) PDF (1619 KB) ( 346 )

	1995	Research on and Correction of Interference Fringes Phenomenon in Dispersive Hyperspectral Imaging Spectrometer Using Back-Illuminated CCDs in Near-Infrared Band
		MA Liang, WEI Jun, HUANG Xiao-xian
		DOI: 10.3964/j.issn.1000-0593(2014)07-1995-05
		Dispersive hyperspectral imaging spectrometer using back-illuminated CCDs will cause interference fringes in near-infrared band, reducing the near-infrared spectral resolution. To solve this problem, we established a multi-beam interference model similar to a Farby-Pérot interferometer, estimated the intensity of distribution of interference fringes from 700 to 900 nm, verified its correctness with measured data, and analyzed the relationship between CCD photosensitive zone thickness and the interference phenomenon. On this base, the authors used the improved flat-field correction algorithm to correct the interference. From 751.83 to 1 010.04 nm wavelength, the correction efficiency can reach 96.6%. The results show that the algorithm can effectively eliminate the interference of dispersive hyperspectral imaging spectrometer in near-infrared band.
		2014 Vol. 34 (07): 1995-1999 [Abstract] ( 592 ) PDF (2486 KB) ( 227 )

	2000	Manufacture Tolerance Analysis of Solid Mach-Zehnder Interferometer in Large Aperture Static Imaging Spectrometer (LASIS)
		LIU Qing^{1, 2}, ZHOU Jin-song^1*, NIE Yun-feng¹, Lü Qun-bo¹
		DOI: 10.3964/j.issn.1000-0593(2014)07-2000-05
		The principle and instrumental structure of large aperture static imaging spectrometer(LASIS) were briefly described in the present paper, the principle of the Mach-Zehnder imaging spectrometer was introduced, and the Mach-Zehnder interferometers’ working way in the imaging spectrometer was illustrated. The structure of solid Mach-Zehnder interferometer was analyzed, and discussion was made based on the requirements of field of view(FOV) in image space and single sided interferogram with a small portion around zero path difference(ZPD). The additional optical path difference (OPD) created by manufacturing and matching tolerance of two asymmetrical pentagonal prisms will lead to the displacement of shearing and OPD nonlinearity. It was showed that the additional OPD from non-common optical path structure of solid Mach-Zehnder spectrometer implies more requirements on the manufacture of this element, compared with Sagnac interferometer, for the matching tolerance of two asymmetrical pentagonal prisms to br lower than 0.02 mm. The recovery spectrum error caused by the OPD nonlinearity is lower than 0.2% and can be ignored.
		2014 Vol. 34 (07): 2000-2004 [Abstract] ( 745 ) PDF (1681 KB) ( 262 )

	2005	Wavelength Selection of the Oximetry Based on Test Analysis of Variance
		LIN Ling¹, LI Wei¹, ZENG Rui-li², LIU Rui-an³, LI Gang⁴, WU Xiao-rong^3*
		DOI: 10.3964/j.issn.1000-0593(2014)07-2005-05
		In order to improve the precision and reliability of the spectral measurement of blood oxygen saturation，and enhance the validity of the measurement, the method of test analysis of variance was employed. Preferred wavelength combination was selected by the analysis of the distribution of the coefficient of oximetry at different wavelength combinations and rational use of statistical theory. Calculated by different combinations of wavelengths (660 and 940 nm, 660 and 805 nm and 805 and 940 nm) through the clinical data under different oxygen saturation，the single factor test analysis of variance model of the oxygen saturation coefficient was established, the relative preferabe wavelength combination can be selected by comparative analysis of different combinations of wavelengths from the photoelectric volume pulse to provide a reliable intermediate data for further modeling. The experiment results showed that the wavelength combination of 660 and 805 nm responded more significantly to the changes in blood oxygen saturation and the introduced noise and method error were relatively smaller of this combination than other wavelength combination，which could improve the measurement accuracy of oximetry. The study applied the test variance analysis to the selection of wavelength combination in the blood oxygen result measurement，and the result was significant. The study provided a new idea for the blood oxygen measurements and other related spectroscopy quantitative analysis. The method of test analysis of variance can help extract the valid information which represents the measured values from the spectrum.
		2014 Vol. 34 (07): 2005-2009 [Abstract] ( 580 ) PDF (1266 KB) ( 401 )

	2010	The Technology of Fast Spectral Reconstruction in the Longer Optical Path Difference PEM-FTS
		ZHANG Min-juan³, WANG Zhao-ba^{1, 2}, WANG Zhi-bin³, LI Xiao³, LI Shi-wei³, LI Jin-hua³
		DOI: 10.3964/j.issn.1000-0593(2014)07-2010-05
		The optical path difference of the photoelastic modulator Fourier transform spectrometers(PEM-FTS) changes rapidly and nonlinearly, while the instrument preserves the speed as high as about 10⁵ interferograms per second, so that the interferograms of PEM-FTS are sampled by equal interval. In order to fleetly and accurately reconstruct these spectrums, the principle of PEM-FTS and accelerated NUFFT algorithm were studied in the present article. The accelerating NUFFT algorithm integrates interpolation based on convolution kernel and fast Fourier transform(FFT). And the velocity and precision of the algorithm are affected by the type and parameter τ of kernel function, the single-side spreading distance q and the oversampling ratio μ, and so on. In the paper these parameters were analysed, under the condition N=1 024, q=10, μ=2 and τ＝1×10^-6 in the Gaussian scaling factor, and the accelerated NUFFT algorithm was applied to the longer optical path difference PEM-FTS to rebuild the spectrums of 632.8 nm laser and Xenon lamp，The frequency error of the rebuilt spectrums of 632.8 nm laser is less than 0.013 52, the spent time of interpolation is less than 0.267 s. the velocity is fast and the error is less. The accelerated nonuniform fast Fourier transform is fit for the longer optical path difference PEM-FTS.
		2014 Vol. 34 (07): 2010-2014 [Abstract] ( 588 ) PDF (3651 KB) ( 274 )

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