Journals >Spectroscopy and Spectral Analysis
Contents
2014
Volume: 34 Issue 1
57 Article(s)
Export citation format
Research Article
Research on Night Visibility Estimation Method Based on Image Features of Dual Light Sources
DAI Pang-da, ZHANG Yu-jun, LU Chang-hua, ZHOU Yi, LIU Jing, XIAO Xue, LIU Wen-qing, and WANG Jing-li
Haze, rain and snow bring a lot of inconvenience in our daily life, especially produce serious potential safety hazard for night transport. In the present paper the authors propose the vision-based dual light sources visibility method to estimate night visibility. This method is significantly advantaged with wide rangeHaze, rain and snow bring a lot of inconvenience in our daily life, especially produce serious potential safety hazard for night transport. In the present paper the authors propose the vision-based dual light sources visibility method to estimate night visibility. This method is significantly advantaged with wide range, high precision and low cost, and has a good robustness in many kinds of weather conditions. Firstly, the authors give the basic visibility estimation model under the atmosphere multiple scattering theory. Secondly, the authors propose the dual light sources method to remove the luminance fluctuations of light sources and the atmosphere light effect, and formulize the algorithm to accurately gain information of light sources from the dual light sources image. At last, the authors design the dual light sources system and conduct a long time experiments under various atmosphere conditions. The experiments show that, with the baseline of 35 m, the visibility range is up to 15 000 m, and relative error is below 20%. This method and system can satisfy the demand of meteorological department and transport agency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 1 (2014)
Research on Testing the Nonlinear Optical Performance of Nonlinear Optical Materials Based on the Effect of Second-Harmonic Generation
LI Bing-xuan, WEI Yong, HUANG Cheng-hui, ZHUANG Feng-jiang, ZHANG Ge, and GUO Guo-cong
In the present paper the authors report a research on testing the nonlinear optical performance of optical materials in visible and infrared band. Based on the second order nonlinear optic principle and the photoelectric signal detection technology, the authors have proposed a new testing scheme in which a infrared OPOIn the present paper the authors report a research on testing the nonlinear optical performance of optical materials in visible and infrared band. Based on the second order nonlinear optic principle and the photoelectric signal detection technology, the authors have proposed a new testing scheme in which a infrared OPO laser and a method for separating the beams arising from frequency matching and the light produced by other optical effects were used. The OPO laser is adopted as light source to avoid the error of measurement caused by absorption because the double frequency signal of the material is in the transmittance band Our research work includes testing system composition, operational principle and experimental method. The experimental results of KTP, KDP, AGS tested by this method were presented. In the experiment several new infrared nonlinear materials were found. This method possesses the merits of good stability and reliability, high sensitivity, simple operation and good reproducibility, which can effectively make qualitative and semi-quantitative test for optical material's nonlinear optical properties from visible to infrared. This work provides an important test method for the research on second order nonlinear optical materials in visible, infrared and ultraviolet bands..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 6 (2014)
Study on Influence of Source Spectra on Retro-Reflection Coefficient
YANG Yong, ZHANG Zhi-yong, LI Xu, ZHU Chuan-zheng, ZHU Li-wei, and SUN Yue
Based on emission spectra of light sources and reflectivity curve of retroreflective materials, relative relations and changing trend of retroreflection coefficient of materials in different light sources was researched through data fitting. The tests were carried on the standard A light source test system. One kind ofBased on emission spectra of light sources and reflectivity curve of retroreflective materials, relative relations and changing trend of retroreflection coefficient of materials in different light sources was researched through data fitting. The tests were carried on the standard A light source test system. One kind of test results are emission spectra of halogen light source, xenon light source and white LED with different color temperature. And another kind of results are reflectivity curve of retroreflective materials with five different colors such as red, yellow, white, green and blue. Then the correction factors of retroreflection coefficient in different light sources were obtained by test results and data fitting. It shows that the change inlight source spectra has no effect on retroreflection coefficient of white material, which has continuous reflectivity curve in the range of visible light, but has some effect on retroreflection coefficient of the other color materials. Compared with halogen light source, white LED and xenon light source can increase retroreflection coefficient of red and yellow materials, and the increase in the color temperature of light source will decrease retroreflection coefficient of red and yellow materials by the maximum of 47.7% and 4.9%. Conversely, retroreflection coefficient of green and blue materials will increase by the maximum of 16.5% and 28.9%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 12 (2014)
Spectroscopic Characteristics of DC Excited Atmospheric Pressure Glow Discharges Generated in a Needle-Plate Electrode Device and a Needle-Water Electrode One
LI Xue-chen, BAO Wen-ting, JIA Peng-ying, ZHAO Huan-huan, and DI Cong
Glow discharge characteristics in two discharge devices, i.e. in a needle-plate electrode geometry and a needle-water electrode one were compared by using spectroscopic method. Results show that the different emission regions were found in both discharges generated by the two devices. From the cathode to the anode, theGlow discharge characteristics in two discharge devices, i.e. in a needle-plate electrode geometry and a needle-water electrode one were compared by using spectroscopic method. Results show that the different emission regions were found in both discharges generated by the two devices. From the cathode to the anode, there are a cathode glow region, cathode dark glow, a positive column, and an anode glow region. The anode dark region can be clearly discerned in the glow discharge in the needle-plate electrode device, while it almost cannot be found in the needle-water electrode discharge. Comparing the current-voltage characteristics of the two glow discharges, it was found that the voltage across the electrodes decreases with increasing the discharge current in both discharge devices, while the voltage in the needle-water glow discharge is higher than that of the needle-plate one at the same current value. The current-voltage curves have a negative slope and their current densities lie in the range from 10-5 to 10-4 A?cm-2, which indicates that a normal glow discharge mechanism was involved in the two discharges. Comparing the optical spectra scanning from 300nm to 800nm and emitted from the whole normal glow discharge in the two electrode devices, similar spectral lines from the two discharges can be found on the optical emission spectrum, including the second positive system of nitrogen molecules (337.1nm) and the first negative system of nitrogen molecular ions (391.4nm). However, the intensity ratio of spectral lines is different. The intensity ratio (391.4nm to 337.1nm) and vibrational temperature were investigated at different locations. It was found that the intensity ratio of the needle-water electrode discharge is larger than that of the needle-plate electrode discharge at the same location. Furthermore, the vibrational temperature in the needle-water electrode discharge is higher than that of the needle-plate one at the same location..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 16 (2014)
Investigation of Spectroscopy of ZnCuInS/ZnSe/ZnS Quantum Dots
LIN Yi-jun, LIU Wen-yan, ZHANG Yu, BI Ke, ZHANG Tie-qiang, FENG Yi, and WANG Yi-ding
ZnCuInS/ZnSe/ZnS quantum dots were non-toxic and heavy-metal free semiconductor nanocrystals. In the present paper, ZnCuInS/ZnSe/ZnS core/shell/shell quantum dots were prepared with the particle size of 3.3, 2.7 and 2.3 nm. The photoluminescence of ZnCuInS/ZnSe/ZnS quantum dots with different size were measured, and thZnCuInS/ZnSe/ZnS quantum dots were non-toxic and heavy-metal free semiconductor nanocrystals. In the present paper, ZnCuInS/ZnSe/ZnS core/shell/shell quantum dots were prepared with the particle size of 3.3, 2.7 and 2.3 nm. The photoluminescence of ZnCuInS/ZnSe/ZnS quantum dots with different size were measured, and the wavelength of peak was blue-shifted with decreasing the diameter. The wavelength of absorption peaks and photoluminescence peaks were 510 nm, 611 nm (3.3 nm), 483 nm, 583 nm (2.7 nm) and 447 nm and 545 nm(2.3 nm). The obvious size-dependence of ZnCuInS/ZnSe/ZnS quantum dots was shown. The Stokes shifts of ZnCuInS/ZnSe/ZnS quantum dots were 398 meV (3.3 nm), 436 meV (2.7 nm) and 498 meV (2.3 nm). Such large Stokes shifts indicate that the emission should be ascribed to the defect-related recombination. The temperature-dependent photoluminescence of ZnCuInS/ZnSe/ZnS quantum dots with the particle size of 3.3 nm were measured. The wavelength of peaks was red-shifted with increasing temperature and the intensity of photoluminescence spectra was decreased with increasing temperature. Therefore, the emission was concluded to be the transition from the conduction band to defect state..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 20 (2014)
Preparation of Tb3+, Yb3+ Doped Y2O3 Luminescent Powders and Near-Infrared Quantum Cutting Research
ZHANG Liang, HE Qing-li, HU Xiao-yun, LIU En-zhou, ZHAN Su-chang, JI Ruo-nan, and JING Juan
Y2O3∶Tb3+ and Y2O3∶Tb3+, Yb3+ samples were prepared by co-precipitation method. The morphology, microstructure and fluorescence spectra at room temperature of samples were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD) and fluorescence spectrometer, TheY2O3∶Tb3+ and Y2O3∶Tb3+, Yb3+ samples were prepared by co-precipitation method. The morphology, microstructure and fluorescence spectra at room temperature of samples were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD) and fluorescence spectrometer, The optimal process conditions of Y2O3∶Tb3+ under different doping concentrations, annealing temperature, and pH value of the solution were obtained: Tb3+ concentration is 1.5%, annealing temperature is 1 400 ℃, an alkaline solution environment, and samples under 300 nm light excitation have the largest green light emission at 543 nm. The corresponding relation of Tb3+ ion level structure and transition properties and experimental spectra were analyzed in detail, and we explained the influence mechanism of process conditions and the fluorescence quenching process mainly effects luminous intensity of samples. The energy transfer from sensitizing ions Tb3+ to active ion Yb3+ was confirmed, it made the sample have considerable emitting light in the near-infrared region; the authors described the process of cooperation conversion luminescence between the two ions from the level transition angle, and also analyzed the system of fluorescence quenching process. Test results showed that the near infrared quantum cutting can effectively improve the luminous efficiency of doped ions, and will have broad application prospects in the silicon solar cells and other fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 23 (2014)
White Organic Light-Emitting Diodes Applied for Lighting Technology
HUANG Qing-yu, ZHAO Su-ling, XU Zheng, FAN Xing, WANG Jian, and YANG Qian-qian
Lighting accounts for approximately 22 percent of the electricity consumed in buildings in the United States, with 40 percent of that amount consumed by inefficient incandescent lamps. This has generated increased interest in the use of white electroluminescent organic light-emitting devices（WOLEDS）as the next generatiLighting accounts for approximately 22 percent of the electricity consumed in buildings in the United States, with 40 percent of that amount consumed by inefficient incandescent lamps. This has generated increased interest in the use of white electroluminescent organic light-emitting devices（WOLEDS）as the next generation solid-state lighting source, owing to their potential for significantly improved efficiency over incandescent sources, combined with low-cost, high-throughput manufacturability. The research and application of the devices have witnessed great progress. WOLEDS have incomparable advantages for its special characteristics. This progress report sketched the principle of WOLEDS and provided some common structures, and further investigation of the mechanism of different structures was made. Meanwhile, the key technologies of WOLEDS were summarized. Finally, the latest research progress of WOLEDS was reviewed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 27 (2014)
Effect of Critical Process Parameters on Luminescence Properties of Eu2+/Dy3+ Co-Doped High Silica Luminescence Glass
JIN Lei, LEI Xiao-hua, REN Lin-jiao, FENG Yong-an, DU Xiao-qing, and CHEN Wei-min
In the present work, Eu2+/Dy3+ co-doped high silica glasses with different process parameters were prepared and the effect of critical process parameters including phase separation temperature, solution concentration and sintering temperature on the luminescence properties of Eu2+/Dy3+ co-doped high silica glasses was In the present work, Eu2+/Dy3+ co-doped high silica glasses with different process parameters were prepared and the effect of critical process parameters including phase separation temperature, solution concentration and sintering temperature on the luminescence properties of Eu2+/Dy3+ co-doped high silica glasses was investigated by means of measuring pore surface parameters of porous glasses, emission spectra, infrared absorption spectra and densities of high silica glasses. Pore structure parameters of porous glass samples and emission spectra of corresponding high silica glass samples with different phase separation temperatures show that the phase separation temperature has indirect effect on luminescence properties of high silica glass by influencing specific surface area value of corresponding porous glass. Specific surface area of porous glass changes when phase separation temperature changes. High silica glass achieves maximum emission intensity when the maximum specific surface area of porous glass is obtained. Luminescence intensity of high silica glass increases when specific surface area of porous glass increases. Emission spectra of high silica glass samples with different solution concentrations show that the emission intensities of Eu2+ and Dy3+ in high silica glass are enhanced with the increase in the Dy3+ concentration in solution; when the Dy3+ concentration is beyond 0.1 mol·L-1, the emission intensities of Eu2+ and Dy3+ in high silica glass are both decreased due to the occurring of concentration quench of Dy3+ in the glass. Emission spectra and infrared absorption spectra of high silica glass samples with different sintering temperatures show that the emission intensity of high silica glass is increased with the increase in the sintering temperature because the content of residual hydroxyl groups —OH in the glass is decreased; when the sintering temperature is beyond 1 000 ℃, the high silica glass exhibits crystalline and the luminescence intensity decreases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 34 (2014)
The Optical Characteristics of Hollow Cathode Discharge Striations in Nitrogen
HE Shou-jie, HA Jing, GUO Shu-qing, LIU Zhi-qiang, and DONG Li-fang
The characteristics of striations in cylindrical hollow cathode discharge were investigated experimentally. The spectra of striations were measured at a pressure of 20 Pa in a discharge of 1.3 mA, in which the main spectra are the emission spectrum lines of the N2 first positive band（B3Пg→A3Пu）and second positive band The characteristics of striations in cylindrical hollow cathode discharge were investigated experimentally. The spectra of striations were measured at a pressure of 20 Pa in a discharge of 1.3 mA, in which the main spectra are the emission spectrum lines of the N2 first positive band（B3Пg→A3Пu）and second positive band system (C3Пu→B3Пg). The spatial characteristics of vibrational temperature of N2 were calculated based on the theory of double molecular spectrum. It is shown that the emission intensity exhibits a periodic structure with an unequal magnitude, and the spectral intensity of bright striation is higher than that of dark striations. The vibrational temperature of bright striation is of the value of 3500-4400K, moreover the vibrational temperature in the bright regions decreases from the cathode to the anode. In addition, the characteristics of striations at 1.0 mA and 1.5 mA were obtained, and the influence of discharge current on the striations was investigated. It is shown that the vibrational temperature and the distance between two striations increase. Finally the reduced electric field was calculated, which is about 44～49 m-1·Pa-1, moreover it decreases with the increase in discharge current. The results are very useful for understanding the mechanism of discharge striations and for improving the stability of hollow cathode discharge..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 39 (2014)
Synthesis and Fluorescence Properties of SrZn(WO4)2∶Tb3+, Ce3+ Phosphors
WU Wen, YIN Jiang-long, XUAN Ya-wen, ZHANG Xin-lei, LIU Chun-xia, and WANG Zhen-ling
SrZn1-x(WO4)2∶xTb3+, yCe3+ green fluorescent phosphors for near ultraviolet excitation were prepared using chemical co-precipitation. The phases of different doping ratio samples were characterized by the X-ray diffraction (XRD). The emission spectrum and excitation spectrum of samples were characterized by fluorescencSrZn1-x(WO4)2∶xTb3+, yCe3+ green fluorescent phosphors for near ultraviolet excitation were prepared using chemical co-precipitation. The phases of different doping ratio samples were characterized by the X-ray diffraction (XRD). The emission spectrum and excitation spectrum of samples were characterized by fluorescence spectroscopy (PL). The luminescence properties of the rare-earth Tb3+ ion doped and Ce3+ and Tb3+ ion codoped samples were discussed. XRD analysis shows that the main diffraction peaks of samples were consistent with the standard card (JCPDS 08-0490 and the JCPDS 15-0774) of the diffraction peak data. This showed that the doping rare earth ions did not change matrix lattice structure. The excitation spectrum showed that the excitation spectrum peaks at 223 nm which is assigned to the 7F—7D absorption transitions of Tb3+. The emission spectrum excited by 223 nm exhibits sharp lines peaking at 543 nm which was assigned to the 5D4→7F5 transitions of the Tb3+ ions. With Tb3+ and Ce3+ co-doping, the spectrum didn’t change much. The intensity of fluorescence reached the strongest when the concentration of Tb3+∶Ce3+ arrived at 0.06∶0.02 which may means that there was energy transfer between the ions of Ce3+ and Tb3+..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 43 (2014)
IR Spectrum Simulation of Molecular Structure Model of Shendong Coal Vitrinite by Using Quantum Chemistry Method
JIA Jian-bo, WANG Ying, LI Feng-hai, YI Gui-yun, ZENG Fan-gui, and GUO Hong-yu
The structure of coal needs to be understood from a molecular point of view for clean, effective and high value-added utilization of coal. In the literature, molecular structure model of Shendong coal vitrinite (SV) was established by the authors on the basis of experimental results of ultimate analysis and13 C NMR , aThe structure of coal needs to be understood from a molecular point of view for clean, effective and high value-added utilization of coal. In the literature<参考文献原文>, molecular structure model of Shendong coal vitrinite (SV) was established by the authors on the basis of experimental results of ultimate analysis and13 C NMR , and the calculated13 C NMR spectrum of SV model was consistent with the experimental spectrum. In order to further verify the accuracy of SV structure model established by the authors, the infrared spectrum of SV structure model was calculated using quantum chemistry semi-empirical VAMP in this thesis. The results showed that the peak shape of calculated IR spectrum of SV structure model was similar to the experiment's, but the wave number of calculated IR spectrum was obviously higher than that of experimental spectrum. According to the calculated results for model compounds by using the same method, calculated vibrational frequency was higher than that of experiment for the same functional groups. Hence, the calculated IR spectrum should be corrected. After correction the calculated IR spectrum of SV structure model matched well with the experimental spectrum. In other words, the SV structure model can truly reflect the structure characteristics of SV..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 47 (2014)
Studies on Corrosion Property of the Anodic Coating on the Mg Alloy by Micro-FTIR Mapping
LI Mei-chao, YI Jing-miao, LU Jin-jin, LI Jing, and ZHAO Wei-juan
Micro-FTIR mapping technology was used to monitor the amount and distribution of Mg(OH)2 on the anodic coating of magnesium alloy which was immersed in the 7.3 Wt% Na2SO4 solution for different time. In the solution, part of the MgO on the surface of the Mg alloy could gradually transform into Mg(OH)2 which could be deMicro-FTIR mapping technology was used to monitor the amount and distribution of Mg(OH)2 on the anodic coating of magnesium alloy which was immersed in the 7.3 Wt% Na2SO4 solution for different time. In the solution, part of the MgO on the surface of the Mg alloy could gradually transform into Mg(OH)2 which could be detached from the Mg alloy surface and dissolved into the solution. With immersion time of 2 h in 7.3 Wt% Na2SO4 solution 2h, FTIR mapping results showed that FTIR absorption signal of Mg(OH)2 was strongest and Mg(OH)2 was most on the surface of the anodic coating. After 4 hours, the content of Mg(OH)2 began to decrease, and the Mg alloy was etched gradually. The FTIR mapping results of another component Al2O3 with immersion time were almost similar to those of Mg(OH)2. The impedance of the oxide film was also analyzed using electrochemical impedance spectroscopy. It showed that the impedance changed with the immersion time and conformed to the corrosion law of the oxide coating. This research has a good guidance and application value for characterization of the anodic coating on magnesium alloy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 52 (2014)
Analysis of Infrared Spectra of 60 Kinds of Plant Extract of Traditional Chinese Medicine and Study on the Identification and Evaluation of Characteristics of the Regional Markers Associated with Cold and Heat Nature
WANG Peng, ZHOU Hong-lei, XUE Fu-zhong, and WANG Zhen-guo
By using the Fourier transform infrared spectroscopy and linear discriminant analysis(LDA）, logistic discriminant analysis（Logistic-DA）, principal component analysis-linear discriminant analysis（PCA-LDA）, partial least-squares discriminant analysis（PLS-DA）, random forest（RF）, support vector machine（SVM）, infrared spectBy using the Fourier transform infrared spectroscopy and linear discriminant analysis(LDA）, logistic discriminant analysis（Logistic-DA）, principal component analysis-linear discriminant analysis（PCA-LDA）, partial least-squares discriminant analysis（PLS-DA）, random forest（RF）, support vector machine（SVM）, infrared spectra of 60 kinds of plant extract of Chinese traditional medicine were analyzed and the identification and evaluation of characteristics of the regional markers associated with cold and heat nature were studied. Results indicated that LDA and SVM are suitable for the recognition model of water extract infrared spectral data, LDA is suitable for the identification model of anhydrous ethanol extract infrared spectral data, SVM is suitable for the identification model of chloroform extract infrared spectral data, while petroleum ether extract group recognition effect is not ideal. According to the suitable characteristic parameters identification model, data were analyzed by infrared spectroscopy, and parameters and resistance characteristics of the traditional Chinese drug composition can be obtained. Regional characteristics of these two parameters can be used to identify drug ingredients, and can also be used to indicate different degrees of resistance characteristics of traditional Chinese medicine. Component parameter is model identification coefficient corresponding to the position of spectrum and infrared, with a value greater than zero it is cold nature marker, while with a value less than zero it is heat nature marker; model identification score is a parameter reflecting the degree of cold and heat nature, the greater the score (positive), the more it is cold, while the smaller the score, the more it is hot.a parameter reflecting the degree of cold and heat,the greater the score (positive) is cold more strong, the score is small (negative) heat stronger..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 58 (2014)
Identification of Transmission Fluid Based on NIR Spectroscopy by Combining Sparse Representation Method with Manifold Learning
JIANG Lu-lu, LUO Mei-fu, ZHANG Yu, YU Xin-jie, KONG Wen-wen, and LIU Fei
An identification method based on sparse representation (SR) combined with autoencoder network (AN) manifold learning was proposed for discriminating the varieties of transmission fluid by using near infrared (NIR) spectroscopy technology. NIR transmittance spectra from 600 to 1 800 nm were collected from 300 transmissAn identification method based on sparse representation (SR) combined with autoencoder network (AN) manifold learning was proposed for discriminating the varieties of transmission fluid by using near infrared (NIR) spectroscopy technology. NIR transmittance spectra from 600 to 1 800 nm were collected from 300 transmission fluid samples of five varieties (each variety consists of 60 samples). For each variety, 30 samples were randomly selected as training set (totally 150 samples), and the rest 30 ones as testing set (totally 150 samples). Autoencoder network manifold learning was applied to obtain the characteristic information in the 600~1 800 nm spectra and the number of characteristics was reduced to 10. Principal component analysis (PCA) was applied to extract several relevant variables to represent the useful information of spectral variables. All of the training samples made up a data dictionary of the sparse representation (SR). Then the transmission fluid variety identification problem was reduced to the problem as how to represent the testing samples from the data dictionary (training samples data). The identification result thus could be achieved by solving the L-1 norm-based optimization problem. We compared the effectiveness of the proposed method with that of linear discriminant analysis (LDA), least squares support vector machine (LS-SVM) and sparse representation (SR) using the relevant variables selected by principal component analysis (PCA) and AN. Experimental results demonstrated that the overall identification accuracy of the proposed method for the five transmission fluid varieties was 97.33% by AN-SR, which was significantly higher than that of LDA or LS-SVM. Therefore, the proposed method can provide a new effective method for identification of transmission fluid variety..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 64 (2014)
New Method of Near Infrared Spectra Analysis for the Content of Acid Soluble Lignin of Acacia
LIU Sheng
The near infrared spectra analysis model of the content of the acid soluble lignin and the model of the content of the Klason lignin were built by the iterative method separately at first. The results show that the prediction effect of the content of the Klason lignin is obviously better than that of the acid soluble lThe near infrared spectra analysis model of the content of the acid soluble lignin and the model of the content of the Klason lignin were built by the iterative method separately at first. The results show that the prediction effect of the content of the Klason lignin is obviously better than that of the acid soluble lignin. Different from usual methods of building near infrared spectra analysis model, the approximate linear relation between the contents of the acid soluble lignin and the contents of the Klason lignin was used. Combined with the near infrared spectroscopy data of multi-wavelength, twenty sub models of prediction of the content of the acid soluble lignin were built with the help of the Klason lignin content whose prediction effect is better than that of the acid soluble lignin. By calculating the weighted mean value of the prediction values of these sub models, the new prediction value of the content of the acid soluble lignin of each acacia specimen was obtained at last. The prediction error of the new model is obviously less than that of the model built by the iterative method. It is possible that the method of modeling in the paper can be used to some chemical component contents when the predictions of them by usual methods are not very effective, and the effects of the near infrared spectra analysis of them will be improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 69 (2014)
Quantitative Analysis of Contents in Compound Fertilizer and Application Research Using Near Infrared Reflectance Spectroscopy
SONG Le, ZHANG Hong, NI Xiao-yu, WU Lin, LIU Bin-mei, YU Li-xiang, WANG Qi, and WU Yue-jin
In the present study, a new approach to fast determining the content of urea, biuret and moisture in compound fertilizer composed of urea, ammonium dihydrogenphosphate and potassium chloride was proposed by using near infrared diffuse reflectance spectroscopy. After preprocessing the original spectrum, partial least sqIn the present study, a new approach to fast determining the content of urea, biuret and moisture in compound fertilizer composed of urea, ammonium dihydrogenphosphate and potassium chloride was proposed by using near infrared diffuse reflectance spectroscopy. After preprocessing the original spectrum, partial least squares (PLS) models of urea, biuret and moisture were built with the R2 values of 0.986 1, 0.977 0 and 0.971 3 respectively, the root mean square errors of cross validation were 2.59, 0.38, 0.132 respectively. And the prediction correlation factors were 0.973 3, 0.921 5 and 0.967 9 respectively. The authors detected six kinds of compound fertilizer in market for the model verification, the correlation factors were 0.923 7, 0.978 6 and 0.987 4 respectively. The data implied that the new method can be used for situ quality control in the production process of compound fertilizer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 73 (2014)
Adsorption Behaviors of Protonation Modified Chitosan and the Analysis of Spectra
GUO Ying-juan, XUE Juan-qin, ZHANG Jie, MA Jing, QUAN Xue-ting, and LIU Yao
In order to improve adsorbing performance and stability of chitosan in acid simultaneously, cross-linking was employed after the protection of amino groups for improving its stability, then the protection of amino groups was removed and protonated to obtain high adsorption performance. With formaldehyde as amino-group In order to improve adsorbing performance and stability of chitosan in acid simultaneously, cross-linking was employed after the protection of amino groups for improving its stability, then the protection of amino groups was removed and protonated to obtain high adsorption performance. With formaldehyde as amino-group protective agent and glutaraldehyde as cross-linking reagent, cross-linked chitosan(CCTS) was prepared by reversed phase suspension method in this paper, then it was protonated to make protonation modified chitosan adsorbent(P-CCTS). The adsorption performance of sulfate ion onto P-CCTS was firstly studied and investigated by static adsorption test. Elemental analysis by energy dispersive spectrometer of X-rays (EDS) and identifying of functional groups by Fourier transform infrared spectroscopy (FTIR) were used to analyze the preparation and adsorption of the adsorbent, and the reaction mechanism of cross-linking and adsorption was investigated. The results show that the adsorption performance of P-CCTS towards sulfate ion is 10 times higher than that of unmodified chitosan, and formaldehyde and glutaraldehyde mainly react with amino (—NH2) and part of hydroxy (C6—OH) of chitosn. A salt of chitosan protonated amino chlorine was formed through the process of the protonation of amino, the adsorption of sulfate ion mainly occurs on the protonated amino on which ion exchange happened between chlorine ion and sulfate ion..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 78 (2014)
Rapid Identification of Dendrobium Plants Based on Near Infrared Diffuse Reflection Spectroscopy
DING Chang-chun, FANG Xiang-jing, ZHAO Yan-li, LI Gui-xiang, LI Tao, WANG Yuan-zhong, and XIA Nian-he
Near infrared diffuse reflection spectra of 15 species’ 171 samples of Dendrobium combined with chemometrics statistical analysis were used to build prediction model, in order to discriminate different species of Dendrobium quickly and nondestructively. Hotelling T2 was applied to stability analysis of spectrum of 5 raNear infrared diffuse reflection spectra of 15 species’ 171 samples of Dendrobium combined with chemometrics statistical analysis were used to build prediction model, in order to discriminate different species of Dendrobium quickly and nondestructively. Hotelling T2 was applied to stability analysis of spectrum of 5 random drawing samples, and the results showed that the samples spectrum possessed good stability. Orthogonal test L24（2×4×3×8） was designed to optimize optical path type, spectral band, derivative and smooth. The result of orthogonal test was analyzed by principal component analysis, which revealed that when 6 500～4 000 cm-1 spectral band was applied, and with multiplicative scatter correction, second derivative, Norris smooth, and the number of principal components 7, the spectrum distinguishing accuracy was 100%. With the optimized condition of orthogonal test as the input value of partial least squares discriminant analysis and random drawing 123 samples as calibration set to establish the prediction model, and the rest 48 samples as prediction set were use to assess the property of the prediction model, the results indicated that the accumulating contribution rate of the first 3 principal components of the model was 99.36%, the identification of the standard deviation was ±0.1, and the correct recognition rate of the model was 97.92%. The results were satisfied. The method provided a new way for the rapid identification of different species of Dendrobium, and also supplied a reference for the authentication of medicinal plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 82 (2014)
Research on Raman Spectra of Chalcopyrite under 0~1 400 MPa and Ambient Temperature
YUAN Xue-yin, and ZHENG Hai-fei
The variation characters of the A1 mode Raman spectra of chalcopyrite under 0.1～1 400 MPa and ambient temperature were researched using diamond anvil cell. The results show that the shape and intensity of the Raman peak remains constant under experimental conditions, indicating that the chemical bounds of Cu-S and Fe-SThe variation characters of the A1 mode Raman spectra of chalcopyrite under 0.1～1 400 MPa and ambient temperature were researched using diamond anvil cell. The results show that the shape and intensity of the Raman peak remains constant under experimental conditions, indicating that the chemical bounds of Cu-S and Fe-S remain unchanged. The authors have also noticed that the position of the Raman peak shifts to higher frequency with increasing pressure, which could be described as: ν290＝0.031 2p+290.60(0.1≤ｐ<58.8 MPa) and ν290＝0.005 72p+292.10(58.8≤p<1 400 MPa). The rate of the Raman peak shifting with increasing pressure changed abruptly at about 58.8 MPa, the dν/dp is 31.2 and 5.72 cm-1·GPa-1 below and above 58.8 MPa respectively, which perhaps indicate that some structural changes occurred in the chalcopyrite..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 87 (2014)
Spectroscopic Investigation of the Influence of Calcium Ion on the Structures of Casein Micelles
WANG Peng-jie, WU Jian-ping, ZHANG Hao, GUO Hui-yuan, LIU Hong-na, and REN Fa-zheng
The effects of calcium ion on the structural properties of casein micelles in the course of heat treatment were synthetically examined by non-structure-invasive spectrometry. The hydrophobicity, reflected by extrinsic fluorescence (ANS fluorescence), was positively correlated with the concentration of the calcium ion, The effects of calcium ion on the structural properties of casein micelles in the course of heat treatment were synthetically examined by non-structure-invasive spectrometry. The hydrophobicity, reflected by extrinsic fluorescence (ANS fluorescence), was positively correlated with the concentration of the calcium ion, within the range of 0 to 12 mmol·L-1. Meanwhile, the turbidity and stability of casein micelles also increased with the growth of calcium concentrations. However, opposite results were observed for hydrodynamic diameter and polydispersity index. Compared with the calcium ion, the calcium-chelator (citrate) has an opposite effect on the structural characteristics of casein micelles. Within the calcium concentrations range of 0 to 12 mmol·L-1, the hydrophobicity, stability and turbidity were negatively correlated with the concentration of the calcium ion, nevertheless, opposite results were observed for hydrodynamic diameter and polydispersity index. All the results indicate that the calcium ion could be used to modify the structures of casein micelles during heat heatment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 92 (2014)
Reserach on Raman Spectra of Organic Ingredients on Colored Pearls
HU Yang, FAN Lu-wei, and HUANG Yi-lan
Based on the visible spectra and Raman spectra test of a variety of colored pearls samples to study the relationship between the organic component and the pearl’s color was studied. The study results show that both the freshwater and seawater pearls exhibit strong characteristic peaks in 1 121～1 132 and 1 506～1 524 cm-Based on the visible spectra and Raman spectra test of a variety of colored pearls samples to study the relationship between the organic component and the pearl’s color was studied. The study results show that both the freshwater and seawater pearls exhibit strong characteristic peaks in 1 121～1 132 and 1 506～1 524 cm-1 range, which is respectively attributed to the C—C and CC stretching vibration; the peak intensity in 1 117～1 132, 1 502～1 524 and 2 000～3 500 cm-1 range increases as the color deepens, which is closely related to the pearl’s color; The peak in the 1 475～1 575 cm-1 range is divided into 8～10 secondary peaks of purple freshwater pearl and deep orange seawater pearl. The number of CC double bonds is N=9～27 and N=7～27 respectively after calculation. Polyene compound of different varieties and content could be the reason for the pearls’ color..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 98 (2014)
A New Peak Detection Algorithm of Raman Spectra
JIANG Cheng-zhi, SUN Qiang, LIU Ying, LIANG Jing-qiu, AN Yan, and LIU Bing
The authors proposed a new Raman peak recognition method named bi-scale correlation algorithm. The algorithm uses the combination of the correlation coefficient and the local signal-to-noise ratio under two scales to achieve Raman peak identification. We compared the performance of the proposed algorithm with that of tThe authors proposed a new Raman peak recognition method named bi-scale correlation algorithm. The algorithm uses the combination of the correlation coefficient and the local signal-to-noise ratio under two scales to achieve Raman peak identification. We compared the performance of the proposed algorithm with that of the traditional continuous wavelet transform method through MATLAB, and then tested the algorithm with real Raman spectra. The results show that the average time for identifying a Raman spectrum is 0.51 s with the algorithm, while it is 0.71 s with the continuous wavelet transform. When the signal-to-noise ratio of Raman peak is greater than or equal to 6(modern Raman spectrometers feature an excellent signal-to-noise ratio), the recognition accuracy with the algorithm is higher than 99%, while it is less than 84% with the continuous wavelet transform method. The mean and the standard deviations of the peak position identification error of the algorithm are both less than that of the continuous wavelet transform method. Simulation analysis and experimental verification prove that the new algorithm possesses the following advantages: no needs of human intervention, no needs of de-noising and background removal operation, higher recognition speed and higher recognition accuracy. The proposed algorithm is operable in Raman peak identification..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 103 (2014)
Low-Temperature-Dependent Characteristics of Raman Scattering in N-Type 4H-SiC
MIAO Rui-xia, ZHAO Ping, LIU Wei-hong, and TANG Xiao-yan
In the present paper, Raman scattering techniques for N-type 4H-SiC single crystal material were performed at the temperatures ranging from 30 to 300 K. These measurements revealed that the Raman phonon modes have a redshift and the linewidth gradually broadens with temperature increasing. Based on the experimental resIn the present paper, Raman scattering techniques for N-type 4H-SiC single crystal material were performed at the temperatures ranging from 30 to 300 K. These measurements revealed that the Raman phonon modes have a redshift and the linewidth gradually broadens with temperature increasing. Based on the experimental results, the reason for the redshift and broadening is discussed. With the temperature increasing, the lattice thermal vibration restoring force decreases with the lattice thermal vibration increasing, and the interaction between the atom and unit cell is weakened, resulting in the redshift of the acoustic phonon modes and optical phonon modes. The mean number of phonons increase with the temperature increasing, which leads to an increase in scattering probability, in result of decreasing the phonon lifetime. The linewidth and phonon lifetime is inversely proportional, so the linewidth gradually broadens with temperature increasing. Phonon mode intensity with increasing temperature showed different laws that the intensity of E2 (LA), E2 (TA), E1 (TA) and A1 (LA) phonon mode monotonously increases as the temperature increases, while the intensity of E2 (TO), E1(TO) and A1 (LO) phonon mode decreases after 138 K. The reason is that the high-energy phonons split into multiple lower energy phonons..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 108 (2014)
Quantitative Analysis of Two Food Colors Using Excitation-Emission Matrix Spectra Coupled with Parallel Factor Algorithm
LI Run, CHEN Guo-qing, ZHU Chun, and KONG Fan-biao
In the present paper, British Edinburgh FLS920P Steady State and Time-Resolved Fluorescence Spectrometer was applied to measure three dimensional fluorescence spectra of 12 pigment solution samples and the parallel factor algorithm was combined with the excitation-emission matrix to find a way to detect the food colorsIn the present paper, British Edinburgh FLS920P Steady State and Time-Resolved Fluorescence Spectrometer was applied to measure three dimensional fluorescence spectra of 12 pigment solution samples and the parallel factor algorithm was combined with the excitation-emission matrix to find a way to detect the food colors. In the experiment, making use of CORCONDIA determination method to confirm that the number of the components is 3 in mixed solution, and then by using parallel factor analysis (PARAFAC) algorithms,get the average recoveries of carminum and Allura red were 99.3%±5.0% and 102.2%±5.6%, and the root mean square errors of prediction (RMSEP) were 0.054 and 0.205, respectively。The results show that the method can be applied to determine carminum and Allura red in the mixed solution simultaneously even in the presence of interfering amaranth, which was simple and convenient, rapid, etc, and provides references for synthetic food pigments detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 111 (2014)
Assessment of Inner Filter Effect Corrections in Fluorimetry of the Interaction Between Polyphenols and Proteins
ZHANG Ying, ZHONG Li, DU Jing, CHEN Jin-yu, DONG Xiao-qian, and LI Chun-mei
Using persimmon tannin fraction (PT40), epicatechin-3-gallate-(4β→8, 2β→O→7)-epicatechin-3-gallate (A-type ECG dimer) and epigallocatechin-3-gallate (EGCG) as representatives of polyphenols and Chinese cobra snake venom phospholipase A2 (PLA2) as a model protein, different mathematical equations were compared to correcUsing persimmon tannin fraction (PT40), epicatechin-3-gallate-(4β→8, 2β→O→7)-epicatechin-3-gallate (A-type ECG dimer) and epigallocatechin-3-gallate (EGCG) as representatives of polyphenols and Chinese cobra snake venom phospholipase A2 (PLA2) as a model protein, different mathematical equations were compared to correct the inner filter effects produced by the fluorescence quenching of those polyphenols to PLA2 based on the gradient, linearity and intercept of Stern-Volmer regression equation. The results revealed that correction by the equation developed by Gauthier et al made a significant reduction in gradients. Besides, the linearity was clearly improved and the intercepts were closer to 1 after correction in all cases. The binding constant of PT40 and PLA2 declined by 60% and the inferred interaction forces were more convinced after correction by the above equation. Therefore, the equation developed by Gauthier et al was the most appropriate equation for correcting the inner filter effects when studying the interaction of polyphenols and protein using fluorescence quenching method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 116 (2014)
DFT/TDDFT Study on the Structure and Absorption Spectra of Free Base, N-/Neo-Confused Porphyrin
LIU Guo-kui, CAO Hong-yu, LI Shen-min, TANG Qian, YANG Yan-jie, and ZHENG Xue-fang
Porphyrin is an important class of photochemical materials, which has been widely used in various fields. Computational investigations into the ground state structures and orbital energy levels of free base porphyrin (FBP), neo-confused porphyrin (NECP) and N-confused porphyrin (NCP) were performed with density functioPorphyrin is an important class of photochemical materials, which has been widely used in various fields. Computational investigations into the ground state structures and orbital energy levels of free base porphyrin (FBP), neo-confused porphyrin (NECP) and N-confused porphyrin (NCP) were performed with density functional theory(DFT). Absorption spectra were calculated at TD-B3LYP/6-31+G(d). Degeneracy of HOMO and HOMO-1 is lost, which would account for the shoulder peaks about the most intense transitions of FBP and NECP. Following FBP, NECP and NCP order, the orbital energy level (OEL) of LUMO decreases while the OEL of HOMO increases, which lead to the red shift of adsorption spectra. The energy difference between LUMO and LUMO+1 is almost the same as the difference between HOMO and HOMO-1, which would account for the only most intense transition of NCP. Solvent effect on ground state structures and absorption spectra was also investigated. The data shows that the character peak of Soret band and Q band changes in different solvent (benzene, chloroform, acetonitrile and water). So we further focus on discussing the N atom position and solvent effects on the energy level and Soret/Q bands of FBP, NCP and NECP, as well as clarifying its variation regularity and mechanism..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 128 (2014)
A Novel Spectral Fingerprint Analysis to Discriminate Dry Red Wines
WEN Yan, TAO Yong-sheng, HOU Xiao-fan, and Marta Dizy
A novel spectral fingerprint to discriminate different dry red wines was built using data visualization method. Twelve red wines with different vintages, cultivars and ageing methods from Changli and Shacheng were sampled. Nine fractions of each wine were collected with a reversed-phase C18 column, and then they were lA novel spectral fingerprint to discriminate different dry red wines was built using data visualization method. Twelve red wines with different vintages, cultivars and ageing methods from Changli and Shacheng were sampled. Nine fractions of each wine were collected with a reversed-phase C18 column, and then they were lyophilized. The residue of each fraction was resolved with synthetic wine of the same volume with the fraction sample. The transmittance spectra of wines and their fractions were recorded from 190 to 1 100 nm. And the spectral data were visualized to show their visual differences directly. Mono-phenols in wine and fractions were analyzed by HPLC-DAD at wavelengths in the range where located the obvious differences of the spectral fingerprints. The results showed that the spectral differences of wine samples lied in the range of 190 to 600 nm. There were obvious differences in visual maps among wines with different vintages, mainly around 520 nm. The visualization differences among wines with distinct geographical origins lay in the F8 maps, and the differences from the aging methods almost cover the whole wavelength range visualized. However, wines from different grape cultivars had the similar visual characteristics. HPLC-DAD identified the possible mono-phenol groups for the spectral differences at 280, 313, 365 and 520 nm. It was concluded that the visualization of spectral data from 190 to 600 nm could be used to build red wine spectral fingerprint to distinguish dry red wines with different vintages, origins, and ageing methods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 133 (2014)
Quantum Chemical Study of Ultraviolet and Visible Spectra of Four Amino Cobalt Phthalocyanin
XUE Juan-qin, BI Qiang, ZHAO Xiao, MA Jing, YU Li-hua, and ZHANG Jie
Four amino cobalt phthalocyanine is well known as a promising photosensitizer. In order to enrich and complete the theoretical system of structural properties and reactivity, four amino cobalt phthalocyanine was synthesized and its ultraviolet-visible spectrum was obtained by experimental research. Then the experimentaFour amino cobalt phthalocyanine is well known as a promising photosensitizer. In order to enrich and complete the theoretical system of structural properties and reactivity, four amino cobalt phthalocyanine was synthesized and its ultraviolet-visible spectrum was obtained by experimental research. Then the experimental spectrum was compared with that obtained from theoretical calculation by quantum chemistry. The experimental results show that there are two obvious absorption peaks at 324.98 and 709.94 nm respectively in the ultraviolet-visible spectrum of four amino cobalt phthalocyanine. The density functional B3LYP/3-21G* method was used in simulating ultraviolet-visible absorption spectra of four amino cobalt phthalocyanine. The calculation results show that there should be two absorption peaks at 321.41 and 709.92 nm respectively. The simulation results agree well with the experimental values, which demonstrates that the density functional theory is valid and reliable in the theoretical research on four amino cobalt phthalocyanine. The contribution rate of various electron transitions in every absorption peak was determined by quantum computation. The contribution rate of various electron transition in every absorption peak was determined by quantum computation. The absorption peak at 326.22 nm is mainly resulted from electronic transition from 152 to 163 LUMO orbit, the absorption peak at 314.42 nm is due to electronic transition from 149 to 164 LUMO+1 orbit, the absorption peak at 747.57 nm is mainly caused by electronic transition from 162 to 163 LUMO orbit, and the absorption peak at 676.01 nm is mainly caused by electronic transition from 162 to 164 LUMO+1 orbit. These data provide great theoretical complement to experimental study. The quantum chemical study for four amino cobalt phthalocyanine ultraviolet-visible spectrum has very important theoretical significance for experimental research in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 141 (2014)
Study on the Polarized Reflectance Characteristics of Single Greenhouse Tomato Nutrient Deficiency Leaves
ZHU Wen-jing, MAO Han-ping, LIU Hong-yu, ZHANG Xiao-dong, and NI Ji-heng
In order to improve accuracy of quantitative analysis model for the greenhouse tomato nitrogen, phosphorus and potassium nutrient stress, and explore the advantages of polarization non-destructive detection in single-leaf plants scale, polarized reflectance characteristics of greenhouse nutrient deficiency tomato leaveIn order to improve accuracy of quantitative analysis model for the greenhouse tomato nitrogen, phosphorus and potassium nutrient stress, and explore the advantages of polarization non-destructive detection in single-leaf plants scale, polarized reflectance characteristics of greenhouse nutrient deficiency tomato leaves in different growing seasons and different deficiency extents were both examined via means of polarized reflectance spectroscopy system, which was self-developed by the research group. The main factors with effects on the polarized reflectance characteristics of tomato leaves were discussed, such as incident zenith angle, azimuth angle, detection zenith angle, light source polarizer degree, and detector polarizer degree. Experiments were carried out to verify the optimum level of above five parameters by means of range analysis of orthogonal experiments, through that way we can know the best angle combination of five parameters. Based on the above analysis, the angle combination and sorting of detecting tomato nutrients deficiency leaves via means of polarization spectroscopy system were obtained as follows: incident zenith angle 60°, light source polarizer degree 0°, detection zenith angle 45°, detector polarizer degree 45° and azimuth angle 180°. At the same time, both the spectra of nitrogen, phosphorus and potassium deficiency leaves in different growth stages and different deficiency extent leaves were compared with each other. Results show that there is a positive correlation between the greenhouse nutrient deficiency tomato leaves growth cycle and tomato leaves polarized reflectance spectra. Nutrient excess or nutrient deficiency can both lead to polarized reflectance decline and polarized reflectance decline extent of greenhouse tomato leaves is more obvious during the fruiting and harvest period. This paper has a certain theoretical and practical significance in the research on nutrition rapid detection on the plant single leaf scale by means of polarized reflectance spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 145 (2014)
A Novel Pol SAR Image Classification Method with Subsequent Category Adjustment by Terrain Scattering Characteristic
LIU Li-min, YU Jie, WANG Yan-bing, CHEN Mi, ZHU Teng, and YE Qiu-hong
The present paper, on the basis of analyzing the terrain scattering characteristics, proposed a novel supervised classification method combined with complex Wishart classifier ideology. This method used coherent matrix which almost contains all the polarization information to make subsequent adjustments for the superviThe present paper, on the basis of analyzing the terrain scattering characteristics, proposed a novel supervised classification method combined with complex Wishart classifier ideology. This method used coherent matrix which almost contains all the polarization information to make subsequent adjustments for the supervised classification result to achieve higher accuracy division categories. For the first beginning, supervised classification was carried out on the Cloude & Pottier polarimetric characteristics combination to get the initial classification result．Then, in order to achieve the purpose to correct the mistakes resulting from just using the spatial distribution of feature vectors in supervised classification, we did some analysis as follow. The accuracy analysis of the classification results and the analysis of study area feature scattering similarity play an important role in our study to help us make the determination that the pixels need to be adjusted. Furthermore, taking the mean value of each category coherence matrix as the initial cluster centers of subsequent iterations, and using Kernel Fuzzy C-Means algorithm to adjust the fixed pixel set categories by subsequent category iterative correction, the fine and high-accuracy classification results were obtained, combined with complex Wishart distribution of coherence matrix. The domestic X-band full polarization SAR data of Lingshui area in Hainan province was applied in this classification experiment. The experiment results demonstrate that the proposed method can obtain a favorable classification accuracy polarization SAR image classification results, and better meet the scattering characteristics of the surface objects compared to the original method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 151 (2014)
A Fluoride-Sensor for Kink Structure in DNA Condensation Process
LIU Yan-hui, ZHANG Jing, CHEN Ying-bing, LI Yu-pu, and HU Lin
Bloomfield has pointed out that the kink structure occurs for sharp bending during DNA condensation process, until now, which has not been proved by experiments. Using UV Spectrophotometer, the effects of fluoride and chlorine on the polyamine-DNA condensation system can be detected. Fluoride and chlorine both belong tBloomfield has pointed out that the kink structure occurs for sharp bending during DNA condensation process, until now, which has not been proved by experiments. Using UV Spectrophotometer, the effects of fluoride and chlorine on the polyamine-DNA condensation system can be detected. Fluoride and chlorine both belong to the halogen family, but their effects on spermine-DNA condensation system are totally different. Fluoride ions make blue-shift and hyperchromicity appear in the spermine-DNA condensation system, but chlorine ions only make insignificant hyperchromicity happen in this system. Both fluoride ions and chlorine ions only make insignificant hyperchromicity happen in spermidine-DNA condensation system. Based on the distinguished character of fluoride, a fluoride-sensor for “kink” structure in DNA condensation was developed and the second kind of “kink” structure only appear in the spermine-DNA condensation system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 157 (2014)
Characteristics and Antioxidant Activity of Bovine Serum Albumin and Quercetin Interaction in Different Solvent Systems
DONG Xue-yan, YAO Hui-fang, REN Fa-zheng, and JING Hao
Modes and influencing factors of bovine serum albumin (BSA) and quercetin (QUE) interaction will help us understand the interaction mechanisms and functional changes of bioactive small molecules and biomacromolecules. The fluorescence spectroscopy, UV-Vis spectroscopy, synchronous fluorescence spectroscopy, DPPH and ABModes and influencing factors of bovine serum albumin (BSA) and quercetin (QUE) interaction will help us understand the interaction mechanisms and functional changes of bioactive small molecules and biomacromolecules. The fluorescence spectroscopy, UV-Vis spectroscopy, synchronous fluorescence spectroscopy, DPPH and ABTS radical scavenging assays were used to investigate the characteristics and antioxidant activity of BSA and QUE interaction in three solvent systems (deionized water, dH2O; dimethyl sulfoxide, DMSO and ethanol, EtOH). The results revealed that QUE had a great ability to quench BSA’s fluorescence in both static and dynamic modes, and that hydrophobic interaction played a dominant role in BSA and QUE interaction in three solvent systems. The binding constant values and binding site numbers between BSA and QUE were in the order of dH2O＞DMSO＞EtOH. The binding distances were in the order of EtOH＞DMSO＞dH2O. On the basis of the binding distance, the binding forces were in the order of dH2O＞DMSO＞EtOH. The synchronous fluorescence spectra demonstrated that QUE interacted with both tyrosine and tryptophan residues of BSA in three solvent systems. Moreover, the DPPH radical scavenging rates of both QUE and BSA-QUE were 30%. While, the ABTS radical scavenging rate of QUE was significantly decreased from 80% to 70% when bound to BSA. No significant difference in antioxidant activity between QUE and BSA-QUE was observed in three solvent systems..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 162 (2014)
Responses of Vegetation Changes to Climatic Variations in Panxi Area Based on the MODIS Multispectral Data
SHAO Huai-yong, WU Jin-hui, LIU Meng, and YANG Wu-nian
It is an important research area to quantitatively studying the relationship between global climatic change and vegetation change based on the remote sensing technology. Panxi area is the ecological barrier of the upper reaches of the Yangtze River, and it is essential for the stability of the ecological environment ofIt is an important research area to quantitatively studying the relationship between global climatic change and vegetation change based on the remote sensing technology. Panxi area is the ecological barrier of the upper reaches of the Yangtze River, and it is essential for the stability of the ecological environment of Sichuan as well as that of the whole China. The present article analyzes the vegetation change in 2001—2008 and the relationship between vegetation change and climatic variations of Panxi area, based on MODIS multispectral data and meteorological data. The results indicate that NDVI is positively correlated with temperature and precipitation. The precipitation is the major factor that affects the change of vegetation in the Panxi region and the trend of NDVI is similar with autumn precipitation; while at the same time the influence of climate has a one-month- time-lag..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 167 (2014)
Atomic Layer Deposited Aluminum Oxide on SnO2 Particles and Its Impact on Dye-Sensitized Solar Cells Performance
DONG Wan, MENG Tao, and CHEN Qiang
An ultra-thin deposition of alumina covered the SnO2 photoelectrode surface by atomic layer deposition for dye sensitized cell. Trimethyl aluminum (TMA) and water were used as precursor. The influence of alumina on dye-sensitized cells photoelectric conversion efficiency was discussed. The results showed that atomic laAn ultra-thin deposition of alumina covered the SnO2 photoelectrode surface by atomic layer deposition for dye sensitized cell. Trimethyl aluminum (TMA) and water were used as precursor. The influence of alumina on dye-sensitized cells photoelectric conversion efficiency was discussed. The results showed that atomic layer deposition rate per cycle was about 0.12 nm by use of elliptic polarization apparatus (SE). The SnO2 crystal structure and surface morphology were not changed by deposited alumina as observed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The dye adsorption capacity increased with the deposition alumina cycles as found by ultraviolet-visible spectra (UV-Vis). Finally, the mechanism of the effect of deposited alumina using atomic layer deposition was discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 172 (2014)
Research on Living Tree Volume Forecast Based on PSO Embedding SVM
JIAO You-quan, FENG Zhong-ke, ZHAO Li-xi, XU Wei-heng, and CAO Zhong
In order to establish volume model, living trees have to be fallen and be divided into many sections, which is a kind of destructive experiment. So hundreds of thousands of trees have been fallen down each year in China. To solve this problem, a new method called living tree volume accurate measurement without falling In order to establish volume model, living trees have to be fallen and be divided into many sections, which is a kind of destructive experiment. So hundreds of thousands of trees have been fallen down each year in China. To solve this problem, a new method called living tree volume accurate measurement without falling tree was proposed in the present paper. In the method, new measuring methods and calculation ways are used by using photoelectric theodolite and auxiliary artificial measurement. The diameter at breast height and diameter at ground was measured manually, and diameters at other heights were obtained by photoelectric theodolite. Tree volume and height of each tree was calculated by a special software that was programmed by the authors. Zhonglin aspens No.107 were selected as experiment object, and 400 data records were obtained. Based on these data, a nonlinear intelligent living tree volume prediction model with Particle Swarm Optimization algorithm based on support vector machines (PSO-SVM) was established. Three hundred data records including tree height and diameter at breast height were randomly selected form a total of 400 data records as input data, tree volume as output data, using PSO-SVM tool box of Matlab7.11, thus a tree volume model was obtained. One hundred data records were used to test the volume model. The results show that the complex correlation coefficient (R2) between predicted and measured values is 0.91, which is 2% higher than the value calculated by classic Spurr binary volume model, and the mean absolute error rates were reduced by 0.44%. Compared with Spurr binary volume model, PSO-SVM model has self-learning and self-adaption ability, moreover, with the characteristics of high prediction accuracy, fast learning speed, and a small sample size requirement, PSO-SVM model with well prospect is worth popularization and application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 175 (2014)
Rapid Determination of Total Phosphorus by Ultrasonic Assisted Sample Digestion-Spectrum Analysis
WEI Kang-lin, WANG Fei, CHEN Ming, WEN Zhi-yu, and MO Zhi-hong
Aiming at the technological shortage of national standard method for the determination of total phosphorus, a rapid determination method of total phosphorus based on ultrasonic assisted sample digestion-spectrum analysis was put forward, and the on-line analysis experiment system was designed. Relying on the experimentAiming at the technological shortage of national standard method for the determination of total phosphorus, a rapid determination method of total phosphorus based on ultrasonic assisted sample digestion-spectrum analysis was put forward, and the on-line analysis experiment system was designed. Relying on the experiment system, the experimental method and technology was studied. In view of the actual environmental water samples, contrast test experiment with the national standard method for determination method of total phosphorus was carried on. The experimental results showed that the digestion rate of ultrasonic assisted sample digestion using fenton reagents could reach 97%~100% in 13.5 minutes, and the determination method could complete one copy of sample analysis within 16 minutes. This determination method can solve national standard method’s technical problems. All of this research work provides the important experimental basis and technical support for the development of the rapid on-line monitoring instrument for determination of total phosphorus..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 180 (2014)
Monte Carlo Simulation Based on Diffuse Hyperspectrum Collection with Detection Fiber
LIN Ling, ZHANG Lin-na, LI Xiao-xia, LI Gang, WANG Wei, and LIU Rui-an
The present paper brings the parameters of the detection fiber into Monte Carlo model, and we studied the influence of fiber optic parameters and the distance of fiber from the detector on the detected optic signal,. The simulation results show that signals are obviously different when the NA (numerical aperture) and dThe present paper brings the parameters of the detection fiber into Monte Carlo model, and we studied the influence of fiber optic parameters and the distance of fiber from the detector on the detected optic signal,. The simulation results show that signals are obviously different when the NA (numerical aperture) and diameter of the fiber are different respectively. With the increase in NA and diameter of the fiber, the diffuse reflectance and diffuse transmission increase gradually. However, the distance from the sample surface, to some extent, brings little influence when we control it within 1 mm. By further study of the simulation result, we found that the collection efficient of the fiber is the same in different spatial positions. And the collection efficient of strong scattering material is a constant, in spite of absorption coefficient and scattering coefficient. We can normalize the diffuse signals collected by fibers with different angular aperture β by the collection efficient. Meanwhile, this paper provided the fitting curve of the collection efficient in a certain range. For fibers with different diameters, we can get a good consistence by area normalization. Therefore, the research on the effects of the difference of the detection fiber on diffuse hyper-spectrum has great significance for practical measurement. And the detection results can be transplanted by collection efficient and area normalization when we change the actual detecting fiber..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 185 (2014)
Study on the Modeling of Earth-Atmosphere Coupling over Rugged Scenes for Hyperspectral Remote Sensing
ZHAO Hui-jie, JIANG Cheng, and JIA Guo-rui
Adjacency effects may introduce errors in the quantitative applications of hyperspectral remote sensing, of which the significant item is the earth-atmosphere coupling radiance. However, the surrounding relief and shadow induce strong changes in hyperspectral images acquired from rugged terrain, which is not accurate tAdjacency effects may introduce errors in the quantitative applications of hyperspectral remote sensing, of which the significant item is the earth-atmosphere coupling radiance. However, the surrounding relief and shadow induce strong changes in hyperspectral images acquired from rugged terrain, which is not accurate to describe the spectral characteristics. Furthermore, the radiative coupling process between the earth and the atmosphere is more complex over the rugged scenes. In order to meet the requirements of real-time processing in data simulation, an equivalent reflectance of background was developed by taking into account the topography and the geometry between surroundings and targets based on the radiative transfer process. The contributions of the coupling to the signal at sensor level were then evaluated. This approach was integrated to the sensor-level radiance simulation model and then validated through simulating a set of actual radiance data. The results show that the visual effect of simulated images is consistent with that of observed images. It was also shown that the spectral similarity is improved over rugged scenes. In addition, the model precision is maintained at the same level over flat scenes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 191 (2014)
Effective Endmembers Based Bilinear Unmixing Model
SONG Mei-ping, ZHANG Yong-rong, AN Ju-bai, and BAO Hai-mo
An effective endmembers based bilinear unmixing algorithm is prompted in the present paper together with an endmember subset selection algorithm as well. Firstly, the endmembers are ranked according to their distance to the mixed pixel, involving the Euclidean distance and spectral angle. And then, an effective subset An effective endmembers based bilinear unmixing algorithm is prompted in the present paper together with an endmember subset selection algorithm as well. Firstly, the endmembers are ranked according to their distance to the mixed pixel, involving the Euclidean distance and spectral angle. And then, an effective subset of the endmembers is abstracted considering both the ranking result and the change of error. The algorithm reduces the influence of endmembers which are not component of the mixed pixel, decrease the number of endmembers involved in unmixing and improve the accuracy of abundance. The test results for simulation image prove that the algorithm would provide a lower reconstructing error. And the analysis results of actual airborne hyperspectral oil spill image further illustrate its effectiveness..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 196 (2014)
Inversion of Organic Matter Content of the North Fluvo-Aquic Soil Based on Hyperspectral and Multi-Spectra
WANG Yan-cang, GU Xiao-he, ZHU Jin-shan, LONG Hui-ling, XU Peng, and LIAO Qin-hong
The present study aims to assess the feasibility of multi-spectral data in monitoring soil organic matter content. The data source comes from hyperspectral measured under laboratory condition, and simulated multi-spectral data from the hyperspectral. According to the reflectance response functions of Landsat TM and HJ-The present study aims to assess the feasibility of multi-spectral data in monitoring soil organic matter content. The data source comes from hyperspectral measured under laboratory condition, and simulated multi-spectral data from the hyperspectral. According to the reflectance response functions of Landsat TM and HJ-CCD (the Environment and Disaster Reduction Small Satellites, HJ), the hyperspectra were resampled for the corresponding bands of multi-spectral sensors. The correlation between hyperspectral, simulated reflectance spectra and organic matter content was calculated, and used to extract the sensitive bands of the organic matter in the north fluvo-aquic soil. The partial least square regression (PLSR) method was used to establish experiential models to estimate soil organic matter content. Both root mean squared error (RMSE) and coefficient of the determination (R2) were introduced to test the precision and stability of the modes. Results demonstrate that compared with the hyperspectral data, the best model established by simulated multi-spectral data gives a good result for organic matter content, with R2=0.586, and RMSE=0.280. Therefore, using multi-spectral data to predict tide soil organic matter content is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 201 (2014)
Inversion of LAI by Considering the Hotspot Effect for Different Geometrical Wheat
ZHAO Juan, ZHANG Yao-hong, HUANG Wen-jiang, JING Yuan-shu, PENG Dai-liang, WANG Li, and SONG Xiao-yu
Aimed to deal with the limitation of canopy geometry to crop LAI inversion accuracy a new LAI inversion method for different geometrical winter wheat was proposed based on hotspot indices with field-measured experimental data. The present paper analyzed bidirectional reflectance characteristics of erective and loose vaAimed to deal with the limitation of canopy geometry to crop LAI inversion accuracy a new LAI inversion method for different geometrical winter wheat was proposed based on hotspot indices with field-measured experimental data. The present paper analyzed bidirectional reflectance characteristics of erective and loose varieties at red (680 nm) and NIR wavelengths(800 nm and 860 nm) and developed modified normalized difference between hotspot and dark-spot (MNDHD) and hotspot and dark-spot ratio index(HDRI) using hotspot and dark-spot index(HDS) and normalized difference between hotspot and dark-spot(NDHD) for reference. Combined indices were proposed in the form of the product between HDS, NDHD, MNDHD, HDRI and three ordinary vegetation indices NDVI, SR and EVI to inverse LAI for erective and loose wheat. The analysis results showed that LAI inversion accuracy of erective wheat Jing411 were 0.943 1 and 0.909 2 retrieved from the combined indices between NDVI and MNDHD and HDRI at 860 nm which were better than that of HDS and NDHD, the LAI inversion accuracy of loose wheat Zhongyou9507 were 0.964 8 and 0.895 6 retrieved from the combined indices between SR and HDRI and MNDHD at 800 nm which were also higher than that of HDS and NDHD. It was finally concluded that the combined indices between hotspot-signature indices and ordinary vegetation indices were feasible enough to inverse LAI for different crop geometrical wheat and multi-angle remote sensing data was much more advantageous than perpendicular observation data to extract crop structural parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 207 (2014)
Development of Prediction Models for Determining N Content in Citrus Leaves Based on Hyperspectral Imaging Technology
LI Jin-meng, YE Xu-jun, WANG Qiao-nan, ZHANG Chu, and HE Yong
The present study presents prediction models for determining the N content in citrus leaves by using hyperspectral imaging technology combined with several chemometrics methods. The steps followed in this study are: hyperspectral image scanning, extracting average spectra curves, pretreatment of raw spectra data, extraThe present study presents prediction models for determining the N content in citrus leaves by using hyperspectral imaging technology combined with several chemometrics methods. The steps followed in this study are: hyperspectral image scanning, extracting average spectra curves, pretreatment of raw spectra data, extracting characteristic wavelengths with successive projection algorithm and developing prediction models for determining N content in citrus leaves. The authors obtained three optimal pretreatment methods through comparing eleven different pretreatment methods including Savitzky-Golay（SG）smoothing, standard normal variate(SNV), multiplicative scatter correction(MSC), first derivative(1-Der) and so on. These selected pretreatment methods are SG smoothing, detrending and SG smoothing-detrending. Based on these three pretreatment methods, the authros first extracted the characteristic wavelengths respectively with successive projection algorithm, and then used the spectral reflectance of the extracted characteristic wavelengths as input variables of partial least squares regression (PLS), multiple linear regression (MLR) and back propagation neural network (BPNN) modeling. Hence, the authors developed three prediction models with each pretreatment method, and obtained nine models in total. Among all the nine prediction models, the two models based on the methods of SG smoothing-detrending-SPA-BPNN (Rp: 0.851 3, RMSEP: 0.188 1）and detrending-SPA-BPNN (Rp: 0.860 9, RMSEP: 0.159 5）were found to have achieved the best prediction results. The final results show that using hyperspectra data to determine N content in citrus leaves is feasible. This would provide a theoretical basis for real-time and accurate monitoring of N content in citrus leaves as well as rational N fertilizer application during the plants growth..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 212 (2014)
Quantitative Analysis of Vanadium and Titanium in Steel Samples Using LIBS
GUO Lian-bo, ZHANG Yong, HAO Zhong-qi, SHEN Meng, LI Chang-mao, REN Zhao, LI Xiang-you, and ZENG Xiao-yan
The concentrations of vanadium and titanium elements in the steel samples were quantitatively analyzed by Laser-induced breakdown spectroscopy technique in the present paper. The lines of V (V Ⅰ: 440.85 nm) and Ti (Ti Ⅰ: 334.19 nm) were chosen as the quantitative analysis spectral lines, while spectral line of Fe (Fe ⅠThe concentrations of vanadium and titanium elements in the steel samples were quantitatively analyzed by Laser-induced breakdown spectroscopy technique in the present paper. The lines of V (V Ⅰ: 440.85 nm) and Ti (Ti Ⅰ: 334.19 nm) were chosen as the quantitative analysis spectral lines, while spectral line of Fe (Fe Ⅰ: 438.35 nm) was chosen as the internal calibration line due to it being the matrix element. Then the calibration curves of V and Ti elements were established with basic calibration method and internal calibration method respectively to quantitatively analyze the concentrations of vanadium and titanium elements in steel. The experimental results showed that the fitting correlation coefficient (R2) of vanadium and titanium elements are 0.987 5 and 0.990 9 when using basic calibration method, and their maximum relative errors of measurement are 11.09% and 4% respectively; while the fitting correlation coefficient (R2) of vanadium and titanium elements reachs 0.995 2 and 0.992 1 respectively when using internal calibration method, at the same time, the relative errors of measurement for vanadium and titanium elements were decreased to be lower than 4%. The results of this study demonstrated that the concentration measurement of vanadium and titanium elements in the steel was more suitable with internal calibration method in laser-induced breakdown spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 217 (2014)
Study of Laser Energy in Multi-Element Detection of Pulverized Coal Flow with Laser-Induced Breakdown Spectroscopy
ZHENG Jian-ping, LU Ji-dong, ZHANG Bo, CHEN Shi-he, YAO Shun-chun, PAN Feng-ping, DONG Xuan, and ZHANG Xi
The logical range of laser power density and optimum laser power density were explored for multi-element analysis of pulverized coal flow with laser-induced breakdown spectroscopy in the present paper. The range of laser energy was chosen from 20 to 160 mJ in the experiment. Pulverized coal less than 200 μm in diameterThe logical range of laser power density and optimum laser power density were explored for multi-element analysis of pulverized coal flow with laser-induced breakdown spectroscopy in the present paper. The range of laser energy was chosen from 20 to 160 mJ in the experiment. Pulverized coal less than 200 μm in diameter of particles fell freely through feeder outlet and the rate of flow was controlled by screw feeder. Emissions were collected with pulse laser at 1 064 nm focusing on pulverized coal flow and plasma was generated. The intensity and cause of fluctuation of emission spectra at various laser energy levels were studied. A suitable range of laser power density is from 14.4 to 34.4 GW·cm-2, and the optimum laser power density is 19.5 GW·cm-2 for the determination of pulverized coal flow with LIBS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 221 (2014)
Determination and Uncertainty Evaluation of Microelements in Flaxseed by Using ICP-MS Under Two Modes
XING Li, WANG Mei, ZHAO Feng-min, CAO You-fu, ZHANG Xiao-yan, and CAI Zhi-yong
Copper, iron, zinc and manganese in flaxseed were determined by inductively coupled plasma mass spectrometry(ICP-MS). After digestion by microwave-assisted, Cu, Fe, Zn and Mn were analyzed by using Standard and KED modes．In the present study, testing effectiveness of the two modes was compared. On this base, valid deteCopper, iron, zinc and manganese in flaxseed were determined by inductively coupled plasma mass spectrometry(ICP-MS). After digestion by microwave-assisted, Cu, Fe, Zn and Mn were analyzed by using Standard and KED modes．In the present study, testing effectiveness of the two modes was compared. On this base, valid determination mode was selected for each of the elements and uncertainty evaluations of the four microelements were explored. According to JJFl059-1999 (Evaluation and Expression of Uncertainty in Measurement), the main influence factors were analyzed one by one. Each of the uncertainties was calculated separately. It was showed that the results of Cu, Fe, Zn and Mn in flaxseed determined by ICP-MS method were satisfactory. At the same time, the results obtained in this work were considered to be valuable as a reference for the evaluation of uncertainty in measurement of Fe, Cu, Zn and Mn with ICP-MS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 226 (2014)
Analysis of Mineral Elements of Sunflower (Helianthus annuus L.) Grown on Saline Land in Hetao Irrigation District by ICP-AES
TONG Wen-jie, CHEN Fu, and WEN Xin-ya
The absorption and accumulation of ten mineral elements in four kinds of organs (root, steam, leaf and flower disc) in Helianthus annuus L. plants cultured in Hetao Irrigation District under different level of salinity stress were determined by ICP-AES with wet digestion (HNO3+HClO4). The results showed that: (1) The cThe absorption and accumulation of ten mineral elements in four kinds of organs (root, steam, leaf and flower disc) in Helianthus annuus L. plants cultured in Hetao Irrigation District under different level of salinity stress were determined by ICP-AES with wet digestion (HNO3+HClO4). The results showed that: (1) The contents of Fe, Mn, Zn, Ca, and Na were highest in roots, so was K in stems, B and Mg in leaves and P in flower discs, while no significant difference was detected in the content of Cu among these organs; (2) The cumulants of Ca, Mg, P, Cu, B and Zn were highest in flower discs, so were Na, Fe and Mn in roots and K in stems; (3) In sunflower plants, the proportion of mineral element cumulant for K∶ Ca∶Mg∶P∶Na was 16.71∶5.23∶3.86∶1.23∶1.00, and for Zn∶Fe∶B∶Mn∶Cu was 56.28∶27.75∶1.93∶1.17∶1.00, respectively; (4) The effect of salinity stress on absorption of mineral elements differed according to the kind of organ and element, root was the most sensitive to soil salt content, followed by stem and leaf, and the effect on flower disc seemed complex..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 231 (2014)
Determination of Trace Selenium in Plants by Hydride Generation Atomic Fluorescence Spectrometry with Program Temperature-Controlled Graphite Digestion
Qian Wei, Jiang Qian, Wang Ruhai, Gong Hua, and Han Yong
Discussed several methods of pretreatment for the determination of selenium were discussed, and a program temperature-controlled graphite digestion method was developed to digest 5 kinds of representative standard plant samples of citrus leaves, tea, cabbage leaves, shrubs and rice. The effect of the pretreatment methoDiscussed several methods of pretreatment for the determination of selenium were discussed, and a program temperature-controlled graphite digestion method was developed to digest 5 kinds of representative standard plant samples of citrus leaves, tea, cabbage leaves, shrubs and rice. The effect of the pretreatment method of digestion solution, digestion temperature and digestion time on the extraction of selenium was investigated in detail. The instrumental working parameters were optimized. For the reaction conditions of hydride generation atomic fluorescence spectrometry (HG-AFS), the effect of the concentration of KBH4 and HCl on the determination of selenium was emphasized. Not only the effect of the concentration of carrier fiow HCl was considered, but also the effect of the concentration of sample HCl on the determination of selenium was studied. The best method for determination of trace selenium in plant samples by atomic fluorescence spectrometry with program temperature-controlled graphite digestion was established. Results indicated that the recovery of the method of selenium was 87.1%～106.2%, the detection limit was 0.018 μg·L-1 and the relative standard deviation (RSD) was less than 6.0%. In the range of 0～10 μg·L-1 (low standard) and 0～100 μg·L-1 (high standard) fluorescence was linearly related to the concentration of selenium, the coefficient of r was 0.999 9 and r was 0.999 7. Therefore, this method has wide linear range, high sensitivity, low detection limit and good stability, which was very suitable for the determination of trace selenium of plant. And the method was of easy and safe operation, strong practicability, low cost, and low toxicity of chemicals used, so it can be used as a routine analysis method in general laboratory..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 235 (2014)
Sensitive Determination of Hemoglobin in Human Blood and Serum by Flow Injection Coupled with Chemiluminescence Detection
CAO Jun-tao, WANG Hui, CHEN Yong-hong, and LIU Yan-ming
A sensitive method to detect hemoglobin (Hb) by flow injection (FI) coupled with chemiluminescence (CL) detection was described, which based on Hb strong enhancing effect on weak luminol-hydrazine CL system in alkaline medium. Parameters affecting the CL detection conditions and FI-CL system were optimized. The effectsA sensitive method to detect hemoglobin (Hb) by flow injection (FI) coupled with chemiluminescence (CL) detection was described, which based on Hb strong enhancing effect on weak luminol-hydrazine CL system in alkaline medium. Parameters affecting the CL detection conditions and FI-CL system were optimized. The effects of possible coexisting substances in human blood and serum of detection Hb were evaluated. Under the optimum conditions, the net CL intensity versus Hb concentration was linear in the range of 5.0×10-9～6.0×10-5 g·mL-1 with the detection limit of 5.8×10-10 g·mL-1 (9.0×10-12 mol·L-1). The relative standard deviations (RSDs) for 8 replicate determinations of 5.0×10-7 and 3.0×10-6 g·mL-1 Hb were 1.6% and 1.5%, respectively. In addition, the recoveries of Hb in human blood and serum were carried out and varied from 83.0% to 101.0%. The proposed method has been successfully applied for the determination of Hb in healthy human blood and serum. The possible mechanism of Hb enhancing the weak CL emission of luminol-hydrazine system in NaOH solution was discussed by fluorescence spectrophotometer and UV-Vis spectrophotometer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 241 (2014)
Research on Optimization of Mathematical Model of Flow Injection-Hydride Generation-Atomic Fluorescence Spectrometry
CUI Jian, ZHAO Xue-hong, WANG Yan, XIAO Ya-bing, JIANG Xue-hui, and DAI Li
Flow injection-hydride generation-atomic fluorescence spectrometry was a widely used method in the industries of health, environmental, geological and metallurgical fields for the merit of high sensitivity, wide measurement range and fast analytical speed. However, optimization of this method was too difficult as thereFlow injection-hydride generation-atomic fluorescence spectrometry was a widely used method in the industries of health, environmental, geological and metallurgical fields for the merit of high sensitivity, wide measurement range and fast analytical speed. However, optimization of this method was too difficult as there exist so many parameters affecting the sensitivity and broadening. Generally, the optimal conditions were sought through several experiments. The present paper proposed a mathematical model between the parameters and sensitivity/broadening coefficients using the law of conservation of mass according to the characteristics of hydride chemical reaction and the composition of the system, which was proved to be accurate as comparing the theoretical simulation and experimental results through the test of arsanilic acid standard solution. Finally, this paper has put a relation map between the parameters and sensitivity/broadening coefficients, and summarized that GLS volume, carrier solution flow rate and sample loop volume were the most factors affecting sensitivity and broadening coefficients. Optimizing these three factors with this relation map, the relative sensitivity was advanced by 2.9 times and relative broadening was reduced by 0.76 times. This model can provide a theoretical guidance for the optimization of the experimental conditions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 246 (2014)
Research on Spectral Characteristic of Miniature X-Ray Tube and Determination of Beryllium Window Thickness
GU Yi, XIONG Sheng-qing, GE Liang-quan, FAN Zheng-guo, ZHANG Qing-xian, and ZHU Zhen-ya
Applying Monte Carlo method, the present paper simulates the emitted X-ray spectrum of miniature X-ray tube with thirteen thickness of beryllium window in the range from 50 to 500 μm. By analyzing the characteristic of the spectrums, the reasonable choice of thickness of beryllium window relies on the application and fApplying Monte Carlo method, the present paper simulates the emitted X-ray spectrum of miniature X-ray tube with thirteen thickness of beryllium window in the range from 50 to 500 μm. By analyzing the characteristic of the spectrums, the reasonable choice of thickness of beryllium window relies on the application and for the beryllium window it is not the thinner the better. Taking in-situ EDXRF as an example, though the emission X-ray intensity is higher as the thickness of the beryllium window becomes thinner, the proportion of useless low-energy X-ray (<5 keV) intensity to all energy X-ray intensity also is higher (>20%). The accuracy of in-situ EDXRF will be reduced when the high-throughput low-energy X-ray enters the detector. Therefore, this paper puts forward several parameters as judgment index for beryllium window thickness, which is described as follows: ①The intensity ratios of the K-series X-ray to middle-energy (5～25 keV) bremsstrahlung and middle-high-energy (5～50 keV) bremsstrahlung (F1 and F3); ②The intensity ratios of useless low-energy X-ray (<5 keV) to middle-energy (5～25 keV) X-ray and middle-high-energy (5～50 keV) X-ray (F2 and F4), it can reflect the relative intensity of useless low-energy X-ray. The simulation results demonstrate that with the increase in the beryllium window thickness, the value of F1 (F3) improves slowly, and the value of F2 (F4) decreases rapidly. In addition to the judgment index discussed above, and considering the X-ray shielded by beryllium window, the beryllium window of miniature X-ray tube can be determined. Based on simulation analysis, the thickness of around 250μm is appropriate to miniature X-ray tube applied in the in-situ EDXRF. Comparing the emitted spectrum with 50 μm-thick beryllium window, 71.66% of low-energy X-rays are shielded, only 21.31% of X-rays with energy from 5 to 50 keV is shielded, the intensity ratio of low-energy X-ray to total energy X-ray is less than 10%, and the intensity proportion of K-series X-ray to middle-high energy X-ray maintains a high level. In other words, when the mobile X-ray source with 250 μm beryllium window is used in the in-situ EDXRF, proportion of effective signal is higher, and effect of energy resolution of the detection is least; Moreover, the relative intensity of the excitation spectral scattering background, which is obtained by detection for specimen excitation analysis, will remain at low level, thus to ensure the precision of the result of element analysis. For the beryllium window in the application of radiation therapy, the thicker the better. At this time, low-energy X-ray flux maintains a high level, and it can ensure that radiation dose is concentrated on treatment tissue..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 252 (2014)
Nondestructive Analysis of the Silicate Artifacts Excavated from Baofeng and Xinzheng, Henan Province
FU Qiang, ZHAO Hong-xia, DONG Jun-qing, LI Qing-hui, and HU Yong-qing
Nondestructive analysis plays an important role in the studies of ancient artifacts. The present paper reports the chemical compositions and micro-area phases of 21 silicate artifacts samples analyzed by portable X-ray fluorescence spectrometer and laser Raman spectrometer. Based on the chemical compositions, these samNondestructive analysis plays an important role in the studies of ancient artifacts. The present paper reports the chemical compositions and micro-area phases of 21 silicate artifacts samples analyzed by portable X-ray fluorescence spectrometer and laser Raman spectrometer. Based on the chemical compositions, these samples can be divided into PbO-BaO-SiO2, K2O-SiO2 glass systems, faience and PbO-BaO glassy faience which were discussed respectively, and preliminary investigation of colorants in different parts of some samples was also involved. By laser Raman spectroscopy, Chinese blue(BaCuSi4O10), Chinese purple(BaCuSi2O6) and Chinese dark blue(BaCu2Si2O7) were identified invasively in the blue pigment of some eye beads and circle beads, and then a variety of mineral phase including quartz, calcite, lead carbonate, burnt umber and terre verte were also analyzed successfully in the same way. According to the archaeological research results, the provenances of these samples were discussed briefly. PbO-BaO-SiO2 glass, K2O-SiO2 ear pendant and PbO-BaO glassy faience were made in China while the faience was suspected to be from the west. Those results illustrated the communications of culture and technologies among different regions of ancient China, and between ancient China and the western regions. The combination of portable X-ray fluorescence spectrometer and laser Raman spectrometer can provide chemical and phase information of relics, and has great advantages in scientific analysis of ancient artifacts, which supports future studies of archaeology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 257 (2014)
Automatic Classification Method of Star Spectra Data Based on Manifold-Based Discriminant Anaysis and Support Vector Machine
LIU Zhong-bao, WANG Zhao-ba, and ZHAO Wen-juan
Although Support Vector Machine (SVM) is widely used in astronomy, it only takes the margin between classes into consideration while neglects the data distribution in each class, which seriously limits the classification efficiency. In view of this, a novel automatic classification method of star spectra data based on Although Support Vector Machine (SVM) is widely used in astronomy, it only takes the margin between classes into consideration while neglects the data distribution in each class, which seriously limits the classification efficiency. In view of this, a novel automatic classification method of star spectra data based on manifold-based discriminant analysis (MDA) and SVM is proposed in this paper. Two important concepts in MDA, manifold-based within-class scatter (MWCS) and manifold-based between-class scatter (MBCS), are introduced in the proposed method, the separating hyperplane found by which ensures MWCS is minimized and MBCS is maximized. Based on the above analysis, the corresponding optimal problem can be established, and then MDA transforms the original optimization problem to the QP dual form and we can obtain the support vectors and decision function. The classes of test samples are decided by the decision function. The advantage of the proposed method is that it not only focuses on the information between classes and distribution characteristics, but also preserves the manifold structure of each class. Experiments on SDSS star spectra datasets verify the effectiveness of the proposed method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 263 (2014)
Stellar Spectral Outliers Detection Based on Isomap
BU Yu-de, PAN Jing-chang, and CHEN Fu-qiang
How to find the spectra misclassified by traditional methods is the key problem that has been widely studied by the experts of astronomical data processing. We found that Isomap algorithm performs well for this problem. By comparing the performance of Isomap with that of principal component analysis (PCA), we found thaHow to find the spectra misclassified by traditional methods is the key problem that has been widely studied by the experts of astronomical data processing. We found that Isomap algorithm performs well for this problem. By comparing the performance of Isomap with that of principal component analysis (PCA), we found that (1) Isomap can project the spectra with similar features together and project the spectra with different features far away, while PCA may project the spectra with different features into nearby regions; (2) the outliers given by Isomap can be easily determined, and most of the outliers are binary stars with high scientific values; while the outliers given by PCA are difficult to determine and most of outliers are not binary stars. Thus, Isomap is more efficient than PCA in finding the outliers. Since the spectral data used in experiment are the spectra from the ninth data release of Sloan Digital Sky Survey (SDSS DR9), Isomap can find the spectra misclassified by SDSS pipeline efficiently and improve the classification accuracy obviously. Furthermore, since most of the spectra misclassified by SDSS pipeline are binary stars, Isomap can improve the efficiency of finding the binary stars with high scientific values. Though the experiment results show that Isomap is more sensitive to the noise than PCA, this disadvantage will not affect the application of Isomap in spectral classification since most of the spectra with low signal-to-noise ratios are the spectra whose spectral type cant be determined manually..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 267 (2014)
Influence of Collimation System on Static Fourier Transform Spectrometer
JIANG Cheng-zhi, LIANG Jing-qiu, LIANG Zhong-zhu, SUN Qiang, and WANG Wei-biao
Collimation system provides collimated light for the static Fourier-transform spectroscopy (SFTS). Its quality is crucial to the signal to noise ratio (SNR) of SFTS. In the present paper, the physical model of SFTS was established based on the Fresnel diffraction theory by means of numerical software. The influence of Collimation system provides collimated light for the static Fourier-transform spectroscopy (SFTS). Its quality is crucial to the signal to noise ratio (SNR) of SFTS. In the present paper, the physical model of SFTS was established based on the Fresnel diffraction theory by means of numerical software. The influence of collimation system on the SFTS was discussed in detail focusing on the aberrations of collimation lens and the quality of extended source. The results of simulation show that the influences of different kinds of aberrations on SNR take on obvious regularity, and in particular, the influences of off-axis aberrations on SNR are closely related to the location of off-axis point source. Finally the extended sources maximum radius allowed was obtained by simulation, which equals to 0.65 mm. The discussion results will be used for the design of collimation system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 274 (2014)
Integration Design and Diffraction Characteristics Analysis of Prism-Grating-Prism
HE Tian-bo, Bayanheshig, LI Wen-hao, KONG Peng, and TANG Yu-guo
Prism-grating-prism (PGP) module is the important dispersing component in the hyper spectral imager. In order to effectively predict the distribution of diffraction efficiency of the whole PGP component and its diffraction characteristics before fabrication, a method of the PGP integration design is proposed. From the Prism-grating-prism (PGP) module is the important dispersing component in the hyper spectral imager. In order to effectively predict the distribution of diffraction efficiency of the whole PGP component and its diffraction characteristics before fabrication, a method of the PGP integration design is proposed. From the point of view of the volume phase holographic grating (VPHG) design, combined with the restrictive correlation between the various parameters of prisms and grating, we compiled the analysis software for calculating the whole PGPs diffraction efficiency. Furthermore, the effects of the structure parameters of prisms and grating on the PGPs diffraction characteristics were researched in detail. In particular we discussed the Bragg wavelength shift behaviour of the grating and a broadband PGP spectral component with high diffraction efficiency was designed for the imaging spectrometers. The result of simulation indicated that the spectral bandwidth of the PGP becomes narrower with the dispersion coefficient of prism 1 material decreasing; Bragg wavelength shift characteristics broaden the bandwidth of VPHG both spectrally and angularly, higher angular selectivity is desirable for selection requirements of the prism 1 material, and it can be easily tuned to achieve spectral bandwidth suitable for imaging PGP spectrograph; the vertex angle of prism 1, the film thickness and relative permittivity modulation of the grating have a significant impact on the distribution of PGPs diffraction efficiency, so precision control is necessary when fabrication. The diffraction efficiency of the whole PGP component designed by this method is no less than 50% in the wavelength range from 400 to 1 000 nm, the specific design parameters have been given in this paper that have a certain reference value for PGP fabrication..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 279 (2014)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 1 (2014)
Research Articles
Density Functional Theory Investigations of the Spectroscopic Characteristics and Luminescent Mechanisms of Dipterex and Dichlorvos
LI Li-qing, CHENG Xue-li, ZHAO Yan-yun, HE Guo-fang, and LI Feng
By using G09 program package, the ground-state structures, infrared spectra, NMR spectra, UV-Vis spectra as well as the excited structures and fluorescence/phosphorescence spectra of dipterex and dichlorvos were investigated systematically, and luminescence principles were analyzed with the molecular orbitals to providBy using G09 program package, the ground-state structures, infrared spectra, NMR spectra, UV-Vis spectra as well as the excited structures and fluorescence/phosphorescence spectra of dipterex and dichlorvos were investigated systematically, and luminescence principles were analyzed with the molecular orbitals to provide the theoretical foundation for the detection of trace dipterex and dichlorvos. Our theoretical model revealed that the IR spectra of dipterex and dichlorvos bear strong absorptions at about 1 107 cm-1, which belong to the P—O stretch modes, but dipterex has strong absorption peaks involving the O—H bond; for UV-Vis spectra, dichlorvos has a strong absorption peak at 182.03 nm, but dipterex has a weak one at 192.42 nm, which are assigned to ππ* and σπ* transitions, respectively; the emission spectra of dichlorvos are very weak, and has double fluorescence/phosphorescence characteristics, which may be attributed to the resonance structures of dichlorvos; the fluorescence of dipterex has a unique broad peak at 1 849.22 nm, corresponding to the LUMO→HOMO transition of S1 state..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 1, 122 (2014)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20