Journals >Spectroscopy and Spectral Analysis
Contents
2013
Volume: 33 Issue 8
63 Article(s)
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Research Article
Measurements of Stable Isotopes in Atmospheric CO2 and H2O by Open-Path Fourier Transform Infrared Spectrometry
WANG Wei, LIU Wen-qing, and ZHANG Tian-shu
The development of spectroscopic techniques has offered continuous measurement of stable isotopes in the ambient air. The method of measuring environmental stable isotopes based on Fourier transform infrared spectrometry (FTIR) is described. In order to verify the feasibility of the method for continuous measurement ofThe development of spectroscopic techniques has offered continuous measurement of stable isotopes in the ambient air. The method of measuring environmental stable isotopes based on Fourier transform infrared spectrometry (FTIR) is described. In order to verify the feasibility of the method for continuous measurement of the stable isotopes, an open-path FTIR system was used to measure stable isotopes of CO2 and H2O in ambient air directly in a seven-day field experiment, including 12CO2, 3CO2, H216O and HD16O. Also, the time course of carbon isotopic ratio δ13C and deuterium isotope composition δD was calculated. The measurement precision is about 1.08‰ for δ13C and 1.32‰ for δD. The measured stable isotopes of CO2 and H2O were analyzed on different time scales by Keeling plot methods, and the deuterium isotopic ratios of evapotranspiration were determined. The results of the field experiment demonstrate the potential of the open-path FTIR system for continuous measurement of stable isotopes in the air..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2017 (2013)
Extracting Municipal Solid Waste Dumps Based on High Resolution Images
ZHANG Fang-li, DU Shi-hong, and GUO Zhou
The dramatically increasing informal MSW dumps are endangering the urban environment. Remote sensing (RS) technologies are more efficient to monitor and manage municipal solid wastes (MSW) than traditional survey-based methods. In high spatial resolution remotely sensed images, these irregularly distributed dumps have The dramatically increasing informal MSW dumps are endangering the urban environment. Remote sensing (RS) technologies are more efficient to monitor and manage municipal solid wastes (MSW) than traditional survey-based methods. In high spatial resolution remotely sensed images, these irregularly distributed dumps have complex compositions and strong heterogeneities, thus it is still hard to extract them automatically no matter the pixel-or object-based image analysis method is used. Therefore, based on the analysis of MSW characteristics, the present study develops a multiresolution strategy to extract MSW dumps by combining image features at both high resolution and resampled lowheterogeneity images, while the high resolution images can provide detailed information and the low resolution images can suppress the strong heterogeneities of informal MSW dumps. Taking the QuickBird image covering part of Beijing as an example, this multi-resolution strategy produced a high accuracy (75%), indicating that this multi-resolution strategy is quite effective for extracting the open-air informal MSW dumps..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2024 (2013)
Enhancing Stimulated Raman Scattering of Water and Heavy Water Lattice Vibration by Laser Induced Plasma
SHAN Xiao-ning, MEN Zhi-wei, ZHOU Mi, SUN Cheng-lin, LI Zuo-wei, WANG Yi-ding, and LI Zhan-long
Stimulated Raman scattering was studied in water and heavy water using pulse laser at the wavelength of 532nm, not only obtaining the stimulated Raman of O—H and O—D stretching vibration, but also obtaining the stimulated Raman lattice vibration. When the laser energy was 130 mJ, the low frequency Stokes and anti-StokeStimulated Raman scattering was studied in water and heavy water using pulse laser at the wavelength of 532nm, not only obtaining the stimulated Raman of O—H and O—D stretching vibration, but also obtaining the stimulated Raman lattice vibration. When the laser energy was 130 mJ, the low frequency Stokes and anti-Stokes 313 cm-1 line of water could be observed; When the laser energy was 160 mJ, the low frequnecy Stokes and anti-Stokes 280 cm-1 line of heavy water could be observed. The results were explained by physics mechanism of laser induced plasma..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2031 (2013)
Spectroscopic Study of Dilute Magnetic Semiconductors Zn1-xFexO Nanoparticles
WU Xiao-juan, WEI Zhi-qiang, WU Yong-fu, ZHANG Ling-ling, JIANG Jin-long, and YANG Hua
Diluted magnetic semiconductors Zn1-xFexO nanoparticles with different content (x=0, 0.01, 0.05, 0.10 and 0.20) were successfully synthesized via hydrothermal method. The X-ray diffraction (XRD) shows that the samples are wurtzite structure and metallic Fe or other secondary phases were not found in the samples. The trDiluted magnetic semiconductors Zn1-xFexO nanoparticles with different content (x=0, 0.01, 0.05, 0.10 and 0.20) were successfully synthesized via hydrothermal method. The X-ray diffraction (XRD) shows that the samples are wurtzite structure and metallic Fe or other secondary phases were not found in the samples. The transmission electron microscopy (TEM) shows that the morphology is nanoparticles with good dispersion, and the lattice is clearly visible. Raman scattering spectrum (Raman spectra) shows that E2(High) mode broadened, shifted towards the high-frequencies side and decreased the peak intensity. Photoluminescence spectra (PL) shows that the peaks moved to lower energy and the photoluminescence intensity was quenched with increasing Fe doping concentration. The ultraviolet-visible spectrophotometry (UV-Vis) indicates that the optical band gap decreased and red shift occured. All the results indicate that Fe3+ ions successfully substituted for Zn2+ and were incorporated into the crystal lattice of ZnO..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2035 (2013)
Effect of Flat-Mirror Device on Laser-Induced Plasma Radiation Characteristics
CHEN Jin-zhong, BAI Jin-ning, CHEN Zhen-yu, CHENG Chen, SUN Jiang, and WEI Yan-hong
To improve the quality of laser-induced breakdown spectroscopy, flat-mirror device was proposed. The effects of flat-mirror device on the radiation characteristics of laser-induced plasma were studied. The experimental results showed that when the device consisted of three flat-mirrors placed around the plasma, the speTo improve the quality of laser-induced breakdown spectroscopy, flat-mirror device was proposed. The effects of flat-mirror device on the radiation characteristics of laser-induced plasma were studied. The experimental results showed that when the device consisted of three flat-mirrors placed around the plasma, the spectral line intensity of Mg, Fe, Ba, Ti and Al increases by about 116.2%, 96.43%, 90.93%, 102.1% and 98.57% than that without flat-mirror device, and the signal-to-noise raises by around 39.17%, 32.48%, 38.07%, 39.95% and 21.30%, respectively. By measuring the plasma parameters, the mechanism of the radiation enhancement obtained with the device consisting of three flat-mirrors was explained. This method was an effective way to improve the detection capacity of LIBS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2039 (2013)
Spectroscopic Diagnosis of Dielectric Barrier Discharge in Long Gap Under Low Presssure
SU Chen, XU Hao-jun, LIN Min, ZHANG Yan-hua, LIANG Hua, and WEI Xiao-long
In the present paper, a dielectric barrier discharge(DBD) plasma was generated at low pressure in a DBD device with the eletrode distance of 10cm and using Ar as working gas. The changes in electronic temperature and density in the discharge cavum were studied by means of emission spectrometry. The changes in electroniIn the present paper, a dielectric barrier discharge(DBD) plasma was generated at low pressure in a DBD device with the eletrode distance of 10cm and using Ar as working gas. The changes in electronic temperature and density in the discharge cavum were studied by means of emission spectrometry. The changes in electronic temperature measured by using corona model were obtained. The variations in electronic density were analyzed using 750.4 nm line intensity. It was found that the plasma electronic temperature and density is various at different positions in the discharge cavum. With the measuring point moving from cathode to anode, the electronic temperature firstly increases slowly, then decreases quickly. While the electronic density increases slowly at first, and then rapidly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2043 (2013)
Measurement of Nonuniform Temperature and Concentration Distribution by Absorption Spectroscopy Based on Least-Square Fitting
SONG Jun-ling, HONG Yan-ji, WANG Guang-yu, and PAN Hu
The measurement of nonuniform temperature and concentration distributions was investigated based on tunable diode laser absorption spectroscopy technology. Through direct scanning multiple absorption lines of H2O, two zones for temperature and concentration distribution were achieved by solving nonlinear equations by lThe measurement of nonuniform temperature and concentration distributions was investigated based on tunable diode laser absorption spectroscopy technology. Through direct scanning multiple absorption lines of H2O, two zones for temperature and concentration distribution were achieved by solving nonlinear equations by least-square fitting from numerical and experimental studies. The numerical results show that the calculated temperature and concentration have relative errors of 8.3% and 7.6% compared to the model, respectively. The calculating accuracy can be improved by increasing the number of absorption lines and reduction in unknown numbers. Compared with the thermocouple readings, the high and low temperatures have relative errors of 13.8% and 3.5% respectively. The numerical results are in agreement with the experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2047 (2013)
Effect of Substrate Temperature on Structure and Photoluminescence of ZnMgO Films
DONG Li-na, WANG Yu-xin, SUN Jing-chang, ZHENG Ya-ru, ZHANG Huan, LIANG Ming, LIN Mao-kui, and CUI Shuo
ZnMgO films were deposited on quartz glass substrates by the ultrasonic spray pyrolysis at different substrate temperatures（450～550 ℃）. The structural, surface morphological and optical properties of the samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) ZnMgO films were deposited on quartz glass substrates by the ultrasonic spray pyrolysis at different substrate temperatures（450～550 ℃）. The structural, surface morphological and optical properties of the samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) spectroscopy. The results demonstrate that the substrate temperature has important effect on structural and optical characteristics. All the films have hexagonal wurtzite polycrystalline structures and the c-axis preferential orientation has an optimum temperature of 530 ℃. The sample prepared at this temperature owns uniform grain size, smooth surface morphology and better crystalline quality. The width of deep-level emission decreases and the near band edge (NBE) ultraviolet emission peak appears with the increase in temperature by the PL spectrum. When the temperature arrives to 530℃, a distinct NBE emission peak can be observed at 374.5 nm, while the deep-level emission is almost undetectable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2051 (2013)
Color-Tunable Nano-Material α-NaYF4∶Yb, Er, Tm Prepared by Microemulsion-Hydrothermal Method
LONG Dan-dan, ZHANG Qing-xia, WANG Yu, ZHANG Fan, WANG Yan-fei, ZHOU Xin, QI Xiao-hua, ZHANG Heng, YAN Jing-hui, and ZOU Ming-qiang
NaYF4∶Yb3+, Er3+, Tm3+ nanoparticles were prepared by microemulsion-hydrothermal method. Crystal phase, morphology and structure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The luminescence properties were studied by up-conversional fluorescence spectroscopy. TheNaYF4∶Yb3+, Er3+, Tm3+ nanoparticles were prepared by microemulsion-hydrothermal method. Crystal phase, morphology and structure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The luminescence properties were studied by up-conversional fluorescence spectroscopy. The XRD patterns of as-prepared samples were in agreement with the PDF #77-2042 of cubic NaYF4. SEM images of the particles showed that the samples were cotton-like spherical in shape and which were assembled by smaller nano-particles. The average size was 120 nm, while the shape was regular and the particle size was homogeneous. Under the excitation of 980 nm, the as-prepared particles could emit blue (438 and 486 nm), green (523 and 539 nm) and red (650 nm) light simultaneously. It can be seen from the color coordinates figure (CIE) that when doping concentration ratio of Tm3+ and Er3+ increased from 0 to 2, the whole emitting light color of samples movedto green region. While the ratio was 1∶1, pseudo white light was obtained. As the ratio changed from 2 to 7, the luminous color was moved to red region..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2055 (2013)
Emission Spectrum Temperature Sensitivity of Mg4FGeO6∶Mn Induced by Laser
WANG Sheng, LIU Jing-ru, SHAO Jun, HU Zhi-yun, TAO Bo, and HUANG Mei-sheng
In order to develop a new sort of thermally sensitive phosphor coating, the emission spectrum thermally sensitivity of Mg4FGeO6∶Mn induced by laser was studied. The spectrum measurement system with heating function was set up, and the emission spectrum of Mg4FGeO6∶Mn at various temperatures were measured. Absorption spIn order to develop a new sort of thermally sensitive phosphor coating, the emission spectrum thermally sensitivity of Mg4FGeO6∶Mn induced by laser was studied. The spectrum measurement system with heating function was set up, and the emission spectrum of Mg4FGeO6∶Mn at various temperatures were measured. Absorption spectrum was measured, and the mechanism of formation of the structure of double peak was analyzed with the perturbation theory of crystal lattice. The group of peaks around 630 nm is represented by the transitions 4F″2 to 4A2, whereas the group of peaks around 660 nm is due to the transitions 4F′2 to 4A2. The occupancy of both excited states 4F′2 and 4F″2 is in thermal equilibrium. Thus increasing temperature causes the intensity of the emission in the group around 630 nm to increase at the expense of the emission intensity of the group around 660 nm. The various spectral regions in emission differ with temperature, which could be used to support the intensity-ratio measurement method. The intensity-ratio change curve as a function of temperature was fitted, which shows that the range of temperature measurement is between room temperature and 800 K..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2060 (2013)
Application of Terahertz Technology in Medical Testing and Diagnosis
QI Na, ZHANG Zhuo-yong, and XIANG Yu-hong
Terahertz science and technology is increasingly emphasized in science and industry, and has progressed significantly in recent years．There is an important aspect of attention in the application of terahertz technology to medicine．The overview of the terahertz characters, terahertz spectroscopy and terahertz imaging teTerahertz science and technology is increasingly emphasized in science and industry, and has progressed significantly in recent years．There is an important aspect of attention in the application of terahertz technology to medicine．The overview of the terahertz characters, terahertz spectroscopy and terahertz imaging technology is introduced．This paper focuses on reviewing the use of and research progress in terahertz spectroscopy and terahertz imaging technology in medical testing and diagnosis．Furthermore, the problems to be solved and development directions of terahertz spectroscopy and terahertz imaging technology are discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2064 (2013)
Study on the Response to the Soil Moisture Polarized Spectrum under Visible-Near Infrared Band
HAN Yang, ZHAO Yun-sheng, and WANG Ye-qiao
Moisture is one of the important parameters in soil polarized spectrum. It has great significance in soil remote sensing band selection and image interpretation; it also provides the information for soil investigation and analysis on physical and chemical properties. In the present paper we tested and analyzed the soilMoisture is one of the important parameters in soil polarized spectrum. It has great significance in soil remote sensing band selection and image interpretation; it also provides the information for soil investigation and analysis on physical and chemical properties. In the present paper we tested and analyzed the soil polarized spectrum with different moisture in 350~2 500 nm wavelength range to study on the relationship between soil polarized spectral data and moisture, to determine the spectral response and changes in soil moisture, to establish models between spectral data and soil moisture and select the best forecast model. The results show that the accuracy of the polarized derivative spectra model is higher than the polarized spectral model and absorbance model. All the models showed a water content threshold, and found that it is a certain regularity that critical value of soil moisture in different polarization is near 30%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2071 (2013)
Multiple Scattering of Visible and Infrared Light by Sea Fog over Wind Driving Rough Sea Surface
SUN Xian-ming, WANG Hai-hua, LEI Cheng-xin, and SHEN Jin
The present paper is concerned with computing the multiple scattering characteristics of a sea fog-sea surface couple system within this context. The single scattering characteristics of sea fog were studied by Mie theory, and the multiple scattering of sunlight by single sea fog layer was studied by radiative transferThe present paper is concerned with computing the multiple scattering characteristics of a sea fog-sea surface couple system within this context. The single scattering characteristics of sea fog were studied by Mie theory, and the multiple scattering of sunlight by single sea fog layer was studied by radiative transfer theory. The reflection function of a statistically rough ocean surface was obtained using the standard Kirchhoff formulation, with shadowing effects taken into account. The reflection properties of the combined sea fog and ocean surface were obtained employing the adding method, and the results indicated that the reflected light intensity of sea fog increased with the sea background..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2075 (2013)
Low Carbon Number Fatty Acid Content Prediction Based on Near-Infrared Spectroscopy
SONG Zhi-qiang, SHEN Xiong, ZHENG Xiao, HE Dong-ping, QI Pei-shi, YANG Yong, and FANG Hui-wen
The rapid prediction of the low-carbon fatty acids (C≤14) content in grease samples was achieved by a mathematical model established by near infrared spectroscopy combined with support vector machine regression (SVR). In the present project, near-infrared spectrometer SupNIR-5700 was used to collect near-infrared spectThe rapid prediction of the low-carbon fatty acids (C≤14) content in grease samples was achieved by a mathematical model established by near infrared spectroscopy combined with support vector machine regression (SVR). In the present project, near-infrared spectrometer SupNIR-5700 was used to collect near-infrared spectra of 58 samples; partial least square (PLS) was applied to remove the strange samples, and principal component analysis (PCA) was conducted on the measurements; radial basis function (RBF) kernel function was selected to establish a regression model supporting vector machine, and then detailed analysis and discussions were conducted concerning their spectral preprocessing and parameters optimization methods. Experimental results showed that by applying particle swarm optimization (PSO) the model demonstrated improved performance, stronger generalization ability, better prediction accuracy and robustness. In the second pretreatment method after PSO, when the optimization parameters are: C=2.085, γ=22.20, the prediction set and calibration set correlation coefficient (r) reached 0.998 0 and 0.925 8, respectively; and root mean square errors (MSE) were 0.000 4 and 0.014 3, respectively. Research results proved that the method based on near infrared spectroscopy and PSO-SVR for accurate and fast prediction of the low-carbon fatty acid content in vegetable oil is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2079 (2013)
Application of Kernel Orthogonal Projection to Latent Structure Discriminant Analysis in the Discrimination of Adulterated Milk
LIU Rong, YANG Ren-jie, MIAO Jing, and XU Ke-xin
Based on the method of kernet Orthogonal Projection to Latent Structure Discriminant Analysis, discrimination models for adulterated milk were established in the present paper. Forty adulterated milk samples with melamine（0.01～3 g·L-1）and 40 adulterated milk samples with urea （1～20 g·L-1）were prepared, respecBased on the method of kernet Orthogonal Projection to Latent Structure Discriminant Analysis, discrimination models for adulterated milk were established in the present paper. Forty adulterated milk samples with melamine（0.01～3 g·L-1）and 40 adulterated milk samples with urea （1～20 g·L-1）were prepared, respectively. Then the near-infrared absorption spectra of all samples were measured. The spectra in the range of 4 200～4 800 cm-1 were selected to construct the KOPLS-DA models for milk adulterated with melamine, milk adulterated with urea and milk adulterated with both melamine and urea. The results showed that, compared with PLS-DA and OPLS-DA models, KOPLS-DA model had better discriminant ability for the adulterated milk, and its classification accuracy rate (CAR) for milk adulterated with melamine, milk adulterated with urea and milk adulterated with both melamine and urea were 95%, 100% and 97.5%, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2083 (2013)
IR Spectrum Characteristics and Significance of Luodian Jade from Guizhou
YANG Lin, LIN Jin-hui, WANG Lei, WANG Bing, and DU Ying
In the present paper we selected some typical samples from Luodian jade to perform FTIR test in order to study the vibration attribution of crystals structure. The results confirm that the main mineral composition of Luodian jade is tremolite. Not only has it been not reported in other IR study on natural nephrite thatIn the present paper we selected some typical samples from Luodian jade to perform FTIR test in order to study the vibration attribution of crystals structure. The results confirm that the main mineral composition of Luodian jade is tremolite. Not only has it been not reported in other IR study on natural nephrite that the absorption bands at wave numbers between 840 and 860 cm-1 caused by residual diopside exist in Luodian jade with the process of tremolite rock transformed to nephrite, but is also the biggest difference between the Luodian jade and other nephrite. The results reveal important mineralogy evidence of metamorphism of Luodian jade, and on the other hand, it also shows that there is a certain difference in the process of nephrite change between Luodian jade and other natural nephrite. Moreover, it further suggests that Luodian jade is a kind of new genetic nephrite ore..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2087 (2013)
Use of Visible and Near Infrared Reflectance Spectroscopy to Identify the Cashmere and Wool
LIU Xin-ru, ZHANG Li-ping, WANG Jian-fu, WU Jian-ping, and WANG Xin-rong
The wool and cashmere samples (n=130) from different areas of Gansu province were identified by visible and near-infrared reflectance spectroscopy(Vis/NIRs). The result shows that principal component-mahalanobis distance pattern can identify the wool and cashmere, and the boundary between two categories was clear; The The wool and cashmere samples (n=130) from different areas of Gansu province were identified by visible and near-infrared reflectance spectroscopy(Vis/NIRs). The result shows that principal component-mahalanobis distance pattern can identify the wool and cashmere, and the boundary between two categories was clear; The calibration set samples were used to establish calibration qualitative model using PCR combined with the best pretreatment of the spectra and math, including multivariate scattering correction (MSC), first derivative, eight for the best principal component factor, one for uncertainty factor, this calibration model of the predicted was the best, and the result of the external validation was correct completely. Results from this experiment indicate that Vis/NIRs can be utilized to identify the wool and cashmere..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2092 (2013)
Characterization of Processing Batch for Preparation of Radix Scutellariae Based on Dependent Component Analysis and Infrared Spectrometry
WANG Jian-ling, ZHAO Jian-bo, LIU Ying-fan, ZHAO Shao-wei, and WANG Guo-qing
Dependent component analysis (DCA) was applied to directly estimate source spectral profiles from IR spectra of synthetic mixtures and characterize processing batch for preparation of radix scutellariae. The results show that DCA can estimate information of dependent components (DCs) from the measured infrared spectralDependent component analysis (DCA) was applied to directly estimate source spectral profiles from IR spectra of synthetic mixtures and characterize processing batch for preparation of radix scutellariae. The results show that DCA can estimate information of dependent components (DCs) from the measured infrared spectral (IR) signal obtained during the processing batch for preparation of radix scutellariae, and the estimated information of DCs is corresponding to the IR features of the active components of scutelliare; by inspection of the change trends of the estimated DCs, the endpoint of the processing batch was determined as 55 min. The proposed approach provides a novel way for process analysis and endpoint determination of procedure for preparation of scutellariae..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2096 (2013)
Application of Wavenumber-Linear Scaling to the Calculated Raman Frequencies of Polyenes and Carotenoids
LIU Wei-long, JIANG Li-lin, WANG Yang, HE Xing, SONG Yun-fei, ZHENG Zhi-ren, YANG Yan-qiang, and ZHAO Lian-cheng
Raman spectra of two typical carotenoids(β-carotene and lutein) and some short(n=2~5) polyenes were calculated using density functional theory. The wavenumber-linear scaling (WLS) and other frequency scaling methods were used to calibrate the calculated frequencies. It was found that the most commonly used uniform scalRaman spectra of two typical carotenoids(β-carotene and lutein) and some short(n=2~5) polyenes were calculated using density functional theory. The wavenumber-linear scaling (WLS) and other frequency scaling methods were used to calibrate the calculated frequencies. It was found that the most commonly used uniform scaling (UFS) method can only calibrate several individual frequencies perfectly, and the systematic result of this method is not very good. The fitting parameters obtained by the WLS method are νobs／νcalc=0.999 9－0.000 027 4νcalc and νobs／νcalc=0.993 8－0.000 024 8νcalc for short polyenes and carotenoids, respectively. The calibration results of the WLS method are much better than the UFS method. This result suggests that the WLS method can be used for the frequency scaling of the molecules as large as carotenoids. The similar fitting parameters for short polyenes and carotenoids indicate that the fitting parameters obtained by WLS for short polyenes can be used for calibrating the calculated vibrational frequencies of carotenoids. This presents a new frequency scaling method for vibrational spectroscopic analysis of carotenoids..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2100 (2013)
Strain in GaN Epi-Layer Grown by Hydride Vapor Phase Epitaxy
LIU Zhan-hui, XIU Xiang-qian, ZHANG Li-li, ZHANG Rong, ZHANG Ya-nan, SU Jing, XIE Zi-li, LIU Bin, and SHAN Yun
In the present paper, strain in GaN epitaxial layer grown by hydride vapor phase epitaxy (HVPE) was investigated by means of high-resolution X-ray diffraction (HRXRD), Raman spectra and photoluminescence (PL) measurements. Both the biaxial in-plane and out-of-plane strains (of the order of ～10-4 and 10-4, respectively)In the present paper, strain in GaN epitaxial layer grown by hydride vapor phase epitaxy (HVPE) was investigated by means of high-resolution X-ray diffraction (HRXRD), Raman spectra and photoluminescence (PL) measurements. Both the biaxial in-plane and out-of-plane strains (of the order of ～10-4 and 10-4, respectively) and the hydrostatic strain component (of the order of ～10-5) were extracted from HRXRD measurements. These values agreed well with the ones computed from the blue-shift of E2 Raman mode and the near-band-edge PL peak. The results showed that strains in GaN layer were superposed by the biaxial strain and hydrostatic strain..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2105 (2013)
The Analysis and Identification of Fritillaria Cirrhosa by Raman Spectra
WANG Wen-na, CHEN Di-ling, ZHU Mei-fang, and ZHANG He-ming
Laser Raman spectrum technology was used to distinguish fritillaria cirrhosa from its adulterants rapidly and accurately. The study is based on that different traditional Chinese medicine contains different chemical compositions, and the differences could be displayed in Raman spectra. The Raman spectra of fritillaria Laser Raman spectrum technology was used to distinguish fritillaria cirrhosa from its adulterants rapidly and accurately. The study is based on that different traditional Chinese medicine contains different chemical compositions, and the differences could be displayed in Raman spectra. The Raman spectra of fritillaria cirrhosas shows that several characteristic strong peaks could be found at 442, 480, 863, 941, 1 083, 1 129, 1 342, 1 463 and 2 910 cm-1, and a few obvious peaks appear at 111, 302, 360, 409, 527, 579, 618, 718, 767, 1 052, 1 083, 1 207 and 1 261 cm-1. According to the Raman spectra, a Raman fingerprint of fritillaria cirrhosa was set up, which could be used to distinguish its adulterants. This analysis could be used in identifying fritillaria cirrhosa rapidly, accurately and nondestructively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2109 (2013)
Study on Confinement Effect of Phonon Like Modes for Mesoscopic Aggregation Structure of Glasses Phases in the Imitating Magmatic Rocks by Raman Spectra
XU Pei-cang, LI Ru-bi, SHANG Tong-ming, ZHOU Jian, SUN Jian-hua, and WANG Yuan-yuan
In the present paper,the mesoscopic aggregation structure parameters and the phonon confinement effect like modes of these glass phases in the imitating ultrabasic rock(MU), imitating basic rock(MB), imitating intermediate rock(MI) & imitating acidic rock(MA) were detected by means of phonon dispersion theory, quatIn the present paper,the mesoscopic aggregation structure parameters and the phonon confinement effect like modes of these glass phases in the imitating ultrabasic rock(MU), imitating basic rock(MB), imitating intermediate rock(MI) & imitating acidic rock(MA) were detected by means of phonon dispersion theory, quatume chemical calculation(ab initio)and LWRS, RS analysis technology. The phonon dispersion curves like modes of the MU, MB, MI and MA have were established. It was obtained that as fast as the mesoscopic aggregation size was increasing,the low frequency changes of the phonics phonon like modes transverse wave(TA) & longitudinal wave(LA) were red shifted, the medium & high frequency changes of the optics phonon like modes transverse wave(TO) & longitudinal wave(LO) were blue shifted, the width at half maximum of Raman spectra peak(FWHM) was decreasing and the change bound of the aggregation size was increasing. These conclusions not only enriched the theory of phonon dispersion like modes in the low dimension silicates and its melts, but also exploited new field of Raman spectroscopic study of mesoscopic structure in magmatic rocks. It provides important information for deliberating crystallization,evolution and ore-forming rule of natural magma..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2112 (2013)
Study of Interaction of Umbelliferone with Three Aromatic Amino Acids by Fluorescence Spectroscopy
JIANG Huan, ZHU Yan-wu, WANG Yan, and HE Jian-bo
The interaction between umbelliferone (UMB) with tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) was studied by using fluorescence (FS) and ultraviolet (UV) spectroscopy. The results show that UMB can strongly quench the fluorescence of the three aromatic amino acids with the maximum quenching wavelengths at 3The interaction between umbelliferone (UMB) with tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) was studied by using fluorescence (FS) and ultraviolet (UV) spectroscopy. The results show that UMB can strongly quench the fluorescence of the three aromatic amino acids with the maximum quenching wavelengths at 347, 303 and 282 nm, respectively. Data analyses based on the Stern-Volmer curve and the UV spectroscopy show that static quenching occurred through the formation of the complexes of UMB with each aromatic amino acid in a molar ratio of 1∶1. The binding constant Kc of UMB with Trp, Tyr and Phe is 2.993×106, 7.858×104 and 1.186×103 L·mol-1(298.15 K) and 2.702×104, 1.063×105 and 8.352×103 L·mol-1(310.15 K), respectively. The thermodynamic parameters indicate that UMB has a strong interaction with the three aromatic amino acids. Hydrogen bond and Van der Waals force may play a major role in the reaction of UMB with Trp, whereas hydrophobic interaction should be responsible for the binding of UMB with Tyr and Phe. In addition, the dipole-dipole interaction may be another factor in the reactions between UMB and the three aromatic amino acids..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2117 (2013)
Characterizing Composition and Transformation of Dissolved Organic Matter in Subsurface Wastewater Infiltration System
WANG Li-jun, LIU Yu-zhong, ZHANG Lie-yu, XI Bei-dou, XIA Xun-feng, and LIU Ya-ru
In the present study, the soil column with radius of 30 cm and height of 200 cm was used to simulate a subsurface wastewater infiltration system. Under the hydraulic loading of 4 cm·d-1, composition and transformation of dissolved organic matter (DOM) from different depths were analyzed in a subsurface wastewater In the present study, the soil column with radius of 30 cm and height of 200 cm was used to simulate a subsurface wastewater infiltration system. Under the hydraulic loading of 4 cm·d-1, composition and transformation of dissolved organic matter (DOM) from different depths were analyzed in a subsurface wastewater infiltration system for treatment of septic tank effluent using three-dimensional excitation emission matrix fluorescence spectroscopy (3D-EEM) with regional integration analysis (FRI). The results indicate that: (1) from different depth, the composition of DOM was also different; influent with the depth of 0.5 m was mainly composed of protein-like substances, and that at other depths was mainly composed of humic- and fulvic-like substances. (2) DOM stability gradually increased and part of the nonbiodegradable organic matter can be removed during organic pollutants degradation process. (3) Not only the organic pollutants concentration was reduced effectively, but also the stability of the DOM improved in subsurface wastewater infiltration system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2123 (2013)
Studies on Thermal Denaturation of Peanut Allergen Ara h1 and its Interaction with Reducing Sugars
XU Hong, SHEN Liang-liang, HU Zhang-li, XIAO Jie, XIAO Hua-xin, WU Jin-xia, LI Yi, WEI Bo, NI Zhuo, WU Xu-li, and LIU Zhi-gang
The thermal denaturation of peanut allergen Ara h1, its interaction with reducing sugars and the corresponding changes in allergenicity were investigated by circular dichroism(CD), fluorescence and ELISA method comprehensively. The experimental results indicate that the secondary structure of Ara h1 changes significantThe thermal denaturation of peanut allergen Ara h1, its interaction with reducing sugars and the corresponding changes in allergenicity were investigated by circular dichroism(CD), fluorescence and ELISA method comprehensively. The experimental results indicate that the secondary structure of Ara h1 changes significantly along with decreasing α-helical structure and its allergenicity with the temperature higher than 85 ℃, and that both xylose and fructose can stabilize Ara h1 protein structure through interacting with Ara h1 protein and decrease its allergenicity obviously. This study should be helpful to the further understanding of sensitization mechanism of food allergy and be useful for the guidance on reasonable manufacturing of peanut foods..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2128 (2013)
Super-Low-Frequency Spectrum Analysis for Buried Faults in Coalfield
CHEN Li, QIN Qi-ming, ZHEN Guang-wei, WANG Nan, BAI Yan-bing, and CHEN Chao
Based on the super-low-frequency (SLF) electromagnetic detection technology, the advanced detection for the buried fault in the coalfield is still at the exploratory stage, while the technology has a strong practical significance for production and design of the coal mine. Firstly, in this paper, the SLF electromagnetiBased on the super-low-frequency (SLF) electromagnetic detection technology, the advanced detection for the buried fault in the coalfield is still at the exploratory stage, while the technology has a strong practical significance for production and design of the coal mine. Firstly, in this paper, the SLF electromagnetic detection signals were collected in study area. Spectrum analysis of SLF signal by wavelet transform can remove high-frequency noise. Secondly, the profile of the measuring line across the fault was analyzed and interpreted geologically. Accordingly SLF spectrum characteristics of the buried fault could be researched. Finally, combined with the geological and seismic data, the characteristics and distribution of fault structures can be verified in the mining area. The results show that: the buried fault could be detected quickly and effectively by SLF electromagnetic detection. Hence, SLF electromagnetic detection technology is an effective method for buried fault detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2132 (2013)
Study on the Co-Adsorption Mechanism of Pb(Ⅱ) and Chlorpyrifos on Arid Loess in Northwestern China
FAN Chun-hui, ZHANG Ying-chao, and WANG Jia-hong
The co-adsorption characteristics of Pb(Ⅱ) and chlorpyrifos on arid loess were investigated with batch adsorption procedures, and the co-adsorption mechanism was studied with approaches of SEM, FT-IR, XRD and theoretical analysis. The experimental results indicated that the adsorption process of Pb(Ⅱ) and chlorpyrifos The co-adsorption characteristics of Pb(Ⅱ) and chlorpyrifos on arid loess were investigated with batch adsorption procedures, and the co-adsorption mechanism was studied with approaches of SEM, FT-IR, XRD and theoretical analysis. The experimental results indicated that the adsorption process of Pb(Ⅱ) and chlorpyrifos on loess fit better the Langmuir isotherm, the maximum adsorption capacity of qm is 12.5 and 0.64 mg·g-1 for Pb(Ⅱ) and chlorpyrifos on loess, respectively, and the reaction could be illustrated with pseudo-second order kinetic equation. The SEM micrograph of loess surface varies little after the adsorption process of Pb(Ⅱ) and chlorpyrifos, and certain wave peaks of FTIR spectra red-shift, disappears or intensity-decrease, with the XRD pattern and theoretical analysis, the adsorption mechanism is described as follows: the adsorption of Pb(Ⅱ) on arid loess is the chemical-effect of coordination-complexation and Van der Waals force; the physical-adsorption on chlorpyrifos involves the interception function, hydrogen bonds and Van der Waals force, and chemical adsorption effect to some extent. The organic matter in arid loess plays an important role in Pb(Ⅱ) and chlorpyrifos adsorption..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2137 (2013)
Effects of Water Stress on Red-Edge Parameters and Yield in Wheat Cropping
HE Ke-xun, ZAHO Shu-he, LAI Jian-bin, LUO Yun-xiao, and QIN Zhi-hao
The objective of the present paper is to study the influence of water stress on wheat spectrum red edge parameters by using field wheat spectrum data obtained from water stress experiment. Firstly, the authors analyzed the influence of water stress on wheat spectrum reflectance. Then the authors got the wheat red edge The objective of the present paper is to study the influence of water stress on wheat spectrum red edge parameters by using field wheat spectrum data obtained from water stress experiment. Firstly, the authors analyzed the influence of water stress on wheat spectrum reflectance. Then the authors got the wheat red edge position and red edge peak through calculating wheat spectrum first-order differential and analyzed the influence of water stress on wheat red edge parameters. Finally the authors discussed the relationship between red peak and wheat yield. The results showed that the wheat red edge position shows “red shift” at the beginning of the wheat growth period and “blue shift” at the later period of the wheat growth period under the water stress experiment. Also, the red edge peak of the wheat showed that red edge peak increased with the water stress sharpening at the beginning of the wheat growth period, and then the red edge peak reduced with the water stress sharpening. The wheat red edge peak presented positive correlation with the wheat yield before the elongation period, and exhibited negative correlation after that period..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2143 (2013)
Spectral Properties, Photodynamic Anticancer Activity and the Interaction with Albumin of Silicon Phthalocyanine Axially Modified by Pyrimidine Derivatives
SHEN Xiao-min, JIANG Xiong-jie, ZHU Yu-jiao, ZHANG Han-hui, and HUANG Jian-dong
Photophysical photochemical properties, in vitro photodynamic anticancer activity and interaction with albumin of a new axially modified silicon phthalocyanine,i.e. di (2-amino-6-trifluoromethyl-4-pyrimidinyloxy) silicon phthalocyanine (SiPcF), were studied in the present paper. The Q band maximum absorption of SiPcF lPhotophysical photochemical properties, in vitro photodynamic anticancer activity and interaction with albumin of a new axially modified silicon phthalocyanine,i.e. di (2-amino-6-trifluoromethyl-4-pyrimidinyloxy) silicon phthalocyanine (SiPcF), were studied in the present paper. The Q band maximum absorption of SiPcF located at 686 nm with the molar absorption coefficient of 2.3×105 mol-1·L·cm-1. The fluorescence emission of SiPcF peaked at 694 nm with a fluorescence quantum yield of 0.46. Its singlet oxygen quantum yield produced by photosensitization is 0.38, suggesting that SiPcF is an effective 1O2 photosensitizer. There is strong interaction between SiPcF and bovine serum albumin (BSA). The binding constant is 4.33×105 mol·L-1and the number of binding sites is 1. In vitro experiments show that SiPcF had a high photodynamic anticancer activity against human hepatoma cells HepG2 with an IC50 value down to 5×10－7mol·L-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2148 (2013)
Research on Methane Concentration Monitoring System Based on Electro-Optical Modulation Interference
YAN Jie, and MENG Peng-hua
Gas monitoring for methane concentration has been applied in many areas, while the vast majority of methods were based on the chemical reaction. There is a low security and poor stability shortcomings. In contrast, it is of high stability and strong anti-interference ability to monitor methane concentration using opticGas monitoring for methane concentration has been applied in many areas, while the vast majority of methods were based on the chemical reaction. There is a low security and poor stability shortcomings. In contrast, it is of high stability and strong anti-interference ability to monitor methane concentration using optical interferometry for quantitative analysis. As the system static interference limits the spectrcum resolution, we designed the electro-optical modulation interference system to further improve the detection accuracy for methane concentration. In the interferometer system, a variable refractive index crystal LiNbO3 was used for electro-optical modulation, and the static optical path length scan range was increased to improve the spectrum resolution. Both sides of the crystal were loaded with opposite phase modulated signal, so that it does not change the improved spectrum resolution interferometer size. By derivation of refractive index modulation as a function of optical path difference, the simulation found that the resolution was increased by nearly an order of magnitude than interference system spectrum resolution of the same size. The experiments used the SGT-3-type acousto-optical modulator and the 1 650 nm infrared lasers to detect different concentrations of methane gas. The experimental results show that the method is better than the traditional pyroelectric method in terms of accuracy and stability, and more suitable for application in the mine complex environment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2153 (2013)
Study of Spatial Interpolation of Soil Cd Contents in Sewage Irrigated Area Based on Soil Spectral Information Assistance
CHEN Tao, CHANG Qing-rui, and LIU Jing
To acquire the accuracy distribution information of soil heavy metal, improving interpolation precision is very important for agricultural safety production and soil environment protection. In the present study, the spatial variation and Cokriging interpolation of soil Cd was studied in a sewage irrigation area. Fifty To acquire the accuracy distribution information of soil heavy metal, improving interpolation precision is very important for agricultural safety production and soil environment protection. In the present study, the spatial variation and Cokriging interpolation of soil Cd was studied in a sewage irrigation area. Fifty two soil samples were collected to measure the contents of soil total Cd (TCd), available Cd (ACd), pH, organic matter (OM), iron oxide (Fe2O3) and soil reflection spectrum. Through correlation analysis, it was found that TCd and ACd had a significant correlation with soil first-order differential spectrum (-0.585** at 759 nm and -0.551** at 719 nm, respectively), which were much higher than the correlation coefficients between soil Cd contents and other environmental variables (pH, OM and Fe2O3). The spatial patterns of soil Cd were predicted by Cokriging which used soil first-order differential spectrum as covariate. Compared with the Kriging, the root-mean-square error decreased by 8.22% for TCd and 20.09% for ACd, respectively; the correlation coefficients between the predicted values and measured values increased by 27.45% for TCd and by 53.13% for ACd, respectively. Meanwhile, the prediction accuracy improved by Cokriging with soil spectrum as covariate was still higher than by Cokriging with soil environment variables (OM and Fe2O3). Therefore, it was found that Cokriging was a more accurate interpolation method which could provide more precise distribution information of soil heavy metal. At the same time, soil reflection spectrum was shown to be more economic, time-saving and easier to acquire than these usual environment variables, which indicated that soil spectrum information is more suited as a covariate used in Cokriging..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2157 (2013)
Study on the Enhanced Spectrum Quantitative Analysis of SDBS Induced by β-Cyclodextrin
SHI Dong-po, YIN Xian-qing, ZHENG Yan-cheng, CHEN Wu, FU Jia-xin, and REN Zhao-hua
A novel enhanced ultraviolet absorption spectrometry method was developed for the quantitative analysis of SDBS induced by β-cyclodextrin(β-CD) with strong interferences. The ultraviolet absorption spectra of SDBS indicated that the presence of β-CD could result in the enhancement of absorption intensities of SDBS. A gA novel enhanced ultraviolet absorption spectrometry method was developed for the quantitative analysis of SDBS induced by β-cyclodextrin(β-CD) with strong interferences. The ultraviolet absorption spectra of SDBS indicated that the presence of β-CD could result in the enhancement of absorption intensities of SDBS. A good linearity was obtained between the UV-absorption intensity of the system and the concentration of SDBS. The results indicated that the determination precision and the determination ranges of SDBS could be greatly improved by β-CD. The effect of several common interfering substances(SDS, OP-10, HPAM) on the determination of SDBS could be significantly reduced in β-CD aqueous solution. Therefore, the maximum errors of the determined SDBS were less than 2.0% under multifactor interferences, and the precision of the method was also as high as 10－2～10－3 mg·L-1. The stable inclusion of β-CD and SDBS could be automatically formed in water with molar ratio of 1∶1. The stability constant of the inclusion, Ka, was 87 and the standard Gibbs function of molar reaction, ΔγGmΘ(298 K), was －11.064 kJ·mol－1. FTIR analysis exhibited that SDBS could be induced by β-CD since the phenyl group in SDBS molecule could exist stably in the cavity of β-CD and form the inclusion..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2163 (2013)
Study on Early Detection of Gray Mold on Tomato Leaves Using Hyperspectral Imaging Technique
YU Jia-jia, and HE Yong
The present paper put forward the technology route for feature images extraction of grey mold sick on tomato leaves based on SIMCA—combination image extraction based on MLR—grey mold sick information extraction based on minimum distance method. Firstly, through the 680～740 nm band’s variance image and the discriminatioThe present paper put forward the technology route for feature images extraction of grey mold sick on tomato leaves based on SIMCA—combination image extraction based on MLR—grey mold sick information extraction based on minimum distance method. Firstly, through the 680～740 nm band’s variance image and the discrimination power parameter, the feature band images was found, then the feature bands information was used as the input of MLR analysis, and under the 0.5 accuracy threshold value, 99% accuracy was obtained, which showed the discrimination power of the features bands for grey mold sick tomato leaf detection, and using the MLR regression coefficient to extract a band combination image, and through the minimum distance method, tomato grey mold sick information was found. The result shows that the proposed method has a very good prediction ability and greatly reduces the hyperspectral data processing time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2168 (2013)
The Noise Filtering and Baseline Correction for Harmonic Spectrum Based on Wavelet Transform
GUO Yuan, ZHAO Xue-hong, ZHANG Rui, HU Ya-jun, and WANG Yan
The problem of noise and baseline drift is a hot topic in infrared spectral harmonic detection system. This paper presents a new algorithm based on wavelet transform Mallet decomposition to solve the problem of eliminating a variety of complex noise and baseline drift in the harmonic detection. In the algorithm, the apThe problem of noise and baseline drift is a hot topic in infrared spectral harmonic detection system. This paper presents a new algorithm based on wavelet transform Mallet decomposition to solve the problem of eliminating a variety of complex noise and baseline drift in the harmonic detection. In the algorithm, the appropriate wavelet function and decomposition level were selected to decomposed the noise, baseline drift and useful signal in the harmonic curve into different frequency bands. the bands’ information was analysed and a detecting band was set, then the information in useful frequency was reserved by zeroing method of treatment and the coefficient of the threshold. We can just use once transform and reconstruction to remove interference noise and baseline from double-harmonic signal by applying the wavelet transform technique to the harmonic detection spectrum pretreatment. Experiments show that the wavelet transform method can be used to different harmonic detection systems and has universal applicability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2172 (2013)
Research on Spectral Characteristics of the Water Content of Snow in the Northern Slope of Tianshan Mountain During Snow Melt
ZHANG Bo, LIU Zhi-hui, and XU Qian
The research on water content of snow has the real meaning of the flow of runoff and flood in Spring. Our team got the original data from ASD and Snow Folk, meanwhile these data were anglicized and handled under the help of SPSS19.0 and Excel. The result shows that there are several valleys for the absorbing in visibleThe research on water content of snow has the real meaning of the flow of runoff and flood in Spring. Our team got the original data from ASD and Snow Folk, meanwhile these data were anglicized and handled under the help of SPSS19.0 and Excel. The result shows that there are several valleys for the absorbing in visible and near-infrared region in the curve of spectrum characteristics; the spectrum characteristics and the water content of surface snow are negative correlated, and this kind of relation will change with the increase in wavelength, and there lies three minimum values of correlation in the visible and near infrared region. The prediction model wasconstructed, which lies in the visible light band, the result is positive, the model in the band of 350 nm has high-precision, reaching 75.9%, and there is high fitting degree of the predicted and measured values, while in the near infrared, the model constructed in the band of 1 204 nm holds the highest accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2177 (2013)
Study of the Effect of Surface Reflectance on Atmospheric CO2 Retrieval and Ratio Spectrometry
YE Han-han, WANG Xian-hua, WU Jun, FANG Yong-hua, MA Jin-ji, JIANG Xin-hua, and WEI Qiu-ye
Retrieving atmospheric CO2 concentration from space-based infrared measurements is an ill-posed problem, and the uncertainty of ground properties is an important impacting factor. For the requirement of high precision retrieval of atmospheric CO2, the effects of surface reflectance must be corrected. Thus a surface refRetrieving atmospheric CO2 concentration from space-based infrared measurements is an ill-posed problem, and the uncertainty of ground properties is an important impacting factor. For the requirement of high precision retrieval of atmospheric CO2, the effects of surface reflectance must be corrected. Thus a surface reflectance correction method is proposed. In this correction method, the selection of non-CO2 absorption (off-line) channel is an important part, so several different types of off-line channels were compared and analyzed. We finally found that averaging all data of multi-channels as off-line channel is the best way, in which the retrieval precision is highest and dispersion is lowest, because the advantage is that averaging many data can reduce random error. The effects of surface reflectance on CO2 retrieval decreased significantly after correction using ratio spectrometry combined with the selected off-line channel, and CO2 retrieval precision improved greatly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2182 (2013)
Using In-Situ Reflectance to Monitor the Chlorophyll Concentration in the Surface Layer of Tidal Flat
XING Qian-guo, YU Ding-feng, LOU Ming-jing, L Ying-chun, LI Shao-peng, and HAN Qiu-ying
An optical monitoring method is proposed for the rapid, non destructive measurements of chlorophyll concentration (Chl-a) in the surface sediments of emerged tidal flat, and it can be further applied in remote sensing work. Hyperspectral reflectance of intertidal sediments were measured in day time at the tidal flats oAn optical monitoring method is proposed for the rapid, non destructive measurements of chlorophyll concentration (Chl-a) in the surface sediments of emerged tidal flat, and it can be further applied in remote sensing work. Hyperspectral reflectance of intertidal sediments were measured in day time at the tidal flats of the Sishili Bay, the Northern Yellow Sea, and surface sediments (3 mm) were sampled for the in-door measurements of Chl-a. On the basis of the reflectance at 650, 675 and 700 nm, the indices of normalized difference index of microbenthos (NDI-MPB) and trough depth (T-depth) were proposed for the measurements of microphytobenthos biomass. T-depth can be used to remove the linear background spectral noises and indicate the existence of microphytobenthos; Good linear relationship was observed between NDI-MPB and Chl-a content in sediments (2.22～49.36 mg·m-2, r> 0.99), which may be used to monitor the biomass of microphy to benthos..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2188 (2013)
Classification of Hyperspectral Imagery Based on Ant Colony Compositely Optimizing SVM in Spatial and Spectral Features
CHEN Shan-jing, HU Yi-hua, SHI Liang, WANG Lei, SUN Du-juan, and XU Shi-long
A novel classification algorithm of hyperspectral imagery based on ant colony compositely optimizing support vector machine in spatial and spectral features was proposed. Two types of virtual ants searched for the bands combination with the maximum class separation distance and heterogeneous samples in spatial and specA novel classification algorithm of hyperspectral imagery based on ant colony compositely optimizing support vector machine in spatial and spectral features was proposed. Two types of virtual ants searched for the bands combination with the maximum class separation distance and heterogeneous samples in spatial and spectral features alternately. The optimal characteristic bands were extracted, and bands redundancy of hyperspectral imagery decreased. The heterogeneous samples were eliminated form the training samples, and the distribution of samples was optimized in feature space. The hyperspectral imagery and training samples which had been optimized were used in classification algorithm of support vector machine, so that the class separation distance was extended and the accuracy of classification was improved. Experimental results demonstrate that the proposed algorithm, which acquires an overall accuracy 95.45% and Kappa coefficient 0.925 2, can obtain greater accuracy than traditional hyperspectral image classification algorithms..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2192 (2013)
The Impact of Load Density Differences on Land Subsidence Based on Build-Up Index and PS-InSAR Technology
CHEN Bei-bei, GONG Hui-li, LI Xiao-juan, LEI Kun-chao, ZHU Lin, and WANG Yan-bing
The excessive mining for underground water is the main reason inducing the land subsidence in Beijing, while, increasing of load brought by the urban construction aggravate the local land subsidence in a certain degree. As an international metropolis, the problems of land subsidence that caused by urban construction arThe excessive mining for underground water is the main reason inducing the land subsidence in Beijing, while, increasing of load brought by the urban construction aggravate the local land subsidence in a certain degree. As an international metropolis, the problems of land subsidence that caused by urban construction are becoming increasingly highlights, so revealing the relationship between regional load increase and the response of land subsidence also becomes one of the key problems in the land subsidence research field. In order to analyze the relationship between the load changes in construction and the land subsidence quantitatively, the present study selected the TM remote sensing image covering Beijing plain and used Erdas Modeler tool to invert the index based on building site (IBI), acquired the spatial and temporal change information in research area further; Based on results monitored by PS-InSAR (permanent scatterer interferometry) and IBI index method, and combined with the GIS spatial analysis method in the view of pixels in different scales, this paper analyzes the correlation between typical area load change and land subsidence, The conclusions show that there is a positive correlation between the density of load and the homogeneity of subsidence, especially in area which has a high sedimentation rate. Owing to such characteristics as the complexity and hysteretic nature of soil and geological structure, it is not obvious that the land subsidence caused by the increase of load in a short period. But with the increasing of local land load made by high density buildings and additional settlement of each monomer building superposed with each other, regional land subsidence is still a question that cannot be ignored and needs long-term systematic research and discussion..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2198 (2013)
Estimation of Chlorophyll Content in Apple Tree Canopy Based on Hyperspectral Parameters
PAN Bei, ZHAO Geng-xing, ZHU Xi-cun, LIU Hai-teng, LIANG Shuang, and TIAN Da-de
The hyperspectral reflectance of apple tree canopy during spring shoots stopping growth period was measured using ASD FieldSpec3 field spectrometer. Original spectral data were processed in deviation forms, and significant spectrum parameters correlated with chlorophyll content were found out with correlation analysis.The hyperspectral reflectance of apple tree canopy during spring shoots stopping growth period was measured using ASD FieldSpec3 field spectrometer. Original spectral data were processed in deviation forms, and significant spectrum parameters correlated with chlorophyll content were found out with correlation analysis. The best vegetation indices were chosen and the apple canopy chlorophyll content estimation model was established by analyzing vegetation index of two-band combination in the sensitive region 400～1 350 nm. The result showed that (1) The sensitive band region of apple canopy chlorophyll content is 400～1 350 nm. (2) The vegetation index CCI（D794/D763）can commendably estimate the apple canopy chlorophyll content. (3) The model with CCI（D794/D763）as the independent variables was determined to be the best for chlorophyll content prediction of apple tree canopy. Therefore, using hyperspectral technology can estimate apple canopy chlorophyll content more rapidly and accurately, and provides a theoretical basis for rapid apple tree canopy nutrition diagnosis and growth monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2203 (2013)
Analysis of the Mineral Elements of Lactuca Sativa under the Condition of Different Spectral Components
CHEN Xiao-li, GUO Wen-zhong, XUE Xu-zhang, WANG Li-chun, LI Liang, and CHEN Fei
Mineral elements absorption and content of Lactuca sativa under different spectral component conditions were studied by ICP-AES technology. The results showed that: (1) For Lactuca sativa, the average proportion for Ca∶Mg∶K∶Na∶P was 5.5∶2.5∶2.3∶1.5∶1.0, the average proportion for Fe∶Mn∶Zn∶Cu∶B was 25.9∶5.9∶2.8∶1.1∶1.0;Mineral elements absorption and content of Lactuca sativa under different spectral component conditions were studied by ICP-AES technology. The results showed that: (1) For Lactuca sativa, the average proportion for Ca∶Mg∶K∶Na∶P was 5.5∶2.5∶2.3∶1.5∶1.0, the average proportion for Fe∶Mn∶Zn∶Cu∶B was 25.9∶5.9∶2.8∶1.1∶1.0; （2）The absorptions for K, P, Ca, Mg and B are the largest under the LED treatment R/B=1∶2.75, red light from fluorescent lamps and LED can both promote the absorptions of Fe and Cu; （3）The LED treatments exhibiting relatively higher content of mineral elements are R/B=1∶2.75 and R/W=1∶1 while higher dry matter accumulations are R/B=1∶2.75 and B/W=1 ∶1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2207 (2013)
Indirect Determination of Cr(Ⅲ) and Cr(Ⅵ) in Milks by Hydride Generation-Fluorescence Spectrometry
ZHANG Li-ying, TAN Fang-wei, LU Jian-ping, and TANG Yan-kui
In the medium of 3 mol·L-1 hydrochloric acid, Cr(Ⅵ) oxidized As(Ⅲ) to be As(Ⅴ), the As(Ⅲ) content, which was left over, was determined by hydride generation-fluorescence spectrometry, giving that it was inversely proportional to Cr(Ⅵ) content. Based on the same principle and combined with potassium permanganate oxIn the medium of 3 mol·L-1 hydrochloric acid, Cr(Ⅵ) oxidized As(Ⅲ) to be As(Ⅴ), the As(Ⅲ) content, which was left over, was determined by hydride generation-fluorescence spectrometry, giving that it was inversely proportional to Cr(Ⅵ) content. Based on the same principle and combined with potassium permanganate oxidation of Cr(Ⅲ) to be Cr(Ⅵ), the Cr(Ⅲ) was, therefore, determined. The sample digestion procedures and co-existing ions which might have interference were investigated. The instrumental operation parameters, reaction acidity and other influence factors were studied. Under optimum operation conditions, a good linear relationship was obtained in the range of 4.0～20 μg·L-1 Cr. The detection limit of the method was 2.5 μg·L-1. When the method was applied to milk analysis, a relative standard deviation(RSD, n=6) of 1.6%～2.7% was found. The recovery was 96.5%～104.2%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2211 (2013)
Determination of Heavy Metals in Artificial Soil on Railway Rock-Cut Slopes by Microwave Digestion-AAS
CHEN Zhao-qiong, FANG Chen, AI Ying-wei, GAO Hong-ying, PAN Dan-dan, and LI Xin-yue
The purpose of this paper is as follows: (1) Optimizing the parameters of microwave digestion-atomic absorption spectroscopy (AAS) and establishing method for the determination of heavy metals in artificial soils. (2) Evaluating heavy metal pollution conditions in artificial soil samples from railway rock-cut slopes. TThe purpose of this paper is as follows: (1) Optimizing the parameters of microwave digestion-atomic absorption spectroscopy (AAS) and establishing method for the determination of heavy metals in artificial soils. (2) Evaluating heavy metal pollution conditions in artificial soil samples from railway rock-cut slopes. The results showed that the mixture of HNO3-H2O2-HF was found to have the best digestion efficiency; under the optimized conditions, the recoveries of the method ranged from 95% to 105%; the measurement precision and the relative deviation were less than 4% and 5%, respectively; the concentrations of Cd, Pb and Zn were significantly higher in the artificial soil on railway rock-cut slope than in the control soil, and they were 4.7, 1.3 and 1.2 times as much as the control soil, respectively; compared to the contents of Cr, Cu and Fe in control soils, there was no significant difference. This research will provide a reliable method for determining metal elements in artificial soils on rock-cut slopes and a theoretical basis for the management of the railway rock-cut slopes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2215 (2013)
Synthesis of Crosslinked Polymer Containing β-Cyclodextrin and Its Adsorption for Pb2+ and Zn2+ Studied by AAS
ZHAO Meng-qi, and Nurulla Ismayil
Crosslinked copolymer(AA/β-CD-AA/ABE) containing β-cyclodextrin was synthesized by microwave heating with acylation, allyl-biphenyl-ether(ABE), crylic acid(AA) as monomer and N,N-methylenebisacrylamide (MBA) as cross-linking agent, and characterized by means of FTIR. The adsorption of Pb2+ and Zn2+ on the synthesized cCrosslinked copolymer(AA/β-CD-AA/ABE) containing β-cyclodextrin was synthesized by microwave heating with acylation, allyl-biphenyl-ether(ABE), crylic acid(AA) as monomer and N,N-methylenebisacrylamide (MBA) as cross-linking agent, and characterized by means of FTIR. The adsorption of Pb2+ and Zn2+ on the synthesized copolymer and the factors (adsorption time, pH and temperature) which affect the adsorption capacity were investigated by atomic absorption spectrometry (AAS) as the detection means. The results show that the optimum experimental conditions of adsorption: 35 ℃, 2 h and pH 2～3, adsorbance Q for Pb2+ reached maximum 29.5 mg·g-1; 30 ℃, 3 h and pH 3～4, adsorbance Q for Zn2+ reached maximum 43.7 mg·g-1; the adsorption equilibriums for Pb2+ and Zn2+ fit the Freundlich on the whole..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2219 (2013)
Application of Confocal Technology Based on Polycapillary X-Ray Lens in Measuring Thickness
PENG Song, LIU Zhi-guo, SUN Tian-xi, LI Yu-de, LIU He-he, ZHAO Wei-gang, ZHAO Guang-cui, LIN Xiao-yan, LUO Ping, PAN Qiu-li, and DING Xun-liang
A confocal micro X-ray fluorescence thickness gauge based on a polycapillary focusing X-ray lens, a polycapillary parallel X-ray lens and a laboratory X-ray source was designed in order to analyze nondestructively the thickness of thin film and cladding material. The performances of this confocal thickness gauge were sA confocal micro X-ray fluorescence thickness gauge based on a polycapillary focusing X-ray lens, a polycapillary parallel X-ray lens and a laboratory X-ray source was designed in order to analyze nondestructively the thickness of thin film and cladding material. The performances of this confocal thickness gauge were studied. Two Ni films with a thickness of about 25 and 15 μm respectively were measured. The relative errors corresponding to them were 3.5% and 7.1%, respectively. The thickness uniformity of a Ni films with a thickness of about 10 μm was analyzed. This confocal technology for measuring the thickness was both spatially resolved and elemental sensitive, and therefore, it could be used to measure the thickness of the multilayer sample and analyze the thickness uniformity of the sample. This confocal thickness gauge had potential applications in analyzing the thickness of sample..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2223 (2013)
Study on High-Temperature Phase Change of Tobermorite
YANG Xiu-li, CUI Xiao-yu, CUI Chong, MA Hai-long, and YANG Qing
In the present paper, the high-temperature phase change of pure tobermorite was investigated by TGA/DSC, X-ray diffraction and infrared spectroscopy (IR) respectively. The DSC results showed that four interlayer water molecules were lost when they were heated at 300 ℃. As the temperature increased to 724 ℃, Si—O—H bondIn the present paper, the high-temperature phase change of pure tobermorite was investigated by TGA/DSC, X-ray diffraction and infrared spectroscopy (IR) respectively. The DSC results showed that four interlayer water molecules were lost when they were heated at 300 ℃. As the temperature increased to 724 ℃, Si—O—H bonds were cleaved and dehydroxylation occurred. The XRD results showed that many diffraction peaks of tobermorite disappeared and the crystal structure was broken and collapsed. Then tobermorite tends to be disordered and amorphous. When the calcination temperature increased to 861 ℃, the disordered structure recombined to wollastonite, and the crystal structure became ordered and stable. Finally, the structure completely transformed to 2M-wollastonite at 1 000 ℃. It should include the process of high-temperature phase change of tobermorite: tobermorite→dehydration tobermorite→dehydroxylation tobermorite→wollastonite..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2227 (2013)
Study on the Effect of Target Thickness on Output Spectrum in Transmission Anode Micro X-Ray Tube by MC Method
ZHANG Qing-xian, GE Liang-quan, GU Yi, ZENG Guo-qiang, YANG Qiang, and LUO Yao-yao
The transmission anode micro X-ray tube is a key component of energy dispersive X-ray Fluorescence Analysis (EDXRFA) as exciting source. So in EDXRFA we hope to get the primary X-ray spectrum which is simply distributed. In the present paper, the authors used the Monte Carlo (MC) method to study the spectrum character The transmission anode micro X-ray tube is a key component of energy dispersive X-ray Fluorescence Analysis (EDXRFA) as exciting source. So in EDXRFA we hope to get the primary X-ray spectrum which is simply distributed. In the present paper, the authors used the Monte Carlo (MC) method to study the spectrum character of the transmission anode micro X-ray tube with different thickness of target. We cut the spectrum into high energy (5keV~50keV) part and low energy (<5 keV) part and compared them to each other. The result showed that the flux of high energy part is big and the flux of low energy part is small when the electron energy is 50 keV and the target is 4 μｍ thick Ag. This is better for EDXRFA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2231 (2013)
The Characteristics of Microstructure and Chemical Compositions of K-Feldspar, Sphene and Zircon with Zoning Structure
LIU Chun-hua, WU Cai-lai, LEI Min, QIN Hai-peng, and LI Ming-ze
K-feldspar, sphene and zircon in quartz monzonite from Shahewan, south Qinling, showing strong zoning structure. Characteristics of microstructure and chemical compositions of K-feldspar, sphene and zircon with zoning structure were investigated using advanced instruments of electron probe micro analyses equipped with K-feldspar, sphene and zircon in quartz monzonite from Shahewan, south Qinling, showing strong zoning structure. Characteristics of microstructure and chemical compositions of K-feldspar, sphene and zircon with zoning structure were investigated using advanced instruments of electron probe micro analyses equipped with wavelength dispersive spectrometer (EPM-WDS), scanning electron microscopy with energy dispersive spectrometer (SEM-EDS) and laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS). Our study suggests that K+ could be substituted by small amounts of Na+, Ca2+, Ba2+, Fe2+ and Ce3+. Ca2+ in sphene could be replaced by V3+, Ce3+, Ba2+ and Ti4+ could be substituted by both Fe2+ and Al3+. Zircon contains trace elements like Fe, Th, U, Nb, Ta, Y, Hf, Yb and Pb. Concentration of Si, Al, K, Ca, Na, Mg and Ba in K-feldspar ranked from high to low, among which the contents of K and Na are negatively correlated, the lighter part of BSE images featuring K-feldspar is attributed to comparably higher Ba content, additionally, Si and K contents are elevated while Na content decreased rimward. Ca, Si, Ti, Ba, V, Ce, Al and Fe concentration listed downward, among which higher iron content corresponds to brighter portion of BSE images. Element concentration of zircon could be ranked from high to low as Zr, Si, Nd, Ce, Hf, U, Pb and Th, in which Hf and Zr exhibit negatively correlated. Zr concentration increased while Hf, U and Th concentration decreased from core to rim..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2235 (2013)
Research on the Content Prediction Model for the Determination of Nickel in Soil by Portable Energy Dispersive X-Ray Fluorescence Analyzer
WANG Guang-xi, LI Dan, LAI Wan-chang, ZHAI Juan, YANG Zhong-jian, HOU Xin, and CAO Fa-ming
The present paper discusses the influence of matrix effect on measurement results when portable energy dispersive X-ray fluorescence analyzer is used for the determination of Ni in soil. Based on the scattered X-ray intensity of WLα emitted from the X-ray tube on the sample, a correction method was proposed, and it comThe present paper discusses the influence of matrix effect on measurement results when portable energy dispersive X-ray fluorescence analyzer is used for the determination of Ni in soil. Based on the scattered X-ray intensity of WLα emitted from the X-ray tube on the sample, a correction method was proposed, and it combines with the correction of absorption element, which can effectively overcome the matrix effect. The correlation coefficient of the content prediction model based on this method is 0.999 and the residual standard deviation is 2.541. The average relative error is 3.90% when the content prediction model is used to measure the content of Ni in the national standard soil samples, so the results coincide well with standard values, and the precision is high..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2242 (2013)
Research on the Composition Characteristics of Imitated Longquan Celadon in Jingdezhen and Longquan Celadon
WU Juan, WU Yan-fang, WU Jun-ming, ZHANG Mao-lin, LI Qi-jiang, WU Tao-tao, and XU Lu
Longquan celadon not only has been loved widely by the domestic and international ceramic lovers, but also imitated by the kiln workers from different places. Among all of the imitated celadons, the most representative products appeared in Ming and Qing dynasties. This paper used EDXRF to test 38 pieces of Longquan celLongquan celadon not only has been loved widely by the domestic and international ceramic lovers, but also imitated by the kiln workers from different places. Among all of the imitated celadons, the most representative products appeared in Ming and Qing dynasties. This paper used EDXRF to test 38 pieces of Longquan celadon of Song,Yuan and Ming dynasty and imitated Longquan celadon in Jingdezhen of Ming dynasty, combined with firing temperature in order to analyze the different composition characteristics of the bodies and the glaze, evolution rule and formation reasons of these samples in the two different places from the views of time and space. It will be contributed to realising the evolution development, mutual communication and influence of the southern celadon and also provide a scientific basis to get the exact information of the celadon including its time and place of origin and so on..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2246 (2013)
The Study of M Dwarf Spectral Classification
YI Zhen-ping, PAN Jing-chang, and LUO A-li
As the most common stars in the galaxy, M dwarfs can be used to trace the structure and evolution of the Milky Way. Besides, investigating M dwarfs is important for searching for habitability of extrasolar planets orbiting M dwarfs. Spectral classification of M dwarfs is a fundamental work. The authros used DR7 M dwarfAs the most common stars in the galaxy, M dwarfs can be used to trace the structure and evolution of the Milky Way. Besides, investigating M dwarfs is important for searching for habitability of extrasolar planets orbiting M dwarfs. Spectral classification of M dwarfs is a fundamental work. The authros used DR7 M dwarf sample of SLOAN to extract important features from the range of 600~900 nm by random forest method. Compared to the features used in Hammer Code, the authors added three new indices. Our test showed that the improved Hammer with new indices is more accurate. Our method has been applied to classify M dwarf spectra of LAMOST..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2251 (2013)
An Abnormal Characteristic Line Mining Method of Celestial Spectrum Based on Attribute Weight and wk-Distance
LOU Sheng-jin, ZHANG Ji-fu, and YANG Hai-feng
Outlier mining is one of the effective methods to find the abnormal celestial spectrum data, and is also one of effective ways to discover the special and unknown celestial bodies. In the present paper, an abnormal characteristic line mining method of celestial spectrum is presented based on the attribute weight and wkOutlier mining is one of the effective methods to find the abnormal celestial spectrum data, and is also one of effective ways to discover the special and unknown celestial bodies. In the present paper, an abnormal characteristic line mining method of celestial spectrum is presented based on the attribute weight and wk-distance by using the idea of information entropy. Based on it, an abnormal characteristic line mining system of celestial spectrum was designed and implemented. Firstly, attribute weight of characteristic line was determined by using the idea of information entropy, so that important degree was effectively reflected for each characteristic line. Secondly, massive characteristic line data set of celestial spectrum was reduced by utilizing pruning technique based on neighborhood radius, so that candidate set of abnormal characteristic line was obtained by deleting data objects in which there may not be abnormal characteristic lines. Thirdly, wk-distance sum was computed according to the deviation between the data objects in the candidate set, and the objects whose wk-distance sum value ranks the first top n were regarded as abnormal characteristic line data objects. In the end, the experimental and the system’s running results validated the effectiveness and feasibility of the method by using the SDSS star spectral data set..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2255 (2013)
Automatic Recognition of M-Star Spectral Subtype Based on Fractal Coding
HAN Jin-shu
According to the local fractal feature in an astronomical spectrum, the data in the spectrum were coded in three bands 400~510, 600~700 and 780~900 nm. In the present paper, using the position of the matching data block and the minimum matching error, the fractal coding method was used to recognize the subtypes of astrAccording to the local fractal feature in an astronomical spectrum, the data in the spectrum were coded in three bands 400~510, 600~700 and 780~900 nm. In the present paper, using the position of the matching data block and the minimum matching error, the fractal coding method was used to recognize the subtypes of astronomical spectra for the first time. The experimental results show that the fractal coding method has certain noise immunity and cannot be affected by the calibration error and the effective curves of LAMOST. The fractal method can effectively recognize the subtype of M stars of LAMOST and SDSS..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2259 (2013)
The Realization of Moving Mirror Scanning in FTIR Spectrometer Using Completely Digital Control Method
REN Li-bing, YANG Hong-lei, WEI Hao-yun, and LI Yan
In view of the complexity of the conventional control of scanning mirror based on a digital-analog hybrid design, this paper focuses on a concise and efficient control method around the completely digital signal. The quadrate-encoder pulses A and B generated by the scanning mirror were sent into CPLD pins where an algoIn view of the complexity of the conventional control of scanning mirror based on a digital-analog hybrid design, this paper focuses on a concise and efficient control method around the completely digital signal. The quadrate-encoder pulses A and B generated by the scanning mirror were sent into CPLD pins where an algorithm on position control and velocity control had been built. As a result, the CPLD will generate two PWM signals. These two signals are regenerated by a digital power chip to drive the voice of motor bundled with the moving mirror. Experiments validated that the stability of velocity of moving mirror is better than 97.2% and the method can improve the SNR of the measured spectrum and guarantee the accuracy of spectral qualitative and quantitative analyses..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2263 (2013)
Correction Method for Infrared Spectral Emissivity Measurement System Based on Integrating Sphere Reflectometer
ZHANG Yu-feng, DAI Jing-min, ZHANG Yu, PAN Wei-dong, and ZHANG Lei
In view of the influence of non-ideal reference standard on spectral emissivity measurement, by analyzing the principle of infrared emissivity measurement system based on integrating sphere reflectometer, a calibration method suitable for measuring spectral emissivity system using the reflection measurement was proposeIn view of the influence of non-ideal reference standard on spectral emissivity measurement, by analyzing the principle of infrared emissivity measurement system based on integrating sphere reflectometer, a calibration method suitable for measuring spectral emissivity system using the reflection measurement was proposed. By fitting a spectral reflectance curve of the reference standard sample to the given reflectance data, the correction coefficient of measurement system was computed. Then the output voltage curve of reference standard sample was corrected by this coefficient. The system error caused by the imperfection of reference standard was eliminated. The correction method was applied to the spectral emissivity measurement system based on integrating sphere reflectometer. The results measured by the corrected system and the results measured by energy comparison measurement were compared to verify the feasibility and effectivity of this correction method in improving the accuracy of spectral emissivity measurement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2267 (2013)
Sub-Field Imaging Spectrometer Design Based on Offner Structure
WU Cong-jun, YAN Chang-xiang, LIU Wei, and DAI Hu
To satisfy imaging spectrometers’s miniaturization, lightweight and large field requirements in space application, the current optical design of imaging spectrometer with Offner structure was analyzed, and an simple method to design imaging spectrometer with concave grating based on current ways was given. Using the meTo satisfy imaging spectrometers’s miniaturization, lightweight and large field requirements in space application, the current optical design of imaging spectrometer with Offner structure was analyzed, and an simple method to design imaging spectrometer with concave grating based on current ways was given. Using the method offered, the sub-field imaging spectrometer with 400 km altitude, 0.4~1.0 μm wavelength range, 5 F-number of 720 mm focal length and 4.3°total field was designed. Optical fiber was used to transfer the image in telescope’s focal plane to three slits arranged in the same plane so as to achieve sub-field. The CCD detector with 1 024×1 024 and 18 μm×18 μm was used to receive the image of the three slits after dispersing. Using ZEMAX software optimization and tolerance analysis, the system can satisfy 5 nm spectrum resolution and 5 m field resolution, and the MTF is over 0.62 with 28 lp·mm-1. The field of the system is almost 3 times that of similar instruments used in space probe..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2272 (2013)
The Coding Correction of Slit Diffraction in Hadamard Transform Spectrometer
LI Bo, WANG Shu-rong, HUANG Yu, and WANG Jun-bo
According to the principles of Hadamard transform spectrometer and the slit diffraction characteristics, the influence of spectrometer entrance slit diffraction of Hadamard transform spectrometer on the measurement result was analyzed, for the diffraction case, the Hadamard transform spectrometer instrument structure mAccording to the principles of Hadamard transform spectrometer and the slit diffraction characteristics, the influence of spectrometer entrance slit diffraction of Hadamard transform spectrometer on the measurement result was analyzed, for the diffraction case, the Hadamard transform spectrometer instrument structure matrix was studied, and the Hadamard transform spectrometer encoding/decoding method was established. The analysis of incident spectral verified the correctness of the coding/decoding. This method is very important for the high precision measurement of Hadamard transform spectrometer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2277 (2013)
Central Wavelength Shift Analysis between Laboratory and Field Spectral Calibrations of Grating Based Imaging Spectrometer
WANG Ming-zhi, YAN Lei, YANG Bin, and GOU Zhi-yang
Spectral calibration must be carried out in order to determine its central wavelength and half-wave band width of each pixel before the usage of imaging spectrometer. But it was found out that these parameters vary as environment changes. The present paper studies the effect based on test field data. The authors analyzSpectral calibration must be carried out in order to determine its central wavelength and half-wave band width of each pixel before the usage of imaging spectrometer. But it was found out that these parameters vary as environment changes. The present paper studies the effect based on test field data. The authors analyzed the optical structure and compared the working environmental parameters. Then a theoretical model is established and the influences of vibration, distortion and temperature parameters are evaluated. The theoretical model and the caculation results are in good consistency, which testifies the theoretical model. This research will shed some light on the high accuracy spectral calibration of the grating based imaging spectrometer and its manufacture..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2280 (2013)
Study on the Advanced Schwarzschild Imaging Spectrometer with High Resolution in Broadband
LIU Jian-fang
The Schwarzschild optical structure was studied for the application of imaging spectrometer. The perfect astigmatism-corrected condition was obtained based on the analysis of the astigmatism of the Schwarzschild structure. The structure was advanced in the paper. The Schwarzschild imaging spectrum system is composed ofThe Schwarzschild optical structure was studied for the application of imaging spectrometer. The perfect astigmatism-corrected condition was obtained based on the analysis of the astigmatism of the Schwarzschild structure. The structure was advanced in the paper. The Schwarzschild imaging spectrum system is composed of two Schwarzschild structures, which are the collimating mirror-convex mirror and the convex mirror-focusing mirror. The calculation was given to present the parameters of the imaging spectrum system. An example of the imaging spectrum system in the waveband of 340~500 nm was designed and proved our design theory. The solution of the initial optimum structure was designed by our theory and simulated. A system with NA 1.25, of which the modulation transfer functions (MTF) of all fields of view are more than 0.58 in the waveband in the required Nyquist frequency (20 lp·mm-1), is presented in the paper. The form of the design structure can be changed as C-T system, Ebert-Fastie system and Offner system. The result also certificated that the optical system theory can be applied to the small scale imaging spectrometer with high resolution and spectral broadband..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2286 (2013)
Research on the Transmittance Spectrum of Wedge Thin Film Filter with Oblique Incidence
YU Kan, HUANG De-xiu, YIN Juan-juan, and BAO Jia-qi
Angle-tuned thin film filter is widely used in the DWDM system for its broad tunable wavelength range and high rectangular degree. The transmissivity and the half bandwidth is greatly influenced not only by the incident angle, but also by the wedge angle of the non-paralleled thin film filter. In the present paper, theAngle-tuned thin film filter is widely used in the DWDM system for its broad tunable wavelength range and high rectangular degree. The transmissivity and the half bandwidth is greatly influenced not only by the incident angle, but also by the wedge angle of the non-paralleled thin film filter. In the present paper, the influences of the wedge angle on the transmissivity and the half bandwidth were detailedly analyzed. The proper wedge angle and the orientation can greatly improve the characteristics of the transmittance spectrum. The angle-tuned thin film filter with 0.8°wedge angle was also fabricated. The experimental results show that keeping the wedge angle with the same orientation to the incident angle will worsen the transmissivity and the rectangular degree of the transmittance spectrum. However, keeping the wedge angle orientation reverse to the incident angle will greatly enhance the transmissivity and the rectangular degree of the filter and its tunable wavelength range will broaden by 10 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2290 (2013)
Design of A Compact Structure Interferometer
SHI Lei, LI Kai, GAO Zhi-fan, ZENG Li-bo, and WU Qiong-shui
A novel interferometer system based on the combinations of cube-corner reflectors and fixed plane mirrors was designed, the moving mirror drive system was designed and analysed, and its governor PID algorithm was used to ensure that the movement of the moving mirror is collimated, uniform and smooth. The parameters of A novel interferometer system based on the combinations of cube-corner reflectors and fixed plane mirrors was designed, the moving mirror drive system was designed and analysed, and its governor PID algorithm was used to ensure that the movement of the moving mirror is collimated, uniform and smooth. The parameters of the optical system of the interferometer and the optical devices were described. Finally, after validation of the experiment, it was indicated that the wave number accuracy, resolution, signal to noise ratio and other key indicators can meet the needs of practical application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2294 (2013)
Design and Development of Trace Cr(Ⅵ) Sensor
ZHENG Shou-guo, LI Miao, ZENG Xin-hua, JIANG Hai-yang, WAN Li, and QIAO Lei
Hexavalent chromium detection in medicine capsules is generally analyzed in the laboratory, it is difficult to meet the demand for field detection, and to address this problem, a sensor which can be used for on-site detection of trace amounts of hexavalent chromium was designed. It mainly includes chemically sensitive Hexavalent chromium detection in medicine capsules is generally analyzed in the laboratory, it is difficult to meet the demand for field detection, and to address this problem, a sensor which can be used for on-site detection of trace amounts of hexavalent chromium was designed. It mainly includes chemically sensitive materials, optical sensing module and signal processing module, the chemical sensitive materials is to achieve the conversion of the hexavalent chromium concentration signal, the optical sensing module is to complete a stable output of the laser light source, and the signal processing module is to complete a photoelectric conversion of the weak fluorescence signal, signal amplification, and data processing and displaying. With using the indigenously developed photoelectric acquisition, conversion and signal processing system to complete the rapid detection of trace amounts of hexavalent chromium, so the miniaturization of testing instruments and on-site detection were achieved. Experimental results show that: the sensor detection results have a good linear relationship when the hexavalent chromium concentration is 10～500 μg·L-1, the linear equation is Y=1.542 47*X－2.353 47, and the linearity is 0.998 62, the detection limit reaches 10 μg·L-1, the sensor response time is about 90 seconds, 5 capsule samples were selected to do the contrast detection, and the results show that the sensor quantitative detection data is reliable, which meets trace hexavalent low cost, fast and field detection demands..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 2299 (2013)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 8, 1 (2013)
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