Journals >Spectroscopy and Spectral Analysis
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2010
Volume: 30 Issue 6
61 Article(s)
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Research Article
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1 (2010)
Synthesis, Spectroscopy and Antibacterial Activity of Charge Transfer Complexes of Heteropolytungstate Containing Sulfanilamide
FENG Chang-gen, XIONG Yu-di, and LIU Xia
Two charge transfer complexes of heteropolytungstate with Keggin structure, (C6H9N2O2S)3PW12O40·6H2O (SPW12) and (C6H9N2O2S)4SiW12O40·5H2O (SSiW12) were synthesized with 12-tungstophosphoric (silicic) acid and sulfanilamide in aqueous phase. The title complexes were characterized by means of elementary analysTwo charge transfer complexes of heteropolytungstate with Keggin structure, (C6H9N2O2S)3PW12O40·6H2O (SPW12) and (C6H9N2O2S)4SiW12O40·5H2O (SSiW12) were synthesized with 12-tungstophosphoric (silicic) acid and sulfanilamide in aqueous phase. The title complexes were characterized by means of elementary analysis, FTIR, UV, 1H NMR, XRD and TG-DSC. The results indicate that the title complexes are new heteropoly compounds, and the UV results reveal that there is a charge transfer interaction between sulfanilamide and heteropoly anion. Thermal analysis shows that the process of mass loss of the title complexes is carried out in four stages, and the two complexes begin to decompose at 272.8 ℃ and 330.4 ℃, respectively. The intermediates of the thermal decomposition were identified by FTIR. Antibacterial test results show that the title complexes both have good antibacterial activity, and the inhibition rate of SPW12 to Escherichia coli, Staphylococcus aurous is 73.28% and 99.36%, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1441 (2010)
Study of the Microwave Emissivity Characteristics over Different Land Cover Types
ZHANG Yong-pan, JIANG Ling-mei, QIU Yu-bao, WU Sheng-li, SHI Jian-cheng, and ZHANG Li-xin
The microwave emissivity over land is very important for describing the characteristics of the lands, and it is also a key factor for retrieving the parameters of land and atmosphere. Different land covers have their emission behavior as a function of structure, water content, and surface roughness. In the present studThe microwave emissivity over land is very important for describing the characteristics of the lands, and it is also a key factor for retrieving the parameters of land and atmosphere. Different land covers have their emission behavior as a function of structure, water content, and surface roughness. In the present study the global land surface emissivities were calculated using six month (June, 2003-August, 2003, Dec, 2003-Feb, 2004) AMSR-E L2A brightness temperature, MODIS land surface temperature and the layered atmosphere temperature, and humidity and pressure profiles data retrieved from MODIS/Aqua under clear sky conditions. With the information of IGBP land cover types, “pure” pixels were used, which are defined when the fraction cover of each land type is larger than 85%. Then, the emissivity of sixteen land covers at different frequencies, polarization and their seasonal variation were analyzed respectively. The results show that the emissivity of vegetation including forests, grasslands and croplands is higher than that over bare soil, and the polarization difference of vegetation is smaller than that of bare soil. In summer, the emissivity of vegetation is relatively stable because it is in bloom, therefore the authors can use it as its emissivity in our microwave emissivity database over different land cover types. Furthermore, snow cover can heavily impact the change in land cover emissivity, especially in winter..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1446 (2010)
The Enhancement of Electric Field Distribution in One-Dimensional Metallic-Dielectric Photonic Crystals
DENG Li-er, WANG Yong-sheng, WANG Dong-dong, XU Zheng, FU Ming, HE Da-wei, ZHAO Ai-lun, and TAO Ying-lei
The authors theoretically study the transmission properties and electric filed distribution in one-dimensional metallic-dielectric photonic crystals with the transfer matrix method. The results show that the physical properties can be improved considerably after the introduction of antireflection layer and optimizing sThe authors theoretically study the transmission properties and electric filed distribution in one-dimensional metallic-dielectric photonic crystals with the transfer matrix method. The results show that the physical properties can be improved considerably after the introduction of antireflection layer and optimizing structural parameters, e.g., 77% electric file distribution in metal layers can be obtained under 19% transmittance, and 72% transmittance can be obtained with 28% electric field distribution in metal layers. These photonic crystal structures, whose transmission properties and electric field in metal layers are tunable, could be widely used in nonlinear photon device based on the enhancement of electric field in metal layers..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1452 (2010)
The Upconversion Luminescence Characteristics of Ho3+/Yb3+ Codoped ZrO2-ZnO
ZHANG Xiang-hua, YANG Si-yang, DING Qing-lei, and LIU Zheng-wei
Samples of Ho3+/Yb3+ codoped ZrO2-ZnO powder were prepared by a solid-state reaction. Upconversion luminescence of Ho3+/Yb3+ codoped ZrO2-ZnO powders was reported in the present paper. The excitation spectrum detected at room temperature suggests three excitation peaks centered at 540, 671 and 762 nm respectively, corrSamples of Ho3+/Yb3+ codoped ZrO2-ZnO powder were prepared by a solid-state reaction. Upconversion luminescence of Ho3+/Yb3+ codoped ZrO2-ZnO powders was reported in the present paper. The excitation spectrum detected at room temperature suggests three excitation peaks centered at 540, 671 and 762 nm respectively, corresponding to 5S2/5F4→5I8, 5F5→5I8, and 5S2/5F4→5I7 or 5I4→5I8 of Ho3+ ions. The contents of rare-earth ions could influence the property of upconversion lumunescence. When the Ho3+ content was 0.1 mol%, with the increase in Yb3+ content, the intensity of red luminescence and green luminescence decreased first and then increased, but the intensity of infrared luminescence increased first and then decreased. Furthermore, the ratio of the intensity of green emission to red emission decreased. When the Yb3+ content was 4.7 mol%, with the increase in Ho3+ content, the intensity of all emission decreased, but the ratio of the intensity of green emission to red emission was almost constant. The logI-logP curve shows that all the upconversion luminescence is double-photon processes. And the upconversion mechanisms of the samples were introduced. It is shown from the XRD spectrum that the powder of samples is uniform..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1456 (2010)
Effects of White Organic Light-Emitting Devices Using Color Conversion Films on Electroluminescence Spectra
HOU Qing-chuan, WU Xiao-ming, HUA Yu-lin, QI Qing-jin, LI Lan, and YIN Shou-gen
The authors report a novel white organic light-emitting device (WOLED), which uses a strategy of exciting organic/inorganic color conversion film with a blue organic light-emitting diode (OLED). The luminescent layer of the blue OLED was prepared by use of CBP host blended with a blue highly fluorescent dye N-BDAVBi. TThe authors report a novel white organic light-emitting device (WOLED), which uses a strategy of exciting organic/inorganic color conversion film with a blue organic light-emitting diode (OLED). The luminescent layer of the blue OLED was prepared by use of CBP host blended with a blue highly fluorescent dye N-BDAVBi. The organic/inorganic color conversion film was prepared by dispersing a mixture of red pigment VQ-D25 and YAG∶Ce3+ phosphor in PMMA. The authors have achieved a novel WOLED with the high color stability by optimizing the thickness and fluorescent pigment concentration of the color conversion film. When the driving voltage varied between 6 and 14 V, the color coordinates (CIE) varied slightly from (0.354, 0.304) to (0.357, 0.312) and the maximum current efficiency is about 5.8 cd·A－１(4.35 mA·cm－2)， the maximum brightness is 16 800 cd·m－2 at the operating voltage of 14 V..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1460 (2010)
Mid-Infrared Emission and Multiphonon Relaxation in Tm3+-Doped Ge-Ga-Se Glasses
ZHANG Peng-jun, DAI Shi-xun, LE Fang-da, PENG Bo, XU Tie-feng, NIE Qiu-hua, and ZHANG Xiang-hua
A series of chalcogenide glasses based on the composition Ge30Ga5Se65 (at.%) doped with the different Tm3+ ions were synthesized by melt-quenching technique. The refractive indexes, Raman spectra, absorption spectra, near-and mid-infrared fluorescence, and lifetimes of glass samples under 800 nm laser excitation were mA series of chalcogenide glasses based on the composition Ge30Ga5Se65 (at.%) doped with the different Tm3+ ions were synthesized by melt-quenching technique. The refractive indexes, Raman spectra, absorption spectra, near-and mid-infrared fluorescence, and lifetimes of glass samples under 800 nm laser excitation were measured. The intensity parameters Ωi(i=2, 4, 6), transition probabilities, branching ratios and radiative lifetimes have been predicted for Tm3+ ions in samples by using the Judd-Ofelt theory. The near-infrared emission spectra at 1.23, 1.48 and 1.8 μm were observed and their quantum efficiencies were evaluated respectively in glass doped with 1 Wt% Tm3+-ions under 800 nm excitation. The mid-infrared fluorescence spectra were investigated with the different Tm3+ ion concentration under 800 nm excitation. The multiphonon relaxation rate of Tm3+: 3H5→3F4 by the measured and calculated lifetimes, and the relative parameters of W(0) and α in Ge30Ga5Se65 glass were evaluated. Results show that the multiphonon relaxation rates were significantly lower than other glasses due to the lower maximum phonon energy, so the selenide glasses are promising as host materials for doping by rare earth ions and for preparation of mid-infrared optical elements..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1464 (2010)
Spectra Analysis of Lignin Small Molecular Guaiacyl Coniferyl Alcohol Biological Modification Treated by Laccase
LIU Hai-tang, PEI Ji-cheng, HU Hui-ren, and PEI Ya
The enzymatic modification mechanism of lignin small molecular lignin guaiacyl coniferyl alcohol existing in softwood and hardwood treated by laccase was studied. Gas chromatography-mass spectrometry (GC-MS), gel permeation chromatography (GPC), FTIR spectrum and PCD(particle charge detector) etc were used for the measThe enzymatic modification mechanism of lignin small molecular lignin guaiacyl coniferyl alcohol existing in softwood and hardwood treated by laccase was studied. Gas chromatography-mass spectrometry (GC-MS), gel permeation chromatography (GPC), FTIR spectrum and PCD(particle charge detector) etc were used for the measurement. GC-MS could not detect the coniferyl alcohol monomer after treated by laccase, so it was speculated that coniferyl alcohol participated in the reaction totally, and the structure of coniferyl alcohol was changed. GPC demonstrated that the molecular weight of coniferyl alcohol increased when it was treated by laccase, and coniferyl alcohol was polymerized. FTIR spectrum determined the reaction point of coniferyl alcohol when treated by laccase, and it is mainly phenolic hydroxyl， aromatic ring side chain substituent such as methoxy, double bound in side chain, β-carbonyl groups, and γ-carbonyl groups. PCD gave a result that the cationic demandv(CD) decreased by 88.38%..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1469 (2010)
New Progress in Noninvasive Method of Blood Glucose Measurement Using FT-Mid-IR Spectroscopy
WANG Man-man, BAI Qian, PAN Qing-hua, ZHANG Yuan-fu, WENG Shi-fu, ZHOU Feng-shan, GONG Rong-ye, WU Hui-zhong, XU Yi-zhuang, and WU Jin-guang
The blood glucose concentrations of volunteers from diabetes patients and healthy adults (all patients and volunteers who joined this experiment gave their consents) were measured by using a modified WQF-200 FTIR spectrometer with a newly designed ATR accessory from the Beijing Rayleigh Analytical Instrument Corp. The The blood glucose concentrations of volunteers from diabetes patients and healthy adults (all patients and volunteers who joined this experiment gave their consents) were measured by using a modified WQF-200 FTIR spectrometer with a newly designed ATR accessory from the Beijing Rayleigh Analytical Instrument Corp. The determination basis for this technique from the physiological point of view is also discussed based on the experimental results, which indicated that the glucose measured by the FT-Mid-IR-ATR instrument is from the secretions on the skin and glucose components within the body. The secreted glucose components will increase with the time increasing. The authors’ previous study［3-8］ demonstrated 1 120 cm-1 band as an index to characterize the blood glucose. During the experiments, the authors used the band of 1 455 cm-1 as internal standard because of its stability, and because the relative intensity of I1 120/I1 455 band possesses the higher sensitivity. Meanwhile, from the spectra, the relative intensity of I1 120/I1 455 band of the glucose in both sources exhibits a linear relationship with blood glucose concentration within the body. The dried blood has the similar spectra as fingers’. The fingers’ spectra will exhibit higher sensitivity if the time of measurement is longer after washing hand, and the results showed that when measured 10 minutes after washing hand, the sensitivity will be higher than that when measured 4 minutes after washing hand. All the results can be used in promoting a convenient, rapid and noninvasive way to monitor the continuous variation of blood glucose concentration of diabetes patients in real time..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1474 (2010)
Application of SOF-FTIR Method to Measuring Ammonia Emission Flux of Chemical Plant
JIN Ling, GAO Min-guang, LIU Wen-qing, LU Yi-huai, ZHANG Yu-jun, WANG Ya-ping, ZHANG Tian-shu, XU Liang, LIU Zhi-ming, and CHEN Jun
In the present paper, a new method is introduced for real-time monitoring polluted gas emission flux of chemical plant, which is called FTIR based on the solar occultation flux technique (SOF-FTIR). The model to obtain background spectrum, measured spectrum and atmospheric penetration rate surrounding polluted gas undeIn the present paper, a new method is introduced for real-time monitoring polluted gas emission flux of chemical plant, which is called FTIR based on the solar occultation flux technique (SOF-FTIR). The model to obtain background spectrum, measured spectrum and atmospheric penetration rate surrounding polluted gas under complicated conditions is also proposed. Continuous measurements were preformed at a closed loop surrounding the contaminated areas that need to be mornitored to obtain measured spectrum, and finally column concentration of polluted gas was retrieved by using the nonlinear least squares fitting algorithm (NLLS). Then the flux information combined with the meteorological data and GPS information of the time was obtained when the experiments were done. Using this method， remote sensing experiment of ammonia emission around a chemical plant was done, and the concentration distribution and its emission flux was quantitatively analyzed. Compared with traditional FTIR methods of monitoring, this method is featured by convenient operation and high maneuverability, so it has a good application prospect in pollution monitoring and other applications in regional air pollution contingency monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1478 (2010)
Near Infrared Reflectance Spectroscopy (NIRS) and Its Application in the Determination for the Quality of Animal Feed and Products
WANG Li, MENG Qing-xiang, REN Li-ping, and YANG Jian-song
Near-infrared reflectance spectroscopy (NIRS) has been the most rapidly developing and noticeable spectrographic analytical technique in recent years. The determining principle and progresses of near-infrared reflectance spectroscopy are presented briefly. It mainly includes the progresses in pre-processing technique aNear-infrared reflectance spectroscopy (NIRS) has been the most rapidly developing and noticeable spectrographic analytical technique in recent years. The determining principle and progresses of near-infrared reflectance spectroscopy are presented briefly. It mainly includes the progresses in pre-processing technique and analyzing model of near-infrared reflectance spectroscopy. Two pre-processing techniques, including differential coefficient-dealt with technique, the signal-smoothing technique, and four analyzing models of near-infrared spectroscopy, including the multiplied lined regression (MLR), principal component analysis (PCA), partial least squares (PLS), and artificial nerve network (ANN). The application of near-infrared reflectance spectroscopy to the first time. The investigation of reviewed papers shows that the near- infrared reflectance spectroscopy is widely applied in feed analysis and animal products analysis because of its rapidness, non-destruction and non-pollution. The near infrared reflectance spectroscopy has been used to determine the feed common ingredient, such as dry matter, crude protein, crude fiber, crude fat and so on, micro-components including amino acid， vitamin, and noxious components, and to determine the physical and chemical properties of animal products which including egg, mutton, beef and pork. Details of the analytical characteristics of feed and animal products described in the reviewed papers are given. New trends and limits to the application of near-infrared reflectance spectroscopy in these fields are also discussed.Application.
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1482 (2010)
Study on Rapid Determination of Active Ingredient of Agrochemicals by Near-Infrared Spectroscopy
XIONG Yan-mei, DUAN Yun-qing, WANG Dong, DUAN Jia, and MIN Shun-geng
The main problem of disqualification of the agrochemicals is the insufficiency and abuse of its active ingredient, but lacking of the rapid and on the site analysis method. In the present thesis, the content of haloxyfop-r-methyl in the emulsifiable concentration was analyzed quantitatively by the FT-NIR spectroscopy cThe main problem of disqualification of the agrochemicals is the insufficiency and abuse of its active ingredient, but lacking of the rapid and on the site analysis method. In the present thesis, the content of haloxyfop-r-methyl in the emulsifiable concentration was analyzed quantitatively by the FT-NIR spectroscopy combined with partial least square (PLS) method. The calibration models of haloxyfop-r-methyl were developed, the determination coefficients (R2) of the calibration models were no less than 0.999 9, the SEC were less than 0.019, and the SEP were less than 0.030. Meanwhile, the factors affecting the calibration model were studied and the validation was done by the actual sample. The result indicated that the method of near-infrared spectroscopy can predict the content of the active ingredient in emulsifiable concentration accurately; while the resolution of the instrument and the content of addition agent will not affect the prediction precision of the calibration model remarkably. Therefore, it is a feasible, convenient and quick method to analyze the active ingredient in the commodity agrochemicals by near-infrared spectroscopy, which has an important significance in the on-line determination, analysis on site in the enterprise and the rapid quantitative analysis of agrichemicals in the department of quality monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1488 (2010)
Study on Chinese Herb Astragalus Membranceus by FTIR Fingerprint
LI Gui-lan, ZHAO Hui-hui, LIU Yang-qing, ZHAO Ping, PEI Xiao-li, SUN Yu-jing, and TANG Xiang-yuan
The aim of the study is to find new approach to identifing different growth years and different producing areas of astragalus membranceus simply and rapidly. The FTIR spectrometry, which is accurate, simple and efficient and has high resolution, was used to obtain the sample’s FTIR spectrometry. After simple separationThe aim of the study is to find new approach to identifing different growth years and different producing areas of astragalus membranceus simply and rapidly. The FTIR spectrometry, which is accurate, simple and efficient and has high resolution, was used to obtain the sample’s FTIR spectrometry. After simple separation and extraction, the drying powder of the sample was detected. In 22 samples, there were 9 common peaks for identifying the authenticity of astragalus membranceus and 5 different peaks. According to the number, shape, and relative intensity of the peak, different growth years and different producing areas of astragalus membranceus can be distinguished. Conclusion: It is convenient and fast to identify different growth years and different producing areas of astragalus membranceus by FTIR fingerprint..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1493 (2010)
Study on the Prediction of Soil Heavy Metal Elements Content Based on Mid-Infrared Diffuse Reflectance Spectra
WU Deng-wei, WU Yun-zhao, and MA Hong-rui
The present paper analyzed the possibility of mid-infrared diffuse reflectance spectra for quick assessment of heavy metal element content in soil quickly. Soil samples were collected from Jiangning District and Baguazhou Island, and the numbers of sample were 103 and 58 separately. Jiangning District samples were usedThe present paper analyzed the possibility of mid-infrared diffuse reflectance spectra for quick assessment of heavy metal element content in soil quickly. Soil samples were collected from Jiangning District and Baguazhou Island, and the numbers of sample were 103 and 58 separately. Jiangning District samples were used as calibration set while Baguazhou Island samples as validation set. To assess the utility of different pre-treatment process of MIR spectroscopy for soil heavy metal element content analysis, we used PLSR method to develop the calibration between spectral data and soil elements content. Three spectral pre-treating techniques such as smooth, log(1/N), baseline correction, multiplicative scatter correction were used for promotion of predicting performance. The result showed that the progress of (log-BC-MSC) in turn achieved optimal calibration of MIR spectra and better prediction for ex-situ soils. Though the calibration data were treated by different pre-treating schema, the R2 of the 8 elements followed the same law: Ni>0.8> Cr, Cu, Zn, Pb, Hg>0.6> As, Cd. When we applied these calibrations to Baguazhou Island soils, (log-BC-MSC) treated data results in the smallest RMSEp-BGZ. We used the same calibration method to compare the predictive ability of MIR spectra to VNIR spectra. The R2 of 8 elements developed by VNIR spectral calibration are sometime larger than MIR’s, but after we applied these calibrations to validation set, the RSME of MIR data for prediction of BGZ soil samples is 21% to 73% of VNIR’s. This result showed us that for predicting ex-situ soils, MIR analysis substantially outperformed VNIR. These results indicated that MIR spectra can be used to predict soil heavy metal content quickly and non-destructively..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1498 (2010)
Measurement of Methane and Carbon Dioxide Emissions from Ruminants Based on the NDIR Technique
DING Xue-zhi, LONG Rui-jun, MI Jian-dui, and GUO Xu-sheng
Methane (CH4) production in the rumen represents a loss of energy for the host animal; in addition, methane eructated by ruminants may contribute to a greenhouse effect or global warming. The dinumal CH4 and carbon dioxide (CO2) emissions from sheep were continuously recorded using the flow-through chamber method. A tyMethane (CH4) production in the rumen represents a loss of energy for the host animal; in addition, methane eructated by ruminants may contribute to a greenhouse effect or global warming. The dinumal CH4 and carbon dioxide (CO2) emissions from sheep were continuously recorded using the flow-through chamber method. A type new type of non-disperse infrared (NDIR) gas sensors based on pulse IR source was introduced, and by using the high performance pyroelectric IR sensor with built in interference filter and the “single light and two wavelengths” technology, CH4 and CO2 measurement from ruminants was achieved. Animals were given dry oat hay as the basic diet and supplemented concentrate with the ratio of 7∶3. The results showed that the recovery was 96.7% and 96.2% for CH4 and CO2, respectively. Methane and carbon dioxide output from sheep respectively averaged 15.6 g per day and 184.7 g per day, equivalent to 6.8 and 71.1 kg per animal. Diurnal fluctuations in hourly rates of CH4 and CO2 production in hourly of methane increased during day light to reach a peak at or near sunset and then declined towards sunrise, and consideration was given to the dry matter intake of the animals used in these studies and its possible effects on CH4 production..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1503 (2010)
High Temperature Raman Spectra and Structure Study of Stolzite-Structured PbWO4 Crystals and Its Melt
ZHOU Feng-yu, YOU Jing-lin, WANG Yuan-yuan, and WANG Wei
Raman spectra of stolzite-structured PbWO4 crystal were recorded from 298 to 1 473 K. All the appearing vibrational modes were interpreted and assigned. The most intense mode at 902.7 cm-1, which is identified as the internal mode ν1(Ag)of symmetrical stretching attributed to the vibration of ［WO4］2- tetrahedron. TempeRaman spectra of stolzite-structured PbWO4 crystal were recorded from 298 to 1 473 K. All the appearing vibrational modes were interpreted and assigned. The most intense mode at 902.7 cm-1, which is identified as the internal mode ν1(Ag)of symmetrical stretching attributed to the vibration of ［WO4］2- tetrahedron. Temperature dependent characteristics of the Raman spectra of the crystal were investigated. Band half-widths widened accompanied by the relative intensity decreased, and the lattice became more disorder with the increase in temperature. As being heated up to 1 398 K, PbWO4 crystals began to be melting and have completely transformed to liquid state at 1 473 K, while the internal vibrational modes of isolated ［WO4］2- tetrahedron have appeared and the symmetry of vibrational modes transformed from S4 in crystal into Td of ［WO4］2- in melt. It suggested that the isolated ［WO4］2- structure unit exists in the melt..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1507 (2010)
Raman Micro Spectroscopic Analysis of Relationship between DNA Degradation in Tissue Cells and Postmortem Interval
XIONG Ping, GUO Ping, and ZHANG Jing
The present work is to study the relationship between DNA degradation in tissue cells and estimation of postmortem interval, and to provide a new way for the estimation of postmortem interval(PMI). The tissue cells of kidney and liver in vitro obtained at different time points were kept in a controlled environment. TheThe present work is to study the relationship between DNA degradation in tissue cells and estimation of postmortem interval, and to provide a new way for the estimation of postmortem interval(PMI). The tissue cells of kidney and liver in vitro obtained at different time points were kept in a controlled environment. The kidney tissue and liver tissue were taken out every 4 h， during 48-72 h after death at 25 ℃. The DNA content in different tissue cells was examined by means of confocal Raman micro spectroscopy with an excitation wavelength of 532 nm. Results show that the relative peak intensities (I1 094/I2 923) of confocal Raman microscopy for the tissue cells decreased gradually with the prolongation of postmortem interval from 48 to 72 h after death, while the peak intensity at 1 094 cm-1 was reduced obviously; and the peak intensity at 1 454 and 2 923 cm-1 did not change significantly. It is concluded that the DNA content in tissue cells decreased gradually with the prolongation of postmortem interval from 48 to 72 h after death. There is a linear relationship between the degradation rate of DNA in the tissue cells and postmortem interval. This investigation shows that Raman micro spectroscopy is useful to the estimation of postmortem interval (PMI)．.
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1511 (2010)
Rapid Estimate of the Depth of Single Point Fluorescence Source for Fluorescence Molecular Tomography
CHEN Yan-ping, and BAI Jing
Fluorescence molecular tomography (FMT) supports monitoring molecular events non-invasively in vivo over a span of long time, and meets the demands of monitoring a process of life. Priori information can be applied to speed the complex and time-consuming reconstruction process and to enhance the quality of the reconstrFluorescence molecular tomography (FMT) supports monitoring molecular events non-invasively in vivo over a span of long time, and meets the demands of monitoring a process of life. Priori information can be applied to speed the complex and time-consuming reconstruction process and to enhance the quality of the reconstructed images for FMT. A method was proposed in the present paper to estimate rapidly the depth of fluorescence source. The estimation process was accomplished with an optimization algorithm, particle swarm optimization (PSO). Firstly the fluorescence intensity ratio Rf of two positions on the boundary of tissue was derived under extrapolated boundary condition and a diffusion model for the propagation of near-infrared photons in biological tissue. Then a PSO algorithm was applied to minimize the difference between the theoretical ratio RTf and the measured ratio RMf. The depth of fluorescence source was estimated after the rapid PSO optimization process. Two phantoms indicated that the proposed method can estimate the depth of single fluorescence source rapidly and easily without the time-consuming mesh generation and reconstruction process..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1516 (2010)
A Fluorescent-Probe Detecting CYP2C9*3 DNA
LI Qing-yong, QU Zhen-huan, ZU Yuan-gang, and FU Yu-jie
The mismatched CYP2C9*3 DNA was detected by a exciplex fluorescent-probe system. The exciplex fluorescent-probe model system comprises of two 12-mer oligonucleotides fluorescent-probes, complementary to neighbouring sites of a 24(47) -mer DNA target and plasmid target, each equipped with moieties able to form an exciplThe mismatched CYP2C9*3 DNA was detected by a exciplex fluorescent-probe system. The exciplex fluorescent-probe model system comprises of two 12-mer oligonucleotides fluorescent-probes, complementary to neighbouring sites of a 24(47) -mer DNA target and plasmid target, each equipped with moieties able to form an exciplex on correct, contiguous hybridization. Very similar results were obtained between the 24-mer target and the 47-mer target when WT and MT systems were detected by the exciplex fluorescent-probe. Exciplex bands at 505 nm were found for both 24(47)-mer WT and 24(47)-mer MT-targets at 5 ℃ , but were not distinctive enough to distinguish 24(47)-mer WT-target and 24(47)-mer MT-target. However the experiments were carried out at Tm, the exciplex band disappeared almost completely for 24(47)-mer MT-target system like control system, and there was still a strong exciplex band for the 24(47)-mer WT target system. Exciplex peaks at 505 nm were seen for the WT circular plasmids system, but not for MT circular plasmids. Therefore, mismatches of CYP2C9*3 DNA can be effectively detected by this exciplex construct, giving potential for single nucleotide polymorphism detection..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1520 (2010)
Fluorescence Properties of Lake Water
JIANG Jian-kai, WU Jing, and LIU Xue-hua
Fluorescence spectrum technique has advantages of high sensitivity, high selectivity and quick-and-easy detection, and excitation-emission matrix (EEM) can provide abundant information. Fluorescence spectrum is unique for each water sample and is named as “fluorescence fingerprint”. In the present paper, excitation-emiFluorescence spectrum technique has advantages of high sensitivity, high selectivity and quick-and-easy detection, and excitation-emission matrix (EEM) can provide abundant information. Fluorescence spectrum is unique for each water sample and is named as “fluorescence fingerprint”. In the present paper, excitation-emission matrix was used to study the variability of water quality from spring to winter of two neighboring lakes in an urban park in Beijing. There was typical protein-like and humic-like fluorescence in the EEMs of the two lakes and the intensity of the protein-like fluorescence was significantly stronger. The close relationships between the fluorescence intensities and natural/anthropogenic activities showed that the water quality changed obviously with the season: the water quality in spring and summer was better than in autumn and winter. Natural factor like the growth of algae and plants etc was the major impact factor for the lake for pleasure boats, and anthropogenic factor such as planting was significantly important for the lake with ornamental plants. So the variability of water quality of lake is determined by the function of lake. To remove the remains of algae and plants in spring and autumn benefits the water quality of the lakes..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1525 (2010)
Fluorescence Spectroscopy Characterization of Asphaltene Liquefied from Coal and Study of Its Association Structure
WANG Zhi-cai, CUI Xue-ping, SHUI Heng-fu, WANG Zu-shan, LEI Zhi-ping, and KANG Shi-gang
Structure and association of asphaltenes from coal direct hydroliquefaction were studied by fluorescence spectrometry and UV-Vis absorption spectrometry in this paper. The results indicate that asphaltene is aromatic mixtures mainly containing naphthalene nucleus and shows strong fluorescent characteristic. The formingStructure and association of asphaltenes from coal direct hydroliquefaction were studied by fluorescence spectrometry and UV-Vis absorption spectrometry in this paper. The results indicate that asphaltene is aromatic mixtures mainly containing naphthalene nucleus and shows strong fluorescent characteristic. The forming of exciplex between asphaltene and solvent results in the red shift of fluorescence peak and fluorescence quenching of asphaltene that increases with the polarity and electron acceptability. The self-aggregation of asphaltene is formed by non-covalent bond interaction, so that the asphaltene liquefied at higher temperture that shows high aromaticity has stronger association than that liquefied at lower temperature. Aggregation of asphaltene has been found to be a gradual process, in which there is no critical aggregation constant observed, and the inflection point of the plot of apparent fluorescence intensity as a function of asphaltene concentration varies with the excitation wavelength..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1530 (2010)
Spectral Properties and Energy Transfer of Ce3+ and Tb3+ Ions Co-Doped Ca2SrAl2O6 Phosphor
LI Xu, GUAN Li, LIU Chong, YANG Zhi-ping, and GUO Qing-lin
Ce3+, Tb3+ co-doped green phosphor Ca2SrAl2O6 was synthesized by solid state method and its excitation and emission spectra were measured and studied. The results showed that the emission spectrum is composed of four groups of narrow bands and the peaks are located at 497, 545, 595 and 623 nm. The strongest emission peCe3+, Tb3+ co-doped green phosphor Ca2SrAl2O6 was synthesized by solid state method and its excitation and emission spectra were measured and studied. The results showed that the emission spectrum is composed of four groups of narrow bands and the peaks are located at 497, 545, 595 and 623 nm. The strongest emission peak islocated at 545 nm and chromaticity coordinate (x, y) is (0.300 5, 0.500 2) at 4 mol% Ce3+ and Tb3+ doping, which indicate that Ca2SrAl2O6∶Ce3+, Tb3+ was a good green phosphor. The excitation spectrum for 545 nm was in the region of 320-400 nm, which indicated that this phosphor could be effectively excited by UVLED. Duo to the overlap of the Ce3+ emission bands and the Tb3+ excitation bands, the energy transfer between Ce3+ and Tb3+ is expected to be very efficient. The emission intensity of co-doped Ca2SrAl2O6 phosphor was stronger than that of Tb3+ doped phosphor. The luminescence intensity reached the maximum when the concentration of Ce3+ and Tb3+ was 4 mol%..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1535 (2010)
Fluorescence Excitation-Emission Matrix Spectroscopy of CDOM from Yundang Lagoon and Its Indication for Organic Pollution
ZHUO Jian-fu, GUO Wei-dong, DENG Xun, ZHANG Zhi-ying, XU Jing, and HUANG Ling-feng
Fluorescence excitation-emission matrix spectroscopy (EEMs) combined with absorption spectroscopy were applied to study the optical properties of CDOM samples from highly-polluted Yundang Lagoon in Xiamen in order to demonstrate the feasibility of using these spectral properties as a tracer of the degree of organic polFluorescence excitation-emission matrix spectroscopy (EEMs) combined with absorption spectroscopy were applied to study the optical properties of CDOM samples from highly-polluted Yundang Lagoon in Xiamen in order to demonstrate the feasibility of using these spectral properties as a tracer of the degree of organic pollution in similar polluted coastal waters. Surface water samples were collected from 13 stations 4 times during April and May, 2008. Parallel factor analysis (PARAFAC) model was used to resolve the EEMs of CDOM. Five separate fluorescent components were identified, including two humic-like components (C1: 240, 325/422 nm; C5: 260, 380/474 nm), two protein-like components (C2: 225, 275/350 nm; C4: 240, 300/354 nm) and one xenobiotic-like component (C3: 225/342 nm), which could be used as a good tracer for the input of the anthropogenic organic pollutants. The concentrations of component C3 and dissolved organic carbon (DOC) are much higher near the inlet of sewage discharge, demonstrating that the discharge of surrounding sewage is a major source of organic pollutants in Yundang Lagoon. CDOM absorption coefficient a(280) and the score of humic-like component C1 showed significant linear relationships with CODMn, and a strong positive correlation was also found between the score of protein-like component C2 and BOD5. This suggested that the optical properties of CDOM may provide a fast in-situ way to monitor the variation of the water quality in Yundang Lagoon and that of similar polluted coastal waters..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1539 (2010)
Fluorescence Research on Reaction Mechanism of Nucleic Acid with Small Organic Molecules
ZHANG Nuo, WU Dan, HAN Yan-yan, CAI Yan-yan, LI Ru, ZHAO Yan-fang, and WEI Qin
The interaction mechanism of nucleic acid with small organic molecules plays an important role in the recognition of the structure and function of nucleic acids, which can also reveal the biological function of nucleic acids and the mechanism of some drugs. Research on the interaction between nucleic acid and small orgThe interaction mechanism of nucleic acid with small organic molecules plays an important role in the recognition of the structure and function of nucleic acids, which can also reveal the biological function of nucleic acids and the mechanism of some drugs. Research on the interaction between nucleic acid and small organic molecules plays an important part in simulating the life process and exploring the essence of life. In the present article, detailed description of the fluorescence spectroscopy research methods used in this field is presented. The fluorescence quenching types of the interaction between nucleic acid and small organic molecules(including dyes and drugs)are discussed. There are many factors influencing the fluorescence quenching type, including the temperature, the rate constant of bimolecular quenching process, the fluorescence lifetime, changes of the absorption spectra and so on. So according to different affecting factors, the fluorescence quenching type can be determined based on corresponding theories. Many different kinds of calculation methods are also summarized, including the calculations of the binding constant, the distance between fluorescence donor and receptor, the interaction force type and the binding mode of nucleic acid with small organic molecules. Furthermore, the formation constant of nucleic acid with small organic molecules is studied with different binding numbers. These conclusions have guiding significance for studying the interaction between nucleic acid and small organic molecules. These results can also provide guidance for the development of new nucleic acid probe, and the design of new drug molecules, of which nucleic acid is the important target..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1545 (2010)
Experimental Studies on Three-Dimensional Fluorescence Spectral of Mineral Oil in Ethanol
XIAO Xue, ZHANG Yu-jun, WANG Zhi-gang, JIN Dan, YIN Gao-fang, ZHAO Nan-jing, and LIU Wen-qing
Three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy was applied to characterize the mineral oil in ethanol. In the paper, a simple way of treating the first-order Rayleigh, Raman and second-order Rayleigh scatter is used involving subtracting an EEM of a solvent blank, and removing and replacinThree-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy was applied to characterize the mineral oil in ethanol. In the paper, a simple way of treating the first-order Rayleigh, Raman and second-order Rayleigh scatter is used involving subtracting an EEM of a solvent blank, and removing and replacing the values with zeros. The corrected results showed that the characteristic three-dimensional fluorescence spectra of mineral oil were as follows: there was one mainly peak in the fluorescence spectrum of the kerosene, and the peak was identified at excitation/emission wavelengths (Ex/Em) of 270/290 nm; there were two intense fluorescence peaks in the fluorescence spectrum of 0# diesel, located at (Ex/Em) of 240/344 nm and 270/362 nm respectively; there were several fluorescence peaks in the fluorescence spectrum of lubricating oil, with the two intense peaks located at (Ex/Em) of 240/348 nm and 258/358 nm respectively. Furthermore, the relation between the relative fluorescence intensity and the concentration of mineral oil was studied, and the sensitivity and the limitation of detection of the method were also analyzed. The results of this study show that the method of three-dimensional fluorescence can be used to detect the low concentration of oil..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1549 (2010)
Quantitative Fluorescence Characterization of Organic Matter Stability during Chicken Manure Composting
ZHAO Yue, HE Xiao-song, XI Bei-dou, YU Hui-bin, WEI Zi-min, LI Ming-xiao, and WANG Wei
Due to its high sensitivity, good selectivity and nondestructive nature, fluorescence spectroscopy was widely applied to characterize the nature of dissolved organic matter (DOM) from different source since the last decade. In the present study, dissolved organic matter (DOM) extracted from chicken manure samples durinDue to its high sensitivity, good selectivity and nondestructive nature, fluorescence spectroscopy was widely applied to characterize the nature of dissolved organic matter (DOM) from different source since the last decade. In the present study, dissolved organic matter (DOM) extracted from chicken manure samples during composting progress was quantitatively characterized by fluorescence analysis techniques and mathematical analysis methods. The results showed that, the ratio between the fluorescence intensities at 330 nm (humic-like matter) and 280 nm(protein-like matter) (I330/I280) in synchronous-scan excitation mode spectra, the area of a fluorescence spectrum obtained by excitation at the blue wavelength of 465 nm(A470-640), and the ratio between the area of the last quarter (435-480 nm) and the area of the first quarter (300-345 nm) of the emission spectrum (A435-480 nm/A300-345 nm) by exciting the sample with ultraviolet radiation of 240 nm, all increased during composting, and the humification degree of compost increased as well. Three-dimensional excitation emission matrix fluorescence spectroscopy showed that the intensity of protein-like matter decreased during composting progress and diminished at the end, while that of fulvic-like matter increased all the time. The ratio between the intensity of the ultraviolet fulvic-like fluorescence (Peak A) and that of the visible fulvic-like fluorescence r(A, C) showed an overall significant downward trend during composting, but fluctuated in the progress. The correlation analysis showed that, I330/I280, A470-640 and A435-480 nm/A300-345 nm were all significant correlative, while r(A, C) was not correlative with the above-mentioned three parameters at 0.05 level due to effect by other factors, The results show that, I330/I280, A470-640 and A435-480 nm/A300-345 nm can be effectively used in the process of the evaluation of humification degree during composting..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1555 (2010)
A Study of Developing Fingermarks by Nano-Titanium Dioxide Shielding Ultraviolet-Ray
WANG Yong-gang, YANG Rui-qin, and WANG Yan-ji
In view of the difficulty in developing fingermarks on the color or strong fluorescence surface, the present paper reported a novel method to develop fingermark by shielding ultraviolet-ray. Nano-titanium dioxide with rutile phase had extremely high shielding ability of ultraviolet-ray. The TEM indicatedthat the averagIn view of the difficulty in developing fingermarks on the color or strong fluorescence surface, the present paper reported a novel method to develop fingermark by shielding ultraviolet-ray. Nano-titanium dioxide with rutile phase had extremely high shielding ability of ultraviolet-ray. The TEM indicatedthat the average particle size of rutile titanium dioxide in experiment was about 30 nm, and they were mostly sphericity. The UV-Vis spectra indicatedthat the rutile nanoparticles shield UV with wavelength less than 400 nm. The rutile nanoparticles were physically adsorbed on the ridges of fingermarks on the color or strong fluorescence surface adequately and were not or a little adsorbed on the object surface by dusting or shaking. The ridges of the developed fingermarks were dark and the background was light under irradiation of 365 nm. We could obtain good images, and the contrast of lightness between the ridge and the background was obvious. In contrast to traditional developing technique-superglue fuming-Rhodamine 6G (or BBD) dyeing strengthening technique, the effect of nano-titanium dioxide shielding ultraviolet-ray detection technique was better. By the new detection technique，the ridges of the developed fingermarks were smooth and the detail characteristics of the developed fingermarkes were clear. The research results indicatethat the nano-titanium dioxide particle is an effective and convenient developer of fingermark on the color or strong-fluorescence or color-strong fluorescence surface under irradiation of 365 nm with its shielding ultraviolet-ray property. Especially, the developer also has quite satisfactory effect on old fingermarks on the non-porous objects in contrast to traditional methods. The new detection technique is convenient, efficient, fast, and economical and has a wide application foreground in the field of fingermark developing..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1561 (2010)
UV/Visible Spectroscopic Study of the β-Diketonate Zirconium Active Species for Olefin Polymerization
YANG Min, WANG Lu-hai, LIU Pan-ge, REN He-gang, LIU Bin-yuan, and YAN Wei-dong
The method of UV/Visible absorption spectroscopy for olefin catalytic system was introduced in this paper, whose testing condition was much closer to the polymerization conditions. The actions of olefin polymerization catalyst (dbm)2ZrCl2 with cocatalyst AlEt2Cl (or MAO) were investigated by UV/visible absorption spectThe method of UV/Visible absorption spectroscopy for olefin catalytic system was introduced in this paper, whose testing condition was much closer to the polymerization conditions. The actions of olefin polymerization catalyst (dbm)2ZrCl2 with cocatalyst AlEt2Cl (or MAO) were investigated by UV/visible absorption spectroscopy at atmosphere temperature. It was shown that the UV/Visible main absorption band of the zirconocenium, which can be related to the ligand to metal charge transfer bands (LMCT), varies greatly upon incremental addition of AlEt2Cl or MAO. For the low molar ratios of Al/Zr in the catalytic system, there was the substitution of an electron withdrawing chlorine atom by a donating alkyl group. Then a hypsochromic shift of the initial catalyst absorption band, corresponding to the monomethylation of the catalyst, was observed in each catalytic system (dbm)2ZrCl2/AlEt2Cl (or (dbm)2ZrCl2/MAO). On the contrary, further addition of AlEt2Cl (or MAO) was accompanied by a continuous bathochromic shift of the maximal wavelength, which corresponding to the formation of more dissociated ionic active species. Then, there would be a coordination of monomer to the ionic active species..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1566 (2010)
Vegetation Change of Yamzho Yumco Basin in Southern Tibet Based on SPOT-VGT NDVI
YU Shu-mei, LIU Jing-shi, and YUAN Jin-guo
The area we studied is Lake Yamzho Yumco Basin (28°27′-29°12′N, 90°08′-91°45′E), the largest inland lake basin in southern Tibetan Plateau, China. Using the SPOT-VGT NDVI vegetation index from 1998 to 2007 in the basin, the temporal and spatial variation characteristics of NDVI and its correlation wThe area we studied is Lake Yamzho Yumco Basin (28°27′-29°12′N, 90°08′-91°45′E), the largest inland lake basin in southern Tibetan Plateau, China. Using the SPOT-VGT NDVI vegetation index from 1998 to 2007 in the basin, the temporal and spatial variation characteristics of NDVI and its correlation with the major climatic factors (air temperature, precipitation) were analyzed. The results show that the average NDVI of the lake basin ranges from 0.12 to 0.31 and its seasonal change is obvious; the NDVI begins to rise rapidly in May and reaches the maximum value in early September. The average NDVI of the basin shows the slow increasing trend during 1998 to 2007, and it indicates that the eco-environment of the basin is recovering. The high value of NDVI has close relationships with water supply, altitude and vegetation types, so NDVI is relatively high near water sources and is the highest in meadow grassland. The summer air temperature and precipitation are the important climate elements that influence the vegetation in the basin, and the linear correlation coefficients between NDVI and air temperature and precipitation are 0.7 and 0.71, respectively. In recent years, warm and humid trend of the local climate is prevailing to improve the ecological environment in YamzhoYumco Basin..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1570 (2010)
Evaluation of Complex Diet Dry Matter Digestibility of Sheep Using Spectra Difference
WANG Hai, ZHANG Ying-jun, LIN Li-jun, SHU Bin, NA Ri-su, WANG Ning, and QIN Yan
The present study aimed to predict the dry matter digestibility (DMD) of animals fed complex diet using the spectra difference between diets and feces by near infrared reflectance spectroscopy (NIRS). Four indoor experiments were carried out with artificial mixed complex diets in the state field observatory stations loThe present study aimed to predict the dry matter digestibility (DMD) of animals fed complex diet using the spectra difference between diets and feces by near infrared reflectance spectroscopy (NIRS). Four indoor experiments were carried out with artificial mixed complex diets in the state field observatory stations located at Hebei province. The sheep were used as tested animals. One hundred and four parts of “diet-feces” were obtained and divided into a calibration sample set (70 samples) and a validation sample set (34 samples). The spectra difference between diets and feces, and the partial least square (PLS) were used to calibrate the models of DMD of sheep. The results indicated that the optimum range of spectrum was 8 656-4 310 cm-1. The optimum proceeding method was multivariate scattering correction + first derivative + Norris smoothing. The optimum number of factors was 7. The root mean square error of prediction (RMSEP) was 2.46%, and the RPD value of validation was above 2.5. The coefficient of correlation between the actual and predicted DMD using the NIRS was 0.8339, indicating that the NIRS could be used to evaluate dry matter digestibility of sheep fed complex diets..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1575 (2010)
Monitoring of Winter Wheat Stripe Rust Based on the Spectral Knowledge Base for TM Images
ZHANG Jing-cheng, LI Jian-yuan, YANG Gui-jun, HUANG Wen-jiang, LUO Ju-hua, and WANG Ji-hua
In most cases, the reversion model for monitoring the severity degree of stripe rust based on the hyperspectral information can not be directly applied by the satellite images with relatively broad bandwidth, while the airborne hyperspectral images can not be applied for large-scale monitoring either, due to the scale In most cases, the reversion model for monitoring the severity degree of stripe rust based on the hyperspectral information can not be directly applied by the satellite images with relatively broad bandwidth, while the airborne hyperspectral images can not be applied for large-scale monitoring either, due to the scale limitation of its data and high cost. For resolving this dilemma, we developed a monitoring method based on PHI images, which relies on the construction of spectral knowledge base of winter wheat stripe rust. Three PHI images corresponding to the winter wheat experimental field that included different severity degree of stripe rust were used as a medium to establish the spectral knowledge base of relationships between disease index (DI) and the simulated reflectance of TM bands by using the empirical reversion model of DI(%) and the relative spectral response (RSR) function of TM-5 sensor. Based on this, we can monitor and identify the winter wheat stripe rust by matching the spectral information of an untested pixel to the spectral knowledge base via Mahalanobis distance or spectral angle mapping (SAM). The precision of monitoring was validated by simulated TM pixels, while the effectiveness of identification was tested by pixels from TM images. The results showed that the method can provide high precision for monitoring and reasonable accuracy for identification in some certain growth stages of winter wheat. Based on the simulated TM pixels, the model performed best in the pustulation period, yielded a coefficient of determination R2=0.93, while the precision of estimates dropped in the milk stage, and performed worst in the jointing stage, which is basically inappropriate for monitoring. Moreover, by using the pixels from TM images, the infected pixels could be identified accurately in pustulation and milk stages, while failed to be identified in jointing stage. For matching algorithms, the Mahalanobis distance method produced a slightly better result than SAM method..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1579 (2010)
Study on Fault Diagnosis of Power-Shift Steering Transmission Based on Spectrometric Analysis and SVM
ZHANG Ying-feng, MA Biao, ZHANG Jin-le, CHEN Man, FAN Yu-heng, and LI Wen-chang
Spectrometric oil analysis is an important method to study the running state of Power- Shift Steering Transmission (PSST). A method of multiple out least squares support vector regression was developed using spectrometric oil analysis data and SVM(Support Vector Machine). The spectrometric oil analysis data were studieSpectrometric oil analysis is an important method to study the running state of Power- Shift Steering Transmission (PSST). A method of multiple out least squares support vector regression was developed using spectrometric oil analysis data and SVM(Support Vector Machine). The spectrometric oil analysis data were studied using multiple out least squares support vector regression. It has been proved that the regression data are good in approximation effect for No.1 PSST. And the predictive values for No.2 PSST are highly veracious with the test data. The fault information was found and the fault position was determined through comparative analysis. This method has been proved to have practice significance for finding fault-hidden dangers and judging fault positions..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1586 (2010)
Standardization of Technical Methods for Apple Florescence Canopy Spectral Detection
ZHU Xi-cun, ZHAO Geng-xing, LEI Tong, WANG Ling, DONG Fang, and WANG Jing-an
Aiming at spectral detection of apple florescence canopy, the present paper carried out spectral detection tests under different weather conditions, different detection times, and different detection heights and angles to apple canopy in the two years of 2008 and 2009, so as to analyze impacts of these factors on appleAiming at spectral detection of apple florescence canopy, the present paper carried out spectral detection tests under different weather conditions, different detection times, and different detection heights and angles to apple canopy in the two years of 2008 and 2009, so as to analyze impacts of these factors on apple canopy spectral characteristics and explore standardized spectral detection methods for apple florescence canopy. The results indicated the regularity in spectral reflectance of apple florescence canopy to a certain degree under different conditions, especially in the 760-1 350 nm near-infrared bands. The authors found that canopy spectral reflectance declined along with the decrease in sunshine and it is appropriate to detect canopy spectrum in sunny days with few clouds. In addition, spectral reflectance tended to be stable when the wind scale was below grade 2. The discrepancy of canopy spectra is small during the time period from 10:00 to 15:00 of a day compared to that of other times. For maintaining stable spectral curves, the height of detector to apple canopy needed to be adjusted to cover the whole canopy within the field of view according to detection angle of the detector. The vertical or approximately vertical detection was the best for canopy spectral reflectance acquisition. The standardization of technical methods of spectral detection for apple florescence canopy was proposed accordingly, which provided theoretical references for spectral detection and information extraction of apple tree canopy..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1591 (2010)
Spectral Analysis of Cyanobacteria Chlorophyll in Polluted Wate
ZHAO Zhi-min, HONG Xiao-qin, LI Peng, and JIN Xiao-dong
he polluted water with abundant nourishment cause phytoplankton, such as cyanobacteria, to grow rapidly, which brings great harm to environment. In the present paper, the absorption spectrum of cyanobacteria was measured and analyzed in order to estimate the content of the chlorophyll accurately. The same amount of cyahe polluted water with abundant nourishment cause phytoplankton, such as cyanobacteria, to grow rapidly, which brings great harm to environment. In the present paper, the absorption spectrum of cyanobacteria was measured and analyzed in order to estimate the content of the chlorophyll accurately. The same amount of cyanobacteria was separately cultured in pure water and lake water for different time. The chlorophyll was extracted from the cyanobacteria for the same time by 95% of ethanol. Then the ethanol extract was tested by ultraviolet visible spectrometry. The results show that the absorption spectrum of the chlorophyll has three absorption peaks at 279.5， 436.0 and 664.5 nm respectively. However, the absorbency at 279.5 nm cannot reflect the content of the chlorophyll. The absorbencies at 436.0 and 664.5 nm have linear relationship with the content of chlorophyll. Moreover, the dispersion between the absorbency at 436.0 nm and the absorbency at 664.5 nm can reflect the content of chlorophyll more accurately. The research provides the experimental and theoretical basis for the highly accurate detection of the water quality..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1596 (2010)
Analysis of Directional Characteristics of Winter Wheat Canopy Spectra
ZHANG Xue-hong, TIAN Qing-jiu, and SHEN Run-ping
The bidirectional reflectance factors vary as the incidence directions and the view angles change. At present the remote sensing is almost at nadir, therefore it is possible to improve the accuracy of remote sensing application by reasonably selecting the looking angle, solar zenith angle, and so on. Based on the multiThe bidirectional reflectance factors vary as the incidence directions and the view angles change. At present the remote sensing is almost at nadir, therefore it is possible to improve the accuracy of remote sensing application by reasonably selecting the looking angle, solar zenith angle, and so on. Based on the multidirectional spectra of winter wheat canopy at several critical growth stages, the paper quantitatively analyzed the sensitivity of narrowband bidirectional reflectance to view planes, view zenith angle, solar zenith angle, growth stage, and band by using anisotropy factor (ANIF) and anisotropy index (ANIX). The change of NDVI with view zenith angle, solar zenith angle and growth stage was also studied. The results show that the anisotropy characteristics of bidirectional reflectance factors at solar principal plane was stronger than that at the other planes, and orthogonal principal plane was the weakest. The ANIX at solar principal plane was the biggest. The reason was that the shadow of canopy changed more dramatically at solar principal plane than at the other planes. The sensitivity of bidirectional reflectance factor at visible bands to zenith angles was stronger than in near infrared regions, the reason for which was that the shadow effect in visible regions was stronger than in near infrared regions. The ANIX in visible regions was bigger than in near infrared regions. The sensitivity of bidirectional reflectance factor to solar zenith angles increased as the view zenith angle increased. The NDVIs at every looking zenith angle all increased with the leaf area index increasing. The NDVIs at forward direction were larger than at backward direction, which resulted from that the shadow effect in visible regions was stronger than in near infrared regions. The solar principal plane implies rich internal structure information on object. In order to reduce the uncertainty from the observing method, the near infrared bands and small solar zenith angle should be chosen. The retrieve of structure parameters ought to select solar principal plane, and avoid hot spot region when inversing biological parameters using NDVI..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1600 (2010)
Synthesis and Spectroscopic Study of Polyamine-Type Cellulose-Based Chelating Fiber
HUANG Jun, ZHAI Hua-min, and WANG Xiao-jun
The graft copolymer (CPGMA) made from bleached chemical eucalyptus pulp (BCEP) and glycidyl methacrylate (GMA) was reacted with ethylenediamine (EDA) to synthesize the polyamine-type cellulose-based chelating fiber CPGMA-EDA. The chelating fiber was characterized by means of Fourier transform infrared spectroscopy (FTIThe graft copolymer (CPGMA) made from bleached chemical eucalyptus pulp (BCEP) and glycidyl methacrylate (GMA) was reacted with ethylenediamine (EDA) to synthesize the polyamine-type cellulose-based chelating fiber CPGMA-EDA. The chelating fiber was characterized by means of Fourier transform infrared spectroscopy (FTIR), 13C cross polarization magic angle spinning NMR spectra (13C CP/MAS NMR) and X-ray diffraction (XRD). The results of FTIR and 13C CP/MAS NMR show that the characteristic absorption peak (904 cm-1) of epoxy group in CPGMA disappeared, and the absorption peak around 3 200-3 500 cm-1 broadened due to the vibration of new formed N—H bond while the CPGMA reacted with EDA. Both of these indicate that amino group was grafted onto CPGMA through the ring-opening reaction. The XRD results indicate that the crystallinity of CPGMA-EDA was 48.1%, and decreased by 31.1% compared to that of BECP, indicating that the reaction not only takes place in the noncrystal regions, but also in the crystal regions of cellulose..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1606 (2010)
Design and Application of Hyperspectral Radiation System for Sea Ice Observation
YANG Yue-zhong, XU Zhan-tang, SUN Zhao-hua, CAO Wen-xi, and LU Gui-xin
Sea ice plays an important role in the global climate system. In the present article, a hyperspectral radiation system for the observation of optical properties of sea ice was designed. The system consists of three optical channels, which can operate simultaneously. Two kinds of optical detectors were designed, and theSea ice plays an important role in the global climate system. In the present article, a hyperspectral radiation system for the observation of optical properties of sea ice was designed. The system consists of three optical channels, which can operate simultaneously. Two kinds of optical detectors were designed, and the problem relevant to the water-tightness was resolved. The system can be used to measure the solar radiation beneath the sea ice by an “L” bracket. Another bracket for detecting bidirectional reflectance was designed, which can fix the optical detector at any angle ranging over 0-180 measured with an angle detector. In order to make a most suitable and automatic integrated time, the system can adjust the integrated time intelligently by itself. The system can work stably under extremely low temperature. Furthermore, the system was equipped with four thermistors and one GPS. The system was validated showing a good stability and veracity in situ in the Liaodong Bay..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1610 (2010)
Using the Distance between Hyperspectral Red Edge Position and Yellow Edge Position to Identify Wheat Yellow Rust Disease
JIANG Jin-bao, CHEN Yun-hao, and HUANG Wen-jiang
The objective of the present paper is to identify healthy wheat and disease wheat by using hyeprspectral remote sensing as soon as possible. The canopy spectral reflectance of winter wheat infected by different severity yellow rust was measured and the disease indices (DI) were investigated in the field respectively. SThe objective of the present paper is to identify healthy wheat and disease wheat by using hyeprspectral remote sensing as soon as possible. The canopy spectral reflectance of winter wheat infected by different severity yellow rust was measured and the disease indices (DI) were investigated in the field respectively. Smoothing the canopy spectra and calculating the first derivative values, the two methods were used to calculate the red edge position (REP) and yellow edge position (YEP) of the first derivative values: (a) maximum of the first derivative value; (b) Cho and Skidmore method. The result showed that REP gradually shifted to short-wave band, and the YEP gradually shifted to long-wave band with disease severity increasing, however, REP-YEP quickly became smaller. Analyzing and comparing the prediction precision of REP, YEP and REP-YEP for DI, the result indicated that the model REP-YEP as variable has the best estimation precision for DI than REP and YEP, the model estimation error is 6.22, and relative error is 14.3%, and it could identify healthy and disease wheat 12 days before the disease symptom apparently appeared. Therefore, this study not only can provide theory and technology for large areas monitoring of wheat disease by using hyperspectral remote sensing in the future, but also has the important meaning and practical application value for implementing precision agriculture..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1614 (2010)
Special Decorrelation Technique Used for DWT-Based Hyperspectral Image Compression
CHEN Lei, ZHANG Xiao-lin, LIU Rong-ke, and LEI Zhi-dong
Hyperspectral images are massive data consisting of hundreds of spectral bands and have been used in a large number of applications. With growth of spectral resolution and spatial resolution of hyperspectral data， data size increases rapidly. How to effectively compress hyperspectral image becomes a key problem that afHyperspectral images are massive data consisting of hundreds of spectral bands and have been used in a large number of applications. With growth of spectral resolution and spatial resolution of hyperspectral data， data size increases rapidly. How to effectively compress hyperspectral image becomes a key problem that affects the development and popularization of hyperspectral image. Recently， DWT-based methods have been proved promising for hyperspectral image. But their performances are restricted because it is difficult for them to efficiently take advantage of the various properties of hyperspectral image. For the traditional wavelet transform, the specific properties of hyperspectral images are basically utilized by corresponding to characteristics of wavelet coefficients. So the present paper proposes a new DWT-based method using decorrelation technique according to the spectral characters of hyperspectral image. Block predictive coding is designed to remove the spectral correlation as well as spatial correlation simultaneously and is applied into the DWT-based method. Firstly, hyperspectral image is divided into several image blocks. The bands in a single block possess high spectral correlation. Afterwards, it is deduced that bands of a single block tend to be proportional in altitudes. Bands prediction, which is done in the range of each block respectively, is designed according to this and others characteristics of hyperspectral images. Finally, reference bands of block prediction and the deviation data obtained after block prediction are compressed by 2D-DWT algorithm and 3D-DWT algorithm respectively. Experiment results indicate that compared with the well known techniques the proposed method can significantly improve SNR and PSNR performance, even to 4.2 dB (compared with AT-3DSPIHT algorithm). And the code efficiency at low bit rates is also competitive..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1619 (2010)
An Object-Oriented Remote Sensing Image Segmentation Approach Based on Edge Detection
TAN Yu-min, HUAI Jian-zhu, and TANG Zhong-shi
Satellite sensor technology endorsed better discrimination of various landscape objects. Image segmentation approaches to extracting conceptual objects and patterns hence have been explored and a wide variety of such algorithms abound. To this end, in order to effectively utilize edge and topological information in higSatellite sensor technology endorsed better discrimination of various landscape objects. Image segmentation approaches to extracting conceptual objects and patterns hence have been explored and a wide variety of such algorithms abound. To this end, in order to effectively utilize edge and topological information in high resolution remote sensing imagery, an object-oriented algorithm combining edge detection and region merging is proposed. Susan edge filter is firstly applied to the panchromatic band of Quickbird imagery with spatial resolution of 0.61 m to obtain the edge map. Thanks to the resulting edge map, a two-phrase region-based segmentation method operates on the fusion image from panchromatic and multispectral Quickbird images to get the final partition result. In the first phase, a quad tree grid consisting of squares with sides parallel to the image left and top borders agglomerates the square subsets recursively where the uniform measure is satisfied to derive image object primitives. Before the merger of the second phrase, the contextual and spatial information, (e.g., neighbor relationship, boundary coding) of the resulting squares are retrieved efficiently by means of the quad tree structure. Then a region merging operation is performed with those primitives, during which the criterion for region merging integrates edge map and region-based features. This approach has been tested on the QuickBird images of some site in Sanxia area and the result is compared with those of ENVI Zoom and Definiens. In addition, quantitative evaluation of the quality of segmentation results is also presented. Experiment results demonstrate stable convergence and efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1624 (2010)
Independent Component Analysis for Spectral Unmixing in Hyperspectral Remote Sensing Image
LUO Wen-fei, ZHONG Liang, ZHANG Bing, and GAO Lian-ru
Hyperspectral remote sensing plays an important role in earth observation on land, ocean and atmosphere. A key issue in hyperspectral data exploitation is to extract the spectra of the constituent materials (endmembers) as well as their proportions (fractional abundances) from each measured spectrum of mixed pixel in hHyperspectral remote sensing plays an important role in earth observation on land, ocean and atmosphere. A key issue in hyperspectral data exploitation is to extract the spectra of the constituent materials (endmembers) as well as their proportions (fractional abundances) from each measured spectrum of mixed pixel in hyperspectral remote sensing image, called spectral unmixing. Linear spectral mixture model (LSMM) provides an effective analytical model for spectral unmixing, which assumes that there is a linear relationship among the fractional abundances of the substances within a mixed pixel. To be physically meaningful, LSMM is subject to two constraints: the first constraint requires all abundances to be nonnegative and the second one requires all abundances to be summed to one. Independent component analysis (ICA) has been proposed as an advanced tool to unmix hyperspectral image. However, ICA is based on the assumption of mutually independent sources, which violates the constraint conditions in LSMM. This embarrassment compromises ICA applicability to hyperspectral data. To overcome this problem, the present paper introduces a solution of minimization of total correlation of the components. Interestingly, with the minimization of total correlation of the components, the angle of the direction between each components is invariable. A Parallel oblique-ICA (Pob-ICA) algorithm is proposed to correct the angle of the searching direction between the components. Two novelties result from our proposed Pob-ICA algorithm. First, the algorithm completely satisfies the physical constraint conditions in LSMM and overcomes the limitation of statistical independency assumed by ICA. Second, the last component, which is missed in other existing ICA algorithms, can be estimated by our proposed algorithm. In experiments, Pob-ICA algorithm demonstrates excellent performance in the simulative and real hyperspectral images..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1628 (2010)
Comparisons and Analysis of the Spectral Response Functions’ Difference between FY-2E’s and FY2C’s Split Window Channels
ZHANG Yong, LI Yuan, and RONG Zhi-guo
Remote sensors’ channel spectral response function (SRF) was one of the key factors to influence the quantitative products’ inversion algorithm, accuracy and the geophysical characteristics. Aiming at the adjustments of FY-2E’s split window channels’ SRF, detailed comparisons between the FY-2E and FY-2C corresponding cRemote sensors’ channel spectral response function (SRF) was one of the key factors to influence the quantitative products’ inversion algorithm, accuracy and the geophysical characteristics. Aiming at the adjustments of FY-2E’s split window channels’ SRF, detailed comparisons between the FY-2E and FY-2C corresponding channels’ SRF differences were carried out based on three data collections: the NOAA AVHRR corresponding channels’ calibration look up tables, field measured water surface radiance and atmospheric profiles at Lake Qinghai and radiance calculated from the PLANK function within all dynamic range of FY-2E/C. The results showed that the adjustments of FY-2E’s split window channels’ SRF would result in the spectral range’s movements and influence the inversion algorithms of some ground quantitative products. On the other hand, these adjustments of FY-2E SRFs would increase the brightness temperature differences between FY-2E’s two split window channels within all dynamic range relative to FY-2C’s. This would improve the inversion ability of FY-2E’s split window channels..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1634 (2010)
Progress in Retrieving Vegetation Water Content under Different Vegetation Coverage Condition Based on Remote Sensing Spectral Information
ZHANG Jia-hua, LI Li, and YAO Feng-mei
The present paper reviews the progress in the methods of retrieving vegetation water content using remote sensing spectral information, including vegetation spectral reflectance information (VIR, SWIR, and NIR) to directly extract vegetation water content and establish vegetation water indices (WI), i.e. NDWI=(R860-R1 The present paper reviews the progress in the methods of retrieving vegetation water content using remote sensing spectral information, including vegetation spectral reflectance information (VIR, SWIR, and NIR) to directly extract vegetation water content and establish vegetation water indices (WI), i.e. NDWI=(R860-R1 240)/(R860+R1 240) and PWI=R970/R900; and using radiation transfer (RT) model such as PROSPAIL to detect plant water content information. The authors analyze the method of retrieving vegetation water content under low crop coverage condition. The plant water can be estimated by using canopy physiological parameters firstly, and using vegetation indices and radiation transfer model secondly, which can eliminate soil background effect. The estimated agricultural drought and vegetation water content by using multi-angle polarized reflectance and bi-directional reflectance (BRDF) was discussed in this paper. In the end, the possible development trend of retrieval methods for plant water information under plant low coverage conditions was discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1638 (2010)
The Active Conformation of Allophycocyanin from Spirulina platensis Studied with Spectroscopic Analysis
SHAO Si-mi, SU Hai-nan, ZHANG Xi-ying, PENG Guo-hong, ZHOU Bai-cheng, and ZHANG Yu-zhong
Allophycocyanin (APC) was purified from Spirulina platensis using hydroxylapatite chromatography and ion-exchange chromatography. Effects of solution pH on spectra of APC were studied. APC has an absorption maximum at 650 nm, and a shoulder at 620 nm. The fluorescence emission peak is at 660 nm. The efficiency of energAllophycocyanin (APC) was purified from Spirulina platensis using hydroxylapatite chromatography and ion-exchange chromatography. Effects of solution pH on spectra of APC were studied. APC has an absorption maximum at 650 nm, and a shoulder at 620 nm. The fluorescence emission peak is at 660 nm. The efficiency of energy absorbing and transfer in APC could be reflected by the absorption spectra and fluorescence spectra, respectively. Structural variations of APC could be monitored by means of circular dichroism spectra. APC showed good absorbance and fluorescence stability at varying pH with only minor changes between pH 4-10. The trimeric structure of APC was maintained while local variations of protein peptides were allowed in response to the environmental disturbance. Beyond this pH range, secondary structure as well as overall conformation of APC dramatically changed, and the energy absorption and transfer ability were also disrupted..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1643 (2010)
Decoloration and Degradation of Direct Pink 12B by Microwave-Promoted Heterogeneous Fenton-Like Reaction
ZHENG Huai-li, XIE Li-guo, HU Peng, JIAO Shi-jun, HU Xue-bin, LIU Lan, and WU You-quan
Microwave-promoted heterogeneous Fenton-like reaction, the combination of Fenton-like reagent with microwave, is an efficient method for waste water treatment. In the present paper, the degradation of direct pink 12B (a kind of organic dye) was studied using this method was studied. Through numerous experiments, the inMicrowave-promoted heterogeneous Fenton-like reaction, the combination of Fenton-like reagent with microwave, is an efficient method for waste water treatment. In the present paper, the degradation of direct pink 12B (a kind of organic dye) was studied using this method was studied. Through numerous experiments, the influences of various parameters including the initial pH value, dosage of Fe-Ni-Mn/Al2O3,dosage of H2O2 and microwave were investigated intensively. The characteristic curve of direct pink12B, the concentration-absorbency curve of direct pink12B, the orthogonal optimization tests and comparative tests were given. In this paper, the mechanisms of this reaction were also been probed. It is concluded from the experiments that the microwave can accelerate the process of degradation effectively. Under optimal conditions, the overall color removal was more than 99.0% within 10 min. In the study, all the characterization was carried out using UV-Vis spectral-analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1647 (2010)
on Rapid Detection of Lead by LIBS Based on Common Spectrograph
JIANG Chen-yu, ZHANG Gui-zhong, FU Rao, LU Yin-fei, WANG Miao, and YAO Jian-quan
In the present paper, the lead concentrations of samples including glass, soldering tin and so on were determined by LIBS based on a Nd∶YAG Q-switched pulse laser with wavelength 1 064 nm as an exciting source and CCD in common spectrograph as the detector. The pulse energy on the surface of samples is about 95 mJ and In the present paper, the lead concentrations of samples including glass, soldering tin and so on were determined by LIBS based on a Nd∶YAG Q-switched pulse laser with wavelength 1 064 nm as an exciting source and CCD in common spectrograph as the detector. The pulse energy on the surface of samples is about 95 mJ and the pulse width is 12 ns. By the detection of different samples, the detection limit of lead in samples was found to be 0.007 4% and the maximum relative standard deviation of quantitative analysis was about 4.0% based on the LIBS system of the instruments all made in China. The quantitative analysis can be done in two or three minutes and will spend one minute finishing the process by software in the future. The results suggest that the accuracy of determination of lead meets the challenge of quantitative analysis and the CCD can displace the very expensive ICCD as detector. The feasibility and low cost of the method, which uses common spectrometer and CCD to realize the LIBS detection, is proved by the result and our investigation will be beneficial to the LIBS application..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1652 (2010)
Characteristic Study of Plasma Plume Produced by Nanosecond Pulsed Laser Ablation of Silicon Using Optical Emission Spectroscopy
GAO Xun, JIN Ming-xing, DING Da-jun, and LIN Jing-quan
The 355 nm laser pulse from THG (Third Harmonic Generation) of a Q-switched Nd3+∶YAG laser was used to ablate silicon mounted in air. The time-and space-resolved optical emission spectra were measured for different pulse energy in the wavelength range of 380-420 nm, the emission spectra of N+ was found for impact ionizThe 355 nm laser pulse from THG (Third Harmonic Generation) of a Q-switched Nd3+∶YAG laser was used to ablate silicon mounted in air. The time-and space-resolved optical emission spectra were measured for different pulse energy in the wavelength range of 380-420 nm, the emission spectra of N+ was found for impact ionization of air near target surface on the early stage of plasma plume expansion. Under the model of local thermodynamic equilibrium, the electronic temperature of plasma was deduced to be in the range of 18 000-40 000 K using the Saha equation by the relative line intensities, and the electron density was deduced to be in the 1017 cm-3 scale by FWHM (the full width at half maximum) of Si spectral lines, the temporal and spatial evolution of the electronic temperature and electron density was given, showing that the electronic temperature and electron density exhibited second order exponential decreasing with laser delay time and a Lorentz distribution in space. The reason for the spatial position deviation of the maximum electron density from the maximum spectral intensity was analyzed. The relationship between the plasma plume parameters and laser pulse energy was discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1657 (2010)
Application of AAS to Detecting the Influence of Railway on the Soil of Navel Orange Garden
LIU Hao, CHEN Li-ping, AI Ying-wei, PEI Juan, LI Wei, ZHOU Nan-hua, and GUO Cong
Railway transportation has boosted the economy of railway road area, meanwhile it brings some undesirable impacts on the environment of the railway road area. The quality of the fruits is directly related with the elements of the soil, so understanding the element contents of soil in navel oranges garden in the vicinitRailway transportation has boosted the economy of railway road area, meanwhile it brings some undesirable impacts on the environment of the railway road area. The quality of the fruits is directly related with the elements of the soil, so understanding the element contents of soil in navel oranges garden in the vicinity of railway is meaningful to the security of agriculture products and ecological conditions in the areas surrounding the railways. As a favorite fruit, navel orange is widely planted around the railway in the south China, especially in Sichuan, Chongqing, Hubei, Jiangxi and Guizhou. The present paper studied the contents of Pb, Cd, Mn, Cu, Zn etc in the soil planting navel orange in the vicinity of Chengdu-Dazhou railway by AAS. The railway was built in 1997 and the research area was sited in Jintang county, Sichuan. The results showed that the contents of Pb and Mn in soil planting navel orange were significantly higher than those in the control soil, but the contents of Cd, Cu and Zn showed no significant difference..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1663 (2010)
Studies on Cold Resistance of Hazel Determined and Analyzed by Atomic Absorption Spectrometry
LI Xiu-xia, LIU Cheng-cai, ZHANG Wei-dong, SHAO Hong, WU Heng-mei, WANG Zhong, YANG Yong-nian, and LI Ji-lin
Using annual branch of hazel as the experimental materials, the K+-leakage and relative electric conductivity of three hazel species (six hazel clones) which had been treated with different low temperature were determined by electro-conductivity gauge and atomic absorption spectrometry. Regression models were establishUsing annual branch of hazel as the experimental materials, the K+-leakage and relative electric conductivity of three hazel species (six hazel clones) which had been treated with different low temperature were determined by electro-conductivity gauge and atomic absorption spectrometry. Regression models were established for low temperature to the K+ -leakage or the relative electric conductivity of six hazel clones. The results showed that there was the same result of cold resistance for all clones using the two methods of comprehensive evaluation, and the indicator of K+ -leakage rate determined by atomic absorption spectrometry can be used as a means of early identification of cold resistance of hazel clones. There were obvious differences among the clones in the ability of cold resistance. The order of the ability of cold resistance for the six hazel clones was C7R7＞Z-9-40＞C6R1＞CS2R1＞Z-9-22＞Z-9-30, and the order of the ability of cold resistance for the three hazel species was C. heterophylla ＞C. heterophylla×(C. heterophylla×C. avellana)＞C.heterophylla×C.avellana. The median lethal temperature of tissue for all clones is －26-－40 ℃..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1666 (2010)
Thickness Measurement of Ultrathin SiO2 Layer on Si by Using XPS Standard Curve
ZHAO Zhi-juan, LIU Fen, WANG Hai, ZHAO Liang-zhong, YAN Shou-ke, and SONG Xiao-ping
A new method of standard curve analysis associated with X-ray photoelectron spectroscopy (XPS) is presented for measuring the thickness of ultrathin SiO2 layer on Si substrate. In this method, XPS spectra of series SiO2/Si standard samples with different known thicknesses of silicon oxides are firstly recorded, and theA new method of standard curve analysis associated with X-ray photoelectron spectroscopy (XPS) is presented for measuring the thickness of ultrathin SiO2 layer on Si substrate. In this method, XPS spectra of series SiO2/Si standard samples with different known thicknesses of silicon oxides are firstly recorded, and then the ratios of Si2p peak heights corresponding to SiO2 and Si, viz. R=HSiO2/HSi, are calculated. The known thicknesses of silicon oxides are plotted against the peak height ratios and an XPS standard curve is derived. Under the same experimental conditions, the samples with unknown thicknesses are measured by using XPS technique and then their thicknesses can be obtained from the XPS standard curve. The SiO2/Si standard samples were provided by authoritative lab with the advanced analytical equipments and rich experiences, and the oxide thicknesses were measured by multiple techniques. The present results show that the standard curve, plotted in terms of accuracy of the oxide thickness from the standard samples, can be used for the thickness measurement for ultrathin SiO2 on Si, and this method is valuable in practice owing to the swiftness, convenience and accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1670 (2010)
Analysis of Decayed Wood by Fungi with X-Ray Diffractometry and Fourier Transform Infrared Spectroscopy
Lin Jian, Zhao Guang-jie, Meng Ling-xuan, and Li Zhi-ping
In order to make clear the changes in the micro crystal structures of celluloses and the functional group of main components including cellulose, hemicelluloses and lignin in wood decayed by fungi, the crystallinity, layer spacing d in crystalline unit cell, width of crystallite and functional group of main components In order to make clear the changes in the micro crystal structures of celluloses and the functional group of main components including cellulose, hemicelluloses and lignin in wood decayed by fungi, the crystallinity, layer spacing d in crystalline unit cell, width of crystallite and functional group of main components of Populus tomentosa Carr wood, which was decayed by Phanerochaete Chysosporium (white-rot) and Postia Placenta (brown-rot) with various durations， for two weeks, four weeks, six weeks, eight weeks and ten weeks, respectively, were investigated by means of X-ray diffraction and FTIR spectroscopy methods. It was concluded that the lattice structures of crystallite in wood cellulose were not destroyed by PC and PP, and the two theta angles and layer spacing d in crystallite were constant, although the decaying treatment times were different for each other when decayed by the same fungi. However, the crystallinity and width of crystallite decreased with the decaying treatment times increasing, and the decaying effects by PP were more significantly than those by PC, which showed that the damage extent of celluloses decayed by PP was greater than that by PC. It was estimated that the xylan in hemicelluloses had been degraded to various extents with the process of decaying in wood, resulting in the carbonyl content increasing, and the effects of degradation on hemicelluloses and celluloses by PC and PP were almost the same. Furthermore, benzene rings in lignin, which had no remarkable changes by PP, were oxidized into chain hydrocarbon after decaying by PC..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1674 (2010)
Comparison of Correction Methods for Nonlinear Optic Path Difference of Reflecting Rotating Fourier Transform Spectrometer
JING Juan-juan, ZHOU Jin-song, XIANGLI Bin, Qun-bo, and WEI Ru-yi
The principle of reflecting rotating Fourier transform spectrometer was introduced in the present paper. The nonlinear problem of optical path difference (OPD) of rotating Fourier transform spectrometer universally exists, produced by the rotation of rotating mirror. The nonlinear OPD will lead to fictitious recovery sThe principle of reflecting rotating Fourier transform spectrometer was introduced in the present paper. The nonlinear problem of optical path difference (OPD) of rotating Fourier transform spectrometer universally exists, produced by the rotation of rotating mirror. The nonlinear OPD will lead to fictitious recovery spectrum, so it is necessary to compensate the nonlinear OPD. Three methods of correction for the nonlinear OPD were described and compared in this paper, namely NUFFT method, OPD replace method and interferograms fitting method. The result indicates that NUFFT was the best method for the compensation of nonlinear OPD, OPD replace method was better, its precision was almost the same as NUFFT method, and their relative error are superior to 0.13%, but the computation efficiency of OPD replace method is slower than NUFFT method, while the precision and computation efficiency of interferograms fitting method are not so satisfied, because the interferograms are rapid fluctuant especially around the zero optical path difference, so it is unsuitable for polynomial fitting, and because this method needs piecewise fitting, its computation efficiency is the slowest, thus the NUFFT method is the most suited method for the nonlinear OPD compensation of reflecting rotating Fourier transform spectrometer..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1678 (2010)
Study on Calibration Method of Spatial Heterodyne Spectrometer
SHI Hai-liang, XIONG Wei, ZUO Ming-min, LUO Hai-yan, WU Jun, FANG Yong-hua, and QIAO Yan-li
Spatial heterodyne spectroscopy (SHS) is a novel method for hyperspectral analysis, but the calibration methods have not been thoroughly studied. The present paper gives some basic theories of SHS, and investigates the laboratory calibration methods, including spectral calibration and radiometric calibration. AccordingSpatial heterodyne spectroscopy (SHS) is a novel method for hyperspectral analysis, but the calibration methods have not been thoroughly studied. The present paper gives some basic theories of SHS, and investigates the laboratory calibration methods, including spectral calibration and radiometric calibration. According to emission lines and the relation between detector size and system bandwidth, we designed the spectral calibration plan for SHS, which uses tunable laser and halogen lamp. Experiments show that the actual spectral range and resolution of our instrument is the same as it was designed, and the spectral shift is less by stability testing. For radiometric calibration, we measured the system’s stability by using integrating sphere, and its responses were also calibrated by using standard lamp and diffuser. The experimental results, after validation, proved that our method can be used for SHS calibration. This is a fundamental work for quantified retrieval..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1683 (2010)
Baseline Correction Method for Spectrum Signal of SF6 Insulating Air with Optimum Wavelet Basis
LIU Yan, LIU Kai, TAO Wei-liang, and WANG Xian-pei
SF6 gas has been widely used in the power equipments as an excellent electric insulating and arc-quenching medium. In the present paper, a baseline correction method based on the optimum wavelet basis for spectrum detection is proposed to measure the composition content of the SF6 insulating gas to secure the power safSF6 gas has been widely used in the power equipments as an excellent electric insulating and arc-quenching medium. In the present paper, a baseline correction method based on the optimum wavelet basis for spectrum detection is proposed to measure the composition content of the SF6 insulating gas to secure the power safety. In this method, the optimum wavelet basis is selected in the wavelet packet according to constructor function on the energy concentration criterion to express the spectrum signal in the time-frequency domain. Then the strong spectrum composition is removed from the spectrum signal with the threshold method to eliminate the interference with the continuous spectrum fitting. Finally we remove the continuous spectrum which is fitting result from the origin spectrum and obtain the useful signal of line spectrum. The intensities of spectral line processed with the proposed algorithm could reflect the concentration of the conponents to be measured in SF6 gas. Experiments to analyze the absorption spectrum of the SF6 insulating gas mixture show that the proposed algorithm can estimate and correct the drifting baseline accurately, and its performance is better than the algorithm based on iterative wavelet..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1688 (2010)
Coma and Resolution in Wide Spectral Region Czerny-Turner Spectrometer
CHEN Tan-xuan, YANG Huai-dong, CHEN Ke-xin, TAN Qiao-feng, and JIN Guo-fan
The Czerny-Turner layout, which is most frequently used in miniature spectrometers, should follow Shafer’s coma-free condition and Fastie’s flat-field principal to eliminate the central wave’s primary coma and maximize its resolution. However, the design process does not take the comas and resolutions at non-central waThe Czerny-Turner layout, which is most frequently used in miniature spectrometers, should follow Shafer’s coma-free condition and Fastie’s flat-field principal to eliminate the central wave’s primary coma and maximize its resolution. However, the design process does not take the comas and resolutions at non-central waves into consideration. Based on the theory of primary coma in reflection optical system, the present paper points out that in the crossed beam design, the resolutions at wide spectral region present a “V” shape, while in the M design, the resolutions change little over the whole region, and present an approximately straight line shape, so the latter kind of spectrometer maintains a far more consistent resolution than the former one. Accordingly, this paper designs two kinds of spectrometers with spectrum regions from 400 to 600 nm, and carries out theoretical simulation and contrast experiment. The result demonstrates that for the two designs the resolutions at the fringe wavelength are 3.8 times and 1.5 times respectively that at the central wavelength, which accords with the conclusion of the theoretical simulation..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1692 (2010)
Analysis and Experimental Validation of Sgnal-to-Noise for Limb Imaging Sectrometer
XUE Qing-sheng, WANG Shu-rong, LI Fu-tian, LIN Guang-yu, and DUAN Ming-zheng
Limb imaging spectrometer is an important new remote sensor for research and application. Signal-to-noise ratio (SNR) is one of the key parameters to quantitatively evaluate the image quality and radiometric performance of an imaging spectrometer. The estimation and testing of SNR are very important for developing an iLimb imaging spectrometer is an important new remote sensor for research and application. Signal-to-noise ratio (SNR) is one of the key parameters to quantitatively evaluate the image quality and radiometric performance of an imaging spectrometer. The estimation and testing of SNR are very important for developing an imaging spectrometer. From the perspectives of radiative transmission and energy conversion, the SNR model is proposed, and the SNR equation of dispersive-type limb imaging spectrometer is derived, and the SNR values under several observing conditions for an limb imaging spectrometer prototype developed are theoretically evaluated based on atmospheric radiative transfer code MODTRAN 4.0. The results show that the SNR of the prototype under typical viewing geometry is not less than 8. As experimental validation, SNR testing was performed using an internally illuminated integrating sphere, and the experimental results have proved the correctness of this theoretical model..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1697 (2010)
Thermal Spectral Property of Prism in Hyper Spectral Imager
LIANG Jiu-sheng, WU Qing-wen, LI Ze-xue, CHEN Li-heng, and GUO Liang
Prism is one of the most key parts in the hyper spectral imager (HSI). Consequently，to set thermal control target and make thermal control design, the thermal spectral property of prism in the HSI was studied. The working principle of the HSI and the definition of its thermal spectral property were introduced. The workPrism is one of the most key parts in the hyper spectral imager (HSI). Consequently，to set thermal control target and make thermal control design, the thermal spectral property of prism in the HSI was studied. The working principle of the HSI and the definition of its thermal spectral property were introduced. The working environment of prism and its thermal effect were analyzed; also the study contents and technical route of the prism’s thermal spectral property were discussed. The effects of different uniform temperature field on deflexion angle and angular dispersion of the prism in the HSI were deduced, and the changes in displacement of the spectra and the spectral bandwidth under different uniform temperature were obtained. For one instance, the thermal spectral property of the K9 prism and the fused silica prism were compared based on FEM and combined experiments, furthermore, its thermal control target was ascertained and a thermal spectral property test was carried out to validate the rationality of the thermal spectral property analysis. The results of analysis indicated that the changes in spectral bandwidth and spectrum resolution brought by thermal distortions can be ignored according to current fixing mode, and the displacement of the spectra is mainly determined by thermal coefficient of material refractive index; because of it’s the lower thermal coefficient of material refractive index, the displacement of the spectra of the K9 prism is smaller under the same temperature changes; the material deflexion changes (dn/dλ) of prism are not sensitive to the temperature, so the changes in spectral bandwidth caused by them are not obvious. And the results of test proved that the studied method of thermal spectral property is reasonable and essential, and the results are authentic and credible. So it can provide some guidance for setting thermal control target and optimizing thermal control design..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1702 (2010)
Galaxy Spectrum Subtraction of a Mixed Spectrum Based on Two Class PCA Eigen-Spectra
TU Liang-ping, WU Fu-chao, LUO A-li, and ZHAO Yong-heng
The authors present a new method called two class PCA for decomposing the mixed spectra, namely, for subtracting the host galaxy contamination from each SN spectrum. The authors improved the quality of reconstructed galaxy spectrum and computational efficiency, and these improvements were realized because we used both The authors present a new method called two class PCA for decomposing the mixed spectra, namely, for subtracting the host galaxy contamination from each SN spectrum. The authors improved the quality of reconstructed galaxy spectrum and computational efficiency, and these improvements were realized because we used both the PCA eigen spectra of galaxy templates library and SN templates library to model the mixed spectrum. The method includes mainly three steps described as follows. The first step is calculating two class PCA eigen spectra of galaxy templates and SN templates respectively. The second step is determining all reconstructed coefficients by the SVD matrix decomposition or orthogonal transformation. And the third step is computing a reconstructed galaxy spectrum and subtracting it from each mixed spectrum. Experiments show that this method can obtain an accurate decomposition of a mixed synthetic spectrum, and is a method with low time-consumption to get the reliable SN spectrum without galaxy contamination and can be used for spectral analysis of large amount of spectra. The time consumption using our method is much lower than that using χ2-template fitting for a spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1707 (2010)
Techniques for Pixel Response Nonuniformity Correction of CCD in Interferential Imaging Spectrometer
YAO Tao, YIN Shi-min, XIANGLI Bin, and L Qun-bo
Based on in-depth analysis of the relative radiation scaling theorem and acquired scaling data of pixel response nonuniformity correction of CCD (charge-coupled device) in spaceborne visible interferential imaging spectrometer, a pixel response nonuniformity correction method of CCD adapted to visible and infrared inteBased on in-depth analysis of the relative radiation scaling theorem and acquired scaling data of pixel response nonuniformity correction of CCD (charge-coupled device) in spaceborne visible interferential imaging spectrometer, a pixel response nonuniformity correction method of CCD adapted to visible and infrared interferential imaging spectrometer system was studied out, and it availably resolved the engineering technical problem of nonuniformity correction in detector arrays for interferential imaging spectrometer system. The quantitative impact of CCD nonuniformity on interferogram correction and recovery spectrum accuracy was given simultaneously. Furthermore, an improved method with calibration and nonuniformity correction done after the instrument is successfully assembled was proposed. The method can save time and manpower. It can correct nonuniformity caused by other reasons in spectrometer system besides CCD itself’s nonuniformity, can acquire recalibration data when working environment is changed, and can also more effectively improve the nonuniformity calibration accuracy of interferential imaging spectrometer system..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1712 (2010)
Research on Laser Spectrum Detecting Technology Based on the Bilateral-Wedges Fourier Interferometer
YU Ben-guo, and WANG Jian-zhong
To increase the spectrum resolution without changing the size of static Fourier interferometer, the bilateral-wedges Fourier transform interferometer was designed and the methods of stretching interference fringes in the same optical path difference were proposed. Through analyzing the optical path difference function To increase the spectrum resolution without changing the size of static Fourier interferometer, the bilateral-wedges Fourier transform interferometer was designed and the methods of stretching interference fringes in the same optical path difference were proposed. Through analyzing the optical path difference function between the bilateral-wedges Fourier transform interferometer and static Fourier transform interferometer, the spectrum resolution was enhanced to 9.1 cm-1 with the same size, and the enhancement was nearly 8 times. It will not bring about being unable to collect the interference fringes due to fringe aliasing. In the experiments, the bilateral-wedges Fourier transform interferometer was made by the BK7, using laser with six different wavelengths to show analysis of interference fringes. The experimental result demonstrated the interference fringes to be longer than normal with the augmentation of the reflection position. Of course, the kind of this error can be calibrated, because it is linear augmentation by wavelength. According to the calculation, it is known that each 1nm of the laser wavelength change causes 0.021 1 nm increase in the error. After the spectrum calibration, the system can detect the correct spectrum data, raising the spectrum resolution with the same size..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1717 (2010)
Fiber Monitoring Network of Methane Concentration Based on Space Division Multiplexing in Coal Mine
ZHANG Ji-long, WANG Peng, WANG Zhi-bin, LI Xiao, and WANG Zhi-wen
Methane explosion accidents occur frequently, and accurate and real-time detection and early warning of methane concentration are the effective means of preventing these accidents. The research was based on the spectrum absorption properties of methane, and a near-infrared tunable DFB laser diode of 1.65 μm wave band wMethane explosion accidents occur frequently, and accurate and real-time detection and early warning of methane concentration are the effective means of preventing these accidents. The research was based on the spectrum absorption properties of methane, and a near-infrared tunable DFB laser diode of 1.65 μm wave band was used. With the mode-hopping features of laser diode, a differential absorption of double-wavelength and single-fiber optical sensor network was designed. Sixteen methane sensors were multiplexed in this system with space division multiple access technology and optical switch, and the key technologies of anti-dust in gas absorption cell were researched. All signals were gathered by the PCI data acquisition card，and information of each way was analyzed and displayed with virtual instrument. The results of experiment show that the method can reach the sensitivity of 0.05% even without using a phase-locked amplifier and the absorption light path is only 10 centimeters. Long-time accuracy and stability of all sensors could meet the practical demands, and the response time of each sensor was less than 1 seconds. With the replacement of lasers, the network can be used for the real-time detection of other gases..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 29, 2021
- Vol. 30, Issue 6, 1722 (2010)
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