Journals >Spectroscopy and Spectral Analysis
Contents
2012
Volume: 32 Issue 10
63 Article(s)
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Research Article
All Wavelength Picosecond Fluorescent Anisotropy of Aligned MEH-PPV/PVP Electrospun Fibers
CHEN Jia-long, GAO Guang-yu, CHU Sai-sai, WANG Shu-feng, and GONG Qi-huang
Electrospinning is a simple and effect technology which can produce continuous nanofibers. We get aligned electrospun nanofibers successfully by using parallel electrodes. We report our studies on transient fluorescence of aligned electrospun fibers. The fibers are excited and their fluorescences are observed both at aElectrospinning is a simple and effect technology which can produce continuous nanofibers. We get aligned electrospun nanofibers successfully by using parallel electrodes. We report our studies on transient fluorescence of aligned electrospun fibers. The fibers are excited and their fluorescences are observed both at axial and radial polarization. Steady-state PL spectra shows radial emission blue-shift more than axial!emission, due to weakened aggregation of molecular chains in radial direction. At all emission wavelength, radial emission excitons migrate faster than axial emission excitons..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2593 (2012)
Infrared Multiphoton Quantum Cutting Phenomena of Rare Earth Materials
CHEN Xiao-bo, YANG Guo-jian, ZHANG Yun-zhi, DENG Zhi-wei, HU Li-li, LI Song, YU Chun-lei, CHEN Zhi-jian, CUI Jian-sheng, CHEN Xiao-duan, ZHOU Hong-yu, and WU Zheng-long
Infrared quantum cutting of rare earth ion is an international hot research field. It is significant for the enhancement of solar cell efficiency and for the reduction of solar cell price. The present paper summarizes the research significance of infrared quantum cutting of rare earth ion. Based on the summarization ofInfrared quantum cutting of rare earth ion is an international hot research field. It is significant for the enhancement of solar cell efficiency and for the reduction of solar cell price. The present paper summarizes the research significance of infrared quantum cutting of rare earth ion. Based on the summarization of general principle and loss mechanism of solar cell, the possible method to enhance the solar cell efficiency by infrared quantum cutting is analyzed. Meanwhile, the present paper summarizes the infrared quantum cutting phenomena of Er3+ ion single-doped material. There is intense 4I13/2→4I15/2 infrared quantum cutting luminescence of Er3+ ion when the 2H11/2 energy level is excited. The intense {2H11/2→4I9/2, 4I15/2→4I13/2} cross energy transfer is the main reason for the result in the high quantum cutting efficiency when the 2H11/2 energy level is excited..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2597 (2012)
The Reconstruction of Welding Arc 3D Electron Density Distribution Based on Stark Broadening
ZHANG Wang, HUA Xue-ming, PAN Cheng-gang, LI Fang, and WANG Min
The three-dimensional electron density is very important for welding arc quality control. In the present paper, Side-on characteristic line profile was collected by a spectrometer, and the lateral experimental data were approximated by a polynomial fitting. By applying an Abel inversion technique, the authors obtained The three-dimensional electron density is very important for welding arc quality control. In the present paper, Side-on characteristic line profile was collected by a spectrometer, and the lateral experimental data were approximated by a polynomial fitting. By applying an Abel inversion technique, the authors obtained the radial intensity distribution at each wavelength and thus constructed a profile for the radial positions. The Fourier transform was used to separate the Lorentz linear from the spectrum reconstructed, thus got the accurate Stark width. And we calculated the electronic density three-dimensional distribution of the TIG welding arc plasma..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2601 (2012)
Preparation and Luminescent Properties of ZnMoO4∶Tb3+
Namila, WANG Fu-ming, WANG Xi-gui, and Aolegen
Tb3+ doped ZnMoO4 materials were synthesized by combustion method. XRD results show that the samples completely formed single ZnMoO4 phase at 700 ℃ which belongs to Trigonal, while the incorporation of Tb3+ does not affect the basic structure of ZnMoO4. The TG-DTA results show that the samples fully formed ZnMoO4 phaseTb3+ doped ZnMoO4 materials were synthesized by combustion method. XRD results show that the samples completely formed single ZnMoO4 phase at 700 ℃ which belongs to Trigonal, while the incorporation of Tb3+ does not affect the basic structure of ZnMoO4. The TG-DTA results show that the samples fully formed ZnMoO4 phase due to the energy absorption at about 680 ℃. IR results show that there were no other organic peaks after burning at 700 ℃, indicating that citric acid has been completely decomposed and Tb3+ ions have been fully integrated into the lattice of ZnMoO4. SEM results show that the dispersion of particles gradually increases along with the improvement of the temperature.The best excitation wavelength was 488 nm when the monitoring wavelength was 544 nm, which corresponds to the 5D4→7F5 transition of Tb3+. Finally, a valuable green fluorescent powder of ZnMoO4∶Tb3+ has been obtained..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2605 (2012)
Analysis on the Degradation of Optical Properties of High Power White LED
ZHOU Zhou, FENG Shi-wei, GUO Chun-sheng, ZHANG Guang-chen, and WU Yan-yan
One watt white light emitting diodes (LEDs) were made by GaN-based blue light chips. The chips were coated by YAG phosphor and transparent silica gel. Current of 900 mA as electrical stress was carried on the LED samples and the optical properties of the samples were observed by measuring the main optical parameters duOne watt white light emitting diodes (LEDs) were made by GaN-based blue light chips. The chips were coated by YAG phosphor and transparent silica gel. Current of 900 mA as electrical stress was carried on the LED samples and the optical properties of the samples were observed by measuring the main optical parameters during the aging test. After 4 200 hours of aging, the luminous flux rate of LEDs declined by a factor between 15% and 18%. Changes in I-V curves indicated the increase in leakage current, which were caused by the increase in defect density. Radiant flux of the blue light drawn from the spectrogram didn’t decrease while the yellow light decreased obviously, which implies the degradation of conversion efficiency of YAG phosphor. Reasons for the increase in color temperature and keeping constant in color rendering index (CRI) were theoretically analyzed. The results of the experiment will provide a reference to the illumination applications of the high power white LED..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2611 (2012)
Spectral Analysis Method for Precisely Measuring Specific Rotation of Quartz
MA Li-li, WU Fu-quan, HAO Dian-zhong, SU Fu-fang, and SHI Meng
A spectral analysis method for precisely measuring specific rotation of quartz is proposed. The measuring principle is analyzed by using the method of optical matrix. The result indicates that the specific rotation of quartz can be exactly calculated by measuring the transmittance curve of a sample quartz plate sandwicA spectral analysis method for precisely measuring specific rotation of quartz is proposed. The measuring principle is analyzed by using the method of optical matrix. The result indicates that the specific rotation of quartz can be exactly calculated by measuring the transmittance curve of a sample quartz plate sandwiched between two paralleled polarizing prisms, and the correctness of the method is validated by a designed experiment using a spectrophotometer. The data is analyzed, and the rotary dispersion formula of quartz is fitted. Compared with Lowry’ formula, our formula is more accurate in visible spectral scope. Errors in the experiment is analyzed and the result shows that the measuring accuracy will be improved by choosing thicker quartz plate, longer wave band, lower scan speed, and smaller slit width..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2615 (2012)
Measurement of Molecular Vibrational Temperature of the White-Eye Pattern in Dielectric Barrier Discharge
DONG Li-fang, YAN Dong-mei, GENG Yi-qing, SHEN Zhong-kai, and TONG Guo-liang
The white-eye pattern, whose cell is composed of a bright dot surrounded by a closed hexagon, was observed in air/argon dielectric barrier discharge. It was found that the center dot, the vertex of hexagon and the center of hexagon side in a cell have different brightness. By using optical emission spectra, the vibratiThe white-eye pattern, whose cell is composed of a bright dot surrounded by a closed hexagon, was observed in air/argon dielectric barrier discharge. It was found that the center dot, the vertex of hexagon and the center of hexagon side in a cell have different brightness. By using optical emission spectra, the vibrational temperature in the center dot, the vertex of hexagon and the center of hexagon side was measured, respectively. The variations in the vibrational temperature at these three places as a function of the content of argon in gas mixture were also studied. The vibrational temperature was calculated by emission spectral lines of the N2 second positive band system (C3Πu→B3Πg). The experimental results show that the vibrational temperature of the center dot, the vertex of hexagon and the center of hexagon side is in the ascending order and decreases with the increase in the content of argon in gas mixture..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2620 (2012)
Laser-Induced Fluorescence Spectroscopy Characterization of Farmland Soil Moisture Content
ZHANG Shi-rui, DONG Da-ming, ZHENG Wen-gang, ZHAO Xian-de, and WANG Ji-hua
Online measurement of soil moisture is significant for agricultural production. The abundance and deficiency of leaf water shortage has been able to effect measured by fluorescence, but the research of correlation between soil moisture and laser-induced fluorescence spectroscopy has not been carried out yet. In this paOnline measurement of soil moisture is significant for agricultural production. The abundance and deficiency of leaf water shortage has been able to effect measured by fluorescence, but the research of correlation between soil moisture and laser-induced fluorescence spectroscopy has not been carried out yet. In this paper, the relationship between laser-induced plant chlorophyll fluorescence and soil moisture was studied. In the experiment with rice as the research object, the chlorophyll fluorescence induced by a 450 nm LED light source was measured by a Y-shaped fiber probe, and the soil moisture was obtained by TDR sensors. The changes in the peak intensity near 743 nm of chlorophyll fluorescence under continuous water stress and intermittent water stress were studied. The result showed that the intensity decreased with the soil moisture content. Finally, the model between the soil water content and the intensity of chlorophyll fluorescence under continuous water stress was created by using Lorentzian equation, and the coefficient of determination (R2) of the model was high. The result indicated that the method mentioned in paper can be applied to measure soil moisture in agricultural production..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2623 (2012)
Influence of Lighting Sources Spectra on the Human Visual Brightness Identification under the Mesopic Vision
YANG Yong, GUAN Li, ZHU Chuan-zheng, ZHU Li-wei, XU Nuo, LI Xu, and LI Pan-lai
Based on the MOVE models and the measurement of emission spectra of various light sources, the photopic function weights x and the mesopic equivalent brightness of human visual spectral luminous efficiency in different background brightness were calculated. Results showed that in the mesopic scope, human visual functioBased on the MOVE models and the measurement of emission spectra of various light sources, the photopic function weights x and the mesopic equivalent brightness of human visual spectral luminous efficiency in different background brightness were calculated. Results showed that in the mesopic scope, human visual function peak value gradually increases with the brightness decreasing, and is moving towards the short-wave direction. The change rate is inversely proportional to the s/p index. In the case of ambient brightness for 0.5 cd·m-2, peak values increase by 30% compared to the photopic function. Compared to the traditional test results, the mesopic equivalent brightness of fluorescent lamp and other different color temperature white light LED showed a positive gain that reaches 40%. On the other hand, the high pressure sodium lamp showed a negative gain. Results also showed that there was a decreasing trend when the ambient light level increased, and once the brightness level reaches that when cone cells play a full role, the equivalent brightness will equal photopic brightness. The methods and conclusions of this paper can help evaluate light sources, light-emitting material spectrum and characteristics of apparent brightness..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2628 (2012)
Luminescent Properties of Eu3+ Doped Layered Perovskite Structure M2TiO4(M=Ca,Sr,Ba) Red-Emitting Phosphors
LU Zhou, ZHANG Le, XU Nai-cen, WANG Li-xi, and ZHANG Qi-tu
Series of Eu3+ doped layered perovskite structure M2TiO4∶Eu3+ (M=Ca,Sr,Ba) red phosphors were prepared by the high-temperature solid state reaction method. Their phase compositions and photoluminescence properties were investigated by XRD, UV-Vis DRS and fluorescence spectra. The results indicated that pure Sr2TiO4 andSeries of Eu3+ doped layered perovskite structure M2TiO4∶Eu3+ (M=Ca,Sr,Ba) red phosphors were prepared by the high-temperature solid state reaction method. Their phase compositions and photoluminescence properties were investigated by XRD, UV-Vis DRS and fluorescence spectra. The results indicated that pure Sr2TiO4 and Ba2TiO4 powers could be prepared under 1 100 ℃ for 2 hours, but Ca2TiO4 powers could not be synthesized even raising the calcination temperature and lengthening the calcination time. Ba2TiO4∶Eu3+ phosphor emitted 594 nm(5D0→7F1) and 615 nm(5D0→7F2) orange-red light under the excitation of 395 nm. Sr2TiO4∶Eu3+ phosphor gave a unusual and strong orange-red emission of 578 nm(5D0→7F0) and 626 nm(5D0→7F2) under the excitation of near ultraviolet or blue light, resulting in the better color purity and higher luminescent intensity. In addition, this phosphor had the highest luminous efficiency when excited by the charge migration excitation at 363 nm and it had the great potential to be a red phosphor for N-UV LED and blue light chip..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2632 (2012)
Preparation and Up-Conversion Luminescence Dynamic Process of Yb3+/Er3+ Co-Doped BaGd2ZnO5
YANG Yan-min, JIAO Fu-yun, SU Hong-xin, LI Zi-qiang, LIU Yun-feng, LI Zhi-qiang, and YANG Zhi-ping
Yb3+/Er3+ co-doped BaGd2ZnO5 phosphors were prepared by using the sol-gel method. The up-conversion luminescence powers and efficiencies were measured under different excitation densities. The obtained data showed that the green luminescence power was proportional to the second-order of that of the excitation power undYb3+/Er3+ co-doped BaGd2ZnO5 phosphors were prepared by using the sol-gel method. The up-conversion luminescence powers and efficiencies were measured under different excitation densities. The obtained data showed that the green luminescence power was proportional to the second-order of that of the excitation power under the lower excitation density and linearly in the higher one. The up-conversion mechanism under different excitation power was described by a rate equation. Yb3+/Er3+ co-doped BaGd2ZnO5 was excited by 971 nm LD laser with a square wave signal modulation and the rise and decay processes of green up-conversion luminescence were measured. In a low excitation condition, the rate equation of the energy level 4S3/2 for Er3+ ions was used to fit the green rise and decay processes in order to fix the relevant parameters, and confirm that the population of 4S3/2 energy level of Er3+ ion mainly came from the energy transfer from Yb3+ to Er3+..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2637 (2012)
Synthesis and White Light Emission Upconversion of Tm3+, Ho3+, Yb3+ Co-Doped YPO4 Micro-Nano Tubes
ZHAN Shi-ping, GAO Yong-yi, HUANG Hai, and ZHONG Hui
Tm3+, Ho3+, Yb3+ co-doped YPO4 micro-nano tubes were synthesized by hydrothermal method. Under the 980 nm near infrared(NI) excitation, the micro-nano tubes emitted red, green, blue visible light and a near infrared emission centered at 795 nm. The optical properties and structure of the synthesized Tm3+, Ho3+, Yb3+ coTm3+, Ho3+, Yb3+ co-doped YPO4 micro-nano tubes were synthesized by hydrothermal method. Under the 980 nm near infrared(NI) excitation, the micro-nano tubes emitted red, green, blue visible light and a near infrared emission centered at 795 nm. The optical properties and structure of the synthesized Tm3+, Ho3+, Yb3+ co-doped YPO4 micro-nano tubes were characterized by testing the TEM, XRD and fluorescence spectra. The results showed that the micro-nano tubes are pure hexagonal phase. The hydrothermal temperature had obvious effect on fluorescence spectra but little effect on phase. The intensity of the emission peaks didn’t increase with the concentration of doping ions monotonously under the same reaction temperature, but changed non-monotonously due to the concentration quenching and cross relation. The possible upconversion(UC) mechanism was discussed in this paper. This UC emission intensity controllable fluorescent material has potential application in three dimension solid display, UC illumination, fluorescence detection and some other fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2642 (2012)
Investigation of N-Hexadecylated Poly(p-Phenylene Terephthamide) by Infrared Spectroscopy
KONG Lei, LI Rong-bo, ZHAO Ying, SHI Hai-feng, WANG Du-jin, XU Duan-fu, and WU Jin-guang
N-hexadecylated poly(p-phenylene terephthamide) (PPTA) comb-like polymers (PPTAC16), which are composed of PPTA backbone and hexadecyl side chains, were prepared by method of N-alkylation reaction. The molecular structure and thermal transition behavior of PPTAC16 were characterized by a combination of differential scaN-hexadecylated poly(p-phenylene terephthamide) (PPTA) comb-like polymers (PPTAC16), which are composed of PPTA backbone and hexadecyl side chains, were prepared by method of N-alkylation reaction. The molecular structure and thermal transition behavior of PPTAC16 were characterized by a combination of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) technique. DSC results indicated that the crystallization of hexadecyl side chains, and the side chain crystallization is less perfect than that of n-hexadecane crystal. IR results showed that the ordered degree of the packing of CH2 group in the side chain crystallization is lower than that of n-hexadecane crystal. Variable temperature IR spectroscopic results revealed that the stretching vibration and bending vibration bands of methylene group experience an abrupt change with increasing of temperature which indicate the melting of the side chain crystallization, furthermore the main chain of PPTAC16 was found to undergo an irreversible change accompanying the melting of the alkyl side chain crystallization. And the molten state of CH2 group in the hexadecyl of PPTAC16 is different from that of liquid n-hexadecane..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2647 (2012)
Investigation of Articular Cartilage Using FTIR Microspectroscopy for Guinea Pig with Spontaneous Osteoarthritis
YANG Li-ping, ZHAO Tie-jun, LIU Jian-ling, WANG Jin-hong, SONG Qing-hui, ZHU Jia, ZHANG Wan-qiang, and KONG Huan-yu
In-situ analysis the chemical composition of tibial articular cartilage of female Hartley guinea pigs with Fourier transform infrared (FTIR) microspectroscopy was conducted. The infrared spectrum survey consists of three ages (1 months, 2 months and 3 months)and three cartilage layers(surface, middle and deep). The resIn-situ analysis the chemical composition of tibial articular cartilage of female Hartley guinea pigs with Fourier transform infrared (FTIR) microspectroscopy was conducted. The infrared spectrum survey consists of three ages (1 months, 2 months and 3 months)and three cartilage layers(surface, middle and deep). The results demonstrated that with ages increasing, the peak positions of main absorbance bands in surface and middle shifted to a lower wavenumber, and in deep they shifted to a lower wavenumber first, then shifted to a higher wavenumber. Infrared spectrum character of collagen, nucleic acid and proteoglycan were compared and analyzed, The ratios of I1 657/I1 548, I1 074/I1 548 and I1 074/I1 237 tend to decrease with ages increasing in surface and middle. However, the ratios at 2 months are less than other ages in deep. These results are consistent with the regular pattern of cartilage ingredient change in different degradation stage, while the tibial platform images created by microscopic spectral imaging technology is highly compliant with pathology description. The authors’ primary result illustrated that FTIR microspectroscopy can be used for in-situ analysis of molecular constituents of different levels cartilages. The molecular information obtained from the study is important for understanding the pathogenesis of cartilage diseases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2651 (2012)
Investigation of N-Hexadecylated Polycaprolactam by Infrared Spectroscopy
KONG Lei, ZHAO Ying, SHI Hai-feng, WANG Du-jin, XU Duan-fu, and WU Jin-guang
N-hexadecylated polycaprolactam (PA6) comb-like polymers (PA6C16) with different alkylation degree, were synthesized using the method of N-alkylation reaction. The thermal transition behavior of these polymers were characterized by a combination of differential scanning calorimetry (DSC) and Fourier transform infrared N-hexadecylated polycaprolactam (PA6) comb-like polymers (PA6C16) with different alkylation degree, were synthesized using the method of N-alkylation reaction. The thermal transition behavior of these polymers were characterized by a combination of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). DSC results indicated that the hexadecyl side chain can crystallize. Furthermore, the melting point of the hexadecyl side chain crystallization of the sample with high alkylation degree(PA6C16-H) is lower than that of sample with lower alkylation degree(PA6C16-L). FT-IR spectroscopic results showed that the methylene groups of the hexadecyl side chain of PA6C16-L tend to crystallize in orthorhombic form, while the methylene groups of the hexadecyl side chain of PA6C16-H tend to be packed into hexagonal form. Variable temperature IR spectroscopic results revealed that accompanying the melting of the side chain crystallization, the backbones of PA6C16-H undergo a conformation transition, while the conformation of backbones of PA6C16-L shows no obvious transition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2656 (2012)
Mechanism of Pigment Content on Infrared Emissivity of Composite Coatings
ZHANG Wei-gang, XU Guo-yue, XU Fei-feng, DING Ru-ya, and TAN Shu-juan
Polyurethane (PU)/flaky metal composite coatings were prepared by using PU and flaky metal powders as adhesives and pigments, respectively. The infrared emissivity of coatings with different metal content was measured by infrared emissometer, and the microstructure of PU/flaky metal composite coatings was observed by sPolyurethane (PU)/flaky metal composite coatings were prepared by using PU and flaky metal powders as adhesives and pigments, respectively. The infrared emissivity of coatings with different metal content was measured by infrared emissometer, and the microstructure of PU/flaky metal composite coatings was observed by scanning electron microscopy. The results of infrared emissivity measurement indicate that the emissivity changes significantly with increasing metal content and presents a “U” type. The results of microstructure observation indicate that PU/flaky metal composite coatings have one-dimensional photonic structural characteristics. According to the microstructure characteristics, the optical reflection spectra of one-dimensional photonic structure in PU/flaky metal composite coatings with different metal content were simulated, and the results show that “U” type variation of emissivity with increasing metal content is derived from the blue-shift of reflection peak wavelength with increasing metal content of one-dimensional photonic structure in coatings..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2661 (2012)
Study of the Epimers of Dexamethasone Sodium Phosphate and Betamethasone Sodium Phosphate by FTIR, FT-Raman and SERS
DOU Wen-hu, ZHOU Guang-ming, and KANG Qian-qian
Infrared spectroscopy (FTIR), normal Raman spectroscopy (NRS) of the solids and saturated solutions and surface-enhanced Raman spectroscopy (SERS) on the silver colloidal substrate were reported. The vibrational modes of each group were analyzed, and the enhanced peaks were assigned and compared. The results showed thaInfrared spectroscopy (FTIR), normal Raman spectroscopy (NRS) of the solids and saturated solutions and surface-enhanced Raman spectroscopy (SERS) on the silver colloidal substrate were reported. The vibrational modes of each group were analyzed, and the enhanced peaks were assigned and compared. The results showed that the major differences between the epimers were the frequency of the CH3 asymmetric stretching vibration and symmetric in-plane deformation vibration of them. According to the mechanism and laws of SERS, the epimers were absorbed on the silver colloid through the P—O bond, carboxyl group and the five-membered ring perpendicularly. The establishment of this adsorption model which realized the rapid identification and the discrimination between the epimers provided important information and useful reference of the adrenal cortical hormone drugs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2664 (2012)
Analysis of the Harvest Seasons of Scutellaria Baicalensis Georgi by Tri-Step Identification of Infrared Spectroscopy and Principal Component Analysis
LIU Su-li, CHEN Jian-bo, ZHOU Qun, SUN Su-qin, and LI Shou-zhuo
In the present paper, a tri-step infrared (IR) spectroscopy was used to study Scutellaria baicalensis Georgi (SBG) harvested in spring and autumn. The positions of peaks in the IR spectra of SBG harvested in spring and autumn were rather similar. However, according to the differences in the relative intensities of thosIn the present paper, a tri-step infrared (IR) spectroscopy was used to study Scutellaria baicalensis Georgi (SBG) harvested in spring and autumn. The positions of peaks in the IR spectra of SBG harvested in spring and autumn were rather similar. However, according to the differences in the relative intensities of those characteristic peaks which include the ester carbonyl CO absorption peak at 1 740 cm-1, the peak near 1 614 cm-1 assigned to the flavonoids, and the peak near 1 071 cm-1 assigned to the carbohydrates, the amount of flavonoids and esters of spring SBGs was higher than that of autumn SBGs. Their carbohydrates were different by comparing the second derivative infrared spectra in the range of 1 300～400 cm-1. Furthermore, the above differences were visually validated by two-dimensional correlation spectroscopy(2D-COS). Moreover, the FTIR spectra of 16 batches of SBG harvested in spring and autumn were analyzed with principal component analysis, and subsequently they were exactly identified and classified. Therefore, tri-step identification of IR spectroscopy combined with principal component analysis can be employed to fast and accurately identify the SBG harvested in spring and autumn and differentiate the differences of their chemical constituents..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2669 (2012)
Assessment of Humic and Fulvic Acids in Black Soils Using Near-Infrared Reflectance Spectroscopy
FAN Ru-qin, SHEN Yan, YANG Xue-ming, ZHANG Xiao-ping, LIANG Ai-zhen, JIA Shu-xia, CHEN Xue-wen, and WEI Shou-cai
The organic carbon content and optical densities of humic acids in black soils of China were predicted and assessed using near infrared spectroscopy technique. The contents of humic acid (HA) and fulvic acid (FA) in 136 black soil samples in China were analyzed and the NIR spectra were collected using a VECTOR/22 (FourThe organic carbon content and optical densities of humic acids in black soils of China were predicted and assessed using near infrared spectroscopy technique. The contents of humic acid (HA) and fulvic acid (FA) in 136 black soil samples in China were analyzed and the NIR spectra were collected using a VECTOR/22 (Fourier transform infrared spectroscopy). Partial least squares (PLS) regression with cross validation was used to develop prediction models with reference data and soil NIRS spectra, and the model was validated using an independent set of samples. NIRS well predicted (HAC+FAC), HAC and FAC contents, with R2 = 0.92, 0.92 and 0.86, RPD=3.66, 3.82 and 2.69, and high correlation coefficients between predicted and measured values (r=0.90, 0.85 and 0.82). Predictions for the E4 values of HA and FA were also good (R2=0.85, 0.85; RPD=2.88, 2.65; r=0.92, 0.80). Predictions for optical densities of HA and FA at 665 nm (E6) was acceptable. Generally, NIRS showed a good potential to predict C content and optical densities of humic acid and fulvic acid in blacks soils and may reveal information on SOC quality..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2674 (2012)
Partial Least Squares Regression Variable Screening Studies on Apple Soluble Solids NIR Spectral Detection
OUYANG Ai-guo, XIE Xiao-qiang, ZHOU Yan-rui, and LIU Yan-de
To improve the predictive ability and robustness of the NIR correction model of the soluble solid content (SSC) of apple, the reverse interval partial least squares method, genetic algorithm and the continuous projection method were implemented to select variables of the NIR spectroscopy of the soluble solid content (STo improve the predictive ability and robustness of the NIR correction model of the soluble solid content (SSC) of apple, the reverse interval partial least squares method, genetic algorithm and the continuous projection method were implemented to select variables of the NIR spectroscopy of the soluble solid content (SSC) of apple, and the partial least squares regression model was established. By genetic algorithm for screening of the 141 variables of the correction model, prediction has the best effect. And compared to the full spectrum correction model, the correlation coefficient increased to 0.96 from 0.93, forecast root mean square error decreased from 0.30°Brix to 0.23°Brix. This experimental results show that the genetic algorithm combined with partial least squares regression method improved the detection precision of the NIR model of the soluble solid content (SSC) of apple..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2680 (2012)
Study on Camellia Sect. Chrysantha Chang Species Identification by FTIR Technology
QIN Xiao-ling, SHI Yan-cai, LI Cheng-zhuo, WEI Xiao, HUANG Rong-shao, KONG De-xin, and HUANG Shu-shi
FTIR spectra from 16 kinds of Camellia Sect. Chrysantha by Fourier transform infrared spectroscopy (FTIR) method combined with the system clustering and correlation coefficient method were used to analyze and compare these spectral data. The results show that: Camellia Sect. Chrysantha of 16 kinds were divided into thrFTIR spectra from 16 kinds of Camellia Sect. Chrysantha by Fourier transform infrared spectroscopy (FTIR) method combined with the system clustering and correlation coefficient method were used to analyze and compare these spectral data. The results show that: Camellia Sect. Chrysantha of 16 kinds were divided into three groups, the first kind was: C. longzhouensis etc, in all eleven kinds; The second kind was: C. achrysantha, C. limonia, C. pingguoensis and C. chuongtsoensis; The third kind was C. microcarpa, which for a class alone. According to the difference in related anatomy and morphology, this study supported that C. longgangensis and C. ptilosperma should be incorporated into one kind; C. multipetala, C. longgangensis, C. parvipetala, C. tunghinensis and C. limonia, C. achrysantha, C. microcarpa, C. nitidissima, C. terminalis and C. pingguoensis should be divided into separate species. FTIR-cluster analysis can be used as a possible means for the identification of Camellia Sect. Chrysantha..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2685 (2012)
Spectroscopy Analysis Application on Proton Exchange Membrane with 1,3,4-Oxadiazole
REN Chun-li, ZHAO Cheng-ji, WANG Zhe, REN Fei, CHENG Hai-long, XU Jing-mei, and ZHANG Hui-xuan
A series of novel Sulfonted poly(arylene ether sulfone)s (SPAES) containing 1,3,4-oxadiazole are prepared via direct polycondensation reactions to precisely control the degree of sulfonation. The structures of these compounds were confirmed by FTIR, H-NMR and TGA. The characteristic peaks of transmittances spectra of CA series of novel Sulfonted poly(arylene ether sulfone)s (SPAES) containing 1,3,4-oxadiazole are prepared via direct polycondensation reactions to precisely control the degree of sulfonation. The structures of these compounds were confirmed by FTIR, H-NMR and TGA. The characteristic peaks of transmittances spectra of C=N were found at 1 603 cm-1 and by H-NMR further confirm the structures, which has been successful introducing the oxadiazole ring. In each TGA curve can observe two distinct weight loss steps, which the one at 300 ℃and the second at 450 ℃ were mainly attributed to the splitting-off of sulfonic acid groups and decomposition of the main chain of the SPAES. The TGA exhibit excellent thermal properties may be satisfied with the basic requirements of proton exchange membrane (PEM) for fuel cells..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2690 (2012)
Tobacco Quality Analysis of Industrial Classification of Different Producing Area Using Near-Infrared (NIR) Spectrum
WANG Yi, MA Xiang, WEN Ya-dong, YU Chun-xia, WANG Luo-ping, ZHAO Long-lian, and LI Jun-hui
In this study, tobacco quality analysis of industrial classification of different producing area was carried out applying spectrum projection and correlation methods. The group of industrial classification data was near-infrared (NIR) spectrum in 2010 year from different tobacco plant parts and colors of Hongta TobaccoIn this study, tobacco quality analysis of industrial classification of different producing area was carried out applying spectrum projection and correlation methods. The group of industrial classification data was near-infrared (NIR) spectrum in 2010 year from different tobacco plant parts and colors of Hongta Tobacco(Group)Co.,Ltd. 6 064 tobacco leaf samples of 17 classes from Yuxi, Chuxiong and Zhaotong, in Yunnan province and 6 industrial classifications were collected using near infrared spectroscopy, which from different parts and colors and all belong to tobacco varieties of K326. The conclusion showed that, the probability of the grading belonging by the first dimension was 84%, the probability of the producing area belonging by the second dimension was 71%. The study can explain the difference of tobacco quality of industrial classification and producing area by a projection method to get the quantitative similarity values. The quantitative similarity values were instructive in combination of tobacco leaf blending..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2694 (2012)
Surface-Enhanced Raman Spectra of Thymine Calculated by DFT and ab Inition HF
CHEN Shan-jun, CHEN Yan, ZHOU Xiu-wen, LUO Bing-chi, LI Xi-bo, TANG Yong-jian, and SUN Wei-guo
In the present paper, B3LYP (Becke’s three-parameter hybrid method with the Lee, Yang, and Parr gradientcorrected correlation functional) and HF (Hartree-Fock) methods at 6-31+G**(C, H, N, O)/LANL2DZ(Ag) level were used to optimize molecular configurations of thymine. Base on the optimized structure, the normal Raman sIn the present paper, B3LYP (Becke’s three-parameter hybrid method with the Lee, Yang, and Parr gradientcorrected correlation functional) and HF (Hartree-Fock) methods at 6-31+G**(C, H, N, O)/LANL2DZ(Ag) level were used to optimize molecular configurations of thymine. Base on the optimized structure, the normal Raman spectrum (NRS) of thymine and the surface-enhanced Raman spectrum (SERS) of thymine adsorbed on Ag and Ag2 were calculated, which were compared with the experimental values. The calculation results indicated that the result of the DFT for NRS was more approximate to the ever reported experimental date than those of HF results. A better conformity of SERS was found between the HF computed and the experimental results. At the end, detailed analysis of the Raman spectrum and more comprehensive assignments of the vibration mode for thymine were studied by the software of GaussView..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2698 (2012)
Preliminary Study on the Surface Enhanced Raman Spectrum of Tea
CHEN Yong-jian, FENG Shang-yuan, GUO Xiao-lin, XI Gang-qin, WANG Jing, and CHEN Rong
In the present paper, taking Tiegunyin tea as an example, surface enhanced Raman scattering (SERS) spectrum of tea was obtained, the effects of different active substrates were explored from the aspects of enhanced factor, background noise, repeatability, and signal to noise ratio (SNR), while the impact of adsorption In the present paper, taking Tiegunyin tea as an example, surface enhanced Raman scattering (SERS) spectrum of tea was obtained, the effects of different active substrates were explored from the aspects of enhanced factor, background noise, repeatability, and signal to noise ratio (SNR), while the impact of adsorption time on the measurement was also discussed. The results show that it is feasible to obtain the SERS spectrum of tea, and Raman signal of SERS spectrum was greatly enhanced compared with that of regular Raman spectrum. The active substrate of silver colloid prepared by the reduction of silver nitrate and trisodium citrate has a better enhanced effect, while different adsorption times have no direct influences on the SERS measurement. The method based on SERS firstly proposed in this paper may provide an alternative method for the discriminant analysis and quality identification of tea..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2702 (2012)
Raman, FTIR Spectra and Normal Mode Analysis of Acetanilide
LIANG Hui-qin, TAO Ya-ping, HAN Li-gang, HAN Yun-xia, and MO Yu-jun
The Raman and FTIR spectra of acetanilide (ACN) were measured experimentally in the regions of 3 500～50 and 3 500～600 cm-1 respectively. The equilibrium geometry and vibration frequencies of ACN were calculated based on density functional theory (DFT) method (B3LYP/6-311G(d,p)). The results showed that the theoretical The Raman and FTIR spectra of acetanilide (ACN) were measured experimentally in the regions of 3 500～50 and 3 500～600 cm-1 respectively. The equilibrium geometry and vibration frequencies of ACN were calculated based on density functional theory (DFT) method (B3LYP/6-311G(d,p)). The results showed that the theoretical calculation of molecular structure parameters are in good agreement with previous report and better than the ones calculated based on 6-31G(d), and the calculated frequencies agree well with the experimental ones. Potential energy distribution of each frequency was worked out by normal mode analysis, and based on this, a detailed and accurate vibration frequency assignment of ACN was obtained..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2706 (2012)
Study on the Fluorescence Properties of Carbon Dots Prepared by One Step Microwave Method
WANG Shan-shan, MI Wei-qing, ZHU Hong, and WANG Fang-hui
In recent years, more and more researchers pay attention to the synthesis of water-soluble fluorescent carbon dots. Compared with the traditional cadmium-based, silicon-based quantum dots and organic dyes, carbon dots with low toxicity and high stability can be chemically modified and be compatible with a variety of orIn recent years, more and more researchers pay attention to the synthesis of water-soluble fluorescent carbon dots. Compared with the traditional cadmium-based, silicon-based quantum dots and organic dyes, carbon dots with low toxicity and high stability can be chemically modified and be compatible with a variety of organic, inorganic, and biological molecules, and can be applied in many areas. The fluorescence carbon dots were prepared by one step microwave method using ascorbic acid as raw materials. The carbon dots were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), ultraviolet-visible spectrophotometry, fluorescence spectrophotometry, and Fourier transform infrared spectrophotometry(FTIR). The results showed that the carbon dots have approximate spherical morphology, uniform size, good dispersion and non-agglomeration, good fluorescence properties. The carbon dots were rich in carboxyl and hydroxyl groups and had highly hydrophilic nature. The emission wavelength of carbon dots depended on the excitation wavelength. Furthermore, these carbon dots also had good fluorescence properties in a wide pH range..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2710 (2012)
Steady-State Spectroscopy on Complementary Tissue Structural and Functional Information Extraction
LIU Cheng-bo, SONG Jing-bo, LONG Tao, and ZHANG Zhen-xi
Steady-state spectroscopy is prevailing for complementary tissue structural and functional information extraction. The goal of the present study is to experimentally validate the merit of this technique for optical properties and intrinsic fluorescence extraction from tissue mimicking phantoms. Phantom studies were carSteady-state spectroscopy is prevailing for complementary tissue structural and functional information extraction. The goal of the present study is to experimentally validate the merit of this technique for optical properties and intrinsic fluorescence extraction from tissue mimicking phantoms. Phantom studies were carried out in which HbO2 was used as absorber, polystyrene sphere was used as scatterer, and stilbene was used for fluorescence emission. Two sets of phantoms corresponding to two absorption levels and one scattering level were made, and 4 fluorophore concentrations were titrated in each set. The results indicate that both optical properties and intrinsic fluorescence can be extracted with high accuracy, implying that it’s feasible to extract complementary structural and functional information with steady-state spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2714 (2012)
Factors Influencing the Ability of Fluorescence Emission and Fluorescence Quenching Experimental Research
YAN Zhi-dan, SUN Li-dong, HU Chun-guang, HU Xiao-tang, and Peter Zeppenfeld
The fluorescence emission intensity is vital to scientific observation using fluorescence microscopy. Three important factors influencing the intensity of fluorescence emission were theoretical analyzed, including the absorption ability of excitation photons, fluorescence quantum yield, and fluorescence saturation &The fluorescence emission intensity is vital to scientific observation using fluorescence microscopy. Three important factors influencing the intensity of fluorescence emission were theoretical analyzed, including the absorption ability of excitation photons, fluorescence quantum yield, and fluorescence saturation & fluorescence quenching. The authors pointed out that fluorescence molecules with large optical absorption cross section and high quantum yield can effectively guarantee the fluorescence emission intensity, and one also can avoid unnecessary fluorescence saturation if excitation intensity was determined in a reasonable range. Furthermore, fluorescence quenching experiments were studied in ultra-high vacuum (UHV) and atmospheric environment, respectively. We found that fluorescence quenching in UHV was imperceptible, while the fluorescence intensity in the atmosphere decreased exponentially..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2718 (2012)
Study on Spectral Properties of 5-(Dimethylamino)-N-(4-(2-(2-Hydroxybenzylidene)Hydrazinecarbonyl)Phenyl)Naphthalene-1-Sulfonamide for Selective Detection of Zn2+
WU Hong-mei, GUO Yu, and ZHOU Peng
A novel dansyl sulfonamide-based fluorescence probe DH1 ［(E)-5-(dimethylamino)-N-(4-(2-(quinolin-2-ylmethylene)hydrazinecarbonyl)phenyl)aphthalene-1-sulfonamide］ was synthesized for detection of Zn2+. Spectral properties of DH1 such as UV-Vis, fluorescence spectra and ESI-MS for recognition of Zn2+ were studied. SpectrA novel dansyl sulfonamide-based fluorescence probe DH1 ［(E)-5-(dimethylamino)-N-(4-(2-(quinolin-2-ylmethylene)hydrazinecarbonyl)phenyl)aphthalene-1-sulfonamide］ was synthesized for detection of Zn2+. Spectral properties of DH1 such as UV-Vis, fluorescence spectra and ESI-MS for recognition of Zn2+ were studied. Spectrophotometric titration and ESI-MS spectra indicate the formation of a 1∶1 complex of Zn2+ with DH1. The results show that DH1 has high quantum yield of 0.53 and low the detection limit of 1.0×10－7 mol·L-1 for detection of Zn2+ in acetonitrile/water(9∶1, volume ratio). Moreover, no fluorescence intensity changes were observed in the presence of other common metal ions such as K+, Li+, Na+, Mg2+, Ca2+, Cr3+, Mn2+, Ni2+, Pb2+, Cu2+, Cd2+, Co2+, Fe2+ and Hg2+, indicating that DH1 has excellent selectivity and high sensitivity for detection of Zn2+..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2722 (2012)
Rapid Identification of Hogwash Oil by Using Synchronous Fluorescence Spectroscopy
SUN Yan-hui, AN Hai-yang, JIA Xiao-li, and WANG Juan
To identify hogwash oil quickly, the characteristic delta lambda of hogwash oil was analyzed by three dimensional fluorescence spectroscopy with parallel factor analysis, and the model was built up by using synchronous fluorescence spectroscopy with support vector machines (SVM). The results showed that the characterisTo identify hogwash oil quickly, the characteristic delta lambda of hogwash oil was analyzed by three dimensional fluorescence spectroscopy with parallel factor analysis, and the model was built up by using synchronous fluorescence spectroscopy with support vector machines (SVM). The results showed that the characteristic delta lambda of hogwash oil was 60 nm. Collecting original spectrum of different samples under the condition of characteristic delta lambda 60 nm, the best model was established while 5 principal components were selected from original spectrum and the radial basis function (RBF) was used as the kernel function, and the optimal penalty factor C and kernel function g were 512 and 0.5 respectively obtained by the grid searching and 6-fold cross validation. The discrimination rate of the model was 100 % for both training sets and prediction sets. Thus, it is quick and accurate to apply synchronous fluorescence spectroscopy to identification of hogwash oil..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2726 (2012)
An Improved Characteristic Spectral Selection Method for Multicomponent Gas Quantitative Analysis Based on Tikhonov Regularization
TANG Xiao-jun, ZHANG Lei, WANG Er-zhen, LI Zhe-bu, MENG Yong-peng, and LIU Jun-hua
In the present paper, an improved approach to the TR characteristic spectral selection is presented. For this approach, two ideas of TR1-norm and TR2-norm are used, two constraint items, spectral line distance and minimizing absolute value of coefficient are introduced, and a general formula of ill-posed optimization pIn the present paper, an improved approach to the TR characteristic spectral selection is presented. For this approach, two ideas of TR1-norm and TR2-norm are used, two constraint items, spectral line distance and minimizing absolute value of coefficient are introduced, and a general formula of ill-posed optimization problem is established. The formula can reduce effectively the errors caused by experienced and experimental method when used in determining the regular matrix and parameter. Finally, the improved approach presented in the paper was used in the analysis of alkane gas mixture, with methane, ethane, propane, n-butane, iso-butane, n-pentane and iso-pentane included. The concentration range is 0.01%~20%. The experimental results show that the predicting error square is only 2.6×10-4, and the coefficient of determination is 0.959 2, which means that preceding accuracy is high, and that the practicability of TR regularization has been enhanced..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2730 (2012)
Radiation Thermometry Based on Calibration of Spectral Responsivity
XIN Cheng-yun, CHENG Xiao-fang, and ZHANG Zhong-zheng
True surface temperatures can be determined by measurements of radiation emitted by the object. The non-spectral parameter in the radiation measurement equation is the function of the relative position between the target and the lens, so calibration of space position is necessary for temperature measurement, when emissTrue surface temperatures can be determined by measurements of radiation emitted by the object. The non-spectral parameter in the radiation measurement equation is the function of the relative position between the target and the lens, so calibration of space position is necessary for temperature measurement, when emissivity and temperature are measured simultaneously. In the present paper, the non-spectral parameter was included into the undetermined coefficients of emissivity modeled by finite series, which will not affect the solution of true surface temperature. Therefore, radiation thermometry can be accomplished without calibration of space position and normalization of measurement data. And not the true spectral emissivity but the trend of it can be measured. Two special examples were investigated, respectively. The results indicate that when the effective wavelength of each channel is different, multi-wavelength radiation thermometry equations have the unique solution, while the number of the multiband ones may be zero, one, two or even three..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2735 (2012)
Analysis of UV-Visible Absorption Spectrum on the Decolorization of Industrial Wastewater by Disinfection
HUANG Xin, WANG Long-yong, GAO Nai-yun, and LI Wei-guo
The UV-Visible absorption spectrum of industrial wastewater was explored to introduce a substituting method determining the color of water, and to compare the decolorization efficacy of different disinfectants. The results show that the visible absorption spectrum(350～600 nm), instead of ultraviolet absorption spectrumThe UV-Visible absorption spectrum of industrial wastewater was explored to introduce a substituting method determining the color of water, and to compare the decolorization efficacy of different disinfectants. The results show that the visible absorption spectrum(350～600 nm), instead of ultraviolet absorption spectrum, should be applied to characterize the color of wastewater. There is a good correlation between the features of visible absorption spectrum and the true color of wastewater. Both ozone and chlorine dioxide has a better decolorization performance than chlorine. However, the color of chlorine dioxide itself has a negative effect on decolorization. The changes in the features of visible absorption spectrum effectively reflect the variations in the color of wastewater after disinfection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2739 (2012)
Spatial Localized Distribution of Modes in Two-Dimension Random Medium
YAO Ke, FENG Guo-ying, YANG Li-ling, YI Jia-yu, and ZHOU Shou-huan
Based on the time dependent theory, FDTD algorithm was used to numerically solve Maxwell’s equations and rate equations. By dividing the two-dimension random medium, the emission spectra of different region under different pumping intensities were obtained. The calculated results show that the emission spectra of diffeBased on the time dependent theory, FDTD algorithm was used to numerically solve Maxwell’s equations and rate equations. By dividing the two-dimension random medium, the emission spectra of different region under different pumping intensities were obtained. The calculated results show that the emission spectra of different region are different, the energy of emission is mainly distributed in some certain region, and the pumping efficiency is different. Also spatial extent overlap of modes is reproduced. With this method, the dependence of random distribution on lasing can be analyzed and it should be useful for the preparation of pseudo-random medium..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2743 (2012)
A Study on Blood Flow Measurement by Diffuse Correlation Spectroscopy
LIANG Jia-ming, WANG Jing, MEI Jian-sheng, and ZHANG Zhen-xi
Blood flow plays an important role in clinical diagnosis and treatment, and noninvasive measurement of blood flow is the expectation of both doctors and patients. In the present work, the authors employed near-infrared diffuse correlation spectroscopy (DCS) method to measure blood flow noninvasively. The relationship bBlood flow plays an important role in clinical diagnosis and treatment, and noninvasive measurement of blood flow is the expectation of both doctors and patients. In the present work, the authors employed near-infrared diffuse correlation spectroscopy (DCS) method to measure blood flow noninvasively. The relationship between speckle intensity fluctuations of the scattering light and moving blood cells in tissue was theoretically analyzed. A theoretical model and blood flow measurement system were built. Blood flow was derived by calculating the electric field temporal autocorrelation function of speckle on tissue surface. Forearm blood flow was measured in healthy human subject during cuff inflation and deflation. Experimental results show that noninvasive blood flow measurement by this system is feasible. The results also suggest that this approach can provide blood flow information throughout the whole depth profile of the tissue..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2749 (2012)
Observations of Snow Mixed Pixel Spectral Characteristics Using a Ground-Based Spectral Radiometer and Comparing with Unmixing Algorithms
HAO Xiao-hua, WANG Jie, WANG Jian, HUANG Xiao-dong, LI Hong-yi, and LIU Yan
The unmixing algorithms of mixed snow pixels and the fractional snow cover products are an important research direction for snow remote sensing. In the present study, we first designed the mixed snow pixels of different snow fraction/proportion in Northern Xinjiang, China as ground truth. Then, a SVC HR-1024 ground-basThe unmixing algorithms of mixed snow pixels and the fractional snow cover products are an important research direction for snow remote sensing. In the present study, we first designed the mixed snow pixels of different snow fraction/proportion in Northern Xinjiang, China as ground truth. Then, a SVC HR-1024 ground-based spectral radiometer was used for measuring the spectral property of this designed pixel for different snow fractions and different underlying surfaces. Finally, using the measured spectral data, the four mixed-pixel decomposition models were validated and evaluated for their performance in terms of accuracy and computational efficiency. The results showed that the reflectivity does not decline linearly with the reduction of snow ratio in the pixel, and that the unmixing accuracy inversely depends on the scales of the observation. Further, the comparison of the above mentioned unmixing algotihms showed that the linear regression method has the worst accuracy, especially when the snow proportion is less than 50%; the accuracy of sparse regression algorithm and non-negative matrix factorization were slightly higher than the full constrained linear mixed-pixel decomposition; however, full constrained linear mixed-pixel decomposition method had higher computational efficiency than the other two methods; the sparse regression algorithm has lowest computational efficiency. With unmixing remote sensing images, due to the large data volumes, we must consider the algorithms’ computational efficiency. This study would promote quantitative researches on snow mixed pixel decomposition, and provide a theoretical basis for accurately extracting the snow coverage of interest area using remote sensing images..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2753 (2012)
Mineralogy and Genesis of Mixed-Layer Clay Minerals in the Jiujiang Net-Like Red Soil
YIN Ke, HONG Han-lie, LI Rong-biao, HAN Wen, WU Yu, GAO Wen-peng, and JIA Jin-sheng
Mineralogy and genesis were investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) to understand the mineralogy and its genesis significance of mixed-layer clay minerals in Jiujiang red soil section. XRD and FTIR results sMineralogy and genesis were investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) to understand the mineralogy and its genesis significance of mixed-layer clay minerals in Jiujiang red soil section. XRD and FTIR results show that the net-like red soil sediments are composed of illite, kaolinite, minor smectite and mixed-layer illite-smectite and minor mixed-layer kaolinite-smectite. HRTEM observation indicates that some smectite layers have transformed into kaolinite layers in net-like red soil. Mixed-layer illite-smectite is a transition phase of illite transforming into smectite, and mixed-layer kaolinite-smectite is a transitional product relative to kaolinite and smectite. The occurrence of two mixed-layer clay species suggests that the weathering sequence of clay minerals in net-like red soil traversed from illite to mixed-layer illite-smectite to smectite to mixed-layer kaolinite-smectite to kaolinite, which indicates that net-like red soil formed under a warm and humid climate with strengthening of weathering..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2765 (2012)
Effect of Near Infrared Spectrum on the Precision of PLS Model for Oil Yield from Oil Shale
WANG Zhi-hong, LIU Jie, CHEN Xiao-chao, SUN Yu-yang, YU Yang, and LIN Jun
It is impossible to use present measurement methods for the oil yield of oil shale to realize in-situ detection and these methods unable to meet the requirements of the oil shale resources exploration and exploitation. But in-situ oil yield analysis of oil shale can be achieved by the portable near infrared spectroscopIt is impossible to use present measurement methods for the oil yield of oil shale to realize in-situ detection and these methods unable to meet the requirements of the oil shale resources exploration and exploitation. But in-situ oil yield analysis of oil shale can be achieved by the portable near infrared spectroscopy technique. There are different correlativities of NIR spectrum data formats and contents of sample components, and the different absorption specialities of sample components shows in different NIR spectral regions. So with the proportioning samples, the PLS modeling experiments were done by 3 formats (reflectance, absorbance and K-M function) and 4 regions of modeling spectrum, and the effect of NIR spectral format and region to the precision of PLS model for oil yield from oil shale was studied. The results show that the best data format is reflectance and the best modeling region is combination spectral range by PLS model method and proportioning samples. Therefore, the appropriate data format and the proper characteristic spectral region can increase the precision of PLS model for oil yield form oil shale..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2770 (2012)
Spectral Characteristics and Identification Research of Soybean under Different Disease Stressed
JIANG Jin-bao, LI Yi-fan, GUO Hai-qiang, LIU Yi-qing, and CHEN Yun-hao
The objective of this paper is to identify disease and its severity of soybean by using single leaf spectral data in the field. The soybean spectral were measured in the Sutton Bonington Campus of University of Nottingham( 52.8°N, 1.2°W), which infected rust disease(RD) and common mosaic disease (CMD), respecThe objective of this paper is to identify disease and its severity of soybean by using single leaf spectral data in the field. The soybean spectral were measured in the Sutton Bonington Campus of University of Nottingham( 52.8°N, 1.2°W), which infected rust disease(RD) and common mosaic disease (CMD), respectively, and continuum removal method was used to process the original spectral data, and sensitive bands were selected for disease and disease severity, and vegetation index was designed for identifying RD and CMD of soybean. The result showed spectral reflectance of soybean under CMD stressed is more than that of health in the visible region. However, spectral reflectance of soybean under RD stressed will decrease in the green region and that will increase in the red region with disease severity increasing. According to the spectral changing features, a new index R500×R550/R680 was designed for identifying the disease of soybean. In order to test the index identifying disease ability, the J-M distances were calculated among health, RD and CMD. The result indicated index R500×R550/R680 can better identify RD and CMD, at the same time, the index has good ability for discriminating the disease severity of soybean. The research results of this paper has important theoretical value for crops disease monitoring and prevention and practical application meanings..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2775 (2012)
Study on the Nutrition of Alpine Meadow Based on Hyperspectral Data
WANG Xun, LIU Shu-jie, JIA Hai-feng, CHAI Sha-tuo, DANG An-rong, LIU Xue-hua, HAO Li-zhuang, and CUI Zhan-hong
Remote sensing monitoring of alpine grassland nutritional status is a key factor of grassland reasonable utilization, also a difficulty for dynamic vegetation monitoring. The present paper studies the correlations between vegetation nutrition and hyperspectral data. The results showed that two band ratio models have a Remote sensing monitoring of alpine grassland nutritional status is a key factor of grassland reasonable utilization, also a difficulty for dynamic vegetation monitoring. The present paper studies the correlations between vegetation nutrition and hyperspectral data. The results showed that two band ratio models have a significant correlation with biomass, air-DM, P, CF, and CP. MAXR models have a significant correlation with most of nutrition index when selected wavebands equaled five. On the whole, the MAXR model precedes two band ratio models. Using MAXR models to estimate air-DM, P and CF can obtain higher accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2780 (2012)
Research on the Parameter Drift Problem of Near Infrared Spectra Based Corn Variety Discrimination Technology
ZHANG Li-ping, LI Wei-jun, WANG Ping, and AN Dong
Aiming to differentiate 13 varieties of corn, present paper proposes an effective approach to solving the parameter drift problem of spectrum instruments. Remarkable drift has been found among the inter-day data when using the identical spectrum instrument to acquire sample data at different times, modeling with the inAiming to differentiate 13 varieties of corn, present paper proposes an effective approach to solving the parameter drift problem of spectrum instruments. Remarkable drift has been found among the inter-day data when using the identical spectrum instrument to acquire sample data at different times, modeling with the intra-day data, and testing with the rest. The correct recognition rate is reduced to only 7.69% in the condition of severe drift. To tackle this problem, this paper proposes a supervised feature-based inter-day combination modeling approach, at first, the representative sample data acquired at multiple times will be selected to make up the modeling set, and then the PLS+LDA algorithm will be applied to extract the feature of varieties which is independent on instrument parameter drift, and finally BPR will be used to identify the varieties. The experiment results indicate that this approach is effective to rectify the data drift at different times, can bring higher recognition rate, and also shows its stability in practice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2785 (2012)
Study on Inversion of Temperature Distribution Based on Principal Components Analysis
HU Xin-yue, GAO Ming-xi, REN Yu, TAN Jian-yao, LI Wei, JIN Kun, SHI San-zhi, and CAI Hong-xing
Multispectral radiation thermometry(MRT) is one of the methods for non-contact temperature measurement. The present MRT could invert only one approximate temperature value, and the actual temperature distribution could not be given. In the present article principal component analysis(PCA) was applied to solve the problMultispectral radiation thermometry(MRT) is one of the methods for non-contact temperature measurement. The present MRT could invert only one approximate temperature value, and the actual temperature distribution could not be given. In the present article principal component analysis(PCA) was applied to solve the problem based on Planck’s laws. For example, in the laser damage target experiments, input laser pulse energy is 34.2 J, the inversion temperature value is 2 700 K from the thermal radiation spectrum. The fitting relative deviation is 0.5%, and when the temperature distribution is from 2 600 to 2 800 K, the fitting relative deviation is reduced to 0.13%. Temperature distribution inversion was shown based on PCA for the first time, and the measurement accuracy of non-contact temperature was improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2789 (2012)
Quantitative Analysis Method of Natural Gas Combustion Process Combining Wavelength Selection and Outlier Spectra Detection
CAO Hui, HU Luo-na, and ZHOU Yan
The present paper uses a combination method of wavelength selection and outlier spectra detection for quantitative analysis of nature gas combustion process based on its near infrared spectra. According to the statistical distribution of partial least squares (PLS) model coefficients and prediction errors, the method rThe present paper uses a combination method of wavelength selection and outlier spectra detection for quantitative analysis of nature gas combustion process based on its near infrared spectra. According to the statistical distribution of partial least squares (PLS) model coefficients and prediction errors, the method realized wavelength selection and outlier spectra detection, respectively. In contrast with PLS, PLS after leave-one-out for outlier detection (LOO-PLS), uninformative variable elimination by PLS (UVE-PLS) and UVE-PLS after leave-one-out for outlier detection (LOO-UVE-PLS), the root-mean-squared error of prediction (RMSEP)based on the method for CH4 prediction model is reduced by 14.33%, 14.33%, 10.96% and 12.21%; the RMSEP value for CO prediction model is reduced by 67.26%, 72.58%, 11.32% and 4.52%; the RMSEP value for CO2 prediction model is reduced by 5.95%, 19.7%, 36.71% and 4.04% respectively. Experimental results demonstrate that the method can significantly decrease the number of selected wavelengths, reduce model complexity and effectively detect outlier spectra. The established prediction model of analytes is more accurate as well as robust..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2799 (2012)
Rapid Determination of Componential Contents and Calorific Value of Selected Agricultural Biomass Feedstocks Using Spectroscopic Technology
SHENG Kui-chuan, SHEN Ying-ying, YANG Hai-qing, WANG Wen-jin, and LUO Wei-qiang
Rapid determination of biomass feedstock properties is of value for the production of biomass densification briquetting fuel with high quality. In the present study, visible and near-infrared (Vis-NIR) spectroscopy was employed to build prediction models of componential contents, i.e. moisture, ash, volatile matter andRapid determination of biomass feedstock properties is of value for the production of biomass densification briquetting fuel with high quality. In the present study, visible and near-infrared (Vis-NIR) spectroscopy was employed to build prediction models of componential contents, i.e. moisture, ash, volatile matter and fixed-carbon, and calorific value of three selected species of agricultural biomass feedstock, i.e. pine wood, cedar wood, and cotton stalk. The partial least squares (PLS) cross validation results showed that compared with original reflection spectra, PLS regression models developed for first derivative spectra produced higher prediction accuracy with coefficients of determination (R2) of 0.97, 0.94 and 0.90, and residual prediction deviation (RPD) of 6.57, 4.00 and 3.01 for ash, volatile matter and moisture, respectively. Good prediction accuracy was achieved with R2 of 0.85 and RPD of 2.55 for fixed carbon, and R2 of 0.87 and RPD of 2.73 for calorific value. It is concluded that the Vis-NIR spectroscopy is promising as an alternative of traditional proximate analysis for rapid determination of componential contents and calorific value of agricultural biomass feedstock..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2805 (2012)
Analysis on Vegetations Spectral Characteristics along the Altitudinal Gradients in South-Facing Slope of Dangxiong Valley
JIAO Quan-jun, ZHANG Bing, LIU Liang-yun, HE Yong-tao, and HU Yong
The present study focused on variation of vegetation types and canopy spectra along the altitudinal gradients in south-facing slope of Dangxiong valley in Tibet. Spectral extraction methods including red edge analysis and vegetation indices were used for vegetation spectral characteristics analysis. Through the hierarcThe present study focused on variation of vegetation types and canopy spectra along the altitudinal gradients in south-facing slope of Dangxiong valley in Tibet. Spectral extraction methods including red edge analysis and vegetation indices were used for vegetation spectral characteristics analysis. Through the hierarchical clustering analysis based on the vegetation spectral features, the feasibility of remote sensing classification of vegetation types along the elevation gradients in the experimental area was evaluated. The experimental results showed that: there were significant differences in spectral features including water index (WI), red edge POSITION (REP), and normalized difference vegetation index (NDVI) in different plots along elevation gradients in the study area, and there were strong correlations between WI and leaf water content, REP and dry biomass, NDVI and vegetation coverage. The hierarchical clustering analysis result of 12 vegetation samples along the altitudinal gradients is consistent with the ground survey, which shows that the selected vegetation spectral features can characterize the vertical distribution of vegetation types in the experimental area. The vegetation spectral analysis in this study can provide the priori knowledge support of spectral characteristics for the vegetation vertical distribution information extraction in the Tibet Plateau..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2810 (2012)
Application of EMD and SPA Algorithm in the Detection of Benzoyl Peroxide Addition in Flour by Spectroscopy
ZHANG Zhi-yong, LI Gang, LIN Ling, CUI Xin-yi, and ZHANG Bao-ju
In order to improve the accuracy of spectroscopy analysis and reduce the modeling wavelength numbers, empirical mode decomposition (EMD) and successive projections algorithm (SPA) were applied together in the measurement of benzoyl peroxide (BPO) additive amount in flour by near infrared spectroscopy. Spectra of flour In order to improve the accuracy of spectroscopy analysis and reduce the modeling wavelength numbers, empirical mode decomposition (EMD) and successive projections algorithm (SPA) were applied together in the measurement of benzoyl peroxide (BPO) additive amount in flour by near infrared spectroscopy. Spectra of flour samples into which BPO were added were collected. Firstly, EMD was implemented to eliminate the noise of original spectra, and then SPA was employed to select the characteristic wavelengths. The precision of the model based on the processed spectra by EMD was greatly improved compared with the model based on the original spectra, with the calibration determination coefficient R2cal increased from 0.81 to 0.899 and the prediction determination coefficient R2pred increased from 0.755 4 to 0.86. Seven characteristic variables were selected from 512 wavelength variables by SPA. And the performance of the model built by the selected characteristic variables (R2cal is 0.863, R2pred is 0.86) was as good as full-spectrum model’s, while the number of modeling variables was greatly reduced by 96.4%. The results indicated that empirical mode decomposition and successive projections algorithm can be effectively used to denoise the spectra and selected characteristic wavelengths for the detection of BPO addition in flour. The seven selected wavelengths in this paper can be a reference for designing portable BPO detection meter..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2815 (2012)
Determination of Trace Cu in Water by Laser-Induced Breakdown Spectroscopy
QIAN Hui-guo, and ZHOU Wei-dong
In the present article, the ordinary printing paper was immerged in the aqueous solution of CuCl2, and used as an absorber for the enrichment of heavy metal copper in liquid, After being taken from the solution and dried, the paper was then analyzed using laser-induced breakdown spectroscopy. This method overcomes the In the present article, the ordinary printing paper was immerged in the aqueous solution of CuCl2, and used as an absorber for the enrichment of heavy metal copper in liquid, After being taken from the solution and dried, the paper was then analyzed using laser-induced breakdown spectroscopy. This method overcomes the drawbacks of splashing and low sensitivity in the process of direct analysis of heavy metal in water sample with LIBS. The Cu 324.7 nm spectral line was used as the analysis line in experiment. The variation in the line intensity at different enrichment time was studied. The calibration curve for the quantitative measurement of Cu in water was established, the detection limit was 0.023 mg·L-1, which is about three orders of magnitude improvement compared with that in ordinary LIBS analysis of heavy metal in solution. It is likely that this technique will be practically helpful in the sensitive analysis of the heavy metal in water..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2820 (2012)
Determination of the Content of Mineral Elements in Cistanche Tubulosa from Different Areas
DU You, SHENG Jin-hua, CUI Xu-sheng, ZHAI Zhi-xi, DONG Xue-hui, and GUO Yu-hai
The contents of mineral elements in Cistanche tubulosa from different areas and in the soil in which they grew were determined by ICP-AES. The results showed that:(1)the contents of K, P, Ca, Mg, Na, Fe, Mn, Zn and B were rich among different samples collected in five locations. (2) the concentrations of 5 macroelementThe contents of mineral elements in Cistanche tubulosa from different areas and in the soil in which they grew were determined by ICP-AES. The results showed that:(1)the contents of K, P, Ca, Mg, Na, Fe, Mn, Zn and B were rich among different samples collected in five locations. (2) the concentrations of 5 macroelements were high values, in which the content of K was the highest in different aeras. the content of Fe was higher than other microelements and specilally, the Fe content from Xinjiang sample reached to 433.56 μg·g-1. (3) the mineral elements absorption rate of Cistanche tubulosa is different in different areas and the absorption ability of K, Na and P was higher than other elements in Cistanche tubulosa.(4)the concentrations and utilization rate of mineral elements in Cistanche tubulosa from Xinjiang was higher than other areas. The results maybe provided scientific data and suggestion for the quality control of Cistanche tubulosa..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2824 (2012)
Analysis of Mineral Elements in Different Organs of Chrysanthemum Indicum L. Based on ICP-AES
CUI Xu-sheng, and GUO Yu-hai
ICP-AES technique was used to analyse the mineral elements in different organs of Chrysanthemum indicum L.. The results show that: (1) The content of K in root, stem, leaves and flower was the highest among macroelements, and can respectively reach to 15.84, 17.74, 31.52 and 37.55 mg·g-1, while the content of Fe wICP-AES technique was used to analyse the mineral elements in different organs of Chrysanthemum indicum L.. The results show that: (1) The content of K in root, stem, leaves and flower was the highest among macroelements, and can respectively reach to 15.84, 17.74, 31.52 and 37.55 mg·g-1, while the content of Fe was the highest in microelements in root, stem, leaves and flower, and can respectively reach to 3 219.90, 433.36, 1 519.46, and 1 426.63 μg·g-1. (2) The accumulation of K, P, Ca, Mg, Mn, Zn and Mo was highest in stem of Chrysanthemum indicum L., and can respectively reach to 240.61, 19.67, 74.87, 18.31 mg·plant-1 and 893.00, 1 039.08, 2.85 μg·plant-1, while the accumulation of Na, Fe and Cu was highest in root, and can respectively reach to 11.51 mg·plant-1, 11 725.27 μg·plant-1, and 235.24 μg·plant-1. (3) The proportion of K∶P, Ca∶Mg, Fe∶Mn, Zn∶Cu was varied in different organs. The results of the study pinpoint the mineral elements in different organs of Chrysanthemum indicum L.and will be a scientific basis for fertilization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2828 (2012)
Determination of Impurity Elements in Edible Phosphate by ICP-MS
LI Tan-ping, and XIE Hua-lin
An octopole reaction system (ORS) inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of Mg, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Cd and Pb in edible phosphate. The sample was digested by HNO3 followed by dilution with ultrapure water, then the above 12 impurity elements in the solutAn octopole reaction system (ORS) inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of Mg, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Cd and Pb in edible phosphate. The sample was digested by HNO3 followed by dilution with ultrapure water, then the above 12 impurity elements in the solution were analyzed directly by ICP-MS. The use of ORS can eliminate the interference of polyatomic ions dramatically. Sc, Y, In and Bi were used to correct the matrix interference and drift. The detection limits of the 12 elements are in the range of 0.004～0.362 μg·L-1. This method is rapid, simple and applicable for the analysis of trace elements in edible phosphate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2834 (2012)
Direct Determination of Heavy Metal Elements in Sweeteners by Inductively Coupled Plasma Mass Spectrometry
NIE Xi-du, LIANG Yi-zeng, FU Liang, and XIE Hua-lin
An analysis method of microwave digestion and inductively coupled plasma-mass spectrometry (ICP-MS) with octopole reaction system (ORS) was established for the determination of 10 heavy metal elements including Cr, Co, Ni, Cu, As, Cd, Sn, Sb, Hg and Pb in sweetener. Samples were decomposed by HNO3 and H2O2 followed by An analysis method of microwave digestion and inductively coupled plasma-mass spectrometry (ICP-MS) with octopole reaction system (ORS) was established for the determination of 10 heavy metal elements including Cr, Co, Ni, Cu, As, Cd, Sn, Sb, Hg and Pb in sweetener. Samples were decomposed by HNO3 and H2O2 followed by dilution with ultrapure water then the above 10 heavy metal elements in the solution were analyzed directly by ICP-MS. The use of ORS can eliminate the interference of polyatomic ions dramatically. 45Sc, 89Y, 115In and 209Bi as internal standard elements were used to compensate matrix effect and signal drift. The optimum conditions for the determination was tested and discussed. Under the optimal conditions, the detection limits of the 10 elements were in the range of 0.003～0.038 μg·L-1, the recovery of the samples was in the range of 93.0%～106.6% and the relative standard deviation(RSD)≤3.4%, which showed that the method was very precise. The technique was applied for the quality control and safety evaluation of sweetener..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2838 (2012)
Adsorption of Heavy Metal Ions on Two Types of Manganese Oxides Analyzed by AAS and AFS
XU Liu, ZHANG Li-chun, HOU Xian-deng, and XU Kai-lai
Two types of manganese oxides, the octahedral layer structure(OL) and the octahedral molecular tunnel structure(OMS), were controllably synthesized via a facilely hydrothermal route and used to remove heavy metal ions(Pb2+, Cu2+, Ni2+, Hg2+) in solutions. The heavy metal ion concentrations before and after adsorption wTwo types of manganese oxides, the octahedral layer structure(OL) and the octahedral molecular tunnel structure(OMS), were controllably synthesized via a facilely hydrothermal route and used to remove heavy metal ions(Pb2+, Cu2+, Ni2+, Hg2+) in solutions. The heavy metal ion concentrations before and after adsorption were determined by atomic absorption spectroscopy (AAS) and atomic fluorescence spectroscopy (AFS) to evaluate the material adsorption performance. The competitive adsorption of the four ions (Pb2+, Cu2+, Ni2+, Hg2+) on manganese oxides was also investigated. The results showed that OMS exhibited better adsorption ability than OL and had excellent adsorption selectivity to Pb2+, with 98% adsorption efficiency in two minutes. Therefore, this can be proposed as a simple, green and efficient method for treatment of polluted water..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2842 (2012)
Determination of Trace Lead in Environmental Water by Cloud Point Extraction-High Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry
SUN Bo-si, REN Ting, ZHAO Li-jiao, and ZHONG Ru-gang
Comparison investigations were performed for the enrichment method of lead in environmental waters, including coprecipitation, ion exchange and cloud point extraction(CPE). CPE was selected as the optimal enrichment method because of its less consumption of water sample, higher enrichment factor and simpler procedure tComparison investigations were performed for the enrichment method of lead in environmental waters, including coprecipitation, ion exchange and cloud point extraction(CPE). CPE was selected as the optimal enrichment method because of its less consumption of water sample, higher enrichment factor and simpler procedure than the other enrichment methods. Pb contents in the water samples from Tonghui River in Beijing were determined by high resolution continuum source graphite furnace atomic absorption spectrometry coupled with CPE enrichment. The results indicate that the limit of detection of the method is 0.08 μg·L-1, the relative standard deviation (RSD) is 1.3% to 4.5% (n=6), the recovery of Pb contents is 93% to 108%, and the enrichment factor of CPE method is 29. The Pb contents in the 13 water samples from Tonghui River all conform to the Environmental Quality Standards for Surface Water (Grade I). Moreover, the Pb content in the whole river exhibits a decreasing trend from Tongzhou district to Chaoyang district..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2847 (2012)
Effects of Long-Term Fertilization on Organic Carbon Functional Groups in Black Soil as Revealed by Synchrotron Radiation Soft X-Ray Near-Edge Absorption Spectroscopy
WANG Nan, WANG Shuai, WANG Qing-he, DONG Pei-bo, LI Cui-lan, ZHANG Jin-jing, GAO Qiang, and ZHAO Yi-dong
A 20 years (1984—2004) stationary field experiment was conducted to evaluate the effects of long-term application of chemical fertilizers (N or NPK) alone or in combination with low (0.125 kg·hm-2) or high dose of corn stalk (0.25 kg·hm-2) on organic carbon functional groups in black soil using synchrotron raA 20 years (1984—2004) stationary field experiment was conducted to evaluate the effects of long-term application of chemical fertilizers (N or NPK) alone or in combination with low (0.125 kg·hm-2) or high dose of corn stalk (0.25 kg·hm-2) on organic carbon functional groups in black soil using synchrotron radiation soft X-ray near-edge absorption spectroscopy (C-1s NEXAFS). Compared with the control (CK) treatment, the aromatic C and the carboxyl C of soil increased, whereas the aliphatic C, the carbonyl C and the aliphatic C/aromatic C ratio decreased after the application of chemical fertilizer alone. After the application of chemical fertilizations in combined with corn stalk, the aromatic C decreased while the aliphatic C and the aliphatic C/aromatic C ratio increased as compared to N or NPK fertilizer treatment. And the change tendency was more obvious with the increase in the dose of corn stalk applied. Regardless of corn stalk application, the aromatic C, the aliphatic C, and the aliphatic C/aromatic C ratio were all higher for NPK than for N fertilizer treatment. The above results indicated that, compared with the no-fertilizer control treatment, the application of chemical fertilizers alone resulted in the relative proportion of aromatic compounds increased whereas that of aliphatic hydrocarbon compounds decreased. On the other hand, the relative proportion of the aliphatic hydrocarbon compounds was higher after the application of chemical fertilizers with than without corn stalk, with high than with low dose of corn stalk, and with NPK than with N fertilization. C-1s NEXAFS spectroscopy could characterize in situ the changes of organic carbon functional groups in soil under long-term stationary fertilization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2853 (2012)
A Novel Method to Determine the Redshifts of Active Galaxies Based on Wavelet Transform
TU Liang-ping, LUO A-li, JIANG Bin, WEI Peng, ZHAO Yong-heng, and LIU Rong
Automatically determining redshifts of galaxies is very important for astronomical research on large samples, such as large-scale structure of cosmological significance. Galaxies are generally divided into normal galaxies and active galaxies, and the spectra of active galaxies mostly have more obvious emission lines. IAutomatically determining redshifts of galaxies is very important for astronomical research on large samples, such as large-scale structure of cosmological significance. Galaxies are generally divided into normal galaxies and active galaxies, and the spectra of active galaxies mostly have more obvious emission lines. In the present paper, the authors present a novel method to determine spectral redshifts of active galaxies rapidly based on wavelet transformation mainly, and it does not need to extract line information accurately. This method includes the following steps: Firstly, we denoised a spectrum to be processed; Secondly, the low-frequency spectrum was extracted based on wavelet transform, and then we could get the residual spectrum through the denoised spectrum subtracting the low-frequency spectrum; Thirdly, the authors calculated the standard deviation of the residual spectrum and determined a threshold value T, then retained the wavelength set whose corresponding flux was greater than T; Fourthly, according to the wavelength form of all the standard lines, we calculated all the candidate redshifts; Finally, utilizing the density estimation method based on Parzen window, we determined the redshift point with maximum density, and the average value of its neighborhood would be the final redshift of this spectrum. The experiments on simulated data and real data from SDSS-DR7 show that this method is robust and its correct rate is encouraging. And it can be expected to be applied in the project of LAMOST..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2858 (2012)
Virtual Design of X-Ray Multi-Spectrum CT Imaging Based on Variable Voltage
CHEN Ping, HAN Yan, and PAN Jin-xiao
In the conventional X-ray imaging, the ray image of the complicated structural component (shape, structure complex and multi-materials) easily exhibits the overexposed and underexposed phenomenon. This is because of the bigger variations in the effective thickness in the orientation of X-ray penetration and the limit oIn the conventional X-ray imaging, the ray image of the complicated structural component (shape, structure complex and multi-materials) easily exhibits the overexposed and underexposed phenomenon. This is because of the bigger variations in the effective thickness in the orientation of X-ray penetration and the limit of the dynamic range of X-ray imaging system. The complete structure information can’t be obtained, and it will impact the quality of X-ray CT image. So the present paper has improved the theory and method of variable voltage X-ray multi-spectrum CT imaging. The new method changes the distribution of X-ray spectrum by changing the voltage, and can realize the matching between the X-ray spectrum and the effective thickness of workpieces. This can expand the dynamic range and ensure the integrity of projection about the workpieces. At the same time, based on the idea of virtual design, the paper has built the variable voltage virtual CT mode based on single-energy and multi-energy, and realized virtual simulation of the variable voltage X-ray CT. At last, the virtual experiment has proved that the theory and method of variable voltage CT imaging is feasible, and the variable voltage CT imaging is the effective method for the complicated structural component..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2863 (2012)
High-Precision Wavelength Calibration of Wide-Band Monochromator
ZHANG Zi-hui, WANG Shu-rong, HUANG Yu, LI Bo, YU Xiang-yang, and LIN Guan-yu
Usually the monochromator is used to output monochromatic light to calibrate the space remote sensing spectrometer. In the present paper, the confidence of space remote sensing spectrometer is used as a standard to evaluate the precision of wide-band monochromator wavelength calibration. Through analysis of the accuracUsually the monochromator is used to output monochromatic light to calibrate the space remote sensing spectrometer. In the present paper, the confidence of space remote sensing spectrometer is used as a standard to evaluate the precision of wide-band monochromator wavelength calibration. Through analysis of the accuracy of the instrument, the monochromator wavelength repeatability error and deviations was obtained respectively. And the intrinsic spectrum of the high pressure mercury lamp and the grating diffraction was used as calibration lines to avoid the error caused by replacing the light source. Through the special method of wavelength calibration to shorten the scan time, the Gaussian fitting was used to look for peaks of wavelength to reduce error. Finally, the relationship derived from polynomial fitting to measure the exact wavelengths’ accuracy of the monochromator and calculate the calibration confidence of the space remote sensing spectrometer. Using this method, we can make wavelength accuracy of the 1.5 M monochromator with wavelength band from 200 to 840 nm to reach to ±0.016 nm, then the confidence of the space remote sensing spectrometer can reach to 99.82%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2870 (2012)
Tunable Diode Laser Absorption Spectroscopy System for Trace Ethylene Detection
PAN Wei-dong, ZHANG Jia-wei, DAI Jing-min, and SONG Kai
Tunable diode laser absorption spectroscopy (TDLAS) was characterized by ultra-narrow line width laser and wavelength modulation, which makes it possible to scan a single absorption line. TDLAS has an advantage in trace gas analysis for its high resolution, high sensitivity and quick response. The 1 626.8 nm absorptionTunable diode laser absorption spectroscopy (TDLAS) was characterized by ultra-narrow line width laser and wavelength modulation, which makes it possible to scan a single absorption line. TDLAS has an advantage in trace gas analysis for its high resolution, high sensitivity and quick response. The 1 626.8 nm absorption line of ethylene was selected for detecting by analyzing its absorption line characteristic. The TDLAS system was developed with a white type multi-pass cell, combined with wavelength modulation and harmonic detection. Ethylene concentration ranges from 20 to 1 200 ppmv were tested using this system. The estimated detection limit of the system is 10 ppmv..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2875 (2012)
Analysis of the Mineral Elements of Sophora Alopecuroides L. at Different Growth Stages
CHEN Xiao-li, WU Yan, ZHENG Lei, DONG Xue-hui, and GUO Yu-hai
Mineral elements content, absoption proportion and requirement of Sophora alopecuroides L. at different stages were studied by ICP-AES technology. The results showed that (1) During mature period, the average proportion for N∶K∶Ca∶Mg∶P∶Na was 11.91∶8.27∶7.54∶1.02∶1.00, and the average proportion for Fe∶Zn∶B∶Cu∶Mn was 2Mineral elements content, absoption proportion and requirement of Sophora alopecuroides L. at different stages were studied by ICP-AES technology. The results showed that (1) During mature period, the average proportion for N∶K∶Ca∶Mg∶P∶Na was 11.91∶8.27∶7.54∶1.02∶1.00, and the average proportion for Fe∶Zn∶B∶Cu∶Mn was 28.91∶2.12∶1.40∶1.18∶1.00； (2)Mineral elements content of every part differs in each period, and stems at vegetative growth stage and seeds at mature period have the highest mineral elements content proportions of the whole plant which were about 45.6% and 36.7% respectively；(3)Sophora alopecuroides L. plants at vegetative growth stage have the largest fertilizer requirement, followed by the flowering period, and the smallest during pod period..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2931 (2012)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 1 (2012)
Research Articles
Determination of Sparfloxacin Concentrations in Chicken Serums and Residues in Chicken Tissues and Manures Using Self-Ordered Ring Fluorescence Microscopic Imaging Technique
DONG Cheng-yu, LIU Yuan-yuan, and LIU Ying
Based on the self-ordered ring (SOR) fluorescence microscopic imaging technique on a hydrophobic glass slide with Zn2+ and cetyltrimethyl ammonium bromide (CTMAB) as sensitizer, and poly (vinyl alcohol) -124 (PVA-124) and NH3-NH4Cl (pH 10.00) as the medium, a method has been developed for determining sparfloxacin (SPFXBased on the self-ordered ring (SOR) fluorescence microscopic imaging technique on a hydrophobic glass slide with Zn2+ and cetyltrimethyl ammonium bromide (CTMAB) as sensitizer, and poly (vinyl alcohol) -124 (PVA-124) and NH3-NH4Cl (pH 10.00) as the medium, a method has been developed for determining sparfloxacin (SPFX) concentrations in chicken serum and residues in chicken tissues and manures. When the droplet volume was 0.20 μL, SPFX was determined in the range of 1.38×10-13～2.03×10-12 mol·ring-1 (or 6.90×10-7～1.02×10-5 mol·L-1), and the limit of detection (LOD) was 14 fmol·ring-1 (or 6.90×10-8 mol·L-1). The recoveries of SPFX at all different spiked levels are in the range of 90.74%～106.61% when the methanol or acetonitrile were used as extracting agent, respectively, and the relative standard deviations (RSDs) are less than 3.0%. This study expands the applied fields of SOR technique in drug concentrations and residues determination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2759 (2012)
Rapid Nondestructive Detection of Water Content in Fresh Pork Based on Spectroscopy Technique Combined with Support Vector Machine
ZHANG Hai-yun, PENG Yan-kun, WANG Wei, ZHAO Song-wei, and LIU Qiao-qiao
Visible near infrared reflectance spectra in the range of 350 nm to 1700 nm were collected from 98 pork samples to develop online, rapid and nondestructive detection system for water content in fresh pork. Median smoothing filter (M-filter), multiplication scatter correlation (MSC) and first derivative (FD) were used aVisible near infrared reflectance spectra in the range of 350 nm to 1700 nm were collected from 98 pork samples to develop online, rapid and nondestructive detection system for water content in fresh pork. Median smoothing filter (M-filter), multiplication scatter correlation (MSC) and first derivative (FD) were used as compound preprocessing method to reduce noise present in the original spectrum. Seventy four samples were randomly selected to develop training model and remaining 24 samples were used to test the model. The optimal punishment parameters for the support vector machine (SVM) were determined by using cross-validation and grid-search in the training set. SVM prediction model was developed with the radial basis function (RBF) and the developed model was compared with the model developed by partial least squares regression (PLSR) method. SVM prediction model based on RBF had the correlation coefficient and root mean standard error of 0.96 and 0.32 respectively in the training set. The model obtained correlation coefficient of 0.87 and root mean square error of 0.67 in the test set. The result thus obtained demonstrates the applicability of SVM model for rapid, nondestructive detection of water content in pork..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 10, 2794 (2012)
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