Journals >Spectroscopy and Spectral Analysis
Contents
2011
Volume: 31 Issue 10
62 Article(s)
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Research Article
Molecular Hyperspectral Imaging (MHSI) System and Application in Biochemical Medicine
LIU Hong-ying, LI Qing-li, WANG Yi-ting, LIU Jin-gao, and XUE Yong-qi
A novel molecular hyperspectral imaging (MHSI) system based on AOTF (acousto-optic tunable filters) was presented. The system consists of microscope, AOTF-based spectrometer, matrix CCD, image collection card and computer. The spectral range of the MHSI is from 550 to 1 000 nm. The spectral resolution is less than 2 nmA novel molecular hyperspectral imaging (MHSI) system based on AOTF (acousto-optic tunable filters) was presented. The system consists of microscope, AOTF-based spectrometer, matrix CCD, image collection card and computer. The spectral range of the MHSI is from 550 to 1 000 nm. The spectral resolution is less than 2 nm, and the spatial resolution is about 0.3 μm. This paper has also presented that spectral curves extracted from the corrected hyperspectral data of the sample, which have been preprocessed by the gray correction coefficient, can more truly represent biochemical characteristic of the sample. The system can supply not only single band images in the visible range, but also spectrum curve of random pixel of sample image. This system can be widely used in various fields of biomedicine, clinical medicine, material science and microelectronics..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2593 (2011)
Rapid Detection of Escherichia coli O157∶H7 Using Surface Plasmon Resonance (SPR) Biosensor
SI Cheng-yan, YE Zun-zhong, WANG Yi-xian, GAI Ling, WANG Jian-ping, and YING Yi-bin
A biosensor based on surface plasmon resonance (SPR) was developed for rapid detection of Escherichia coli O157∶H7. BIACORE 3000 SPR instrument and a dextran-modified sensor chip (CM5) were used. After activation with EDC/NHS, anti-E. coli O157∶H7 antibody was immobilized on the gold surface of the SPR sensor, and thenA biosensor based on surface plasmon resonance (SPR) was developed for rapid detection of Escherichia coli O157∶H7. BIACORE 3000 SPR instrument and a dextran-modified sensor chip (CM5) were used. After activation with EDC/NHS, anti-E. coli O157∶H7 antibody was immobilized on the gold surface of the SPR sensor, and then following ethanolamine was injected, and the chip was ready for E. coli O157∶H7. Regeneration was achieved using NaOH in order to detect several samples. The limit of detection was found to be 3×105 CFU·mL-1 for E. coli O157∶H7, and the change of RU was linearly correlated with the concentration of E. coli O157∶H7 cells (R2=0.99). The detection time ranged from 5 to 7 min, and the result of regeneration was effective which allowed the chip to be reused for more than 50 samples. This method is convenient, and stable, and shows potentials for applications in food areas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2598 (2011)
Transmission Efficiency Analysis of Near-Field Fiber Probe Using FDTD Simulation
HUANG Wei, DAI Song-tao, WANG Huai-yu, and ZHOU Yun-song
A fiber probe is the key component of near-field optical technology which is widely used in high resolution imaging, spectroscopy detection and nano processing. How to improve the transmission efficiency of the fiber probe is a very important problem in the application of near-field optical technology. Based on the resA fiber probe is the key component of near-field optical technology which is widely used in high resolution imaging, spectroscopy detection and nano processing. How to improve the transmission efficiency of the fiber probe is a very important problem in the application of near-field optical technology. Based on the results of 3D-FDTD computation, the dependence of the transmission efficiency on the cone angle, the aperture diameter, the wavelength and the thickness of metal cladding is revealed. The authors have also made a comparison between naked probe and the probe with metal cladding in terms of transmission efficiency and spatial resolution. In addition, the authors have discovered the fluctuation phenomena of transmission efficiency as the wavelength of incident laser increases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2602 (2011)
Studies on the Anomalous IR Properties of CoPt Nanorods
ZHOU Xin-wen, ZHANG Rong-hua, JIANG Yan-xia, and SUN Shi-gang
One-dimensional CoPt nanorods were obtained through the galvanic displacement reaction and chemical reduction. The average diameter of the nanorods was measured to be about 166.3 nm and the length was mostly between 1.0 and 5.0 μm obtained from the scanning electron microscopy (SEM) measurement. The IR optical propertiOne-dimensional CoPt nanorods were obtained through the galvanic displacement reaction and chemical reduction. The average diameter of the nanorods was measured to be about 166.3 nm and the length was mostly between 1.0 and 5.0 μm obtained from the scanning electron microscopy (SEM) measurement. The IR optical properties of the CoPt nanorods and bulk Pt were investigated by in situ FTIR reflection spectroscopy employing CO adsorption as probe reaction at the solid/gas interface. The results of in situ FTIR indicated that bulk Pt shows a normal IR optical property and the CoPt nanorods display abnormal infrared effects (AIREs). The authors can obtain the same results whether the CoPt nanorods were loaded on glassy carbon (GC) or Au substrates. These results demonstrated that the AIREs were generated mainly by CoPt nanorods and the influence of the substrate materials can be neglected. The study confirmed that one-dimensional CoPt nanorods show AIREs, and throw a new sense to comprehend the anomalous IR properties observed on low-dimensional nanomaterials..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2606 (2011)
Study on Spectral Gain Characterization of FWM Processes with Multi-Frequency Pumps in Photonic Crystal Fiber
HUI Zhan-qiang
Spectral gain induced by four-wave-mixing with multi-frequency pump was investigated by exploiting the data signal and continue lights co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of pump lights, polarization state of orthogonal or parallel of pump Spectral gain induced by four-wave-mixing with multi-frequency pump was investigated by exploiting the data signal and continue lights co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of pump lights, polarization state of orthogonal or parallel of pump lights, polarization mismatch of signal light versus orthogonal pump lights, total power of signal and probe light on the spectrum gain were analyzed. The results show that good FWM gain effects with multi-frequency pump can be obtained in 36.4 nm wavelength range when power ratio of pump to probe light is appropriate and with identical polarization. Furthermore, the gain of FWM with multi-frequency pump is very sensitive to polarization fluctuation and the different idle waves obtain different gain with the variation in signal polarization state. Moreover, the impact of pump numbers was investigated. The obtained results would be helpful for further research on ultrahigh-speed all optical signal processing devices exploiting the FWM with multi-frequency pump in PCF for future photonics network..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2611 (2011)
A Review of Classification Methods of Remote Sensing Imagery
JIA Kun, LI Qiang-zi, TIAN Yi-chen, and WU Bing-fang
Remote sensing data classification is an important way of information extraction and a hot research topic of remote sensing technique. Classification method of remote sensing data is an important issue, and effective selection of appropriate classifier is especially significant for improving classification accuracy. AlRemote sensing data classification is an important way of information extraction and a hot research topic of remote sensing technique. Classification method of remote sensing data is an important issue, and effective selection of appropriate classifier is especially significant for improving classification accuracy. Along with the development of remote sensing technique, traditional parametric classifier is difficult to meet accuracy requirement, leading to the rapid development of intelligent algorithm based non-parametric classifiers. Recently, combined classifiers become a new hot topic for its ability of utilizing complement information of single classifier. In the present paper, characters and advantages of different classifiers as well as the research prospect are analyzed. The paper provides a scientific reference for the development of remote sensing data classification technique..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2618 (2011)
Terahertz Spectroscopic Investigation of Lanthanide-Doped Nano-TiO2
FENG Xiu-jun, HUANG Wan-xia, SHI Qi-wu, ZHANG Yu-bo, LUO Yi, and ZHANG Ya-xin
Lanthanide-doped nano-TiO2 samples with different Ti/Ln (Ln=Ce, Nd, and Sm) were synthesized by sol-gel method. The samples were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS) and terahertz time-domain spectroscopy(THz-TDS). The results indiLanthanide-doped nano-TiO2 samples with different Ti/Ln (Ln=Ce, Nd, and Sm) were synthesized by sol-gel method. The samples were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS) and terahertz time-domain spectroscopy(THz-TDS). The results indicate that Ce, Nd, and Sm ions were uniformly dispersed into the TiO2; and the infrared activities of lanthanide-deped nano-TiO2 were much stronger than Undoped nano-TiO2, the refractive index of anatase TiO2 declines with frequency increasing in the frequency range of 0.2～1.70 THz at room temperature, and it exhibits anomalous dispersion. Unique characteristic absorption peaks at 1.35 and 1.58 THz were observed from Ce-doped nano-TiO2. Compared with undoped nano-TiO2, the absorption edges of Ce-doped nano-TiO2 were red-shifted remarkably and those of Nd and Sm ions doped nano-TiO2 were blue-shifted. Sm-doped nano-TiO2 has induced the least dielectric losses in the frequency range of 0.2～1.7 THz, and the average value is 0.05..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2624 (2011)
Terahertz Spectroscopic Investigation of Elaidic Acid
KANG Xu-sheng, ZHANG Guang-xin, CHEN Xi-ai, HUANG Ping-jie, HOU Di-bo, and ZHOU Ze-kui
The optical properties of elaidic acid in the THz band were investigated by using THz time-domain spectroscopy (THZ-TDS). The absorption and refractive index spectra in the frequency range from 0.5 to 2.5 THz were obtained at room temperature under nitrogen atmosphere, and the results show that elaidic acid had some chThe optical properties of elaidic acid in the THz band were investigated by using THz time-domain spectroscopy (THZ-TDS). The absorption and refractive index spectra in the frequency range from 0.5 to 2.5 THz were obtained at room temperature under nitrogen atmosphere, and the results show that elaidic acid had some characteristic absorption peaks, and the average refractive index of the sample was 1.43. The structure and vibrational frequencies of elaidic acid molecule in the THz range were simulated by the B3LYP algorithm of density functional theory, and the THz characteristic absorption peaks of elaidic acid molecule were identified by using Gaussian View software. The results show that the experimental and theoretical results agree in general, and the observed absorption peaks in the THz range were mainly caused by the intramolecular and intermolecular vibrations jointly. At the same time, the fingerprint spectra of elaidic acid in the THz band verify that the time-domain terahertz spectroscopy can be used to detect oleic acid, and this study provides a new experimental method for the detection of trans fatty acids in food..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2629 (2011)
Influence of Laser Power and Incident Angle as well as Testing Distance on Laser Inducted Breakdown Spectroscopy (LIBS) Technology for
ZHAI Yang, ZHU Ri-hong, SHEN Hua, and GU Jin-liang
Laser inducted breakdown spectroscopy (LIBS) technology has been used widely for the multi-element analysis of different samples and also an effective way to realize the spectroscopy diagnosis applied to calculating the electron temperature and vibration-rotation temperature etc of some certain elements. It is a highlyLaser inducted breakdown spectroscopy (LIBS) technology has been used widely for the multi-element analysis of different samples and also an effective way to realize the spectroscopy diagnosis applied to calculating the electron temperature and vibration-rotation temperature etc of some certain elements. It is a highly effective measurement for its non-contact and nondestructive on-line analysis with the help of a high-speed response CCD camera. In the present paper, the authors tested an alley though LIBS technology to determine its elements in terms of species and quantities and also discussed some influences of the incident angle and the power changes of the laser beam as well as the measurement distance changes on the experimental results and and gave appropriate theoretical explanation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2634 (2011)
Application of Data Fusion of Microscopic Spectral Imaging in Reservoir Characterization
LI Jing, ZHA Ming, GUO Yuan-ling, and CHEN yong
In recent years, spectral imaging technique has been applied widely in mineralogy and petrology. The technique combines the spectral technique with imaging technique. The samples can be analyzed and recognized both in spectra and space by using the technique. However, the problem is how to acquire the needful informatiIn recent years, spectral imaging technique has been applied widely in mineralogy and petrology. The technique combines the spectral technique with imaging technique. The samples can be analyzed and recognized both in spectra and space by using the technique. However, the problem is how to acquire the needful information from a large number of data of spectral imaging, and how to enhance the needful information. In the present paper, the experimental data were processed by using the technique of data fusion of microscopic spectral imaging. The space distribution map of chemical composition and physical parameters of samples were obtained. The result showed that the distribution of different hydrocarbon in the reservoirs, pore connectivity, etc. were revealed well. The technique of data fusion of microscopic spectral imaging provided a new method for reservoir characterization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2639 (2011)
Simulation of Polarization SAR Imaging of Ocean Surface
GUO Ding, GU Xing-fa, YU Tao, Fernado N, LI Juan, and CHEN Xing-feng
The polarization synthetic aperture radar (SAR) imaging simulation is of great significance to ocean surface scattering. According to the theory of wind-wave spectrum, rough ocean surface was modeled in the present paper using the two-scale-model. This treatment takes both the large scale and small scale surface into aThe polarization synthetic aperture radar (SAR) imaging simulation is of great significance to ocean surface scattering. According to the theory of wind-wave spectrum, rough ocean surface was modeled in the present paper using the two-scale-model. This treatment takes both the large scale and small scale surface into account. By using the velocity bunching (VB) theory, Bragg scattering model and the small perturbation model (SPM), the polarization SAR system can simulate the ocean surface with various parameters and ocean states. The effects of the parameters of ocean waves and the parameters of SAR system were analyzed. Finally, some useful conclusions were drawn, which are helpful for extracting the information of ocean surface. The method is an effective way in the ocean SAR design and the ocean surface research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2643 (2011)
Measuring Method of Spatial and Spectral Distribution of Hollow Cathode Lamp
WU Zhen-zhou, DU Xue-wei, LI Chao-yang, KE Gang-yang, and WANG Qiu-ping
In the present paper, the authors propose a method to measure the spatial and spectral distribution of hollow cathode lamp by imaging spectrometer. A push-broom convex grating imaging spectrometer based on Offner system is presented, with wavelength range 400~1 000 nm, field angle 22° and spectral resolution 2~3 nIn the present paper, the authors propose a method to measure the spatial and spectral distribution of hollow cathode lamp by imaging spectrometer. A push-broom convex grating imaging spectrometer based on Offner system is presented, with wavelength range 400~1 000 nm, field angle 22° and spectral resolution 2~3 nm. The spatial distribution of Hg hollow cathode lamp was measured for the first time; this gives the spatial intensity distribution for different wavelengths and spectral distribution at different positions, with high spatial and spectral resolution. Also the hyperspectral data under different working current condition was obtained in order to analyze the differences of the distribution. It will be a powerful tool for the spatial and spectral properties measurement of hollow cathode lamps and other kinds of light sources..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2647 (2011)
Study of Plasma Temperature Measurements for Oxygen Discharge
LI Liu-cheng, WANG Zeng-qiang, LI Guo-fu, and DUO Li-ping
A radio-frequency discharge setup was constructed by two shell-shaped copper electrodes and a 30 cm long pyrex glass tube (i.d.=1.65 cm) to examine the gas temperature of oxygen plasma in electric discharge oxygen iodine laser. The discharge was supplied by a 500 watt, 13.56 MHz radio-frequency power. The gas pressure A radio-frequency discharge setup was constructed by two shell-shaped copper electrodes and a 30 cm long pyrex glass tube (i.d.=1.65 cm) to examine the gas temperature of oxygen plasma in electric discharge oxygen iodine laser. The discharge was supplied by a 500 watt, 13.56 MHz radio-frequency power. The gas pressure in the discharge cavity was 1 330 Pa. The temperature of oxygen discharge plasma was measured by using the P branch of O2(b, ν=0) rotational emission spectrum. Two methods were used to deduce the oxygen gas temperature. They are Boltzman plotting method and computer simulating spectrum method, respectively. Gauss fitting method was used to distinguish spectrum peaks for lower resolution spectrum. The spectrum peak area was used to characterize the optical emission intensity. The gas temperature of oxygen discharge plasma was obtained by Boltzmann plotting method. Alternatively, the optical emission spectrum was simulated by computer modeling with spectrometer slit function which was obtained by He-Ne laser. Consequently, the gas temperature of oxygen plasma was obtained by comparing the computer simulating spectrum and the experimentally observed spectrum according to the least square fitting rule. The measurement results with the two methods agree well. It was concluded that the simple optical technique can be used conveniently in the temperature diagnostics of oxygen radio-frequency discharge plasma..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2651 (2011)
The Spectral Response Analysis of Activated GaN Photocathode
WANG Xiao-hui, CHANG Ben-kang, ZHANG Yi-jun, HOU Rui-li, and XIONG Ya-juan
GaN photocathode has a wide applicaion in ultraviolet detection because of the outstanding performance. GaN photocathode was activated in ultrahigh vacuum (UHV) system by Cs/O, and the reflection-mode quantum efficiency (QE) was analyzed. The QE is 30%～10% corresponding to the wavelength 240～350 nm , and the QE curve iGaN photocathode has a wide applicaion in ultraviolet detection because of the outstanding performance. GaN photocathode was activated in ultrahigh vacuum (UHV) system by Cs/O, and the reflection-mode quantum efficiency (QE) was analyzed. The QE is 30%～10% corresponding to the wavelength 240～350 nm , and the QE curve is flat. The QE reaches the maximum of 30% at 240 nm. Compared with the abroad result, the QE obtained by us is still inadequate at the short wavelength. The atom arrangement of GaN (0001) was studied. The atom arrangement on the surface was simulated by 3D, and in this way the adsorption of Cs on the GaN(0001) was speculated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2655 (2011)
Measurement of OH Radicals in Flame with High Resolution Differential Optical Absorption Spectroscopy
LIU Yu, LIU Wen-qing, KAN Rui-feng, SI Fu-qi, XU Zhen-yu, HU Ren-zhi, and XIE Pin-hua
The present paper describes a new developed high resolution differential optical absorption spectroscopy instrument used for the measurement of OH radicals in flame. The instrument consists of a Xenon lamp for light source; a double pass high resolution echelle spectrometer with a resolution of 3.3 pm; a multiple-refleThe present paper describes a new developed high resolution differential optical absorption spectroscopy instrument used for the measurement of OH radicals in flame. The instrument consists of a Xenon lamp for light source; a double pass high resolution echelle spectrometer with a resolution of 3.3 pm; a multiple-reflection cell of 20 meter base length, in which the light reflects in the cell for 176 times, so the whole path length of light can achieve 3 520 meters. The OH radicals’6 absorption lines around 308 nm were simultaneously observed in the experiment. By using high resolution DOAS technology, the OH radicals in candles, kerosene lamp, and alcohol burner flames were monitored, and their concentrations were also inverted..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2659 (2011)
Study of the Physical Properties of SnS Thin Films Deposited by Ultrasonic Spray Pyrolysis Method
TANG Ping, LI Bing, LEI Zhi, FENG Liang-huan, CAI Ya-ping, ZHENG Jia-gui, ZHANG Jing-quan, LI Wei, WU Li-li, and ZENG Guang-gen
In the present paper, SnS thin films were deposited by ultrasonic spray pyrolysis method. The influence of the three different precursor concentrations on the properties of SnS thin films was compared. XRD shows that when precursor solution is thiourea (0.5 mol·L-1) + tin tetrachloride (0.5 mol·L-1)+deionizedIn the present paper, SnS thin films were deposited by ultrasonic spray pyrolysis method. The influence of the three different precursor concentrations on the properties of SnS thin films was compared. XRD shows that when precursor solution is thiourea (0.5 mol·L-1) + tin tetrachloride (0.5 mol·L-1)+deionized water, there are SnS and SnO2 mixed phases; when precursor solution is thiourea (0.6 mol·L-1)+tin tetrachloride (0.5 mol·L-1)+deionized water, SnS phase is the dominant diffraction peak, although a certain amount of SnO2 phase is contained; when precursor solution is thiourea (0.7 mol·L-1)+tin tetrachloride (0.5 mol·L-1)+deionized water, thin film after being annealed is single SnS thin film with orthorhombic structure. SEM shows that films are uniform and dense. Furthermore, the particles of films are bigger when thiourea concentration is higher. Transmittance spectrum shows that the influence of precursor concentration on transmittance of thin films is less. Dark I-V and C-V tests of the devices show that junction characteristics of the devices were similar when prepared by three different concentrations of precursor solution, and as the thiourea concentration is higher, the carrier concentration is relatively larger..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2664 (2011)
Investigation on the Molecular Structures and Electronic Absorption Spectra of Tanshinone ⅡA and Tanshinone ⅡA -Cu(Ⅱ) Complex
SHI Jing, SONG Yi, ZHANG Chang-hua, PENG Jin-feng, and LI Ping
Using an intensified spectroscopic detector CCD, the UV-Vis absorption spectra of tanshinone ⅡA and Tanshinone ⅡA-Cu(Ⅱ) complex were acquired. The stable geometric structures of Tanshinone ⅡA and TanshinoneⅡA -Cu(Ⅱ) complex were obtained by using density functional theory method. Based on the optimized geometric structUsing an intensified spectroscopic detector CCD, the UV-Vis absorption spectra of tanshinone ⅡA and Tanshinone ⅡA-Cu(Ⅱ) complex were acquired. The stable geometric structures of Tanshinone ⅡA and TanshinoneⅡA -Cu(Ⅱ) complex were obtained by using density functional theory method. Based on the optimized geometric structures, the electronic absorption spectra of Tanshinone ⅡA and TanshinoneⅡA-Cu(Ⅱ) complex in gas phase and in ethanol solution were calculated by using time-dependent density functional theory. Results show that the solvent effect induces the red shift of spectrum for Tanshinone ⅡA and the blue shift of spectrum for Tanshinone ⅡA-Cu(Ⅱ) complex. The calculated absorption spectra including the solvent effect are in good agreement with the experimental results. The present work first measured and computed the electronic absorption spectra of Tanshinone ⅡA-Cu(Ⅱ) complex..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2668 (2011)
Research on LC-Based Spectral Imaging System for Visible Band
SHEN Zhi-xue, LI Jian-feng, ZHANG Da-yong, WU Jun, LONG Yan, HUANG Li-xian, LIU Hai-tao, LUO Yong-quan, LUO Fei, ZHANG Cui-juan, and YANG Jun-jie
LC-based tunable filter with large aperture has been developed utilizing the effect of electric controlled birefringence. Spectral test indicated that this filter can operate in the visible band with an average 20 nm FWHM. A small scale spectral imaging system was established based on this tunable filter. Spectral imagLC-based tunable filter with large aperture has been developed utilizing the effect of electric controlled birefringence. Spectral test indicated that this filter can operate in the visible band with an average 20 nm FWHM. A small scale spectral imaging system was established based on this tunable filter. Spectral imaging experiments on a certain number of samples show that this system can be tuned continuously with random-access selection of any wavelength, and has a higher level of resolving power in respect of both imaging and spectral tuning in the visible band, which has a brilliant application potentiality in biology, iatrology, environmental protection, resource detection through hyper-spectral imaging or ultra-spectral imaging..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2672 (2011)
Luminescence Characteristics of PVK Doped with Eu-Complex Eu(UVA)3Phen
SUN Qin-jun, XU Zheng, ZHAO Su-ling, ZHANG Fu-jun, and GAO Li-yan
The present work investigates the photoluminescence (PL) and electroluminescence (EL) characteristics of Eu-complex Eu(UVA)3Phen doped PVK with different doping concentrations. The results indicate that there exists Frster energy transfer from PVK to Eu(UVA)3phen in the mixed system. It can get good color purity by opThe present work investigates the photoluminescence (PL) and electroluminescence (EL) characteristics of Eu-complex Eu(UVA)3Phen doped PVK with different doping concentrations. The results indicate that there exists Frster energy transfer from PVK to Eu(UVA)3phen in the mixed system. It can get good color purity by optimizing the doping concentration of host and guest materials. And the authors can obtain the best doping concentration to be 4% in EL device..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2676 (2011)
The Property of White Powder LED with Different Ratio of Phosphor
GUO Wei-ling, CUI De-sheng, CUI Bi-feng, YAN Wei-wei, and LIU Ying
White powder light emitting diodes (LED) with different color temperature were made by using different ratio of yellow to orange silicate phosphor. When the ratio of yellow to orange phosphor was less than 7, the peak wavelength of yellow light in spectra was about 570 nm and the wavelength was about 590 nm as the ratiWhite powder light emitting diodes (LED) with different color temperature were made by using different ratio of yellow to orange silicate phosphor. When the ratio of yellow to orange phosphor was less than 7, the peak wavelength of yellow light in spectra was about 570 nm and the wavelength was about 590 nm as the ratio was greater than 7. With the color temperature increasing, the color rendering index and the luminous efficiency increased at the beginning and then decreased. And color temperature of 5 521 K is the optimal value. The reason was the ineffective excitation of blue light due to higher concentration of phosphor and excess red light in spectra. In contrast, blue light was not excited effectively and red light in spectra was little when the color temperature was higher than 5 521 K. The luminous efficiency was decreased, and the decreased magnitude was inconsistency with the testing temperature from 10 to 80 ℃. This suggests that, besides Auger recombination, the decrease in excitation efficiency of yellow and orange phosphors is different as the temperature rises and orange phosphor’s temperature characteristic is superior to that of yellow phosphor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2680 (2011)
Influence of P3HT∶PCBM Film Formation Process on the Performance of Polymer Solar Cells
ZHOU Jian-ping, CHEN Xiao-hong, and XU Zheng
The performance of heterojunction polymer solar cells (PSCs) based on poly(3-hexylthiophene) (P3HT) and ［6, 6］-phenyl C61-butyric acid methyl ester (PCBM) blends was investigated by changing P3HT∶PCBM film fabrication procedures with fast growth and slow growth methods, respectively. The optimal time of slow growth of The performance of heterojunction polymer solar cells (PSCs) based on poly(3-hexylthiophene) (P3HT) and ［6, 6］-phenyl C61-butyric acid methyl ester (PCBM) blends was investigated by changing P3HT∶PCBM film fabrication procedures with fast growth and slow growth methods, respectively. The optimal time of slow growth of P3HT∶PCBM films was gotten after we systematically changed spin-coating time and preset time before annealing blended films. When P3HT∶PCBM film was spin coated at the speed of 800RPM and spin time ranged from 50 to 80 sec, and then put in petri dish for 30 min before annealing blended films, the power conversion efficiency (PCE) of PSCs reached 3%. Yet PCE of PSCs based on P3HT∶PCBM with fast-growth was only 1.8%. The improved PCE is attributable to the reasonable phase-separation between P3HT and PCBM blended film, which boosted carriers transport and hop. The result indicates that half an hour of preset time for P3HT∶PCBM films before annealing can efficiently finish the slow-growth of blended films, which can save time and decrease cost to fabricate efficient PSCs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2684 (2011)
Near Infrared Reflectance Spectroscopy (NIRS): a Novel Approach to Reconstructing Historical Changes of Primary Productivity in Antarctic Lake
CHEN Qian-qian, LIU Xiao-dong, LIU Wen-qi, and JIANG Shan
Compared with traditional chemical analysis methods, reflectance spectroscopy has the advantages of speed, minimal or no sample preparation, non-destruction, and low cost. In order to explore the potential application of spectroscopy technology in the paleolimnological study on Antarctic lakes, we took a lake sediment Compared with traditional chemical analysis methods, reflectance spectroscopy has the advantages of speed, minimal or no sample preparation, non-destruction, and low cost. In order to explore the potential application of spectroscopy technology in the paleolimnological study on Antarctic lakes, we took a lake sediment core in Mochou Lake at Zhongshan Station of Antarctic, and analyzed the near infrared reflectance spectroscopy (NIRS) data in the sedimentary samples. The results showed that the factor loadings of principal component analysis (PCA) displayed very similar depth-profile change pattern with the S2 index, a reliable proxy for the change in historical lake primary productivity. The correlation analysis showed that the values of PCA factor loading and S2 were correlated significantly, suggesting that it is feasible to infer paleoproductivity changes recorded in Antarctic lakes using NIRS technology. Compared to the traditional method of the trough area between 650 and 700 nm, the authors found that the PCA statistical approach was more accurate for reconstructing the change in historical lake primary productivity. The results reported here demonstrate that reflectance spectroscopy can provide a rapid method for the reconstruction of lake palaeoenviro nmental change in the remote Antarctic regions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2688 (2011)
Determination of Amino Acid Contents in Cottonseeds Using Near Infrared Reflectance Spectroscopy
HUANG Zhuang-rong, CHEN Jin-hong, LIU Hai-ying, and ZHU Shui-jin
A total of 445 samples with great variability in amino acid contents were harvested for different seasons in different regions for developing calibration equations of amino acid content in cottonseeds. The spectral data of cotton kernel powder was processed using the first derivative mathematical treatment combined witA total of 445 samples with great variability in amino acid contents were harvested for different seasons in different regions for developing calibration equations of amino acid content in cottonseeds. The spectral data of cotton kernel powder was processed using the first derivative mathematical treatment combined with SNV and de-trend, as well as modified partial least squares (MPLS) regression method. The chemometric models for 17 amino acids present in cottonseed were developed, and 12 of them were excellent for the determination of related amino acids, namely asparagic acid, threonine, glutamic acid, glycine, alanine, valine, isoleucine, leucine, phenylalanine, lysine, histidine, and arginine, with RPDc of 3.735~7.132 and determination coefficient (r2) of 0.910~0.979 in external validation. For those 12 amino acids, their values predicted by NIRS are comparable to those obtained by the chemical method with good accuracy. The RPDc of serine, methionine, tyrosine and proline were 2.205~2.814, and their determination coefficient (r2) were 0.800~0.830 in external validation. For those 4 amino acids, the values from NIRS are not so accurate as chemical analysis, but could be used in sample screening in cotton breeding program. While the equation for cystine was useless as its RPDc was only 1.358, which was not suitable for estimating its content in cottonseeds..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2692 (2011)
Application of Two FTIR Pattern Recognition Methods to the Zanthoxylum nitidum Geographical Origins Determination
MAO Xiao-li, ZHENG Juan-mei, LI Zi-da, LEI Xin-chao, HUANG Shu-shi, and LIU Hua-gang
In the present work, the authors explored a rapid method of the Zanthoxylum nitidum geographical origins determination. Based on Fourier transform infrared spectroscopy (FTIR) technology, the band of 1 800～400 cm-1 which is the IR fingerprint of Zanthoxylum nitidum, the Fisher ratio and the soft independent modeling ofIn the present work, the authors explored a rapid method of the Zanthoxylum nitidum geographical origins determination. Based on Fourier transform infrared spectroscopy (FTIR) technology, the band of 1 800～400 cm-1 which is the IR fingerprint of Zanthoxylum nitidum, the Fisher ratio and the soft independent modeling of class analogies (SIMCA) were used to build a classification model. Respectively, four kinds of Zanthoxylum nitidum in the Guangxi region were detected by the model, and the model was verified by calculating their recognition rate and rejection rate. The results show that the authors can accurately extract the overall information of Chinese herbal medicines by using the FTIR, also established a pattern recognition model to predict unknown samples, and obtained satisfactory recognition rate and rejection rate, indicating that the model has stronger ability of identification. The detection on real time was carried out rapidly with the Fisher model, suggesting that the model has more practical value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2697 (2011)
A Novel Approach to NIR Spectral Quantitative Analysis:Semi-Supervised Least-Squares Support Vector Regression Machine
LI Lin, XU Shuo, AN Xin, and ZHANG Lu-da
In near infrared spectral quantitative analysis, the precision of measured samples’ chemical values is the theoretical limit of those of quantitative analysis with mathematical models. However, the number of samples that can obtain accurately their chemical values is few. Many models exclude the amount of samples withoIn near infrared spectral quantitative analysis, the precision of measured samples’ chemical values is the theoretical limit of those of quantitative analysis with mathematical models. However, the number of samples that can obtain accurately their chemical values is few. Many models exclude the amount of samples without chemical values, and consider only these samples with chemical values when modeling sample compositions’ contents. To address this problem, a semi-supervised LS-SVR(S2LS-SVR) model is proposed on the basis of LS-SVR, which can utilize samples without chemical values as well as those with chemical values. Similar to the LS-SVR, to train this model is equivalent to solving a linear system. Finally, the samples of flue-cured tobacco were taken as experimental material, and corresponding quantitative analysis models were constructed for four sample compositions’ content(total sugar, reducing sugar, total nitrogen and nicotine) with PLS regression, LS-SVR and S2LS-SVR. For the S2LS-SVR model, the average relative errors between actual values and predicted ones for the four sample compositions’ contents are 6.62%, 7.56%, 6.11% and 8.20%, respectively, and the correlation coefficients are 0.974 1, 0.973 3, 0.923 0 and 0.948 6, respectively. Experimental results show the S2LS-SVR model outperforms the other two, which verifies the feasibility and efficiency of the S2LS-SVR model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2702 (2011)
Quantitative Analysis of Hybrid Maize Seed Purity Using Near Infrared Spectroscopy
HUANG Yan-yan, ZHU Li-wei, MA Han-xu, LI Jun-hui, SUN Bao-qi, and SUN Qun
A quantitative identification model for testing the purity of hybrid maize seeds was built by near infrared reflectance spectroscopy with quantitative partial least squares (QPLS). The NIR spectra of 123 seeds powder samples (Nongda108 and mother178) with the purity of 60%～100% were collected using MPA spectrometer. AlA quantitative identification model for testing the purity of hybrid maize seeds was built by near infrared reflectance spectroscopy with quantitative partial least squares (QPLS). The NIR spectra of 123 seeds powder samples (Nongda108 and mother178) with the purity of 60%～100% were collected using MPA spectrometer. All samples were divided into two groups: calibration set (82 samples) and validation set (41 samples). Synergy interval partial least squares (SiPLSu) was used for selecting effective spectral regions and building models. The influences of different spectral regions and different calibration samples on the prediction results and different main components were compared. The result showed that the spectral regions 6 000～8 000, 6 000～9 000 and 6 000～10 000 cm-1 all had better prediction results (R2 over 95%). Spectral region 6 000～10 000 cm-1 was regarded the optimum spectral region for building the model with less main components(8), and the determination coefficient (R2) of calibration and validation sets were 96.61% and 97.67% respectively, SEC (standard error of calibration) and SEP (standard error of prediction) were 2.15% and 1.78% respectively, RSDs (relative standard deviation) were 2.04% and 1.94% respectively. Even with different calibration samples, the average determination coefficients (R2) of calibration and validation sets were 96.21% and 95.75%, SEC (standard error of calibration) and SEP (standard error of prediction) were 2.29% and 2.23% respectively, RSDs (relative standard deviation) were 2.81% and 2.73% respectively, which further proved the model’s stability. With the increase in the number of main components, the identification rates in calibration set and validation set gradually increased, when the number of main components reached 8, the model determination coefficients reached the best (96.61% and 97.67%), and related coefficients of true value and predicted value were 98.29% and 98.87% respectively. The results have important value for rapid and accurate testing of hybrid maize seed purity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2706 (2011)
Analysis of Different Parts of Scorpio by Fourier Transform Infrared Spectroscopy
ZHANG Sheng-jun, XU Chang-hua, CHEN Jian-bo, ZHOU Qun, and SUN Su-qin
Fourier transform infrared (FTIR) spectroscopy and second derivative IR spectroscopy were applied to analyze and evaluate different parts of Scorpio. The second derivative IR spectra show clear differences while the origin spectra are quite similar. It was found that proteins are the dominant components in each part anFourier transform infrared (FTIR) spectroscopy and second derivative IR spectroscopy were applied to analyze and evaluate different parts of Scorpio. The second derivative IR spectra show clear differences while the origin spectra are quite similar. It was found that proteins are the dominant components in each part and the tail has distinct proteins compared to the others; fats are mainly stored in the trunk; sulfates are ubiquitous in all parts. Interestingly, the back part of the trunk of degenerative Scorpio contains some purine. It was demonstrated that FTIR spectroscopy integrated with second derivative IR spectroscopy not only can offer a fast, comprehensive and objective methodology for analyzing and evaluating the micro-differences among the various parts of same medicinal materials, but also can provide a rational guidance for medicinal and pharmacological studies..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2711 (2011)
Similarity Analysis of FTIR of Lapis Micae Aureum
WANG Dong, WANG Yong-lu, GUO Xiao, WANG Yi-qun, and WANG Bo-tao
Similarity analysis of FTIR of Lapis Micae Aureum was carried out to find out the relationship between similarity of infrared spectra and the quality of medicine samples, and try to provide a new method for its quality assessment. FTIR was used to analyze Lapis Micae Aureum samples. Then 6 samples with good quality werSimilarity analysis of FTIR of Lapis Micae Aureum was carried out to find out the relationship between similarity of infrared spectra and the quality of medicine samples, and try to provide a new method for its quality assessment. FTIR was used to analyze Lapis Micae Aureum samples. Then 6 samples with good quality were picked up to establish a reference infrared spectra by their infrared spectra. Correlation coefficient method and the included angle cosine method were used to calculate the similarity between sample’s infrared spectra and the reference infrared spectra. For all those 19 samples with characters in accordance with Ch.P, the similarity is above 0.94, and for the others the similarity is less than 0.94. Although some samples’ source meets the requirement of Ch.P, but with poor quality by traditional experience, the similarity is lower than those of good quality. It was concluded that the similarity of infrared spectra of Lapis Micae Aureum is closely related to the quality of medicines. As a result, similarity analysis of FTIR of Lapis Micae Aureum is reliable, and can be used for its quality assessment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2715 (2011)
Research on the Method of Interference Correction for Nondispersive Infrared Multi-Component Gas Analysis
SUN You-wen, LIU Wen-qing, WANG Shi-mei, HUANG Shu-hua, and YU Xiao-man
A method of interference correction for nondispersive infrared multi-component gas analysis was described. According to the successive integral gas absorption models and methods, the influence of temperature and air pressure on the integral line strengths and linetype was considered, and based on Lorentz detuning linetA method of interference correction for nondispersive infrared multi-component gas analysis was described. According to the successive integral gas absorption models and methods, the influence of temperature and air pressure on the integral line strengths and linetype was considered, and based on Lorentz detuning linetypes, the absorption cross sections and response coefficients of H2O, CO2, CO, and NO on each filter channel were obtained. The four dimension linear regression equations for interference correction were established by response coefficients, the absorption cross interference was corrected by solving the multi-dimensional linear regression equations, and after interference correction, the pure absorbance signal on each filter channel was only controlled by the corresponding target gas concentration. When the sample cell was filled with gas mixture with a certain concentration proportion of CO, NO and CO2, the pure absorbance after interference correction was used for concentration inversion, the inversion concentration error for CO2 is 2.0%, the inversion concentration error for CO is 1.6%, and the inversion concentration error for NO is 1.7%. Both the theory and experiment prove that the interference correction method proposed for NDIR multi-component gas analysis is feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2719 (2011)
Application of Near Infrared Spectroscopy (NIR) for Evaluating Cheese Quality
ZOU Qiang, FANG Hui, ZHANG Wei, and HE Yong
Near infrared spectrocopy, widely used in food industry, is a fast, nondestructive analysis method. Although it has been in the detection of the quality of cheese for many years, related research is few in our country. The principle of near infrared spectroscopy and the characteristics are introduced. Cheese process, sNear infrared spectrocopy, widely used in food industry, is a fast, nondestructive analysis method. Although it has been in the detection of the quality of cheese for many years, related research is few in our country. The principle of near infrared spectroscopy and the characteristics are introduced. Cheese process, shrinkage control, maturation process, shelf life, brand classification and detection of components in the application of near infrared spectroscopy are summarized. There is great potential to apply near infrared spectroscopy in cheese quality analysis. It is an urgent task to promote the application of near infrared spectroscopy and the development of China’s cheese industry..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2725 (2011)
Determination of Leymus Chinensis Quality by Near Infrared Reflectance Spectroscopy
SHI Dan, and ZHANG Ying-jun
One hundred fifty Leymus chinensis samples with different growth stage, areas, and preparing method (oven-drying and shading natural dry), were selected to study the potential of determination of crude protein(CP), neutral detergent fiber(NDF)and acid detergent fiber(ADF)in the present research. The quality parameters One hundred fifty Leymus chinensis samples with different growth stage, areas, and preparing method (oven-drying and shading natural dry), were selected to study the potential of determination of crude protein(CP), neutral detergent fiber(NDF)and acid detergent fiber(ADF)in the present research. The quality parameters of Leymus chinensis were firstly predicted using the near infrared reflectance spectroscopy in China. The three models were validated by cross-validation and external-validation. The results indicated that the NIRS models of Leymus chinensis quality prediction highly accessed the precision of chemical analysis. The coefficient of correlation of cross-validation of crude protein, neutral detergent fiber and acid detergent fiber were 0.963 7, 0.959 4 and 0.947 9, and the RMSECV of the three models were 1.41%, 1.27% and 1.27%, respectively; the correlation coefficients of external-validation were 0.965, 0.956 and 0.953, and all the ratios of standard deviation to root mean square error of prediction were higher than 3. Thus it can be testified that using NIRS analysis can rapidly and accurately determine the quality of Leymus chinensis. This method is of great significance for quick analysis of the trait of Leymus chinensis production and screening of breeding materials in Leymus spp. research of China..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2730 (2011)
Prediction of Minced Pork Quality Attributes Using Visible and Near Infrared Reflectance Spectroscopy
FAN Yu-xia, LIAO Yi-tao, and CHENG Fang
The objective of the present study was to estimate minced pork meat quality using visible and near infrared (Vis-NIR) spectroscopy. Two hundred twenty five carcasses samples from longissimus dorsi muscle were scanned over the Vis-NIR spectral range from 350 to 1 015 nm and analysed for intramuscular fat (IMF), protein The objective of the present study was to estimate minced pork meat quality using visible and near infrared (Vis-NIR) spectroscopy. Two hundred twenty five carcasses samples from longissimus dorsi muscle were scanned over the Vis-NIR spectral range from 350 to 1 015 nm and analysed for intramuscular fat (IMF), protein and moisture according to the official methods. Wavelet transform was employed to eliminate the spectra noise. Partial least square regression (PLSR) and support vector machine (SVM) were used to develop Vis-NIR spectroscopy models for chemical composition detection. According to calibration statistics, the best model to predict intramuscular fat content was developed by SVM with the denoised spectra, the correlation coefficient was 0.889 for calibration and 0.888 for validation. For protein and moisture, the best model was achieved with the PLS method with the correlation coefficient of 0.869 and 0.881 for protein calibration and validation sets and 0.877 and 0.848 for moisture calibration and validation sets, respectively. And all the ratios of standard deviation of validation set to root mean square error of prediction (RPD) were not more than 3.0. Results indicated that it was possible to predict chemical composition in minced pork meat. As a fast predictor of meat quality using Vis-NIR spectroscopy, it is necessary to improve the precision and the robustness of the model for practice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2734 (2011)
Hydration of Liquid Ethanol Probed by Raman Spectra
WU Bin, LIU Ying, HAN Cai-qin, LUO Xiao-sen, LU Jian, and NI Xiao-wu
In order to study the concentration dependence of the molecular interactions in ethanol-water hydrogen bonded system, Raman spectra of ethanol-water mixtures with different water contents were obtained at room temperature. It was found that the positions of the 3 C—H stretching vibration bands of ethanol molecule locatIn order to study the concentration dependence of the molecular interactions in ethanol-water hydrogen bonded system, Raman spectra of ethanol-water mixtures with different water contents were obtained at room temperature. It was found that the positions of the 3 C—H stretching vibration bands of ethanol molecule located in the range of 2 800~3 050 cm-1 would generally present blue shifts when more water was added into the mixture; at the same time, however, the C—O stretching vibration band located at around 1 048 cm-1 showed an opposite behavior. The different hydration, which is induced by hydrogen bonding, which happened in different concentration mixtures, was thought to be responsible for this situation, the hydration process of liquid ethanol was thus deduced: when adding a small amount of water into pure ethanol, and clusters containing one water molecule and several ethanol molecules were formed instead of ethanol self-association short chain clusters existing in pure ethanol; the clusters would combine more water molecules to form ringlike clusters through hydrogen bond association when adding more water into the mixture, then a temporary saturation would be seen when the volume percent of water reached 50%, and this saturation state would last until the water content reached 70 vol%; after that, the large number of water molecules would dissociate the ringlike clusters to smaller clusters and then associate to the ends of these dissociated clusters through hydrogen bonding; in addition, the improper hydrogen bonding between oxygen atom of water molecule and C—H bond of ethanol molecule is considered to be formed after the content of water reached a high value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2738 (2011)
Raman Spectroscopic Study of the Complex and Quantitative Analysis in the System CuCl2-H2O体系和FeCl3-H2O and FeCl3-H2O
YANG Dan, and XU Wen-yi
In the present paper, the Raman peaks of complex in the CuCl2-H2O system and FeCl3-H2O system were studied in detail. In the CuCl2-H2O system, the superimposed characteristic peaks of various complex formed by Cu2+and Cl-(such as ［CuCl4］2- and ［CuCl6］4-) may be formed the peak of 286 cm-1, and the superimposed characteIn the present paper, the Raman peaks of complex in the CuCl2-H2O system and FeCl3-H2O system were studied in detail. In the CuCl2-H2O system, the superimposed characteristic peaks of various complex formed by Cu2+and Cl-(such as ［CuCl4］2- and ［CuCl6］4-) may be formed the peak of 286 cm-1, and the superimposed characteristic peaks of various complex formed by Cu2+ hydrate(［Cu(H2O)4］2+ and ［Cu(H2O)6］2+ based ) may be formed the peak of 412 cm-1 ; Through the analysis of peak parameters, we has founded two quantitative relationships : ① The peak intensity ratio (I1/I3 400 or I2/I3 400) of 286 cm-1(or 412 cm-1)and OH stretching Raman spectrum of water (at 3 400 cm-1) and concentration ; ② The integral area of 286 cm-1 (or 412 cm-1 ) and concentration. In the FeCl3-H2O system, 173 and 331 cm-1 might be attributed to ［FeCl4］- that is the most common form of FeCl3 complex in aqueous solution. The superimposed characteristic peaks of various complex formed by Fe3+and Cl-(such as ［FeCl］2+, ［FeCl2］+ etc) may be formed the broad peak of 173 cm-1, and the superimposed characteristic peaks of various complex formed by Fe3+ hydrate(［Fe(H2O)4］3+ and ［Fe(H2O)6］3+ based) may be formed the broad weak peak behind of 331 cm-1. Through the analysis of peak parameters, we has founded two quantitative relationships : ①The integral area of 331 cm-1(A2) and concentration ; ②The integral area ratio of 173 and 331 cm-1(A1/A2)and concentration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2742 (2011)
A Fast Classification Method for Petroleum Products Based on the Raman Spectroscopy
LI Sheng, and DAI Lian-kui
A fast and effective method for classification of petroleum products based on Raman spectroscopy is proposed. A knowledge base composed by Raman spectra of training samples, intra-class feature spectra and intra-class thresholds of all classes was firstly established. Then, correlation coefficients between the test samA fast and effective method for classification of petroleum products based on Raman spectroscopy is proposed. A knowledge base composed by Raman spectra of training samples, intra-class feature spectra and intra-class thresholds of all classes was firstly established. Then, correlation coefficients between the test sample and the intra-class feature spectra were calculated. If the maximal correlation coefficient of the test sample is larger than or equal to the corresponding intra-class threshold, the test sample is determined to belong to the corresponding class. For 96 petroleum product samples belonging to 7 classes and 4 unknown samples, the experimental results show that this method can accurately classify known test samples and can also find the unknown test samples. This method costs little calculation time and human interference. Moreover, it can be easily implemented in the practical application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2747 (2011)
Nondestructive Imaging of Elements Distribution in Biomedical Samples by X-Ray Fluorescence Computed Tomography
YANG Qun, DENG Biao, L Wei-wei, DU Guo-hao, YAN Fu-hua, XIAO Ti-qiao, and XU Hong-jie
X-ray fluorescence computed tomography is a stimulated emission tomography that allows nondestructive reconstruction of the elements distribution in the sample, which is important for biomedical investigations. Owing to the high flux density and easy energy tunability of highly collimated synchrotron X-rays, it is possX-ray fluorescence computed tomography is a stimulated emission tomography that allows nondestructive reconstruction of the elements distribution in the sample, which is important for biomedical investigations. Owing to the high flux density and easy energy tunability of highly collimated synchrotron X-rays, it is possible to apply X-ray fluorescence CT to biomedical samples. Reported in the present paper, an X-ray fluorescence CT system was established at Shanghai Synchrotron Radiation Facility for the investigations of trace elements distribution inside biomedical samples. By optimizing the experiment setup, the spatial resolution was improved and the data acquisition process was obviously speeded up. The maximum-likelihood expectation-maximization algorithm was introduced for the image reconstruction, which remarkably improved the imaging accuracy of element distributions. The developed system was verified by the test sample and medical sample respectively. The results showed that the distribution of interested elements could be imaged correctly, and the spatial resolution of 150 m was achieved. In conclusion, the developed system could be applied to the research on large-size biomedical samples, concerning imaging accuracy, spatial resolution and data collection time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2753 (2011)
Fluorescence Spectroscopic Characteristics of Fulvic Acid from the Long-Term Located Fertilization in Black Soil
LI Yan-ping, WEI Dan, ZHOU Bao-ku, ZHAO Yue, ZHANG Xi-lin, WEI Zi-min, and LI Shu-ling
In order to investigate the effect of long-term located fertilization on soil fulvic acid (FA), in this study, four soil samples were taken from black soil with long-term located fertilization (about 30 year) in Harbin, Heilongjiang province. The fertilization treatments included control (CK), N, P and K fertilization In order to investigate the effect of long-term located fertilization on soil fulvic acid (FA), in this study, four soil samples were taken from black soil with long-term located fertilization (about 30 year) in Harbin, Heilongjiang province. The fertilization treatments included control (CK), N, P and K fertilization (NPK), horse manure (OM), combination of organic manure and chemical fertilizations (MNPK). Soil FA was extracted from the samples and purified. The excitation, emission, synchronous, and three-dimensional-excitation emission matrix fluorescence spectroscopy (3DEEM) characteristics of the FA were determined. The excitation, emission and synchronous scan spectra all indicated that the main peaks of FA in the NPK treatment exhibited a significantly blue shift compared with CK, while those of MNPK, OM treatment caused a red shift to some extent. 3DEEM spectra of FA in all treatments exhibited four peaks (peak a, peak b, peak c, and peak d), compared with FA in CK, the wavelengths shift tendency of peak a, peak b, and peak c of FA 3DEEM in NPK, MNPK and OM treatments were similar to that of traditional spectra in FA. In order to provide quantitative information of FA humification degree in different treatments, we investigated the fluorescence index f450/500 (FI), area integration (A370～600 nm, A1 370～412 nm, A4 538～600 nm). Compared with CK, the f450/500, ratio of A1/A in NPK and A4/A in MNPK treatment increased by 4.62%, 6.12%, 7.22%, respectively. However, the f450/500, the ratio of A1/A in MNPK and A4/A in NPK treatment decreased by 3.86%, 15.31%, and 7.22% respectively. This indicated that NPK application gave a lower degree of FA humification, and combination of organic manure and chemical fertilizations would lead to a greater degree of FA aromatization in black soil with long-term located fertilization than CK..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2758 (2011)
Fluorescence Spectra and Absorption Spectra of Carvacrol
LI Li-ran, LIU Cui-ge, and WEI Yong-ju
Fluorescence spectra and absorption spectra of carvacrol, an active component of Chinese herbal medicines, have been studied. The ionization constant and fluorescence quantum yield of carvacrol were measured according to spectral data. Under the condition of pH8.0, the fluorescence intensity decreases with the increaseFluorescence spectra and absorption spectra of carvacrol, an active component of Chinese herbal medicines, have been studied. The ionization constant and fluorescence quantum yield of carvacrol were measured according to spectral data. Under the condition of pH<2.0, fluorescence intensity of carvacrol increases with the increase in pH value. In the range of pH 2.0~8.0, carvacrol gives a strong and steady fluorescence with maximum excitation wavelength 278 nm and emission wavelength 306 nm. When pH>8.0, the fluorescence intensity decreases with the increase in pH value. Ionization constant of carvacrol was measured to be pKa=10.44±0.06 using a pH-absorbance method; and pKa=10.40±0.04 using a pH-fluorescence method. Fluorescence intensity of carvacrol was remarkably enhanced when methanol was added into its aqueous solution. Using L-tryptophane as a reference, the fluorescence quantum yield of carvacrol aqueous solution was measured to be 0.121 at excitation wavelength 278 nm; while in a solution containing 80% methanol, the quantum yield was measured to be 0.324..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2763 (2011)
Fluorescence of Early Stage Leachates DOM Using RO Membrane as Tertiary Treatment
ZENG Xiao-lan, HAN Le, DING Wen-chuan, LI Zuo-xin, WAN Peng, and LIU Jian-dong
In the present study, fluorescence spectra of the dissolved organic matter (DOM) extracted from early stage leachate samples obtained from biologically pretreated leachate fed to RO tertiary treatment, the permeated, the concentrate, and liquids collected after cleaning the membrane with acid and then with base were deIn the present study, fluorescence spectra of the dissolved organic matter (DOM) extracted from early stage leachate samples obtained from biologically pretreated leachate fed to RO tertiary treatment, the permeated, the concentrate, and liquids collected after cleaning the membrane with acid and then with base were determined. The results of synchronous fluorescence spectra analysis showed the RO membrane effectively removed the high content of organic matter corresponding to short wavelengths of 280, 340, and 370 nm of the feed. Liquids collected after cleaning membrane with acid and base showed obvious influence on the organic pollutant matters in the range of 300～420 nm. The results of three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectra showed three protein-like peaks, namely low-excitation wavelength, tyrosine-like high-excitation wavelength, tyrosine-like high-excitation wavelength, tryptophan-like and two fulvic-like peaks, visible and ultra visible fulvic-like were found in the feed. The permeated contains two peaks with higher intensity than the feed, low-excitation wavelength tyrosine-like and high-excitation wavelength tyrosine-like, while the other three peaks were shown in the concentrate. The acid and the base cleaning had great influence on the molecule chemical structure of the organic pollutants on the RO membrane and caused obvious location shifts. It can be concluded that the RO mainly separated the fulvic matter in the early stage leachate and the fouling consisted of fulvic-like matter together with the protein-like, and low-excitation wavelength tyrosine-like..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2767 (2011)
Flower Species Identification and Coverage Estimation Based on Hyperspectral Remote Sensing Data in Hulunbeier Grassland
GAI Ying-ying, FAN Wen-jie, XU Xi-ru, YAN Bin-yan, WANG Huan-jiong, and LIU Yuan
Monitoring grassland species and area real-timely and accurately is of great significance in species diversity research, as well as in sustainable development of ecosystem. Flowers have their own unique spectral characteristics. Compared with the nutrient stage, species are more easily identified by florescence. So, flMonitoring grassland species and area real-timely and accurately is of great significance in species diversity research, as well as in sustainable development of ecosystem. Flowers have their own unique spectral characteristics. Compared with the nutrient stage, species are more easily identified by florescence. So, florescence is a critical period for identification. In the present paper, spectral differences among such flowers as Galium verum Linn., Hemerocallis citrina Baroni, Serratula centauroides Linn., Clematis hexapetala Pall., Lilium concolor var. pulchellum, Lilium pumilum and Artemisia frigida Willd. Sp. Pl. were found, along with identification methods, by analyzing canopies spectra and parametrizing characteristics. Verification results showed that when the coverage of flowers was greater than 10%, the accuracy of identification methods would be higher than 90%. On this basis, linear unmixing model was adopted to calculate the area of flowers in quadrates. Results showed that linear unmixing model was an effective method for estimating the coverage of flowers in grassland because the accuracy was about 4%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2778 (2011)
A Snow Depth Inversion Method for the HJ-1B Satellite Data
DONG Ting-xu, JIANG Hong-bo, CHEN Chao, and QIN Qi-ming
The importance of the snow is self-evident, while the harms caused by the snow have also received more and more attention. At present, the retrieval of snow depth mainly focused on the use of microwave remote sensing data or a small amount of optical remote sensing data, such as the meteorological data or the MODIS datThe importance of the snow is self-evident, while the harms caused by the snow have also received more and more attention. At present, the retrieval of snow depth mainly focused on the use of microwave remote sensing data or a small amount of optical remote sensing data, such as the meteorological data or the MODIS data. The small satellites for environment and disaster monitoring of China are quite different form the meteorological data and MODIS data, both in the spectral resolution or spatial resolution. In this paper, aimed at the HJ-1B data, snow spectral of different underlying surfaces and depths were surveyed. The correlation between snow cover index and snow depth was also analyzed to establish the model for the snow depth retrieval using the HJ-1B data. The validation results showed that it can meet the requirements of real-time monitoring the snow depth on the condition of conventional snow depth..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2784 (2011)
Study of Environmental Vegetation Index Based on Environment Satellite CCD Data and LAI Inversion
ZHANG Ying, MENG Qing-yan, WU Jia-li, and ZHAO Feng
The present study used the PROSAIL forward model to simulate vegetation canopy spectrum, introducing blue and green bands to amend the effects of atmosphere and soil background, and constructing HuanJing vegetation Index (HJVI) to avoid premature saturation. Based on ground observation data of different typical winter The present study used the PROSAIL forward model to simulate vegetation canopy spectrum, introducing blue and green bands to amend the effects of atmosphere and soil background, and constructing HuanJing vegetation Index (HJVI) to avoid premature saturation. Based on ground observation data of different typical winter wheat, we established HJVI-LAI long time series inversion models and implemented different varieties cross-validation to the models. The results show that the LAI inversion model of HJVI has higher precision than similar vegetation index model, has good universality, and can be applied to remote sensing multi-temporal winter wheat growth monitoring and LAI inversion..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2789 (2011)
Remote Sensing of Pollutant Gases Using Brightness Temperature and Principal Component Analysis
CUI Fang-xiao, FANG Yong-hua, LAN Tian-ge, XIONG Wei, and YUAN Yue-ming
On the mobile platform, the remote sensing system for pollutant gases can not effectively obtain background spectra. It is the key step to remove background information and extract target spectral characteristics utilizing specific algorithm. The present paper addressed an algorithm based on principal component iteratiOn the mobile platform, the remote sensing system for pollutant gases can not effectively obtain background spectra. It is the key step to remove background information and extract target spectral characteristics utilizing specific algorithm. The present paper addressed an algorithm based on principal component iterative fitting and brightness temperature spectrum. The algorithm didn’t require strict measurement of instrumental response function. Combining the temperature spectrum, principal component analysis and iterative fitting algorithm, the target spectral feature could be effectively extracted..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2794 (2011)
Atmospheric Correction Method for HJ-1 CCD Imagery over Waters Based on Radiative Transfer Model
XU Hua, GU Xing-fa, LI Zheng-qiang, LI Li, and CHEN Xing-feng
Atmospheric correction is a bottleneck in quantitative application of Chinese satellites HJ-1 data to remote sensing of water color. According to the characteristics of CCD sensors, the present paper made use of air-water coupled radiative transfer model to work out the look-up table (LUT) of atmospheric corrected paraAtmospheric correction is a bottleneck in quantitative application of Chinese satellites HJ-1 data to remote sensing of water color. According to the characteristics of CCD sensors, the present paper made use of air-water coupled radiative transfer model to work out the look-up table (LUT) of atmospheric corrected parameters, and thereafter developed pixel-by-pixel atmospheric correction method over waters accomplishing the water-leaving remote sensing reflectance with accessorial meteorological input. The paper validates the HJ-1 CCD retrievals with MODIS and in-situ results. It was found that the accuracy in blue and green bands is good. However, the accuracy in red or NIR bands is much worse than blue or green ones. It was also demonstrated that the aerosol model is a sensitive factor to the atmospheric correction accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2798 (2011)
Vegetation Water Content Retrieval and Application of Drought Monitoring Using Multi-Spectral Remote Sensing
WANG Li-tao, WANG Shi-xin, ZHOU Yi, LIU Wen-liang, and WANG Fu-tao
The vegetation is one of main drying carriers. The change of Vegetation Water Content (VWC) reflects the spatial-temporal distribution of drought situation and the degree of drought. In the present paper, a method of retrieving the VWC based on remote sensing data is introduced and analyzed, including the monitoring thThe vegetation is one of main drying carriers. The change of Vegetation Water Content (VWC) reflects the spatial-temporal distribution of drought situation and the degree of drought. In the present paper, a method of retrieving the VWC based on remote sensing data is introduced and analyzed, including the monitoring theory, vegetation water content indicator and retrieving model. The application was carried out in the region of Southwest China in the spring, 2010. The VWC data was calculated from MODIS data and spatially-temporally analyzed. Combined with the meteorological data from weather stations, the relationship between the EWT and weather data shows that precipitation has impact on the change in vegetation moisture to a certain extent. However, there is a process of delay during the course of vegetation absorbing water. So precipitation has a delaying impact on VWC. Based on the above analysis, the probability of drought monitoring and evaluation based on multi-spectral VWC data was discussed. Through temporal synthesis and combined with auxiliary data (i.e. historical data), it will help overcome the limitation of data itself and enhance the application of drought monitoring and evaluation based on the multi-spectral remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2804 (2011)
The Retrieval of Fine and Coarse Aerosol from MODIS
WANG Zhong-ting, LI Qing, CHEN Liang-fu, WANG Zi-feng, LI Shen-shen, and JIANG Zhe
Generally, aerosols over land are composed of fine and coarse aerosols, which have different optical properties. How to derive the fine mode and coarse mode aerosols from satellite observations is an important issue in the aerosol retrieving. In the present paper, information of aerosol models (including refractive indGenerally, aerosols over land are composed of fine and coarse aerosols, which have different optical properties. How to derive the fine mode and coarse mode aerosols from satellite observations is an important issue in the aerosol retrieving. In the present paper, information of aerosol models (including refractive index and size distribution function) was retrieved from the ground-based measurement of the AERONET/PHOTONS site in Beijing. The retrievals indicate that, aerosols over Beijing have a bi-model distribution, and the optical properties of fine and coarse aerosols are distinct. Based on the dark dense vegetation (DDV) method, optical depth of the fine, coarse and total aerosols were derived from MODIS data over Beijing area in 2007. The validation of these satellite retrievals shows that from MODIS data, the optical depth of fine and total aerosols can be retrieved well (with correlation coefficients greater than 0.8), and so can the Angstrom exponent (having a correlation coefficient of 0.517). However, relatively poor results were obtained when retrieving the optical depth of coarse aerosols..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2809 (2011)
A Spatial Adaptive Algorithm for Endmember Extraction on Multispectral Remote Sensing Image
ZHU Chang-ming, LUO Jian-cheng, SHEN Zhan-feng, LI Jun-li, and HU Xiao-dong
Due to the problem that the convex cone analysis (CCA) method can only extract limited endmember in multispectral imagery, this paper proposed a new endmember extraction method by spatial adaptive spectral feature analysis in multispectral remote sensing image based on spatial clustering and imagery slice. Firstly, in Due to the problem that the convex cone analysis (CCA) method can only extract limited endmember in multispectral imagery, this paper proposed a new endmember extraction method by spatial adaptive spectral feature analysis in multispectral remote sensing image based on spatial clustering and imagery slice. Firstly, in order to remove spatial and spectral redundancies, the principal component analysis (PCA) algorithm was used for lowering the dimensions of the multispectral data. Secondly, iterative self-organizing data analysis technology algorithm (ISODATA) was used for image cluster through the similarity of the pixel spectral. And then, through clustering post process and litter clusters combination, we divided the whole image data into several blocks (tiles). Lastly, according to the complexity of image blocks’ landscape and the feature of the scatter diagrams analysis, the authors can determine the number of endmembers. Then using hourglass algorithm extracts endmembers. Through the endmember extraction experiment on TM multispectral imagery, the experiment result showed that the method can extract endmember spectra form multispectral imagery effectively. What’s more, the method resolved the problem of the amount of endmember limitation and improved accuracy of the endmember extraction. The method has provided a new way for multispectral image endmember extraction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2814 (2011)
Biosorption Properties of Extracellular Polymeric Substances Produced by Sulfate-Reducing Bacteria Towards Cu(Ⅱ) Ion
FANG Di, ZHANG Rui-chang, and ZHAO Yang-guo
The purpose of the present study was to investigate the Cu2+ biosorption properties of extracellular polymeric substances (EPS) produced by sulfate-reducing bacteria. The composition and physicochemical characteristics of EPS were determined. The adsorption characteristics of EPS towards Cu2+ were examined using thermoThe purpose of the present study was to investigate the Cu2+ biosorption properties of extracellular polymeric substances (EPS) produced by sulfate-reducing bacteria. The composition and physicochemical characteristics of EPS were determined. The adsorption characteristics of EPS towards Cu2+ were examined using thermodynamic equilibrium equations and determined by FTIR and SEM-EDS. The EPS was shown to have a strong copper-binding capacity and the biosorption data obtained were well described by the Freundlich isotherm model. The results of FTIR spectra and SEM-EDS confirmed the importance of the C—O—C group, —OH group and carbonyl group from polysaccharides and proteins in Cu2+ sorption by EPS. These findings suggest the potential of EPS produced by sulfate-reducing bacteria for the removal of Cu(Ⅱ) ion from aqueous solution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2819 (2011)
The Response Characteristics of TM Image Reflectance to the Arid Region of Soil Moisture
LI Bao-fu, LI Wei-hong, and CAO Zhi-chao
The response characteristics of TM image to the soil moisture in the Tarim River are the research object. Selected the image spectrum (R), spectrum reciprocal (1/R), the logarithm of reciprocal spectrum lg(1/R) and removal normalized difference vegetation index (Rc) of four spectral index were selected to establish theThe response characteristics of TM image to the soil moisture in the Tarim River are the research object. Selected the image spectrum (R), spectrum reciprocal (1/R), the logarithm of reciprocal spectrum lg(1/R) and removal normalized difference vegetation index (Rc) of four spectral index were selected to establish the soil moisture content prediction model, the variance test was used to validate the model significance, the model accuracy level was divided by the posterior variance examination. The results showed that: the model accuracy of the logarithm of reciprocal spectrum lg(1/R) prediction of soil moisture is the highest, and achieved a good level for the monitoring of soil moisture content (0～30 cm). The model accuracy of the spectral (R) and spectral reciprocal (1/R) prediction of soil moisture is lower than logarithm of reciprocal spectrum with only the individual layers (0～30, 0～50 cm, etc.) reaching the qualified level or narrouly qualified level. The model accuracy of the removal normalized difference vegetation index (Rc) prediction of soil moisture is the lowest. Besides, the best prediction depth of every model is the depth of 0～30 cm, and if the soil depth is too deep or too shallow, the prediction accuracy will decrease..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2824 (2011)
Research on Carbon Monoxide Multi-Parameter Detection Based on Ultra-Narrow-Linewidth Laser
CHEN Xiao, SUI Qing-mei, MIAO Fei, JIA Lei, WANG Jing, and JIANG Ming-shun
Through measuring and analyzing the infrared absorption spectrum of carbon monoxide, a kind of carbon monoxide multi-parameter detection system was designed based on the characteristics of ultra-narrow-linewidth laser and the spectrum scanning technology. A ultra-narrow-linewidth tunable semiconductor laser was utilizeThrough measuring and analyzing the infrared absorption spectrum of carbon monoxide, a kind of carbon monoxide multi-parameter detection system was designed based on the characteristics of ultra-narrow-linewidth laser and the spectrum scanning technology. A ultra-narrow-linewidth tunable semiconductor laser was utilized as light source and carbon monoxide temperature detection was achieved by measuring direct absorption spectra at different temperatures. According to temperature data and the principle of differential absorption concentration detection, carbon monoxide concentration and temperature were obtained simultaneously. With the spectrum scanning technology of ultra-narrow-linewidth laser, the spectra of carbon monoxide near the region of 6 354.179 and 6 383.09 cm-1 at different temperatures were measured, and also analyzed and fitted by Voigt profile. Finally the experiments indicate that the temperature measurement relative error is less than 4% and relative temperature fluctuation is less than 3.5%; the concentration measurement relative error is less than 5%, and the minimum detectable carbon monoxide is 0.05%. The multi-parameter detecting system has advantages of high accuracy and good stability, and can be used in power transformer fault gases on-line monitoring in real time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2829 (2011)
Research on Identification of Cucumber, Stem and Leaf Based on Spectrum Analysis Technology
WANG Hai-qing, JI Chang-ying, and CHEN Kun-jie
To be able to quickly identify the cucumber real time, the present paper studied the near infrared reflectance characteristics of cucumber, stem and leaf. Spectral reflectance of 138 samples (46 cucumbers, 46 stems and 46 leaves) was collected using near infrared spectroscopy in the band range of 600～1 099 nm indoor. ATo be able to quickly identify the cucumber real time, the present paper studied the near infrared reflectance characteristics of cucumber, stem and leaf. Spectral reflectance of 138 samples (46 cucumbers, 46 stems and 46 leaves) was collected using near infrared spectroscopy in the band range of 600～1 099 nm indoor. After Savitzky-Golay smoothing preprocessing, random 108 spectral samples were put forward as calibration set. The weighted deviation method was used for choosing the spectral bands 690～950 nm that include much more information. The samples were analyzed by PCA method to extract the principal component scores, combining the Mahalanobis distance method the recognition model was established, and seven abnormal samples were excluded. The partial least squares (PLS) model was established by remaining 101 samples spectra of calibration set, which was used for predicting the validation set (30 samples except of the calibration set). The result shows that the correlation of the predicted value and the actual value reaches up to 0.994 1, and the correct recognition rate is 100%. This significantly illustrates that the near infrared spectral reflectance characteristics are different among the cucumbers, stems and leaves, which can be successfully applied to recognition of cucumber by the method. The developed technique can provide a new method for cucumber identification..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2834 (2011)
Spectrophotometry Analysis of Different Valence State of Vanadium in Vanadium Battery Electrolyte
CHEN Fu-yu, CHEN Hui, HOU Shao-yu, LIU Jian-guo, and YAN Chuan-wei
In the present paper, oxalic acid was used to reduce V(Ⅴ) ion to V(Ⅳ) ion, then its complex with V(Ⅳ) was formed. By this method, four valence states of vanadium ions had different characteristic absorption peaks in the UV-Visible range. Based on these characteristic absorption peaks, qualitative and quantitative spectIn the present paper, oxalic acid was used to reduce V(Ⅴ) ion to V(Ⅳ) ion, then its complex with V(Ⅳ) was formed. By this method, four valence states of vanadium ions had different characteristic absorption peaks in the UV-Visible range. Based on these characteristic absorption peaks, qualitative and quantitative spectrophotometric analysis methods for different valence states of vanadium in vanadium battery electrolyte were established. The results showed that the related coefficients of four standard curves of different valence states were greater than 0.999 0, linearity ranges were 0.326~2.445, 0.326~2.445, 0.720~5.403, and 1.784~13.437 g·L-1, respectively. The measurement of samples suggested that the spectrophotometric analysis method was suitable for analyzing the concentration of valence states of vanadium with the RSDs (n=6) in the range of 0.594%~3.535%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2839 (2011)
Optimization of Ultrasound-Assisted Extraction Combined with AFS by Response Surface Methodology for Rapid Determination of Trace Mercury in Tea Leaves
XIONG Chun-hong, PENG Kang-nian, and XIE Ming-yong
A rapid ultrasound-assisted extraction (UAE) procedure was developed for the determination of trace mercury (Hg) in tea leaves combined with atomic fluorescence spectrometry. Three variables including sonication time (St), ultrasonic bath temperature (T) and HNO3∶H2O2 (1∶1, φ)volume (A2) showed the significant effect oA rapid ultrasound-assisted extraction (UAE) procedure was developed for the determination of trace mercury (Hg) in tea leaves combined with atomic fluorescence spectrometry. Three variables including sonication time (St), ultrasonic bath temperature (T) and HNO3∶H2O2 (1∶1, φ)volume (A2) showed the significant effect on extraction rate of total Hg evaluated by a Plackett-Burman design, and they were further optimized by a central composite design and response surface methodology. The results showed that the optimum extraction conditions were as follows: presonication time 6 min, St 8.1 min, T 70.5 ℃, A2 4.4 mL, and sample mass 300 mg. GBW10016 (tea leaves) was used as certified reference material; for comparative purposes, a microwave-assisted digestion (MAD) was used. The result obtained by optimized UAE method showed good agreement with the certified values. Under optimal conditions, recovery was evaluated to be 94.2%～102.0% and the limit of detection 0.007 8 μg·L-1. The relative standard deviation (RSD) of replicate measurements was generally less than 10%. The proposed UAE method was successfully applied to the determination of Hg in 63 samples of fresh tea leaves and 10 different branded tea samples. No significant differences were established between the analytical results of UAE method and MAD method. The Hg concentrations of them were found in the range of 4.6～17.3 μg·kg-1 on a dried basis, which were within the permissible limit of the NY659-2003..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2843 (2011)
The Recycling Rate and Budget of Trace Element Mn and Cu in Agroecosystem Using ICP-AES
ZHOU Hua, XU Yong-gang, and JIANG Chun-ming
The recycling rate and budget of Mn and Cu under different fertilization regimes by using long-term field experiment and ICP-AES analysis were investigated in the present paper. The results showed that the recycling rates of Mn and Cu were greater than 80% because of sediment recycling type, and the values increased wiThe recycling rate and budget of Mn and Cu under different fertilization regimes by using long-term field experiment and ICP-AES analysis were investigated in the present paper. The results showed that the recycling rates of Mn and Cu were greater than 80% because of sediment recycling type, and the values increased with the amount of feed stuffs increasing. Both the two elements under different fertilization regimes showed budget deficit, with the deficit order of M<(or≤)NPK+M＜CK＜NPK, showing that chemical fertilizer application might induce severe deficit, while application of recycling organic matter might minimize the unbalance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2848 (2011)
Determination of Components in Chromium-Containing Refractory with X-Ray Fluorescence Spectrometry
SONG Xia, ZHANG Shao-wen, and ZHANG Jun
Components like SiO2, Al2O3, Fe2O3, CaO, MgO and Cr2O3 dominate the performance of chromium-containing amorphous refractory. That’s still a hard task for product evaluation and quality control for amorphous refractory due to various component content, less available standard product and difficulty in fusion bead preparComponents like SiO2, Al2O3, Fe2O3, CaO, MgO and Cr2O3 dominate the performance of chromium-containing amorphous refractory. That’s still a hard task for product evaluation and quality control for amorphous refractory due to various component content, less available standard product and difficulty in fusion bead preparation. In the present study, series calibration standards were made from reagents and marked standards depend upon the content of components in real samples. The fusion bead was prepared with lithium tetraborate-lithium metaborate (67∶33 by weight) as mixed flux and ammonium iodide as release agent, which was added during fusion process. The calibration curve derivated from the relationship between light intensity and components concentration and calibrated by theoretical α coefficient. The results of measurement were consistent with standard by this newly developed method. And good precision was also achieved in determination of real amorphous samples. It is easy in operation with less time spent, and practical in application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2851 (2011)
A Novel Spectrum Feature Extraction Method
LI Xiang-ru, FENG Chun-ming, WANG Yong-jun, and LU Yu
The present focuses on the celestial spectra feature extraction problem, which is a key procedure in automatic spectra classification. By extracting features, the authors can reduce redundancy, alleviate noise influence, and improve accuracy and efficiency in spectra classification. The authors introduced a novel featuThe present focuses on the celestial spectra feature extraction problem, which is a key procedure in automatic spectra classification. By extracting features, the authors can reduce redundancy, alleviate noise influence, and improve accuracy and efficiency in spectra classification. The authors introduced a novel feature analysis framework STP (space transformation and partition), which focuses on four essential components in feature extraction: decompose and reorganize spectrum components, reorganize, alleviate noise influence and eliminate redundancy. Based on STP, we can analyze most of the available feature extraction methods, for example, the unsupervised methods principal component analysis (PCA), wavelet transform, the supervised methods support vector machine (SVM), relevance vector machine (RVM), linear discriminant analysis (LDA), etc. We introduced a novel feature analysis framework and proposed a novel feature extraction method. The outstanding characteristics of the proposed method are its simplicity and efficiency. Researches show that it is sufficient to extract features by the proposed method in some cases, and it is not necessary to use the sophisticated methods, which is usually more complex in computation. The proposed method is evaluated in classifying Galaxy and QSO spectra, which is disturbed by red shift and is representative in automatic spectra classification research. The results are practical and helpful to gain novel insight into the traditional feature extraction methods and design more efficient spectrum classification method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2856 (2011)
Effect of Spectrum Distortion on Modulation Transfer Function in Imaging Fiber-Optic Spectrometer
CHENG Xin, WANG Jing, ZHANG Bao, and HONG Yong-feng
Imaging fiber bundles were introduced to dispersion imaging spectrometer and substituted for slit, connecting the telescope and spectrometer to yield the imaging fiber-optic spectrometer. It is a double sampling system, the misalignment between image of optical fiber and detector pixel has arisen because of the spectruImaging fiber bundles were introduced to dispersion imaging spectrometer and substituted for slit, connecting the telescope and spectrometer to yield the imaging fiber-optic spectrometer. It is a double sampling system, the misalignment between image of optical fiber and detector pixel has arisen because of the spectrum distortion of spectrometer, which affected the second sampling process, and the modulation transfer function (MTF) therefore degraded. Optical transfer function of sampling process was derived from line spread function. The effect of spectrum distortion on system MTF was analyzed, and a model evaluating the MTF of imaging fiber-optic spectrometer was developed. Compared to the computation model of MTF of slit imaging spectrometer, a MTF item of sampling by optical fiber and a MTF item of misalignment arising from spectrum distortion were added in this model. Employing this, the MTF of an airborne imaging fiber-optic spectrometer for visible near infrared band was evaluated. The approach ro deriving and developing the MTF model has a reference signification for the computation of MTF of double sampling system, which can direct the design of imaging fiber-optic spectrometer also..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2861 (2011)
Analysis of Collimation Error in Fourier Transform Infrared Spectrometer Based on Step Mirrors
L Jin-guang, LIANG Zhong-zhu, FU Jian-guo, and LIANG Jing-qiu
The collimation error in Fourier transform spectrometer has many effects on the interferogram and the spectrogram. By means of modulation, the authors found the reverse of contrast in the interferogram and the side slope noise in the spectrogram due to the collimation error. The authors analyzed the signal-to-noise ratThe collimation error in Fourier transform spectrometer has many effects on the interferogram and the spectrogram. By means of modulation, the authors found the reverse of contrast in the interferogram and the side slope noise in the spectrogram due to the collimation error. The authors analyzed the signal-to-noise ratio and resolution at different factor of beam divergence. When the factor of the beam divergence is 0.15°·mm-1, the signal-to-noise ratio can reduce to 6 dB and the resolution can go bad to 13.4 cm-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2865 (2011)
Hadamard Transform Spectrometer Mixed Pixels’ Unmixing Method
YAN Peng, HU Bing-liang, LIU Xue-bin, SUN Wei, LI Li-bo, FENG Yu-tao, and LIU Yong-zheng
Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory dHadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2870 (2011)
A Digital Micromirror Device-Based Hadamard Transform Near Infrared Spectrometer
LIU Jia, CHEN Fen-fei, LIAO Cheng-sheng, XU Qian, ZENG Li-bo, and WU Qiong-shui
A Hadamard transform near infrared spectrometer based on a digital micromirror device was constructed. The optical signal was collected by optical fiber, a grating was used for light diffraction, a digital micromirror device (DMD) was applied instead of traditional mechanical Hadamard masks for optical modulation, and A Hadamard transform near infrared spectrometer based on a digital micromirror device was constructed. The optical signal was collected by optical fiber, a grating was used for light diffraction, a digital micromirror device (DMD) was applied instead of traditional mechanical Hadamard masks for optical modulation, and an InGaAs near infrared detector was used as the optic sensor. The original spectrum was recovered by fast Hadamard transform algrithms. The advantages of the spectrometer, such as high resolution, signal-noise-ratio, stability, sensitivity and response speed were proved by experiments, which indicated that it is very suitable for oil and food-safety applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2874 (2011)
[in Chinese]
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 1 (2011)
Research Articles
Spectral Target-Detecting System Using Sine-Wave Modulation
DENG Wei, ZHAO Chun-jiang, ZHANG Lu-da, CHENG Li-ping, and Andrew Landers
Target detection is one of the key technology of precision chemical application. Previously the digital coding modulation technique was commonly used to emit and receive the optical signal in the target detection systems previously in China. It was difficult to adjust the output power, and the anti-interference abilityTarget detection is one of the key technology of precision chemical application. Previously the digital coding modulation technique was commonly used to emit and receive the optical signal in the target detection systems previously in China. It was difficult to adjust the output power, and the anti-interference ability was weak in these systems. In order to resolve these problems, the target detection method based on analog sine-wave modulation was studied. The spectral detecting system was set up in the aspects of working principle, electric circuit, and optical path. Lab testing was performed. The results showed that the reflected signal from the target varied inversely with detection distances. It indicated that it was feasible to establish the target detection system using analog sine-wave modulation technology. Furthermore, quantitative measurement of the reflected optical signal for near-infrared and visible light could be achieved by using this system. The research laid the foundation for the future development of the corresponding instrument..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 10, 2771 (2011)
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