Journals >Spectroscopy and Spectral Analysis
Contents
2014
Volume: 34 Issue 4
60 Article(s)
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Research Article
A Method for Time-Resolved Laser-Induced Breakdown Spectroscopy Measurement
PAN Cong-yuan, HAN Zhen-yu, LI Chao-yang, YU Yun-si, WANG Sheng-bo, and WANG Qiu-ping
Laser-Induced Breakdown Spectroscopy (LIBS) is strongly time related. Time-resolved LIBS measurement is an important technique for the research on laser induced plasma evolution and self-absorption of the emission lines. Concerning the temporal characteristics of LIBS spectrum, a method is proposed in the present paperLaser-Induced Breakdown Spectroscopy (LIBS) is strongly time related. Time-resolved LIBS measurement is an important technique for the research on laser induced plasma evolution and self-absorption of the emission lines. Concerning the temporal characteristics of LIBS spectrum, a method is proposed in the present paper which can achieve μs-scale time-resolved LIBS measurement by using general ms-scale detector. By setting different integration delay time of the ms-scale spectrum detector, a series of spectrum are recorded. And the integration delay time interval should be longer than the worst temporal precision. After baseline correction and spectrum fitting, the intensity of the character line was obtained. Calculating this intensity with differential method at a certain time interval and then the difference value is the time-resolved line intensity. Setting the plasma duration time as X-axis and the time-resolved line intensity as Y-axis, the evolution curve of the character line intensity can be plotted. Character line with overlap-free and smooth background should be a priority to be chosen for analysis. Using spectrometer with ms-scale integration time and a control system with temporal accuracy is 0.021 μs, experiments carried out. The results validate that this method can be used to characterize the evolution of LIBS characteristic lines and can reduce the cost of the time-resolved LIBS measurement system. This method makes high time-resolved LIBS spectrum measurement possible with cheaper system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 865 (2014)
Research on Parameter Optimization of LIBS Used for Multi-Element Measurements in Water
HU Li, ZHAO Nan-jing, LIU Wen-qing, WANG Yin, MENG De-shuo, YU Yang, ZHANG Da-hai, ZHANG Xiao-ling, and MA Ming-jun
The one of the advantages about Laser Induced Breakdown Spectroscopy (LIBS) is multielement detection at the same time.In order to obtain the optimum signal in the multi-element measurements of water with LIBS, the present paper firstly models the numerical relationship between the signal-to-background ratio of charactThe one of the advantages about Laser Induced Breakdown Spectroscopy (LIBS) is multielement detection at the same time.In order to obtain the optimum signal in the multi-element measurements of water with LIBS, the present paper firstly models the numerical relationship between the signal-to-background ratio of characteristic spectral lines and the delay time and gate width time with BP neural network, using DM design experiment data as the checking sample to ensure the generalization ability of the BP neural network model. Based on the above model, genetic algorithm is used to optimize measurement parameters and the fitness function φ is defined. When the optimum delay time and gate width time is (15.5 μs, 21.5 μs), the minimum value of φ is 0.102 4. The optimization results of genetic algorithm are further confirmed with experimental results. So the method of parameters optimization overall improves S/B of multi-element measurements in water with LBS, and provides the reference for parameter optimization of other experiments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 869 (2014)
Development of Raman Spectroscopy Study of Fluid Inclusions
YANG Dan, and XU Wen-yi
In the present paper, the exploration process of the laser Raman analysis of fluid inclusions was reviewed and summarized. The authors tried to outlook the future research work on laser Raman analysis of fluid inclusions at low and room temperature. Research work at low temperatures:(１)Common multiple salt systems in tIn the present paper, the exploration process of the laser Raman analysis of fluid inclusions was reviewed and summarized. The authors tried to outlook the future research work on laser Raman analysis of fluid inclusions at low and room temperature. Research work at low temperatures:(１)Common multiple salt systems in the fluid inclusions; (２)Trying qualitative and quantitative analysis of ingredients in natural fluid inclusions; (３)Microthermometry considered first melting temperature as the eutectic temperature, and this view was suspected, so further research is needed; (４)chloride hydrate structure is inconclusive at low temperatures. Research work at room temperatures: (１) how Fe3+, Zn2+, Cu2+ and other ions being considered as the main metal ions of mineralization combine with Cl-and H2O are how to combine; (２) The reason for different concentrations of NaCl, CaCl2, MgCl2, CuCl2, ZnCl2, FeCl3 solution resulting in the shift of Raman OH stretching region (2 800～3 800 cm-1)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 874 (2014)
Theory Study on Glycine Linear Oligopeptide Vibrational Spectrum Frequency Shift
YE Zhi-peng, LI Xin, YANG Meng-shi, CHEN Liang, XU Can, and CHU Xiu-xiang
By using the density functional theory, glycine linear oligopeptide of different lengths was geometrically optimized on the 6-31G (d) basis set level, their growth processes were simulated, and the average binding energy and vibration frequency were calculated with geometry. The results showed that the average binding By using the density functional theory, glycine linear oligopeptide of different lengths was geometrically optimized on the 6-31G (d) basis set level, their growth processes were simulated, and the average binding energy and vibration frequency were calculated with geometry. The results showed that the average binding energies tend to change in a regular pattern and stabilize with the number of residues increasing; With the oligopeptide chain bond length analysis it was found that the chain to the radial direction there is a opposite trend for chain and radial direction, which is anisotropic. It was found by the IR spectrum analysis that red shifts and blue shifts occur respectively when the same group of peptide bond vibrate, which is anisotropic; These phenomena originate from that quasi one-dimensional nanostructures lead to the anisotropy of the bond length; the induced effects, coupling effects and hydrogen bonding etc. between the same groups lead to the vibration frequency red shifts and blue shifts. The authors conclude that the growth of glycine linear oligopeptide is conducive to stability of the structure, and the authors infer that the oligopeptide has the tendency of self-assembled growth; Through the conformation and spectrum, the authors infer that there is a size effect in physical and chemical properties. The physical and chemical properties of peptide chain end group are extremely stable and unaffected by the impact of the oligopeptide chain length. The results are significant to measuring the length and the number of residue of peptide, and to manufacturing the special features oligopeptide chain..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 879 (2014)
Transfer Energy Disposal in Collisions of NaK(61Σ+) with H2
ZHU Yong-le, WANG Shu-ying, LIU Jing, ZHONG Chong-yu, A·Yolwas, DAI Kang, and SHEN Yi-fan
The radiative lifetimes and rate coefficients for deactivation of high lying 61Σ+ state of NaK by collisions with H2 were studied. An OPO laser was set to a particular 21Σ+←11Σ+ transition. Another single mode Ti sapphire laser was then used to excite molecule from 21Σ+ level to the 61Σ+ state. The predissociation was The radiative lifetimes and rate coefficients for deactivation of high lying 61Σ+ state of NaK by collisions with H2 were studied. An OPO laser was set to a particular 21Σ+←11Σ+ transition. Another single mode Ti sapphire laser was then used to excite molecule from 21Σ+ level to the 61Σ+ state. The predissociation was monitored by the atomic potassium emission at the 3D→4P (1.7 μm) or the S→4P(1.24 μm), while bound state radiative processes were monitored by total fluorescence from the upper state to the various levels, all studied as a function of H2 density. The values for predissociation, collisional dissociation and collisional depopulation rate coefficients were obtained. The decay signal of the time resolved fluorescence from the 61Σ+→21Σ+, 61Σ+→11Σ+ or 21Σ+→11Σ+ transition was monitored. Based on the Stern-Volmer equation, the radiative lifetimes were monitored for 61Σ+→21Σ+ and 21Σ+→11Σ+ transition. The rate coefficients for deactivation of collisions with H2 were monitored for 61Σ+→21Σ+, 61Σ+→11Σ+ and 21Σ+→11Σ+. When the density of H2 was 1019 cm-3, the total collisional transfer energy (15 426 cm-1) and radiative energy (10 215 cm-1) were obtained. The relative fraction (〈fv〉, 〈fR〉, 〈fT〉) of average energy disposal was derived as (0.58, 0.03, 0.39); 〈fv〉, 〈fR〉, 〈fT〉 represent separately the relative fraction of average energy disposal among vibration, rotation and translation. The major vibrational and translational energy release supports the assumption that the 61Σ+-H2 collision occurs primarily in a collisional energy transfer mechanism. In this experiment, alkali molecules relative energy population ratio was determined through using the time integrated intensity, so we can get the total transfer energy. That the NaK (61Σ+) energy transfers to the H2 vibrational, rotational and translational energy was quantitatively given for the first time, which illustrates the collisional mechanism..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 884 (2014)
Spectral Analysis of the Effects of 1.7 MeV Electron Irradiation on the Current Transfer Characteristic of Cadmium Telluride Solar Cells
TIAN Jin-xiu, ZENG Guang-gen, HE Xu-lin, ZHANG Jing-quan, WU Li-li, LI Wei, LI Bing, WANG Wen-wu, and FENG Liang-huan
The effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystalline thin film solar cells with the structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe∶Cu/Ni have been studied. Light and dark I-V characteristics, dark C-V characteristics, quantum efficiency (QE), admittance spThe effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystalline thin film solar cells with the structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe∶Cu/Ni have been studied. Light and dark I-V characteristics, dark C-V characteristics, quantum efficiency (QE), admittance spectrum (AS) and other testing methods were used to analyze cells performance such as the open-circuit voltage (Voc), short-circuit current (Isc), fill factor (FF) and conversion efficiency (η). It was explored to find out the effects of irradiation on the current transfer characteristic of solar cells combined with the dark current density (Jo), diode ideal factor (A), quantum efficiency, carrier concentration and the depletion layer width. The decline in short-circuit current was very large and the efficiency of solar cells decreased obviously after irradiation. Reverse saturation current density increased, which indicates that p-n junction characteristics of solar cells were damaged, and diode ideal factor was almost the same, so current transport mechanism of solar cells has not changed. Quantum efficiency curves proved that the damage of solar cells’ p-n junction influenced the collection of photo-generated carriers. Irradiation made carrier concentration reduce to 40.6%. The analyses have shown that. A new defect was induced by electron irradiation, whose position is close to 0.58 eV above the valence band in the forbidden band, and capture cross section is 1.78×10-16 cm2. These results indicate that irradiation influences the generation of photo-generated carriers, increases the risk of the carrier recombination and the reverse dark current, and eventually makes the short-circuit current of solar cells decay..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 888 (2014)
Study of Fermi Resonance Characteristic of CS2 in THF
LI Shuai-peng, LIN Xiao-long, ZHANG Feng-qin, JIANG Yong-heng, SUN Yu, LI Si-yuan, ZHU Dong-you, and LIU Meng-hui
In the present paper, an innovative experiment was done. The authors measured the Raman spectra of CS2 mixed with THF at different volume fractions. According to the J. F. Bertran theory, we analyzed the changing regularity of ν1-2ν2 Fermi resonance along with the different concentration. It was shown that the characteIn the present paper, an innovative experiment was done. The authors measured the Raman spectra of CS2 mixed with THF at different volume fractions. According to the J. F. Bertran theory, we analyzed the changing regularity of ν1-2ν2 Fermi resonance along with the different concentration. It was shown that the characteristic parameters of Fermi resonance in solution, such as spectra intensity, frequency space, coupling coefficient and anharmonic constant, will make changes along with solution concentration variation. Because of the existing of solvent effects, the spectra intensity decreases gradually, and the coupling coefficient increases gradually. The explanation of such changes is that the vibration spectra are affected not only by scattering coefficient, but also by more weak hydrogen bonds formation. In addition, the asymmetric frequency shift of the Raman spectra was also found in the paper. The fundamental frequency ν1 basically has no shifts, but the overtone frequency 2ν2 moves towards the high wave number gradually, which is inconsistent with the theory of symmetrical movement. According to the study of molecular microcosmic action, the formation and mechanism of the weak hydrogen bond can preferably explain the above phenomenon. The research has a major influence on the further study of solvent effects in Fermi resonance. And the paper will also provide certain reference value for the study of molecule vibration spectra in solution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 894 (2014)
Influence of Parameters of ZnS Film on the Organic/Inorganic Composite Luminescence Devices
SONG Ling-yun, CAI Chun-feng, LIU Bo-zhi, HU Lian, ZHANG Bing-po, WU Jian-zhong, BI Gang, and WU Hui-zhen
In the present paper, to fabricate electroluminescent devices CdSe QDs were used as active materials, TPD (N,N′-biphenyl-N,N′-bis-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine) was used as a hole transport layer, and ZnS was used as an electron transport layer. The electroluminescent properties of the organic/inorganic cIn the present paper, to fabricate electroluminescent devices CdSe QDs were used as active materials, TPD (N,N′-biphenyl-N,N′-bis-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine) was used as a hole transport layer, and ZnS was used as an electron transport layer. The electroluminescent properties of the organic/inorganic composite ITO/TPD/CdSe QDs/ZnS/Ag light emitting devices were studied. Both TPD and CdSe QDs thin films were spin-coated and ZnS thin films were deposited by magnetron sputtering. The surfaces of the devices are smooth. The luminescence (EL) peak of the CdSe QDs is at 580 nm which is assigned to the band-edge exciton emission. Compared to the previous EL device of ITO/ZnS/CdSe QDs/ZnS/Ag, it is seen that the new devices do not display surface state related emission peaks and EL intensity is about 10 folds that of the previous device. The enhancement of luminescence efficiency is attributed to both of the excitation of CdSe QDs by accelerated electron collision and carriers injection into QDs: (1) electrons are accelerated by the ZnS layer and collide with CdSe QDs, which excites electrons in QDs to excited states and allows them to emit photons; (2) the holes injected into QDs recombine with some of electrons excited in the QDs. The authors further studied the influence of thickness variation of ZnS on the luminescent properties. ZnS thin films are of 80, 120, and 160 nm thickness, respectively. It was found that as the thickness of ZnS increases the threshold voltage rises and EL intensity increases, but breakdown voltage decreases. The EL peak position blue shifts when the thickness of ZnS decreases. The explanation of underlying mechanism is given..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 898 (2014)
Improved Color Purity of Green OLED Device Based on Au Thin Film
ZHANG Yan-fei, ZHAO Su-ling, and XU Zheng
Au was used as anode in some kind of organic electroluminescent devices. Sometimes transparent Au electrodes are required, which means that the thickness of Au electrode should be as thin as possible. Therefore, two metals together forming an electrode become a choice. In the present paper, translucent Au/Al layer was Au was used as anode in some kind of organic electroluminescent devices. Sometimes transparent Au electrodes are required, which means that the thickness of Au electrode should be as thin as possible. Therefore, two metals together forming an electrode become a choice. In the present paper, translucent Au/Al layer was inserted to anode side, and OLED device with the structure of ITO/Al (16 nm)/Au (10 nm)/TPD (30 nm)/AlQ (30 nm)/LiF(0.5 nm)/Al was prepared. There is a spectral narrowing phenomenon on the device ITO/TPD (30 nm)/AlQ (30 nm)/LiF (0.5 nm)/Al, and through analysis and experiment it was found that this phenomenon comes from selective permeability to light of Au thin film rather than the microcavity effect. The device maintains wide viewing angle, without the angular dependence. And the color purity of device with Au thin film is improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 903 (2014)
A New Method to Improve the Luminous Efficiency of Organic Light-Emitting Device: Metal Thin Layer
ZHANG Yan-fei, ZHAO Su-ling, and XU Zheng
Inserting metal thin layer into organic electroluminescent device often brings some unexpected effect. By inserting 5 nm Au thin layer between MoO3 and TPD, we prepared the OLED device with the structure of ITO/MoO3(5 nm)/Au(5 nm)/TPD/AlQ/LiF/Al. The luminous efficiency is improved as compared to the device without theInserting metal thin layer into organic electroluminescent device often brings some unexpected effect. By inserting 5 nm Au thin layer between MoO3 and TPD, we prepared the OLED device with the structure of ITO/MoO3(5 nm)/Au(5 nm)/TPD/AlQ/LiF/Al. The luminous efficiency is improved as compared to the device without the Au. By analysis, we believe that the Au between MoO3 and TPD formed a small trap for hole to reduce the current density in device. At the same time, since the light transmittance of green light (AlQ) of 5 nm Au is greater than 80%, the brightness of the device was not significantly affected. That is the reasons for the improved luminous efficiency. This work provides some new ideas and experimental evidence for how to improve the luminous efficiency of OLED devices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 906 (2014)
Study on the Absorption Spectrum Properties of Flexible Black Silicon Doped with Sulfur and Fluorine Based on First-Principles
WEI Wei, ZHU Yong, LIN Cheng, TIAN Li, XU Zu-wen, and NONG Jin-peng
It is quite urgent to need a flexible photodetector in the ultraviolet-visible-near infrared region for building a miniaturization broadband spectrometer. In the present paper, one kind of flexible black silicon doped with sulfur and fluorine was proposed and the optical absorption spectrum was investigated in broadbanIt is quite urgent to need a flexible photodetector in the ultraviolet-visible-near infrared region for building a miniaturization broadband spectrometer. In the present paper, one kind of flexible black silicon doped with sulfur and fluorine was proposed and the optical absorption spectrum was investigated in broadband region. Firstly, the electronic structure, band structure and the optical absorption properties of the flexible black silicon doped with sulfur and fluoride were calculated using the first-principles pseudo potential calculations based on density-functional theory. Then, the absorption spectrum model of the flexible black silicon was built based on both the first-principles and finite domain time difference method. The results show that the cut-off wavelength has a red shift as the band gap of doped material becomes narrower. The higher the doping concentration is, the higher the optical absorption coefficient is obtained. The absorption coefficient of flexible black silicon doped with 50% sulfur is 8.3 times higher than that of 1.5% sulfur doping sample at the wavelength of 1 500 nm while the ratio turns to be 3 times when doped with 50% and 1.5% fluoride. The black silicon with small-size surface microstructure has the highest absorptance in the near-infrared region at the same doping concentration of 50%. Finally, a sample of flexible black silicon was fabricated by the femtosecond laser auto scanning system. The test results indicate that the absorptance of the sample is higher than 95% both in the ultraviolet and visible region and is fluctuated from 70% to 80% in the near-infrared region. It shows that as a novel light-absorbing material in broadband region the flexible black silicon doped with Sulfur and Fluorine has an potential application in exploring miniaturization broadband spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 910 (2014)
Study on Formation Process of Honeycomb Pattern in Dielectric Barrier Discharge by Optical Emission Spectrum
DONG Li-fang, ZHU Ping, YANG Jing, and ZHANG Yu
The authors report on the first investigation of the variations in the plasma parameters in the formation process of the honeycomb pattern in a dielectric barrier discharge by optical emission spectrum in argon and air mixture. The discharge undergoes hexagonal lattice, concentric spot-ring pattern and honeycomb patterThe authors report on the first investigation of the variations in the plasma parameters in the formation process of the honeycomb pattern in a dielectric barrier discharge by optical emission spectrum in argon and air mixture. The discharge undergoes hexagonal lattice, concentric spot-ring pattern and honeycomb pattern with the applied voltage increasing. The molecular vibration temperature, electron excitation temperature and electronic density of the three kinds of patterns were investigated by the emission spectra of nitrogen band of second positive system (C3Πu→B3Πg), the relative intensity ratio method of spectral lines of ArⅠ763.51 nm (2P6→1S5) and ArⅠ772.42 nm (2P2→1S3) and the broadening of spectral line 696.5 nm respectively. It was found that the molecular vibration temperature and electron excitation temperature of the honeycomb pattern are higher than those of the hexagonal lattice, but the electron density of the former is lower than that of the latter. The discharge powers of the patterns were also measured with the capacitance method. The discharge power of the honeycomb pattern is much higher than that of the hexagonal lattice. These results are of great importance to the formation mechanism of the patterns in dielectric barrier discharge..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 915 (2014)
Study on Plasma Temperature of a Large Area Surface Discharge by Optical Emission Spectrum
DONG Li-fang, TONG Guo-liang, ZHANG Yu, and ZHOU Bin
A large area surface discharge was realized in air/argon gas mixture by designing a discharge device with water electrodes. By using optical emission spectrum, the variations of the molecular vibrational temperature, the mean energy of electron, and the electronic excitation temperature as a function of the gas pressurA large area surface discharge was realized in air/argon gas mixture by designing a discharge device with water electrodes. By using optical emission spectrum, the variations of the molecular vibrational temperature, the mean energy of electron, and the electronic excitation temperature as a function of the gas pressure were studied. The nitrogen molecular vibrational temperature was calculated according to the emission line of the second positive band system of the nitrogen molecule (C3Πu→B3Πg). The electronic excitation temperature was obtained by using the intensity ratio of Ar Ⅰ 763.51 nm(2P6→1S5) to Ar Ⅰ 772.42 nm (2P2→1S3). The changes in the mean energy of electron were studied by the relative intensity ratio of the nitrogen molecular ion 391.4 nm to nitrogen 337.1 nm. It was found that the intensity of emission spectral line increases with the increase in the gas pressure, meanwhile, the outline and the ratios of different spectral lines intensity also change. The molecular vibrational temperature, the mean energy of electron, and the electronic excitation temperature decrease as the gas pressure increases from 0.75×105Pa to 1×105 Pa..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 919 (2014)
Kinetic Models for Determination of Yeast in Fresh Jujube Using Near Infrared Spectroscopy
HU Yao-hua, LIU Cong, and HE Yong
The objectives of this study were: (1) to optimize a near-infrared (NIR) spectroscopy model for fresh jujube stored at room temperature to predict the quality change (yeast growth), (2) to establish a kinetic model of yeast growth for fresh jujubes at room temperature according to NIR spectroscopy data and storage timeThe objectives of this study were: (1) to optimize a near-infrared (NIR) spectroscopy model for fresh jujube stored at room temperature to predict the quality change (yeast growth), (2) to establish a kinetic model of yeast growth for fresh jujubes at room temperature according to NIR spectroscopy data and storage time, and (3) to predict the shelf life of fresh jujube at room temperature. The Lizao samples of fresh jujubes were adopted as the research object in the study. The NIR spectral data were achieved before yeast infection level measured. In order to optimize the NIR model, the pretreatment techniques such as Savitzky-Golay smoothing (S-G smoothing), multiplicative scatter correction (MSC), first derivative (1-Der) and second derivative (2-Der) were compared with the raw spectra by using a statistical software package (Unscrambler 9.8), and the regression coefficient (RC) method was used to choose the characteristic wavenumber. Multiple linear regression (MLR) was applied as NIR modeling method. According to the predicted yeast infection level using NIR model, the chemical kinetic models of spectral data and storage time at room temperature with zero-order and first-order reaction were established by using a statistical software package (SPSS 18). The shelf life could be predicted based on the chemical kinetic model. The results showed that the characteristic wave numbers of 10 300, 8 330, 6 900, 5 666, 5 150 and 4 060 cm-1 in the whole near-infrared range with MSC technique could be chosen to model the quality deterioration of fresh jujube at room temperature. The NIR model that produced the best prediction had the form of B=320.027-233.920x1-206.663x2-61.584x3-14.847x4-2.680x5-9.131x6, where B is yeast value (lg/cfu·g-1), x1～x6 are absorbance value of characteristic wavenumber. The correlation coefficient of calibration (Rc) was 0.950, the root mean square error of calibration (RMSEC) was 2.560, the correlation coefficient of prediction (Rp) was 0.863, and the root mean square error of prediction (RMSEP) was 2.447.The zero-order reaction kinetic model performed better than the first-order model. The zero-order reaction kinetic model of yeast growth with storage time was predicted by Bt=171.395-124.445x1-109.945x2-32.763x3-7.899x4-1.426x5-4.857x6+0.045t with a correlation coefficient of 0.996. Based on the linear correlation between the NIR measurement and storage time, the shelf life of fresh jujube at room temperature was predicted to be 8 days for the yeast infection level less than 10 cfu·g-1. The study showed that the NIR when combed with kinetic models could be used as a non-destructive, rapid method to detect the yeast growth in fresh jujube, and to predict the shelf life and ensure the quality and safety of fresh jujube..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 922 (2014)
Study on In-Orbit VIS/SWIR Relative Calibration Monitoring System with High Stability
LIU Yi, and YIN Da-yi
The present paper studied the in-orbit relative calibration monitoring system with high stability for onboard remote sensing calibration. The realizing principle and the critical technologies are described in detail. The calibration detector assembly with high stability was developed based on both visual (Vis) and shorThe present paper studied the in-orbit relative calibration monitoring system with high stability for onboard remote sensing calibration. The realizing principle and the critical technologies are described in detail. The calibration detector assembly with high stability was developed based on both visual (Vis) and shortwave infrared (SWIR) trap structure. Vis and SWIR photodetectors with high sensitivity were chosen to realize the photoelectric conversion. On the one hand, the detectors worked in the zero-bias photovoltaic mode with better linearity and lower dark current. On the other hand, the critical parameters of the analog operational amplifier circuit and data acquisition circuit were designed so that the trap-structure detector assembly could work properly. Thus the relative calibration monitoring system with high stability for measurement of spaceborne calibration radiance source was realized. The experiments were carried out using the laboratory integrating spheres and the standard lamps provided by the national measurement institution. The results showed that the relative standard deviation of the digital numbers that the system acquired reached to 0.030%~0.046% (Vis) and 0.040%~0.059% (SWIR). It was proved that the accuracy and the stability of the monitoring system could meet the in-orbit calibration system requirement and it could serve as a good solution for in-orbit relative calibration of remote sensor in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 927 (2014)
Objective Assessment of Facial Paralysis Using Infrared Thermography and Formal Concept Analysis
LIU Xu-long, HONG Wen-xue, and LIU Jie-min
This paper presented a novel approach to objective assessment of facial nerve paralysis based on infrared thermography and formal concept analysis. Sixty five patients with facial nerve paralysis on one side were included in the study. The facial temperature distribution images of these 65 patients were captured by infThis paper presented a novel approach to objective assessment of facial nerve paralysis based on infrared thermography and formal concept analysis. Sixty five patients with facial nerve paralysis on one side were included in the study. The facial temperature distribution images of these 65 patients were captured by infrared thermography every five days during one-month period. First, the facial thermal images were pre-processed to identify six potential regions of bilateral symmetry by using image segmentation techniques. Then, the temperature differences on the left and right sides of the facial regions were extracted and analyzed. Finally, the authors explored the relationships between the statistical averages of those temperature differences and the House-Brackmann score for objective assessment degree of nerve damage in a facial nerve paralysis by using formal concept analysis. The results showed that the facial temperature distribution of patients with facial nerve paralysis exhibited a contralateral asymmetry, and the bilateral temperature differences of the facial regions were greater than 0.2 ℃, whereas in normal healthy individuals these temperature differences were less than 0.2 ℃. Spearman correlation coefficient between the bilateral temperature differences of the facial regions and the degree of facial nerve damage was an average of 0.508, which was statistically significant (p<0.05). Furthermore, if one of the temperature differences of bilateral symmetry on facial regions was greater than 0.2 ℃, and all were less than 0.5 ℃, facial nerve paralysis could be determined as for the mild to moderate; if one of the temperature differences of bilateral symmetry was greater than 0.5 ℃, facial nerve paralysis could be determined as for serious. In conclusion, this paper presents an automated technique for the computerized analysis of thermal images to objectively assess facial nerve related thermal dysfunction by using formal concept analysis theory, which may benefit the clinical diagnosis and treatment of facial nerve paralysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 932 (2014)
Study on Freshness Evaluation of Ice-Stored Large Yellow Croaker (Pseudosciaena Crocea) Using Near Infrared Spectroscopy
LIU Yuan, CHEN Wei-hua, HOU Qiao-juan, WANG Xi-chang, DONG Ruo-yan, and WU Hao
Near infrared spectroscopy (NIR) was used in this experiment to evaluate the freshness of ice-stored large yellow croaker (pseudosciaena crocea) during different storage periods. And the TVB-N was used as an index to evaluate the freshness. Through comparing the correlation coefficent and standard deviations of calibraNear infrared spectroscopy (NIR) was used in this experiment to evaluate the freshness of ice-stored large yellow croaker (pseudosciaena crocea) during different storage periods. And the TVB-N was used as an index to evaluate the freshness. Through comparing the correlation coefficent and standard deviations of calibration set and validation set of models established by singly and combined using of different pretreatment methods, different modeling methods and different wavelength region, the best TVB-N models of ice-stored large yellow croaker sold in the market were established to predict the freshness quickly. According to the research, the model shows that the best performance could be established by using the normalization by closure (Ncl) with 1st derivative (Db1) and normalization to unit length (Nle) with 1st derivative as the pretreated method and partial least square (PLS) as the modeling method combined with choosing the wavelength region of 5 000~7 144, and 7 404~10 000 cm-1. The calibration model gave the correlation coefficient of 0.992, with a standard error of calibration of 1.045 and the validation model gave the correlation coefficient of 0.999, with a standard error of prediction of 0.990. This experiment attempted to combine several pretreatment methods and choose the best wavelength region, which has got a good result. It could have a good prospective application of freshness detection and quality evaluation of large yellow croaker in the market..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 937 (2014)
Study on the Best Detector-Distance of Noninvasive Biochemical Examination by Monte Carlo Simulation
DONG Yan-fei, LU Qi-peng, DING Hai-quan, and GAO Hong-zhi
The present paper studies the best detector-distance to improve the near-infrared spectrum signal intensity of the dermis layer and eliminate the interference of the epidermis and subcutaneous layer. First, we analyzed the organizational structure of the skin and calculated the tissue optical parameters of different laThe present paper studies the best detector-distance to improve the near-infrared spectrum signal intensity of the dermis layer and eliminate the interference of the epidermis and subcutaneous layer. First, we analyzed the organizational structure of the skin and calculated the tissue optical parameters of different layers. And we established the Monte Carlo model with the example of glucose absorption peak at 2 270 nm. Then, we used the Monte Carlo method to simulate the light transmission rules in the skin, obtaining the average path length, the average visit depth and the fractions of absorbed energy at each layer with the change in critical angle and detector-distance. The results show that when the photons are incident at an angle less than 45 degrees, you can ignore the effect of the incident angle on photon transmission path, and when the detector-distance is 1 mm, the fraction of absorbed photon energy by the dermis layer is the largest, while it can ensure more energy received by detector. We determined that the best detector-distance is 1mm, which successfully avoids the interference of the epidermis spectral information and obtains large amounts of blood in the dermis layer, which is conducive to the near-infrared non-invasive measurement of biochemical components and the subsequent experiments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 942 (2014)
An Optimal Selection Method of Samples of Calibration Set and Validation Set for Spectral Multivariate Analysis
LIU Wei, ZHAO Zhong, YUAN Hong-fu, SONG Chun-feng, and LI Xiao-yu
The side effects in spectral multivariate modeling caused by the uneven distribution of sample numbers in the region of the calibration set and validation set were analyzed, and the “average” phenomenon that samples with small property values are predicted with larger values, and those with large property values are prThe side effects in spectral multivariate modeling caused by the uneven distribution of sample numbers in the region of the calibration set and validation set were analyzed, and the “average” phenomenon that samples with small property values are predicted with larger values, and those with large property values are predicted with less values in spectral multivariate calibration is showed in this paper. Considering the distribution feature of spectral space and property space simultaneously, a new method of optimal sample selection named Rank-KS is proposed. Rank-KS aims at improving the uniformity of calibration set and validation set. Y-space was divided into some regions uniformly, samples of calibration set and validation set were extracted by Kennard-Stone(KS) and Random-Select(RS) algorithm respectively in every region, so the calibration set was distributed evenly and had a strong presentation. The proposed method were applied to the prediction of dimethylcarbonate (DMC) content in gasoline with infrared spectra and dimethylsulfoxide in its aqueous solution with near infrared spectra. The “average” phenomenon showed in the prediction of multiple linear regression (MLR) model of dimethylsulfoxide was weakened effectively by Rank-KS. For comparison, the MLR models and PLS1 models of MDC and dimethylsulfoxide were constructed by using RS, KS, Rank-Select, sample set partitioning based on joint X- and Y-blocks (SPXY) and proposed Rank-KS algorithms to select the calibration set, respectively. Application results verified that the best prediction was achieved by using Rank-KS. Especially, for the distribution of sample set with more in the middle and less on the boundaries, or none in the local, prediction of the model constructed by calibration set selected using Rank-KS can be improved obviously..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 947 (2014)
Characterization and Simulation of Far-Infrared Spectroscopy for Saturated Monohydric Alcohols
MA Chun-qian, XU Xiang-dong, DING Lian, LIU Yi-ke, LUO Meng-jia, HE Qiong, HUANG Rui, WEN Yue-jiang, and SUN Zi-qiang
Fourier transform infrared-attenuated total reflection (FTIR-ATR) was employed to measure the far-infrared (FIR) spectra in wavenumbers of 30～300 cm-1 for six kinds of saturated monohydric alcohols, namely: methanol, ethanol, propanol, isopropanol, butanol and isobutanol. Further analysis of the FIR spectra for these mFourier transform infrared-attenuated total reflection (FTIR-ATR) was employed to measure the far-infrared (FIR) spectra in wavenumbers of 30～300 cm-1 for six kinds of saturated monohydric alcohols, namely: methanol, ethanol, propanol, isopropanol, butanol and isobutanol. Further analysis of the FIR spectra for these monohydric alcohols with similar chemical structures reveals that absorption peaks are observed obviously for these alcohols in the 30～150 cm-1 band, whereas not obvious peaks are measured in the 150～300 cm-1 band. Moreover, it was found that the monohydric alcohols with higher hydroxy concentration possess lower average FIR transmission. In addition, the average FIR transmissions of linear chain monohydric alcohols are higher than those of the branched chain ones. Furthermore, the density functional theory (DFT) B3LYP/6-311G(d,p) basis set was employed to simulate the structures optimization and to calculate the responding frequencies of the methanol monomer and polymer. Simulation result indicates that no absorption peaks are found in the 30～150 cm-1 band for the methanol monomer molecule, whereas there are obvious absorption peaks for the methanol polymers in the same band. In addition, the simulated absorption peak positions for the methanol polymers are in agreement with those experimentally measured. Both results indicate that the absorption of the methanol in Terahertz (THz) is attributed to the collective vibrations of different kinds of polymer, and that the polymer for methanol is mainly trimmer. This paper not only provides a new way to investigate the responding frequencies of organic molecule in THz band, but also is helpful for the FTIR-ATR study of other organic molecules..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 952 (2014)
Characteristic Wavelength Variable Optimization of Near-Infrared Spectroscopy Based on Kalman Filtering
WANG Li-qi, GE Hui-fang, LI Gui-bin, YU Dian-yu, HU Li-zhi, and JIANG Lian-zhou
Combining classical Kalman filter with NIR analysis technology, a new method of characteristic wavelength variable selection, namely Kalman filtering method, is presented. The principle of Kalman filter for selecting optimal wavelength variable was analyzed. The wavelength selection algorithm was designed and applied tCombining classical Kalman filter with NIR analysis technology, a new method of characteristic wavelength variable selection, namely Kalman filtering method, is presented. The principle of Kalman filter for selecting optimal wavelength variable was analyzed. The wavelength selection algorithm was designed and applied to NIR detection of soybean oil acid value. First, the PLS (partial least squares) models were established by using different absorption bands of oil. The 4 472～5 000 cm-1 characteristic band of oil acid value, including 132 wavelengths, was selected preliminarily. Then the Kalman filter was used to select characteristic wavelengths further. The PLS calibration model was established using selected 22 characteristic wavelength variables, the determination coefficient R2 of prediction set and RMSEP (root mean squared error of prediction) are 0.970 8 and 0.125 4 respectively, equivalent to that of 132 wavelengths, however, the number of wavelength variables was reduced to 16.67%. This algorithm is deterministic iteration, without complex parameters setting and randomicity of variable selection, and its physical significance was well defined. The modeling using a few selected characteristic wavelength variables which affected modeling effect heavily, instead of total spectrum, can make the complexity of model decreased, meanwhile the robustness of model improved. The research offered important reference for developing special oil near infrared spectroscopy analysis instruments on next step..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 958 (2014)
Study on Structural Properties of Biochar under Different Materials and Carbonized by FTIR
ZHENG Qing-fu, WANG Yong-he, SUN Yue-guang, NIU He-he, ZHOU Jia-ru, WANG Zhi-min, and ZHAO Ji
Infrared spectroscopy (IR) is an important means of seeing the characteristics of the structural properties. Fourier transform infrared spectroscopy (FTIR ) was applied to analyze the structural properties of biochar from different materials with different methods. The results showed that: the biochars have IR absorptiInfrared spectroscopy (IR) is an important means of seeing the characteristics of the structural properties. Fourier transform infrared spectroscopy (FTIR ) was applied to analyze the structural properties of biochar from different materials with different methods. The results showed that: the biochars have IR absorption peaks of hydroxyls group, aromatic group and containing organic group with the activated?charcoal, but in other absorption peaks, with a significant difference. The high temperature can make —OH, —CH3, —CH2—, CO to be associated or loss, and promotes the formation of aromatic groups during Carbonization of corn straw. At the different carbonization mode, the heating and microwave carbonization, has a carbonize mechanism of biochar, heating method may make —OH in alcohol and phenol to combinative with each other or loss, and to form benzene ring group and an aromatic group, Aromatic group in microwave method was so preventing to participate in the hot reaction, to form the more benzene substances. These results show that the Infrared spectrum can well analysis the structural characteristics of biochar, and showed that it comprises —OH, the aromatic group and other active groups..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 962 (2014)
Study on DNA Fourier Infrared Spectroscopy of Three Kinds of Nicotiana Tabacum L.
QIU Lu, YANG Hai-yan, YANG Chun-sheng, LIU Peng, FAN Shu-guo, LIU Ren-ming, and ZHOU Lin-zong
The aim is analyzing genetic reLationship and identifying varieties by detecting DNA differences of three kinds of Nicotiana tabacum L. using Fourier infrared spectrum (FTIR). Results show that DNA FTIR of three kinds of Nicotiana tabacum L. is relatively similar. They all have four obvious characteristic peaks. 1 105 The aim is analyzing genetic reLationship and identifying varieties by detecting DNA differences of three kinds of Nicotiana tabacum L. using Fourier infrared spectrum (FTIR). Results show that DNA FTIR of three kinds of Nicotiana tabacum L. is relatively similar. They all have four obvious characteristic peaks. 1 105 cm-1 beLongs to symmetrical stretching vibration of phosphodiester bond, 1 250 cm-1 is unsymmetrical stretching vibration of phosphodiester bond, 1 400 cm-1 is contributed to glucosidic bond, and 1 622 cm-1 belongs to C4C5C6 stretching vibration of cytosine. DNA FTIR data was handled by smoothing, standardizing, second derivative, principal component analysis and Hierarchical cluster analysis. The standard model of Hierarchical cluster combined with principal component of the second derivative was set up. The correct rate of identification is 100%. Yunyan 87 and K326 were clustered into one by using the model. The distance coefficient is 0.003, and DNA similarity is 99.7%, Hongda was clustered into one by itself. The correct rate of cluster is 100%. The study provides a reference for Nicotiana tabacum L. variety identification and genetic breeding..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 967 (2014)
Discrimination of Types of Polyacrylamide Based on Near Infrared Spectroscopy Coupled with Least Square Support Vector Machine
ZHANG Hong-guang, YANG Qin-min, and LU Jian-gang
In this paper, a novel discriminant methodology based on near infrared spectroscopic analysis technique and least square support vector machine was proposed for rapid and nondestructive discrimination of different types of Polyacrylamide. The diffuse reflectance spectra of samples of Non-ionic Polyacrylamide, Anionic PIn this paper, a novel discriminant methodology based on near infrared spectroscopic analysis technique and least square support vector machine was proposed for rapid and nondestructive discrimination of different types of Polyacrylamide. The diffuse reflectance spectra of samples of Non-ionic Polyacrylamide, Anionic Polyacrylamide and Cationic Polyacrylamide were measured. Then principal component analysis method was applied to reduce the dimension of the spectral data and extract of the principal compnents. The first three principal components were used for cluster analysis of the three different types of Polyacrylamide. Then those principal components were also used as inputs of least square support vector machine model. The optimization of the parameters and the number of principal components used as inputs of least square support vector machine model was performed through cross validation based on grid search. 60 samples of each type of Polyacrylamide were collected. Thus a total of 180 samples were obtained. 135 samples, 45 samples for each type of Polyacrylamide, were randomly split into a training set to build calibration model and the rest 45 samples were used as test set to evaluate the performance of the developed model. In addition, 5 Cationic Polyacrylamide samples and 5 Anionic Polyacrylamide samples adulterated with different proportion of Non-ionic Polyacrylamide were also prepared to show the feasibilty of the proposed method to discriminate the adulterated Polyacrylamide samples. The prediction error threshold for each type of Polyacrylamide was determined by F statistical significance test method based on the prediction error of the training set of corresponding type of Polyacrylamide in cross validation. The discrimination accuracy of the built model was 100% for prediction of the test set. The prediction of the model for the 10 mixing samples was also presented, and all mixing samples were accurately discriminated as adulterated samples. The overall results demonstrate that the discrimination method proposed in the present paper can rapidly and nondestructively discriminate the different types of Polyacrylamide and the adulterated Polyacrylamide samples, and offered a new approach to discriminate the types of Polyacrylamide..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 972 (2014)
Long Optical Path Gas Detection Based on MEMS Infrared Light Source
DU Bin-bin, ZHANG Peng, GAO Wen-hong, SHI Yun-bo, and ZHU Lin-quan
According to the requirements of infrared gas sensor for the light source, a broad wavelength, high modulation frequency, low power consumption and small size MEMS infrared light source is chosen as the radiation source, whose performance meets the requirements of infrared sensing system for the light source greatly. HAccording to the requirements of infrared gas sensor for the light source, a broad wavelength, high modulation frequency, low power consumption and small size MEMS infrared light source is chosen as the radiation source, whose performance meets the requirements of infrared sensing system for the light source greatly. However, the infrared light source with the lamberation radiation characteristics is a surface light source, which is still with a large numerical aperture after shaping. It is difficult to increase the detection sensitivity by using a traditional long optical gas cell in a MEMS infrared light source detection system. Based on the dual-wavelength single beam differential detection method, an integrating sphere as the gas cell for long optical path is designed, which is able to realize long optical path for high sensitivity gas detection. The physical dimension is deduced for the equivalent optical path according to the flux conservation principle in the process of light transmission, solving the calculation problem of equivalent optical path of the integrating sphere cell. Using FPGA control chip, the MEMS infrared light source is droved at high frequency modulation and the detector output signal is processed, which makes the external circuit design much simple and flexible. It turns out that 166.7 cm equivalent optical path and the minimum concentration of methane of 0.001×10-6 are achieved by the use of a 5 cm diameter integrating sphere in the research, improving the sensitivity of infrared detection system greatly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 977 (2014)
Study on Raman Spectra of Multi-Walled Carbon Nanotubes with Different Parameters
WU Rong-lin, SHAO Zheng-zheng, CHANG Sheng-li, ZHANG Xue-ao, LI He-ping, and LI Xin-hua
In order to study the influencing factors on Raman spectroscopy, we research a series of comparative Raman spectroscopy of multi-walled carbon nanotubes (MWCNT) with different tube diameter and length. The results suggest that the G peak and D peak of MWCNT are all red-shifted as compared to that of polycrystalline graIn order to study the influencing factors on Raman spectroscopy, we research a series of comparative Raman spectroscopy of multi-walled carbon nanotubes (MWCNT) with different tube diameter and length. The results suggest that the G peak and D peak of MWCNT are all red-shifted as compared to that of polycrystalline graphite; In the same conditions, the peak intensity (G peak and D peak) is directly proportional to the diameter of the MWCNT, and inversely proportional to the length of the MWCNT; G peak frequency shift is closely related to the MWCNT diameter and length, which are inversely proportional to the diameter (with identical results of the single-walled carbon nanotube radial breathing modes) and direct proportional to the length. While, the influences of the diameter and length on D peak frequency shift are weak, and future analysis for the reason of this kind of phenomenon is as follows. Subsequently, we investigated the relation between D peak frequency shift and MWCNT aspect ratio, the relationship between G peak frequency shift and aspect ratio is nearly linear increase. Using the same analysis method, we plotted the different graphs of G peak and D peak intensity vs the aspect ratio of MWCNT, respectively. As the expected, the linear degression relation are existent in the two relationships..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 982 (2014)
Surface-Enhanced Raman Spectra Analysis of Trace Degradation Products from Goat Horn
PAN Yan-ting, AO Ning-jian, SHAN Guang-hua, ZHANG Gang-ping, ZHANG Quan-bin, YANG Ji-wang, HE Chun-lan, and HUANG Yao-xiong
Nano-silver colloid was synthesized by using microwave method on the mixtures of sodium citrate solution and silver nitrate solution. The method has advantages of fast heating speed, uniform temperature distribution and easily controlled reaction conditions. The sizes and size distributions of the silver particles wereNano-silver colloid was synthesized by using microwave method on the mixtures of sodium citrate solution and silver nitrate solution. The method has advantages of fast heating speed, uniform temperature distribution and easily controlled reaction conditions. The sizes and size distributions of the silver particles were characterized by means of quasi-elastic laser scattering (QLS). The average particles size was (53.27±2.65) nm and the size of the particles was mainly distributed around 56 nm. Surface-enhanced Raman spectra of the degradation products from goat horn were obtained with silver colloid as active substrate. It was observed that the Raman signal of SERS was enhanced significantly compared with that of regular Raman spectrum, especially at the Raman bands of 659, 830, 850, 929, 999, 1 028, 1 280, 1 439 and 1 599 cm-1 which reflect the biochemical components in degradation products. The characteristic Raman bands of degradation products from goat horn were preliminary assigned. The assignments showed that the main constituents of the degradation products from goat horn were amino acids and polypeptides. It was for the first time that Surface-enhanced Raman spectroscopy was used to detect trace degradation products from the horns. Raman signal enhancement can be obtained with high sensitivity for the trace concentrations as low as ppm level. It is concluded that surface-enhanced Raman spectroscopy can provide a fast, direct and precise detecting method for the detection of trace degradation solution from horns..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 986 (2014)
Rapid Detection of Four Antipertensive Chemicals Adulterated in Traditional Chinese Medicine for Hypertension Using TLC-SERS
ZHU Qing-xia, CAO Yong-bing, CAO Ying-ying, and LU Feng
A novel facile method for on-site detection of antipertensive chemicals (e.g. nicardipine hydrochloride, doxazosin mesylate, propranolol hydrochloride, and hydrochlorothiazide) adulterated in traditional Chinese medicine for hypertension using thin layer chromatography (TLC) combined with surface enhanced Raman spectroA novel facile method for on-site detection of antipertensive chemicals (e.g. nicardipine hydrochloride, doxazosin mesylate, propranolol hydrochloride, and hydrochlorothiazide) adulterated in traditional Chinese medicine for hypertension using thin layer chromatography (TLC) combined with surface enhanced Raman spectroscopy (SERS) was reported in the present paper. Analytes and pharmaceutical matrices was separated by TLC, then SERS method was used to complete qualitative identification of trace substances on TLC plate. By optimizing colloidal silver concentration and developing solvent, as well as exploring the optimal limits of detection (LOD), the initially established TLC-SERS method was used to detect real hypertension Chinese pharmaceuticals. The results showed that this method had good specificity for the four chemicals and high sensitivity with a limit of detection as lower as to 0.005 μg. Finally, two of the ten antipertensive drugs were detected to be adulterated with chemicals. This simple and fast method can realize rapid detection of chemicals illegally for doping in antipertensive Chinese pharmaceuticals, and would have good prospects in on-site detection of chemicals for doping in Chinese pharmaceuticals..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 990 (2014)
Study on Synthesis and Matching Degree of Energy Level of Terbium Complexes Using o-Fluoro-Benzoic Acid as Ligand
TAO Dong-liang, ZHANG Kun, ZHANG Hong, CUI Yu-min, XU Yi-zhuang, and LIU Yu-hai
Tb(2-FBA)3·2H2O and Tb(2-FBA)3phen were synthesized using o-fluoro-benzoic acid (2-FBA) as the first ligand, and 1,10-phenanthroline (phen) as the second ligand. Elemental analysis and IR spectra were employed to characterize the molecular composition of the two kinds of lanthanide complexes. The UV absorption speTb(2-FBA)3·2H2O and Tb(2-FBA)3phen were synthesized using o-fluoro-benzoic acid (2-FBA) as the first ligand, and 1,10-phenanthroline (phen) as the second ligand. Elemental analysis and IR spectra were employed to characterize the molecular composition of the two kinds of lanthanide complexes. The UV absorption spectra with same concentration show that the second ligand phen of Tb(2-FBA)3phen absorbs the portion of the UV light instead of the first ligand 2-FBA. Liquid fluorescence spectra with same concentration show that the fluorescence intensity of Tb(2-FBA)3·2H2O is higher than that of Tb(2-FBA)3phen. The analytical results show that the energy level of 2-FBA matches the lowest excited state energy level of Tb3+ (5D4) better than that of phen. The O—H oscillation of the crystal water in Tb(2-FBA)3·2H2O will greatly consume the absorbed energy by ligands, and cause the fluorescence intensity of Tb(2-FBA)3·2H2O significantly decline. The energy level of triplet state of the first ligand 2-FBA corresponding to the absorption peak 273 nm has poor matching degree with the 5D4 energy level of Tb3+. In this case, the emission intensity of Tb(2-FBA)3·2H2O is still stronger than that of Tb(2-FBA)3phen. It illustrates that the energy level of the triplet state of the first ligand 2-FBA corresponding to 252 nm has much better matching degree with the lowest excited state of 5D4 energy level of Tb3+ than that of phen. It is the only way to compensate for energy loss by thermal vibration of water molecules and low energy transfer efficiency for poor matching degree between the energy level of corresponding to 273 nm of the first ligand 2-FBA and 5D4 energy level of Tb3+. By combining UV absorption spectra with fluorescence spectra of lanthanide complexes to qualitatively analyze energy level of ligands, the contribution of different types of ligands to the fluorescence properties can be preliminarily understood..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 994 (2014)
Theoretical Study on Fluorescence Spectra of Four Kinds of p-Substituted Curcumin Analogues
JIA Fei-yun, SU Yu, RAN Ming, ZHU Jiang, and ZHANG Bo
Four kinds of p-substituted curcumin analogues were optimized at B3LYP/6-31G (d, p) level. On this basis, the excited states geometry structure was optimized by the CIS method, and finally the fluorescence emission spectra were calculated through the TD-DFT method. The results showed that: the four compounds, a large cFour kinds of p-substituted curcumin analogues were optimized at B3LYP/6-31G (d, p) level. On this basis, the excited states geometry structure was optimized by the CIS method, and finally the fluorescence emission spectra were calculated through the TD-DFT method. The results showed that: the four compounds, a large conjugated system, is preferably coplanar structure. Because of introducing hydroxyl and halogen atom on the benzene ring, the molecular π-electron conjugation is relatively larger, emission wavelength is relatively longer, and fluorescence spectra show different degrees of red shift. As the electron donating group is hydroxy, the fluorescence phenomenon is more obviously red shifted..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 999 (2014)
Rice Blast Prediction Model Based on Analysis of Chlorophyll Fluorescence Spectrum
ZHOU Li-na, YU Hai-ye, ZHANG Lei, REN Shun, SUI Yuan-yuan, and YU Lian-jun
In order to detect rice blast more rapidly, accurately and nondestructively, the identification and early warning models of rice blast were established in the present research. First of all, rice blast was divided into three grades according to the relative area of disease spots in rice leaf and laser-induced chlorophyIn order to detect rice blast more rapidly, accurately and nondestructively, the identification and early warning models of rice blast were established in the present research. First of all, rice blast was divided into three grades according to the relative area of disease spots in rice leaf and laser-induced chlorophyll fluorescence spectra of rice leaves at different disease levels were measured in the paddy fields. Meanwhile, 502～830 nm bands of laser-induced chlorophyll fluorescence spectra were selected for the study of rice blast. Savitzky-Golay(SG) smoothing and First Derivative Transform(FDT) were applied for the pretreatment of laser-induced chlorophyll fluorescence spectra. Then the method of Principal Components Analysis(PCA) was used to achieve the dimension reduction on spectral information, three principal components whose variance are greater than 1 and cumulative credibility is 99.924% were extracted by this method. Furthermore, the tentative data were divided into calibration set and validation set, the levels of rice blast were taken as the predictors. Combined with the calibration set which contains the disease and spectral information of 133 leaves, Discriminant Analysis(DA), Multiple Logistic Regression Analysis(MLRA) and Multilayer Perceptron(MLP) were used respectively to establish the identification and early warning models of rice blast. The Prediction examinations of the three models were made based on the validation set which contains the disease and spectral information of 89 leaves. The results show that all the models of PCA-DA, PCA-MLRA and PCA-MLP can carry on the prediction of rice blast, and the average prediction accuracy of PCA-MLP prediction model is 91.7% which is improved compared with PCA- DA and PCA- MLRA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1003 (2014)
The Study on the Fluorescence Spectrometry for a Novel Photosensitizer of Chlorine e6-C15-Monomethyl Ester and Its Application in Biosamples Analysis
YANG Dan, ZHAO Xin, SUN Fan-lu, QI Tian, LIU Cheng-chu, and FAN Guo-rong
This paper studied the fluorescence spectral characteristic of chlorin e6-C15-monomethyl ester in different solvents to develop a fluorescence spectrometry for determining the concentration of chlorin e6-C15-monomethyl ester in plasma. By comparing the fluorescence spectral characteristics of chlorin e6-C15-monomethyl This paper studied the fluorescence spectral characteristic of chlorin e6-C15-monomethyl ester in different solvents to develop a fluorescence spectrometry for determining the concentration of chlorin e6-C15-monomethyl ester in plasma. By comparing the fluorescence spectral characteristics of chlorin e6-C15-monomethyl ester in six different solvents including methanol, ethanol, acetone, acetonitrile, phosphate buffered saline and water, the influence of different solvents on the fluorescence spectral characteristic of chlorin e6-C15-monomethyl ester has been examined. The results indicated that methanol and acetonitrile are the ideal solvent system, and the effect of phosphate buffered saline is better than water. The effect of organic solvent content and solution pH value on emission wavelength and fluorescence intensity was further evaluated. It was found that the fluorescence intensity of chlorin e6-C15-monomethyl ester was strong and stable in pH 7.2 phosphate buffered saline -acetonitrile (3∶7) solution and can be detected at the excitation wavelength of 498.00 nm and the emission wavelength of 664.05 nm. Based on this, we developed the fluorescence spectrometry for determining chlorin e6-C15-monomethyl ester. It is specific and sensitive with good linearity over the range of 0.5～50 μg·mL-1. The intra-batch and inter-batch precisions (RSD) were less than 10%, the extraction recoveries were all over 90%. The established method in this paper was simple, fast, effective and could be successfully applied to study the pharmacokinetics of chlorine e6-C15-monomethyl ester in SD rats..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1007 (2014)
Rapid Determination of Ractopamine Content in Pork by Using Three-Dimensional Synchronous Fluorescence Spectrum Coupled with APTLD
ZHAO Jin-hui, YUAN Hai-chao, LIU Mu-hua*, XIAO Hai-bin, and HONG Qian
In order to realize the rapid determination of ractopamine content in pork, quantitative determination model of ractopamine content in pork was established by using three-dimensional synchronous fluorescence spectrum coupled with alternating penalty trilinear decomposition (APTLD). Firstly, the generation mechanism of In order to realize the rapid determination of ractopamine content in pork, quantitative determination model of ractopamine content in pork was established by using three-dimensional synchronous fluorescence spectrum coupled with alternating penalty trilinear decomposition (APTLD). Firstly, the generation mechanism of the fluorescence spectrum for ractopamine and three-dimensional synchronous fluorescence spectrum for samples were analyzed. Secondly, concentration quenching phenomenon of fluorescence of ractopamine in pork extract was investigated. Thirdly, the number of components for three linear decomposition of APTLD was set as 2 by using the core consistency diagnostic method, and the calibration curve of the relative fluorescence intensity of ractopamine between pork extract and the training sample was established for the correction of relative fluorescence intensity of prediction samples. Finally, three-dimensional synchronous fluorescence spectrum combined with APTLD was used to build the prediction model of ractopamine content in pork. The experimental results showed that the method adopted in the paper could better solve the problem of serious synchronous fluorescence spectrum overlapping between ractopamine in pork samples and backgrounds, and leave out some trivial process of chemical separation for the identification of ractopamine in pork. The determination coefficient (R2) and the root mean squared error of prediction (RMSEP) for the model proposed in this paper were 0.986 3 and 0.496 6 mg·L-1, respectively. The method in this paper has achieved the goal of rapid quantitative detection of ractopamine content in pork..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1012 (2014)
Spatial-Temporal Evolution Characterization of Land Subsidence by Multi-Temporal InSAR Method and GIS Technology
CHEN Bei-bei, GONG Hui-li, LI Xiao-juan, LEI Kun-chao, DUAN Guang-yao, and XIE Jin-rong
Long-term over-exploitation of underground resources, and static and dynamic load increase year by year influence the occurrence and development of regional land subsidence to a certain extent. Choosing 29 scenes Envisat ASAR images covering plain area of Beijing, China, the present paper used the multi-temporal InSAR Long-term over-exploitation of underground resources, and static and dynamic load increase year by year influence the occurrence and development of regional land subsidence to a certain extent. Choosing 29 scenes Envisat ASAR images covering plain area of Beijing, China, the present paper used the multi-temporal InSAR method incorporating both persistent scatterer and small baseline approaches, and obtained monitoring information of regional land subsidence. Under different situation of space development and utilization, the authors chose five typical settlement areas; With classified information of land-use, multi-spectral remote sensing image, and geological data, and adopting GIS spatial analysis methods, the authors analyzed the time series evolution characteristics of uneven settlement. The comprehensive analysis results suggests that the complex situations of space development and utilization affect the trend of uneven settlement; the easier the situation of space development and utilization, the smaller the settlement gradient, and the less the uneven settlement trend..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1017 (2014)
Preliminary Study on Internal Information of the Measured Tissue Based on Distributed Multi-Position Scattering Spectroscopy
WANG Li-yun, LI Gang, LI Zhe, LIN Ling, and BI Ping
The present paper describes the design of pellicle-milk double-layer phantom experiment. Milk solution of 40 different concentrations represents internal information of tissue, 1 to 5 pellicle which covers above the milk solution represents interference information of superficial tissue. The experiment collected 200 scThe present paper describes the design of pellicle-milk double-layer phantom experiment. Milk solution of 40 different concentrations represents internal information of tissue, 1 to 5 pellicle which covers above the milk solution represents interference information of superficial tissue. The experiment collected 200 scattering spectral data of two positions and took the one single position spectral group as control, and then respectively predicted the milk solution concentration on bottom layer with the ratio of 3:1 through the BP neural network method. The experimental results show that single position scattering spectrum and two-position scattering spectrum both reached more than 90% training fitting rates and prediction accuracy, and the prediction accuracy of two-position scattering spectra is higher, reaching 98.41%. It was verified by the experimental results that scattering spectrum based on photon dissemination path can efficiently predict the milk solution concentration and eliminate the influence of superficial tissue for measurement of internal organization, and considering multi-position in modeling process can improve the accuracy of the prediction. This study validates the feasibility of the method for exploring internal information of tissue without damaging tissue integrity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1026 (2014)
Synthesis and Characterization of Dihydroeugenol Acrylate
LIU Xiao-huan, WANG Chun-peng, WANG Ji-fu, XU Yu-zhi, and CHU Fu-xiang
Dihydroeugenol acrylate was synthesized by the reaction of acryloyl chloride (AC) with lignin mode compound dihydroeugenol (DH) in the presence of TEA and characterized by using FTIR, GC/MS, 1H-NMR and GPC. FTIR spectra showed that, after the esterification with acryloyl chloride, the intensity of stretching vibration Dihydroeugenol acrylate was synthesized by the reaction of acryloyl chloride (AC) with lignin mode compound dihydroeugenol (DH) in the presence of TEA and characterized by using FTIR, GC/MS, 1H-NMR and GPC. FTIR spectra showed that, after the esterification with acryloyl chloride, the intensity of stretching vibration peak of O—H (centered at 3 495 cm-1) of DH was disappeared. At the same time, a new peak appeared at 1 762 cm-1 which was assigned to ester group. Additionally, the appearance of 1 631 and 981 cm-1 were attributed to the carbon–carbon double bond confirmed the success in the synthesis of DH-AC. 1H-NMR spectra showed that, after the esterification with acryloyl chloride, the proton signal of O—H at 5.5 ppm was disappeared. Meanwhile, the appearance of three new proton signals at 6.0 ppm, 6.4 and 6.7 ppm, attributed to the vinylic protons, indicated that acryloyl chloride was successfully grafted onto DH. The results further confirmed the structures of the DH-AC. GC-MS results showed the DH-AC had a high purity of 98.63%. GPC results showed that dihydroeugenol acrylate could polymerize in the 1,4-dioxane using a thermal initiator of AIBN (2.0 Wt% of total monomers). The weight average molecular mass (Mw) of the homopolymer is 37 400 g·mol-1, and the number average molecular mass is 23 400 g·mol-1 with a polydispersity index Mw/Mn of 1.60, indicating that the dihydroeugenol acrylate has high polymerization activity. This strategy provides a novel approach for extending the comprehensive utilization of lignin..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1031 (2014)
Ex-Situ Remediation on Co-Contaminated Arid Loess in Column with Spectral Methods
FAN Chun-hui, ZHANG Ying-chao, WANG Xiao-na, and WANG Jia-hong
The arid loess in northwestern China is one of the dominant soil types nationwide, the removal efficiency of Pb and chlorpyrifos in simulated co-contaminated loess was investigated by ethylene diamine tetra-acetic acid (EDTA) in ex-situ column experiment, and methods of ultraviolet spectroscopy (UV), atomic absorption The arid loess in northwestern China is one of the dominant soil types nationwide, the removal efficiency of Pb and chlorpyrifos in simulated co-contaminated loess was investigated by ethylene diamine tetra-acetic acid (EDTA) in ex-situ column experiment, and methods of ultraviolet spectroscopy (UV), atomic absorption spectroscopy (AAS), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR) were used to reveal the remediation characteristics and mechanism. The results showed that the flow rate and pH value of EDTA are responsible for the reaction curves. In the experimental conditions, the removal rates of Pb and chlorpyrifos are more than 70% and 90%, respectively, and the bioavailability of heavy metals decreases greatly. The SEM micrographs indicate the dense and rough surface of loess, and unclear surface and enhanced dispersion of particles appear after the reaction. The EDS results explain the phenomenon of Pb removal and elemental loss. The move, disappearance and decrease of wave peaks, shown from FTIR spectra, are the effect of various chemical environment in loess, and the reaction is more appropriate for physisorbed pollutants removal. The achievements are acceptable for co-contaminated loess remediation by EDTA in ex-situ column, showing potential for future application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1035 (2014)
Investigation of Exogenous Stimulus Effect on the Interaction of CdSe/ZnS Quantum Dots/TiO2 Nanocomposites with Human Serum Albumin by Resonance Light Scattering
LI Yue-sheng, DU Ji-fu, SUN Shao-fa, and ZHAO Long
The interaction between CdSe/ZnS(quantum dots)/TiO2 nanocomposites and human serum albumin(HSA) was investigated by resonance light scattering (RLS) spectroscopic methods under approximate physiological conditions. Much important information of the interaction between CdSe/ZnS(Quantum Dots)/TiO2 nanocomposites and HSA The interaction between CdSe/ZnS(quantum dots)/TiO2 nanocomposites and human serum albumin(HSA) was investigated by resonance light scattering (RLS) spectroscopic methods under approximate physiological conditions. Much important information of the interaction between CdSe/ZnS(Quantum Dots)/TiO2 nanocomposites and HSA was obtained by studying comprehensively the Exogenous influence factors of nanocomposites concentration, pH, NaCl concentration, reaction temperature, detection time, coexisting ions, surfactants, sequence of adding to the sample etc. It was showed that the new formation of complex system is likely to enhance the protein hydrophobic cavity and tend to focus the hydrophobic interface in aqueous solution, resulting in strengthening the intensity of resonance light scattering; Also it is very sensitive to the changes in the pH value in the system; The sensitivity of IRLS in system can be increased by the appropriate NaCl concentration; The value of IRLS in system would be changed with the change in the concentration of coexisting ions; The value of IRLS in system is basically stable when the reaction time reaches 5 min; The value of IRLS in system is not exactly the same with a surfactant, and strong electrostatic interaction has occurred between oppositely charged surfactant and nano composites; It is obvious that the value of IRLS in complex system is affected by the sequence of adding to sample; It has the incomplete monotonically increasing trend with the changes in temperature. The information is useful for providing theoretical supporting for the mechanism of interaction between nanomaterials and bio-macromolecule, and for understanding the biocompatibility and safety of nano-materials..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1040 (2014)
Spectral Characteristics of Decomposition of Incorporated Straw in Compound Polluted Arid Loess
FAN Chun-hui, ZHANG Ying-chao, XU Ji-ting, and WANG Jia-hong
The original loess from western China was used as soil sample, the spectral methods of scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR) were used to investigate the characteristicThe original loess from western China was used as soil sample, the spectral methods of scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), elemental analysis, Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR) were used to investigate the characteristics of decomposed straw and formed humic acids in compound polluted arid loess. The SEM micrographs show the variation from dense to decomposed surface, and finally to damaged structure, and the EDS data reveal the phenomenon of element transfer. The newly-formed humic acids are of low aromaticity, helpful for increasing the activity of organic matters in loess. The FTIR spectra in the whole process are similar, indicating the complexity of transformation dynamics of humic acids. The molecular structure of humic acids becomes simpler, shown from 13C NMR spectra. The spectral methods are useful for humic acids identification in loess region in straw incorporation process..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1045 (2014)
Study of Collagen Mimetic Peptide’s Triple-Helix Structure and Its Thermostability by Circular Dichroism
ZHANG Zhi-bao, WANG Jing-jie, CHEN Hui-juan, XIONG Qing-qing, LIU Ling-rong, and ZHANG Qi-qing
In the present study, the authors explore the triple-helix conformation and thermal stability of collagen mimetic peptides (CMPs) as a function of peptide sequence and/or chain length by circular dichroism(CD). Five CMPs were designed and synthetized varying the number of POG triplets or incorporating an integrin α2β1 In the present study, the authors explore the triple-helix conformation and thermal stability of collagen mimetic peptides (CMPs) as a function of peptide sequence and/or chain length by circular dichroism(CD). Five CMPs were designed and synthetized varying the number of POG triplets or incorporating an integrin α2β1 binding motif Gly-Phe-Hyp-Gly-Glu-Arg (GFOGER). CD spectroscopy from 260 to 190 nm was recorded to confirm the existence of triple-helix conformation at room temperature, while thermal melting and thermal annealing of triple-helix (thermal unfolding and refolding of triple-helix, respectively) was characterized by monitoring ellipticity at 225 nm as a function of temperature. The results demonstrated that all the CMPs adopted triple-helix conformation, and the thermal stability of the CMPs was enhanced with increasing the number of POG triplets. In contrast to natural collagen, the thermal denaturation processes of CMPs were reversible, i.e. the triple-helix unfolded upon heating while refolded upon cooling. Meanwhile, the phenomenon of “hysteresis” was observed by comparing melting and thermal curves. These findings add new insights to the mechanisms of collagen and CMPs assembly, as well as provide an alternative approach to the fabrication of artificial collagen-likes biomaterials..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1050 (2014)
Process Monitoring of Dissolution of Valsartan and Hydrochlorothiazide Tablets by Fiber-Chemical Sensor Assisted by Mathematical Separation Model of Linear Equations
DING Hai-yan, LI Gai-ru, YU Ying-ge, ZHOU Dong-dong, GUO Wei, ZHI Ling, and LI Xin-xia
A method for on-line monitoring the dissolution of Valsartan and hydrochlorothiazide tablets assisted by mathematical separation model of linear equations was established. UV spectrums of valsartan and hydrochlorothiazide were overlapping completely at the maximum absorption wavelength respectively. According to the BeA method for on-line monitoring the dissolution of Valsartan and hydrochlorothiazide tablets assisted by mathematical separation model of linear equations was established. UV spectrums of valsartan and hydrochlorothiazide were overlapping completely at the maximum absorption wavelength respectively. According to the Beer-Lambert principle of absorbance additivity, the absorptivity of Valsartan and hydrochlorothiazide was determined at the maximum absorption wavelength, and the dissolubility of Valsartan and hydrochlorothiazide tablets was detected by fiber-optic dissolution test (FODT) assisted by the mathematical separation model of linear equations and compared with the HPLC method. Results show that two ingredients were real-time determined simultaneously in given medium. There was no significant difference for FODT compared with HPLC (p>0.05). Due to the dissolution behavior consistency, the preparation process of different batches was stable and with good uniformity. The dissolution curves of valsartan were faster and higher than hydrochlorothiazide. The dissolutions at 30 min of Valsartan and hydrochlorothiazide were concordant with US Pharmacopoeia. It was concluded that fiber-optic dissolution test system assisted by the mathematical separation model of linear equations that can detect the dissolubility of Valsartan and hydrochlorothiazide simultaneously, and get dissolution profiles and overall data, which can directly reflect the dissolution speed at each time. It can provide the basis for establishing standards of the drug. Compared to HPLC method with one-point data, there are obvious advantages to evaluate and analyze quality of sampling drug by FODT..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1056 (2014)
Porphyrins with Different Electron Groups: Spectral and DFT Study
WU Hai, FAN Su-hua*, ZHANG Hong, LI Hui-quan, YANG Man-qing, and ZHANG Cheng-ye
UV-Vis absorption spectra and electrochemical properties of 5-(o-hydroxyphenyl)-10, 15, 20-tri-(p-phenyl)porphyrin (TPPOH) and 5-(o-hydroxyphenyl)-10, 15, 20-tri-(p-methoxyphenyl)porphyrin ［(p-OCH3)TPPOH］ with different electron groups were investigated by experiments and density functional theory (DFT). Due to the intUV-Vis absorption spectra and electrochemical properties of 5-(o-hydroxyphenyl)-10, 15, 20-tri-(p-phenyl)porphyrin (TPPOH) and 5-(o-hydroxyphenyl)-10, 15, 20-tri-(p-methoxyphenyl)porphyrin ［(p-OCH3)TPPOH］ with different electron groups were investigated by experiments and density functional theory (DFT). Due to the introduction of para-methoxyl group (—OCH3), obvious red shift of 3 nm in the maximum absorbance of the UV-Vis spectra, negative shift in redox potential of (p-OCH3)TPPOH, and the decrease (0.06 eV) in the energy gap (DE) of the frontier highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) (of (p-OCH3)TPPOH occurred as compared to those of TPPOH. The results are due to that electron donating groups of —OCH3 increase the electron density of porphyrin ring in (p-OCH3)TPPOH. Electron distributions of the frontier orbital calculated by DFT showed that the increase in the energy levels of HOMO and LUMO, while the decrease of 0.05 eV in the energy gap. The agreement between experimental result and theoretical value and the further illustration of the mechanism for the spectral change and electrochemical properties provide important bases for the design and application of the porphyrin derivatives with different electron groups..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1060 (2014)
Study of Interaction between Levofloxacin and Human Serum Albumin by Multi-Spectroscopic and Molecular Modeling Methods
HUANG Fang, DONG Cheng-yu, ZHANG Li-yang, and LIU Ying
Levofloxacin (LVFX) is widely used in clinical treatment due to it has a broad spectrum of in vitro activity against Gram-positive and Gram-negative bacteria. Human serum albumin (HSA) is the most abundant protein in plasma and constitutes approximately half of the protein founds in human blood. And more than 90% of thLevofloxacin (LVFX) is widely used in clinical treatment due to it has a broad spectrum of in vitro activity against Gram-positive and Gram-negative bacteria. Human serum albumin (HSA) is the most abundant protein in plasma and constitutes approximately half of the protein founds in human blood. And more than 90% of the drugs used in people are bound to HSA. So it is commonly used for the investigation of drug-serum albumin interaction because the binding will significantly influence the absorption, distribution, metabolism excretion, stability and toxicity of the drugs. Therefore, detailed investigating the interaction of LVFX with HSA is very important to understand the pharmacokinetic behavior of the LVFX. In this paper, the interaction of LVFX and HSA has been studied fluorescence, UV, Fourier transform infrared (FT-IR) and molecular modeling method. The results indicated that LVFX induced the intrinsic fluorescence quenching of HSA though a static quenching procedure, and the effective binding constants (Ka) were calculated to be 9.44×104 L·mol-1 (294 K) and 2.74×104 L·mol-1 (310 K) by used of the Stern-Volmer equation. According to the Vant’s Hoff equation, the reaction was characterized by negative enthalpy (ΔH=-59.00 kJ·mol-1) and negative entropy (ΔS=-105.38 J·mol-1·K-1), indicated that the predominant forces in the LVFX-HSA complex were hydrogen bonding and van der Waals forces. By displacement measurements, the specific binding of LVFX in the vicinity of Site Ⅰ of HSA was clarified. The binding distance of 3.66 nm between Trp214 and HSA was obtained by the Frster theory on resonance energy transfer. Furthermore, the binding details between LVFX and HSA were further confirmed by molecular docking studies, which were consistent with the experimental results. The alternations of protein secondary structure were calculated from FT-IR spectra. Upon formation of LVFX-HSA complexes, the amount of α-helical structures were decrease, but the numbers of β-sheet structures, β-turn structures and random structures were increase, respectively. This result indicated that LVFX induced unfolding of the polypeptides of HSA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1064 (2014)
Study of the Mn-Doped ZnS Quantum Dots as the Phosphorescence Probes to Detect the Micro-Quantity Hg2+
DU Bao-an, LIU Cheng, CAO Yu-hong, and CHEN Li-na
In the present paper, the Mn-doped ZnS quantum dots were synthesized in water, and the MPA was used as the stabilizer. Utilizing the strong quenching effect of Hg2+ to the phosphorescence of the ZnS:Mn quantum dots, the method to detect micro-quantity Hg2+ in water was established by using the quantum dots as the phospIn the present paper, the Mn-doped ZnS quantum dots were synthesized in water, and the MPA was used as the stabilizer. Utilizing the strong quenching effect of Hg2+ to the phosphorescence of the ZnS:Mn quantum dots, the method to detect micro-quantity Hg2+ in water was established by using the quantum dots as the phosphorescence probes. Compared to the fluorescence methods, the phosphorescence has longer lifetime and higher selectivity, and avoids the interference of the fluorescence and the scattering light. The result showed that under the optimum conditions, the relationship between the ΔP/P and Hg2+ concentration was linearity which was ruled by the Stern-Volmer equation while the Hg2+ concentration was between 1.0×10-5 and 1.0×10-3 mol·L-1, and the linear correlation coefficient was 0.998 8. The recovery of the method was between 85.2% and 106.1%, the RSD was 3.46%, and the detection limit was 9.7×10-6 mol·L-1.The mechanism of quenching of phosphorescence was discussed. The interferences of some metal ions could be effectively eliminated by adding appropriate masking agents in the solution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1070 (2014)
Comparison of Performances in Retrieving Impervious Surface between Hyperspectral (Hyperion) and Multispectral (TM/ETM+) Images
TANG Fei, and XU Han-qiu
The retrieval of impervious surface is a hot topic in the remote sensing field in the past decade. Nevertheless, studies on retrieving impervious surface from hyperspectral image and the comparison of the performances in retrieving impervious surface between hyperspectral and multispectral images are rarely reported. TThe retrieval of impervious surface is a hot topic in the remote sensing field in the past decade. Nevertheless, studies on retrieving impervious surface from hyperspectral image and the comparison of the performances in retrieving impervious surface between hyperspectral and multispectral images are rarely reported. Therefore, The present paper focuses on the characteristics of hyperspectral (EO-1 Hyperion) and multispectral (Landsat TM/ETM+) images and implements a complementary study on the comparison based on the retrieved impervious surface information between Hyperion and TM/ETM+ data. For up to 242 bands of Hyperion image, a further study was carried out to select feature bands for impervious surface retrieving using stepwise discriminant analysis. As a result, 11 feature bands were selected and a new image named Hyperion’ was thus composed. The new Hyperion’ image was used to investigate whether this band-reduced image could obtain higher accuracy in retrieving impervious surface. The three test regions were selected from Fuzhou, Guangzhou and Hangzhou of China, with date-coincident or nearly coincident image pairs of the used sensors. The linear spectral mixture analysis (LSMA) was employed to retrieve impervious surface and the results were accessed for their accuracy. The comparison shows that the Hyperion image has higher accuracy than TM/ETM+, and the Hyperion’ composed of the selected 11 feature bands has the highest accuracy. The advantages of Hyperion in spectral and radiometric resolutions over TM/ETM+ are believed to be the main factors contributing to the higher accuracy. The high spectral and radiometric resolutions of Hyperion image allow the sensor to have higher sensitivity in distinguishing subtle spectral changes of ground objects. While, the highest accuracy the 11-band Hyperion’ image achieved is owing to the significant reduction of the band dimension of the image and thus the band redundancy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1075 (2014)
Research on Hyperspectral Inversion of Soil Salinity in Typical Semiarid Area
LI Xiao-ming, HAN Ji-chang, and LI Juan
Hysperspectral inversion of soil salinity was researched in the present paper with the chosen study object of typical semiarid area in North Shaanxi Province. The studying sites were selected, the hyperspectral data were collected, and the soil samples were taken back for experiment analysis. The reflectance of soils (Hysperspectral inversion of soil salinity was researched in the present paper with the chosen study object of typical semiarid area in North Shaanxi Province. The studying sites were selected, the hyperspectral data were collected, and the soil samples were taken back for experiment analysis. The reflectance of soils (R), the logarithm of the reciprocal of the reflectance (Log(1/R)) and the continual removed reflectance (Rcr) were used to research the soil salinity. The correlations between the hyperspectral character and soil salinity was studied to filter the characteristics bands. Then the partial least squares regression (PLSR) was used to study the inversion model of soil salinity with Matlab program, and the precision was compared with the verifying sites. The research result showed that the root mean square error (RMSE) of the inversion with Rcr was the least (1.253<1.367<1.575), and its precision was the best; the correlation between the predicted value and the measured value was well (r2=0.761), the trend line was near y=x. In conclusion, the quantificational inversion model with the variables of Rcr establised by PLSR was well, which will improve the survey efficiency of soil salinity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1081 (2014)
Study on Extraction Process of Coumarin in a Mongolian Drug Chagan-Sorlo (Radix Glehniae)
BORJIGIDAI Almaz, CUI Xun, PANG Zong-ran, CUI Jian, and KANG Feng
The present paper discusses ultrasonic extraction method aided extraction of coumarin from a Mongolian drug, Chagan-sorlo (Radix Glehniae), aiming to study out how much coumarin contained in Chagan-sorlo, and to provide the scientific basis and production guidance for extracting coumarin from Chagan-sorlo. Under differThe present paper discusses ultrasonic extraction method aided extraction of coumarin from a Mongolian drug, Chagan-sorlo (Radix Glehniae), aiming to study out how much coumarin contained in Chagan-sorlo, and to provide the scientific basis and production guidance for extracting coumarin from Chagan-sorlo. Under different conditions the coumarin in Chagan-sorlo was extracted by ultrasonic, measured and analyzed, and then HPLC was used to carry out the measurement. Result showed that with solvent volume fraction of 70%, extraction time of 20 min, ultrasonic power of 175 W, temperature of 25 ℃, solid-liquid ratio of 1∶20, and 80～100 mesh extraction, the coumarin extraction reaches the highest yield..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1085 (2014)
Element Distribution Analysis of Welded Fusion Zone by Laser-Induced Breakdown Spectroscopy
YANG Chun, ZHANG Yong, JIA Yun-hai, and WANG Hai-zhou
Over the past decade there has been intense activity in the study and development of laser-induced breakdown spectroscopy (LIBS). As a new tool for surface microanalysis, it caused widespread in materials science because of the advantage of rapid and high sensitivity. In the present paper, the distribution of Ni, Mn, COver the past decade there has been intense activity in the study and development of laser-induced breakdown spectroscopy (LIBS). As a new tool for surface microanalysis, it caused widespread in materials science because of the advantage of rapid and high sensitivity. In the present paper, the distribution of Ni, Mn, C and Si near weld fusion line was analyzed on two kinds of weld sample. Line scanning mode analysis was carried out by three different kinds of methods, namely laser-induced breakdown spectroscopy (LIBS), scanning electron microscope/energy dispersive spectrometer (SEM/EDS) and electron probe X-ray microanalyser (EPMA). The concentration variation trend of Ni and Mn acquired by LIBS is coincident with SEM/EDS and EPMA. The result shows that the content of Ni and Mn was significantly different between weld seam and base metal on both the samples. The content of Ni and Mn was much higher in weld seam than in base metal, and a sharp concentration gradient was analyzed in the fusion zone. According to the distribution of Ni and Mn, all the three methods got a similar value of welded fusion zone width. The concentration variation trend of C and Si acquired by LIBS is not coincident with SEM/EDS and EPMA. The concentration difference between weld seam and base metal was analyzed by LIBS, but had not by SEM/EDS and EPMA, because of the low concentration and slight difference. The concentration gradient of C and Si in fusion zone was shows clearly by LIBS. For higher sensitivity performance, LIBS is much more adapted to analyze low content element than SEM/EDS and EPMA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1089 (2014)
The Content of Mineral Elements in Camellia Oleifera Ovary at Pollination and Fertilization Stages Determined by Auto Discrete Analyzers and Atomic Absorption Spectrophotometer
ZOU Feng, YUAN De-yi, GAO Chao, LIAO Ting, CHEN Wen-tao, HAN Zhi-qiang, and ZHANG Lin
In order to elucidate the nutrition of Camellia oleifera at pollination and fertilization stages, the contents of mineral elements were determined by auto discrete analyzers and atomic absorption spectrophotometer, and the change in the contents of mineral elements was studied and analysed under the condition of self- In order to elucidate the nutrition of Camellia oleifera at pollination and fertilization stages, the contents of mineral elements were determined by auto discrete analyzers and atomic absorption spectrophotometer, and the change in the contents of mineral elements was studied and analysed under the condition of self- and cross-pollination. The results are showed that nine kinds of mineral elements contents were of “S” or “W” type curve changes at the pollination and fertilization stages of Camellia oleifera. N, K, Zn, Cu, Ca, Mn element content changes showed “S” curve under the self- and out-crossing, the content of N reaching the highest was 3.445 8 mg·g-1 in self-pollination of 20 d; K content reaching the highest at the cross-pollination 20 d was 6.275 5 mg·g-1; Zn content in self-pollination of 10 d reaching the highest was 0.070 5 mg·g-1; Cu content in the cross-pollination of 5 d up to the highest was 0.061 0 mg·g-1; Ca content in the cross-pollination of 15 d up to the highest was 3.714 5 mg·g-1; the content of Mn reaching the highest in self-pollination 30 d was 2.161 5 mg·g-1. Fe, P, Mg element content changes was of “S” type curve in selfing and was of “W” type curve in outcrossing, Fe content in the self-pollination 10 d up to the highest was 0.453 0 mg·g-1; P content in self-pollination of 20 d reaching the highest was 6.731 8 mg·g-1; the content of Mg up to the highest in self-pollination 25 d was 2.724 0 mg·g-1. The results can be used as a reference for spraying foliar fertilizer, and improving seed setting rate and yield in Camellia oleifera..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1095 (2014)
Simultaneous Determination of Arsanilic, Nitarsone and Roxarsone Residues in Foods of Animal Origin by ASE-LC-AFS
XIAO Ya-bing, ZHANG Man, and WEN Hua-wei
A method for simultaneous determination of arsanilic, nitarsone and roxarsone(ROX) residues in foods of animal origin was developed by accelerated solvent extraction-liquid chromatography-atomic fluorescence spectrometry (ASE-LC-AFS). The ultrasound centrifugation extraction and accelerated solvent extraction were compA method for simultaneous determination of arsanilic, nitarsone and roxarsone(ROX) residues in foods of animal origin was developed by accelerated solvent extraction-liquid chromatography-atomic fluorescence spectrometry (ASE-LC-AFS). The ultrasound centrifugation extraction and accelerated solvent extraction were compared, and the accelerated solvent extraction conditions, namely the proportion of the extraction solvent, the extraction temperature, extraction time and extraction times, were optimized. The operating conditions of LC-AFS and the mobile phase were optimized. Under the optimal conditions, the calibration curves for ASA, NIT and ROX were linear over the concentration range of 0～2.0 mg·L-1 and their correlation coefficients were 0.999 2～0.999 8. The detection limits of ASA, NIT and ROX were 2.4, 7.4 and 4.1 μg·L-1 respectively. The average recoveries of ASA, NIT and ROX from two samples spiked at three levels of 0.5, 2, 5 mg·kg-1 were in the ranges of 87.1%～93.2%, 85.2%～93.9%, and 84.2%～93.7% with RSDs of 1.4%～4.6%, 1.2%～4.2%, and 1.1%～4.5%, respectively. This method possesses the merits of convenience and good repeatability, and is a feasible method for analysis of ASA,NIT and ROX in foods of animal origin..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1100 (2014)
X-Ray Radiographic Imaging Technique with High Dynamic Range
LIU Bin, WANG Li-ming, and SU Xin-yan
In conventional X-ray radiographic imaging system with a fixed energy parameter, the acquired X-ray images are usually overexposed and have no useful information available. It is due to some constraints, like special structure of component, different attenuation coefficients of materials and dynamic range of optoelectrIn conventional X-ray radiographic imaging system with a fixed energy parameter, the acquired X-ray images are usually overexposed and have no useful information available. It is due to some constraints, like special structure of component, different attenuation coefficients of materials and dynamic range of optoelectronic devices. When maximum of transmitted X-ray luminous exceed capacity limitation of X-ray radiographic imaging system in one scene, the device up to saturate. Also when minimum of transmitted X-ray luminous is below the thermal noise level of imaging system, no useful information is available for imaging. To solve the problem of difficulties in acquiring transmitted X-ray luminous in a wide dynamic range by conventional X-ray radiographic imaging system, we put forward a new X-ray radiographic imaging technique with high dynamic range based on adjusting tube voltage. In the article, the influence by charge capacity of X-ray radiographic imaging system on effective irradiating thickness is analyzed. Through experiments of some standard samples, we gained the relationship between voltage range of X-ray tube and materials or structure of component for best testing sensitivity. Then we put forward an adjusting strategy of tube voltage and effective subgraphs extraction method from acquired raw X-ray images. By the mentioned method, we carried out X-ray radiographic imaging experiments with high dynamic range for components with thickness from 0 to 20 mm. The results show that X-ray radiographic imaging technique with high dynamic range is effective to realize imaging for some components with different thickness. It is available for us to find more detailed projection information from fusion images..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1104 (2014)
Preparation of Electrodeposited Mo-Ni Coating and Its Spectral Properties
LIU Xiao-zhen, XIONG Li-ping, LIU Xiao-zhou, CHEN Jie, LUO Yi-fan, and SUN Ying
Mo-Ni coatings were prepared on Ni alloy by electrodeposition method. The properties of microhardness, wear weight loss and friction coefficients, and thermal expansion of the coatings were investigated, respectively. Mo-Ni coatings were characterized with inductively coupled plasma-atomic emission spectroscopy (ICP-AEMo-Ni coatings were prepared on Ni alloy by electrodeposition method. The properties of microhardness, wear weight loss and friction coefficients, and thermal expansion of the coatings were investigated, respectively. Mo-Ni coatings were characterized with inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive analyses of X-ray (EDAX), scanning electron microcopy (SEM), and X-ray diffraction (XRD) techniques, respectively. Mo-Ni coating shows higher microhardness, lower wear weight loss and friction coefficient compared with those of Ni alloy. The microhardness of Mo-Ni coating is as high as 518 HV, which is 72.67% higher than that of the Ni alloy (300 HV). The wear weight losses of Mo-Ni coating is 1.94 times lower than that of Ni alloy. The friction coefficient of Ni alloy and Mo-Ni coating are 0.640 and 0.559 respectively. The physical thermal expansion curve of Ni alloy has two the peaks in the ranges of 100～120 and 570～640 ℃ respectively; and that of Ni alloy+Mo-Ni coating has one the peaks in the ranges of 570～640 ℃. The peak of the physical thermal expansion curve of Ni alloy+Mo-Ni coating in the ranges of 570～640 ℃ is much smaller than that of the Ni alloy. Because the part of nickel was replaced by molybdenum in the Ni lattice, molybdenum decreases the lattices transformation of nickel (bcc→fcc). The reason for the formation of the small peak of the physical thermal expansion curve of Ni alloy+Mo-Ni coating in the ranges of 595～625 ℃ is the changes of MoNi4 and MoNi from the semi-crystalline structure to the crystalline structure respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1109 (2014)
Microanalysis Study of the Inspirable Nano-Particles into Lungs by SEM and XREDS
QIU Man-de, LI Xu, WANG Xiao-yan, and ZHAI Yong-qing
Inspirable nano-particles into lungs in the atmosphere were studied in this paper. Field emission scanning electron microscope (FSEM) and X-ray energy dispersive spectrometer were used to investigate the morphology and major constituents of inspirable nano-particles into lungs systematically. The results showed that moInspirable nano-particles into lungs in the atmosphere were studied in this paper. Field emission scanning electron microscope (FSEM) and X-ray energy dispersive spectrometer were used to investigate the morphology and major constituents of inspirable nano-particles into lungs systematically. The results showed that most of the inspirable nano-particles in the atmosphere are spherical and ellipsoidal, with smooth surface and dense structure. The smaller nano-particles are clustered into loose floccule, with the sizes in the range of 30 to 100 nm. The constant elements in the nano-particles are close consistent with the large particle pollutants, which mainly contain C, O, A1, Si, Na, Mg, K, Ca, Fe, S and Cl etc. The point Analysis of EDS confirmed that the element content of Cl and S in some nano-particles is significantly increased, while others mainly contain C and O. It is believed that the surface of nano inorganic dust particles was adsorbed by the organic pollutants to form the core-shell structure nano-particles pollutants in the process of aerosol formation. Thus, reducing anthropogenic emissions of organic pollutants has great influence on the formation of inspirable nano-particles..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1114 (2014)
The Uncertainty Evaluation of Analytical Results of 27 Elements in Geological Samples by X-Ray Fluorescence Spectrometry
WANG Yi-ya, and ZHAN Xiu-chun
Evaluating uncertainty of analytical results with 165 geological samples by polarized dispersive X-ray fluorescence spectrometry (P-EDXRF) has been reported according to the internationally accepted guidelines. One hundred sixty five pressed pellets of similar matrix geological samples with reliable values were analyzeEvaluating uncertainty of analytical results with 165 geological samples by polarized dispersive X-ray fluorescence spectrometry (P-EDXRF) has been reported according to the internationally accepted guidelines. One hundred sixty five pressed pellets of similar matrix geological samples with reliable values were analyzed by P-EDXRF. These samples were divided into several different concentration sections in the concentration ranges of every component. The relative uncertainties caused by precision and accuracy of 27 components were evaluated respectively. For one element in one concentration, the relative uncertainty caused by precision can be calculated according to the average value of relative standard deviation with different concentration level in one concentration section, n=6 stands for the 6 results of one concentration level. The relative uncertainty caused by accuracy in one concentration section can be evaluated by the relative standard deviation of relative deviation with different concentration level in one concentration section. According to the error propagation theory, combining the precision uncertainty and the accuracy uncertainty into a global uncertainty, this global uncertainty acted as method uncertainty. This model of evaluating uncertainty can solve a series of difficult questions in the process of evaluating uncertainty, such as uncertainties caused by complex matrix of geological samples, calibration procedure, standard samples, unknown samples, matrix correction, overlap correction, sample preparation, instrument condition and mathematics model. The uncertainty of analytical results in this method can act as the uncertainty of the results of the similar matrix unknown sample in one concentration section. This evaluation model is a basic statistical method owning the practical application value, which can provide a strong base for the building of model of the following uncertainty evaluation function. However, this model used a lot of samples which cannot simply be applied to other types of samples with different matrix samples. The number of samples is too large to adapt to other types samples. We will strive for using this study as a basis to establish a reasonable basis of mathematical statistics function mode to be applied to different types of samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1118 (2014)
Model Design and Stray Light Suppression Technology of Stray-Light Testing Equipment for Plane Grating
ZHAI Shan-shan, YANG Jin, Bayanheshig, CUI Ji-cheng, QI Xiang-dong, and TANG Yu-guo
Grating scatter is an important performance index for plane grating, and its measurement is a difficult problem for grating research field. In order to achieve stray-light of the instrument itself to be less than 10-8 so that the grating scatter can be accurately measured, stray light in diffraction grating monochromatGrating scatter is an important performance index for plane grating, and its measurement is a difficult problem for grating research field. In order to achieve stray-light of the instrument itself to be less than 10-8 so that the grating scatter can be accurately measured, stray light in diffraction grating monochromators has been studied and an opto-mechanical model of measure instrument for plane grating is designed, which works in parallel light environment and based on the scalar diffraction theory and classical Fresnel-Kirchhoff diffraction theory. Main pathway of the instrumentation’s stray light is calculated and analyzed by the simulation of stray-light testing equipment with ASAP software. Accordingly, four stray-light suppression structures including blocking rings, vanes, aperture stops and light traps are proposed to reduce instrument’s scattered light and grating’s multiple diffraction. Finally, contrast analysis of the instrumentation’s stray light is made before and after adding stray-light suppression structures. Simulation and analysis results show that the max of instrument’s stray light reduces from more than 10-6 to less than 10-8 after adding stray-light suppression structures and has met the stray-light testing equipment’s design requirements whose goal is to realize accurate measurement greater than or equal to 10-7 for grating scatter with grating’s groove density changing from 300 to 3 600 gr·mm-1. The research methods and results above will provide a theoretical basis for the research and development of the stray-light testing equipment for plane grating..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1124 (2014)
Study of Time Characteristics in Spectrometer Dynamic Sampling
XIONG Hui, YANG Xue, ZHOU Mei, LI Gang, and LIN Ling
The present paper uses the relationship between sawtooth wave’s amplitude and time’s linear code to test and analyze a spectrometer. The result shows that the sampling time is associated with the integration time and the sampling interval closely relates with integral time, and the fluctuation range of sampling intervaThe present paper uses the relationship between sawtooth wave’s amplitude and time’s linear code to test and analyze a spectrometer. The result shows that the sampling time is associated with the integration time and the sampling interval closely relates with integral time, and the fluctuation range of sampling interval was further explored. This paper provides the reference of the integral time for the analysis focused on spectrum time characteristic, proposes a method to evaluate the dynamic time properties, and contributes to the assessment and application of the dynamic characteristics of the spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1130 (2014)
Study and Design on Dyson Imaging Spectrometer in Spectral Broadband with High Resolution
YAN Ling-wei
The paper designs and improves a telecentric imaging spectrometer, the Dyson imaging spectrometer. The optical structure of the imaging spectrometer is simple and compact, which is only composed of a hemispherical lens and a concave grating. Based on the Rowland circle and refraction theory, the broadband anastigmatic The paper designs and improves a telecentric imaging spectrometer, the Dyson imaging spectrometer. The optical structure of the imaging spectrometer is simple and compact, which is only composed of a hemispherical lens and a concave grating. Based on the Rowland circle and refraction theory, the broadband anastigmatic imaging condition of Dyson imaging spectrometer which is the ratio of the grating radius and hemispherical lens radius has been analyzed. By imposing this condition for two different wavelengths, the parameters of the optical system presenting low aberrations and excellent imaging quality are obtained. To make the design spectrometer more suitable for the engineering application, the paper studies the method making the detector not to attach the surface of the hemispherical lens. A design example using optimal conditions was designed to prove our theory. The Dyson imaging spectrometer of which the imaging RMS radii are less than 2.5 μm and the advanced spectrometer of which the imaging RMS radii are less than 8 μm, with NA 0.33, waveband 0.38~1.7 μm and the slit length 15 mm, have been obtained. The design method and results are more feasible and predominant, and can be applied in the areas of the industry and remote sensing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1135 (2014)
Research on the Neas Infrared Focal Plane Array Detector Imaging Technology Used in the Laser Warning
WANG Zhi-bin, HUANG Yan-fei, WANG Yao-li, ZHANG Rui, and WANG Yan-chao
In order to achieve the incoming laser’s accurate position, it is necessary to improve the detected laser’s direction resolution. The InGaAs focal plane array detector with the type of FPA-320x256-C was selected as the core component of the diffraction grating laser warning device. The detection theory of laser wavelenIn order to achieve the incoming laser’s accurate position, it is necessary to improve the detected laser’s direction resolution. The InGaAs focal plane array detector with the type of FPA-320x256-C was selected as the core component of the diffraction grating laser warning device. The detection theory of laser wavelength and direction based on diffraction grating was introduced. The drive circuit was designed through the analysis of the detector’s performance and parameters. Under the FPGA’s timing control, the detector’s analog output was sampled by the high-speed AD. The data was cached to FPGA’s extended SRAM, and then transferred to a PC through USB. Labview on a PC collects the raw data for processing and displaying. The imaging experiments were completed with the above method. With the wavelength of 1550 nm and 980 nm laser from different directions the diffraction images were detected. Through analysis the location of the zero order and one order can be determined. According to the grating diffraction theory, the wavelength and the direction of the two-dimensional angle can be calculated. It indicates that the wavelength error is less than 10 nm, and the angle error is less than 1°..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1140 (2014)
Fusion of Dual Color MWIR Images Based on Support Value Transform and top-hat Decomposition
LIN Su-zhen, YANG Feng-bao, and CHEN Lei
Fusion method of dual color mid-wave infrared images is presented in this paper in order to solve such frequently rising issues as limited contrast ratio improvement and serious marginal area distortion in the fusion of the above two images using multi-scale top-hat decomposition. The detailed procedure is shown as theFusion method of dual color mid-wave infrared images is presented in this paper in order to solve such frequently rising issues as limited contrast ratio improvement and serious marginal area distortion in the fusion of the above two images using multi-scale top-hat decomposition. The detailed procedure is shown as the following: A low-frequency component image and a sequence of support value images of the two subdivision band images of mid-wave infrared are obtained respectively with support value transform. Multi-scale bright and dim information are first extracted from the last layer of low-frequency image using the multi-scale top-hat decomposition method respectively. Then they are fused by selecting the maximum gray of each pixel in two subdivision band images of mid-wave infrared respectively. Following that, the two resulted images are enhanced using the gray-scale normalization and Gaussian filtering and fused with the two low-frequency images to get the low-frequency fusion image. After that, this fusion image is reversely transformed with the support sequence image fused by selecting the maximum gray. The final image is got at last. The result shows that compared with the simple support value transform fusion and the multi-scale top-hat decomposition fusion, the method suggested in this paper successfully increases the contrast ratio by 11.69%, decreases the distortion factor by 63.42%, and increases the local coarseness by 38.12%. All these show that the validity of fusion method proposed has been proved, which indicates that both bright and dim information from low-frequency images can effectively solve the contradiction between improving fused image’s contrast ratio and reducing its’ distortion after the both are fused and enhanced respectively, and then fused with the two low-frequency images, which provides a new useful method for improving the quality of fused inferred images..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1144 (2014)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 4, 1 (2014)
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