Journals >Spectroscopy and Spectral Analysis
Contents
2015
Volume: 35 Issue 7
60 Article(s)
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Research Article
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1 (2015)
A Method to Reconstruct Surface Reflectance Spectrum from Multispectral Image Based on Canopy Radiation Transfer Model
ZHAO Yong-guang, MA Ling-ling, LI Chuan-rong, ZHU Xiao-hua, and TANG Ling-li
Due to the lack of enough spectral bands for multi-spectral sensor,it is difficult to reconstruct surface reflectance spectrum from finite spectral information acquired by multi-spectral instrument.Here,taking into full account of the heterogeneity of pixel from remote sensing image,a method is proposed to simulate hypDue to the lack of enough spectral bands for multi-spectral sensor,it is difficult to reconstruct surface reflectance spectrum from finite spectral information acquired by multi-spectral instrument.Here,taking into full account of the heterogeneity of pixel from remote sensing image,a method is proposed to simulate hyperspectral data from multispectral data based on canopy radiation transfer model.This method first assumes the mixed pixels contain two types of land cover,i.e.vegetation and soil.The sensitive parameters of Soil-Leaf-Canopy(SLC) model and a soil ratio factor were retrieved from multi-spectral data based on Look-Up Table(LUT) technology.Then,by combined with a soil ratio factor,all the parameters were input into the SLC model to simulate the surface reflectance spectrum from 400 to 2 400 nm.Taking Landsat Enhanced Thematic Mapper Plus(ETM+) image as reference image,the surface reflectance spectrum was simulated.The simulated reflectance spectrum revealed different feature information of different surface types.To test the performance of this method,the simulated reflectance spectrum was convolved with the Landsat ETM+ spectral response curves and Moderate Resolution Imaging Spectrometer(MODIS) spectral response curves to obtain the simulated Landsat ETM+ and MODIS image.Finally,the simulated Landsat ETM+ and MODIS images were compared with the observed Landsat ETM+ and MODIS images.The results generally showed high correction coefficients(Landsat:0.90~0.99,MODIS:0.74~0.85) between most simulated bands and observed bands and indicated that the simulated reflectance spectrum was well simulated and reliable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1763 (2015)
Spectral Characteristics of Si Quantum Dots Embedded in SiNx Thin Films Prepared by Magnetron Co-Sputtering
CHEN Xiao-bo, YANG Wen, DUAN Liang-fei, ZHANG Li-yuan, YANG Pei-zhi, and SONG Zhao-ning
The silicon-rich SiNx films were fabricated on Si(100) substrate and quartz substrate at different substrate temperatures varying from room temperature to 400 ℃ by bipolar pulse ane RF magnetron co-sputtering deposition technique.After deposition,the films were annealed in a nitrogen atmosphere by rapid photo-thermal aThe silicon-rich SiNx films were fabricated on Si(100) substrate and quartz substrate at different substrate temperatures varying from room temperature to 400 ℃ by bipolar pulse ane RF magnetron co-sputtering deposition technique.After deposition,the films were annealed in a nitrogen atmosphere by rapid photo-thermal annealing at 1 050 ℃ for 3 minutes.This thermal step allows the formation of the silicon quantum dots.Fourier transform infrared spectroscopy,Raman spectroscopy,grazing incidence X-ray diffraction and photoluminescence spectroscopy were used to analyze the bonding configurations,microstructures and luminescence properties of the films.The experimental results showed that:silicon-rich Si-N bonds were found in Fourier transform infrared spectra,suggesting that the silicon-rich SiNx films were successfully prepared;when the substrate temperature was not lower than 200 ℃,the Raman spectra of the films showed the transverse optical mode of Si-Si vibration,while the significant diffraction peaks of Si(111) and Si(311) were shown in grazing incidence X-ray diffraction spectra,confirming the formation of silicon quantum dots;our work indicated that there was an optimal substrate temperature(300 ℃),which could significantly increase the amount and the crystalline volume fraction of silicon quantum dots;three visible photoluminescence bands can be obtained for both 300 ℃ sample and 400 ℃ sample,and in combination with Raman results,the emission peaks were reasonably explained by using the quantum confinement effect and radiative recombination defect state of Si nanocrystals;the average size of the silicon quantum dots is 3.5 and 3.4 nm for the 300 ℃ sample and 400 ℃ sample,respectively.These results are useful for optimizing the fabrication parameters of silicon quantum dots embedded in SiNx thin films and have valuable implications for silicon based photoelectric device applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1770 (2015)
Two Data Inversion Algorithms of Aerosol Horizontal Distribution Detected by MPL and Error Analysis
Lv Li-hui, LIU Wen-qing, ZHANG Tian-shu, LU Yi-huai, DONG Yun-sheng, CHEN Zhen-yi, FAN Guang-qiang, and QI Shao-shuai
Atmospheric aerosols have important impacts on human health,the environment and the climate system.Micro Pulse Lidar(MPL) is a new effective tool for detecting atmosphere aerosol horizontal distribution.And the extinction coefficient inversion and error analysis are important aspects of data processing.In order to deteAtmospheric aerosols have important impacts on human health,the environment and the climate system.Micro Pulse Lidar(MPL) is a new effective tool for detecting atmosphere aerosol horizontal distribution.And the extinction coefficient inversion and error analysis are important aspects of data processing.In order to detect the horizontal distribution of atmospheric aerosol near the ground,slope and Fernald algorithms were both used to invert horizontal MPL data and then the results were compared.The error analysis showed that the error of the slope algorithm and Fernald algorithm were mainly from theoretical model and some assumptions respectively.Though there still some problems exist in those two horizontal extinction coefficient inversions,they can present the spatial and temporal distribution of aerosol particles accurately,and the correlations with the forward-scattering visibility sensor are both high with the value of 95%.Furthermore relatively speaking,Fernald algorithm is more suitable for the inversion of horizontal extinction coefficient..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1774 (2015)
Absorption Characteristics and Simulation of LLM-105 in the Terahertz Range
MENG Zeng-rui, SHANG Li-ping, DU Yu, and DENG Hu
2,6-diamino-3,5-dinitropyrazine-1-oxide(LLM-105),a novel explosive with high energy and low sensibility.In order to study the molecular structure characteristics of the explosive,the absorption spectra of LLM-105 in the frequency range of 0.2 ～2.4 THz were detected by terahertz time-domain spectroscopy(THz-TDS).The res2,6-diamino-3,5-dinitropyrazine-1-oxide(LLM-105),a novel explosive with high energy and low sensibility.In order to study the molecular structure characteristics of the explosive,the absorption spectra of LLM-105 in the frequency range of 0.2 ～2.4 THz were detected by terahertz time-domain spectroscopy(THz-TDS).The results showed that a number of characteristic absorption peaks with different intensity located at 1.27,1.59,2.00,2.08,2.20,2.29 THz.The article also simulated the absorption spectra of LLM-105 molecular crystal within 0.2～2.5 THz region by using Materials Studio 6.0 software based on density functional theory(DFT),and the simulated results agreed well with the experimental data except for the peak at 2.29 THz,which verified theoretically the accuracy of the experimental data.In addition,the vibrational modes of the characteristic peaks in the experimental absorption spectra were analyzed and identified,the results showed that the forming of the characteristic absorption peaks and the molecular vibration were closely related,which further provided important laboratory and technology support for the study of the transformation of molecule structure of LLM-105.There was no simulated frequency agreed with the experimental absorption peak at 2.29 THz,which may be caused by the vibration of the crystal lattice or other reasons..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1779 (2015)
The Effects of Complex of Benzoquinone on Fermi Resonance
LI Shuai-peng, ZHANG Feng-qin, JIANG Li-tong, LIN Xiao-long, JIANG Yong-heng, ZHANG Liu-yang, LIN Bo, and GU Hao
Fermi resonance phenomenon exists in simple compounds and it also widely exists in vibration spectra of complex.The complex can be formed by adding up simple compounds.As a result,the characteristic parameters of some parts of molecule will make changes,and the molecular spectra have a significant change along with it.Fermi resonance phenomenon exists in simple compounds and it also widely exists in vibration spectra of complex.The complex can be formed by adding up simple compounds.As a result,the characteristic parameters of some parts of molecule will make changes,and the molecular spectra have a significant change along with it.Benzoquinone and proline in the solution form charge-transfer complex under certain conditions,but the spectra intensity is weak,our research uses Teflon liquid-core optical fiber technology to gain high quality resonance Raman spectra.We acquire Raman spectra of Benzoquinone and its complex in experiments,and analyze the characteristic parameters of Fermi resonance according to J.F.Bertran quantum theory.The results shows that,because of the formation of complex,Fermi resonance peak of CO bond shifts to high wavelength,the spectra intensity decreases,the frequency space increases,the coupling coefficient increases.The explanation is that,in the solution of complex,proline is donor,while benzoquinone is acceptor,the non-bonding electron of N atom which is belong to proline transfers to the π anti-bonding orbital of benzoquinone,then n—π* charge transfer complex is produced.That causes the change of molecular energy level,changes the Raman spectra.All these researches provide new idea and clue for spectral line certification and attribution of complex molecules,complexes and polymer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1783 (2015)
Optical Properties Investigation of p-Type ZnO Film Based on Doping by Diffusion
CHEN Fang, FANG Dan, WANG Shuang-peng, FANG Xuan, TANG Ji-long, ZHAO Hai-feng, FANG Fang, CHU Xue-ying, LI Jin-hua, WANG Fei, WANG Xiao-hua, LIU Guo-jun, MA Xiao-hui, and WEI Zhi-peng
The main purpose of this paper is to investigate the optical properties of p-type ZnO film based on P doping.ZnO film was grown by Atomic layer deposition(ALD) on InP subsrate in this experiment,and phosphorus diffused into ZnO lattice by annealing treatment at different temperature(500,700 ℃).The optical properties ofThe main purpose of this paper is to investigate the optical properties of p-type ZnO film based on P doping.ZnO film was grown by Atomic layer deposition(ALD) on InP subsrate in this experiment,and phosphorus diffused into ZnO lattice by annealing treatment at different temperature(500,700 ℃).The optical properties of samples were investigated by photoluminescence(PL) spectroscopy,which indicated that the annealing temperature is the important factor influencing the phosphorus diffusion doping.The low-temperature PL spectra of the sample which annealed at 700 ℃ for 1 h exhibited acceptor related emission peaks located at 3.351,3.311,3.246 and 3.177 eV,which were attributed to A°X,FA,DAP and DAP-1LO,respectively.The acceptor binding energy is estimated to be about 122 meV,which is agreed with the theoretic values in phosphorus-doped ZnO films.In this paper,through thermal diffusion method to realize the p-type doped ZnO thin films,it solved the main problems which limited the development of ZnO based optoelectronic devices,and has an important significance for the development of the ZnO semiconductor materials and ZnO based photoelectric device..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1787 (2015)
The Characteristic Research of ·OH Induced by Water on an Argon Plasma Jet
LIU Kun, LIAO Hua, ZHENG Pei-chao, WANG Chen-ying, LIU Hong-di, and Dobrynin Danil
·OH plays a crucial role in many fields,having aroused wide public concern in the world.Atmospheric Pressure Plasma Jet,which can be achieved by portable device due to working without the vacuum environment,has the advantages of high concentration of reactive species,high electron temperature and low gas temperatu·OH plays a crucial role in many fields,having aroused wide public concern in the world.Atmospheric Pressure Plasma Jet,which can be achieved by portable device due to working without the vacuum environment,has the advantages of high concentration of reactive species,high electron temperature and low gas temperature.It has become an important research topic in the field of gas discharge with a strong prospect.Especially,how to induce plasma jet to produce ·OH has become a new hotpot in the field of low-temperature plasma.It has been reported that mass ·OH can be induced successfully when water vapor is added to the working gas,but it will be unstable when the concentrate of water reaches a certain degree.Thus,a device of argon plasma jet with a Ring-to-Ring Electrode Configuration has been designed to interact with water in the surrounding air to generate ·OH under atmospheric pressure.In order to increase the production of ·OH,ultrasonic atomizing device is introduced to promote water concentration around the plasma plume.The generating rule of OH(A2Σ+) induced by water has been extensively studied under different voltages and flow rate.·OH output induced by the plasma has been tested by emission spectrometry,and at the meanwhile,Ar atomic spectral lines at 810.41 and 811.48 nm are also recorded in order to calculate the electron temperature in argon plasma plume.The results show that the water surrounding the plasma plume can be induced to produce ·OH,and OH(A2Σ+) output increases with the electrode voltage rising from 20 to 28 kV.When the flow rate increases from 100 to 200 L·h-1,the OH(A2Σ+) output increases,but from 200 to 600 L·h-1,it decreases.The production rules of OH(A2Σ+) is the same as that of electron temperature.Therefore,the presumption is proved that ·OH output mainly affected by electron temperature..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1791 (2015)
Synthesis and Spectroscopic Study of a Chemosensor for Naked Eye Recognition of Cu2+ and Hg2+
CAO Li, QIAN Ya-ao, HUANG Yan, CAO Juan, JIA Chun-man, LIU Chun-ling, ZHANG Qi, and Lv Zheng-rong
Compound L,as the procedural sensor for the detection of Cu2+ and Hg2+,was designed and synthesized based on the coumarin-modified rhodamine derivative.The structure of compound L was characterized by NMR,high resolution mass spectrometry and infrared method.Its sensing behavior toward various metal ions was investigatCompound L,as the procedural sensor for the detection of Cu2+ and Hg2+,was designed and synthesized based on the coumarin-modified rhodamine derivative.The structure of compound L was characterized by NMR,high resolution mass spectrometry and infrared method.Its sensing behavior toward various metal ions was investigated with absorbance methods.The study found that L had good selectivity and sensitivity for Cu2+.When addition of various metal ions(Zn2+,Hg2+,Cu2+,Fe3+,Cd2+,Co2+,Ni2+,Mg2+,Ca2+,Al3+,La3+,K+,Na+,Mn2+,Pb2+and Ag+),only Cu2+ could induce a visible change of solution from colourless to pink and a new absorption band centered at 534 nm appear,which indicated that compound L could be used for the naked eye detection of Cu2+.From UV titration,the detection limit was about 1.9×10-8 mol·L-1.Test strips based on L were fabricated,and this test strips could act as a convenient and efficient Cu2+ test kit.The binding ratio of the complex of L-Cu2+ was 1∶1 according to the Job’s plot and high resolution mass spectrometer(HRMS) experiments.Moreover,Upon addition of 1 equiv.EDTA to the mixture of L and Cu2+ in DMSO solution,colour changed from pink to almost colourless,indicating that the EDTA replaced the receptor L to coordinate with Cu2+.Therefore,L could be classified as a reversible sensor for Cu2+.In addition,when adding Hg2+ to L-Cu2+ complexes,a visible change of solution from pink to colourless was observed,while other metal ions didn’t cause this change.Thus,L-Cu2+ complex also could be used for the naked eye recognition of Hg2+,and the detection limit was calculated about 2.9×10-7 mol·L-1 according to the UV titration.Consequently,this procedural sensor L could be use for the orderly naked eye recognition of Cu2+ and Hg2+..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1797 (2015)
The High Precision Analysis Research of Multichannel BOTDR Scattering Spectral Information Based on the TTDF and CNS Algorithm
ZHANG Yan-jun, LIU Wen-zhe, FU Xing-hu, and BI Wei-hong
Traditional BOTDR optical fiber sensing system uses single channel sensing fiber to measure the information features.Uncontrolled factors such as cross-sensitivity can lead to a lower scattering spectrum fitting precision and make the information analysis deflection get worse.Therefore,a BOTDR system for detecting the Traditional BOTDR optical fiber sensing system uses single channel sensing fiber to measure the information features.Uncontrolled factors such as cross-sensitivity can lead to a lower scattering spectrum fitting precision and make the information analysis deflection get worse.Therefore,a BOTDR system for detecting the multichannel sensor information at the same time is proposed.Also it provides a scattering spectrum analysis method for multichannel Brillouin optical time-domain reflection(BOTDR) sensing system in order to extract high precision spectrum feature.This method combines the three times data fusion(TTDF) and the cuckoo Newton search(CNS) algorithm.First,according to the rule of Dixon and Grubbs criteria,the method uses the ability of TTDF algorithm in data fusion to eliminate the influence of abnormal value and reduce the error signal.Second,it uses the Cuckoo Newton search algorithm to improve the spectrum fitting and enhance the accuracy of Brillouin scattering spectrum information analysis.We can obtain the global optimal solution by smart cuckoo search.By using the optimal solution as the initial value of Newton algorithm for local optimization,it can ensure the spectrum fitting precision.The information extraction at different linewidths is analyzed in temperature information scattering spectrum under the condition of linear weight ratio of 1∶9.The variances of the multichannel data fusion is about 0.003 0,the center frequency of scattering spectrum is 11.213 GHz and the temperature error is less than 0.15 K.Theoretical analysis and simulation results show that the algorithm can be used in multichannel distributed optical fiber sensing system based on Brillouin optical time domain reflection.It can improve the accuracy of multichannel sensing signals and the precision of Brillouin scattering spectrum analysis effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1802 (2015)
Theoretical Investigation of the Electron Paramagnetic Resonance Parameters and Local Structures for Zinc Phosphate Glass Doped with VO2+
LI Chao-ying, HUANG Xian-kai, TU Qiu, WANG Wei-yang, and ZHENG Xue-mei
As an important model system,3d1 ions(VO2+,V4+ et al) have been extensively investigated by means of electron paramagnetic resonance(EPR),and many experimental results of EPR parameters were also measured.The optical absorption and EPR parameters(g factors g‖,g⊥ and hyperfine structure constants A‖,A⊥) of a tetragonal As an important model system,3d1 ions(VO2+,V4+ et al) have been extensively investigated by means of electron paramagnetic resonance(EPR),and many experimental results of EPR parameters were also measured.The optical absorption and EPR parameters(g factors g‖,g⊥ and hyperfine structure constants A‖,A⊥) of a tetragonal V4+ center in zinc phosphate glass are theoretically investigated,using the perturbation formulas for a 3d1 ion in tetragonally compressed octahedra.Since the spin-orbit coupling parameter ζ0p(≈150 cm-1) of ligand O2- is close to that ζ0d(≈248 cm-1) of the central 3d1 ion in zinc phosphate glass doped VO2+,the effect of the spin-orbit coupling parameter ζp0 on the EPR spectra and optical absorption spectra should be taken into account.In this work,the relationship between the EPR parameters as well as the optical absorption spectra and the local structure of the impurity center are established based on the superposition model.By fitting the calculated EPR parameters and optical absorption spectra for V4+ center in zinc phosphate glass to the experimental data,the local structure parameters of ［VO6］8- cluster are obtained.According to the investigation,the magnitudes of the metal-ligand distances parallel and perpendicular to the C4-axis of ［VO6］8- cluster are,respectively,R‖≈0.175 nm and R⊥≈0.197 nm,the local structure around the V4+ ions possesses a compressed tetragonal distortion along C4 axis.Theoretical results of EPR parameters and optical absorption spectra are in good agreement with experimental data,the validity of the calculated results has also been discussed.Thus,perturbation method is effective to the studies the EPR parameters and optical spectra of transition-metal 3d1 ions in crystals.In addition,based on the studies of the hyperfine structure constants(A‖ and A⊥),one can found that the large value of κ indicates a large contribution to the hyperfine constant bv the unpaired s-electron..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1808 (2015)
The Study of Large OPD’s PEM Based on Micro Trapezoidal Photo-Elastic Crystals
ZHANG Rui, WANG Zhi-bin, WANG Yao-li, CHEN You-hua, and CHEN Yuan-yuan
Existing Photoelastic Modulator(PEM),whose optical path difference(OPD) is small,has strict requirements on the incident spot size and is poor in the aspect of light use efficiency under multiple reflections.What’s more,Photoelastic Modulator based Fourier transform spectrometer(PEM-FTS) spectral resolution is relativeExisting Photoelastic Modulator(PEM),whose optical path difference(OPD) is small,has strict requirements on the incident spot size and is poor in the aspect of light use efficiency under multiple reflections.What’s more,Photoelastic Modulator based Fourier transform spectrometer(PEM-FTS) spectral resolution is relatively poor.Because there are these disadvantages in the PEM,this paper presents a method of large optical path difference whose PEM is based on micro trapezoidal photoelastic crystals.By improving the structure of photoelastic crystal,the PEM becomes micro trapezoidal octagonal structure.And two transmission surfaces are changed slightly into a certain angle.Therefore,the PEM improved can not only increase the optical path difference of the PEM,but also have less requirements on the incident spot size.Firstly,a detailed analysis of the maximum modulation optical path difference was made in this paper.Secondly,the equation of maximum optical path difference was deduced under any angle and any position of incident light,vibration displacement and stress distribution of PEM are analyzed by the way of COMSOL Multiphysics 4.3a.Again,a method was analyzed to find the best angle of incidence,combining with maximum optical path difference and energy efficiency.Then the large OPD’s PEM is designed and processed,including two parts:photoelastic crystal and piezoelectric crystal.Moreover,ZnSe crystal is used as photoelastic crystal,and piezoelectric quartz crystal is used as piezoelectric crystal.With experiment analyzed by 632.8 nm He-Ne laser,the results show that under the same driving voltage,the optical path difference of the PEM improved is about 19.25 times bigger than the normal PEM,and the relative error is 1.3%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1812 (2015)
The Effects of Skin Thickness on Optical Transmission Characteristics in Fruits Tissues
SHI Shu-ning, TAN Zuo-jun, XIE Jing, and LU Jun
Fruit quality inspection techniques play a very important role in the production and consumption of fruits.In the field of quality non-destructive inspection and grading for fruits,the light-based techniques using optical properties of fruit products were widely used as one of the most practical and the most successfulFruit quality inspection techniques play a very important role in the production and consumption of fruits.In the field of quality non-destructive inspection and grading for fruits,the light-based techniques using optical properties of fruit products were widely used as one of the most practical and the most successful techniques.Quantitative understanding of light interaction with fruits is critical to designing better optical systems for inspection of food quality.In this paper,a fruit model consisted of two layer tissues was developed using Monte Carlo simulations to explore the light transport process and properties in the pome fruits,such as apples and mandarins,which were used as the thin-skinned and thick-skinned fruits respectively.The simulation results obtained are based on the assumption that the light source is a Gaussian beam at the wavelength 808 nm.This paper reports that the effects of skin thickness on light transmission characteristics in fruit tissues,including diffuse reflectance,transmittance,absorptivity,penetration depth etc.The inspection efficiency of flesh tissues was also demonstrated.The results indicated that the transmittance and the penetration depth decreases with the fruit skin increasing.As for the absorbed energy density,the fruit skin tissues have the wider distribution at the radial distance than the fruit flesh tissues.The absorbed energy density always tended to decrease with the inside depth of the fruit tissues increasing,especially decreased more apparently at the radial direction.The diffuse reflectance at the radial distance from 0.2 to 1.2 cm decreased with the decreasing of fruit skin,however it showed the inverse relationship in the radial distance range from 1.2 to 4.0 cm,the diffuse reflectance decreases with the increasing fruit skin.This paper proposed that the interaction between light and fruits skin in transmission or reflective approach,should be considered for developing optical techniques of non-destructive fruit quality inspection.And it provided a theoretical basis for designing more efficient optical detection device,including how to confirm the light source power,size and position of the detector,etc.It has very important significance for fruit quality inspection by optical techniques..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1817 (2015)
Research on Spectrum Radiation Characteristics of a New Type Infrared/Ultraviolet Dual Color Decoy
CHEN Chun-sheng, DAI Meng-yan, LIU Hai-feng, XIE Chang-you, ZHANG Tong, and FANG Guo-feng
The advantage of traditional MTV infrared decoys which are mainly consist of magnesium,Teflon and VITON is that it emits high radiant energy,so it is an effective countermeasure to traditional seekers which seek the target by heat source.The spectral radiant intensity which generated from high temperature combustion ofThe advantage of traditional MTV infrared decoys which are mainly consist of magnesium,Teflon and VITON is that it emits high radiant energy,so it is an effective countermeasure to traditional seekers which seek the target by heat source.The spectral radiant intensity which generated from high temperature combustion of MTV infrared decoys in near infrared region and ultraviolet band is very high,and that in Mid-IR region is relative lower,however the radiant intensity of real jet fighter in ultraviolet band is low and the infrared radiant intensity ratio of Mid-IR to near IR band is greater than 1.Thus,the traditional MTV infrared decoys are hardly able to counter the seekers equipped with dual color combined guidance system.Based on the spectral matching principle,we designed and prepared a new infrared/ultraviolet dual color decoy which is mainly consist of oxidant(wt% 45~75),fuel(wt% 10~25),energetic binder(wt% 25~50) and additives.We conducted theoretical calculations on combustion products of the reagent combinations using CEA(Chemic equilibrium & Application) software and initially determined the content of each component of the decoy formulation on the basis of the calculations results,then investigated the infrared radiation characteristics of decoys employing SR5000 spectrum radiometer and remote sensing interferometer spectrometer Tensor37 and analyzed the possible reasons for test results difference of the two systems separately from the test principle and calculation method,the testing environment,stability of testing results and other aspects.We studied the ultraviolet radiation characteristics of decoys using S2000 fiber optical spectrometer and the test results were consistent with the fighter ultraviolet radiant intensity which gained from theoretical calculation.We researched on the temperature characteristics of decoys by Imager IR 8325 mid-infrared thermal imager and it turned out that the dual color decoy is similar to the real fighter target in temperature characteristics.The results indicates that the infrared radiant intensity ratio of Mid-IR to near IR band is from 1 to 3(1
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1824 (2015)
Study on an Algorithm for Near Infrared Singular Sample Identification Based on Strong Influence Degree
WU Zhao-na, DING Xiang-qian, GONG Hui-li, DONG Mei, and WANG Mei-xun
Correcting sample selection and elimination of singular sample is very important for the quantitative and qualitative modeling of near infrared spectroscopy.However,methods for identification of singular sample available are generally based on data center estimates which require an experience decision threshold,this laCorrecting sample selection and elimination of singular sample is very important for the quantitative and qualitative modeling of near infrared spectroscopy.However,methods for identification of singular sample available are generally based on data center estimates which require an experience decision threshold,this largely limit its recognition accuracy and practicability.Aiming at the low accuracy of the existing methods of singular sample recognition problem,this paper improves the existing metric - Leverage value and presents a new algorithm for near infrared singular sample identification based on strong influence degree.This metric reduces the dependence on the data center to a certain extent,so that the normal samples become more aggregation,and the distance between the singular samples and the normal samples is opened;at the same time,in order to avoid artificial setting threshold unreasonably according to experience,this paper introduces the concept of the jump degree in the field of statistics,and proposes an automatic threshold setting method to distinguish singular samples.In order to verify the validity of our algorithm,abnormal samples of 200 representative samples were eliminated in the calibration set with using Mahalanobis distance,Leverage- Spectral residual method and the algorithm presented in this paper respectively;then through partial least squares(PLS),the rest of the calibration samples were made quantitative modelings(took Nicotine as index),and the results of quantitative modelings were made a comparative analysis;besides,60 representative testing samples were made a prediction through the modelings;at last,all the algorithms above were made a comparison with took Root Mean Square Error of Cross Validation(RMSECV),Correlation Coefficient(r) and Root Mean Square Error of Prediction(RMSEP) as evaluation Index.The experimental results demonstrate that the algorithm for near infrared singular sample identification based on strong influence degree significantly improves the accuracy of singular sample identification over existing methods.With lower RMSECV(0.104),RMSEP(0.112) and higher r(0.983),it also contribute to boost the stability and prediction ability of the model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1830 (2015)
Design and Preparation of Plant Bionic Materials Based on Optical and Infrared Features Simulation
JIANG Xiao-jun, Lv Xu-liang, PAN Jia-liang, and ZHANG Shuan-qin
Due to the life characteristics such as physiological structure and transpiration,plants have unique optical and infrared features.In the optical band,because of the common effects of chlorophyll and water,plant leafs show spectral reflectance characteristics change in 550,680,1 400 and 1 900 nm significantly.In the inDue to the life characteristics such as physiological structure and transpiration,plants have unique optical and infrared features.In the optical band,because of the common effects of chlorophyll and water,plant leafs show spectral reflectance characteristics change in 550,680,1 400 and 1 900 nm significantly.In the infrared wave band,driven by transpiration,plants could regulate temperature on their own initiative,which make the infrared characteristics of plants different from artificial materials.So palnt bionic materials were proposed to simulate optical and infrared characteristics of plants.By analyzing formation mechanism of optical and infrared features about green plants,the component design and heat-transfer process of plants bionic materials were studied,above these the heat-transfer control formulation was established.Based on water adsorption/release compound,optical pigments and other man-made materials,plant bionic materials preparation methods were designed which could simulate the optical and infrared features of green plants.By chemical casting methods plant bionic material films were prepared,which use polyvinyl alcohol as film forming and water adsorption/release compound,and use optical pigments like chrome green and macromolecule yellow as colouring materials.The research conclusions achieved by testings figured out:water adsorption/release testing showed that the plant bionic materials with a certain thickness could absorb 1.3 kg water per square meter,which could satisfy the water usage of transpiration simulation one day;the optical and infrared simulated effect tests indicated that the plant bionic materials could preferably simulate the spectral reflective performance of green plants in optical wave band(380～2 500 nm,expecially in 1 400 and 1 900 nm which were water absorption wave band of plants),and also it had similar daily infrared radiation variations with green plants,daily average radiation temperature difference was 0.37 ℃,maximum radiation temperature difference was 0.9 ℃;so according to the testing results,the materials behave well plant bionic performance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1835 (2015)
Determination of Chloride Salt Solution by NIR Spectroscopy
ZHANG Bin, CHEN Jian-hong, and JIAO Ming-xing
Determination of chloride salt solution by near infrared spectrum plays a very important role in Biomedicine.The near infrared spectrum analysis of Sodium chloride,potassium chloride,calcium chloride aqueous solution shows that the concentration change of chloride salt can affect hydrogen bond,resulting in the variatioDetermination of chloride salt solution by near infrared spectrum plays a very important role in Biomedicine.The near infrared spectrum analysis of Sodium chloride,potassium chloride,calcium chloride aqueous solution shows that the concentration change of chloride salt can affect hydrogen bond,resulting in the variation of near infrared spectrum of water.The temperature influence on NIR spectrum has been decreased by choosing reasonable wavelength range and the wavelength where the temperature effects are zero(isosbestic point).Chlorine salt prediction model was established based on partial least squares method and used for predicting the concentration of the chlorine ion.The impact on near infrared spectrum of the cation ionic radius,the number of ionic charge,the complex effect of ionic in water has also discussed in this article and the reason of every factor are analysed.Experimental results show that the temperature and concentration will affect the near-infrared spectrum of the solution,It is found that the effect of temperature plays the dominant role at low concentrations of chlorine salt;rather,the ionic dominates at high concentration.Chloride complexes are formed in aqueous solution,It has an effect on hydrogen bond of water combining with the cations in chlorine salt solution,Comparing different chloride solutions at the same concentration,the destruction effects of chloride complexes and catnions on the hydrogen bond of water increases in the sequences:CaCl2>NaCl>KCl.The modeling result shows that the determination coefficients(R2)=99.97%,the root mean square error of cross validation(RMSECV)=4.51,and the residual prediction deviation(RPD)=62.7,it meets the daily requirements of biochemical detection accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1840 (2015)
Preliminary Study on the Structural Characteristics of Residue from Rice Straw Burning in Field
HU Lin-chao, CHEN Li-na, YIN Yong, HUANG Zhao-qin, and DAI Jing-yu
Because of their special structural characteristics,straw burning residues(biochar) have important impacts on the soil carbon sequestration and the transport and transformation behavior of pollutants.In this paper,a series of qualitative and quantitative analysis methods such as scanning electron microscopy(SEM),X-ray Because of their special structural characteristics,straw burning residues(biochar) have important impacts on the soil carbon sequestration and the transport and transformation behavior of pollutants.In this paper,a series of qualitative and quantitative analysis methods such as scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR) have been used to study the basic physical and chemical properties and structural features of rice straw burning residues generating at different incineration intensity in field.The results show that:the basic physical and chemical properties of straw burning residues from field were closely associated with the burning intensity.The higher the burning intensity,the lower the TOC content.Meanwhile,the order degree of carbon atoms in the resulting residue increased.Wherein the fatty component of rice straw burning residues is gradually reduced with the burning intensity while the aromaticity of rice straw burning residues is gradually increased.In addition,the organic components in the straw burning residues from field have more significant contribution to the surface area..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1844 (2015)
Research on the Thermal Infrared Polarization Properties of Fresh Snow
WANG Ting-ting, LI Zhao-liang, TANG Bo-hui, SUN Wei-qi, and ZHAO Yun-sheng
Snow can directly affect the surface energy balance and climate change and has a significant impact on human life and production.It is therefore of great significance to study the fresh snow emission spectroscopy properties by using the thermal infrared Polarization technique.This can provide a basis for quantitative tSnow can directly affect the surface energy balance and climate change and has a significant impact on human life and production.It is therefore of great significance to study the fresh snow emission spectroscopy properties by using the thermal infrared Polarization technique.This can provide a basis for quantitative thermal infrared remote sensing monitoring of snow as well as a deeper understanding of global warming and appropriate countermeasures.This paper focuses on the investigation of the thermal infrared polarization properties of the fresh snow.The results show that the thermal emissive polarization properties of fresh snow depend significantly on the wavelengths(channels) and view angles used to measure them.Four channels are considered in this study,their spectral response ranges are 8~14 μm for channel 1(CH1),11.5~12.5 μm for channel 2(CH2),10.3~11.5 μm for channel 3(CH3) and 8.2~9.2 μm for channel 4(CH4).The snow polarized radiance(L) and its polarized brightness temperature(T) manifest as LCH1>LCH3>LCH4>LCH2 and TCH4>TCH1>TCH2>TCH3,respectively,while the degree of polarization(P) manifests as P0>P30>P40>P20>P10>P50 where the subscript of P denotes the view angle.The maximum of both L and T occurs at the view angle of 50 degree and polarization angle of 90 degree while their minimum appears at the view angle of 30 degree and polarization angle of 75 degree for each channel.In addition,the results show that:CH3 is more appropriate for better investigation of the emissive polarization properties of snow.Linear relationship is found between the fresh snow polarized T and the polarization angle with the coefficient of determination larger than 0.77 for all four channels.The polarized brightness temperature of the fresh snow is found to be increased about 0.003 K per polarization angle within 0~135 degree.The degree of polarization of snow is almost independent of the channels we used(CH1 to CH4).The snow emissive polarization is isotropic and the relative azimuth view angle has no significant impact on the snow emissive polarization properties.The impact of the polarization angle may be neglected if the investigation of the relative azimuth view angle on the fresh snow thermal emissive polarization is conducted.The difference of the fresh snow emissive polarization properties mainly comes from the snow surface roughness and structure..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1848 (2015)
Spectral Analysis about the Pharmaceutical Cocrystal Formation of Piracetam and 3-Hydroxybenzoic Acid
ZHANG Hui-li, XIA Yi, HONG Zhi, and DU Yong
Pharmaceutical cocrystal can improve physical and chemical properties of active pharmaceutical ingredient(API),meanwhile this feature has shown great potential in improving the pharmaceutical’s properties and characteristics.In this study,cocrystal formation between piracetam and 3-hydroxybenzoic acid(3HBA) using grindPharmaceutical cocrystal can improve physical and chemical properties of active pharmaceutical ingredient(API),meanwhile this feature has shown great potential in improving the pharmaceutical’s properties and characteristics.In this study,cocrystal formation between piracetam and 3-hydroxybenzoic acid(3HBA) using grinding method has been characterized by Fourier transform infrared(FTIR),Raman and terahertz(THz) spectroscopical techniques.The vibrational modes of different motions are obtained by the assignment of the peaks in the spectra of the starting materials and the cocrystal components.FTIR,Raman and THz spectroscopical results show that the vibrational modes of the cocrystal are different from those of the starting materials.In addition,the dynamic process of the above cocrystal formation is investigated in-depth with Raman and THz spectra.Piracetam-3HBA cocrystal is formed pretty fast in first several minutes,and then the formation rate becomes slow.After 35 minutes,such formation process has been completed.The results offer the theoretical benchmark and unique means for real-time monitoring pharmaceutical cocrystal formation and also the corresponding quantitative analysis in the pharmaceutical field..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1854 (2015)
Aging Process of Puer Black Tea Studied by FTIR Spectroscopy Combined with Curve-Fitting Analysis
LI Dong-yu, SHI You-ming, and YI Shi-lai
For better determination of the chemical components in the Puer black tea,Fourier transform infrared spectroscopy was used for obtaining vibrational spectra of Puer black tea at different aging time.Fourier transform infrared(FTIR) spectra indicated that the chemical components had change in Puer black tea at differentFor better determination of the chemical components in the Puer black tea,Fourier transform infrared spectroscopy was used for obtaining vibrational spectra of Puer black tea at different aging time.Fourier transform infrared(FTIR) spectra indicated that the chemical components had change in Puer black tea at different aging time.The leaf of Puer black tea was a complex system,its Fourier transform infrared spectrum showed a total overlap of each absorption spectrum of various components.Each band represented an overall overlap of some characteristic absorption peaks of functional groups in the Puer black tea.In order to explore the change of characteristic absorption peaks of functional groups with aging time,the prediction positions and the number of second peaks in the range of 1 900～900 cm-1 were determined by Fourier self-deconvolution at first,and later the curve fitting analysis was performed in this overlap band.At different aging time of Puer black tea,the wave number of second peaks of amide Ⅱ,tea polyphenol,pectin and polysaccharides at overlap band were assigned by curve fitting analysis.The second peak at 1 520 cm-1 was characteristic absorption band of amide Ⅱ,the second peaks of tea polyphenol and pectin appeared at 1 278 and 1 103 cm-1 respectively.Two second peaks at 1 063 and 1 037 cm-1,corresponds mainly to glucomannan and arabinan.The relative area of these second peaks could be indicated the content of protein,tea polyphenol,pectin and polysaccharides in the Puer black tea.The results of curve fitting analysis showed that the relative area of amide Ⅱ was increasing first and then decreasing,it indicated the change of protein in Puer black tea.At the same time,the content of tea polyphenol and pectin were decreased with the increase of aging time,but the glucomannan and arabinan were increased in reverse.It explained that the bitter taste was become weak and a sweet taste appeared in the tea with the increase of aging time.The present study suggested that Fourier transform infrared spectroscopy combined with curve-fitting analysis could reveal the biochemical changed of Puer black tea with the increase of aging time,and it was evidence for evaluation the quality of Puer black tea..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1860 (2015)
Biomass Compositional Analysis Using Sparse Partial Least Squares Regression and Near Infrared Spectrum Technique
YAO Yan, WANG Chang-yue, LIU Hui-jun, TANG Jian-bin, CAI Jin-hui, and WANG Jing-jun
Forest bio-fuel,a new type renewable energy,has attracted increasing attention as a promising alternative.In this study,a new method called Sparse Partial Least Squares Regression(SPLS) is used to construct the proximate analysis model to analyze the fuel characteristics of sawdust combining Near Infrared Spectrum TechForest bio-fuel,a new type renewable energy,has attracted increasing attention as a promising alternative.In this study,a new method called Sparse Partial Least Squares Regression(SPLS) is used to construct the proximate analysis model to analyze the fuel characteristics of sawdust combining Near Infrared Spectrum Technique.Moisture,Ash,Volatile and Fixed Carbon percentage of 80 samples have been measured by traditional proximate analysis.Spectroscopic data were collected by Nicolet NIR spectrometer.After being filtered by wavelet transform,all of the samples are divided into training set and validation set according to sample category and producing area.SPLS,Principle Component Regression(PCR),Partial Least Squares Regression(PLS) and Least Absolute Shrinkage and Selection Operator(LASSO) are presented to construct prediction model.The result advocated that SPLS can select grouped wavelengths and improve the prediction performance.The absorption peaks of the Moisture is covered in the selected wavelengths,well other compositions have not been confirmed yet.In a word,SPLS can reduce the dimensionality of complex data sets and interpret the relationship between spectroscopic data and composition concentration,which will play an increasingly important role in the field of NIR application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1864 (2015)
Dynamic Detection of Fresh Jujube Based on ELM And Visible/Near Infrared Spectra
YANG Yi, ZHANG Shu-juan, and HE Yong
Jujube was rich in nutrition and variety.In different varieties,there were very different from the market price to the qualities of internal and external.In order to realize the rapid and non-destructive detection of fresh jujubes’ classification,Ban jujube,Jixin jujube and Xiang jujube were selected as research objectJujube was rich in nutrition and variety.In different varieties,there were very different from the market price to the qualities of internal and external.In order to realize the rapid and non-destructive detection of fresh jujubes’ classification,Ban jujube,Jixin jujube and Xiang jujube were selected as research objects to collect their visible/near infrared spectral data dynamically.A combination of Moving Smoothing and Multiplicative Scatter Correction(MSC) was applied as the pretreatment method.After the pretreatment,the characteristic wavelengths extracted by Successive Projections Algorithm(SPA) were 980 nm,1 860,1 341,1 386,2 096,1 831,1 910,1 628,441,768 and 601 nm,respectively.And the importance reduced in accordance with the order.The 11 characteristic wavelengths were adopted as input variable to established Extreme Learning Machine(ELM) classification model,which was used for prediction.Comparing the ELM model’s classification accuracy with other methods’ classification accuracy such as Partial Least Squares Discriminant Analysis(PLS-DA) and Least Squares Support Vector Machines(LS-SVM),the result indicated that:the R2 and the RMSEC of the SPA-ELM model was 0.972 38 and 0.0187 24,respectively.The classification accuracy of the SPA-ELM model was 100% as good as the SPA-PLS-DA and SPA-LS-SVM.ELM was an effective classification method.This study provides a new theoretical basis for detection of fresh jujubes’ classification..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1870 (2015)
Preparation of Rubber Accelerator Tetramethyl Thiuram Monosulfide and Its Spectral Analysis
WANG Zhen-xiang, LI Hong-liang, JIA Tai-xuan, ZHANG Nan, and JIN Xin
In the study,rubber accelerator tetramethyl thiuram monosulfide(TMTM) was synthesized firstly.Single crystal TMTM was cultivated by solvent evaporation method.TMTM was detected and characterized by XRD single crystal diffraction,FTIR,TG-DSC.The micro-structure and intrinsic regularity were revealed.The TMTM microstructIn the study,rubber accelerator tetramethyl thiuram monosulfide(TMTM) was synthesized firstly.Single crystal TMTM was cultivated by solvent evaporation method.TMTM was detected and characterized by XRD single crystal diffraction,FTIR,TG-DSC.The micro-structure and intrinsic regularity were revealed.The TMTM microstructure was revealed by XRD single crystal diffraction from the diffraction data,part of bond length and bond angle.Its highly efficient performance of rubber vulcanization promotion was decided due to its orientation structure and high order.Properties of TMTM was disclosed by TG-DSC analysis from the heat effect.The results of TG-DSC and FTIR showed that single crystal TMTM possessed with little CS2.The chemical bond types in TMTM were revealed by FTIR the same as single crystal diffraction testing by different way.The decomposition temperature of TMTM was very high.It could provided reference with research on rubber vulcanizing properties by TMTM on rubber vulcanizing machine.This study can help the enterprises to designate the working standard tracing detection of TMTM industrialized production.Performance index of TMTM was judged.The project of TMTM industry standard can be declared by the enterprises,written a draft standard.It can provide the basis experimental data on completing the revision of the national ministry of industry and information technology standard system project plan..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1875 (2015)
Research on Rapid Discrimination of Edible Oil by ATR Infrared Spectroscopy
MA Xiao, YUAN Hong-fu, SONG Chun-feng, HU Ai-qin, LI Xiao-yu, ZHAO Zhong, LI Xiu-qin, GUO Zhen, and ZHU Zhi-qiang
A rapid discrimination method of edible oils,KL-BP model,was proposed by attenuated total reflectance infrared spectroscopy.The model extracts the characteristic of classification from source data by KL and reduces data dimension at the same time.Then the neural network model is constructed by the new data which as theA rapid discrimination method of edible oils,KL-BP model,was proposed by attenuated total reflectance infrared spectroscopy.The model extracts the characteristic of classification from source data by KL and reduces data dimension at the same time.Then the neural network model is constructed by the new data which as the input of the model.84 edible oil samples which include sesame oil,corn oil,canola oil,blend oil,sunflower oil,peanut oil,olive oil,soybean oil and tea seed oil,were collected and their infrared spectra determined using an ATR FT-IR spectrometer.In order to compare the method performance,principal component analysis(PCA) direct-classification model,KL direct-classification model,PLS-DA model,PCA-BP model and KL-BP model are constructed in this paper.The results show that the recognition rates of PCA,PCA-BP,KL,PLS-DA and KL-BP are 59.1%,68.2%,77.3%,77.3% and 90.9% for discriminating the 9 kinds of edible oils,respectively.KL extracts the eigenvector which make the distance between different class and distance of every class ratio is the largest.So the method can get much more classify information than PCA.BP neural network can effectively enhance the classification ability and accuracy.Taking full of the advantages of KL in extracting more category information in dimension reducing and the features of BP neural network in self-learning,adaptive,nonlinear,the KL-BP method has the best classification ability and recognition accuracy and great importance for rapidly recognizing edible oil in practice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1879 (2015)
Determination of Ginsenosides Amount and Geographical Origins of Ginseng by NIR Spectroscopy
WANG Jing-jing, YAN Shu-mo, and YANG Bin
In the study,74 samples of ginseng were harvested from three provinces located in the northeast of China.Method for the quantification of total amount of ginsenosides Rg1,Rb1,and Re in samples with near infrared(NIR) spectroscopy was developed with the application of partial least squares regression(PLSR).The referenceIn the study,74 samples of ginseng were harvested from three provinces located in the northeast of China.Method for the quantification of total amount of ginsenosides Rg1,Rb1,and Re in samples with near infrared(NIR) spectroscopy was developed with the application of partial least squares regression(PLSR).The reference analysis was performed using a UPLC method.Different pretreatments like multiplicative scatter correction(MSC),Norris-Derivative were applied on the spectra to optimize the calibration and the spectral regions from 6 001 to 4 007 cm-1 and from 10 000 to 8 786 cm-1 were selected for the calculation of the PLSR model.The root mean square error of cross-validation(RMSECV) and root mean square error of prediction(RMSEP) were 0.115 and 0.167,respectively,and the correlation coefficients were 0.947 7 and 0.915 3,respectively.At the same time,the spectral region from 8 531 to 7 559 cm-1 was chosen to establish a model for identification the geographical origins of ginseng samples.MSC and Savitzky-Golay smoothing were utilized on the spectral preprocessing.According to the result,74 samples were separated into three clusters,corresponding to the three geographical origins,i.e.,Jilin,Liaoning and Heilongjiang Province.The cross-validation ability and the prediction ability were 96% and 90%,respectively.In Chinese Pharmacopeia,the total amount of ginsenosides Rg1,Rb1,and Re is used as one of the indexes to evaluate the quality of ginseng,the established quantification method herein is rapid and accurate,it can be applied as an alternative method for quality control of ginseng sample..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1885 (2015)
Study on Brand Discrimination of Differential oil Using Near-Infrared Spectroscopy with Different Resolutions
ZHANG Yu, TAN Li-hong, and HE Yong
The performance and influence of near-infrared spectroscopy with different resolutions for brand discrimination of differential oil was studied.Spectral data with resolutions of 4,8,16 and 32 cm-1 were collected,and 10 522.28～4 443.425 cm-1 spectra were analyzed after the removal of the absolute noises.The principal coThe performance and influence of near-infrared spectroscopy with different resolutions for brand discrimination of differential oil was studied.Spectral data with resolutions of 4,8,16 and 32 cm-1 were collected,and 10 522.28～4 443.425 cm-1 spectra were analyzed after the removal of the absolute noises.The principal component analysis(PCA) of the spectral data at different resolutions indicated that the brands of differential oil could be discriminated.Partial least squares-discriminant analysis(PLS-DA) and support vector machine(SVM) models were built based on the full spectra with different resolutions.The discrimination results showed that all models obtained similar and good performances with the classification rate over 90%,and the best results were obtained when the model was built based on the full spectra with the resolution of 8 cm-1.Successive projections algorithm was applied to select effective wavenumbers,and different effective wavenumbers were selected for the spectra with different resolutions.PLS-DA and SVM models based on the selected effective wavenumbers both obtained good results.Their results were similar to the models established based on full spectra.The results indicated that spectral resolution had little effect on the discrimination results,and spectral resolution effected the selection of effective wavenumbers,and spectral resolution should be taken into consideration for the selection of effective wavenumbers in practical applications.In all,near-infrared spectroscopy with different resolutions and the corresponding selected effective wavenumbers could be used for discrimination of differential oil brands..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1889 (2015)
Effect of Optical Length on Detection Accuracy of Camellia Oil Adulteration by Near Infrared Spectroscopy
SUN Tong, WU Yi-qing, XU Peng, WEN Zhen-cai, HU Tian, and LIU Mu-hua
In this research,near infrared spectroscopy was used to detect adulterated percent of camellia oil adulterated with soybean oil quantificationally at different optical lengths,and the effect of optical length on detection accuracy of adulterated percent was investigated.Soybean oil was put into camellia oil according tIn this research,near infrared spectroscopy was used to detect adulterated percent of camellia oil adulterated with soybean oil quantificationally at different optical lengths,and the effect of optical length on detection accuracy of adulterated percent was investigated.Soybean oil was put into camellia oil according to different mass fraction,the adulterated mass fraction was ranged from 1% to 50%.Transmission spectra of samples were acquired by a Quality Specspectrometer at different optical lengths(1,2,4,10 mm),and effect of optical length on detection accuracy of adulterated percent was analyzed by comparing quantitative prediction models that developed at different calibration methods,pretreatment methods and wavelength range.The results indicate that the performance of quantitative prediction model of adulterated percent is improved as the optical length is increasing from 1 to 4 mm,while the performance of quantitative prediction model of adulterated percent is deteriorated as the optical length is increasing from 4 to 10 mm.4 mm is a better optical length for camellia oil adulteration.The coefficients of determination of prediction(R2P) and root mean square error of prediction(RMSEP) in quantitative prediction models of adulterated percent for optical lengths of 1,2,4,10 mm are 0.923,0.977,0.989,0.962 and 4.58%,2.54%,1.72%,3.20%,respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1894 (2015)
Preparation Polyacrylonitrile/Ag Nanoparticle Composite Nanofibers Via an Elelctrospinning Technique and Their Surface Enhanced Raman Scattering Study
SONG Wei, LI Ting-ting, WANG Xu, and ZHAO Bing
In this paper,we have prepared polyacrylonitrile(PAN)/Ag nanoparticle composite nanofibers as a surface enhanced Raman scattering(SERS) substrate via an elelctrospinning technique.First,the PAN and AgNO3 were dissolved in N,N’-dimethylformamide solvent to get PAN/Ag seed solution;then the PAN/Ag seed solution was electIn this paper,we have prepared polyacrylonitrile(PAN)/Ag nanoparticle composite nanofibers as a surface enhanced Raman scattering(SERS) substrate via an elelctrospinning technique.First,the PAN and AgNO3 were dissolved in N,N’-dimethylformamide solvent to get PAN/Ag seed solution;then the PAN/Ag seed solution was electrospun for the preparation of PAN/Ag seed composite nanofibers;Finally,the PAN/Ag seed composite nanofibers were treated by hydrazine hydrate to synthesize PAN/Ag nanoparticle composite nanofibers.The as-prepared PAN/Ag nanoparticle composite nanofibers were mixed with the probes for the SERS detection to get the SERS spectrum of the probes.The PAN/Ag nanoparticle composite nanofibers substate showed a good SERS signal when the concentration of PATP is as low as 10－6 mol·L-1.Furthermore,this kind of SERS substrate could be large-scale prepared,which showed a high commercial value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1899 (2015)
Resonance Raman Spectral Properties Studies of β-Carotene in Solution
SUN Mei-jiao, LIU Shuo, LIU Tian-yuan, XU Sheng-nan, SUN Cheng-lin, ZHOU Mi, and LI Zuo-wei
β-carotene is an important kind of polyene biomolecules,which has significant applications on researching optoelectronic and functional materials.In-situ high pressure Raman spectra of β-carotene are measured in CS2 solution and water respectively at pressure range from 0～0.60 GPa.Then we compared both of them the Ramaβ-carotene is an important kind of polyene biomolecules,which has significant applications on researching optoelectronic and functional materials.In-situ high pressure Raman spectra of β-carotene are measured in CS2 solution and water respectively at pressure range from 0～0.60 GPa.Then we compared both of them the Raman shift and CC bond of the full width at half maximum(FWHM) of the Raman spectra.It is therefore concluded that both of the samples’ Raman shift moved to the high wave number and the full width at half maximum increased depending of the pressure.The experiment phenomena were interpreted by the theory of “coherent weakly damped electronic-lattice vibration model” and “effective conjugation length model”.The mechanism is that the β-carotene is compressed and has the lower structure order,shorte the effective conjugation length,decreased Raman active,weaker the coherent weakly damping CC bond vibration in high pressure.Because of the CC bond length become short,so the Raman spectra are found to blueshift.The CC bond of the full width at half maximum(FWHM) of the Raman spectra increased is attributed to the increase of difference in C—C and CC bond lengths.Moreover,due to dissolving in non-polar CS2 solvent,the β-carotene encounters the interaction of the surrounding solvent molecules.So the dispersion force interaction between solute and solvent is more sensitive to pressure.Then it makes that the slop of Raman shift and the full width at half maximum in the CS2 solution are faster than dissolved in water with increasing pressure.This paper provides an application value for research on molecular structure change under the external field and the presence form of polyenes biomolecules in the solvent..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1904 (2015)
Microalgae Species Identification Study with Raman Microspectroscopy Technology
SHAO Yong-ni, PAN Jian, JIANG Lu-lu, and HE Yong
Identification and classification of microalgae are basis and premise in the study of physiological and biochemical characteristics for microalgae.Microalgae cells mainly consist of five kinds of biological molecules,including proteins,carbonhydrates,lipids,nucleic acids and pigments.These five kinds of biological moleIdentification and classification of microalgae are basis and premise in the study of physiological and biochemical characteristics for microalgae.Microalgae cells mainly consist of five kinds of biological molecules,including proteins,carbonhydrates,lipids,nucleic acids and pigments.These five kinds of biological molecules contents with different ratio in microalgae cells can be utilized to identify microalgae species as a supplement method.This paper investigated the application of Raman microspectroscopy technology in the field of rapid identification on different algae species such as aschlorella sp.and chlamydomonas sp..Cultivated in the same conditions of culture medium,illumination duration and intensity,these two kinds of species of microalgae cells were immobilized by using agar,and then the samples were placed under 514.5 nm Raman laser to collect Raman spectra of different growth periods of different species.An approach to remove fluorescence background in Raman spectra called Rolling Circle Filter(RCF) algorithm was adopted to remove the fluorescent background,and then some preprocessing methods were used to offset the baseline and smooth method of Savitzky-Golay was tried to make the spectra curves of total 80 samples smoother.Then 50 samples were randomly extracted from 80 samples for modeling,and the remaining 30 samples for independent validation.This paper adopted different pretreatment methods,and used the partial least squares(PLS) to establish model between the spectral data and the microalgae species,then compared the effects of different pretreatment methods.The results showed that with Raman microspectroscopy technology,the pretreatment method of max-peak ratio standardization was a more effective identification approach which utilizes the different content ratios of pigments of different microalgae species.This method could efficiently eliminate the influence on Raman signal due to different growth stages of microalgae and decomposition of pigments contents of microalgae in vivo.Compared with other traditional classification methods,this method had significant advantages like simpler procedure and shorter testing time,and it can also avoid some subjective measurement errors caused by unskilled operations.If the threshold was set to ±0.5,the prediction accuracy can reach 100%,and when the threshold was ±0.2,the prediction accuracy reached 86.67%,which proves the proposed new method can be a good approach to identify different algae varieties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1908 (2015)
Quantitative Analysis of the Hydration Process of Mine Gas Mixture Based on Raman Spectroscopy
ZHANG Bao-yong, YU Yue, WU Qiang, and GAO Xia
The research on micro crystal structure of mine gas hydrate is especially significant for the technology of gas hydrate separation.Using Raman spectroscopy to observe hydration process of 3 kinds of mine gas mixture on line which contains high concentration of carbon dioxide,this experiment obtained the information of The research on micro crystal structure of mine gas hydrate is especially significant for the technology of gas hydrate separation.Using Raman spectroscopy to observe hydration process of 3 kinds of mine gas mixture on line which contains high concentration of carbon dioxide,this experiment obtained the information of the hydrate crystals including large and small cage occupancy.Meanwhile obtained the hydration number indirectly based on the statistical thermodynamic model of van der Waals and Platteeuw.The results show that cage occupancy and hydration number of mine gas hydrates change little during different growth stages.The large cages of hydrate phases are nearly full occupied by carbon dioxide and methane molecules together,with the occupancy ratios between 97.70% and 98.68%.Most of the guest molecules in large cages is carbon dioxide(78.58%~94.09%) and only a few(4.52%~19.12%) is filled with methane,it is because carbon dioxide concentration in the gas sample is higher than methane and there is competition between them.However the small cage occupancy ratios is generally low in the range from 17.93% to 82.41%,and the guest molecules are all methane.With the increase of methane concentration in gas sample,the cage occupancy both large and small which methane occupied has increased,meanwhile the large cage occupancy which methane occupied is lower than small cage.The hydration numbers of mine gas hydrate during different growth stages are between 6.13 and 7.33.Small cage occupancy has increased with the increase of methane concentration,this lead to hydration number decreases.Because of the uneven distribution of hydrate growth,the hydration numbers of 3 kinds of gas samples show irregular change during different growth stages..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1912 (2015)
Synthesis,Crystal Structure and Fluorescence Properties of Two Tb(Ⅲ) Complexes
FAN Ting-ting, SONG Shuang, ZHANG Yi-hua, HUO Rui, LI Xia, DING Xing-yi, LIU Yang, ZHAO Xu, and YAN Chun-hui
Two coordination polymers with formula of ［Tb(3-SBA)(IP)OH(H2O)］·H2O(1) and ［Tb(dpdc)1.5(IP)(H2O)］n(2)(3-SBA=3-sulfobenzoate,dpdc=2,2′-diphenyldicarboxylate and IP=1H-imidazo［4,5-f］［1,10］-phenanthroline) have been synthesised under hydrothermal condition and characterizated by X-ray single crystal diffraction.The Two coordination polymers with formula of ［Tb(3-SBA)(IP)OH(H2O)］·H2O(1) and ［Tb(dpdc)1.5(IP)(H2O)］n(2)(3-SBA=3-sulfobenzoate,dpdc=2,2′-diphenyldicarboxylate and IP=1H-imidazo［4,5-f］［1,10］-phenanthroline) have been synthesised under hydrothermal condition and characterizated by X-ray single crystal diffraction.The complex 1 possesses a 1D chain structure constructed from Tb(Ⅲ) ions by 3-SBA ligands and OH groups.Complex 2 shows a 1D chain structure constructed from Tb(Ⅲ) ions by dpdc ligands.The two complexes display the characteristic 5D4→7FJ(J=6-3) transitions at 492,544 584 and 619 nm of Tb(Ⅲ) ion,respectively.No emission from the ligand could be observed,which indicates that the ligands absorb and transfer energy efficiently to central Tb(Ⅲ) ion.The emission decay curves reveal a monoexponential behaviour yielding the lifetime values of 0.287 ms for 1 and 0.439 ms for 2.The quantum yields of luminescence are 9.28% for 1 and 7.07% for 2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1917 (2015)
A Method for Determination of Migratable Fluorescent Whitening Agents in Paper Products by Dual-Wavelength UV Spectroscopy
ZHANG Shu-xin, CHAI Xin-sheng, TIAN Ying-xin, and CHEN Run-quan
The current national standard method GB/T 27741—2011,i.e.,“quantitative determination of migratable fluorescent whitening agents-UV spectroscopy”,overestimates the migratable fluorescent whitening agents(FWA) in the paper based products because of the spectral interference of the leached lignin from the cellulose fiberThe current national standard method GB/T 27741—2011,i.e.,“quantitative determination of migratable fluorescent whitening agents-UV spectroscopy”,overestimates the migratable fluorescent whitening agents(FWA) in the paper based products because of the spectral interference of the leached lignin from the cellulose fibers.To minimize such interference,a spectroscopic method based on dual-wavelength(305 and 348 nm) measurement was proposed.It was observed that the dual-wavelength spectroscopy can effectively subtract the spectral absorption contributed by the leached lignin in the extraction medium,thus more accurately determination of migratable FWA can be performed.The results showed that the present method has a relative standard deviation of 2.17%,the quantitative detection limit of 16.9 mg·kg-1,and recovery of 98%～103%.Compared with the current alternative standard-HPLC method,the present method possesses advantages of low operation and maintenance costs,simple,and practical in application.Therefore,it is more suitable for the rapid determination of migratable FWA in the product quality control in the production process and sample examination in the commercial market..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1921 (2015)
Using Three-Dimensional Fluorescence Spectrum Technology to Analyze the Effects of Natural Dissolved Organic Matter on the Pesticide Residues in the Soil
LEI Hong-jun, PAN Hong-wei, HAN Yu-ping, LIU Xin, and XU Jian-xin
The behavior of pesticide in soil is influenced by dissolved organic matter(DOM) through competition adsorption,adsorption,solubilization,accelerated degradation,and so on.Thus DOM and its components play an important role in the environmental risk in the soil ecosystem and groundwater environment.Currently,most studieThe behavior of pesticide in soil is influenced by dissolved organic matter(DOM) through competition adsorption,adsorption,solubilization,accelerated degradation,and so on.Thus DOM and its components play an important role in the environmental risk in the soil ecosystem and groundwater environment.Currently,most studies focused on the short-term effect of high concentration of DOM on the pesticide residues.However,soil DOM is mainly at low level.Therefore,there is of some practical significance to probe into the environmental behavior of soil pesticides under natural level of DOM.Thus a site investigation was conducted in the farmland with long-term application history of pesticide.By using the three dimensional excitation-emission fluorescence matrix(3D-EEM) technology,together with the fluorescence regional integration(FRI) quantitative method,the long-term effects of pesticide residues under low concentration of natural DOM were analyzed.Results showed that:(1) The long-term effects of the natural DOM components on the environment behavior of most soil organo-chlorine pesticides were not significant except for a few pesticides such as γ-HCH,p,p’-DDE,etc.(2) The influencing effects of DOM components on different type of pesticides were varied.Among which,the content of tyrosine component showed a significantly negative correlation(p<0.05) with the concentration of γ-HCH and p,p’-DDE.There were significant positive correlations(p<0.05) between the by-products of microbial degradation in DOM components and the concentration of heptachlor.There were also a significant positive correlation(p<0.05) between the content of active humus component of humic acid in the DOM and the concentration of heptachlor epoxide.These results suggested that the distribution of different types of pesticides residue in the soil was influenced by different components at different levels of significance.(3) The humification degree of soil organic matter showed minor effect of DOM on the pesticide residues in the soil.In this study,3D-EEM and FRI technology were firstly coupled in use for studying the influence of different components of DOM in soil on the environmental behavior of pesticides,which provides a new idea for the research on the mechanism of pesticides transportation and transformation in soil and groundwater environment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1926 (2015)
Effect of pH on the Ultraviolet Spectra and Fluorescence Characteristics of Dissolved Organic Matter in the Process of Straw Humification
FAN Chun-hui, ZHANG Ying-chao, and WANG Jia-hong
Crop straw is the dominant by-product from agriculture and is regarded as the new source of non-point contamination.Straw incorporation is possible to solve the issues of straw reduction and reutilization,which is clearly required in the twelfth five-year-plan for national economic and social development of the People’Crop straw is the dominant by-product from agriculture and is regarded as the new source of non-point contamination.Straw incorporation is possible to solve the issues of straw reduction and reutilization,which is clearly required in the twelfth five-year-plan for national economic and social development of the People’s Republic of China.At present,it is of noticeable lack of the investigation on straw incorporation behavior and detail humification product analysis in the representative regions under different environmental conditions.The ultraviolet and fluorescence spectrometry were used to reveal the characteristics of dissolved organic matter(DOM),affected by pH values,in the straw humification process in loess region.The results showed:the ultraviolet absorbance of DOM samples increased firstly and then decreased with the increasing wavelength from 200 to 700 nm,and the maximum absorbance peaks appeared around the wavelength of 240 nm.The maximum absorbance peaks(λmax) were greater at pH values of 6,8 and 9 than that of 7,and the low degree of humification was indicated from the values of SUVA254,E3/E4 and A253/A203,caused by the short period of humification.The fluorescence peaks of extracted DOM from loess appeared around the regions of λex/em=250/330 and λex/em=325/450,referred as UV fulvic-like fluorescence,and visible fulvic-like and humic-like fluorescence,respectively.The increasing pH values resulted in the greater wavelength of absorbance peak,suggesting the increased aromaticity and conjugated degree,and the novel fluorescence peak was found in λex/em=250/450.The pH values were more effective to change the UV fulvic-like fluorescence peaks intensity(increased firstly and then decreased) than that of visible fulvic-like and humic-like fluorescence,which might be related to buffer effect,fluorescence quenching(side effects) and component structure.The ultraviolet and fluorescence spectrometry were acceptable to illustrate the characteristics variation of DOM affected by pH values in the straw humification process..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1933 (2015)
A Quick Quantitative Analysis for Group Composition of Coal Liquefaction Oil by Ultraviolet Spectroscopy
FAN Wen-jun, WU Mei-xiang, HAO Jian-shu, FENG Jie*, and LI Wen-ying
Gas chromatography is now the primary analysis method for the coal liquefaction oil.However,a simple and rapid quantification/qualification of the coal liquefaction oil can hardly be realized,because the coal liquefaction oil is in a heterogeneous state with a long boiling range.The aim of this study was to establish aGas chromatography is now the primary analysis method for the coal liquefaction oil.However,a simple and rapid quantification/qualification of the coal liquefaction oil can hardly be realized,because the coal liquefaction oil is in a heterogeneous state with a long boiling range.The aim of this study was to establish a rapid and accurate method for the quantification of phenolic compounds,aromatics and aliphatic hydrocarbons in coal liquefaction oil.A representative composition of coal liquefaction light oil,i.e.the distillate fractions of the boiling point range 180～200 ℃,was chosen as the investigated object.The characteristic absorption peaks of the samples in the UV spectra(200～400 nm) were examined,using three kinds of solvents,cyclohexane,ethanol,50 Wt% NaOH/ethanol mixture.Among them,the mixture solvent provided the best performance,where the aromatics interfered minimally with the quantification of phenolic compounds by avoiding the peak overlapping problem.By comparison of the UV absorption standard curves between the standard compounds(phenol,m-cresol,p-cresol and o-cresol) and the phenolic mixtures in coal liquefaction oil,m-cresol was selected for the quantification of phenolic compounds in coal liquefaction oil.The content of phenolic compounds was determined to be 32.14% according to the calibration curve of m-cresol at 290 nm,and this result is largely consistent with that determined by weighing after separation.Based on UV and GC analysis of the dephenolized oil,the standard curve of tetrahydronaphthalene at 266 nm was used for the quantification of aromatic hydrocarbons in coal liquefaction oil.The contents of aromatic and aliphatic hydrocarbons were determined to be 44.91% and 22.95%,respectively.To verify the accuracy of the method,recovery of added standards in the oil samples was determined and found to be 104.3%～110.75% and 84.3%～91.75% for phenolic compounds and aromatics,respectively.These results indicate that the contents of phenolic compounds and aromatics can be determined simultaneously with the UV standard curves of m-cresol and tetrahydronaphthalene,respectively,and the aliphatic compounds can be determined by difference..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1938 (2015)
Determination of Trace Lead in Water by UV-Visible Diffuse Reflectance Spectroscopy Combined with Surfactant and Membrane Filtration-Enrichment
ZHANG Xiao-fang, ZHU Bi-lin, LI Wei, WANG Lei, ZHANG Lei, WU Ting, and DU Yi-ping
In this paper,a method of determination of trace lead in water by UV-Visible diffuse reflectance spectroscopy combined with surfactant and membrane filtration enrichment was proposed.In the NH3·H2O-NH4Cl buffer solution with pH 8.5,the lead(Ⅱ) ion would react with dithizone to form the red complex under vigorous sIn this paper,a method of determination of trace lead in water by UV-Visible diffuse reflectance spectroscopy combined with surfactant and membrane filtration enrichment was proposed.In the NH3·H2O-NH4Cl buffer solution with pH 8.5,the lead(Ⅱ) ion would react with dithizone to form the red complex under vigorous stirring,which is hydrophobic and can be enriched by the mixed cellulose ester membrane.In addition,the nonionic surfactant Polyoxyethylene lauryl ether(Brij-30) was added into the solution to improve the enrichment efficiency,then visible diffuse reflectance spectra of the membrane were measured directly after the membrane were naturally dried.We also optimized the reaction conditions which may affect the complexation reaction process,such as type of surfactants,the concentration of the surfactant,the reaction acidity,the concentration of dithizone as well as the reaction time.The research results show that under the optimum conditions,a good linear correlation between absorbance at 485 nm and concentration of lead in the range of 5.0～100.0 μg·L-1 was obtained with a squared correlation coefficient(R2) of 0.990 6,and the detection limit was estimated accordingly to be 2.88 μg·L-1.To determine real water sample,the interference from some potential coexisting ions was also studied at the optimal conditions when the concentration of lead(Ⅱ) ion standard solution was fixed to 20 μg·L-1.The results indicate that the following ions cannot interfere in the determination of lead with the proposed method:500 times of the K+,Na+,Ca2+,Mg2+,NH+4,NO-3,Cl-,CH3COO-,SO2-4;10 times of the Al3+(using 10% NaF as a masking reagent to avoid the interference);10 times of the Fe3+(using 10 % NaF and 10% sodium potassium tartrate as masking reagents);10 times of Hg2+ or Zn2+(using 10% NaSCN and 10% potassium sodium tartrate as masking reagents);the same amount of Cd2+,Cu2+.The proposed method was applied to the determnation of lead(Ⅱ) in bottled water as a real sample.The determination results show good agreements between the proposed method and graphite furnace atomic absorption spectrometry(GFAAS) method.The recoveries in case of spiked real samples were between 95.4% and 104.5%,and the standard deviations(SD) were between 0.5 μg·L-1 and 1.5 μg·L-1,which indicate that the method developed in the present work with advantages of accuracy,simpleness,sensitiveness are of potential application for the determination of trace lead in water samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1944 (2015)
Review of Crop Canopy Spectral Information Detection Technology and Methods
FANG Xiao-rong, GAO Jun-feng, XIE Chuan-qi, ZHU Feng-le, HUANG Ling-xia, and HE Yong
Compared with the traditional chemical methods and the subjective visual ways for measuring plant physiology information indicators,the assessments of crop canopy information through spectral radiometer are more simple,rapid and accurate.The applications of different types of spectral radiometer,especially for internatCompared with the traditional chemical methods and the subjective visual ways for measuring plant physiology information indicators,the assessments of crop canopy information through spectral radiometer are more simple,rapid and accurate.The applications of different types of spectral radiometer,especially for international general used Cropscan multispectral radiometer,for predicting crop canopy leaf area index under different growth stage,biomass,nitrogen,chlorophyll and yield,and monitoring plant diseases and insect pests were summarized based on crop group information acquisition methods in recent years.The varity of vegetation indices(VIs) were concluded after comparing regression coefficients of related models among different crops.In general,the correlation coefficients of mathematical models were high and it can realize the crop detection of various kinds of physiological information.Besides,the combination of multispectral radiometer and other sensors can provide useful information to evaluate the status of crops growth,which is very important in practice..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1949 (2015)
Estimating Winter Wheat Nitrogen Vertical Distribution Based on Bidirectional Canopy Reflected Spectrum
YANG Shao-yuan, HUANG Wen-jiang, LIANG Dong, HUANG Lin-sheng, YANG Gui-jun, ZHANG Dong-yan, and CAI Shu-hong
The vertical distribution of crop nitrogen is increased with plant height,timely and non-damaging measurement of crop nitrogen vertical distribution is critical for the crop production and quality,improving fertilizer utilization and reducing enviro nmental impact.The objective of this study was to discuss the method oThe vertical distribution of crop nitrogen is increased with plant height,timely and non-damaging measurement of crop nitrogen vertical distribution is critical for the crop production and quality,improving fertilizer utilization and reducing enviro nmental impact.The objective of this study was to discuss the method of estimating winter wheat nitrogen vertical distribution by exploring bidirectional reflectance distribution function(BRDF) data using partial least square(PLS) algorithm.The canopy reflectance at nadir,±50°and ±60°;at nadir,±30°and ±40°;and at nadir,±20°and ±30°were selected to estimate foliage nitrogen density(FND) at upper layer,middle layer and bottom layer,respectively.Three PLS analysis models with FND as the dependent variable and vegetation indices at corresponding angles as the explicative variables were established.The impact of soil reflectance and the canopy non-photosynthetic materials was minimized by seven kinds of modifying vegetation indices with the ratio R700/R670.The estimated accuracy is significant raised at upper layer,middle layer and bottom layer in modeling experiment.Independent model verification selected the best three vegetation indices for further research.The research result showed that the modified Green normalized difference vegetation index(GNDVI) shows better performance than other vegetation indices at each layer,which means modified GNDVI could be used in estimating winter wheat nitrogen vertical distribution.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1956 (2015)
Spectrum Variance Analysis of Tree Leaves under the Condition of Different Leaf water Content
WU Jian, CHEN Tai-sheng, and PAN Li-xin
Leaf water content is an important factor affecting tree spectral characteristics.So Exploring the leaf spectral characteristics change rule of the same tree under the condition of different leaf water content and the spectral differences of different tree leaves under the condition of the same leaf water content are nLeaf water content is an important factor affecting tree spectral characteristics.So Exploring the leaf spectral characteristics change rule of the same tree under the condition of different leaf water content and the spectral differences of different tree leaves under the condition of the same leaf water content are not only the keys of hyperspectral vegetation remote sensing information identification but also the theoretical support of research on vegetation spectrum change as the differences in leaf water content.The spectrometer was used to observe six species of tree leaves,and the reflectivity and first order differential spectrum of different leaf water content were obtained.Then,the spectral characteristics of each tree species leaves under the condition of different leaf water content were analyzed,and the spectral differences of different tree species leaves under the condition of the same leaf water content were compared to explore possible bands of the leaf water content identification by hyperspectral remote sensing.Results show that the spectra of each tree leaf have changed a lot with the change of the leaf water content,but the change laws are different.Leaf spectral of different tree species has lager differences in some wavelength range under the condition of same leaf water content,and it provides some possibility for high precision identification of tree species..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1961 (2015)
Spectral Study on Coordination Reaction between metMyoglobin and Nitric Oxide
TANG Qian, ZHANG Yue, CAO Hong-yu, SHI Shan-shan, and ZHENG Xue-fang
As we all known,the instantaneous reaction between protein and ligands are very important to adjust the normal playing of biological function.And nitric oxide interactions with iron are the most important biological reactions in which NO participates.Unlike carbon monoxide or oxygen,NO can also bind reversibly to ferriAs we all known,the instantaneous reaction between protein and ligands are very important to adjust the normal playing of biological function.And nitric oxide interactions with iron are the most important biological reactions in which NO participates.Unlike carbon monoxide or oxygen,NO can also bind reversibly to ferric iron.In this paper,UV-Vis absorption and CD spectra were used to study coordination reaction process between horse heart metMb and NO,to demonstrate the coordination reaction mechanism and to explore the influencing factors of metMb with NO.The experimental results showed that metMb could react with NO,and obtained three new peaks at 420 nm,534 and 568 nm,respectively,which implied metMb and NO have reacted and generated a new complex-nitrosylmetmyoglobin(metMbNO).Then as time went on,NO concentration decreased in the solution,and the Fe-N bond fractured under the attack of H2O,then NO leaves slowly from metMbNO,and metMb was regenerated.In this experiment,we also found that external conditions such as buffer medium,ionic strength,pH,temperature,etc,had an important influence on the coordination reaction between metMb and NO.It was favorable for the coordination reaction,when the 0.01 mol·L-1 phosphate buffer solution is near neutral condition,the temperature is 280 K,the coordination reaction could reach equilibrium at a fastest speed.In addition,the CD date show that NO only reacts with Fe atom in the center of heme and has less effect on the secondary structuers of protein.The research of metMb and NO played an important role to further study the function of NO.Especially the establish of equilibrium reaction mechanism between NO and heme protein has an important research value on maintaining the balance of NO in vivo and keeping the normal function in the body’s cells..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1967 (2015)
Extending Hyperspectral Detecting Model of pH in Fresh Pork to New Breeds
LIU Jiao, LI Xiao-yu, JIN Rui, XU Sen-miao, and KU Jing
Calibration transfer is an effective approach to solve model invalidation problems caused by the change of instruments or the prediction samples.However,most studies on calibration transfer were based on different instruments,and models were established by Near Infrared Spectroscopy.In this study,hyperspectral detectinCalibration transfer is an effective approach to solve model invalidation problems caused by the change of instruments or the prediction samples.However,most studies on calibration transfer were based on different instruments,and models were established by Near Infrared Spectroscopy.In this study,hyperspectral detecting model of pork pH value was established,and in order to enhance the applicability of model to different breeds of pork samples,a new transfer algorithm based on spectra Mahalanobis distance,sync correction of spectrum and prediction value(CSPV),has been proposed,and was compared with model updating method.Equations with correlation coefficient of prediction(rp)≥0.837 and residual prediction deviation(RPD)≥1.9 were considered as applicable to predict pork quality.In this paper,three breeds,duchangda,maojia and linghao pork were researched,and a pH detecting model of duchangda(the primary breed) was established using partial least squares(PLS) regression method with rc of 0.922,rp of 0.904,root mean squared error of cross validation(RMSECV) of 0.045,root mean squared error of prediction(RMSEP) of 0.046 and RPD of 2.380.However,the prediction of the model to samples from maojia and linghao breeds(the secondary breeds) was very poor with rp of 0.770 and 0.731 respectively,RMSEP of 0.111 and 0.209,RPD reached only 1.533 and 1.234 separately.Obviously,the PLS model of duchangda was unable to achieve the prediction to maojia and linghao samples.With the transformation of CSPV algorithm to duchangda model,only 9 and 10 standard samples from maojia and linghao breeds were used respectively,the prediction ability was improved with rp of 0.889 and 0.900,RPD grew to 2.071 and 2.231,which met the requirement of rp≥0.837 and RPD≥1.9.While with model updating method,when 11 and 9 representative samples from maojia and linghao breeds were added to calibration set of duchangda model,rp increased to 0.869 and 0.845,but RPD only raised to 1.934 and 1.804 exclusively,even though tally rp≥0.837,it didn’t meet that RPD≥1.9.The results demonstrate that CSPV transfer algorithm could realize the pH value prediction of duchangda model to maojia and linghao samples,while model updating method was only applicable for maojia samples instead of linghao samples,and the performance of CSPV transfer algorithm was better than model updating..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1973 (2015)
An Analysis of the Spectrums between Different Canopy Structures Based on Hyperion Hyperspectral Data in a Temperate Forest of Northeast China
YU Quan-zhou, WANG Shao-qiang, HUANG Kun, ZHOU Lei, and CHEN Die-cong
Canopy is a major structural layer for vegetation to carry out ecological activities.The differences of light radiative transfer processes in canopies caused by forest canopy structure directly influence remote sensing inversion of forest canopy biochemical composition.Thus an analysis of spectral characteristics betweCanopy is a major structural layer for vegetation to carry out ecological activities.The differences of light radiative transfer processes in canopies caused by forest canopy structure directly influence remote sensing inversion of forest canopy biochemical composition.Thus an analysis of spectral characteristics between different canopy structures contributes to improve the accuracy of remote sensing inversion of forest canopy biochemical components.Based on a Hyperion hyperspectral image in the north Slope of Changbai Mountain Nature Reserve,through FLAASH(the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes) atmospheric correction,different canopy reflectance spectra were extracted,and spectral transforms were carried out using continuum removal method and first derivative method for quantitative analysis of the spectral characteristics.A set of spectral indices were calculated,including NIR(near infrared reflectance),NDVI(normalized difference vegetation index),EVI(Enhanced Vegetation Index),NDNI(normalized difference nitrogen index),SPRI(normalized photochemical reflectance index)*NDVI and SPRI*EVI(vegetation productivity index).Combined with the broad foliar dominance index(BFDI),the relationships between the spectral indices and canopy structure composition were investigated.The characteristics of canopy structure composition impacting its spectral curve and indices were clarified in the temperate forest.The results showed that:(1) there existed significantly different spectral characteristics between different canopy structures:comparing to the spectrum of broad-leaved forest canopies,the red edge moved to the left and their slope decreased,blue edge and yellow edge features were also weakened,near-infrared reflectance decreased,normalized reflectance in visible region risen for the spectrum of conifer forest canopies;(2) the spectrum variation were controlled by BFDI.The correlations between BFDI and the spectral indices were significant(P<0.01).It was suggested the ratio of broad-leaved and conifer in canopy played an important role in variation of spectral indices.The coefficients of determination(R2) of BFDI and NDVI,EVI,SPRI*EVI,SPRI*NDVI and NDNI were 0.90,0.83,0.83,0.81,0.68 and 0.59 respectively.It was revealed that BFDI could control the variation of the canopy structure,greenness,leaf nitrogen concentration,leaf area index and productivity in temperate coniferous and broad-leaved mixed forests.Our findings were very significant foundation for accurate determination of forest type,quantitative extraction of canopy biochemical components,estimation of regional forest ecosystem productivity and other related researches..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1980 (2015)
Backscattering Characteristics of Machining Surfaces and Retrieval of Surface Multi-Parameters
TAO Hui-rong, ZHANG Fu-min, and QU Xing-hua
For no cooperation target laser ranging,the backscattering properties of the long-range and real machined surfaces are uncertain which seriously affect the ranging accuracy.It is an important bottleneck restricting the development of no cooperation ranging technology.In this paper,the backscattering characteristics of For no cooperation target laser ranging,the backscattering properties of the long-range and real machined surfaces are uncertain which seriously affect the ranging accuracy.It is an important bottleneck restricting the development of no cooperation ranging technology.In this paper,the backscattering characteristics of three typical machining surfaces(vertical milling processing method,horizontal milling processing method and plain grinding processing method) under the infrared laser irradiation with 1 550 nm were measured.The relation between the surface machining texture,incident azimuth,roughness and the backscattering distribution were analyzed and the reasons for different processing methods specific backscattering field formed were explored.The experimental results show that the distribution of backscattering spectra is greatly affected by the machined processing methods.Incident angle and roughness have regularity effect on the actual rough surface of each mode.To be able to get enough backscattering,knowing the surface texture direction and the roughness of machined metal is essential for the optimization of the non-contact measurement program in industry.On this basis,a method based on an artificial neural network(ANN) and genetic algorithm(GA),is proposed to retrieve the surface multi-parameters of the machined metal.The generalized regression neural network(GRNN) was investigated and used in this application for the backscattering modeling.A genetic algorithm was used to retrieve the multi-parameters of incident azimuth angle,roughness and processing methods of machined metal surface.Another processing method of sample(planer processing method) was used to validate data.The final results demonstrated that the method presented was efficient in parameters retrieval tasks.This model can accurately distinguish processing methods and the relative error of incident azimuth and roughness is 1.21% and 1.03%,respectively.The inversion accuracy is high.It can reduce the impact of surface texture,the incident azimuth and incidence angle to the ranging scope.The experiments proved that the inversion of the surface parameters greatly broadened the ranging scope in no cooperation target laser ranging.Taking the Vertical milling sample with roughness Ra=6.3 μm for example,the measuring range can be increased by about 22 m when the incidence angle is increased in the incidence plane which is vertical to the surface texture.The study results of this paper have a certain reference value to the research of the backscattering of machined surface and its application in other areas..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1986 (2015)
Stability Study of Nano-Silver Particles Dispersed in Various Solvents by Turbiscan Lab Optical Analyzer
XIA Zhao-hui, Lv Li-yun, and WANG Hong
Nano-silver particles were synthesized through chemical reduction method,using silver nitrate,m-dihydroxybenzene and polyvinylpyrrolidone as silver source,reduction agent and protective agent respectively;and redundant reactants were removed through centrifugation and washing operation.Then different nano-silver colloiNano-silver particles were synthesized through chemical reduction method,using silver nitrate,m-dihydroxybenzene and polyvinylpyrrolidone as silver source,reduction agent and protective agent respectively;and redundant reactants were removed through centrifugation and washing operation.Then different nano-silver colloids were acquired by dispersing the nano-silver particles in water,ethanol and ethylene glycol respectively through ultrasonic dispersion.For comparison,the nano-silver particles mass fraction of all the colloids was 0.2 Wt% during the research.Nano-silver particles were characterized by laser particle size analyzer,transmission electron microscopy(TEM) and scanning electron microscopy(SEM);and the concentration of nano-silver colloids was confirmed through synchronized thermal analyzer(STA).The size distribution result of laser particle size analyzer showed that nano-silver particles were about 100 nm and had uniform size distribution.The images of TEM and SEM showed that the size of nano-silver particles was in nanoscale as well.To evaluate the dispersion stabilities of different nano-silver colloids,Turbiscan optical analyzer which was based on multiple light scattering analysis had been employed in the research;and the principle factors leading to instabilities of nano-silver colloids were also discussed.Results showed that particle size variation and particle migration were major factors which affected the dispersion stabilities of nano-silver colloids.For the nano-silver colloid dispersed in water phase,the backscattering light signal in middle of the sample cell stayed unchanged with time while the backscattering light signals at top and bottom of the sample cell showed dramatic variation during the measurement,which indicated that particle migration was the main reason why the nano-silver colloids was unstable.But for the nano-silver colloids dispersed in ethanol and ethylene glycol phase,the backscattering light signals in bottom,middle and top of the sample cell presented obvious variation at the end of the tests,which certificated that both particle size variation and particle migration affected the stabilities of nano-silver colloids.At last,by comparing the Turbiscan Stability Index(TSI) of three different nano-silver colloids,the stabilities of the systems were outlined by a descending order:ethylene glycol,water and ethanol..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1992 (2015)
A Study on Preparation and Photocatalytic Activity of Mn-BiOCl
CUI Yu-min, LI Hui-quan, MIAO Hui, TAO Dong-liang, FAN Su-hua, ZHANG Kun, and HUO Xiao-feng
Using Bi2O3 and MnCl2·4H2O as raw materials,with HCl as solvent,photocatalysts of Mn-BiOCl with different molar ratio of Mn and Bi were prepared by a hydrolysis method.The obtained samples were characterized by XRD,HRTEM,TEM,UV-Vis DRS and SPS.The UV light photocatalytic activity of Mn-BiOCl was evaluated by usingUsing Bi2O3 and MnCl2·4H2O as raw materials,with HCl as solvent,photocatalysts of Mn-BiOCl with different molar ratio of Mn and Bi were prepared by a hydrolysis method.The obtained samples were characterized by XRD,HRTEM,TEM,UV-Vis DRS and SPS.The UV light photocatalytic activity of Mn-BiOCl was evaluated by using methyl orange as model compounds of photocatalytic reaction.The active species in the degradation process of methyl orange were studied.The results show that the Mn content of Mn-BiOCl photocatalysts has an important effect on the catalytic activity.When the molar ratio of Mn and Bi is 0.25%,the as-prepared Mn-BiOCl photocatalyst has the highest catalytic activity toward the degradation of methyl orange.Photocatalytic degradation rate of methyl orange can reach 95.1%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 1997 (2015)
A New HAC Unsupervised Classifier Based on Spectral Harmonic Analysis
YANG Ke-ming, WEI Hua-feng, SHI Gang-qiang, SUN Yang-yang, and LIU Fei
Hyperspectral images classification is one of the important methods to identify image information,which has great significance for feature identification,dynamic monitoring and thematic information extraction,etc.Unsupervised classification without prior knowledge is widely used in hyperspectral image classification.ThHyperspectral images classification is one of the important methods to identify image information,which has great significance for feature identification,dynamic monitoring and thematic information extraction,etc.Unsupervised classification without prior knowledge is widely used in hyperspectral image classification.This article proposes a new hyperspectral images unsupervised classification algorithm based on harmonic analysis(HA),which is called the harmonic analysis classifer(HAC).First,the HAC algorithm counts the first harmonic component and draws the histogram,so it can determine the initial feature categories and the pixel of cluster centers according to the number and location of the peak.Then,the algorithm is to map the waveform information of pixels to be classified spectrum into the feature space made up of harmonic decomposition times,amplitude and phase,and the similar features can be gotten together in the feature space,these pixels will be classified according to the principle of minimum distance.Finally,the algorithm computes the Euclidean distance of these pixels between cluster center,and merges the initial classification by setting the distance threshold.so the HAC can achieve the purpose of hyperspectral images classification.The paper collects spectral curves of two feature categories,and obtains harmonic decomposition times,amplitude and phase after harmonic analysis,the distribution of HA components in the feature space verified the correctness of the HAC.While the HAC algorithm is applied to EO-1 satellite Hyperion hyperspectral image and obtains the results of classification.Comparing with the hyperspectral image classifying results of K-MEANS,ISODATA and HAC classifiers,the HAC,as a unsupervised classification method,is confirmed to have better application on hyperspectral image classification..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2001 (2015)
The Progress in Remote Laser-Induced Breakdown Spectroscopy
ZHANG Ting-ting, WAN Xiong, SHU Rong, and LIU Peng-xi
As a kind of spectroscopic technique,the remote laser-induced breakdown spectroscopy(Remote LIBS) can measure elemental compositions of remote targets by using high-power lasers and focusing approaches.In this paper,three remote detection approaches(open path LIBS,fiber optic LIBS and compact probe fiber optic LIBS) anAs a kind of spectroscopic technique,the remote laser-induced breakdown spectroscopy(Remote LIBS) can measure elemental compositions of remote targets by using high-power lasers and focusing approaches.In this paper,three remote detection approaches(open path LIBS,fiber optic LIBS and compact probe fiber optic LIBS) and their system architectures are summarized and analyzed.Conventional open path LIBS,with high requirement of specifications of lasers,optical systems,spectrographs and detectors,has always been a research focus in remote testing field.Fiber optic LIBS has the advantages of simplification of optical focusing system and high collection efficiency of the plasma light.This paper reviews the progress in new techniques of LIBS,for instance Filament-LIBS techniques and LIBS combines with other spectral detection techniques,and emphatically analyzes their characteristics and advantages.These new techniques have greatly broadened the detection range of LIBS,enhanced material recognition ability of LIBS,and made a great contribution to expanding applications of remote LIBS.Latest development of applications of remote LIBS in fields of deep space exploration,hazardous material detection,pollution testing,metallurgical industries and heritage restoration is introduced in detail.With the development of laser techniques,spectral detection and calibration techniques,the detection range of remote LIBS has been expended,their application fields has been extended,and the detection precision and accuracy have been improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2007 (2015)
Detection of Lead in Water by Electrolyte Cathode Atmospheric Glow Discharge Emission Spectroscopy
ZHENG Pei-chao, ZHANG Bin, WANG Jin-mei, WANG Xiao-meng, LIU Hong-di, and YANG Rui
A device based on electrolyte cathode atmospheric glow discharge atomic emission spectroscopy(ELCAD-AES) has been developed to determine the metal ion Pb in water.The emission intensity of Pb was significantly enhanced with the increase concentration of Pb,and the emission intensity has a linear relationship with conceA device based on electrolyte cathode atmospheric glow discharge atomic emission spectroscopy(ELCAD-AES) has been developed to determine the metal ion Pb in water.The emission intensity of Pb was significantly enhanced with the increase concentration of Pb,and the emission intensity has a linear relationship with concentration while the concentration of Pb in the range of 10~80 mg·L-1.The effects of discharge current and easily ionizable elements on the emission spectral of Pb were investigated,and the emission intensity reached greatest when the discharge current increased to 70 mA,and the easily ionizable elements generated weak effect on the emission spectral of Pb.The effect of acidification regent on emission spectral of Pb was discussed.It was found that it perform best when acidified with HNO3,and reducing the pH can improve the emission intensity of Pb effectively.The emission intensity of Pb at different region was detected near cathode region,thus obtained the best detection position.Under the optimized experimental parameters,the detection limit of Pb was 0.7 mg·L-1 and relative standard deviation was 1.7%.The recovery of samples was 95%~106%,result and shows that this method has better accuracy.These results provide an available method for further research of detection trace heavy mental elements in water using ELCAD-AES..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2012 (2015)
Quantitative Analysis of Heavy Metals in Water with LIBS Based on Signal-to-Background Ratio
HU Li, ZHAO Nan-jing, LIU Wen-qing, FANG Li, ZHANG Da-hai, WANG Yin, MENG De-shuo, YU Yang, and MA Ming-jun
There are many influence factors in the precision and accuracy of the quantitative analysis with LIBS technology.According to approximately the same characteristics trend of background spectrum and characteristic spectrum along with the change of temperature through in-depth analysis,signal-to-background ratio(S/B) meaThere are many influence factors in the precision and accuracy of the quantitative analysis with LIBS technology.According to approximately the same characteristics trend of background spectrum and characteristic spectrum along with the change of temperature through in-depth analysis,signal-to-background ratio(S/B) measurement and regression analysis could compensate the spectral line intensity changes caused by system parameters such as laser power,spectral efficiency of receiving.Because the measurement dates were limited and nonlinear,we used support vector machine(SVM) for regression algorithm.The experimental results showed that the method could improve the stability and the accuracy of quantitative analysis of LIBS,and the relative standard deviation and average relative error of test set respectively were 4.7% and 9.5%.Data fitting method based on signal-to-background ratio(S/B) is Less susceptible to matrix elements and background spectrum etc,and provides data processing reference for real-time online LIBS quantitative analysis technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2017 (2015)
Effect of Characteristic Variable Extraction on Accuracy of Cu in Navel Orange Peel by LIBS
LI Wen-bing, YAO Ming-yin, HUANG Lin, CHEN Tian-bing, ZHENG Jian-hong, FAN Shi-quan, LIU Mu-hua, HE Xiu-wen, LIN Jin-long, and OUYANG Jing-yi
Heavy metals pollution in foodstuffs is more and more serious.It is impossible to satisfy the modern agricultural development by conventional chemical analysis.Laser induced breakdown spectroscopy(LIBS) is an emerging technology with the characteristic of rapid and nondestructive detection.But LIBS’s repeatability,sensHeavy metals pollution in foodstuffs is more and more serious.It is impossible to satisfy the modern agricultural development by conventional chemical analysis.Laser induced breakdown spectroscopy(LIBS) is an emerging technology with the characteristic of rapid and nondestructive detection.But LIBS’s repeatability,sensitivity and accuracy has much room to improve.In this work,heavy metal Cu in Gannan Navel Orange which is the Jiangxi specialty fruit will be predicted by LIBS.Firstly,the navel orange samples were contaminated in our lab.The spectra of samples were collected by irradiating the peel by optimized LIBS parameters.The laser energy was set as 20 mJ,delay time of Spectral Data Gathering was set as 1.2 μs,the integration time of Spectral data gathering was set as 2 ms.The real concentration in samples was obtained by AAS(atom absorption spectroscopy).The characteristic variables Cu Ⅰ 324.7 and Cu Ⅰ 327.4 were extracted.And the calibration model was constructed between LIBS spectra and real concentration about Cu.The results show that relative error of the predicted concentrations of three relational model were 7.01% or less,reached a minimum of 0.02%,0.01% and 0.02% respectively.The average relative errors were 2.33%,3.10% and 26.3%.Tests showed that different characteristic variables decided different accuracy.It is very important to choose suitable characteristic variable.At the same time,this work is helpful to explore the distribution of heavy metals between pulp and peel..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2021 (2015)
Analysis of H2S/PH3/NH3/AsH3/Cl2 by Full-Spectral FlamePhotometric Detector
DING Zhi-jun, WANG Pu-hong, LI Zhi-jun, DU Bin, GUO Lei, and YU Jian-hua
Flame photometric analysis technology has been proven to be a rapid and sensitive method for sulfur and phosphorus detection.It has been widely used in enviro nmental inspections,pesticide detection,industrial and agricultural production.By improving the design of the traditional flame photometric detector,using gratinFlame photometric analysis technology has been proven to be a rapid and sensitive method for sulfur and phosphorus detection.It has been widely used in enviro nmental inspections,pesticide detection,industrial and agricultural production.By improving the design of the traditional flame photometric detector,using grating and CCD sensor array as a photoelectric conversion device,the types of compounds that can be detected were expanded.Instead of a single point of characteristic spectral lines,full spectral information has been used for qualitative and quantitative analysis of H2S,PH3,NH3,AsH3 and Cl2.Combined with chemometric method,flame photometric analysis technology is expected to become an alternative fast,real-time on-site detection technology to simultaneously detect multiple toxic and harmful gases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2025 (2015)
Rapid Detection of Trace Dimethoate Pesticide Residues Based on Colorimetric Spectroscopy
LI Wen, SUN Ming, LI Min-zan, and SUN Hong
In order to detect dimethoate pesticide residues rapidly and safely,a feasible method based on colorimetric spectroscopy was developed.Because dimethoate is one of organophosphorus pesticides containing sulfur,its sulfenyl can react with Pd2+ to produce a yellow complex named palladium sulfide.PdCl2 was used as the colIn order to detect dimethoate pesticide residues rapidly and safely,a feasible method based on colorimetric spectroscopy was developed.Because dimethoate is one of organophosphorus pesticides containing sulfur,its sulfenyl can react with Pd2+ to produce a yellow complex named palladium sulfide.PdCl2 was used as the color agent,which was dissolved in acetic acid instead of the common concentrated hydrochloric acid.The dimethoate solution was prepared by dissolving the commercial pesticides into distilled water at different concentrations.The pesticide samples were reacted with the same amount of PdCl2 solution respectively.The absorbance spectra of the samples after coloring reaction were measured in the region of 300～900 nm by a spectrophotometer.The result showed that the effect of using acetic acid instead of concentrated hydrochloric acid was not only safe but also preferable,and 0.5 mg·kg-1 was the minimum concentration of the pesticide that could be distinguished in the spectra.The result met the pesticide residue detecting requirements of part fruits and vegetables in the national standard GB2763—2012 regulations.Further studies on random 40 dimethoate samples from 0.5 to 88 mg·kg-1 were carried out.Thirty samples were randomly selected to establish the training model and remaining 10 samples were used to test the model.The preprocessing methods were carried on the spectrum data such as normalization and smoothing to get a better effect through comparison their prediction results with the correlation coefficient(r) and the root mean square error of cross-validation(RMSEP).The principal component analysis(PCA) method and partial least squares(PLS)method were used to establish prediction models respectively in the different wave ranges.By calculating the correlation coefficient of dimethoate samples in 350～900 nm the maximum of 0.957 2 was obtained at wavelength 458 nm,so 453～463 and 400～600 nm were selected as feather regions.Experiments showed that the effect of SG preprocessing on the absorbance spectra in the region of 350～900 and 400～600 nm was obvious,and PLS method were better than PCA method.The optimum model was obtained in the region of 400～600 nm,when principal component number was 4,the training set r=0.994 1,RMSEP=2.770 3 and the validation set r=0.993 3,RMSEP=2.214 8.This method was safe in operation and the colorimetric reaction time was 2 min,which provided theoretical and technical support for further studying on development of rapid,safe organophosphorus pesticide detection instrument..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2029 (2015)
The Study of Advanced Fundamental Parameter Method in EDXRFA
CHENG Feng, ZHANG Qing-xian, GE Liang-quan, GU Yi, ZENG Guo-qiang, LUO Yao-yao, CHEN Shuang, WANG Lei, and ZHAO Jian-kun
The X-ray Fluorescence Analysis(XRFA) is an important and efficient method on the element anylsis and is used in geology,industry and environment protection.But XRFA has a backdraw that the determination limit and accuracy are effected by the matrix of the sample.Now the fundamental parameter is usually used to calculaThe X-ray Fluorescence Analysis(XRFA) is an important and efficient method on the element anylsis and is used in geology,industry and environment protection.But XRFA has a backdraw that the determination limit and accuracy are effected by the matrix of the sample.Now the fundamental parameter is usually used to calculate the content of elements in XRFA,and it is an efficient method if the matrix and net area of characteristic X-ray peak are obtained.But this is invalide in in-stu XRFA.Also the method of net area and the “black material” of sample are the key point of the fundamental parameter method when the Energy Dispersive X-ray Fluorescence Analysis(EDXRFA) method is used in the low content sample.In this paper a advanced fundamental parameter method is discussed.The advanced fundamental parameter method includes the spectra analysis and the fundamental parameter method,which inserts the overlapping peaks separation method into the iteration process of the fundamental parameter method.The advanced method can resolve the net area and the quantitative analysis.The advanced method is used to analyse the standard sample.Compare to the content obtained from the coefficient method,the precision of Cu,Ni and Zn is better than coeffieciency method.The result shows that the advanced method could improve the precision of the EDXRFA,so the advanced method is better than the coefficient method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2034 (2015)
Effect of Long-Term Fertilization on Organic Nitrogen Functional Groups in Black Soil as Revealed by Synchrotron-Based X-Ray Absorption Near-Edge Structure Spectroscopy
LI Hui, GAO Qiang, WANG Shuai, ZHU Ping, ZHANG Jin-jing, and ZHAO Yi-dong
Nitrogen(N) is a common limiting nutrient in crop production.The N content of soil has been used as an important soil fertility index.Organic N is the major form of N in soil.In most agricultural surface soils,more than 90% of total N occurs in organic forms.Therefore,understanding the compositional characteristics of Nitrogen(N) is a common limiting nutrient in crop production.The N content of soil has been used as an important soil fertility index.Organic N is the major form of N in soil.In most agricultural surface soils,more than 90% of total N occurs in organic forms.Therefore,understanding the compositional characteristics of soil organic N functional groups can provide the scientific basis for formulating the reasonable farmland management strategies.Synchrotron radiation soft X-ray absorption near-edge structure(N K-edge XANES) spectroscopy is the most powerful tool to characterize in situ organic N functional groups compositions in soil.However,to our most knowledge,no studies have been conducted to examine the organic N functional groups compositions of soil using N K-edge XANES spectroscopy under long-term fertilization practices.Based on a long-term field experiment(started in 1990) in a black soil(Gongzhuling,Northeast China),we investigated the differences in organic N functional groups compositions in bulk soil and clay-size soil fraction among fertilization patterns using synchrotron-based N K-edge XANES spectroscopy.Composite soil samples(0～20 cm) were collected in 2008.The present study included six treatments:farmland fallow(FALL),no-fertilization control(CK),chemical nitrogen,phosphorus,and potassium fertilization(NPK),NPK in combination with organic manure(NPKM),1.5 times of NPKM(1.5 NPKM),and NPK in combination with maize straw(NPKS).The results showed that N K-edge XANES spectra of all the treatments under study exhibited characteristic absorption peaks in the ranges of 401.2～401.6 and 402.7～403.1 eV,which were assigned as amides/amine-N and pyrrole-N,respectively.These characteristic absorption peaks were more obvious in clay-size soil fraction than in bulk soil.The results obtained from the semi-quantitative analysis of N K-edge XANES spectra indicated that the relative proportion of amides/amine-N was the highest in both bulk soil and clay-size soil fraction,and it was the most major forms in soil organic nitrogen functional groups.Compared with the FALL treatment,the relative proportion of amide/amine-N was lower whereas that of Pyrrole-N was higher in the CK treatment.In the treatments with combined chemical fertilizers and organic manure,the relative proportion of amide/amine-N decreased with increasing application rates of organic manure,while that of Pyrrole-N had an opposite trend.In bulk soil,the relative proportion of amide/amine-N was the highest for the NPKS treatment than for the other treatments.On the other hand,the relative proportion of nitrile/aromatic-N was the highest for the Fallow treatment than for the other treatments in clay-size soil fraction.It is feasible to use N K-edge XANES spectroscopy for characterizing in situ the changes of organic N functional groups in soil under different fertilization practices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2038 (2015)
Determination of 22 Elements in Herb Tea by X-Ray Fluorescence Spectrometry
LI Dan, GE Liang-quan, WANG Guang-xi, LAI Wan-chang, ZHAI Juan, and CHEN Lu
N,Na,Mg,Al,Si,P,S,Cl,K,Ca,Ti,Cr,Mn,Fe,Ni,Cu,Zn,Br,Rb,Sr,Ba and Pb in herb tea were determined by X-ray fluorescence spectrometry with pressed powder pellets.The measuring conditions of target elements were investigated,including how to select its analytical line.In addition to Ba and Pb using L line,Kα line was selecteN,Na,Mg,Al,Si,P,S,Cl,K,Ca,Ti,Cr,Mn,Fe,Ni,Cu,Zn,Br,Rb,Sr,Ba and Pb in herb tea were determined by X-ray fluorescence spectrometry with pressed powder pellets.The measuring conditions of target elements were investigated,including how to select its analytical line.In addition to Ba and Pb using L line,Kα line was selected for the rest.When the Compton scattered radiation of Rh Kα was measured,The X-ray tube voltage should be appropriately reduced,and the appropriate tube current should be selected.The matrix effect was corrected by empirical coefficient method and using scattered radiation(the Rayleigh scattered radiation of Rh Lα,the scattered background of 0.187 6 nm wavelength position and the Compton scattered radiation of Rh Kα) as internal standard,and the spectral overlapping interference of some elements(N,Na,Ca,Ti,Mn,Sr and Ba) was corrected.For the target elements,the detection limit of this method was low,and its accuracy and precision were high.The results showed that there were abandon of elements in herb tea,of which different kinds had different components,even the same kind of herb tea with different source had some difference in element and content more or less,however,there was a lot of similarity between the features of its components.In a word,this method could achieve multi-element determination of herb tea,and it was simple in operation,low cost,rapid,and accurate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2043 (2015)
Spectral Calibration of Space-born Imaging Spectrometers Using Spectrum-Matching Technique
ZHAO Min-jie, SI Fu-qi, LU Yi-huai, WANG Yu, WANG Shi-mei, JIANG Yu, ZHOU Hai-jin, and LIU Wen-qing
Spectral calibration of space-born imaging spectrometers based on spectrum-matching technique is presented,which adopts atmospheric absorption lines as the matching lines,and chooses correlation coefficient method as the criteria.In order to simulation the onboard spectral calibration,the spectrum-matching technique isSpectral calibration of space-born imaging spectrometers based on spectrum-matching technique is presented,which adopts atmospheric absorption lines as the matching lines,and chooses correlation coefficient method as the criteria.In order to simulation the onboard spectral calibration,the spectrum-matching technique is applied on the imaging spectrometers that after the vibration test.The vibration test is able to simulation the launching.The spectral resolution,center wavelength of two-dimensional pixel is determined during onboard spectral calibration.As the calibration results show,the spectral resolution of imaging spectrometers after the vibration test is 0.40 nm,it is the same comparing to the value before the vibration,the wavelength shifts 0.08 nm towards the long wave for the spectral pixels,and the spectral smile is determined for all spatial elements,which shifts towards the short wave direction,with the max smile value is 0.96 nm,the result is similar to that before the vibration.As a result,the spectrum-matching technique is tested and verified..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2049 (2015)
Based on Trigger Sampling Method and Phase Correction of Infrared Spectrum Measurement Applications
LI Yan, GAO Min-guang, XU Liang, LI Sheng, LI Xiang-xian, YE Shu-bin, and LIU Jian-guo
Fourier transform infrared spectrometer can be realized in high temperature flue gas multicomponent measurement at the same time,has wide application prospects in the field.And one of the important factors to determine the success of application,lies in the measuring system of infrared interference figure sampling phasFourier transform infrared spectrometer can be realized in high temperature flue gas multicomponent measurement at the same time,has wide application prospects in the field.And one of the important factors to determine the success of application,lies in the measuring system of infrared interference figure sampling phase error control.This paper discusses the main reasons of the appearance of phase error in the system,through the analysis of Helium-neon laser interference signal zero uniformity,illustrates the produce phase error is the main reason of the laser signal and reference signal phase difference.At the meantime,the quantitative analysis of the phase error influence on instrument signal to noise ratio(SNR),also the Mertz phase correction method for the instrument improves the thousands of times of the original signal to noise ratio.And the related experiment,the experimental results show that the system based on the interference figure sampling method satisfy the needs of high temperature flue gas measurements..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2054 (2015)
Design of Dual-Beam Spectrometer in Spectrophotometer for Colorimetry
LIU Yi-xuan, and YAN Chang-xiang
Spectrophotometers for colorimetry are usually composed of two independent and identical spectrometers.In order to reduce the volume of spectrophotometer for colorimetry,a design method of double-beam spectrometer is put forward.A traditional spectrometer is modified so that a new spectrometer can realize the function Spectrophotometers for colorimetry are usually composed of two independent and identical spectrometers.In order to reduce the volume of spectrophotometer for colorimetry,a design method of double-beam spectrometer is put forward.A traditional spectrometer is modified so that a new spectrometer can realize the function of double spectrometers,which is especially suitable for portable instruments.One slit is replaced by the double-slit,than two beams of spectrum can be detected.The working principle and design requirement of double-beam spectrometer are described.A spectrometer of portable spectrophotometer is designed by this method.A toroidal imaging mirror is used for the Czerny-Turner double-beam spectrometer in this paper,which can better correct astigmatism,and prevent the dual-beam spectral crosstalk.The results demonstrate that the double-beam spectrometer designed by this method meets the design specifications,with the spectral resolution less than 10 nm,the spectral length of 9.12 mm,and the volume of 57 mm×54 mm×23 mm,and without the dual-beam spectral overlap in the detector either.Comparing with a traditional spectrophotometer,the modified spectrophotometer uses a set of double-beam spectrometer instead of two sets of spectrometers,which can greatly reduce the volume.This design method can be specially applied in portable spectrophotometers,also can be widely applied in other double-beam spectrophotometers,which offers a new idea for the design of dual-beam spectrophotometers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 2060 (2015)
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