Journals >Spectroscopy and Spectral Analysis
Contents
2018
Volume: 38 Issue 4
55 Article(s)
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Study on the Spectral Features of Space-Borne Aluminum Diffuser
CHANG Zhen, ZHAO Min-jie, WANG Yu, SI Fu-qi, ZHOU Hai-jin, and LIU Wen-qing
Imaging spectrometer uses a space-borne diffuser to obtain solar reference spectrum. The spectral features of space-borne diffuser will be introduced to the solar reference spectrum. The spectral features that interferes the gas absorption structure influence the inversion precision of gases. The causes of spectral strImaging spectrometer uses a space-borne diffuser to obtain solar reference spectrum. The spectral features of space-borne diffuser will be introduced to the solar reference spectrum. The spectral features that interferes the gas absorption structure influence the inversion precision of gases. The causes of spectral structure of aluminum diffuser is analyzed, and the spectral structures in the observation angle ［15°, 40°］ are measured in laboratory. The results show that the spectral structuse increases with wavelength: 450～600 nm, the spectral structure is 0.2%～0.6%； 600～750 nm, the spectral structure is 0.3%～1.6%. Spectral structure reduction method is discussed. The spectral structure can be reduced about 76% by smoothing the spectrum of aluminum diffuser..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 997 (2018)
Theoretical Study of Ro-Vibrational Spectrum of CO Molecule
ZHANG Xue-fu, L Bing, SONG Xiao-shu, and LINGHU Rong-feng
The potential energy curve (PEC) and dipole moment curve (DMC) for the ground state (X1Σ+) of CO molecule have been computed using the multi-reference configuration interaction (MRCI) method with aug-cc-pCVQZ basis sets. Results showed that the calculated PEC, DMC are in accord with RKR, reference, respectively. With tThe potential energy curve (PEC) and dipole moment curve (DMC) for the ground state (X1Σ+) of CO molecule have been computed using the multi-reference configuration interaction (MRCI) method with aug-cc-pCVQZ basis sets. Results showed that the calculated PEC, DMC are in accord with RKR, reference, respectively. With the potential energy obtained at the MRCI/aug-cc-pCVQZ level of theory, 70 vibrational states (J=0) of the ground state of CO molecule are obtained by numerically solving the radical Schrdinger equation of nuclear motion. For each vibrational state, the vibrational energy levels G(v), the inertial rotation constants Bv and the centrifugal distortion constants Dv are reported, which accord well with the experimental values. The inertial rotation constants Bv, vibrational energy levels G(v) were fitted to determine spectroscopy constants, which the rotation coupling constant ωe(2 160.1 cm-1), the anharmonic constant ωeχe(13.3 cm-1), the equilibrium rotation constant Be(1.931 cm-1) and the vibration-rotation coupling constant αe(0.017 5 cm-1) are in good agreement with the experiment data ［ωe(2 169.8 cm-1), ωeχe(13.3 cm-1), Be(1.931 cm-1), αe(0.017 5 cm-1)］, it is evident that MRCI/Aug-cc-pCVQZ is reliable for the calculation for the ground state of CO molecule. The line intensity of 1-0 transition band for the ground state of CO molecule is calculated by directly calculating the partition function at 296 K, the agreement between the calculated line intensity data and the data in HITRAN database is fairly good at 296 K. Band intensities of 1-0, 2-0, 3-0, 4-0, 2-1, 3-1, 4-1 bands are calculated for the ground state of CO molecule, which are in better agreement with the experimental values. Therefore, the line intensities and band intensities of 3-2 transition band, 4-2 transition band are firstly calculated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1001 (2018)
Spectroscopic Diagnostics on Discharge Characteristics of RF Capacitive Coupled Plasma
LIU Chong, HE Xiang, ZHANG Ya-chun, CHEN Jian-ping, CHEN Yu-dong, ZENG Xiao-jun, CHEN Bing-yan, and ZHU Wei-hua
A method of combiningthe fluid model simulation and the emission spectrum was used to study the discharge characteristics of Radio-frequency (RF) capacitive coupled plasma in medium pressure and medium power. In theory, one-dimensional discharged plasma model is taken using COMSOL software based on the fluid model. TheA method of combiningthe fluid model simulation and the emission spectrum was used to study the discharge characteristics of Radio-frequency (RF) capacitive coupled plasma in medium pressure and medium power. In theory, one-dimensional discharged plasma model is taken using COMSOL software based on the fluid model. The distributions of electron temperature and electron density of plasma were studied under different air pressures and different radio-frequency powers with the Ar gas as the working gas. In experiment, a glass sealed cavity and a pair of plate electrodeswere designed and fabricated with the same sizes of the simulation model. Using 13.56 MHz radio frequency discharge technology to ionize the working gas of Ar gas in the cavity. The emission spectra of discharge plasma at different pressures and different RF input powers were measured. Through the analysis and selection of suitable spectral lines of ArⅠ and ArⅡ, the electron temperature and electron density of the plasma were calculated by the Boltzmann method and the Shah-Boltzmann equation, respectively. And then these results of spectral diagnosis were modified by combining with simulation results. The results show that when the gas pressure is 300~400 Pa and the radio-frequency power is 600~800 W, the plasma satisfy the Boltzmann distribution approximately. The plasma parameters obtained by the spectroscopic method are in agreement with the simulation results. The discharge parameters of the plasma under the medium pressure can be diagnosed by the method of combing the fluid model simulation and the emission spectrum, which provides a reference for the following study about the plasma properties. The method combining the fluid model simulation and the experimental spectrum diagnosis can be used to diagnose the plasma discharge parameters at medium pressure and medium power, which increases the range of use in plasma discharge in the Boltzmann slope method and the Saha-Boltzmann equation, and expands the application of spectroscopy in low electron density capacitive coupled plasma diagnostics. Also it provides an important physical state analysis for the study of medium pressure capacitive coupled plasma in industrial and military applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1007 (2018)
A Rapid and Accurate Optimizing Algorithm for IPDA Lidar Data Inversion
MA Hui, LIU Dong, LI Wen-feng, LIAO He, XIE Chen-bo, WANG Zhen-zhu, WANG Bang-xin, HUANG Jian, and WANG Ying-jian
Influences of Lorentz shape instead of Voigt shape on airborne CO2 column ratio precision measurement in integrated path differential absorption (IPDA) lidar are studied in this paper. The differences of temperature and pressure sensitivity, and relative random error between two line shapes with the platform height areInfluences of Lorentz shape instead of Voigt shape on airborne CO2 column ratio precision measurement in integrated path differential absorption (IPDA) lidar are studied in this paper. The differences of temperature and pressure sensitivity, and relative random error between two line shapes with the platform height are investigated by model simulation. The result shows that, there are small differences between two line shapes in the bottom atmosphere for absorption cross-section, temperature and pressure sensitivity, and relative random error, which are 0.860%, -0.703% and 0.224% respectively, while the time of computation of spectral parameters can be effectively reduced by using Lorentz shape. The airborne IPDA lidar using Lorentz shape can provide rapid and efficiency ability to retrieve CO2 column ratio along the flight track, lower requirement of system computational capability, retrieve and analyze data during flight and manage flight strategy on the emergency. Meanwhile it will further contribute to realize the miniaturization and integration of airborne lidar system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1014 (2018)
Inversion of Aerosol Optical Depth over Land Surface from Airborne Polarimetric Measurements
WANG Han, YANG Lei-ku, DU Wei-bing, LIU Pei, and SUN Xiao-bing
The diversity of land surfaceleads to an increase of the uncertainty in surface reflectance calculation, whichreduces theaccuracy of land-atmospheric decoupling, and then of the aerosol retrieval. The multi-spectral, multi-angle and polarized information, which can be provided by the Atmosphere Multi-angle PolarizationThe diversity of land surfaceleads to an increase of the uncertainty in surface reflectance calculation, whichreduces theaccuracy of land-atmospheric decoupling, and then of the aerosol retrieval. The multi-spectral, multi-angle and polarized information, which can be provided by the Atmosphere Multi-angle Polarization Radiometer (AMPR), is helpful to solve the problem. The behavior of aerosol scattering amongdifferent wavelengths is smooth. At the same time the land surface polarized reflectance does not show any dependence in the measurement bands. Based on these conclusions, we developed a method to separate land surface and atmosphericradiation by successive atmospheric correction. Further on, the aerosol retrieval algorithm was build. In the algorithm, the aerosol optical thickness was retrieved at 665 and 865 nm, while thesurface polarized reflectance was reobtained at 1 640 nm by atmospheric correction. The atmospheric correction (1 640 nm) and aerosol retrieval (665 and 865 nm) form a cycle. Then, an iteration method was employed and it approaches to the real radiant values of atmosphere and land surface step by step. At last, we retrieved aerosol optical depth from a look-up table which was builtby 6 fine and 6 coarseaerosol modes. The AMPR have performedat least 5 flights mission over Beijing, Tianjin and Tangshan region. Data of theseobservations were used to verify the algorithm and it was found that the AOD retrieved from AMPR and CE318 have good coherence. When the AOD is lower than 0.5, the average deviation is below 0.03..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1019 (2018)
Remote Sensing of Particle Mass Concentration Using Multi-Wavelength Lidar
RAO Zhi-min, HE Ting-yao, HUA Deng-xin, and CHEN Ruo-xi
A novel method for particulate matter mass concentration measurement has been proposed based on a multi-wavelength lidar covering the ultraviolet to the near infrared spectra. The proposed method combined extinction coefficients at working wavelengths with quantity of mass extinction efficiency (MEE), which is defined A novel method for particulate matter mass concentration measurement has been proposed based on a multi-wavelength lidar covering the ultraviolet to the near infrared spectra. The proposed method combined extinction coefficients at working wavelengths with quantity of mass extinction efficiency (MEE), which is defined as the ratio of extinction coefficient and mass concentration of particulate matter in unit volume, makes the mass concentration of particulate matter retrievable. To determine the values of the MEE, a mathematical model was developed based on the extinction efficiency data of certain wavelength reported with the Mie theory and the particle size distribution data derived from a multi-wavelength lidar. Retrieved results of mass concentration from two experimental cases with clear and fog/haze weather conditions, which s in line with the monitoring results at the ground level reported by the Environmental Agency. The proposed method invert the recent problem on aerosol sources monitoring and open new lidar capabilities on atmospheric research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1025 (2018)
Calibration Method of Pressure Gauges Based on Cavity Ring-Down Spectroscopy Technique
ZHOU Sheng, HAN Yan-ling, and LI Bin-cheng
The accurate measurement of pressure is of great importance to industry process control. In absorption spectroscopy, the spectral line profile and line-width of gas depend on the molecular interactions, temperature, pressure and other factors. The pressure induced line- broadening effect of narrow-band absorption linesThe accurate measurement of pressure is of great importance to industry process control. In absorption spectroscopy, the spectral line profile and line-width of gas depend on the molecular interactions, temperature, pressure and other factors. The pressure induced line- broadening effect of narrow-band absorption lines of gases can be used for pressure measurement and calibration. A novel pressure gauge calibration method based on cavity ring-down spectroscopy (CRDS) and pressure induced line-broadening effect is presented and experimentally demonstrated at room temperature with a CRDS setup employing a 5.2 μm tunable quantum cascade laser and an absorption line of trace moisture in air near 1 877 cm-1 wavenumber. The measured line-width is 0.084 21 cm-1, and the corresponding pressure is 98.12 kPa, which is in good agreement with a high-precision pressure gauge reading 98.14 kPa. A pressure measurement limit of 0.18 kPa is achieved, estimated from the line-width measurement uncertainty. In addition, the measured pressure broadening coefficient is (0.087 12±0.000 965) cm-1·atm-1, which is in good agreement with the reference value 0.087 1 cm-1·atm-1 given by HITARN database at the same temperature. The proposed method is applied to calibrate a small-scale pressure gauge with sufficient accuracy. The results indicate that high-resolution measurement of absorption line based on CRDS has the potential for high-accuracy pressure measurement and calibration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1031 (2018)
The Thermal Variation Behavior of “Water” in Nominally Anhydrous Jadeite Mineral
XING Ying-ying
Take the nominally anhydrous jadeite mineral in jadeitite as research objects, useing FTIR with normal temperature and heterotherm, to analyse representation of structure water and thermal variation behavior of jadeite. The result shows: Representation of FTIR of M—OH stretching vibration concentrates mainly on four arTake the nominally anhydrous jadeite mineral in jadeitite as research objects, useing FTIR with normal temperature and heterotherm, to analyse representation of structure water and thermal variation behavior of jadeite. The result shows: Representation of FTIR of M—OH stretching vibration concentrates mainly on four areas, 3 700～3 600, 3 570～3 520, 3 500～3 300 and 3 230～3 140 cm-1, but with different characterization in different jadeite. In the process of varying temperature, the relative absorption intensity of absorption band in 500 ℃ decreased obviously, and the content of structure water gradually decreased, further characterization of the “water” in jadeite minerals is in the form of structure water. But the absorption spectrum caused by M—OH stretching vibration, the content of structure water and fingerprint spectra near 850 ℃ changesobviously, indicating that the temperature of jadeite mineral composition has mutated. The thermal variation behavior of “water” in jadeite mineral provides some evidence in order to further understand the occurrence state and binding mode of water and diagenetic mechanism..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1036 (2018)
Detection of Adsorption for Heavy Metals Ions Based on Terahertz Time Domain Spectroscopy
YAN Fang, ZOU Liang-hui, and WANG Zhi-chun
With the continuous progress of industrialization, heavy metal pollution in water is becoming more and more serious. Straw has many advantages such as wide availibility, low cost and easy production, which makes it an ideal biological adsorbent to deal with heavy metal pollution.In order to study the application prospeWith the continuous progress of industrialization, heavy metal pollution in water is becoming more and more serious. Straw has many advantages such as wide availibility, low cost and easy production, which makes it an ideal biological adsorbent to deal with heavy metal pollution.In order to study the application prospect of terahertz wave technology in the detection of heavy metal pollution in water body, original straw and alkaline straw were selected to absorb heavy metal ions. Terahertz time-domain spectroscopy (THz-TDS) was utilized at a room temperature under nitrogen atmosphere to conduct spectral measurement for original straw samples, alkaline straw samples, samples of original straw with heavy metal ions absorbed, samples of alkaline straw with heavy metal ions absorbed, and samples of desorbed alkaline straw. The absorption coefficient of the alkali-treated straw under 1.75~1.85 THz hybrid absorption peak band was significantly decreased, accompanied by an acromion backward shifting phenomenon of the absorption band. After absorbing heavy metal ions, the intrinsic 1.75~1.85 THz hybrid absorption band was disappeared in original straw samples, but formed a hybrid absorption band in the range from 1.8 to 2.05 THz. Alkaline straw in 1.7~2.05 THz presented a number of complex acromino-absorption, while heavy metal ions absorbed alkaline straw showed a smooth and strong absorption band in 1.7~2.05 THz. In addition, the absorption spectrum of the hydrolyzed heavy metal ion absorbed alkaline straw was nearly parallel. Though integrating the chemical reaction process of the samples, absorption spectrum was analyzed, and the information of molecular vibration and functional group of different components were gained. Furthermore, the conclusion that complex adsorption and electrostatic adsorption are the two methods for alkaline straw to absorb heavy metal can be drawn. It proved the reliability and good application prospect of the terahertz time-domain spectroscopy on detecting heavy metal pollution in water..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1044 (2018)
Moisture Content Determination of Transformer Oil by Using Terahertz Time-Domain Spectroscopy
JIANG Qiang, WANG Yue, WEN Zhe, and WANG Ji-hua
The maintenance of the transformer is more and more important and the analysis of moisture content in transformer oil has become a very important part of transformer maintenance. Water is known as a strong absorber for THz radiation due to its distinctive intermolecular vibration in this frequency range. In the presentThe maintenance of the transformer is more and more important and the analysis of moisture content in transformer oil has become a very important part of transformer maintenance. Water is known as a strong absorber for THz radiation due to its distinctive intermolecular vibration in this frequency range. In the present work, we analyzed transformer oils regarding their water content by THz spectroscopy. Based on THz time-domain spectroscopy, information about the absorption coefficient and the refractive index of the oil samples is provided. By comparing the results with relevant theories we demonstrate that both the absorption coefficient and the refractive index are linearly related to the concentration of water in the oil solutions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1049 (2018)
An Outlier Determination Method for Near-Infrared Spectroscopy Based on the Simplified Orthogonal Distance
MENG Dan-rui, FU Bo, XU Ke-xin, and LIU Rong
Fast detecting and eliminating the outliers is of great significance to improve the reliability of the near-infrared(NIR) spectroscopy analysis. In this paper, the principle of outlier determination method based on orthogonal distance and robust principal component analysis was introduced firstly with the analysis of iFast detecting and eliminating the outliers is of great significance to improve the reliability of the near-infrared(NIR) spectroscopy analysis. In this paper, the principle of outlier determination method based on orthogonal distance and robust principal component analysis was introduced firstly with the analysis of its limitations. Then an outlier determination method based on the simplified orthogonal distance was proposed, where the spectra of the samples with high concentration were employed to estimate the first robust principal component directly and the statistical parameters of the orthogonal distance were obtained with repeated measurements to detect outliers. Finally, the outliers caused by the temperature fluctuations in the NIR transmission spectra of glucose aqueous solutions and 2% Intralipid solutions, were determined by these two methods. Results showed that, for the orthogonal distance combined with robust principal component analysis method, all the outliers induced by temperature variations could be correctly determined under the collapse value of 40%, while the false negative rates for the glucose aqueous solutions and Intralipid solutions under the collapse value of 25% were 54.5% and 72.7%, respectively. Besides, all the outliers induced by temperature variations also could be recognized with the method based on the simplified orthogonal distance, which saves the need for collapse value and shortens the tine for measurement. Therefore, the outlier determination method based on the simplified orthogonal distance is more practical than the robust principal component analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1053 (2018)
Infrared and Raman Spectra of High-Quality Turquoises from Hubei and Anhui, China: Characteristics and Significance
CHEN Wen-jun, SHI Guang-hai, WANG Yan, REN Jia, YUAN Ye, and DAI Hui
Recently, attentions has been paid to the origin of high-quality turquoise. However, few researches of spectroscopic characteristics of them have been performed to differentiate its original location. Although the general characteristics of spectra are resembled for Qingu, Wenfeng (Hubei province) and Bijiashan (Anhui Recently, attentions has been paid to the origin of high-quality turquoise. However, few researches of spectroscopic characteristics of them have been performed to differentiate its original location. Although the general characteristics of spectra are resembled for Qingu, Wenfeng (Hubei province) and Bijiashan (Anhui province) turquoises, minute difference can be observed among them. Infrared spectra of the studied samples in this investigation show that peak near 783 cm-1 caused by OH bending vibration of turquoise from Qingu separates into two peaks, 797 and 779 cm-1. While the peak appears at 787 cm-1 for turquoises from Wenfeng and 783 cm-1 for the ones from Bijiashan. Intensity ratios of infrared absorption peaks at 783 and 837 cm-1(R=I783 cm-1/I837 cm-1) are different among them, more than 0.98 in samples from Qingu, 0.85 from Wenfeng and 0.93 from Bijianshan samples. Infrared band at 609 cm-1, which is related to the ν4(PO4) stretching vibrations, is quite obvious and sharp of Wenfeng samples, appears wider and less sharp of Qingu samples, while for Bijiashan sample, is the most plane. Peaks in Raman spectra around 3 500 cm-1 are different among the three locations, namely 3 506 and 3 505 cm-1 for samples from Bijiashan, 3 495 to 3 500 cm-1 for samples from Hubei province. Peak intensity around 3 472 cm-1 of turquoise from Bijiashan is larger than those from Hubei with the same situation occurring at peak ~551 cm-1. These findings, combining with appearance of the turquoises, can be used as important spectroscopic characteristics to recognize origins of the high-quality turquoises, which also have potential important implications in archaeology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1059 (2018)
Studies on Dimensional Stability of Wood under Different Moisture Conditions by Near Infrared Spectroscopy Technology
WANG Li-shuang, ZHANG Wen-bo, and TONG Li
Relationship between wood and moisture content has always been a focus in wood science research field. Shrinkage or swelling that affects dimensional stability of wood occurs while moisture content changes. The problem is closely related to the end use of wood. Generally wood deformation is mainly depend on polysaccharRelationship between wood and moisture content has always been a focus in wood science research field. Shrinkage or swelling that affects dimensional stability of wood occurs while moisture content changes. The problem is closely related to the end use of wood. Generally wood deformation is mainly depend on polysaccharides of wood chemical composition containing hydroxyl and water to form hydrogen bonding. Near-infrared spectroscopy (NIR) with a high sensitivity to organic materials containing hydrogen groups will be a useful tool to realize on-line rapid detection on shrinkage or swelling of wood. Relationships between moisture contents and size changes of wood were investigated in this research by using NIR technology, furthermore the predicted models of size changes induced by moisture content were built. The near infrared spectra coupled with chemometric techniques were collected on three sections of wood. Prediction models of size change of wood were constructed on base of partial least squares and corresponding cross-validation. The results showed that size changes of wood in tangential and radial section under several different moisture contents had a high correlation with the corresponding near infrared spectra. It is feasible to detect size change of wood by NIR. On the other hand determine coefficients (R2) of prediction models in tangential and radial direction are over 0.90, which are satisfactory to predict wood deformation under different moisture content conditions. Additionally the prediction model of size change in tangential is better than that of in radial direction. The above results showed size changes induced by moisture content could be predicted quickly and accurately by NIR technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1066 (2018)
Feature Wavelength Selection and Efficiency Analysis for Paddy Moisture Content Prediction by Near Infrared Spectroscopy
HUANG Hua, WU Xi-yu, and ZHU Shi-ping
In order to obtain the best feature wavelength region for predicting paddy moisture content (PMC) by near infrared spectroscopy (NIR), this research selected 364 paddy samples of “Gangyou 916” which moisture content varied from 32.66% to 2.24%, the pretreatments methods such as mean centering (Mean), standard normalizeIn order to obtain the best feature wavelength region for predicting paddy moisture content (PMC) by near infrared spectroscopy (NIR), this research selected 364 paddy samples of “Gangyou 916” which moisture content varied from 32.66% to 2.24%, the pretreatments methods such as mean centering (Mean), standard normalized variate (SNV), Savitzky-Golay derivative (SG1) and multiplicative scatter correction (MSC) were performed, and adopted the feature wavelengths selection methods include interval method (IM), synergy interval method (SIM), moving window method (MWM) and backward interval method (BIM), then used partial least squares (PLS) and principal component regression (PCR) quantitative analysis algorithms for the PMC NIR modeling. The calculation formulas of complexity for wavelengths selection methods with IM, SIM, MWM and BIM are firstly provided in this paper. And this paper also compares and analyzes the program operating efficiency of these methods. The results show that the prediction ability of PLS is better than PCR, but the modeling efficiency of PLS is lower than PCR. The BIM is the optimum prediction model for PMC among the four wavelengths selection methods, which root mean square error of prediction (RMSEP) and correlation coefficient (Rp) in prediction set are 0.995 6 and 0.78%, respectively. The second is MWM, which RMSEP and RP are 0.994 3 and 0.89%, respectively. However, the program running efficiency of these two methods is relatively low. The average running time of BIM is 4.87 h, and average running time of MWM is 29.82 h. This work provided a reference comparison for a fast algorithm of near infrared spectroscopy prediction model in parallel computing and distributed computing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1070 (2018)
Feasibility Analysis of Rapid Estimation of Soil Erosion Factor Using Vis-NIR Spectroscopy
YU Wu, JIA Xiao-lin, CHEN Song-chao, ZHOU Lian-qing, and SHI Zhou
Soil erosion reduces the productivity of the soil, leading to the deterioration of soil environment. Water erosion is one of the most important forms of soil erosion. Soil erodibility K value is an important indicator to evaluate soil susceptibility to erosion, the aim of this paper is to evaluate whether Vis-NIR can bSoil erosion reduces the productivity of the soil, leading to the deterioration of soil environment. Water erosion is one of the most important forms of soil erosion. Soil erodibility K value is an important indicator to evaluate soil susceptibility to erosion, the aim of this paper is to evaluate whether Vis-NIR can be used in predicting K value as a rapid method. Soil samples were sampled from Henan, Fujian and Zhejiang provinces, after air-drying and grinding, visible-near infrared (Vis-NIR) diffuse reflectance spectra were measured. Then, soil reflectance spectra were transformed to absorbance spectra and Savitzky-Golay (SG) algorithm was used to eliminate noise. Data mining methods were used to predict soil organic matter (SOM) and soil texture with Vis-NIR spectra, then K values were estimated with EPIC and RUSLE2 models based on predicted SOM and soil texture. The results were as follows: (1) The prediction models with the highest performance were obtained about the SOM and soil texture (sand, silt and clay), the best model for soil texture prediction gained from support vector machine (SVM) model and the best SOM result was performed using locally weighted regression (LWR) model, of which the ratio of performance to inter-quartile distance (RPIQ) was 2.27, 3.17, 2.18 and 3.44 for sand. Silt, clay and SOM. (2) Based on predicted soil texture, the classification accuracy for grade of soil permeability was good (Kappa coefficient was 0.62), and the spatial distribution between predicted values and measured values was similar in soil texture triangle, of which the main types were silty clay, sandy clay loam, loam, loamy sand and sandy loam. (3) The EPIC and RUSLE2 models both had the accurate prediction ability. EPIC model performed better than RUSLE2 model, of which root mean square error of prediction (RMSEP) was 0.006 6 (t·ha·h)/(ha·MJ·mm) and RPIQ reached 1.58, while the accuracy of RUSLE2 model was lower (RPIQ is 1.43). Therefore EPIC model was recommended to estimate K values in combination with Vis-NIR spectroscopic technique. This study presents the potential for estimating soil erodibility K values using Vis-NIR spectroscopy, which provides supplementary method for monitoring soil erosion in large area..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1076 (2018)
Model Transfer of On-Line Pilot-Scale Near Infrared Quantitative Model Based on Orthogonal Signal Regression
WANG An-dong, WU Zhi-sheng, JIA Yi-fei, ZHANG Ying-ying, ZHAN Xue-yan, and MA Chang-hua
Model established under a certain condition can be applied to the new samples, environmental conditions or instrument status through the model transfer. In the process of pilot-on-line water extraction of Flos Lonicerae Japonicae, the content of chlorogenic acid is measured with High Performance Liquid Chromatography (Model established under a certain condition can be applied to the new samples, environmental conditions or instrument status through the model transfer. In the process of pilot-on-line water extraction of Flos Lonicerae Japonicae, the content of chlorogenic acid is measured with High Performance Liquid Chromatography (HPLC) as a reference method, and a NIR quantitative model of chlorogenic acid is established by partial least square regression (PLSR)。 In order to solve the problem of model’s failure to predict accurately the content of chlorogenic acid in the samples of Flos Lonicerae Japonicae from different sources, the KS algorithm is used to select the representative samples from samples to be transferred, orthogonal signal regression (OSR)algorithm is used to correct the NIR spectral background of the samples from different sources. And deeply discussing how the OSR worked in the model transfer from different sources. After the model transferred, the RSEP of transferred model predicting the new batch samples decreases from 14.91% to 7.11%, RPD rises from 2.95 to 5.36, indicating the obvious improvement of prediction accuracy. The results show that the model transfer method which combines the KS algorithm with OSR can diminish the spectral background variation between the samples of different sources effectively, because it not only reduces the accidental errors of the spectral background from the pharmaceutical raw materials from different sources, but also eliminates the system errors in the preparation process of pilot-on-line water extraction and the OSR algorithm. Based on this, it could correct model failure caused by different sample sources. This paper explains the application principle of OSR. Make NIR model to be transferred between the pilot samples which medicinal raw material come from different sources by spectral background and selecting the representative samples regression. Strengthen the model’s adjustment with the batch variations of medicinal raw material and improve the robustness of the NIR quantitative model. It will provide a method for the rapid and on-line detection of the active ingredient content of multi-sources samples during the process of pilot-on line water extraction, and promote the application of NIR quantitative model in the preparation process of TCM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1082 (2018)
Study of Maize Haploid Identification Based on Oil Content Detection with Near Infrared Spectroscopy
LI Hao-guang, YU Yun-hua, PANG Yan, and SHEN Xue-feng
At present, oil content difference between Haploid and diploid was used to identify haploid in maize breeding with NMR quantitative analysis. The method has been applied in the practical work, but NMR method is slow, expensive and difficult to maintain etc. It hindered its application in haploid breeding. NIR(Near infrAt present, oil content difference between Haploid and diploid was used to identify haploid in maize breeding with NMR quantitative analysis. The method has been applied in the practical work, but NMR method is slow, expensive and difficult to maintain etc. It hindered its application in haploid breeding. NIR(Near infrared) spectroscopy technology has been widely used in petroleum, food, medicine and other fields due to its nondestructive, convenient advantages. The NIR qualitative analysis to identify Maize Haploid seeds also achieved a certain effect, but maize varieties used in NIR qualitative method in past research for identification is relatively small, for some varieties the recognition effect is not good. The internal mechanism of NIR qualitative analysis is similar to the black box, therefore it is difficult to distinguish content difference between haploid or diploid seeds, so it is difficult to get the approval of agricultural experts in the field. According to the principle of Xenia effect, there are obvious differences between oil content of Haploid and diploid, the oil identification principle is easy to understand intuitively. Therefore, a NIR quantitative analysis method for the identification of haploid maize is proposed. The experimental results show that the precision of NIR quantitative analysis method and NMR method are very close, under same condition, compared with several qualitative methods, recognition rate of NIR quantitative analysis method is superior to several qualitative analysis, which further proved that NIR quantitative analysis method has certain advantages. The method proposed can meet the requirements of precision of maize breeding industry, and it can boost the progress of maize breeding research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1089 (2018)
Discrimination of Transgenic Maize Containing the Cry1Ab/Cry2Aj and G10evo Genes Using Near Infrared Spectroscopy (NIR)
PENG Cheng, FENG Xu-ping, HE Yong, ZHANG Chu, ZHAO Yi-ying, and XU Jun-feng
Genetic engineering technique has made rapid strides in the past decades, however, the potential problems of this technique for environmental, ethical and religious impact are unknown. It is necessary to research on the detection of genetically modified organisms in agricultural crops and in products derived. In the prGenetic engineering technique has made rapid strides in the past decades, however, the potential problems of this technique for environmental, ethical and religious impact are unknown. It is necessary to research on the detection of genetically modified organisms in agricultural crops and in products derived. In the present study, Near infrared spectroscopy (NIR) combined with chemometrics was successfully proposed to identify transgenic and non-transgenic maize. Transgenic maize single kernel and flour containing both cry1Ab/cry2Aj-G10evo protein and their parent, non-transgenic ones were measured in NIR diffuse reflectance mode with spectral range of 900～1 700 nm. Savitzky-Golay(SG)was used to preprocess the selection spectral region with absolute noises. Two classification methods, partial least square (PLS) and support vector machine (SVM): were used to build discrimination models based on the preprocessed full spectra and the dimension reduction information extracted by principal component analysis (PCA). Discriminant results of transgenic maize kernel based on SVM obtained a better performance by using the preprocessed full spectra compared to PLS model. The SVM achieved more than 90% calibration accuracy, while the PLS obtained just about 85% accuracy. By applying the PCA dimension reduction of the NIR reflectance in conjunction with the SVM model, the discrimination of transgenic from non-transgenic maize kernel was with accuracy up to 100% for both calibration set and validation set. The correct classification for transgenic and non-transgenic maize flour was 90.625% using SVM based on preprocessed full spectra, although degration of exogenous gene and protein existed during the milling. The results indicated that INR spectroscopy techniques and chemometrics methods could be feasible ways to differentiate transgenic maize and other transgenic food..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1095 (2018)
Rapid Discrimination of the Different Processed Paris polyphylla var. yunnanensis with Infrared Spectroscopy Combined with Chemometrics
WU Zhe, ZHANG Ji, ZUO Zhi-tian, XU Fu-rong, WANG Yuan-zhong, and ZHANG Jin-yu
Based on the theory of Chinese medicine, the processing which improves efficacy, property and flavor of traditional Chinese medicine (TCM) is an effective way to moderate property, enhance therapeutic effect or reduce toxicity of TCM. The processing has significant influence on the chemical components, efficacy and toxBased on the theory of Chinese medicine, the processing which improves efficacy, property and flavor of traditional Chinese medicine (TCM) is an effective way to moderate property, enhance therapeutic effect or reduce toxicity of TCM. The processing has significant influence on the chemical components, efficacy and toxicity of TCM. Therefore, it is vital to establish a system method to discriminate and evaluate different processed products of TCM, which can provide an important support for the quality and clinical medication security of TCM. In this paper, Paris polyphylla var. yunnanensis which were processed with nine different methods were conducted comparative analysis by infrared spectroscopy combined with chemometrics, and the principal component analysis-Mahalanobis distance (PCA-MD) discriminant model was established to differentiate them. The original infrared spectra data was preprocessed by automatic baseline correction and ordinate normalization, and the averaged spectra were obtained. The averaged and second derivative spectra showed that: (1) The main characteristic absorption peaks were 3 387, 2 923, 1 745, 1 463, 1 338, 1 240, 1 207, 1 158, 1 180, 1 080, 1 048, 1 020, 988, 921, 895, 859, 833, 765, 708, 572 and 529 cm-1. (2) The peak shape of samples was almost alike, which could exhibit the infrared spectral features of processed P. yunnanensis. (3) Some differences of a few characteristic absorption peaks existed in number, position and absorption intensity, which indicated that the chemical components and content were changed after different processing. The infrared spectra data was pretreated by multiplicative scatter correction (MSC), standard normal variate (SNV), first derivative (1st Der), second derivative (2nd Der) and Savitzky-Golay (SG) smoothing. Samples were divided into calibration set and prediction set at the ratio of 3∶1 by Kennard-Stone algorithm. Then, the optimized spectra data were used to establish the discrimination model based on PCA-MD. The results showed that the best spectral pretreatment of PCA-MD model was 1st Der+SG (11∶3). The cumulative accounting was 88.2%, when extracted the first five principal components. The first three principal components were selected for establishing the 3D scattered plot of PCA-DA model. It is obvious that samples with different processed methods could be grouped completely. The clustering result of P. yunnanensis I, H, G and F were better than others, and the first three (I, H and G) were nearer. It indicated that the chemical composition of processing by sun-drying and oven drying were similar to traditional processing method. Additionally, P. yunnanensis D was close to P. yunnanensis E, it conjectured that chemical compositions of processing by microwave drying and steam treatment were similar. The prediction set could accurately conform to the calibration set, and the accuracy of PCA-MD model was 100%. Infrared spectroscopy combined with PCA-MD could distinguish different processed P. yunnanensis accurately. Furthermore, it could provide references for clinical application, discriminating of processed P. yunnanensis as well as other processed TCM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1101 (2018)
Experimental Investigations on the Hydrogen Isotope Fractionation between Benzene and Heavy Water with in-situ Raman Spectrograph
WANG Shi-xia, ZHAO Hao-chen, WU Jia, and ZHENG Hai-fei
Hydrothermal diamond-anvil cell and Raman spectrograph were used to measure the hydrogen isotope fractionation factor between benzene and heavy water at high P-T condition. The isotope fractionation factor is determined when the isotope fractionation between phases reached equilibrium. This research shows that hydrogenHydrothermal diamond-anvil cell and Raman spectrograph were used to measure the hydrogen isotope fractionation factor between benzene and heavy water at high P-T condition. The isotope fractionation factor is determined when the isotope fractionation between phases reached equilibrium. This research shows that hydrogen isotope fractionated easily between benezene and water, different from hydrogen isotope fractionation betweenwater and n-alkanes or cycloalkanes. In this study, benzene was dispersed to many small particles, indicating the increasing contacting area to heavy water when temperature reached 300 ℃. Sufficient heating time enabled that stable isotope phases to reach the fractionation equilibrium. The ratio of Raman peak intensities and ratio of corresponding amount of substances is linearly correlated. The calculated hydrogen isotope fractionation factors between benzene and heavy water is 0.909 9 at 300 ℃. Taken together, it is feasible to determine the stable isotope fractionation factor between liquid phases with Hydrothermal Diamond-Anvil Cell combining with Raman spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1107 (2018)
Study on ［M(H2O)n］+(M=Li, K) Hydrated Clusters by Mass and Raman Spectra
WU Xiao-jing, LIU A-zuan, YU Xue-hui, and CHENG Long-jiu
［M(H2O)n］+(M=Li, K) hydrated clusters have been studied by Mass spectra, Raman spectra and the theoretical calculation. ［M(H2O)n］+(M=Li, K) hydrated clusters ion peaks could be obtained by Mass spectra, which could speculate that their maximum hydration numbers are 12 and 13 in their aqueous solution respectively. The ［M(H2O)n］+(M=Li, K) hydrated clusters have been studied by Mass spectra, Raman spectra and the theoretical calculation. ［M(H2O)n］+(M=Li, K) hydrated clusters ion peaks could be obtained by Mass spectra, which could speculate that their maximum hydration numbers are 12 and 13 in their aqueous solution respectively. The same concentration gradient LiCl and KCl aqueous solutions of Raman spectra have been discussed and compared, the ~3 208 cm-1 Raman spectra of water structure had obvious changes because of the hydration of Li+ and K+. Between the 0～2.0 and 0～2.5 mol·L-1 concentration range of LiCl and KCl aqueous solution, respectively, their differential Raman spectra of ~3 208 cm-1 negative peak integral strength decreased in a linear, and hydration increased gradually. While concentration was more than 2.0 and 2.5 mol·L-1, the decrease of ~3 208 cm-1 negative peak integral strength deviated from linear relationship, and began to appear association. Theoretical calculation of structure and Raman spectra of ［M(H2O)n］+(M=Li, K) hydrated clusters showed that Li+ and K+ would form their second hydrated layer while n>4 and n>6 respectively, and O—H stretching vibration occurred blue shift, hydrogen bonding structures should been destroyed, thus was in agreement with the experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1112 (2018)
The Effect of Incident Laser Power on Raman Spectra and Photoluminescence Spectra of Silicon Nanowires
ZHANG Qiu-hui, GUO Zhuang-zhi, and FENG Guo-ying
Silicon nanowires is one of key photoelectric materials. In this paper, silicon nanowires have been fabricated by chemical vapor deposition, the Raman spectra and photoluminescence spectra excited by 532 nm laser have been studied, first-order Raman peaks were found to red shift and broaden with the increase of incidenSilicon nanowires is one of key photoelectric materials. In this paper, silicon nanowires have been fabricated by chemical vapor deposition, the Raman spectra and photoluminescence spectra excited by 532 nm laser have been studied, first-order Raman peaks were found to red shift and broaden with the increase of incident power, photoluminescence blueshifted to shorter wavelength and another peak appeared. The experiment results were analyzed by phonon confinement effect, lattice stress, and nonuniform heating effect of laser, the relation between laser power and Raman shift simulated by Matlab, it was found that the nonuniform heating effect of laser is the main reason for Raman spectra and photoluminescence spectra change with incident power..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1118 (2018)
Rapid on-site TLC-SERS Detection of Four Sleep Problems Drugs Used as Adulterants in Health-Care Food
LI Jing-hui, CHENG Nao-nao, LIU Ji-cheng, LI Li, and JIA Shou-shi
A novel facile method for on-site detection of sleep problems chemicals (e. g. triazolam, estazolam, clonazepam and oxazepam) adulterated in health-care food for promoting sleep using thin layer chromatography (TLC) combined with surface enhanced Raman spectroscopy (SERS) was reported in the present paper. Firstly, cheA novel facile method for on-site detection of sleep problems chemicals (e. g. triazolam, estazolam, clonazepam and oxazepam) adulterated in health-care food for promoting sleep using thin layer chromatography (TLC) combined with surface enhanced Raman spectroscopy (SERS) was reported in the present paper. Firstly, chemical drugs added in simulation of positive drugs were separated with substrate in health-care food by TLC initially, mobile phase was cyclohexane-ethyl acetate-ethanol (5∶3.5∶2); detected and located by UV under 254 nm. Then trace substances were qualitative detected by SERS, excitation wavelength was 780 nm, surface enhancer was aqueous phase silver sol. The effect of matrix on the addition of health-care food was investigated by TLC-SERS in the positive experiment, and the detection limits of the 4 kinds of chemical components were also investigated. TLC-SERS detection method for 4 kinds of chemical components, which were illegally added in sleep health care products, was established. The characteristic peaks of Raman spectra of the chemical drugs added into health-care food obtained by TLC-SERS method were nearly consistent with the reference substance. TLC-SERS of matrix of health-care food to add ingredients was almost no interference. The LOD of 4 kinds of chemical components was from 1 to 4 μg. In addition, commercially available five kinds of Chinese medicine and health-care food for improving sleep were tested, randomly; there was no illegal substance added in the case. In this study, TLC-SERS method is applied in rapid testing of health-care food adulteration for the first time, with obtaining some ideal results, such as SERS spectra of 4 kinds of sedative hypnotics chemical drugs, as well as TLC-SERS detection methods for 4 frequently adulterated sedative hypnotics chemical drugs. TLC-SERS method is specific, sensitive, rapid, and without significant detection time constraints, would have good prospects in on-site detection of chemicals for doping in health-care food..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1122 (2018)
Raman Spectroscopy Study of Ganoderma Spore Oil
GUO Peng-cheng, XUE Jing-hong, and CHEN Xiang-bai
Raman spectroscopy has been applied for rapid analysis of ganoderma spore oil. It is found that the Raman spectrum of ganoderma spore oil has a weak and broad characteristic phonon mode at 1 563 cm-1, which is not observed in olive oil, sunflower seed oil, and cod-liver oil. In addition, the relative intensity ratio ofRaman spectroscopy has been applied for rapid analysis of ganoderma spore oil. It is found that the Raman spectrum of ganoderma spore oil has a weak and broad characteristic phonon mode at 1 563 cm-1, which is not observed in olive oil, sunflower seed oil, and cod-liver oil. In addition, the relative intensity ratio of the two phonon modes at 1 445 and 1 660 cm-1 in ganoderma spore oil is very different comparing with that in olive oil, sunflower seed oil, and cod-liver oil. Furthermore, Raman analysis of deteriorated ganoderma spore oil and fake ganoderma spore oil is investigated. Our results showed that when ganoderma spore oil is exposed in air, its active ingredients will be oxidized, and the fake ganoderma spore oil on market could be a mixture of deteriorated ganoderma spore oil, sunflower seed oil, or other cheap vegetable oils..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1129 (2018)
Studies of the Fluorescence Properties of Methanol and Ethanol Based on the Density Functional Theory
ZHU Cong-hai, CHEN Guo-qing, ZHU Chun, ZHAO Jin-chen, LIU Huai-bo, ZHANG Xiao-he, and SONG Xin-shu
The absorption and the emission spectra of methanol and ethanol, scanned by the Edinburgh FLS920P steady-instantaneous fluorescence spectrometer, are studied on this paper. Aiming at comparison on the molecular structuresof methanol and ethanol under different states, we employ the density functional theory (DFT) and tThe absorption and the emission spectra of methanol and ethanol, scanned by the Edinburgh FLS920P steady-instantaneous fluorescence spectrometer, are studied on this paper. Aiming at comparison on the molecular structuresof methanol and ethanol under different states, we employ the density functional theory (DFT) and the single-excitation configuration interaction (CIS) to optimizemolecular structures under the ground and excited state. The absorption and emission spectra of methanol and ethanol on the base of 6-31++G (d, p) are estimated based on the time-dependent density functional theory (TD-DFT) with the polarized continuous model (PCM), which are in agreements with the experimental results. Furthermore, we analyze the fluorescence mechanism of methanol and ethanol, and investigate the effect caused by different exchange correlation functions on the calculated spectra. The results indicate that methanol and ethanol have weak absorption in ultraviolet regionand produce Raman band and weak fluorescence peaks through UV excitation. Meanwhile, the absorption spectra of methanol and ethanol are produced by Rydberg excitation, of which the orbit jumps from σ to π. Our results show that the OLYP function can reproduce the experimental absorption spectrum well and the MPWK function can predict the emission energy well. There exist differences on calculations of transition energy varying from different pure functions. Our results can provide a reliable tool to study alcohols’ molecular properties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1133 (2018)
Compositional Characteristics of Interstitial Water Dissolved Organic Matter in Bioretention Systems with Different Filling
FAN Gong-duan, LIN Xiu-yong, WANG Shu-min, LUO Jing, XIE Zhi-gang, and LI Qiang
To find out the impact of different saturation filling in the treatment process of bioretention systems, composition and dynamics of dissolved organic matter in runoff were analyzed using three-dimensional excitation emission matrix fluorescence spectroscopy (EEM). The results indicated that the major organic compoundsTo find out the impact of different saturation filling in the treatment process of bioretention systems, composition and dynamics of dissolved organic matter in runoff were analyzed using three-dimensional excitation emission matrix fluorescence spectroscopy (EEM). The results indicated that the major organic compounds of interstitial water were microbial metabolites from sponge iron, fulvic-like substances from brick bat and volcanic, and aromatic protein-like substances, fulvic-like substances and biometabolism from chippings. After 48 h treatment, fluorescence peakof interstitial water associated with fulvic-like and brick bat were weakened, but volcanic and chippings were strengthened. The best purification of organic substance was obtained by sponge iron at 84.52%, followed by volcanic and brick bat at 77.25% and 77.90% respectively, and chippings at 29.20%. Thevolume fluorescence integral of fulvic-like substances in effluent of bioretention decreased to 58.04% on average, but aromatic protein-like substances increased on average to 65.36%. HIX of all samples were smaller than 4, which means the organic compounds mainly come from microorganism supersession activity. Aromatic protein-like substances degraded by microbes easily, which could promote microorganism activity and nitrogen removal by denitrification. The design suggests that sponge iron and brick bat would be better as the saturation filling. External carbon source would be able to choose organic compounds which are easily utilized by microbe..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1139 (2018)
Compositional Characteristics of Dissolved Organic Matter in Water Treatment Systems of Water Source Heat Pump Based on
OUYANG Heng, XIAO Jian-ren, LIN Xiu-yong, and FAN Gong-duan
To comprehend the water purification process of Water Source Heat Pump (WSHP) water treatment system and improve the efficiency of WSHP, the fluorescence of DOM in water treatment system was studied with three-dimensional fluorescence spectroscopy. The results showed that the WSHP water treatment system has poor effectTo comprehend the water purification process of Water Source Heat Pump (WSHP) water treatment system and improve the efficiency of WSHP, the fluorescence of DOM in water treatment system was studied with three-dimensional fluorescence spectroscopy. The results showed that the WSHP water treatment system has poor effect on the treatment of DOM, which has long been neglected, which affecting energy efficiency of WSHP. The filter cleaning cycle has a significant effect on the removal of protein organic components, microbial metabolites and humus. The HIX index of water in the system smaller than 4, and the main source of DOM is microbial metabolites. A long cleaning cycle will cause the system internal sludge clogging, triggering the DOM leak. The rich fulvic acid and protein organic components may be derived from Cyclotella sp., and humus may be derived from other algae. DOM removal effect is mainly affected by the filter operating cycle. To prevent the scaling problem in WSHP, more water treatment measures, such as frequent cleaning and intensive processing, should be taken to enhance the efficacy of WSHP..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1146 (2018)
Modeling Excitation-Emission Fluorescence Matrices with Multidimensional Pattern Recognition Algorithms for Classification of Raisin
HU Le-qian, MA Shuai, YIN Chun-ling, and LIU Zhi-min
With the improvement of living standards, raisins are accepted by an increasing number of people for its abundant nutrients and delicious. The quality of different kinds of raisins is very distinct because of its wide variety, diverse geographical origin, and various manufacturing technology. It is very important to esWith the improvement of living standards, raisins are accepted by an increasing number of people for its abundant nutrients and delicious. The quality of different kinds of raisins is very distinct because of its wide variety, diverse geographical origin, and various manufacturing technology. It is very important to establish scientific and accurate identification of variety of raisins, geographical origin and quality analysis method. These methods can not only ensure good quality of raisins and protect the consumer’s interest, but also helpful for the maintenance of the market competition order. Raisin can be measured with three-dimensional fluorescence spectrometry methods, for it contains muti-fluorescent components. In this research, fluorescence components in raisins samples were extracted with microwave method with methanol as solvent. Excitation emission spectra were obtained for 150 raisins samples of different varieties by recording emission from 300 to 700 nm with excitation in the range of 360~720 nm. The fluorescence matrix data were then analyzed by multidimensional pattern recognition methods, such as the multidimensional principal components analysis (M-PCA), multi-dimensional discrimination analysis of least squares (N-PLS-DA) and partial least square based on parallel factor algorithm discrimination analysis (PARAFAC-PLS-DA), to classify the variety of raisin. The result of M-PCA revealed the clustering tendency for the different kinds of raisins, and N-PLS-DA and PARAFAC-PLS-DA could give satisfactory classification results. In comparison, The PLS-DA classification model, constructed from PARAFAC model scores, detected the variety of raisins samples with 100% sensitivity and specificity. The study demonstrated that the excitation emission fluorescence spectrometry combining with multidimensional pattern recognition is a valuable and reliable technique for raisins classification. The results also showed that this method is promising to discriminate the quality and trace the geographical origin of raisins..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1153 (2018)
A Fluorescent Probe Based Host-Guest Complexation Between Cucurbit[7]uril and Neutral Red for the Detection of Paraquat Herbicide in Water Sample
TANG Qing, ZHANG Jing, SONG Gui-xian, XI Yun-yun, HUANG Ying, TAO Zhu, ZHOU Qing-di, and WEI Gang
We have now shown that a host-guest complex between cucurbit[7]uril (Q[7]) and neutral red (NR) can be used as a fluorescent probe for detecting the herbicide paraquat. The Q[7]/NR complex can be used to detect paraquat with high selectivity using fluorescence spectrometry. A linear correlation (ΔF=4.98+0.32c, ｒ=0.999 We have now shown that a host-guest complex between cucurbit[7]uril (Q[7]) and neutral red (NR) can be used as a fluorescent probe for detecting the herbicide paraquat. The Q[7]/NR complex can be used to detect paraquat with high selectivity using fluorescence spectrometry. A linear correlation (ΔF=4.98+0.32c, ｒ=0.999 1) was observed between the fluorescence intensity and the concentration of PQ over the concentration range (1~8)×10-6 mol·L-1. The detection limit for PQ was 1.40×10-8 mol·L-1. Recoveries obtained with the proposed method in river water examples were 104%~108%. Such method provides a rapid, selective and sensitive strategy for herbicide detection in real samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1160 (2018)
Rapid Identification of Sunflower Seed Oil Quality by Three-Dimensional Synchronous Fluorescence Spectrometry
LI Shuang-fang, GUO Yu-bao, SUN Yan-hui, and GU Hai-yang
Fluorescence spectra of sunflower oil under different oxidation conditions were obtained by three-dimensional synchronous fluorescence spectrometry, and the quality indexes were collected at the same time. The parallel-factor method was used to reduce the dimension of the three-dimensional synchronous fluorescence specFluorescence spectra of sunflower oil under different oxidation conditions were obtained by three-dimensional synchronous fluorescence spectrometry, and the quality indexes were collected at the same time. The parallel-factor method was used to reduce the dimension of the three-dimensional synchronous fluorescence spectrum, and the mathematical models were established by iPLS, BiPLS and SiPLS pattern recognition methods. The results show: the two-dimensional synchronous fluorescence spectra of the samples have significant differences when the wavelength difference Δλ=50 nm, which are used for mathematical modeling of initial values. The results of partial least squares modeling show that the correlation coefficients of calibration set and prediction set of iPLS, BiPLS, SiPLS are 0.908 3, 0.961 2, 0.954 5 and 0.872 3, 0.925 2, 0.852 5. It’s found that BiPLS method is test. The study provides the theoretical basis and technical support for rapid identification of sunflower oil quality, and offers a theoretical basis for other related oil rapid detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1165 (2018)
Determination of Polycyclic Aromatic Hydrocarbons in Water Based on Three Dimensional Fluorescence Spectroscopy Combined with Wavelet Compression and APTLD
WANG Yu-tian, LIU Ting-ting, LIU Ling-fei, YANG Zhe, and CUI Yao-yao
Based on the three-dimensional fluorescence spectroscopy combined with wavelet compression and APTLD for the detection of polycyclic aromatic hydrocarbons (PAHs) in water, the rapid determination of PAHs in water was achieved. The samples were prepared by using three kinds of PAHs, naphthalene (NAP), fluorene (FLU) andBased on the three-dimensional fluorescence spectroscopy combined with wavelet compression and APTLD for the detection of polycyclic aromatic hydrocarbons (PAHs) in water, the rapid determination of PAHs in water was achieved. The samples were prepared by using three kinds of PAHs, naphthalene (NAP), fluorene (FLU) and acenaphthene (ANA). First, the three-dimensional fluorescence spectra of the samples were measured with FLS920 steady-state fluorescence spectrometer. The data were excited and emitted by calibration and de-scattering to obtain the real spectrum. In order to solve the redundant information problem of three- dimensional fluorescence spectral data, the experimental spectral data is compressed by wavelet transform, and the compression score and data recovery fraction can reach 92% and 95% respectively. APTLD was applied to analyze the compressed data and reflect the second-order advantage. The experimental results show that the method can still be used for rapid determination, and the recovery rate is more than 94% and the predicted root mean square error is less than 0.29 with seriously overlapped and intermittent fluorescence spectra of PAHs..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1171 (2018)
The Measurement Study and Analysis of Ultraviolet Features of High Voltage Arc and Coronaindoors
FANG Chen-yan, LI Qing-ling, YU Jin-tao, and YIN Da-yi
With the rapid development of electric power technology, problems about high voltage equipment damage and high voltage line transmission loss caused by arc and corona discharge are increasingly paid more attention to. This paper has done the work about the measurement of arc and corona spectrum with its wavelength fromWith the rapid development of electric power technology, problems about high voltage equipment damage and high voltage line transmission loss caused by arc and corona discharge are increasingly paid more attention to. This paper has done the work about the measurement of arc and corona spectrum with its wavelength from 200 to 1 000 nm. We have found that the arc and corona spectrum intensity distribution is mainly concentrated on ultraviolet waveband, whose band is between 200 to 400 nm. This paper has proposed a way of using ultraviolet focal plane array imaging technology to detect arc and corona discharge. By means of using a set of self-built UV imaging system, wehave successfully got UV images about the targets of high voltage arc and corona in the laboratory, radiometric calibration by xenon lamp integrating sphere and target inversion. The result of experiments shows that this set of UV imaging system can be used on real-time detection for arc and corona discharge. This paper firstly verifies the ultraviolet features of arc and corona, and gets radiance of 5.4×10-6 W·cm-2·sr-1 of 6 kV arc in 240～280 nm ultraviolet band from the distance of 2 m by the means of target inversion, which provides strong supports for further study on the ultraviolet features of arc and corona..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1178 (2018)
Study on Quantitative Assessment of Ginkgo biloba Tree Health Based on Characteristics of Leaf Spectral Reflectance
JIN Gui-xiang, LIU Hai-xuan, LIU Yu, WU Ju, and XU Cheng-yang
Accurate diagnosis of tree health is the foundation of urban forest management as well as a technology urgently needed in the production. Tree health diagnosis through the analysis of the soil and plant nutrient health shows poor reliability while morphological diagnosis appears time-consuming and laborious, so how to Accurate diagnosis of tree health is the foundation of urban forest management as well as a technology urgently needed in the production. Tree health diagnosis through the analysis of the soil and plant nutrient health shows poor reliability while morphological diagnosis appears time-consuming and laborious, so how to diagnose the tree health fast, accurately and nondestructively has become an important technical bottlenecks of urban trees health management. This paper, took ginkgo trees in Beijing as the research object, has studied the trees health diagnosis technology based on the leaf spectral reflectance characteristics. Based on the clustering analysis of 13 exterior shape features, trees were divided to four healthy levels, excellent, good, fair, and poor. Leaf pigment content between different healthy levels of trees is extremely significant different (p<0.001). Because there is relationship between the spectral reflectance and chlorophyll content, the tree leaf spectral reflectance characteristics used for health diagnosis is feasible. Adopted the factor analysis, we constructed green degree index, index of pigment, trilateral index, reflecting leaf spectral reflectance characteristics, according to 15 leaf spectral reflectance indices. Leaf spectral reflectance indexes and three reflection spectrum indexes between different healthy levels of trees had extremely significant difference (p<0.001). Three reflection spectrum indexes were used to construct the multiple quadratic model of the ginkgo trees health evaluation, with prediction accuracy of up to 79%. Therefore, this method can be used as a rapid diagnosis method to evaluate ginkgo trees health. This study selected relatively comprehensive and concise spectral indexes, determined the comprehensive score and score range for the tree core morphological index, green degree index, index of pigment, trilateral index of leaves of different healthy levels of trees. It provides a standard for the health diagnosis of ginkgo trees in practical forest management..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1184 (2018)
Performance Assessment of Atmospheric Correction for Multispectral Data of GF-4 on Inland Case Ⅱ Turbid Water
SONG Ting, GONG Shao-qi, LIU Jun-zhi, GU Zheng-fan, SHI Jun-zhe, and WU Wei
GF-4 satellite is the first geostationary satellite with high spatial resolution in China, which has great potential in the aspects of inland water monitoring. This paper takes the Taihu Lake as study area to evaluate the accuracy of GF-4 derived spectral reflectance after atmospheric correction, aiming to provide valuGF-4 satellite is the first geostationary satellite with high spatial resolution in China, which has great potential in the aspects of inland water monitoring. This paper takes the Taihu Lake as study area to evaluate the accuracy of GF-4 derived spectral reflectance after atmospheric correction, aiming to provide valuable information for the application of GF-4 data to water color remote sensing. The MODIS-aided improved Gordon atmospheric correction algorithm was used to conduct atmospheric correction for GF-4 images obtained on 2016-07-21 and 2016-08-17. In situ measurements of quasi-synchronous samples and atmospheric corrected GOCI (Geostationary Ocean Color Imager) data were used to validate the GF-4 derived spectral reflectance. The results show that the red-light B4 band had the highest accuracy with RMSE (Root Mean Square Error) of 1.25×10-3 and MAPE (Mean Absolute Percentage Error) of 10.71%, the green-light B3 band had RMSE of 2.43×10-3 and MAPE of 13.21%, and the near-infrared B5 band had RMSE of 1.95×10-3 and MAPE of 33.06%. The blue-light B2 band had the worst accuracy with RMSE of 6.81×10-3 and MAPE of 53.55%. The accuracy of B3, B4 and B5 bands of GF-4 were higher than those of GOCI. This is because that the spatial resolution of GF-4 is much higher than that of GOCI, so the errors caused by mixed pixel were relatively smaller, showing the advantage of GF-4 as a high-resolution geostationary satellite when used in water color remote sensing. The accuracy of B2 band of GF-4 was lower than that of GOCI, indicating the B2 band of GF-4 still has room for improvement. In the future, the B2 band should be corrected separately, and the usage of this band in water color remote sensing should be avoided if it is not corrected properly. Overall, the multispectral data of GF-4 has relatively high accuracy and can used to monitor the inland case II turbidwater. In order to improve the accuracy of GF-4 derived spectral reflectance, several researches should be conducted in the future. First, aerosol observation stations should be established to obtained long-term data needed by the multiple scattering algorithm forlocalaerosol. Second, the study area should be divided into several sub-regions in order to reduce the errors caused by the assumption that the air condition was the same for the whole study area. The third, the spatial resolution of GF-4 was 50 m, while the effective area of thespectrograph probe was only 1 m2. Spectrum data should be collected at multiple points within one GF-4 pixel, so that the errors caused by scale mismatch can be reduced..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1191 (2018)
Preparation and Characterization of Silicon, Silver, Fluorine Co-Modified Hydroxyapatite Nano-Biofilms
YE Ting, QIAO Hai-xia, HUANG Yong, GUO Jia-chi, MA Meng-chu, RU Ping, CHEN Fang-fang, YUAN Cui-fang, LIU Huan, SU Zhuo-bin, ZHANG Xue-jiao, and GAO Yuan
In this study, a novel silicon, silver, fluorine co-modified hydroxyapatite (Si-Ag-F-HA) nano-biofilms was deposited on CP-Ti through electrodeposition. Ag was incorporated into HA coating to improve the antimicrobial properties. Si was added as a second binary element to offset the potential cytotoxicity of Ag. The asIn this study, a novel silicon, silver, fluorine co-modified hydroxyapatite (Si-Ag-F-HA) nano-biofilms was deposited on CP-Ti through electrodeposition. Ag was incorporated into HA coating to improve the antimicrobial properties. Si was added as a second binary element to offset the potential cytotoxicity of Ag. The as-prepared coatings were examined by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests. Results highlight that F-, Si4+ and Ag+ could be evenly incorporated into the Si-Ag-F-HA coating. The results indicate that the Si-Ag-F-HA coatings take the morphology of nanoscale- villous-like, the composite coating becomes more compact. The composite coatings were found to be bioactive, based on the promotion of additional apatite onto the Si-Ag-F-HA coating surface from SBF. Potentiodynamic polarisation tests revealed that the corrosion resistance increased after Si-Ag-F-HA coating. The release of Si and Ag ions from Si-Ag-F-HA coatings shows sustained release kinetics without burst release, which reached a near steady state afterwards, thereby revealing long-term sustainable release. FTIR and ICP-MS provide a rapid and effective method for the development of new antibacterial hard tissue repair materials..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1198 (2018)
Adsorption Properties of Thiol-Modified, Sodium-Modified and Acidified Bentonite for Cu2+, Pb2+ and Zn2+
PANG Ting-wen, YANG Zhi-jun, HUANG Yi-cong, LEI Xue-ying, ZENG Xuan, and LI Xiao-xiao
In order to investigate the adsorbability of modified bentonite, Fourier Transform Infrared Spectrometer (FTIR Spectrometer) and Scanning Electron Microscope(SEM) were carried outto characterize the properties of samples. The amount of Cu2+, Pb2+ and Zn2+absorbed by three kinds of modified bentonite, thiol-modified benIn order to investigate the adsorbability of modified bentonite, Fourier Transform Infrared Spectrometer (FTIR Spectrometer) and Scanning Electron Microscope(SEM) were carried outto characterize the properties of samples. The amount of Cu2+, Pb2+ and Zn2+absorbed by three kinds of modified bentonite, thiol-modified bentonite, sodium-modified bentonite and acidified bentonite, in the environment of isothermal adsorption and competitive adsorption, were investigated and analyzed respectively. The results show that in the environment of isothermal adsorption, the adsorption capacity of thiol-modified bentonite is much superior to others, especially appearing adsorptive selectivity for Pb2+, the adsorption rate amounts to nearly 100%. In the environment of competitive adsorption, the adsorption rate for three kinds of modified bentonite on Cu2+, Pb2+and Zn2+ all decrease to some extent, but thiol-modified bentonite performs better in generally, which shows 10%～40% higher than the others, besides, the competitive adsorption ability of three metal ions can be given as Cu2+>Pb2+>Zn2+, which relate to their competitive ability, chemical affinity and so on. The modified process of thiol-modified bentonite is simple and the effect on adsorbing heavy metals is desirable. Therefore, it is an important study of modified bentonite and its application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1203 (2018)
Calculating the Electron Temperature of Lightning Channel Based on the Continuous Radiation
DONG Xiang-cheng, and YUAN Ping
Based on the continuous radiation theory, the relation between the energy of the continuous radiation and the electron temperature of the plasma is obtained. According to the spectrum of the lightning return stroke processes in Qinghai area, separating the continuous radiation intensity from it. In order to reduce the Based on the continuous radiation theory, the relation between the energy of the continuous radiation and the electron temperature of the plasma is obtained. According to the spectrum of the lightning return stroke processes in Qinghai area, separating the continuous radiation intensity from it. In order to reduce the calculation error caused by absorption, the absorption characteristics are analyzed. The electron temperature of lightning discharge channel is obtained by fitting the curves of the continuous spectrum intensity. The peak temperature is 29 800 K and the temperature lower limit is 16 200 K. The electron temperature is calculated respectively with the OⅠ line and NⅡ line in the same band spectrum. The comparison shows the electron temperature calculated by the continuous radiation transits from high temperature to low temperature. High temperature values are in good agreement with the temperature of the lightning core current channel calculated by the ion line information, while the low temperature is close to the result of the atomic line calculation, which reflects the temperature of the outer corona discharge channel. Therefore, the results obtained from the continuous spectrum can more fully reflect the distribution of the temperature along the radial direction. For the lightning thermal plasma channel, the continuous spectrum method provides a new way to calculate the electron temperature of lightning discharge channel. It is of great significance to the study of the lightning return stroke..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1209 (2018)
Study of the Multi-Spectral Characterization Model for Inkjet Printing System and Its Application
LIANG Jing, HUANG Hao, LIAN Yu-sheng, NING Si-yu, and SUN Liang
With the development of spectroscopy, spectral characteristics of the model of the printing system become a research focus. Characterization model based on spectral matching by direct prediction device color spectral reflectance data can effectively reduce mesmerism phenomenon, provide the conditions for the realizatioWith the development of spectroscopy, spectral characteristics of the model of the printing system become a research focus. Characterization model based on spectral matching by direct prediction device color spectral reflectance data can effectively reduce mesmerism phenomenon, provide the conditions for the realization of high-fidelity printing. This article is based on model Yule-Nielsen Spectral Neugebauer amended, carried out research on the accuracy of the model twelve-color printing system spectral characteristics of the model and how to improve. This topic first by color measurement instruments and measurement conditions, the ink jet printer system stability and accuracy of the study, the feasibility of providing the basis for subsequent sample design and measurement. Then, the establishment of this research forward YNSN equipment for model experiments, based on the principles CIELAB color space uniformly distributed brightness value, design, and outputs a 1 331 test sample, color and characteristics of the model based on the establishment of spectrum through, Meanwhile, the extraction section samples do training samples, the established forward model for verification. Final show, feature-based model to predict high precision spectroscopy, has obvious advantages, but also through the introduction of post-Yule-Nielsen correction parameter value of n, proven, can be further improved spectral prediction accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1213 (2018)
Spectral Characteristic of Graphene Modified Zinc Stannate Materials and It’s Photocatalytic Properties
XUE Juan-qin, DAI Ji-zhe, WANG Zhen-xing, and LI Di
Semiconductor photocatalytic oxidation technology has a very wide application in dealing with energy crisis and environmental pollution problems. In this paper, the grapheme was used to modify Zn2SnO4 prepared by hydrothermal method. The structure characteristics of grapheme/Zn2SnO4 were investigated by X-ray diffractiSemiconductor photocatalytic oxidation technology has a very wide application in dealing with energy crisis and environmental pollution problems. In this paper, the grapheme was used to modify Zn2SnO4 prepared by hydrothermal method. The structure characteristics of grapheme/Zn2SnO4 were investigated by X-ray diffraction (XRD), Infrared spectroscopy (FT-IR) and Raman spectroscopy. The transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy were used to observe its morphology and analyze chemical composition, respectively. The photocatalytic performance of graphene/Zn2SnO4 photocatalytic degradation of methylene blue (MB) under UV irradiation was investigated by UV-Vis spectrophotometer. The photocatalytic mechanism of degradation of MB was dicussed by photocatalytic experiment with free radical scavenger, electron paramagnetic resonance spectrum and fluorescence spectrum. The stability of the photocatalyst was evaluatedby repetitive photocatalytic experiments. The results showed that the addition of graphene had no influence on the structure and morphology of Zn2SnO4. And when the additive amount of Graphene oxide (GO) is 4Wt%, the grapheme/Zn2SnO4 can exhibited the highest photocatalytic activity. During the photocatalytic process, ·OH was the dominant photooxidant, and there was indirect reaction between ·OH and organic chemical dyes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1219 (2018)
The Coordination Complexes of Cr(Ⅲ) in ［1ChCl∶2EG］/CrCl3·6H2O ILs
ZHANG Xian-jie, LI Lin-fei, LI Yan, LI Jian, HUA Yi-xin, XU Cun-ying, and ZHANG Qi-bo
The existing forms of Cr(Ⅲ) complexes in aqueous solution and ［1ChCl∶2EG］/CrCl3·6H2O ILs containing 0.1～0.6 mol·L-1 CrCl3·6H2O, respectively, were investigated by using ESI-MS and UV-Vis absorption spectra. The results showed that Cr(Ⅲ) combined with Cl－ and H2O to form ［Cr(H2O)nCl6-n］n-3 in both cases, The existing forms of Cr(Ⅲ) complexes in aqueous solution and ［1ChCl∶2EG］/CrCl3·6H2O ILs containing 0.1～0.6 mol·L-1 CrCl3·6H2O, respectively, were investigated by using ESI-MS and UV-Vis absorption spectra. The results showed that Cr(Ⅲ) combined with Cl－ and H2O to form ［Cr(H2O)nCl6-n］n-3 in both cases, and the dominant species of which were affected by the concentration of CrCl3·6H2O. Concretely, the dominant complexes of Cr(Ⅲ) in aqueous solution are ［Cr(H2O)6］3+ and ［Cr(H2O)5Cl］2+, and the UV-Vis absorption spectra is observed to redshift with an increase in the concentration of CrCl3·6H2O, along with enhancement in the mole fraction of ［Cr(H2O)5Cl］2+. By contrast, the dominant species of Cr(Ⅲ) in ［1ChCl∶2EG］/CrCl3·6H2O ILs are ［Cr(H2O)2Cl4］－ and ［Cr(H2O)3Cl3］. Increasing the concentration of CrCl3·6H2O results in gradual color change of the solution from light orange-red to dark green, blue shift of the UV-Vis absorption spectra, and higher mole fraction of ［Cr(H2O)3Cl3］. Both the coordination number of Cl－ and H2O that complexes with Cr(Ⅲ) as well as the relative content of the dominant complexes of Cr(Ⅲ) in solvent is proved to be influenced by variation in the concentration of CrCl3·6H2O..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1225 (2018)
Study on Mineralogy and Spectroscopy of Turquoises from Hami, Xinjiang
LIU Xi-feng, LIN Chen-lu, LI Dan-dan, ZHU Lin, SONG Shuang, LIU Yan, and SHEN Chong-hui
Recently, turquoise from Hami, Xinjiang Provence has been discovered with gem quality and large quantity. In this work, turquoise samples from Hami, Xinjiang were studied with X-ray diffractometer (XRD), laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS), scanning electronic microscopy (SEM), FouriRecently, turquoise from Hami, Xinjiang Provence has been discovered with gem quality and large quantity. In this work, turquoise samples from Hami, Xinjiang were studied with X-ray diffractometer (XRD), laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS), scanning electronic microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), and ultraviolet-visible spectroscopy (UV-Vis) to obtain the mineralogy and spectra characteristics. The chemical composition of turquoise from Hami was characterized by rich Cr (1 617 ppm), V (435 ppm), Ti (428 ppm) and poor Ba (99.9 ppm). And, the color of turquoise gradually changed from green to blue with the decrease of the rate of Fe2O3/CuO. The SEM results showed that the turquoise crystals were mainly needle, columnar and long plate shape with the size of 0.2～3 μm. The infrared and Raman spectra of turquoise were induced by the vibration of phosphate group (located at 1 000~1 200 and 420~650 cm-1), hydroxy group (located at 3 400~3 600 cm-1) and crystal water (located at 3 000~3 300 cm-1). Besides, the UV-Vis spectra of the turquoise samples showed that the absorption peaks at 430 nm and 600~700 nm belonged to the electron transition of Fe3+and Cu2+, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1231 (2018)
Study on the Determination of Mineral Elements in Three Caragana Fabr. Species in Inner Mongolia by Inductively Coupled Plasma Mass Spectrometry
HUI Cen-yi, FENG Jin-chao, and SHI Sha
Based on the same habitat conditions of typical steppe in Inner Mongolia, studies were carried out about the response of mineral elements of Caragana korshinskii, C. microphylla and C. stenophylla as the representative of shrub species to plant drought resistance. Samples of the grass leaves were digested with microwavBased on the same habitat conditions of typical steppe in Inner Mongolia, studies were carried out about the response of mineral elements of Caragana korshinskii, C. microphylla and C. stenophylla as the representative of shrub species to plant drought resistance. Samples of the grass leaves were digested with microwave digestion, and 11 mineral elements contents of K, Ca, Mg, P, Mn, B, Na, Zn, Cu, Ni and Mo in the solution were determined with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) with the equipment of collision/reaction pool (ORS) which effectively eliminate interference. HNO3 and H2O2 was used to achieve the complete decomposition of the complex matrix in a closed-vessel microwave oven. The results showed that the limit of detection for the K, Na, Ca, Mg and P varied from 0.62 to 2.90 μg·L-1, and the Cu, Zn, Mn, Ni, Mo and B from 0.01 to 0.12 μg·L-1. The recovery rate was found to be 82.0%~117.2% in adding standard recovery experiment and the relative standard deviation(RSD) was between 1.12% and 3.68%, which mean that this method was simple, sensitive and precise. The results showed that the contents of mineral elements in the leaves of three species were K>Mg>P>Ca, and it is possible that the determination of the contents of mineral elements in the plant species were made in the same time, promptitude and batch analysis. The concentration of Mn, Cu and Zn in C. microphylla were higher than that of C. korshinskii and C. stenophylla, and the latter were similar. Of the total amount of the 11 kinds of mineral ions of the three species, C. korshinskii was the highest (40 089.32 μg·g-1), which was significantly higher than that of C. microphylla and C. stenophylla. As the routine method in our laboratory, the satisfactory results indicate that it has great potential for the determination of all mineral elements by one single analysis and batch measurement in plant samples. This study provides basic data for the study of plant nutrition and ion groups..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1240 (2018)
Assessment of Pollution and Heavy Metals in Filtered Water and Surface Sediments of Taihu Lake by Using ICP-MS
FANG Fang, JI Yu-shan, LI Xiang, BAI Na, and LIU Ying
Cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn) and lead (Pb) of filtered water in 22 sampling sites and surface sediments of 18 sampling sites in Taihu Lake were measured with inductively coupled plasma mass spectrometry (ICP-MS). Meanwhile, in filtered water and surface sediments, the pollution evaluCadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn) and lead (Pb) of filtered water in 22 sampling sites and surface sediments of 18 sampling sites in Taihu Lake were measured with inductively coupled plasma mass spectrometry (ICP-MS). Meanwhile, in filtered water and surface sediments, the pollution evaluation were conducted by using singer factor pollution (Ii), intergrated Nemerow pollution index (I), index of geoaccumulation (Igeo), potential ecological risk index (RI) and mean potential effects concentration quotient (mPEC-Q), respectively. The results showed that the contents of Cu, Ni and Zn were the highest in filtered water except S3, S4, S20 and S22 sampling sites. The sequence of heavy metals content levels: Zn>Ni>Cu>Cr>Cd>Pb. The Ii and I values in the study area were less than 1, indicating that five heavy metals (Ni has no standard limit) were in clean condition in all sampling points. The contents of the six elements in the surface sediments exceeded the local background values, and the sequence of average contents: Zn>Cr>Pb>Ni>Cu>Cd, and at S12 sampling point (Fisherman’s Ecological Park), the content of the six elements were the highest. They had the largest Igeo, RI (327) and mPEC-Q (0.605), indicating that there were different degrees of pollution in sediments. The results of source analysis showed that the six heavy metals had a large correlation, Cd, Cu, Pb, Zn were greatly influenced by electroplating, smelting industrial production and the use of chemical fertilizers at agricultural activities. The results will provide a credible experimental basis for tracing the origin, migration, biological effects and comprehensive management of heavy metals in Taihu Lake..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1245 (2018)
Detection of Dimethoate Content with Laser Induced Breakdown Spectroscopy Combined with LSSVM and Internal Standard Method
SUN Tong, LIU Jin, GAN Lan-ping, WU Yi-qing, and LIU Mu-hua
In this research, collineardouble pulselaser induced breakdown spectroscopy (LIBS) was used to detect dimethoate content in solutionquantificationally. Fortune paulownia wood chip with cylinder shape was used to enrichmentdimethoate, and the spectra of samples were acquired with a two-channel high precision spectrometeIn this research, collineardouble pulselaser induced breakdown spectroscopy (LIBS) was used to detect dimethoate content in solutionquantificationally. Fortune paulownia wood chip with cylinder shape was used to enrichmentdimethoate, and the spectra of samples were acquired with a two-channel high precision spectrometer in the wavelength range of 206.28~481.77 nm. Four spectral linesof phosphorus (213.618, 214.91, 253.56, 255.325 nm) were selected as analytical lines, and carbonspectral line (247.856 nm) was used as internal standard line. Then, univariatelinear fitting and least squares support vector machine (LSSVM) were used to develop univariate calibration model, LSSVM calibration model and LSSVM calibration model based on internal standard method, and the performance of threecalibration models were compared. The results indicate that collinear double pulse LIBS combined with LSSVM and internal standard method is feasible for detecting dimethoate content in solution quantificationally. The coefficient of determination (R2) of LSSVM calibration model based on internal standard method is 0.999 7, and the average relative errors in training set and validation set are 11.24% and 12.01%, respectively. In the three calibration models, LSSVM calibration model based on internal standard method has the best performance, and the performance of LSSVM calibration model is the second, while univariatecalibration model hasthe worstperformance. So it can be concluded that LSSVM and internal standard method can improve the performance of calibration model to some extent, and improve the prediction accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1251 (2018)
Continuous Pushbroom Computational Imaging Spectrometry
XIANGLI Bin, L Qun-bo, LIU Yang-yang, SUN Jian-ying, WANG Jian-wei, YAO Tao, PEI Lin-lin, and LI Wei-yan
Computational imaging spectrometry (CIS) has drawn great attention in recent years. It has the advantages of high optical throughput, snapshot imaging and so on. On the other hand, CIS has the disadvantage of insufficiency in sparse sampling which reduce the accuracy of reconstructed spatial-spectral data. By analyzingComputational imaging spectrometry (CIS) has drawn great attention in recent years. It has the advantages of high optical throughput, snapshot imaging and so on. On the other hand, CIS has the disadvantage of insufficiency in sparse sampling which reduce the accuracy of reconstructed spatial-spectral data. By analyzing the optical property of CIS, a continuous pushbroom computational imaging spectrometry (CPCIS) is presented. In CPCIS, the orthogonal cyclic coded aperture was used, and the continuous scanning line by line was implemented through platform moving. The entire spatial-spectral data was reconstructed by orthogonal inversion. According to the imaging simulation and experiment, the aliasing in spatial-spectral image was eliminated, and the reconstructed image was well satisfied. Comparing to multiframe CIS, CPCIS has no moveable element, which can image without staring the object, thus it is suitable for the airborne and spaceborne remote sensing applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1256 (2018)
In-situ Absolute Intensity Calibration of Fast-Response Extreme Ultraviolet Spectrometer on Experimental Advanced Superconducting Tokamak
YANG Xiu-da, ZHANG Ling, XU Zong, ZHANG Peng-fei, CHEN Ying-jie, HUANG Juan, WU Zhen-wei, GONG Xian-zu, and HU Li-qun
In the magnetic confinement device, the existence of impurity, especially the high-Z impurity, will cause the large enhancement of the radiation power loss and serious degradation of plasma performance. Quantitative study of impurity behavior requires the absolute intensity calibration of spectroscopy diagnostic systemIn the magnetic confinement device, the existence of impurity, especially the high-Z impurity, will cause the large enhancement of the radiation power loss and serious degradation of plasma performance. Quantitative study of impurity behavior requires the absolute intensity calibration of spectroscopy diagnostic system for impurity firstly. In this work, a precise in-situ absolute intensity calibration of a fast-response flat-field extreme ultraviolet (EUV) spectrometer is carried out by using different methods in different wavelength range. In the range of 20～150 , the sensitivity curve is obtained by comparing EUV bremsstrahlung between the measurement and calculation, in which the latter one is calculated by combining the profile of electron density, temperature and the effective charge Zeff deduced from the absolutely measured visible bremsstrahlung intensity in the range of (523±1) nm. The measured EUV bremsstrahlung intensity is the continuous counts subtracting the background noise at different wavelengths from the detector. In the longer wavelength range, i. e. 130～280 , the relative intensity calibration is addressed by comparing the measured and simulated line intensity ratio of resonance transition doubles from Li-like ions, e. g. Fe23+, Cr21+, Ar15+, and Na-like ions, e. g. Mo31+, Fe15+, with the transition of 1s22s2S1/2 —1s22p2P1/2, 3/2 and 2p63s2S1/2—2p63p2P1/2, 3/2, respectively. For the simulated line intensity ratio, it is modeled using the collisional-radiative model, in which the energy level populations are determined by electron collisional excitation, de-excitation and radiative decay. By combining those two methods, the absolute calibration of EUV spectrometer is achieved in the wavelength range of 20～280 . In addition, the uncertainty of the calibration is estimated to be about 30%, considering the measurement uncertainties of electron temperature, electron density and bremsstrahlung. Based on the obtained absolute sensitivity curve, the quantitative study of impurity concentration is being carried out by comparing the absolute measurement of emission line intensity with that simulated by combining the one-dimensional impurity transport simulation and ADAS (Atomic Data and Analysis Structure) database..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1262 (2018)
Study of High Accuracy Spectral Calibration of Fourier Transform Spectrometer
ZOU Yao-pu, ZHANG Lei, HAN Chang-pei, and LI Li-bing
In order to improve the Fourier spectrometer spectral calibration accuracy and reduce spectral calibration error, we studied the Fourier spectrometer spectral calibration algorithm. The study is based on the data of spectral calibration experiment of the atmospheric vertical detector, which is a payload of FY-4 meteoroIn order to improve the Fourier spectrometer spectral calibration accuracy and reduce spectral calibration error, we studied the Fourier spectrometer spectral calibration algorithm. The study is based on the data of spectral calibration experiment of the atmospheric vertical detector, which is a payload of FY-4 meteorology satellite. Firstly, the spectroscopic principle of the Fourier spectrometer is analyzed. Secondly, after analyzing the principle of the spectrum shift caused by the reference laser wave number drift, the light off-axis, and the limited field of view, the Fourier spectrometer spectral calibration formula and the calibration parameter calculation method are obtained. Then, the reasons for the large spectral calibration error caused by the barrier effect of Fast Fourier Transform(FFT) and the toe function generated by the truncation of the interferogram are analyzed. By comparing several different spectral refinement methods, fast Chirp Z-transform(CZT) for spectral refinement is selected to solve the problem of lower spectral resolution of FFT resulting in larger spectral error. Gaussian expansion and convoluting the sinc function of reference gas spectral can reduce the calibration error caused by limited optical path difference. At last, the spectral calibration algorithm is validated by using experimentally measured data. By comparing the calibration errors before and after refining the spectra using CZT, and the calibration errors before and after the processing of the reference gas spectrum, the algorithm is proved to be effective in improving spectral calibration accuracy. Spectral calibration error can be reduced about 10 times at most..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1268 (2018)
Computational Studies on the Ground State Tautomer, Hydrogen Conformations and Vibrational Spectroscopic Analysis of Antitumor Agents: 3-Deazauracil and 6-Azauracil
ar rak, Nurettin Krzlü, Yusuf Sert, and Fatih Ucun
The ground state hydrogen conformations and vibrational analysis of 3-deazauracil (3DAU) and 6-azauracil (6AU) tautomers (4-enol and 2,4-diol forms) have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-311++G(d,p) basis set level. The calculations have shown that tThe ground state hydrogen conformations and vibrational analysis of 3-deazauracil (3DAU) and 6-azauracil (6AU) tautomers (4-enol and 2,4-diol forms) have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-311++G(d,p) basis set level. The calculations have shown that the most probably preferential tautomer of 3DAU and 6AU are the 4-enol form, which gives best fit to the corresponding experimental data. The ground state conformer of the 2,4-diol form has two O—H bonds which are oriented externally and internally (to the N—H bond). The vibrational analyses of the ground state conformer of each tautomeric form of 3DAU and 6AU were done and their optimized geometry parameters (bond lengths and bond angles) were given. Furthermore, from the correlations values it was concluded that the B3LYP method is superior to the HF method for both the vibrational frequencies and the geometric parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1276 (2018)
A Solid Phase Extraction Application of Hybrid Nano B2O3/ZrO2 for Separation and Determination of Trace Indium in Environmental Samples
Ozcan Yalcinkaya, Harun Ciftci, Cigdem Er Caliskan, Ozge Kalender, and Ali Rehber Turker
Hybrid nanomaterials have attracted considerable interest in environmental science, analytical chemistry and atomic spectroscopy. In the present study, a column solid phase extractioo procedure was developed for the separation and preconcentration of indium in various matrixes by using hybrid nanomaterial B2O3/ZrO2 (HNHybrid nanomaterials have attracted considerable interest in environmental science, analytical chemistry and atomic spectroscopy. In the present study, a column solid phase extractioo procedure was developed for the separation and preconcentration of indium in various matrixes by using hybrid nanomaterial B2O3/ZrO2 (HNMBZ). Various experimental and analytical parameters such as sample solution pH, sample solution volume, flow rate of sample solution and eluent, volume and concentration of eluent aod amount of HNMBZ, effect of common matrix ions and capacity of sorbent were investigated. The adsorbed metal ions on HNMBZ were eluted with 6 mL of 1 mol·L-1 HNO3 solutions and their concentrations were determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimized conditions, detection limits for indium for 3 pixels and 5 pixels were found as 0.20 and 0.16 μg·L-1, respectively. The accuracy of the procedure was checked by spiked water samples. The developed procedure was successfully applied to real samples for the separation and determination of indium..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1283 (2018)
Luminescence Properties of Carbazole-Substituted Alq3 Derivative: a Potential Multifunctional Fluorescent Sensing Material
ZHANG Chun-yan, LUO Jian-xin, OU Li-juan, LIU Yong, HU Bo-nian, YU Gui-peng, and PAN Chun-yue
This work presents a study on the luminescence properties of a carbazole-substituted aluminum quinolone (Alq3) derivative. Firstly, the effect of solvents on the luminescence properties of the Alq3 derivative was studied. The results indicate that energy transfer can occur from carbazole to Alq3 for the Alq3 derivativeThis work presents a study on the luminescence properties of a carbazole-substituted aluminum quinolone (Alq3) derivative. Firstly, the effect of solvents on the luminescence properties of the Alq3 derivative was studied. The results indicate that energy transfer can occur from carbazole to Alq3 for the Alq3 derivative in all different solvent systems. However, solvent affects the spatial structure and electronic structure of the Alq3 derivative that have an impact on the efficiency of energy transfer, leading to different luminescence spectra, efficiency and lifetime for different solvent systems. Among them, toluene plays a role of bridge in energy transfer, but a large amount of DMF plays negative role in energy transfer. Like DMF, DMA acting as an electron donor also plays similar role. Besides, effects of metal ions on the luminescence properties of the Alq3 derivative were also studied. The results show that Fe3+ and Cu2+ can cause fluorescence quenching, and the fluorescence quench effect is also affected by acid counteranions. These results indicate that the Alq3 derivative might be exploited as a multifunctional fluorescent sensing material..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1290 (2018)
Fourier Transform Infrared Spectroscopy Analysis of Humic Acids from Brown and Cinnamon Soils under Robinia pseudoacacia Forest
ZHANG Guang-na, LIN Xiang-jie, LI Yun-mei, XU Shu-jian, and ZHANG Yu-lan
Forest soil contains lots of carbon, which presented in different fractions with various functions. This study collected surface and subsurface soil samples from brown soil and cinnamon soil under 45 years old Robinia pseudoacacia forest. Difference within soil humic substances under long-term forest, the influence froForest soil contains lots of carbon, which presented in different fractions with various functions. This study collected surface and subsurface soil samples from brown soil and cinnamon soil under 45 years old Robinia pseudoacacia forest. Difference within soil humic substances under long-term forest, the influence from soil type and depth were studied in this paper. Surface and subsurface soil samples collected from cinnamon and brown soil were defined as CO and CA, BO and BA, respectively. Humic substances were separated as fulvic acid (FA), humic acid (HA) and humin (HM) and analyzed by Fourier transform infrared spectroscopy (FT-IR). Results showed that FA contained mainly stretching vibration of carbohydrate H-bonded OH at 3 400 cm-1, aromatic CC at 1 655 cm-1 and C—OH stretching of aliphatic at 1 110 cm-1. Compared with FA, HA has weaker peaks at similar wave numbers than those in FA. HM fraction has stronger peaks at 1 110 and 1 030 cm-1 than HA, which assigned as C—OH stretching of aliphatic OH and C—O stretching of polysaccharide or polysaccharide-like compounds. Results also showed that more peaks were collected in surface soils and the absorption intensity are also stronger than those in subsurface soils. In addition, absorption bands richness and intensity of FA fraction suffered less influence from soil type and depth than those in HA and HM fractions. Through analysis of absorption bands, FA fractions had strong aromatization, while aromatization of HA and HM were only stronger under surface soil. The aromatic and aliphatic structures in HA fractions under BO soil were much stronger than those in cinnamon soil. Thus, we conclude that humic substances in 45 years old Robinia pseudoacacia forest soils is influenced by soil depth and soil type, especially in HA and HM fractions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1298 (2018)
Rice Germination Rate Detection Based on Fluorescent Spectrometry and Deep Belief Network
LU Wei, GUO Yang-ming, DAI De-jian, ZHANG Cheng-yu, and WANG Xin-yu
Traditional rice seed germination rate detection methods have low efficiency, poor accuracy and high specialization. The paper proposed a novel method by using fluorescent spectrometry combined with Deep Belief Network (DBN) to establish forecasting model for rice seed germination rate. Firstly, two varieties of seeds,Traditional rice seed germination rate detection methods have low efficiency, poor accuracy and high specialization. The paper proposed a novel method by using fluorescent spectrometry combined with Deep Belief Network (DBN) to establish forecasting model for rice seed germination rate. Firstly, two varieties of seeds, Lianjing 7 and Wuyunjing, with 0～7 artificial aged days separately were soaked into purified water for 5～30 minutes with every 5 minutes’ interval. Then the fluorescence spectrums of the soak solutions were detected using fluorescence spectrometer. In addition, the spectrum data were centralized and then denoised with Ensemble Empirical Mode Decomposition (EEMD). The characteristic fluorescence wavelength of 441.5nm was extracted using Principal Component Anamysis (PCA). Finally, the rice seed germination predicting models were establishee with Partial Least Squares Regression (PLSR), Back Propagation Neural Network (BPNN), Radial Basis Function Neural Network (RBFNN) and Deep Belief Network (DBN), respectively. The results showed that the accuracy of DBN model was the highest in the case of less data and weak signal, and Rp=0.979 2, RMSEP=0.101. At the same time,we got the best soaking time is 22.1 min by analyzing the changing trend of mixed rice seed fluorescent data Rp, actually, it took about 5 min to get the accuracy more than 0.95 (Rp). The research results demonstrated the feasibility and high accuracy for predicting rice seed germination rate non-invasively by combining the fluorescent spectrometry and EEMD-DBN model, moreover, it adapts to the detection of rice seeds with different colors and contaminated levels..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1303 (2018)
A Comparative Study on the Pyrolysis Characteristics of Direct-Coal-Liquefaction Residue Through Microwave and Conventional Methods
SONG Yong-hui, MA Qiao-na, HE Wen-jin, TIAN Yu-hong, and LAN Xin-zhe
The pyrolysis of direct-coal-liquefaction residue (DCLR) was prepared using microwave and conventional pyrolysis. The composition and structure of solid coke, tar and gas were investigated and the pyrolysis products were compared after characterization by infrared spectroscopy (FTIR) and gas chromatography-mass spectroThe pyrolysis of direct-coal-liquefaction residue (DCLR) was prepared using microwave and conventional pyrolysis. The composition and structure of solid coke, tar and gas were investigated and the pyrolysis products were compared after characterization by infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS).Results showed that DCLR was rapidly heated up to 900 ℃ in 20 min with the maximum heating rate of 329 ℃·min-1 in the microwave field, while the heating rate of conventional heating was constant. Compared with conventional pyrolysis,coke yield decreased by 3% after microwave pyrolysis, whereas the tar and gas yields increased by 0.66% and 2.19%, respectively.After the pyrolysis of DCLR, the extracted compositions consisting of heavy oil(HS), as phaltene (A), and pre-asphaltene (PA) decreased significantly, while the content of tetrahydrofuran insolubles (THFIS) increased. The Soxhlet compositions of the solid coke did not evidently change compared with those after conventional pyrolysis, which indicated that the pyrolysis process of DCLR is mainly based on the conversion of HS, A and PA. After microwave pyrolysis,the intensity of the absorption peak at 3 437.6, 1 632 and 1 079.99 cm-1 on the infrared spectrum of the solid coke was significantly lower than that of conventional pyrolysis, which indicated that DCLR was more thoroughly pyrolyzed in the microwave field.Both tar and gas yields increased after pyrolysis, and the content of H2 in gas reached above 60%. The results of GC-MS showed that no obvious change in the composition for aliphatics, aromatics, alcohol and the contents of C1~5, C11~20 and C>20in tar was observed after extraction with petroleum ether. The asphaltene content of tar decreased by 7.7% after microwave pyrolysis, which indicated that microwave pyrolysis can effectively promote asphaltene decomposition in DCLR, which benefited tar conversion to light fraction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1313 (2018)
Detecting H2S Gas Concentration by 1,8-Naphthalimides Fluorescent Probe
TANG Dong-lin, WANG Qiao, CHU Yi-neng, and LI Rui-hai
Aiming at the low sensitivity of traditional hydrogen sulfide detection method, a small-molecule fluorescent probe was designed and synthesized for hydrogen sulfide detection via introducing oxidizing group of nitro on the 1,8-naphthalimide fluorescence group, based on the nitro group could be reduced by hydrogen sulfiAiming at the low sensitivity of traditional hydrogen sulfide detection method, a small-molecule fluorescent probe was designed and synthesized for hydrogen sulfide detection via introducing oxidizing group of nitro on the 1,8-naphthalimide fluorescence group, based on the nitro group could be reduced by hydrogen sulfide to produce the corresponding amino group. The fluorescence intensity of probe was very weak, and the fluorescence peaks were at λ=467 nm and λ=522 nm. After reacting with H2S, fluorescent effect disappeared at 522 nm, it significantly enhanced at 467 nm. The fluorescence spectrum of fluorescent probe was measured after being introduced into H2S, and the fluorescence intensity at 467 nm was analyzed. The experimental result showed an excellent linear relationship between H2S gas concentration and fluorescence intensity, while the linear correlation coefficient was up to 0.979 3. Meanwhile, the minimum H2S gas concentration that could be detected was only 0.88×10-6 mol·L-1. Fluorescence spectrometric detection of 1,8-naphthalimides solution can be used for the H2S gas rapid determination in oil and gas fields..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1319 (2018)
Preparation of the Porous CeO2 Film and Its Spectral Properties
LIU Xiao-zhen, SHI Xing-ju, LIU Xiao-zhou, REN Xiao-hui, CHEN Jie, and ZHOU Jie-hua
The porous CeO2 films were prepared with anodization and heat treating method with cerium foils as raw materials. The anodic cerium oxide films were heat treated at 400, 500 and 800 ℃ respectively. The crystal structures, compositions, surface morphologies of the cerium dioxide films were investigated, respectively. ThThe porous CeO2 films were prepared with anodization and heat treating method with cerium foils as raw materials. The anodic cerium oxide films were heat treated at 400, 500 and 800 ℃ respectively. The crystal structures, compositions, surface morphologies of the cerium dioxide films were investigated, respectively. The properties of IR characteristic absorption and thermal expansion of the porous CeO2 film were investigated respectively. The anodic cerium oxide film is composed of Ce(OH)3, CeF3, CeO2, Ce2O3 and Ce, and the crystal structures of Ce(OH)3, CeF3, Ce2O3 and CeO2, Ce are hexagonal and cubic respectively. Water and ethylene glycol are adsorbed on the anodic cerium oxide film. When the anodic cerium oxide films were heat treated at 400 and 500 ℃ respectively, Ce(OH)3, Ce2O3 and Ce in the anodic cerium oxide film may be converted to CeO2, and the heat treated films are composed of CeF3 and CeO2 respectively. When the anodic cerium oxide film was heat treated at 800 ℃, Ce(OH)3, CeF3, Ce2O3 and Ce in the anodic cerium oxide film are converted to CeO2, and the heat treated film is composed of CeO2. The heat treated anodic cerium oxide film of heat treatment at 800 ℃ is CeO2 film. The CeO2 film is porous film, and the hole is a straight hole. The porous CeO2 film has strong absorption in the range of 1 600～4 000 cm-1. The coefficients of thermal expansion of the porous CeO2 film are almost constant in the range of 170～900 ℃. The porous CeO2 film has good thermal stability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 38, Issue 4, 1324 (2018)
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