Journals >Spectroscopy and Spectral Analysis
Contents
2009
Volume: 29 Issue 10
68 Article(s)
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Research Article
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 1 (2009)
Monitoring of Oxygen Concentration Based on Tunable Diode Laser Absorption Spectroscopy
ZHANG Shuai, DONG Feng-zhong, ZHANG Zhi-rong, WANG Yu, KAN Rui-feng, ZHANG Yu-jun, LIU Jian-guo, and LIU Wen-qing
Oxygen is a widely used important gas in the industrial process. It is very meaningful to on-line monitor the oxygen concentration for the enhancement of combustion efficiency and reduction in environmental pollution. Tunable diode laser absorption spectroscopy (TDLAS) is a highly sensitive, highly selective and fast tOxygen is a widely used important gas in the industrial process. It is very meaningful to on-line monitor the oxygen concentration for the enhancement of combustion efficiency and reduction in environmental pollution. Tunable diode laser absorption spectroscopy (TDLAS) is a highly sensitive, highly selective and fast time response trace gas detection technique. With the features of tunability and narrow linewidth of distributed feedback (DFB) diode laser and by precisely tuning the laser output wavelength to a single isolated absorption line of the gas, TDLAS technique can be utilized to accurately implement gas concentration measurement with very high sensitivity. In the present paper, the authors used a DFB laser was used as the light source, and by employing wavelength modulation method and measuring the second harmonic signal of one absorption line near 760 nm of oxygen molecule, the authors built a system for online monitoring of oxygen concentration. The characteristics of the system are as follows： the scope of detection is 0.01%-20% ; detection accuracy is 0.1 %, long term stability is 1 %..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2593 (2009)
Ammonia Gas Concentration and Velocity Measurement Using Tunable Diode Laser Absorption Spectroscopy and Optical Signal Cross-Correlation Method
ZHANG Chun-xiao, WANG Fei, LI Ning, YAN Jian-hua, CHI Yong, and CEN Ke-fa
Simultaneous online measurement of gas concentration and velocity can be realized by tunable diode laser absorption spectroscopy (TDLAS) technique and optical signal cross correlation method. The fundamental and relative factors of gas concentration and velocity measurement are described in the present paper. The spectSimultaneous online measurement of gas concentration and velocity can be realized by tunable diode laser absorption spectroscopy (TDLAS) technique and optical signal cross correlation method. The fundamental and relative factors of gas concentration and velocity measurement are described in the present paper. The spectral lines of NHa used for gas sensing at communication band in near infrared range were selected and analyzed by the calculation based on the HITRAN database. In the verification experiment, NH3 and N2 were mixed by two mass flow meters and sent to flow through the quartz tube 0. 016 m in inner diameter and 1 m in length at normal temperature and pressure. The spectral line located at 6 548.7 cm^-1 was scanned at high frequency by the diode laser of 15 MHz linewidth and 1 cm^-1 tunable range with no mode hoppings. The instantaneous NH3 absorbance was obtained using direct absorption method and the gas concentration was calculated. At the same time, the non-intru sive optical absorption signal cross-correlation method was utilized to obtain two concentration signals from two adjacent detectors mounted along the gas tube. The corresponding transit time of gas passing through the detectors was calculated by crosscorrelation algorithm, and the average gas velocity was inferred according to the distance between the two detectors and the transit time. The relative errors were less than 7% for the gas concentration measurement, and less than 10% for the gas velocity measurement. Experimental results were proved to be of high precision and good repeatability in the lab. The feature of fast response and capacity immune to the in-silu disturbance would lead to a potential in industry application for the real time measurement and control of gas pollutant emission in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2597 (2009)
Comparison of Two Spectral Mixture Analysis Models
WANG Qin-jun, LIN Qi-zhong, LI Ming-xia, and WANG Li-ming
A spectral mixture analysis experiment was designed to compare the spectral unmixing effects of linear spectral mixture analysis (LSMA) and constraint linear spectral mixture analysis (CLSMA). In the experiment, red, green, blue and yellow colors were printed on a coarse album as four end members. Thirty nine mixed samA spectral mixture analysis experiment was designed to compare the spectral unmixing effects of linear spectral mixture analysis (LSMA) and constraint linear spectral mixture analysis (CLSMA). In the experiment, red, green, blue and yellow colors were printed on a coarse album as four end members. Thirty nine mixed samples were made according to each end mem her＇s different percent in one pixel. Then, field spectrometer was located on the top of the mixed samples＇ center to measure spectrum one by one. Inversion percent of each end member in the pixel was extracted using LSMA and CLSMA models. Finally, normalized mean squared error was calculated between inversion and real percent to compare the two models ＇ effects on spec tral unmixing. Results from experiment showed that the total error of LSMA was 0. 300 87 and that of CLSMA was 0. 375 52 when using all bands in the spectrum. Therefore, LSMA was 0. 075 less than that of CLSMA when the whole bands of four end members＇ spectra were used. On the other hand, the total error of LSMA was 0. 280 95 and that of CLSMA was 0. 298 05 after band selection. So, LSMA was 0. 017 less than that of CLSMA when bands selection was performed. Therefore, whether all or selected bands were used, the accuracy of LSMA was better than that of CLSMA because during the process of spectrum measurement, errors caused by instrument or human were introduced into the model, leading to that the measured data could not mean the strict requirement of CLSMA and therefore reduced its accuracy. Furthermore, the total error of LSMA using selected bands was 0. 02 less than that using the whole bands. The total error of CLSMA using selected bands was 0. 077 less than that using the whole bands. So, in the same model, spectral unmixing using selected bands to reduce the correlation of end members＇ spectra was superior to that using the whole bands..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2602 (2009)
Effect of Ambient Atmosphere on Laser Micro-Plasma Radiant Intensity
GUO Qing-lin, HAN Mei-ying, ZHANG Lei, ZHANG Qiu lin, ZHANG Jin-ping, and CHEN Jin-zhong
The plasma radiant intensity was investigated by a laser micro-plasma spectral analysis system. The system consists of an YJC- Ⅱ laser micro-spectral analyzer and a CCD data acquisition and processing system. National standard soil samples were studied in the experiment under different ambient atmosphere with argon, heThe plasma radiant intensity was investigated by a laser micro-plasma spectral analysis system. The system consists of an YJC- Ⅱ laser micro-spectral analyzer and a CCD data acquisition and processing system. National standard soil samples were studied in the experiment under different ambient atmosphere with argon, helium and the mixture of argon and helium by using the analysis lines, CaⅡ 393. 367 nm and Ca Ⅱ 396. 847 nm. The results of this research suggest that both the time of plasma illumination and the radiant intensity of plasma in an atmosphere of helium argon mixture were better than that in pure helium or argon gas. The plasma radiant intensity was obviously enhanced when the proportion of helium and argon was 66. 7% and 33.3%, respectively. Under these conditions, the influence of the height of auxiliary electrode on laser micro-plasma radiant intensity was also investigated. The maximum laser micro-plasma radiant intensity was reached when the height of auxiliary elec trode was 3 mm..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2606 (2009)
Temperature Dependence of Cross Sections for Energy Transfer Processes of Rb(7S-5D)-H2, He
WANG Jun, WANG Min, DAI Kang, WANG Qian, and SHEN Yi-fan
Rb vapor, mixed with H2 or He, was irradiated in a glass fluorescence cell with pulses of radiation from a YAG-laserpumped OPO laser, populating 5D or 7S state by two-photon absorption. The temperature dependence of the cross sections for 5D-7S transfer induced by collisions with He atoms and H2 molecules was determineRb vapor, mixed with H2 or He, was irradiated in a glass fluorescence cell with pulses of radiation from a YAG-laserpumped OPO laser, populating 5D or 7S state by two-photon absorption. The temperature dependence of the cross sections for 5D-7S transfer induced by collisions with He atoms and H2 molecules was determined using methods of atomic fluorescence. The resulting fluorescence included a direct component emitted in the decay of the optically excited state and a sensitized component arising from the eollisionally populated state. At the different densities, the authors have measured the relative time-integrated intensities of the components and fitted a three-state rate equation model to obtain the reactive and nonreactive cross sections for Rb(7S-5D) H2, He collisions. The cross sections of transfer for Rb(7S)+ H2→Rb(SD)+ H2 decrease with increasing T. The cross sections for 5D-+7S increase with increasing T. At the different temperatures, the cross sections of transfer for (7S-5D)- He collisions coincide with the principle of detailed balance. The total transfer rate coefficients out of the 7S or 5D state for He were small. The total quenching rate coefficient out of the 7S or 5D state was much larger for H2. In the case of H2, the quenching rate coefficient corresponds to reaction and nonreactive energy transfer. In reaction of Rb(7S, 5D)+ Hz→RbH+H, the ratio between the reactive cross sections was found to be σ^- [Rb (7S) + H2 ]/σ^- ( Rb (5D) + H2 ] = 1.5. The relative reactivity with H2 was in an order of Rb(7S)〉Rb(SD)..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2610 (2009)
Application of lmmunomagnetic Separation to E. coli O157:H7 Detection
TANG Qian qian, WANG Jian-ping, YE Zun-zhong, GAI Ling, and YING Yi-bin
In the present paper, the capture efficiencies of four different proportions of E. coli O157:H7 and immunomagnetic beads (IMB) (1:6.34, 1:12.69, 1:25.38 and 1:30.07) and three different proportions orE. coli O157:H7 and Bacillus suhtilis(0. 3 mL:0.1 mL, 0.2 mL:0.2 mL and 0.1 mL:0. 3 mL)were compared, with the total volIn the present paper, the capture efficiencies of four different proportions of E. coli O157:H7 and immunomagnetic beads (IMB) (1:6.34, 1:12.69, 1:25.38 and 1:30.07) and three different proportions orE. coli O157:H7 and Bacillus suhtilis(0. 3 mL:0.1 mL, 0.2 mL:0.2 mL and 0.1 mL:0. 3 mL)were compared, with the total volume and capacity of IMB remaining constant. It was revealed that the capture efficiency could reach 100% when the proportion of E. coli O157:H7 and IMB was 1:30, meaning that almost all targets E. coli O157:H7 could be captured at 1:30, and that the capture efficiency decreased and then increased with the number of Bacillus subtilis increasing. Moreover, the combination of ATP bioluminescence and IMS was correlated well with conventional culture methods, R^2 = 0. 988 2, and the detection limit was as low as 10^2 CFU · mL^-1..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2614 (2009)
Investigation of Guanidine Hydrochloride Induced Chlorophylls Denaturation by Terahertz Time-Domain Spectroscopy
CHEN Hua, and WANG Li
In investigating guanidine hydrochloride (GuHCl) denatured chlorophylls using the terahertz time-domain spectroscopy, the authors explored the feasibility and sensitivity of the terahertz technology in sensing protein denaturation and associated conformation changes. It was found that the conformation change was induceIn investigating guanidine hydrochloride (GuHCl) denatured chlorophylls using the terahertz time-domain spectroscopy, the authors explored the feasibility and sensitivity of the terahertz technology in sensing protein denaturation and associated conformation changes. It was found that the conformation change was induced by the C=O group of chlorophyll, interacting with the N H group of GuHCl to form hydrogen bonds, which shows higher absorption than the native ones and an absorption peak around 1.7 THz in our THz spectra. The results presented here demonstrate that THz-TDS has both advantages and disad vantages in monitoring denaturation process of proteins, which is important in applying THz-TDS technique to the study of biomolecules..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2619 (2009)
Terahertz Spectroscopic Investigation of Organophosphorus Pesticide Parathion-Methyl
YAN Zhi-gang, ZHENG Song, XIE Qiang-jun, and ZHOU Ze-kui
The present paper reports the theoretical and experimental vibrational spectra of organophosphorus pesticide parathion-methyl in the frequency range from 0. 2 to 2.0 THz respectively. Under the room temperature and nitrogen conditions, the absorption peaks were found at 0.65, 1.33, 1.81 and 1.91 THz, and the average reThe present paper reports the theoretical and experimental vibrational spectra of organophosphorus pesticide parathion-methyl in the frequency range from 0. 2 to 2.0 THz respectively. Under the room temperature and nitrogen conditions, the absorption peaks were found at 0.65, 1.33, 1.81 and 1.91 THz, and the average refractive index was 1.39 based on the terahertz time-domain spectroscopy (THz-TDS). In parallel with the experimental study, density functional theory (DFT) was applied to obtain the structure and vibrational frequencies of parathion-methyl in the terahertz region. The calculated results are in reasonable agreement with the experimental data. The absorption features are caused by the collective vibrational and torsional modes, and the different absorption peaks correspond to different vibrational modes..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2622 (2009)
Study on the Sensitizing Effect of fac-Tris(2-Phenylpyridinato-N, C2′) Iridium( Ⅲ ) on Two Different Fluorescent Materials
SONG Dan-dan, ZHAO Su-ling, XU Zheng, ZHANG Fu-jun, YUE Xin, and ZHU Hai-na
It is considered that the efficiency of fluorescent material based organic light emitting diodes can be enhanced by introducing a phosphorescent sensitizer. In the present work, devices with emission layers (EML) of fac-tris(2-phenylpyridinato-N,C^2′) iridium (Ⅲ) (Ir(ppy)3)-sensitized-fluorescent materials were fabricaIt is considered that the efficiency of fluorescent material based organic light emitting diodes can be enhanced by introducing a phosphorescent sensitizer. In the present work, devices with emission layers (EML) of fac-tris(2-phenylpyridinato-N,C^2′) iridium (Ⅲ) (Ir(ppy)3)-sensitized-fluorescent materials were fabricated. Ir(ppy)3 was co-doped with DCJTB and rubrene in PVK matrix, respectively. When the doping ratio was proper, pure emission from fluorescent material can be achieved. Furthermore, the sensitizing mechanism and effect were analyzed. A weak effect between Ir(ppy)3 and DCJTB was found. It was deduced that the weaker sensitizing effect is related to the poor film appearance..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2626 (2009)
The General Analytical Methods for Gases Dissolved in Liquids： Sonol uminescence
DENG Jiu-shuai, and LIU Yan
How to analyze the gases dissolved in water or organic liquids is a challenging problem in analytical chemistry. Till the present time, only the dissolved oxygen in water can be analyzed by chemical and instrumental methods, while other gases, e. g. CO2, N2, CH4, Ar, He, Ke, still can not be analyzed by chemical or insHow to analyze the gases dissolved in water or organic liquids is a challenging problem in analytical chemistry. Till the present time, only the dissolved oxygen in water can be analyzed by chemical and instrumental methods, while other gases, e. g. CO2, N2, CH4, Ar, He, Ke, still can not be analyzed by chemical or instrumental methods. The present paper gives a review on using sonoluminescence for gas analysis in water or organic liquids..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2630 (2009)
Development of an Analyzing System for Soil Parameters Based on NIR Spectroscopy
ZHENG Li-hua, LI Min-za, and SUN Hong
A rapid estimation system for soil parameters based on spectral analysis was developed by using object-oriented (OO) technology. A class of SOIL was designed. The instance of the SOIL class is the object of the soil samples with the particular type, specific physical properties and spectral characteristics. Through extA rapid estimation system for soil parameters based on spectral analysis was developed by using object-oriented (OO) technology. A class of SOIL was designed. The instance of the SOIL class is the object of the soil samples with the particular type, specific physical properties and spectral characteristics. Through extracting the effective information from the modeling spectral data of soil object, a map model was established between the soil parameters and its spectral data, while it was possible to save the mapping model parameters in the database of the model. When forecasting the content of any soil parameter, the corresponding prediction model of this parameter can be selected with the same soil type and the similar soil physical properties of objects. And after the object of target soil samples was carried into the prediction model and processed by the system, the aceurate forecasting content of the target soil samples could be obtained. The system includes modules such as file operations, spectra pretreatment, sample analysis, calibrating and validating, and samples content forecasting. The system was designed to run ou tof equipment. The parameters and spectral data files ( ＊. xls) of the known soil samples can be input into the system. Due to various data pretreatment being selected according to the concrete conditions, the results of predicting content will appear in the terminal and the forecasting model can be stored in the model database. The system reads the predicting models and their param- eters are saved in the model database from the module interface, and then the data of the tested samples are transferred into the selected model. Finally the content of soil parameters can be predicted by the developed system. The system was programmed with Visual C+ +6.0 and Matlab 7.0. And the Access XP was used to create and manage the model database..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2633 (2009)
Selection of Variables for MLR in Vis/NIR Spectroscopy Based on BiPLS Combined with GA
LI Peng-fei, WANG Jia-hua, CAO Nan-ning, and HAN Dong-hai
The feasibility of using efficient selection of variables in Vis/NIR for a rapid and conclusive determination of fruit inner qualities such as soluble solids content (SSC) of plums was investigated. A new strategy was proposed in the present paper, i. e. two-stage variable selection using the backward interval partial The feasibility of using efficient selection of variables in Vis/NIR for a rapid and conclusive determination of fruit inner qualities such as soluble solids content (SSC) of plums was investigated. A new strategy was proposed in the present paper, i. e. two-stage variable selection using the backward interval partial least squares (BiPLS) combined with genetic algorithm (GA). Firstly, it splits the whole spectral region into equidistant sub-regions and then develops all BiPLS regression models, and the informative regions which are used to constructed PLS models with the lowest error can be located. Secondly, GA method is used to select variable in these informative regions, which are used for regression variables of MLR model. The Vis/NIR spectra containing 225 individual data points were processed by Savizky-Golay filter smoothing and second-order derivative, and 9 sub-regions were selected by BiPLS procedure when the spectra were divided into 25 sub-regions. The optimal 12 variables, which were the output of the GA procedure, were selected by the higher occurrence frequency while the GA procedure ran 100 times. In order to simplify the multiple linear regression (MLR) modeling, the wavelength variables with the maximum occurrence frequency were chosen when the adjacent wavelengths were selected by GA. Finally, 638, 734, 752, 868, 910, 916 and 938 nm were used to build a MLR model. The results show that MLR model produced by BiPLS-GA performs well with correlation coefficients (R) of 0. 984, root mean standard error of calibration (RMSEC) of 0. 364 and root mean standard error of prediction (RMSEP) of 0. 471 for SSC, which outperforms models using stepwise regression analysis (SRA). This work proved that the BiPLS-GA could determine optimal variables in Vis/NIR spectra and improve the accuracy of model..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2637 (2009)
Effect of Different Tillage Managements on Black Humic Fractions and IR Spectral Feature
LU Yi-zhong, CONG Wei-wei, and LIAN Xiao-juan
The present study was based on the long-term (10 years) field conservation tillage experiment, in which four tillage treatments were designed as following： Conventional tillage (CT) by moldboard plowing with ridge culture; Rotary tillage with ridge culture (RT) ; Alternant tillage by rotary on wide row and loosing on nThe present study was based on the long-term (10 years) field conservation tillage experiment, in which four tillage treatments were designed as following： Conventional tillage (CT) by moldboard plowing with ridge culture; Rotary tillage with ridge culture (RT) ; Alternant tillage by rotary on wide row and loosing on narrow row (WN) ; Rotary tillage plus deep loosing annually (RD). Humic acids were extracted from black soil profiles under these tillage managements. The elements visible spectra and FTIR of HA in black soil were analyzed. The results indicated that the elements of HA were affected by different tillage managements, WN increased N/C, H/C and O/C values of HA in the 0-20 cm layer. The lowest E4/E6 value of HA was found under CT treatment, while the highest E4/E6 value was found under WN treatment; FTIR indicated that CT treatment increased the amount of C=N groups and aromatic ring condensation of HA in 0-20 cm soil, while WN decreased aromatic ring condensation and increased the content of nitrogen compound and aliphatic compound. RT increased the functional groups of OH, aliphatie CH2 and nitrogen compound. CT and RD increased the content of C=O and C=O..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2642 (2009)
Identification and Analysis of Rice Infrared Diffuse Reflection Spectra Drought Tolerance Using Near of Leaves
LI Jun-hui, WANG Chang-gui, KANG Ding-ming, WANG Hua-qi, YU Chun-xia, and ZHANG Lu-da
In the present study, different drought tolerance rice from different countries and areas were selected and grown in water field and drought field respectively, including 4 traditional varieties of drought rice, 18 varieties of modified drought rice, 2 varieties of drought traits rice, 2 varieties of drought tolerance In the present study, different drought tolerance rice from different countries and areas were selected and grown in water field and drought field respectively, including 4 traditional varieties of drought rice, 18 varieties of modified drought rice, 2 varieties of drought traits rice, 2 varieties of drought tolerance rice, and a total of 30 different varieties of drought tolerance rice were involved. Using near infrared diffuse reflection spectra of leaves from water field and drought field, we studied the rice drought tolerance identification analysis. Results showed that： using the average spectra of several leaves＇ spectra, selecting 4 500-7 500 cm ^-1 as effective analysis spectra zone, choosing the first derivative and multiple scattering correction (MSC) as spectra preprocessing method, we can set up the calibration models between the spectra of leaves from drought field and the yield of rice. Simultaneously, we concluded that the performance of calibration model for rice yield and drought tolerance identification indexes in the upper booting stage was better than in the previous booting stage whose correlation coefficient of cross validation could reach 0. 8. But there was no obvious relation between the spectra from water field and the yield, the drought tolerance identification indexes. We explained the difference in these two series models＇ performance from the relationship between some parameter of the leaves＇ biochemistry (chlorophyll, moisture, etc) and yield, the drought tolerance identification indexes..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2646 (2009)
Study on Fixation Mechanism of CuAz Preservatives in Bamboo by ATR-FTIR
WANG Ya-mei, WANG Xi-ming, and LIU Jun liang
The fixation mechanism of CuAz preservatives in bamboo was studied with bamboo as the experimental material in the present paper. The purpose of the study is to understand the interaction between preservatives and bamboo, provide a theoretical basis for the design and optimization of preservatives formula and for improThe fixation mechanism of CuAz preservatives in bamboo was studied with bamboo as the experimental material in the present paper. The purpose of the study is to understand the interaction between preservatives and bamboo, provide a theoretical basis for the design and optimization of preservatives formula and for improving preservative treatment. The chemical combination between preservatives and bamboo components was analysed by ATR Fourier transform infrared spectroscopy (ATR-FTIR), and the results show that the infrared spectra of lignin after treatment changed significantly. The lignin characteristic peaks (1 510 cm^-1 ) changed obviously. Lignin phenolic hydroxyl was involved in the lignin-copper complex formation. Holocellulose＇ s spectra after treatment changed little, with just a change in hemicellulose carboxyl and hemicellulose acyl-oxygen bond (C-O) stretching vibration..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2651 (2009)
Analysis of Cell Arrangements in Biota Orientalis Using Fourier Transformation
DUO Hua-qiong, and WANG Xi-ming
Fourier transform image-processing technology is applied for determining the cross section cell arrangement of earlywood in Biota orientalis. In this method, the disc-convoluted dot map from each cell radius with 10 pixels is transformed by Fourier transform, generating the angle distribution function in the power specFourier transform image-processing technology is applied for determining the cross section cell arrangement of earlywood in Biota orientalis. In this method, the disc-convoluted dot map from each cell radius with 10 pixels is transformed by Fourier transform, generating the angle distribution function in the power spectral pattern. The maximum value is the arrangement of the cell. The results of Fourier transform image-processing technology indicated that the arrangements of the cell of Biota orientalis are 15° in oblique direction, respectively. This method provides a new basis for the digitized identification of the wood, and also the new theoretical research direction for the digitized identification and examination of the wood species..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2654 (2009)
Study on Temperature Measurement of Solution by Reference-Wavelength Method
CHEN Yun, LIANG Yu-jie, CHEN Wen- liang, and XU Ke-xin
Near-infrared (NIR) spectroscopy has been widely used in agriculture, medicine, petrochemical and food industries. However, the measurement precision of NIR spectroscopy is adversely affected by the change in external conditions. Among these influence factors, temperature fluctuation is harder to be controlled than othNear-infrared (NIR) spectroscopy has been widely used in agriculture, medicine, petrochemical and food industries. However, the measurement precision of NIR spectroscopy is adversely affected by the change in external conditions. Among these influence factors, temperature fluctuation is harder to be controlled than other conditions such as contact pressure and measurement position. Based on the displacement effect between solvent and solute molecules in solution, a reference-wavelength method for temperature measurement of solution is presented in the present paper. The theoretical expression of the method was introduced. The experiment was designed to measure the spectra of glucose aqueous solution under different temperatures, and the effect of eliminating the temperature disturbance was evaluated. When the temperature and solute concentration of solution change simultaneously, the absorbency difference value at reference-wavelength is insensitive＇ to solute concentration, and is totally affected by temperature fluctuation. Therefore, according to the absorbanee difference, the actual temperature of the sample can be calculated. The regression model of temperature measurement was.established, and the solution temperature was calculated based on this model. The information about temperature can be acquired exactly by reference-wavelength method, and the experimental results showed that the average error of calculated temperature is 0. 03 ℃..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2657 (2009)
Study on a Method of Selecting Calibration Samples in NIR Spectral Analysis
QIN Chong, CHEN Wen-wen, HE Xiong-kui, ZHANG Lu-da, and MA Xiang
In the present paper, a simple but novel method based on maximum linearly independent group was introduced into near-infrared (NIR) spectral analysis for selecting representative calibration samples. The experiment materials contained 2 652 tobacco powder samples, with 1 001 samples randomly selected as prediction set,In the present paper, a simple but novel method based on maximum linearly independent group was introduced into near-infrared (NIR) spectral analysis for selecting representative calibration samples. The experiment materials contained 2 652 tobacco powder samples, with 1 001 samples randomly selected as prediction set, and the others as representative sample candidate set from which calibration sample set was selected. The method of locating maximum linearly independent vectors was used to select representative samples from the spectral vectors of representative samples candidate set. The arithmetic was accomplished by function rref(X, q) in Matlab. The maximum linearly independent spectral vectors were treated as calibration samples set. When different calculating precision q was given, different amount of representative samples were acquired. The selected calibration sample set was used to build regression model to predict the total sugar of tobacco powder samples by PLS. The model was used to analyze 1001 samples in the prediction set. When selecting 32 representative samples, the model presented a good predictive veracity, whose predictive mean relative error was 3. 621 0%, and correlation coefficient was 0. 964 3. By paired- samples t-test, we found that the difference between the predicting result of model obtained by 32 samples and that obtained by 146 samples was not significant (a=0. 05). Also, we compared the methods of randomly selecting calibration samples and maximum linearly independent selection by their predicting effects of models. In the experiment, correspondingly, six calibration sample sets were selected, one of which included 28 samples, while the others included 32, 41, 76, 146 and 163 samples respectively. The method of maximum linearly independent selecting samples turned out to be obviously better than that of randomly selecting. The result indicated that the proposed method can not only effectively enhance the cost-effectiveness of NIR spectral analysis by reducing the number of samples required for cockamamie and expensive chemical measurement, but also improve the analysis accuracy. In conclusion, this method can be applied to select representative samples in near-infrared spectral analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2661 (2009)
Injection by Near Infrared Diffuse Reflectance Spectroscopy
SONG Yan, XIE Yun-fei, ZHANG Yong, LI Zhi-shi, CONG Qian, and ZHAO Bing
In the present study, a total of 47 levofloxacin hydrochloride injection samples were detected by near infrared (NIR) spectroscopy, and 37 samples were randomly selected to establish the quantitative models by partial least squares (PLS) and artificial neural network (ANN) technology, while other 12 samples were used fIn the present study, a total of 47 levofloxacin hydrochloride injection samples were detected by near infrared (NIR) spectroscopy, and 37 samples were randomly selected to establish the quantitative models by partial least squares (PLS) and artificial neural network (ANN) technology, while other 12 samples were used for prediction. On the one hand, the model was established by PLS, the coefficient of determination (R^2) of the prediction is 0. 964, and the root mean squared error of prediction (RMSEP) is 0. 242 8. On the other hand, after the spectrum variables were highly effectively compressed using the wavelet transformation technology, the quantitative analysis model of levofloxaein hydrochloride was established through the ANN technology. The R^2 and RMSEP of the model is 0. 944 and 0. 572 2, respectively. In this work, we have a detailed comparison between the two technologies in the progress of two quantitative models and optimizing correlative parameter, and finally we got a satisfied result. The simulation experiment indicated that the above PLS model is more steady and precise than ANN model, which can get hold of a rapid and nondestructive quantitative analysis result of the injection. Thus, the research can provide powerful scientific basis and technical support for further analysis of levofloxacin hydrochloride injection..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2665 (2009)
Identification of Hardness of Licorice Single Seed Using Near Infrared Spectroscopy
SUN Qun, LI Jun-hui, WANG Jian-hua, and SUN Bao-qi
To break the dilemma on judging hard seeds and soft seeds of licorice and other legume families nondestructively, a distinguishing model for the hardness of licorice single seed was tried to be built by near infrared reflectance spectroscopy with distinguished partial least squares(DPLS). A total of 244 licorice seeds To break the dilemma on judging hard seeds and soft seeds of licorice and other legume families nondestructively, a distinguishing model for the hardness of licorice single seed was tried to be built by near infrared reflectance spectroscopy with distinguished partial least squares(DPLS). A total of 244 licorice seeds were divided into three groups： calibration set (120 samples), validation set (60 samples) and prediction set (64 samples), and each group has the same number of hard seeds and soft seeds. To eliminate the human error as far as possible, a specially made sample cup was designed for spectrum acquisition. Then the locations of the seed and the fiber-optic probe were fixed during each spectrum acquisition process. The influences of different replicate time, different spectral region and different calibration samples on the identification rate were compared. The result indicated that four replicates could increase the identification rate of the model significantly, the identification rates of the model of four replicates in calibration, validation and prediction set samples were 95.83%, 95.00% and 96.88% respectively, while that of one replicate were 93.33%, 91.67% and 82.81% respectively. The model of the spectral region between 4 000 and 80 000 cm ^-1 was better than that of other regions, and the identification rate in calibration, validation and prediction set samples were 95.53%, 95. 94% and 94. 53% respectively. Even with different samples, the predication rates were all more than 90%. The identification rates of hard seed and soft seed in prediction set samples were 92.50% and 96.56% respectively. The prediction for seeds with different size and different color showed that this model was not suitable for bigger and smaller seeds, especially not for black seeds. NIR offered a new way to distinguish the hardness of licorice singe seed quickly, precisely and nondestructively, which will advance the study on the mechanism of hardness of crop seeds..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2669 (2009)
Determination of Sinigrin in Semen Thlaspi From Sichuan and Tibet Using Near Infrared Diffuse Reflectance Spectroscopy
WANG Lei-lei, CHEN Cong, ZHOU Min, WANG Jian-zhong, LUO Xia, HUANG Guoa, and YE Li-ming
The objective of the present study was to develop a method for the determination of sinigrin in semen Thlaspi from Sichuan using near infrared diffuse reflectance spectroscopy. Near infrared spectra (NIR) in the region of 7 502.1-5 446.2 cm^-1 were recorded for the 246 semen Thlaspi samples containing sinigrin in the cThe objective of the present study was to develop a method for the determination of sinigrin in semen Thlaspi from Sichuan using near infrared diffuse reflectance spectroscopy. Near infrared spectra (NIR) in the region of 7 502.1-5 446.2 cm^-1 were recorded for the 246 semen Thlaspi samples containing sinigrin in the content of 1. 962%-3. 917%. Calibration models were established using the PLS (partial least squares). Different spectra pretreatment methods were compared. The study showed that spectral information can be extracted thoroughly by minimum and maximum normalization pretreatment methods. In this calibration model, the correlation coefficient (R^2) was 0. 928 0, the SEC (standard deviation of the calibration sets) was 0. 314 and the SEP (standard deviation of the prediction sets) was 0. 388. Results indicated that near infrared diffuse reflectance spectroscopy method can be used to rapidly analyze the valid component in traditional Chinese medicine, and also can be used in the quality control of traditional Chinese medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2673 (2009)
Analysis of Polysaccharides Contents in Ophiopogon daponicus by NIR
WANG Yuan, QIN Min-jian, QI Jin, YU Bo-yang, and TANG Li
In the present paper the polysaccharides in Ophiopogon japonicus was analysed quantitatively by using near infrared spectroscopy. The spectral characteristics of the primary ingredients in ophiopogonis were obtained by applying first derivative, second derivative, smoothing,SNV (standard normal variate), and MSC (multiIn the present paper the polysaccharides in Ophiopogon japonicus was analysed quantitatively by using near infrared spectroscopy. The spectral characteristics of the primary ingredients in ophiopogonis were obtained by applying first derivative, second derivative, smoothing,SNV (standard normal variate), and MSC (multiple scatter correction), and the wavelengths were selected for the best model. Meantime, in combination with the PLS algorithm the calibration process was performed for the quantitative analysis of the polysaccharides in Ophiopogonjaponicus. The result showed that after optimizing all the factors, the best model of equation was using ＂first derivative＂+＂MSC＂+＂SG＂, and the wavelengths for the best model were selected in 4 000-4 900, 5 100-6 900 and 7 050-10 000 cm^-1. The result showed a fine precision of the method, with R^2, RMSEC, R^2cv, RMSECV and principal factors being 0. 996, 0. 237, 0. 973, 0. 583 and 6, respectively. A set of representative samples were used to check the model, and the prediction coefficient of determination was 96.88%..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2677 (2009)
Detection of Single-Walled Carbon Nanotube Bundles by Tip-Enhanced Raman Spectroscopy
WU Xiao-bin, WANG Jia, WANG Rui, XU Ji-ying, TIAN Qian, and YU Jian-yuan
Raman spectroscopy is a powerful technique in the characterization of carbon nanotubes (CNTs). However, this spectral method is subject to two obstacles. One is spatial resolution, namely the diffraction limits of light, and the other is its inherent small Raman cross section and weak signal. To resolve these problems,Raman spectroscopy is a powerful technique in the characterization of carbon nanotubes (CNTs). However, this spectral method is subject to two obstacles. One is spatial resolution, namely the diffraction limits of light, and the other is its inherent small Raman cross section and weak signal. To resolve these problems, a new approach has been developed, denoted tip-enhanced Raman spectroscopy (TERS). TERS has been demonstrated to be a powerful spectroscopic and microscopic technique to characterize nanomaterial or nanostructures. Excited by a focused laser beam, an enhanced electric field is generated in the vicinity of a metallic tip because of the surface plasmon polariton (SPP) and lightening rod effect. Consequently, Raman signal from the sample area illuminated by the enhanced field nearby the tip is enhanced. At the same time, the topography is obtained in the nanometer scale. The exact corresponding relationship between the localized Raman and the topography makes the Raman identification at the nanometer scale to be feasible. In the present paper, based on an inverted microscope and a metallic AFM tip, a tip-enhanced Raman system was set up. The radius of the Au- coated metallic tip is about 30 nm. The 532 nm laser passes through a high numerical objective (NA0.95) from the bottom to illuminate the tip to excite the enhanced electric field. Corresponding with the AFM image, the tip-enhanced near-field Raman of a 100 nm diameter single-walled carbon nanotube (SWNT) bundles was obtained. The SWNTs were prepared by arc method. Furthermore, the near-field Raman of about 3 SWNTs of the bundles was received with the spatial resolution beyond the diffraction limit. Compared with the far-field Raman, the enhancement factor of the tip-enhanced Raman is more than 230. With the super-diffraction spatial resolution and the tip-enhanced Raman ability, tip-enhanced Raman spectroscopy will play an important role in the nano-material and nano-structure characterization..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2681 (2009)
Study of Biological Molecules in Water by Using the Resonance Raman Spectra in Liquid-Core Optical Fiber
JIA Li-hua, WANG Yi-ding, SUN Cheng-lin, LI Zhan-long, LI Zuo-wei, and WANG Li-jun
Raman spectrum is an important and effective method for the study of biological molecules in water. Measuring the Raman spectra for biological molecules in water, however, is very difficult because of the small Raman scattering cross section and the high electronic excitation energy of water molecules. In the present pRaman spectrum is an important and effective method for the study of biological molecules in water. Measuring the Raman spectra for biological molecules in water, however, is very difficult because of the small Raman scattering cross section and the high electronic excitation energy of water molecules. In the present paper, the authors applied both technologies of liquid-core optical fiber and the resonance Raman spectra, then the intensity of Raman spectra was enhanced to a great extent. In this experiment, we chose the laser wavelength 514. 5 of Ar^+ ion laser as excitation laser, because we could obtain the maximal intensity of resonance Raman spectra at this wavelength. The experiment results show that, for the trace inspecting study of β-carotene biological molecules in water, the concentration in the range of 10^-7-10^-9 mol · L^-1 can be detected by quartz liquidcore optical fiber and the concentration in the range of 10^-9-10^-10 mol · L^-1 by Teflon liquid-core optical fiber. The detecting utmost will be further reduced if improving the quality of optical fiber..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2686 (2009)
Raman and FTIR Characteristics of Otolith of Ornamental Carp
GAO Yong-hua, LI Zhuo, QIAO Li, REN Dong-ni, and FENG Qing-ling
Otolith is a typical natural biomineral as functional deposit existing in teleost＇s ears, which is mainly composed of calcium carbonate and organic matter. There is a pair of lapillus, sagitta and asteriscus in fish＇s inner ear, respectively. The authors compare the asteriscus and lapillus in cultured ornamental carp uOtolith is a typical natural biomineral as functional deposit existing in teleost＇s ears, which is mainly composed of calcium carbonate and organic matter. There is a pair of lapillus, sagitta and asteriscus in fish＇s inner ear, respectively. The authors compare the asteriscus and lapillus in cultured ornamental carp using FTIR and Raman. The result shows that the mineral phase in lapillus is aragonite, while the mineral phase in asteriscus is vaterite. The pure aragonite and vaterite existing respectively in otolith are of importance as being used as sample to study aragonite/vaterite biomineralization mechanism. Compared with inorganic induced aragonite and vaterite using FTIR and Raman, the authors found that the spectra of aragonite in lapillus are between those of inorganic induced aragonite and other bio induced aragonite; while the spectra of vaterite in asteriscus are similar to those of other bio induced vaterite. It is possible that unstable vaterite was stabilized through the organic effects in biomineralization process..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2689 (2009)
Effects of Cations in Chlorine Salt Solution on O-H Stretching Raman Spectra of Water
YANG Dan, and XU Wen-yi
In order to understand the effects of the common cations in geofluids on the structure of water, the present paper systematically studied the Raman spectra of NaCl-H2O, CaCl2-H2O, MgCl2-H2O, CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O solutions by two methods. (1) The frequency shifts of the peak maximum around 3 400 cm^-1 in OIn order to understand the effects of the common cations in geofluids on the structure of water, the present paper systematically studied the Raman spectra of NaCl-H2O, CaCl2-H2O, MgCl2-H2O, CuCl2-H2O, ZnCl2-H2O and FeCl3-H2O solutions by two methods. (1) The frequency shifts of the peak maximum around 3 400 cm^-1 in O-H stretching Raman spectra of water reveal the destruction effects of these cations on the structure of water： Ca^2+〉Mg^2+ 〉Na^+, Fe^3+ 〉Zn^2+ 〉 Cu^2+ ; (2) Comparing the intensities of the shoulder peak around 3 250 cm^-1 in the O-H stretching Raman spectra of water. (1) all salts concerned destruct the structure of water; (2)with respect to the same chloride, the destruction extent of hydrogen-bond increases with concentration increasing; (3) comparing different chloride solutions at the same concentration, the destruction effects of catnions on the structure of water decrease in the sequences Ca^2+ 〉Mg^2+〉Na^+ and Fe^3+ 〉Zn^2+ 〉Cu^2+. (4)A hydrogen bond-affected mechanism combining cation destruction with complex compound production is supposed for the first time, and is used to explain the effects of the canions on the structure of water： CaCl2 〉MgCl2 〉FeCl3 〉NaCl〉ZnCl2 〉CuCl2..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2694 (2009)
Reproduction Features of Reflectance Spectrum of Natural Plant Flower Color
LI Sui-xian, SUN Yi, and LIAO Ning-fang
Based on the sRGB color space as an important color space of computer display, the authors explored color reproduction features in sRGB. In the terms of ＂color clipping＂ of color space transformation from CIE1931XYZ to sRGB, the color reproduction errors in sRGB of 218 reflectance spectra of natural plant flower color Based on the sRGB color space as an important color space of computer display, the authors explored color reproduction features in sRGB. In the terms of ＂color clipping＂ of color space transformation from CIE1931XYZ to sRGB, the color reproduction errors in sRGB of 218 reflectance spectra of natural plant flower color were examined. Considering the importance of D65 illumination, the reproduction features of natural color under D65 were emphasized. It was concluded as follows. Firstly, ＂color clipping＂ is the key cause of color transformation error of the natural plant color when it is transformed from CIE1931XYZ to sRGB color space. Secondly, under I365 eight orange and yellow reflectance spectra in 218 natural color show clipping in sRGB color space, accounting for 3.7% of all samples. Finally, the color reproduction of natural plant flower color in sRGB under 1365 is the best, while the A illumination is the worst..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2699 (2009)
Farmland Parcel Extraction Based on High Resolution Remote Sensing Image
HU Tan-gao, ZHU Wen-quan, YANG Xiao-qiong, PAN Yao-zhong, and ZHANG Jin-shui
A new method of farmland parcel extraction from high resolution remote sensing image based on wavelet and watershed segmentation was proposed in the present paper. First, classification results were used to enhance the contrast of gray-scale value of typical pixels in the original image using the high resolution remoteA new method of farmland parcel extraction from high resolution remote sensing image based on wavelet and watershed segmentation was proposed in the present paper. First, classification results were used to enhance the contrast of gray-scale value of typical pixels in the original image using the high resolution remote sensing image＇s spectral information. Second, wavelet transform and watershed segmentation were applied to the enhanced image, then improved region merger algorithm was used to solve the problem of over-segmentation. Finally, inverse wavelet transform was taken to get the reconstructed image, then Canny operator was introduced to add the edge information, and the result of farmland parcel segmentation was obtained. To validate the proposed approach, experiments on Quickbird images were performed, we rapidly extracted the farmland parcel from the test image, and the results had a high accuracy. Despite it had a lot to do in extracting the small size parcels, on the whole the method this paper proposed had a very good robustness. Compared with the traditional methods, it had the following advantages. (1) it was an automatic extraction method, did not need too much manual intervention, and could extract the large area of farmland parcels accurately and effectively. (2) It was a very good solution to the problem of over-segmentation by using improved region merger algorithm, and improved the accuracy of the extraction. All these indicated that the proposed approach was an effective farmland parcel extraction method based on high resolution remote sensing image..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2703 (2009)
Study on Hyperspectral Characteristics of Apple Florescence Canopy
ZHU Xi-cun, ZHAO Geng-xing, LEI Tong, LI Xi-can, and CHEN Zhi-qiang
The present study aims to systematically analyze the hyperspectral characteristics of apple florescence canopy and explore the sensitive spectra to provide the theoretical basis for large area apple information extracting and remote sensing retrieval for nutrition diagnosis. Based on the 120 hyperspectral data of appleThe present study aims to systematically analyze the hyperspectral characteristics of apple florescence canopy and explore the sensitive spectra to provide the theoretical basis for large area apple information extracting and remote sensing retrieval for nutrition diagnosis. Based on the 120 hyperspectral data of apple florescence canopy acquired with ASD Field Spec 3 portable object spectrometer, the effects of different sample numbers on hyperspectral characteristics were analyzed. Using variance analysis method, the hyperspectral characteristics of apple florescence canopy and the sensitive wave bands were obtained. The results showed that with the increase in cumulative sample numbers, the hyperspectrurn curves of apple florescence became stable and smooth. At the 550 nm green peak and the 760-1 300 nm reflection plateau, the reflection rate reduced with the increase in flowering amount, while in the red valley of 670 nm, the reflection rate increased with the increase in flowering amount; At the wave bands of 350-500, 600 680 and 760-1 300nm the variance analysis results showed very significant differences, indicating that they were sensitive wave bands of florescence canopy. With the increase in flowering amount, the red-edge position, the red-edge slope and red-edge area tended to decrease gradually..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2708 (2009)
Research on Hyperspectral Information Parameters of Chlorophyll Content of Rice Leaf in Cd-Polluted Soil Environment
GUAN Li, LIU Xiang-nan, and CHENG Cheng-qi
The remote sensing pollution mechanism in Cd-polluted soil is discussed depending on the research into the chlorophyll content of Cd-polluted rice leaf in the present paper. The response models of remote sensing information parameters, which reflected chlorophyll content variety of rice canopy with soil CA pollution deThe remote sensing pollution mechanism in Cd-polluted soil is discussed depending on the research into the chlorophyll content of Cd-polluted rice leaf in the present paper. The response models of remote sensing information parameters, which reflected chlorophyll content variety of rice canopy with soil CA pollution degree, were established based on Hyperion satellite data and a great number of ground experiment data. To extract sensitive remote sensing parameters for CA pollution, multiple discriminant analysis (MDA) was applied to the reflectivity of 447-925 nm in Hyperion data and five remote sensing information parameters, including MCARI, NPCI, RVSI, NDVI and Depth671. Experiments indicated that MCARI is the most sensitive parameter to the chlorophyll content of Cd-polluted rice, whose response coefficient is 0. 59. In the extent of 1.0-2. 0 mg · kg^-1 of Cd pollution concentration in soil, MCARI curve shows a small decline. In the extent of 2.0-3.0 mg · kg^-1 of CA pollution concentration in soil, MCARI curve is horizontal. Above 3.0 mg · kg^-1, MCARI shows a significant drop trend and so on. The research results showed that the chlorophyll content is a good indicator for nutrition situation of plant, capacity of photosynthesis and each developmental stage. And the chlorophyll remote sensing parameters in crop have a great significance for monitoring heavy metal pollution. This study will help improve the precision and limitation of statistical methods and provide theoretical basis for and technical approach to monitoring soil Cd pollution in large area using hyperspectral remote sensing technology. However, the precision of pollution model needs to be improved..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2713 (2009)
Three-Dimensional Hybrid Denoising Algorithm in Derivative Domain for Hyperspectral Remote Sensing Imagery
SUN Lei, and LUO Jian-shu
To tackle denosing problems in hyperspectral remote sensing imagery, a three-dimensional hybrid denoising algorithm in derivative domain was proposed. At first, hyperspectral imagery is transformed into spectral derivative domain where the subtle noise level can be elevated. And then in derivative domain, a wavelet basTo tackle denosing problems in hyperspectral remote sensing imagery, a three-dimensional hybrid denoising algorithm in derivative domain was proposed. At first, hyperspectral imagery is transformed into spectral derivative domain where the subtle noise level can be elevated. And then in derivative domain, a wavelet based non-linear threshold denoising method, Bayes-Shrink algorithm, is performed in the two-dimensional spatial domain. In the spectral derivative domain, considering that the noise variance is different from band to band, the spectrum is smoothed using Savitzky-Golay filter instead of wavelet threshold denoising method. Finally, the data smoothed in derivative domain are integrated along the spectral axis and corrected for the accumulated errors brought by spectral integration. The algorithm was tested on airborne visible/infrared imaging spectrometer (AVIRIS) data cubes with signal-to-noise ratio (SNR) of 600:1. Experimental results show that the proposed algorithm can reduce the noise efficiently, and the SNR is improved to more than 2 000:1..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2717 (2009)
Automatically Smoothing the Spectroscopic Data by Cubic B-Spline Basis Functions
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In the present paper, a new criterion is derived to obtain the optimum fitting curve while using Cubic B-spline basis functions to remove the statistical noise in the spectroscopic data. In this criterion, firstly, smoothed fitting curves using Cubic B-spline basis functions are selected with the increasing knot numberIn the present paper, a new criterion is derived to obtain the optimum fitting curve while using Cubic B-spline basis functions to remove the statistical noise in the spectroscopic data. In this criterion, firstly, smoothed fitting curves using Cubic B-spline basis functions are selected with the increasing knot number. Then, the best fitting curves are selected according to the value of the minimum residual sum of squares (RSS) of two adjacent fitting curves. In the case of more than one best fitting curves, the authors use Reinsch＇s first condition to find a better one. The minimum residual sum of squares (RSS) of fitting curve with noisy data is not recommended as the criterion to determine the best fitting curve, because this value decreases to zero as the number of selected channels increases and the minimum value gives no smoothing effect. Compared with Reinsch＇s method, the derived criterion is simple and enables the smoothing conditions to be determined automatically without any initial .input parameter. With the derived criterion, the satisfactory result was obtained for the experimental spectroscopic data to remove the statistical noise using Cubic B-spline basis functions..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2721 (2009)
Estimation of Regional Leaf Area Index by Remote Sensing Inversion of PROSAIL Canopy Spectral Model
LI Shu-min, LI Hong, SUN Dan-feng, and ZHOU Lian-di
The present paper selected Qingyundian town and Weishanzhuang town in DaXing District, and C, aolingying town in Shunyi District as test areas, using MODIS data and ASTER data in different scales. The feasibility of winter wheat LAI inversion by PROSAIL physical model, especially the stability of remote sensing data inThe present paper selected Qingyundian town and Weishanzhuang town in DaXing District, and C, aolingying town in Shunyi District as test areas, using MODIS data and ASTER data in different scales. The feasibility of winter wheat LAI inversion by PROSAIL physical model, especially the stability of remote sensing data in different scales, was discussed, and the results from experience model inversion were compared with that from statistical methods. The values of all samples LAI inversion from experience model are close in a region, which means experience model is a reflection of general growing trend, ignoring spatial heterogeneity of the regional leaf area index. But the value of LAI inversion from physical model can be truer in reflecting spatial heterogeneity of the regional leaf area index. The value of LAI inversion from physical model is more real, compared with experience model. With the method of linear weighing, the scale conversion was accomplished, and the LAI inversion results from different remote sensing scale data were compared, and were found similar. The result shows that in the process of largescale regional LAI inversion, physical model inversion is more valid..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2725 (2009)
Identification and Classification of Rice Leaf Blast Based on Multi-Spectral Imaging Sensor
FENG Lei, CHAI Ron-yao, SUN Guang-ming, WU Di, LOU Bing-gan, and HE Yong
Site-specific variable pesticide application is one of the major precision crop production management operations. Rice blast is a severe threat for rice production. Traditional chemistry methods can do the accurate crop disease identification, however they are time-consuming, require being executed by professionals andSite-specific variable pesticide application is one of the major precision crop production management operations. Rice blast is a severe threat for rice production. Traditional chemistry methods can do the accurate crop disease identification, however they are time-consuming, require being executed by professionals and are of high cost. Crop disease identification and classification by human sight need special crop protection knowledge, and is low efficient. To obtain fast, reliable, accurate rice blast disease information is essential for achieving effective site-specific pesticide applications and crop management. The present paper describes a multi-spectral leaf blast identification and classification image sensor, which uses three channels of crop leaf and canopy images. The objective of this work was to develop and evaluate an algorithm under simplified lighting conditions for identifying damaged rice plants by the leaf blast using digital color images. Based on the results obtained from this study, the seed blast identification accuracy can be achieved at 95 %, and the leaf blast identification accuracy can be achieved at 90% during the rice growing season. Thus it can be concluded that mult-spectral camera can provide sufficient information to perform reasonable rice leaf blast estimation..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2730 (2009)
Study on Combinatorial Optimization of Spectral Principal Components Using Successive Projections Algorithm
WU Di, JIN Chun-hua, and HE Yong
Successive projections algorithm (SPA) was employed to select the optimal combination of principal components (PCs) which were obtained by principal component analysis. Short-wave near infrared spectra of milk powder was firstly analyzed by PCA, and the optimal combination of obtained first eight PCs was determined by Successive projections algorithm (SPA) was employed to select the optimal combination of principal components (PCs) which were obtained by principal component analysis. Short-wave near infrared spectra of milk powder was firstly analyzed by PCA, and the optimal combination of obtained first eight PCs was determined by SPA. The optimal PC combination of fat content prediction was PC1, PC2, PC4, PC5, PC6 and PC7, and the combination for protein content prediction was PC1, PC2, PC3, PC4, PC5 and PC6. Least-squares support vector machine models inputted by different PC combination were established to predict fat and protein content, respectively. Both the fat and protein content prediction results of the PC combination selected by SPA were better than those of first four PCs to first eight PCs. R^2p, and root mean square errors for prediction and residual predictive deviation of prediction results of the PC combination selected by SPA were 0. 989, 0. 170 3 and 9. 534 3, respectively for fat, and 0. 987 6, 0. 134 8 and 8. 927 4 for protein. The overall results demonstrate that SPA can fast and effectively select the optimal PC combination. The selecting process is simple and does not need abundant parameter debugging..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2734 (2009)
Spectroscopic Study on the Interaction of Glass Matrixes and Nanoparticles in Tm3+ Doped Oxyfluoride Glass Ceramics
ZHANG Xiang-yu, LI Lin, GAO Dang-li, and ZHENG Hai-rong
Fluorescence emission spectra from Tm^3+ in crystal phase and glass phase were separated under selective excitation of ^1D2 level in Tm^3+ doped transparent oxyfluoride glass ceramics containing LaF3 nanocrystals. Emissions from the crystal phase and from the glass phase were detected. The influence of the interaction Fluorescence emission spectra from Tm^3+ in crystal phase and glass phase were separated under selective excitation of ^1D2 level in Tm^3+ doped transparent oxyfluoride glass ceramics containing LaF3 nanocrystals. Emissions from the crystal phase and from the glass phase were detected. The influence of the interaction between glass matrix and nanoerystals on the optical characteristics of Tm^3+ ions in the two different local environments was investigated. The results indicate that the increase in nanocrystal size results in a decrease in the impact of oxides glass on Tm^3+ in the crystal phase, and an enhancement of the impact of nanocrystals on Tm^3+ in the glass phase. For smaller nanoparticles, the emission efficiency of Tm^3+ ions in the crystal phase was reduced, and the influence of nanocrystals on the ions in the glass phase was reduced too. The larger the nanocrystal size, the weaker the influence of oxide glass on the Tm^3+ ions in the crystal phase, and the better performance of fluorescence emission. It was also found that the content of SiO2 in glass matrix could affect the emission efficiency of Tm^3+ in both environments..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2738 (2009)
Application of 1D Wavelet Analysis in Detecting Species of Harmful Algae Blooms with Absorption Spectra of Phytoplankton
ZHANG Ting-lu, DU Xiang-zhi, XU Qing-na, and QIU Guo-qiang
In the present study, the feasibility of using wavelet analysis to extract the eigen spectra from the absorption spectra of phytoplankton for species detection was investigated. Thirteen absorption spectra taken from single species cultures, representing four divisions (Dinophyta, Bacillariophyta, Haptophyta, and ChlorIn the present study, the feasibility of using wavelet analysis to extract the eigen spectra from the absorption spectra of phytoplankton for species detection was investigated. Thirteen absorption spectra taken from single species cultures, representing four divisions (Dinophyta, Bacillariophyta, Haptophyta, and Chlorophyta), six genus (Gymnodinium, Prorocentrurn, Skeletonerna, Guinardia, Phaeoc ystis, and Prasinoph yte ) and seven species ( Karenia mikirnotoi, Karenia brevis, Prorocentrum minimum, Skeletonema costatuma, Guinardia delicatula, Phaeocystis globosa, and Pyramimonas parkeae ), were used. First, the 1D wavelet analysis with five levels was applied to the thirteen absorption spectra, so each spectrum was decomposed with 5 levels. The 5th level component of low frequency corresponds to the background without information for species detection, and 1st and 2nd level component of high frequency is the random noise. The other levels (3rd to 5th) of high frequency are the useful information, and the sum of levels (3rd to 5th) of high frequency was retained as the eigen spectra for species deteetion Second, the clustering analysis was used to the eigen spectra for examining the performance of the wavelet analysis in extracting species information. The clustering results were compared with the known species class information, and the results show that the 13 absorption spectra are correctly classified at the level of division, genus and species. This means that the wavelet analysis has good performance in extracting the eigen spectra for species detection. However, the above results were obtained with only limited species, and the more species data are required to identify the extensive validity of the conclusion..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2743 (2009)
Study on the Circular Dichroism of (S)- and (R)- Wuweizisu C
LI Yan-feng, DONG Li-hong, WANG Wei, WANG Qiang, WANG Shu-yang, ZHAO Peng, and CHANG Jun-biao
The circular dichroism (CD) is an excellent method for determining the absolute stereochemistry of organic compounds. The CD spectra of four biphenyl compounds were determined by using CD spectrometer, and two pairs of symmetrical CD spectra were obtained. The absolute configuration of biphenyl bond was confirmed by thThe circular dichroism (CD) is an excellent method for determining the absolute stereochemistry of organic compounds. The CD spectra of four biphenyl compounds were determined by using CD spectrometer, and two pairs of symmetrical CD spectra were obtained. The absolute configuration of biphenyl bond was confirmed by the Cotton effect according to the CD rule. The CD spectrum of compound 3 shows a negative Cotton effect at 256 nm, and a positive Cotton effect at 220 nm, which predicts an S-configuration of biphenyl according to an experimental CD rule. Conversely, the CD spectrum of compound 3＇ displays a positive Cotton effect at 256 nm, and a negative Cotton effect at 219 nm, which predicts an R-configuration of biphenyl. And the regularity of oxazoline-mediated Ullmann reaction was obtained, too..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2748 (2009)
Spectral Characteristics of Normal Breast Samples in the 350-850 nm Wavelength Range
WANG Yu-hua, YANG Hong-qin, XIE Shu-sen, YE Zhen, and SU Yi-ming
Spectral characteristics of normal female breast samples in the 350-850 nm wavelength range were measured using a UV/Vis/NIR spectrophotometer system with integrating sphere attachment for measuring the diffuse reflectance and transmittance. The optical properties of normal breast tissue in vitro were obtained by the iSpectral characteristics of normal female breast samples in the 350-850 nm wavelength range were measured using a UV/Vis/NIR spectrophotometer system with integrating sphere attachment for measuring the diffuse reflectance and transmittance. The optical properties of normal breast tissue in vitro were obtained by the inverse adding doubling method. And then the optical penetration depths in this spectral range were analyzed based on the principle of tissue optics. The results show that the reduced scattering coefficient of normal female breast tissue is significantly higher than the absorption coefficient in the 350-850 nm wavelength range. The reduced scattering coefficient decreases with the wavelength increment. It reaches maximum at shorter wavelengths with a decrease at longer wavelengths and ranges from 9. 731 mm^-1 at 350 nm to 1. 476 mm^-1 at 850 nm. The absorption coefficient of normal breast tissue is about from 0. 798 mm^- 1 at 350 nm to 0. 102 mm^-1 at 850 nm. The maximal and minimal values are at 350 nm and 850 nm respectively. An absorption peak for the normal breast tissue is at 410 nm of wavelength with the value of 0. 506 mm^-1, which belongs to hemoglobin. The absorption coefficient remains relatively constant when the wavelength is longer than 600 nm. The optical penetration depth increases with the wavelength increment and ranges about from 0. 199 mm at 350 nm to 1. 439 mm at 850 nm. Deep penetration depth noted in normal breast samples, especially at longer wavelengths, reflects the weak absorption and reduced scattering at these wavelengths. The calculated optical parameters of normal breast samples by the inverse adding doubling method agree well with the Monte Carlo simulations. This study may be useful for breast optical biopsy or the optical diagnosis of breast diseases..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2751 (2009)
Spectroscopy Study of Methyl Parathion Molecularly Imprinted Polymers
LIU Jiao, MENG Fan-ping, YAO Rui-hua, and LI Zhuo-na
Three molecularly imprinted polymers were synthesized with different functional monomers respectively, using methyl parathion as the template. These monomers are methacrylic acid, acrylamide and 4-vinylpyridine. According to the UV spectrum study the interaction between methyl parathion and 4-vinylpyridine was strongerThree molecularly imprinted polymers were synthesized with different functional monomers respectively, using methyl parathion as the template. These monomers are methacrylic acid, acrylamide and 4-vinylpyridine. According to the UV spectrum study the interaction between methyl parathion and 4-vinylpyridine was stronger than that of the others. Comparably, the infrared spectrum study showed the same results which indicated that 4-vinylpyridine could associate with the template at two different kinds of binding sites, the P--O--C and the --NO2 site, and is most likely to form steady covalent bonds with methyl parathion, while the other two monomers could only associate with the template at the P--O--C site. Furthermore, the infrared spectra of the synthesized polymers confirmed the existence of the functional groups in each kind of polymer, which might interact with the template..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2756 (2009)
Analysis of NIR Characteristic Wavelengths for Apple Flesh Firmness Based on GA and iPLS
TU Zhen-hua, JI Bao-ping, MENG Chao-ying, ZHU Da-zhou, SHI Bo-lin, and QING Zhao-shen
In the present study, the fruit flesh firmness of apple was analyzed by near infrared (NIR) spectroscopy using an FTNIR spectrometer. The sensitive spectral regions that provide the lowest prediction error were analyzed by different well-known variable selection methods, including dynamic backward interval partial leasIn the present study, the fruit flesh firmness of apple was analyzed by near infrared (NIR) spectroscopy using an FTNIR spectrometer. The sensitive spectral regions that provide the lowest prediction error were analyzed by different well-known variable selection methods, including dynamic backward interval partial least-squares (dynamic biPLS), sequential application of backward interval partial least-squares and genetic algorithm(dynamic biPLS ＆ GA-PLS), and iterative genetic algorithm partial least-squares (iterative GA-PLS). Iterative GA-PLS, dynamic biPLS ＆ GA-PLS led to a distinct reduction in the number of spectral data points with better predictive quality. Furthermore, the majority of selected wavelengths were content with the characteristic of the sorption bands of fruit flesh firmness. Pectin constituents, complex non-starch polysaceharides, which are related to texture change in apple, play an important role in their harvest maturity, ripening and storage. Comparing NIR characteristic wavelengths of apple flesh firmness and typical absorption bands for pectin, it was found that characteristic wavelengths of apple flesh firmness were consistent with the pectins relevant spectral regions. Therefore, the NIR characteristic wavelengths of apple firmness based on GA and iPLS reflected the chemical component of apple and the results were reasonable..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2760 (2009)
Structure and Vibrational Spectroscopy of Ginsenoside Re： Density Functional Theory Study
SHANG Xiao-hong, HUI Ge, ZHAO Yu, WANG Xu, ZHAO Da-qing, WU Feng-qing, and ZHAO Bing
Density functional theory was used to optimize the geometry structure of two isomers of ginsenoside, Re, 20-(R)-R and 20-(S)-Re. The ginsenoside Re is an active constituent in ginseng. The calculated results show that there is an obvious difference in space structure between 20-(R)-R and 20-(S)-Re. The main reason for Density functional theory was used to optimize the geometry structure of two isomers of ginsenoside, Re, 20-(R)-R and 20-(S)-Re. The ginsenoside Re is an active constituent in ginseng. The calculated results show that there is an obvious difference in space structure between 20-(R)-R and 20-(S)-Re. The main reason for that can be the difference in the space orientation of the four constituents in the 20th carbon (chiral), which leads to the different stacking mode and causes the difference in vibrational spectra in the two isomers. The experimental IR and Raman spectra were assigned according to the calculated frequency, theoretical IR intensity and Raman active. The calculated vibrational peaks at 1 541, 1 456 and 1 424 cm^-1 can be used to distinguish the two isomers. The result shows a good agreement between the calculated and the experimental Raman spectra. The vibrational spectra can be used to identify the active constituent in ginseng..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2765 (2009)
Increasing SNR of Dynamic Spectrum Method Using Harmonic Waves
LIN Ling, YANG Ying-chao, LI Gang, ZENG Rui-li, and WANG Yan
The sources of noise in dynamic spectrum (DS) method and their corresponding frequency characteristic wereanalyzed in order to improve the signal to noise ratio (SNR) of DS method. The processes of DS data in frequency domain were reviewed by means of energy, then the harmonic waves of DS data were taken into account iThe sources of noise in dynamic spectrum (DS) method and their corresponding frequency characteristic wereanalyzed in order to improve the signal to noise ratio (SNR) of DS method. The processes of DS data in frequency domain were reviewed by means of energy, then the harmonic waves of DS data were taken into account in the DS signal and some experiments were done to test whether the modified method works well. In addition, corresponding experiments were carried out to seek the relationship between the SNR and the number of harmonic waves, and to determine how many harmonic waves should be involved in order to get the best SNR in DS method. Results showed when harmonic waves were used in the method properly, the modified method can distinguish DS more precisely. And it was also showed that as the number of harmonic waves increased, the correlation coefficient of DS data from different volunteers became smaller at first and then bigger later, while the correlation coefficient of DS data from different sampling site of the same volunteer kept increasing all the time. When the number of harmonic waves was set to 5, the correlation coefficient of DS data from different volunteers goes from 0. 737 52 to 0. 736 76, while the one from the same volunteer goes from 0. 994 16 to 0. 995 33, which means the modified method can reflect the information about blood component more precisely than the old ones, and thus the SNR of DS reaches the highest..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2769 (2009)
Spectroscopy and Thermostability of Series Rare-Earth Complexes with 3-Nitrophthalic Acid
ZHANG Fan, DENG Yu-heng, ZHU Hui-ju, YANG Yong-li, and WANG Shao-ting
A series of rare-earth compound RE2 L2 (HL) 2 (H2O) 6 · 2H2O (RE= La, Nd, Eu, Tb, Er, Y) containing 3-nitrophthalic acid(H2L) ligand were synthesized from ethanol-water solution, and characterized and investigated by the element analysis, infrared and ultraviolet absorption spectra and different thermal-thermogravA series of rare-earth compound RE2 L2 (HL) 2 (H2O) 6 · 2H2O (RE= La, Nd, Eu, Tb, Er, Y) containing 3-nitrophthalic acid(H2L) ligand were synthesized from ethanol-water solution, and characterized and investigated by the element analysis, infrared and ultraviolet absorption spectra and different thermal-thermogravimetric analysis. The results of the spectroscopic analysis were conformed to the crystal structures determined by X-ray diffraction, showing that the carboxylate (-COO-) and carboxyl (-COOH) groups of the ligand link to the rare-earth ions by bridging and terminal mode respectively. Two rare-earth ions were linked by two di-deprotonated ligand L^2- in bridging-chelating mode to form a dinuclear structure, and coordinated by the other two mono-deprotonated ligands HL-in terminal chelating mode using their carboxylate (-COO) and carboxyl (- COOH) group together, respectively. The IR spectra shows the existence of the carboxylate (-COO-) and carboxyl (- COOH) group and the hydrogen bond interactions between the carboxyl (-COOH) group and crystal water. The DTA-TGA data were consistent with the composition of compounds, exhibiting an endothermic peak of the loss of the crystal and coordinated waters at about 150℃ and two exothermic peaks of the oxidation and decomposition of ligands in the rang of about 340 to 460℃..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2773 (2009)
Preparation and Optical Properties of Fluorescent Nanofiber Containing Europium Complex
WANG Dong-mei, WANG Liang, DONG Huai, LIU Wei, and JIANG Jian-zhuang
Through electrospinning technique, the lanthanide complex with good luminescent property, Eu(DBM)3 · H2O and Eu(DBM)4 · CPC, were incorporated into water soluble polymer PVP, and the polymer nanofibers with red characteristic fluorescent light from europium ion were obtained. The microstructure of the rare eaThrough electrospinning technique, the lanthanide complex with good luminescent property, Eu(DBM)3 · H2O and Eu(DBM)4 · CPC, were incorporated into water soluble polymer PVP, and the polymer nanofibers with red characteristic fluorescent light from europium ion were obtained. The microstructure of the rare earth complexes and polymer nanofibers product was studied by scanning electron microscopy and transmission electron microscopy, and the result indicated that when the rare earth complexes were compounded into the polymer nanofibers, it＇s microstructure changed due to its good compatibility with PVP ethanol solution, and the polymer nanofibers with one dimension were of 50-100 nm relatively uniform line shape structure. In addition, the fluorescence excitation and emission spectra and fluorescence lifetime of the rare earth complexes and polymer nanofibers product were studied. Photoluminescence measurements indicate that the lanthanide complexes show superior emission lines, higher intensities and longer fluorescent lifetime in the polymer nanofibers than in the corresponding pure complex powders, which is due to the composite nanofibers providing a relatively stable environment for lanthanide complexes..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2777 (2009)
Fluorescence Study on the Interactions between G3.0 PAMAM Dendrimers and Bovine Serum Albumin
HE Hua, LI Shan-shan, LU Jin-rong, GU Yan, and Chuong Pham-Huy
The interaction between amine terminated G3.0 PAMAM dendrimers and bovine serum albumin (BSA) under physiological condition was studied by fluorescence spectroscopy. Our experiments demonstrated that the fluorescence intensity of BSA decreased after the addition of G3.0 PAMAM dendrimers and the quenching mechanism was The interaction between amine terminated G3.0 PAMAM dendrimers and bovine serum albumin (BSA) under physiological condition was studied by fluorescence spectroscopy. Our experiments demonstrated that the fluorescence intensity of BSA decreased after the addition of G3.0 PAMAM dendrimers and the quenching mechanism was suggested as static quenching according to the Stern-Volmer equation. The binding constant of G3.0 PAMAM dendrimers with BSA was calculated to be 1. 067 ±0. 025 L ·mmol^-1. At the same time, synchronous fluorescence and red edge excitation shift(REES)were adopted to review the conformational changes of BSA influenced by G3.0 PAMAM dendrimers, which provides important significance for clinical medication. And the results indicated that G3.0 PAMAM dendrimers can change the conformation of BSA. Furthermore, this article also examined the influence of pH and ionic strength on the interactions, from which we can conclude that electrostatic interaction played major roles in the binding process. In conclusion, the fluorescence method is a highly sensitive and convenient way to study intermolecular interaction. Further investigation in this field will provide more important information for understanding the pharmacological effects and toxicities of drugs in human body..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2782 (2009)
Value of Auto-Fluorescence Spectrum Combined with Tumor Markers in Diagnosis of Lung Cancer
WU Yong-jun, HAO Yan-hong, WU Wei-chao, and WU Yi-ming
To improve the diagnostic efficiency of cancer, serum fluorescence spectrum combined with tumor marker groups was proved more powerful, especially when used with mathematical evaluation model, that is, artificial neural network (ANN) modeling. ANN modeling is very suitable for the discrimination of lung cancer. ANN hasTo improve the diagnostic efficiency of cancer, serum fluorescence spectrum combined with tumor marker groups was proved more powerful, especially when used with mathematical evaluation model, that is, artificial neural network (ANN) modeling. ANN modeling is very suitable for the discrimination of lung cancer. ANN has evident superiority in solving nonlinear, multi-parameter and uncertain complicated problems. In the present paper, serum fluorescence spectrum was applied to study the difference among normal, benign and malignant groups and develop the relevant method of determination. On the other hand, combined with tumor markers, CEA, NSE, SCC-Ag, CYFRA21-1 and p16 methylation, artificial neural network and Fisher linear discriminatory analysis were used to develop the prediction models of diagnosis of lung cancer, and compared by ROC. It was shown that the result of the fluorescence spectrum combined with tumor markers based on ANN model is superior to that of the fluorescence spectrum ANN model. The performance of ANN model is superior to that of Fisher linear discriminatory analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2787 (2009)
Study on the Designed Self-Assembling Peptide as Potential Drug Carrier by Fluorescence Spectra
LIN Juan, ZHOU Qing-han, and ZHAO Xiao-jun
Amphiphilic peptide is becoming attractive as a potential drug carrier to improve the dissolvability of hydrophobie drugs in aqueous system thus facilitating the drug undertaken by target cells. Here, we reported the ability of a novel designed self-assembling peptide RGA16 (Ac-RADAGAGARADAGAGS-NHz) in drug encapsulatiAmphiphilic peptide is becoming attractive as a potential drug carrier to improve the dissolvability of hydrophobie drugs in aqueous system thus facilitating the drug undertaken by target cells. Here, we reported the ability of a novel designed self-assembling peptide RGA16 (Ac-RADAGAGARADAGAGS-NHz) in drug encapsulation and transfer into lipid vesicles. Pyrene was used as a model hydrophobic drug, and egg phosphatidylcholine (EPC) vesicles were used as plasma membranes mimic. It was found that the pyrene and peptide formed complex in water with mechanical stirring, and the time duration over which the complex formed was about 5 days. Initial evidence of the association between RGA16 and pyrene was theobservation of a clouding phenomenon. Further investigation on the interaction between RGA16 and pyrene was carried out using fluorescence spectra and scanning electron microscopy (SEM). SEM micrographs showed that pyrene crystals and peptide were absorbed by each other and the size of the pyrene-peptide complexes was larger than 10 μm, which provided an evidence for the encapsulation of pyrene molecule by the amphiphilic peptide. The steady-fluorescence excitation profiles showed that the pyrene was presented in the crystalline form when stabilized by RGA16 and molecularly migrated from its peptide coating into the membrane bilayers of EPC vesicles when the suspension was mixed with EPC vesicles. The release behavior of pyrene into EPC vesicles was investigated by steady-fluorescence emission spectra, and a calibration curve for the amount of pyrene released into the EPC vesicles at a given time was used to determine the final concentration of pyrene released into lipid vesicles from peptide-pyrene complex. It was found that the pyrene concentration in EPC vesicles was displayed as a function of time. The data presented in the present work suggested that the novel designed amphiphilic peptide could stabilize the hydropholic drug in aqueous solution and deliver it into the membrane bilayers of EPC vesicles..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2792 (2009)
Study on Interaction of Caffeine with Myoglobin by Fluorescence Spectroscopy
HUANG He-yong, GU Xiao-tian, DING Yan, ZHOU Jia-hong, and FENG Yu-ying
The interaction of caffein and myoglobin was investigated by fluorescence spectroscopy and synchronous fluorescence spectroscopy. The intrinsic fluorescence of myoglobin was significantly quenched by caffein under the physiological condition (pHT. 4) . The results indicated that caffeine was capable of binding with myoThe interaction of caffein and myoglobin was investigated by fluorescence spectroscopy and synchronous fluorescence spectroscopy. The intrinsic fluorescence of myoglobin was significantly quenched by caffein under the physiological condition (pHT. 4) . The results indicated that caffeine was capable of binding with myoglobin to form a 1:1 complex and the quenching mechanism of myoglobin affected by caffeine was shown to be a static quenching procedure by calculating quenching constant, binding sites and binding constant. According to the thermodynamic parameters, the main binding force of the interaction is electrostatic force and hydrophobic force. The change in the micro-circumstance of aminos of myoglobin was analyzed by synchronous fluorescence spectrometry. The result indicated that caffeine can change the conformation of the protein, leading to the change in the micro-environment of tryptophane and tyrosine residues from hydrophobic environment to hydrophilic environment to different extent..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2798 (2009)
Synthesis, Characterization and Fluorescence of Zn3(NCS)6(L1)6(NO3)2 and Ni3(NCS)6(L2)6(NO3)2
MAO Ju-lin, ZHAO Qing-shan, ZHOU Hui-liang, HU Qi-lin, and LIU Wan-yi
The complexes of Zn^2+, Ni^2+ with 4-amino-3,5-dimethyl-1,2,4-triazole and 4-amino-i, 2,4-triazote were synthesized in water, respectively. By elemental analysis, coordination titration and molar conductivities studies, the compositions of the complexes were suggested as Zna (NCS)6 (L1)6 (NO3)2 and Ni3 (NCS)6 (L2)6 (NOThe complexes of Zn^2+, Ni^2+ with 4-amino-3,5-dimethyl-1,2,4-triazole and 4-amino-i, 2,4-triazote were synthesized in water, respectively. By elemental analysis, coordination titration and molar conductivities studies, the compositions of the complexes were suggested as Zna (NCS)6 (L1)6 (NO3)2 and Ni3 (NCS)6 (L2)6 (NO3)2 respectively. The ligands and coordination compounds were studied by means of IR spectra, UV and fluorescence excitation and emission spectra. The IR spectra studies indicate that triazolate was bonded with RE ( Ⅱ ) through nitrogen atoms in the heterocyclic ring. The fluorescence spectra showed that the fluorescence emission intensity of Ni3 (NCS) 6 (L2) 6 (NO3) 2 was stronger than that of Zn3 (NCS) 6 ( L1 ) 6 (NO3) 2..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2803 (2009)
Simultaneous Determination of PAHs in Food by Low-Temperature Constant-Energy Synchronous Fluorescence Spectrometry
ZHANG Wei, ZHOU Na, LI Na, XIE Yong-sheng, LUO He-dong, and LI Yao-qun
The authors developed a rapid analytical method that could determine the PAHs in food samples simultaneously by the coupled approach of Shpol＇ skii spectroscopy and constant-energy synchronous fluorescence scanning technique. Low-fat food samples, which were just extracted with octane and high-fat food samples pre-procThe authors developed a rapid analytical method that could determine the PAHs in food samples simultaneously by the coupled approach of Shpol＇ skii spectroscopy and constant-energy synchronous fluorescence scanning technique. Low-fat food samples, which were just extracted with octane and high-fat food samples pre-processed with saponification and extracting, could be analyzed immediately. The recoveries ranged from 80. 2 % to 98. 9 % and the correlation coefficients of the linearity were higher than 0. 993 8. This method was selective, simple, rapid and inexpensive..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2806 (2009)
Synthesis and Spectrum of Novel Pyrazoline Fluorescent Compounds
LIU Qiu-jun, GAO Lei, WANG Lei, XIE Zhi-yuan, and LI Dong-feng
Pyrazoline derivatives have been used widely in dyeing industry as fluorescent whitening agents due to their excellent capability. According to Schellhammer theory of the relation between chemical structure and fluorescent quality, six new fluorescent compounds were designed and synthesized which contained the benzothiPyrazoline derivatives have been used widely in dyeing industry as fluorescent whitening agents due to their excellent capability. According to Schellhammer theory of the relation between chemical structure and fluorescent quality, six new fluorescent compounds were designed and synthesized which contained the benzothiazole group in the 1-pyrazoline, the indole group in the 3-pyrazoline and the derivatives of phenyl in the 5-pyrazoline. The structure of target compounds was confirmed by IR, ^1H NMR, MS and elementary analysis. The fluorescence spectra showed that these compounds had good fluorescence. They could absorb ultraviolet light at near 353 nm. The fluorescence maximum emission wavelengths were about 430-443 nm. It was a kind of promising fluorescence compounds. The largest fluorescence emission wavelength and the fluorescence intensity were related to the substituted group of the compounds. When the 6-Br group was introduced into benzothiazole, the fluorescence emission wavelength exhibited a blue shift, and the fluorescence intensity increased. Otherwise, the CH3 group was introduced to benzothiazole, the fluorescence emission wavelength red-shift occurred, and the intensity was lower. The fluorescence quantum yield of the compounds was little affected by the substituted group and polarity of the solvent. The relative fluorescence intensity and fluorescence quantum yield were not directly related..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2810 (2009)
UV-Vis Studies on the Course of Reaction of Au/Ag Alloy Colloid with Hydrogen Tetrachloroaurate( Ⅲ) Hydrate
JIN Yi-liang, YAO Jian-lin, and GU Ren-ao
Using citrate as protector, Au-Ag alloy nanoparticles with different molar ratios were prepared with hydrazine as the reducer. One plasmon band between monometallic Ag and Au was observed in their UV-Vis spectra. And the peak of alloy shifted linearly with the ratio of Au changing in the alloy. By UV-Vis spectra, the cUsing citrate as protector, Au-Ag alloy nanoparticles with different molar ratios were prepared with hydrazine as the reducer. One plasmon band between monometallic Ag and Au was observed in their UV-Vis spectra. And the peak of alloy shifted linearly with the ratio of Au changing in the alloy. By UV-Vis spectra, the course of reaction of the alloy colloid with HAuCl4 was studied. The result shows that the UV-Vis spectra of the alloy colloid changed regularly with the adding volume of HAuCl4 increasing. And there is a linear interval in it with the change in the calculated ratio of Au. With the former studies, the course can be attributed to the dealloy of Au/Ag alloy..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2815 (2009)
Kinetic Study on Inhibition Effects of Dansyl-L-Phenylalanine and L-Phenylalanine on Calf Intestinal Alkaline phosphatase
LI Li-na, WU Yu-qing, and Rene Buchet
To evaluate the inhibition effect of dansyl-L-phenylalanine on calf intestinal alkaline phosphatase (CIAP), UV-Vis spectrophotometric method was employed. It was found that dansyl-L-phenylalanine can selectively inhibit CLAP. The kinetic inhibition processes of dansyl-L-phenylalanine and L-phenylalanine were comparativTo evaluate the inhibition effect of dansyl-L-phenylalanine on calf intestinal alkaline phosphatase (CIAP), UV-Vis spectrophotometric method was employed. It was found that dansyl-L-phenylalanine can selectively inhibit CLAP. The kinetic inhibition processes of dansyl-L-phenylalanine and L-phenylalanine were comparatively studied. The authors ＇ finding elucidates that at the optimized alkaline pH of alkaline phosphatase (pH 10. 4) and 37 ℃, dansyl-L-phenylalanine can inhibit alkaline phosphatase activity of CIAP efficiently and specifically, similar as L-phenylalanine. Both inhibition types were uncompetitive inhibition resulting from the double reciprocal curve fitting of v versus substrate concentrations, and the inhibition constants Ki of both inhibitors were determined to be 2.3 and 1.1mmol· L^-1 respectively, both of which were at millimolar level. The investigation of the inhibition effect of dansyl modified L-phenylalanine on calf intestinal alkaline phosphatase not only helped get insight into the detailed inhibition mechanism of L-phenylalanine on tissue specific alkaline phosphatase, such as in the case of intestinal alkaline phosphatase, but also provided the possibility to employ fluorescence spectroscopy by labeling the specific inhibitors of alkaline phosphatase with chromophoric groups..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2820 (2009)
BPNN Simulation of Photocatalytic Degradation of Reactive Scarlet BES by UV-Vis Spectrophotometer
ZHANG Yun-tao, HE Guo-li, and XIANG Ming-li
The use of chemometric techniques and multivariate experimental designs for the photoeatalytic reaction of reactive scarlet BES in aqueous solution under ultraviolet light irradiation is described. The efficiency of photocatalytic degradation was evaluated by the analysis of the parameter of deeoloration efficiency detThe use of chemometric techniques and multivariate experimental designs for the photoeatalytic reaction of reactive scarlet BES in aqueous solution under ultraviolet light irradiation is described. The efficiency of photocatalytic degradation was evaluated by the analysis of the parameter of deeoloration efficiency determined by UV absorption at 540 nm using a UV-Vis spectrophotometer in different conditions. Five factors, such as the amount of titanium oxide ([TiO2]), the concentrations of reactive searlet BES (c0), irradiation time (t), the pH value (pH) and temperature (T), were studied. [TiO2]. c0, t and pH selected on the basis of the results of variance analysis by Plaekett-Burman design were used as independent variables. Training sets and test sets of back propagation neural network (BPNN) were formed by Box-Behnken design and uniform design U10 (10× 52 ×2) respectively. The process of photoeatalytie degradation of the target object was simulated by the BPNN model. The correlation coefficient (r) of the calculation results for training set and test set by BPNN is 0. 996 4 and 0. 963 6 respectively, and the mean relative errors between the predictive value and experimental value of deeoloration efficiency are 6. 14 and 7. 76, respectively. The modeled BPNN was applied to analyze the influence of four factors on deeoloration efficiency. The results showed that the initial conditions of co being lower, pH 5.0 and appropriate amount of [TiO2] contribute to improving the deeoloratione fficiency of reactive scarlet BES. Under the condition of c0 =40 mg · L^-1, the optimized experimental condition of the system was obtained. [TiO2 ] = 1.20 g · L^-1 and pH 5.0. Under the optimized experimental condition, the experimental value of decoloration efficiency is 98. 20% when irradiation time is 35 minutes and the predictive value of decoloration efficiency is 99. 16% under the same condition. The relative error of decoloration efficiency between the predictive value and experimental value is only -0. 96%. The experimental value is very close to the model predicted value..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2824 (2009)
Effect of Octadecyl Amine (ODA) on the Complex Titration of Magnesium and Calcium Ions Studied with UV-Visible Spectrophotometry
QING Bin-ju, LIU Hai-ning, YE Xiu-shen, LI Quan, GUO Min, LIU Teng-yun, and WU Zhi-jian
The effect of flotation agent octadecyl amine (ODA) on the complex titration of both magnesium and calcium ions was studied with two groups of comparative experiments： (1) Before titration, the suspension was not filtered. In this case, ODA had a great effect on the complex titration of both magnesium and calcium ions.The effect of flotation agent octadecyl amine (ODA) on the complex titration of both magnesium and calcium ions was studied with two groups of comparative experiments： (1) Before titration, the suspension was not filtered. In this case, ODA had a great effect on the complex titration of both magnesium and calcium ions. The titration end-point of magnesium ions was difficult to he determined. Although the titration end-point of calcium ions could be determined, there was an obvious experimental error compared with the blank solution without ODA. These results were confirmed by the UV-Visible spectrum analyses of the related solutions. (2) Before titration, the suspension was filtered. In this case, the influence of ODA on the complex titration of both magnesium and calcium ions could be removed. UV-Visihle spectrum studies showed that, in this case, both the spectra and time scanning curves of the tested solutions were similar to those of the blank solutions..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2829 (2009)
Simultaneous Determination of Platinum (Ⅳ) and Palladium ( Ⅱ ) Using Spectrophotometry Method
MA Dong-lan, WANG Yun, MA Kuang-biao, and WANG Jin-ye
The N-(m-methylphenyl)-N＇-(sodium p-aminobenzenesulfonate)-thiourea (MMT) was good reagent of water solu-bility. In the medium of an HAc-NaAc buffer solution and hexadecyltrimethylammonium bromide (CTMAB), MMPT can react with platinum (Ⅳ) and palladium ( Ⅱ ) to form green and brown soluble complex. The maximum absorbanThe N-(m-methylphenyl)-N＇-(sodium p-aminobenzenesulfonate)-thiourea (MMT) was good reagent of water solu-bility. In the medium of an HAc-NaAc buffer solution and hexadecyltrimethylammonium bromide (CTMAB), MMPT can react with platinum (Ⅳ) and palladium ( Ⅱ ) to form green and brown soluble complex. The maximum absorbance of the complex was at λ^Ptmax=754. 4nm and,λ^Ptmax=304.6 Beer＇s law was obeyed with the concentration in the range of 0-32.0μg Pt(Ⅳ)/25 mLand 0-25.0μg Pd( Ⅱ )/25 mL for platinum (Ⅳ) and palladium( Ⅱ ) respectively. The correlated coefficient was r754.4=0. 999 5 for platinum (Ⅳ) ; and r304, 6 = 0. 999 9 for palladium ( Ⅱ ). Their molar absorption coefficients were ε^Pd304.6=7.4×10^4L·mol^-1·cm^-1 and ε^Pd304.6=7.4×10^4 L·mol^-1·cm^-1 respectively. The contents of platinum (Ⅳ) and palladium (Ⅱ) were converted by determination of the absorbency of mix solution of platinum (Ⅳ) and palladium ( Ⅱ) at 754.4 and 304. 6 nm. Only Cu^2+ and Co^2+ interfered with the determination of palladium ( Ⅱ ) among 50 coexistent ions, so the selectivity was good. It can be used for the determination of content of synthesis samples. The relative standard deviation (RSD) was less than 2.0%, and the recovery(%) was in the range of 96 %-104 %. The results are satisfactory. Because the reagent reacts with platinum (Ⅳ) and palladium ( Ⅱ) to form water soluble complex and does not require pre-separation for simultaneous determination of platinum (Ⅳ) and palladium ( Ⅱ ), the method is easy to operate, rapid and environment-friendly..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2833 (2009)
Progress in the Method of Laser Ablation Solid Sample Introduction to Inductively Coupled Plasma Source
CHEN Jin-zhong, ZHENG Jie, LIANG Jun-lu, SU Hong-xin, LI Guang, and WEI Yan-hong
On the basis of consulting the home and abroad literatures in recent years, the research progress in the method of laser ablation solid sampling to the inductively coupled plasma source and its application in the analysis of material compositions are described, The present paper emphatically reviewed the influence of tOn the basis of consulting the home and abroad literatures in recent years, the research progress in the method of laser ablation solid sampling to the inductively coupled plasma source and its application in the analysis of material compositions are described, The present paper emphatically reviewed the influence of the laser-beam properties (output wavelength, pulse duration, repetition frequency, energy density) and atmosphere gases (helium and argon) on the sample ablation process, and discussed the functions of the laser ablation chamber, aerosol transmission pipelines, and sample introduction devices improved in the process of the evaporated material transferring to the inductively coupled plasma source. Getting small uniform aerosol particles and transporting the ablated materials to the inductively coupled plasma source efficiently and steadily are the key points to make laser ablation solid sampling technique more perfect, and the elements fractionation and evaporation deposition are important influence factors for the analysis performance. As a practical example, the application of laser ablation solid sampling inductively coupled plasma atomic emission spectrometry/mass spectrometry in the analysis of metal, glass, organic substance, and other samples was also discussed. The accuracy, precision, detection limits, and sensitivity of the analysis method were briefly reviewed..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2843 (2009)
Determination of Contents of Many Kinds of Metal Elements in Phellodendron by ICP-AES
ZHANG Yun-liang, LIU Yan-cheng, SHI Shao-ming, CHEN Zhen-feng, and LIANG Hong
Dry and wet methods were used to digest Phellodendron grown in Jinxiu Dayaoshan of Guangxi with a high-pressure jar and to prepare the samples. The contents of microelements Cu, Fe, Zn, Mn and Ni and macroelements K, Ca, Mg, Sr and Na in Phellodendron were determined by using ICP-AES. Meanwhile, the optimal digestion cDry and wet methods were used to digest Phellodendron grown in Jinxiu Dayaoshan of Guangxi with a high-pressure jar and to prepare the samples. The contents of microelements Cu, Fe, Zn, Mn and Ni and macroelements K, Ca, Mg, Sr and Na in Phellodendron were determined by using ICP-AES. Meanwhile, the optimal digestion conditions were found： 7 mL of HNO3 + HClO4 + H2O2 (volume ratio 5:1:1) for 4 h. The work condition and the optical wavelength were selected. The RSD was found to be less than 5% and the recovery rates of all elements were within the range of 89. 4%-113.1%. The determined results agree with the analytical demand, and also indicate that Phellodendron contains high contents of Cu, Fe, Zn and Mn microelements. It is important to assess the medicinal value and understand pharmacological action of Phellodendron by the deterruination of microelements in the Chinese medicine with ICP-AES..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2848 (2009)
Determination of Trace Metal Elements in Zanthoxylum Nitidum by ICP-AES
QIN Jiao-lan, CHEN Zhen-feng, LIU Yan-cheng, and LIANG Hong
The contents of twenty microelements were determined in the root, stem and leaf of traditional Chinese herbs, Zanthoxylumnitidum by ICP-AES (inductively coupled plasma-atomic emission spectrometry) analytical technology. For such method, their recovery ratio obtained by standard addition method ranged between 89% and 1The contents of twenty microelements were determined in the root, stem and leaf of traditional Chinese herbs, Zanthoxylumnitidum by ICP-AES (inductively coupled plasma-atomic emission spectrometry) analytical technology. For such method, their recovery ratio obtained by standard addition method ranged between 89% and 107. 5%, and most of RSDs were lower than 4%, with good correction and precision. The analytical results show that there exist different contents from the different parts of the plant. There are most rich elements such as Mg, Na, K, and Ca in its three parts, while Mn, Zn, Fe, Cu, Co, Sr and some toxic elements Cd, Cr, Pb and Bi were also detected; four elements, Se, V, Mo and Hg, were not detected in all parts. There exist many kinds of metal elements benefiting human being health, which may provide useful information for the usage of the herbs and for the study of the relationship between the elements in Chinese traditional medicine and its bioactivities..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2851 (2009)
Simultaneous Determination of Multi-Organotin Compounds in Seawater by Liquid-Liquid Extraction-High Performance Liquid ChromatographyInductively Coupled Plasma Mass Spectrometry
YU Zhen-hua, JING Miao, WANG Xiao-ru, CHEN Deng-yun, and HUANG Yan-liang
The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds (trimethyltin, dibutyltin, tributyltin, diphenyltin and triphenyltin) in seawater samples. Agilent TC-C18 cThe hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was applied to the simultaneous determination of five organotin compounds (trimethyltin, dibutyltin, tributyltin, diphenyltin and triphenyltin) in seawater samples. Agilent TC-C18 column was used for the separation, the mobile phase of HPLC was CH3CN:H2O:CH3COOH=65:23:12 (φ),0.05% TEA, and pH value was adjusted to 3.0 by diluent ammonia. The flow rate was 0. 6 mL · min^-1. Five mixed organotin compounds in a mix standard solution from 100 to 0. 5 μg · L^-1 were applied for the method assessment. The experimental results indicate that the correlation coefficient of calibration curves (Rz ) for each organotin compound was over 0. 998 and the detection limits of the five organotin compounds were lower than 3 μg · L^-1. Different mixed organic solvents including dichloromethane or toluene were used for extraction of organotin and the extraction condition of organotin from seawater was optimized. The 100 mL seawater acidized by hydrochloric acid was extracted by 10 mL carbon dichloride (CH2 Cl2 ) with 2 % tropolone for 10 min twice. Extracted organic solvents were mixed and blown to one drop by nitrogen with the rate of 1.7 mL · min^-1, then 1 mL acetonitrile was added to the drop for redissolving theorganotin compounds. Finally, the mixed redissolution was filtered by 0. 22 btm organic filter membrane before analysis. It was found that the only organotin compound in seawater was triphenyltin (TPHT) and the content was 53.2 ng · L^-1. The recoveries test from the standard addition for diphenyltin (DPHT), dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPHT) were over 80%. However, the recovery for trimethyltin (TMT) was relatively low and the value was 50%. The reason might be attributed to the decomposition or adsorption of those compounds during the extraction procedure. Further study on this subject is in progress..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2855 (2009)
Research on Discrimination Method of Vinegar Varieties and Brands Based on the Content of Inorganic Elements
CHEN Yan-qing, NI Yong-nian, and SHU Hong-ying
Classification of brands and quality of food products is a very active area with the application of chemometric classification procedures. The content of inorganic elements such as Mg, K, Pb, Zn, Fe, Mn, Ca and Cu in 32 vinegar samples was determined by atomic absorption spectrophotometer. The similarity of Chencu and Classification of brands and quality of food products is a very active area with the application of chemometric classification procedures. The content of inorganic elements such as Mg, K, Pb, Zn, Fe, Mn, Ca and Cu in 32 vinegar samples was determined by atomic absorption spectrophotometer. The similarity of Chencu and Baicu as well as different brands of vinegar samples of the same kind was calculated by vector similarity analysis. The characteristic discrimination of vinegar samples of four brands from Beijing, Jiangxi, Jiangsu and Shanxi was accomplished through cluster analysis and principal component analysis, and the classification of different kinds of vinegar samples (Chencu and Baicu) was performed as well. Vinegar samples were divided into two main groups by cluster analysis and principal component analysis. Each main group was discriminated according to different brands. The contents of inorganic elements in vinegar were good chemical descriptors for differentiation of their kinds and brands..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2860 (2009)
Determination of Trace Free Copper and Zinc in Serum Samples by Graphite Furnace Atomic Absorption Spectrometry after Two-Step Precipitation of Protein
ZHANG Yuan, LIN Zhe-xuan, LI Wei-qiu, ZHANG Qiao-xin, LI Hui, LUO Hong-jun, and LUO Wen-hong
A method was developed for the determination of trace free copper and zinc in serum sample by GFAAS after two-step precipitation. The serum and ethanol were mixed with volume ratio of 1:2. The mixture was subsequently denatured at 70 ℃ and centrifuged to precipitate proteins. The determination, limit of copper (3σ) wasA method was developed for the determination of trace free copper and zinc in serum sample by GFAAS after two-step precipitation. The serum and ethanol were mixed with volume ratio of 1:2. The mixture was subsequently denatured at 70 ℃ and centrifuged to precipitate proteins. The determination, limit of copper (3σ) was 1.2μg ·L^-1 and the recovery was 92. 3%- 104%, and the determination. Limit of zinc(3σ) was 0. 098μg ·L^-1 and the recovery was 90%-107%. This two-step precipitation method can be used to determine non-protein-bound copper in tumor patients and healthy people..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2864 (2009)
Spectral Analysis of Some Brass Coins Excavsted from Ezhou of Hubei Province
XIA Dong-qing, QIN Ying, JIN Pu-jun, MAO Zheng-wei, and DONG Ya-wei
XRD and XRF were used to identify several brass coins of Qing dynasty collected in the Ezhou Museum and excavated from Ezhou of Hubei province. The reality of the coins contains 36. 53%-37.75% of Zn, 54. 12%-59. 04% of Cu and 3. 51%- 7. 56% of Pb, and the ration of the alloy is steady and scientific, indicating that thXRD and XRF were used to identify several brass coins of Qing dynasty collected in the Ezhou Museum and excavated from Ezhou of Hubei province. The reality of the coins contains 36. 53%-37.75% of Zn, 54. 12%-59. 04% of Cu and 3. 51%- 7. 56% of Pb, and the ration of the alloy is steady and scientific, indicating that the technic of the alloy of brass was quite perfect in the mid to late of Qing dynasty. Zn3Cu2 (OH)6 (CO3)2 was found in the corrosion for the first time, and CuO, ZnO, Fe2O3 and CuCI were found too. The high content of Cl^-, around the local condition (including the polluted environment), may be the main reason for those brass coins to be eroded seriously. These findings provide some reference for collecting and protecting coins..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2867 (2009)
Preparation, Characterization and Property of Bamboo-Like α-Fe2O3 Nanobars
CHEN Chuan-sheng, LIU Yong, HUANG Bai-yun, LEI Ting, and CHEN Xiao-hua
Firstly, hydroxide iron precursor was prepared by the co-precipitation method through using nitric iron as the source of iron, ammonia as precipitants, and poly-glycol as dispersant. Secondly, the precursor was calcined at 450 ℃ for 2 h under the protection of nitrogen. Finally, the images and structures of resultant pFirstly, hydroxide iron precursor was prepared by the co-precipitation method through using nitric iron as the source of iron, ammonia as precipitants, and poly-glycol as dispersant. Secondly, the precursor was calcined at 450 ℃ for 2 h under the protection of nitrogen. Finally, the images and structures of resultant powders were investigated by transmission electron microscopes (TEM), X-ray diffraction (XRD), Raman spectrum and the near-edge X-ray absorption fine structure (NEXAFS), respectively, and the magnetic property of resultant powders was measured by a vibrating sample magnetometer (VSM HH-50). The experimental results of TEM show that the products are composed of Fe2O3 nano-particles with sizes in the range of 50-100 nm and bamboo-like Fe2O3 nanobars about 10 nm in diameter. The experimental results of XRD and spectrum illuminate that the structures of products are a-Fe2O3. Moreover, magnetic properties measurement reveals that the products exhibit typical magnetic hysteresis loops of ferromagnetism materials, and their saturation magnetization and coercive force are approximately 64. 65 emu · g^-1 and 15.13 Oe, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2871 (2009)
Development of Chlorophyll Concentration Nondestructive Measurement Instrument Based on Spectral Analysis Technology
LI Qing-bo, XU Yu-po, ZHANG Chao-hang, ZHANG Guang-jun, and WU Jin-guang
A portable nondestructive measuring instrument for plant chlorophyll was developed, which can perform real-time, quick and nondestructive measurement of chlorophyll. The instrument is mainly composed of four parts, including leaves clamp, driving circuit of light source, photoelectric detection and signal conditioning A portable nondestructive measuring instrument for plant chlorophyll was developed, which can perform real-time, quick and nondestructive measurement of chlorophyll. The instrument is mainly composed of four parts, including leaves clamp, driving circuit of light source, photoelectric detection and signal conditioning circuit and micro-control system. A new scheme of light source driving was proposed, which can not only achieve constant current, but also control the current by digital signal. The driving current can be changed depending on different light source and measurement situation by actual operation, which resolves the matching problem of output intensity of light source and input range of photoelectric detector. In addition, an integrative leaves clamp was designed, which simplified the optical structure, enhanced the stability of apparatus, decreased the loss of incident light and improved the signal-to-noise ratio and precision. The photoelectric detection and signal conditioning circuit achieve the conversion between optical signal and electrical signal, and make the electrical signal meet the requirement of AD conversion, and the photo detector is S1133-14 of Hamamatsu Company, with a high detection precision. The micro-control system mainly achieves control function, dealing with data, data storage and so on. As the most important component, microprocessor MSP430F149 of TI Company has many advantages, such as high processing speed, low power, high stability and so on. And it has an in-built 12 bit AD converter, so the data-acquisition circuit is simpler. MSP430F149 is suitable for portable instrument. In the calibration experiment of the instrument, the standard value was measured by chlorophyll meter SPAD-502, multiple linear calibration models were built, and the instrument performance was evaluated. The correlation coefficient between chlorophyll prediction value and standard value is 0. 97, and the root mean square error of prediction is about 1.3 SPAD. In the evaluation experiment of the instrument repeatability, the root mean square error is 0. 1 SPAD. Results of the calibration experiment show that the instrument has high measuring precision and high stability..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 10, 2875 (2009)
Research Articles
The Application of Inductively Coupled Plasma Atomic Emission Spectrometry/Mass Spectrometry to the Analysis of Advanced Ceramic Materials
WANG Zheng, WANG Shi-wei, QIU De-ren, and YANG Peng-yuan
Advanced ceramics have been applied to various important fields such as information science, aeronautics and astronautics, and life sciences. However, the optics and electric properties of ceramics are significantly affected by the micro and trace impurities existing in the material even at very low concentration levelAdvanced ceramics have been applied to various important fields such as information science, aeronautics and astronautics, and life sciences. However, the optics and electric properties of ceramics are significantly affected by the micro and trace impurities existing in the material even at very low concentration level Thus, the accurate determination of impurities is important for materials preparation and performance. Methodology of the analysis of advanced ceramic materials using ICP-AES/MS was reviewed in the present paper for the past decade. Various techniques of sample introduction, especially advances in the authors＇ recent work, are described in detail. The developing trend is also presented. Sixty references are cited..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 20, 2021
- Vol. 29, Issue 10, 2838 (2009)
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