Journals >Spectroscopy and Spectral Analysis
Contents
2014
Volume: 34 Issue 9
54 Article(s)
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Research Article
The Spectroscopic and Electronic Properties of Dimethylpyrazole and Its Derivatives Using the Experimental and Computational Methods
Adebayo A Adeniyi, and Peter A Ajibade
In this paper the spectroscopic and the geometric properties of four ligands with pyrazole unit are studied at both experimental and computational levels. The computational results are perfectly in good agreement with the experimental results especially in terms of the IR, 1H-NMR and 13C-NMR shifts. The spectroscopic fIn this paper the spectroscopic and the geometric properties of four ligands with pyrazole unit are studied at both experimental and computational levels. The computational results are perfectly in good agreement with the experimental results especially in terms of the IR, 1H-NMR and 13C-NMR shifts. The spectroscopic features as well as the computed properties help to establish the successful synthesis of ligands bdmpzm and bdmpza. The theoretical and the experimental IR and Raman significantly help in distinguishing the four ligands. The results show that the Raman spectral is better applicable in characterising the CH3 deformation, the C—H, CNN and CCNNout of the ligands but vibrations like N—H in dmpz and O—H, CO in bdmpza are observed to be Raman inactive. A significant variations are observed among the two available *N atoms characterising the bidentate features of bdmpzm, bdmpza and bdcpzm which indicates a possible different affinities for metal coordination. Also the result suggest that bdmpza will be the best starting material for NLO application than other while bdcpzm is predicted to have potential of been a poor coordinating ligand. The computed variations in the properties of *N atoms that are the characteristic features of their power of coordination can be of immense help since these type of ligands have a wide application in transition metal coordination..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2305 (2014)
Polymer Crystallization Dynamics Investigated by Synchronous Scanning Spectrum
LUO Wei-ang, CHENG Ling, DAI Li-zong, CHEN Xu-dong, MAI Kan-cheng, CHEN Yu-jie, and LIAO Zheng-fu
There is a cosine function between the reflected light intensity of a solid surface and its refractive index. And the mean squared fluctuation of refractive index is related to fluctuation of density and concentration. So some internal structures changes of materials can be reflected by changes in reflected light. BaseThere is a cosine function between the reflected light intensity of a solid surface and its refractive index. And the mean squared fluctuation of refractive index is related to fluctuation of density and concentration. So some internal structures changes of materials can be reflected by changes in reflected light. Based on this theory, the synchronous scanning spectrum (SSS) technique was successfully applied to monitor melting and nonisothermal melt-crystallization of poly(ε-caprolactone) (PCL) film on a copper substrate. SSS can be implemented on a spectrofluorimeter by simultaneously scanning the excitation and emission monochromators (i.e. Δλ=λex-λem=0 nm). In SSS of PCL films, two dominant peaks correlated to the light source spectrum of the spectrofluorimeter (at 467 and 473 nm) were used to characterize the macromolecular structure evolution during the melting and nonisothermal melt-crystallization processes. Detailed thermodynamic and crystallization kinetics parameters obtained by SSS method. The Avrami exponent n obtained by SSS method is in the range of 2.8～3.2 with an average of 3.13, illustrating a heterogeneous nucleation process followed by a three-dimensional spherulitic crystal growth mechanism. The crystallization activation energy is -158.2 kJ·mol-1. These results are in agreement with values determined from differential scanning calorimetry (DSC) method. It indicates that SSS technique is a simple, effective in situ method for measuring the dynamic melting and crystallization process of polymers. Moreover, the SSS method is a universal spectroscopic technique based on a spectrofluorimeter for monitoring both luminescent and non-luminous solid polymers..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2320 (2014)
Spectral Characteristics of Novel Accelerometer Based on Optical Microring Resonator
LI Xin, GUO Shi-liang, YANG Ming, and LI Zhi-quan
A structure of an optical accelerometer based on an optical single ring resonator located onto the cantilever is proposed to meet the requirements of microminiaturization and economical applications in the present paper. The spectra of out port are obtained using transfer matrix method and theory of coupled modes. AccoA structure of an optical accelerometer based on an optical single ring resonator located onto the cantilever is proposed to meet the requirements of microminiaturization and economical applications in the present paper. The spectra of out port are obtained using transfer matrix method and theory of coupled modes. According to the measurement of intensity of drop port at the same wavelength, the influences of different structure parameters on the sensitivity of the whole acceleration sensor are analyzed. The results show that the cantilever length and thickness and the ring resonator position are all key factors which can influence the sensing property of acceleration sensor. Hence the sensitivity can be effectively improved by adjusting the factors mentioned above. The sensitivity reaches up to 2.112 g-1 and the limit of detection can achieve 1.421 10-3 at 1.515 μm with a cantilever of 180 μm in length and 3 in thickness for a 30 dB signal-noise system. Such structure has great potential to develop low-cost and easy made high sensitive acceleration meter..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2327 (2014)
Study of the Termination of Two Acrylonitrile Radicals and Infrared Spectrum
LI Xin, YANG Meng-shi, XU Can, SONG Ping-an, CHEN Liang, DU Hong-chen, and WANG Yu
By using the density functional theory, the study of reaction termination mechanism of two (CH3)2(CN)C—CH2—(CN)CH was carried out at the B3LYP/6-31G(d) level. The initiator AIBN was used. Reactants, coupled intermediates, transition states and disproportionation products were optimized at the B3LYP/6-31G(d) level. ThenBy using the density functional theory, the study of reaction termination mechanism of two (CH3)2(CN)C—CH2—(CN)CH was carried out at the B3LYP/6-31G(d) level. The initiator AIBN was used. Reactants, coupled intermediates, transition states and disproportionation products were optimized at the B3LYP/6-31G(d) level. Then the total energies corrected by zero-point energy, vibrational frequencies and electronic structures were calculated, the transition states structure was also verified. The results show that it forms the energy-rich adducts a through the coupling termination. Then, the disproportionation product P［p1(CH3)2(CN)C〖: JＹ〗CH〖: ＪＬＸ, Ｙ〗CHCN+p2(CH3)2(CN)C—CH2—CH2CN］formed via hydrogen shift and dissociation. The reactions of coupling termination and disproportionation termination are all exothermic reactions, and the coupled product has lower energy. The rate constant of step a→TS→P is k(298.15 K)=2.71 10－59 at the normal atmospheric temperature. Disproportionation termination occurs more easily with the reaction temperature rising, so the proportion of disproportionation products is increasing. Also, the analysis of infrared spectrogram of each species in reaction process shows chemical change of free radicals in the whole termination reaction. The authors give the HOMO-LUMO in this paper to verify the accuracy of biradical coupling termination and structures. It has important guiding significance to controlling the free radicals termination methods of acrylonitrile monomer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2331 (2014)
Study of Self-Absorption Effect on Laser-Induced Metal Plasma
CHEN Jin-zhong, MA Rui-ling, WANG Jing, LI Xu, and SU Hong-xin
In order to reduce the effect of the spectral line self-absorption on the analysis result in the laser induced plasma and enhance the qualities of spectrum, the spectral information was recorded by the spectral analysis system consisting of a modular multifunctional grating spectrometer and a CCD detector etc., and theIn order to reduce the effect of the spectral line self-absorption on the analysis result in the laser induced plasma and enhance the qualities of spectrum, the spectral information was recorded by the spectral analysis system consisting of a modular multifunctional grating spectrometer and a CCD detector etc., and the electron temperature and electron density of the plasma were measured with the spectroscopic methods. A plane mirror device was used to constraint the laser plasma, and a reasonable explanation was got through comparing the linear evolution under different experimental conditions and measuring the temperature, electronic density and sample evaporation. The result shows that when an appropriate plane mirror device was used to constraint the laser plasma, the axial temperature of the plasma increased and the radial distribution of the plasma becomes uniform; the electron density increased dramatically; however, obviously sample evaporation decreased, which may be the reasons for being able to effectively reduce the level of self-absorption spectral lines. Therefore, the plane mirror device could reduce the self-absorption effect in the laser-induced plasma. This makes it possible to choose a sensitive line that acts as analysis line in the quantitative analysis of the major elements. In other words, this promotes the measurement precision in the laser-induced breakdown spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2337 (2014)
Research on Locking of the Output Power of Pulsed Laser in Laser-Induced Breakdown Spectroscopy
WANG Xin, HUANG Dan, FAN Juan-juan, ZHANG Lei, MA Wei-guang, DONG Lei, YIN Wang-bao, and JIA Suo-tang
Laser-induced breakdown spectroscopy (LIBS) as a rapid spectral analysis technology shows the outstanding application foreground and research value in coal quality on-line monitoring. In the practical application of this technology, the pulsed laser power fluctuation leads to the worse performance of long term stabilitLaser-induced breakdown spectroscopy (LIBS) as a rapid spectral analysis technology shows the outstanding application foreground and research value in coal quality on-line monitoring. In the practical application of this technology, the pulsed laser power fluctuation leads to the worse performance of long term stability, so a closed-loop feedback pulsed laser power locking device is set up, using laser power feedback signal to control and lock Nd∶YAG laser output power. The laser power locking experiments are investigated in the same pre-set value with different splitting ratios, the different laser output power with the same proportion and the long time running modes. The results show that the beam split ration has little impact to the stability of the laser power, and the smaller split ration leads to the faster stabilization. This device can keep the output power of the pulsed laser being locked in the pre-set range for a long-term running, RSD values decrease from 2.4% of free-running to 1.1%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2342 (2014)
Studies on Carbonization of Saccharides by Using Aqueous Solution of Various Acids
ZHANG Xin, HE An-qi, KANG Ting-guo, XIA Jin-ming, WENG Shi-fu, XU Yi-zhuang, and WU Jin-guang
The authors tried to establish an approach to use acids to convert biomass into a fuel with higher carbon content and lower oxygen content in a zero-energy-consumption fashion. Considering that biomass is composed of monosaccharide, we used aqueous solutions of variation acids including hydrochloric acid, sulfuric acidThe authors tried to establish an approach to use acids to convert biomass into a fuel with higher carbon content and lower oxygen content in a zero-energy-consumption fashion. Considering that biomass is composed of monosaccharide, we used aqueous solutions of variation acids including hydrochloric acid, sulfuric acid and perchloric acid to treat 2-deoxy-ribose and fructose at ambient temperature and pressure. Black substances were produced after a period of time when 2-deoxy-ribose and fructose were mixed with aqueous solutions containing 8 mol·L-1 acids. The black substance was collected and characterized by using elemental analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Elemental analysis results indicate that the contents of carbon increases significantly in the black substances in comparison with 2-deoxy-ribose and fructose. Moreover, XPS results indicate that the content of oxygen in the black substance undergoes a significant decrease comparedwith pure 2-deoxy-ribose and fructose. In the XPS spectra, the 1s peaks of 2-deoxy-ribose, strong sub peak at 286.05 eV, which is assigned to carbon linked to oxygen directly, dominate in the C 1s peak envelop. After treatment by HClO4, the peak decreased dramatically. This result also supports the conclusion that the content of oxygen in mono-saccharide is significantly reduced after treatment by acids. In the FTIR spectra of the black substances, strong peaks can be observed around 1 600 cm-1, indicating that CC bond is formed in the product. The above results suggest that treatments with acids may be developed as a new zero-energy-consumption approach to convert biomass in a new fuel with improved energy output efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2346 (2014)
Research on Night Visibility Inversion Algorithm Based on the Dual Light Sources Image and Curve Evolution Theory
DAI Pang-da, ZHANG Yu-jun, LU Chang-hua, ZHOU Yi, WANG Jing-li, and XIAO Xue
In the present paper, we propose a novel night visibility inversion algorithm. The key idea is based on the curve evolution theory in the context of dual light sources. First, we describe the features of the dual light sources night visibility inversion method, and explain the relationship between fluctuation of light In the present paper, we propose a novel night visibility inversion algorithm. The key idea is based on the curve evolution theory in the context of dual light sources. First, we describe the features of the dual light sources night visibility inversion method, and explain the relationship between fluctuation of light source intensity and curve evolution with the special characters. Then, level set method is introduced ito define the light source intensity and establish the model with visibility inversion, and the algorithm formula is detailed. Experiments results show that, the algorithm is characterized with a strong robustness and compared with the standard visibility, the correlation of visibility result reaches up to 0.98 in the range of 2 000 meter to 12 000 meter, which can be used in the visibility monitoring with a large range, high precision and strong robustness..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2351 (2014)
Preparation of MgxZn1-xO/Au/MgxZn1-xO Multilayer Transparent Conductive Film and Studies of Its Photoelectric Properties
Lv Shan-shan, FANG Xuan, WANG Jia-qi, FANG Fang, ZHAO Hai-feng, CHU Xue-ying, LI Jin-hua1, FANG Dan, TANG Ji-long, WEI Zhi-peng, MA Xiao-hui, WANG Xiao-hua, PU Shuang-shuang, and XU Li
In the present paper, MgxZn1-xO and MgxZn1-xO/Au/MgxZn1-xO multilayer structures of transparent conductive film were prepared by the simple operation of sol-gel and RF magnetron sputtering method on quartz substrate respectively and then they were annealed. The surface, electrical, crystal and optical properties of theIn the present paper, MgxZn1-xO and MgxZn1-xO/Au/MgxZn1-xO multilayer structures of transparent conductive film were prepared by the simple operation of sol-gel and RF magnetron sputtering method on quartz substrate respectively and then they were annealed. The surface, electrical, crystal and optical properties of the films at different annealing temperature were determined by UV-Vis spectrophotometer, X-ray diffraction, photoluminescence and Hall effect, respectively. The influence of annealing temperature on the films was also investigated. The testing results indicated that the films with good c-axis orientation presented hexagonal wurtzite structure. With increasing Mg components, the optical band gap of ZnO thin film increased gradually. There was an obvious blue shift phenomenon in PL spectrum and absorption spectrum line. But the electrical properties of the films declined. In MgxZn1-xO/Au/MgxZn1-xO multilayer structure of thin film samples, the existence of Au interlining led to the poor optical properties of thin film, and the light transmittance in the ultraviolet region was 60%. Compared with MgxZn1-xO film, the electrical properties of MgxZn1-xO/Au/MgxZn1-xO multilayer structure of transparent conductive film were improved, the resistivity and migration rate were significantly increased. In addition, high temperature annealing treatment could effectively improve the crystal quality of thin film and further improve the electrical characteristics of the samples. After the annealing treatment at 500 ℃, migration rate of the film reached to 40.9 cm2·Vs-1 while the resistivity was 0.005 7 Ω·cm. Due to the rising of temperature, the crystal size increased from 25.1 to 32.4 nm to reduce the mobility of the film. Therefore, MgxZn1-xO/Au/MgxZn1-xO multilayer structure of transparent conductive film played an important role in promoting the ZnO transparent conductive film application in deep ultraviolet devices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2355 (2014)
Highly Efficient, Color-Stable White Top-Emitting Organic Light-Emitting Diodes
LI Xue, SHAO Qiu-ping, CHEN Shu-fen, and HUANG Wei
Top-emitting white organic light-emitting diodes (WOLEDs) have potential applications in lighting and full color displays due to the potential realization of a large aperture ratio and a high resolution when recombining top-emitting WOLEDs with active-matrix driving circuits. In the present paper, the authors fabricateTop-emitting white organic light-emitting diodes (WOLEDs) have potential applications in lighting and full color displays due to the potential realization of a large aperture ratio and a high resolution when recombining top-emitting WOLEDs with active-matrix driving circuits. In the present paper, the authors fabricated top-emitting WOLEDs based on the red/blue dual-phosphorescent emitting layers and improved luminous efficiency and color stability in WOLEDs through inserting an tris(phenypyrazole)iridium (Ir(ppz)3) thin film as an electron-blocking layer between the red layer and the blue one. The insertion of an Ir(ppz)3 thin film can easily generate white emission through the enhancement of doping concentration of the red dopant, thus reducing the serious requirements of manufacture technology and improving the reproducibility of process technology. In addition, the authors analyzed the mechanism of color stability, optimized the concentrations of the red and blue phosphorescent dopants, and realized a luminous efficiency of as high as 7.9 cd·A-1 in the authors’ top-emitting WOLED. The white emission lies in the warm-white region with a very small chromaticity change of (0.006, 0.01) under a wide brightness range of 87~2 403 cd·m-2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2360 (2014)
Research Progress in the Application of Biosensors by Using Metamaterial in Terahertz Wave
YAN Xin, ZHANG Xing-fang, LIANG Lan-ju, and YAO Jian-quan
In the present paper, the recent progress in terahertz metamaterials-based sensing is reviewed with the principle of metamaterial biosensor, metamaterial substrate, and structure design, respectively. The paper introduces the principle in detail, analyzes the sensitivity of the biosensor with the material and the thickIn the present paper, the recent progress in terahertz metamaterials-based sensing is reviewed with the principle of metamaterial biosensor, metamaterial substrate, and structure design, respectively. The paper introduces the principle in detail, analyzes the sensitivity of the biosensor with the material and the thickness of the substrate and the structure of metamaterial. The analysis shows that we can enhance the sensitivity and resolution of biosensor by designing specific metamaterial structure, using low dielectric constant and low loss thin substrate, especially many materials have a specific response in the terahertz frequency. So, there is a large potential application for label-free sensing by using the terahertz metamaterials. This paper also presents the future development of THz metamaterial sensors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2365 (2014)
Determination of Degree of Polymerization of Natural Cellulose Pulp Using Near-Infrared Diffuse Reflectance Spectroscopy
YI Ying, SONG Chun-feng, YUAN Hong-fu, XIE Jin-chun, DU Jun-qi, and LI Xiao-yu
A new method of near-infrared (NIR) diffuse reflectance spectroscopy is proposed to rapidly determine the degree of polymerization (DP) of natural cellulose (cotton and wood) pulp produced by a new clean pulping process. One hundred and ninety five samples were collected and their DP data were determined by standard meA new method of near-infrared (NIR) diffuse reflectance spectroscopy is proposed to rapidly determine the degree of polymerization (DP) of natural cellulose (cotton and wood) pulp produced by a new clean pulping process. One hundred and ninety five samples were collected and their DP data were determined by standard method GB/T 9107—1999. The spectroscopy measurement method of the samples was studied and their near-infrared diffuse reflectance spectra were collected. The quantitative DP calibration models of one mixed cotton & wood and two separate cotton and wood pulps were established by partial least squares (PLS). The optimum models were developed using the spectra pretreated by derivative, autoscaling and mean-centering, and their performance is as follows: correlation coefficient of 0.980, 0.993 and 0.886, and RMSEP of 147, 143 and 53, respectively. The accuracy of NIR method was also studied. The results show that the accuracy of the two separate models of cotton and wood is better than that of the mixed model, and the precision of the two separate models is better than that of GB/T9107—1999. The identification model of cotton and wood was also established using principal component analysis (PCA). The result shows that the spectra of cotton and wood pulp have obvious difference, and the model can identify successfully the two kinds of pulp. The result indicates that the new NIR method is feasible to realize the on-line analysis of polymerization degree of natural cellulose pulp with its advantage of rapidness and easy operation..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2372 (2014)
Research Progress and Application Prospect of Near-Infrared Spectroscopy in Analysis of Food Amino Acid
YU Xiao-lan, XU Ning, and HE Yong
To investigate the progress and application of near infrared spectroscopy (NIR) used to detect amino acids in the growth of crops and food processing process. With online searching databases including ISI (Web of Knowledge), CNKI (China Knowledge Network), summarize the detection of chemical value using high performancTo investigate the progress and application of near infrared spectroscopy (NIR) used to detect amino acids in the growth of crops and food processing process. With online searching databases including ISI (Web of Knowledge), CNKI (China Knowledge Network), summarize the detection of chemical value using high performance liquid chromatography (HPLC) and chemometric methods involved in the application of NIR used to analyze amino acids in food, meanwhile summarize the data, materials and main topics in relevant original literature. Overview the methods of chemical value detection using HPLC and chemometric analysis, their applications in detecting the quality of crops, determining the content of water, amino acids and polyphenol in green tea, detecting the quality of feed and determining the content of amino acids in cheese, ham and meat products. We forecasted the application of NIR in determining the content of amino acids in food and analyzed its merits and drawbacks. The development of NIR’s application in amino acids detection should be based on the HPLC detection, and the problem of model transfer mainly restricts its large-scale promotion currently. Online analysis can monitor the entire reaction and change process from raw materials to products and thus meets the needs of real-time monitoring food quality from production to sales, and it will be an important direction for future..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2377 (2014)
Application of Visible/Near-Infrared Spectroscopy to the Determination of Catalase and Peroxidase Content in Barley Leaves
ZHAO Yun, ZHANG Chu, LIU Fei, KONG Wen-wen, and HE Yong
Visible/near-infrared spectroscopy was applied to determine the content of catalase (CAT) and peroxidase (POD) in barley leaves under the herbicide stress of propyl 4-(2-(4, 6-dimethoxypyrimidin-2-yloxy) benzylamino) benzoate (ZJ0273). The spectral data of the barley leaves in the range of 500~900 nm were preprocessed Visible/near-infrared spectroscopy was applied to determine the content of catalase (CAT) and peroxidase (POD) in barley leaves under the herbicide stress of propyl 4-(2-(4, 6-dimethoxypyrimidin-2-yloxy) benzylamino) benzoate (ZJ0273). The spectral data of the barley leaves in the range of 500~900 nm were preprocessed by moving average with 11 points. Seven outlier samples for CAT and 8 outlier samples for POD were detected and removed by Monte Carlo-partial least squares (MCPLS). PLS, least-squares support vector machine (LS-SVM) and extreme learning machine (ELM) models were built for both CAT and POD. ELM model obtained best results for CAT, with correlation coefficient of calibration (Rc) of 0.916 and correlation coefficient of prediction (Rp) of 0.786. PLS model obtained best prediction results for POD, with Rc of 0.984 and Rp of 0.876. Successive projections algorithm (SPA) was applied to select 8 and 19 effective wavelengths for CAT and POD, respectively. PLS, LS-SVM and ELM models were built using the selected effective wavelengths of CAT and POD. ELM model performed best for CAT and POD prediction, with Rc of 0.928 and Rp of 0.790 for CAT and Rc of 0.965 and Rp of 0.941 for POD. The prediction results using the full spectral data and the effective wavelengths were quite close, and the prediction performance for POD was much better than the prediction performance for CAT, and the studies should be further explored to build more precise and more robust models for CAT and POD determination. The overall results indicated that it was feasible to use visible/near-infrared spectroscopy for CAT and POD content determination in barley leaves under the stress of ZJ0273..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2382 (2014)
The Effect of MSC Spectral Pretreatment Regions on Near Infrared Spectroscopy Calibration Results
WANG Dong-min, JI Jun-min, and GAO Hong-zhi
In the present paper, 60 whole wheat flour samples were prepared and corresponding NIR spectra were collected. After the determinations of calibration range, several spectral sub-regions containing calibration range and prepared for the correction using multiple scattering correction (MSC) were obtained in the whole spIn the present paper, 60 whole wheat flour samples were prepared and corresponding NIR spectra were collected. After the determinations of calibration range, several spectral sub-regions containing calibration range and prepared for the correction using multiple scattering correction (MSC) were obtained in the whole spectral region firstly, and MSC correction based on different spectral sub-region followed subsequently. Corresponding spectral data were obtained from the fixed calibration range of the spectra corrected based on different regions. Several partial least squares regression (PLSR) calibration models for analyzing protein content of whole wheat flour were established based on corresponding spectral data, and according to the performance about the calibration coefficient and the root mean square error of cross validation (RMSEV) of every calibration, the effects of MSC pretreatment spectral region on PLSR calibration results were investigated and the pretreatment spectral regions were optimized by comparing the performance of more calibration models. For the optimized calibration, the calibration coefficient and the RMSECV improved compared with the calibration established based on the spectral data corrected using MSC in the fixed region of calibration. The correlation coefficient can be raised from 0.96 to 0.98 and RMSECV can be decreased from 0.37% to 0.32%. The results show that the capability of MSC on correcting the spectral interference information of non-chemical absorption can be influenced by preprocessing spectral regions, the performance of calibration model can be improved by optimizing the MSC pretreatment spectral region, and the appropriate pretreatment spectral region is prerequisite to obtain the best calibration results while using MSC for near-infrared spectra analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2387 (2014)
Rapid Assessment of Critical Quality Attributes of Chinese Materia Medica (Ⅱ): Strategy of NIR Assignment
PEI Yan-ling, WU Zhi-sheng, SHI Xin-yuan, ZHOU Lu-wei, and QIAO Yan-jiang
The present paper firstly reviewed the research progress and main methods of NIR spectral assignment coupled with our research results. Principal component analysis was focused on characteristic signal extraction to reflect spectral differences. Partial least squares method was concerned with variable selection to discThe present paper firstly reviewed the research progress and main methods of NIR spectral assignment coupled with our research results. Principal component analysis was focused on characteristic signal extraction to reflect spectral differences. Partial least squares method was concerned with variable selection to discover characteristic absorption band. Two-dimensional correlation spectroscopy was mainly adopted for spectral assignment. Autocorrelation peaks were obtained from spectral changes, which were disturbed by external factors, such as concentration, temperature and pressure. Density functional theory was used to calculate energy from substance structure to establish the relationship between molecular energy and spectra change. Based on the above reviewed method, taking a NIR spectral assignment of chlorogenic acid as example, a reliable spectral assignment for critical quality attributes of Chinese materia medica (CMM) was established using deuterium technology and spectral variable selection. The result demonstrated the assignment consistency according to spectral features of different concentrations of chlorogenic acid and variable selection region of on-line NIR model in extract process. Although spectral assignment was initial using an active pharmaceutical ingredient, it is meaningful to look forward to the futurity of the complex components in CMM. Therefore, it provided methodology for NIR spectral assignment of critical quality attributes in CMM..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2391 (2014)
Myanmar Jadeitite Low-Temperature Metamorphic Water-Rock Reaction: Eveidence from Microscopic Fourier Transform Infrared Spectroscopy
YAN Ruo-gu, QIU Zhi-li, FENG Ming, JIN Chun-mei, LI Liu-fen, SHI Gui-yong, and WANG Ping
Weathering & transporting and depositing processes may improve the quality of some natural low-quality jadeite through reaction with surrounding water fluids. But the mechanism of such water-rock reaction has not been known clearly to date. Applying microscopic Fourier transform infrared spectroscopy (Micro-FTIR), Weathering & transporting and depositing processes may improve the quality of some natural low-quality jadeite through reaction with surrounding water fluids. But the mechanism of such water-rock reaction has not been known clearly to date. Applying microscopic Fourier transform infrared spectroscopy (Micro-FTIR), this paper carried out comparatively in-situ research of jadeites’ mineral composition before and after water-rock reaction. The results show that water-rock reaction cannot impact jadeites in their major and minor element composition, but greatly change their water content. Jadeites became richer, with even several times increase, in water content, after experiencing water-rock reaction, and hence show a shift of absorption peak at 3 550 cm-1 to higher frequency. The mineral crystals of these jadeites showed reglar variation in water content from core to edge, and these jadeites have more water in marginal area than in center area, being opposite to the change in water content in jadeite during high temperature and pressure metamorphic process, hence implying that there are different mechanism and shift direction for H+/OH- of jadeite between high pressure metamorphic process and low temperature water-rock reaction. We think that this finding may contribute to understanding the behavior of water in jadeite during metamorphic process and the mechanism of jadeite quality improvement..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2397 (2014)
Study on Brand Traceability of Vinegar Based on Near Infrared Spectroscopy Technology
GUAN Xiao, LIU Jing, GU Fang-qing, and YANG Yong-jian
In the present paper, 152 vinegar samples with four different brands were chosen as research targets, and their near infrared spectra were collected by diffusion reflection mode and transmission mode, respectively. Furthermore, the brand traceability models for edible vinegar were constructed. The effects of the collecIn the present paper, 152 vinegar samples with four different brands were chosen as research targets, and their near infrared spectra were collected by diffusion reflection mode and transmission mode, respectively. Furthermore, the brand traceability models for edible vinegar were constructed. The effects of the collection mode and pretreatment methods of spectrum on the precision of traceability models were investigated intensively. The models constructed by PLS1-DA modeling method using spectrum data of 114 training samples were applied to predict 38 test samples, and R2, RMSEC and RMSEP of the model based on transmission mode data were 0.92, 0.113 and 0.127, respectively, with recognition rate of 76.32%, and those based on diffusion reflection mode data were 0.97, 0.102 and 0.119, with recognition rate of 86.84%. The results demonstrated that the near infrared spectrum combined with PLS1-DA can be used to establish the brand traceability models for edible vinegar, and diffuse reflection mode is more beneficial for predictive ability of the model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2402 (2014)
Influence of Silver/Silicon Dioxide on Infrared Absorption Spectroscopy of Sodium Nitrate
YANG Shi-ling, YUE Li, and JIA Zhi-jun
Quickly detecting of ocean nutrient was one important task in marine pollution monitoring. We discovered the application of surface-enhanced infrared absorption spectroscopy in the detection of ocean nutrient through researching the evaporation of sodium nitrate solution. The silicon dioxide (SiO2) with highly dispersiQuickly detecting of ocean nutrient was one important task in marine pollution monitoring. We discovered the application of surface-enhanced infrared absorption spectroscopy in the detection of ocean nutrient through researching the evaporation of sodium nitrate solution. The silicon dioxide (SiO2) with highly dispersion was prepared by Stober method, The silver/silica (Ag/SiO2) composite materials were prepared by mixing ammonia solution and silicon dioxide aqueous solution. Three kinds of composite materials with different surface morphology were fabricated through optimizing the experimental parameter and changing the experimental process. The surface morphology, crystal orientation and surface plasmon resonance were investigated by means of the scanning electronic microscope (SEM), X-ray diffraction (XRD), UV-Visible absorption spectrum and infrared absorption spectroscopy. The SEM images showed that the sample A was purified SiO2, sample B and sample C were mixture of silver nanoparticle and silicon dioxide, while sample D was completed nanoshell structure. The absorption spectroscopy showed that there was surface plasmon resonance in the UV-visible region, while there was possibility of surface plasmon resonance in the Infrared absorption region. The effect of Ag/SiO2 composite material on the infrared absorption spectra of sodium nitrite solution was investigated through systematically analyzing the infrared absorption spectroscopy of sodium nitrate solution during its evaporation, i. e. the peak integration area of nitrate and the peak integration area of water molecule. The experimental results show that the integration area of nitrate was enhanced greatly during the evaporation process while the integration area of water molecule decreased continuously. The integration area of nitrate comes from the anti-symmetric stretch vibration and the enhancement of the vibration is attributed to the interface effect of Ag/SiO2. which is consistent with Jensen T. R.’s result..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2407 (2014)
Analysis on the Impact of Composting with Different Proportions of Corn Stalks and Pig Manure on Humic Acid Fractions and IR Spectral Feature
SUN Xiang-ping, LI Guo-xue, XIAO Ai-ping, SHI Hong, WANG Yi-ming, and LI Yang-yang
Using pig manure and corn straw as raw materials for high-temperature composting, setting three different treatments: C/N 15, C/N 25, and C/N 35. Composting period is 120 days, which contains 30 days for ventilation cycle by forced continuous ventilation. Sampled on 0, 22, 30, 60, 90, 120th days, they were analyzed by Using pig manure and corn straw as raw materials for high-temperature composting, setting three different treatments: C/N 15, C/N 25, and C/N 35. Composting period is 120 days, which contains 30 days for ventilation cycle by forced continuous ventilation. Sampled on 0, 22, 30, 60, 90, 120th days, they were analyzed by elemental analysis and IR spectroscopy to study effect of different lignin content on compost humic acid (HA) composition and molecular structure. The results showed that the change in composting humic acid C focused on the first 30 days, while after composting, the O/C of compost HA increased, H/C decreased, and N content increased. Low C/N (15) and higher C/N ratio (35) had higher degree of oxidation than the C/N 25 in compost HA. FTIR indicated that the infrared spectrum shapes with different lignin content treatment are similar during the composting process, but the peak intensity is obviously different. Research results proved that the composting stage is more conducive to enhanced aromatic in compost HA. After composting, C/N 15 had less polysaccharide and fat ingredients and more aromatic structural components in compost HA, compared with C/N 25 and 35. In addition, compost HA of C/N 15 had higher degree of humification and its structure was more stable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2413 (2014)
Identification of Some Piper Crude Drugs Based on Fourier Transform Infrared Spectrometry
ZHOU Ye, ZHANG Qing-wei, LUO Xue-jun, LI Pei-fu, SONG Heng, and ZHANG Bo-li
The common peak ratio and variant peak ratio were calculated by FTIR spectroscopy of seven medicinal plants of Piper. The dual index sequence of common peak ratio and variant peak ratio was established, which showed the sibship of the medicinal plants. The common peak ratio of Piper kadsura (Choisy) Ohwi, Piper wallichThe common peak ratio and variant peak ratio were calculated by FTIR spectroscopy of seven medicinal plants of Piper. The dual index sequence of common peak ratio and variant peak ratio was established, which showed the sibship of the medicinal plants. The common peak ratio of Piper kadsura (Choisy) Ohwi, Piper wallichii (Miq.) Hand.-Mazz. Piper laetispicum (C.DC.) was greater than 77%, and the variant peak ratio was less than 30%. The results showed the near sibship between the three drugs. The common peak ratio of Piper kadsura (Choisy) Ohwi, Piper nigrum L. and Piper boehmeriaefolium Wall (Miq.) C.DC. Var. tonkinense (C.DC.) was about 61% which showed the farther sibship. The common peak ratio of Piper kadsura (Choisy) Ohwi and Piper betle (Linn.) was only 44%, which showed the farthest sibship. Piper kadsura (choisy) Ohwi and its adulterants, such as Piper wallichii(Miq. ) Hand.-Mazz., Piper boehmeriaefolium Wall(Miq.) C.DC. Var. tonkinense C.DC., Piper laetispicum C.DC., Piper nigrum L., could be identified by comparing their second order derivative IR spectrum of the samples. FTIR technique is a non-destructive analysis method which provides information of functional group, type and hydrogen bond without complex pretreatment procedures such as extraction and separation. FTIR method has some characteristics such as rapid and simple analysis procedure, good reproducibility, non-destructive testing, few amount of required sample and low cost and is environment-friendly. The method solved the problems of limit in resource of Piper kadsura (Choisy) Ohwi, many fakes and difficulties in identification, and brought the security for the clinical medication. FTIR provides a new method for identification of Piper kadsura(choisy) Ohwi and its fakes and meets the requirement for comprehensive analysis and global analysis of traditional Chinese medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2419 (2014)
Identification of Pearl Powder Using Microscopic Infrared Reflectance Spectroscopy
ZHANG Xuan, HU Chao, YAN Yan, YANG Hai-feng, LI Jun-fang, BAI Hua, XI Guang-cheng, and LIAO Jie
Pearl is a precious ornament and traditional Chinese medicine, which application history in China is more than 2000 years. It is well known that the chemical ingredients of shell and pearl are very similar, which all of them including calcium carbonate and various amino acids. Generally, shell powders also can be used Pearl is a precious ornament and traditional Chinese medicine, which application history in China is more than 2000 years. It is well known that the chemical ingredients of shell and pearl are very similar, which all of them including calcium carbonate and various amino acids. Generally, shell powders also can be used as medicine; however, its medicinal value is much lower than that of pearl powders. Due to the feature similarity between pearl powders and shell powders, the distinguishment of them by detecting chemical composition and morphology is very difficult. It should be noted that shell powders have been often posing as pearl powders in markets, which seriously infringes the interests of consumers. Identification of pearl powder was investigated by microscopic infrared reflectance spectroscopy, and pearl powder as well as shell powder was calcined at different temperatures for different time before infrared reflectance spectroscopy analysis. The experimental results indicated that when calcined at 400 ℃ for 30 minutes under atmospheric pressure, aragonite in pearl powder partly transformed into calcite, while aragonite in shell powder completely transformed into calcite. At the same time, the difference in phase transition between the pearl powders and shell powders can be easily detected by using the microscopic infrared reflectance spectroscopy. Therefore, based on the difference in their phase transition process, infrared reflectance spectroscopy can be used to identify phase transformation differences between pearl powder and shell powder. It’s more meaningfully that the proposed infrared reflectance spectroscopy method was also investigated for the applicability to other common counterfeits, such as oyster shell powders and abalone shell powders, and the results show that the method can be a simple, efficiently and accurately method for identification of pearl powder..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2424 (2014)
Analysis and Identification of Semen Glycines Nigrae and Semen Pharbitidis by Infrared Spectroscopy
DU Juan, PENG Xi-yuan, MA Fang, CHEN Jian-bo, ZHOU Qun, JIN Zhe-xiong, and SUN Su-qin
Semen Glycines Nigrae and Semen Pharbitidis containing a large amount of fats and proteins are commonly used in Chinese herbal medicine. Tri-step infrared spectroscopy was applied to fast analyze and identify the two samples. In the conventional infrared spectroscopy, the samples both have obvious characteristic absorpSemen Glycines Nigrae and Semen Pharbitidis containing a large amount of fats and proteins are commonly used in Chinese herbal medicine. Tri-step infrared spectroscopy was applied to fast analyze and identify the two samples. In the conventional infrared spectroscopy, the samples both have obvious characteristic absorption peaks at 1 745 cm-1 assigned to the stretching mode of CO in esters. Furthermore, the two kinds of herbs have the peaks at 1 656 and 1 547 cm-1 assigned to the amide Ⅰ and Ⅱ bands of protein. Obviously, the infrared spectra of herbs demonstrate that protein and fat is the major component in two kinds of herbs, and the relative intensity of the peaks assigned to fat and protein indicate their relative content is different. And the result is consistent with the reported. In the second derivative spectra, Semen Pharbitidis has a peak at 1 712 cm-1 assigned to the organic acid, however, Semen Glycines Nigrae has not this absorption peak. In addition, in the second derivative spectra, appeared more differences between the two samples in shape and intensity of the peaks. In two-dimensional correlation infrared spectra, the two samples were visually distinguished due to their significant differences in auto-peak position and intensity. In the region of 1 500~1 700 cm-1, Semen Glycines Nigrae has two autopeaks and Semen Pharbitidis has three autopeaks. In the region of 2 800~3 000 cm-1, the samples both have two autopeaks, but the position of the strongest autopeak is different. It was demonstrated that the Tri-step infrared spectroscopy were successfully applied to fast analyze and identify the two kinds of samples containing the same major component, and made sure the foundation for future researches..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2429 (2014)
The Analyses and Identification of Flos Rhododendri Mollis and Flos Chrysanthemi Indici Via Infrared Spectroscopy
JIN Zhe-xiong, WANG Yue, ZHOU Qun, CHEN Jian-bo, MA Fang, and SUN Su-qin
In this study, major chemical components of Flos rhododendri mollis and Flos chrysanthemi indici were characterized using Fourier transform infrared spectroscopy (FTIR). For Flos rhododendri mollis, the bands at 1 648 and 1 543 cm-1 were attributed to amide Ⅰ and amide Ⅱ, respectively, indicating that it contained protIn this study, major chemical components of Flos rhododendri mollis and Flos chrysanthemi indici were characterized using Fourier transform infrared spectroscopy (FTIR). For Flos rhododendri mollis, the bands at 1 648 and 1 543 cm-1 were attributed to amide Ⅰ and amide Ⅱ, respectively, indicating that it contained proteins probably resulting in immunization. In case of Flos chrysanthemi indici, stretching vibration of CO function group was responsible for the bands at 1 734 and 1 515 cm-1, as a result of essential oils, lipids, etc. Since FTIR spectra of Flos rhododendri mollis and Flos chrysanthemi indici are almost identical and it is difficult to discriminate them, two-step identification was investigated via secondary derivative of the FTIR spectra. The bands at 1 656 and 1 515 cm-1 corresponds to flavonoides in Flos rhododendri mollis and Flos chrysanthemi indici. In the secondary derivative of the FTIR spectrum of Flos chrysanthemi indici, characteristic bands of inulin were present at 1 163, 1 077, 1 026, 986 and 869 cm-1, and therefore Flos chrysanthemi indici contained inulin as well. Tri-step identification was carried out for Flos rhododendri mollis and Flos chrysanthemi indici by means of comparing their 2D-IR correlation spectra in different wave number range. In the characteristic range of flavonoides (1 700~1 400 cm-1), Flos rhododendri mollis exhibited 3 obvious autopeaks, while 10 autopeaks were visualized in the 2D-IR correlation spectrum of Flos chrysanthemi indici Moreover, in the characteristic range of glucoside (1 250~900 cm-1), 10 and 9 autopeaks were present in the 2D-IR correlation spectra of Flos rhododendri mollis and Flos chrysanthemi indici, respectively. Therefore, the tri-step identification of FTIR is a time-saving, accurate, cost-saving and convenient method to effectively distinguish traditional Chinese medicines..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2434 (2014)
Micro-Raman Spectral Characteristics and Implication of FeS2 from Augen Granites in West Of Guangdong
AN Yan-fei, ZHONG Li-li, and JIANG Da-peng
Some FeS2 samples among Augen granite from Guanshanzhang mass in the west of Guangdong Province were retrieved to characterize the spectral signature of Raman. The results show that three distinct scattering modes active of Fe-［S2］2- Liberational Motion (Eg), Fe-［S2］2- Stretching Motion (Ag) and S—S Stretching Motion (Some FeS2 samples among Augen granite from Guanshanzhang mass in the west of Guangdong Province were retrieved to characterize the spectral signature of Raman. The results show that three distinct scattering modes active of Fe-［S2］2- Liberational Motion (Eg), Fe-［S2］2- Stretching Motion (Ag) and S—S Stretching Motion (Tg) are observed from all samples. Detailed analyses indicate that Raman shift (Δν), Modes intensity (I) and full width at half maximum (FWHM) are different between each type pyrite. The spectra show that there are three peaks respectively about 318 cm-1 (Δν1), 381 cm-1(Δν1) and 440 cm-1(Δν1) in Banded pyrite and three peaks in others samples about 344 cm-1 (Δν1), 379 cm-1 (Δν1) and 430 cm-1 (Δν1). Under compression to Alterated pyrite, all modes (Eg, Ag and Tg ) shift continuously to higher frequencies from Deformed samples to Euhedral type. Eg mode is much intenser than Ag mode as well as the latter is intenser than Tg mode too in Banded samples (IEgIAgITg), the intensity of Ag mode is higher than Eg mode, and the latter is much higher than Tg mode in other samples (IAg>IEgITg). Compared with Alterated pyrite, all modes of Eg, Ag and Tg intense continuously to higher frequencies from Euhedral samples to Deformed type. Those spectral characteristics above evidence that, the Raman shift and intensity of Banded samples is similar to marcasite, while those of others show characteristics of the pyrite. The crystallization temperature of Euhedral pyrite is higher than Deformed as well as Euhedral is higher than Alterated too. The formation pressure of Euhedral samples is higher than Alterated pyrite the same as Deformed pyrite hingher than Euhedral one too. Thus, The authors’ studies suggest that the forming conditions of FeS2 in Guanshanzhang mass experienced marcasite period→high-pressure pyrite period→high-temperature pyrite period→Alterated pyrite period..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2439 (2014)
Three-Dimensional Vertically Aligned CNTs Coated by Ag Nanoparticles for Surface-Enhanced Raman Scattering
ZHANG Xiao-lei, ZHANG Jie, FAN Tuo, REN Wen-jie, and LAI Chun-hong
In order to make surface-enhanced Raman scattering (SERS) substrates contained more “hot spots” in a three-dimensional (3D) focal volume, and can be adsorbed more probe molecules and metal nanoparticles, to obtain stronger Raman spectral signal, a new structure based on vertically aligned carbon nanotubes (CNTs) coatedIn order to make surface-enhanced Raman scattering (SERS) substrates contained more “hot spots” in a three-dimensional (3D) focal volume, and can be adsorbed more probe molecules and metal nanoparticles, to obtain stronger Raman spectral signal, a new structure based on vertically aligned carbon nanotubes (CNTs) coated by Ag nanoparticles for surface Raman enhancement is presented. The vertically aligned CNTs are synthesized by chemical vapor deposition (CVD). A silver film is first deposited on the vertically aligned CNTs by magnetron sputtering. The samples are then annealed at different temperature to cause the different size silver nanoparticles to coat on the surface and sidewalls of vertically aligned CNTs. The result of scanning electron microscopy(SEM) shows that Ag nanoparticles are attached onto the sidewalls and tips of the vertically aligned CNTs, as the annealing temperature is different , pitch size, morphology and space between the silver nanoparticles is vary. Rhodamine 6G is served as the probe analyte. Raman spectrum measurement indicates that: the higher the concentration of R6G, the stronger the Raman intensity, but R6G concentration increase with the enhanced Raman intensity varies nonlinearly; when annealing temperature is 450 ℃, the average size of silver nanoparticles is about 100 to 120 nm, while annealing temperature is 400 ℃, the average size is about 70 nm, and the Raman intensity of 450 ℃ is superior to the annealing temperature that of 400 ℃ and 350 ℃..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2444 (2014)
Study of Volatile Organic Compounds of Fresh Allium Species Using Headspace Combined with Surface-Enhanced Raman Scattering
SI Min-zhen, ZHANG De-qing, and LIU Ren-ming
In order to identify volatile organic compounds of fresh plants at room temperature and avoid sample pretreatment and extractions which can be labor intensive, garlic, Chinese chives and scallion were chopped into pieces. Then some of them were placed in the headspace vial and sealed. The gases were drawn from the vialIn order to identify volatile organic compounds of fresh plants at room temperature and avoid sample pretreatment and extractions which can be labor intensive, garlic, Chinese chives and scallion were chopped into pieces. Then some of them were placed in the headspace vial and sealed. The gases were drawn from the vial with a syringe and were injected very slowly into Ag colloids for test using R-3000 portable Raman spectrometer. The spectra of volatile organic compounds of allium species, fresh garlic, Chinese chive and shallot plants were successfully recorded for the first time. For garlic high intensity bands are present at 307, 399, 569, 711, 1 182, 1 287, 1 397 and 1 622 cm-1. For Chinese chives the high intensity band is present at 672 cm-1. Low intensity bands are present at 274, 412, 575, 1 185, 1 289, 1 396, 1 618 cm-1. For shallot high intensity bands are present at 693 cm-1. Lower intensity bands are present at 372, 888, 1 023 cm-1. Low intensity bands are present at 1 088, 1 211 and 1 322 cm-1. The SERS of dially1 disulfide, allyl methyl sulfide and 1-propanethiol in liquid state and gas state were also obtained. The main volatile organic compound of fresh garlic, Chinese chive and shallot are diallyl disulfide, allyl methyl sulfide and 1-propanethiol respectively, and the volatile organic compound of fresh onion, scallion, shallot and chive are all 1-propanethiol. The presented results illustrate that combining headspace and SERS is a powerful tool for volatile organic compound analysis in fresh plants. The volatile organic compound can be detected in fresh plant samples directly and quickly without extraction..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2449 (2014)
Theoretical Investigation on the Structure and Vibration Spectrum of D-Luciferin
ZHU Yuan-qiang, ZHANG Li, and GUO Jian-chun
In the present study, the geometry of D-Luciferin was fully optimized by the density functional theory at the B3LYP/6-311++G** and B3PW91/6-311++G** level, and the Cartesian coordinate force constant was calculated at the same level. The scaled quantum mechanism force field (SQM) method was performed to analyze the vibIn the present study, the geometry of D-Luciferin was fully optimized by the density functional theory at the B3LYP/6-311++G** and B3PW91/6-311++G** level, and the Cartesian coordinate force constant was calculated at the same level. The scaled quantum mechanism force field (SQM) method was performed to analyze the vibration spectrum. The local internal symmetry coordinates were defined using the method given by Pulay. The theoretical force field matrix, which was obtained through molecular vibration calculation programs, was transformed from Cartesian coordinates into the local internal coordinates. A normal coordinate analysis was carried out using GF matrix method developed by Wilson to give the scaled vibration frequencies and the potential energy distributions (PEDs). In order to make the vibration frequencies in good agreement with the experimental values, we empirically scale the theoretical force fields. According to PEDs, all vibration modes were assigned reliably to certain vibration frequencies. The calculated results show that the D-Luciferin molecule belongs to the point group C1 and involves 66 free degrees of vibration. All vibration modes are infrared and Raman activity. In the Infrared spectrum, the vibration frequency of the strongest absorption peak is 1 780 cm-1, and the absorption intensity is 507 KM·mol-1, which is mainly contributed by the stretching vibration mode of the C21O22 double bond with the PEDs of 93%. In the Raman spectrum, the vibration frequency in the range of 1 200～1 700 cm-1 presented strong Raman activity, the frequency of the strongest absorption peak is 1 573 cm-1, and the absorption intensity is 297 KM·mol-1, which is mainly contributed by the stretching vibration mode of the C21N22 double bond in the five-membered ring. The results are helpful to further studying the structure and the luminescence activity of Luciferin derivatives in experiment and theory..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2453 (2014)
Study on Quantitative Mechanism and the Interference of the UV Spectrum of HABS Reduced by β-Cyclodextrin
SHI Dong-po, YIN Xian-qing, ZHENG Yan-cheng, CHEN Wu, FU Jia-xin, and REN Zhao-hua
A novel ultraviolet absorption spectrometry method was developed for the quantitative determination of HABS by adding β-cyclodextrin with the molar ratio of 1∶1 in strong interference aqueous solution. The results indicated that the effect of several common interfering flooding agents (SAS, OP-10, HPAM) on the determinA novel ultraviolet absorption spectrometry method was developed for the quantitative determination of HABS by adding β-cyclodextrin with the molar ratio of 1∶1 in strong interference aqueous solution. The results indicated that the effect of several common interfering flooding agents (SAS, OP-10, HPAM) on the determination of HABS could be greatly reduced in β-cyclodextrin aqueous solution. Thus, the determination errors of the determined HABS were less than 2.0% under strong interference, and the detection limit (S/N=3) of the method could be also as high was 8.3～9.1 10－4 mg·L－1. Various characterization results including 1H-NMR, TG-DSC and FTIR showed the interaction between β-cyclodextrin and HABS. The results of 1H-NMR analysis showed that HABS molecule could enter into the interior of the cavity of β-cyclodextrin molecule. TG-DSC analysis exhibited that the stable inclusion of β-cyclodextrin and HABS could be automatically formed. The interactions between the functional groups of β-cyclodextrin and HABS were showed by FTIR analysis, which also exhibited that the stable inclusion could be formed by HABS entering from the narrow or the broad mouth of the β-cyclodextrin. The interference of the UV spectrum of HABS could be reduced by β-cyclodextrin since the interaction between β-cyclodextrin due to the interaction between β-cyclodextrin and HABS in the inclusion complex..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2460 (2014)
Analysis of Fluorescence Spectrum of Petroleum-Polluted Water
HUANG Miao-fen, SONG Qing-jun, XING Xu-feng, JIAN Wei-jun, LIU Yuan, and ZHAO Zu-long
In four ratio experiments, natural waters, sampled from the mountain reservoir and the sea water around Dalian city, were mixed with the sewage from petroleum refinery and petroleum exploitation plants. The fluorescence spectra of water samples containing only chromophoric dissolved organic matters(CDOM), samples contaIn four ratio experiments, natural waters, sampled from the mountain reservoir and the sea water around Dalian city, were mixed with the sewage from petroleum refinery and petroleum exploitation plants. The fluorescence spectra of water samples containing only chromophoric dissolved organic matters(CDOM), samples containing only petroleum, and samples containing a mixture of petroleum and CDOM were analyzed, respectively. The purpose of this analysis is to provide a basis for determining the contribution of petroleum substances and CDOM to the total absorption coefficient of the petroleum-contaminated water by using fluorescence technique. The results showed that firstly, CDOM in seawater had three main fluorescence peaks at Ex: 225～230 nm/Em: 320～330 nm, Ex: 280 nm/Em: 340 nm and Ex: 225～240 nm/Em: 430～470 nm, respectively, and these may arise from the oceanic chlorophyll. CDOM in natural reservoir water had two main fluorescence peaks at EX: 240～260 nm/Em: 420～450 nm and Ex: 310～350 nm/Em: 420～440 nm, respectively, and these may arise from the terrestrial sources; secondly, the water samples containing only petroleum extracted with n-hexane had one to three fluorescence spectral peaks at Ex: 220～240 nm/Em: 320～340 nm, Ex: 270～290 nm/Em: 310～340 nm and Ex: 220～235 nm/Em: 280～310 nm, respectively, caused by their hydrocarbon component; finally, the water samples containing both petroleum and CDOM showed a very strong fluorescence peak at Ex: 230～250 nm/Em: 320～370 nm, caused by the combined effect of CDOM and petroleum hydrocarbons..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2466 (2014)
Study of the Air Plasma Expansion Dynamics by Fluorescence Method
WANG Ji-xun, GAO Xun, LI Qi, ZHENG Yi-ni, and LIN Jing-quan
The expansion dynamics of air plasma induced by 1 064 nm nanosecond laser pulse was studied by plasma fluorescence method. The time evolution images of air plasma expansion were acquired using the ICCD camera at different laser pulse energy, and the expansion velocity of air plasma was deduced based on the air plasma fThe expansion dynamics of air plasma induced by 1 064 nm nanosecond laser pulse was studied by plasma fluorescence method. The time evolution images of air plasma expansion were acquired using the ICCD camera at different laser pulse energy, and the expansion velocity of air plasma was deduced based on the air plasma frontier expansion wave front distance at 150 mJ. The experimental results show that the plasma fluorescence was mainly distributed in the plasma expansion region, the plasma fluorescence intensity firstly increased then became weaker and the expansion area increased gradually with time evolution,. The biggest expansion distance was 3.76 mm with 300 mJ at 20 ns. The plasma expansion speed was the order of magnitude of 105 m·s-1 at the early stage of expansion process. The expansion speed of air plasma decayed rapidly within 16ns, then changed slowly with time. The time of air breakdown was close to the rising phase of laser pulse when the greater laser pulse energy was radiated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2472 (2014)
The Field Radiometric Calibration and Validation of ZY-3 Multispectral Sensor
ZHANG Xue-wen, FU Qiao-yan, HAN Qi-jin, PAN Zhi-qiang, and YANG Lei
A field calibration campaign of ZY-3 multispectral sensor (MUS) was performed by the China Center for Resources Satellite Data and Application at the Dunhuang site. The reflectance-based method with two-point sites was used to obtain MUS absolute calibration coefficients in 2013. Compared to the calibration results in A field calibration campaign of ZY-3 multispectral sensor (MUS) was performed by the China Center for Resources Satellite Data and Application at the Dunhuang site. The reflectance-based method with two-point sites was used to obtain MUS absolute calibration coefficients in 2013. Compared to the calibration results in 2012, the calibration coefficients in 2013 changed by about 1%～8.5% in different bands. The results were also validated by intercalibration method using the Landsat 8 Operational Land Imager (OLI) data. It shows largely good consistency between field calibration and intercalibration. It was concluded that the absolute calibration coefficients were highly reliable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2476 (2014)
Resonance Rayleigh Scattering Determination of Trace Tobramycin Using Aptamer-Modified Nanogold as Probe
MA Lu, WEN Gui-qing, LIU Qing-ye, LIANG Ai-hui, and JIANG Zhi-liang
Nanogold (NG) was prepared using NaBH4 reduction of HAuCl4. The NG was modified by the tobramycin-aptamer to obtain a stable Apt-NG probe for tobramycin. The three aptamers containing 15, 21 and 27 bases were examined, and results showed that the aptamer with 21 bases was best and was chosen for use. In pH 6.8 PBS buffNanogold (NG) was prepared using NaBH4 reduction of HAuCl4. The NG was modified by the tobramycin-aptamer to obtain a stable Apt-NG probe for tobramycin. The three aptamers containing 15, 21 and 27 bases were examined, and results showed that the aptamer with 21 bases was best and was chosen for use. In pH 6.8 PBS buffer solution and in the presence of NaCl, the Apt-GN probes were not aggregated. When tobramycin was added, it reacted with the Apt of Apt-NG probe to form a very stable Apt-Tbc complex and released NGs that were aggregated into big particles under the action of NaCl with three resonance Rayleigh scattering peaks at 285, 368 and 525 nm respectively. The resonance Rayleigh scattering peak increased at 368 nm due to the formation of big NG particles from the probe. The effect of pH buffer solution, its volume, and Apt-GN probe concentration on the ΔI value was considered. A 200 μL pH 6.8 PBS buffer solution and 19.1 nmol·L-3 Apt-GN, giving max ΔI value, were chosen for use. Under the chosen conditions, the increased resonance Rayleigh scattering intensity ΔI368 nm was linear with Tbc concentration in the range of 1.9～58.3 ng·mL-3, with a regress equation of ΔI=35.3ｃ-23 and a detection limit of 0.8 ng·mL-3 Tbc. A 10.0, 20.0 and 30.0 ng·mL-3 Tbc was determined five times respectively, and the relative standard deviations were 6.8%, 5.0% and 4.4%. The influence of some foreign substances was examined on the determination of 38.9 ng·mL-3 Tbc, within ±10% related error. Results showed that a 80 times of Zn2+, 40 times of L-glutamic acid, Cu2+, Mg2+ and Ca2+, 20 times of glucose and terramycin, 10 times of L-phenylalanine and glycin, 2 times of L-aspartic acid, and 6 times of bovine serum albumin (BSA) and human serum albumin (HSA) do not interfere with the RRS determination of Tbc. The results showed that this aptamer-nanogold RRS method is of good selectivity. Tbc in real sample was analyzed, and the analytical result was in agreement with that of reference results, with a relative standard deviation of 6.5%～7.6% and a recovery of 95.0%～107%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2481 (2014)
Models for Estimating Foliar Fe and Mn Concentration of Armeniaca vulgaris cv. Luntaibaixing Using Spectral Reflectance
HU Zhen-zhu, PAN Cun-de, WANG Shi-wei, GUO Zhi-chao, WANG Qing-tao, DING Fan, and LI Yuan
Aimed at providing technology for a rapid nutrition diagnosis system of micronutrients in Armeniaca vulgaris cv. Luntaibaixing, we established an element concentration estimation model for its foliar ferrum (Fe) and manganese (Mn) concentration based on spectrum analysis. The foliar spectrum reflectance at various phenAimed at providing technology for a rapid nutrition diagnosis system of micronutrients in Armeniaca vulgaris cv. Luntaibaixing, we established an element concentration estimation model for its foliar ferrum (Fe) and manganese (Mn) concentration based on spectrum analysis. The foliar spectrum reflectance at various phenological periods of fruit development under different soil fertility conditions was measured by Unispec-SC spectrometer. By analyzing the correlation of foliar Fe, Mn concentration at various phenological periods of fruit development, the spectrum reflectance Rλ and its first-order differential ｆ′(Rλ), we filtered out its sensitive bands. And we established an element concentration estimation model for its foliar Fe and Mn at various phenological periods of fruit development with the linear regression model. The results showed that the spectral sensitive bands of foliar Fe in fruit setting period were 873 and 874 nm, 375 and 437 nm in fruit core-hardening period, 836 and 837 nm in maturity period and 325 and 1 054 nm in post-harvest period. However, the spectral sensitive bands of Mn were 913 and 1 129 nm, 425 and 970 nm, 390 and 466 nm, 423 and 424 nm, respectively. The Fe and Mn concentration of A. vulgaris cv. Luntaibaixing leaves were the most relevant to the first-order differential ｆ′(Rλ) of its spectrum reflectance, whose linear spectrum estimation model fitting degree was the highest and reached to a significant or highly significant level. It showed that the spectral sensitive bands of Fe and Mn element varied with different phenological periods of fruit development. The spectrum estimation models for its foliar Fe and Mn concentration could be established with linear model according to its first-order differential ｆ′(Rλ)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2485 (2014)
Response of Winter Wheat (Triticum aestivum L. ) Hyperspectral Characteristics to Low Temperature Stress
REN Peng, FENG Mei-chen, YANG Wu-de, WANG Chao, LIU Ting-ting, and WANG Hui-qin
The simple winter wheat variety was conducted under the low temperature treatment at -2, -4, and -6 ℃, the canopy reflectance was measured and the red edge parameters were extracted to study the winter wheat canopy spectral characteristics effected by the low temperature stress and the hyperspectral response to the lowThe simple winter wheat variety was conducted under the low temperature treatment at -2, -4, and -6 ℃, the canopy reflectance was measured and the red edge parameters were extracted to study the winter wheat canopy spectral characteristics effected by the low temperature stress and the hyperspectral response to the low temperature stress of winter wheat at jointing stage. The results showed that the canopy reflectance decreased in visible region and increases at near infrared band with the high intensively low temperature stress, and "green peak" was weakened and “red well” was not distinctive. Moreover, the derivate spectrum had the trend of shift to short wavelength direction with the strengthening of low temperature stress and the red edge presented the blue shift. The area of red edge and red edge amplitude exhibit increase. It indicated that the canopy spectrum of winter wheat is sensitive to the low temperature stress, and the hyperspectral technology can be used to monitor the low temperature stress of winter wheat at jointing stage..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2490 (2014)
Analysis of Related Factors of Slope Plant Hyperspectral Remote Sensing
SUN Wei-qi, ZHAO Yun-sheng, and TU Lin-ling
In the present paper, the slope gradient, aspect, detection zenith angle and plant types were analyzed. In order to strengthen the theoretical discussion, the research was under laboratory condition, and modeled uniform slope for slope plant. Through experiments we found that these factors indeed have influence on planIn the present paper, the slope gradient, aspect, detection zenith angle and plant types were analyzed. In order to strengthen the theoretical discussion, the research was under laboratory condition, and modeled uniform slope for slope plant. Through experiments we found that these factors indeed have influence on plant hyperspectral remote sensing. When choosing slope gradient as the variate, the blade reflection first increases and then decreases as the slope gradient changes from 0° to 36°; When keeping other factors constant, and only detection zenith angle increasing from 0° to 60°, the spectral characteristic of slope plants do not change significantly in visible light band, but decreases gradually in near infrared band; With only slope aspect changing, when the dome meets the light direction, the blade reflectance gets maximum, and when the dome meets the backlit direction, the blade reflectance gets minimum, furthermore, setting the line of vertical intersection of incidence plane and the dome as an axis, the reflectance on the axis’s both sides shows symmetric distribution; In addition, spectral curves of different plant types have a lot differences between each other, which means that the plant types also affect hyperspectral remote sensing results of slope plants. This research breaks through the limitations of the traditional vertical remote sensing data collection and uses the multi-angle and hyperspectral information to analyze spectral characteristics of slope plants. So this research has theoretical significance to the development of quantitative remote sensing, and has application value to the plant remote sensing monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2495 (2014)
Study on the Polarized Reflectance-Hyperspectral Information Fusion Technology of Tomato Leaves Nutrient Diagnoses
ZHU Wen-jing, MAO Han-ping, LI Qing-lin, LIU Hong-yu, SUN Jun, ZUO Zhi-yu, and CHEN Yong
With 25%, 50%, 75%, 100% and 150%, five levels of, nitrogen(N), phosphorus(P) and potassium(K) nutrition stress samples cultivated in Venlo type greenhouse soilless cultivation mode as the research object, polarized reflectance spectra and hyperspectral images of different nutrient deficiency greenhouse tomato leaves wWith 25%, 50%, 75%, 100% and 150%, five levels of, nitrogen(N), phosphorus(P) and potassium(K) nutrition stress samples cultivated in Venlo type greenhouse soilless cultivation mode as the research object, polarized reflectance spectra and hyperspectral images of different nutrient deficiency greenhouse tomato leaves were acquired by using polarized reflectance spectroscopy system developed by our own research group and hyperspectral imaging system respectively. The relationship between a certain number of changes in the bump and texture of non-smooth surface of the nutrient stress leaf and the level of polarization reflected radiation was clarified by scanning electron microscopy (SEM). On the one hand, the polarization spectrum was converted into the degree of polarization through Stokes equation, and the four polarization characteristics between the polarization spectroscopy and reference measurement values of N, P and K respectively were extracted. On the other hand, the four characteristic wavelengths of N, P, K hyperspectral image data were determined respectively through the principal component analysis, followed by eight hyperspectral texture features extracted corresponding to the four characteristic wavelengths through correlation analysis. Polarization characteristics and hyperspectral texture features combined with each characteristics of N, P, K were extracted. These 12 characteristic variables were normalized by maximum-minimum value method. N, P, K nutrient levels quantitative diagnostic models were established by SVR. Results of models are as follows: the correlation coefficient of nitrogen r=0.961 8, root mean square error RMSE=0.451; correlation coefficient of phosphorus ｒ=0.916 3, root mean square error RMSE=0.620; correlation coefficient of potassium ｒ=0.940 6, root mean square error RMSE=0.494. The results show that high precision tomato leaves nutrition prediction model could be built by using polarized reflectance spectroscopy combined with high spectral information fusion technology and achieve good diagnoses effect. It has a great significance for the improvement of model accuracy and the development of special instruments. The research provides a new idea for the rapid detection of tomato nutrient content..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2500 (2014)
Determination of Photosynthetic Pigments in Citrus Leaves Based on Hyperspectral Images Datas
TIAN Xi, HE Shao-lan, Lv Qiang, YI Shi-lai, XIE Rang-jin, ZHENG Yong-qiang, LIAO Qiu-hong, and DENG Lie
The effective region was segmented from the hyperspectral image of citrus leaf by threshold method with the average spectrum extracted and used to describe the corresponding leaf. Based on the different spectral pre-processing methods, the prediction models of three photosynthetic pigments (i.e., chlorophyll a, chloropThe effective region was segmented from the hyperspectral image of citrus leaf by threshold method with the average spectrum extracted and used to describe the corresponding leaf. Based on the different spectral pre-processing methods, the prediction models of three photosynthetic pigments (i.e., chlorophyll a, chlorophyll b, and carotenoid) were calibrated by partial least squares (PLS), BP neural network (BPNN) and least square support vector machine (LS-SVM). The LS-SVM model for chlorophyll a was established based on multiplicative scatter correction (MSC), and the correlation coefficient (Rp) and the root mean square error of prediction (RMSEP) were 0.898 3 and 0.140 4, respectively. The LS-SVM model for chlorophyll b with Rp=0.912 3 and RMSEP=0.042 6, was established based on standard normal variable (SNV). The PLS model for carotenoid was established with Rp=0.712 8 and RMSEP=0.062 4 based on moving average smoothing (MAS), but the result was no better than the other two. The results illustrated that these three photosynthetic pigments could be nondestructively and real time estimated by hyperspectral image..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2506 (2014)
Rapid Detection of Nitrogen Content and Distribution in Oilseed Rape Leaves Based on Hyperspectral Imaging
ZHANG Xiao-lei, LIU Fei, NIE Peng-cheng, HE Yong, and BAO Yi-dan
Visible and near infrared (Vis-NIR) hyperspectral imaging system was carried out to rapidly determinate the content and estimate the distribution of nitrogen (N) in oilseed rape leaves. Hyperspectral images of 420 leaf samples were acquired at seedling, flowering and pod stages. The spectral data of rape leaves were exVisible and near infrared (Vis-NIR) hyperspectral imaging system was carried out to rapidly determinate the content and estimate the distribution of nitrogen (N) in oilseed rape leaves. Hyperspectral images of 420 leaf samples were acquired at seedling, flowering and pod stages. The spectral data of rape leaves were extracted from the region of interest (ROI)in the wavelength range of 380～1 030 nm. Different spectra preprocessing including Savitzky-Golay smoothing (SG), standard normal variate (SNV), multiplicative scatter correction (MSC), first and second derivatives were applied to improve the signal to noise ratio. Among 471 wavelengths, only twelve wavelengths (467, 557, 665, 686, 706, 752, 874, 879, 886, 900, 978 and 995 nm) were selected by successive projections algorithm(SPA) as the effective wavelengths for N prediction. Based on these effective wavelengths, partial least squares(PLS) and least-squares support vector machines (LS-SVM) calibration models were established for the determination of N content. Reasonable estimation accuracy was obtained, with RP of 0.807 and RMSEP of 0.387 by PLS and RP of 0.836 and RMSEP of 0.358 by LS-SVM, respectively. Considering the simple structure and satisfying results of PLS model, SPA-PLS model was used to generate the distribution maps of N content in rape leaves. The concentrations of N were calculated at each pixel of hyperspectral images at the selected effective wavelengths by inputting its corresponding spectrum into the established SPA-PLS model. Different colour represented the change in N content in the rape leaves under different fertilizer treatments. By including all pixels within the selected ROI, the average N status can be displayed in more detail and visualised. The visualization of N distribution could be helpful to understanding the change in N content in rape leaves during rape growth period and facilitate discovering the difference of N content within one sample as well as among the samples from different fertilising plots. The overall results revealed that hyperspectral imaging is a promising technique to detect N content and distribution within oilseed rape leaves rapidly and nondestructively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2513 (2014)
Variety Recognition of Chinese Cabbage Seeds by Hyperspectral Imaging Combined with Machine Learning
CHENG Shu-xi, KONG Wen-wen, ZHANG Chu, LIU Fei, and HE Yong
The variety of Chinese cabbage seeds were recognized using hyperspectral imaging with 256 bands from 874 to 1 734 nm in the present paper. A total of 239 Chinese cabbage seed samples including 8 varieties were acquired by hyperspectral image system, 158 for calibration and the rest 81 for validation. A region of 15 pixThe variety of Chinese cabbage seeds were recognized using hyperspectral imaging with 256 bands from 874 to 1 734 nm in the present paper. A total of 239 Chinese cabbage seed samples including 8 varieties were acquired by hyperspectral image system, 158 for calibration and the rest 81 for validation. A region of 15 pixel 15 pixel was selected as region of interest (ROI) and the average spectral information of ROI was obtained as sample spectral information. Multiplicative scatter correction was selected as pretreatment method to reduce the noise of spectrum. The performance of four classification algorithms including Ada-boost algorithm, extreme learning machine (ELM), random forest (RF) and support vector machine (SVM) were examined in this study. In order to simplify the input variables, 10 effective wavelengths (EMS) including 1 002, 1 005, 1 015, 1 019, 1 022, 1 103, 1 106, 1 167, 1 237 and 1 409 nm were selected by analysis of variable load distribution in PLS model. The reflectance of effective wavelengths was taken as the input variables to build effective wavelengths based models. The results indicated that the classification accuracy of the four models based on full-spectral were over 90%, the optimal models were extreme learning machine and random forest, and the classification accuracy achieved 100%. The classification accuracy of effective wavelengths based models declined slightly but the input variables compressed greatly, the efficiency of data processing was improved, and the classification accuracy of EW-ELM model achieved 100%. ELM performed well both in full-spectral model and in effective wavelength based model in this study, it was proven to be a useful tool for spectral analysis. So rapid and nondestructive recognition of Chinese cabbage seeds by hyperspectral imaging combined with machine learning is feasible, and it provides a new method for on line batch variety recognition of Chinese cabbage seeds..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2519 (2014)
Research on Algorithm for Self-Absorption Correction Based on Multi-Particles LIBS Spectra
NI Zhi-bo, DONG Feng-zhong, CHEN Xing-long, WANG Jing-ge, HE Wen-gan, and FU Hong-bo
In order to overcome the influence of self-absorption on quantitative analysis, the optimizing process of very fast simulated annealing algorithm was studied. According to basic theory of plasma emission spectrum, a new algorithm for self-absorption correction based on multi-particles spectra was proposed, and the algoIn order to overcome the influence of self-absorption on quantitative analysis, the optimizing process of very fast simulated annealing algorithm was studied. According to basic theory of plasma emission spectrum, a new algorithm for self-absorption correction based on multi-particles spectra was proposed, and the algorithm flowchart was given. With the self-absorption correction algorithm mentioned above, the spectra of refining slag and blast furnace slag were corrected. The effect of self-absorption correction on the quantitative analysis results was analyzed based on calibration free method. Comparison of Boltzmann plots before and after self-absorption correction indicated that the plasma temperatures calculated with spectra after self-absorption correction tended to be uniform, and remained stable around 11 600 K. The Boltzmann plots constructed with plasma spectra of the same particle after self-absorption correction indicated that the intercepts were almost the same except for one group data. With calibration free method and spectra after self-absorption correction, the contents of components in slag were analyzed. For refining slag, quantitative analysis precision of MgO was low. If ignoring the existence of MgO, the relative errors of quantitative analysis results of CaO, Al2O3 and SiO2 were much smaller. For blast furnace slag in which the content of MgO was 8.49%, the relative error of quantitative analysis result of Al2O3 was 2.38%, which was the smallest. And the relative error of quantitative analysis result of MgO was 28.27%, which was still the biggest..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2523 (2014)
Effects of Temperature and Heating Time on Armco Iron Spectral Emissivity in Atmospheric Environment
YU Kun, WANG Wen-bao, ZHANG Kai-hua, and LIU Yu-fang
The spectral emissivity of pure iron at 1.55 μm was investigated systematically by using our self-designed reflective experimental apparatus based on the Kirchhoff’s law, and the influences of temperature and heating time on the spectral emissivity of pure iron were also discussed. The experimental data showed that theThe spectral emissivity of pure iron at 1.55 μm was investigated systematically by using our self-designed reflective experimental apparatus based on the Kirchhoff’s law, and the influences of temperature and heating time on the spectral emissivity of pure iron were also discussed. The experimental data showed that the spectral emissivity of pure iron increased with temperature rising and its peak value and valley value appeared at certain temperatures. By analyzing the emissivity model of metal with oxidation layer, the variation of the spectral emissivity of pure iron was illustrated. The influence of heating time on the spectral emissivity was different at different temperature. The research results will further enrich pure iron spectral emissivity data, and provide the experimental basis for its application in atmospheric environment..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2529 (2014)
Determination of Trace Element Silver in Animal Serum, Tissues and Organs by Microwave Digestion-ICP-MS
YUAN Jun-jie, XIE You-zhuan, HAN Chen, SUN Wei, ZHANG Kai, ZHAO Jie, LU Xiao, LU Jian-xi, and REN Wei
Nowadays, the silver is widely used in the biological field and its biological safety catches great attention. It is important to know the distribution of silver ions within the biological organism and the toxic threshold concentration in the tissue. Therefore, a highly sensitive method for measurement of trace amount Nowadays, the silver is widely used in the biological field and its biological safety catches great attention. It is important to know the distribution of silver ions within the biological organism and the toxic threshold concentration in the tissue. Therefore, a highly sensitive method for measurement of trace amount of silver ion in the medical biological samples is needed. With its high sensitivity for detection of metal ions, inductively coupled plasma mass spectrometry (ICP-MS) method is well suited for quantification of trace amount of silver ion in such samples, but method development is still in its infancy. Consequently, a simple and convenient method for determination of trace amount of silver in the animal serum, tissues or organs was developed, in which the samples were subjected to the microwave digestion, followed by the ICP-MS analysis. To begin with, the samples of serum, muscle, bone marrow, bone, heart, liver, spleen, and kidney were sequently processed in 5 mL of HNO3 and 2 mL of H2O2 solution. Then the samples were completely digested by microwave with the power of 2 000 watts. The temperature was raised gradually by 3-step program. Moreover, the data achieved were reproducible and the method was time saving and especially for large amounts of sample processing. Then the digested solutions were diluted to constant volume. Finally, the concentration of 107Ag in the samples was analyzed by the method of ICP-MS under the optimized conditions. Element yttrium (Y) was used as the internal standard to compensate for matrix suppression effect and improve the accuracy of measurement. For one thing, the analytical results showed that the detection limit of the trace element 107Ag was 0.98 μg·kg－1, and furthermore, the correlation coefficient of standard curve was 0.999 9. For another thing, the recovery rate of the silver element ranged from 98% to 107%, which was calculated according to measured quantity before adding standard, adding standard and measured quantity after adding standard. At the same time, the relative standard deviation (RSD) of the method was in the range of 2.0%～4.3%. The concentrations of element silver in animal serum, tissues and organs were determined by the aboved method. The obtained results showed that silver ions were mainly accumulated in the liver after they were intaken into the body. The results suggested that the microwave digestion-ICP-MS method could accurately determine the trace element Ag in the body. The method developed has good feasibility and is suitable for the determination of trace element Ag in various types of medical and biological samples, especially for large quantities of biological samples. The process has the advantages of easy sample processing and it is simple and convenient. In addition, the accurate results could be obtained in a short time with high sensitivity. Last but not least, the method provides the guidance for the determination of trace elements in other biological samples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2533 (2014)
Principal Component Analysis of Mineral Elements and Fatty Acids Composition in Flaxseed from Ten Different Regions
XING Li, ZHAO Feng-min, CAO You-fu, WANG Mei, MEI Shuai, LI Shao-ping, and CAI Zhi-yong
Flaxseed is a kind of biomass with high edible and medical value. It is rich in many kinds of nutrients and mineral elements. China is one of the important producing places of flaxseed. In order to explore the main characteristic constituents of mineral elements and fatty acids in flaxseed, the study of analyzing the mFlaxseed is a kind of biomass with high edible and medical value. It is rich in many kinds of nutrients and mineral elements. China is one of the important producing places of flaxseed. In order to explore the main characteristic constituents of mineral elements and fatty acids in flaxseed, the study of analyzing the mineral elements and fatty acid composition from 10 different regions was carried out. The contents of seventeen kinds of mineral elements in flaxseed were determined by inductively coupled plasma mass spectrometry (ICP-MS). The contents of fatty acids of the flaxseed oil obtained under the same conditions were determined by gas chromatography-mass spectrometer(GC-MS). The principal component analysis(PCA) method was applied to the study of analyzing the mineral elements and fatty acid compositions in flaxseeds. The difference in mineral elements and fatty acids of flaxseed from different regions were discussed. The main characteristic constituents of mineral elements and fatty acids were analyzed. The results showed that K, Sr, Mg, Ni, Co, Cr, Cd, Se, Zn and Cu were the main characteristic constituents of the mineral elements. At the same time, C16∶0, C18∶0, C18∶2, C18∶3, C20∶0 and C20∶1 were the main characteristic constituents of the fatty acids. The combination of ICP-MS, GS-MS and PCA can reveal the characteristics and difference of mineral elements and fatty acids from different regions. The results would provide important theoretical basis for the reasonable and effective utilization of flaxseed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2538 (2014)
Characteristics of Trace Elements in Freshwater and Seawater Cultured Pearls
ZHANG En, HUANG Fu-quan, WANG Zi-tong, and LI Qian
Trace elements in pearls have characteristic disciplines and functions. The previous work had paid attention to different characteristics of trace elements in freshwater and seawater cultured pearls, but only limited species of trace elements have been detected by former testing techniques and analysis methods, and theTrace elements in pearls have characteristic disciplines and functions. The previous work had paid attention to different characteristics of trace elements in freshwater and seawater cultured pearls, but only limited species of trace elements have been detected by former testing techniques and analysis methods, and the test results have not been further analyzed. With the advantages of detection in good capability and high speed, inductively coupled plasma mass spectrometer (ICP-MS) can concurrently test various trace and ultra-trace elements. In the present paper, trace elements of cultured pearls in freshwater and seawater were measured by ICP-MS, and analyzed compared by a method of data processing. The results show that: (1) The kinds of higher content of trace elements(Sr, Zn, Ni, Ba, Mn, Cr, Cu, Pb, Ti, Co, Ce, Zr, La, Rb)in cultured pearls are approximately the same, but the total amount of trace elements in freshwater cultured pearls is significantly less than that of seawater cultured pearls. (2) The content of trace elements (Sr, Mn, Ba, Ni, Cr, Pb) in freshwater cultured pearls is more regular, and has a relatively fixed sequence from high to low, namely Sr>Mn>Ba>Ni>Cr>Pb. The content of trace elements in seawater cultured pearls is quite different. Sr is enriched in all samples. There is no a stable order of contents for the other trace elements. (3) There is a significant correlation among some trace elements in cultured pearls. The conclusion is instructive to indicate cultured environment, cultured technology, identification, comprehensive development and utilization of cultured pearls..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2544 (2014)
Determination of Elements by Atomic Absorption Spectrometry in Medicinal Plants Employed to Alleviate Common Cold Symptoms
F Zehra Kücükbay, and Ebru Kuyumcu
Eleven important medicinal plants generally used by the people of Turkey for the treatment of common cold have been studied for their mineral contents. Eleven minor and major elements (essential, non-essential and toxic) were identified in the Asplenium adiantum-nigrum L., Althaea officinalis L., Verbascum phlomoides LEleven important medicinal plants generally used by the people of Turkey for the treatment of common cold have been studied for their mineral contents. Eleven minor and major elements (essential, non-essential and toxic) were identified in the Asplenium adiantum-nigrum L., Althaea officinalis L., Verbascum phlomoides L., Euphorbia chamaesyce L., Zizyphus jujube Miller, Peganum harmala L., Arum dioscoridis Sm., Sambucus nigra L., Piper longum L., Tussilago farfara L. and Elettaria cardamomum Maton by employing flame atomic absorption and emission spectrometry and electro-thermal atomic absorption spectrometry. Microwave digestion procedure for total concentration was applied under optimized conditions for dissolution of medicinal plants. Plant based biological certified reference materials (CRMs) served as standards for quantification. These elements are found to be present in varying concentrations in the studied plants. The baseline data presented in this work can be used in understanding the role of essential, non-essential and toxic elements in nutritive, preventive and therapeutic properties of medicinal plants..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2548 (2014)
Measuring the Content of 17 Elements in the Flesh of Prunus Cerasifera and Its Cultivars by ICP-MS
SHEN Jing, XUE Hai-yan, LI Gai-ru, LU Yi, and YAO Jun
The present study compared the contents of inorganic elements in the pulp of purple, red, and yellow Prunus cerasifera with its cultivars. A method was established for the analysis of 17 kinds of trace elements (K, Ca, Mg, Na, Fe, M n, Cu, Zn, Be, Li, Se, Sr, Cr, Pb, Cd, As and Hg) in the flesh of Prunus cerasifera by The present study compared the contents of inorganic elements in the pulp of purple, red, and yellow Prunus cerasifera with its cultivars. A method was established for the analysis of 17 kinds of trace elements (K, Ca, Mg, Na, Fe, M n, Cu, Zn, Be, Li, Se, Sr, Cr, Pb, Cd, As and Hg) in the flesh of Prunus cerasifera by microwave digestion- ICP-MS. The detection method is simple and quick, yet shoes high precision and high sensitivity. The recovery rate of 17 elements ranged from 93.5% to 110.4%. The analysis results showed that the contents of 17 elements in the flesh of purple, red, and yellow Prunus cerasifera and its cultivars are similar, containing extremely rich K elements (as high as 1 ‰) and higher contents of Ca, Mg, Na, Fe and Mn. The contents of Cu, Zn, Li, Se, Sr and Cr are also present. The contents of Pb, Cd, As, Hg and other harmful element are either very low or not detectable. The experimental results for the study of trace elements in pulp of Prunus cerasifera and its cultivars provide empirical data for future research in this area..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2557 (2014)
Excitation-Emission Matrix Spectroscopy and Parallel Factor Analysis for Micro-Content Petroleum Pollutant
CHEN Zhi-kun, WANG Yang, WANG Fu-bin, WANG Yu-tian, and ZHOU Yan
In order to solve the identification problem of oil pollutants containing micro content, the fluorescence characteristics of oil samples were studied using fluorescence excitation emission matrix spectra (EEMs) combined with parallel factor (PARAFAC) analysis. According to the conventional standard of oil content in waIn order to solve the identification problem of oil pollutants containing micro content, the fluorescence characteristics of oil samples were studied using fluorescence excitation emission matrix spectra (EEMs) combined with parallel factor (PARAFAC) analysis. According to the conventional standard of oil content in water, simulated the component of oil pollution in Ⅰ-Ⅴ water was simulated by preparing samples of CCL4 with oil content. Firstly, measured the EEMs of 97# gasoline, 0# diesel, kerosene and CCL4 were measured individually, then the EEMs of 97# gasoline, 0# diesel, and kerosene in CCL4 were measured, and finally, the EEMs of the composite sample with all three oil contents in CCL4 were measured. The EEMs of the composite sample were superimposed by the EEMs of all its different components. It is therefore difficult to analyze the fluorescence component by chemical separation or simple fluorescence analysis. Since the EEMs of each oil component are already measured, we used the PARAFAC analysis to decompose the EEMs of the composite sample, and then extract the concentration ratio of each component. In this work, we solved the problem of identifying and quantifying the main micro-content petroleum pollutant in composite oil samples using EEMs and PARAFAC analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2561 (2014)
Simultaneous Determination of Four Flavone C-Glycosides in Phyllostachys edulis Leaves by High-Performance Liquid Chromatography with Ultraviolet Spectrometry
ZHANG Chun-juan, MENG Zhi-fen, GUO Xue-feng, YUE Yong-de, TANG Feng, YU Jin, and CHEN Chao
High-performance liquid chromatography with ultraviolet spectrometer (HPLC-UV) was used to simultaneously detect the four flavone C-glycosides, i.e. orientin, isoorientin, vitexin and isovitexin. Analytes were separated with Waters XTerra MS C18 column (250 mm 4.6 mm, 5 μm) using acetonitrile and 0.5% (φ) formic acid aHigh-performance liquid chromatography with ultraviolet spectrometer (HPLC-UV) was used to simultaneously detect the four flavone C-glycosides, i.e. orientin, isoorientin, vitexin and isovitexin. Analytes were separated with Waters XTerra MS C18 column (250 mm 4.6 mm, 5 μm) using acetonitrile and 0.5% (φ) formic acid as mobile phase. The flow rate was set at 1.0 mL·min-1 with the column temperature at 30 ℃, and the detection wavelength was 360 nm. The calibration curve was linear over the concentration range of 0.1~10.0 mg·L-1 for the mixed standard solution. Analytes were separated in 22 minutes, and the relative standard deviation values were all above 0.999. LOD values of standards were found to be between 0.03 and 0.07 mg·L-1, and LOQ values were in the range of 0.04~0.08 mg·L-1. After comparing the spectra (240~400 nm) of four flavone C-glycosides in mixed standards and the final product purified by macroporous resin, respectively, the curve shape and characteristic ultraviolet absorption wavelength of each flavone C-glycoside including orientin, isoorientin, vitexin and isovitexin were fitted well. The bamboo leaves sample was extracted by ethanol under reflux, and then partitioned with water and petroleum ether. The aqueous phase was added onto macroporous resin(AB-8), and the fraction of ethanol-water (40%, φ) was concentrated. It was found that the contents of orientin, isoorientin, vitexin and isovitexin relative to the fraction of ethanol-water were 13.73, 49.68, 7.85 and 30.70 mg·g-1, respectively. In addition, the average recovery of the four flavone C-glycosides ranged from 34.90% to 87.64% with RSD values from 0.41% to 10.83%. The results showed that bamboo leaves sample had good stability and repeatability. The new method was used to analyze the four flavone C-glycosides quickly and provide quality control for commercial products..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2568 (2014)
Sandmeier Model Based Topographic Correction to Lunar Spectral Profiler (SP) Data from KAGUYA Satellite
CHEN Sheng-bo, WANG Jing-ran, GUO Peng-ju, and WANG Ming-chang
The Moon may be considered as the frontier base for the deep space exploration. The spectral analysis is one of the key techniques to determine the lunar surface rock and mineral compositions. But the lunar topographic relief is more remarkable than that of the Earth. It is necessary to conduct the topographic correctiThe Moon may be considered as the frontier base for the deep space exploration. The spectral analysis is one of the key techniques to determine the lunar surface rock and mineral compositions. But the lunar topographic relief is more remarkable than that of the Earth. It is necessary to conduct the topographic correction for lunar spectral data before they are used to retrieve the compositions. In the present paper, a lunar Sandmeier model was proposed by considering the radiance effect from the macro and ambient topographic relief. And the reflectance correction model was also reduced based on the Sandmeier model. The Spectral Profile (SP) data from KAGUYA satellite in the Sinus Iridum quadrangle was taken as an example. And the digital elevation data from Lunar Orbiter Laser Altimeter are used to calculate the slope, aspect, incidence and emergence angles, and terrain-viewing factor for the topographic correction. Thus, the lunar surface reflectance from the SP data was corrected by the proposed model after the direct component of irradiance on a horizontal surface was derived. As a result, the high spectral reflectance facing the sun is decreased and low spectral reflectance back to the sun is compensated. The statistical histogram of reflectance-corrected pixel numbers presents Gaussian distribution. Therefore, the model is robust to correct lunar topographic effect and estimate lunar surface reflectance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2573 (2014)
Thermal Effect on Optical Properties of Spatial Heterodyne Spectroscopy
LUO Hai-yan, SHI Hai-liang, LI Zhi-wei, LI Shuang, XIONG Wei, and HONG Jin
To study the thermal effort on optical properties of spatial heterodyne spectroscopy (SHS), the relation between the change in temperature and the degradation of optical properties was analyzed, including collimator lens, imaging lens and interferometer unit. The theoretical model was verified and corrected by simulatiTo study the thermal effort on optical properties of spatial heterodyne spectroscopy (SHS), the relation between the change in temperature and the degradation of optical properties was analyzed, including collimator lens, imaging lens and interferometer unit. The theoretical model was verified and corrected by simulation and thermal-optical test, which was established to describe the relation between spectral-line shift and groove density change of gratings. The results show that spectrum measurements are not affected by small temperature changes in the instrument since the primary effects are a slight defocus of the focal plane array in collimating lens and re-imaging lens under the temperature from 15 to 25 ℃. Spectral-line shift obtained by the thermal optical analysis is well coincident with the ones calculated by thermal optical experiment because of the temperature changes of interferometer unit. The Littrow wavelength accuracy is better than 2.3 nm unless the temperature change is less than 2.5 ℃ under the interferometer unit by use of the material BK7..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2578 (2014)
Passive Ranging of Infrared Target Using Oxygen A-Band and Elsasser Model
LI Jin-hua, WANG Zhao-ba, and WANG Zhi-bin
Passive ranging method of short range and single band was developed based on target radiation and attenuation characteristic of oxygen spectrum absorption. The relation between transmittance of oxygen A band and range of measured target was analyzed. Radiation strength distribution of measured target can be obtained acPassive ranging method of short range and single band was developed based on target radiation and attenuation characteristic of oxygen spectrum absorption. The relation between transmittance of oxygen A band and range of measured target was analyzed. Radiation strength distribution of measured target can be obtained according to the distribution law of absorption coefficient with environmental parameters. Passive ranging mathematical model of short ranges was established using Elsasser model with Lorentz line shape based on the computational methods of band average transmittance and high-temperature gas radiation narrowband model. The range of measured object was obtained using transmittance fitting with test data calculation and theoretical model. Besides, ranging precision was corrected considering the influence of oxygen absorption with enviromental parameter. The ranging experiment platform was established. The source was a 10 watt black body, and a grating spectrometer with 17 cm-1 resolution was used. In order to improve the light receiving efficiency, light input was collected with 23 mm calibre telescope. The test data was processed for different range in 200 m. The results show that the transmittance accuracy was better than 2.18% in short range compared to the test data with predicted value in the same conditions..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2582 (2014)
Development and Application of Six-Channel Fiber Optic Sensing Drug Dissolution Monitor
YAO Jun, SHEN Jing, LI Li, LI Xin-xia, and CHEN Jian
The drug dissolution test is an important examination of drug testing, which plays a very important role in the drug quality assessment. Automation and proceduring monitoring of drug dissolution can be implemented by the optical fiber sensing technology. Two modes of detection of UV-Vis absorption and fluorescence quenThe drug dissolution test is an important examination of drug testing, which plays a very important role in the drug quality assessment. Automation and proceduring monitoring of drug dissolution can be implemented by the optical fiber sensing technology. Two modes of detection of UV-Vis absorption and fluorescence quenching were established by software implementation, with xenon lamp, deuterium lamp or halogen tungsten lamp as fluorescence, UV and visible light source, branch Y type optical fiber as light path transmission medium, UV-Vis probe and fluorescence molecular probe as light response devices, and CCD as detector. Optical fiber sensing drug dissolution monitor not only solves the current problems of time-consuming, and sampling of off-line analysis, but also provides real-time information of drug dissolution process. Thus, our study may provide a better evaluation method for the drug quality control..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 2587 (2014)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue 9, 1 (2014)
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