Journals >Spectroscopy and Spectral Analysis
Contents
2011
Volume: 31 Issue 9
64 Article(s)
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Research Article
Advances in Researches on Hyperspectral Remote Sensing Forestry Information-Extracting Technology
WU Jian, and PENG Dao-li
The hyperspectral remote sensing technology has become one of the leading technologies in forestry remote sensing domain. In the present review paper, the advances in researches on hyperspectral remote sensing technology in forestry information extraction both at home and abroad were reviewed, and the five main researcThe hyperspectral remote sensing technology has become one of the leading technologies in forestry remote sensing domain. In the present review paper, the advances in researches on hyperspectral remote sensing technology in forestry information extraction both at home and abroad were reviewed, and the five main research aspects including the hyperspectral classification and recognition of forest tree species, the hyperspectral inversion and extraction of forest ecological physical parameters, the hyperspectral monitoring and diagnosis of forest nutrient element, the forest crown density information extraction and the hyperspectral monitoring of forest disasters were summarized. The unresolved problems of hyperspectral technology in the forestry remote sensing applications were pointed out and the possible ways to solve these problems were expounded. Finally, the application prospect of hyperspectral remote sensing technology in forestry was analyzed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2305 (2011)
FTIR Microspectroscopy and Its Progress in Application
LI Xiao-ting, ZHU Da-zhou, PAN Li-gang, MA Zhi-hong, LU An-xiang, WANG Dong, and WANG Ji-hua
FTIR microspectroscopy technique was born in the mid-nineties. The research on this technique has just began abroad, and this technology has not yet been widely recognized in China. It is a rapid, nondestructive testing technology, has the advantages of microdomain, visualization, high precision and high sensitivity. IFTIR microspectroscopy technique was born in the mid-nineties. The research on this technique has just began abroad, and this technology has not yet been widely recognized in China. It is a rapid, nondestructive testing technology, has the advantages of microdomain, visualization, high precision and high sensitivity. In the present study, the composition, operational principle and working mode of FTIR microspectroscopy were summarized. The progress in application of FTIR microspectroscopy technique was investigated in some fields, including biomedicine, microbiology, forensic science, materials science, nutrition and feed science and agricultural products. The difficulty of FTIR microspectroscopy research and the prospects of this technique were also discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2313 (2011)
Applications of Surface-Enhanced Raman Spectroscopy to Detection of Polycyclic Aromatic Hydrocarbons
XIE Yun-fei, WANG Xu, RUAN Wei-dong, SONG Wei, and ZHAO Bing
In the present review article, the methodology and recent advances of surface-enhanced Raman scattering (SERS) were described in detection of polycyclic aromatic hydrocarbons (PAHs). PAHs, a series of organic compounds, are of much concern because some of them as pollutants have been identified as carcinogenic, mutagenIn the present review article, the methodology and recent advances of surface-enhanced Raman scattering (SERS) were described in detection of polycyclic aromatic hydrocarbons (PAHs). PAHs, a series of organic compounds, are of much concern because some of them as pollutants have been identified as carcinogenic, mutagenic and teratogenic compounds. They show low affinity to metallic surface, which confines applications of SERS to their detections. This article reviewed the development trends in PAHs analysis by using of SERS substrate modified by supramolecular system. And perspective SERS in PAHs studies have also been presented..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2319 (2011)
Effects of Ag Nanocrystals on Electroluminescence in Si Oxide Films
RAN Guang-zhao, WEN Jie, YOU Li-ping, and XU Wan-jin
Ag nanocrystal-embedded silicon oxide (SiO2∶Ag) films with varying Ag fractions were prepared on p-Si substrate by magnetron co-sputtering and thermal annealing. Visible electroluminescence (EL) was observed from the structures of ITO/SiO2∶Ag/p-Si. The authors found that Ag nanocrystals in the SiO2 film can not only shAg nanocrystal-embedded silicon oxide (SiO2∶Ag) films with varying Ag fractions were prepared on p-Si substrate by magnetron co-sputtering and thermal annealing. Visible electroluminescence (EL) was observed from the structures of ITO/SiO2∶Ag/p-Si. The authors found that Ag nanocrystals in the SiO2 film can not only shift the EL peak evidently but also enhance the EL intensity markedly. The larger the Ag fractions in the EL structures, the longer the peak wavelengths. The electromagnetic interactions of the Ag nanocrystals with the emitters in the film via local surface plasmons are considered responsible for these experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2324 (2011)
Luminescence Characteristics of PVK Doped with Ir(Fppy)3
GAO Li-yan, ZHAO Su-ling, XU Zheng, ZHANG Fu-jun, SUN Qin-jun, and ZHANG Yan-fei
In the present work, the photoluminescence (PL) and electroluminescence (EL) characteristics of Tris［2-(2,4-difluorophenyl)pyridine］iridium(Ⅲ) (Ir(Fppy)3) doped poly(n-vinylcarbazole) (PVK) with different doping concentrations were investigated. And a blue phosphorescent organic light-emitting diode (OLED) with the strIn the present work, the photoluminescence (PL) and electroluminescence (EL) characteristics of Tris［2-(2,4-difluorophenyl)pyridine］iridium(Ⅲ) (Ir(Fppy)3) doped poly(n-vinylcarbazole) (PVK) with different doping concentrations were investigated. And a blue phosphorescent organic light-emitting diode (OLED) with the structures of ITO/PEDOT∶PSS/PVK∶Ir(Fppy)3/BCP/Alq3/LiF/Al was fabricated. The experimental results show that the luminescence performances of devices are different as the doping concentration of Ir(Fppy)3 is different. When the doping concentration of Ir(Fppy)3 is lower, the luminescence of PVK can be found in EL spectra. When the doping concentration is too high, concentration quenching may occur. As the doping concentration is suitable, the luminescence of PVK can not be found, only the luminescence of Ir(Fppy)3 can be found in EL spectra. It is concluded that the device with doping concentration of 4% has the best photoelectric performance according to its current density-voltage-luminance curve..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2328 (2011)
Near-Infrared Luminescence and Energy Transfer of ACaPO4∶Eu2+, Nd3+(A=Li, K, Na)
XIAO Quan-lan, ZOU Shao-yu, LIU Guan-xi, PENG Wen-fang, WAN Chui-ming, XIE Li-juan, and MENG Jian-xin
Near-infrared (NIR) luminescence phosphors ACaPO4∶Eu2+,Nd3+(A=Li, K, Na) were prepared by conventional solid state method and the sensitization of Nd3+ near-infrared luminescence by Eu2+ was investigated. The characteristic NIR luminescence of Nd3+ in ACaPO4 matrix is greatly enhanced by co-doping of Eu2+. The fluorescNear-infrared (NIR) luminescence phosphors ACaPO4∶Eu2+,Nd3+(A=Li, K, Na) were prepared by conventional solid state method and the sensitization of Nd3+ near-infrared luminescence by Eu2+ was investigated. The characteristic NIR luminescence of Nd3+ in ACaPO4 matrix is greatly enhanced by co-doping of Eu2+. The fluorescence properties of ACaPO4∶Eu2+, the NIR luminescence properties of ACaPO4∶Eu2+,Nd3+ and the fluorescence lifetime were studied. The effect of emission wavelength of Eu2+ on NIR luminescence of Nd3+ was investigated; The energy transfer mechanism between Eu2+ and Nd3+ was also discussed. Emission peak wavelength of Eu2+ In ACaPO4 matrixes was found red shift with the series of A=Li, K, Na and the extent of the overlap with the different excitation peaks of Nd3+ changes obviously. It was concluded that the emission peak position of Eu2+ is a very important factor for energy transfer, and the optimal wavelength range for Eu2+→Nd3+ energy transfer is 500 to 550 nm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2332 (2011)
The Spectrogram Characteristics of Organic Blue-Emissive Light-Emitting Excitated YAG∶Ce Phosphor
XI Jian-fei, ZHANG Fang-hui, MU Qiang, and ZHANG Mai-li
It is demonstrated that the panchromatic luminescence devices with organic blue-emissive light-emitting was fabricated. This technique used down conversion, which was already popular in inorganic power LEDs to obtain white light emission. A blue OLED device with a configuration of ITO/2T-NATA(30 nm)/AND∶TBPe(50 Wt%, 40It is demonstrated that the panchromatic luminescence devices with organic blue-emissive light-emitting was fabricated. This technique used down conversion, which was already popular in inorganic power LEDs to obtain white light emission. A blue OLED device with a configuration of ITO/2T-NATA(30 nm)/AND∶TBPe(50 Wt%, 40 nm)/Alq3(100 nm)/LiF(1 nm)/Al(100 nm) was prepared via vacuum deposition process, and then coated with YAG∶Ce phosphor layers of different thicknesses to obtain a controllable and uniform shape while the CIE coordinates were fine tuned. This development not only decreased steps of technics and degree of difficulty, but also applied the mature technology of phosphor. The results showed that steady spectrogram was obtained in the devices with phosphor, with a best performance of a maximum luminance of 13 840 cd·m-2 which was about 2 times of that of the devices without phosphor; a maximum current efficiency of 17.3 cd·A-1 was increased more two times more than the devices without phosphor. The emission spectrum could be adjusted by varying the concentration and thickness of the phosphor layers. Absoulte spectrogram of devices was in direct proportion with different driving current corresponding..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2337 (2011)
Luminescence Investigation of NazCa1-x-2y-zBiyMoO4∶Eu3+x+y Red Phosphors
KANG Feng-wen, HU Yi-hua, WANG Yin-hai, WU Hao-yi, MU Zhong-fei, JU Gui-fang, and FU Chu-jun
A series of red phosphors with the composition NazCa1-x-2y-zBiyMoO4∶Eu３＋ｘ＋ｙ(y, z=0, x=0.24, 0.26, 0.30, 0.34, 0.38; x=0.30, y=0.01, 0.02, 0.03, 0.03, 0.05, 0.06, 0.07; x=0.30, y=0.04, z=0.38) were prepared via traditional solid-state method. The crystal structures of the obtained phosphors were identified by X-ray powdA series of red phosphors with the composition NazCa1-x-2y-zBiyMoO4∶Eu３＋ｘ＋ｙ(y, z=0, x=0.24, 0.26, 0.30, 0.34, 0.38; x=0.30, y=0.01, 0.02, 0.03, 0.03, 0.05, 0.06, 0.07; x=0.30, y=0.04, z=0.38) were prepared via traditional solid-state method. The crystal structures of the obtained phosphors were identified by X-ray powder diffraction (XRD) method. The photoluminescence properties of the samples were characterized by fluorescence spectrophotometer. The results indicated that the concentration of Eu3+ single doped Ca1-xMoO4∶Eu３＋ｘ with the maximum luminescence intensity was found to be 0.30 (namely, Ca0.70MoO4∶Eu３＋0.30); the photoluminescence properties with different ratio of Bi3+/Eu3+ codoped Ca0.70-2yBiyMoO4∶Eu３＋0.30＋ｙ were also investigated, and the results showed that the charge band (CTB) reached the maximum value when the y value was equal to 0.03; for the characteristic excitation peaks of Eu3+, however, the intensity of the excitation spectral line locating at 393 nm was stronger than that at 464 nm when y<0.03, while the intensity at 464 nm was greater than that at 393 nm when y≥0.03; the intensity of excitation peaks locating at 393 and 464 nm respectively both reached the maximum intensity when the y value was 0.04. The relative intensity of the excitation and emission of the above phosphor was enhanced greatly when Na2CO3 acting as charge compensation was added. The above results showed that the relative intensity between 393 and 464 nm could be changed by adjusting the ratio of Bi3+/Eu3+ codoping concentrations..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2341 (2011)
Synthesis, Characterization and Luminescence Properties of Novel β-Diketone and Eu(Ⅲ) Ternary Complex
CHENG Guo, WEI Chang-ping, REN Xiao-ming, WANG He, and WEI Wen-tao
The novel β-diketone 1-(4-bromophenyl)-3-phenylpropane-1,3-dione (L) was synthesized at room temperature by classical Claisen condensation reaction. With the β-diketone L as the first ligand and phen as the secondary ligand, and a new rare-earth Eu (Ⅲ) ternary complex was prepared. The ligand L and ternary complex wereThe novel β-diketone 1-(4-bromophenyl)-3-phenylpropane-1,3-dione (L) was synthesized at room temperature by classical Claisen condensation reaction. With the β-diketone L as the first ligand and phen as the secondary ligand, and a new rare-earth Eu (Ⅲ) ternary complex was prepared. The ligand L and ternary complex were characterized by elemental analysis, IR spectra, UV spectra and fluorescence spectra. IR spectra indicated that: the novel ligand L contained the structure of β-diketone, where the content of enol was high; the Eu3+ ion in the ternary complex was coordinated with six oxygen atoms of three L ligands and two nitrogen atoms of the second ligand phen. UV spectra showed that the main absorption was from the first ligand L in the Eu (Ⅲ) ternary complex. The excitation and emission spectra of the ternary complex were measured and investigated. Fluorescence spectra demonstrated that the ternary complex could emit characteristic fluorescence of rare earth Eu3+ ion and the strongest emission band was narrow which was attributed to the 5D0 →7F2 transitions of the 4f electrons of the central Eu3+ ions. So, the new Eu(Ⅲ) ternary complex is an excellent red-emitter which would be regarded as a valuable material with bright red fluorescence because it presents good monochromaticity..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2346 (2011)
Growth of Codoped CdWO4 Crystals by Bridgman Method and Their Optical Spectra
YU Can, XIA Hai-ping, WANG Dong-jie, and CHEN Hong-bing
The CdWO4 crystals with good quality in the size of Φ25 mm×120 mm, doped with Co in 0.5% molar fraction in the raw composition, were grown by the Bridgman method by taking ～70 ℃·cm-1 of solid-liquid interface and ~0.50 mm·h-1 growth rate. The crystal presents transparence and deep blue. The X-ray diffracThe CdWO4 crystals with good quality in the size of Φ25 mm×120 mm, doped with Co in 0.5% molar fraction in the raw composition, were grown by the Bridgman method by taking ～70 ℃·cm-1 of solid-liquid interface and ~0.50 mm·h-1 growth rate. The crystal presents transparence and deep blue. The X-ray diffraction (XRD) was used to characterize the crystals. Three absorption peaks at 518, 564 and 655 nm respectively, which are attributed to the overlapping of 4T1(4F)→4A2(4F) and 4T1(4F)→4T1(4P) of Co2+ octahedrons, and a wide band centered at 1 863 nm, which is attributed to 4T1(4F)→4T2(4F), was observed. The absorption results indicated that the Co ions presented +2 valence in crystal and located within the distorted oxygen octahedrons. The crystal-field parameter Dq and the Racah parameter B were estimated to be 990 and 726.3 cm-1 respectively based on the absorption spectra. A fluorescence emission at 778 nm (4T1(4P)→4T1(4F)) for codoped CdWO4 crystals was observed under excitation by 520 nm light. It can be deduced from the changes in absorption and emission intensity of different parts of crystal that the concentration of Co2+ ion in crystal increased along growing direction and the effective distribution coefficient of Co2+ ion in CdWO4 crystal is less than 1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2350 (2011)
Research on Parameters Optimization of Laser-Induced Breakdown Spectroscopy Based Experimental Device
ZHANG Lei, MA Wei-guang, YAN Xiao-juan, LI Zhi-xin, HU Zhi-yu, ZHANG Yong-zhi, WANG Le, DONG Lei, YIN Wang-bao, and JIA Suo-tang
For a better application of laser-induced breakdown spectroscopy (LIBS) to coal quality analysis, it is necessary to optimize the key parameters of the experimental LIBS-based device. The relationships between the key parameters and the signal-to-noise ratios (S/N) of the elemental emission lines in the plasma spectrumFor a better application of laser-induced breakdown spectroscopy (LIBS) to coal quality analysis, it is necessary to optimize the key parameters of the experimental LIBS-based device. The relationships between the key parameters and the signal-to-noise ratios (S/N) of the elemental emission lines in the plasma spectrum of the pulverized coal were studied, according to which the optimal parameters can be selected. Experimental results indicate that the optimal settings for our LIBS-based device are laser pulse energy=120 mJ·Pulse-1, delay time of spectrometer=200 ns, laser focal point be located 3～5 mm underneath the sample surface, rotation speed of sample cell=2.7 rev·min-1, a narrow-band filter with center frequency of 1 064 nm and a diaphragm with center hole diameter of 1.5 mm be placed in the path of the laser beam. Quantitative analysis results of pulverized coal show that, by using the optimal LIBS-based device, the standard deviation (SD) of C has been reduced from 6.7% to 1.6%, while the relative standard deviation (RSD) of other trace elements has been reduced from 28% to 10%. As a result, the accuracy has been improved greatly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2355 (2011)
Enhancement of the Radiation of Laser-Induced Stainless Steel Plasmas by Prefabricated Keyhole
CHEN Jin-zhong, YU Shi-juan, SUN Jiang, LI Xun, and WANG Chun-sheng
The prefabricated keyhole effects on the radiation characteristic of laser-induced stainless steel plasma were investigated. A high-energy neodymium glass pulse laser was used to ablate stainless steel sample in air at atmospheric pressure. Combined-type multi-function grating spectroscope and CCD spectral acquainting The prefabricated keyhole effects on the radiation characteristic of laser-induced stainless steel plasma were investigated. A high-energy neodymium glass pulse laser was used to ablate stainless steel sample in air at atmospheric pressure. Combined-type multi-function grating spectroscope and CCD spectral acquainting and processing system were used to record plasma spectrum. The electron temperature and the full width at half maximum of spectral line, respectively. The study results showed that the spectral intensity and signal-to-background ratio of laser plasma increase in the range of 71.5%～125.8% and 7.6%~18.5% respectively when a laser beam (～5 J) acted on the stainless steel sample on which prefabricated keyholes (d=1.5 mm, h=0.8 mm) were placed. The plasma temperature and electron density increased by about 1 200 K and 1.21×1016 cm-3, respectively. This proved that prefabricated keyhole had a significant enhancement effect on the radiation of laser-induced stainless steel plasma..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2361 (2011)
Measurement of Molecular Vibrational Temperature of Circle-Dot Filament in Dielectric Barrier Discharge
DONG Li-fang, LI Yuan-yuan, SONG Qian, CHEN Jun-ying, and YUAN Ning
Vibrational temperature in circle discharge channel and central dot discharge channel of circle-dot filament in argon/air dielectric barrier discharge was firstly measured by using optical emission spectra. The variations of the vibrational temperature in central-dot discharge channel and circle discharge channel as a Vibrational temperature in circle discharge channel and central dot discharge channel of circle-dot filament in argon/air dielectric barrier discharge was firstly measured by using optical emission spectra. The variations of the vibrational temperature in central-dot discharge channel and circle discharge channel as a function of air content were also studied. Emission spectral lines of the N2 second positive band system (Ｃ ３Πｕ→Ｂ ３Πｇ) were used to calculate the vabrational temperature. It was found that the vibrational temperature of circle is higher than that of the central dot. The vibrational temperature of circle increases more rapidly than that of central dot although both increase with the increase in air content. These results are of great importance to the study of microdischarge in dielectric barrier discharge system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2366 (2011)
Structural Characterization of Lignins Isolated from Caragana sinica Using FT-IR and NMR Spectroscopy
XIAO Ling-ping, SHI Zheng-jun, XU Feng, SUN Run-cang, and Amar K Mohanty
In order to efficiently explore and use woody biomass, six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions. The lignin structures were characterized by Fourier transform infrared spectroscopy (FT-IR) and 1D and 2D Nuclear Magnetic ResonaIn order to efficiently explore and use woody biomass, six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions. The lignin structures were characterized by Fourier transform infrared spectroscopy (FT-IR) and 1D and 2D Nuclear Magnetic Resonance (NMR). FT-IR spectra revealed that the “core” of the lignin structure did not significantly change during the treatment under the conditions given. The results of 1H and 13C NMR demonstrated that the lignin fraction L2, isolated with 70% ethanol containing 1% NaOH, was mainly composed of β-O-4 ether bonds together with G and S units and trace p-hydroxyphenyl unit. Based on the 2D HSQC NMR spectrum, the ethanol organosolv lignin fraction L1, extracted with 70% ethanol, presents a predominance of β-O-4′ aryl ether linkages (61% of total side chains), and a low abundance of condensed carbon-carbon linked structures (such as β-β′, β-1′, and β-5′) and a lower S/G ratio. Furthermore, a small percentage (ca. 9%) of the linkage side chain was found to be acylated at the γ-carbon..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2369 (2011)
Comparative Research on the NIR and MIR Micro-Imaging of Two Similar Plastic Materials
WANG Dong, MA Zhi-hong, ZHAO Liu, PAN Li-gang, LI Xiao-ting, and WANG Ji-hua
The NIR/MIR micro-imaging can supply not only the information of spectra, but also the information of spacial distribution of the sample, which is superior to the traditional NIR/MIR spectroscopy analysis. In the present paper, polyethylene and parafilm, with similar appearances, were regarded as the research objects, The NIR/MIR micro-imaging can supply not only the information of spectra, but also the information of spacial distribution of the sample, which is superior to the traditional NIR/MIR spectroscopy analysis. In the present paper, polyethylene and parafilm, with similar appearances, were regarded as the research objects, of which the NIR/MIR micro-imaging was collected. Chemical imaging (CI) and compare correlation imaging were carried out for the two materials respectively to discuss the imaging methods of the two materials. The result indicated that the differentiation of the CI values of the two materials in the NIR/MIR CI for material Ⅱ was 0.004 8 and 0.254 8 respectively, while those in the NIR/MIR CI for material Ⅰ were 0.002 6 and 0.326 5, respectively. Clear CI was acquired, and the two materials could be differentiated. The result of the compare correlation imagings indicated that the compare correlation imagings, in which the NIR/MIR spectra of the two materials were regarded as reference spectra respectively, can differentiate the two materials remarkably with clear imagings. In the compare correlation imagings of MIR micro-imaging, the difference of the correlation coefficients between the two materials’ MIR spectra and the reference spectrum was more than 0.12, which showed a better imaging result; while a tiny difference of the correlation coefficients between the two materials’ NIR spectra and the reference spectrum could be employed to show a clear imaging result for NIR compare correlation imaging so as to differentiate the two materials. This thesis, to some extent, can supply the reference to not only the rapid discrimination of the safety of the packaging material for agri-food, but also the imaging methods for NIR/MIR micro-imaging to differentiate the different materials..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2377 (2011)
Adulteration Detection of Urea in Milk by Mid-Infrared Spectroscopy
YANG Ren-jie, LIU Rong, and XU Ke-xin
In the present study, a technique of mid-infrared spectroscopy for detection of urea in milk was put forward. Eighteen adulterated milk samples with added different content of urea (1～18 g·L-1) were prepared. The mid-infrared spectra of these milk samples were measured. The infrared characteristics of pure milk anIn the present study, a technique of mid-infrared spectroscopy for detection of urea in milk was put forward. Eighteen adulterated milk samples with added different content of urea (1～18 g·L-1) were prepared. The mid-infrared spectra of these milk samples were measured. The infrared characteristics of pure milk and adulterated milk were studied, and analysis and comparisons of the differences were carried out. The absorption peak area (A1 562) of 1 562 cm-1, which was assigned to the C—N stretching vibration for urea, and the absorption peak area (A1 464) of 1 464 cm-1, which was assigned to the CO stretching vibration for amide Ⅲ’, were calculated by origin. Linear fitting of relation was made between A1 562/A1 464 and urea concentration in milk. The results show that the A1 562/A1 464 is linear with urea concentration in milk, with a regression coefficient of 0.96. The study is important to improving quality of dairy products and protecting the benefit of consumers, and takes on crucial social significance and application prospect..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2383 (2011)
Determination of Acidity and Vitamin C in Apples Using Portable NIR Analyzer
YANG Fan, LI Ya-ting, GU Xuan, MA Jiang, FAN Xing, WANG Xiao-xuan, and ZHANG Zhuo-yong
Near infrared (NIR) spectroscopy technology based on a portable NIR analyzer, combined with kernel Isomap algorithm and generalized regression neural network (GRNN) has been applied to establishing quantitative models for prediction of acidity and vitamin C in six kinds of apple samples. The obtained results demonstratNear infrared (NIR) spectroscopy technology based on a portable NIR analyzer, combined with kernel Isomap algorithm and generalized regression neural network (GRNN) has been applied to establishing quantitative models for prediction of acidity and vitamin C in six kinds of apple samples. The obtained results demonstrated that the fitting and the predictive accuracy of the models with kernel Isomap algorithm were satisfactory. The correlation between actual and predicted values of calibration samples (Rc) obtained by the acidity model was 0.999 4, and for prediction samples (Rp) was 0.979 9. The root mean square error of prediction set (RMSEP) was 0.055 8. For the vitamin C model, Rc was 0.989 1, Rp was 0.927 2, and RMSEP was 4.043 1. Results proved that the portable NIR analyzer can be a feasible tool for the determination of acidity and vitamin C in apples..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2386 (2011)
Identification of Pu’er Teas with Different Storage Years by FTIR Spectroscopy
NING Jing-ming, ZHNAG Zheng-zhu, WANG Sheng-peng, WAN Xiao-chun, and ZENG Xin-sheng
Infrared spectra of Pu’er raw tea and Pu’er ripe tea were investigated using Fourier transform spectroscopy， in order to exploit a rapid method for discrimination of aging period for Pu’er tea samples. The results showed that the two kinds of Pu’er teas shared a similar woveform of infrared spectrum. However, due to thInfrared spectra of Pu’er raw tea and Pu’er ripe tea were investigated using Fourier transform spectroscopy， in order to exploit a rapid method for discrimination of aging period for Pu’er tea samples. The results showed that the two kinds of Pu’er teas shared a similar woveform of infrared spectrum. However, due to the variations of aging time, leading to different chemical composition in pu’er teas, both Pu’er raw tea and ripe tea displayed corresponding different characteristic peaks. And the extent of aging of Pu’er tea had a significant relationship with optical density and waveforms of absorption peaks in the wave number range of 1 120～1 570 cm-1 and 400～853 cm-1, suggesting that the extent of aging of Pu’er tea may be identified by infrared spectrum technology rapidly and simply..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2390 (2011)
Second Structure of the Protein Factions from Lotus Seeds
CAI Lian-hui, ZENG Hong-yan, CAI Xi-ling, and WANG Ya-ju
Following the sequential Osborne extraction procedure, the proteins of lotus seeds were classified. The secondary structures of albumin, globulin, prolamine and glutelin fractions were determined by Fourier transform infrared spectroscopy (FTIR). The FTIR images of amide Ⅰ and Ⅲ bands from the four protein fractions weFollowing the sequential Osborne extraction procedure, the proteins of lotus seeds were classified. The secondary structures of albumin, globulin, prolamine and glutelin fractions were determined by Fourier transform infrared spectroscopy (FTIR). The FTIR images of amide Ⅰ and Ⅲ bands from the four protein fractions were analyzed using Fourier deconvolution and curve-fitting technique. The results showed that there were minor differences in every corresponding peak position and peak area percent of secondary structure between albumin and globulin as well as between prolamin and glutelin. But there were differences in every corresponding peak position between albumin (or globulin) and prolamin (or glutelin). Especially the area percents of the corresponding nonrandom structures (α-helix and β-sheet) of albumin and globulin were significantly larger than those of prolamin and glutelin. The contents of nonrandom structures of albumin and globulin extracted with 0.1 mol·L-1 NaCl solution were about 55% and those of prolamine and glutelin fractions were only at round 40%, indicating that the secondary structures of the salt-extraction protein were ordered and stable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2394 (2011)
Selection of Visible-NIR Variables Based on Extraction and Successive Projections Algorithm
SUN Xu-dong, HAO Yong, CAI Li-jun, and LIU Yan-de
The pixels were 2 048 or 3 648 for the most Si charge coupled device dector. The interval between the adjacent wavelengths was few. The pretreatment could not deal with the spectra well. Spectral matrix was reconstructed by equal interval extraction in the wavelength range of 600.09～980.47nm. The variables for developiThe pixels were 2 048 or 3 648 for the most Si charge coupled device dector. The interval between the adjacent wavelengths was few. The pretreatment could not deal with the spectra well. Spectral matrix was reconstructed by equal interval extraction in the wavelength range of 600.09～980.47nm. The variables for developing partial least squares (PLS) models were chosen by genetic algorithm (GA) and successive projections algorithm (SPA) from the pretreatment spectra. The models’ predictive ability was evaluated by leave-one-out cross validation. By comparison, the best results were obtained by the SPA-PLS models. The standard errors of cross validation (SECV) were 0.661°Brix, 0.067% and 2.91 mg·(100 g)-1 for soluble solids, total adicity and vitamin C, respectively. The results suggested that the predictive ability can be improved by equal interval extraction method and SPA for determinating the quality of Nanfeng mandarin fruits..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2399 (2011)
FTIR Spectroscopic Analysis of Cu2+ Adsorption on Hematite and Bayerite
WANG Shuai, WANG Nan, LI Cui-lan, ZHANG Jin-jing, and DOU Sen
The changes in surface hydroxyl structures and their absorption peaks after the adsorption of Cu2+ on the hematite and bayerite were studied by FTIR spectroscopy under the different pH values and Cu2+ concentrations. The result indicated that: (1) with the increase of Cu2+ concentrations, the H—O—H and OH deformation vThe changes in surface hydroxyl structures and their absorption peaks after the adsorption of Cu2+ on the hematite and bayerite were studied by FTIR spectroscopy under the different pH values and Cu2+ concentrations. The result indicated that: (1) with the increase of Cu2+ concentrations, the H—O—H and OH deformation vibration of the hematite participated in the adsorption and Cu2+ combined with the Fe—O structure strongly, then Fe—O—(Cu) had been formed on the hematite surface. (2) In acid conditions, H+ in the solution destroyed the O—H structure of hematite surface and the existence of NO-3 prompted the production of a new peak (1 131 cm-1). With pH value increasing, the hydroxy structure of hematite surface changed gradually from stretching vibration to deformation vibration, then the structures of Fe—OH and Fe3+—O2- constantly changed. (3) The adsorption of Cu2+ on the bayerite happened in the high wave position. With the Cu2+ concentration increasing, the free OH bending vibration, the OH- stretching vibration and its H—O—H bending vibration were all involved in the adsorption, and at the same time, Al3+ of Al—O was gradually replaced by Cu2+, which enhanced the vibration intensity of the low waves position. (4) With the increase in pH, the Al—OH bending vibration and Al—O stretching vibration changed gradually, which indicated that AlOCu+ and AlOCuOH structure had been formed on the bayerite surface after the adsorption..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2403 (2011)
Identification of Yougui and Jisheng Shenqi Pills with FTIR and EDS Fingerprint Spectra by New Visual Comparison
WANG Li-shuang, ZOU Hua-bin, TIAN Fang, DU Ai-qin, DONG Feng-juan, and ZHANG Xin-ling
FTIR combined with EDS fingerprint spectra was first applied to the identification of two kind of traditional Chinese compound formulae-Yougui pill and Jisheng shenqi pills, which have the similar composition. The IR FPS of extraction of two kinds of pills extracted with chloroform were measured by liquid membrane methFTIR combined with EDS fingerprint spectra was first applied to the identification of two kind of traditional Chinese compound formulae-Yougui pill and Jisheng shenqi pills, which have the similar composition. The IR FPS of extraction of two kinds of pills extracted with chloroform were measured by liquid membrane method. The exclusively characteristic peak groups of these two kinds of formulae were theoretically established based on the Shapiro-Wilk W testing method，and the characteristic radicals and compound species corresponding to each characteristic peak were determined. Meanwhile, EDS fingerprint spectra of the two kinds of original powders were also measured which can reflect the element species and content information. Based on the three kinds of information (characteristic peak groups, radicals and compound species, different elements), Yougui and Jisheng shenqi pills were identified quickly, precisely and reliably. In this method, infrared fingerprint spectra possess the similar ability with chromatograph fingerprint spectra in identification of traditional Chinese compound formulae. The results show that the new visual comparison method is suitable for identifying traditional Chinese compound formulae with the same dosage-form and similar composition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2407 (2011)
Research on the Measurement of Urinary Albumin by Visible-Near Infrared Spectroscopy
LI Gang, ZHAO Zhe, LIU Rui, WANG Hui-quan, LIN Ling, ZHANG Bao-ju, and WU Xiao-rong
The urinary albumin (UMALB) is the most reliable diagnostic indicator of renal injury in clinical. Attempting to realize the rapid and free reagent measurement of UMALB, the visible-near infrared multiple optical path length spectra of 207 urine samples were collected. By the nonlinear characteristics of multiple opticThe urinary albumin (UMALB) is the most reliable diagnostic indicator of renal injury in clinical. Attempting to realize the rapid and free reagent measurement of UMALB, the visible-near infrared multiple optical path length spectra of 207 urine samples were collected. By the nonlinear characteristics of multiple optical path length spectra, more information about the component of sample contents can be obtained. The PLS model of the spectra and UMALB was firstly established. Based on it, the PLS-ANN modeling method was built to introduce nonlinear information. By contrast, the PLS-ANN modeling method can obtain a better model to improve the accuracy of quantitative analysis. The R2 of predicted model was 0.951 1 and the RMSEP was 5.02 mg·L-1. The results showed the feasibility of the visible-near infrared multiple optical path length spectroscopy technique for urinary albumin analysis. This research establishes the foundation of detecting the urinary albumin and other components free of reagent conveniently and rapidly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2412 (2011)
Study on the Application of DBPSO Algorithm to Thickness Measurement of Surface Insulation Coating of Silicon Steel By NIR Spectrometry
HE Jian-ping, and JIN Ping
A novel thickness measurement NIR spectrometry for surface insulation coating of silicon steel based on discrete binary particle swarm optimization (DBPSO) algorithm is presented. First, we used NIR spectrometer to collect the NIR spectra of insulation coating of silicon steel, and then, DBPSO algorithm was used to selA novel thickness measurement NIR spectrometry for surface insulation coating of silicon steel based on discrete binary particle swarm optimization (DBPSO) algorithm is presented. First, we used NIR spectrometer to collect the NIR spectra of insulation coating of silicon steel, and then, DBPSO algorithm was used to select the optimal wavelength variates and composed a new spectra set. Last, the authors created the thickness quantitative analysis model using kernel partial least square algorithm. The experimental results show that the absolute error range analyzed by created model was from -0.12 to 0.19 μm, and the maximal relative error was 14.31%, which completely met the practical measurement need. The research indicates that DBPSO is effective wavelength selection methods, which can efficiently select the wavelength variates carrying more useful information, improve the analysis accuracy and speed. And the NIR spectroscopy is an effective measurement method for thickness analysis of silicon steel insulation coating..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2416 (2011)
Analysis and Evaluation of Different Radial Parts of Cordyceps Kyushuensis by Fourier Transform Infrared Spectroscopy
GONG Ben-jiao, RONG Rong, ZHANG Guo-ying, LING Jian-ya, and ZHANG Chang-kai
Fourier-transform infrared spectroscopy (FTIR) and second derivative spectra were used to analyze and evaluate the different parts of Cordyceps kyushuensis Kob in the present work. The results showed that C. kyushuensis contained proteins, polysaccharides, nucleosides, lipids and other active ingredients, the single-diFourier-transform infrared spectroscopy (FTIR) and second derivative spectra were used to analyze and evaluate the different parts of Cordyceps kyushuensis Kob in the present work. The results showed that C. kyushuensis contained proteins, polysaccharides, nucleosides, lipids and other active ingredients, the single-dimensional IR spectra of the various parts were highly similar, the similarity coefficient between the cultured stroma and medium reached up to 0.992 7, and the natural stroma was more different from the parasites, with similarity coefficient of 0.949 9. Second derivative spectrum further enriched and confirmed the feature of corresponding spectrum peaks, proved the existence of active substances such as cordycepin and adenosine, and prompted the presence of α- and β-glycosidic bonds. The diversity and complexity of chemical constituents in different parts of C. kyushuensis were synthetically described by IR spectra, which provided a fast, comprehensive and objective approach to the analysis and evaluation of the imperceptible differences, and the quality control of Cordyceps. This work supplies a theoretical basis for development and utilization of genetic resources C. kyushuensis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2420 (2011)
A New Approach to Rapid Determination of Compound Fertilizer Composition
GUO Zheng, YUAN Hong-fu, ZHANG Xian, SONG Chun-feng, LI Xiao-yu, and XIE Jin-chun
In the present paper, a new approach to rapid determination of compound fertilizer composition was introduced, namely first preparing aqueous solution of solid fertilizer, then predicting the compound fertilizer composition using the near infrared transmission spectra of the solution. Using the new method, models were In the present paper, a new approach to rapid determination of compound fertilizer composition was introduced, namely first preparing aqueous solution of solid fertilizer, then predicting the compound fertilizer composition using the near infrared transmission spectra of the solution. Using the new method, models were built by means of PLS regression, and the standard errors of prediction of total nitrogen content, P2O5 content, and K2O content are 0.5, 0.7, 0.8, and 2.0, respectively. This has solved the problem of large prediction error for K content of compound fertilizer using near infrared reflectance spectroscopy due to the fact that KCl dose not have near infrared absorption, and achieved rapid analysis of all compositions of compound fertilizer in 5 minutes..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2424 (2011)
Water Raman Spectrum Suppression with Low-Pass Filter in Underwater In-Situ Raman Spectroscopy
GUO Jin-jia, and LIU Zhi-shen
As a powerful tool for studying chemical structures, Raman spectroscopy has been used in aquatic environments in-situ measurement widely, and has been used in deep sea research recently. For underwater in-situ detection, O—H vibration Raman peak of water is inherent and strong compared with other dissolved matter’s RamAs a powerful tool for studying chemical structures, Raman spectroscopy has been used in aquatic environments in-situ measurement widely, and has been used in deep sea research recently. For underwater in-situ detection, O—H vibration Raman peak of water is inherent and strong compared with other dissolved matter’s Raman signals. When the authors want to get a good SNR Raman signal of dissolved matter by increasing detection time, O—H vibration Raman peak of water will get to saturation easily, which influences other Raman signal’s detection. In the present paper, a specially designed short-pass optical filter was used for suppression of water’s O—H vibration Raman peak. The authors calculated the suppression effect of short-pass optical filter with linear and exponential edges. The simulation shows that exponential edge filter has better performance and can suppress water’s O—H vibration Raman peak effectively. The experiment also proves the calculation results. With the suppression optical filter, the intensity of water’s O—H vibration Raman signal and other dissolved matters’ become similar. And the influence of suppression optical filter on other dissolved matters’ Raman signal is little. So the suppression optical filter is feasible for in-situ underwater Raman spectroscopy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2428 (2011)
Mid-Infrared and Raman Spectral Analysis of Geometrically Frustrated Natural Atacamite
TAO Wan-jun, LIU Xiao-dong, ZHENG Xu-guang, MENG Dong-dong, and GUO Qi-xin
At room temperature, the mid-infrared spectra of geometrically frustrated natural atacamite (hydroxyl copper chloride, β-Cu2(OH)3Cl) in the range of 4 000~400 cm-1 were measured by FTIR spectrometers, and meanwhile its Raman spectrum in the range of 4 000~95 cm-1 was obtained by Jobin Yvon LabRAM HR800 Raman spectrometAt room temperature, the mid-infrared spectra of geometrically frustrated natural atacamite (hydroxyl copper chloride, β-Cu2(OH)3Cl) in the range of 4 000~400 cm-1 were measured by FTIR spectrometers, and meanwhile its Raman spectrum in the range of 4 000~95 cm-1 was obtained by Jobin Yvon LabRAM HR800 Raman spectrometer. According to its crystal structure parameters, the authors confirmed the characteristic peaks of sample 4 000~2 500~1 000 cm-1 in the functional group region and 1 000~550~200~95 cm-1 in the fingerprint region, and also explored its microscopic origin. Five distinct regions were assigned: the hydroxyl stretching vibration νO—H determined by the overall environment around the hydroxyl group; the overtones generated by the sum or multiplication of fundamental frequencies of hydroxyl bending vibration; the hydroxyl bending vibration modes δO—H of the combination of δCu—O—H and δO—H…Cl; the vibration modes of strongly bonded planar CuO4 units; the vibration modes of weakly bonded linear-triatomic chain Cl—Cu—O/Cl. The bands were assigned in accordance with its crystal structure parameters, which is more reasonable to establish the relationship between its molecular structure and its respective spectral properties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2431 (2011)
3-D Fluorescence Properties of Petrochemical Wastewater
WU Jing, CAOZhi ping, XIEChao bo, SUN Ya nan, DAIChun yan, and XIANG Xi
Petrochemical wastewater is one of major types of industrial wastewater in China. It is of huge quantity and causes serious pollution. Wastewater contains lots of fluorescence matters. Its fluorescence spectrum could exhibit organic components and unique for each sample like fingerprint. Thus it is referred to as fluorPetrochemical wastewater is one of major types of industrial wastewater in China. It is of huge quantity and causes serious pollution. Wastewater contains lots of fluorescence matters. Its fluorescence spectrum could exhibit organic components and unique for each sample like fingerprint. Thus it is referred to as fluorescence fingerprint of water quality, in brief aqueous fingerprint. This paper presented that there were almost 10 peaks in the aqueous fingerprint of petrochemical wastewater from a large-scale petrochemical plant, including the peak at the excitation/emission wavelengths (λex/λem) of around 230/340 nm. That peak exists in the fluorescence spectra of various petroleum materials. The aqueous fingerprint was divided into 3 zones according to the relationship of fluorescence intensity of peaks: the linear relation between the peaks from different zones was not significant while that between the peaks from same zone was significant with coefficients of above 0.85. The zone around λex/λem=230/305 nm might relate to benzene compounds and the zone around λex/λem =220～320/230～440 nm (excluding the zone around λex/λem=230/305 nm) showed close relation with the raw materials (petroleum materials). The intensity of each peak had a fixed range. That range and relationships between peaks could be the evidences for diagnosing if the performance of the production processes is proper..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2437 (2011)
Study on the Transient and Steady State Property of Fluorescence of Free Radical Photoinitiator
LI Xin-zheng, LI Xiao-wei, LAI Wei-dong, BAI Bing, and AN Wen
The fluorescence characteristic of various free radical photoinitiators was investigated by fluorescence spectroscopy. The influence of conjugated structure on fluorescence spectrum was analyzed from the molecular structure. The results show that: the wave length of fluorescence excitation spectrum gradually augments wThe fluorescence characteristic of various free radical photoinitiators was investigated by fluorescence spectroscopy. The influence of conjugated structure on fluorescence spectrum was analyzed from the molecular structure. The results show that: the wave length of fluorescence excitation spectrum gradually augments with the conjugative effect enhancement, and so does the peak of fluorescence emission spectrum. The transient fluorescence spectrum of photoinitiator is affected by electron groups and the fluorescence decay of photoinitiators with electron-withdrawing groups is faster than that of photoinitiators with electron-donating groups. The excitation peak of photoinitiator has evident red shift with the polarity of solvent increasing, which shows that transition type is π—π* transition, and the fluorescence decay is postponed with the solvent glutinosity changing. When the photoinitiator density is at 10-2mol·L-1, the fluorescence decay is evidently fast because of quenching effect caused by self-absorption and collisions between particles..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2442 (2011)
Studies on the Interaction of Rhein with Bovine Serum Albumin by Spectroscopic and Voltammetric Methods
LIANG Hui, ZHAO Fang, and LI Bing-qi
The interaction between rhein and bovine serum albumin(BSA) was studied by UV-Visible， fluorescence spectroscopy and circular dichroism in conjunction with electrochemical method. The results indicated that rhein has a powerful ability to quench the albumin’s fluorescence in a static mode. The binding constants(KA) andThe interaction between rhein and bovine serum albumin(BSA) was studied by UV-Visible， fluorescence spectroscopy and circular dichroism in conjunction with electrochemical method. The results indicated that rhein has a powerful ability to quench the albumin’s fluorescence in a static mode. The binding constants(KA) and binding site numbers (n) obtained at different temperatures were 3.67×105, 0.99 (298 K) and 2.60×104, 0.83 (309 K) respectively. According to the thermodynamic parameters the main sorts of binding force of rhein-BSA was fixed as electrostatic. The distance between donor and acceptor in rhein-BSA was 3.28 nm based on the Frster energy transfer theory. Results of the circular dichroism and synchronous fluorescence show that the binding can cause conformation change of BSA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2446 (2011)
Using Extraction of Red Edge Position to Validate Consistency of Hyperspectral Imaging and Non-Imaging Data
WANG Da-cheng, ZHANG Dong-yan, ZHAO Jin-ling, LI Cun-jun, ZHU Da-zhou, HUANG Wen-jiang, LI Yu-fei, and YANG Xiao-dong
Using Pushbroom imaging spectrometer (PIS) and FieldSpec ProFR2500 (ASD), spectral reflectances of winter wheat and maize at different stages were collected synchronously. In order to validate the reliability of imaging spectral data, the red edge position of hyperspectral data for PIS and ASD were extracted by differeUsing Pushbroom imaging spectrometer (PIS) and FieldSpec ProFR2500 (ASD), spectral reflectances of winter wheat and maize at different stages were collected synchronously. In order to validate the reliability of imaging spectral data, the red edge position of hyperspectral data for PIS and ASD were extracted by different algorithms, respectively. The following results were obtained: (1) The original spectrum of both instruments had high inosculation in red light region (670～740 nm); (2) With the spectra collected under laboratory condition (maize leaf), the extracted red edge position was is concentrated between 700 and 720 nm for the two instruments; (3) With the spectra collected undre field condition (wheat leaf), the extracted red edge position for PIS and ASD were different, the red edge position of PIS data was in 760 nm, while it was in 720 nm for ASD data. The main reason might be that the imaging spectral data were influenced by oxygen absorbtion; (4) the red edge rangeability of PIS and ASD were different, but the trends were the same. The above results could provide some references for hyperspectral imaging data’s extensive application..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2450 (2011)
A Method of Endmember Extraction in Hyperspectral Remote Sensing Images Based on Discrete Particle Swarm Optimization (D-PSO)
ZHANG Bing, SUN Xu, GAO Lian-ru, and YANG Li-na
For the inaccuracy of endmember extraction caused by abnormal noises of data during the mixed pixel decomposition process, particle swarm optimization (PSO), a swarm intelligence algorithm was introduced and improved in the present paper. By re-defining the position and velocity representation and data updating strategFor the inaccuracy of endmember extraction caused by abnormal noises of data during the mixed pixel decomposition process, particle swarm optimization (PSO), a swarm intelligence algorithm was introduced and improved in the present paper. By re-defining the position and velocity representation and data updating strategies, the algorithm of discrete particle swarm optimization (D-PSO) was proposed, which made it possible to search resolutions in discrete space and ultimately resolve combinatorial optimization problems. In addition, by defining objective functions and feasible solution spaces, endmember extraction was converted to combinatorial optimization problem, which can be resolved by D-PSO. After giving the detailed flow of applying D-PSO to endmember extraction and experiments based on simulative data and real data, it has been verified the algorithm’s flexibility to handle data with abnormal noise and the reliability of endmember extraction were verified. Furthermore, the influence of different parameters on the algorithm’s performances was analyzed thoroughly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2455 (2011)
Hyperspectral Feature Band Selection Based on Mean Confidence Interval and Tree Species Discrimination
CHEN Yong-gang, DING Li-xia, GE Hong-li, ZHANG Mao-zhen, and HU Yun
In the present study, based on the leaf-level hyperspectral data of BaiMu, LeiZhu and WuHuanZi, the authors come up with two solutions through the theory of statistics; the first one is that optimal discriminating band between tree species is extracted by mean interval confidence, the other one is that tree species is In the present study, based on the leaf-level hyperspectral data of BaiMu, LeiZhu and WuHuanZi, the authors come up with two solutions through the theory of statistics; the first one is that optimal discriminating band between tree species is extracted by mean interval confidence, the other one is that tree species is discriminated by the Manhattan distance and the Min～Max interval similarity. The research results showed that (1) the optimal discriminating bands between BaiMu and LeiZhu are around 350~446, 497~527, 553~1 330, 1 355~2 400 and 2 436~2 500 nm; the optimal discriminating bands between BaiMu and WuHuanZi are around 434~555, 580~1 903, 1 914~2 089, 2 172~2 457 and 2 475~2 500 nm; the optimal discriminating bands between LeiZhu and WuHuanZi are around 434~555, 580~1 903, 1 914~2 089, 2 172~2 457 and 2 475~2 500 nm; and this result is helpful for us to find maximum difference to identifying tree species respectively. (2) In these optimal discriminating bands, we find that the Manhattan distance between the same species is far less than the different species; but the Min～Max interval similarity between the same species is far more than the different species, so this result could help us to discriminate and identify different types of tree species effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2462 (2011)
A Remote Sensing Band Simulation Approach Based on Image Spectral Library
SHEN Jin-xiang, CHEN Xi, YANG Liao, BAO An-ming, WU Xiao-bo, and WANG Jie
The authors proposed an image spectral library based band simulation method. Firstly, the authors clustered the reference image which has the same class composition with the target image by using its pixel spectrum similarity. Secondly, the authors fetched sample from the reference image base on the former cluster imagThe authors proposed an image spectral library based band simulation method. Firstly, the authors clustered the reference image which has the same class composition with the target image by using its pixel spectrum similarity. Secondly, the authors fetched sample from the reference image base on the former cluster image, and then built the image spectral library. Thirdly, the authors fetched the same count of each type of samples to train the simulation model. Finally, the authors simulated the target band of the target image. The experiment results show that: firstly, this method can be more precise to simulate TM blue band, and increase more than 1.2 RMSE value than that of the “Spectral Library-image” model and more than 0.6 RMSE value than that of the “image-image” model. On the other hand, our method is more stable and reliable than the “image-image” and “Spectral Library-Image” simulation model; finally, this method can be successfully applied to the blue band simulation that SPOT and MSS lacked.
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2467 (2011)
The Hierarchical Clustering Analysis of Hyperspectral Image Based on Probabilistic Latent Semantic Analysis
YI Wen-bin, SHEN Li, QI Yin-feng, and TANG Hong
The paper introduces the Probabilistic Latent Semantic Analysis (PLSA) to the image clustering and an effective image clustering algorithm using the semantic information from PLSA is proposed which is used for hyperspectral images. Firstly, the ISODATA algorithm is used to obtain the initial clustering result of hypersThe paper introduces the Probabilistic Latent Semantic Analysis (PLSA) to the image clustering and an effective image clustering algorithm using the semantic information from PLSA is proposed which is used for hyperspectral images. Firstly, the ISODATA algorithm is used to obtain the initial clustering result of hyperspectral image and the clusters of the initial clustering result are considered as the visual words of the PLSA. Secondly, the object-oriented image segmentation algorithm is used to partition the hyperspectral image and segments with relatively pure pixels are regarded as documents in PLSA. Thirdly, a variety of identification methods which can estimate the best number of cluster centers is combined to get the number of latent semantic topics. Then the conditional distributions of visual words in topics and the mixtures of topics in different documents are estimated by using PLSA. Finally, the conditional probabilistic of latent semantic topics are distinguished using statistical pattern recognition method, the topic type for each visual in each document will be given and the clustering result of hyperspectral image are then achieved. Experimental results show the clusters of the proposed algorithm are better than K-MEANS and ISODATA in terms of object-oriented property and the clustering result is closer to the distribution of real spatial distribution of surface..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2471 (2011)
Synthesis and Spectral Characteristic of Pharmaceutical Dipfluzine Hydrochloride-Benzoic Acid Co-Crystal
YANG Cai-qin, WANG Jing, and ZHANG Zhen-wei
Pharmaceutical co-crystals can improve the chemical and physical properties of active pharmaceutical ingredient (API), which is new idea and expected to provide new stable structures. Pharmaceutical co-crystals have the potential to be much more useful in pharmaceutical products than salts, solvates or hydrates, polymoPharmaceutical co-crystals can improve the chemical and physical properties of active pharmaceutical ingredient (API), which is new idea and expected to provide new stable structures. Pharmaceutical co-crystals have the potential to be much more useful in pharmaceutical products than salts, solvates or hydrates, polymorphs and stoichiometric solvates (pseudo-polymorphs). In our study, dipfluzine hydrochloride-benzoic acid co-crystal was synthesized by solid co-grinding. The samples were subjected to IR, DSC, XRD, Raman and THz spectral analysis. The results indicated that dipfluzine hydrochloride-benzoic acid complex was new phase compared with the single API and CCF. THz-TDS characterization indicated that hydrogen bond formed between API and CCF, which confirmed the formation of co-crystal..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2476 (2011)
Quantitative Spectrum Analysis of Characteristic Gases of Spontaneous Combustion Coal
LIANG Yun-tao, TANG Xiao-jun, LUO Hai-zhu, and SUN Yong
Aimed at the characteristics of spontaneous combustion gas such as a variety of gases, lou limit of detection, and critical requirement of safety, Fourier transform infrared (FTIR) spectral analysis is presented to analyze characteristic gases of spontaneous combustion. In this paper, analysis method is introduced at fAimed at the characteristics of spontaneous combustion gas such as a variety of gases, lou limit of detection, and critical requirement of safety, Fourier transform infrared (FTIR) spectral analysis is presented to analyze characteristic gases of spontaneous combustion. In this paper, analysis method is introduced at first by combing characteristics of absorption spectra of analyte and analysis requirement. Parameter setting method, sample preparation, feature variable abstract and analysis model building are taken into consideration. The methods of sample preparation, feature abstraction and analysis model are introduced in detail. And then, eleven kinds of gases were tested with Tensor 27 spectrometer. CH4, C2H6, C3H8, iC4H10, nC4H10, C2H4, C3H6, C3H2, SF6, CO and CO2 were included. The optical path length was 10 cm while the spectra resolution was set as 1 cm-1. The testing results show that the detection limit of all analytes is less than 2×10-6. All the detection limits fit the measurement requirement of spontaneous combustion gas, which means that FTIR may be an ideal instrument and the analysis method used in this paper is competent for spontaneous combustion gas measurement on line..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2480 (2011)
Use of Ensemble Kalman Smoother Algorithm for the Time-Series Retrieval of Leaf Area Index from Remote Sensing Data
JIN Hua-an, WANG Jin-di, XIAO Zhi-qiang, and LI Xi-jia
In the present paper, the empirical LAI dynamic model was constructed using the MOD15A2 data set, and the canopy radiative transfer model MCRM2 was coupled with the LAI dynamic model through LAI. The scheme was proposed to retrieve LAI by assimilating MOD09A1 data set into the coupled model. The ensemble Kalman smootheIn the present paper, the empirical LAI dynamic model was constructed using the MOD15A2 data set, and the canopy radiative transfer model MCRM2 was coupled with the LAI dynamic model through LAI. The scheme was proposed to retrieve LAI by assimilating MOD09A1 data set into the coupled model. The ensemble Kalman smoother (EnKS) method was first introduced. In order to preferably assess the feasibility of EnKS, the LAI retrieval results of EnKS were compared with the ensemble Kalman filter (EnKF) solutions and MODIS LAI product. The results indicated that the EnKS method achieved ideal results. The retrieved LAI temporal profiles by the EnKS method were smoother and more continuous than the EnKF solutions and the MODIS LAI product, which were in good agreement with the realistic LAI climatology. The developed inversion method in this paper can be applied to retrieve LAI time-continuous profiles effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2485 (2011)
Effect of Carbon Nanotubes on the Crystallization Behaviors of MC Nylon 6
QIU Shang-chang, ZHENG Yu-ying, ZENG An-ran, and GUO Yong
Multi-walled carbon nanotubes bearing hydroxyl group were modified with toluene diisocyanate (TDI) and stabilized with caprolactam. The functionalized carbon nanotubes were used to prepare monomer casting polyamide 6(MC nylon 6)/carbon nanotubes nanocomposites. The results of FTIR proved that isocynate groups have beenMulti-walled carbon nanotubes bearing hydroxyl group were modified with toluene diisocyanate (TDI) and stabilized with caprolactam. The functionalized carbon nanotubes were used to prepare monomer casting polyamide 6(MC nylon 6)/carbon nanotubes nanocomposites. The results of FTIR proved that isocynate groups have been incorporated into carbon nanotubes successfully. XRD results showed that the addition of the functionalized carbon nanotubes has no significant influence on the crystal structure of MC nylon 6, whereas the untreated carbon nanotubes could hinder the growth of α2-crystal of nylon 6; with the loading of 0.3 Wt% of the functionalized carbon nanotubes, the crystallinity degree of the nanocomposites is almost equal to that of pure MC nylon 6, whereas as the loading increased to 0.5 Wt%, the crystallinity degree of MC nylon 6 decreased. DSC revealed that carbon nanotubes in MC nylon 6 acted as effective nucleation agents. The peak temperature of crystallization for MC nylon 6 increased by 10 ℃ from 173.4 to 183.5 ℃, and the temperature range of crystallization decreased, indicating that the carbon nanotubes act as heterogeneous nucleation agents for MC nylon 6..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2491 (2011)
Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene
WANG Xin-yun, GUO Zhi-feng, QIN Wen-han, and SUN Guo-qing
It is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigated in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerful in remote sensing of heterogeneous coniIt is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigated in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerful in remote sensing of heterogeneous coniferous forests over a large-scale region. L-systems is applied to render 3-D coniferous forest scenarios, and RGM model was used to calculate BRF (bidirectional reflectance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhile at a tree and forest level, the results are also good..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2495 (2011)
Spectral Reflectance Characteristics of Different Snow and Snow-Covered Land Surface Objects and Mixed Spectrum Fitting
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The field spectroradiometer was used to measure spectra of different snow and snow-covered land surface objects in Beijing area. The result showed that for a pure snow spectrum, the snow reflectance peaks appeared from visible to 800 nm band locations; there was an obvious absorption valley of snow spectrum near 1 030 The field spectroradiometer was used to measure spectra of different snow and snow-covered land surface objects in Beijing area. The result showed that for a pure snow spectrum, the snow reflectance peaks appeared from visible to 800 nm band locations; there was an obvious absorption valley of snow spectrum near 1 030 nm wavelength. Compared with fresh snow, the reflection peaks of the old snow and melting snow showed different degrees of decline in the ranges of 300～1 300, 1 700～1 800 and 2 200～2 300 nm, the lowest was from the compacted snow and frozen ice. For the vegetation and snow mixed spectral characteristics, it was indicated that the spectral reflectance increased for the snow-covered land types (including pine leaf with snow and pine leaf on snow background), due to the influence of snow background in the range of 350～1 300 nm. However, the spectrum reflectance of mixed pixel remained a vegetation spectral characteristic. In the end, based on the spectrum analysis of snow, vegetation, and mixed snow/vegetation pixels, the mixed spectral fitting equations were established, and the results showed that there was good correlation between spectral curves by simulation fitting and observed ones (correlation coefficient R2=0.950 9)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2499 (2011)
Study of Ignition Characteristic of DC Voltage Plasma Ignitor
WANG Feng, HE Li-ming, LAN Yu-dan, and DU Hong-liang
The changing law between interelectrode current, discharge characteristic and jet characteristic of plasma ignitor under different inlet Ar pressure and working current was researched by adopting self-made plasma ignitor. Still, four channels CCD spectrometer was adopted to measure the spectrum characteristic at the exThe changing law between interelectrode current, discharge characteristic and jet characteristic of plasma ignitor under different inlet Ar pressure and working current was researched by adopting self-made plasma ignitor. Still, four channels CCD spectrometer was adopted to measure the spectrum characteristic at the exit of ignitor and electron temperature of plasma was calculated according to the spectrum characteristic.The results show that the interelectrode current gradually reduced with rising inlet Ar pressure; The jet length of plasma ignitor firstly increased then reduced with rising inlet Ar flowrate, and also increased with rising working current; The working current of plasma ignitor reduced with rising inlet Ar flowrate, and increased with rising source output current; the electron temperature of plasma ignitor jet increased with rising working current and reduced with rising Ar flowrate. The research results are of certain guidance meanings and reference values for the practical application of plasma ignition system in aeroengine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2503 (2011)
Light Absorption Characteristic of Natural Pyrite
WANG Xiu-hong, HUANG Tao, HUANG Fei, ZHANG Sheng-nan, WANG Yi, and GAO Chao
In the present paper, the natural pyrite was the sample. With the UV-visible near-infrared spectrophotometer Cary 500, we measured the absorption and reflection spectra of the sample within 200～2 000 nm range, calculated the absorption coefficient and figured out the forbidden band of the sample according to the Tauc rIn the present paper, the natural pyrite was the sample. With the UV-visible near-infrared spectrophotometer Cary 500, we measured the absorption and reflection spectra of the sample within 200～2 000 nm range, calculated the absorption coefficient and figured out the forbidden band of the sample according to the Tauc regulation. The authors discovered that the light absorption coefficient of natural pyrite measured is 105 order of magnitude; in the absorption pattern we found obvious shoulder line structure and we can judge that the sample belongs to indirect forbidden band semiconductor, its forbidden band was 0.64 eV in width and the “limit conversion efficiency” corresponding to 0.64 eV could reach 14% or so. With the comparison of the results of this paper and the forbidden band of the solar battery materials at present in common, this paper mainly analyzed the effect of the light absorption coefficient and forbidden band on the photoelectric conversion efficiency of pyrite. The authors found that its high absorption coefficient provided the possibility that pyrite will be used as solar battery with the film form, but its forbidden band was narrower than the theoretical number. The authors could broaden its forbidden band or make composite films to use..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2508 (2011)
Comparison between Myoglobin and Its Mutant(D60K) Interacting with Hydrogen Peroxide by Spectrum
ZHI Qiu-yan, TANG Qian, CAO Hong-yu, AN Liang-mei, ZHANG Ying-ying, and ZHENG Xue-fang
To characterize the roles played by surface-charged residue Asp60 in the structure stability of myoglobin when it was replaced with Lys, the interaction of myoglobin［Mb(WT)］ and its mutant［Mb(D60K)］ with hydrogen peroxide (H2O2) were studied by the method of ultraviolet-visible (UV-Vis) absorption spectroscopy, fluoresTo characterize the roles played by surface-charged residue Asp60 in the structure stability of myoglobin when it was replaced with Lys, the interaction of myoglobin［Mb(WT)］ and its mutant［Mb(D60K)］ with hydrogen peroxide (H2O2) were studied by the method of ultraviolet-visible (UV-Vis) absorption spectroscopy, fluorescence spectroscopy and stopped-flow fluorescence spectroscopy under simulative physiological conditions. There are remarkable differences between Mb(D60K) and Mb(WT) in the UV-Vis absorption spectroscopy and fluorescence spectroscopy of iron porphyrin during the process of interaction. Although we only altered one external amino acide, the data showed that the function and structure stability of Mb(D60K) was greatly changed. Furthermore, results from synchronous fluorescence spectroscopy and stopped-flow fluorescence spectroscopy all indicated that H2O2 had less effect on the structure of Mb(D60K) while the structure of Mb(WT) was notably changed. From a comprehensive and comparative data analysis, the authors determined that the structure of Mb(D60K) was improved when it interacted with H2O2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2512 (2011)
Determination of Serum Proteins by Resonance Light Scattering Method with Lidocaine as a Probe
WANG Jun-tao, SONG Shuang-ju, WU Qiu-hua, WANG Chun, and WANG Zhi
A new method for the determination of bovine serum albumin (BSA) and human serum albumin (HSA) was developed by using resonance light scattering (RLS) technique via an interaction of serum albumin with lidocaine and sodium dodecylbenzene sulphonate (SDBS). The RLS intensity of serum albumin was enhanced in the presenceA new method for the determination of bovine serum albumin (BSA) and human serum albumin (HSA) was developed by using resonance light scattering (RLS) technique via an interaction of serum albumin with lidocaine and sodium dodecylbenzene sulphonate (SDBS). The RLS intensity of serum albumin was enhanced in the presence of lidocaine and SDBS. The influences of some experimental factors, including incubation time, addition sequence of reagents, pH values, foreign substances and the concentrations of lidocaine and SDBS, on the enhancement of the RLS intensity were investigated. Under the optimal conditions, the enhanced RLS intensities were proportional to the concentrations of serum albumin in the range of 1.0~45.0 mg·L-1 for BSA and 0.5~30.0 mg·L-1 for HSA. The method was successfully applied to the determination of real human serum samples, with the relative standard deviations of 4.9%~5.7% (n=5) and standard addition recoveries of 90%~103%. The method only involves the use of conventional fluorescence spectrometer and chemical reagents. It is simple, easy to operate and sensitive with the limit of detection of 0.14 mg·L-1. The fresh human serum samples can be directly analyzed without the need of any prior pretreatment. The method can be a good alternative of choice for the determination of BSA and HSA..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2517 (2011)
Spectroscopic Study on the Combustion Reaction Characteristics of Methylcyclohexane
LI Cong-shan, LI Ping, ZHANG Chang-hua, NIE Xiao-fei, and LI Xiang-yuan
Using a measurement system consisting of monochromators, photomultiplier tubes, piezoelectric pressure sensors and a digital oscilloscope, characteristic emissions of intermediate products OH, CH and C2 produced in the combustion reaction of methylcyclohexane were measured behind reflected shock waves in a shock tube, Using a measurement system consisting of monochromators, photomultiplier tubes, piezoelectric pressure sensors and a digital oscilloscope, characteristic emissions of intermediate products OH, CH and C2 produced in the combustion reaction of methylcyclohexane were measured behind reflected shock waves in a shock tube, and ignition delay times of methylcyclohexane/oxygen/argon were acquired. Experimental conditions cover temperatures from 1 164 to 1 566 K, pressures from 1.03 to 1.99 atm, a fuel concentration of 1.0%, and an equivalence ratio of 1.0. Combustion reaction characteristics of methylcyclohexane were obtained qualitatively by analyzing emissions from intermediate products OH, CH and C2. The measured ignition delay times agree with available experimental data and the prediction of a combustion reaction mechanism. Current work provides experimental data for constructing and validating the combustion reaction mechanism of methylcyclohexane..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2521 (2011)
Research on Spectral Characteristics of Yb3+ Doped Double-Cladding Large-Mode-Area Micro-Structured Optical Fiber
LIU Zhuo-qun, ZHOU Gui-yao, XIA Chang-ming, and HOU Lan-tian
Yb3+ doped double-cladding large-mode-area micro-structured optical fibers (Micro-structured fibers, MSF) are the ideal medium for the super high-power optical fiber laser applications. In the present paper, the authors fabricated the Yb3+ doped silica-based glass using the method of non-chemical vapor deposition, and Yb3+ doped double-cladding large-mode-area micro-structured optical fibers (Micro-structured fibers, MSF) are the ideal medium for the super high-power optical fiber laser applications. In the present paper, the authors fabricated the Yb3+ doped silica-based glass using the method of non-chemical vapor deposition, and fabricated the Yb3+ doped double-cladding large-mode-area MSF by stack-drawing method using this glass as the core of MSF, according to the design requirements. Fluorescence spectrum of the MSF was obtained using Ti: sapphire femtosecond laser with the wavelength of 975 nm and LD laser with the wavelength of 980 nm as pumping source. The experimental results show that the optical fiber has strong fluorescence at the wavelength of 1 050 nm, and it can inhibit generation of cooperative luminescence effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2525 (2011)
Preparation and Catalytic Activity of Surface-Modification CNTs/TiO2 Composite Photocatalysts
WANG Huan-ying, LI Wen-jun, CHANG Zhi-dong, ZHOU Hua-lei, and GUO Hui-chao
A novel kind of carbon nanotubes/titanium dioxide (CNTs/TiO2) composite photocatalyst was prepared by a modified sol-gel method in which the nanoscaled TiO2 particles were uniformly deposited on the CNTs modified with poly(vinyl pyrrolidone) (PVP). The composites were characterized by a range of analytical techniques iA novel kind of carbon nanotubes/titanium dioxide (CNTs/TiO2) composite photocatalyst was prepared by a modified sol-gel method in which the nanoscaled TiO2 particles were uniformly deposited on the CNTs modified with poly(vinyl pyrrolidone) (PVP). The composites were characterized by a range of analytical techniques including high resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show the successful covering of the CNTs with PVP, forming core-shell structure. The nanoscaled TiO2 particles were uniformly deposited on the surface of CNTs reducing the bare CNTs which avoid losing the absorption and scattering of photons. The combination of CNTs and TiO2 particles imply the enhanced interactions between the CNTs and TiO2 interface which possibly becomes heterojunction. The composites become mesoporous crystalline TiO2 (anatase) clusters after annealing at 500 ℃, and the surface area increases obviously. The photocatalytic activities of surface modification CNTs/TiO2 (smCNTs/TiO2) composites are extremely enhanced from the results of the photodegradation of methylene blue (MB)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2529 (2011)
Study on the Distribution of Plasma Parameters in Electrodeless Lamp Using Emission Spectrometry
WANG Chang-quan, ZHANG Gui-xin, WANG Xin-xin, SHAO Ming-song, DONG Jin-yang, and WANG Zan-ji
Electrodeless lamp in pear shape was ignited using inductively coupled discharge setup and Ar-Hg mixtures as working gas. The changes in electronic temperature and density with axial and radial positions at 5 s of igniting were studied by means of emission spectrometry. The changes in electronic temperature were obtainElectrodeless lamp in pear shape was ignited using inductively coupled discharge setup and Ar-Hg mixtures as working gas. The changes in electronic temperature and density with axial and radial positions at 5 s of igniting were studied by means of emission spectrometry. The changes in electronic temperature were obtained according to the Ar line intensity ratio of 425.9 nm/750.4 nm. And the variations in electronic density were analyzed using 750.4 nm line intensity. It was found that plasma electronic temperature and density is various at different axial or radial positions. The electronic temperatures first increase, then decrease, and then increase quickly, and finally decline. While the electronic density firstly increase quickly, the decrease, and then rise slowly and finally decline again with axial distance increasing. With radial distance increasing, electronic temperature increases to a stable area, then continues to rise, while electronic density decreases..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2533 (2011)
A Real-Time Determination Method with Laser Measurement for Depth Profile Analysis of GD-OES
WAN Zhen-zhen, LI Xiao-jia, WANG Yong-qing, SHI Ning, and SUN Rong-xia
This paper presents the traditional methods of GD depth analysis method and also its limitations, and the earlier studies of real-time depth measurement technology. A new method of real-time depth determination by laser technology for GD-OES depth analysis is proposed. The real-time depth measurement system is composedThis paper presents the traditional methods of GD depth analysis method and also its limitations, and the earlier studies of real-time depth measurement technology. A new method of real-time depth determination by laser technology for GD-OES depth analysis is proposed. The real-time depth measurement system is composed of laser displacement sensor and new designed Grimm-type GD source based on laser measurement method, and the system design and technical principles are described in detail. Sputtering depth measurement signal and element spectrum signal can be synchronously collected by this system. The displacement phenomenon of glow discharge source during real-time sputtering depth measurement process is analyzed. The real-time sputtering depth measurement curve of zinc alloy standard sample was tested by two laser displacement sensors measurement system. The actual value of sputtering depth was obtained by adding the depth measurement curve of sputtering surface and the reference plane curve, and the actual depth result is in line with Dektak8-type surface profilometer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2536 (2011)
Plasma Spectral Analysis of Laser Cleaning Process in Air
TONG Yan-qun, ZHANG Yong-kang, YAO Hong-bing, MENG Chun-mei, and GUAN Hai-bing
It is quick and accurate to on-line monitor the sample condition of laser cleaning by means of laser-induced plasma spectrum in air. In the present article, the echelle grating spectrometer was used to detect the plasma spectral lines induced by pulsed laser interaction with copper coin samples with or without contaminIt is quick and accurate to on-line monitor the sample condition of laser cleaning by means of laser-induced plasma spectrum in air. In the present article, the echelle grating spectrometer was used to detect the plasma spectral lines induced by pulsed laser interaction with copper coin samples with or without contamination. The spectrogram showed that there were clear CuⅠ spectrum lines and air atom spectrum lines of NⅠand OⅠ. In order to eliminate the uncertainty of single measurement, the statistical regularity of NⅠand OⅠspectrum lines was analyzed. Their intensity distribution laws were consistent and their relative standard deviations were the same basically. So a single measurement spectrum could be used to monitor cleaning process. The spectra of copper samples with contamination consisted of many elements atomic spectral lines and continuous spectral lines. But there are CuⅠ spectral lines in the spectra of clean copper samples. As a result, the authors could detect the change of spectral lines to judge whether the laser cleaning samples were clean..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2542 (2011)
Quantitative Analysis of Mn， Cr in Steel Based on Laser-Induced Breakdown Spectroscopy
WANG Qi, CHEN Xing-long, YU Rong-hua, XU Ming-ming, YANG Yang, WU Bian, NI Zhi-bo, and DONG Feng-zhong
Quantitative analysis of trace elements such as manganese and chromium in steel was performed employing laser-induced breakdown spectroscopy (LIBS) technique in the present paper. The experimental measurements indicate that the optimal delay, focal plane and detecting position from the sample surface are 2 μs, -3.5 mm Quantitative analysis of trace elements such as manganese and chromium in steel was performed employing laser-induced breakdown spectroscopy (LIBS) technique in the present paper. The experimental measurements indicate that the optimal delay, focal plane and detecting position from the sample surface are 2 μs, -3.5 mm and 1.5 mm，respectively. Mn Ⅰ: 403.07 nm and Cr Ⅰ: 427.48 nm were selected as the analytical lines and their contents in the target steel sample were analyzed with traditional quantitative analysis and internal standard methods. Comparison of the results with two kinds of quantitatively analytical methods show that the coefficients of determination gained by internal standard method are 0.998 and 0.979 which are much better than the results obtained by traditional quantitative analysis method. According to the established calibration curve by internal standard method the detection limits of manganese and chromium calculated are 0.005% and 0.040 6%, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2546 (2011)
Study on of Deferrization Mechanism of Apoferritin and the Effect of Spectra Variation with Holoferritin
LIU Wen-ying, ZHANG Jian, TONG Jun-mao, and ZHAO Guang-hua
The deferrization mechanism of apoferritin was established, and the spectra variation of apoferritin was compared with that of holoferritin. Sodium hyposulfite is a strong reducing agent, therefore, was applied to deoxidize holoferritin to release iron ion，and connection of iron of buffer was measured by the 2,2-dipyriThe deferrization mechanism of apoferritin was established, and the spectra variation of apoferritin was compared with that of holoferritin. Sodium hyposulfite is a strong reducing agent, therefore, was applied to deoxidize holoferritin to release iron ion，and connection of iron of buffer was measured by the 2,2-dipyridyl. Apoferritin was detected by ICP-MS. Holoferritin was found to have no absorption compared with apoferritin by UV analysis, and have no fluorescence emission spectra in contrast with apoferritin by fluorescence analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2552 (2011)
Content of Nutritional Elements in Sudangrass and Ryegrass Determined by ICP-AES
LI Wen-xi, LU Jian-wei, Saman P Seneweera, WU Ji, CHEN Fang, LU Jun-ming, and LI Xiao-kun
The sudangrass (Sorghum sudanense) and ryegrass (Lolium multiflorum L.) rotation is a new type of cropping system, which has developed rapidly in recent years in the south of China. The contents of nutritional elements for forage grass in the sudangrass and ryegrass rotation system were determined by ICP-AES. The resulThe sudangrass (Sorghum sudanense) and ryegrass (Lolium multiflorum L.) rotation is a new type of cropping system, which has developed rapidly in recent years in the south of China. The contents of nutritional elements for forage grass in the sudangrass and ryegrass rotation system were determined by ICP-AES. The results showed that there were abundant and essential nutritional elements for animals in sudangrass and ryegrass. The contents of P, K, Ca, Mg, S, Fe, B, Cu, Zn and Mn for sudangrass were 0.20%～0.29%, 1.94%～2.57%, 0.62%～0.97%, 0.39%～0.69%, 0.12%～0.18%, 108.35～180.12, 3.04～5.96, 6.17～10.02, 20.37～31.36 and 46.80～101.29 mg·kg-1, respectively. The contents of P, K, Ca, Mg, S, Fe, B, Cu, Zn, Mn for ryegrass were 0.39%～0.70%, 3.77%～5.07%, 0.61%～0.84%, 0.28%～0.47%, 0.32%～0.41%, 291.65～632.20, 2.13～3.23, 13.29～15.19, 30.73～42.98 and 92.08～156.04 mg·kg-1, respectively, and there were differences between various periods in nutritional elements in the two forage grasses. The application of ICP-AES could reflect fast and efficiently the content of nutritional elements for forage grass as animals feed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2555 (2011)
Determination of Cr, Ni, Cu, Mn, P, Si, Mo and Ti in High Chromium Cast Iron by Inductively Coupled Plasma Atomic Emission Spectrometry
WANG Hui, WANG Guo-xin, XU Yu-yu, YU Lu, and YANG Peng-yuan
The high-chromium cast iron sample was microwave-assisted digested with aqueous regia in a closed vessel. Series standards were prepared with matching Fe matrix and adding Y as internal standard. Line intensities of the prepared standards and the digested sample solutions were determined by inductively coupled plasma aThe high-chromium cast iron sample was microwave-assisted digested with aqueous regia in a closed vessel. Series standards were prepared with matching Fe matrix and adding Y as internal standard. Line intensities of the prepared standards and the digested sample solutions were determined by inductively coupled plasma atomic emission spectrometry. Accuracy of the proposed method was verified by the analysis of three national standard Materials GSBH 41018, GBW 01120 and GBW 01121, and the results were well agreed with the certification data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2558 (2011)
Study of Symbolic Element in Roasting Slag of Pyrite by Inductively Coupled Plasma Mass Spectrometry
WU Ying-juan, CHEN Yong-heng, YANG Chun-xia, CHANG Xiang-yang, WANG Chun-lin, and LIANG Chun-ying
In the present paper, the correlations between sixteen elements from the dry method roasted dust-slag of pyrite and sixteen elements from the soil layer near and far from the store area were studied by ICP-MS. Similar radio and outstanding different radio of the elements between the dust-slag and the soil were studied In the present paper, the correlations between sixteen elements from the dry method roasted dust-slag of pyrite and sixteen elements from the soil layer near and far from the store area were studied by ICP-MS. Similar radio and outstanding different radio of the elements between the dust-slag and the soil were studied too. It was discovered that in the pollution soil layer Tl, Cd, Cs, Cu, Zn, Mn, Pb and Ni were easy to be identified and had similar radio with the elements in the dust-slag. But only Tl, Cd, Zn and Ni are suitable for criterion of element similar properties. In dust-slag and soil, distinct composition element radios of Tl, Cs, Co, Mo, Zn, Cr, V, Sr, Sb, Pb, Rb, Mn and Ni had striking differentiation. Only Tl, V, Sb and Cu corresponded to both the uncorrelated elements analysis of surface layer and middle-base layer soil. Tl could be used as an inspection target of similar elements and outstanding different elements between the dust-slag and the soil in the meanwhile. So we suggested that Tl can be used as a symbolic element in the roasting dust-slag of pyrite to find the dust-slag of pyrite in dust-recognition and to differentiate the metallurgy dust of pyrite and soil dust..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2561 (2011)
Determination of Metals in Waste Bag Filter of Steel Works by Microwave Digestion-Flame Atomic Absorption Spectrometry
NING Xun-an, ZHOU Yun, LIU Jing-yong, WANG Jiang-hui, LI Lei, and MA Xiao-guo
A method of microwave digestion technique-flame atomic absorption spectrometry was proposed to determine the total contents of Cu, Zn, Pb, Cd, Cr and Ni in five different kinds of waste bag filters from a steel plant. The digestion effects of the six acid systems on the heavy metals digestion were studied for the firstA method of microwave digestion technique-flame atomic absorption spectrometry was proposed to determine the total contents of Cu, Zn, Pb, Cd, Cr and Ni in five different kinds of waste bag filters from a steel plant. The digestion effects of the six acid systems on the heavy metals digestion were studied for the first time. The relative standard deviation (RSD) of the method was between 1.02% and 9.35%, and the recovery rates obtained by standard addition method ranged from 87.7% to 105.6%. The results indicated that the proposed method exhibited the advantages of simplicity, speediness, accuracy and repeatability, and it was suitable for determining the metal elements of the waste bag filter. The results also showed that different digestion systems should be used according to different waste bag filters. The waste bag filter samples from different production processes had different metal elements content. The Pb and Zn were the highest in the waste bag filters, while the Cu, Ni, Cd and Cr were relatively lower. These determination results provided the scientific data for further treatment and disposal of the waste bag filter..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2565 (2011)
XPS and SEM Spectroscopy Study of Hyperdispersant on Atrazine Surface
XU Yan, SUN Bao-li, MA Chao, ZHANG Ping, CAI Meng-ling, and WU Xue-min
The authors studied the electronic condition of comb-shaped copolymer of polycarboxylic acid type hyperdispersant adsorbed on the surface of atrazine particles with X-ray photoelectron spectroscopy (XPS). The thickness of the adsorption was calculated. The results suggested that after adsorbing the dispersant, the peakThe authors studied the electronic condition of comb-shaped copolymer of polycarboxylic acid type hyperdispersant adsorbed on the surface of atrazine particles with X-ray photoelectron spectroscopy (XPS). The thickness of the adsorption was calculated. The results suggested that after adsorbing the dispersant, the peak intensity of N(1s) and Cl(2p) of the interface of atrazine particle decreased sharply, while the absorption of Cl(2s) almost diminished. Meanwhile the peak intensity of C(1s), O(1s) and Na(1s) increased obviously owing to the second emission of C, O, and Na from the dispersant molecule. After adsorption, the dispersant formed a favorable protecting membrane on the surface of atrazine particles whose thickness was about 24 nm. The authors also studied the surface state of the sample with scanning electron microscope (SEM). The results of which showed that after adsorption, the atrazine particles became smaller and their dispersion was in good order. These changes allowed the atrazine particle to have a stable suspension property. This study provided significant information for the application of environment friendly atrazine suspension concentrate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2569 (2011)
The Influence of the Gain on Ignition and Correction in X-Ray Fluorescence Spectrometry
WANG Qian, YING Xiao-hu, and ZHANG Jian-bo
Research on the gain on ignition question for preparing ore with fusion sample preparation technique was done, and a new correction method was worked out. After fusion sample preparation, sulphide ore would have a lot of sulfate, which would change the sample matrix dramatically, and the matrix effect was corrected witResearch on the gain on ignition question for preparing ore with fusion sample preparation technique was done, and a new correction method was worked out. After fusion sample preparation, sulphide ore would have a lot of sulfate, which would change the sample matrix dramatically, and the matrix effect was corrected with errors. In this paper, a new solution to measuring gain on ignition was put forward, and it was committed step that the sample having gain on ignition was redefined by sample having loss on ignition. Through conversion, the gain on ignition was corrected by subtraction method, and the matrix effect was corrected by theoretical influence coefficients. The analysis results of redefinition samples were converted into the primal samples lastly. The project took copper concentrates as the experimental object, it was found that the gain on ignition of this method was obviously different from the gravimetric method, but through influence evaluation, this error had little effect on test results, and may be reduced by flux. After correction of the gain on ignition, the standard deviation of the elements calibration curves for Cu, Fe and S were less than 0.14%, 0.074% and 0.14% respectively, which were obviousely superior to 0.21%, 0.15% and 0.19%. The results got from this method were in satisfactory agreement with certified values..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2574 (2011)
Searching QSO Candidates and Calculating Their Redshfit from a Flood of Spectra
SONG Yi-han, LUO A-li, and ZHAO Yong-heng
In the present paper the author offers a method to search the QSO candidates and calculate their redshfit using their broad emission lines which are the most important character of quasars. It is hard to identify the lines in the quasar’s spectra due to their redshifts distributing on a broad range. Spectra contain twoIn the present paper the author offers a method to search the QSO candidates and calculate their redshfit using their broad emission lines which are the most important character of quasars. It is hard to identify the lines in the quasar’s spectra due to their redshifts distributing on a broad range. Spectra contain two components. One is continuum and the other is lines. The author uses a method of LFPS (low frequency points set) to build the continuum and detect the obvious emission lines, a method that can avoid the broad emission lines as a part of the continuum. The redshift can be calculated by comparing the extracted lines with the line table. The classification can be done with both emission lines and the redshift. For a better accurate rate to recognize the lines, this paper provides a method to estimate the level of the local noise. The method this paper used is independent of the flux calibration of the spectra. It can work for the spectra of the present LAMOST..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2578 (2011)
One Step Method to Design Concave Holographic Grating for Monochromator
ZENG Jin, Bayanheshig, LI Wen-hao, and ZHANG Jin-ping
The present paper put forward a new method, named one step method, to design concave holographic grating for a monochromator. This new method is simple and direct and easy to understand. Additionally, in this new method, we can control the whole aberrations of concave grating very well. Genetic algorithm was applied toThe present paper put forward a new method, named one step method, to design concave holographic grating for a monochromator. This new method is simple and direct and easy to understand. Additionally, in this new method, we can control the whole aberrations of concave grating very well. Genetic algorithm was applied to optimize the objective function of this new method for its strong ability to search the extremum of nonlinear functions and a comparison was made between this new method and the classical method. The result shows that, for coma correction or astigmatism correction, the imaging properties of the concave grating designed by the new method is much better than the grating designed by the classical method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2586 (2011)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 1 (2011)
Research Articles
Galaxy/Quasar Classification Based on Nearest Neighbor Method
LI Xiang-ru, LU Yu, ZHOU Jian-ming, and WANG Yong-jun
With the wide application of high-quality CCD in celestial spectrum imagery and the implementation of many large sky survey programs (e.g., Sloan Digital Sky Survey (SDSS), Two-degree-Field Galaxy Redshift Survey (2dF), Spectroscopic Survey Telescope(SST)，Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOSWith the wide application of high-quality CCD in celestial spectrum imagery and the implementation of many large sky survey programs (e.g., Sloan Digital Sky Survey (SDSS), Two-degree-Field Galaxy Redshift Survey (2dF), Spectroscopic Survey Telescope(SST)，Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) program and Large Synoptic Survey Telescope (LSST) program, etc.), celestial observational data are coming into the world like torrential rain. Therefore, to utilize them effectively and fully, research on automated processing methods for celestial data is imperative. In the present work, we investigated how to recognizing galaxies and quasars from spectra based on nearest neighbor method. Galaxies and quasars are extragalactic objects, they are far away from earth, and their spectra are usually contaminated by various noise. Therefore, it is a typical problem to recognize these two types of spectra in automatic spectra classification. Furthermore, the utilized method, nearest neighbor, is one of the most typical, classic, mature algorithms in pattern recognition and data mining, and often is used as a benchmark in developing novel algorithm. For applicability in practice, it is shown that the recognition ratio of nearest neighbor method (NN) is comparable to the best results reported in the literature based on more complicated methods, and the superiority of NN is that this method does not need to be trained, which is useful in incremental learning and parallel computation in mass spectral data processing. In conclusion, the results in this work are helpful for studying galaxies and quasars spectra classification..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 31, Issue 9, 2582 (2011)
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