Journals >Spectroscopy and Spectral Analysis
Contents
2009
Volume: 29 Issue 8
67 Article(s)
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Research Article
Gas Pipeline Leak Detection Based on Tunable Diode Laser Absorption Spectroscopy
ZHANG Qi-xing, WANG Jin-jun, LIU Bing-hai, CAI Ting-li, QIAO Li-feng, and ZHANG Yong-ming
The principle of tunable diode laser absorption spectroscopy and harmonic detection technique was introduced. An experimental device was developed by point sampling through small multi-reflection gas cell. A specific line near 1 653.7 nm was targeted for methane measurement using a distributed feedback diode laser as tThe principle of tunable diode laser absorption spectroscopy and harmonic detection technique was introduced. An experimental device was developed by point sampling through small multi-reflection gas cell. A specific line near 1 653.7 nm was targeted for methane measurement using a distributed feedback diode laser as tunable light source. The linearity between the intensity of second harmonic signal and the concentration of methane was determined. The background content of methane in air was measured. The results show that gas sensors using tunable diode lasers provide a high sensitivity and high selectivity method for city gas pipeline leak detection..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2017 (2009)
Characterizations of InP in Terahertz Region
ZHANG Cai-hong, WANG Yuan-yuan, MA Jin-long, JIN Biao-bing, XU Wei-wei, KANG Lin, CHEN Jian, and WU Pei-heng
Terahertz time-domain spectroscopy (THz-TDS), which directly measures the THz wave’s temporal electric field, can give the amplitude and phase of the THz wave pulse simultaneously. THz-TDS is attracting more attention among scientists. InP with short carrier average collision time and low effective mass is growing up aTerahertz time-domain spectroscopy (THz-TDS), which directly measures the THz wave’s temporal electric field, can give the amplitude and phase of the THz wave pulse simultaneously. THz-TDS is attracting more attention among scientists. InP with short carrier average collision time and low effective mass is growing up as one of the best photoconductive materials for emitting and detecting THz waves. An n-type InP of 0.35 Ω·cm was characterized over the range from 0.2 to 4 THz at room temperature in the present paper with THz time-domain spectroscopy, which was placed in a closed box purged with dry nitrogen gas. Some THz optical properties, such as complex refractive index, dielectric constant, and conductivity, were extracted, based on more exact iterative method with new initial function. Drude model was also applied for simulation, which fitted well with the experimental results. Finally, the carrier average collision time, density and mobility of the InP were also characterized..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2021 (2009)
Impact of Laser Energy on Measurement of Fly Ash Carbon Content
YAO Shun-chun, LU Ji-dong, XIE Cheng-li, LI Jie, PAN Sheng-hua, and HE Ze-xiong
A laser induced breakdown spectroscopy-based apparatus for the analysis of element, employing a 532 nm laser and a multi-channel optical spectrometer with a non-intensified CCD array, has been built and tested. It was applied to analyze the carbon content of coal fly ash. Seven groups of pulse laser in the range of 35 A laser induced breakdown spectroscopy-based apparatus for the analysis of element, employing a 532 nm laser and a multi-channel optical spectrometer with a non-intensified CCD array, has been built and tested. It was applied to analyze the carbon content of coal fly ash. Seven groups of pulse laser in the range of 35 to 98 mJ were used to ablate the fly ash samples. The electron densities and plasma temperatures with different laser energy were determined, and the influence of laser energy on the intensity of analysis carbon lines was also analyzed. The results show that carbon line intensity increases slowly with the increase in laser energy in the range of 35 to 46 mJ, and increases fast in the range of 46 to 78 mJ, then trends to saturation and has a little drop. At the same time, air breakdown has increased significantly, and has an obvious effect on sample plasma. Furthermore, the electron density and plasma temperature increase with the laser energy until 78 mJ and then begin to decrease. It indicates that a proper laser energy can enhance the plasma emission signal, and avoid the negative impact of air breakdown that prevent the pulse laser from reaching the surface of sample and ablating it. In this experiment situation, the measurement accuracy of the carbon line can be improved..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2025 (2009)
Tunable Fiber Laser Based Photoacoustic Spectroscopy for Acetylene Detection
PENG Yong, and YU Qing-xu
An acetylene detection system has been constructed with a tunable erbium-doped fiber laser (TEDFL) based photoacoustic spectrometer. Combining wavelength modulation and second harmonic signal detection technique, the system is able to effectively eliminate the background noise generated by absorption of the cell windowAn acetylene detection system has been constructed with a tunable erbium-doped fiber laser (TEDFL) based photoacoustic spectrometer. Combining wavelength modulation and second harmonic signal detection technique, the system is able to effectively eliminate the background noise generated by absorption of the cell windows and the wall of the acoustic resonator. The system was applied to low concentration acetylene flowing measurement, through optimizing the systemic optics, acoustics and electron detection technique condition. The experimental results show that the second harmonic amplitude is directly proportional to gas concentration. Their linear pertinence coefficient is 0.999 53. The system sensitivity limit for acetylene detection is 0.3 ppm under atmosphere pressure with 100 ms time constant and 3.5 mW average optical power. The TEDFL was used as light source in stead of the DFB diode laser which is relatively costly. The system appears promising as a basis for developing cheap, practical, portable spectroscopy instruments for trace gas detection. The detection sensitivity could be greatly improved by using multi-path cell or increasing the laser power with EDFA..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2030 (2009)
Absorption Spectrum Study of HeLa Cells Treated with Vacuum and Low-Energy Ions Implantation
ZHANG Feng-qiu, ZHAO Yuan-li, GE Xiang-hong, LIU Wei, ZHANG Guang-shui, and QIN Guang-yong
Mineral oil was selected to protect HeLa cells from water evaporation during low-energy ions implantation in the present paper. Then, HeLa cells having been treated with vacuum and low-energy N+ ions implantation were used to collect ultraviolet absorption spectrum by spectrophotometer. Analytical results indicated thaMineral oil was selected to protect HeLa cells from water evaporation during low-energy ions implantation in the present paper. Then, HeLa cells having been treated with vacuum and low-energy N+ ions implantation were used to collect ultraviolet absorption spectrum by spectrophotometer. Analytical results indicated that HeLa cells had some characteristic absorption peaks near 202 and 260 nm, respectively. And then the study also found: (1) The spectral intensity increased with the vacuum treatment time. In addition, the effect of vacuum on cellular spectrum was greater than that of mineral oil. (2) The influence of low energy N+ ions on absorption spectrum was far more than that of vacuum. (3) The spectral intensity increased with the implantation dose. According to these results, the effect of low-energy N+ ions implantation and vacuum on tumorous cells (HeLa cells), especially on the molecular configuration and component of tumorous cells (HeLa cells) was discussed. In a word, this study provides a basis for further research on the functionary mechanism of low-energy ions implantation on biomaterial..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2034 (2009)
Collisional Energy Transfer between Excited Rb Atoms
WU Hong-ping, GUO Qi-cun, DAI Kang, and SHEN Yi-fan
Energy pooling (EP) was observed in Rb vapor following pulsed optical excitation to the5P1/2 state. The 5P3/2 state was populated by the energy transfer process: Rb(5P1/2)+Rb(5S1/2)→Rb(5P3/2)+Rb(5S1/2). The resulting densities of Rb atoms at the 5P1/2 level were obtained from the absorption of narrow spectral line fromEnergy pooling (EP) was observed in Rb vapor following pulsed optical excitation to the5P1/2 state. The 5P3/2 state was populated by the energy transfer process: Rb(5P1/2)+Rb(5S1/2)→Rb(5P3/2)+Rb(5S1/2). The resulting densities of Rb atoms at the 5P1/2 level were obtained from the absorption of narrow spectral line from a Rb hollow cathode lamp, connecting the 5P1/2 state to 7S state. Since the effective lifetimes of the 5P1/2 and 5P3/2 states are approximately equal, the densities of the 5P3/2 level were obtained from the D2 to D1 fluorescence ratios where D1 and D2 are lines of the 5P1/2→5S1/2 and 5P3/2→5S1/2transition. Because the time of the fine structure exchanging is much shorter than the lifetime of the 5D state, the fluorescence originating from the 5D state produced by the 5P1/2+5P3/2 and 5P3/2+5P3/2 processes follows the instantaneous production rate of the 5P1/2+5P1/2 process. It is clear that 5P1/2+5P3/2 and 5P3/2+5P3/2 collisions can significantly influence the results obtained for the 5P1/2+5P1/2 rate since the energy defect for 5D state is much smaller for 5P1/2+5P3/2 and 5P3/2+5P3/2 collisions than for 5P1/2+5P1/2 collisions. Effective lifetimes of the 5P levels were calculated using radiation trapping theory. The time-integrated populations and signals were studied and analyzed. The resulting fluorescence included the direct component emitted in the decay of the optically excited 5P1/2 state and the sensitized component arising from the collisions for populating 5D state at different cell temperature. These relative intensities were combined with the measured excited atom densities to yield absolute energy-pooling rate coefficients. The cross sections (in units of 10-14 cm2) for the energy-pooling collisions ［i.e., 5P1/2+5P1/2， 5P1/2+5P3/2， 5P3/2+5P3/2］ are 0.78, 2.9 and 3.1, respectively. The dependence of the rates upon energy defect ΔＥ was examined, but the 5D3/2 level was approximately equally populated in 5P3/2+5P3/2(ΔＥ=68 cm-1) and 5P3/2+5P1/2(ΔＥ=306 cm-1) collisions. The 5P1/2+5P3/2 collisions are as efficient as 5P3/2+5P3/2 for populating 5D3/2 state..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2038 (2009)
Reactive and Nonreactive Energy Transfer in Cs(6DJ)+(H2, He) Collisions
WAN Hong-fei, ZHANG Yan-wen, CUI Xiu-hua, DAI Kang, GUO Qi-cun, and SHEN Yi-fan
Cs vapor, mixed with a gas was irradiated in a glass fluorescence cell with pulses of 886nm radiation from a YAG-laser-pumped OPO laser, populating 6D3/2 state by two-photon absorption. Cross sections for 6D3/2→6D5/2 transition induced by collisions with various He atoms and H2 molecules were determined using methods oCs vapor, mixed with a gas was irradiated in a glass fluorescence cell with pulses of 886nm radiation from a YAG-laser-pumped OPO laser, populating 6D3/2 state by two-photon absorption. Cross sections for 6D3/2→6D5/2 transition induced by collisions with various He atoms and H2 molecules were determined using methods of atomic fluorescence. The resulting fluorescence included a direct component emitted in the decay of the optically excited state and a sensitized component arising from the collisionally populated state. At the different densities, we have measured the relative time-integrated intensities of the components and fitted a three-state rate equation model to obtain the cross sections for 6D3/2→6D5/2transfer: σ=(55±13)×10-16 and (16±4)×10-16 cm2 for H2 and He, respectively. The cross sections for the effective quenching of the 6D5/2 state were also determined. The total transfer rate coefficients from the 6D5/2 state for He is small ［1.2×10-10 cm3·s-1］. The total quenching rate coefficient of the 6D5/2 state is larger for H2［6.7×10-10 cm3·s-1］. For H2 case, the quenching rate coefficient corresponds to reaction and nonreactive energy transfer. Evidence suggests that the nonreactive energy transfer rate coefficient is ［6.3×10-10 cm3·s-1］. Hence the authors estimated the cross section (2.0±0.8)×10-16 cm2 for reactive process Cs(6D5/2)+H2→CsH+H. Using the dependence on the pressure of H2（or He）of the integrated fluorescence monitored at the 6D5/2→6P3/2 transition the cross section (4.0±1.6)×10-16 cm2 for Cs(6D3/2)+H2→CsH+H was obtained. Thus, the relative reactivity with H2 follows an order of Cs(6D3/2)>Cs(6D5/2)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2042 (2009)
Influence of Fluorescent Dye Ultrathin Layer on Luminescence Spectra in Organic Light-Emitting Diodes
YU Jun-sheng, LI Lu, WEN Wen, LI Wei-zhi, and JIANG Ya-dong
By using an ultrathin dopant dye layer deposited on the top of host materials, the influence of concentration of three fluorescent dyes, dimethylquinacridone (DMQA), 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), and 5,6,11,12-tetraphenylnaphthacene (rubrene), on the luminescenBy using an ultrathin dopant dye layer deposited on the top of host materials, the influence of concentration of three fluorescent dyes, dimethylquinacridone (DMQA), 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), and 5,6,11,12-tetraphenylnaphthacene (rubrene), on the luminescence spectra of OLEDs was studied. The characteristic of the brightness-efficiency-bias voltage performance was investigated. The results showed that compared to the conventional doping devices, the devices consisting of ultrathin dye layer exhibited a weak peak originating from host matrix, and the more obvious concentration quenching was existent. The degree of concentration quenching for the three ultrathin doping dyes from high to low is in the order of DMQA, DCJTB and rubrene. Meanwhile, the authors used the photoluminescence spectra of these three dopants dilute solution to testify the relationship between EL properties of OLEDs and concentration quenching of these dyes..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2046 (2009)
Luminescence Dynamics Analysis on Ruthenium Polypyridyl Complexes Bonding to DNA
ZHU Wei-ling, LIU Xue-wen, WANG Hui, ZHENG Kang-cheng, and JI Liang-nian
Time-resolved spectra of six kinds of ruthenium polypyridyl complexes ［Ru(L)2(R)］2+（L=bpy， phen， bpy=2,2’-bipyridine, phen=1,10-phenanthroline， R=7-CH3-dppz， 7-F-dppz， dpbpd(NH2)2） bonding to calf thymus DNA in aqueous solution were compared and analyzed by using the three energy level kinetic model. And the effects ofTime-resolved spectra of six kinds of ruthenium polypyridyl complexes ［Ru(L)2(R)］2+（L=bpy， phen， bpy=2,2’-bipyridine, phen=1,10-phenanthroline， R=7-CH3-dppz， 7-F-dppz， dpbpd(NH2)2） bonding to calf thymus DNA in aqueous solution were compared and analyzed by using the three energy level kinetic model. And the effects of the substituent groups on the interaction ways for the ruthenium complexes bonding to DNA were discussed. The result shows that first, the six complexes all show two binding modes on bonding to DNA, i.e. the side-on binding mode and the perpendicular binding mode, and the later one is considered as a main binding way. Second, the properties of substituent groups have an important impact on the relative weight of the two binding modes. The conclusion offers a dynamics argument to study the interaction mechanism for the complex bonding to DNA further..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2050 (2009)
Detecting the Information of Cucumber in Greenhouse for Picking Based on NIR Image
YUAN Ting, XU Chen-guang, REN Yong-xin, FENG Qing-chun, TAN Yu-zhi, and LI Wei
For the cucumber harvesting robot, the identification of target information is one of important tasks in the automation of fruit-picking. In order to implement spatial fruit localization and quality discrimination in greenhouse, this paper presented a machine vision algorithm for the recognition and detection of cucumbFor the cucumber harvesting robot, the identification of target information is one of important tasks in the automation of fruit-picking. In order to implement spatial fruit localization and quality discrimination in greenhouse, this paper presented a machine vision algorithm for the recognition and detection of cucumber fruits based on near-infrared spectral imaging. By comparing the spectral reflectance of cucumber plant (fruit, leaf and stem) from visible to infrared region (325-1 075 nm) measured by ASD FieldSpec Pro VNIR spectrometer, a monospectral near-infrared image at the 850 nm sensitive wavelength was captured to cope with the similar-color segmentation problem in complex environment. Then, a method of fruit extraction was developed on the basis of the following steps. Firstly, from the gray level histogram it was observed that the pixels of fruit distributed on the right are lesser than that of background, so “P parameter threshold method” was used to image segmentation. Subsequently, divided local image was partitioned into several sub-blocks by the application of adaptive template mining, which was feasible for processing the fruit with long-column feature. Finally, noises including parts of stem and leaf were eliminated using estimation condition of barycentre position and area size, proved by relative experiment. In addition, the region for robotic grasping was established by gray variation between fruit-handle and fruit pedicel, as the quality feature was extracted with morphological characteristics of the centre-line length and the fruit flexure degree. A detecting experiment was carried out on 30 images with cucumber fruits and 10 images with no fruits, which were taken in a changing greenhouse environment. The results indicate that the accuracy rate of the recognition was 83.3% and 100%, while the success rate of effectively acquiring the grasping region was 83.3%, which can meet the demand of robotic fruit-harvesting..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2054 (2009)
Study on Denoising Near Infrared Spectra of Wood Based on Wavelet Transform
WANG Xue-shun, QI Da-wei, and HUANG An-min
Near infrared (NIR) spectra of wood samples are often confused by a series of noise, which greatly influences accurate analytical result. In order to improve analytical precision, the authors need to pretreat the spectrum data. Derivative can correct baseline and background effects, increasing the resolution ratio of tNear infrared (NIR) spectra of wood samples are often confused by a series of noise, which greatly influences accurate analytical result. In order to improve analytical precision, the authors need to pretreat the spectrum data. Derivative can correct baseline and background effects, increasing the resolution ratio of the spectra. However, it also increases the noise at the same time. The present paper aims at using wavelet transform to eliminate the noise of the near infrared first derivative spectrum of wood with the methods of 9 point smoothing spectrum, 25 point smoothing spectrum, the nonlinear wavelet hard-threshold spectrum, the nonlinear wavelet soft-threshold spectrum, 9 point smoothing+wavelet transform and 25 point smoothing spectrum+wavelet transform. The results show that the wavelet transform has particular advantage on noise elimination of the near infrared spectra while reserving the useful information of spectrum. It can also improve the signal to noise ratio of spectrum, promising the prospect of a wide application in the wood near infrared spectroscopic analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2059 (2009)
Egg Quality Prediction by Using Fourier Transform Near Infrared Reflectance Spectroscopy (FT-NIR)
HOU Zhuo-cheng, YANG Ning, LI Jun-ying, and XU Gui-yun
The objective of the present study is to investigate the feasibility of using FT-NIR to determine egg quality: egg albumen height (EAH); Haugh unit (HU); air cell height (ACH); air cell diameter (ACD); egg shape index (ESI) and egg weight (EW). All eggs were stored in the same environment with 16 ℃ and 75% relative humThe objective of the present study is to investigate the feasibility of using FT-NIR to determine egg quality: egg albumen height (EAH); Haugh unit (HU); air cell height (ACH); air cell diameter (ACD); egg shape index (ESI) and egg weight (EW). All eggs were stored in the same environment with 16 ℃ and 75% relative humidity after collection. Calibrations were developed using a leave-one-out cross validation procedure under partial least-squares regression. The different optimal parameter comparisons showed that Savitzky-Golay filter method and second derivatives can give the best calibration for all the measured values. The partial least-square analysis showed that R2 of the EAH, ACD and ACH are 0.867, 0.821 and 0.865, respectively. The RMSECV values are 0.476, 0.014 and 0.479 for EAH, ACD and ACH, respectively. The correlation coefficients of external-validation for 33 eggs are 0.873, 0.861 and 0.895 for EAH, ACD and ACH, respectively. The external-validation results are not significant different from actual measurements (P＞0.05) for EAH, ACD and ACH. All models cannot give the reasonable results for EW, ESI and HU. As the HU cannot be measured correctly by using FT-NIR and also is highly correlated with EAH, the authors suggested the possibility to revise the currently used measurement standard. Our results showed that FT-NIR could be used to test the egg albumen height, air cell height and air cell diameter..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2063 (2009)
FTIR and XRD Analysis Studies of Intercalation of Kaolinite with Benzamide
ZHANG Sheng-hui, QIANG Ying-huai, OU Xue-mei, and XIA Hua
Benzamide was intercalated into kaolinite by replacing DMSO pre-intercalated. Pure kaolinite-benzamide intercalation compounds were obtained by washing resulting products with acetone. The analysis of XRD shows that the basal spacing of kaolinite-benzamide intercalation compounds increased to 1.437 nm from 0.717 nm of Benzamide was intercalated into kaolinite by replacing DMSO pre-intercalated. Pure kaolinite-benzamide intercalation compounds were obtained by washing resulting products with acetone. The analysis of XRD shows that the basal spacing of kaolinite-benzamide intercalation compounds increased to 1.437 nm from 0.717 nm of kaolinite. The analysis of FTIR shows that intercalation caused the shifts of the inner surface OH stretching bands from 3 696 and 3 657 cm-1 of the raw kaolinite to 3 701 and 3 651 cm-1 of the kaolinite-benzamide intercalation compounds, respectively, and the blue shift of CO stretching bands from 1 659 cm-1 of benzamdie to 1 640 cm-1 of the kaolinite-benzamide intercalation compounds, and the NH vibrations at 3 368 and 3 172 cm-1 of benzamdie shifted to 3 474 and 3 184 cm-1, respectively. These changes in IR bands implied the breaking of the H-bonds between layers of kaolinite and the formation of new H-bonds between the inner-surface hydroxyls of the kaolinite and the benzamide in the intercalation compounds. The experimental results show that the intercalation reaction comes to equilibrium rapidly during 30 min, and the highest intercalation ratio occurs when the reaction temperature is 180 ℃. Washed by acetone, the residual benzamide and that adsorbed on the surface of the resulting products could be eliminated without significant influence on the structure of the intercalation compounds..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2067 (2009)
Research on Static Fourier Interferometer in Target Identification
LI Jing, and HUANG Zheng
A new method was proposed for target identification with static Fourier interferometer. Considering the complex structure of mechanical scanning interferometer and the poor stability of identification, a remote detection technique for target identification based on the static spectrum analysis is proposed. Using the stA new method was proposed for target identification with static Fourier interferometer. Considering the complex structure of mechanical scanning interferometer and the poor stability of identification, a remote detection technique for target identification based on the static spectrum analysis is proposed. Using the static scanning technique to replace mechanical scanning of optical path and applying spectrum analysis method to analyze the interference fringes, the target identification in the bad environment in the wide range field of view was realized. By the simulation computation, the present work obtained the spectroradiometric function with temperature, wavelength and the air transmittance as the parameters, and got the characteristic of data from difference background radiation. The spectrum D-value function shows the energy of the spectrum in different situation. Performing experiments with the AViiVA-M2 CCD camera, Static Fourier Interferometer, and 1 m×1 m iron-sheet as the target separately at different time in one day, with different probing range, and under different background condition, the limited distance in each situation was obtained by the system. According to the result of experiment and spectrum data analysis, the target identification mothod with difference spectrum is feasible, and the average probability of detection is 92.8%..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2071 (2009)
Determination of Soil Quality from Chinese Apple Plant Area by NIR Spectroscopy
DONG Yi-wei, HUANG Jin-li, SUN Bao-li, BAI Wei, FAN Zhong-nan, WANG Ya-nan, LIU Ya-wei, and TONG Cheng-feng
In the present work, 111 soil samples from 11 different Chinese apple plant areas were used to take the diffuse reflection spectra from 12 500 to 4 000 cm-1 by FT-NIR. The models of organic substance and pH value of soil samples were built by using partial least square regression (PLSR). The calibration model gave the In the present work, 111 soil samples from 11 different Chinese apple plant areas were used to take the diffuse reflection spectra from 12 500 to 4 000 cm-1 by FT-NIR. The models of organic substance and pH value of soil samples were built by using partial least square regression (PLSR). The calibration model gave the correlation coefficients of 0.818 and 0.836 for the two values respectively, with the root mean square error of prediction (RMSEP) of 0.377 (%) and 0.251, respectively. In order to improve the robustness and performance of calibration, several spectra preprocessing methods were employed, including standard normalized variate (SNV), multiplicative scatter correction (MSC) and direct orthogonal signal correction (DOSC). Finally, the performance of DOSC was found to be the best for organic substance and pH value with RMSEP of 0.258(%) and 0.248, respectively. The results showed that the technology of NIR spectroscopy was useful to nondestructive determination of the organic substance and pH value of soil. These research findings provide theoretic base for fertilization and pomiculture by means of NIR diffuse reflection..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2075 (2009)
Detection of Fatty Acid Composition in Intramuscular Fat of Packed Pork Loin by Near Infrared Spectroscopy
HU Yao-hua, GUO Kang-quan, NOGUCHI Gou, and SATAKE Takaaki
Near infrared spectroscopy as a new method was proposed for rapid and non-destructive measurement of fatty acid composition in intramuscular fat of packed pork loin. Gas chromatography was used as a reference method for the spectral analysis of fatty acid composition. The fiber optic in interactance mode was adopted toNear infrared spectroscopy as a new method was proposed for rapid and non-destructive measurement of fatty acid composition in intramuscular fat of packed pork loin. Gas chromatography was used as a reference method for the spectral analysis of fatty acid composition. The fiber optic in interactance mode was adopted to measure the spectra of packed pork loins by low density polythene. The original spectra were pretreated by smoothing and 2nd derivative， and then PLS calibration model was builtby using software of Unscrambler 9.6. A total of eighty two samples were used in the experiment. The samples were divided into calibration set and validation set after removing the outliers. The calibration set was used to set up calibration model and then the model was adopted to predict the samples of validation set. The results show that the correlation coefficient for C14∶0， C15∶1， C16∶0， C16∶1， C18∶0， C18∶1， C18∶2， C18∶3， C20∶1， C20∶4， SFA， MUFA， PUFA is 0.57， 0.76， 0.71， 0.77， 0.62， 0.81， 0.86， 0.91， 0.85， 0.91， 0.67， 0.81 and 0.95, respectively. It means that evaluating fatty acid using near infrared spectroscopy in interactance mode has higher precision. Near infrared spectroscopy technique is a feasible and rapid method for nondestructive detection of fatty acid composition in intramuscular fat of packed pork loin..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2079 (2009)
Detection of the Main Quality Indicators in Red Wine with Infrared Spectroscopy Based on FastICA and Neural Network
FANG Li-min, and LIN Min
For the rapid detection of the ethanol, pH and rest sugar in red wine, infrared (IR) spectra of 44 wine samples were analyzed. The algorithm of fast independent component analysis (FastICA) was used to decompose the data of IR spectra, and their independent components and the mixing matrix were obtained. Then, the ICA-For the rapid detection of the ethanol, pH and rest sugar in red wine, infrared (IR) spectra of 44 wine samples were analyzed. The algorithm of fast independent component analysis (FastICA) was used to decompose the data of IR spectra, and their independent components and the mixing matrix were obtained. Then, the ICA-NNR calibration model with three-level artificial neural network (ANN) structure was built by using back-propagation (BP) algorithm. The models were used to estimate the contents of ethanol, pH and rest sugar in red wine samples for both in calibration set and predicted set. Correlation coefficient (r) of prediction and root mean square error of prediction (RMSEP) were used as the evaluation indexes. The results indicate that the r and RMSEP for the prediction of ethanol content, pH and rest sugar content are 0.953, 0.983 and 0.994, and 0.161, 0.017 and 0.181, respectively. The maximum relative deviations between the ICA-NNR method predicted value and referenced value of the 22 samples in predicted set are less than 4%. The results of this paper provide a foundation for the application and further development of IR on-line red wine analyzer..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2083 (2009)
Exploratory Research on Quantitative Analysis of Gaseous Mixtures by AOTF-NIR Spectrometer
HAO Hui-min, CAO Jian-an, YU Zhi-qiang, Ken Jia, and LIU Jun-hua
Due to its many advantages, such as miniaturization, high accuracy, high resolution, fast scanning speed, increased robustness and good stability, acousto-optic tunable filter (AOTF)-near infrared (NIR) spectrometer has been successfully applied in many fields. However, up to now, the commercial AOTF-NIR spectrometers Due to its many advantages, such as miniaturization, high accuracy, high resolution, fast scanning speed, increased robustness and good stability, acousto-optic tunable filter (AOTF)-near infrared (NIR) spectrometer has been successfully applied in many fields. However, up to now, the commercial AOTF-NIR spectrometers can only be used for liquid and solid detection, but not for the detection of gaseous samples. In the present paper, the feasibility of quantitative analysis of gaseous mixtures by using AOTF-NIR spectrometer was investigated. A homemade gas cell was assembled to an AOTF-NIR spectrometer with probe for liquid detection to obtain NIR spectra of detected gas samples. The gas samples were composed of two groups: single-component CH4 and ternary component gaseous mixture of CH4, C2H6, and C3H8. The detection ability of fitted AOTF-NIR spectrometer was tested firstly. Comparing the absorption spectra of various concentrations, the absorbance of CH4 in absorption bands obviously increased with concentration increasing when the concentration was over 0.1%. According to the detection results, the lower limit of detection (LLD) of the AOTF-NIR spectrometer with gas cell was estimated to be 898 μL·L-1. Subsequently, the NIR spectra of ternary mixtures were collected. The kernel partial least squares (KPLS) regression was employed to create the quantitative analysis model of three components gases. To evaluate the analysis ability of KPLS model, the PLS model was also created. The prediction results of the identical testing set show that the root mean square error of prediction (RMSEP) of three components predicted by KPLS model was 1.08%, 0.87%, and 0.79%, respectively, less than the RMSEP by PLS model. The exploratory work indicates that accurate quantitative analysis of ternary component alkane gaseous mixtures can be achieved by fitted AOTF-NIR spectrometer despite of some limitations, and KPLS regression is an excellent approach to NIR spectra analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2087 (2009)
Common and Variant Peak Ratios in IR Fingerprint of Cacumen Platycladi with Dual-Index Sequence Analysis
SHAN Ming-qiu, YAO Xiao-dong, CHI Yu-mei, ZHANG Li, and DING An-wei
To establish a new method to analyze IR fingerprint， which is in line with the characteristic of traditional Chinese medicine, two indexes， common peak ratio and variant peak ratio， were applied and their values were calculated by means of sequential analysis， in which each Cacumen platycladi sample’s IR fingerprint spTo establish a new method to analyze IR fingerprint， which is in line with the characteristic of traditional Chinese medicine, two indexes， common peak ratio and variant peak ratio， were applied and their values were calculated by means of sequential analysis， in which each Cacumen platycladi sample’s IR fingerprint spectra were set up and the common peak ratio sequences were arranged in the order of size in comparison with other samples. The analytical results showed that samples G1 and G8 from the same region, and G4, G2 and G6 from the closer regions were the most similar samples with higher common peak ratio (≥90.0%) and lower variant peak ratio (≤11.1%). However， the samples G10, G3, G4 and G5 from the closer regions collected in different years， and G2 and G7 from the farther regions，were of significant disparity with common peak ratio less than 50% and variant peak ratio larger than 50%. As a result， the method could be used to distinguish Cacumen platycladi of different areas and batches. The dual index sequential analysis enables us to distinguish two or more herb’s IR fingerprints, is a new method to analyze IR fingerprint spectra， and can be used in line with the characteristics of traditional Chinese medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2092 (2009)
Measuring and Analyzing Infrared Spectrum of Periodically Polarized Lithium Niobate
WANG Hong-jie, CHEN Shao-fu, ZHOU Yan, WENG Yu-jia, YAN Cai-fan, LU Fu-yun, and ZHANG Guang-yin
The present paper reports theoretical and experimental research on the tunable output characteristics of periodically polarized lithium niobate. We made six equal distance crystal grating sections, with each distance being 0.5 mm and the polarization period range of 29.0-31.5 mm. Especially, at room temperature, the siThe present paper reports theoretical and experimental research on the tunable output characteristics of periodically polarized lithium niobate. We made six equal distance crystal grating sections, with each distance being 0.5 mm and the polarization period range of 29.0-31.5 mm. Especially, at room temperature, the signal-wavelength tunable output in the range of 1 449.7-1 665.0 nm and idle-wavelength tunable output in the range of 3 989.2-2 946.0 nm were achieved by LD end-pumped Nd∶YVO4 laser with Q-switch in sound-wave. The lowest excitation threshold was 108.0 mW, while the highest excitation threshold was 149.2 mW. When the pump power was 649 mW, the highest gained signal-wave output was 118.5 mW and its conversion efficiency was 18.26%. Meanwhile, the idle-wave output was 46.6 mW and its conversion efficiency was 7.18%. These parameters approached the practicality level..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2096 (2009)
Rapid Determination of the Components in Ternary Blended Edible Oil Using Near Infrared Transmission Spectroscopy
LIU Fu-li, and CHEN Hua-cai
The FT-NIR transmission spectra of ternary blended edible oil samples were collected over 10 000-4 200 cm-1. After being pretreated with different methods, the calibration models of quantitative analysis of soybean oil, peanut oil and corn oil contents in ternary blended edible oil were established using partial least The FT-NIR transmission spectra of ternary blended edible oil samples were collected over 10 000-4 200 cm-1. After being pretreated with different methods, the calibration models of quantitative analysis of soybean oil, peanut oil and corn oil contents in ternary blended edible oil were established using partial least square (PLS) regression. The accuracy and precision of the models for the predicted sample set were examined to make sure of the practicability of the models. After being pretreated with first derivative and multiplicative signal correction (FD+MSC), the optimal soybean oil NIR model was built over 5 450.1-4 597.7 cm-1. The best prediction model for peanut oil was established between 7 521.3 and 6 098.1 cm-1 after using first derivative with straight line subtraction (FD+SLS) preprocess method. The best pretreated method and the best spectrum range for corn oil content model were first derivative (FD) and 9 993.7-7 498.2 cm-1, respectively. The best correlation coefficients (R2) of the three prediction models were 99.89%, 99.88% and 99.76%, respectively. The RMSEP of the soybean oil content model was 1.09%, while the peanut oil prediction model’s RMSEP was 1.17%, and 1.48% for the corn oil prediction model. The values of the t-test were between 0.007 9 and 0.371 9, and all values of the relative standard deviation (RSD) were less than 1.50%. The results showed that NIR could be an ideal tool for fast determination of the soybean oil, peanut oil and corn oil contents in ternary blended edible oil..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2099 (2009)
The Progress in Retrieving Land Surface Temperature Based on Thermal Infrared and Microwave Remote Sensing Technologies
ZHANG Jia-hua, LI Xin, YAO Feng-mei, and LI Xian-hua
Land surface temperature (LST) is an important parameter in the study on the exchange of substance and energy between land surface and air for the land surface physics process at regional and global scales. Many applications of satellites remotely sensed data must provide exact and quantificational LST, such as droughtLand surface temperature (LST) is an important parameter in the study on the exchange of substance and energy between land surface and air for the land surface physics process at regional and global scales. Many applications of satellites remotely sensed data must provide exact and quantificational LST, such as drought, high temperature, forest fire, earthquake, hydrology and the vegetation monitor, and the models of global circulation and regional climate also need LST as input parameter. Therefore, the retrieval of LST using remote sensing technology becomes one of the key tasks in quantificational remote sensing study. Normally, in the spectrum bands, the thermal infrared (TIR, 3-15 μm) and microwave bands (1 mm-1 m) are important for retrieval of the LST. In the present paper, firstly, several methods for estimating the LST on the basis of thermal infrared (TIR) remote sensing were synthetically reviewed, i.e., the LST measured with an ground-base infrared thermometer, the LST retrieval from mono-window algorithm (MWA), single-channel algorithm (SCA), split-window techniques (SWT) and multi-channels algorithm(MCA), single-channel & multi-angle algorithm and multi-channels algorithm & multi-angle algorithm, and retrieval method of land surface component temperature using thermal infrared remotely sensed satellite observation. Secondly, the study status of land surface emissivity (ε) was presented. Thirdly, in order to retrieve LST for all weather conditions, microwave remotely sensed data, instead of thermal infrared data, have been developed recently, and the LST retrieval method from passive microwave remotely sensed data was also introduced. Finally, the main merits and shortcomings of different kinds of LST retrieval methods were discussed, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2103 (2009)
Low-Temperature-Dependent Raman Study on A1(LO) Mode of 6H-SiC
SONG Sheng-hua, WANG Wei, CHEN Yi-ting, and DU Wei-min
Variable temperature method was lent for low temperature Raman study on bulk monocrystal 6H-SiC in the temperature range from 80 to 320 K. Some Raman folding modes of 6H-SiC were assigned in the spectrum. The peak position and line width of optical phonon A1(LO) versus temperature mainly below RT was focused on by 3-phVariable temperature method was lent for low temperature Raman study on bulk monocrystal 6H-SiC in the temperature range from 80 to 320 K. Some Raman folding modes of 6H-SiC were assigned in the spectrum. The peak position and line width of optical phonon A1(LO) versus temperature mainly below RT was focused on by 3-phonon and 4-phonon models. The result showed that as the temperature decreased the line width decreased, while the peak position shifted to high wave number. It was found that as the temperature varied below 160 K, the change in peak position and line width was little, different from it was at RT, revealing that the line type of A1(LO) mode was mainly decided by the phonon characteristics and the effect of temperature could be ignored when it was below 160 K. It was showed that 4-phonon model was closer to the experiment data for fitting. Both the third and forth anharmonic vibration contributed to the spectrum, while the former was the main process. Moreover, the phonon lifetime became longer when the temperature fell because of the decrease in the atomic thermal motion..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2108 (2009)
Study on Structure and Phase Transformation Laws of Natural FeS2 Whisker by Raman Spectroscopy
HUANG Fei, KOU Da-ming, YAO Yu-zeng, NI Pei, and DING Jun-ying
FeS2 belongs to sulfide, including pyrite of isometric system and marcasite of orthorhombic system. The FeS2 discovered in Gengzhuang, Shanxi Province, was growing in the form of whisker. The study with scanning electron microscopy and electron probe show that the mineral components of FeS2 vary regularly. The structurFeS2 belongs to sulfide, including pyrite of isometric system and marcasite of orthorhombic system. The FeS2 discovered in Gengzhuang, Shanxi Province, was growing in the form of whisker. The study with scanning electron microscopy and electron probe show that the mineral components of FeS2 vary regularly. The structure of natural nano-micron FeS2 whisker was determined by micro-Raman spectroscopy. The results show that there exist two types of structure in FeS2 whiskers: pyrite and marcasite. Marcasite presents irregular shapes, such as coarse lotus root joints, crude columnar or beaded. Pyrite exists in the shape of straight line and smooth surface. In the early growing stage, Gengzhuang FeS2 whisker was mainly marcasite-type structure; in the middle stage it was coexistent structure of pyrite- and marcasite-type; in the late stage it was mainly pyrite-type. The growing stages of the whisker FeS2 show the phase transformation laws. Moreover, during the growing process marcasite was growing with pyrite coated on. Study on FeS2 whisker structure shows that there are correlations between phase transformation laws of the structure and forms, and between the forming time and the composition characteristics..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2112 (2009)
The Effect of Abnormal Cell Shape on the Spectral Distinguishing of Erythrocytes Using Laser Tweezers Raman Spectroscopy
WANG Gui-wen, PENG Li-xin, YAO Hui-lu, HUANG Shu-shi, CHEN Ping, and LI Yong-qing
Erythrocyte is a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues. Erythrocyte, which takes on a biconcave disc that has no nucleus, is flexible and changeful. Erythrocyte is so sensitive to the environment that the shape of cell goes crimpy, even acanthoid. A laser tweezers Raman spectrErythrocyte is a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues. Erythrocyte, which takes on a biconcave disc that has no nucleus, is flexible and changeful. Erythrocyte is so sensitive to the environment that the shape of cell goes crimpy, even acanthoid. A laser tweezers Raman spectroscopy (LTRS) setup was used to trap single erythrocyte from healthy donors and patients with thalassemia and to collect the Raman scattering of trapping cell. Normal shape, crimpy erythrocytes and acanthoid erythrocytes were tested, and the averaged spectra, and principal component analysis (PCA) which detailed the spectral difference and the change of hemoglobin, were used to evaluate the effects of different cell shape on the spectral distinguishing of erythrocyte. The results reveal that in normal physiological environment the change in cell shape does not effect the spectral distinguishing of abnormal erythrocyte..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2117 (2009)
Spectral Analysis of Polyphenol Oxidase (PPO) and Lipoxygenase (LOX) Treated by Pulsed Electric Field
LUO Wei, ZHANG Ruo-bing, CHEN Jie, WANG Li-ming, GUAN Zhi-cheng, and JIA Zhi-dong
Inactivation effect of pulsed electric field (PEF) on polyphenol oxidase (PPO) and lipoxygenase (LOX) was investigated using a laboratory PEF system with a coaxial treatment chamber. Circular dichroism (CD) and fluorescence analysis were used to study the conformation change of the protein. The experimental results shoInactivation effect of pulsed electric field (PEF) on polyphenol oxidase (PPO) and lipoxygenase (LOX) was investigated using a laboratory PEF system with a coaxial treatment chamber. Circular dichroism (CD) and fluorescence analysis were used to study the conformation change of the protein. The experimental results show that PPO and LOX can be effectively inactivated by the PEF treatment. Inactivation effect of PPO and LOX increases with the increase in the applied electric strength and the treatment time. Activity of PPO and LOX can be reduced by 60.3% and 21.7% at 20 kV·cm-1 after being treated for 320 μs respectively. The decrease of the negative peaks (208 and 215 nm in PPO spectra, 208 nm and 218 nm in LOX spectra) in CD spectra of PPO and LOX shows that PEF treatment caused a loss of α-helix and increase in β-sheet content, indicating that conformation changes occur in the secondary structure of PPO and LOX enzyme. This effect was strengthened as the applied electric field increased: α-helical content of PPO and LOX was 56% and 29% after being treated at 8 kV·cm-1, however, when the electric field was increased up to 20 kV·cm-1, α-helical content of PPO and LOX decreased to 21% and 16% respectively. The decrease rate of α-helix and increase rate of β-sheet in PPO are higher than LOX, indicating that the second conformation of PPO is less resistant to PEF treatment than LOX. The fluorescence intensity of LOX increases after PEF treatment. At the same time, increasing the applied pulsed electric field increases the fluorescence intensity emitted. Fluorescence measurements confirm that tertiary conformation changes occur in the local structure of LOX. However the possible mechanism of the conformation change induced by the PEF treatment is beyond the scope of the present investigation..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2122 (2009)
The Effect of Spectral Range on the Measurement of Ozone in the Atmosphere by DOAS
FU Qiang, PENG Fu-min, LIU Wen-qing, XIE Pin-hua, LUO Tao, SI Fu-qi, and LI Su-wen
Ozone (O3) often serves as the benchmark for the overall pollution level of a given airshed and it is critical that the measurement technique be accurate and precise. In the DOAS measurement, the accuracy of O3 concentration is determined by the selected spectral range. The present paper focuses on the effect of spectrOzone (O3) often serves as the benchmark for the overall pollution level of a given airshed and it is critical that the measurement technique be accurate and precise. In the DOAS measurement, the accuracy of O3 concentration is determined by the selected spectral range. The present paper focuses on the effect of spectral range on the detected characteristic absorption structure of O3, and the variation of differential cross section of O3 with the change in spectral range and the source of interference in different spectral range. The effect of practical atmospheric light extinction on the light intensities of different spectral ranges was deduced; the effect of spectral range on the accuracy was determined by detecting the standard gases at different concentration and different spectral resolution. The optimized spectral range was determined for O3, which can yield high sensitivity, good selectivity and a reasonable time resolution for the accurate qualitative and quantitative analysis of O3..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2126 (2009)
Urban Land Use Change Detection Based on High Accuracy Classification of Multispectral Remote Sensing Imagery
TONG Xiao-hua, ZHANG Xue, and LIU Miao-long
In the present paper, the urban land change in Jiading district of Shanghai was studied on the basis of high accuracy classification for 4 epochs of multispectral remotely sensed imageries. A further improved genetic-algorithm optimized back propagation neural network approach was first employed in our study to obtain In the present paper, the urban land change in Jiading district of Shanghai was studied on the basis of high accuracy classification for 4 epochs of multispectral remotely sensed imageries. A further improved genetic-algorithm optimized back propagation neural network approach was first employed in our study to obtain sorts of land cover types from the remotely sensed imageries. The urban land and non-urban land types were thus extracted based on the classification result. According to the 16 corresponding relationships between the pixel values in the four urban land imageries and the ones in the generated urban land change imagery, the amount of each type pixel in the generated imagery was calculated according to the four plates, and the situation of urban land change was analyzed and investigated for the study area in three year intervals. The urban development in the study area was also preliminarily revealed..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2131 (2009)
Using Fractal Dimensions of Hyperspectral Curves to Analyze the Healthy Status of Vegetation
DU Hua-qiang, JIN Wei, GE Hong-li, FAN Wen-yi, and XU Xiao-jun
The reflectance spectral curves of leaves can reflect many information of vegetation growth, and its variation maybe means that the healthy status of vegetation will change. Many spectral feature parameters such as red edge position, height of green peak, depth of red band absorption, the area of red edge and some vegeThe reflectance spectral curves of leaves can reflect many information of vegetation growth, and its variation maybe means that the healthy status of vegetation will change. Many spectral feature parameters such as red edge position, height of green peak, depth of red band absorption, the area of red edge and some vegetation index have been used to describe this change. However, the change of vegetation healthy status is not some feature parameters, but a comprehensive variation of the whole curve. So, a comprehensive index maybe has more value to describe the change of hyperspectral curve of vegetation and indicates its healthy status. Fractal is an appropriate mathematical tool, and fractal dimension can be used to explain the comprehensive variation of a curve. Therefore, in the present study, fractal theory was used to analyze the healthy status of different vegetation. Firstly, analytical spectral devices (ASD) were used to measure the hyperspectral curves of different vegetations with different healthy status. Secondly, spectral curves were analyzed, and some parameters which can really reflect different healthy status were obtained. Finally, the fractal dimension of reflectance spectral curves inside a spectral band zone between 450 and 780nm was computed by variation method, and the relationship between fractal dimensions and spectral feature parameters was established The research results showed that (1) the hyperspectral curves of vegetation have fractal feature, and their fractal dimensions gradually decrease with the health deterioration of leaves, (2) fractal dimension has positive correlation with the height of green peak, the depth of red band absorption and the area of red edge, (3) multivariate analysis showed that fractal dimensions have a significant linear relationship with the three spectral feature parameters just mentioned above. So, the fractal dimension of hyperspectral curve can serve as a new comprehensive parameter to analyze quantitatively the healthy status of vegetations..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2136 (2009)
The Research on Bidirectional Reflectance Computer Simulation of Forest Canopy at Pixel Scale
SONG Jin-ling, WANG Jin-di, SHUAI Yan-min, and XIAO Zhi-qiang
Computer simulation is based on computer graphics to generate the realistic 3D structure scene of vegetation, and to simulate the canopy regime using radiosity method. In the present paper, the authors expand the computer simulation model to simulate forest canopy bidirectional reflectance at pixel scale. But usually, Computer simulation is based on computer graphics to generate the realistic 3D structure scene of vegetation, and to simulate the canopy regime using radiosity method. In the present paper, the authors expand the computer simulation model to simulate forest canopy bidirectional reflectance at pixel scale. But usually, the trees are complex structures, which are tall and have many branches. So there is almost a need for hundreds of thousands or even millions of facets to built up the realistic structure scene for the forest. It is difficult for the radiosity method to compute so many facets. In order to make the radiosity method to simulate the forest scene at pixel scale, in the authors’ research, the authors proposed one idea to simplify the structure of forest crowns, and abstract the crowns to ellipsoids. And based on the optical characteristics of the tree component and the characteristics of the internal energy transmission of photon in real crown, the authors valued the optical characteristics of ellipsoid surface facets. In the computer simulation of the forest, with the idea of geometrical optics model, the gap model is considered to get the forest canopy bidirectional reflectance at pixel scale. Comparing the computer simulation results with the GOMS model, and Multi-angle Imaging SpectroRadiometer (MISR) multi-angle remote sensing data, the simulation results are in agreement with the GOMS simulation result and MISR BRF. But there are also some problems to be solved. So the authors can conclude that the study has important value for the application of multi-angle remote sensing and the inversion of vegetation canopy structure parameters..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2141 (2009)
Study on the pH-Sensitive Secondary Structure of γ-PGA Embedded with Magnetite Nanoparticles
ZHANG Ju-hua, XING Jian-min, JIANG Yang-yang, GAO Hong-shuai, and LIU Hui-zhou
The conformational transition of poly γ-glutamic acid (γ-PGA) embedded with magnetite nanoparticles under various pH conditions was investigated by Fourier transform infrared spectroscopy (FTIR). The secondary structure content was determined through the analysis of amide Ⅰ bands of Fourier deconvolution spectra, seconThe conformational transition of poly γ-glutamic acid (γ-PGA) embedded with magnetite nanoparticles under various pH conditions was investigated by Fourier transform infrared spectroscopy (FTIR). The secondary structure content was determined through the analysis of amide Ⅰ bands of Fourier deconvolution spectra, secondary derivative spectra and the Gaussian curve fitting of the original infrared spectra. The results showed that the conformation of the γ-PGA was affected by solution pH. The total contents of β-sheet and β-turn were higher than 65％, while α-helix and random coil were low. The content of β-turn increased with increasing pH, while the β-sheet decreased. Additionally, the zeta potential results showed that the pH-sensitive secondary structure of γ-PGA had influence on the stability of suspension of magnetic γ-PGA nanospheres. The minimum value of zeta potential (-35.4 mV) was obtained at pH 10.2..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2148 (2009)
Compositions and Structure Characterizations of Coal Tar Refined Soft Pitch
GAO Li-juan, ZHAO Xue-fei, LAI Shi-quan, CHENG Jun-xia, and LU Yi-qiang
High temperature coal tar was used as raw materials, and was distilled to 280 ℃ for getting coal tar soft pitch. Then refined soft pitch was obtained by solvent extracting and subsequent settlement method. Its soft point was 32 ℃; the group compositions consisted of 53.67% heptane soluble, 39.47% heptane insoluble but High temperature coal tar was used as raw materials, and was distilled to 280 ℃ for getting coal tar soft pitch. Then refined soft pitch was obtained by solvent extracting and subsequent settlement method. Its soft point was 32 ℃; the group compositions consisted of 53.67% heptane soluble, 39.47% heptane insoluble but toluene soluble, 6.86% toluene insoluble and 0.06% quinoline insoluble. The relative average molecular weight was about 292. Its average molecular formula was C22.22H16.32N0.12S0.06O0.33; the total content of heteroatom was less than 1. IR analytic results showed that its heteroatom O existed in the R—O—R and Ar—O—R structure; its heteroatom N existed in the R—NH—R and N, with the latter being primary. Its average structure was obtained by improved Brown-Lander model: five-membered condensed rings. UV analysis indicated that the majority was linear arrangement, and the minority was surface arrangement; namely, the chemical structure of the samples was mainly the cata-condensed structure, while the minority was peri-condensation..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2152 (2009)
Relationship between the Laccase Production of Pleurotus Ostreatus and the Full Wavelength Scan for the Fermentation Liquid
CHENG Fan-sheng, SHENG Ji-ping, WANG Ren-ai, and SHEN Lin
Laccase, widely distributed in fungi lacking high substrate specificity, plays an important role in lignin degradation in nature and environmental protection. In order to determine or estimate the laccase production during the fermentation of liquid media, the authors studied the full-length wave scan on the rough fermLaccase, widely distributed in fungi lacking high substrate specificity, plays an important role in lignin degradation in nature and environmental protection. In order to determine or estimate the laccase production during the fermentation of liquid media, the authors studied the full-length wave scan on the rough fermentation liquid of the Pleurotus ostreatus, which produces laccase high. Combined with the normal chemical method and diameter of the laccase and mycelium stain, which grew on the PDA (potato dextrose agar) plate with guaiacol added, we could get the exact information of laccase production. The result showed that the laccase activity increased in a rapid way in the first 5 days during the fermentation process, remained almost at the same level in the following 4 days, then increased rapidly until the 11 day, which was 148.7 U·L-1, increased 17.9 times. The diameter of laccase and mycelium stain increased with the culture time. The number of the wave peaks around 300 nm had a positive correlation with the laccase production; the peak width of OD over 1.5 around 300 nm had a positive correlation with the laccase production, which ranges from 5 nm on the first day to 80 nm on the 11th day. The light absorption line between the wavelengths 300 and 400 nm had a positive correlation with the laccase production with peaks at 349, 365 and 388 nm, and at 365 the peak gets its highest. Using these parameters, the authors could get the general production of the laccase production of liquid fermentation. Compared with the normal chemical method, the full-length wave scan method is much easier, cheap and simple. Furthermore, there are no special chemical substances used. It is really a new method for the evaluation and determination of laccase..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2157 (2009)
Comparison of Principal Component Analysis with VI-Empirical Approach for Estimating Severity of Yellow Rust of Winter Wheat
CHEN Yun-hao, JIANG Jin-bao, HUANG Wen-jiang, and WANG Yuan-yuan
The canopy reflectance of winter wheat infected by yellow rust with different severity was measured through artificial inoculation, and the disease index (DI) of the wheat corresponding to the spectra acquired in the field was obtained. Principal component analysis（PCA）was used to compute the first 5 principal componenThe canopy reflectance of winter wheat infected by yellow rust with different severity was measured through artificial inoculation, and the disease index (DI) of the wheat corresponding to the spectra acquired in the field was obtained. Principal component analysis（PCA）was used to compute the first 5 principal components (PCs) of canopy spectra in the 350-1 350 nm range and the first 3 PCs of first-order derivative in blue edge (490-530 nm), yellow edge (550-582 nm) and red edge (630-673 nm), respectively. Step-wise regression was used to build models, the results of those models are compared with that of Ⅵ-empirical models, and the result shows that the model based on PCs of first-order derivative is particularly accurate compared to others, with the RMSE of 7.65 and relative error of 15.59％. Comparison was made between the estimated DI and the measured DI, indicating that the model based on SDr′/SDg′ is suitable to monitoring early disease and the model based on PCs of first-order derivative is suitable to monitoring the more severe disease of yellow rust of winter wheat. The conclusion has great practical and application value to acquiring and evaluating wheat disease severity using hyperspectral remote sensing, and has an important meaning for increasing yields of crops and ensuring security of food supplies..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2161 (2009)
Studies on Ag-TiO2/KIT-6 Composite Nanosized Photocatalyst
ZHANG Feng-li, ZHENG Yuan-hui, ZHAN Ying-ying, LIN Xing-yi, ZHANG Han-hui, and ZHENG Qi
In the present paper, ordered mesoporous silica (KIT-6) as support, nanosized TiO2 into KIT-6 was synthesized by titanium tetraisopropoxide hydrolysis. Then silver was loaded by deposition-precipitation method. Ag-TiO2/KIT-6 composite nanosized photocatalyst was firstly synthesized and a series of correlated catalysts In the present paper, ordered mesoporous silica (KIT-6) as support, nanosized TiO2 into KIT-6 was synthesized by titanium tetraisopropoxide hydrolysis. Then silver was loaded by deposition-precipitation method. Ag-TiO2/KIT-6 composite nanosized photocatalyst was firstly synthesized and a series of correlated catalysts were synthesized by the same preparation method. Methyl orange is presently adopted as a representative organic pollutant to evaluate the photocatalytic performance of the as-synthesized catalysts. The order of photocatalytic activity of the as-synthesized samples was found as Ag-TiO2/KIT-6＞Ag/TiO2＞TiO2/KIT-6＞TiO2＞Ag/KIT-6. Detailed characterizations were conducted by techniques including XRD, N2 physical adsorption, XPS, UV-Vis DRS and TEM. It was found that the Ag-TiO2/KIT-6 sample shows the highest photocatalytic activity, which should be attributed to the Ag-TiO2 heterojunction structure and higher BET surface area of the Ag-TiO2/KIT-6 sample. Ag-TiO2 heterojunction improves the separation of photogenerated electron-hole pairs, thus enhancing the photocatalytic activity; Ag-TiO2/KIT-6 sample possesses high BET surface area, which facilitates adsorption and transportation of dye molecules, also leading to higher photocatalytic activity..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2166 (2009)
Diagnoses of Rice Nitrogen Status Based on Characteristics of Scanning Leaf
ZHU Jin-xia, DENG Jin-song, SHI Yuan-yuan, CHEN Zhu-lu, HAN Ning, and WANG Ke
In the present research, the scanner was adopted as the digital image sensor, and a new method to diagnose the status of rice based on image processing technology was established. The main results are as follows: (1) According to the analysis of relations between leaf percentage nitrogen contents and color parameter, tIn the present research, the scanner was adopted as the digital image sensor, and a new method to diagnose the status of rice based on image processing technology was established. The main results are as follows: (1) According to the analysis of relations between leaf percentage nitrogen contents and color parameter, the sensitive color parameters were abstracted as B, b, b/(r+g), b/r and b/g. The leaf position (vertical spatial variation) effects on leaf chlorophyll contents were investigated, and the third fully expanded leaf was selected as the diagnosis leaf. (2) Field ground data such as ASD were collected simultaneously. Then study on the relationships between scanned leaf color characteristics and hyperspectral was carried out. The results indicated that the diagnosis of nitrogen status based on the scanned color characteristic is able to partly reflect the hyperspectral properties. (3) The leaf color and shape features were intergrated and the model of diagnosing the status of rice was established with calculated at YIQ color system. The distinct accuracy of nitrogen status was as follows: N0: 74.9％；N1: 52％；N2: 84.7％；N3: 75％. The preliminary study showed that the methodology has been proved successful in this study and provides the potential to monitor nitrogen status in a cost-effective and accurate way based on the scanned digital image. Although, some confusion exists, with rapidly increasing resolution of digital platform and development of digital image technology, it will be more convenient for larger farms that can afford to use mechanized systems for site-specific nutrient management. Moreover, deeper theory research and practice experiment should be needed in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2171 (2009)
Nitrogen Status Diagnosis of Rice by Using a Digital Camera
JIA Liang-liang, FAN Ming-sheng, ZHANG Fu-suo, CHEN Xin-ping, LU Shi-hua, and SUN Yan-ming
In the present research, a field experiment with different N application rate was conducted to study the possibility of using visible band color analysis methods to monitor the N status of rice canopy. The Correlations of visible spectrum band color intensity between rice canopy image acquired from a digital camera andIn the present research, a field experiment with different N application rate was conducted to study the possibility of using visible band color analysis methods to monitor the N status of rice canopy. The Correlations of visible spectrum band color intensity between rice canopy image acquired from a digital camera and conventional nitrogen status diagnosis parameters of leaf SPAD chlorophyll meter readings, total N content, upland biomass and N uptake were studied. The results showed that the red color intensity (R), green color intensity (G) and normalized redness intensity (NRI) have significant inverse linear correlations with the conventional N diagnosis parameters of SPAD readings, total N content, upland biomass and total N uptake. The correlation coefficient values (r) were from -0.561 to -0.714 for red band (R), from -0.452 to -0.505 for green band (G), and from -0.541 to 0.817 for normalized redness intensity (NRI). But the normalized greenness intensity (NGI) showed a significant positive correlation with conventional N parameters and the correlation coefficient values (r) were from 0.505 to 0.559. Compared with SPAD readings, the normalized redness intensity (NRI), with a high r value of 0.541-0.780 with conventional N parameters, could better express the N status of rice. The digital image color analysis method showed the potential of being used in rice N status diagnosis in the future..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2176 (2009)
Decoloration and Degradation of Rhodamine B by Microwave-Promoted Fenton-Like Reaction
ZHENG Huai-li, YANG You, TANG Xue, JIAO Shi-jun, LIU Lan, and ZHANG Peng
Microwave-promoted Fenton-like reaction, the combination of Fenton-like reagent with microwave, is an efficient method for waste water treatment. In the present paper, the degradation of rhodamine B (a kind of organic dye) using this method was studied. Through numerous experiments, the influences of various parametersMicrowave-promoted Fenton-like reaction, the combination of Fenton-like reagent with microwave, is an efficient method for waste water treatment. In the present paper, the degradation of rhodamine B (a kind of organic dye) using this method was studied. Through numerous experiments, the influences of various parameters including the initial pH value, reaction time, dosage of K2Cr2O7, dosage of H2O2 and microwave were investigated intensively. The characteristic curve of rhodamine B, the concentration-absorbency curve of rhodamine B, the orthogonal optimization tests and comparative tests were given. The mechanism of this reaction was also probed. It is concluded from the experiments that the microwave can accelerate the process of degradation effectively. Under optimal conditions, the overall color removal was more than 99.9% within 9 min. In the study, the method for characterization was entirely UV-Vis spectral analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2180 (2009)
La-Ce-Codoping Nano-Titania Photocatalyst: Preparation Via Microwave-Assisted Sol Process, Spectroscopy Characterization and Photocatalytic Activity
GUO Li, WANG Dan-jun, LI Dong-sheng, FU Feng, PU Yong, and YAN Hong-tao
La-Ce codoping nano-TiO2 catalyst was prepared by microwave-assisted sol process with TBT and distilled water as forerunner body, ethanol as solvent and glacial acetic acid as inhibitor. The prepared samples were characterized by using XRD, XPS and UV-Vis techniques. Results of structural characterization indicated thaLa-Ce codoping nano-TiO2 catalyst was prepared by microwave-assisted sol process with TBT and distilled water as forerunner body, ethanol as solvent and glacial acetic acid as inhibitor. The prepared samples were characterized by using XRD, XPS and UV-Vis techniques. Results of structural characterization indicated that the prepared samples were all pure anatase phase nano-TiO2 and their diffraction peak broadened obviously after La and Ce doping. Results of XPS analysis revealed that La—O bond existed in the samples and many oxygen vacancies were produced on the surface of TiO2 nanoparticles after La and Ce codoping. UV-Vis absorption spectra demonstrated that the prepared samples had strong and wide absorption band between 200 and 400 nm and the absorption intensity increased after La and Ce doping because of La(Ⅲ)—O charge-transfer transition, Ce(Ⅳ) f→d transition and Ce(Ⅳ)—O charge-transfer transition. Photocatalytic experiment results showed that the titanium dioxide’s photocatalytic activity increased obviously after La and Ce codoping. The optimal parameters for the preparation were obtained by adjusting the mole ratio of La and Ce in photocatalysts. When the doping amount of La and Ce was 2% and 0.04% respectively, the prepared sample exhibited high photocatalytic activity, the decoloration ratio of methyl orange solution was above 90%, and COD removal of cigarette factory wastewater was 86.11%..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2185 (2009)
Exploring Novel Hyperspectral Band and Key Index for Leaf Nitrogen Accumulation in Wheat
YAO Xia, ZHU Yan, FENG Wei, TIAN Yong-chao, and CAO Wei-xing
The objectives of the present study were to explore new sensitive spectral bands and ratio spectral indices based on precise analysis of ground-based hyperspectral information, and then develop regression model for estimating leaf N accumulation per unit soil area (LNA) in winter wheat (Triticum aestivum L.). Three fieThe objectives of the present study were to explore new sensitive spectral bands and ratio spectral indices based on precise analysis of ground-based hyperspectral information, and then develop regression model for estimating leaf N accumulation per unit soil area (LNA) in winter wheat (Triticum aestivum L.). Three field experiments were conducted with different N rates and cultivar types in three consecutive growing seasons, and time-course measurements were taken on canopy hyperspectral reflectance and LNA under the various treatments. By adopting the method of reduced precise sampling, the detailed ratio spectral indices (RSI) within the range of 350-2 500 nm were constructed, and the quantitative relationships between LNA (gN·m-2) and RSI (i, j) were analyzed. It was found that several key spectral bands and spectral indices were suitable for estimating LNA in wheat, and the spectral parameter RSI (990, 720) was the most reliable indicator for LNA in wheat. The regression model based on the best RSI was formulated as y=5.095x-6.040, with R2 of 0.814. From testing of the derived equations with independent experiment data, the model on RSI (990, 720) had R2 of 0.847 and RRMSE of 24.7%. Thus, it is concluded that the present hyperspectral parameter of RSI (990, 720) and derived regression model can be reliably used for estimating LNA in winter wheat. These results provide the feasible key bands and technical basis for developing the portable instrument of monitoring wheat nitrogen status and for extracting useful spectral information from remote sensing images..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2191 (2009)
A Spectral Analysis Method for Total Volatile Base Nitrogen
YAO Yan, ZHANG Ping, CHEN Yong-heng, TIAN Chang-en, LIU Wen-feng, WANG Zhen-chun, and SHEN Shui-bao
A new method for the determination of the total volatile basic nitrogen (TVB-N) by reflectance spectroscopy was developed. The method was based on the reaction of TVB-N with Nessler’s reagent treated by molecular sieve and the reflectance-absorption value F(R), which is directly proportional to the amount of NH2Hg2IO iA new method for the determination of the total volatile basic nitrogen (TVB-N) by reflectance spectroscopy was developed. The method was based on the reaction of TVB-N with Nessler’s reagent treated by molecular sieve and the reflectance-absorption value F(R), which is directly proportional to the amount of NH2Hg2IO in solid phase, was measured by the reflection spectrometer. The fundamental principle, effective factors and experimental conditions of the method were discussed. The special features of this method were its simplicity in operation, relatively high sensitivity of determination and the use of a small amount of reagent. Linear calibration graph was obtained in the range 1-8 μg·mL-1 with a detection limit of 0.1 μg·mL-1. The method was applied to monitor the fresh degree of fish and pork. The result discovered that the total volatile basic nitrogen increased rapidly along with the time extension, indicating that the deterioration of fish and pork was an acceleration process, and the deterioration speed of fish was faster than that of pork..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2196 (2009)
Study on the Interaction of Sm(Ⅲ) Complexes of Rutin with Serum Albumin
WU Jin-xiu, LI Mei, SONG Yu-min, LIU Zhao-gang, and HU Yan-hong
The binding reaction of rutin-Sm with serum albumin (SA) was investigated by the fluorescence method in physiological condition. The authors studied mainly the quenching mechanism of the fluorescence of SA by rutin-Sm, and calculation of the binding constants KLB of human serum albumin （HSA） and bovine serum albumin（BSThe binding reaction of rutin-Sm with serum albumin (SA) was investigated by the fluorescence method in physiological condition. The authors studied mainly the quenching mechanism of the fluorescence of SA by rutin-Sm, and calculation of the binding constants KLB of human serum albumin （HSA） and bovine serum albumin（BSA）with rutin-Sm by Lineweaver-Burk equation at different temperatures respectively, then obtained the thermodynamic parameters of HSA and BSA with rutin-Sm according to the calculated binding constants KLB at different temperature, meanwhile the type of binding forces of HSA and BSA with rutin-Sm was determined. The results showed that the emission spectra of BSA（HSA）in the presence and absence of rutin-Sm are different. The emission spectra of BSA（HSA）in the presence of rutin-Sm can be quenched. The quenching mechanism of rutin-Sm to SA was static quenching with non-radiation energy transfer for new complex of SA and rutin-Sm. The binding constants KLB （L·moL-1）were 6.540×105 and 3.265×105 for BSA, and 6.830×105 and 4.665×105 for HSA at 295 K and 310 K respectively. And the type of bonding forces was estimated by the calculation of thermodynamic parameters of the reaction of rutin-Sm with SA at different temperatures, and the result showed that the binding forces were mainly H-bond and Van der Waals between BSA and rutin-Sm due to the ΔH＜0 and ΔS＜0, and the main electrostatic interaction of rutin-Sm and HSA because of ΔH＜0 and ΔS＞0. The effect of rutin-Sm on the conformation of serum albumin was also studied by using synchronous fluorescence spectroscopy. Results indicated that rutin-Sm could be deposited and transported by serum protein in vivo..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2199 (2009)
Fluorescence Spectroscopic Chracterization of the Complexation between Mercury(Ⅱ) and Dissolved Organic Matter
HE Xiao-song, LIU Xiao-yu, WEI Dong, WEI Zi-min, XI Bei-dou, JIANG Yong-hai, LI Ming-xiao, and YANG Tian-xue
In this study, conventional fluorescence spectroscopy in the excitation, emission and synchronous scan modes and three-dimensional fluorescence spectroscopy in the form of excitation-emission matrix of fluorescence intensity as a function of excitation and emission wavelengths were applied to study the complexation betIn this study, conventional fluorescence spectroscopy in the excitation, emission and synchronous scan modes and three-dimensional fluorescence spectroscopy in the form of excitation-emission matrix of fluorescence intensity as a function of excitation and emission wavelengths were applied to study the complexation between DOM extracted from landfill leachates and Hg(Ⅱ) ions. The emission spectrum of DOM exhibited a broad peak with a center at 425 nm and a disorder change of the peak with increasing Hg(Ⅱ) concentrations, which suggested that the structure of DOM was comparatively simple and the fluorescence character of DOM-Hg(Ⅱ) complexes resulted from interaction of all fluorescence groups. The excitation spectrum of DOM showed that the intensities of two peaks at 392 and 458 nm both decreased with the addition of Hg(Ⅱ), indicating that different sources, hydroxy and amido groups, were all involved in the DOM-Hg(Ⅱ) complexation process. Synchronous-scan excitation spectra of DOM-Hg(Ⅱ) complexation showed that Hg(Ⅱ) not only produced fluorescence quenching effect, but also enhanced the rigid structure of DOM at a low concentration. The three-dimensional fluorescence spectra of DOM-Hg(Ⅱ) showed that the peaks A and B reduced strongly and the two peaks tended to shift toward longer wavelength with the concentrations of Hg(Ⅱ) increasing. These results indicated that protein-like matter reacted with Hg(Ⅱ) and there was a charge-transfer transition either between energy level in its ligand and a mercury energy level or between two mercury energy levels at the same time. Besides, the decrease in fluorescence intensity of peaks C and D in three-dimensional fluorescence spectra suggested that carbonyl and carboxyl formed bonds with Hg(Ⅱ) when DOM was complexed with Hg(Ⅱ)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2204 (2009)
Effects of Exogenous Salicylic Acid on Photosynthesis in Arabidopsis Leaves Based on Fluorescence Spectra and Delayed Fluorescence Technique
CHEN Zhi-qiang, CHEN Wen-li, and YANG Cheng-wei
Salicylic acid plays an important role in the active oxygen metabolism and the photosynthesis of the plant. Wild type Arabidopsis thaliana (ecotype Columbia) and it’s two different mutants were used as experimental material: one is the cpr5 mutant which has an abundant endogenesis SA level under stress conditions, and Salicylic acid plays an important role in the active oxygen metabolism and the photosynthesis of the plant. Wild type Arabidopsis thaliana (ecotype Columbia) and it’s two different mutants were used as experimental material: one is the cpr5 mutant which has an abundant endogenesis SA level under stress conditions, and the other is the eds-4 mutant which has a lacking endogenesis SA level under stress conditions. The leaves of those three different Arabidopsis were treated with 100, 300, and 500 μmol·L-1 concentrations of salicylic acid, respectively. The fluorescence emission spectra and the delayed fluorescence were detected respectively. The authors found that there was a slight elevation in the photosynthetic efficiency of PSⅡof the WT and eds-4 leaves with 100 and 300 μmol·L-1 SA treatment. However, there was a decrease in the photosynthetic efficiency and even a stress of the cpr5 leaves with 100 and 300 μmol·L-1 SA treatment. It was also showed that there came to be an obvious stress of the leaves of all three different kinds of Arabidopsis with 500 μmol·L-1 SA treatment and the photosynthetic efficiency of them decreases sharply. The generation of active oxygen was also detected with the DCF labeling under 500 μmol·L-1 SA treatment. The authors found that there was an obvious accumulation of active oxygen along with the time under SA treatment..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2208 (2009)
Quantitative Analysis of Phenanthrene and Humic Acid in Solution Based on Fluorescence Method
JIN Dan, LI Guo-gang, ZHANG Yu-jun, XIAO Xue, ZHAO Nan-jing, YIN Gao-fang, and LIU Wen-qing
Polycyclic aromatic hydrocarbons as a universal concern in the monitoring of priority pollutants have low content in the water environment and are interfered with the coexistence of humic acid. The spectra of humic acid and polycyclic aromatic hydrocarbons overlap seriously, so it was difficult to use the conventional Polycyclic aromatic hydrocarbons as a universal concern in the monitoring of priority pollutants have low content in the water environment and are interfered with the coexistence of humic acid. The spectra of humic acid and polycyclic aromatic hydrocarbons overlap seriously, so it was difficult to use the conventional methods for rapid quantitative detection. As a model compound of polycyclic aromatic hydrocarbons, Phenanthrene (PHE) was chosen in the experiment. The fluorescence spectra of PHE and humic acid (HA) were investigated by three dimensional fluorescence excitation-emission matrix. The method combined excitation-emission matrix fluorescence spectra with parallel factor analysis and was applied to determine PHE and HA directly. The excitation wavelength changed from 240 to 360 nm at an interval of 5 nm. The emission wavelength varied from 260 to 575 nm at an interval of 5nm. The satisfactory results show that this experiment can be easily performed without paying out time-consuming and complicated procedures..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2213 (2009)
Application of Fluorescence Microscopic Imaging Technique with Self- Ordered Ring to Residues Detection of Antibiotics
LIU Ying, FENG Jin-chao, LI Dan, CUI Jian, XU Si-fan, and SHEN Gang-yi
Fluorescence microscopic self-ordered ring (SOR) technique with microwave heating is proposed for minocycline based on the capillary flow of solvent on the surface of hydrophobic glass slide and applied to residues detection of the antibiotics in milks of Inner Mongolia. In the reaction medium of hexahydropyridine contFluorescence microscopic self-ordered ring (SOR) technique with microwave heating is proposed for minocycline based on the capillary flow of solvent on the surface of hydrophobic glass slide and applied to residues detection of the antibiotics in milks of Inner Mongolia. In the reaction medium of hexahydropyridine containing polyvinyl alcohol-124 (PVA-124), a SOR of minocycline with the outer diameter of 1.54 mm and the ring belt width of 22.6 μm can be formed. When a 0.30 μL droplet of minocycline mixture was spotted on the solid surface, minocycline in the range of 4.2×10-12-1.8×10-11 mol·ring-1 (1.4×10-6-0.60×10-5 mol·L-1) can be detected, the maximum fluorescence intensity was found to be proportional to the minocycline concentration, and the limit of detection can reach 4.2×10-13 mol·ring-1 (1.4×10-7 mol·L-1) with three times of signal to noise ratio. With the present method, the contents of minocycline in milk samples of Inner Mongolia and minocycline hydrochloride capsule sample were satisfactorily determined with recoveries of 97.2%-103% and 99.4%-102%, respectively, and RSD lower than 1.2%, correspondingly. Therefore, a highly sensitive and selective analysis method for detecting content of trace drug contaminations was established. The method provided theory basis to quantificational analysis of the residues of the antibiotics in milks which was Inner Mongolia’ preponderant resource products. It has important realistic meaning and broad application prospect.
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2217 (2009)
Determination of Norfloxacin by Its Enhancement Effect on the Fluorescence Intensity of Functionalized CdS Nanoparticles
CAO Feng-qi, LI Dan, and YAN Zheng-yu
A novel assay of Norfloxacin with a sensitivity at the microgram level is proposed based on the measurement of enhanced fluorescence intensity signals by the interaction of functionalized nano-CdS with Norfloxacin. The CdS nanoparticles were synthesized by thioacetamide (TAA) and cadmium nitrate (Cd(NO3)2) in the alkalA novel assay of Norfloxacin with a sensitivity at the microgram level is proposed based on the measurement of enhanced fluorescence intensity signals by the interaction of functionalized nano-CdS with Norfloxacin. The CdS nanoparticles were synthesized by thioacetamide (TAA) and cadmium nitrate (Cd(NO3)2) in the alkaline solution, and the nanoparticles proved to be stable in the aqueous solution. At pH 7.4, the fluorescence signals of functionalized nano-CdS were greatly enhanced by Norfloxacin in the region of 300-700 nm characterized by the peak around 495 nm, and the surface defect-related emission located at 565 nm, However, the surface defect-related emission was unconspicuous, thus we concluded that the functionalized nano-CdS QDs (Quantum Dots) possessed excellent luminescence capability and favourable structure. At the same time, the absorption spectra and transmission electron microscopy (TEM) also proved this deduction. The external reaction conditions (such as effect of buffer system, pH, ionic strength, reaction time and temperature, colloid concentration) were discussed. The result showed that better fluorescence signals could be obtained in the condition of 0.10 mol·L-1 Tris-HCl, pH 7.4, 0.1 mol·L-1 NaCl and the reaction time 5 min. The fluorescence emission spectra of CdS QDs with increasing Norfloxacin concentration were recorded under the optimal condition. From the fluorescence intensity and peak position of nano-CdS colloidal as different concentration of Norfloxacin was added, the possible mechanism of reaction between mercapto-acetic acid capped CdS and Norfloxacin was discussed. Linear relationship can be established between the enhanced fluorescence intensity and Norfloxacin concentration in the range of 1.25-11.25 μg·mL-1 (3.92-35.27 μmol·L-1) or 11.25-100.0 μg·mL-1 (35.27-313.5 μmol·L-1).The limit of detection is 1.5×10-3 μg·mL-1, which can be applied to the determination of blood serum samples. Based on this, a new direct quantitative determination method for Norfloxacin in synthetic samples without separation of foreign substances is established. At the same time, the possible enhancing mechanism is due to the formation of exciplex during reaction between nano-CdS and Norfloxacin, providing a guidance for the study of pharmacokinetics..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2222 (2009)
Study on the Determination of Permanganate Index by UV-Vis Spectrometry
JIANG Shao-jie, SHI Fu-rong, and ZHENG Huai-li
Permanganate index is an important parameter to evaluate the organic pollution for water sources, and the current national standard method is titration analysis which needs large sample and is complicated. A new analytical method of measuring permanganate index in surface water using UV-Vis spectrometry has thus been sPermanganate index is an important parameter to evaluate the organic pollution for water sources, and the current national standard method is titration analysis which needs large sample and is complicated. A new analytical method of measuring permanganate index in surface water using UV-Vis spectrometry has thus been studied. In the laboratory work, analytical wavelength of UV-Vis spectrometry was chosen. The effect of sulfuric acid dosage, concentration and dosage of KMnO4 together with heating temperature and time was identified. In order to evaluate this new method, the linear relationship of this method was tested and the analysis results were compared with those by titration method. The selected optimum analysis parameters were: 525 nm wavelength, 25% H2SO4 dosage of 5.00 mL, 0.012 50 mol·L-1 KMnO4 dosage of 2.00 mL, 30 min heating time at the temperature of 100 ℃. This UV-Vis spectrometry method was successfully applied to measuring the permanganate index of the samples collected from the Jialing River and the Yangtze River. Compared with the current national standard method, this method is time and cost efficient, sensitive and precise, with low reagent usage; and is also easy to be manipulated and can be employed for online monitor, thus making it an environmental friendly analysing method..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2227 (2009)
Study of Determination of Phenol Derivatives Based on Ultraviolet Absorption Spectra
JUAN Ying-hua, WU Zhi-jie, and CHEN Li-jun
The ultraviolet absorption spectra of phenol and its derivatives were studied under water solution condition. The results show that the introduction of 2-, 3- and 4- substituent of group leads to a bathochromic shift of position of the maximum absorption wavelength λmax, and also increases the molar extinction coefficiThe ultraviolet absorption spectra of phenol and its derivatives were studied under water solution condition. The results show that the introduction of 2-, 3- and 4- substituent of group leads to a bathochromic shift of position of the maximum absorption wavelength λmax, and also increases the molar extinction coefficient εmax. However, the extent of influence of substituent of group on λmax and εmax differs with the introduction position. Compared with 2- and 3- substituent, the 4- substituent induces a bathochromic shift of λmax and the increase of εmax more greatly, due to the more formation of conjugated structure between 4- substituent of group and benzene ring. The characteristics of 4-nitrophenol’s λmax and εmax supply evidence that nitro is a better auxochrome for phenol derivatives. So UV methods were established for the determination of the contents of phenol derivatives. Using these methods, the adsorptive percentage of four phenol derivatives with εmax＞10 000 was determined, which indicates that phenol derivatives have larger adsorptive percentage in soils with heavy texture, and the solution of inorganic compound with larger concentrations could increase its adsorptive percentage..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2232 (2009)
Effect of Strengthening Solar Ultraviolet B Band Irradiation on Oat(Avena Sativa L. )Yield and Its Components in Qing Tibetan Plateau
WANG Sheng-yao, WANG Kun, ZHAO Yong-lai, and XIN You-jun
Stratospheric ozone depletion occurs mainly over polar regions during the spring when the solar Ultraviolet B-band (280-315 nm, UV-B) radiation is most intense in a year， but over the Qing Tibetan Plateau region, the highest intensity is from June to September when the amount of UV-B radiation reaching the regions is mStratospheric ozone depletion occurs mainly over polar regions during the spring when the solar Ultraviolet B-band (280-315 nm, UV-B) radiation is most intense in a year， but over the Qing Tibetan Plateau region, the highest intensity is from June to September when the amount of UV-B radiation reaching the regions is more than that in the adjacent areas lying in the same latitude by 10%. From June to September is just the time of plant’s germination, development, and reproduction in the alpine region. UV-B radiation may alter the reproduction of the forage plant, oat (Avena sativa.), which plays the vital role in developing indigenous herdsman’s animal husbandry industry. The responses of oat yield and its components to the enhanced ultraviolet B band irradiation under the field condition were surveyed. The effect shows that the grain yield is decreased significantly by strengthened UV-B irradiation, and at the same time the main consequence is the decrease in both the number of ears per square meter and the number of grains per ear, but the weight of 1 000 grains appears not significantly different. Compared with the same respective location in a spikelet, the grain weight is decreased significantly under the treated condition, mostly because of the decreases in the number of the third and forth floret grain and the grain weight at those respective positions, and the percentage of the first and second floret grain and their weight are evidently approved on the contrary..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2236 (2009)
Study of Microelements in Plant’s Ash and Environmental Soil by Microwave Digestion ICP-AES
ZHANG Yu-ling, WANG Song-jun, WANG Pu-jun, and CAI Yu
A model MDS-2002A microwave digestion sample preparation system with auto control pressure in obturation was developed for the determination of microelements in clearing-up plant’s ash and environment soil sample by ICP-AES. The authors discussed sample preparation result influenced by mixed acid system, scale of mixedA model MDS-2002A microwave digestion sample preparation system with auto control pressure in obturation was developed for the determination of microelements in clearing-up plant’s ash and environment soil sample by ICP-AES. The authors discussed sample preparation result influenced by mixed acid system, scale of mixed acid dispensation, proportion between solid and liquid and time of microwave clearing. Excellent project was A2B1C2，work procedure 2 in microwave process. When the dispensation scale was 6∶2∶1∶1 and mixed acid system was HNO3-HCl-HF-HClO4, the result was the best in 10 min of microwave clearing at highest power. The reagent was dried at constant temperature electric heating board, with its salinity being dissolved by aqua fortis. The method was validated through the soil （GBW07401） and plant （GBW07603） for national standard matter. The relative error of its result is between 0.00% and 7.14%, and the relative standard deviation is between 0.87% and 5.25%. The method is quick, handy, saving reagent and completely digesting in dealing with plant’s ash and soil sample, and the accuracy and precision of results are satisfying..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2240 (2009)
Analysis of Some Nutrients and Minerals in Organic and Traditional Cherry Tomato by ICP-OES Method
SHENG Ji-ping, LIU Can, and SHEN Lin
In the present study, the contents of nutritional elements such as Ca, Mg, K, Zn, Fe and Mn and heavy elements such as Cu, Cd and Pb in organic and traditional cherry tomato fruit were analyzed by ICP-OES, and the contents of some nutritional ingredients such as water, total soluble solid, soluble sugar and asorbic aciIn the present study, the contents of nutritional elements such as Ca, Mg, K, Zn, Fe and Mn and heavy elements such as Cu, Cd and Pb in organic and traditional cherry tomato fruit were analyzed by ICP-OES, and the contents of some nutritional ingredients such as water, total soluble solid, soluble sugar and asorbic acid were also investigated. The results showed that the contents of K, Ca and Zn in organic cherry tomato were 1.62, 71.7 and 1.34 mg·g-1, which were 4.52%, 129.81% and 65.43% respectively higher than those in traditional tomato. There were no significant differences in the contents of Mg and Fe, which showed 73.8 and 2.05 mg·g-1 in organic cherry tomato. But the content of Mn in organic tomato was 0.475 mg·g-1, 11.22% lower than that in traditional one (α=0.05). The contents of Cu, Cd and Pb showed no significant differences in the two kinds of tomato, which were 0.457 mg·g-1, 4.86 ng·g-1 and 0.127 mg·g-1 respectively in organic cherry tomato, and all the contents were lower than the national requirement. There were no significant differences in the contents of water, soluble sugar, and asorbic acid, but the total soluble solid and the content of soluble protein were significantly higher in organic cherry tomato. The differences in the nutritional ingredients and mineral elements and safety status in the two kinds of tomato provide academic data for the evaluation of organic vegetables and traditional ones..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2244 (2009)
Determination of Trace Elements in Paris Polyphylla var. Yunnanensis by ICP-AES
ZHANG Jin-yu, WANG Yuan-zhong, JIN Hang, and YANG Wei-ze
Determination of metal elements in Paris polyphylla var. yunnanensis was studied by ICP-AES after HNO3-H2O2 digestion. The average recovery of the method for K, Mg and trace elements such as Cu, Fe, Cr, Zn, Mn and Pb in the Paris polyphylla var . yunnanensis was found to be 93.7%-108.2%, while RSD (n=5) was 0.7%-4.6% fDetermination of metal elements in Paris polyphylla var. yunnanensis was studied by ICP-AES after HNO3-H2O2 digestion. The average recovery of the method for K, Mg and trace elements such as Cu, Fe, Cr, Zn, Mn and Pb in the Paris polyphylla var . yunnanensis was found to be 93.7%-108.2%, while RSD (n=5) was 0.7%-4.6% for the metal elements. The method was applied to the analysis of some practical samples, and the results obtained were satisfactory. There is rich Fe in the samples. It is of important significance to assess the value of the Chinese medicine by the determination of trace elements in it with ICP-AES..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2247 (2009)
Simultaneous Determination of Impurities in K2CrO4 by ICP-AES
YU Zhi-hui, QI Tao, QU Jing-kui, CHU Jing-long, and WANG Li-na
The trace elements, Ca, Mg, Ba, Co, Cd, Cu, Mn, Pb, Sr, Zn, Al, Fe, Ni, Ti, Si and V, in K2CrO4 were simultaneously determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Optimum spectral lines were selected for each analyzed element. The matrix effect was studied and eliminated through matrixThe trace elements, Ca, Mg, Ba, Co, Cd, Cu, Mn, Pb, Sr, Zn, Al, Fe, Ni, Ti, Si and V, in K2CrO4 were simultaneously determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Optimum spectral lines were selected for each analyzed element. The matrix effect was studied and eliminated through matrix matching. The results show that the linear correlations of standard curves are good (R2=0.998 6-1.000) under the determined conditions. The recoveries of standard addition are in the range of 83.7%-113.0%, and the relative standard deviations are lower than 9.48％(n=9). Detection limits of these impurities are in the range of 0.075-2.625 mg·kg-1. The method is rapid, simple, accurate and credible, so it can be used for the determination of impurities in K2CrO4 product. The results also show that there is relatively high content of Ca, Mg, Al and Si in K2CrO4 product, so the K2CrO4 product can’t be directly used for the ion membrane electrochemical synthesis of chromic anhydride and the product must be taken for further purification..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2250 (2009)
Study on Ultrasonic Nebulizer Sample Feeding System for ICP-AES
ZHOU Shi-ping, DUAN Chang-qun, FU Hui, LI Jing, HAN Qing-li, and AO Xin-yu
The sample feeding system of inductively coupled plasma atomic emission spectrometry (ICP-AES) is pneumatic nebulization system, but its efficiency is not good. The ultrasonic nebulization technology possesses advantages of high nebulization efficient and fine droplets, and it is free of blocking phenomenon. It has gooThe sample feeding system of inductively coupled plasma atomic emission spectrometry (ICP-AES) is pneumatic nebulization system, but its efficiency is not good. The ultrasonic nebulization technology possesses advantages of high nebulization efficient and fine droplets, and it is free of blocking phenomenon. It has good application perspective in nebulization technology. In the present paper the authors study the working conditions of ultrasonic nebulizer such as carrier gas flow, injection time, injection rate and mode of washing that are likely to affect the detection results, and study the detecting conditions of several elements such as As and Se etc. that have poorly detection limits in normal ICP-AES methods. At the same time， the application of them in biochemical samples was studied. Testing results show that carrier gas flow, injection rate and injection time can greatly affect the intensity of spectral lines, and the ultrasonic nebulizer sample feeding system can increase the spectral line intensity and decrease the detection limit elements such as As, Pb, Se, Bi, Ge, Mo, Cd and Cu by about 10-25 times. Moreover, this ultrasonic nebulizer sample feeding system can reduce the time of memory effect by washing the sample cell..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2254 (2009)
Determination of Inorganic Elements in Oleum Camelliae by ICP-AES
LI Jing, XIE Ming-yong, NIE Shao-ping, GUO Lan, and HU Jie-lun
In the present study, the contents of eighteen inorganic elements such as Ca, K, Mg, Cu, Cr, Zn and Sr in oleum camelliae during different stages of refining process were determined using ICP-AES technique. The recoveries obtained by the standard addition method ranged between 82.7% and 112.5%, and RSDs were lower thanIn the present study, the contents of eighteen inorganic elements such as Ca, K, Mg, Cu, Cr, Zn and Sr in oleum camelliae during different stages of refining process were determined using ICP-AES technique. The recoveries obtained by the standard addition method ranged between 82.7% and 112.5%, and RSDs were lower than 6.66%. The detection limits of the method for the eighteen elements were in the range of 0.4-10 μg·L-1. The experimental results proved that oleum camelliae is rich in inorganic elements. The results also showed that depending on the intensity of refining, the contents of elements will decrease accordingly. After the degumming process, the contents of elements P, Ca and Mg in oleum camelliae declined remarkably. Besides, the contents of some trace elements such as Fe, Cu, Mn and Ni that cause oxidation to occur decreased significantly after refining. In addition, Pb was not detected after the degumming and deacidification process while Co and Cd were not detected both in the crude oil and the refined oil. In conclusion, through refining many excessive metal elements in oleum camelliae were removed effectively and the levels of these elements were able to meet the national standards set by the government. Meanwhile, the experimental results indicated that the ICP-AES technique, which can be used to determine the inorganic elements in oleum camelliae, is easy to operate, rapid, accurate, and highly sensitive, and can also determine many elements simultaneously..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2258 (2009)
Determination of Trace Hg Element in Gas by CVAAS with Single Optical Path
WANG Shuai, WANG Peng, WANG Xi-he, GAO Ji-hui, ZHANG Zhi-guo, and WU Shao-hua
Since the anthropogenic emissions of mercury into environment were mostly entering the atmosphere through flue gas, continuous monitoring of mercury in the flue gas was significant for mercury emission control. A bench scale test rig was set up for the measurement of mercury through both wet chemical method and CVAAS (Since the anthropogenic emissions of mercury into environment were mostly entering the atmosphere through flue gas, continuous monitoring of mercury in the flue gas was significant for mercury emission control. A bench scale test rig was set up for the measurement of mercury through both wet chemical method and CVAAS (cold vapor atomic absorption spectrometry) with single optical path. The concentration of Hg in absorbent solution was determined by Hydra AA mercury analyzer. The concentration of Hg in gas was calculated in terms of wet chemical testing results, which showed a stable rate of permeation device. Hg atom absorption signal intensity was detected and analyzed in comparison with the test results of wet chemical methods according to Beer-Lambert law. Experimental data well agreed with the theory analysis, which indicated that the single optical path was suitable for the determination of trace Hg element in pure gas. Further research work should aim at the improvement of system adaptability and anti-jamming ability. To reduce the intensity fluctuation of mercury lamp, another spectral line could be detected simultaneously. Interference from surroundings, e.g. dust in gas or spot on the quartz surface, could be eliminated by optoelectronic coupling..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2262 (2009)
The Study of Trace Elements in Capparis Spinosa L
Meiliwan·Abudureyimu, Ainiwaer·Aikemu, Hajinisha, and WANG Yan
To provide a scientific basis for the research and development of Capparis spinosa L and determine the content of trace elements abundant in seeds. Determination of eight predictive trace elements, Cu, Zn, Fe, Mn, Ca, K, Mg and Cr, was carried out by ICP-AES. Among the determined eight predictive trace elements, the coTo provide a scientific basis for the research and development of Capparis spinosa L and determine the content of trace elements abundant in seeds. Determination of eight predictive trace elements, Cu, Zn, Fe, Mn, Ca, K, Mg and Cr, was carried out by ICP-AES. Among the determined eight predictive trace elements, the contents of Fe， Zn， Cu and Cr are the highest. Capparis spinosa L is worth researching deeply not only Chemically but also pharmacologically as a Chinese Uygur herb..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2266 (2009)
Determination of Major, Minor Elements in the Samples of SrCO3 Product by X-Ray Fluorescence Spectrometry
WANG Xiao-huan, DONG Ya-ping, MENG Qing-fen, BIAN Shao-ju, FENG Hai-tao, and LIU Xin
In the present paper a method for the determination of strontium， barium， calcium， magnesium， silicon， iron， aluminum and sulfur in the product of strontium carbonate by X-ray fluorescence spectrometry with pressed powder sample preparation was developed, and the standard samples were synthesized by high purity reagentIn the present paper a method for the determination of strontium， barium， calcium， magnesium， silicon， iron， aluminum and sulfur in the product of strontium carbonate by X-ray fluorescence spectrometry with pressed powder sample preparation was developed, and the standard samples were synthesized by high purity reagent. As the contents of strontium in the product of strontium carbonate were very high, the phenomenon of spectrum-peak-saturated occurred and the count rate was overflowed according to the measuring condition which was automatically given by the software system of X-ray fluorescence spectrometry. As a result, the deviation of the measurement is greater. According to analyzing the measuring condition of strontium, a method was given for reducing the count rate by reducing the measuring power of strontium, thus achieving the goal of measurement. When sulfate was measured with pressed powder sample, the results were enhanced with the increase in measuring number. In light of this situation, a method was proposed to solve the problem. As the self-forming characteristic of the product of strontium carbonate was not so well, it was very difficult to press the sample successfully. So, the condition of squash method involving the kinds of the adhesives, the mixing technique with powder sample and the pressing-time technique was discussed. During making the sample, it was found that the effects of pellet formation were better if the time could be delayed by 120 seconds. Matrix effect was corrected by alpha coefficient method, the accuracy of the method was evaluated by analysis of synthetic sample. Detection limits of 0.623-107.6 mg·g-1 were obtained. The results were in good agreement with certified values with precision of ＜2.5% RSD..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2268 (2009)
X-Ray Excited Luminescence Property of ZnS∶Au, Cu Fine Particles Synthesized by Hydrothermal Method
XIN Mei, and CAO Wang-he
Highly luminescent ZnS∶Au, Cu X-ray phosphor fine particles synthesized by hydrothermal method is reported for the first time and its photoluminescence (PL) and X-ray excited luminescence (XEL) properties were studied in detail. With direct hydrothermal treatment at 200 ℃ for 12 h, the average gain size of samples is aHighly luminescent ZnS∶Au, Cu X-ray phosphor fine particles synthesized by hydrothermal method is reported for the first time and its photoluminescence (PL) and X-ray excited luminescence (XEL) properties were studied in detail. With direct hydrothermal treatment at 200 ℃ for 12 h, the average gain size of samples is about 15 nm; the synthesized sphere-like nanocrystals with well dispersity and narrow gain size distribution show cubic structure. After baking in argon at 1 000 ℃ for 1h the sample agglomerate size is about 1-2 μm and the roughly spherical fine particles show pure hexagonal structure. The PL and XEL spectra of all the samples show a broad emission band and an intense emission band in the range of 400-600 nm. The maximum XEL intensity of sample directly synthesized by hydrothermal treatment was observed when Cu/Zn and Cu/Al were 3×10-5 and 2, respectively. In this condition, the strongest PL emission was observed for the direct synthesized sample being further baked in argon at 900 ℃ for 1 h and the PL peak was centered at about 529 nm. The strongest XEL emission was observed for the direct synthesized sample being further baked in argon at 1 000 ℃ for 1h and the XEL peak was centered at about 445 and 513 nm, respectively. In the meantime, the XEL intensity increased about ten times compared with that directly synthesized without baking. The difference between PL and XEL spectra is due to its different excitation mechanism. The luminescence mechanism and different excitation mechanism of PL and XEL were discussed. The red shift of XEL spectrum with directly synthesized sample was observed with increasing the Cu/Zn. The reason can also be explained by the luminescence mechanism and excitation mechanism of XEL..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2272 (2009)
A Quantitative Trabecular Structural Analysis Using X-Ray Micro CT in Ovariectomized Rats
GUO Hui-yuan, ZHANG Lu-da, ZHENG Li-min, ZHANG Hao, and REN Fa-zheng
The objective of the present paper was to evaluate the X-ray three-dimensional micro-computed tomography (X-μCT) method applied in assessing the trabecular structure in ovariectomized rats. Three-month-old female Sprague-Dawley rats (n=30) were ovariectomized (OVX) or sham-operated (SHAM). OVX rats were treated with veThe objective of the present paper was to evaluate the X-ray three-dimensional micro-computed tomography (X-μCT) method applied in assessing the trabecular structure in ovariectomized rats. Three-month-old female Sprague-Dawley rats (n=30) were ovariectomized (OVX) or sham-operated (SHAM). OVX rats were treated with vehicle, or 17β-estradiol (E2, positive control) for 3 months. For the conventional histomorphometric analysis, undecalcified sections were prepared and stained with the Li Chunhong technique to obtain high-contrast two-dimensional images. Prior to the histologic sectioning the samples were measured by X-μCT, providing a 14 μm resolution. The morphometric parameters computed by both methods in two or three dimensions, respectively, were bone volume over total volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp). Results showed that there were significant differences in the trabecular structure among three groups. In the OVX control group, the platelike structure was mostly resolved into a rodlike structure, with lots of the connecting rods missing. Whereas in OVX+E2 groups, this loss of trabecular bone mass and connectivity was prevented, with the results being nearly the same as those in the SHAM group. It was shown that highly significant correlations between conventional histology and X-μCT for BV/TV，Tb.Th，Tb.N and Tb.Sp were 0.984, 0.960, 0.995, and 0.988 in tibia，and 0.938，0.968，0.877 and 0.951 in lumbar. The high correlations between conventional histomorphometric and micro-tomographic analysis are very promising for the use of micro-tomographic imaging. X-μCT is a nondestructive, fast, and very precise procedure that allows the measurement of cancellous tissue in unprocessed biopsies or small bones, as well as a fully automatic determination of three-dimensional morphometric indices..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2276 (2009)
Design Method of Convex Master Gratings for Replicating Flat-Field Concave Gratings
ZHOU Qian, and LI Li-feng
Flat-field concave diffraction grating is the key device of a portable grating spectrometer with the advantage of integrating dispersion, focusing and flat-field in a single device. It directly determines the quality of a spectrometer. The most important two performances determining the quality of the spectrometer are Flat-field concave diffraction grating is the key device of a portable grating spectrometer with the advantage of integrating dispersion, focusing and flat-field in a single device. It directly determines the quality of a spectrometer. The most important two performances determining the quality of the spectrometer are spectral image quality and diffraction efficiency. The diffraction efficiency of a grating depends mainly on its groove shape. But it has long been a problem to get a uniform predetermined groove shape across the whole concave grating area, because the incident angle of the ion beam is restricted by the curvature of the concave substrate, and this severely limits the diffraction efficiency and restricts the application of concave gratings. the authors present a two-step method for designing convex gratings, which are made holographically with two exposure point sources placed behind a plano-convex transparent glass substrate, to solve this problem. The convex gratings are intended to be used as the master gratings for making aberration-corrected flat-field concave gratings. To achieve high spectral image quality for the replicated concave gratings, the refraction effect at the planar back surface and the extra optical path lengths through the substrate thickness experienced by the two divergent recording beams are considered during optimization. This two-step method combines the optical-path-length function method and the ZEMAX software to complete the optimization with a high success rate and high efficiency. In the first step, the optical-path-length function method is used without considering the refraction effect to get an approximate optimization result. In the second step, the approximate result of the first step is used as the initial value for ZEMAX to complete the optimization including the refraction effect. An example of design problem was considered. The simulation results of ZEMAX proved that the spectral image quality of a replicated concave grating is comparable with that of a directly recorded concave grating..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2281 (2009)
Research on the Near-Infrared Spectrometer System
XIANG Xian-yi, WEN Zhi-yu, LONG Zai-chuan, HONG Ming-jian, LIANG Yu-qian, and XU Yi
Near-infrared spectrometer is the integration of spectrum test technology, stoichiometry technology and computer technology. In the present paper, based on effective food ingredients and non-invasive quantitative detection，the development process of the micro-near-infrared spectrometer system was introduced. SpectrometNear-infrared spectrometer is the integration of spectrum test technology, stoichiometry technology and computer technology. In the present paper, based on effective food ingredients and non-invasive quantitative detection，the development process of the micro-near-infrared spectrometer system was introduced. Spectrometer is the basis of the system. This paper focuses on the development of the micro-near-infrared spectrometer applicable to on-line real-time testing. A micro-near-infrared spectrometer prototype was developed successfully， its main technical parameter was tested, and the result shows: its operating wavelength is: 850-1 690 nm, optical resolution is: less than 10 nm, and its performance has achieved the level of the congener foreign products. Stoichiometric technology and computer technology is the core of the system. LS-LWR modeling methods were proposed. Finally, the quantitative test for glucose water solution using the micro-near-infrared spectrometer shows that the correlation coefficient of prediction model is 0.995, and the corresponding RMSEP is 0.06..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2286 (2009)
Development of X-Ray Excited Fluorescence Spectrometer
NI Chen, GU Mu, WANG Di, CAO Dun-hua, LIU Xiao-lin, and HUANG Shi-ming
An X-ray excited fluorescence spectrometer was developed with an X-ray tube and a spectrometer. The X-ray tube, spectrometer, autocontrol method and data processing selected were roundly evaluated. The wavelength and detecting efficiency of the apparatus were calibrated with the mercury and tungsten bromine standard laAn X-ray excited fluorescence spectrometer was developed with an X-ray tube and a spectrometer. The X-ray tube, spectrometer, autocontrol method and data processing selected were roundly evaluated. The wavelength and detecting efficiency of the apparatus were calibrated with the mercury and tungsten bromine standard lamps, and the X-ray excited emission spectra of BaF2, CsⅠ(Tl) crystals were measured. The results indicate that the apparatus has advantages of good wavelength resolution, high stability, easy to operation and good radioprotection. It is a wery effective tool for exploration of new scintillation materials..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2291 (2009)
Experimental Research on Remote Sensing Spectrometer’s Instrument Response Function
OUYANG Jian-ming, CHANG Sheng-li, and SHAO Fu-qiu
Remote sensing spectrometers were widely used in the fields such as spectral measure and trace gas supervision in atmosphere. The instrument response functions should be measured to eliminate the effect of the spectrometer. The instrument response functions of MCT detector and InSb detector in BLUKER TENSOR 37 passive Remote sensing spectrometers were widely used in the fields such as spectral measure and trace gas supervision in atmosphere. The instrument response functions should be measured to eliminate the effect of the spectrometer. The instrument response functions of MCT detector and InSb detector in BLUKER TENSOR 37 passive FTIR spectrometer were measured in the present paper. The instrument response functions and background functions were offered with different temperature interval. The instrument response functions of MCT detector increased with temperature, but it was the reverse for InSb detector. The background functions of InSb detector increased with temperature, and the reverse for MCT detector..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2295 (2009)
Design of Advanced Glycation Endproducts Fluorescence Spectrum Detecting System
XU Liang-yuan, ZHU Ling, ZHANG Long, YU Feng, LIU Yong, ZHANG Gong, and WU Lu-sheng
The method of making use of the technique of fluorescence spectrum to detect advanced glycation endproducts is discussed in the present pape. The emphasis is on the principle and structure of the fluorescence spectrum detecting system．In the end, the authors made use of the system to detect the excitation spectrum at tThe method of making use of the technique of fluorescence spectrum to detect advanced glycation endproducts is discussed in the present pape. The emphasis is on the principle and structure of the fluorescence spectrum detecting system．In the end, the authors made use of the system to detect the excitation spectrum at the wavelengths of 365nm, 370nm, 375nm, 380nm and 385nm, respectively, and the authors found that 375nm is the best excitation wavelength. At the same time, the emission spectrum was also detected on the skin of nondiabetic people and patients with diabetes respectively. The result of the experiment indicates that there is a difference distinctly at about 450nm between them, and has proved the feasibility of the system. The detecting system does not need collecting blood sample, is a noninvasive detection technology, and avoids pain and infection to the patients. The process of detection is very rapid and convenient, and the repetitiveness is well. The patient can benefit from it to forecast and diagnose the state of illness such as diabetes, decrepitude and oxidative stress etc conveniently..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 2298 (2009)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 8, 1 (2009)
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