Journals >Spectroscopy and Spectral Analysis
Contents
2013
Volume: 33 Issue 4
61 Article(s)
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Research Article
New Type Distributed Optical Fiber Temperature Sensor (DTS) Based on Raman Scattering and Its’ Application
WANG Jian-feng, LIU Hong-lin, ZHANG Shu-qin, YU Xiang-dong, SUN Zhong-zhou, JIN Shang-zhong, and ZHANG Zai-xuan
Basic principles, development trends and applications status of distributed optical fiber Raman temperature sensor (DTS) are introduced. Performance parameters of DTS system include the sensing optical fiber length, temperature measurement uncertainty, spatial resolution and measurement time. These parameters have a ceBasic principles, development trends and applications status of distributed optical fiber Raman temperature sensor (DTS) are introduced. Performance parameters of DTS system include the sensing optical fiber length, temperature measurement uncertainty, spatial resolution and measurement time. These parameters have a certain correlation and it is difficult to improve them at the same time by single technology. So a variety of key techniques such as Raman amplification, pulse coding technique, Raman related dual-wavelength self-correction technique and embedding optical switching technique are researched to improve the performance of the DTS system. A 1 467 nm continuous laser is used as pump laser and the light source of DTS system (1 550 nm pulse laser) is amplified. When the length of sensing optical fiber is 50 km the Raman gain is about 17 dB. Raman gain can partially compensate the transmission loss of optical fiber, so that the sensing length can reach 50 km. In DTS system using pulse coding technique, pulse laser is coded by 211 bits loop encoder and correlation calculation is used to demodulate temperature. The encoded laser signal is related, whereas the noise is not relevant. So that signal-to-noise ratio (SNR) of DTS system can be improved significantly. The experiments are carried out in DTS system with single mode optical fiber and multimode optical fiber respectively. Temperature measurement uncertainty can all reach 1 ℃. In DTS system using Raman related dual-wavelength self-correction technique, the wavelength difference of the two light sources must be one Raman frequency shift in optical fiber. For example, wavelength of the main laser is 1 550 nm and wavelength of the second laser must be 1 450 nm. Spatial resolution of DTS system is improved to 2 m by using dual-wavelength self-correction technique. Optical switch is embedded in DTS system, so that the temperature measurement channel multiply extended and the total length of the sensing optical fiber effectively extended. Optical fiber sensor network is composed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 865 (2013)
Study on the Preparation and Properties of Novel Silica Microporous Antireflective Coating by Sol-Gel Process
SHANG Meng-ying, CAO Lin-hong, LIU Miao, LUO Xuan, REN Hong-bo, YE Xin, TANG Yong-jian, and JIANG Xiao-dong
Silica sol was prepared by acid catalyzed sol-gel process using tetraethylorthosilicate (TEOS) as precursor and dimethyldietoxysilane (DDS) as pore-forming agent. A novel kind of monolayer microporous silica anti-reflective (AR) coating was obtained on K9 glass substrate by dip-coating technique and then heat treated aSilica sol was prepared by acid catalyzed sol-gel process using tetraethylorthosilicate (TEOS) as precursor and dimethyldietoxysilane (DDS) as pore-forming agent. A novel kind of monolayer microporous silica anti-reflective (AR) coating was obtained on K9 glass substrate by dip-coating technique and then heat treated at 500 ℃. The effects of different DDS/TEOS molar ratios on refractive index, transmittance and hardness were investigated. A positive correlation was found between the transmittance and the DDS/TEOS molar ratio due to the increasing porosity. The maximum transmittance can reach 99.7％ with the molar ratio of DDS/TEOS rising to 1∶1. Meanwhile, the refractive index was found quite close to the ideal value 1.22. Nevertheless, higher molar ratio will lead to a bad film-forming property. On the other hand, the hardness of the coatings decreased with the DDS increasing but still remained more than 2 h when the transmittance reached highest. Besides, these coatings exhibit a well abrasion-resistance and excellent adhesivity. The maximum transmittance was only dropped by 0.071% and 0.112% after abrasion for 500 and 1 000 times respectively. Accelerated corrosion tests indicated that the transmittance of traditional coatings rapidly fell down to the substrate level (～92%) after immersion for 5 min, while the transmittance of our novel coating almost linearly decreased and was kept 93.2% after 56 min. In other words, the environment-resistance of our novel silica AR coating is ten times higher than that of traditional ones. The promotions of the coating performances benefit from its micropore structure(～0.4 nm) with which water molecule can be effectively prevented. With its high transmittance, good mechanical properties and high environment-resistance, this kind of novel coating has a potential application in the field of solar glass modification to improve its anti-reflective properties..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 872 (2013)
A Method for Real-Time Observation of Intracellular Free Ca2+ Concentration in Single Bovine Retinal Neurons
YANG Xun, LIU Xiao-chen, and MA Wan-yun
In order to observe the neurotrophin’s influence on intracellular free calcium concentration, the test neuron was labeled by fluorescence indicator Fluo-3, and imaged by self-built real-time fluorescence microscopy system. The authors observed the changes in intracellular free calcium concentration (［Ca2+］i) in the bovIn order to observe the neurotrophin’s influence on intracellular free calcium concentration, the test neuron was labeled by fluorescence indicator Fluo-3, and imaged by self-built real-time fluorescence microscopy system. The authors observed the changes in intracellular free calcium concentration (［Ca2+］i) in the bovine retinal neurons under the influence of four kinds of neurotrophins such as brain derived neurotrophic factor BDNF. On account of the fact that fluorescence indicator’s intensity decays over time, it is necessary to apply a “decay removal correction” to the fluorescence intensity in order to show the fluorescence intensity that solely represents ［Ca2+］i. The corrected data shows an increase after adding neurotrophins to neurons, which is consistent with similar results published by other groups. Thus, our method of imaging living cells is feasible, and “decay removal correction” is reliable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 877 (2013)
Simulation and Analysis of Second-Harmonic Signal Based on Tunable Diode Laser Absorption Spectroscopy
LI Han, LIU Jian-guo, HE Ya-bai, HE Jun-feng, YAO Lu, XU Zhen-yu, CHEN Jiu-ying, YUAN Song, and KAN Rui-feng
Tunable diode laser absorption spectroscopy (TDLAS) is a new gas detection technique developed recently with high spectral resolution, high sensitivity and fast time response. The second-harmonic signal of wavelength modulation spectroscopy (WMS) is often used as the detection signal for gas concentration inversion. UsTunable diode laser absorption spectroscopy (TDLAS) is a new gas detection technique developed recently with high spectral resolution, high sensitivity and fast time response. The second-harmonic signal of wavelength modulation spectroscopy (WMS) is often used as the detection signal for gas concentration inversion. Using Simulink, a visual modeling and simulation platform, the authors simulated the WMS signal based on TDLAS, and got the second-harmonic signal by using lock-in amplifier algorithm. Digital orthogonal algorithm was studied in this paper. The relationship between second-harmonic signals and the modulation indexes was analyzed by comparing changes of second-harmonic under different modulation indexes, in order to find out the optimized parameters for second-harmonic detection..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 881 (2013)
Research on Detecting Explosive Content of 2,4-Dimitroanisole Based on THz Spectroscopy
WANG Gao, XU De-gang, and YAO Jian-quan
In order to detect the content of a new kind of insensitive melting-cast explosive (DNAN), the system detected the THz characteristics wavelength of DNAN, and solved the content of DNAN by the Bill-Lambert law. Time coherent THz spectroscopy detection system was designed, in which the master system controlled stepper mIn order to detect the content of a new kind of insensitive melting-cast explosive (DNAN), the system detected the THz characteristics wavelength of DNAN, and solved the content of DNAN by the Bill-Lambert law. Time coherent THz spectroscopy detection system was designed, in which the master system controlled stepper motor to get the micro-scanning of the photoelectric detector. The system parameters were calculated and derived for solving the content of DNAN, and THz characteristic spectrum of DNAN was obtained. Experiment used three methods to detect explosives samples with different content of DNAN, and the results show that the accuracy of this system is close to that of MINI-Z terahertz spectrometer currently broadly applied in THz spectroscopy detection equipment at home and abroad. On this basis, the optimization algorithm of characteristic absorption peak was designed, and by the origin software simulation analysis, it shows that the algorithm can further improve accuracy and stability of the detection system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 886 (2013)
Plasma Temperature Calculation and Coupling Mechanism Analysis of Laser-Double Wire Hybrid Welding
ZHENG Kai, LI Huan, YANG Li-jun, GU Xiao-yan, and GAO Ying
The plasma radiation of laser-double wire hybrid welding was collected by using fiber spectrometer, the coupling mechanism of arc with laser was studied through high-speed photography during welding process, and the temperature of hybrid plasma was calculated by using the method of Boltzmann plot. The results indicatedThe plasma radiation of laser-double wire hybrid welding was collected by using fiber spectrometer, the coupling mechanism of arc with laser was studied through high-speed photography during welding process, and the temperature of hybrid plasma was calculated by using the method of Boltzmann plot. The results indicated that with laser hybrid, luminance was enhanced; radiation intensity became stronger; arc was attracted to the laser point; cross section contracted and arc was more stable. The laser power, welding current and arc-arc distance are important factors that have great influence on electron temperature. Increase in the laser power, amplification of welding current and reduction of arc-arc distance can all result in the rise of temperature..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 890 (2013)
Research on the NO2 Mean Concentration Measurement with Target Differential Optical Absorption Spectroscopy Technology
LIU Jin, SI Fu-qi, ZHOU Hai-jin, ZHAO Min-jie, DOU Ke, and LIU Wen-qing
A new monitoring method of NO2 concentration near ground with the target difference absorption spectrum technology (Target DOAS) is introduced in the present paper. This method is based on the passive difference absorption spectrum technology. The instrument collects solar reflection spectrum of remote objectives, suchA new monitoring method of NO2 concentration near ground with the target difference absorption spectrum technology (Target DOAS) is introduced in the present paper. This method is based on the passive difference absorption spectrum technology. The instrument collects solar reflection spectrum of remote objectives, such as wall of building and mountain, and a specific reference spectrum is chosen to subtract the influence of trace gases from the target to atmospheric top, then integrated concentration of NO2 along the path between the target and instrument can be calculated through the differential absorption spectra inversion algorithm. Since the distance between the instrument and target is given, the mean concentration of NO2 can be derived. With developed Target DOAS instrument, NO2 concentration measurement was carried out in Hefei. And comparison was made between the target DOAS and long path difference absorption spectrometer. Good consistency was presented, proving the feasibility of this method..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 895 (2013)
Thermodynamics Process of Laser Drilling on Copper Surface
LI Shi-wen, ZHANG Qiu-hui, and NIU Rui-hua
The laser drilling experiment was carried out on the copper surface by ns laser pulse, then the micro-morphology of the micro-hole was observed and the thermodynamic process was analyzed accordingly. The research results show that micro-hole is made of the pit in the center and surrounding uplift. The pit becomes deepeThe laser drilling experiment was carried out on the copper surface by ns laser pulse, then the micro-morphology of the micro-hole was observed and the thermodynamic process was analyzed accordingly. The research results show that micro-hole is made of the pit in the center and surrounding uplift. The pit becomes deeper with the incident laser pulse energy. The thermodynamic analysis indicates that laser drilling on the metal requires two basic conditions: the first is the deposition of laser pulse energy, which makes the occurrence of melting, vaporization and ionization. Such phase transition can make the materials easy to remove and the laser plasma can accelerate the laser pulse energy deposition as the secondary heat source. The second condition is the production of the laser plasma shock wave, it can eject the materials of phase transition effectively and timely, thus the micro hole can be formed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 899 (2013)
Superhigh Spectral Resolution Measurement of Spectrometer
LIU Sheng-gang, WENG Ji-dong, and TAO Tian-jiong
The spectral resolution is one of the most important indexes of spectrometer. A new method is put forward for measuring the superhigh spectral resolution based on the Rayleigh criterion and the optical heterodyne, and the uncertainty of this method is analyzed. The spectral resolution of some spectrometer was measured The spectral resolution is one of the most important indexes of spectrometer. A new method is put forward for measuring the superhigh spectral resolution based on the Rayleigh criterion and the optical heterodyne, and the uncertainty of this method is analyzed. The spectral resolution of some spectrometer was measured using this method, and the experimental results show that the spectral resolution is higher than 18.9 pm, and the standard uncertainty is 2.3 pm. When showed using wave number, the spectral resolution is higher than 0.078 8 cm-1, and the standard uncertainty is 0.009 6 cm-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 903 (2013)
Effects of Morphology Evolution on Surface Plasmon Resonance of Nano-Ag Films Treated by Different Thermal Annealing Temperatures
YU Wei, LIU Yu-mei, DAI Wan-lei, WANG Xin-zhan, LU Wan-bing, LI Xiao-wei, and FU Guang-sheng
The nano-Ag films were prepared by RF magnetron sputtering technique, and all of them were treated by rapid thermal annealing at different temperatures. The structure, the morphology and the optical properties of the annealed nano-Ag films were characterized by X-ray diffraction, scanning electron microscopy, and UV-ViThe nano-Ag films were prepared by RF magnetron sputtering technique, and all of them were treated by rapid thermal annealing at different temperatures. The structure, the morphology and the optical properties of the annealed nano-Ag films were characterized by X-ray diffraction, scanning electron microscopy, and UV-Vis-NIR spectroscopy. The experimental results show that the open area fraction of the film and spacing between islands or nanoparticles increase with the increase of the annealing temperature, while the aspect ratio decreases. The anisotropic worm-like island films have been reshaped into isotropic nanospheres. The surface plasmon (SP) resonance band blue shifts and narrows continuously with increasing heating temperature. Analyses show that the SP resonance of the nano-Ag films can be modulated by morphology evolution induced by rapid thermal annealing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 906 (2013)
Analysis of Cloud Spectral Structure Characteristics Based on Cloud Profile Radar Data
HAN Yong, and LV Da-ren
Cloud plays a very important role in the earth-atmosphere system. However, the current climate models are still lacking data about internal fine structure of cloud. And when the traditional passive satellite radiometer is used for remote sense, a plentiful information of the vertical distribution of cloud layer will beCloud plays a very important role in the earth-atmosphere system. However, the current climate models are still lacking data about internal fine structure of cloud. And when the traditional passive satellite radiometer is used for remote sense, a plentiful information of the vertical distribution of cloud layer will be lost. For these reasons, NASA proposed the launch project of CloudSat, Whose purpose is to provide the necessary observation, and then allow us to understand better the internal structure of the cloud. CloudSat was successfully launched on April 28, 2006. It carried the first cloud profile radar (CPR) with W band (94 GHz), which can provide continuous and global time sequence vertical structure and characteristics of cloud. In the present paper, using CloudSat satellite data, we analyzed the 8th “Morakot” and 15th “ Koppu” typhoon cloud systems. According to the “typhoon” cloud detection results, the radar reflectivity, cloud types and optical thickness successive variation of cloud layer were gotten, which will provide a reference for studying optical properties of typhoon cloud system..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 911 (2013)
Laser Photolysis Study on Photo-Oxidation Reactions of Aromatic Amino Acids with Triplet 2-Methylanthraquinone
CAO Xi-yan, FU Hai-ying, ZHU Li, and WＵ Guo-zhong
The transient photo-sensitive oxidation between 2-methylanthraquinone (MAQ) and aromatic amino acids (namely tryptophan, tyrosine and phenylalanine) in acetonitrile/water (1∶1, V/V) solution was investigated by laser photolysis techniques with the excitation wavelength of 355 nm. The triplet state absorption of 2-methyThe transient photo-sensitive oxidation between 2-methylanthraquinone (MAQ) and aromatic amino acids (namely tryptophan, tyrosine and phenylalanine) in acetonitrile/water (1∶1, V/V) solution was investigated by laser photolysis techniques with the excitation wavelength of 355 nm. The triplet state absorption of 2-methylanthraquinone was attributed to 390, 450 and 590 nm and the anion radical absorption of MAQ was due to 390 and 490 nm identified by the electron transfer reactions from 4-diazabicyclo ［2.2.2］ octane (DABCO) or diphenylamine (DPA) to 3MAQ*. With the decay of 3MAQ*, the MAQ·- at 490 nm appeared, which indicated that the electron transfer reactions between 3MAQ* and amino acids occurred. Moreover, the rate constants were deduced to be 3.0×109, 1.1×109 and1.8×108 L·mol-1·s-1 for TrpH, TyrOH and PHE, respectively. On the other hand, the free energy changes (ΔG) of the reactions showed that the proposed electron transfer steps are thermodynamically feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 916 (2013)
Intrinsic Section and Its Interception Model for Temporal Pulse of THz-TDS
SU Hai-xia, ZHANG Zhao-hui, ZHAO Xiao-yan, LI Zhi, YAN Fang, and ZHANG Han
Using THz-TDS to detect the THz temporal pulse and calculate the absorption spectrum of the sample is the main access to qualitative and quantitative analysis. The shape and the amplitude of the THz absorption spectra are not only related to the sample, but also closely related to the length of the chosen THz pulse in Using THz-TDS to detect the THz temporal pulse and calculate the absorption spectrum of the sample is the main access to qualitative and quantitative analysis. The shape and the amplitude of the THz absorption spectra are not only related to the sample, but also closely related to the length of the chosen THz pulse in the calculation, which was discovered in our experiments. It is the main cause of this problem that the flaky sample reflects the THz wave many times, which will give rise to the Fabry-Perot effect. So the sample-probing temporal signal is divided into the intrinsic section with the sample’s information directly, low SNR noise section, and unwanted Fabry-Perot reflections section with the overlapped information. Based on THz pulse generation mechanism and the relationship between the pulse amplitude and the attenuate process, a model of intercepting the intrinsic section in terahertz time-domain pulse was proposed and was proved reliable and stable by the results from experiments performed with amino acids: glutamine(Gln), histidine(His), and cystine(Cys)..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 921 (2013)
Comparative Investigation of the Discharge Characteristics of a Single Needle Jet and Needle-Plate Jet
LI Xue-chen, CHANG Yuan-yuan, JIA Peng-ying, ZHAO Huan-huan, LIU Run-fu, and DI Cong
In the present paper, discharge characteristics were studied in atmospheric pressure argon by a single needle jet and needle-plate jet through combination of optical measurement and electrical one. Results show that the length and cross-sectional area of the plasmas generated in the two jets increase with increasing thIn the present paper, discharge characteristics were studied in atmospheric pressure argon by a single needle jet and needle-plate jet through combination of optical measurement and electrical one. Results show that the length and cross-sectional area of the plasmas generated in the two jets increase with increasing the peak value of the applied voltage. The cross-sectional area generated by needle-plate jet is bigger than that of the single needle jet at the same voltage. A lower inception voltage is needed for the needle-plate jet compared with the single needle jet at the same Up. Through the spectra emitted from the two jets, electron temperature and vibration temperature wee compared for the plasmas generated by the single needle jet and needle-plate jet, respectively. It can be found that the electron temperature and the vibrational temperature of the two jets increase with increasing Up. The needle-plate jet has higher values of electron temperature and vibrational temperature than the single needle jet at the same Up. These results have significant values for the industrial application of the atmospheric pressure plasma jet..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 926 (2013)
Optical Constants Determination of Zinc Selenide by Inversing Transmittance Spectrogram
LI Dong, AI Qing, and XIA Xin-lin
The transmittance models of single slab and two spliced slabs were built, and a new method to determine optical constants of materials was proposed based on inversing the transmittance spectrograms of single slab and two spliced slabs. The measurements of transmittance spectrogram of zinc selenide glass slabs with diffThe transmittance models of single slab and two spliced slabs were built, and a new method to determine optical constants of materials was proposed based on inversing the transmittance spectrograms of single slab and two spliced slabs. The measurements of transmittance spectrogram of zinc selenide glass slabs with different thickness in the infrared wavelength range of 1.33~21 μm at normal incidence were investigated by Bruke V70 FTIR spectrometer. The optical constants of zinc selenide were achieved by the inverse methods. The results indicate that the optical constants of zinc selenide determined by the new inverse method are in good agreement with previous data sets..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 930 (2013)
Spectra Characteristics and Electroluminescence Performance of Novel Fluorene Derivatives with Aggregation Fluorescence Enhancement
MA Zhu, YU Jun-sheng, JIANG Long-feng, DONG Shou-cheng, LI Zhen, and HU Song
The photoluminescence (PL) spectra and UV-Visible absorption spectra of three novel fluorene derivatives solution containing different triphenylamine (TPA) and tetraphenyl-benzene (TPB) groups were systematically investigated. The PL spectra of the acetone/water solution were tested to analyze the capability of suppresThe photoluminescence (PL) spectra and UV-Visible absorption spectra of three novel fluorene derivatives solution containing different triphenylamine (TPA) and tetraphenyl-benzene (TPB) groups were systematically investigated. The PL spectra of the acetone/water solution were tested to analyze the capability of suppression concentration quenching (SCQ). The results showed that when water fraction ranged from 50% to 90%, the spectral irradiance of the mixture was obviously increased. Meanwhile, the PL spectra had blue shift due to the blue crystalline aggregation of novel fluorene derivatives, and the blue shift is proportional to the order of crystalline aggregation. Moreover, since the tetraphenyl-benzene and triphenylamine functional groups were tailored to fluorene backbone to suppress the concentration quenching of the fluorene dye and improve the charge carrier transporting ability, the non-doped organic light-emitting devices (OLEDs) were achieved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 935 (2013)
Synthesis and Luminescence Properties of Mg2Y8Si6O26∶Ce3+, Mn2+ Phosphor
YANG Yan-min, SU Xian-yuan, JIAO Fu-yun, LI Zi-qiang, and ZHANG Shao-yang
Mg2Y8Si6O26∶Ce3+, Mn2+ phosphor was synthesized by the high temperature solid-state reaction, and the structure and luminescence properties were characterized by X-ray diffraction (XRD) and fluorescence spectrophotometer. The XRD pattern demonstrated that the synthetic material belongs to the hexagonal phase of Mg2Y8SiMg2Y8Si6O26∶Ce3+, Mn2+ phosphor was synthesized by the high temperature solid-state reaction, and the structure and luminescence properties were characterized by X-ray diffraction (XRD) and fluorescence spectrophotometer. The XRD pattern demonstrated that the synthetic material belongs to the hexagonal phase of Mg2Y8Si6O26 crystal without detectable impurity and space group P63/m. The excitation and emission spectrum showed that there exist two lattice positions for Ce3+ in Mg2Y8Si6O26 crystal and their luminescence properties were compared. There are two emission peaks at 400 and 600 nm in the emission spectra under excitation at 286 nm, which come from Ce3+ and Mn2+ emission, respectively. It was demonstrated that there exists energy transfer between Ce3+ and Mn2+. The white light can be achieved by changing Mn2+ concentration. It can be used as a potential single-phased white phosphor excited by ultraviolet light..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 940 (2013)
Study on Sr3LiMgV3O12∶Eu3+ Single-Phase Phosphor for White LED
XU Guo-tang, LIANG Pei, HUANG Jie, WANG Le, DONG Qian-min, LIU Yang, and HUA You-jie
A novel broadband emission phosphor Sr3-2xLi1+xMgV3O12∶xEu3+ was synthesized by a solid-state reaction method. Then discussed the luminous property under the influence of temperature and doping density of Eu3+, was discussed. X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectra werA novel broadband emission phosphor Sr3-2xLi1+xMgV3O12∶xEu3+ was synthesized by a solid-state reaction method. Then discussed the luminous property under the influence of temperature and doping density of Eu3+, was discussed. X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectra were used to characterize the feature of Sr3-2xLi1+xMgV3O12∶xEu3+. The excitation and emission spectra exhibit that the phosphor of Sr3-2xLi1+xMgV3O12∶xEu3+ matches with nearly ultraviolet chip. The emission band covers from 450 to 630 nm, which shows that the phosphor is promising single-phase phosphors for white LED..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 945 (2013)
Infrared Spectroscopy Based on Quantum Cascade Lasers
WEN Zhong-quan, CHEN Gang, PENG Chen, and YUAN Wei-qing
Quantum cascade lasers (QCLs) are promising infrared coherent sources. Thanks to the quantum theory and band-gap engineering, QCL can access the wavelength in the range from 3 to 100 μm. Since the fingerprint spectrum of most gases are located in the mid-infrared range, mid-infrared quantum cascade laser based gas sensQuantum cascade lasers (QCLs) are promising infrared coherent sources. Thanks to the quantum theory and band-gap engineering, QCL can access the wavelength in the range from 3 to 100 μm. Since the fingerprint spectrum of most gases are located in the mid-infrared range, mid-infrared quantum cascade laser based gas sensing technique has become the research focus world wide because of its high power, narrow linewidth and fast scanning. Recent progress in the QCL technology leads to a great improvement in laser output power and efficiency, which stimulates a fast development in the infrared laser spectroscopy. The present paper gives a broad review on the QCL based spectroscopy techniques according to their working principles. A discussion on their applications in gas sensing and explosive detecting is also given at the end of the paper..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 949 (2013)
A Method of Hyperspectral Quantificational Identification of Minerals Based on Infrared Spectral Artificial Immune Calculation
LIU Qing-jie, JING Lin-hai, LI Xin-wu, BI Jian-tao, WANG Meng-fei, and LIN Qi-zhong
Rapid identification of minerals based on near infrared (NIR) and shortwave infrared (SWIR) hyperspectra is vital to remote sensing mine exploration, remote sensing minerals mapping and field geological documentation of drill core, and have leaded to many identification methods including spectral angle mapping (SAM), sRapid identification of minerals based on near infrared (NIR) and shortwave infrared (SWIR) hyperspectra is vital to remote sensing mine exploration, remote sensing minerals mapping and field geological documentation of drill core, and have leaded to many identification methods including spectral angle mapping (SAM), spectral distance mapping(SDM), spectral feature fitting(SFF), linear spectral mixture model(LSMM), mathematical combination feature spectral linear inversion model(CFSLIM) etc. However, limitations of these methods affect their actual applications. The present paper firstly gives a unified minerals components spectral inversion (MCSI) model based on target sample spectrum and standard endmember spectral library evaluated by spectral similarity indexes. Then taking LSMM and SAM evaluation index for example, a specific formulation of unified MCSI model is presented in the form of a kind of combinatorial optimization. And then, an artificial immune colonial selection algorithm is used for solving minerals feature spectral linear inversion model optimization problem, which is named ICSFSLIM. Finally, an experiment was performed to use ICSFSLIM and CFSLIM to identify the contained minerals of 22 rock samples selected in Baogutu in Xinjiang China. The mean value of correctness and validness identification of ICSFSLIM are 34.22% and 54.08% respectively, which is better than that of CFSLIM 31.97% and 37.38%; the correctness and validness variance of ICSFSLIM are 0.11 and 0.13 smaller than that of CFSLIM, 0.15 and 0.25, indicating better identification stability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 954 (2013)
Quantum Chemical Study of Molecular Structure and Infrared Spectra of Four Amino Cobalt Phthalocyanine
XUE Juan-qin, ZHAO Xiao, MA Jing, LIU Yao, WANG Cong, and LI Jing-xian
Four amino cobalt phthalocyanine is a promising photosensitizer, so the study of its spectrum is of great significance. The density functional B3LYP/3-21G* method was used in optimizing the structure of the four configurations of four amino cobalt phthalocyanine, which can calculate the energy of its most stable structFour amino cobalt phthalocyanine is a promising photosensitizer, so the study of its spectrum is of great significance. The density functional B3LYP/3-21G* method was used in optimizing the structure of the four configurations of four amino cobalt phthalocyanine, which can calculate the energy of its most stable structure and infrared spectra in a simulated way. It is concluded that the simulated infrared spectra and the vibration obtained from experiment are in good fitting..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 959 (2013)
Research on NIR Equivalent Spectral Measurement
WANG Zhi-hong, LIU Jie, SUN Yu-yang, TENG Fei, and LIN Jun
When the spectra of the diffuse reflectance of low reflectivity samples or the transmittance of low transmisivity samples are measured by a portable near infrared (NIR) spectrometer, because there is the noise of the spectrometer, the smaller the reflectance or transmittance of the sample, the lower its SNR. Even if trWhen the spectra of the diffuse reflectance of low reflectivity samples or the transmittance of low transmisivity samples are measured by a portable near infrared (NIR) spectrometer, because there is the noise of the spectrometer, the smaller the reflectance or transmittance of the sample, the lower its SNR. Even if treated by denoise methods, the spectra can not meet the requirement of NIR analysis. So the equivalent spectrum measure method was researched. Based on the intensity of the reflected or transmitted signal by the sample under the traditional measure conditions, the light current of the spectrometer was enlarged, and then the signal of the measured sample increased; the reflected or transmitted light of the measure reference was reduced to avoid the signal of the measure reference over range. Moreover the equivalent spectrum of the sample was calculated in order to make it identical with the spectrum measured by traditional method. Thus the NIR spectral SNR was improved. The results of theory analysis and experiments show that if the light signal of the spectrometer was properly increased according to the reflected or transmitted signal of the low reflectivity or transmisivity sample, the equivalent spectrum was the same as the spectrum measured by traditional method and its SNR was improved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 963 (2013)
Application of Wavelet Transform and Neural Network in the Near-Infrared Spectrum Analysis of Oil Shale
LI Su-yi, JI Yan-ju, LIU Wei-yu, and WANG Zhi-hong
In the present study, an innovative method is proposed, employing both wavelet transform and neural network, to analyze the near-infrared spectrum data in oil shale survey. The method entails using db8 wavelet at 3 levels decomposition to process raw data, using the transformed data as the input matrix, and creating thIn the present study, an innovative method is proposed, employing both wavelet transform and neural network, to analyze the near-infrared spectrum data in oil shale survey. The method entails using db8 wavelet at 3 levels decomposition to process raw data, using the transformed data as the input matrix, and creating the model through neural network. To verify the validity of the method, this study analyzes 30 synthesized oil shale samples, in which 20 samples are randomly selected for network training, the other 10 for model prediction, and uses the full spectrum and the wavelet transformed spectrum to carry out 10 network models, respectively. Results show that the mean speed of the full spectrum neural network modeling is 570.33 seconds, and the predicted residual sum of squares (PRESS) and correlation coefficient of prediction are 0.006 012 and 0.843 75, respectively. In contrast, the mean speed of the wavelet network modeling method is 3.15 seconds, and the mean PRESS and correlation coefficient of prediction are 0.002 048 and 0.953 19, respectively. These results demonstrate that the wavelet neural network modeling method is significantly superior to the full spectrum neural network modeling method. This study not only provides a new method for more efficient and accurate detection of the oil content of oil shale, but also indicates the potential for applying wavelet transform and neutral network in broad near-infrared spectrum analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 968 (2013)
Application of Mid-Infrared Wavelength Tunable Laser in Glucose Determination
YU Song-lin, LI Da-chao, ZHONG Hao, SUN Chang-yue, and XU Ke-xin
The authors proposed a method of control and stabilization for laser emission wavelengths and power, and presented the mid-infrared wavelength tunable laser with broad emission spectrum band of 9.19~9.77 μm, half wave width of 4 cm-1, spectral resolution of 2.7×104 and max power of 800 mW with fluctuation ＜0.8% inThe authors proposed a method of control and stabilization for laser emission wavelengths and power, and presented the mid-infrared wavelength tunable laser with broad emission spectrum band of 9.19~9.77 μm, half wave width of 4 cm-1, spectral resolution of 2.7×104 and max power of 800 mW with fluctuation ＜0.8% in the present paper. The tunable laser was employed as the light source in combination with ATR sensor for glucose measurement in PBS solution. In our experiments, absorbance at the five laser emission wavelengths, including 1 081, 1 076, 1 051, 1 041 and 1 037 cm-1 in the 9R and 9P band of the laser emission spectrum, all correlates well with the glucose concentration (R2＞0.99, SD＜0.0004, P＜0.000 1). Especially, the sensitivity of this laser spectroscopy system is about 4 times as high as that of traditional FTIR spectrometer..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 972 (2013)
Analysis of Spirulina Powder by Fourier Transform Infrared Spectroscopy and Calculation of Protein Content
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Spirulina, Spirulina powder and dextrin standard were analyzed and identified by Infrared (IR) spectroscopy. The main components, protein(1 657 and 1 537 cm-1) and carbohydrate(1 069 and 1054 cm-1), had distinct fingerprint characteristics of IR spectra. By comparing the IR spectra of Spirulina, Spirulina powder and deSpirulina, Spirulina powder and dextrin standard were analyzed and identified by Infrared (IR) spectroscopy. The main components, protein(1 657 and 1 537 cm-1) and carbohydrate(1 069 and 1054 cm-1), had distinct fingerprint characteristics of IR spectra. By comparing the IR spectra of Spirulina, Spirulina powder and dextrin standard, the dominant nutrition in Spirulina powder was identified as protein and carbohydrate. The dominant accessory added in Spirulina powder was dextrin. Comparing the IR spectra of Spirulina powder from 28 different factories and figuring out the correlation provides the information about the amount of accessory. A standard curve of the ratio of absorption peak intensities to protein content was constructed to accurately determine the amount of protein in Spirulina powder..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 977 (2013)
Raman Spectra of Different Kinds of Thalassemia Erythrocytes with the Effect of pH
WU Zheng-jie, WANG Cheng, and LIN Zheng-chun
Thalassemia is a kind of blood diseases which has high morbidity and large influence. Previous methods for diagnosis are all very cumbersome and time consuming. By comparing Raman spectra of different kinds of thalassemia and normal erythrocytes at acid or alkaline pH, it was found that β-thalassemia and α-thalassemia Thalassemia is a kind of blood diseases which has high morbidity and large influence. Previous methods for diagnosis are all very cumbersome and time consuming. By comparing Raman spectra of different kinds of thalassemia and normal erythrocytes at acid or alkaline pH, it was found that β-thalassemia and α-thalassemia erythrocytes have dissimilar Raman spectra in the acidic environment, such as the Raman spectra of β-thalassemia erythrocytes showed higher intensity at the characteristic bands assigned to oxyhemoglobin, and the characteristic bands assigned to deoxyhemoglobin were even completely replaced; β-thalassemia erythrocytes membrane has a smaller chain interaction between the transverse order parameters than normal erythrocytes, and the Slat values are different for different stages of anemia, while the Slat values are similar between α-thalassemia and normal erythrocytes, indicating that based on the effect of pH it is possible to diagnose thalassemia more quickly by using Raman spectra..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 982 (2013)
Fabrication of Two Dimensional Silver Cavity Array and Its Application in SERS Detection
GU Xue-fang, SHI Jian, JIANG Guo-qing, JIANG Guo-min, and TIAN Shu
The highly ordered two dimensional micro-/nano-sized silver cavity was fabricated by galvanostatic multistep method using ordered arrays of close-packed 700 nm diameter polystyrene spheres as templates. The morphology and the surface plasmon resonance of this silver cavity array were characterized by scanning electron The highly ordered two dimensional micro-/nano-sized silver cavity was fabricated by galvanostatic multistep method using ordered arrays of close-packed 700 nm diameter polystyrene spheres as templates. The morphology and the surface plasmon resonance of this silver cavity array were characterized by scanning electron microscope and reflectance UV-Vis spectra, and surface-enhanced Raman scattering (SERS) spectra of p-aminothiophenol (PATP) and Rhodamine 6G (R6G) on as-prepared substrate were also studied. The results show that: the depth of cavities can be easily regulated through varying the parameters of the electrochemical deposition. As SERS substrates for the detection of PATP molecules, the two dimensional Ag cavity arrays exhibit excellent performance and the enhancement factors can be as high as the 107 order. In addition to the high-intensity enhancement, it is also found that the SERS spectra are highly reproducible on this Ag cavity arrays. The relative standard deviation of the peak intensity of PATP molecules at 1 077 cm-1 was calculated to be 8.4%. The as-prepated substrate can be used for the quantitative detection of R6G, and the detection limit reaches as low as 0.1 ng·mL-1..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 987 (2013)
Research on the Quantitative Analysis of D2 Using Raman Spectroscopy
WANG Hong-zu, SHEN Chun-lei, LONG Xing-gui, LIANG Jian-hua, and ZHOU Xiao-song
Raman spectroscopy was used for experimental research on D2 signal to noise ratio(SNR) under different conditions. The 32 mW Ar+ laser was injected into the Raman quartz glass cells to study the effect of grating, laser power, exposure time and the gas pressure on D2 Raman spectra SNR. D2 Raman spectral signal to noiseRaman spectroscopy was used for experimental research on D2 signal to noise ratio(SNR) under different conditions. The 32 mW Ar+ laser was injected into the Raman quartz glass cells to study the effect of grating, laser power, exposure time and the gas pressure on D2 Raman spectra SNR. D2 Raman spectral signal to noise ratio is proportional to the laser power, exposure time and gas pressure. The standard curve of the pressure and SNR for this experimental apparatus was obtained. Three sets of random samples were used to verify the formula SNR(J 2→2)=10.6×10-4p+1.271 34. When the deuterium pressure is 21 280 Pa, the relative error is 4.8%. When the pressure increases to 67 235 Pa, the relative error is down to 1.46%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 991 (2013)
Elementary SERS Spectroscopy Studies of Three Kinds of Pathogens in Ag Colloids Prepared by Microwave Method
ZHANG De-qing, SI Min-zhen, LIU Ren-ming, and SU Yong-bo
The normal Raman (NR) and surface enhanced Raman spectroscopy (SERS) for Alternaria alternate, Colletotrichum musae, and fusarium suspensions were measured by a portable Raman spectrometer (785 nm). The result indicates that the silver colloid prepared by microwave method shows high enhancement of Raman scattering for The normal Raman (NR) and surface enhanced Raman spectroscopy (SERS) for Alternaria alternate, Colletotrichum musae, and fusarium suspensions were measured by a portable Raman spectrometer (785 nm). The result indicates that the silver colloid prepared by microwave method shows high enhancement of Raman scattering for the three kinds of pathogens. Comparing SERS spectrums of the three kinds of pathogens, there are some similarities. In these SERS spectrums, the peaks in the range of 500~1 000 cm-1 are very weak. Additionally, the peaks in the range of 1 000~1 600 cm-1 are strong. Meanwhile, the peak at 481 cm-1 is the strongest. Although these spectrums are similar, there are some differences such as the distribution and shape of peaks. Therefore, the three kinds of pathogens can be discriminated quickly..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 996 (2013)
Spectroscopic Characteristics of Different Molecular Weight Dissolved Organic Matter in Water from Yangtze River Estuary
HUANG Wen-dan, ZHOU Li-min, ZHENG Xiang-min, HUANG Jing, and CHEN Shi-ji
Cross flow ultrafiltration systems and three dimensional fluorescence spectrum were used to investigate the fluorescence characterization of different molecular weight dissolved organic matter in water of wet season and dry season from Yangtze River estuary, in order to find out the sources and influencing factors. TheCross flow ultrafiltration systems and three dimensional fluorescence spectrum were used to investigate the fluorescence characterization of different molecular weight dissolved organic matter in water of wet season and dry season from Yangtze River estuary, in order to find out the sources and influencing factors. The results showed that four types of dissolved organic carbon (DOM) fluorescence peaks were observed in the water: humic-like fluorescence peak A and C, and protein-like fluorescence peak B and D. Fluorescent substances mainly existed in the truly dissolved organic matter (UOM, <1 kDa), secondly in low and medium molecular weight of colloidal organic matter (1~500 kDa). Protein of DOM in water mainly originated from anthropogenic sources, then from autochthonous sources. Compared to protein, humic acid of DOM in wet season was both terrigenous and autochthonous sources, while in dry season mainly from terrestrial organic matter. In addition, humic acid in UOM was mainly derived from biological decomposition, however, in colloidal organic matter (COM) came from terrestrial organic matter and was affected by resuspension effects. There was linear correlation between fluorescence intensity and environmental parameters. It was revealed that the complex environmental conditions would influence the fluorescent substance of DOM in water from Yangtze River estuary..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1000 (2013)
Homogeneous Phase Fluorescence Assay Based on NaYF4∶Er3+, Yb3+ UCNPs as Donors
SONG Kai, ZHANG Qing-bin, ZHAO Jun-wei, and KONG Xiang-gui
Upconversion nanoparticles (UCNPs) of small size have great potential in homogeneous assay based on fluorescence resonance energy transfer (FRET). A novel approach of surface ligand-exchange for preparing water-soluble and amido-functionalized NaYF4∶Er3+, Yb3+ UCNPs with 12 nm was developed. The ligand exchange processUpconversion nanoparticles (UCNPs) of small size have great potential in homogeneous assay based on fluorescence resonance energy transfer (FRET). A novel approach of surface ligand-exchange for preparing water-soluble and amido-functionalized NaYF4∶Er3+, Yb3+ UCNPs with 12 nm was developed. The ligand exchange process was confirmed by Fourier transform infrared spectra. Investigations by scan electron microscopy showed no obvious variations in the size and shape of the UCNPs. The circular dichroism characterization demonstrates that the secondary structure of the avidin remains largely intact after the conjugation. Avidin-biotin served as a bridge to make the short enough distance for FRET between the acceptor biotinylated R-phycoerythrin and the donors avidin-conjugated UCNPs. When the free biotins were added into this system, they competitively combined with avidin on the UCNPs surface and impede the FRET to triggered fluorescence changes. According to the relationship between this change and the addition of the amount of biotin, such FRET-based approach can reach a limit of detection in the nanomolar concentration range..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1005 (2013)
The Fluorescence of Terbium Complex and Its Application in Wavelength Conversion Membrane
WANG Man-li, ZHANG Xiao-hui, YIN Hong-zong, and XU Kun
Terbium was selected as test material for its strong fluorescence effect, and sulfosalicylic acid was used as first ligand, polyvinyl alcohol and polyethylene glycol 2000 as co-ligand, the fluorescence property of complexes in the two systems of ethanol solution and aqueous solution was explored. It was obtained that tTerbium was selected as test material for its strong fluorescence effect, and sulfosalicylic acid was used as first ligand, polyvinyl alcohol and polyethylene glycol 2000 as co-ligand, the fluorescence property of complexes in the two systems of ethanol solution and aqueous solution was explored. It was obtained that the polyvinyl alcohol and polyethylene glycol 2000 are the excellent co-ligands. Further study showed that sufactant is good for fluorescence enhancement of the different complexes and especially sodium dodecyl sulfate is best while exploring the impact of acidity on the fluorescence intensity. Terbium-sulfosalicylic acid-polyvinyl alcohol complex was obtained under the conditions of 342 nm for excitation wavelength, and 545 nm for emission wavelength. Mixing the complex into the plastic film in proper proportion, the authors prepared the rare earth light conversion membrane which allowed ultraviolet portion of sunlight to convert to green light the crop photosythesis needed to effectively improve the photosynthetic efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1009 (2013)
Use of Parallel Factor and Two Dimensional Fluorescence Spectroscopy Correlation Technique for Measurement of Reaction between MDA and Cooked Ground Meat
SUN Yan-hui, JIA Xiao-li, MENG Jin-xiu, and PENG Man-li
The fluorescence characteristics of oxidation reaction between MDA and cooked ground meat were analyzed by front face three dimensional synchronous fluorescence spectroscopy, parallel factor and two dimensional correlation technique. The results showed that the reaction system has two synchronous fluorescence peaks, onThe fluorescence characteristics of oxidation reaction between MDA and cooked ground meat were analyzed by front face three dimensional synchronous fluorescence spectroscopy, parallel factor and two dimensional correlation technique. The results showed that the reaction system has two synchronous fluorescence peaks, one is Ex 292 nm and Δλ 50 nm, assigned to the fluorescence characteristics of tryptophan residues in proteins; the other is Ex 400 nm, Δλ 70 nm, corresponding with the fluorescence characteristics of MDA-protein adducts formed during oxidation; The synchronous fluorescence landscape was analyzed using PARAFAC. The loading profiles of 1st and 2nd components had an optimal λ 50 and 70 nm, respectively. During oxidation reaction, the synchronous fluorescence intensity of tryptophan gradually decreased, while the synchronous fluorescence intensity of MDA-protein adducts gradually increased. Two dimensional correlation synchronous fluorescence spectroscopy technique showed that the variation ratio of fluorescence intensity of tryptophan preceded that of MDA-protein adducts..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1014 (2013)
NDVI Difference Rate Recognition Model of Deciduous Broad-Leaved Forest Based on HJ-CCD Remote Sensing Data
WANG Yan, TIAN Qing-jiu, HUANG Yan, and WEI Hong-wei
The present paper takes Chuzhou in Anhui Province as the research area, and deciduous broad-leaved forest as the research object. Then it constructs the recognition model about deciduous broad-leaved forest was constructed using NDVI difference rate between leaf expansion and flowering and fruit-bearing, and the model The present paper takes Chuzhou in Anhui Province as the research area, and deciduous broad-leaved forest as the research object. Then it constructs the recognition model about deciduous broad-leaved forest was constructed using NDVI difference rate between leaf expansion and flowering and fruit-bearing, and the model was applied to HJ-CCD remote sensing image on April 1, 2012 and May 4, 2012. At last, the spatial distribution map of deciduous broad-leaved forest was extracted effectively, and the results of extraction were verified and evaluated. The result shows the validity of NDVI difference rate extraction method proposed in this paper and also verifies the applicability of using HJ-CCD data for vegetation classification and recognition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1018 (2013)
Hyperspectral Estimation of Kalium Content in Apple Florescence Canopy Based on Fuzzy Recognition
ZHU Xi-cun, JIANG Yuan-mao, ZHAO Geng-xing, WANG Ling, and LI Xi-can
The objective of the present paper is fast and nondestructive estimate of kalium content using ASD FieldSpec3 spectrometer determined hyperspectral data in apple florescence canopy. According to detection of hyperspectral data of the apple florescence canopy and kalium content data at laboratory in Qixia city of experiThe objective of the present paper is fast and nondestructive estimate of kalium content using ASD FieldSpec3 spectrometer determined hyperspectral data in apple florescence canopy. According to detection of hyperspectral data of the apple florescence canopy and kalium content data at laboratory in Qixia city of experimental orchards in 2008 and 2009, the correlation analysis of hyperspectral reflectance and its eleven transforms with kalium content was proceeded. The biggest correlation coefficient as independent variable and the estimation model of kalium content were established based on fuzzy recognition algorithms. The model was tested by sample inspection in 2008 and verified by data in 2009. The results showed that the correlation is less for the original spectral reflectance (R) and its reciprocal(1/R), logarithm (lgR), square root (R1/2) and the kalium content, but it is enhanced obviously for their first derivative and second derivative. The correlation coefficient(r) of kalium content estimating model =11.344 5h+1.309 7 is 0.985 1, the total root mean square difference (RMSE) is 0.355 7 and F statistics is 3 085.6. The average relative error of measured values and estimated values for 24 inspection sample is 9.8%, estimation accuracy is 90.2% and verification accuracy is 83.3% utilizing test data in 2009. It was showed that this model is more stable by estimating apple florescence canopy of kalium content and the model precision is able to meet the needs of production..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1023 (2013)
Study of Hyperspectral Polarized Reflectance of Vegetation Canopy at Nadir Viewing Direction
LV Yun-feng
In the present study, corn canopy is the objective. Firstly the polarization of corn canopy was analyzed based on polarization reflection mechanism; then, the polarization of canopy was measured in different growth period at nadir before heading. The result proved the theoretical derivation that the light reflected froIn the present study, corn canopy is the objective. Firstly the polarization of corn canopy was analyzed based on polarization reflection mechanism; then, the polarization of canopy was measured in different growth period at nadir before heading. The result proved the theoretical derivation that the light reflected from corn canopy is polarized, and found that in the total reflection the polarization light accounts for up to 10%. This shows that polarization measurement provides auxiliary information for remote sensing, but also illustrates that the use of the polarization information retrieval of atmospheric parameters should be considered when the surface polarization affects on it..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1028 (2013)
Diagnosis of Nitrogen Content in Upper and Lower Corn Leaves Based on Hyperspectral Data
JIN Liang, HU Ke-lin, TIAN Ming-ming, WEI Dan, LI Hong, BAI You-lu, and ZHANG Jun-zheng
Based on the spectral characters of corn leaf nitrogen content in the space, the spectral models for rapid estimating crop nitrogen content were set up, which is practically meaningful to effectively providing the guidance in fertilization. Spectral technology was applied to explore corn leaves nitrogen content distribBased on the spectral characters of corn leaf nitrogen content in the space, the spectral models for rapid estimating crop nitrogen content were set up, which is practically meaningful to effectively providing the guidance in fertilization. Spectral technology was applied to explore corn leaves nitrogen content distribution regularity and the relationship between the nitrogen content and plant index was analysed and then the estimation models were built. The results showed N content in upper leaves is higher than that in lower leaves in four growing stages; lower leaves at tassel emerge stage are sensitive to nitrogen losses, which could be used in guiding fertilization in grain production; optimum estimation models were built atjointing stage, the full-grown stage and tasseling stage, The research results provided the proof of crop nutrient analysis and rational fertilization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1032 (2013)
Hard and Soft Classification Method of Multi-Spectral Remote Sensing Image Based on Adaptive Thresholds
HU Tan-gao, XU Jun-feng, ZHANG Deng-rong, WANG Jie, and ZHANG Yu-zhou
Hard and soft classification techniques are the conventional methods of image classification for satellite data, but they have their own advantages and drawbacks. In order to obtain accurate classification results, we took advantages of both traditional hard classification methods (HCM) and soft classification models (Hard and soft classification techniques are the conventional methods of image classification for satellite data, but they have their own advantages and drawbacks. In order to obtain accurate classification results, we took advantages of both traditional hard classification methods (HCM) and soft classification models (SCM), and developed a new method called the hard and soft classification model (HSCM) based on adaptive threshold calculation. The authors tested the new method in land cover mapping applications. According to the results of confusion matrix, the overall accuracy of HCM, SCM, and HSCM is 71.06%, 67.86%, and 71.10%, respectively. And the kappa coefficient is 60.03%, 56.12%, and 60.07%, respectively. Therefore, the HSCM is better than HCM and SCM. Experimental results proved that the new method can obviously improve the land cover and land use classification accuracy..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1038 (2013)
Study on the Difference in Canopy Spectral Reflectance and Chlorophyll Content of Spring Wheat at Jointing Stage in Different Land
JIN Yan-hua, XIONG Hei-gang, ZHANG Fang, and WANG Li-feng
Taking chlorophyll content, seedling height, blade width and canopy spectral reflectance of spring wheat at jointing stage in different lands as data source, by analyzing the correlations between canopy spectral reflectance and chlorophyll content, making regression analysis for red edge inflection points of canopy speTaking chlorophyll content, seedling height, blade width and canopy spectral reflectance of spring wheat at jointing stage in different lands as data source, by analyzing the correlations between canopy spectral reflectance and chlorophyll content, making regression analysis for red edge inflection points of canopy spectral reflectance and chlorophyll content of spring wheat, the chlorophyll content monitor models of irrigated and dry land were established respectively. The results showed that there is a significant difference in chlorophyll content of spring wheat, with chlorophyll content of irrigated land much higher. Although there is a good correlation between wheat canopy spectral reflectance and chlorophyll content in the two lands, the correlation of dry spring wheat is lower than irrigated land in visible light and near infrared band. In the visible region, dry spring wheat canopy spectral reflectance is higher, inverse in near-infrared region. Due to high soil moisture, the dry-land spring wheat grows well and there is little difference from irrigated land. The monitor model of red-edge inflection points of canopy spectral reflectance and chlorophyll content of spring wheat at different lands showed that irrigated land wheat is available for linear model, The estimated precision is 94.06%, but dry land is suitable for binomial model, The estimated precision is 97.15%, 10.48% higher than linear model..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1043 (2013)
Application of Relevance Vector Machines in Nitrate Detection of Wastewater
ZENG Tian-ling, WEN Zhi-yu, and WEN Zhong-quan
On account of the high dimension and band overlapping features of the ultraviolet spectrum of complex wastewater, the relevance vector machine (RVM) algorithm combined with contiguous ultraviolet spectrum technology was applied in nitrate modeling to realize the rapid and accurate prediction of nitrate-nitrogen. At firOn account of the high dimension and band overlapping features of the ultraviolet spectrum of complex wastewater, the relevance vector machine (RVM) algorithm combined with contiguous ultraviolet spectrum technology was applied in nitrate modeling to realize the rapid and accurate prediction of nitrate-nitrogen. At first the algorithm principle of RVM was introduced, and then based on the ultraviolet spectra of collected pharmacy effluent samples, ultraviolet absorption data between 230 and 245 nm were selected for modeling. Multivariate linear regression, partial least squares, classical support vector machines (SVM) and RVM methods were applied in nitrate modeling respectively and model performances were compared. Experimental result indicates that RVM method has advantages of higher prediction accuracy, sparser model than other compared methods and faster operation speed than SVM method. The relative full-range error is less than 4.5%F.S.. Finally, it can be concluded that the LS-SVM method is effective in rapid and accurate detection of nitrate in practical wastewater with complicated composition..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1048 (2013)
Study of Coupling Mechanism between Hydrocarbon Generation and Structure Evolution in Low Rank Coal
LI Wu, ZHU Yan-ming, CHEN Shang-bin, and SI Qing-hong
The structure evolution in the process of low rank coal hydrocarbon generation was studied using Fourier transform infrared spectroscopy and gas chromatography. Gaseous hydrocarbon yield and change law of functional groups were obtained. The results show that: the coal pyrolysis products are mainly gaseous hydrocarbon The structure evolution in the process of low rank coal hydrocarbon generation was studied using Fourier transform infrared spectroscopy and gas chromatography. Gaseous hydrocarbon yield and change law of functional groups were obtained. The results show that: the coal pyrolysis products are mainly gaseous hydrocarbon C1-5. Methane generation instantaneous yield curve contains four peak of hydrocarbon pyrolysis. Oxygen-containing functional group and alkyl side chain of low rank coal chemical structure reduced while aromatization degree increased along with coal rank. The characteristic absorption peak of coal structure of aliphatic hydrocarbons, aromatic hydrocarbon, methyl CO base CC of alkanes and aromatic structure of methyl and methylene were characterized by 2 950, 2 920, 2 860, 1 730, 1 705, 1 600 and 1 380～1 460 cm-1 selected in FTIR spectra. Temperature 420 ℃ is the turning point, before the absorption peak intensity gradually decreases, and then increases slightly. Three major structural evolution stages of coalification mechanism were revealed. Finally, the low rank coal hydrocarbon structure evolution pattern was put forward..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1052 (2013)
Measurement and Analysis of Reflected Information from Crops Canopy Suffering from Wind Disaster Influence
BAO Yu-long, ZHANG Ji-quan, LIU Xiao-jing, WANG Yong-fang, MA Dong-lai, and SUN Zhong-qiu
The corn in the grain filling stage fell over in the central region of Jilin province by the Typhoon Bolaven influence. In order to determine the impact of falling over corn canopy on the reflected information, the hyperspectral reflectance was detected at different viewing zenith angles, at the same time, the polarizeThe corn in the grain filling stage fell over in the central region of Jilin province by the Typhoon Bolaven influence. In order to determine the impact of falling over corn canopy on the reflected information, the hyperspectral reflectance was detected at different viewing zenith angles, at the same time, the polarized reflection was also measured. The results from the analysis by combining the reflection and polarization from corn canopy showed that the reflection of falling over corn is low in visible, while increases in the near infrared wavelength. The reflection from falling over corn canopy was more anisotropic than stand-up corn canopy. The reflected light was highly polarized, the polarization of corn canopy provided the probability for distinguishing between falling over corn and stand-up corn. This research provides a basis for estimating the disaster area and lost units..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1057 (2013)
Synthesis and Spectral Characteristics of Selenium-Chelated Methionine with Hexagon
JIN Li-e, WANG Xiao-juan, SHEN Fan-fan, and CAO Qing
Using methionine and anhydrous ethanol as raw material, p-toluene sulfonic acid as catalyst, and benzene as a carrying water agent, methionine ester was first synthesized. Then, selenium-chelated methionine was prepared through the reaction of methionine ester with sodium selenite by a certain proportion, settling and Using methionine and anhydrous ethanol as raw material, p-toluene sulfonic acid as catalyst, and benzene as a carrying water agent, methionine ester was first synthesized. Then, selenium-chelated methionine was prepared through the reaction of methionine ester with sodium selenite by a certain proportion, settling and crystallizing at lower temperature. The ξ potential of the resultant was determined by micro-electrophoresis, through which the isoelectric point was calculated. Based on the principle of isoelectric point, it was separated and purified. The spectral properties of the resultant were analyzed by infrared spectrum, utraviolet spectrum, X ray diffraction analysis and 1H-NMR, from which we got the information of the resultant structure that has a hexagon composing of sulfur atom of methionine, nitrogen of amine and central selenium ion of four-valence..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1061 (2013)
Spectral Response of Maize Leaves and Prediction of Their Nitrogen Content
CHEN Zhi-qiang, WANG Lei, BAI You-lu, YANG Li-ping, LU Yan-li, WANG He, and WANG Zhi-yong
In the present study, a 2-year maize field experiment with different fertilizer dose was conducted. The spectral response sensitive area of maize leaves in different levels was discussed using hyperspectral technology at booting stage. Based on the correlation analysis of original reflectivity and its first derivation In the present study, a 2-year maize field experiment with different fertilizer dose was conducted. The spectral response sensitive area of maize leaves in different levels was discussed using hyperspectral technology at booting stage. Based on the correlation analysis of original reflectivity and its first derivation with maize leaf nitrogen contents, prediction models were constructed. The results indicated that under different fertilizer dose spectral response sensitive areas of maize leaves were in visible band around 550 and 761~1 300 nm; under different levels which was in visible band around 550 nm; maize leaf nitrogen contents were significantly correlated with spectral reflectance and its first derivative in 470~760 nm band. Through further comparison and selection, the index prediction models built with spectral indices DSI(564, 681) and DSI(681, 707) were the best prediction models, the prediction accuracy were 93.43% and 93.39%, therefore nitrogen content of maize leaves could be effectively estimated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1066 (2013)
An Unsupervised Method of Extracting Constructions from Color Remote Sensed Image Based on Mean Shift and Neutrosophic Set
YU Bo, NIU Zheng, WANG Li, LIU Ya-qi, and CHEN Fang
The diversity of spectral and textural information of constructions has become an obstacle in automatically detecting buildings. To overcome that, a method to detect constructions based on remote sensed images is proposed. It synthesizes neutrosophic set and mean shift algorithms to segment images transformed to neutroThe diversity of spectral and textural information of constructions has become an obstacle in automatically detecting buildings. To overcome that, a method to detect constructions based on remote sensed images is proposed. It synthesizes neutrosophic set and mean shift algorithms to segment images transformed to neutrosophic set domain. After segmentation, an image is generated whose pixels mainly describe spectral categories based on main land features. Constructions can be extracted by generated spectral information. The algorithm overcomes the shortcomings of low stability, spectral discontinuity and complicated spectral information by enhancing and segmenting image in neutrosophic set domain. It avoids operations of extracting connected area before recognizing land features as well. Experiments show that the proposed algorithm can not only extract entire constructions steadily, precisely, completely and simply but also satisfies the demand of extracting constructions from high resolution remote sensing images..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1071 (2013)
The Study on Spectral Reflectance Reconstruction Based on Wideband Multi-Spectral Acquisition System
LIU Zhen, WAN Xiao-xia, HUANG Xin-guo, LIU Qiang, and LI Chan
The multispectral image acquisition oriented to reproduction requests that the data is device independent and scenes independent, and can realize the characterization of the original color information. Aiming at disturbance, noise error of system, and the requirement for training samples’ typical representative and corThe multispectral image acquisition oriented to reproduction requests that the data is device independent and scenes independent, and can realize the characterization of the original color information. Aiming at disturbance, noise error of system, and the requirement for training samples’ typical representative and correlation, the authors proposed orthogonal regression spectral algorithm and training samples selection algorithm based on subspace tracking, through the mapping function between the spectral space and color space, by selecting the best samples in typical representative and correlation samples between target samples and selected samples. The modified Sinar 75H trichromatic digital camera combined with bandpass filter glasses were used for experiment, the data show that our method has higher spectral and chromaticity accuracy, the training samples selected by subspace tracking method are uniformly distributed in the sample space, and have good orthogonality. The statistics experimental results indicate that the performance of the proposed method is obviously better than that of previous method, in both color difference error and spectral reflectance error..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1076 (2013)
The Study of LAI Estimation Using a New Vegetation Index Based on CHRIS Data
WANG Li-juan, NIU Zheng, HOU Xue-hui, and GAO Shuai
Leaf area index (LAI) is an important structural parameter of vegetation canopy, the correct estimation of which has been the focus in the remote sensing community. As a kind of hyperspectral and multi-angle remote sensing data with higher resolution (17 m), PROBA/CHRIS has significant application value in LAI inversioLeaf area index (LAI) is an important structural parameter of vegetation canopy, the correct estimation of which has been the focus in the remote sensing community. As a kind of hyperspectral and multi-angle remote sensing data with higher resolution (17 m), PROBA/CHRIS has significant application value in LAI inversion. In the present paper, the analytical two-layer canopy reflectance model (ACRM) was used to simulate a series of reflectances with different LAI values. Based on this, a new vegetation index was built and successfully applied to LAI inversion of PROBA/CHRIS image data. Our results indicated that: compared with the spectral index NDVI and multi-angle index HDS, the new index could make better use of spectrum and multi-angle messages and have a better correlation with LAI of the study area; moreover, the correlation coefficient R2 reached up to 0.734 7. And in order to obtain the figure of LAI distribution of the study area, we used the optimal fit equation between LAI and HDVI to estimate LAI, and the accuracy of the RMSE was 0.619 8..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1082 (2013)
Studies on Preparation of Meso-Hangjin2# Clay and Its Characteristic of Spectrum
Erihemu, Sagala, ZHANG Yu, and Zhaorigetu
The natural clay named Hangjin2# clay was used as raw materials and cetyltrimethylammonium bromide (CTAB) was used as organo-intercalating reagents to synthesize organic modified clay from acid treated Hangjin2# clay. The results of FTIR show that the modified reagents were intercalated to the layer of Hangjin2# clay. The natural clay named Hangjin2# clay was used as raw materials and cetyltrimethylammonium bromide (CTAB) was used as organo-intercalating reagents to synthesize organic modified clay from acid treated Hangjin2# clay. The results of FTIR show that the modified reagents were intercalated to the layer of Hangjin2# clay. The meso-Hangjin2# clay was prepared with organic modified clay calcinated at 550 ℃ and the crystalline phase and morphology were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The surface area and pore volume were analyzed by N2 adsorption desorption, and the characteristics of spectrum were studied via FTIR and UV-Vis(DRS) spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1087 (2013)
Spiropyran-Based Fluorescent Sensor for Hg2+, Cr3+, Ag+ and Their Interaction Spectra
LI Bin-lian, YANG Yun-xu, CHEN Zhang-long, HAN Wen, and ZHU Hai-bo
A 6′,8′-di-tert-butyl-1-hydroxyethyl-3,3-dimethyl-indoline benzospiropyran L1and its derivative L2 were synthesized and characterized. Chelation-enhanced appearswhen L1 with electron donating groups of 6′,8′-di-tert-butyl touch on benzospiro--pyran and affect the stability of cyanine structure. L1 exhibited high selectA 6′,8′-di-tert-butyl-1-hydroxyethyl-3,3-dimethyl-indoline benzospiropyran L1and its derivative L2 were synthesized and characterized. Chelation-enhanced appearswhen L1 with electron donating groups of 6′,8′-di-tert-butyl touch on benzospiro--pyran and affect the stability of cyanine structure. L1 exhibited high selectivity to Hg2+, Cr3+, Ag+ over other metal ions. While, there was no obvious interferences of coexist metal ions on Hg2+, Cr3+, Ag+ detection. The Hg2+, Cr3+, Ag+ recognition of L1 not only could be achieved by means of fluorescense and absorption “turn-on” spectra but also an obvious color change from colorless to yellowish by naked-eyes. The binding of L1 to Ag+, Cr3+, Hg2+ are in 1∶1 stoichometry and the detection limits are 7.435 8×10-6, 6.126 8×10-6, 3.452 4×10-6 mol·L-1. The sensing mechanism was also investigated from L2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1092 (2013)
Research Progress in Water Quality Monitoring Technology Based on Ultraviolet Spectrum Analysis
ZENG Tian-ling, WEN Zhi-yu, WEN Zhong-quan, ZHANG Zhong-wei, and WEI Kang-lin
The water quality monitoring technology based on ultraviolet spectrum analysis has the characteristics of small volume, low cost, and no secondary pollution, and it doesn’t need any reagent and sample pretreatment. On account of these characteristics, the direct ultra-violet technology has remarkable superiority over tThe water quality monitoring technology based on ultraviolet spectrum analysis has the characteristics of small volume, low cost, and no secondary pollution, and it doesn’t need any reagent and sample pretreatment. On account of these characteristics, the direct ultra-violet technology has remarkable superiority over traditional technologies when applied in online monitoring of drinking water, surface water and industrial wastewater, and it has become an important development tendency of modern water monitoring technologies. The principle, characteristics, present situation and development trend of modern water quality monitoring technology based on ultra-violet spectrum analysis were introduced, and the key technical problems were further discussed in this paper..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1098 (2013)
Photometric Determination of Captopril Usinglabel-Free Silver Nanoparticles
LI Rui, and YAN Hong-tao
A simple, rapid and sensitive colorimetric method for the determination of captopril is presented in the present paper. It is based on the fact that captopril can induce the aggregation of AgNPs, thereby resulting in their yellow-to-red color change and the absorbance decrease at λ395 nm. The mechanism of the aggregatiA simple, rapid and sensitive colorimetric method for the determination of captopril is presented in the present paper. It is based on the fact that captopril can induce the aggregation of AgNPs, thereby resulting in their yellow-to-red color change and the absorbance decrease at λ395 nm. The mechanism of the aggregation effect was discussed in detail. Under the optimized conditions, the linear range of determination of captopril was 1~35 μg·mL-1 with correction coefficient 0.998 4. The detection limit of the method for captopril was 0.7 μg·mL-1. The method has been applied to the determination of captopril in tablets with satisfactory result..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1104 (2013)
Optical Emission Analyses of N2/TMG ECR Plasma for Deposition of GaN Film
FU Si-lie, WANG Chun-an, and CHEN Jun-fang
The optical emission spectroscopy of hybrid N2/trimethylgallium (TMG) plasma in an ECR-PECVD system was investigated. The results indicate that the TMG gas is strongly dissociated into Ga*, CH and H even under self-heating condition. Ga species and nitrogen molecule in metastable state are dominant in hybrid ECR plasmaThe optical emission spectroscopy of hybrid N2/trimethylgallium (TMG) plasma in an ECR-PECVD system was investigated. The results indicate that the TMG gas is strongly dissociated into Ga*, CH and H even under self-heating condition. Ga species and nitrogen molecule in metastable state are dominant in hybrid ECR plasma. The concentration of metastable nitrogen molecule increases with the microwave power. On the other hand, the concentration of excited nitrogen molecules and of nitrogen ion decreases when the microwave power is higher than 400 W..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1108 (2013)
Analysis on Concentration, Distribution and Budgets of Mn and Zn in Soybean by Using ICP-AES
ZHOU Hua, JIANG Chun-ming, XU Yong-gang, and MA Qiang
The concentration and distribution of Mn and Zn in soil and soybean in lower reach of Liaohe River Plain were investigated with ICP-AES analysis. The results showed that the available Zn in soils was close to the critical value and the monitoring should be strengthened. Zn concentration in seed and stalk, coupled with The concentration and distribution of Mn and Zn in soil and soybean in lower reach of Liaohe River Plain were investigated with ICP-AES analysis. The results showed that the available Zn in soils was close to the critical value and the monitoring should be strengthened. Zn concentration in seed and stalk, coupled with Mn in stalk, was not affected by fertilization types, while Mn concentration in seed under NPK and NPKO treatments was significantly higher than that with O and CK treatments. Application of organic and inorganic fertilizer increased crop biomass, and consequently increased Mn and Zn storage in soybean. In soil-crop system, Mn and Zn under different fertilization regimes showed budget deficit, with the deficit order of NPKO＜O＜CK＜NPK, indicating that nutrient cycling could decrease the deficit significantly and keep the ecological systems more sustainable..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1112 (2013)
Study on the Contents and Fractionation of Rare Earth Elements in Filtering Water and Suspensions in Gansu, Ningxia and Inner Mongolia Sections of Yellow River by HR-ICP-MS
LIU Jing-jun, HAN Dan, and LIU Ying
In the present paper, high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) was applied to analyse the contents of rare earth elements (REE) in the filtering water and suspensions from 12 sampling sites in Gansu, Ningxia and Inner Mongolia Sections of Yellow River, and the fractionation of REE in susIn the present paper, high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) was applied to analyse the contents of rare earth elements (REE) in the filtering water and suspensions from 12 sampling sites in Gansu, Ningxia and Inner Mongolia Sections of Yellow River, and the fractionation of REE in suspensions was also studied. The results demonstrated that the contents of REE in filtering water were very low, and the element with highest content of elements was La(32.0 ng·L-1). The average concentration of total REE (∑REE) in filtering water was 47.5 ng·L-1, and the Baotou-Dengkou (S1) and Sanhuhekou (S2) sampling sites had a higher ∑REE of 130.0 and 100.0 ng·L-1, which implied that there might be external REE sources in the filtering water. And in suspensions, the average content of ∑REE was 167.8 mg·kg-1, which was similar to the Chinese soil background value. While the heavy rare earth elements (HREE) content in Shenchuanqiao (S11) of Gansu province were significantly higher than other stations, which indicated that it might have external HREE sources. The chondrite-normalized patterns of REE in suspensions from the study area were similar to that of Chinese soil, with light rare earth elements enrichment, and moderate Eu depletion and a bit of Ce depletion. It was showed that the contents of REE in suspensions were mainly from soil weathering..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1116 (2013)
Effect of Treatments of Hydrogen Peroxide and Sodium Dithionite-Citrate-Bicarbonate on Clay Minerals of Red Earth Sediments
LI Rong-biao, HONG Han-lie, YIN Ke, WANG Chao-wen, GAO Wen-peng, HAN Wen, and WU Qing-feng
As classical procedures for pretreatment of soil sediments, hydrogen peroxide (H2O2) and sodium dithionite-citrate-bicarbonate (DCB) treatment methods are very important in removing the organic matter and iron oxides acting as cementing agents in the soils. However, both of these methods have less been focused on the eAs classical procedures for pretreatment of soil sediments, hydrogen peroxide (H2O2) and sodium dithionite-citrate-bicarbonate (DCB) treatment methods are very important in removing the organic matter and iron oxides acting as cementing agents in the soils. However, both of these methods have less been focused on the effect on the clay minerals when separating. Here, we report the comparable methods between H2O2 and DCB to reveal their effect on clay minerals in red earth sediments using X-ray diffraction (XRD). The XRD results suggested that mineral particles can be totally decentralized by either H2O2 or DCB method in the soils and high purity clay minerals can be obtained by separating quartz and other impurities from clay minerals effectively. However, the XRD data were distorted by the DCB treatment owning to the cation exchange between Na+ and interlayer cation. On the contrary, the authentic data can be obtained by H2O2 treatment. Therefore, the H2O2 treatment seems to be a more appropriate method to obtain authentic information of clay mineralogy when separating of clay minerals from red earth sediments..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1122 (2013)
Occurrence Relationship between Iron Minerals and Clay Minerals in Net-Like Red Soils: Evidence from X-Ray Diffraction
YIN Ke, HONG Han-lie, HAN Wen, MA Yu-bo, and LI Rong-biao
The high purity of clay minerals is a key factor to reconstruct the palaeoclimate in clay mineralogy, however, the existence of iron minerals (such as goethite and hematite) and organics lead to the intergrowth of clay minerals and other minerals, producing other mineral impurities in enriched clay minerals. Although tThe high purity of clay minerals is a key factor to reconstruct the palaeoclimate in clay mineralogy, however, the existence of iron minerals (such as goethite and hematite) and organics lead to the intergrowth of clay minerals and other minerals, producing other mineral impurities in enriched clay minerals. Although the removal of organics in soil sediments has been fully investigated, the occurrence state of iron minerals remains controversial, hindering the preparation of high-purity clay minerals. Therefore, the occurrence relationship of iron minerals and clay minerals in Jiujiang net-like red soils of the middle to lower reaches of the Yangtze River was investigated using the sequential separation method, which provided some implications for the removal of iron minerals in soil sediments. The results indicated that goethite and hematite were mostly absorbed on the surface of hydroxy-interlayered smectite and illite in the form of films, and the rest were absorbed by kaolinite..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1126 (2013)
Theoretical Calculation and Simulation Research on Micro X-Ray Tube Target Thickness and Spectra
YANG Qiang, GE Liang-quan, GU Yi, HUA Yong-tao, and LUO Yao-yao
The present paper established a mathematical model, according to the structure of the end-window transmission micro X-ray tube anode. And we discussed the relationship between the average thickness of electron beam targeting and the high voltage. Also we obtained the spectral intensity distribution characteristics of tThe present paper established a mathematical model, according to the structure of the end-window transmission micro X-ray tube anode. And we discussed the relationship between the average thickness of electron beam targeting and the high voltage. Also we obtained the spectral intensity distribution characteristics of the emitted X-ray on the angle, meanwhile by the use of Monte Carlo, the authors simulated the intensity distribution characteristics of the spectrum in the direction of 2π. The results show that the average thickness of the micro X-ray tube anode target is about 2 μm, and we can get much better single-energy spectrum in the vertical direction of the incident electron beam within a few degrees. These conclusions have some theoretical significance for the structural design of the micro X-ray tube and the emitted spectrum monochrome applications..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1130 (2013)
Estimation and Mapping of Soil Organic Matter Based on Vis-NIR Reflectance Spectroscopy
GUO Yan, JI Wen-jun, WU Hong-hai, and SHI Zhou
Visible-near infrared (Vis-NIR) reflectance spectroscopy, which is rapid, cost-effective, in-situ, nondestructive and without hazardous chemicals, is increasingly being used for prediction and digital soil mapping of soil organic matter (SOM). This method is the inevitable demand for precision agriculture and soil remoVisible-near infrared (Vis-NIR) reflectance spectroscopy, which is rapid, cost-effective, in-situ, nondestructive and without hazardous chemicals, is increasingly being used for prediction and digital soil mapping of soil organic matter (SOM). This method is the inevitable demand for precision agriculture and soil remote sensing mapping. In the present study, the Vis-NIR (350~2 500 nm) diffuse reflectance spectral collected by ASD FieldSpec Pro FR spectrometer was truncated by removing the noisy edge values below 400 nm and above 2 450 nm and then was transformed into apparent absorbance spectral using log(1/R). Based on the relationship analysis between absorbance spectral, spectral indices and SOM, partial least squares regression (PLSR) model was applied to predict SOM, and finally the spatial variability of SOM was characterized by geostatistics method. The results indicated that good model was modeling from the characteristic bands (CB, R2=0.91, RPD=3.28) of correlation coefficient more than 0.5, the spectral index (SI) of normalized difference index (NDI, R2=0.90, RPD=3.08), CB integrating SI with which a correlation coefficient was more than 0.5 (R2=0.87, RPD=2.67), and total bands (TA, 400~2 450 nm, R2=0.95, RPD=4.36). While the digital mapping of SOM produced by kriging and cokriging interpolation methods implied a better prediction result, showing similar spatial distribution with the measured SOM, indicating that it is feasible and reliable to use these spectral indices to predict and map the spatial variability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1135 (2013)
Construction and Application of an Onboard Absorption Analyzer Device for CDOM
LIN Jun-fang, SUN Zhao-hua, CAO Wen-xi, HU Shui-bo, and XU Zhan-tang
Colored dissolved organic matter (CDOM) plays an important role in marine ecosystems. In order to solve the current problems in measurement of CDOM absorption, an automated onboard analyzer based on liquid core waveguides (Teflon AF LWCC/LCW) was constructed. This analyzer has remarkable characteristics including adjusColored dissolved organic matter (CDOM) plays an important role in marine ecosystems. In order to solve the current problems in measurement of CDOM absorption, an automated onboard analyzer based on liquid core waveguides (Teflon AF LWCC/LCW) was constructed. This analyzer has remarkable characteristics including adjusted optical pathlength, wide measurement range, and high sensitivity. The model of filtration and injection can implement the function of automated filtration, sample injection, and LWCC cleaning. The LabVIEW software platform can efficiently control the running state of the analyzer and acquire real time data including light absorption spectra, GPS data, and CTW data. By the comparison experiments and shipboard measurements, it was proved that the analyzer was reliable and robust..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1141 (2013)
Research on Granary Temperature Network Monitoring System Based on the Linear Frequency Shift of Spectrum
WANG Gao, LIU Shao-cong, WEN Qiang, ZHAO Hui, and ZHAO Yu
In order to obtain the distribution of the temperature in the range of the granary precisely and stably, we designed a temperature measurement system of the fiber Bragg grating. Through the fiber-optic network the system can detect granary temperature in a wide range, and there is a linear relationship between the measIn order to obtain the distribution of the temperature in the range of the granary precisely and stably, we designed a temperature measurement system of the fiber Bragg grating. Through the fiber-optic network the system can detect granary temperature in a wide range, and there is a linear relationship between the measured temperature by fiber Bragg grating and the center wavelength, so according to the function of spectrum linear frequency shift it obtained precise temperature in the granary. The working wavelengths of each grating in the system are separated from each other. After reflected by 3 dB coupler, the wavelength detection and demodulation system was used to measure the linear frequency shift of the plurality grating, and the system can get temperature data of everywhere in the granary. The experimental obtained the temperature information by equipments, such as LPT-101 light source, optical fiber with FBG encapsulated, magnification processing circuit, simulation granary, etc. With Origin software the diagram of the relationship between the frequency shift of the measured temperature and wavelength was drawn, and compared with the traditional measuring method of the K-type thermocouple measurement data. Experimental results show that the measured temperature of the fiber Bragg grating is closer to standard temperature, and the anti-jamming ability can meet the requirements of the granary large range temperature monitoring..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1146 (2013)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 4, 1 (2013)
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