Journals >Spectroscopy and Spectral Analysis
Contents
2016
Volume: 36 Issue 7
67 Article(s)
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Research Article
The Detection of Atmospheric HONO and NO2 with Fiber Coupling Long-Path Differential Optical Absorption Spectroscopy System
DUAN Jun, QIN Min, LU Xue, FANG Wu, LING Liu-yi, WANG Dan, SHEN Lan-lan, XIE Pin-hua, and LIU Wen-qing
A new type of fiber coupling Long-Path Differential Optical Absorption Spectroscopy System(LP-DOAS) based on schmidt - cassegrain telescope was introduced in detail in this paper and it was applied to the accurate measurement of the actual atmospheric HONO and NO2. This measuring system simplified the structure of tradA new type of fiber coupling Long-Path Differential Optical Absorption Spectroscopy System(LP-DOAS) based on schmidt - cassegrain telescope was introduced in detail in this paper and it was applied to the accurate measurement of the actual atmospheric HONO and NO2. This measuring system simplified the structure of traditional LP-DOAS system, combining with the design of optical fiber coupling.It made full use of the telescope primary mirror’s effective area. The effects of the offset, dark current and telescope stray light to the new LP-DOAS system were discussed in this paper; On a clear day, the ratio between telescope stray light and the optical intensities was less than 1%. To verify the accurate of the new LP-DOAS system, the atmospheric NO2 were simultaneously measured with the new LP-DOAS system and traditional LP-DOAS system. The correlation coefficient R2 was up to 0.968. The observation of atmospheric HONO was carried out by using the fiber coupling LP-DOAS in Gucheng, Hebei Province, China, and the detection limit (2σ) of HONO and NO2 was 84.2 and 144.6 ppt , respectively, with 2 490 m path length and the average time resolution of about 30 s. In the whole measurement in Gucheng, the maximum of HONO and NO2 were 3.2 and 37.8 ppb, respectively, and the minimum were both under the detection limits; the ratio of HONO/NO2 at night was calculated..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2001 (2016)
Temperature Effects on Erbium Doped Optical Fibers Properties
QI Yi, CHEN Wei-min, LEI Xiao-hua, ZHANG Wei, LI Jing-fei, XU Heng-yi, and LIU Xian-ming
In scientific research and engineering application, improving the power of fiber device is an important topic, which leads to observably rise of temperature in fiber core at the same time. In this paper, Thermal effect and its influence on absorption spectrum and lifetime of Erbium-doped fiber are studied with numericaIn scientific research and engineering application, improving the power of fiber device is an important topic, which leads to observably rise of temperature in fiber core at the same time. In this paper, Thermal effect and its influence on absorption spectrum and lifetime of Erbium-doped fiber are studied with numerical modeling. Lorentz broadening of sub-levels is used to build the mathematical relationship between temperature and absorption spectrum. The McCumber Theory is applied to deduce the lifetime of Erbium-doped fiber in different temperature. Temperature experiments of absorption and emission spectrum from 25 to 900 ℃ are carried out, which show that the wavelength of absorption peak near 980nm increase at rate of 0.625 nm/100 ℃, the ratio of absorption peak near 1 530 nm declines at a rate of 0.001 9 dB·(m℃)-1 and the broadband of absorption spectrum near 1 530 nm increase with rising temperature. The linear variation of lifetime and peak absorption in experiment proves that the theoretical model is reasonable when the temperature is below 600 ℃..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2006 (2016)
Supercontinuum Generation in Tapered Microstructure Fibers with Different Taper Length by Using Femtosecond Laser
LIU Zhi-hong, WANG Wei, YANG Jian-ju, HAN Ying, ZHOU Gui-yao, QI Yue-feng, and HOU Lan-tian
Tapered microstructure fibers with different taper lengths and waist diameters are pumped with femtosecond laser for supercontinuum generation. With “fast and cold tapered method”, home made microstructure fiber with air-hole pitch Λ=6.53 μm and normalized air-hole diameter d/Λ=0.79 were tapered to 6, 8, 10 mm taper leTapered microstructure fibers with different taper lengths and waist diameters are pumped with femtosecond laser for supercontinuum generation. With “fast and cold tapered method”, home made microstructure fiber with air-hole pitch Λ=6.53 μm and normalized air-hole diameter d/Λ=0.79 were tapered to 6, 8, 10 mm taper length while keeping d/Λ unchanged. Numerical simulations show that the zero dispersion wavelength shifts to blue when the taper waist shrinks. The zero dispersion wavelengths for untapered and 6, 8, 10 mm length tapered fiber were 1 029, 885, 806, and 637 nm, respectively. In the experiment, 120 fs pulses centered at 810 nm, which is generated by mode-locked Ti:sapphire laser at a repetition rate of 76 MHz, is coupled into the tapered microstructure fiber. With the tapered length of 6 mm, the center wavelength of the pump light locates in the normal dispersion region of the fiber and near the zero dispersion wavelength of the tapered waist. The main factors causes spectra broaden are intrapulse Raman scattering and cascaded four-wave mixing. When the pump power reaches 450 mW, continuous spectra with -5 dB flatness are generated at 390~461 and 1 134~1 512 nm. With 500 mW pump power, supercontinuum spans from 366 to 2 450 nm, which has already covered ultraviolet, visible, near-infrared and mid-infrared. This broadband spectrum almost reaches the red and blue edges of the microstructure fiber’s transmission bandwidth. With 8mm tapered length and 450 mW pump power, the blue edge of the continuous spectrum shifts down to 366 nm as a result of group velocity match and group acceleration mismatch, a 9 nm deeper blue shift compared to results from 6mm tapered length. With the tapered length of 10 mm, because the zero dispersion wavelength of the waist also moves to visible region, phase matching condition can still be satisfied in that region. Due to the effect of cascaded four-wave mixing, the frequency up conversion is realized in visible region. When pump power reaches 500mW, up conversion frequency lies in 30 nm band from 382 to 412 nm, the conversion efficiency is up to 27.7%..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2011 (2016)
Regularity of Gaseous Product Release During Direct Coal Liquefaction Residue Pyrolysis Process
SONG Yong-hui, MA Qiao-na, HE Wen-jin, and LAN Xin-zhe
The pyrolysis characteristic of direct coal liquefaction residue (DCLR) was studied with thermo-gravimetric analyzer (TG) coupled with Fourier transform infrared spectrometry (FTIR), which is used to discuss the emitted regulation of gaseous product during pyrolysis process. This research shows that the weight loss proThe pyrolysis characteristic of direct coal liquefaction residue (DCLR) was studied with thermo-gravimetric analyzer (TG) coupled with Fourier transform infrared spectrometry (FTIR), which is used to discuss the emitted regulation of gaseous product during pyrolysis process. This research shows that the weight loss process of DCLR can be divided into three stages: the first is before the temperature of 405.10 ℃; stage from 405.10 to 523.83 ℃ which is mainly pyrolysis of high boiling point of oil and asphaltene et al, and the total weight loss of DCLR can up to 40.27% when the temperature reaches 478.45 ℃, meanwhile the mass loss rate is maximum; after 523.83 ℃, the weight loss curve becomes gentle and the total weight loss of DCLR reaches 50.55% , which is due to the secondary cracking of residue and decomposition of mineral matter. The emitted process of gaseous product can be divided into three stages too: the first is the generation of H2O and CO2, the second stage mainly emitted CO2,CH4,CO,H2O and a small quantity of SO2, in which plenty of tar is generated from 458.4 to 791.9 ℃, the final stage mainly generated CO2, CO and H2O. CO2 mainly emitted owing to the cracking of oxygenheterocycle and OCO or other oxygen-containing groups, CO emitted due to cracking of ether and oxygenheterocycle, and CH4 generated as a result of cracking of aliphatic hydrocarbon..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2017 (2016)
Study on the Structural, Optical an Surface Plasmon Characteristics of Mo-Doped ZnO Thin Film
WANG Xian-hai, ZHAO Xue-wei, HONG Rui-jin, TAO Chun-xian, and ZHANG Da-wei
Mo-doped zinc oxide (ZnO∶Mo) films were deposited with direct current magnetron sputtering on quartz substrates at room temperature. The effects of Mo doping content on the crystal structure, surface microstructure, optical properties and plasmon characteristics of the ZnO films were investigated with X-ray diffractionMo-doped zinc oxide (ZnO∶Mo) films were deposited with direct current magnetron sputtering on quartz substrates at room temperature. The effects of Mo doping content on the crystal structure, surface microstructure, optical properties and plasmon characteristics of the ZnO films were investigated with X-ray diffraction(XRD),atomic force microscopy (AFM),Spectrophotometer and Raman spectrometer. The XRD pattern reveals that pure ZnO film exhibits good crystallization and c-axis oriented while heavy doping leads to increasing film defects. That results decline the film crystalline quality. When Mo doping content exceeds 3.93 Wt%, the ZnO films transform c-axis oriented into amorphous. The AFM pattern indicates that the surface of amorphous MZO film is extraordinarily flat. The Rq is 498 pm. The transmittance spectra reveal that all samples have an average transmittance of 80% in the visible light range. The optical band gap energy (Eg) increases from 3.28 to 3.60 eV as the Mo doping content increase. The absorbance spectrum indicates that ZnO surface plasmon resonance absorbance perk moves to short-wavelength as the Mo doping content increase. The Raman spectrum suggests that heavy Mo doping make the Raman scattering intensity decrease significantly. This paper obtains amorphous ZnO thin film by Mo doping. That broadens the application field of ZnO thin film materials. Meanwhile, we study the effect of Mo doping concentration on ZnO thin films surface plasmon, which provides important reference value for the preparation of oxidized zinc base photonic devices..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2022 (2016)
Research on the SPR Properties of Copper Thin Film with Regulation of Titanium Dioxide
SANG Xiao-zhou, and ZHANG Da-wei
In this paper, we propose the surface plasmon resonance intensity modulation of the metal copper deposited on a titanium oxide thin film. Surface plasmon resonance (SPR) has a broad application prospect in various types of detectors and sensors. We first used the electron beam evaporation to obtain TiO2 thin films withIn this paper, we propose the surface plasmon resonance intensity modulation of the metal copper deposited on a titanium oxide thin film. Surface plasmon resonance (SPR) has a broad application prospect in various types of detectors and sensors. We first used the electron beam evaporation to obtain TiO2 thin films with the same thickness, and then we prepared copper film with the thickness ranging from 5 to 80 nm with magnetron sputtering method. The results show that the TiO2 film with different thickness copper thin films own different surface plasmon resonance modulation capability. The thinner copper film shows more obvious regulation. When the copper layer thickness is more than 20 nm, the resonance enhancement effect began to weaken because of better extinction capability..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2027 (2016)
Current Status and Recent Advances in Research and Application of THz Technology in Articular Cartilage Detection
MA Yu-ting, ZHANG Jin, SHI Chang-cheng, LI Wei, HAN Xiao-hui, PENG Xiao-yu, WEI Dong-shan, DU Chun-lei, and CUI Hong-liang
Osteoarthritis is a common arthritis disease caused by cartilage tissue damage and degeneration, which is one of the large epidemics that affect human health. The early detection of the pathological changes of articular cartilage can greatly improve the cure rate of disease, but the relevant clinical diagnosis technoloOsteoarthritis is a common arthritis disease caused by cartilage tissue damage and degeneration, which is one of the large epidemics that affect human health. The early detection of the pathological changes of articular cartilage can greatly improve the cure rate of disease, but the relevant clinical diagnosis technology has not been developed. In recent years, the applications and researches of terahertz technology are increasingly valued and it has drawn great attention in the field of medicine. Compared with traditional methods, the terahertz radiation is low-energy and non-ionizing whose spectral-fingerprinting capability is well-known in the biological world. Meanwhile, THz technology has a great potential in diagnosis of articular cartilage early degeneration. This paper briefly introduces the physiological and pathological conditions of the articular cartilage, the current clinical techniques of articular cartilage detection. It mainly summarizes the terahertz technology used for detecting articular cartilage, including detection of animal and human cartilage respectively. At last, the challenges and development prospects of terahertz technology in articular cartilage detection are discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2031 (2016)
Research on Rapid and Non-Destructive Identification of Aging Wheat Based on ATR-Terahertz Spectroscopy Combined with PLS-DA
WANG Dong, PAN Li-gang, LIU Long-hai, JIANG Justin, LI An, JIN Xin-xin, MA Zhi-hong, and WANG Ji-hua
In this research, the terahertz spectra data of the aging wheat processed under manual control environment by ATR accessory were collected. After the data diversity based on the composite score by PCA, the non-destructive identification models of aging wheat were developed by PLS-DA algorithm. The results showed that fIn this research, the terahertz spectra data of the aging wheat processed under manual control environment by ATR accessory were collected. After the data diversity based on the composite score by PCA, the non-destructive identification models of aging wheat were developed by PLS-DA algorithm. The results showed that for the absorption coefficient spectrum, the accuracy of the experimental group, control group of the calibration set and cross validation set were 84.2%, 94.7%, 84.2% and 81.6% respectively, while the accuracy of the experimental group and control group of the external validation set were 73.7% and 100.0% respectively; for the refractive index spectrum, the accuracy of the experimental group, control group of the calibration set and cross validation set were 84.2%, 92.0%, 76.3% and 76.3% respectively, while the accuracy of the experimental group and control group of the external validation set were 84.2% and 89.5% respectively. The research indicates that ATR-THz technology should be of great potentials in the application in the non-destructive identification of aging wheat..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2036 (2016)
The Concentration Effect of Near-Infrared Quantum Cutting Luminescence of Tm3+ Ion Sensitized with Bi3+ Ion in YNbO4 Phosphor
CHEN Xiao-bo, LI Song, CHEN Xiao-duan, WANG Jie-liang, HE Li-zhu, WANG Shui-feng, DENG Zhi-wei, CHENG Huan-li, GAO Yan, and LIU Quan-lin
Searching for new energy source is one of the most important projects faced by the global, while the most ideal new energy source is solar cell. Near infrared quantum cutting luminescence method can doubly transfer large energy photon which is not sensitive to Si or Ge solar cell to small energy photon which is sensitiSearching for new energy source is one of the most important projects faced by the global, while the most ideal new energy source is solar cell. Near infrared quantum cutting luminescence method can doubly transfer large energy photon which is not sensitive to Si or Ge solar cell to small energy photon which is sensitive to Si or Ge solar cell. It can resolve the spectral mismatch problem and largely enhance solar cell efficiency. Therefore, it is significant. The concentration effect of near-infrared quantum cutting luminescence of Tm3+Bi3+∶YNbO4 phosphor is reported in present manuscript. Through the measurement of excitation and emission spectra, it is found that the Tm0.058Bi0.010Y0.932NbO4 powder phosphor has intense 1 820.0 nm near-infrared quantum cutting luminescence. Further analysis finds they are multi-photon quantum cutting luminescence induced by the cross-energy transfer process. The population of 1G4 energy level may be directly transferred to lower energy level mainly through {1G4—3H4, 3H6—3H5} and {1G4—3H5, 3H6—3H4} cross-energy transfer processes, i. e. one population of the 1G4 energy level may effectively lead to two populations, which are positioned at the 3H4 and 3H5 energy levels, respectively, mainly through {1G4—3H4, 3H6—3H5} and {1G4—3H5, 3H6—3H4} cross-energy transfer processes. This may also effectively lead to three populations of the 3F4 energy level through {3H4—3F4, 3H6—3F4} cross-energy transfer process from the 3H4 level and multi-phonon non-radiative relaxation from the 3H5 level, respectively. This results in the effective three-photon near-infrared quantum cutting of the 3F4—3H6 fluorescence of Tm3+ ion. It’s also found that the sensitization action of Bi3+ ion to Tm3+ ion is very strong. The enhancement of the 1 820.0 nm near-infrared quantum cutting luminescence, of Tm0.058Bi0.010Y0.932NbO4 relative to Tm0.005Y0.995NbO4, is about 175.5 times, when excited by the 302.0 nm light. The present results are significant for the exploration of the next-generation multi-photon near-infrared quantum cutting germanium solar cell..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2042 (2016)
Influence of Nitrogen Flow Rate on the Structure and Luminescence Properties of Silicon-Rich Silicon Nitride Film Materials in a High Hydrogen Atmosphere
ZHANG Lin-rui, ZHOU Bing-qing, ZHANG Na, LU Xiao-cui, WUREN Tu-ya, and GAO Ai-ming
High hydrogenated silicon-rich silicon nitride(SiNx∶H)thin films are deposited on the glass and monocrystalline silicon(110) substrates by plasma enhanced chemical vapor deposition using SiH4 and H2 as the main reaction gas with doping the N2. The ultraviolet-visible absorption spectrum, Fourier transform infrared absoHigh hydrogenated silicon-rich silicon nitride(SiNx∶H)thin films are deposited on the glass and monocrystalline silicon(110) substrates by plasma enhanced chemical vapor deposition using SiH4 and H2 as the main reaction gas with doping the N2. The ultraviolet-visible absorption spectrum, Fourier transform infrared absorption spectroscopy, Raman spectroscopy and photoluminescence spectrum are applied to characterize the changes of the band gap, the microstructure and related photoluminescence properties of the nitrogen-doped silicon film. It shows that hydrogen atoms can suppress the defects in the film and make film present silicon-rich under the low SiH4/H2 flow ratio, but they are not beneficial to the formation of silicon clusters in a hydrogen atmosphere. With the incorporation of nitrogen atoms, all the content of Si-N bonds, band gap and the degree of disorder in the microstructure of the films increase, films produce light emission related to the defect states. While the content of doped nitrogen atoms are further increased, it appears the band tail emission. Then the relationships between several light emissions and microstructure to be discussed. These results are useful for the optimization of light emission and microstructure for the silicon-rich silicon nitride film material prepared by PECVD..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2048 (2016)
Study on the Photoluminescence Properties of Tb Doped Si Nanowires
FAN Zhi-dong, ZHOU Zi-chun, LIU Chuo, MA Lei, and PENG Ying-cai
Silicon nanowires with high density, uniform distribution and large area were produced directly from Si(100) based on solid-liquid-solid mechanism under the growth temperature of 1 100 ℃ with 30 min. The flow of N2 is 1 500 sccm and Au-Al films is used as metallic catalyst. The diameters of Si nanowires is 50~120 nm anSilicon nanowires with high density, uniform distribution and large area were produced directly from Si(100) based on solid-liquid-solid mechanism under the growth temperature of 1 100 ℃ with 30 min. The flow of N2 is 1 500 sccm and Au-Al films is used as metallic catalyst. The diameters of Si nanowires is 50~120 nm and the lengths of the formed Si nanowires is hundreds of nanometers. After that Tb-doped Si nanowires were reserched. We experimentally investigated the influences of the different process parameters on the luminescence of Tb-doped Si nanowires.The main process parameters includ doping temperature(1 000~1 200 ℃), doping time (30~90 min) and gas flow rate of N2 (0~1 000 sccm). Finally, Tb-doped bulk silicon substrates have been studied experimentally. We characterized and analyzed the photoluminescence properties of Tb-doped Si nanowires with the Hitachi F-4600 fluorescence spectrophotometer. The corresponding relation of energy level structure and transition properties of Tb ion with the experimental spectrum is analyzed in detail. The experiment result indicates that the Tb-doped Si nanowires have a stronly green luminescencent. The emission peak position of the largest intensity at 554 nm (5D4→7F5) with the doping temperature 1 100 ℃, the flow of N2 1 000 sccm and the excitation wavelength 243 nm. At the same time,three emission bands of 494 nm (5D4→7F6), 593 nm (5D4→7F4) and 628 nm (5D4→7F3) were observed under room temperature. The Tb-doped Si nanowires appeared strong green light emission compared with the bulk silicon substrate. Its application has a certain reference value for studying the characteristics of luminescence of rare earth element doped Si based material. Meanwhile,the photoluminescence properties of Tb-doped Si nanowires affected by the diameter, length, distribution and density of Si nanowires. That is necessary forour further research..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2055 (2016)
Luminescence Mechanism of Near-Infrared Quantum Dots
QIN Ai-miao, ZHAO Lu-lu, DU Wei-lin, KONG De-xia, QIN Feng-liang, MO Rong-wang, and ZHANG Kai-you
Near-infrared quantum dots have unique optical properties, such as high fluorescence quantum yield, long fluorescent life, tunable fluorescence emission wavelength, half peak width and large stokes shift, resisting light bleaching etc. The advantage of “near infrared biological window” gives them great potential applicNear-infrared quantum dots have unique optical properties, such as high fluorescence quantum yield, long fluorescent life, tunable fluorescence emission wavelength, half peak width and large stokes shift, resisting light bleaching etc. The advantage of “near infrared biological window” gives them great potential application value in biological fluorescent tags, solar cells, quantization calculation, photocatalysis, chemical analysis, food detection, vivo imaging and other fields. At present, the luminescence mechanism research of near-infrared quantum dots is still not comprehensive enough. In this paper, the luminescent principle of three different types of near-infrared quantum dots is summarized, including core/shell structure quantum dots (CdTe/CdSe, CdSe/CdTe/ZnSe, etc), ternary quantum dots (Cu-In-Se, CuInS2, etc) and doped quantum dots (Cu∶InP, etc). The luminescence mechanism of Type Ⅱ core/shell structure is most likely to attribute to the interband recombination luminescence, the ternary structure of quantum dots light emitting mechanism is considered to be due to the intrinsic structure defects, and the luminescence mechanism of doped quantum dots is deemed to result from the impurity defects. The existing problems of near-infrared luminescent principle of quantum dots are also discussed and their development tendency is explored t in this review. A systematic study of luminescence mechanism of near-infrared quantum dots will not only help to understand the luminescent properties of near infrared quantum dots, but also contribute to improve the synthesis methods of quantum dots with similarly high quality..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2059 (2016)
Application of Attenuated Total Reflectance Infrared Spectroscopy(ATR-FTIR) for Amber Identification and Research
XING Ying-ying
Infrared spectral analysis is a commonly used means to research the characteristics of mineral material. Attenuated total internal reflectance infrared spectroscopy (ATR -FTIR) is widely used dues to its advantages such as rapidness, non-destructiveness and micro region detection. This paper focuses on different areas Infrared spectral analysis is a commonly used means to research the characteristics of mineral material. Attenuated total internal reflectance infrared spectroscopy (ATR -FTIR) is widely used dues to its advantages such as rapidness, non-destructiveness and micro region detection. This paper focuses on different areas of amber, copal resin, coated amber to further study its ATR-FTIR through the BRUKER LUMOS independent type infrared microscope. The result shows: the two infrared absorption spectrum which are 1 643 cm-1 due to stretching vibration of ν(CC) and 889 cm-1 due to deformation vibration of δ(arene C—H)are present in the amber originated in Dominica and Russia; the infrared absorption spectrum band lies at 1 300～925 cm-1 due to stretching vibration of ν(C—O) has a certain instruction significance for the origin of amber; the three absorption spectrum of 3 080 cm-1 which is due to dis-symmetry stretching vibration of νas(CH2), 1 643 and 887 cm-1 can be used as characteristic of copal resin and have identification significance; coated amber displays amber and artificial resin mixing infrared spectrum, which besides the characteristic infrared spectrum of amber, 760 and 702 cm-1 infrared spectrum are caused by out-plane bending vibration of γ(arene C—H) of resin. ATR-FTIR has important significance in the identification of cause, origin and enhancement varieties of amber..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2066 (2016)
Study on the Anisotropy of Collagenours Fibers in Articular with Infrared Imaging
WU Yue-chao, ZHANG Xue-xi, MAO Zhi-hua, and YIN Jian-hua
Formalin solution has been widely used to solidify the organization of articular cartilage and prevent tissue decomposition in long-time measurement. However, it was rarely investigated that the structural anisotropy changes of collagen fiber (fixation) of articular cartilage when it was immersed in formalin. In this pFormalin solution has been widely used to solidify the organization of articular cartilage and prevent tissue decomposition in long-time measurement. However, it was rarely investigated that the structural anisotropy changes of collagen fiber (fixation) of articular cartilage when it was immersed in formalin. In this paper, Fourier transform infrared spectroscopic imaging with polarization technique was used to investigate the anisotropic structure change of collagen fiber of articular cartilage fixed in formalin through the absorbance change of Amide I and Amide II with immersing time and polarization direction. The degree of anisotropy of collagen fiber in cartilage was characterized with fitting related coefficient of absorbance. The anisotropy of Amide I and Amide II became stronger with immersing extension of articular cartilage in formalin, and the amide I showed more remarkable anisotropy. It was concluded that the formalin solution induced new crosslinks of collagen, which gradually strengthened the collagen fiber anisotropy and was helpful for the structural analysis of the articular cartilage. The study will be significant for the preparation, preservation and anisotropy research of cartilage specimen..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2071 (2016)
Response of FTIR and Raman Spectra on Cell Wall of Calendula Officinalis Seedlings Roots to the Co-Contamination Stress of Lead and Cadmium in Loess
FAN Chun-hui, GAO Ya-lin, and DU Bo
Phytoremediation is a novel method with great potential for site remediation contaminated by heavy metals in future. The cell wall of plant roots is significant to affect the remediation efficiency, for it is related to the multi-interface of heavy metals, pedosphere and plant. The relationship between cell wall of plaPhytoremediation is a novel method with great potential for site remediation contaminated by heavy metals in future. The cell wall of plant roots is significant to affect the remediation efficiency, for it is related to the multi-interface of heavy metals, pedosphere and plant. The relationship between cell wall of plant and heavy metals is complicated, containing the reaction behavior of physical chemistry, physiology and biochemistry. At present, the spectral technologies are not adequately used to investigate the in-situ response characteristics between cell wall of plant roots and heavy metals. The Calendula officinalis seedlings, the remediation plant in loess, were used as experimental sampleswhile the root characteristic variation was revealed on cell wall. The approaches of X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra were applied to analyze the response effect of cell wall to lead/cadmium stress. The results showed: the cell wall appears to be shrinking, and certain amounts of dark particles appear on cell wall. The contents of lead/cadmium increase greatly as shown from XRF, while the representative crystals of lead/cadmium are hardly detected. The absorbance peak at 3 416 cm-1 indicates the coordination effect between lead/cadmium and —OH in FTIR, and the movement of absorbance peaks, from 1 701 to 1 736 cm-1 and 1 593 to 1 618 cm-1, respectively, indicates the different characteristics of protein in cell wall of Calendula officinalis seedlings roots under lead/cadmium stress. The Raman intensity of absorbance peak at 2 960 cm-1 increases under lead/cadmium stress, and it proves the changes on arranging directions of cellulose molecules in cell wall samples. The components (Pectin, protein, cellulose, etc.) and functional groups (—OH, N—H, CO, etc.) of cell wall play an important role in the resistance process of cell wall derived from Calendula officinalis seedlings roots to the stress of lead/cadmium in loess..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2076 (2016)
Study on the Extraction, Geometry Structure and Spectral Characterization of Piperine Alkaloid
LI Xin, SHI Jin-ru, YANG Meng-shi, LU Yi, CHEN Liang, and CAO Hua-ru
Using pepper fruit of Hainan as raw material and 95% ethanol as solvent, the alkaloid in pepper is extracted with reflux method in this paper. The piperonylic acid is removed by adjusting the pH; the fat-soluble substance being removed by adding ethyl ether; the piperine alkaloid being purified with acetone by recrystaUsing pepper fruit of Hainan as raw material and 95% ethanol as solvent, the alkaloid in pepper is extracted with reflux method in this paper. The piperonylic acid is removed by adjusting the pH; the fat-soluble substance being removed by adding ethyl ether; the piperine alkaloid being purified with acetone by recrystallization anddetected with HPLC, as well as characterized with IR. The characterizations of piperine are discussed. Meanwhile, B3LYP/6-31G (d,p) method of DFT is applied to optimize the structure, calculate frequency and energy of pepper alkaloid, then obtain four kinds of configurations (configuration Ⅰ as Piperine, configuration Ⅱ as Iso Piperine, configuration Ⅲ as Iso Chavicine, configuration Ⅳ as Chavicine) with 64 kinds of stability conformational structure. The distribution of the thermodynamic equilibrium of stable conformations of four kinds of configurations of the molecular is calculated with Gibbs free energy at room temperature (298.15 K). And IR spectra of the experimental were compared with the IR spectra of the theoretical. The results show that the alkaloid extracted from pepper is mainly conformer 1 in configuration Ⅰ, that is, Piperine; after purifying, the content of piperine is 7% with the purity of 99%. With analysis, the methods of extraction, separation and purification of piperine in this paper achieve good results. Established models are in good agreement with the experimental results. This research is of great significance in guiding extracting process, building structural model and the characterization and application of piperine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2082 (2016)
Discrimination of Plum Browning with Near Infrared Spectroscopy
ZHAO Zhi-lei, WANG Yan-wei, GONG Dong-jun, NIU Xiao-ying, CHENG Wei, and GU Yu-hong
Flesh browning mostly happens in plum fruit during the post-harvest storage period, which is an important factor affecting the storage quality of plum fruits. Traditional methods used to discriminate plum browning involve the destruction of the intact fruit, which are highly subjective and error-prone. Therefore, the nFlesh browning mostly happens in plum fruit during the post-harvest storage period, which is an important factor affecting the storage quality of plum fruits. Traditional methods used to discriminate plum browning involve the destruction of the intact fruit, which are highly subjective and error-prone. Therefore, the near-infrared (NIR) spectroscopy technique was applied to achieve rapid and non-destructive identification of plum browning and non-browning in this paper. The near infrared diffuse reflectance spectroscopy of 124 plum samples were collected in the band number of 4 000~12 500 cm-1. These samples were classified into two groups, browning (n=70) and non-browning (n=54). In order to find a new way to effectively discriminate plum fruits with flesh browning, three qualitative identification methods: the qualitative test, Mahalanobis distances discriminate analysis (DA) and Back Propagation-artificial neural networks (BP-ANN) were used to compare their capacity of recognizing browning plums and non-browning oneswhile the last two approaches were based on the principal component analysis (PCA) method. These results showed that DA and BP-ANN could be used to conctruct effective classification models for identifying plum browning, and the first ten principal components extracted from original spectra were applied as input variables to build DA and BP-ANN models. The optimal method was obtained with BP-ANN, which gained an accuracy of 100% for calibration set and 97.56% for prediction set, and the identification accuracy rate reached 100% and 98.57% for non-browning samples and browning ones, respectively. It could be concluded that NIR spectroscopy technique combined with chemometrics methods has great potential to recognize plums of browning and non-browning rapidly, non-destructively and effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2089 (2016)
Discrimination of Tea Varieties by Using Infrared Spectroscopy with a Novel Generalized Noise Clustering
WU Bin, CUI Yan-hai, WU Xiao-hong, JIA Hong-wen, and LI Min
The discrimination of tea varieties plays very important role in the production and sale of tea. It is of great significance for the study of a fast, easy and simple method for the identification of tea varieties. The combination of infrared spectroscopy detection technology and fuzzy clustering algorithm is one of theThe discrimination of tea varieties plays very important role in the production and sale of tea. It is of great significance for the study of a fast, easy and simple method for the identification of tea varieties. The combination of infrared spectroscopy detection technology and fuzzy clustering algorithm is one of the most effective and practical techniques in the detection of tea varieties. To realize the rapid discrimination of tea varieties, a novel generalized noise clustering (NGNC) was proposed based on fast generalized noise clustering (FGNC). Euclidean distance in the objective function of FGNC was replaced with the pth power of Euclidean distance and clustering accuracy was being improved. Emeishan Maofeng; high quality Leshan trimeresurus and low quality Leshan trimeresurus were prepared as the research object and the infrared reflectance (IR) spectra of tea samples were collected with FTIR-7600 infrared spectrometer. Firstly, the high-dimensional IR spectra of tea samples were reduced by principal component analysis (PCA). Secondly, linear discriminant analysis (LDA) was used to extract the discriminant information from the low-dimensional data. Finally, FGNC and NGNC were performed to identify tea varieties. The experimental results showed that in comparision with FGNC, NGNC has higher clustering accuracy, better cluster centers and faster convergence speed. Infrared spectroscopy coupled with NGNC, PCA and LDA could cluster IR spectra of tea samples quickly and correctly, which provided a new method and new idea for identifying tea varieties based on infrared spectroscopy and fuzzy clustering..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2094 (2016)
Study on the Identification of Gypsum Fibrosum with FTIR
YAN Wei, ZENG Bo-lin, MENG Jiang, WANG Shu-mei, and LIANG Sheng-wang
To establish a new identification method of Gypsum Fibrosum with FTIR and analyze different kinds of the sulfate mineral medicine with clustering method. With the use of FTIR, identify different kinds of sulfate mineral medicine, such as gypsum fibrosum, gypsum ustum and natrii sulfas , in addition, clustering method aTo establish a new identification method of Gypsum Fibrosum with FTIR and analyze different kinds of the sulfate mineral medicine with clustering method. With the use of FTIR, identify different kinds of sulfate mineral medicine, such as gypsum fibrosum, gypsum ustum and natrii sulfas , in addition, clustering method and first derivative spectra are used to analyze the intrinsic relationship in these kinds of sulfate mineral medicine. What’s more, 24 batches of Gypsum Fibrosum samples which from different production are analyzed with FTIR; then the spectrum control fingerprint with pattern is established with common peaks; at last the similarity between the simple spectrum fingerprint and the spectrum control fingerprint is calculated with angle cosine value and correlation coefficient. There are distinctions about the wave number, the peak position, the spike and the peak intensity in the infrared spectroscopy and first derivative spectra. Therefore, the sulfate mineral medicine is divided into two main regions with the based on these clusters: put the gypsum fibrosum and gypsum ustum in the same class, the natrii sulfas in the other class. Between 400 and 4 000 cm-1, the experiment showed that 24 batches of samples were more than 0.980 0. Provide a new, rapid and specificity method for identification and standard of gypsum fibrosum and build a successful cluster analysis about the sulfate mineral medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2098 (2016)
Discrimination of Lactarius and Russula Mushrooms with FTIR and Two-Dimensional Correlation Infrared Spectroscopy
MA Dian-xu, LIU Gang, OU Quan-hong, YU Hai-chao, LI Hui-mei, and LIU Yan
Tri-step infrared spectroscopy method of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy was firstly used to discriminate six species of mushrooms belonging to the genus Lactarius and Russula. The absorption bands of the original speTri-step infrared spectroscopy method of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy was firstly used to discriminate six species of mushrooms belonging to the genus Lactarius and Russula. The absorption bands of the original spectrum were very similar, which were composed by protein and polysaccharides, but tiny differences were observed at the position, shape and absorption intensities of peaks. Second derivative infrared spectroscopy technology was applied to study 6 species of the samples, there were obvious differences in the range of 1 800～1 400 and 1 200～800 cm-1. Two-dimensional correlation infrared spectroscopy can improve the resolution of spectra. Therefore two-dimensional correlation infrared spectroscopy was used to study 6 kinds of mushrooms. The results showed that there are three auto-peaks in the Lactarius, four in the Russula and significant differences in the number, intensity of auto-peaks and cross peaks were observed in the range of 1 690~1 420 cm-1. In addition, the peaks quantity, position, intensity of auto-peaks and cross peaks were different in the range of 1 110~920 cm-1. It demonstrates that tri-step infrared spectroscopy technology of Fourier transform infrared spectroscopy, second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy is a rapid and effective method for discriminating Lactarius and Russula..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2104 (2016)
Research on the Pre-Processing Methods of Wheat Hardness Prediction Model Based on Visible-Near Infrared Spectroscopy
HUI Guang-yan, SUN Lai-jun, WANG Jia-nan, WANG Le-kai, and DAI Chang-jun
Grain hardness is an important quality parameter of wheat which has great influence on the classification, usage and composition research of wheat. To achieve rapid and accurate detection of wheat hardness, radial basis function (RBF) neural network model was built to predict the hardness of unknown samples on the basiGrain hardness is an important quality parameter of wheat which has great influence on the classification, usage and composition research of wheat. To achieve rapid and accurate detection of wheat hardness, radial basis function (RBF) neural network model was built to predict the hardness of unknown samples on the basis of analyzing the absorptive characteristics of the composition of wheat grain in infrared, besides, the effects of different spectral pretreatment methods on the predictive accuracy of models were emphatically analyzed. 111 wheat samples were collected from major wheat-producing areas in China; then, spectral data were obtained by scanning samples. Mahalanobis distance method was used to identify and eliminated abnormal spectra. The optimized method of sample set partitioning based on joint X-Y distance (SPXY) was used to divide sample set with the number of calibration set samples being 84 and prediction set samples being 24. Successive projections algorithm (SPA) was employed to extract 47 spectral features from 262. SPA, first derivatives, second derivatives, standard normal variety (SNV) and their combinations were applied to preprocess spectral data, and the interplay of different prediction methods was analyzed to find the optimal prediction combination. Radial basis function (RBF) was built with preprocessed spectral data of calibration set being as inputs and the corresponding hardness data determined via hardness index (HI) method being as outputs. Results showed that the model got the best prediction accuracy when using the combination of SNV and SPA to preprocess spectral data, with the discriminant coefficient (R2), standard error of prediction (SEP) and ratio of performance to standard deviate (RPD) being 0.844, 3.983 and 2.529, respectively, which indicated that the RBF neural network model built based on visible-near infrared spectroscopy (Vis-NIR) could accurately predict wheat hardness, having the advantages of easy, fast and nondestructive compared with the traditional method. It provides a more convenient and practical method for estimating wheat hardness..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2111 (2016)
Study on the Discrimination of Boletus Edulis from Different Years and Origins with FTIR
YANG Tian-wei, LI Tao, LI Jie-qing, ZHANG Xue, WANG Yuan-zhong, and LIU Hong-gao
In order to establish a rapid method for discriminating Boletus edulis mushroom, Fourier transform infrared spectroscopy combined with multivariate statistical analysis were used to study B. edulis which were collected from different origins and different years. The original infrared spectra of all the 152 B. edulis saIn order to establish a rapid method for discriminating Boletus edulis mushroom, Fourier transform infrared spectroscopy combined with multivariate statistical analysis were used to study B. edulis which were collected from different origins and different years. The original infrared spectra of all the 152 B. edulis samples collected from 2011 to 2014 and 26 different areas of Yunnan Province were optimized with orthogonal signal correction and wavelet compression (OSCW) method. The spectral data that before and after being preprocessed with OSCW were analyzed with partial least squares discriminant analysis (PLS-DA). The classification results of PLS-DA were compared. Then the 152 B. edulis samples were randomly divided into a training set (120) and a validation set (32) to establish the PLS classification prediction model. The results showed that, after OSCW processing, the classification result of PLS-DA was significantly better than the other one which was not processed by OSCW. Principal component score plot can accurately distinguish B. edulis samples collected from different years and different origins. It indicated that OSCW can effectively eliminate the noise of spectra and reduce the unrelated interference information about the dependent variables to improve the accuracy and calculation speed of spectral analysis. Before OSCW preprocessed, the R2 and RMSEE of PLS model of the training set were 0.790 1 and 21.246 5 respectively while R2 and RMSEP of the model of validation set were 0.922 5 and 14.429 2. After OSCW pretreatment, R2 and RMSEE of the training set were 0.852 3 and 17.238 1 while R2 and RMSEP of validation set were 0.845 4 and 20.87. It suggested that OSCW could improve the predictive effect of the training set, but the over-fitting of OSCW-PLS may reduce the predictive ability of validation set. Therefore, it was unsuitable to establish a model with OSCW combined with PLS. In a conclusion, OSCW combined with PLS-DA can eliminate a large amount of spectrum interference information. This method could accurately distinguish B. edulis samples collected from different years and different origins. It could provide a reliable basis for the discrimination and classification of wild edible fungi..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2117 (2016)
Applications of Real-Time Measurement Technology with Raman Spectroscopy for Polymer Synthesis and Processing
JIN Gang, HUANG Xi, and CHEN Ru-huang
The process of polymer synthesis and processing affects the degree of polymerization, crystallinity, orientation and the uniformity of blending components, which ultimately influences the performance of polymer products. Therefore, real-time monitoring of material properties is very important in the process of polymer The process of polymer synthesis and processing affects the degree of polymerization, crystallinity, orientation and the uniformity of blending components, which ultimately influences the performance of polymer products. Therefore, real-time monitoring of material properties is very important in the process of polymer synthesis and processing. Real-time measurement technology with Raman spectroscopy has been widely applied in the field of polymer synthesis and processing, since it features non-destructive testing, easy sampling and high reliability. It has no specific requirements for the sample’s thickness, shape and state, and it realizes the measurement in high temperature, high pressure and toxic environment directly. Real-time Raman spectroscopy can analyze material chemical composition and physical properties. It controls the process of polymer synthesis and processing to improve the performance of polymeric products. In this paper, the research progress in real-time measurement of polymerization conversion, polymer particle size and distribution, crystallinity, orientation, and components content in multiphase blend polymers with Raman spectroscopy is discussed. The application of real-time measurement technology with Raman spectroscopy has great potential..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2124 (2016)
Detection of High Molecular Weight Polycyclic Aromatic Hydrocarbons in Mixed Colloid Solution of Spherical Au and Urchin-Like Au-Ag Alloy with Surface-Enhanced Raman Scattering
SHI Xiao-feng, MENG Chen, MA Li-zhen, MA Hai-kuan, ZHANG Xin-min, and MA Jun
In this paper, Au nanosphere and Au-Ag alloy nanourchin were prepared by reducing the chloroauric acid. The mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin were used as surface-enhanced Raman scattering (SERS) substrate to detect polycyclic aromatic hydrocarbons (PAHs) in aqueous solution. The size In this paper, Au nanosphere and Au-Ag alloy nanourchin were prepared by reducing the chloroauric acid. The mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin were used as surface-enhanced Raman scattering (SERS) substrate to detect polycyclic aromatic hydrocarbons (PAHs) in aqueous solution. The size of Au-Ag alloy nanourchin particle was about 300~400 nm and the thorn-like bulge covered on it was about 40~100 nm. The mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin which were optimized pH values and other parameters presented a better enhancement than Au nanosphere. The enhancement effect was about three times that of Au nanosphere colloid solution. Three kinds of high molecular weight PAHs, pyrene(4 rings), benzoanthracene(4 rings) and benzo［a］pyrene(5 rings), were detected. The results showed that there were good linear relationships between Raman intensity and concentration in the low concentration range and the mixed SERS substrate had a good reproducibility and stability. Their limits of detection (LODs) were 0.44, 2.92 and 1.64 nmol·L-1, respectively. The innovation of this paper was that the mixed colloid solutions of Au nanosphere and Au-Ag alloy nanourchin are prepared as SERS substrate and the trace-level high molecular weight PAHs are detected. The results show that the detection of trace-level high molecular weight PAHs in aqueous can be realized using the mixed SERS substrate prepared in this study, which proposed an in-situ method for detecting the high molecular weight PAHs in aqueous..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2128 (2016)
Application of Extreme-Ultraviolet Ar Spectra Analysis in the Study of Divertor Impurity Screening in EAST Tokamak
ZHANG Peng-fei, ZHANG Ling, XU Zong, DUAN Yan-min, WU Cheng-rui, HUANG Juan, WU Zhen-wei, GUO Hou-yang, and HU Li-qun
Divertor impurity injection on Tokamak is the most important means to achieve divertor impurity screening efficiency. In this paper, a fast-response extreme-ultraviolet (EUV) spectrometer is used to monitor the Ar emission lines during the EAST(Experimental Advanced Superconducting Tokamak)divertor Ar injection experimDivertor impurity injection on Tokamak is the most important means to achieve divertor impurity screening efficiency. In this paper, a fast-response extreme-ultraviolet (EUV) spectrometer is used to monitor the Ar emission lines during the EAST(Experimental Advanced Superconducting Tokamak)divertor Ar injection experiment. Based on the NIST(National Institute of Standards and Technology)atomic spectrum database, the emission lines from different ionized Ar ions in 2～50 nm wavelength range, e.g. Ar Ⅳ, Ar Ⅳ-Ⅺ and Ar ⅩⅣ-ⅩⅥ, are being identified. Ar ⅩⅥ 35.39 nm and Ar Ⅳ 44.22 nm with the ionization energy of 918.4 and 59.6 eV respectively are being monitored during the experiment with Ar puffing to observe the behavior of Ar impurities in different regions in plasmasimultaneously. The preliminary analysis on divertor impurity screening efficiency is carried outwith the time evolution of intensities of two Ar emission lines. The results of experiment puffing from the same gas puffing inlet (e. g. from lower outer target inlet) and withdifferent plasma configurations (e. g. lower single null, upper single null) show that the screening effect on the impurity injected from the divertor region is better thanfrom the main plasma region; the screening effect of lower divertor and particle pumping by internal cryopump installed in lower divertor is stronger than upper divertor..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2134 (2016)
Research on Denoising Ultraviolet Spectrum Signal with An Improved Effective Singular Value Selection Method
DAI Dang-dang, WANG Xian-pei, ZHAO Yu, TIAN Meng, LONG Jia-chuan, ZHU Guo-wei, and ZHANG Long-fei
Spectrum denoising is an important part of spectrum detection. As we know, spectral signal is susceptible to thermal noise, mechanical vibration on site and random noise, etc. However, online monitoring systems require to reduce the impact of parameter selection caused by human operation on denoising, so a method basedSpectrum denoising is an important part of spectrum detection. As we know, spectral signal is susceptible to thermal noise, mechanical vibration on site and random noise, etc. However, online monitoring systems require to reduce the impact of parameter selection caused by human operation on denoising, so a method based on singular value decomposition is proposed to denoise spectrum signal. An improved effective singular value selection method is also proposed. First, the author specify the maximum peak of the difference spectrum of singular value for the lower bound which named θ1, using the integrated information of singular value and its difference spectrum to select the upper bound, which is called θ2. The interval θ1～θ2 is defined as a fuzzy area. Then, the membership is obtained with Fuzzy C-means clusting and corresponding weight coefficients to the singular values in the fuzzy area are given. Finally, the proposed method is used to denoise UV spectrum signal with different signal to noise ratio. The signal to noise ratio, root mean square error, normalied correlation coefficient and smoothness radio are used to evaluate the result of denoising. The result shows that: based on data-driven, the proposed method has a good denoising effect, which can effectively restore the original signal..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2139 (2016)
Research on Spectroscopy Spectrum De-Noising of Mineral Oil Based on Lifting Scheme Wavelet Transform
WANG Yu-tian, YANG Zhe, HOU Pei-guo, CHENG Peng-fei, and CAO Li-fang
The use of the mineral oil is an important cause of air pollution such as fog. The effectiveness and rapidity of the de-noising processing in mineral oil fluorescence spectroscopy detection system is a hot issue of the online real-time monitoring system. The de-noising method of the lifting wavelet transform (LWT) in tThe use of the mineral oil is an important cause of air pollution such as fog. The effectiveness and rapidity of the de-noising processing in mineral oil fluorescence spectroscopy detection system is a hot issue of the online real-time monitoring system. The de-noising method of the lifting wavelet transform (LWT) in the application of mineral oil fluorescence spectrum is proposed. Compared with traditional discrete wavelet transform (DWT), this wavelet transform method decomposes the existing wavelet filter module into the basic construction modules and steps to complete the transform with simplicity and a fast speed. There are characteristics of low computational complexity, in situ operation and the easy implement in the denoising process of mineral oil fluorescence spectra. The LWT can effectively solve the problems in these respects. The three methods of LWT, DWT and EMD are applied to the fluorescence spectra of 0# diesel oil, 97# gasoline and kerosene. The indicators evaluating de-noising effect such as the Signal-to-Noise Ratio (SNR), Mean Squared Error (MSE) and Normalied Correlation Coefficient (NCC) of the three kinds of mineral oil in the fluorescence spectra denoising prove the effectiveness of the lifting scheme wavelet transform in the application of mineral oil fluorescence spectrum. Meanwhile, the lifting scheme transform can improve the flexibility of structure and operation simplicity that makes the de-noising time reduced by 62%, validating the speediness of the de-noising method of the LWT in the application of mineral oil fluorescence spectrum and it is suitable for mineral oil fast de-noising processing system in real time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2144 (2016)
Discrimination of Honey Varieties Based on Amino Acid Derivative Fluorescence Method Combining with Multilinear Pattern Recognition
HU Le-qian, YIN Chun-ling, WANG Huan, and LIU Zhi-min
Assessing the authenticity about the botanical and geographical origins of food is an important content for food safety research. Amino acids are the most important nutrients of honey. The types and contents of amino acids are different in various honey samples. Thus they can be used as one of the important parameters Assessing the authenticity about the botanical and geographical origins of food is an important content for food safety research. Amino acids are the most important nutrients of honey. The types and contents of amino acids are different in various honey samples. Thus they can be used as one of the important parameters to discriminate the honey variety and quality. In this article, amino acids in honey were first derived with formaldehyde and acetyl acetone solution. In the following step, three-dimensional fluorescence spectrums combing with multidimensional pattern recognition methods were used to distinguish the kinds of honey. Five kinds of honey (total 150 honey samples) from different botanicals were studied in this research. Before fluorescence detection, the effect of the amount of derivation reagent, the time of reaction, temperature and pH to the derivation progress of honey samples were first studied. Research showed that the fluorescence intensity of derivatives of honey was the strongest when the amount of derivation reagent was 4.0 mL, the time of reaction being 2 h, pH being 4 and the temperature being 100 ℃. The derivatives of honey were then scanned with three-dimensional fluorescence spectrometry. The collection of fluorescence intensity values occurred within excitation-emission ranges of 300~500 and 380~580 nm. A 150×41×101 cube matrix data sets can be acquired. The three-dimensional fluorescence data sets were decomposed with multilinear pattern recognition methods, such as multilinear principal components analysis (M-PCA), self-weight alternative trilinear decomposition (SWATLD) and multilinear partial least squares discriminant analysis (N-PLS-DA) methods. All of these multilinear pattern recognition methods showed the clustering tendency for five different kinds of honey. Compared with the other two methods, N-PLS-DA got more accurate and reliable classification results because it made full use of all the fluorescence information of the derivative honey samples. Its total recognition rate reached 88%. The result is acceptable for the complexity of the honey samples. It showed this method could be applied to identify the varieties of honey. Compared with the chromatographic analysis method, this method is relatively simpler and more sensitivity. It avoided the chromatographic separation and reduced the consumption of organic solvent. Thus it can be regarded as a kind of relatively green honey classification method. This research will provide a new idea to directly fluorescence analyze for no or weak fluorescence natural substances..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2148 (2016)
Application of Fluorescence Spectra and Matrix Analysis in the Classification of Edible Vegetable Oils
WU Xi-jun, TIAN Rui-ling, SUN Meng-fei, and PAN Zhao
The fluorescence spectra of 42 vegetable oil samples are measured with FS920 fluorescence spectrometer, including 36 pure vegetable oil samples, 3 blend oil samples and 3 mixed oil samples. The fluorescence matrixs (EEMs) are normalized to determine representative excitation wavelength and matrix analysis model of vegeThe fluorescence spectra of 42 vegetable oil samples are measured with FS920 fluorescence spectrometer, including 36 pure vegetable oil samples, 3 blend oil samples and 3 mixed oil samples. The fluorescence matrixs (EEMs) are normalized to determine representative excitation wavelength and matrix analysis model of vegetable oils. Vegetable oils are divided into three categories by analyzing representative emission spectra and contour maps in the range of emission wavelength from 260 to 750 nm, and excitation wavelengths from 250 to 550 nm. Applying matrix analysis model to identify pure vegetable oils, blend oils and mixed oils, the correct classification rate is 100% for pure vegetable oils, the composition is close to actual for mixed oils, and the conclusion of soybean and rapeseed oil as base for blend oils is reached. The results demonstrate the capability of the combination of fluorescence spectra technology and matrix analysis model for differentiating and characterizing vegetable oils..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2155 (2016)
The Fluorescence Detection of Oil Pollutants Based on Self-Weighted Alternating Trilinear Decomposition
CHENG Peng-fei, WANG Yu-tian, CHEN Zhi-kun, YANG Zhe, and CAO Li-fang
The oil pollutants detector is designed in this paper. The pulse xenon lamp is used as light source; the step type multi-mode pure silica fiber is chosen to transmit the excitation and emission light. The asymmetric Czemy-Turner light path of high precision grating monochromator is adopted. The detector is applied to dThe oil pollutants detector is designed in this paper. The pulse xenon lamp is used as light source; the step type multi-mode pure silica fiber is chosen to transmit the excitation and emission light. The asymmetric Czemy-Turner light path of high precision grating monochromator is adopted. The detector is applied to determine the fluorescence spectrum of diesel, gasoline and kerosene. The optimal excitation /emission wavelengths are: 290/330 nm (diesel), 270/300 nm (gasoline) and 280/330 nm (kerosene). The detection limits are: diesel (0.025 mg·L-1), gasoline (0.042 mg·L-1) and kerosene(0.054 mg·L-1). The relative errors are: diesel(2.55%), gasoline(2.06%) and kerosene(1.71%). Experiment results show that the designed detector has high accuracy of measurement. The different concentration of diesel, gasoline and kerosene mixed solution is configured, and three dimensional fluorescence spectra being measured. The self-weighted alternating trilinear decomposition is adopted to decompose the spectrum data. The predicted concentration and recovery rate show that self-weighted alternating trilinear decomposition has high resolution for mixed oil substance..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2162 (2016)
Study on the 3D Fluorescence Feature of Styrene and Emergent Treatment of Styrene Pollutant in Water
ZHOU Yun, LI Jun, CHEN Fei, MA Ting, and NI Yong-jiong
It has been acknowledged by WHO that styrene is a carcinogen which does great harm to human’s health and natural environment. In recent years, given the frequency of the leakage accidents of styrene that has given rise to potential safety hazard to drinking water, the fast detection of styrene pollutant in water and trIt has been acknowledged by WHO that styrene is a carcinogen which does great harm to human’s health and natural environment. In recent years, given the frequency of the leakage accidents of styrene that has given rise to potential safety hazard to drinking water, the fast detection of styrene pollutant in water and treatment of accidental release are of great significance for supplying safe drinking water. Total scanning fluorescence technique was used to unravel the 3D fluorescence feature of styrene by scanning its aqueous solution. A distinct fluorescence peak of styrene located at Ex255/Em305 was detected. There was a significant linear correlation between the concentration of styrene and the value of fluorescence peak, the correlation index being 0.995 7. The color of the fluorescence peak got darker with the raise of styrene concentration. There were four conjugated double bonds existing in the structure of styrene, among which a cyclic hydrocarbon with a continuous pi bond exists in benzene ring, the other one is in vinyl. All carbon atoms that makes up the structure of styrene were in the same plane, thus styrene molecules were completely planar with certain rigidity, which is the feature of fluorescent substances. Therefore, the concentration of styrene and the pollution of water by the leakage of styrene could be easily detected with the 3D fluorescence spectra. Powdered activated carbon (PAC) had a good effect on the absorption of styrene dissolved in water. Adding PAC(180 mesh) at a dosage of 15 mg·L-1 into source water with the concentration of styrene was 0.02 mg·L-1, which is the limited value in sanitary standard for drinking water, the concentration could be reduced to 0.001 mg·L-1 and the removal rate of styrene was as high as 95.5% ..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2169 (2016)
Polypyrrole Functionalized Gold Nanorods as Novel Contrast Agents for Optical Coherence Tomography
YU Jian-feng, GUO Zhou-yi, JIN Mei, WANG Xin-peng, ZHONG Hui-qing, and LIU Zhi-ming
Polypyrrole (PPy) is easy-prepared with good biocompatibility and strong absorption in near-infrared (NIR) region which can serve as both the photothermal therapeutic agent and contrast agent of optical coherence tomography (OCT) imaging. Herein, gold nanorod (GNR) modified with PPy (GNR-PPy) as contrast agent for optiPolypyrrole (PPy) is easy-prepared with good biocompatibility and strong absorption in near-infrared (NIR) region which can serve as both the photothermal therapeutic agent and contrast agent of optical coherence tomography (OCT) imaging. Herein, gold nanorod (GNR) modified with PPy (GNR-PPy) as contrast agent for optical coherence tomography imaging was investigated. GNR-PPy was synthesized via one-pot facile oxidative polymerization by using pyrrole and GNR as starting materials. Nanoparticles were characterized using ultraviolet-visible absorbance spectroscopy, Raman spectroscopy and transmission electron microscopy. A xenograft tumor mouse model was fabricated to study the OCT contrast effect of GNR-PPy on breast tumor. An OCT system equipped with an 840 nm SLED was used for OCT imaging of the tumors injected with gold nanostructures. The experimental results indicated that the penetration depth of the OCT signals from tumors injected with GNR-PPy was lower than that from tumors injected with gold nanorods, which could be ascribed to the stronger light activity of GNR-PPy in NIR region. To quantitatively analyze the contrast effect, the attenuation coefficients were extracted from the OCT images of tumors injected with the nanostructures. In comparison with the attenuation coefficient extracted from the OCT images containing GNR, the attenuation coefficient of tumors injected with GNR-PPy was significant higher. It was concluded that gold nanorods modified with polypyrrole can enhance the light absorption in near-infrared much better, which would provide a possible detection means for enhancing the contrast effect of tumor tissues..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2173 (2016)
Effect of LLLI on Secretion of ALP and Intracellular Calcium Concentration in Osteoblasts under Mechanical Stress
SHI Rui-xin, FU Xi-hong, ZHUANG Jin-liang, and YANG Lu-yi
In order to reveal the mechanism of LLLI accelerating teeth moving, we investigated the changes of alkaline phosphatase and intracellular calcium concentration when osteoblasts under stress were subjected low-level-laser-irradiation (LLLI). MG-63 cells were divided into four groups: control group, stress group, LLLI grIn order to reveal the mechanism of LLLI accelerating teeth moving, we investigated the changes of alkaline phosphatase and intracellular calcium concentration when osteoblasts under stress were subjected low-level-laser-irradiation (LLLI). MG-63 cells were divided into four groups: control group, stress group, LLLI group and LLLI-stress group. Osteoblasts were subjected to the mechanical stress by a four-point bending system at 0.5 Hz and 3 000 μstrain. The secretions of ALP of each group are measured by spectrophotometer. In the second part, MG-63 cells were divided into two groups: stress group and LLLI-stress group. We checked intracellular calcium concentration via FCM and fluorescent indicator fluo-3/AM at 0, 5, 15, 30 and 60 min under stress. LLLI- stress group will receive LLLI for 1 min after stress. Compared to a control group, increased ALP secretions were observed in the other three groups. But ALP secretions in LLLI-stress group were lower than stress group and LLLI group. THE changing curve of intracellular calcium concentration in laser-stress groups is gentle instead of “jumping” in stress group. Proper stress, LLLI and combined application of these two can increase the secretions of ALP in osteoblasts compared to the control group. But the secretions of ALP decreased when combined application of stress and LLLI compared to using alone. LLLI can regulate the changing rhythm of concentration of the intracellular calcium to promote proliferation of MG-63 cell under stress, which means LLLI can reduce the bone-formation of osteoblasts under stress..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2178 (2016)
A Multi-Peak Brillouin Scattering Spectrum Feature Extraction Method Based on Multi-Criteria Decision-Making and Particle Swarm Optimization-Levenberg Marquardt Hybrid Optimization Algorithm
ZHANG Yan-jun, JIA Wei, FU Xing-hu, LI Da, and YU Chun-juan
As to fitting the multi-peaks Brillouin scattering spectrum with traditional method, the maximum power point is usually selected as the benchmark while other extreme value points which are less than the maximum power are lost. The fitting curve only has one peak because the multi-peaks Brillouin scattering spectrum is As to fitting the multi-peaks Brillouin scattering spectrum with traditional method, the maximum power point is usually selected as the benchmark while other extreme value points which are less than the maximum power are lost. The fitting curve only has one peak because the multi-peaks Brillouin scattering spectrum is simplified into the highest peak and several small peaks. So it will lead to the loss of useful information. In order to improve the feature extraction accuracy of Brillouin scattering spectrum, a hybrid optimization algorithm named MCDM-PSO-LM algorithm is presented based on MCDM and PSO-LM algorithm. The MCDM algorithm can identify and locate the peaks and valleys of multi-peaks Brillouin scattering spectrum accurately. The PSO-LM hybrid algorithm can realize the curve fitting on every peak and valley, and it can seach the center frequency shift of each peak. The PSO-LM hybrid algorithm can solves these disadvantages, which PSO algorithm premature convergence to local minimum and LM algorithm depends on the initial value problem. It can also combine the global search ability of PSO algorithm and the local search ability of LM algorithm. Compared with traditional algorithms, MCDM-PSO-LM algorithm can ensure the solving speed and accuracy to the optimal value, and the analytical solution will be close to the optimal value sufficiently. So it improves the operation ability. With different signal to noise ratio and linewidth, the results of frequency shift and temperature error show that the MCDM-PSO-LM method can locate every peak and valley of multi-peaks Brillouin scattering spectrum accurately. Thus, it can be used for the feature extraction of multi-peaks Brillouin scattering spectrum. The recognition effect of this method is obviously better than that of traditional algorithms and it can improve the accuracy of information analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2183 (2016)
Dual NDVI Ratio Vegetation Index: A Kind of Vegetation Index Assessing Leaf Carotenoid Content Based on Leaf Optical Properties Model
WANG Hong, SHI Run-he, LIU Pu-dong, and GAO Wei
With characteristics of rapidness, non-destructiveness and high precision in detecting plant leaves, hyperspectral technology is promising in assessing the contents of leaf pigments and other biochemical components. Because the spectral absorption features of carotenoid and chlorophyll are overlapped in visible light rWith characteristics of rapidness, non-destructiveness and high precision in detecting plant leaves, hyperspectral technology is promising in assessing the contents of leaf pigments and other biochemical components. Because the spectral absorption features of carotenoid and chlorophyll are overlapped in visible light region and that foliar carotenoid content is far lower than chlorophyll content, studies about constructing vegetation indices (VIs) for carotenoid is rare at home and abroad though carotenoid is one of the most important photosynthetic pigments. Hyperspectral data has abundant spectral information, so this paper proposed a multiple spectral indices collaborative algorithm to construct VIs on the basis of band-combination traversal and correlation analysis. Through a large number of simulated leaf reflectance spectra under different biochemical components contents run on PROSPECT model, a radiative transfer model, we successfully constructed a new kind of stable vegetation index (VI) for assessing carotenoid content at leaf level: RVIDNDVI. Our results indicate that RVIDNDVI is composed of two parts: (1)Narrow band NDVI constructed with 532 and 405 nm is high correlated with both carotenoid content and chlorophyll content while narrow band NDVI constructed with 548 and 498 nm is highly correlated with carotenoid content. The influence of chlorophyll content on RVIDNDVI can be eliminated with the ratio combination of these two indices. (2) The influence of mesophyll structure parameter can be weakened by subtracting the reflectance at 916 nm, which has strong correlation with mesophyll structure parameter. RVIDNDVIonly has high sensitivity to carotenoid content (the correlation coefficient is -0.94) at leaf level and R2 of its exponential fit is 0.834 4. The estimation of RVIDNDVIto carotenoid content can be verified with the validations of both simulated data and measured data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2189 (2016)
Variation Characteristics of Tropospheric NO2 Vertical Column Densities over Large and Small Cities of Xinjiang in Summer
MA Wen, LI Yan-hong, and WANG Pan-pan
Selecting the representative large and small towns which were Urumqi, Korla, Bole cities in Xinjiang, the ground-based mini MAX-DOAS measurement was carried out to observe the tropospheric NO2 vertical column density at town, industrial districts and farmland area in different grade cities from Jul to Aug 2014. It turnSelecting the representative large and small towns which were Urumqi, Korla, Bole cities in Xinjiang, the ground-based mini MAX-DOAS measurement was carried out to observe the tropospheric NO2 vertical column density at town, industrial districts and farmland area in different grade cities from Jul to Aug 2014. It turned out(1) In the diurnal variation of the concentration of tropospheric NO2 vertical column density have peaks and troughs, the difference between its peak in the large and small towns, Urumqi(7.590×1015molec·cm-2)>Korla(7.559×1015molec·cm-2)>Bole(3.578×1015molec·cm-2); (2)During summer the tropospheric NO2 vertical column density has relationship with urban surface condition. Especially it has close relationship with the number of cars in the observational area, town(4.643×1015molec·cm-2)>industrial districts (4.469×1015molec·cm-2)>farmland area(2.425×1015molec·cm-2); (3)Under different weather conditions the tropospheric NO2 vertical column density : the minimum density appeared on a rainy day(3.082×1015molec·cm-2), it turned out the precipitation has an important influence on NO2..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2195 (2016)
Study on the Prediction of Germination Rate of Rice Seeds with Continuous Polarization Spectroscopy
CHENG Yu-qiong, LU Wei, HONG De-lin, DANG Xiao-jing, and LUO Hui
With respect to the problem of long period and low precision in using traditional methods to predict rice seeds germination rate, a novel method based on continuous polarization spectroscopy was proposed to achieve rapid and nondestructive prediction .The paper set different aging rice seeds as prediction targets and tWith respect to the problem of long period and low precision in using traditional methods to predict rice seeds germination rate, a novel method based on continuous polarization spectroscopy was proposed to achieve rapid and nondestructive prediction .The paper set different aging rice seeds as prediction targets and ten minutes as prediction time, using polarizer to modulate optical fiber collimating light source to linearly polarized light which issuing into rice seeds extract vertically before rotating the analyser every 5 degrees . The transmission spectrum was predicted through the optical fiber spectrometer. After normalization pretreatment to the polarization spectrum, the article gave the characteristics of polarization angel and wavelength by 0 degree, 5 degrees, 25 degrees, 620, 788 and 576 nm according to the contribution of polarization angel and wavelength when predicting different germination rate rice seeds and inputted obtained continuous polarization spectrum by wavelength, polarization angel, transmissivity to construct rice seeds germination rate prediction model using three modeling methods to build rice seeds germination rate prediction model in comparison, including Partial Least Squares Regression (PLSR), Back Propagation Neural Network (BPNN) and Radial Basis Function Neural Network (RBFNN).1 520 sets of experimental data were measured in total at different polarization angels through using rice seeds with different aging days (0, 2, 4, 6) respectively, setting 912 sets of data as calibration set and 608 sets of data as predicion set. The modeling results show that RBF model’s prediction accuracy is the highest. Its correlation coefficient is 0.976; the mean square is 0.785; and the average relative error is 0.85%. The research results show that the continuous polarization spectroscopy technique through multidimension spectral information can achieve rapid and accurate prediction of rice seeds germination rate..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2200 (2016)
Non-Destructive Identification of Pigments Printed on the Bank Bill Issued in 1945
JI Jin-xin, ZHOU Wen-hua, YAO Na, GAN Qing, WANG Ji-gang, ZHOU Zhong, and SHI Ji-long
Three-dimensional video microscopy, Raman spectrometer and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) were employed to analyze the pigments of various colors on a sample of bank bill issued in 1945. The results indicated that organic pigments including C. I. Pigment Red 146 and C. I. Pigment Three-dimensional video microscopy, Raman spectrometer and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) were employed to analyze the pigments of various colors on a sample of bank bill issued in 1945. The results indicated that organic pigments including C. I. Pigment Red 146 and C. I. Pigment Red 53∶1, and inorganic pigments such as cinnabar, parareaglar, χ-phase of realgar, carbon black and Prussian blue were used in printing; the brown-black handwriting letters were speculated to be formed from the fading black-blue ink. Most areas of the bank bill were in one single color with one pigment, but two areas of orange-red seals were checked to be colored with cinnabar and two different phases of realgar, and the parareaglar, and χ-phase of realgar were found to be used as printing pigments firstly. This study shows that combining with three technologies above-mentioned is viable and it has great application potential in non-destructive identification of organic and inorganic pigments on paper-based cultural heritage..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2207 (2016)
Study on the Preparation of N-Tert-Butylbenzothiazole-2-Sulphenamide and Its Spectral Analysis
JIA Tai-xuan, SONG Guo-quan, GUO Yao, ZHAO Ling, TIAN Da-yong, and HOU Shao-gang
In the study, N-tert-butylbenzothiazole-2-sulphenamide (TBBS) was synthesized with one-step method with hydrogen peroxide as the oxidant. TBBS was detected and characterized with FTIR, UV-Vis, XRD and TG-DSC. Its micro-structure and intrinsic regularity were revealed. Chemical bond types into TBBS molecule were revealeIn the study, N-tert-butylbenzothiazole-2-sulphenamide (TBBS) was synthesized with one-step method with hydrogen peroxide as the oxidant. TBBS was detected and characterized with FTIR, UV-Vis, XRD and TG-DSC. Its micro-structure and intrinsic regularity were revealed. Chemical bond types into TBBS molecule were revealed with FTIR. The final product was determined TBBS. Three absorption peaks were detected by UV-Vis at 228.3, 281.5, 298.3 nm respectively, due to n→σ*, π→π*, n→π* electronic transitions. It could provide experimental basis with enterprise to test TBBS product quality and speculate its structure. The phase composition and structure of TBBS were revealed by crystallographic data from XRD detecting such as cell parameters, crystal face index. The phase composition and qualitative identification of TBBS structure were completed. Two kinds of information were detected by TG-DSC as quality change and thermal effect. The DSC curve of TBBS was very complex. There were a small absorption peak of 53.3 ℃ as a small amount of tert-butylamine containing in TBBS was oxidized. Three exothermic peaks of 117.4, 269.2, 373.7 ℃, due to transition peak and decomposition phase of TBBS respectively. The decomposition temperature of TBBS was very high. It could provide reference for research on rubber vulcanizing properties by TBBS on rubber vulcanizing machine. This study could provide the basis experimental data on the enterprises to designate the working standard tracing detection of TBBS industrialized production. The performance index of TBBS was judged. The project of TBBS industry standard could be declared by the enterprises, written a draft standard..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2213 (2016)
Remote Sensing Estimation of Plant Litter Cover Based on the Spectra of Plant Litter-Soil Mixed Scenes
XIE Xiao-yan, LIU Yong-mei, LI Jing-zhong, CHANG Wei, and WANG Ling
Quantifying plant litter cover is important to evaluate the effectiveness of vegetation to protect soil against soil erosion. Field campaign was carried out in the Loess Hilly-gully Region of Northern Shaanxi to acquire the spectral reflectance data of plant-soil mixed scenes for two broadleaf forests and rehabilitatedQuantifying plant litter cover is important to evaluate the effectiveness of vegetation to protect soil against soil erosion. Field campaign was carried out in the Loess Hilly-gully Region of Northern Shaanxi to acquire the spectral reflectance data of plant-soil mixed scenes for two broadleaf forests and rehabilitated grassland. Spectral behavior of plant-soil mixed scenes was analyzed and the effectiveness of hyperspectral indexes NDLI (normalized difference lignin index) and CAI (cellulose absorption index) for quantifying plant litter cover was evaluated based on lab and field experiments. The results showed spectra reflectance of plant-soil mixed scenes with different proportions of litter and soil varied greatly by the influence of color and water content. The NDLI and CAI values increased with the rise of proportion of litter within the mixed scene under dry and wet status, regression analysis between the two indexes and plant litter cover of mixed scenes showed that the obviously better result for CAI (R2=0.98, rehabilitated grassland and broadleaf forests under dry status). The discrimination between mixed scenes and soil using CAI significantly outperformed NDLI under dry status; the estimation of plant litter cover by CAI is more effective compared to NDLI. Lab analysis was validated by field measuring: R2=0.90 showed highest correlation between CAI and plant litter cover for rehabilitated grassland. The validity of estimation of plant litter cover by both two indexes reduced to some degree in the field. The research enhanced the scientific basis for remote sensing estimation of plant litter cover..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2217 (2016)
Study on the Detection of Slight Mechanical Injuries on Apples with Hyperspectral Imaging
JIANG Jin-bao, YOU Di, WANG Guo-ping, ZHANG Zheng, and MEN Ze-cheng
Nondestructive detection is one of the hottest spots in the application of hyperspectral remote sensing. The apple is easy to produce slight mechanical injuries that affects its quality in the process of picking and transporting. The hyperspectral images of 54 “yellow banana” and “Yantai Fushi” apples with slight injurNondestructive detection is one of the hottest spots in the application of hyperspectral remote sensing. The apple is easy to produce slight mechanical injuries that affects its quality in the process of picking and transporting. The hyperspectral images of 54 “yellow banana” and “Yantai Fushi” apples with slight injuries in the visible and near-infrared (400~1 000 nm) ranges are acquired; the mean spectral curves of injury regions on apples are extracted; the endmember spectrum are extracted based on minimum noise fraction (MNF) and geometric vertex principle; and the spectral angle is calculated between spectral of injury region and endmember spectral; a model of endmember extraction spectral angle (EESA) is constructed to detect slight mechanical injuries on apples. The slight mechanical injuries on “yellow banana” and “Yantai Fushi” apples are detected by setting spectral angle threshold, and the detection accuracy is compared with MNF and principal component analysis (PCA) method. The results show that the accuracy of EESA model is the highest, and the detection accuracy rate reaches 94.44% and 90.07% respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2224 (2016)
Study of the Enhancement Effect of Copper Alloy Self-Hole Confinement on Plasma Radiation
XU Song-ning, JIANG Ran, NING Ri-bo, LI Qian, and DUAN Wen-zhao
In this paper, self-hole confinement method was used to improve the quality of laser-induced breakdown spectroscopy and explore a convenient method to enhance the plasma radiation intensity. The effect of the self-hole confinement on plasma radiation intensity was investigated. Laser induced breakdown spectroscopy withIn this paper, self-hole confinement method was used to improve the quality of laser-induced breakdown spectroscopy and explore a convenient method to enhance the plasma radiation intensity. The effect of the self-hole confinement on plasma radiation intensity was investigated. Laser induced breakdown spectroscopy with Nd∶YAG laser was used to generate the plasma of HPb59-1 lead copper alloy sample in air. Grating spectrometer and ICCD were used to record plasma spectrum. The plasma radiation intensity of element Cu and Pb with holes of different diameters and depths were measured. Overall, the best signal intensity can be obtained with a confinement self-hole with 3 mm diameter and 1.5 mm depth. The spectral line intensities of elements Cu and Pb with self-hole are increased around 38.3% and 35.4% compared with the case without hole confinement; spectral signal-to-background ratio increased about 200.2% and 137.5%, respectively. The study results showed that the spectral quality of laser-induced lead copper alloy sample can be improved effectively by using the method of self-hole confinement. The method is sample and easy to operate which avoids the interference from the internal surface pollution of additional confinement setup of the experiment results..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2229 (2016)
Application of the Identification of Mine Water Inrush with LIF Spectrometry and KNN Algorithm Combined with PCA
HE Chen-yang, ZHOU Meng-ran, and YAN Peng-cheng
Rapid identification and classification of mine water inrush is important for flood prevention work underground. This paper proposed a method of KNN combined with PCA identification of water inrush in mine with the laser induced fluorescence spectrum with an immersion probe laser into water samples. The fluorescence spRapid identification and classification of mine water inrush is important for flood prevention work underground. This paper proposed a method of KNN combined with PCA identification of water inrush in mine with the laser induced fluorescence spectrum with an immersion probe laser into water samples. The fluorescence spectra of 4 kinds of water samples were obtained. For each set of data preprocessing, the processed data in each sample from 15 sets of data as the training setwith a total of 60 groups. The other 20 groups were used as the prediction set. The data were processed by principal component analysis (PCA), and then the KNN algorithm was used to classify and identify the principal component analysis. During the experiment, the pretreatment method in the principal component number is 2 while the correct rate has reached 100% by KNN classification algorithm..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2234 (2016)
Elementary Analysis of Seashell Based on Calcium Internal Reference with Micro-Probe Laser Induced Breakdown Spectroscopy(Micro-LIBS)
LI Yuan-dong, LU Yuan, QI Fu-jun, LI Ying, and ZHENG Rong-er
The shellfish has been extensively applied as a proxy for marine ecosystem monitoring, and the climate evolution or the shell growth might be derived from the elementary spatial distribution when using calcium (Ca) as the internal reference. Differed from other technique, the calcium emission lines are spread all over The shellfish has been extensively applied as a proxy for marine ecosystem monitoring, and the climate evolution or the shell growth might be derived from the elementary spatial distribution when using calcium (Ca) as the internal reference. Differed from other technique, the calcium emission lines are spread all over the wavelength range when applying Micro-probe Laser Induced Breakdown Spectroscopy (Micro-LIBS) to analyze the shell. So it is crucial to select a suitable calcium line for the shell elementary analysis. In this paper, the scallop shell composition was analyzed by comparing calcium internal references of total-line, atomic line (Ca Ⅰ 422.7 nm/Ca Ⅰ 487.9 nm) and ionic line (Ca Ⅱ 393.3 nm). It was found that, the fluctuation of Sr/Ca ratio was less than 7% and 10% in the investigated area when using total-line and strongest atomic line (Ca Ⅰ 422.7 nm) as the reference respectively, which was in agreement with the shell growth development. What’s more, the obtained results indicated that the element ratio Li/Ca had a high correlation to K/Ca and Na/Ca rather than Mn/Ca, so the light elements might be accumulated in a same pattern during the shell growth development. It was suggested that Micro-LIBS was a practical way for the seashell investigation, and a better elementary analysis could be achieved by using the internal reference of calcium total-line or the strong atomic line, while not in case of calcium ionic line..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2238 (2016)
LIBS Quantitative Analysis of Cr and Ni in Iron Alloys with Support Vector Machine (SVM)
ZHANG Ying, LI Ying, GU Yan-hong, GUO Hao, and LI Na
For the prediction of the contents of Cr and Ni in alloy steel samples, multivariate quantitative analysis model was established by optimizing the input variables of support vector machine (SVM) model, which could solve the problem of complex matrix effect of steel alloy samples. The results achieved by the integral inFor the prediction of the contents of Cr and Ni in alloy steel samples, multivariate quantitative analysis model was established by optimizing the input variables of support vector machine (SVM) model, which could solve the problem of complex matrix effect of steel alloy samples. The results achieved by the integral intensity of characteristic spectral lines as the different inputs of SVM were found better than the intensity, because integral intensity contains more information of spectral line, spectral width and spectral shape; The multiple characteristic spectral lines of the elements as the inputs of SVM were better than using single element characteristic spectral information, because the influence of matrix effect could be corrected by inputting multivariate spectral information. By combining internal calibration with multivariate calibration, the experiment errors can be reduced and the matrix effect can be calibrated, and the repetition rate and accuracy could be improved. With the introduction of the normalized variable as the support vector machine (SVM) model of input variables, the relative errors of the content prediction of Cr in sample S1 and S2 are 6.58% and 1.12% respectively; and the relative errors of the content prediction of Ni in sample S1 and S2 are 13.4% and 4.71% respectively. The experiment results show that the SVM algorithm can be effectively used for LIBS quantitative analysis by combining internal calibration with multivariate calibration..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2244 (2016)
Development of a Laboratory Cement Quality Analysis Apparatus Based on Laser-Induced Breakdown Spectroscopy
GUO Rui, ZHANG Lei, FAN Juan-juan, ZHANG Xiang-jie, and LI Yi
A laboratory cement quality analysis apparatus based on laser-induced breakdown spectroscopy (LIBS) has been developed for rapid analysis of cement composition and ratio values. In this paper, the overall structure, the optical system, the sample preparation process, as well as the spectral data analysis methods are inA laboratory cement quality analysis apparatus based on laser-induced breakdown spectroscopy (LIBS) has been developed for rapid analysis of cement composition and ratio values. In this paper, the overall structure, the optical system, the sample preparation process, as well as the spectral data analysis methods are introduced. The calibration model is established with internal standard method. A comparison as to the measurement results between LIBS and X-ray fluorescence spectrometry (XRF) has been made and being analyzed. It shows that by using the LIBS apparatus, the mean absolute error of CaO, SiO2, Al2O3, and Fe2O3 in cement raw materials is 0.46%, 0.25%, 0.13%, and 0.05%, respectively, while the mean absolute error of the ratio value such as KH, SM, and IM in cement clinker is 0.02, 0.05, and 0.04, respectively. The generated cement plasmas are verified to be in the local thermal equilibrium (LTE) condition by calculating both the plasma temperature and the electron density..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2249 (2016)
In-Situ Analysis of Solid Steel Samples with Remote Double-Pulse Laser-Induced Breakdown Spectroscopy System
XIN Yong, SUN Lan-xiang, YANG Zhi-jia, LI Yang, CONG Zhi-bo, QI Li-feng, ZHANG Peng, and ZENG Peng
In order to realize real-time, online monitoring of the component of steel and other metal smelting process, we designed a remote double-pulse laser-induced breakdown spectroscopy (LIBS) analysis system which can realize non-contact remote measurement and component analysis for long distance sample. The paper first tesIn order to realize real-time, online monitoring of the component of steel and other metal smelting process, we designed a remote double-pulse laser-induced breakdown spectroscopy (LIBS) analysis system which can realize non-contact remote measurement and component analysis for long distance sample. The paper first tests the system on solid standard steel samples, which provides basis for online monitoring the component of molten steel. The experimental results show: laser focal spot is about 1mm in long distance; double-pulse ablation depth is deeper than single pulse’s; the optimum delay of double-pulse is non-consistent in different distances; the enhancement effect of double- pulse in 3.1 m is better than that in 2.1 m, and the maximum enhancement is 5.19 of Ti(Ⅰ) 319.99 nm; the calibration curve of R2 is about 0.99, RSD being less than 5%, RMSE being less than 0.021%, LOD being less than 500 ppm for most elements in 2.1 m, which is better than that in 3.1 m..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2255 (2016)
Research on the Matrix Interference on Major and Minor Elements in Soil Samples with ICP-AES
CAO Lei, CHEN Wei-wei, GAO Xiao-li, and LIAO Qi-lin
According to the commonly used method of analysis with ICP-AES in geochemistry, to study the influence factors of interference from the analysis results, standard soil substances were selected to be the calibration curve of work, and the same method of digestion with soil samples was used to balance and eliminate the mAccording to the commonly used method of analysis with ICP-AES in geochemistry, to study the influence factors of interference from the analysis results, standard soil substances were selected to be the calibration curve of work, and the same method of digestion with soil samples was used to balance and eliminate the matrix interference. The concentrations of major and minor elements in soil samples were measured; the relative deviation of the results was compared under conditions of soil matrix and non-soil matrix interference; the relations and laws were being analyzed. The relative deviation (RE%) of testing results under non-soil-matrix interference were found floating around zero, the ratios of positive deviation and negative deviation were almost the same. Excluding the factors of spectral interference, the method of matrix matching can effectively eliminate the effects of matrix interference on soil. It was found that the analysis results of major elements, such as Al, Ca, Fe, Mg, P, Ti and Ba, were influenced negatively greatly under the condition of soil matrix interference, The maximum deviation of Mg 279.5 nm was up to -14.49%. The degree of influence ranking showed as Ti, Mg>P, Fe>Ca, Ba>Al. However, there is no obvious effect on other elements, including Na, Cr, Cu, V, Li, Mn, Ni and Sr. Contrary to the original ideas, the matrix interference effected greatly on the results of elements of high content, nevertheless, the effects on minor elements were not significant. As to the comprehensive matrix interference , the large proportion of interference from component self-content appeared of elements of Ca and Mg, because obvious linear correlation was found between component self-content and the relative deviation of the testing results of Ca and Mg. But no linear trend appeared between the self-contents of other elements and the results of matrix interference, indicating that the influence weight from self-content of other elements was very small. It was very important to select the right spectral lines, and remove the factors of interference to determinate the results of measurement. Factors and rules of interference effect has always been the research topic by all of scholars in the research field of ICP spectrum. On the guidance of above research results, the spectral lines will be selected and the accuracy judged reasonably, when soil samples being analyzed by ICP-AES..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2260 (2016)
Spectroscopic Characteristics of Minerals in Sliding Zone Soil in Motuo Landslides and Their Engineering Significance
XIE Chao, ZHOU Ben-gang, LI Zheng-fang, ZHANG Long-sheng, LI Jiang-yi, XU Chong, and LIU Hong
The sliding zone soil of Motuo and GelinLandslides were tested with X-ray diffraction, X-ray fluorescence, and infrared absorption spectra. Its compositins of main minerals and clay minerals, even the chemical compositions were comprehensively analyzed. The results show that the composition of the main minerals was conThe sliding zone soil of Motuo and GelinLandslides were tested with X-ray diffraction, X-ray fluorescence, and infrared absorption spectra. Its compositins of main minerals and clay minerals, even the chemical compositions were comprehensively analyzed. The results show that the composition of the main minerals was controlled by alluvial fan composition, and the contents of clay minerals accounted for 9% and 10% respectively, with a large number of illitecontained in the sliding zone soilofMotuoLandslide, which reflects that the landslide had a high slip rate. There were no exotic corbonates minerals or secondary clay minerals contained corrosive substance with poor mechanical properties filled into theslidingplane because of the closed system, based on the infrared absorption spectrum with no peaks arising from CO2-3, HCO1-3 or C—H, as a positive affect result of the stability of these lamdsiles.The samples of sliding zone soil contain a certain amount of halloysite, reflecting that the landslides in the area of Motuo developed in a very humid and warm environment. With Na2O and CaO preserved in the closed system, a large number of illite/montmorillonite mixed layer formed in the sliding zone soilofGelinlandslide due to the strong water-rock interaction in thesliding plane with the decomposition of illite. The frictional strength of sliding zone was largely reduced due to the clay mineral assemblages, leading to the activity risk of landslide increasing..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2266 (2016)
Study on Simultaneous Mercury and Lead Detection in Water Samples with PGNAA-XRF
ZHANG Yan, SHAN Qing, JIA Wen-bao, WU Min-jian, HEI Da-qian, LING Yong-sheng, ZHANG Xin-lei, and CHEN Da
Prompt gamma neutron activation analysis (PGNAA) technology is used in heavy metals measurement. It is found that the detection accuracy of lead (Pb) is impacted heavily by mercury (Hg), because of thermal neutron cross section of mercury is much bigger than lead. In this paper, a new combined detection method was propPrompt gamma neutron activation analysis (PGNAA) technology is used in heavy metals measurement. It is found that the detection accuracy of lead (Pb) is impacted heavily by mercury (Hg), because of thermal neutron cross section of mercury is much bigger than lead. In this paper, a new combined detection method was proposed to improve the lead measurement accuracy in situ environmental water rejects analysis by PGNAA-XRF. Thus, a combined measurement facility was developed to analyze the mercury and lead in water simultaneously. The geometry of set-up is determined by a series of simulations with the MCNP code to improve the detection efficiency of the prompt gamma-ray intensity (Iγ) and characteristic X-ray fluorescence intensity (IX) of element. The ideal sample height and cavity are 33 and 16 cm, respectively. The influence of the relationship between Iγ, IX and different concentration (ｃi) of Hg and Pb was researched by MCNP calculations, respectively. The simulation results showed that there were good linear relationships between Iγ, IX and ｃi, respectively. The empirical formula of combined detection method was proposed based on the above calculations. The limits of detection for Hg and Pb with the combined measurement instrument were 3.89 and 4.80 mg·kg-1, respectively. It is a significant increase in performance of the mercury and lead detection simultaneously..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2271 (2016)
Data Mining for CVs Spectra in LAMOST-DR1
JIANG Bin, LI Zi-xuan, QU Mei-xia, WANG Wen-yu, and LUO A-li
LAMOST-DR1 is the first data released by Guoshoujing telescop, which has the largest number of stellar spectra in the world at present. The data set provides the data source for searching for special and rare celestial objects like cataclysmic variable stars.Meanwhile, it requires more advanced astronomical data procesLAMOST-DR1 is the first data released by Guoshoujing telescop, which has the largest number of stellar spectra in the world at present. The data set provides the data source for searching for special and rare celestial objects like cataclysmic variable stars.Meanwhile, it requires more advanced astronomical data processing methods and techniques. A data mining method for cataclysmic variable spectra in massive spectra data is proposed in this paper. Different types of celestial spectra show obvious difference in the feature space constructed with Laplacian Eigenmap method. The parameters of artificial neural network are optimized with particle swarm optimization method and the total LAMOST-DR1 data is processed. 7 cataclysmic variable star spectra are found in the experiment including 2 dwarf nova, 2 nova like variables and a highly polarized AM Her type. The newly found spectra enrich the current cataclysmic variable spectra library. The experiment is the first attempt of searching for cataclysmic variable star spectra with Guoshoujing telescope data and the results show that our approach is feasible in LAMOST data. This method is also applicable for mining other special celestial objects in sky survey telescope data..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2275 (2016)
Research on M Dwarf Sub-Classification Based on the Measurement of Residual Distribution
KANG Chao, PAN Jing-chang, YI Zhen-ping, WEI Peng, and JIANG Bin
The classification of stellar spectra is an important job in data processing of astronomy, which is mainly used for searching celestial spectra with known types in massive data survey. This paper focuses on LAMOST M dwarfs fine classification based on measurement of residual distribution. Residual distribution measuremThe classification of stellar spectra is an important job in data processing of astronomy, which is mainly used for searching celestial spectra with known types in massive data survey. This paper focuses on LAMOST M dwarfs fine classification based on measurement of residual distribution. Residual distribution measurement is a measurement method used to measure the distance between two spectra. In the process of calculating the distance between two spectra, normalized processing should come first. Then the residuals of the sampling points of corresponding wavelength are calculated. Eventually the standard deviation of the residual distribution as the distance between the spectra is calculated. In this paper, the M star of LAMOST DR2 is used as the experimental data of classification. The experimental results show that the spectra data can be classified more accurately with the measurement method of residual distribution than the use of other traditional classification methods. The effect of spectral classification is affected by signal to noise ratio, outliers, residual standardized coefficient and other factors..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2279 (2016)
Research on Broadband Spectral Imaging Spectrometer Based on CDP
ZHANG Zhou-feng, HU Bing-liang, YIN Qin-ye, and GAO Xiao-hui
In order to satisfy the application requirements of real-time spectral imaging for moving targets, we design a static, snapshot imaging spectrometer based on a CDP(crossed dispersion prism). The spectral imaging principle is studied, and an optical system of broadband spectral imaging spectrometer is designed accordingIn order to satisfy the application requirements of real-time spectral imaging for moving targets, we design a static, snapshot imaging spectrometer based on a CDP(crossed dispersion prism). The spectral imaging principle is studied, and an optical system of broadband spectral imaging spectrometer is designed according to this principle. Imaging spectrometer consists of a CDP, an imaging lens and a detector, with ±2°field of view, spectral coverage from 0.6 to 5.0 μm, The results show that this instrument has a better ability to detect spectral from 0.6 to 5.0 μm while the average spectral resolution is 20 nm. The technology for dynamic target real-time spectral imaging provides a new technical way. It has a great potential for detecting, locating and identifying unknown energetic events in real-time..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2284 (2016)
Optimal Design of Light Folding Imaging Spectrometer Based on Dyson Concentric System
LIU Yu-juan, WANG Cheng-ming, LIN Jun, CUI Ji-cheng, ZHANG Tian-yu, and ZHONG Zhi-cheng
Concave grating spectrometer based on Dyson concentric optical system has advantages of low aberration, large aperture and compact structure. The object plane and image plane of concentric spectrometer subsystem must be reunited into one plane while the distance between the object point and image point is relatively smConcave grating spectrometer based on Dyson concentric optical system has advantages of low aberration, large aperture and compact structure. The object plane and image plane of concentric spectrometer subsystem must be reunited into one plane while the distance between the object point and image point is relatively small. Thus it is difficult to satisfy this requirement for the existing focal plane of detection technology and assembly technology. In order to solve the assembly problem of the object and detector, the traditional Dyson concentric spectrometer was improved by introducing the off-axis mirror to shift the image light beam. The results show that the object plane and image plane of the improved system are separated successfully by the beam folding, and the aberration at all wavelengths is more rational distribution..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2287 (2016)
Study on Asymmetric Spatial Heterodyne Spectroscopy
LI Zhi-wei, XIONG Wei, SHI Hai-liang, LUO Hai-yan, and QIAO Yan-li
Restrictive relationship exists between spectral resolution, spectral range and number of pixels of traditional Spatial Heterodyne Spectroscopy (SHS). The main difference between Asymmetric Spatial Heterodyne Spectroscopy (ASHS) and SHS accelerates the space of one grating from the beamsplitter. It greatly increases spRestrictive relationship exists between spectral resolution, spectral range and number of pixels of traditional Spatial Heterodyne Spectroscopy (SHS). The main difference between Asymmetric Spatial Heterodyne Spectroscopy (ASHS) and SHS accelerates the space of one grating from the beamsplitter. It greatly increases spectral resolution while system parameters remain unchanged. First of all, this paper elaborates the fundamentals of the ASHS, the derived formulas of the system parameters and theoretical relationship between grating offset and the spectral resolution increases. As an important parameter of the ASHS, offset is restricted by the pixel number of short double side interferogram and the spectral resolution requirements. According to the experimental breadboard parameters of laboratory, the selection principle and the results of the offset are presented. In the case of the same device parameters, two types of theoretical performance parameters are calculated. The simulation is carried out. The results show that two of them have the same spectral range, but the ASHS has a higher spectral resolution. The relationship between resolution and offset increased consistent with theoretical calculation. Finally the ASHS breadboard is calibrated with the monochromatic light scanning method. The derived spectral range and resolution are in good agreement with the theoretical value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2291 (2016)
Error Correction of Spectral Calibration for Hyper-Spectral Atmosphere CO2 Monitoring Instrument
SHI Hai-liang, LI Zhi-wei, LUO Hai-yan, and XIONG Wei
The detection of hyper-spectral atmosphere CO2 needs remote sensor to be characterized and calibrated precisely while spectral calibration is the most basic work. The high uncertainty of wavelength calibration coefficient is a big problem as to the traditional laboratory calibration methods. In order to solve this probThe detection of hyper-spectral atmosphere CO2 needs remote sensor to be characterized and calibrated precisely while spectral calibration is the most basic work. The high uncertainty of wavelength calibration coefficient is a big problem as to the traditional laboratory calibration methods. In order to solve this problem, the research of error correction of spectral calibration based on gas absorption principle is carried out. The method is in accordance with the using conditions of instrument and it improves the practicability of the calibration coefficient. First, theoretical spectrum and error components are simulated by using radiative transfer. Then, the experiment of atmosphere CO2 absorption spectrum measurement is performed based on the atmosphere environmental simulation calibration house. Last, spectral error is corrected and optimized with LM algorithm. The result of spectral calibration of error correction shows that the mean value of spectral error deviation decreases from 0.03 cm-1 before correction to 0.008 cm-1 after correction, and systematic and mutable errors are removed. The spectral calibration precision on the ground is improved significantly, which lays the foundation for the subsequent greenhouse gas retrieval..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2296 (2016)
The Study on the Influence of Spectral Diffraction Efficiency Based on the Matching Network of Wide Spectrum AOTF
WANG Yu-jiang, WANG Zhi-bin, WAN Yao-li, SONG Yan-peng, LI Jin-hua, ZHANG Min-juan, and XUE Rui
Given that AOTF (Acousto-Optic Tunable Filter, AOTF) spectral imaging analyzer is widely used in a wide spectral region of the visible and infrared spectrum, the spectral bandwidth, diffraction efficiency and power efficiency of the AOTF need to be improved to meet higher standards. Ultrasonic transducer is the core coGiven that AOTF (Acousto-Optic Tunable Filter, AOTF) spectral imaging analyzer is widely used in a wide spectral region of the visible and infrared spectrum, the spectral bandwidth, diffraction efficiency and power efficiency of the AOTF need to be improved to meet higher standards. Ultrasonic transducer is the core component of AOTF. Its 3 dB working bandwidth determines the spectral diffraction range of AOTF, so it is making two different thicknesses high-low frequency ultrasonic transducer to improve AOTF spectral bandwidth on the same of the acousto-optic medium. Because between the operating frequency of ultrasonic transducer and input impedance there exists non-linear relationship, they have different input impedances at different frequencies. When the between driving signal source’s output impedance and ultrasound transducer have mismatched, It would produce energy consumption and lead to cannot bring the maximum power transfer to the ultrasonic transducer, so that the spectral diffraction efficiency of AOTF is reduced, and it affected spectral imaging quality. So going through to study theoretical ultrasonic transducer impedance frequency characteristics deeply in this paper designed a new broadband impedance matching network, which has important application reference value of the spectral diffraction efficiency improving. By ADS simulation and actual matching circuit experimental test, experimental results show that impedance matching network’ power efficiency reach to more than 90%, spectral diffraction efficiency get up to 90% in the 60~200 MHz bandwidth, and improve to spectral imaging quality within 420~1 150 nm waveband. The higher diffraction efficiency of the matching network has important implications for the current application AOTF based on spectral imaging technology..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2300 (2016)
Chromatism Analysis of Multispectral Imaging System Based on AOTF and Hardware Compensation Strategy
WANG Yao-li, WEN Ting-dun, WANG Zhi-bin, ZHANG Rui, and SONG Yan-peng
In view of the existing chromatism in the AOTF multispectral imaging system causes different wavelength imaging clarity under different focal length , even under the fixed wavelength, due to the horizontal direction (diffraction) spectral broadening, which leads to clear horizontal lines and blurring vertical lines. ThIn view of the existing chromatism in the AOTF multispectral imaging system causes different wavelength imaging clarity under different focal length , even under the fixed wavelength, due to the horizontal direction (diffraction) spectral broadening, which leads to clear horizontal lines and blurring vertical lines. This paper made a concrete analysis of the chromatism of AOTF, pointing out the causes of imaging blurring. According to the imaging characteristics of AOTF multispectral imaging system, this paper proposed an improved algorithm based on SSIM, which can be used to evaluate the image sharpness. The target of the original algorithm was two images (one as a reference image, the other one as the test image), while the algorithm proposed in this paper made similarity analysis between the adjacent lines in one target image, small similarity in change edges declares great contrast, thus the image is clearer. The image quality caused by chromatism in the AOTF multispectral imaging system can be compensated by automatic focusing system, which mainly based on this algorithm. It has small calculated amount and fast speed. The feasibility and practicability of the compensation strategy were verified through experiments. The results show that this strategy can effectively solve the image blurring caused by chromatism in the AOTF multispectral imaging system, which has an important application value..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2306 (2016)
Noninvasive Blood Glucose Analysis Based on Near-Infrared Reflectance Spectroscopy
L Xiao-feng, ZHANG Ting-lin, XIAO Feng, LI Guang, and WANG You
Noninvasive glucose detection is highly required for more convenient and less pain glycaemic monitoring. Most of currently used methods are invasive. In this paper, a near-infrared reflectance spectroscopy (NIRS) is proposed to detect blood glucose to protect patient absent of pain. NIRS is a safe, simple and efficientNoninvasive glucose detection is highly required for more convenient and less pain glycaemic monitoring. Most of currently used methods are invasive. In this paper, a near-infrared reflectance spectroscopy (NIRS) is proposed to detect blood glucose to protect patient absent of pain. NIRS is a safe, simple and efficient technology applied in many fields. Experiments, based on Oral Glucose Tolerance Test (OGTT), were conducted to collect data modeling with partial least squares (PLS) regression. 42 samples of fingertip blood and palm were measured by commercially available blood glucose meter and NIRS separately at the same time. The glucose concentration range is between 5 and 12 mmol·L-1. With leave-one-out cross-validation, we obtained a result of root mean square error of cross-validation (RMSECV) of 1.16 mmol·L-1 for all the data. With the pre-processing methods of normalization and un-informative variables elimination reducing noise and eliminating some additional effects, we get a better result of 0.79 mmol·L-1. A RMSECV of 0.41 mmol·L-1 for individual modeling is much less than the total modeling. It has a broad application prospect in individual customization..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2312 (2016)
Raman Spectroscopy Study Structural Changes in Black Bean Protein Isolate upon Ultrasonic-Treatment
YANG Yong, WANG Zhong-jiang, BI Shuang, SUI Xiao-nan, QI Bao-kun2, LI Yang, and JIANG Lian-zhou
This article focused on the assessment of the potential of Raman spectroscopy for the determination of structural changes in black-bean protein isolate (BBPI) dispersions with low-frequency (20 kHz) ultrasonication applied at various powers (150, 300 or 450 W) and for different durations (12 or 24 min). It also reporteThis article focused on the assessment of the potential of Raman spectroscopy for the determination of structural changes in black-bean protein isolate (BBPI) dispersions with low-frequency (20 kHz) ultrasonication applied at various powers (150, 300 or 450 W) and for different durations (12 or 24 min). It also reported on differential scanning calorimetry analyses. A decrease in TD at low- and medium-power ultrasonication confirmed these ultrasonication treatment disrupted internal hydrophobic interactions of protein molecules and broke up unstable aggregates to smaller soluble protein aggregates, while an increase in TD at high-power was attributed to repolymerization of aggregates. Raman spectroscopy analysis revealed a decrease in the α-helix proportion and an increase in β-sheets after ultrasonic treatment except Sample E (300 W, 24 min). Transformation of aggregation results in a reconstruction in secondary structure of BBPI, especially in β-sheet structure. Ultrasonic-treatment induced a decrease in the normalized intensity of the Raman band near 760 cm-1 which indicated that Tryptophan residues tended to expose and also indicated protein partially unfolding. No significant difference was found in Tyr doublet ratios between unheated and ultrasound-treated BBPI indicated that ultrasound did not change the microenvironment around tyrosyl residues. While the intensity of 1 450 cm-1 band increased with increasing ultrasonic intensity and treatment time, and then decreased with further increase in power and treatment time. In general, the formation of aggregation transferred g-g-t conformation to t-g-t conformation. Though some mechanism of aggregation-repolymerization of BBPI remains to be clearly defined, Raman spectroscopy provide a feasible tool to study the structural changes of BBPI prepared under different ultrasonic conditions, give a new perspective to elucidation of protein structure..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2318 (2016)
Examining the Effects of Biochar Application on Soil Phosphorus Levels and Phosphatase Activities with Visible and Fluorescence Spectroscopy
ZHANG Yu-lan, CHEN Li-jun, ZHANG Yu-ge, WU Zhi-jie, MA Xing-zhu, and YANG Xiao-zhu
Biochar could be got from crop straw which contain rich carbon under oxygen free or oxygen limited conditions at low temperature. The application of biochar into soil is beneficial to ease the pressure of handling straw, reduce pollution, reduce greenhouse gas emissions and improve soil quality. This study was carried Biochar could be got from crop straw which contain rich carbon under oxygen free or oxygen limited conditions at low temperature. The application of biochar into soil is beneficial to ease the pressure of handling straw, reduce pollution, reduce greenhouse gas emissions and improve soil quality. This study was carried out in a cornfield containing meadow brown soil at the lower reaches of Liao River which was treated with different amounts of biochar (0, 360, 1 800, 3 600 kg·ha-1) and fertilizer. We investigated the contents of soil available phosphorus (AP), organic P (OP) and total P (TP). We also investigated the enzyme activities of soil acid phosphatase (AcP), alkaline phosphatase (AlP) and phosphodiesterase (PD) via a fluorescence spectroscopy method by using a fluorescent conjugated polymer as the substrate. Soil AP contents increased drastically with the increasing application of biochar, whereas the OP and TP contents exhibited little change. The increase in AP contents was ascribed to the introduction of P into the soil via biochar. Soil AlP and PD activities increased with increasing biochar application. Soil AcP activity increased significantly after the application of the appropriate amount of biochar (1 800 kg·ha-1), whereas it was inhibited by the application of high levels of biochar (3 600 kg·ha-1), perhaps due to the intrinsic alkalinity of biochar. The effect of Biochar inputs on soil phosphorus element and phosphatase activity is the comprehensive embodiment of the soil physical properties, chemical properties, and microbial community structure and metabolic capacity. We should further study such item. The fluorescent microplate method used in this study has many advantages, such as accuracy, rapidness and simple to perform..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2325 (2016)
Investigation of the Interaction between Perfluorododecanoic Acid and Human Serum Albumin by Multi-Spectroscopic and Molecular Modeling Techniques
HU Tao-ying, WANG Yi-run, ZHOU Shan-shan, and LIU Ying
Perfluorododecanoic acid (PFDoA) is the most toxic emerging environmental contaminant among the 8～12 carbon chain perfluoroalkyl acids (PFAAs). A large amount of knowledge in the field of environmental PFAAs has been accumulated so far, while we are still just at the beginning of research into the interaction between PPerfluorododecanoic acid (PFDoA) is the most toxic emerging environmental contaminant among the 8～12 carbon chain perfluoroalkyl acids (PFAAs). A large amount of knowledge in the field of environmental PFAAs has been accumulated so far, while we are still just at the beginning of research into the interaction between PFDoA and human serum albumin (HSA). The goal of this study was to comprehensively determinate the binding mechanism of PFDoA with HSA by using fluorescence quenching technique in combination with molecular modeling and circular dichroism (CD) spectroscopy under the simulative physiological conditions. The quenching of HSA fluorescence by PFDoA was found to be a result of the combination of dynamic quenching and the formation of PFDoA-HSA complex. The calculated binding distance (r=3.65 nm) indicated that the non-radioactive energy transfer came into being in the interaction between PFDoA (acceptor) and HSA (donor). By performing displacement measurements, the specific binding of PFDoA in the vicinity of site I of HSA was clarified. Furthermore, the binding details between PFDoA and HSA were further confirmed by molecular docking studies, which revealed that PFDoA was bound at subdomain IIA by multiple interactions, such as the interaction between O1 of PFDoA with Arg 257 and Ser 287 predominately through polar force. And the best calculated docking energy is -25.87 kJ·mol-1, this high negative value indicated that the PFDoA molecule exhibited large binding affinity towards HSA. The effects of PFDoA on the conformation of HSA were analyzed by synchronous fluorescence spectra and three-dimensional fluorescence spectra, and the results exhibited that the hydrophobicity of the microenvironment around tryptophan residue was increased and the conformation of HSA was altered after binding PFDoA. The CD spectra quantitatively calculated the protein secondary structure, which suggested a loss of helical stability after the PFDoA-HSA complex formation. The binding research presented in this paper enriches our knowledge of the interaction dynamics of perfluoroalkyl acids to the HSA and reveals the chemical essence of the interaction between biomacromolecule and ligand..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2330 (2016)
Multi-Band Texture Image Fusion Based on the Embedded Multi-Scale Decomposition and Possibility Theory
LIN Su-zhen, WANG Dong-juan, WANG Xiao-xia, and ZHU Xiao-hong
The combination of multi-scale transform and the rules which are “high-frequency coefficients combined by selecting the maximum gray value or energy” and “low-pass ones combined by weighting average” is an effective method in dual-band image fusion. However, when these methods are used to fuse multi-band images, sequenThe combination of multi-scale transform and the rules which are “high-frequency coefficients combined by selecting the maximum gray value or energy” and “low-pass ones combined by weighting average” is an effective method in dual-band image fusion. However, when these methods are used to fuse multi-band images, sequential weighted average often leads the weakening of the inherent different information of original images, which affects the subsequent target recognition and scene understanding. The problem is more obvious when fusing multi-band images with texture features. In order to describe the scene in a more comprehensive and precise way, a new multi-band texture image fusion method based on embedded multi-scale decomposition and possibility theory is proposed. The method consists of three parts. The original multi-band images are decomposed into their high- and low-frequency components through a multi-scale transform. The high-frequency components are fused per-pixel by extracting the maximum gray value, whereas the last layer of low-frequency components of original multi-band images with the largest standard deviation is blocked through the another multi-scale transform. Based on the specific sizes and positions of these blocks, the remaining two original images are divided. All the blocks from three bands are traversely fused according to the possibility theory, and the low-frequency image is formed by mosaicing these fused blocks. Then, this image is inversely transformed with its high-frequency counterparts to get the final fusion image. This method not only integrates the pixel-level with feature-level fusion methods, but also integrates the space domain with transform domain technologies together, and solves the problem of sawtooth effect on the edge of the target through the different fusion rules with the different sizes of blocks. The validity of the method proposed is proved..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2337 (2016)
Identification of the Citrus Greening Disease Using Spectral and Textural Features Based on Hyperspectral Imaging
MA Hao, JI Hai-yan, and Won Suk Lee
In this paper we discussed the application of spectral and textural features in identifying early stage of the citrus greening disease (Huanglongbing or HLB). A total of 176 hyperspectral images of citrus leaves (60 for healthy, 60 for HLB-infected and 56 for zinc-deficient) were captured by using a near-ground hyperspIn this paper we discussed the application of spectral and textural features in identifying early stage of the citrus greening disease (Huanglongbing or HLB). A total of 176 hyperspectral images of citrus leaves (60 for healthy, 60 for HLB-infected and 56 for zinc-deficient) were captured by using a near-ground hyperspectral imaging system. Regions of interest (ROI) were extracted manually from the part of pathological changes in the images to calculate the average reflectance spectra of each sample as the sample spectra, ranging from 396 to 1 010 nm. The dimensions of the sample spectra were reduced with the algorithms of principal component analysis (PCA) and successive projection analysis (SPA). Classification models were built with the original spectra and candidate variables, the first four PCs selected by PCA and a set of wavelengths (630.5, 679.4, 749.4 and 899.9 nm) selected by SPA. The results based on a classifier of least square-support vector machine (LS-SVM) showed that the classification models built with the candidate variables selected by PCA and SPA had a better performance, achieving 89.7% and 87.4% in terms of average accuracy. In addition, two groups of textural features, extracted from gray images of the four selected wavelengths based on gray-level histogram and gray-level co-occurrence matrix (GLCM), were also used for the classifier. The first ten features ranked by SPA promoted the average accuracy of classifier significantly, achieving 100%, 93.3% and 92.9% for the three class samples respectively. The results of this study indicated that it would be feasible to identify HLB using the image textural features based on selected wavelengths, and it provided a basis for developing a portable HLB detection system with multispectral imaging techniques..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2344 (2016)
Characterization of the Interaction between Acetylisovaleryltylosin Tartrat and Bovine Serum Albumin without or with Zn2+ and Cu2+ by Spectroscopic Analysis
DENG Feng-yu, HU Tao-ying, ZHOU Shan-shan, and LIU Ying
Acetylisovaleryltylosin tartrate (ATLL) is a new macrolide veterinary antibiotic, it is necessary to study the binding of ATLL to protein, which will directly correlate with the efficiency in vivo. Bovine serum albumin (BSA) is structure homologous with human serum albumin (HSA), and is commonly chosen as a model to inAcetylisovaleryltylosin tartrate (ATLL) is a new macrolide veterinary antibiotic, it is necessary to study the binding of ATLL to protein, which will directly correlate with the efficiency in vivo. Bovine serum albumin (BSA) is structure homologous with human serum albumin (HSA), and is commonly chosen as a model to investigate drug-protein interaction.There are many metal ions in plasma, as yet, the studies on mainly focus on single metal ion. In this study, the multiple systems formed by ATLL and BSA without or with Zn2+ and Cu2+ have been studied by mult-spectroscopy. The results showed that, the fluorescence of BSA was quenched by ATLL through a static quenching mechanism. The effective quenching constant (Ka) of ATLL to BSA decreased with Zn2+ and increased with Cu2+. Thermodynamic parameters revealed that hydrogen bonds and hydrophobic forces played significant roles in the binding of ATLL to BSA. The polarity of tryptophan and tyrosine residues changed when adding ATLL with or without Zn2+ and Cu2+. FT-IR spectra showed that ATLL changed α-helix and β-sheet of BSA into β-turn and random structure. The UV-Vis spectra indicated that the effects of Zn2+ on ATLL binding to BSA may cause by a competition binding, and Cu2+ possibly formed Cu2+-ATLL complex via metal ion bridge. All the knowledge obtained in this work will be helpful to understand the transport mechanism of ATLL with BSA and the effect of metal ions on the interaction of drug-protein in vivo..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2351 (2016)
Elemental Analysis of Nine Herbal Drugs for Nourishing Blood by Inductively Coupled Plasma Atomic Emission Spectroscopy with Microwave Digestion
CHEN Lin-wei, CAI Hao, WANG Qin, QIAO Feng-xian, QIN Kun-ming, and CAI Bao-chang
An analytical method has been developed for the determination of traces of Zn, Mn, Na, K, Ca, Mg, Ni, Pb, Se, Fe, Cu, Al, B, Ti, Sn, Hg, and Li in nine herbal drugs for nourishing blood by ICP-AES. The data showed that nine herbal drugs for nourishing blood were abundant in the contents of major and trace elements whicAn analytical method has been developed for the determination of traces of Zn, Mn, Na, K, Ca, Mg, Ni, Pb, Se, Fe, Cu, Al, B, Ti, Sn, Hg, and Li in nine herbal drugs for nourishing blood by ICP-AES. The data showed that nine herbal drugs for nourishing blood were abundant in the contents of major and trace elements which are healthy for human body, including the trace elements with higher contents, such as Fe, Se, Ni, Mn, and Zn, which are well known for nourishing blood. Elements (macro-elements, essential elements, non-essential elements, and toxic elements) classified in nine herbal drugs for nourishing blood were illustrated in cylindrical histograms. Principal component analysis and hierarchical cluster analysis were applied to the data matrix to evaluate analytical results. The results of hierarchical cluster analysis showed that dendrogram obtained by Ward’s method of hierarchical cluster analysis for seventeen variables and nine samples mainly displayed three clusters. After optimizing the microwave digestion technology, the recoveries of seventeen elements were in the ranges from 97.89% to 103.25% and the RSDs were all lower than 3.0%. ICP-AES combined with microwave digestion is accurate and precise in determining major and trace elements in nine herbal drugs for nourishing blood..
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 2358 (2016)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Jan. 01, 1900
- Vol. 36, Issue 7, 1 (2016)
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