Journals >Spectroscopy and Spectral Analysis
Contents
2009
Volume: 29 Issue 9
68 Article(s)
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Research Article
Collisional Energy Transfer for K(6S)+H2→K(4D)+H2
WANG Qian, LI Peng, DAI Kang, and SHEN Yi-fan
The K atoms were prepared in either the 6S or the 4D state by two-photon absorption using an OPO laser. The cross sections for deactivation of K(6S) and K(4D) by collisions with H2 were measured. The temperature of the cell body was controlled at 413 K, and H2 pressure was varied between 4 and 40 Pa. The effects of K(6The K atoms were prepared in either the 6S or the 4D state by two-photon absorption using an OPO laser. The cross sections for deactivation of K(6S) and K(4D) by collisions with H2 were measured. The temperature of the cell body was controlled at 413 K, and H2 pressure was varied between 4 and 40 Pa. The effects of K(6S, 4D)-K collisions could be neglected in our experimental condition. On excitation of K(6S) state, the decay signal of the time-resolved fluorescence from the 6S→4P transition was monitored. The logarithmic plot for the time-resolved fluorescence of K(6S) atom was shown and the slope yielded an effective lifetime. When the pressure of H2 was successively increased, the time-resolved spectrum obviously had contributions from two components. At the beginning of the decay, the population of K(6S) was simply determined by the two-photon excitation and the decay curve provided the information on the effective lifetime of the K(6S) state under H2 collisions. After a prolonged period, the additional contribution of the K(6S) population from K(4D) state became important. The population of the K(4D) state increased with increasing the pressure of H2, which leading to more intense emission of the 4D→4P transition by comparison with the case in the absence of H2. The effective lifetime for depopulation of the 4D state by collisions with H2 can be treated analogously to the 6S state. Based on the Stern-Volmer equation, radiation lifetimes are (97±15) ns for the 6S state and (300±45) ns for the 4D state. The radiation lifetimes in the absence of H2 collisions agree with those previously reported. The total cross sections for deactivation of excited K atoms by means of collisions with H2 are (1.6±0.3)×10-14 cm2 for the 6S state and (40±6)×10-14 cm2 for the 4D state. Upon excitation to the K(6S) state, the dependence on H2 pressure of integrated fluorescence in the transition 4D→4P was measured. The cross section (1.4±0.3)×10-14 cm2 for the transition 6S→4D was obtained. The authors conclude that the channel for energy depletion from the 6S state is predominantly through the physical quenching to the 4D state, although the KH product has been observed in the chemical reaction..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2305 (2009)
Experimental Evaluation of the Cross Sections in Cs(6DJ)+Cs(6S1/2) Inelastic Collisions
GUO Qi-cun, WU Hong-ping, KANG Li-kui, WAN Hong-fei, DAI Kang, and SHEN Yi-fan
At a Cs density higher than 9×1014 cm-3, cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from an YAG-laser-pumped OPO laser, populating 6D5/2 state by two-photon absorption. Energy transfer in Cs6(D5/2)＋Cs(6S) collisions was studied using methods of atomic fluorescence. At the difAt a Cs density higher than 9×1014 cm-3, cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from an YAG-laser-pumped OPO laser, populating 6D5/2 state by two-photon absorption. Energy transfer in Cs6(D5/2)＋Cs(6S) collisions was studied using methods of atomic fluorescence. At the different Cs densities, we have measured the time-integrated intensities of the components and fitted a three-state rate equation model to obtain the cross sections. The experimental points were fitted to a straight line very well. The authors converted the gradient and intercept into cross sections. The cross section for 6D5/2→6D3/2 transfer is (2.1±0.4)×10-14 cm2. The cross section for excitation transfer out of the 6D doublet is σQ=(1.6±0.4)×10-14 cm2. The cross section σQ contains information on reverse energy pooling collisions ［i.e., Cs(6D3/2)＋Cs(6S1/2)→Cs(6P)＋6Cs(P)］ and contribution from mining in 6DJ→7PJ′, This latter contribution could be subtracted out using the results of a second experiment. At a Cs density lower than 6.0×1012 cm-3, the laser was used to pump the 6D3/2 and 6D5/2 states, respectively. The resulting fluorescence included the direct component emitted in the decay of the 6DJ state and the sensitized component arising from the collisionally populated 7PJ′state. Relative intensities of the components yielded the cross sections. The cross-sections for the processes Cs(6D5/2)＋Cs(6S1/2)→Cs(7PJ′)＋Cs(6S1/2) are (1.6±0.5)×10-15 cm2. for J′=3/2 and (6.5±2.1)×10-16 cm2, for J′=1/2, respectively. The cross-sections for the processes Cs(6D3/2)＋Cs(6S1/2) →Cs(7PJ′)＋Cs(6S1/2) are (1.9±0.6)×10-15 cm2. for J′=3/2 and (7.6±2.4)×10-16 cm2, for J′=1/2, respectively. The 6DJ→7PJ′, energy transfer rate coefficient is small. The total quenching rate coefficient out of the 6DJ state is much larger. Evidence suggests that the quenching of the 6DJ state is caused predominantly by reverse energy-pooling process. The cross section for this process, i.e., Cs(6D3/2)＋Cs(6S1/2)→Cs(6P)＋Cs(6P) is (1.3±0.4)×10-14 cm2..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2309 (2009)
Study of Scintillating Luminescence Spectra of Lead Tungstate Scintillation Crystal Doped with Ions
WAN You-bao, WU Yu-rong, ZHANG Jian-xin, YANG Pei-zhi, XIAO Lin-rong, and YANG Hui
The light yield of the as-grown PbWO4, annealed PbWO4 and BaF2∶PbWO4 crystals were raised by utilizing our improved crystal growth instrument and technique. Their scintillating properties including transmittance, decay time and light yield were studied. Results reveal that the scintillating performances of the crystalsThe light yield of the as-grown PbWO4, annealed PbWO4 and BaF2∶PbWO4 crystals were raised by utilizing our improved crystal growth instrument and technique. Their scintillating properties including transmittance, decay time and light yield were studied. Results reveal that the scintillating performances of the crystals were improved evidently by using the crystal annealing technique and the ions doping technique, especially the negative ions doping technique. The influence results of the two techniques are different. The ions doping technique raises their transmittance intensity in the whole measuring wavelength range. But the influence of annealing PbWO4 crystal on their transmittance is complicated. It improves its transmittance intensity at the wavelength above 360 nm, but weakens the transmittance intensity of the annealed PbWO4 crystal in the wavelength range from 320 to 360 nm. These phenomena should be related to the crystal defects which have absorption peaks in this wavelength range, especially for V3+Pb defect which has characterized absorption peaks in this wavelength range. Also, the absorption of the defects influences the character of the decay time of these crystals. The big defect concentration relates to the short decay time. It should be mentioned that the ions doping technique reduces the defect content in the crystal, which is beneficial to the high transmittance intensity but induces slightly longer decay time than that of as-grown crystal and well annealed PbWO4 crystal. Also, the ions doping technique of the F- ion doped crystal leads to high light yield. The annealing technique and ions doping technique improve the light yield of crystals. The light yield of BaF2∶PbWO4 reaches 65 p.e./MeV, which is near to the requirement of PET. The good result is related to the degeneration of the ［WO4］2- tetrahedron induced by the F- occupying the O2- site in the crystal cell..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2313 (2009)
Stokes and Anti-Stokes Luminescence Research of NaYF4∶Eu3+, Tm3+, Yb3+
DU Hai-yan, YANG Zhi-ping, and SUN Jia-yue
The sample of NaYF4∶Eu,Tm,Yb was synthesized by coprecipitation method. The emission of NaYF4∶Eu,Tm,Yb excited by 360 nm is blue light with the peak at 452 nm from the transition of 1D2→3F4 of Tm3+. After being excited by 395 nm, NaYF4∶Eu,Tm,Yb emits orange light with the peak at 591 nm originating from the transition The sample of NaYF4∶Eu,Tm,Yb was synthesized by coprecipitation method. The emission of NaYF4∶Eu,Tm,Yb excited by 360 nm is blue light with the peak at 452 nm from the transition of 1D2→3F4 of Tm3+. After being excited by 395 nm, NaYF4∶Eu,Tm,Yb emits orange light with the peak at 591 nm originating from the transition of 5D0→7F1 of Eu3+. When excited by 409 nm, NaYF4∶Eu,Tm,Yb emits red light with the peak at 613 nm from the transition of 5D0→7F2 of Eu3+. The color of upconversion luminescence of NaYF4∶Eu,Tm,Yb excited by 980 nm was blue and red. The upconversion spectrum exhibits distinct emission peaks at 459, 478 and 641 nm. The blue light comes from the transition of 1G4→3H6 and 1D2→3F4 of Tm3+. The absorption spectrum was also researched. The red light results from the transition of 1G4→3F4 of Tm3+. The slope of the emission of 474 and 646 nm is 2.1 and 2.4 respectively. The emission of 478 and 641 nm is all due to three photon process. The structural properties of sample were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that NaYF4∶Tm3+,Yb3+ prepared by coprecipitation method exhibits a hexagonal crystal..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2317 (2009)
Study of Exciton Generation Region of Phosphorescent Light Emitting Devices Based on the Changing Electric Field
LIU Xu-dong, ZHAO Su-ling, SONG Dan-dan, ZHAN Hong-ming, YUAN Guang-cai, and XU Zheng
The changes of exciton generation region are influenced by varying electric field, which affect the color and efficiency performance of devices. Firstly, The authors fabricated two types of phosphorescent light emitting devices, device 1： ITO/PEDOT∶PSS/PVK∶Ir(ppy)3∶DCJTB (100∶2∶1 wt)/ BCP(10 nm)/Alq3(15 nm)/Al, and devThe changes of exciton generation region are influenced by varying electric field, which affect the color and efficiency performance of devices. Firstly, The authors fabricated two types of phosphorescent light emitting devices, device 1： ITO/PEDOT∶PSS/PVK∶Ir(ppy)3∶DCJTB (100∶2∶1 wt)/ BCP(10 nm)/Alq3(15 nm)/Al, and device 2： ITO/PEDOT∶PSS/PVK∶Ir(ppy)3 (100∶2 wt)/BCP (10 nm)/Alq3 (15 nm)/Al. The authors investigated the influences of electric field on exciton generation region in single-layer and multi-doped structure devices. Analysis of the electroluminescence spectrum under different voltages indicates that the emitting of Ir(ppy)3, PVK and DCJTB was enhanced with the increase in applied voltages. Compared to Ir(ppy)3, the emitting of PVK and DCJTB was prominently enhanced. This is because under high electric field it is easier for high energy carrier to generate high energy exciton, and the emitting of wide-band-gap material PVK is stronger; on the other hand, the authors investigated the results from the aspect of energy band gap. DCJTB is narrow-band-gap material, which can capture carrier comparatively easily and emit stronger light. At the same time, we obtained a new emission peak located at 460 nm, which becomes comparatively weak with increasing voltage. In order to explore the reason, we fabricated the device: ITO/PEDOT∶PSS/PVK∶BCP∶Ir(ppy)3 (x∶y∶2 wt)/Alq3 (15 nm)/Al. The 460 nm emission peak doesn’t disappear by changing the mass ratio of x and y. The authors speculate that the emission peak relates to PVK and BCP..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2321 (2009)
The Properties of OTFTs and Pentacene Films Deposited onto Different Insulator Layers
HUANG Jin-ying, XU Zheng, ZHANG Fu-jun, ZHAO Su-ling, YUAN Guang-cai, and KONG Chao
The authors fabricated OTFT devices with different insulator materials. The OTFTs with PMMA as the dielectric layer exhibit better properties, including a mobility of 0.207 cm2·V-1·s-1, an on/off current ratio of 4.93×103, and a threshold voltage of 4.3 V. However, the OTFTs based on oxidized silicon dieThe authors fabricated OTFT devices with different insulator materials. The OTFTs with PMMA as the dielectric layer exhibit better properties, including a mobility of 0.207 cm2·V-1·s-1, an on/off current ratio of 4.93×103, and a threshold voltage of 4.3 V. However, the OTFTs based on oxidized silicon dielectric layer perform not so well, with a mobility of 0.039 cm2·V-1·s-1, an on/off current ratio of 5.98×102, and a threshold voltage of 5.4 V. In order to explain the difference in performances, we compared the surface roughness of the oxidized silicon film with that of the PMMA film according to the results of atomic force microscopy, and found that the former had a roughness mean square (RMS) of 1.579 nm and the latter was more smooth with an RMS of 0.216 nm. The quality of the pentacene films deposited onto oxidized silicon and PMMA was also studied by atomic force microscopy and X-ray diffraction. From the results of AFM, the authors found that the pentacene film deposited on PMMA had high thin film quality with larger grain size and less crystal grain boundaries. From the results of XRD, the authors found that the pentacene film deposited on PMMA had clear diffraction peak, showing that the pentacene film deposited on PMMA had greater crystallite quality once again. Therefore, OTFTs with PMMA as insulator layers have advantages over those OTFTs with oxidized silicon dielectric layer..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2325 (2009)
Fluorescence Spectra and Imaging of Platymonas Subcordiformis via LSCM
CHEN Guan-nan, HUANG Zu-fang, CHEN Rong, LIN Ju-qiang, CHEN Jian-xin, YANG Kun-tao, ZHUANG Hui-ru, and WANG Li-jiang
Primary investigation of Platymonas subcordiformis was performed with laser scanning microscopic technology. Both autofluorescence spectra and autofluorescence imaging of Platymonas subcordiformis were achieved by one photon excitation of 488 nm Ar+ laser. Autofluorescence images revealed cup-shaped object inside the PPrimary investigation of Platymonas subcordiformis was performed with laser scanning microscopic technology. Both autofluorescence spectra and autofluorescence imaging of Platymonas subcordiformis were achieved by one photon excitation of 488 nm Ar+ laser. Autofluorescence images revealed cup-shaped object inside the Platymonas subcordiformis cell, and the corresponding fluorescence peak located at 682 nm was attributed to chloroplast. Moreover, in single channel mode, there existed a round-shaped object in chloroplast center, showing strong fluorescence by 800 nm femtosecond laser excitation. Also, the authors obtained both the individual cup-shaped chloroplast and round-shaped object image and the overlaid images by using dual-channel mode. Meanwhile, six main fluorescence peaks were found. Single photon excitation can be used to obtain autofluorescence image and autofluorescence spectra of Platymonas subcordiformis, while two photon excitation combined with multitrack mode and Lambda mode can be used not only to observe internal structure, but also for the analysis of existence of biological and chemical substances with higher sensitivity than single photon excitation. LSCM technique can be a promising tool for rapid, convenient, real-time and effective investigation in ocean algae..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2330 (2009)
Study on THz Spectra of Nicotinic Acid, Nicotinamide and Nicotine
YU Bin, HUANG Zhen, WANG Xiao-yan, and ZHAO Guo-zhong
The terahertz (THz) spectra of nicotinic acid, nicotinamide and nicotine were studied at room temperature. The time-domain THz spectra were measured. The frequency-domain spectra were obtained by fast Fourier transform (FFT). The spectral response and the dispersive relationship of refractive index in THz spectral rangThe terahertz (THz) spectra of nicotinic acid, nicotinamide and nicotine were studied at room temperature. The time-domain THz spectra were measured. The frequency-domain spectra were obtained by fast Fourier transform (FFT). The spectral response and the dispersive relationship of refractive index in THz spectral range were obtained. The results show that the samples have obvious spectral response in THz spectral range except nicotine. The corresponding stimulated spectra were given by using density functional theory (DFT) method for both nicotinamide and nicotinic acid. The origin of the absorption peaks of nicotinic acid and nicotinamide was explored. It is thought that the absorption peak of nicotinic acid is caused by the torsion and wagging of the molecule, but the absorption peaks of nicotinamide (except 1.93 THz) are caused by intermolecular or phonon mode. It was shown that the molecule structure and vibrational modes of nicotinic acid and nicotinamide can be analyzed by the combination of simulation and experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2334 (2009)
Study on the Terahertz Spectrum of Haojiami
ZHOU Bin-quan, FANG Jian-cheng, and WU Feng-ping
Haojiami is a very effective drug to treat malaria, and as a result of its unique drug efficacy, it is widely used in the clinical medicine. It was studied experimentally by terahertz (THz) time-domain spectroscopy (THz-TDS), and the characteristic absorption spectra were obtained in the range of 0.2 to 3.0 THz. In parHaojiami is a very effective drug to treat malaria, and as a result of its unique drug efficacy, it is widely used in the clinical medicine. It was studied experimentally by terahertz (THz) time-domain spectroscopy (THz-TDS), and the characteristic absorption spectra were obtained in the range of 0.2 to 3.0 THz. In parallel with the experimental study, the density functional theory (DFT) and 6-31G basis set were applied to obtain the structure and vibrational frequencies of the haojiami molecule. The observed vibrational spectra were assigned according to the DFT calculations. Theoretical results show that 1.26 and 2.73 THz in significant agreement with experimental results at 1.24 and 2.73 THz. At the same time, haojiami’s far infrared vibration pattern was recognized. The vibration mode takes the molecular groups skeleton vibration and the reverse as the chief feature. The results suggest that the use of the THz-TDS technique can be an effective way to inspect for Chinese medicine, and provide the theory basis for further study of the haojiami drug efficacy..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2338 (2009)
Time Domain Terahertz Spectroscopy of (Pb,La)TiO3 Ferroelectric Thin Films
ZHANG Ting-ting, ZHANG Ya-xin, WU Jia-gang, LIU Di-wei, HE Zhou, and LIU Sheng-gang
Terahertz time-domain spectroscopic technique was applied to investigate the spectral properties of (Pb, La)TiO3 (PLT) ferroelectric thin films prepared on SiO2/Si substrates. The terahertz spectra of three kinds of PLT thin films with different sintering temperatures were observed. According to the experimental data, Terahertz time-domain spectroscopic technique was applied to investigate the spectral properties of (Pb, La)TiO3 (PLT) ferroelectric thin films prepared on SiO2/Si substrates. The terahertz spectra of three kinds of PLT thin films with different sintering temperatures were observed. According to the experimental data, the absorption coefficients, refraction indexes and dielecric constants of the PLT thin films were computed, and the experimental results of the three kinds of PLT thin films with different sintering temperatures in the effective frequency range were compared. The results indicated that the PLT thin films had strong absorption in the frequency range of measurement, and had an obvious absorption peak at 1.5 THz and a weaker absorption peak at 2.25 THz..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2342 (2009)
Chinese Traditional Medicine Recognition by Support Vector Machine (SVM) Terahertz Spectrum
CHEN Yan-jiang, LIU Yan-yan, ZHAO Guo-zhong, WANG Wei-ning, and LI Fu-li
Identification is very important for the development of Chinese traditional medicines. In recent years, rapid progress in ultrafast laser technology provides a steady and available source for terahertz pulses generation, which greatly promotes the development of THz spectroscopy and imaging technique. SVM is a method fIdentification is very important for the development of Chinese traditional medicines. In recent years, rapid progress in ultrafast laser technology provides a steady and available source for terahertz pulses generation, which greatly promotes the development of THz spectroscopy and imaging technique. SVM is a method for recognition of two kinds of samples. Appling SVM to the identification of Chinese traditional medicines through THz spectrum is a new way. The experiment on three groups of Chinese traditional medicines (zhigancao and shengancao, nanchaihu and beichaihu, shandougen and beidougen) was studied. The THz frequency spectrum and absorptivity were obtained and used to construct the feature space of Chinese traditional medicines. Three kinds of SVM were build, which used three kinds of kernel functions. By comparison, a model of BP artificial neural network was constructed. The result of using three kinds of SVM and BP artificial neural network to identify the Chinese traditional medicines showed that both methods have good prediction ability, but obviously the effect of SVM is better than BP artificial neural network for small samples. Using SVM in terahertz spectrum is a efficacious way for classification of Chinese traditional medicines..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2346 (2009)
Detection of Amino Acids Based on Terahertz Spectroscopy
TANG Zhong-feng, LIN Hai-tao, CHEN Xiao-wei, and ZHANG Zeng-fang
Terahertz (THz) is the frequency region ranging from 0.1 to 2.0 THz, which lies in the far-infrared region. Compared to Fourier transform infrared spectra (FTIR), terahertz time-domain spectra (THz-TDS) has low energy, high signal-to-noise ratio (SNR) and is non-ionizing radiation. Low-frequency vibrational modes of soTerahertz (THz) is the frequency region ranging from 0.1 to 2.0 THz, which lies in the far-infrared region. Compared to Fourier transform infrared spectra (FTIR), terahertz time-domain spectra (THz-TDS) has low energy, high signal-to-noise ratio (SNR) and is non-ionizing radiation. Low-frequency vibrational modes of some amino acids, such as torsional and collective vibrational modes and hydrogen-bond modes, exist in the THz region. Amino acids are important organic compounds and are the fundamental components of proteins. Amino acids can exist with a highly ordered crystal structure linked by hydrogen intermolecular bonds in the solid phase. The absorption spectra of amino acids in the THz region show marked differences while mid-infrared absorption spectra usually show very little difference. Up to now, absorption spectra of twenty kinds of amino acids have been studied by many researchers using THz technique; the quantitative analysis of amino acids by THZ-TDS is also included. Investigation of THz spectra of amino acids are of fundamental interests, and will lead to further understanding of low-frequency vibrations of protein/DNA and relevant biological reactions and activities. In the present paper, the latest progress in absorption spectra of amino acids determined by THz spectroscopy is reviewed and a database is built. Some brief remarks on future developments in and prospects for THz application in amino acids are also provided..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2351 (2009)
Evaluating Fatigue Resistance Effect of Health Food by Near-Infrared Tissue Oximeter
WU Jian, DING Hai-shu, and YE Da-tian
Currently, chronic fatigue syndrome (CFS) seriously affects people’s normal living and work. In the present paper, the physiological parameters, such as tissue oxygenation saturation and heart rate, were used to evaluate the subjects’ fatigue degree, and the fatigue resistance capsule and coffee were taken as a measureCurrently, chronic fatigue syndrome (CFS) seriously affects people’s normal living and work. In the present paper, the physiological parameters, such as tissue oxygenation saturation and heart rate, were used to evaluate the subjects’ fatigue degree, and the fatigue resistance capsule and coffee were taken as a measure to adjust the fatigue. Human tissue oxygen saturation (rSO2) can be monitored noninvasively and in real time by near infrared spectroscopy (NIRS) based on spatially-resolved spectroscopy. Aiming at those brainworkers who need to work in an office for a long time; two static experiments were designed to evaluate the fatigue degree of the subjects who either take the fatigue resistance capsules/coffee or not. The rSO2 and heart rate (HR) of the subjects in the experiment group and contrast group were measured respectively for fatigue evaluation. This work particularly analyzed the changes in rSO2 in these two groups. The results show that the rSO2 of subjects in the experiment group evidently increased compared to that in the contrast group when the subjects took the fatigue resistance capsule or coffee, thereby show that the health food can reduce the fatigue to a certain extent..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2357 (2009)
Methane Optic Fiber Sensor Network Based on Infrared Spectrum Absorption in Coal Mine
WU Xiao-jun1, WANG Peng, WANG Zhi-bin, LI Xiao, and TIAN Er-ming
Through analyzing the infrared absorption spectrum of methane, a multi-point optic fiber sensor network was designed based on the principle of light absorbing capability of gas which varies with gas concentration at its characteristic wavelength. A distributed feedback laser diode (DFB LD) was used as the light source Through analyzing the infrared absorption spectrum of methane, a multi-point optic fiber sensor network was designed based on the principle of light absorbing capability of gas which varies with gas concentration at its characteristic wavelength. A distributed feedback laser diode (DFB LD) was used as the light source and an InGaAs PIN as the photodetector which features high sensitivity and low noise. Sixteen methane sensors were multiplexed in this system with space division multiple access technology (SDMAT), and the faint signals were processed by the filtering and amplifying circuit. All signals were gathered by the PCI data acquisition card, and finally, the signals were analyzed by the fast Fourier transform with software. The results showed that the sensitivity of every sensor reached 200 ppm(μg·mL-1), long-time accuracy and stability of all sensors could meet the practical demands, the response time of each sensor was less than 2 seconds and the detecting period was less than 32 seconds. By theoretical analysis, all sensors could be put in the mine at least 20 km from the ground, and the instruments could be applied to multi-point measurement at real-time in multiple occasions..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2365 (2009)
IR Spectra of Quarternary Ammonium Cellulose and Its Adsorption Properties to POPs
YAO Shi-qin, SHI Wen-jian, CHEN Xiao-yun, YU Yun, and YANG Qin-lin
In the present paper, the IR spectra, adsorption and reusing property of quaternary ammonium cationic cellulose (QACC) towards POPs were studied. The method and technological parameters of adsorption were discussed. The adsorbing isotherm, thermodynamics (ΔH, ΔS and ΔG), adsorption rate constant and adsorption activatiIn the present paper, the IR spectra, adsorption and reusing property of quaternary ammonium cationic cellulose (QACC) towards POPs were studied. The method and technological parameters of adsorption were discussed. The adsorbing isotherm, thermodynamics (ΔH, ΔS and ΔG), adsorption rate constant and adsorption activation energy of QACC on dyes were determined, and the sorption mechanism of QACC was confirmed initially, too. In near neutral water solution, QACC has a better saturated absorptive capability to water-soluble organic contaminations of aromatic series which contain carboxyl, sulfonic and hydroxyl group, and the presence of common coexistent ions in environmental water had no obvious effect on the saturated adsorption capacity of QACC. The adsorption involves both physical adsorption and chemical adsorption, and the chemical adsorption is the main. The adsorption of QACC to water-soluble organic contaminants followed Langmuir adsorption equation and one-order kinetic equation. Furthermore the adsorption rate constants increase with increasing temperature. QACC could be desorbed and reused with 0.5 mol·L-1 sodium hydroxide solution after adsorbing water-soluble organic contaminations. QACC is a new environmental function material with excellent performance and can be used to remove the POPs in the environment..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2370 (2009)
Development of a New FTIR Car-Borne Oil Content Analyzer
YANG Kun, LEI Jun-feng, ZENG Li-bo, and ZHU Qiu-ping
Turlun structure was introduced into the Fourier transform interference system in the present paper in order to decrease the size and cost of the whole system and to increase the ability of vibration resistance to meet the requirement of car-borne outdoor monitoring application. The speed deviation of the voice coil moTurlun structure was introduced into the Fourier transform interference system in the present paper in order to decrease the size and cost of the whole system and to increase the ability of vibration resistance to meet the requirement of car-borne outdoor monitoring application. The speed deviation of the voice coil motor (VCM) driving system, which is based on feedback of interference wavelength of reference laser and DSP control, is within 5%. The standard oil sample was used to test the performance of the spectrometer. The result shows that the highest resolution of the FTIR oil detector is 2 cm-1, and the SNR reached 2 000∶1. Compared with old grating spectrometers, this kind of instrument is faster, and the quality of spectrum was increased significantly. The portable feature of this instrument will be more convenient for the water pollution detection in field..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2375 (2009)
Study of the Fiber Size in Hardwood Using Fourier Transform
DUO Hua-qiong, and WANG Xi-ming
Fourier transform image-processing technology was applied to measuring the fiber size of hardwood. In this method，each cell was mapped by the center point on the cell in the transverse section with extending up and down by four pixels (nine-pixel length in total) and by two pixels in width, and thereafter line convolutFourier transform image-processing technology was applied to measuring the fiber size of hardwood. In this method，each cell was mapped by the center point on the cell in the transverse section with extending up and down by four pixels (nine-pixel length in total) and by two pixels in width, and thereafter line convoluted dot map (LCDM) was obtained. Through Fourier transform, the frequency distribution of power spectrum pattern from both horizontal and vertical directions was obtained and the cell diameter in radial and tangential direction was known from the maximum value except 0 in the distribution. The result indicates that there is no significant difference from that by optical microscope or image-processing software. It suggests that the method can be applied to the cell measurement and expand the Fourier transform application domain. This method provides the new research direction for the microscopic analysis and cell identification, and also provides a theoretical basis for the establishment of the mathematical model to identify cell geometric parameter..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2379 (2009)
Theoretical Study on Infrared Vibration Spectrum of Catalpol by DFT
SUN Xiao-li, DONG Chun-hong, SUN Yu-an, FU De-xue, XIE Bing, and WANG Guo-qing
The catalpol, which can be isolated from the Chinese traditional herbs Rehmannia glutinosa as an effective and active ingredient, is an iridoid glycoside with many pharmacological functions. The molecular structure and the infrared (IR) spectrum of catalpol were calculated using density-functional theory (B3LYP) at 6-3The catalpol, which can be isolated from the Chinese traditional herbs Rehmannia glutinosa as an effective and active ingredient, is an iridoid glycoside with many pharmacological functions. The molecular structure and the infrared (IR) spectrum of catalpol were calculated using density-functional theory (B3LYP) at 6-311G** level, and the theoretical frequency was scaled by 0.96. The vibrational modes of IR spectrum were assigned and compared with that of the experimental data. The calculated IR spectral features from DFT are in good agreement with the experimental ones. The results indicate that DFT is an useful method for the structure optimization and IR spectrum calculation of the iridoid compounds, which can be isolated from natural resources and often with difficulty. The theoretical calculation results of IR spectrum can provide useful information for the prediction of the theoretical property and investigation of the structure-activity relationship of the iridoid compounds..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2383 (2009)
Rapid Selection of White Clover Germplasms’ Crude Protein Traits by SPAD and Fourier Transform Near-Infrared Reflectance Spectroscopy
ZHANG Xian, YAN Rong, CAO Wen-juan, SHU Bin, and ZHANG Ying-jun
White clover is one of the most important forages in the world, with high nutritive value and crude protein content. Crude protein traits of white clover germplasms was selected using SPAD and near infrared reflectance spectroscopy. The SPAD value was measured by Chlorophyll Meter SPAD-502, and was used to evaluate theWhite clover is one of the most important forages in the world, with high nutritive value and crude protein content. Crude protein traits of white clover germplasms was selected using SPAD and near infrared reflectance spectroscopy. The SPAD value was measured by Chlorophyll Meter SPAD-502, and was used to evaluate the crude protein of white clover. In the vegetative period, there was a positive relationship between SPAD value and foliar protein content (y=0.422x+4.984， R2=0.737), but in the flowering period, there was a negative relationship between the two indexes (y=-0.345x+37.50， R2=0.711). Crude protein content of white clover germplasms was predicted using near infrared reflectance spectroscopy with PLS regression and the model was validated by cross validation and external validation. The results showed that the correlation coefficient of cross validation, the RMSECV, and the correlation coefficient of external validation are 0.904, 0.988%, and 0.987, respectively. NIRS model of white clover crude protein content has good accuracy and precision. FT-NIRS was more accurate than SPAD. NIRS is feasible as a rapid analysis method, and can be used in the selection and breeding of white clover germplasms to improve the breeding efficiency..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2388 (2009)
Estimation of Modulus of Elasticity of Eucalyptus Pellita Wood by Near Infrared Spectroscopy
ZHAO Rong-jun, HUO Xiao-mei, and ZHANG Li
In the present study， the rapid prediction of wood modulus of elasticity (MOE) of Eucalyptus pellita by near infrared (NIR) spectroscopy is described. Fast Fourier transform (FFT) and conventional mechanical testing methods were used to measure modulus of elasticity of small clear wood samples of Eucalyptus pellita. AfIn the present study， the rapid prediction of wood modulus of elasticity (MOE) of Eucalyptus pellita by near infrared (NIR) spectroscopy is described. Fast Fourier transform (FFT) and conventional mechanical testing methods were used to measure modulus of elasticity of small clear wood samples of Eucalyptus pellita. After collecting the near-infrared reflectance spectra of each sample from radial and tangential faces， the NIR spectra were preprocessed with the second-derivative methods, and regression models were built between 410 to 2 480 nm. The calibration models were established using two thirds of whole samples with the partial least squares method, and validation models were developed on an independent set (one third of whole samples). The analysis results showed that high correlation coefficients were obtained between the laboratory-determined MOE values and NIR prediction values of Eucalyptus pellita. The correlation coefficients of prediction model for MOE were 0.93 and 0.81， and RPD were 2.70 and 1.71. NIR analysis technique can realize the rapid prediction of the MOE of small clear wood samples of Eucalyptus pellita..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2392 (2009)
Analysis and Identification of Huangqi and Its Counterfeit Ciguogancao by Two Dimensional Corrlation Infrared Spectroscopy
HUANG Dong-lan, SUN Su-qin, XU Yong-qun, and CHEN Xiao-kang
Standard Huangqi (Astragalus membranaceus (Fisch) Bge. Var. monghlicus (Bge.) Hsiao) and its counterfeit Ciguogancao (Glychrrhiza pallidiflora Maxim.) can be discriminated and identified by using multi-steps infrared maro-fingerprint method. In the 1D-IR spectra, the peak intensity at 1 737 cm-1 for Ciguogancao, which Standard Huangqi (Astragalus membranaceus (Fisch) Bge. Var. monghlicus (Bge.) Hsiao) and its counterfeit Ciguogancao (Glychrrhiza pallidiflora Maxim.) can be discriminated and identified by using multi-steps infrared maro-fingerprint method. In the 1D-IR spectra, the peak intensity at 1 737 cm-1 for Ciguogancao, which is the stretching vibration peak of CO, is much stronger than that of Huangqi. It’s proved that the organic ester compounds in Ciguogancao are much more than Huangqi. In the secondary derivative spectra, it’s easy to find the fingerprint characteristic peaks of CaC2O4 in the infrared spectra of Ciguogancao, but not in that of Huangqi. Besides, both secondary derivative spectra also have main characteristic peaks, which are the skeletal stretching of aromatic, round 1 463, 1 511 and 1 596 cm-1, but Ciguogancao aslo has one shoulder peak at 1 453 cm-1. In the 2D-IR spectra, both have three auto-peaks at 1 070, 1 095 and 1 140 cm-1, which are the auto-peaks of glucoside, but the strongest auto-peak of Huangqi is at 1 140 cm-1 and that of Ciguogancao’s is at 1 090 cm-1. The spectra testified that the organic ester compounds, aromatic compounds and glucoside compounds in Huangqi and its counterfeit Ciguogancao were different. The method not only can identify standard Huangqi and its counterfeit Ciguogancao rapidly, but also provides useful information about the differences in organic ester compounds, aromatic compounds and glucoside between Huangqi and its counterfeit Ciguogancao. It’s proved that multi-steps infrared maro-fingerprint method can be used to analyze and distinguish Huangqi and its counterfeit Ciguogancao..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2396 (2009)
An Approach to Predicting Antioxidative Activities of Natural Products Based on Near Infrared Spectroscopy
WANG Yi, YU Ling-yan, FAN Xiao-hui, and QU Hai-bin
The aim of present study is to develop a new approach to predicting antioxidative activities of flavonoid extracts from traditional Chinese medicine based on near-infrared spectroscopy (NIR). The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) method was employed to assay the antioxidative activities of twenty-eight extracts. ThThe aim of present study is to develop a new approach to predicting antioxidative activities of flavonoid extracts from traditional Chinese medicine based on near-infrared spectroscopy (NIR). The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) method was employed to assay the antioxidative activities of twenty-eight extracts. Then, the near infrared diffuse reflectance spectra of those samples were acquired in the range of 4 000-10 000 cm-1. The partial least square (PLS) algorithm was used to generate the calibration model that correlates the spectra and the antioxidative activities of those natural products. The optimal wavenumber ranges and the preprocessing method of original spectrum data were selected during the establishment of calibration model according to the root mean square error of cross-validation (RMSECV). The established model has been successfully applied to predict bioactivities of six samples in the validation set. The value of RMSECV of the proposed model was 9.50% with R2 of 0.901 7, and the value of RMSEP was 14.8%. The result indicated that the method can be used for the fast determination of the antioxidative activities of flavonoids as well as other active components of natural products..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2401 (2009)
FTIR Spectrum and Coagulation Enhancement of Exopolysaccharide Secreted by an Antarctica Bacterium Pseudoalteromona sp. Bsi20310
ZHOU Wei-zhi, SHEN Bo-ling, LIU Sheng-bo, CHEN Bo, and ZHANG Yu-zhong
Bsi20310 exopolysaccharide (Bsi20310 EPS) was secreted by a bacteria named Pseudoalteromonas sp. Bsi20310, isolated from Antarctic Sea ice. Crude Bsi20310 EPS was prepared by precipitation of the culture solution with ethanol, with proteins removed by using chloroform and butanol preparatorily. The results showed that Bsi20310 exopolysaccharide (Bsi20310 EPS) was secreted by a bacteria named Pseudoalteromonas sp. Bsi20310, isolated from Antarctic Sea ice. Crude Bsi20310 EPS was prepared by precipitation of the culture solution with ethanol, with proteins removed by using chloroform and butanol preparatorily. The results showed that Bsi20310 EPS improved the FeCl3 coagulation performance on synthetic water-soluble dye reactive red X-3B dyeing wastewater, obviously. The optimum coagulation enhancement of Bsi20310 EPS expressed by decolorization rate is from 16% to 84%, at pH near 10, Fe(Ⅲ) concentration of 0.98 mmol·L-1 and Bsi20310 EPS concentration of 150 mg·L-1, respectively. Fourier transform infrared spectroscopy (FTIR) was used to investigate the functional groups of Bsi20310 EPS, Fe(Ⅲ)-Bsi20310 EPS floc and Fe(Ⅲ)-Bsi20310 EPS-reactive red X-3B floc. The spectra showed that Bsi20310 EPS contained a large number of functional groups such as —OH, —COOH and glycosidic bond. Some certain functional groups of Bsi20310 EPS changed being combined with Fe(Ⅲ) hydrolysate. For instance, narrow peaks at 3 429 and 1 650 cm-1 became wide; the peak at 2 921 cm-1 weakened or disappeared; the peak at 1 242 cm-1 red-shifted slightly; peaks in the region of 1 151-1 038 cm-1 became single and sharp, etc. The change in spectra indicated that —OH, —OOH and glycosidic bond might be the main functional groups. The study suggested a bright prospect of Bsi20310 EPS performing as an approach to safe and effective microbial coagulation enhancement..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2405 (2009)
FTIR Spectroscopic Analysis of HeLa Cell Irradiated by Low-Energy Ions
YANG Zhan-guo, QI Jian, ZHANG Guang-shui, SU Ming-jie, and ZHANG Feng-qiu
In the present paper, low-energy N+ ions produced by low-energy ionic radiometer were used to simulate low-energy ions in astrospace implanting HeLa cell. Then, the effect and mechanism of low-energy ion on the cell were studied with FTIR spectroscopic analysis. In this study, low-energy ions were produced and acceleraIn the present paper, low-energy N+ ions produced by low-energy ionic radiometer were used to simulate low-energy ions in astrospace implanting HeLa cell. Then, the effect and mechanism of low-energy ion on the cell were studied with FTIR spectroscopic analysis. In this study, low-energy ions were produced and accelerated in vacuum, and cells would be affected by vacuum when they were implanted by low-energy ions, so mineral oil was used to protect cells from water evaporation. Cells were collected after being implanted, then the change in the content and constructional form in cellular macromolecule with infrared spectrometry. Result indicated that the spectroscopic peak position of differently worked cells was obviously different as compared to the control cell (3 300 cm-1). Spectroscopic peak position of all samples except implanting 5×1014 N+·cm-2 removed to longer wavelength, and the peak position in vacuum of 2×1015 N+·cm-2 sample moved to 3 420 cm-1. In addition, the 1 378 and 2 360 cm-1 spectroscopic peak positions in control cell all moved to longer wavelength in every worked group. In a word, FTIR spectroscopic analysis indicates that low-energy ion implantation could arouse change in nucleic acid or protein in HeLa cell..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2409 (2009)
Fast Discrimination of Varieties of Corn Based on Near Infrared Spectra and Biomimetic Pattern Recognition
SU Qian, WU Wen-jin, WANG Hong-wu, WANG Ku, and AN Dong
A new method for fast discrimination of varieties of corn by means of near infrared spectroscopy and biomimetic pattern recognition (BPR) was proposed and the recognition models for seven kinds of corn were built. The experiment adopted 140 samples acquired from seven varieties of corn. Firstly, a field spectroradiometA new method for fast discrimination of varieties of corn by means of near infrared spectroscopy and biomimetic pattern recognition (BPR) was proposed and the recognition models for seven kinds of corn were built. The experiment adopted 140 samples acquired from seven varieties of corn. Firstly, a field spectroradiometer was used for collecting spectra in the wave number range of 4 000 to 12 000 cm-1. Secondly, the original spectral data were pretreated in order to eliminate noise and improve the efficiency of models, and then the characteristic spectral regions were selected by using fixed-sized moving window evolving factor analysis. Thirdly, principal component analysis (PCA) was used to compress spectral data into several variables, and the cumulate reliabilities of the first five components were more than 99.96%. Finally, according to the first five components, the recognition models were established based on BPR. For the samples in each variety, 10 samples were randomly selected as the training set. The remaining samples of the same variety were used as the first testing set, and the 120 samples of the other varieties were used as the second testing set. Under the condition that almost all the samples in the second set were correctly rejected, the average correct recognition rate was 94.3%. The experimental results demonstrated that the recognition models were effective and efficient. In short, it is feasible to discriminate varieties of corn based on near infrared spectroscopy and BPR..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2413 (2009)
Qualitative and Quantitative Analysis Method of Tea by Near Infrared Spectroscopy
NIU Zhi-you, and LIN Xin
Four varieties of tea were collected from different areas in China including jasmine tea, Kuding tea, Longjing tea and Tieguanyin. A total of 120 samples (30 samples for each variety) were prepared. The original samples spectra were obtained using NIRSystem6500 analyzer. Tea was analyzed qualitatively and quantitativelFour varieties of tea were collected from different areas in China including jasmine tea, Kuding tea, Longjing tea and Tieguanyin. A total of 120 samples (30 samples for each variety) were prepared. The original samples spectra were obtained using NIRSystem6500 analyzer. Tea was analyzed qualitatively and quantitatively by near infrared spectroscopy technology. Principal component analysis and discriminant analysis were used to distinguish the four varieties of tea. The optimal calibration model for qualitative discrimination was established according to comparison of different spectral data pretreatment methods and the uncertain factor coefficients. Quantitative analysis models for moisture content, tea polyphenol and caffeine in tea were developed with modified partial least square. The results show that the accurate recognition rate for the four varieties of tea in the validation set reached 100%. The coefficients of determination (Ｒ２ｐ) and relative prediction deviation (RPD) of independent validation sets were more than 0.91 and 3.0, respectively. It is concluded that NIRS can be used as a rapid method to detect the variety and chemical components in tea..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2417 (2009)
Application of Near-Infrared Spectroscopy to Detection of Pesticide Phoxim Residues
SHEN Fei, YAN Zhan-ke, YE Zun-zhong, and YING Yi-bin
Near-infrared (NIR) spectroscopy technique was applied directly to the detection of pesticide phoxim residues. A sample pretreatment method was introduced. Samples were mixed with silica gel. Silica gel as a sorbent was employed to extract and enrich the low-concentration samples. Subsequently, diffuse reflection spectNear-infrared (NIR) spectroscopy technique was applied directly to the detection of pesticide phoxim residues. A sample pretreatment method was introduced. Samples were mixed with silica gel. Silica gel as a sorbent was employed to extract and enrich the low-concentration samples. Subsequently, diffuse reflection spectrum was measured on silica gel. Calibration models were developed using partial least square regression (PLSR) algorithm. Leave-one-out cross-validation was used to evaluate and compare the models. Two experiments were carried out, and the results show that 21 samples with the concentration gradient of 0.5 mg·L-1 exhibited a high correlation coefficient of cross-validation of 0.958, and a root mean square error of cross validation (RMSECV) of 0.872 mg·L-1, while 41 samples with the concentration gradient of 0.25 mg·L-1 gave a correlation coefficient of cross-validation of 0.924 and RMSECV of 1.15 mg·L-1. It is indicated that with the reduction in concentration gradient, the prediction capacity of models dropped, but there still existed a high correlation coefficient with the concentration of phoxim in the samples. The experiments proved that the sample pretreatment method with the introduction of silica gel as an absorber to enrich low concentration analyte was effective. The method was able to lower the detection limit of NIR. The developed technique has a potential application in low-concentration sample detection by NIR spectroscopy, such as pesticide residues..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2421 (2009)
Determination of Baicalin and Total Flavonoids in Radix Scutellariae by Near Infrared Diffuse Reflectance Spectroscopy
HUANG Qian-qian, PAN Rui-le, WEI Jian-he, WU Yan-wei, and ZHANG Lu-da
The objective of the present study was to develop a method for rapid determination of baicalin and total flavonoids in radix scutellariae by near infrared diffuse reflectance spectroscopy. Sixty one samples of radix scutellariae from different areas containing baicalin of 12.24%-21.34% and total flavonoids of 16.08%-26The objective of the present study was to develop a method for rapid determination of baicalin and total flavonoids in radix scutellariae by near infrared diffuse reflectance spectroscopy. Sixty one samples of radix scutellariae from different areas containing baicalin of 12.24%-21.34% and total flavonoids of 16.08%-26.52% were used. The range of 8 000-4 000 cm-1 of near infrared spectra (NIRS) was selected. Calibration models were established using the PLS(partial least squares). Different spectra pretreatment methods were compared and the optimal model was selected. The study showed that first derivative pretreatments and minimum-maximum normalization methods can be used to extracted spectra information thoroughly to analyze the contents of baicalin and total flavonoids, respectively.The correlation coefficient (r)of baicalin was 0.902 4， SEC was 1.01(standard deviation of the calibration sets) and SEP was 0.876 4(standarddeviation ofthe prediction sets). The correlation coefficient(r) of total flavonoids was 0.952 7， SEC was 0.785 0 and SEP was 0.521 1. Results indicated that near infrared diffuse reflectance spectroscopy method can be used to analyze the main active components in radix scutellariae rapidly..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2425 (2009)
Identification and Analysis of Genuine and False Flos Rosae by FTIR and2D Correlation IR Spectroscopy
CAI Fang, SUN Su-qin, YAN Wen-rong, NIU Shi-jie, and LI Xian-en
The genuine and false Flos Rosae Rugosae (Flos Rosae Chinensis and Flos Rosa multiflora) were examined in terms of their differences by using Fourier transforrn infrared spectroscopy (FTIR) combined with two-dimensional (2D) correlation IR spectroscopy. The three species were shown very similar in FTIR spectra. The peaThe genuine and false Flos Rosae Rugosae (Flos Rosae Chinensis and Flos Rosa multiflora) were examined in terms of their differences by using Fourier transforrn infrared spectroscopy (FTIR) combined with two-dimensional (2D) correlation IR spectroscopy. The three species were shown very similar in FTIR spectra. The peak of 1 318 cm-1 of genuine Flos Rosae Rugosae is not obvious but this peak could be found sharp in Flos Rosae Chinensis and Flos Rosa multiflora. Generally, the second derivative IR spectrum can clearly enhance the spectral resolution. Flos Rosae Rugosae and Flos rosae Chinensis have aromatic compounds distinct fingerprint characteristics at 1 617 and 1 618 cm-1, respectively. Nevertheless, Flos Rosa multiflora has the peak at 1 612 cm-1. There is a discrepancy of 5 to 6 cm-1. Flos Rosa multiflora has glucide’s distinct fingerprint characteristics at 1 044 cm-1， but Flos Rosae Rugosae and Flos Rosae Chinensis don’t. The second derivative infrared spectra indicated different fingerprint characteristics. Three of them showed aromatic compounds with autopeaks at 1 620, 1 560 and 1 460 cm-1. Flos Rosae Chinensis and Flos Rosa multiflora have the shoulder peak at 1 660 cm-1. In the range of 850-1 250 cm-1, three of them are distinct different, Flos Rosae Rugosae has the strongest autopeak, Flos Rosae Chinensis has the feeble autopeak and Flos Rosa multiflora has no autopeak at 1 050 cm-1. In third-step identification, the different contents of aromatic compounds and glucide in Flos Rosae Rugosae, Flos Rosae Chinensis and Flos Rosa multiflora were revealed. It is proved that the method is fast and effective for distinguishing and analyzing genuine Flos Rosae Rugosae and false Flos Rosae Rugosae (Flos Rosae Chinensis and Flos Rosa multiflora)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2429 (2009)
Study of Surface Enhanced Raman Spectra of SCN- Adsorbed on the Au-Ag Complex Substrate
HUANG Jie, YAO Jian-lin, and GU Ren-ao
Ag and Au nanoparticles were self-assembled on a silicon substrate simultaneously. The density of Ag and Au nanoparticles was controlled by changing the volume ratio of Au to Ag colloids. The substrate was characterized by UV-Vis diffuse reflectance and SEM, and the results indicated that Ag and Au nanoparticles were dAg and Au nanoparticles were self-assembled on a silicon substrate simultaneously. The density of Ag and Au nanoparticles was controlled by changing the volume ratio of Au to Ag colloids. The substrate was characterized by UV-Vis diffuse reflectance and SEM, and the results indicated that Ag and Au nanoparticles were dispersed on the substrate with mono/submono layers. Using SCN- as a probing molecule, surface enhanced Raman spectroscopic (SERS) effect was investigated on pure Au, pure Ag and Au-Ag mixed nanoparticle surfaces. After a series of calibration, the results revealed that the SERS spectral features of SCN- from the mixture system were similar to those from the pure Ag nanoparticles, indicating the coupling effect between the Ag and Au nanoparticles, which results in the property of Au inclining to Ag..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2434 (2009)
First-Principles Study of Vibrational Raman Spectra of Amorphous Carbon
NIU Li, ZHU Jia-qi, GAO Wei, and DU Shan-yi
The vibrational density of states and nonresonant reduced Raman spectra of amorphous carbon at densities of 2.6, 2.9 and 3.2 g·cm-3 were calculated by the use of a first-principles plane-wave pesudopotential method. Three structural models were generated by liquid-quench method using Car-Parinello molecular dynamiThe vibrational density of states and nonresonant reduced Raman spectra of amorphous carbon at densities of 2.6, 2.9 and 3.2 g·cm-3 were calculated by the use of a first-principles plane-wave pesudopotential method. Three structural models were generated by liquid-quench method using Car-Parinello molecular dynamics, their vibrational frequencies and eigenmodes were determined using the linear response approach, and Raman coupling tensors were calculated using the finite electric field method. The calculated results show that the sp3 fraction increases from 50% to 84.4%, the sp2 configuration changes from mainly rings to short chains, the position of the G peak moves to higher frequencies, the intensity ratio of D and G peaks decreases, the position of the T peak moves to lower frequencies and the intensity ratio of T and G peaks increases as density increases from 2.6 to 3.2 g·cm-3. The authors’ calculated Raman spectra show an overall good agreement with experimental spectra. The analysis in terms of atomic vibrations confirms that the G and D peaks both come from sp2 C contribution, G peak is due to the stretching vibration of any pair of sp2 atoms and the T peak is due to the C—C sp3 vibration. The authors’ analysis also confirms that the dispersion of G and T peaks is due to bond-length changes. The bond length of chains (olefins) is shorter than that of rings, so their vibrational frequency is higher and the G-peak position moves to higher frequencies with increasing the sp3 fraction. The number of sp3-sp2 type bonds decreases as the sp3 fraction increases. These bonds are shorter than pure sp3-sp3 bonds, hence the T-peak position moves to lower frequencies. The research results provide a theoretic basis for analyzing experimental Raman spectra of amorphous carbon..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2438 (2009)
Using Raman Spectroscopy to Analyze Apoptosis of Gastric Cancer Cells Induced by Cisplatin
TAO Zhan-hua, YAO Hui-lu, WANG Gui-wen, HUANG Shu-shi, WANG Yi-bing, PENG Li-xin, and LI Yong-qing
Apoptosis of gastric cancer cells induced by cisplatin was investigated using laser Raman spectroscopy. Gastric cancer cells (SGC7901) were treated with 10 μg·mL-1 cisplatin for 24, 48 and 72 hours, then were divided into two parts, one for fluorescence staining, the other for collection of Raman spectra by means Apoptosis of gastric cancer cells induced by cisplatin was investigated using laser Raman spectroscopy. Gastric cancer cells (SGC7901) were treated with 10 μg·mL-1 cisplatin for 24, 48 and 72 hours, then were divided into two parts, one for fluorescence staining, the other for collection of Raman spectra by means of scanning. The acquired spectra were then preprocessed by background elimination, smoothing, normalization, baseline correction, and peak fitting. Fluorescence staining result showed that the nucleuses from untreated group were uniformly stained, while those from the group treated for 72 hours were densely stained and broken. The spectra results revealed that the intensity of peaks associated with nucleic acid and protein decreased after the cells were incubated with cisplatin for 24, 48 and 72 hours. The intensity of peaks at 783, 1 002 and 1 343 cm-1 respectively fell to 52, 64 and 76 percent of the original value after 72 h of treatment, which indicated that cisplatin could induce apoptosis of gastric cancer cells and reduce the amount of nucleic acid and protein in the cells. The above results suggest that Raman spectra can provide abundant information about the changes in materials in cells and serve as an effective method for real time measurement of apoptosis..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2442 (2009)
Raman Spectroscopic Characteristics of Different Rank Coals and the Relation with XRD Structural Parameters
LI Mei-fen, ZENG Fan-gui, QI Fu-hui, and SUN Bei-lei
The Raman spectroscopic analysis for eleven different rank coals (57.58% to 94.01% of Cdaf, %) indicated that two distinct bands, i.e. D band (1 340-1 380 cm-1) and G band (1 580-1 600 cm-1), exist in the first order of Raman spectra, with the former being broader and the latter rather sharp. As the two bands were overThe Raman spectroscopic analysis for eleven different rank coals (57.58% to 94.01% of Cdaf, %) indicated that two distinct bands, i.e. D band (1 340-1 380 cm-1) and G band (1 580-1 600 cm-1), exist in the first order of Raman spectra, with the former being broader and the latter rather sharp. As the two bands were overlapped each other, each spectrum was fitted with two Lorentz peaks and the Raman information about position, intensity and FWHM of each band was thus obtained. The relation of these Raman parameters with Cdaf% showed that with the increase in C%, the position of D band and G band shifts to lower and higher frequency, respectively; the separation of the two band positions increases with the increase in C%; FWHM-D, FWHM-G and ID/IG have linear relationship with Cdaf% in the range of Cdaf% 75%-94%. The coal structural parameters, d002 and Lc from XRD are related with the position and FWHM of G band; the comparison of La from XRD and both from the Cancado and the KW equation indicated that the values from Cancado and the KW equation are unreasonable..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2446 (2009)
Surface-Enhanced Raman Spectroscopic Analysis of Largehead Atractylodes Rhizome Decoction
CHEN Wei-wei, FENG Shang-yuan, LIN Wen-shuo, CHEN Rong, LI Yong-zeng, LIN Ju-qiang, and HUANG Rui-xiang
The normal Raman spectra and surface-enhanced Raman spectra (SERS) of largehead atractylodes rhizome decoction were tested and analyzed. The characteristic Raman bands of largehead atractylodes rhizome decoction were tentatively assigned. Six obvious Raman bands (396, 548, 617, 730, 955 and 1 327 cm-1) were observed inThe normal Raman spectra and surface-enhanced Raman spectra (SERS) of largehead atractylodes rhizome decoction were tested and analyzed. The characteristic Raman bands of largehead atractylodes rhizome decoction were tentatively assigned. Six obvious Raman bands (396, 548, 617, 730, 955 and 1 327 cm-1) were observed in the SERS of largehead atractylodes rhizome decoction. The absorption spectra of largehead atractylodes rhizome decoction and the mixture of silver colloids and largehead atractylodes rhizome decoction were tested. A new resonance absorption peak (999 nm) appeared in the long-wavelength region in UV-Vis absorption spectra of the mixture. The adsorption characteristics and possible enhancing mechanism of the largehead atractylodes rhizome decoction on silver colloid were speculated. The results showed that the surface-enhanced Raman spectroscopy might provide a new kind of precise, direct and fast detecting method for the largehead atractylodes rhizome decoction or other traditional Chinese medicine..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2450 (2009)
The Microstructure and Raman Spectra Analysis of MAO Film on Pure Titanium
CHANG Hong, WU Han-hua, TANG Yuan-guang, CHEN Gen-yu, and DONG Lin
In the present work, five films on the surface of pure titanium were formed by microarc oxidation technique at various applied voltages: 300, 350, 400, 450 and 500 V. The phase component and microstructure of these films were analyzed by scanning electron microscopy and Raman spectroscopy. The result shows that the surIn the present work, five films on the surface of pure titanium were formed by microarc oxidation technique at various applied voltages: 300, 350, 400, 450 and 500 V. The phase component and microstructure of these films were analyzed by scanning electron microscopy and Raman spectroscopy. The result shows that the surface of the films is covered by numerous micropores. With the increase in applied voltage, the size of these micropores increases, but the density of these micropores declines. These films consist of anatase and rutile phases, and the phase component of the film is closely related to the applied voltage. In the condition of lower applied voltage, the film is mainly composed of anatase phase. With increasing the applied voltage, the content of rutile phase increases, and when the applied voltage ranges from 400 to 450 V, the rutile phase increases sharply and becomes domain phase..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2453 (2009)
Progress in Raman Spectroscopic Measurement of Methane Hydrate
XU Feng, ZHU Li-hua, WU Qiang, and XU Long-jun
Complex thermodynamics and kinetics problems are involved in the methane hydrate formation and decomposition, and these problems are crucial to understanding the mechanisms of hydrate formation and hydrate decomposition. However, it was difficult to accurately obtain such information due to the difficulty of measuremenComplex thermodynamics and kinetics problems are involved in the methane hydrate formation and decomposition, and these problems are crucial to understanding the mechanisms of hydrate formation and hydrate decomposition. However, it was difficult to accurately obtain such information due to the difficulty of measurement since methane hydrate is only stable under low temperature and high pressure condition, and until recent years, methane hydrate has been measured in situ using Raman spectroscopy. Raman spectroscopy, a non-destructive and non-invasive technique, is used to study vibrational modes of molecules. Studies of methane hydrate using Raman spectroscopy have been developed over the last decade. The Raman spectra of CH4 in vapor phase and in hydrate phase are presented in this paper. The progress in the research on methane hydrate formation thermodynamics, formation kinetics, decomposition kinetics and decomposition mechanism based on Raman spectroscopic measurements in the laboratory and deep sea are reviewed. Formation thermodynamic studies, including in situ observation of formation condition of methane hydrate, analysis of structure, and determination of hydrate cage occupancy and hydration numbers by using Raman spectroscopy, are emphasized. In the aspect of formation kinetics, research on variation in hydrate cage amount and methane concentration in water during the growth of hydrate using Raman spectroscopy is also introduced. For the methane hydrate decomposition, the investigation associated with decomposition mechanism, the mutative law of cage occupancy ratio and the formulation of decomposition rate in porous media are described. The important aspects for future hydrate research based on Raman spectroscopy are discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2457 (2009)
Synthesis and Spectral Properties of Stilbene Derivatives as Two-Photon Absorption Materials
GUO Fu-quan, SUN Xiao-lao, XIONG Fei, GUO Bin, LIANG Hao, CHEN Biao, and ZHANG Qi-jin
Three stilbene derivatives with good coplanarity and enhanced charge delocalization in the conjugated molecular system, 4,4′-bis(diphenylamino-trans-styryl)biphenyl (BPSBP), 4,4′-bis(diethylamino-trans-styryl)biphenyl (BESBP) and 4,4′-bis(9-carbazyl-trans-styryl)-biphenyl (BCSBP), were designed, synthesized and charactThree stilbene derivatives with good coplanarity and enhanced charge delocalization in the conjugated molecular system, 4,4′-bis(diphenylamino-trans-styryl)biphenyl (BPSBP), 4,4′-bis(diethylamino-trans-styryl)biphenyl (BESBP) and 4,4′-bis(9-carbazyl-trans-styryl)-biphenyl (BCSBP), were designed, synthesized and characterized by infra-red spectroscopy, hydrogen nuclear magnetic resonance and elemental analysis. Experimental results reveal that the strongest one-photon absorption peaks appear between 350 and 400 nm, which is the energy region of two near infrared photons. The obvious solvatochromism was observed in five different polar solvents and the corresponding one-photon absorption and fluorescence emission spectra validate the character of intramolecular symmetric charge transfer. Two-photon fluorescence spectra show that both one- and two-photon processes share the same emission mechanism although they have different excitation processes and selection rules. The quadratic dependence of fluorescence intensity on excitation intensity indicates a real two-photon absorption process. The two-photon absorption cross section was measured via two-photon induced upconversion fluorescence method. The large values of two-photon absorption cross section, 892 GM, 617 GM and 483 GM for BPSBP, BESBP and BCSBP respectively, were obtained at 800 nm wavelength from a femtosecond laser source, which means potential applications in two-photon absorption fields..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2462 (2009)
Application of Mutual Information to Variable Selection in Diagnosis of Phosphorus Nutrition in Rice
LIN Fen-fang, DING Xiao-dong, FU Zhi-peng, DENG Jin-song, and SHEN Zhang-quan
The present study obtained data of rice canopy spectrum, and P and chlorophyll content at typical growth stages with different rates of P supply by means of solution experiment. The effects of P treatments on leaf P and chlorophyll content were analyzed statistically using LSD’s multiple comparison at a probability of The present study obtained data of rice canopy spectrum, and P and chlorophyll content at typical growth stages with different rates of P supply by means of solution experiment. The effects of P treatments on leaf P and chlorophyll content were analyzed statistically using LSD’s multiple comparison at a probability of 0.05; By mutual information (MI) variable selection procedure, the optimal spectral variables were identified at 536, 630, 1 040, 551 and 656 nm, and their corresponding mutual information values were 1.057 5, 1.103 9, 1.135 3, 1.141 7 and 1.149 4 respectively; based on these sensitive bands, the built feed-forward artificial neural network model (ANN) had higher precision for P content estimation than the multiple linear regression model (MLR). Its RMSE of cross-validation and R were 0.038 8 and 0.988 2, respectively, for the calibration data set, and the RMSE of prediction and R were 0.050 5 and 0.989 2, respectively, for the test data set. Therefore, it was suggested that MI was encouraged for quantitative prediction of leaf P content in rice with visible/near infrared hyperspectral information without assumption on the relationship between independent and dependent variables. But more work is needed to explain why these bands are sensitive to leaf P content in rice..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2467 (2009)
Determination of Hesperidin Content in Guogongjiu Medicinal Wine Based on NIR Spectrometry and Least Squares Support Vector Machines
ZHU Xiang-rong, SHAN Yang, LI Gao-yang, FAN Qiang, SHI Xin-yuan, QIAO Yan-jiang, and ZHANG Zhuo-yong
Near-infrared spectroscopy (NIRS) combined with least squares support vector machines (LS-SVM) was used to establish a new method for the determination of the hesperidin content in guogongjiu medicinal wine. Firstly, training set was partitioned by Kernard-Stone (KS) algorithm. Secondly, spectral pretreatment methods wNear-infrared spectroscopy (NIRS) combined with least squares support vector machines (LS-SVM) was used to establish a new method for the determination of the hesperidin content in guogongjiu medicinal wine. Firstly, training set was partitioned by Kernard-Stone (KS) algorithm. Secondly, spectral pretreatment methods were discussed in detail, comparing smoothing, rangescaling, autoscaling, first derivative, second derivative, along with those methods combined. Smoothing, first derivative and rangescaling were used for the pretreatment of the NIR spectra of guogongjiu medicinal wine. Thirdly, the effective interval was selected for 8 211-8 312 and 9 712-9 808 cm-1 by synergy interval partial least squares (siPLS). Finally, the model was established by LS-SVM, the root mean square error of cross validation (RMSECV) is 0.001, root mean square error of prediction (RMSEP) is 0.004, and relative deviation of predicting set is less than 5%. It was compared with siPLS, radial basis function neural network (RBF-NN), and SVM, The result shows that the method is rapid, non-destructive, and credible. It is an effective measurement for determining the hesperidin content in guogongjiu medicinal wine..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2471 (2009)
Spectroscopic Characterization Indicator of Landfill in the Process of Stabilizing
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In the present study, dissolved organic matter (DOM) extracted from landfill of four different ages was studied with fluorescence and ultraviolet-visible spectroscopy in order to explore the possibility of using spectral characteristic changes of DOM as stabilization indicators for landfill. The three-dimensional fluorIn the present study, dissolved organic matter (DOM) extracted from landfill of four different ages was studied with fluorescence and ultraviolet-visible spectroscopy in order to explore the possibility of using spectral characteristic changes of DOM as stabilization indicators for landfill. The three-dimensional fluorescence excitation-emission matrix spectroscopy (EEM) displayed that DOM of 0-year-old contained mainly protein-like matter, while DOM extracted from 1, 5 and 10-year old consisted chiefly of humic matter-like substance, and the intensity change of DOM of 1, 5 and 10-year old landfill was disordered. Besides, the fluorescence spectroscopy also showed that the r(A、C) value and the fluorescence index f450/500 of DOM of four different years both decreased with landfill age, which indicated that the low molecular weight fraction of DOM was translated into the high molecular aromatic matter and the degree of humification was enhanced with the time increasing. In addition, the specific ultraviolet-visible absorbance (SUVA) increased with landfill age, which also revealed the law that the degree of humification strengthened with the time increasing, but the change regularity of E4/E6 value of DOM was unconspicuous since the E4/E6 value was easily impacted by some other factors. Therefore, the r(A，C) value, the fluorescence index f450/500 and the SUVA value of DOM extracted from aged refuse reflected effectively the law of how landfill changed, and could be employed as simple stabilization indicators for aged refuse and closed landfill compartments..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2475 (2009)
Study on Crystal Chemistry and Spectra of Feldspar from Zhoukoudian Granodiorite
ZHANG Yong-wang, ZENG Jian-hui, LIU Yan, and GUO Jian-yu
The chemical composition and spectra characteristic of feldspar from Zhoukoudian granodiorite were systematically analyzed. Based on the field work, some feldspar samples were selected for crystal chemistry and structure analysis through EMPA, IR, LRM and XRD. The compositions of the feldspar range between Ab(85.21)Or(The chemical composition and spectra characteristic of feldspar from Zhoukoudian granodiorite were systematically analyzed. Based on the field work, some feldspar samples were selected for crystal chemistry and structure analysis through EMPA, IR, LRM and XRD. The compositions of the feldspar range between Ab(85.21)Or(0.18)An(9.11) and Ab(90.06)Or(3.00)An(13.27) by electronic microscope probe analysis. According to the XRD peak and its diffraction intensity, the mineral species was found and the unit cell parameters were calculated. The absorption bands and peaks of infrared and Raman spectra were also assigned and the results show that the characteristics of its infrared and Raman spectra are in accordance with the ideal atlas of albite. The infrared spectra show that all the analyzed feldspar grains contain structural hydrogen, which occur as OH-. On the basis of the above analyses, the crystal chemistry and structure characteristics of feldspar were summarized..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2480 (2009)
Investigation on the Fabrication and Spectrum Properties of Yb3+-Doped Silicate Laser Glasses
DONG Shi-rui, HOU Lan-tian, JIN Tao-tao, HAN Ying, XIA Chang-ming, NIU Jing-xia, ZHOU Gui-yao, LIANG Dan-hua, and LI Rui
Two kinds of Yb3+ doped silicate laser glass with little difference were produced by high temperature of melting process. The absorption and emission spectra of the two glass samples were tested by the correlative spectrographs; the integral absorption cross section, stimulated emission cross section, fluorescence lineTwo kinds of Yb3+ doped silicate laser glass with little difference were produced by high temperature of melting process. The absorption and emission spectra of the two glass samples were tested by the correlative spectrographs; the integral absorption cross section, stimulated emission cross section, fluorescence line-width, fluorescence lifetime, least particle count, saturation pump intensity and least pump intensity of the Yb3+-doped laser glasses were calculated respectively, and by comparison it was found that the chart of the absorption cross section is similar to the stimulated emission cross section calculated by the reciprocity method, and is very different from the stimulated emission cross section calculated by the Fuchbauer-Ladenburger method. This result is precisely in line with the theoretical analysis. The line-types of the absorption spectra of the two glass samples are almost the same, and the first peak value of absorption is located at 975 nm while the second peak value is at 908 nm. As the two components of the samples are not very different, the accord of the line-types of the absorption spectra indicates that the makeup of the glass material is the primary factor influencing the line-type of the absorption spectra. The fluorescence spectra of the two glass samples are very different, and the first fluorescence peak value of sample one is located at 993 nm with the second peak value at 1 029 nm, while the first fluorescence peak value of sample two is located at 1 035 nm with the second peak value at 994 nm. The cause of the major difference in the fluorescence spectra of two samples lies in the different doping density of Yb3+. By comparison we found that the laser performance of sample two is better than that of sample one. The test shows that both samples are suitable for drawing fiber..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2485 (2009)
The study on Supercontinuum Generation of Femtosecond Pulse Propagating in Fused Silica
YANG Li-ling, FENG Guo-ying, YANG Hao, ZHOU Guo-rui, ZHOU Hao, SUI Zhan, and ZHU Qi-hua
Starting from Nonlinear Schrodinger’s equation and using the split-step Fourier method, the authors studied the characters of the supercontinuum generation of femtosecond laser pulse propagating in fused silica, and many physical factors were included such as propagation distance, input pulse peak power, diffraction efStarting from Nonlinear Schrodinger’s equation and using the split-step Fourier method, the authors studied the characters of the supercontinuum generation of femtosecond laser pulse propagating in fused silica, and many physical factors were included such as propagation distance, input pulse peak power, diffraction effect, dispersion effect andnonlinear effect etc. The results show that when the femtosecond pulse propagated inside the fused silica, the process of supercontinuum generation could be divided into two main stages: the pulse compression stage, which was induced by the self-focus and other third nonlinear effects of the fused silica; and the pulse split stage, which was caused by the self-phase modulation and the group velocity dispersion of the fused silica. When the femtosecond pulse propagated inside the fused silica with high input peak power, the 3rd-order nonlinear effect of material induced pulse compression and then the subpulses were produced, so that new frequency components were introduced. At the same time, the authors also studied the spectral distribution of the pulse at different spacial locations, and there are new frequencies around the central frequency. Finally, some experiments were done to demonstrate the supercontinuum generation..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2489 (2009)
Study on the Correlation of Spectral Characteristic and Nitrogen Content of the Soil in Citrus Orchard of Three Gorges Reservoir Area
YI Shi-lai, DENG Lie, HE Shao-lan, ZHENG Yong-qiang, XIE Rang-jin, and ZHANG Xuan
The relationship between the spectrum characteristics and nitrogen content of soils in citrus orchard of the Three Gorges Reservoir Area was studied by analyzing the visible-near infrared spectrum. The results showed that the soil reflectivity increased lineally as the wavelength increases across the visible spectrum aThe relationship between the spectrum characteristics and nitrogen content of soils in citrus orchard of the Three Gorges Reservoir Area was studied by analyzing the visible-near infrared spectrum. The results showed that the soil reflectivity increased lineally as the wavelength increases across the visible spectrum and reached a stable plateau in the short wavelength near-infrared region（780-1 750 nm）without much fluctuation. In the long wavelength near-infrared region （1 750-2 400 nm）the reflectivity of the soils was higher with higher fluctuation. There were three strong absorbance peaks around 1 416, 1 913 and 2 209 nm, respectively, in the long wavelength infrared region. Soil available nitrogen content and total nitrogen content were positively correlated with soil light reflectivity but negatively correlated with catoptric-spectrum values reciprocal logarithm. At 541 nm of visible light region, a high positive correlation was found between the available nitrogen content and the first derivative of the soil reflective spectrum with a correlation coefficient of +0.605** and the best fitting equation was y=2E+09x2-3E+06x+890.49, where R2=0.5， and x is the first derivative of the soil reflective spectrum. At 1 909 nm of the near-infrared long wavelength region, the correlation between the total nitrogen content and the reciprocal-log values of the reflective spectrum of the soils was the best with a correlation coefficient of -0.612**, and the best fitting equation was y=1.372 1x2-2.107 5x+0.859 2, where R2=0.4, and x is the reciprocal values of the log reflective spectrum of the soils..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2494 (2009)
Gastric Cancer Detection Using Kubelka-Munk Spectral Function of DNA and Protein Absorption Bands
LI Lan-quan, WEI Hua-jiang, GUO Zhou-yi, YANG Hong-qin, XIE Shu-sen, CHEN Xue-mei, LI Li-bo, HE Bo-hua, WU Guo-yong, and LU Jian-jun
Differential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. DiDifferential diagnosis for epithelial tissues of normal human gastric, undifferentiation gastric adenocarcinoma, gastric squamous cell carcinomas, and poorly differentiated gastric adenocarcinoma were studied using the Kubelka-Munk spectral function of the DNA and protein absorption bands at 260 and 280 nm in vitro. Diffuse reflectance spectra of tissue were measured using a spectrophotometer with an integrating sphere attachment. The results of measurement showed that for the spectral range from 250 to 650 nm, pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(ｒ∞) and logarithmic Kubelka-Munk function log［f(ｒ∞)］ of the DNA absorption bands at 260 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 68.5%(p＜0.05), 146.5%(p＜0.05), 282.4%(p＜0.05), 32.4%(p＜0.05), 56.0%(p＜0.05) and 83.0%(p＜0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(ｒ∞) and logarithmic Kubelka-Munk function log［f(ｒ∞)］ of the protein absorption bands at 280 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 86.8%(p＜0.05), 262.9%(p＜0.05), 660.1%(p＜0.05) and 34%(p＜0.05), 72.2%(p＜0.05), 113.5%(p＜0.05) respectively. And pathological changes of gastric epithelial tissues induced that there were significant differences in the averaged value of the Kubelka-Munk function f(ｒ∞) and logarithmic Kubelka-Munk function log［f(ｒ∞)］ of the β-carotene absorption bands at 480 nm between epithelial tissues of normal human stomach and human undifferentiation gastric cancer, between epithelial tissues of normal human stomach and human gastric squamous cell carcinomas, and between epithelial tissues of normal human stomach and human poorly differentiated cancer. Their differences were 59.5%(p＜0.05), 73%(p＜0.05), 258.9%(p＜0.05), 118.7%(p＜0.05), 139.2%(p＜0.05), and 324.6%(p＜0.05) respectively. It is obvious that pathological changes of gastric epithelial tissues induced that there were significant changes in the contents of the DNA, protein and β-carotene of gastric epithelial tissues. The conclusion can be applied to rapid, low-cost and noninvasive the optical biopsy for gastric cancer and provides a useful reference..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2499 (2009)
Synthesis and Spectra of Transition Metals Complexes RE3L3(NO3)6(H3O)2
ZHAO Qing-shan, MAO Ju-lin, ZHOU Hui-liang, HU Qi-lin, and LIU Wan-yi
Schiff base 4-(p-dimethylaminobenzaldehydeamino)-4H-1,2,4-triazole(L) was synthesized from 4-amino-1,2,4-triazole and p-dimethylaminobenzaldehyde using acetic acid as the catalyst. The solid complexes RE3L6(NO3)6(H2O)2 (RE=Cu, Co, Zn, Cd; x=3-6) were synthesized with 4-(p-dimethylaminobenzaldehydeamino)-4H-1,2,4-triazoSchiff base 4-(p-dimethylaminobenzaldehydeamino)-4H-1,2,4-triazole(L) was synthesized from 4-amino-1,2,4-triazole and p-dimethylaminobenzaldehyde using acetic acid as the catalyst. The solid complexes RE3L6(NO3)6(H2O)2 (RE=Cu, Co, Zn, Cd; x=3-6) were synthesized with 4-(p-dimethylaminobenzaldehydeamino)-4H-1,2,4-triazole and nitrate of transition metals in ethanol and characterized by elemental analysis, infrared spectroscopy, UV spectrum, and fluorescence spectrum. Experimental results showed that the free ligand is a thermally stable material, and its ethanol solution emitted intense blue fluorescence at the peak wavelength of 416 nm. The absorption band at about 406 nm can be assigned to the intrinsic absorption of CN. Compared with the fluorescence emission of free ligand in ethanol solution, the emission of the complex of RE3L6(NO3)6(H2O)2 was red-shifted to 445 nm and narrow in solution. RE(Ⅱ) was coordinated with N atomy of triazole in 4-(p-dimethylaminobenzaldehydeamino)-4H-1,2,4-triazole..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2505 (2009)
Synthesis of PANI/TiO2 Nanorods Composites by Reverse Micelle Template and Their Properties
SUN Jian-ping, WENG Jia-bao, CHENG Yun-tao, MA Lin-pu, and OUYANG Zhi-bin
PANI/TiO2 nano-composites with different amount of nanometer TiO2 were synthesized by using reverse micelle formed from cationic surfactant cetyltrimethyl ammonium bromide (CTAB) as the template. The structure and properties of PANI/TiO2 nano-composites were investigated by FTIR, UV-Vis, TG, TEM and photoluminescence sPANI/TiO2 nano-composites with different amount of nanometer TiO2 were synthesized by using reverse micelle formed from cationic surfactant cetyltrimethyl ammonium bromide (CTAB) as the template. The structure and properties of PANI/TiO2 nano-composites were investigated by FTIR, UV-Vis, TG, TEM and photoluminescence spectroscopy. The self-assembly mechanism of PANI/TiO2 nanorods composites in reversed micelle was discussed briefly. The results indicate that the synthesized nano-composites are PANI/TiO2 nanorods with an average diameter and length around 30-40 nm and 400 nm respectively. The infrared spectrum shows that a strong interaction exists between PANI and TiO2 nano-particles. The thermal stability of PANI/TiO2 nanorods improves with the contents of TiO2 increasing. The absorption of PANI/TiO2 nano-composites was found to be very intense in the range of violet and visible light by UV-Vis spectrum. The fluorescence of PANI/TiO2 nanorods was excited at 416 nm, and the intensity of fluorescence was strengthened greatly with increasing TiO2 concentration. The mechanism of the strengthened fluorescence quantum efficiency and fluorescence intensity of PANI/TiO2 was investigated through the charge transfer and exciton dissociation in PANI/TiO2 nanorods composites..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2509 (2009)
Synthesis, Characterization and Fluorescent Property of Terbium Binary and Ternary Complexes with p-Aminohippuric Acid
YANG Yong-li, DENG Yu-heng, NIE Feng-mei, ZHANG Fan, and ZONG Rui-fa
A series of binary and ternary rare-earth compounds were synthesized by the reaction of terbium ion with p-aminohippuric (PAH, HL) acid and phenanthroline (phen) or 2,2’-bipyridine(2,2’-bpy) in the ethanol solution. The compositions of the complexes were deduced to be TbL3(1), TbL3·phen·H2O(2) and TbL3·bA series of binary and ternary rare-earth compounds were synthesized by the reaction of terbium ion with p-aminohippuric (PAH, HL) acid and phenanthroline (phen) or 2,2’-bipyridine(2,2’-bpy) in the ethanol solution. The compositions of the complexes were deduced to be TbL3(1), TbL3·phen·H2O(2) and TbL3·bipy·H2O(3) by elemental analysis, TG-DTA, UV-Vis and IR, and the spectra and fluorescent properties of the complexes 1-3 were discussed. The oxygen atoms of the carboxylate group were coordinated with the rare-earth ion in bridging bidentate mode. The result shows that the higher the extent of the ligand coplanarity and conjugation, the better the fluorescent performance of the compound. The fluorescent intensity of the ternary complexes 2 and 3 are stronger than that of the binary complex 1..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2514 (2009)
Fluorescence Spectroscopy Study of Synthetic Food Colors
CHEN Guo-qing, WU Ya-min, WANG Jun, ZHU Tuo, and GAO Shu-mei
According to the characteristic of synthetic food colors molecule and the relationship between fluorescence and molecular structure, and through analyzing, it has been concluded that synthetic food colors is fluorescent material. By using SP-2558 multifunctional spectral measuring system, the three-dimensional fluorescAccording to the characteristic of synthetic food colors molecule and the relationship between fluorescence and molecular structure, and through analyzing, it has been concluded that synthetic food colors is fluorescent material. By using SP-2558 multifunctional spectral measuring system, the three-dimensional fluorescence spectra of ponceau 4R, amaranth, tartrazine, sunset yellow and brilliant blue were measured. The results show that ponceau 4R excited by light at the wavelength of 330-430 nm can generate a strong fluorescence at the 621 nm peak wavelength with its best excitation wavelength being 376 nm, amaranth excited by light at the wavelength of 300-440 nm can generate a strong fluorescence at the 643 nm peak wavelength with its best excitation wavelength being 370 nm, tartrazine excited by light at the wavelength of 280-380 nm can generate a strong fluorescence at the 565 nm peak wavelength with its best excitation wavelength being 315 nm, sunset yellow excited by light with wavelength of 310-410 nm can generate a strong fluorescence at the 592 nm peak wavelength with its best excitation wavelength being 348 nm, and brilliant blue excited by light at the wavelength of 320-390 nm can generate a strong fluorescence at the 456 nm peak wavelength with its best excitation wavelength being 350 nm. Moreover, the fluorescence spectra of the five kinds of synthetic food colors were discussed. These results can provide helps for testing of food colors and food safety..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2518 (2009)
Fluorescence Study on the Interaction of Narrow Distribution Low Polymerization Degree Chitooligosaccharides and Human Serum Albumin
LIU Hai-kuan, WANG Hai-yang, WU Shan-shan, ZHANG Qi, DU Jin-feng, and GU Hai-bo
Chitosan (CTS), a linear binary copolymer of (1→8)-linked 2-acetamido-2-deoxy-β-D-glucopyranose (GlcNAc unit) and 2-amino-2-deoxy-β-D-glucopyranose (GlcNH2 unit), is derived from chitin by alkaline deacetylation. In the present work, the narrow molecular weight distribution chitooligosaccharides were prepared by degradChitosan (CTS), a linear binary copolymer of (1→8)-linked 2-acetamido-2-deoxy-β-D-glucopyranose (GlcNAc unit) and 2-amino-2-deoxy-β-D-glucopyranose (GlcNH2 unit), is derived from chitin by alkaline deacetylation. In the present work, the narrow molecular weight distribution chitooligosaccharides were prepared by degraded CTS with a microwave-assisted-cleavage method of metal-coordinating template-absorption catalytic oxidation. Under physiological pH conditions, the interaction of CTS and the narrow distribution chitooligosaccharides with Human serum albumin (HSA) was preliminarily explored by fluorescence spectra. Low molecular weight CTS in different concentration was added into HSA solution respectively, the absorptivity of the HSA solution decreased considerably. This phenomenon indicated that there was an interaction between these six different low molecular weight CTS with HSA, and the smaller the DP of the narrow distribution chitooligosaccharides, the stronger the interaction with HSA. However, the interaction gradually failed in as the DP was less than eight. The interaction almost disappeared when using glucosamine, the final product of degraded CTS, which revealed that there was a scale effect between chain-like CTS molecule and protein biomacromolecule. The results suggest that the strongest interaction binding occurs in CTS with DP≈8. Whether the DP increases or decreases, the interaction will weaken..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2523 (2009)
Study on the Interaction of Levofloxacin and MCM-41 by Fluorescence Spectrum
CAO Yuan, YUAN Qing-hua, XIA Zhi-ning, XU Yan-qin, and BAI Ying-hao
The mesoporous molecular sieve MCM-41 was synthesized by hydrothermal method under microwave irradiation and the levofloxacin was encapsulated in the hexagonal ordered channels of MCM-41 using pickling process. The structure and property of MCM-41 and LVFX/MCM-41 were characterized by means of small-angle X-ray diffracThe mesoporous molecular sieve MCM-41 was synthesized by hydrothermal method under microwave irradiation and the levofloxacin was encapsulated in the hexagonal ordered channels of MCM-41 using pickling process. The structure and property of MCM-41 and LVFX/MCM-41 were characterized by means of small-angle X-ray diffraction（XRD）, Fourier transform infrared spectroscopy (FTIR), N2 physical adsorption， and thermogravimetric analysis-differential thermal analysis （TGA-DTA）. The pore diameter and the specific surface area of the mesoporous molecular sieve MCM-41 synthesized under microwave irradiation were 2.382 nm and 1 015 m2·g-1 respectively. The fluorescence spectra of MCM-41, LVFX/MCM-41, LVFX （solid） and LVFX （solution） were investigated. The results indicated that there were some visible red shifts in the fluorescence spectrum of the composite of LVFX/MCM-41 as compared with the samples before being encapsulated. It was inferred from the results that hydrogen bonds were formed between levofloxacin and the hydroxy group in the inner pores, and the electron cloud could transfer from the hydroxy group to electro-attracting group. At the same time, the electron cloud could transfer in much larger annulations, and the conjugated system of LVFX was extended because of the new annulations formed, which contributed to the red shifts of the fluorescence spectra. The strong interactions between the LVFX and MCM-41 provided the theory for developing a novel delayed release drug using MCM-41 as the carriers..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2527 (2009)
Determination of Protein in Biological Samples by Synchronous Fluorescence
CUI Feng-ling, YAN Ying-hua, ZHANG Qiang-zhai, QU Gui-rong, and LU Yan
The authors studied the characterization of synchronous fluorescence spectra of 5-methyluridine-protein system; the spectral characterization and intensity of synchronous fluorescence were related to the value of Δλ, reaction medium, reagent concentration, ionic strength, addition sequence, reaction time, reaction tempThe authors studied the characterization of synchronous fluorescence spectra of 5-methyluridine-protein system; the spectral characterization and intensity of synchronous fluorescence were related to the value of Δλ, reaction medium, reagent concentration, ionic strength, addition sequence, reaction time, reaction temperature, and so on. On basis of the experimental results, the new method for the determination of the proteins was developed with 5-methyluridine as a molecular probe. Under the optimum experimental conditions, the synchronous fluorescence intensities of 5-methyluridine-HSA systems were in good proportion to the HSA concentration of the system in the range of 1.38-575.2 μg·mL-1 and the detection limit could achieve 0.12 μg·mL-1. The method is simple and rapid. Biological samples such as human serum, saliva and urine were determined utilizing this method, standard addition experiment was done, and the recovery rate was 98.7%-103.8%. Eleven blank solutions were used for the parallel experiment, resulting in a relative standard deviation of 1.56%. The results show that the method using synchronous fluorescence spectroscopy with 5-methyluridine as a molecular probe is simple, rapid and highly sensitive with a wide linear range, good stability and high selectivity. The method was applied directly to determine the total proteins in human serum, saliva and urine samples, and the results were satisfactory..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2531 (2009)
Fluorescence Analysis of Trace Glucose Using Glucose Oxidase and Horseradish Peroxidase
LIU Qing-ye, LIANG Yue-yuan, LIANG Ai-hui, and JIANG Zhi-liang
In acetate buffer solution and in the presence of glucose oxidase (GOD), glucose reduced the dissolved oxygen to form H2O2 that oxidized catalytically the excess KI to from I-3 by horseradish peroxidase (HRP). The I-3 combines respectively with rhodamine S (RhS), rhodamine 6G(Rh6G), butyl-rhodamine B(b-RhB) and rhodamiIn acetate buffer solution and in the presence of glucose oxidase (GOD), glucose reduced the dissolved oxygen to form H2O2 that oxidized catalytically the excess KI to from I-3 by horseradish peroxidase (HRP). The I-3 combines respectively with rhodamine S (RhS), rhodamine 6G(Rh6G), butyl-rhodamine B(b-RhB) and rhodamine B(RhB) to form RhS-I3, Rh6G-I3, b-RhB-I3 and RhB-I3 associated particles that result in fluorescence quenching at 556, 556, 584 and 584 nm, respectively. Under the optimal conditions, the concentration of glucose in the range of 0.083-9.99, 0.17-8.33, 0.33-8.33 and 0.33-9.99 μmol·L-1 is linear with their fluorescence quenching at 556, 556, 584 and 584 nm, with detection limits of 0.059， 0.17， 0.21 and 0.16 μmol·L-1 glucose. And the regression equation was ΔF=40.0ｃ+3.0, ΔF=23.9ｃ+8.1, ΔF=25.6ｃ+4.2, and ΔF=18.4ｃ+0.8, respectively. The RhS system was the most sensitive and stable, and was chosen for use. Influence of some foreign substances on the RhS fluorescence quenching determination of 6.67 μmol·L-1 glucose was examined, with a relative error of ±10%. Results showed that 1 000-fold Mg2+ and Cu2+, 300-fold Mn2+， 100-fold Zn2+, Al3+ and Co2+, 60-fold L-tyrosine, urea and nicotinic acid, 50-fold Fe3+, HSA and BSA, 10-fold sucrose, vitamin B2, L-lysine, L-glutamic acid and L-cystine did not interfere with the determination. This RhS fluorescence quenching assay was applied to the determination of glucose in the serum samples with satisfactory results..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2535 (2009)
Study on Complex Formation of Quercetin Reacting with Cu2+ Using UV-Vis Absorption Spectroscopy
XUE Jun-peng, LI Ping, WANG Qi-ming, ZHAO Wei, and WU Da-cheng
Using an intensified spectroscopic detector ICCD, the real-time UV-Vis absorption spectra of quercetin (Q) reacting with Cu2+ under neutral and acid conditions were acquired. The exposure time was 0.1 ms for each spectrum, and the molar ratio of Cu2+∶Q was 0.2, 0.5, 1.0, 2.0, 5.0 and 10.0, respectively. Results indicatUsing an intensified spectroscopic detector ICCD, the real-time UV-Vis absorption spectra of quercetin (Q) reacting with Cu2+ under neutral and acid conditions were acquired. The exposure time was 0.1 ms for each spectrum, and the molar ratio of Cu2+∶Q was 0.2, 0.5, 1.0, 2.0, 5.0 and 10.0, respectively. Results indicate that the changes in absorption bands of reaction solutions with different ratio of Cu2+∶Q were similar if other conditions were the same, and the greater the molar ratio, the shorter the reaction time; the reaction processes of complex formation were different under neutral and acid conditions. There was an intermediate product with the absorption peak at 428 nm that occurred during the reaction under neutral condition, but the final product was directly formed under acid condition, and the final products under both conditions had the same absorption bands centered at 296 nm; reaction processes with air and without air showed no difference. The present work first observed that there was an intermediate product formed during the complex formation of quercetin reacting with Cu2+ and the absorption band of the final complex was centered at 296 nm. Results obtained here provide useful experimental evidence for the study of complex mechanism of quercetin with Cu2+..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2539 (2009)
Investigation of Multi-Wavelength Effect During the Measurement of UV-Enhanced Film’s Emission Spectrum
LIU Meng, NI Zheng-ji, ZHANG Da-wei, HUANG Yuan-shen, and ZHUANG Song-lin
The UV-responsive detector is a dual-use device for civilian and military after the laser and IR-responsive sensors. Typical image sensor coated with a layer of down-convert frequency thin film on it’s photosurface to enhance UV response is the key technology of enhancing UV-response. The UV-enhanced thin film was madeThe UV-responsive detector is a dual-use device for civilian and military after the laser and IR-responsive sensors. Typical image sensor coated with a layer of down-convert frequency thin film on it’s photosurface to enhance UV response is the key technology of enhancing UV-response. The UV-enhanced thin film was made in the experimental laboratory using the Zn2SiO4∶Mn phosphor by spin coating method. Two peaks at 520 and 560 nm respectively in the emission spectrum of the UV-enhanced film were found by SP1702 spectrograph when the excitation wavelength was 260 and 280 nm.The peaks were found in the process of experiment of measuring and counting the quantum efficiency of UV-enhanced thin film. But the light peaks at 520 and 560 nm are not the emission light peaks by the exciting light of 260 and 280 nm. The reason why the light at 520 and 560 nm is not the emission light was analyzed based on the measurement principle of grating spectrograph. The reasons for the multi-wavelength of light overlaps during the measurement of emission spectrum were also discussed. And the equipment used to separate the overlapped different wavelengths was designed, which will be used to resolve the problem of the overlap of multi-wavelength..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2543 (2009)
The Study of Cervical Cancer Cells Model Based on UV Absorption Spectrum
LIN Xiao-gang, PAN Ying-jun, GUO Yong-cai, ZHANG Wei, and ZHAO Yi-shi
Cell cycle is the most important process in life, and embodies all the physiological processes in the cell. In order to reflect the process of cell growth simply and accurately, the authors took cell cycle into account when the Hela cell spectral model was designed. The artificially induced cell synchronization method Cell cycle is the most important process in life, and embodies all the physiological processes in the cell. In order to reflect the process of cell growth simply and accurately, the authors took cell cycle into account when the Hela cell spectral model was designed. The artificially induced cell synchronization method was employed to make Hela cell in G1, S, G2 and M phases of the cell cycle. The UV absorption spectra of these Hela cell samples were measured. The absorbability of aromatic amino acid, protein and nucleic acid in different stages of the cell cycle showed the changes in cell cycle. The subsection linear regression model of cell UV absorption spectrum was designed according to the relationship between the stage and the absorbance of samples in different phase at 204 and 260 nm. The models can be used to estimate the cell cycle after experimental verification and provide a new method for analyzing cell cycle and building cell model..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2547 (2009)
Determination of Physiological Indices in Early Kernel at Different Ear Position in Maize(Zea Mays L.) with UV-Visible Spectrophotometry
SHEN Li-xia, WANG Pu, and SUN Xi-huan
To examine the difference between early kernels at different ear position in maize and the effect of nitrogen supply rates on kernel development, physiological indices in apical and mid-basal kernel 5-20 days after pollination in maize under different nitrogen supply rates (0, 120, 180 and 240 kg·ha-1) were determTo examine the difference between early kernels at different ear position in maize and the effect of nitrogen supply rates on kernel development, physiological indices in apical and mid-basal kernel 5-20 days after pollination in maize under different nitrogen supply rates (0, 120, 180 and 240 kg·ha-1) were determined with UV-Vis spectrophotometry. The results showed that nitrogen supply obviously increased the contents of soluble sugar, sucrose and starch, and the activities of enzymes related to sucrose inversion and starch synthesis. Twenty days after pollination, the kernel volume, dry weight and the contents of soluble sugar, sucrose and starch in apical kernel under nitrogen supply rate of 180 kg·ha-1 were higher than those with other treatments. Five to twenty days after pollination, higher activities of acid sucrose invertase (AI), neutral sucrose invertase (NI), sucrose synthase (SS), ADPGase and starch synthase in apical kernel were also obtained under nitrogen supply rate of 180 kg·ha-1, indicating that the sucrose utilization and starch synthesis were improved, the kernel development was promoted and the kernel abortion was reduced, which resulted in higher yield..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2551 (2009)
Crop Geometry Identification Based on Inversion of Semiempirical BRDF Models
ZHAO Chun-jiang, HUANG Wen-jiang, MU Xu-han, WANG Jin-di, and WANG Ji-hua
With the rapid development of remote sensing technology, the application of remote sensing has extended from single view angle to multi-view angles. It was studied for the qualitative and quantitative effect of average leaf angle (ALA) on crop canopy reflected spectrum. Effect of ALA on canopy reflected spectrum can noWith the rapid development of remote sensing technology, the application of remote sensing has extended from single view angle to multi-view angles. It was studied for the qualitative and quantitative effect of average leaf angle (ALA) on crop canopy reflected spectrum. Effect of ALA on canopy reflected spectrum can not be ignored with inversion of leaf area index (LAI) and monitoring of crop growth condition by remote sensing technology. Investigations of the effect of erective and horizontal varieties were conducted by bidirectional canopy reflected spectrum and semiempirical bidirectional reflectance distribution function (BRDF) models. The sensitive analysis was done based on the weight for the volumetric kernel (fvol), the weight for the geometric kernel (fgeo), and the weight for constant corresponding to isotropic reflectance (fiso) at red band (680 nm) and near infrared band (800 nm). By combining the weights of the red and near-infrared bands, the semiempirical models can obtain structural information by retrieving biophysical parameters from the physical BRDF model and a number of bidirectional observations. So, it will allow an on-site and non-sampling mode of crop ALA identification, which is useful for using remote sensing for crop growth monitoring and for improving the LAI inversion accuracy, and it will help the farmers in guiding the fertilizer and irrigation management in the farmland without a priori knowledge..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2555 (2009)
Peak-Width Quantitation for Flow-Injection Microwave Plasma Torch-Atomic Emission Spectrometry
LI Yong-sheng, ZHAO Bo, and SUN Xu-hui
A peak-width quantitation method for flow-injection microwave plasma torch atomic emission spectrometry was proposed. Sensitivity and linearity of the peak-width quantitation were investigated under different emission intensities. Recoveries of Zn2+, Cu2+ and Ag+ existing in various matrix were determined by using the A peak-width quantitation method for flow-injection microwave plasma torch atomic emission spectrometry was proposed. Sensitivity and linearity of the peak-width quantitation were investigated under different emission intensities. Recoveries of Zn2+, Cu2+ and Ag+ existing in various matrix were determined by using the peak-width quantitation, and were compared with the results obtained by the peak-height method. The results indicated that the peak-width quantitation can efficiently remove matrix interference in the FI-MPT-AES system, and expand its linear determination range. The peak-width quantitation (recovery: 92%-107%) surpasses conventional peak-height method (recovery: 61.3%-122%). Optimized determination conditions were as follows: the sampling volume was 350 mL, the flow rate of the carrier was 1.5 mL·min-1, the power of microwave was 110 W, the flow rates of the carrier gas and working gas (argon) were 1.4 and 0.4 L·min-1, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2560 (2009)
Stoichiometry of Multi-Elements in the Zinc-Cadmium Hyperaccumulator Thlaspi Caerulescens Grown Hydroponically under Different Zinc Concentrations Determined by ICP-AES
HAN Wen-xuan, XU Yi-ming, DU Wei, TANG Ao-han, and JIANG Rong-feng
Thlaspi caerulescens is commonly known as a zinc (Zn) and cadmium (Cd) hyperaccumulator, which can be used to clean up the Zn- and/or Cd-contaminated soil. However, it is unclear whether high soil Zn concentrations will stimulate undue accumulations of other elements to such an extent as to cause the nutrient unbalanceThlaspi caerulescens is commonly known as a zinc (Zn) and cadmium (Cd) hyperaccumulator, which can be used to clean up the Zn- and/or Cd-contaminated soil. However, it is unclear whether high soil Zn concentrations will stimulate undue accumulations of other elements to such an extent as to cause the nutrient unbalance in the soil. To address this question, the inductively coupled plasma-atomic emission spectrometry (ICP-AES) was employed to investigate the effect of Zn on the stoichiometry of Zn, Cd, K, P, Mg, Ca, Fe, Mn and Cu in T. caerulescens (Ganges ecotype) exposed to low, middle and high Zn concentrations (5, 50 and 500 μmol·L-1, respectively) in a hydroponic experiment. The results showed that there were no significant variations in contents of Cd, K, P, Mg, Ca, Fe, Mn and Cu in the shoot of T. caerulescens, however, the Zn content in the shoot and root with 500 μmol·L-1 Zn treatment increased as much as 13 times higher than that with low Zn exposure, indicating that the plant is capable of Zn hyperaccumulating. The authors’ study suggests that it is improbable to induce soil nutrient unbalance when T. caerulescensis (Ganges) is used for phytoremediation of Zn-contaminated soil, in that over-uptake of nutrient elements from the soil other than Zn was not observed, at least for the elements K, P, Mg, Ca, Fe, Mn and Cu..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2565 (2009)
Determination of Metal Contents of Two Chinese Medicinal Herbs,Flemingiae Philippinensis and Sophora Tonkinensis, Grown in Guangxi by ICP-AES
MAO Li, TAN Ming-xiong, CHEN Zhen-feng, and LIANG Hong
The metal contents of traditional Chinese medicine, Sophora tonkinensis and Flemingiae philippinensis, grown in Guangxi province of China were determined by ICP-AES methods. The two herbs were digested by applying acid bomb digestion procedure. Considering RF power, nebulized gas flow rate, auxiliary gas flow rate and The metal contents of traditional Chinese medicine, Sophora tonkinensis and Flemingiae philippinensis, grown in Guangxi province of China were determined by ICP-AES methods. The two herbs were digested by applying acid bomb digestion procedure. Considering RF power, nebulized gas flow rate, auxiliary gas flow rate and pump rate, the instrument was optimized. The instrument operating conditions, analytical lines and detection limits of elements determined as well as the contents of elements in these two herbs were reported. The results show that Sophora tonkinensis contains microelements Cu, Zn, Fe, Mn and Cr and macroelements Ca, Mg, Na and K; Flemingiae philippinensis contains microelements Cu, Zn, Fe, Ni, Mn and Cr and macroelements Ca, Mg, Na and K. However, the two traditional Chinese medicines do not contain toxic elements Sn, Pb and Cd. The precision was found to be less than 5% in terms of relative standard deviation mostly. The results indicate that the concentration ratio of zinc to copper in Sophora tonkinensis is 6.4, while the ratio in Flemingiae philippinensis is 5.7. The content of zinc is higher than copper in both two herbs, which agrees with the phenomenon that the zinc content higher than that of copper exists in other antitumor traditional Chinese medicine. All these will afford an apocalypse for understanding the pharmacological mechanism of these anitumor traditional Chinese medicines..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2568 (2009)
Application of ICP-MS to Detection of Mineral Elements in Double-Low and Double-High Rapeseed
ZOU Juan, LU Jian-wei, CHEN Fang, and LI Yin-shui
The object of the present study was to investigate ten necessary mineral elements in different varieties of rapeseed by ICP-MS. Thirty three samples of double-low (low in both glucosinolates and erucic acid) rapeseed (DLR) and 12 samples of double-high rapeseed (DHR) in the Yangtze River Valley were collected. The resuThe object of the present study was to investigate ten necessary mineral elements in different varieties of rapeseed by ICP-MS. Thirty three samples of double-low (low in both glucosinolates and erucic acid) rapeseed (DLR) and 12 samples of double-high rapeseed (DHR) in the Yangtze River Valley were collected. The results showed that rapeseed contained many kinds of necessary elements, and there was a difference between DLR and DHR. The average concentrations of P, K, Ca, Mg, S, Fe, Mn, Cu, Zn and B in DLR were 6.26 mg·g-1, 10.17 mg·g-1, 6.75 mg·g-1, 4.82 mg·g-1, 4.52 mg·g-1, 96.20 μg·g-1, 37.10 μg·g-1, 3.84 μg·g-1, 41.61 μg·g-1 and 12.16 μg·g-1, respectively, while for the mineral elements in DHR, the average values were 5.97 mg·g-1, 10.14 mg·g-1, 6.31 mg·g-1, 4.50 mg·g-1, 9.06 mg·g-1, 77.03 μg·g-1, 49.86 μg·g-1, 3.72 μg·g-1, 40.58 μg·g-1 and 11.79 μg·g-1. The contents of most elements in DLR were higher than those in DHR, such as P, K, Ca, Mg, Fe, Cu, Zn and B. Furthermore, the differences in Ca, Mg and Fe contents between the two varieties were significant. It was concluded that the difference in concentrations of mineral elements can be regarded as a necessary factor for popularizing double-low rapeseed in the Yangtze River Valley..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2571 (2009)
Analysis of 14 Minerals of Mulberry Fruit in Different Mature Stage by ICP-OES Method
SHENG Ji-ping, LIU Can, and SHEN Lin
In the present study, the contents of nutritional elements such as Na, K, Ca, Mg, Fe, Zn, Se, Mn and Mo and heavy elements such as Cu, Cd, Pb, Cr and Co of mulberry fruits in three different mature stages were analyzed by ICP-OES. The results showed that the contents of Na, K, Ca, Mg, Fe, Zn, Mn and Cu decreased with mIn the present study, the contents of nutritional elements such as Na, K, Ca, Mg, Fe, Zn, Se, Mn and Mo and heavy elements such as Cu, Cd, Pb, Cr and Co of mulberry fruits in three different mature stages were analyzed by ICP-OES. The results showed that the contents of Na, K, Ca, Mg, Fe, Zn, Mn and Cu decreased with maturation development. The contents of the above mentioned mineral elements in green stage were 2.99, 2 957.49, 809.00, 559.95, 36.30, 10.07, 2.12 and 1.32 mg·kg-1, respectively, their contents in pink stage were 169%（Zn）to 14%（Na）lower, the contents of these elements in red stage were 1.63, 2 367.13, 489.30, 221.54, 19.01, 2.64, 0.40 and 0.59 mg·kg-1, and the same changing trend remained in black stage, but the difference was much smaller. The content of Se was the highest in green stage (1.24 mg·kg-1), decreased in pink stage, increased in red stage (0.88 mg·kg-1), but decreased to 0.65 mg·kg-1 in black stage. There was no significant change in Pb content in the first three stages, but a substantial decrease occurred in black stage, and the highest content of Pb was 0.27 mg·kg-1 in green stage. The content of Cr increased during ripening, which was 54.07 mg·kg-1 in red stage, but in black stage it decreased to the same level as that in pink stage. Both the Pb and Cr contents were not over allowance of Chinese National Standard. These data can be well reference for harvesting stage design and evaluation of function and safety of mulberry fruits..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2574 (2009)
Methodology Improvement in Background Elimination in Plant Cd Measurement by Graphite Furnace Atom Absorption
YU Hua, FENG Wen-qiang, QIN Yu-sheng, CHEN Qing-rui, ZENG Xiang-zhong, and TU Shi-hua
A problem of higher background value and lower measured Cd value exists when Cd is digested by conventional dry digestion method, measured by graphite furnace atomic absorption, and calculated with peak height numeration. This problem results in difficulty for evaluating samples with Cd contents in the neighborhood of A problem of higher background value and lower measured Cd value exists when Cd is digested by conventional dry digestion method, measured by graphite furnace atomic absorption, and calculated with peak height numeration. This problem results in difficulty for evaluating samples with Cd contents in the neighborhood of critical values. In order to solve the problem, the present paper focused on background measurement with graphite furnace atomic absorption, modified the pre-preparation procedures of the traditional method, and screened the optimal concentration of the modifier. Results showed that addition of Mg(NO3)2 as a modifier into the samples before incineration was preferred. It could not only yield a clear solution but also reduce its background by ten times, considerably eliminating background interference. In addition, using 3% HNO3 in stead of 1 mol·L-1 HCl as dilution for the incinerated sample could eliminate the background. The improved methods could acquire a zero concentration of measurement for the blank, re-correct the values measured by graphite furnace atomic absorption and obtain more reliable results..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2577 (2009)
Beam Hardening Correction Method for X-Ray Computed Tomography Based on Subsection Beam Hardening Curves
HUANG Kui-dong, and ZHANG Ding-hua
After researching the forming principle of X-ray beam hardening and analyzing the usual methods of beam hardening correction, a beam hardening correction model was established, in which the independent variable was the projection gray, and so the computing difficulties in beam hardening correction can be reduced. By coAfter researching the forming principle of X-ray beam hardening and analyzing the usual methods of beam hardening correction, a beam hardening correction model was established, in which the independent variable was the projection gray, and so the computing difficulties in beam hardening correction can be reduced. By considering the advantage and disadvantage of fitting beam hardening curve to polynomial, a new expression method of the subsection beam hardening curves based on polynomial was proposed. In the method, the beam hardening data were fitted firstly to a polynomial curve which traverses the coordinate origin, then whether the got polynomial curve surged in the fore-part or back-part of the fitting range was judged based on the polynomial curvature change. If the polynomial fitting curve surged, the power function curve was applied to replace the surging parts of the polynomial curve, and the C1 continuity was ensured at the joints of the segment curves. The experimental results of computed tomography (CT) simulation show that the method is well stable in the beam hardening correction for the ideal CT images and CT images with added noises, and can mostly remove the beam hardening artifact at the same time..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2581 (2009)
XPS Characterization of TiN Layer on Bearing Steel Surface Treated by Plasma Immersion Ion Implantation and Deposition Technique
LIU Hong-xi, JIANG Ye-hua, ZHAN Zhao-lin, and TANG Bao-yin
Titanium nitride (TiN) hard protective films were fabricated on AISI52100 bearing steel surface employing plasma immersion ion implantation and deposition (PIIID) technique. The TiN films were characterized using a variety of test methods. Atomic force microscope (AFM) revealed that the titanium nitride film has extremTitanium nitride (TiN) hard protective films were fabricated on AISI52100 bearing steel surface employing plasma immersion ion implantation and deposition (PIIID) technique. The TiN films were characterized using a variety of test methods. Atomic force microscope (AFM) revealed that the titanium nitride film has extremely smooth surface, very high uniformity and efficiency of space filling over large areas. X-ray diffraction (XRD) result indicated that （200） crystal face of titanium nitride phase is the preferred orientation and three kinds of titanium components exist in the surface modified layer. Tailor fitting analysis of X-ray photoelectron spectroscopy (XPS) combined with Ar ion etching proved that Ti2p1/2 and Ti2p3/2 have two peaks in the titanium nitride film layer, respectively. It is shown that different chemical state exists in titanium compound. N(1s) bond energy of XPS has also three fitting peaks at 396.51, 397.22 and 399.01 eV, corresponding to the nitrogen atom in TiNxOy， TiN and N—N, respectively. Combined with the XPS Tailor fitting analysis results of O(1s) bond energy, it was shown that there is a large amount of titanium nitride phase in addition to a small amount of simple substance nitrogen and oxide of titanium in the surface layer. The whole film system is made up of TiN, TiO2, N—N and Ti—O—N compound..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 2585 (2009)
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 28, 2021
- Vol. 29, Issue 9, 1 (2009)
Research Articles
Variations of IR-Spectra of Three Coating Materials Before and after Spraying on Urea Fertilizer
LIU Xing-bin, CHEN Li-jun, WU Zhi-jie, and ZHANG Guang-na
Coated fertilizer is a hot spot in the domain of fertilizer research. Related researches mainly focused on the action mechanisms of coating materials in controlling the nutrient release from coated fertilizers, but less information is available on the structural variation of the coating materials before and after sprayCoated fertilizer is a hot spot in the domain of fertilizer research. Related researches mainly focused on the action mechanisms of coating materials in controlling the nutrient release from coated fertilizers, but less information is available on the structural variation of the coating materials before and after spraying on fertilizers, which is the key to whether we can directly use coating materials to extrapolate its mechanisms in controlling coated fertilizers’ nutrient release. With polylactic acid (PLA), poly (butynelenes succinate) (PBS), and polycarbonate (PC) as test materials, the variations of their IR spectra before and after spraying on urea fertilizer were determined, which was aimed to supply theoretical basis for further studying the action mechanisms of coating materials in controlling coated fertilizers' nutrient release. The results showed that PLA and PC had less variation in their IR spectra before and after spraying on urea fertilizer, while PBS acted in reverse, suggesting that the former two coating materials could be directly used for studying the patterns of nutrient release from coated fertilizers..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 20, 2021
- Vol. 29, Issue 9, 2361 (2009)
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