Journals >Spectroscopy and Spectral Analysis
Contents
2009
Volume: 29 Issue 11
68 Article(s)
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Research Article
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 1 (2009)
Surface Emission Characteristics of ZnO Nanoparticles
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The sizedependence of photoluminescence (PL) of ZnO nanoparticles with diameter from 17 to 300 nm was demonstrated by time resolved laser spectroscopy. Broad PL spectra were obtained and found to consist of three Gaussian components. The authors found that the PL peak position and relative amplitude depend on the sizeThe sizedependence of photoluminescence (PL) of ZnO nanoparticles with diameter from 17 to 300 nm was demonstrated by time resolved laser spectroscopy. Broad PL spectra were obtained and found to consist of three Gaussian components. The authors found that the PL peak position and relative amplitude depend on the size of nanoparticles for the Gaussian PL band inside the energy bandgap. The Gaussian band Xc3 is believed to be associated with the transitions between surface states. It is well known that as the dimensions of a semiconductor are reduced to the nanometer scale, one of the key features is the large surfacetovolume ratio. The larger surfacetovolume ratio in nanostructures means the larger bulk density of dangling bonds. The existence of dangling bond in a crystal surface is likely to change a state localized by splitting the state out of the border of the energy gap. The Gaussian peak Xc3 lying inside the band gap of ZnO indicates the existence of such initial states in the forbidden bulk band gap. Furthermore, we found that with the decrease in particle size, the Gaussian curve Xc3 shifts to the lower energy. With the particle size increaseing, the comparative amplitude of PL band Xc3 descends rapidly and so does the corresponding relative PL intensity. The sensitive correlation between the particle size and the optical properties of the below gap broadband shows a key role of the surface states recombination in PL of nanosized particles. Furthermore, our exploration indicates that the surface states recombination plays a dominant role in PL of nanostructures with particle sizes down to a certain degree..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2881 (2009)
Qualitative and Quantitative Analyses of Some Saccharides by THz-TDS
MA Xiao-jing, ZHAO Hong-wei, LIU Gui-feng, JI Te, ZHANG Zeng-yan, and DAI Bin
Terahertz (THz) radiation lies between the infrared and microwave range of the electromagnetic spectrum. Absorption spectrum in the THz range provides rich information about structure and weak interactions of biomolecules. THz absorption spectra of D-(-)-ribose, D-glucose, α-lactose monohydrate and β-lactose were measuTerahertz (THz) radiation lies between the infrared and microwave range of the electromagnetic spectrum. Absorption spectrum in the THz range provides rich information about structure and weak interactions of biomolecules. THz absorption spectra of D-(-)-ribose, D-glucose, α-lactose monohydrate and β-lactose were measured by terahertz time-domain spectroscopy (THz-TDS) in the frequency range of 03-16 THz at room temperature. The experimental results show that different saccharides have distinct THz absorption features, which suggests that THz-TDS is highly sensitive to molecular structures and components. Quantitative analysis of the mixtures of two to four saccharides was studied by linear regression with relative error less than 72%. The reasons for the relative error were discussed. The results demonstrate that THz-TDS is a promising and efficient method for both qualitative and quantitative analyses for pharmaceutical identification and biomolecular detection..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2885 (2009)
Collisional Excitation Transfer between Cs2(B 1Πu) and Cs(6S)
WANG Min, ZHOU Dong-dong, WANG Xue-yan, MU Nisai·NU, DAI Kang, WANG Qian, and SHEN Yi-fan
With a Cs density of ～1015 cm-3 and typically ～2% Cs2, cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from a YAG-laser- pumped OPO laser, populating Cs2(B 1Πu) state by one-photon absorption. Predissocia- tion of the B 1Πu state and energy transfer in Cs2(B 1Πu)+Cs(6S) collisions wereWith a Cs density of ～1015 cm-3 and typically ～2% Cs2, cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from a YAG-laser- pumped OPO laser, populating Cs2(B 1Πu) state by one-photon absorption. Predissocia- tion of the B 1Πu state and energy transfer in Cs2(B 1Πu)+Cs(6S) collisions were studied using methods of atomic and molecular fluorescence. The B 1Πu(v＜10)state does not predissociate in Cs vapor excited at λ=736 nm. The decay signal of the time-resolved fluorescence from the B 1Πu→X 1Σ+g transition was monitored. According to the Stern-Volmer equation, a plot of reciprocal of effective lifetimes of the Cs2(B 1Πu) state quenched by Cs(6S) atoms against its densities yielded a slope that indicated the total cross section for deactivation and an intercept(at which the Cs pressure is zero) that provided the information on the radiative lifetime of the state. The radiative lifetime is (35±7)ns for the B 1Πu state. The total cross section for deactivation of excited Cs2 ［B 1Πu(v＜10)］molecules by means of collisions with Cs atoms is(4.0±0.5)×10-14 cm2. The B 1Πu(v＞30) state predissociates in Cs vapor excited at λ=705 nm. At the different Cs densities, the relative time-integrated intensities of the resulting Cs emission lines, I(6P1/2→6S1/2)［I(D1)］ and I(6P3/2→6S1/2)［I(D2)］, and Cs2 (B 1Πu) band-pass(725→735 nm)I［Cs2(B 1Πu)］ were measured. By combining Cs 6P fine-structure mixing and quenching induced by collisions with ground Cs atoms, the authors obtained absolute values for predissociation and collisional transfer cross sections. The predissociation rates are (4.3±1.7)×106 s-1(for predissociating to 6P3/2) and (4.7±1.9)×106 s-1 (for predissociating to 6P1/2), respectively. The collisional transfer cross sections are (0.45±0.18)×10-14 cm2(for transfering to 6P1/2)and(4.3±1.7)×10-14 cm2 (for transfering to 6P3/2). These experimental results show that if Cs2 excited state is predissociation state, it can produce Cs(6P) atoms by predissociation and collisional transfer; if Cs2 excited state is bound, it can produce produce Cs(6P) atoms by collisional transfer..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2889 (2009)
Evaluating Acceleration Ability of Electrons of Different Acceleration Layers in Solid State Cathodoluminescence
LI Jun-ming, XU Zheng, ZHAO Su-ling, ZHANG Fu-jun, SONG Dan-dan, LIU Xiao-dong, SONG Jing-lu, XU Xu-rong, and WANG Yong-sheng
Solid state cathodoluminescence is a brand-new excitation mode. In the device, electron acceleration layer plays a very important role in obtaining high energy hot electrons to excite organic luminescent materials in solid state cathodoluminescence. Two kinds of structural devices (A： ITO/MEH-PPV/SiO2/Al, B： ITO/MEH-PPSolid state cathodoluminescence is a brand-new excitation mode. In the device, electron acceleration layer plays a very important role in obtaining high energy hot electrons to excite organic luminescent materials in solid state cathodoluminescence. Two kinds of structural devices (A： ITO/MEH-PPV/SiO2/Al, B： ITO/MEH-PPV/ZnO/Al) were fabricated. The theoretical calculation and analysis show that the tunnel current and electric field was higher in SiO2 layer than that in ZnO layer under the same applied driving voltage. The experimental results show that the intensity of device A with SiO2 as electrons acceleration layer is stronger than that of device B with ZnO as electrons acceleration layer under the same driving voltage. And the result demonstrated that electrons in the conduction band of SiO2 can be heated to higher energy than that in ZnO..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2893 (2009)
Synthesis and Photoluminescence of Zn1-x Mo1-ySiyO4∶Eu3+x Phosphor
ZHOU Li-ya, XU Ting-bo, PANG Qi, GONG Fu-zhong, WANG Wei, HUANG Jun-li, and YI Ling-hong
The phosphors Zn1-xMo1-ySiyO4∶Eu3+x(0.05≤x≤0.30, 0≤y≤0.09) were prepared by solid state reaction technique at 800 ℃. The powder X-ray diffraction patterns of the samples show that the phosphors are of single phase and the doping Eu ion and Si ion have little influence on the host structure. The effects of flux and calcThe phosphors Zn1-xMo1-ySiyO4∶Eu3+x(0.05≤x≤0.30, 0≤y≤0.09) were prepared by solid state reaction technique at 800 ℃. The powder X-ray diffraction patterns of the samples show that the phosphors are of single phase and the doping Eu ion and Si ion have little influence on the host structure. The effects of flux and calcination temperature on the luminescent properties of the phosphors were investigated. The results showed that flux content has effects on the luminescent properties, and the optimized flux content and the best calcination temperature is 4% and 800 ℃, respectively. The presence of the Na+ ion strengthens the photoluminescence intensity of the phosphors. The addition of Na+ ions balanced the charge in samples, enhanced the luminescence intensity of samples, and the luminescence intensity reached the maximum when the doping concentration of Na2CO3 was 4 Wt%. The luminescent properties of Zn0.80Mo1-ySiyO4∶Eu3+0.20 were studied by the excitation and emission spectra, and the influence of Eu3+ and Si4+ concentrations on the luminescent property was discussed. As the calcination temperature rises from 700 to 800 ℃, the emission intensity increases due to the improvement of crystallinity. The excitation spectra consist of a broad band and a series of narrow lines, and the narrow lines are attributed to the intrinsic transition from 7FJ(J=1-4) to 5DJ(J=0, 1) of Eu3+. It was found that the PL emission intensity was enhanced with the increase in the Eu3+ doping ratio and reached a maximum value at x=0.20. The result indicated that Zn1-xMo1-ySiyO4∶Eu3+x phosphors can be excited effectively at 393 and 464 nm light. The presence of the Si4+ ion strengthens the photoluminescence intensity of the phosphors and the strong red emission lines at 616 nm correspond to the forced electric dipole 5D0→7F2 transitions on Eu3+. Compared with Y2O2S∶0.05Eu3+, the obtained Zn0.80Mo0.97Si0.03O4∶Eu3+0.20 phosphor shows an enhanced red emission under 393 nm excitation and the emission intensity of Y2O2S∶0.05Eu3+ is only 50% of that of Zn0.80Mo0.97Si0.03O4∶Eu3+0.20. The optical properties suggest that Zn0.80Mo0.97Si0.03O4∶Eu3+0.20 is an efficient red emitting phosphor for light emitting diode (LED) applications..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2897 (2009)
Study on the Mechanism of Sodium Formate Enhancing Luminol Chemiluminescence and Its Application in Micellar Medium
TANG Jun, WANG Tao, and LIU Er-bao
In the presence of sodium dodecylbenzene sulfonate (SDBS) surfactant micelles, the signal of K2Cr2O7-luminol-adenine chemiluminescence system was strongly enhanced by sodium formate, which is conventionally considered as free radical scavenger. The present article discussed the sensitizing mechanism of chemiluminescencIn the presence of sodium dodecylbenzene sulfonate (SDBS) surfactant micelles, the signal of K2Cr2O7-luminol-adenine chemiluminescence system was strongly enhanced by sodium formate, which is conventionally considered as free radical scavenger. The present article discussed the sensitizing mechanism of chemiluminescence through the methods of chemiluminescence emission spectra, UV-visible absorption spectra, and chemical reactions. The result indicated that free radical OH·, which existed in the original chemiluminescence system, was transformed into free radical O·2 by the existence of sodium formate. Based on that, a highly sensitive flow injection-chemiluminescence method to determine adenine was established. Under optimal experimental conditions, the concentration of adenine was linear with the chemiluminescence intensity in the range of 8.18×10-9 to 2.45×10-11 mol·L-1. The limit of detection (3σ) was 8.72×10-12 mol·L-1. The method has been successfully applied to the analysis of adenine in VB4 pills and the results are satisfactory..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2901 (2009)
Study on Photoluminescence of 2-(4-Chloro-Benzoyl）Benzoic Acid
LI Zhao-ye, GENG Xiao-tian, WANG Juan, ZHAO Ying, WU Hong, YAN Jian-bo, WANG Yun-you, and SUN Bo
Eight complexes of europium and terbium were synthesized, with 2-(4-chloro-benzoyl)benzoic acid as an essential ligand and other three distinct ligands, including 1,10-phenanthroline, triphenylphosphine oxide and diphenyl sulfoxide, as selective ligands. They were Eu(CBBA)3(H2O)4, Eu(CBBA)3(Phen)(H2O)6, Eu(CBBA)3(TPPO)Eight complexes of europium and terbium were synthesized, with 2-(4-chloro-benzoyl)benzoic acid as an essential ligand and other three distinct ligands, including 1,10-phenanthroline, triphenylphosphine oxide and diphenyl sulfoxide, as selective ligands. They were Eu(CBBA)3(H2O)4, Eu(CBBA)3(Phen)(H2O)6, Eu(CBBA)3(TPPO)(H2O)4, Eu(CBBA)3(DPSO)(H2O)5, Tb(CBBA)3(H2O)4, Tb(CBBA)3(Phen)(H2O)3, Tb(CBBA)3(TPPO)(H2O)2 and Tb(CBBA)3(DPSO)(H2O)4, respectively. Then their excitation and emission spectra were measured, and that how the central ions were differently impacted by the three second ligands was also compared. It was easily to be seen that from the spectra all the complexes luminesced with the similar special peaks. However, the luminescence intensity was evidently distinct, because 1,10-phenanthroline, triphenylphosphine oxide and diphenyl sulfoxide were coordinated with them, and exerted different effects on transferring energy to the central ions. In the complexes of europium, Eu(CBBA)3(Phen)(H2O)6 and Eu(CBBA)3(DPSO)(H2O)5 each luminesced more strongly than Eu(CBBA)3(H2O)4, however, Eu(CBBA)3(TPPO)(H2O)4 luminesced more weakly than Eu(CBBA)3(H2O)4. Moreover, Eu(CBBA)3(DPSO)(H2O)5 luminesced more intensely than Eu(CBBA)3(Phen)(H2O)6. So 1,10-phenanthroline and diphenyl sulfoxide could sensitize the luminescence, whereas triphenylphosphine oxide could quench the luminescence in the certain Eu complexes. In Tb complexes, diphenyl sulfoxide sensitized the luminescence of Tb(CBBA)3(DPSO)(H2O)4, and reversely, 1,10-phenanthroline and triphenylphosphine oxide quenched differently the luminescence of Tb(CBBA)3(Phen)(H2O)3 and Tb(CBBA)3(TPPO)(H2O)2. 1,10-phenanthroline quenched more strongly than triphenylphosphine. From IR spectra, the structure of the complexes was conjectured approximately. In the region of 3 200-3 600 cm-1, there were some weak vibrant peaks owed to hydroxyl of water, a good proof that there were water molecules in the complexes themselves..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2904 (2009)
Study on Spectral Emissivity of C/C Composites
ZHU Bo, CAO Wei-wei, JING Min, DONG Xing-guang, and WANG Cheng-guo
Different types of C/C composites were prepared by conventional molding, and the changes in normal spectral emissivity of samples were tested. The testing results show that spectral emissivity of C/C composite reinforced by short cut carbon fibers is generally higher than the sample reinforced by carbon cloth in the enDifferent types of C/C composites were prepared by conventional molding, and the changes in normal spectral emissivity of samples were tested. The testing results show that spectral emissivity of C/C composite reinforced by short cut carbon fibers is generally higher than the sample reinforced by carbon cloth in the entire 2500-13000nm wavelength region. The structure of short cut carbon fibers is relatively loose and the number of material particles is less than other samples in unit volume, which increases the penetration depth of electromagnetic waves. This is the reason for higher normal spectral emissivity and better heat radiation property. Meanwhile, the test results of normal spectral emissivity for fiber perform and C/C composite samples show that the spectral emissivity of resin carbon is better than fiber carbon because of the difference in microstructure for the two kinds of carbon materials. Laser Raman spectroscopy was employed to analyze the microstructures of different carbon materials, and the results show that because sp3 and sp2 hybrid states of carbon atoms in resin carbon produced more vibration modes, the resin carbon also has higher normal spectral emissivity and better characteristics of heat radiation..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2909 (2009)
Spectra Characteristics of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ Phosphor
WANG Zhi-jun, LI Pan-lai, YANG Zhi-ping, and GUO Qing-lin
LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors were synthesized by solid state reaction. The starting materials CaCO3, SrCO3, BaCO3, H3BO3, Li2CO3, Na2CO3, K2CO3 and Tb4O7 (99.99% in mass) in appropriate stoichiometric ratio were mixed in the alumina crucible, then the mixed powders were calcined at 700 ℃ for 2 h, and LiCaBO3∶Tb3LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors were synthesized by solid state reaction. The starting materials CaCO3, SrCO3, BaCO3, H3BO3, Li2CO3, Na2CO3, K2CO3 and Tb4O7 (99.99% in mass) in appropriate stoichiometric ratio were mixed in the alumina crucible, then the mixed powders were calcined at 700 ℃ for 2 h, and LiCaBO3∶Tb3+, LiSrBO3∶Tb3+ and LiBaBO3∶Tb3+ phosphors were obtained. The emission and excitation spectra were measured by a Shimadzu RF-540 ultraviolet spectrophotometer. All the photoluminescence properties of these phosphors were measured at room temperature. The emission spectra of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors show several bands, and the main emission peaks correspond to the 5D4→7F6(486, 486, 488 nm), 5D4→7F5(544, 544, 544 nm), 5D4→7F4(590, 595, 593 nm) and 5D4→7F3(620, 620, 616 nm) typical transitions of Tb3+, and the typical transitions of Tb3+ happens to split because of the effects of LiM(M=Ca, Sr, Ba)BO3 crystals field. The excitation spectra for the 544 nm green emission of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors illuminate that these kinds of phosphors can be effectively excited by ultraviolet (350-410 nm) light, and emit green light, therefore, they are promising phosphors for white light emitting diodes. Effects of activation and charge compensation on the luminescence intensities of LiM(M=Ca, Sr, Ba)BO3∶Tb3+ phosphors were studied, and the results show that the intensities were obviously effected..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2914 (2009)
Investigation on Fourier Transform Infrared Spectrum of Metastatic Lymph Node in Thyroid Cancer
LIU Ya-qi, GAO Mei-juan, XU Yi-zhuang, SUN Qi-gang, ZHANG Xiao-qing, XU Zhi, ZHANG Yuan-fu, WU Jin-guang, ZHOU Xiao-si, and LING Xiao-feng
The aim of the study is to explore the possibility of detecting metastatic lymph nodes by FTIR spectra during the surgery of thyroid cancer. The FTIR spectra of 20 metastatic lymph nodes and 69 non-metastatic ones were collected via an ATR (attenuated total reflectance) probe. For each spectrum, 28 variables of 13 bandThe aim of the study is to explore the possibility of detecting metastatic lymph nodes by FTIR spectra during the surgery of thyroid cancer. The FTIR spectra of 20 metastatic lymph nodes and 69 non-metastatic ones were collected via an ATR (attenuated total reflectance) probe. For each spectrum, 28 variables of 13 bands including peak positions and relative intensities were measured. The variables of metastatic lymph node were compared to those of non-metastatic ones using standard statistic methods. The results indicated that the FTIR spectra of metastatic lymph nodes were significantly different from non-metastatic ones in the bands related to protein,lipid,nucleic acid and carbohydrate. (1) Variations of bands related to protein: The relative intensity ratios of I3 280/I1 460, I1 640/I1 460 and I1 546/I1 460 increased significantly (P＜0.05); (2) Variations of bands related to lipid: The relative intensity ratios of I1 743/I1 460 decreased significantly (P＜0.05). On the contrary, I1 400/I1 460 increased significantly (P＜0.05); (3) The peak positions of 1 165 and 1 120 cm-1 which were all assigned to carbohydrate shifted toward higher wave number (P＜0.05). The relative intensity ratio of I1 165/I1 460 decreased significantly (P＜0.05); (4) The peak positions of 1 085 cm-1 related to nucleic acid shifted to the lower wave number (P＜0.05); (5) Other undetermined bands: The relative intensity ratios of I1 303/I1 460 and I1 303/I1 240 increased significantly (P＜0.05). FTIR spectroscopy could be a reliable and practicable method for metastatic lymph nodes diagnosis in the operation of thyroid cancer. It could be applied in detecting metastatic lymph nodes which can not be determined by palpation in surgery..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2917 (2009)
Near-Infrared Spectral Study on Blood Oxygen Saturation in Multilayer Tissue
GAO Bo, WEI Wei, GONG Min, and WANG Li
The technology of non-invasive near-infrared spectral detection of biological tissue blood oxygen saturation has great research and application prospects, and has widespread clinical applications. However, the conventional finger oximeter only reflects local oxygen saturation values, and has limitations in the applicatThe technology of non-invasive near-infrared spectral detection of biological tissue blood oxygen saturation has great research and application prospects, and has widespread clinical applications. However, the conventional finger oximeter only reflects local oxygen saturation values, and has limitations in the application. These oxygenation readings become unreliable or cease, too. In the present paper, a new method is described that the reflectance pulse oximetry with variable incident light intensity is employed to measure biological multilayer tissue. The photoplethysmographic (PPG) signals significantly change with the change in the incident light intensity in the experiment on the fingertip. Further analysis shows that the changes of the PPG signals correspond to the multilayer structure of finger. It means that the blood oxygen saturation of different tissue level must be calculated from the PPG signals. These features show that this method must be feasible..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2922 (2009)
Comparative Study of Reflectance Spectroscopy of Human Laogong Acupoint and Non-Acupoint Tissues Irradiated by Near-Infrared Laser
ZHANG Zu-de, GUO Zhou-yi, WEI Hua-jiang, LIU Han-ping, ZHONG Hui-qing, YANG Hong-qin, XIE Shu-sen, and LIU Song-hao
Characteristics and differences of reflectance spectroscopy of human Laogong acupoint and non-acupoint tissues before and after irradiation by different power of laser were studied in the spectral range from 400 to 1 000 nm. A wavelength 808 nm semiconductor laser was used for irradiation at the power of 20, 50 and 100Characteristics and differences of reflectance spectroscopy of human Laogong acupoint and non-acupoint tissues before and after irradiation by different power of laser were studied in the spectral range from 400 to 1 000 nm. A wavelength 808 nm semiconductor laser was used for irradiation at the power of 20, 50 and 100 mW for ten minutes. Reflectance spectra of human Laogong acupoint and non-acupoint tissues were measured by using an AvaSpec-2048 optical fiber spectroscopy with an integrating sphere attachment. The result shows that before irradiation the shape of the reflectance spectra of Laogong acupoint and non-acupoint is similar, they have the same troughs at 423, 544, 577 and 980 nm, and the reflectance for Laogong acupoint and non-acupoint at these wavelengths is 17.1%, 26.1%, 25.9% and 35.0%, and 17.1%, 27.6%, 28.1% and 36.5% respectively. But from 475 to 1 000 nm, the reflectance of Laogong acupoint is smaller than that of non-acupoint. After being irradiated by semiconductor laser at the power of 20, 50 and 100 mW, there is a very significant decrease in the reflectance of Laogong acupoint compared to that before irradiation, and the higher the power, the lower the reflectance. But there is just a small decrease in the reflectance for non-acupoint compared to that before irradiation. From the above results, it is clearly seen that Laogong acupoint is different from non-acupoint on reflectance spectroscopy, and Laogong acupoint is more sensitive to laser irradiation than non-acupoint tissue..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2930 (2009)
Feasibility of Using NIR Spectroscopy to Detect Melamine in Milk
DONG Yi-wei, TU Zhen-hua, ZHU Da-zhou, LIU Ya-wei, WANG Ya-nan, HUANG Jin-li, SUN Bao-li, and FAN Zhong-nan
In the present study, 22 certified milk samples without melamine were collected, then 50 adulterated milk samples with added different content of melamine (0.1-1 500 mg·kg-1) were prepared. The near-infrared (NIR) spectra of these milk samples were measured. The possibility of using NIR spectra to detect melamine In the present study, 22 certified milk samples without melamine were collected, then 50 adulterated milk samples with added different content of melamine (0.1-1 500 mg·kg-1) were prepared. The near-infrared (NIR) spectra of these milk samples were measured. The possibility of using NIR spectra to detect melamine in milk was studied. Partial least square regression (PLSR) was applied to construct the calibration model between NIR spectra and the content of melamine. The results showed that NIR spectroscopy can not accurately predict the content of melamine because of its poor detection limit. However, the combination of NIR spectra and partial least square-discriminate analysis (PLS-DA) was applied to differentiate the certified milk samples and the adulterated milk sample. The classification accuracy was 100%. Therefore, NIR spectra could be used to preliminarily detect whether the milk was adulterated with melamine. As a complementary detecting method to the high performance liquid chromatography (HPLC), NIR spectra could improve the detecting efficiency of milk..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2934 (2009)
Fast Determination of Melamine Content in Milk Base on Vis/NIR Spectroscopy Method
YUAN Shi-lin, HE Yong, MA Tian-yun, WU Di, and NIE Peng-cheng
In order to investigate the feasibility of near infrared reflectance spectroscopy (NIRS) method for detecting if milk was adulterated with melamine or not, the present work has done the following research. Through adulterating different content of melamine into pure milk, altogether 160 samples were prepared. Using theIn order to investigate the feasibility of near infrared reflectance spectroscopy (NIRS) method for detecting if milk was adulterated with melamine or not, the present work has done the following research. Through adulterating different content of melamine into pure milk, altogether 160 samples were prepared. Using the Handheld Field Spec spectrometer spectral data of the samples were obtained, followed by different pretreatment methods to carry on processing the spectrum data, then establishing the mathematical model separately through comparison with different calibration models using different pretreatment methods, thus we got smoothing of moving average as the pretreatment method. One hundred twenty samples were taken out randomly from 160 samples (all) to set model, with the remaining 40 samples as the validation samples. Two discriminant analysis models were developed by using partial least squares (PLS) method and least squares-support vector machine (LS-SVM) method respectively, and then the other 40 samples were used to test the performance of the models. The coefficients of correlation (r) between the real values and the discriminant analysis models predicted ones were 0.917 4 (PLS) and 0.910 9 (LS-SVM). The root mean standard errors of prediction (RMSEP) were 0.030 4 (PLS) and 0.046 7 (LS-SVM). The results of this study indicated that NIRS method could provide rapid determination for melamine in milk..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2939 (2009)
Research on Discrimination Method of Tomato via Space Mutation Breeding Based on Spectroscopy Technology
SHI Jia-hui, SHAO Yong-ni, HE Yong, LI Duo, FENG Pan, and ZHU Jia-jin
In order to quickly analyze varieties of tomato via space mutation breeding with near infrared spectra, firstly, principal component analysis was used to analyze the clustering of tomato leaf samples, and then abundant spectral data were compressed by wavelet transform and the model was built with radial basis functionIn order to quickly analyze varieties of tomato via space mutation breeding with near infrared spectra, firstly, principal component analysis was used to analyze the clustering of tomato leaf samples, and then abundant spectral data were compressed by wavelet transform and the model was built with radial basis function neural network, which offered a quantitative analysis of tomato varieties discrimination. The model regarded the compressed data as the input of neural network input vectors and the training process speeded up. One hundred and five leaf samples of CK, M1 and M2 were selected randomly to build the training model, and forty five samples formed the prediction set. The discrimination rate of 97.8% was achieved by this method. It offered a new approach to the fast discrimination of varieties of tomato via space mutation breeding..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2943 (2009)
FTIR Spectroscopic Investigation of Normal and Malignant Pleomorphic Adenoma
ZHU Jing-ping, ZHANG Yun-yao, LI Yan, HU Hao-tun, LI Bin, and XIANG Rong
The FTIR (Fourier transform infrared) spectra of malignant pleomorphic adenoma tissues and surrounding normal tissues were investigated using the Spectrum GX FTIR Spectrometer. The results indicate that there were differences in the Fourier transform infrared spectra between the malignant pleomorphic adenoma tissues anThe FTIR (Fourier transform infrared) spectra of malignant pleomorphic adenoma tissues and surrounding normal tissues were investigated using the Spectrum GX FTIR Spectrometer. The results indicate that there were differences in the Fourier transform infrared spectra between the malignant pleomorphic adenoma tissues and the surrounding normal tissues at some bands. (a) Amide I band location related to the protein in milignant pleomorhic adenoma tissues shifted to a higher wave number compared to the normal tissues, and the absorption was increased in tumor tissues. This indicates that the degree of hydrogen-bonding herein increased; (b) The peak position related to PO2-1 group in nucleic acid shifted to a higher wave number after canceration, and the absorption was stronger in tumor tissues compared to the normal tissues; (c) The absorption of band 1 640 cm-1 related to —CH2 group in lipid was stronger but its peak position shifting was disorder..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2947 (2009)
Choice of Characteristic Near-Infrared Wavelengths for Soil Total Nitrogen Based on Successive Projection Algorithm
GAO Hong-zhi, LU Qi-peng, DING Hai-quan, and PENG Zhong-qi
The present paper proposed how to select characteristic near-infrared wavelength for soil total nitrogen by using successive projection algorithm (SPA). Spectral data are compressed by SPA in the first place to obtain the raw wavelengths. Then the group of wavelengths derived from SPA is screened by their contributionsThe present paper proposed how to select characteristic near-infrared wavelength for soil total nitrogen by using successive projection algorithm (SPA). Spectral data are compressed by SPA in the first place to obtain the raw wavelengths. Then the group of wavelengths derived from SPA is screened by their contributions to the total nitrogen. The insensitive wavelengths for total nitrogen are eliminated, improving the parsimony of the calibration model. For the 85 soil samples in total nitrogen, SPA was used to select the raw wavelengths. After screening on contribution, the number of wavelengths dropped from 12 by direct SPA to 6. Finally, the calibration model using wavelengths selected by screening on contribution after SPA showed the correlation coefficient (Rp) of 0.913 and the root mean square error of prediction (RMSEP) of 0.011%. This model is as precise as the one before screening on contribution, and more precise than the result derived from partial least square (PLS) for the whole spectrum. The results demonstrate that the number of wavelengths selected by SPA can be reduced without significantly compromising prediction performance using the screening on contribution. The 6 selected total nitrogen wavelengths in this paper can be a reference for designing smart filter NIR spectrometer..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2951 (2009)
Fast Catalogue of Alien Invasive Weeds by Vis/NIR Spectroscopy
YU Jia-jia, ZOU Wei, HE Yong, and XU Zheng-hao
The feasibility of visible and short-wave near-infrared spectroscopy (VIS/WNIR) techniques as means for the nondestructive and fast detection of alien invasive weeds was evaluated. Selected sensitive bands were found validated. In the present study, 3 kinds of alien invasive weeds, Veronica persica, Veronica polita, anThe feasibility of visible and short-wave near-infrared spectroscopy (VIS/WNIR) techniques as means for the nondestructive and fast detection of alien invasive weeds was evaluated. Selected sensitive bands were found validated. In the present study, 3 kinds of alien invasive weeds, Veronica persica, Veronica polita, and Veronica arvensis Linn, and one kind of local weed, Lamiaceae amplexicaule Linn, were employed. The results showed that visible and NIR (Vis/NIR) technology could be introduced in classification of the alien invasive weeds or local weed with the similar outline. Thirty×4 weeds samples were randomly selected for the calibration set, while the remaining 20×4 samples for the prediction set. Smoothing methods of moving average and standard normal variate (SNV) were used to pretreat spectra data. Based on principal components analysis, soft independent models of class analogy (SIMCA) were applied to make the model. Four frontal principal components of each catalogues were applied as the input of SIMCA, and with a significance level of 0.05, recognition ratio of 78.75% was obtained. The average prediction result is 90% except for Veronica polita. According to the modeling power of each spectra data in SIMCA, some possible sensitive bands, 496-521, 589-626 and 789-926 nm, were founded. By using these possible sensitive bands as the inputs of least squares support vector machine (LS-SVM), and setting the result of LS-SVM as the object function value of genetic algorithm (GA), mutational rate, crossover rate and population size were set up as 0.9, 0.5 and 50 respectively. Finally, recognition ratio of 95.63% was obtained. The prediction results of 95.63% indicated that the selected wavelengths reflected the main characteristics of the four weeds, which proposed a new way to accelerate the research on cataloguing alien invasive weeds..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2955 (2009)
Study on the Application of Supervised Principal Component Regression Procedure to Near-Infrared Spectroscopy Quantitative Analysis
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The present paper introduces the principle of a new modeling method, called supervised principal component regression, with which the model of the near-infrared (NIR) spectroscopy quantitative analysis was established. Usually, there are many difficulties such as collinearity when establishing the quantitative analysisThe present paper introduces the principle of a new modeling method, called supervised principal component regression, with which the model of the near-infrared (NIR) spectroscopy quantitative analysis was established. Usually, there are many difficulties such as collinearity when establishing the quantitative analysis model for the high dimension of the spectral data. Using this new method, firstly according to some criterion, the wavelength information is selected in order to reduce the dimension of spectral data. Then the selected lower dimensional spectral data set is used to establish the principal component regression model. Taking sixty-six wheat samples as experiment materials, forty samples were chosen randomly to establish the predicting model, while the remaining twenty-sixth wheat samples were viewed as prediction set. In this example, 4 wavelengths, 4 632, 4 636, 5 994 and 5 997 cm-1, were selected at first according to the coefficients between the response variable and each spectral data. Then two principal components of the spectral data at those four wavelengths were extracted to establish the principal component regression model. The model was used to the prediction set. The coefficient was 0.991 and the average relative error was 1.5% between the model predication results and Kjeldahl’s value for the protein content. It is very important to select the most significant part of wavelength information from a large number of spectral data, not only because this procedure can alleviate the influence of collinearity in modeling, but also because it can be used to guide the design of special NIR analysis instrument for analyzing specific component in some samples..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2959 (2009)
Study on Temperature Correction of Near-Infrared Spectra of Solution
CHEN Yun, SHI Zhen-zhi, XU Ke-xin, and CHEN Wen-liang
The near-infrared spectrum of some common solvents, such as water, has very high sensitivity to temperature. So, the effect of temperature can not be ignored in NIRS. When temperature changes, the transmission spectra of the solution will also change. The influence of the temperature was deduced theoretically based on The near-infrared spectrum of some common solvents, such as water, has very high sensitivity to temperature. So, the effect of temperature can not be ignored in NIRS. When temperature changes, the transmission spectra of the solution will also change. The influence of the temperature was deduced theoretically based on the Lambert-Beer’s law in the present paper. And a method for temperature correction of sample’s spectra was proposed. By using the change in pure solvent’s absorbency with temperature disturbance, the method is used to correct the spectra of prediction samples. The spectra of glucose aqueous solution and albumin aqueous solution were measured at different temperatures. The calibration models of glucose and albumin concentration prediction were built respectively by using the calibration sample’s spectra at 30 ℃. The absorbency of pure water has different value at different temperature, and this difference was used to correct the spectra of sample which was measured at temperatures other than 30 ℃. The experiment results showed that the curves of absorbancy difference of prediction samples, which were measured at different temperatures, show good superposition after spectra correction. And the root mean square error (RMSEP) of prediction was reduced obviously. It also means that the influence of temperature on the spectra can be eliminated effectively after spectra correction by using the method proposed in this paper..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2966 (2009)
Study on the Projection Method Based on Principal Component of Tobacco Near-Infrared Spectrum and Application in Redrying Model
TAO Shuai, MA Xiang, LI Jun-hui, ZHANG Wen-juan, ZHAO Long-lian, WEN Ya-dong, WANG Yi, and ZHANG Lu-da
The present paper briefly describes the application of near-infrared spectroscopy technology in tobacco. Two methods for solving projection vector based on the principal component of near-infrared spectrum are reported. They are named as projection of basing on principal component and Fisher criterion by principal compThe present paper briefly describes the application of near-infrared spectroscopy technology in tobacco. Two methods for solving projection vector based on the principal component of near-infrared spectrum are reported. They are named as projection of basing on principal component and Fisher criterion by principal component analysis method (PPF_PCA for short) and projection of basing on principal component and Fisher criterion by solving eigenvalue (PPF_Eig for short), and they are studied and compared in the application and evaluation of the redrying model. The result of the first-dimensional projection on 9 kinds of tobacco leaf grading samples shows that, the diversity of the first-dimensional projection values of inter-class and intra-class by the PPF_PCA method is both larger than that by the PPF_Eig method, and the mean absolute deviation of the mean projection values of inter-class by the PPF_PCA method is about 1.26 times that of the PPF_Eig method. At the same time, this result is interpreted by using the contribution rate of the first-dimensional projection values. That is, the contribution rate of first-dimensional projection values by the PPF_PCA method is 93%, while the contribution rate of first-dimensional projection values by the PPF_Eig method is 77%. The former is about 1.21 times the later. Therefore, the first-dimensional projection values by PPF_PCA method include more information of diversity of both inter-class and intra-class. The similarity of samples inter-class and the diversity of samples intra-class can be evaluated more objectively from first-dimensional projection figure（on 9 kinds of tobacco leaf grading samples, 33 kinds of tobacco leaf grading samples and 6 redrying blending models）, so it is more convenient to be used as a reference for the redrying model of tobacco, and it has a good application prospect in other formulation design of agricultural products (traditional Chinese medicine etc.).
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2970 (2009)
Study of Density Functional Theory (DFT) for Raman Spectra of CH3OLi and CH3CH2OLi
YU Hong-jing, LIU Zhao-jun, YIN Yan-feng, FU Juan, DING Li, and MO Yu-jun
Molecular configurations of CH3OLi and CH3CH2OLi were structured based on the previous study that lithium atom and oxygen atom are directly joined by O-Li bond in alkoxy lithium (ROLi). Neither experimental nor theoretical Raman spectra of CH3OLi and CH3CH2OLi have been reported up to now. In the present paper, DFT metMolecular configurations of CH3OLi and CH3CH2OLi were structured based on the previous study that lithium atom and oxygen atom are directly joined by O-Li bond in alkoxy lithium (ROLi). Neither experimental nor theoretical Raman spectra of CH3OLi and CH3CH2OLi have been reported up to now. In the present paper, DFT method at the B3LYP/ 6-31G(d,p) level was used to optimize molecular configurations of CH3OLi and CH3CH2OLi, obtaining each corresponding equilibrium configuration. Vibration frequencies and Raman spectra of these two molecules were calculated based on equilibrium configuration. The vibration frequencies of obtained calculated results were analyzed by normal coordinate analysis. Besides, the Raman vibration modes of CH3OLi and CH3CH2OLi were assigned according to potential energy distribution of each vibration frequency, which will provide theoretical basis for experimental workers to analyze the components of solid electrolyte interface film (SEI film) of lithium ion battery..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2975 (2009)
Study on the Interaction of DNA and Norfloxacin by FT-Raman
REN Yi-hua, ZHOU Guang-ming, WU Jie, and YU Dan-ni
FT-Raman and surface enhanced Raman spectra (SERS) of norfloxacin and norfloxacin capsule on the silver colloidal substrate were recorded, and the vibrational and enhanced peaks were assigned; interactions of norfloxacin and DNA were researched. The experimental results proved that the characteristic vibrations of capsFT-Raman and surface enhanced Raman spectra (SERS) of norfloxacin and norfloxacin capsule on the silver colloidal substrate were recorded, and the vibrational and enhanced peaks were assigned; interactions of norfloxacin and DNA were researched. The experimental results proved that the characteristic vibrations of capsule’s content and NFX standard, which is ν(C—F), νs（O—C—O）, ν(CC), did not change, while the changes in molecular skeleton’s vibrations were substantial. Additives do not affect the Raman spectroscopy of norfloxacin substantively. An analytical method for detecting norfloxacin medcine can be established by FT-Raman. Without any ions,the interaction is mainly caused by the inserting-action mode between the ring of norfloxacin and the double helix structure of DNA, and norfloxacin could interact with DNA directly, providing reliable evidence for antibacterial mechanism of quinoxalone antibiotics..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2980 (2009)
Electrochemical Deposition of Silver by Using Ionic Liquids as Additive and Its Surface-Enhanced Raman Scattering Effect
XU Cun-ying, HUA Yi-xin, DUAN Yun-biao, and ZHANG Peng-xiang
In the present work, the electrochemical deposition of silver was investigated on a glassy carbon electrode from AgNO3 solutions in the presence of RTILs (1-butyl-3-methyl imidazolium nitrate, ［bmim］NO3) additive by cyclic voltammetric technique, scanning electron microscope (SEM) and X-ray photon spectroscopy (XPS). FIn the present work, the electrochemical deposition of silver was investigated on a glassy carbon electrode from AgNO3 solutions in the presence of RTILs (1-butyl-3-methyl imidazolium nitrate, ［bmim］NO3) additive by cyclic voltammetric technique, scanning electron microscope (SEM) and X-ray photon spectroscopy (XPS). For comparison, the electrodeposition of silver from ［bmim］NO3-free AgNO3 solution was also investigated. The voltammograms showed that the cathodic peak potential shifted toward more negative potential and the cathodic peak current decreased when 5×10-6 mol·L-1 ［bmim］NO3 was added into AgNO3 solutions. This indicated that ［bmim］NO3 produced an inhibition of silver deposition, probably related to the adsorption of ［bmim］NO3. SEM images showed that the uniform, shining electrodeposits of silver obtained in AgNO3 solutions were rather compact and that the size of silver grains decreased with the addition of ［bmim］NO3 additive. The surface-enhanced Raman scattering (SERS) activities of silver deposits were measured by using methyl orange (MO) as the probe molecules. The strongly enhanced Raman scattering from the monolayer film of MO demonstrated that the as prepared silver particular film was SERS active. The enhancement factor was calculated to be up to 1.7×105 and 1.1×105 for silver film obtained in AgNO3 solutions with and without ［bmim］NO3 additive, respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2984 (2009)
Application of Raman Spectroscopic Technique to the Identification and Investigation of Chinese Ancient Jades and Jade Artifacts
[in Chinese], [in Chinese], and [in Chinese]
Laser Raman spectroscopic technique is one of the essential methods in scientific archaeological research, which belongs to the nondestructive analysis. As a very good nondestructive analysis approach, it has not been widely applied in the research of the Chinese ancient jade artifacts. First of all in the present papeLaser Raman spectroscopic technique is one of the essential methods in scientific archaeological research, which belongs to the nondestructive analysis. As a very good nondestructive analysis approach, it has not been widely applied in the research of the Chinese ancient jade artifacts. First of all in the present paper the fundamentals of laser Raman spectroscopic technique and the new research progress in this field were reviewed. Secondly, the Raman spectra of five familiar jades including nephrite (mainly composed of tremolite), Xiuyan Jade (mainly composed of serpentine), Dushan Jade (mainly composed of anorthite and Zoisite), turquoise and lapis lazuli were summarized respectively. As for an example, the Raman spectra of the four Chinese ancient jade artifacts excavated from Liangzhu Site of Zhejiang Province and Yinxu Site of Anyang in Henan Province were compared with that of the nephrite sample in Hetian of Xinjiang Province. It was shown that the Raman spectroscopic technique is a good nondestructive approach to the identification and investigation of the structures and mineral composition of Chinese ancient jade artifacts. Finally, the limitations and the foreground of this technique were discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2989 (2009)
Study On Resistance to Motion Artifact in Pulse Oximetry Measurement Using Segment Filter Method
LI Qing-bo, NIE Xin, ZHANG Guang-jun, and WU Jin-guang
The authors proposed a method which combined the differential threshold segment with median filter to eliminate abrupt artifact motion interference in the use of pulse oximeter, and further more, by adding the window moving average filter, this method could reduce the periodic artifact motion interrupt in some way. In The authors proposed a method which combined the differential threshold segment with median filter to eliminate abrupt artifact motion interference in the use of pulse oximeter, and further more, by adding the window moving average filter, this method could reduce the periodic artifact motion interrupt in some way. In the experiment, the authors intently simulated the common finger motion to get the artifact motion “corrupted” signal with our self-made reflectance oximeter system. The comparison of the original PPG signal and processed PPG signal shows that the method we proposed performed well in an effort to reduce the common artifact motion interrupt. Finally, in order to figure out what effort this method can make for the accuracy of oxygen saturation measurement, the ration of AC and DC component in the red and infrared signal directly associated with the pulse oxygen saturation was calculated. The result indicates that this method can reduce the error caused by the artifact motion and stabilize the rate of false reading of pulse oximeter under the finger motion state. More importantly, this method needs only a small calculation cost, so it could be applied in the real-time PPG signal processing without the need of powerful hardware..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2994 (2009)
Spectroscopic Study on Interaction of Rodenticide Brodifacoum with Bovine Serum Albumin
DUAN Yun-qing, LEI Huan-gui, MIN Shun-geng, and DUAN Zhi-qing
The mutual interaction of bovine serum albumin (BSA) with brodifacoum (3-［3-(4’-bromophenyl-4)1,2,3,4-tetralin-10］-4-hydroxyl-coumarin), an anticoagulant rodenticide, was investigated by ultra-violet spectroscopy, flurorescence spectroscopy and synchronous fluorescence spectroscopy under physiological conditions. It waThe mutual interaction of bovine serum albumin (BSA) with brodifacoum (3-［3-(4’-bromophenyl-4)1,2,3,4-tetralin-10］-4-hydroxyl-coumarin), an anticoagulant rodenticide, was investigated by ultra-violet spectroscopy, flurorescence spectroscopy and synchronous fluorescence spectroscopy under physiological conditions. It was proved that the intrinsic fluorescence quenching of BSA by brodifacoum was the result of the formation of brodifacoum-BSA complex. And this quenching is mainly due to static fluorescence quenching. The quenching rate constant (KSV), binding site number (n) and binding constant (KA) at different temperatures were calculated from the double reciprocal Lineweaver-Burk plots and the quenching function of lg［(F0－F)/F］－lg［Q］ plots. The thermodynamic parameters indicated that the process of binding was a spontaneous molecular interaction and the hydrophobic force played a major role in stabilizing the brodifacoum BSA complex. The binding distance r between brodifacoum and BSA was 2.84 and 2.87 nm at 20 and 30 ℃, respectively, which was obtained based on Forster theory of non-radiation energy transfer. The synchronous spectroscopy of BSA and brodifacoum-BSA revealed that the BSA conformation had changed in the presence of brodifacoum. The binding mode and interaction mechanism were suggested as follows: brodifacoum molecules are closed with amino acid residues with electric charge on the hydrophobic cavities of BSA by electrostatic interaction, and binded to the Trp212 residues inside of BSA hydrophobic cavities by hydrophobic interaction force, thereby changed the microenvironment around the Trp residues. The interaction prevented the energy transfer between Tyr and Trp residues, moreover, caused to a non-radiation energy transfer from Trp residues in BSA to brodifacoum, and finally leaded of the quenching the intrinsic fluorescence of BSA..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 2998 (2009)
Estimation of Canopy Chlorophyll Content Using Hyperspectral Data
[in Chinese], [in Chinese], and [in Chinese]
Many researches have developed models to estimate chlorophyl content at leaf and canopy level, but they were species-specific. The objective of the present paper was to develop a new model. First, canopy reflectance was simulated for different species and different canopy architecture using radiative transfer models. BMany researches have developed models to estimate chlorophyl content at leaf and canopy level, but they were species-specific. The objective of the present paper was to develop a new model. First, canopy reflectance was simulated for different species and different canopy architecture using radiative transfer models. Based on the simulated canopy reflectance, the relationship between canopy reflectance and canopy chlorophyll content was studied, and then a chlorophyll estimation model was built using the method of spectral index. The coefficient of determination (Ｒ2) between spectral index based model and canopy chlorophyll content reached 0.75 for simulated data. To investigate the applicability of this chlorophyll model, the authors chose a field sample area in Gansu Province to carry out the measurement of leaf chlorophyll content, canopy reflectance and other parameters. Besides, the authors also ordered the synchronous Hyperion data, a hyperspectral image with a spatial resolution of 30 m. Canopy reflectance from field measurment and reflectance from Hyperion image were respectively used as the input parameter for the chlorophyll estimation model. Both of them got good results, which indicated that the model could be used for accurate canopy chlorophyll estimation using canopy reflectance. However, while using spaceborne hyperspectral data to estimate canopy chlorophyll content, good atmospheric correction is required..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3003 (2009)
Analysis of Spectral Performance of Varied-Doping GaAs Photocathodes
NIU Jun, QIAO Jian-liang, CHANG Ben-kang, YANG Zhi, and ZHANG Yi-jun
For a quantitative analysis of the effect of varied doping structure on the quantum efficiency of cathode, two kinds of reflective gradient doping GaAs photocathode samples were designed and grown respectively. After activation, the dynamic spectral response curves of the two samples were obtained. The spectral responsFor a quantitative analysis of the effect of varied doping structure on the quantum efficiency of cathode, two kinds of reflective gradient doping GaAs photocathode samples were designed and grown respectively. After activation, the dynamic spectral response curves of the two samples were obtained. The spectral response curves were transformed into quantum efficiency curves. The quantum efficiency curves in different wavebands were fit, and the varied doping coefficient K that reflects the contribution of the varied doping structure to the cathode quantum efficiency was obtained. Results show that, the functional effects of the same material varied doping structure responding to the incident photon of different wavebands are different from each other. The same is true for the different material varied doping structures responding to the same waveband incident photon. The fundamental reasons for these differences are that the positions and the intensities of the inside electric fields which build within the materials under different varied doping structures are different from each other. It offers an effective analysis means to evaluate the structure performance of cathodes grown under different doping ways, and has great value for the study on optimization design of cathode varied doping structure..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3007 (2009)
Study on the Preparation and Spectral Characteristics of CeO2 Nanocrystallines
HAN Qiao-feng, CHEN Liang, QIANG Fei, ZHU Wen-chao, XU Bing, and WANG Xin
Ceria (CeO2) nanoparticles were prepared by precipitation method using cerium nitrate（Ce(NO3)3·6H2O）and ammonia (25 Wt%) as raw materials under the reaction for 3 h and ageing for 9 h at 80 ℃ without any surfactants and further calcination. The powder X-ray diffraction (XRD) pattern shows the as-prepared CeO2 crysCeria (CeO2) nanoparticles were prepared by precipitation method using cerium nitrate（Ce(NO3)3·6H2O）and ammonia (25 Wt%) as raw materials under the reaction for 3 h and ageing for 9 h at 80 ℃ without any surfactants and further calcination. The powder X-ray diffraction (XRD) pattern shows the as-prepared CeO2 crystals belong to the cubic phase and are well crystallized. Transmission electron microscopic (TEM) studies reveal that the appearance of as-prepared CeO2 is hexagonal, which is proposed to be the projection of polyhedral shape. The regular fringes spacing of 0.31 nm is in agreement with the d value of (111) lattice planes of cubic phase CeO2 from high-magnification TEM image. Reaction conditions such as the concentration of precipitant, reaction temperature and ageing duration exert important influence on the purity and morphology of the product. Ce(OH)3 was detected when the reaction was processed at lower pH(＜9) or with ageing duration less than 8 h at 80 ℃. The size of polyhedral ceria nanoparticles increased with longer ageing time (＞15 h). If the reaction went on at a temperature lower than 40 ℃, a large quantity of rodlike Ce(OH)3 was produced according to TEM observation. Raman spectra of CeO2 nanocrystallines exhibit a Raman shift at 465 cm-1, corresponding to a F2g Raman band from the space group Fm3m of a cubic fluorite structure, while the Raman shift at about 600 cm-1 may be attributed to the second Raman vibration mode of O2- vacancy due to Ce3+ impurity. Photoluminescence spectrum of CeO2 shows an emission at 465 nm at room temperature, which may be explained by charge transition from the 4f band to the valence band of CeO2..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3011 (2009)
A CMOS Vertically Integrated Device for Monochromatic Spectrum Detection
CHEN Yuan, XU Zhi-hai, and FENG Hua-jun
A vertically integrated sensor based on standard CMOS process, which can detect the wavelength of the monochromatic spectrum, was designed, manufactured and tested. It took the advantage of the two-layer structure of the device which can sense short wavelength and long wavelength illumination (among near UV, visible anA vertically integrated sensor based on standard CMOS process, which can detect the wavelength of the monochromatic spectrum, was designed, manufactured and tested. It took the advantage of the two-layer structure of the device which can sense short wavelength and long wavelength illumination (among near UV, visible and near IR) simultaneously,then through these two different responses, the final device response showed monotonically increasing with the wavelength, and the wavelength can be known through this monotonicity. First we introduced the basic principle of the device, then the ideas in test device design were given. Finally, the authors measured the manufactured device, and the QEs of the device and the monotonic relationship between the device and the wavelength of the monochromatic spectrum were given..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3015 (2009)
Study on the Main Influencing Factors of Black Soil Spectral Characteristics
LIU Huan-jun, YU Wan-tai, ZHANG Xin-le, MA Qiang, ZHOU Hua, and JIANG Zi-shao
To develop soil properties quick measuring methods, promote the development of quantitatively remote sensing studies relating to terrestrial ecosystem, and deepen the application of remote sensing in agriculture, the hyperspectral reflectance of black soil in Songnen Plain, northeast China, was analyzed with spectral aTo develop soil properties quick measuring methods, promote the development of quantitatively remote sensing studies relating to terrestrial ecosystem, and deepen the application of remote sensing in agriculture, the hyperspectral reflectance of black soil in Songnen Plain, northeast China, was analyzed with spectral analysis methods (continuum removal, spectral angle match and spectral feature fitting) and statistic methods to discover the reflectance spectral characteristics and its influencing factors. The results are as follows: the soil parent material determines the basic characteristics of reflectance of the black soil, which is the mixture of montmorillonite and illite, and consistent with mineral analysis result. Organic matter is the main factor determining the curve shape of black soil reflectance in the region shorter than 1 000 nm, and indirectly influencing the reflectance in the region longer than 1 000 nm because of the correlation with soil moisture and mechanical composition. The varying process of soil reflectance with changing soil moisture can be quantitatively described with cubic equation, and moisture mainly changes the reflectance value but not the curve shape. Black soil reflectance is not influenced significantly by Fe, which is different from soils of south China. Roughness mainly impacts on the soil reflectance value but not the shape feature. The spectral feature of straw reflectance is remarkably different to that of black soil, and impacts on both the value and curve shape of black soil reflectance. Different soil tillage measurements result in different moisture holding ability and the amount of straw for different farm fields, and influence the reflectance further, with the order of soil reflectance from high to low is: no tillage, moldboard tillage, combination tillage, reduced tillage, and rotary tillage..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3019 (2009)
3D Temperature Field Reconstruction of Ar Plasma Jet Using CCD Spectrum Tomography Technology
XING Jian, WAN Xiong, SUN Xiao-gang, DAI Jing-min, and GAO Yi-qing
For realizing real-time 3D temperature field reconstruction of Ar plasma jet, an orthogonal area array CCD (charge coupled device) spectrum tomography experimental system was proposed according to spectrum relative intensity diagnosis method. The size of tested field was measured using comparison between the tested fieFor realizing real-time 3D temperature field reconstruction of Ar plasma jet, an orthogonal area array CCD (charge coupled device) spectrum tomography experimental system was proposed according to spectrum relative intensity diagnosis method. The size of tested field was measured using comparison between the tested field image caught through CCD and the plotting paper image when plotting paper was placed in the tested field position with no plasma jet; the emission intensity distribution of tested field was obtained using stepping motor taking fiber probe to scan tested field, and the spectrum analysis instrument was used to show the spectrum intensity information. Based on spectrum selection principle of the spectrum relative intensity method, spectra at 696.5 and 763.5 nm were studied as characteristic spectrum. Novel grad attenuation was designed based on the size and intensity distribution of tested field for not exceeding limen of CCD and avoiding the spectrum information loss at tested field edge. The narrowband filter was set between grad attenuation and CCD, so the whole tested spectrum information can be stored in computer real-time. According to orthogonal two-view spectrum tomography reconstruction algorithm, when tested field is axially symmetric, the reconstruction result is well. So four area array CCDs is placed orthogonally, and the same spectrum narrowband filters are placed in front of two orthogonal CCDs to reconstruct 3D emissivity factor field. Based on the 3D emissivity factor field and spectrum relative intensity theory, 3D temperature field of the tested field was reconstructed satisfactorily. The reconstruction result showed that it agreed with the results from fiber scanning diagnosis system, and the uncertain degreed is 3.3%. The proposed experimental device meets the needs of real-time 3D temperature field reconstruction. It provided a stable base for real-time diagnosis of plasma jet density field, pressure field and velocity field..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3023 (2009)
Study on the Influence of Mineralizer on the Structures and Spectral Properties of Calcium Aluminates
ZHENG Huai-li, LIU Jun-yu, LI Lin-tao, and LI Fang
The present paper investigated the effect of mineralizer on the structure and properties of calcium aluminates formation. Calcium aluminates powder was synthesized under high temperature calcination by mixing bauxite, limestone and a certain amount of mineralizer. The product structure, compositional information and spThe present paper investigated the effect of mineralizer on the structure and properties of calcium aluminates formation. Calcium aluminates powder was synthesized under high temperature calcination by mixing bauxite, limestone and a certain amount of mineralizer. The product structure, compositional information and spectral properties were carefully characterized by XRD, IR and DTA-TG, and the mineralization mechanism of mineralizer was studied during the process of calcium aluminates preparation. The results showed that calcium aluminates powder could be obtained under lower temperature calcination after adding mineralizer to the raw materials. The main products of the reaction were CaAl10O18 and CaAl2Si2O8 without mineralizer, however, the main products of the reaction were CaAl3BO7 and Ca3Al10O18 with mineralizer, in which Al2O3 could be extracted easily, while CaAl2Si2O8 was reduced greatly in which Al2O3 could not be extracted easily. At the same time, it is easy for calcspar to decompose after adding mineralizer. It is favorable to Al—Si bond break and Al stripping from bauxite .These facts could improve the extraction rate of Al2O3 from raw materials. Also, in the case of adding mineralizer to the raw mixes, the crystal structure and composition are changed, which is beneficial to reducing calcination temperature..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3028 (2009)
Features for Leaves of Pinus Massoniana Forest
DU Hua-qiang, GE Hong-li, FAN Wen-yi, JIN Wei, ZHOU Yu-feng, and LI Jin
In the present study, the authors built the relationships between the total chlorophyll and hyperspectral features of P. massoniana. The research results showed that (1) chlorophyll content has a good linear relationship with spectral reflectance around 527, 703, 1 364 and 1 640 nm, and this result is helpful for us toIn the present study, the authors built the relationships between the total chlorophyll and hyperspectral features of P. massoniana. The research results showed that (1) chlorophyll content has a good linear relationship with spectral reflectance around 527, 703, 1 364 and 1 640 nm, and this result is helpful for us to select some important bands when monitoring P. massoniana by remote sensing image; (2) all of the nine kinds of spectral feature parameters including red edge position, mean reflectance of red edge, mean reflectance around red edge position, red edge slope, red edge area, absorption depth of red band,green peak height, red edge normalized difference vegetation index and red edge vegetation stress index, have exponential function relationship (r=0.5-0.7) with the total chlorophyll; (3) the total chlorophyll content can be predicted by multivariate model by the nine spectral feature parameters, and partial least-squares regression model have higher prediction accuracy than the traditional multivariate linear model. The model’s root mean square (RMS) is 0.008 8, and mean absolute percentage error is 0.761 7%. During the growth of vegetation, biochemical parameters such as chlorophyll have vital function, for example, it can indicate the health status or pathological feature. So, the models mentioned just above will help us understand the ecological process of P. massoniana forest and provide valuable reference for monitoring P. massoniana and pine wood nematode disease by remote sensing technique..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3033 (2009)
Determination of Nutrient Elements in Transgenic Insect-Resistant Cotton Tissues by Three Different Spectroscopical Methods
SUN Cai-xia, ZHANG Yu-lan, SUN Yu-quan, YANG Lei, WANG Jie, and CUI Zhen-bo
In order to find out the effects of exogenous genes, such as Bt and Bt coupled with CpTI, on nutrition metabolism in transgenic plants, totally eleven types of nutrient elements in transgenic Bt (Z30) and Bt-CpTI (CCRI41 and SGK321) cotton were determined using methods of flame atomic absorption spectroscopy, flame atoIn order to find out the effects of exogenous genes, such as Bt and Bt coupled with CpTI, on nutrition metabolism in transgenic plants, totally eleven types of nutrient elements in transgenic Bt (Z30) and Bt-CpTI (CCRI41 and SGK321) cotton were determined using methods of flame atomic absorption spectroscopy, flame atomic emission spectroscopy and spectrophotometry at flowering stage and boll-opening stage. The results showed that the chemical composition of plant nutrition in transgenic insect-resistant cotton differed in comparison with non-transgenic cotton counterparts related to varieties, tissues and stages. The content of total N in transgenic cotton changed most significantly. Especially, it increased by 21% for transgenic Bt cotton Z30 compared to non-transgenic cotton Z16. These changes in total N content were probably caused by both transgenes expression in transgenic cotton and other processes not studied in this experiment. The content of Mg, Na and Cu in transgenic cotton varied significantly only in some certain varieties or tissues. It was unobvious how the incorporation of transgenes impacted on the content of organic C, total P, total S, K, Ca, Fe and Zn in transgenic cotton. The authors speculated that there were no significant changes in utilization and accumulation of these nutrient elements between transgenic insect-resistant cotton and their non-transgenic cotton counterparts (Z16, CCRI23 and SY321, respectively)..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3038 (2009)
Recognition of Cucurbit［7 and 8］urils Toward Methylene Blue with Spectroscopy
FENG Yan, XUE Sai-feng, MU Lan, ZHU Qian-jiang, and TAO Zhu
The molecular recognition of cucurbit［7, 8］urils toward a methylene blue dye was investigated by using electronic absorption spectroscopy and fluorescence spectroscopy. The experimental results revealed that the formation of host-guest complexes between Q［7］ and the methylene blue dye were formed with a stoichiometry oThe molecular recognition of cucurbit［7, 8］urils toward a methylene blue dye was investigated by using electronic absorption spectroscopy and fluorescence spectroscopy. The experimental results revealed that the formation of host-guest complexes between Q［7］ and the methylene blue dye were formed with a stoichiometry of 2∶1, while the formation of host-guest complexes between Q［8］ and the methylene blue dye were formed with a stoichiometry of 1∶2. The calculated binding constants are KQ［7］-g=1.34×1012 L2·mol-2 and KQ［8］-g=5.34×1012 L2·mol-2 respectively based on the absorption spectrophotometric analysis, while the calculated binding constants are KQ［7］-g=1.53×1012 L2·mol-2 and KQ［8］-g=6.11×1012 L2·mol-2 respectively based on the fluorescence spectroscopy analysis. The values of K are reasonably consistent. The fluorescence of the guest was found to rapidly increase with the increase in the concentration of Q［7］, while the fluorescence of the guest was found to rapidly decrease with the increase in the concentration of Q［8］. Based on the variation of the absoption or fluorecence of the host-guest complexes of Q［7］ or Q［8］-methylene blue dye with the variation of pH, the interaction of the Q［7］ or Q［8］ and the methylene blue dye with an unchangeable ratio can be observed in the range of pH between 0.5 and 13..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3042 (2009)
Development of Photothermal Microactuator Based on Spectral Analysis of Photothermal Expansion Material
LIU Chao, ZHANG Dong-xia*, and ZHANG Hai-jun
The spectral characteristic of materials is the key factor of the photothermal microactuator’s performance. The present article introduces the operating principle, and analyzes the relationship between the material spectral characteristic and its expansion. As the photothermal microactuator is an innovative microactuatThe spectral characteristic of materials is the key factor of the photothermal microactuator’s performance. The present article introduces the operating principle, and analyzes the relationship between the material spectral characteristic and its expansion. As the photothermal microactuator is an innovative microactuator based on photothermal expansion that absorbs the laser energy and converts it into internal energy to realize the microdrive, the optimal photothermal expansion material with proper absorption spectrum characteristic matching the spectrum of light driving source needs to be found. The reflection and absorption spectra of four types of polymeric material, including PVC, HDPE, LDPE and PET, were obtained by using the single integrating sphere method. The results indicate that the reflection spectrum of the dyed high-density polyethylene (HDPE) is of double-peak structure in visible band, and there is strong absorption within the range of 600-690 nm, which means it would match the light driving source quite well in the broad spectral range. Therefore, HDPE was chosen as the photothermal expansion material. In order to check out the feasibility and performance of the photothermal microactuactor based on HDPE, a prototyping microactuator 1 500 mm in length and 30 mm in thickness was manufactured by using an excimer laser micromachining system. With a laser diode (10 mW/650 nm) as the external power source to activate the microactuator, performance measurement experiments were carried out by using a self-produced video movement measurement system with a CCD-coupled microscope. The experiment results demonstrate that the deflection of the microactuator reaches 18.7 mm at 10 mW of laser power, showing that the characteristics of spectral absorption and light-heat transition are quite well at 650 nm. This novel photothermal microactuator has simple structure, adjustable displacement output, and more mobility, and can be controlled remotely, so it will be quite useful for applications in the fields of micro-optical-electro-mechanical systems (MOEMS)..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3047 (2009)
Investigation of Interaction between Catechin and Bovine Serum Albumin by Spectroscopic Methods
ZHANG Hai-rong, BIAN He-dong, PAN Ying-ming, TIAN Jian-niao, YU Qing, LIANG Hong, and CHEN Zhen-feng
In the present work, the interaction of catechin with bovine serum albumin (BSA) under physiological condition was studied by fluorescence quenching spectra in combination with Fourier transform infrared (FTIR) spectroscopy. The binding constants, the drug-binding mode, the binding site between catechin and BSA in aqueIn the present work, the interaction of catechin with bovine serum albumin (BSA) under physiological condition was studied by fluorescence quenching spectra in combination with Fourier transform infrared (FTIR) spectroscopy. The binding constants, the drug-binding mode, the binding site between catechin and BSA in aqueous solution at pH 7.40, and the effect of common ions were studied. The results show that catechin has the ability to quench the intrinsic fluorescence of BSA because of a complex formed, and the quenching mechanism is static quenching. The binding constants K under 296, 303 and 310 K were 2.368, 2.249 and 2.152×106 L·mol-1 respectively. The thermodynamic parameters showed that the interaction between catechin and BSA was driven mainly by hydrophobic force and electrostatic interaction. The displacement experiment shows that catechin can bind to the site Ⅰ of BSA. The distance between the 214 tryptophan residues in BSA and catechin was estimated to be 1.46 nm using Fster’s equation on the basis of fluorescence energy transfer. According to FTIR, the secondary structure of BSA changed when catechin was added..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3052 (2009)
Real-Time Forecasting Model for Monitoring Pollutant with Differential Optical Absorption Spectroscopy
LI Su-wen, LIU Wen-qing, XIE Pin-hua, WANG Feng-sui, and YANG Yi-jun
For real-time and on-line monitoring DOAS (differential optical absorption spectroscopy) system, a model based on an improved Elman network for monitoring pollutant concentrations was proposed. In order to reduce the systematical complexity, the forecasting factors have been obtained based on the step-wise regression mFor real-time and on-line monitoring DOAS (differential optical absorption spectroscopy) system, a model based on an improved Elman network for monitoring pollutant concentrations was proposed. In order to reduce the systematical complexity, the forecasting factors have been obtained based on the step-wise regression method. The forecasting factors were current concentrations, temperature and relative humidity, and wind speed and wind direction. The dynamic back propagation (BP) algorithm was used for creating training set. The experiment results show that the predicted value follows the real well. So the modified Elman network can meet the demand of DOAS system’s real time forecasting..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3057 (2009)
Determination of Trace Copper(Ⅱ) Based on Fluorescence Quenching of NaGdF4∶Eu Nanoparticles
YU Yong-li, LIU Yan, XU Shu-kun, WANG Nai-zhi, and ZHAI Han
Water-soluble NaGdF4∶Eu fluorescent nanoparticles modified by citrate were synthesized by hydrothermal method with stable fluorescent properties. It was found that the fluorescence of the solution of as-prepared particles could be quenched by Cu2+, and thus a new mathod to determine trace Cu2+ using NaGdF4∶Eu as fluoreWater-soluble NaGdF4∶Eu fluorescent nanoparticles modified by citrate were synthesized by hydrothermal method with stable fluorescent properties. It was found that the fluorescence of the solution of as-prepared particles could be quenched by Cu2+, and thus a new mathod to determine trace Cu2+ using NaGdF4∶Eu as fluorescent probe was established. A pH 10.0 and the concentration 1.0×10－3 mol·L-1 of NaGdF4∶Eu were selected for measurement. Besides, the effect of some foreign ions on the fluorescence signals was investigated and the interference of Fe3+ was found, which was eliminated by adding triethanolamine. The regression equation of standard curve was I=532－0.685c with the correlation coefficient of －0.998 4 when the concentration of Cu2+ was in the range of 3.33×10－6-1.33×10－4 mol·L-1, and the detection limit of 8.9×10－7 mol·L－1 and a RSD of 0.62% for 11 replicates of a 6.0×10－5 mol·L-1 Cu2+ solution were obtained, which suggest a wide linear analytical range, high sensitivity and high precision. Analytical applicability of the particles was demonstrated by tea sample analysis and the results of Cu2+ determination were in good agreement with those obtained by atomic absorption spectrometry. The reason for fluorescence quenching by Cu2+ can be explained in terms of combination of Cu2+ with citrate on the surface of NaGdF4∶Eu particles leading to a change in surface structure and the composition..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3061 (2009)
Fluorescence Spectra of Rubrene Dopant for Organic Light-Emitting Devices
LI Lu, YU Jun-shen*, CHEN Su-jie, and JIANG Ya-dong
The effect of concentration of 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) yellow dye in solution on fluorescence performance was studied through various concentrations. Also the photoluminescence (PL) spectra of rubrene solution with various concentrations were measured to investigate the concentration effect, whichThe effect of concentration of 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) yellow dye in solution on fluorescence performance was studied through various concentrations. Also the photoluminescence (PL) spectra of rubrene solution with various concentrations were measured to investigate the concentration effect, which is beneficial to obtaining an optimum concentration at maximum PL intensity without concentration quenching. One hand was to focus on the range of concentration for quenching. The other hand was to change the solution concentration in the range of concentration. The results showed that the PL intensity was the highest at a rubrene concentration of 2×10-3 mol·L-1, which was fixed on a concentration range from 10-3 to 10-2 mol·L-1. And it was decreased only 11% with the increase in concentration after the optimum concentration. The PL spectra of rubrene: N,N’-Bis(naphthalen-1-y)-N,N’-bis(phenyl)benzidine (NPB) blending system with various proportions in solution were also measured, indicating that the inefficient energy transfer between NPB and rubrene leads to white fluorescence light emission. It was better to realize blue and yellow fluorescence from NPB and rubrene, so the white light was obtained..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3066 (2009)
Fluorescence Resonance Energy Transfer between Gentamycin and Water-Soluble CdTe QDs
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The water-soluble CdTe quantum dots (QDs) were prepared by using mercaptopropionic acid (MPA) as stabilizer in the aqueous system. Fluorescence resonance energy transfer (FRET) system was constructed between gentamycin (acceptor) and water-soluble CdTe QDs (donor). The maximal emission wavelength was 690 nm, and the liThe water-soluble CdTe quantum dots (QDs) were prepared by using mercaptopropionic acid (MPA) as stabilizer in the aqueous system. Fluorescence resonance energy transfer (FRET) system was constructed between gentamycin (acceptor) and water-soluble CdTe QDs (donor). The maximal emission wavelength was 690 nm, and the line width of the fluorescence spectrum was very narrow (with the full width at half-maximum about 10 nm) and symmetric. The transfer of resonance energy from the CdTe QDs to gentamycin (GT) resulted in the fluorescence quenching of the QDs, corresponding to the increase in the concentration of GT. Several factors that impacted the fluorescence spectra of the FRET system, such as the excitation wavelength (305-425 nm), pH(5.0-11.0), ions (0-0.1 mmol·L-1 PBS; 0-0.5 mmol·L-1 NaCl), time (1-120 min), temperature (5-50 ℃), and concentration of GT (2-80 mg·L-1), were investigated and refined. The linear ranges of GT concentration were 2-20 mg·L-1, r=0.986 7. Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC) were used for confirming the chemical construction and relative specificity, respectively. The results indicated that sulfur and oxygen atoms in MPA molecules took part in coordination with rich Cd2+ on the surface of the nanoparticles. Meanwhile the results also demonstrated that the hydrogen bond between carboxyl of mercaptopropionic acid on the surface of quantum dots and amidocyanogen of GT mainly contributes to combining CdTe with GT. The combination ratio between GT and CdTe QDs is 0.35 to 1.0 according to HPLC. GT as an enhancement has first been applied to the determination of the bovine serum albumin (BSA) labeled with CdTe QDs, and the fluorescence intensity of the labeled BSA with GT is 6 times higher than the control. The proposed method might offer an attractive potential for use in future, because it is sensitive and rapid..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3070 (2009)
Denoising and Assessing Method of Additive Noise in the Ultraviolet Spectrum of SO2 in Flue Gas
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The problem of denoising and assessing method of the spectrum of SO2 in flue gas was studied based on DOAS. The denoising procedure of the additive noise in the spectrum was divided into two parts: reducing the additive noise and enhancing the useful signal. When obtaining the absorption feature of measured gas, a multThe problem of denoising and assessing method of the spectrum of SO2 in flue gas was studied based on DOAS. The denoising procedure of the additive noise in the spectrum was divided into two parts: reducing the additive noise and enhancing the useful signal. When obtaining the absorption feature of measured gas, a multi-resolution preprocessing method of original spectrum was adopted for denoising by DWT (discrete wavelet transform). The signal energy operators in different scales were used to choose the denoising threshold and separate the useful signal from the noise. On the other hand, because there was no sudden change in the spectra of flue gas in time series, the useful signal component was enhanced according to the signal time dependence. And the standard absorption cross section was used to build the ideal absorption spectrum with the measured gas temperature and pressure. This ideal spectrum was used as the desired signal instead of the original spectrum in the assessing method to modify the SNR (signal-noise ratio). There were two different environments to do the proof test-in the lab and at the scene. In the lab, SO2 was measured several times with the system using this method mentioned above. The average deviation was less than 1.5%, while the repeatability was less than 1%. And the short range experiment data were better than the large range. In the scene of a power plant whose concentration of flue gas had a large variation range, the maximum deviation of this method was 2.31% in the 18 groups of contrast data. The experimental results show that the denoising effect of the scene spectrum was better than that of the lab spectrum. This means that this method can improve the SNR of the spectrum effectively, which is seriously polluted by additive noise..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3075 (2009)
Application of Successive Projections Algorithm to Nondestructive Determination of Total Amino Acids in Oilseed Rape Leaves
LIU Fei, ZHANG Fan, FANG Hui, JIN Zong-lai, ZHOU Wei-jun, and HE Yong
Near infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for the fast and nondestructive determination of total amino acids (TAA) in oilseed rape leaves. Total amino acids are important indices of the growing status of oilseed rape. A total of 150 leave samples were scannedNear infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for the fast and nondestructive determination of total amino acids (TAA) in oilseed rape leaves. Total amino acids are important indices of the growing status of oilseed rape. A total of 150 leave samples were scanned, the calibration set was composed of 80 samples, the validation set was composed of 40 samples and the prediction set was composed of 30 samples. The optimal partial least squares (PLS) model was developed for the prediction of total amino acids in oilseed rape leaves after the performance comparison of different pretreatments, including smoothing method, standard normal variate (SNV), the first derivative and second derivative. Simultaneously, successive projections algorithm was applied for the extraction of effective wavelengths (EWs), which were thought to have least collinearity and redundancies in the spectral data. The selected effective wavelengths were used as the inputs of multiple linear regression (MLR), partial least squares (PLS) and least square-support vector machine (LS-SVM). Then the SPA-MLR, SPA-PLS and SPA-LS-SVM models were developed for performance comparison. The determination coefficient (R2) and root mean square error (RMSE) were used as the model evaluation indices. The results indicated that both SPA-MLR and SPA-PLS models were better than full-spectrum PLS model, and the best performance was achieved by SPA-LS-SVM model with R2=0.983 0 and RMSEP=0.396 4. An excellent prediction precision was achieved. In conclusion, successive projections algorithm is a powerful way for effective wavelength selection, and it is feasible to determine the total amino acids in oilseed rape leaves using near infrared spectroscopy and SPA-LS-SVM, and an excellent prediction precision was obtained. This study supplied a new and alternative approach to the further application of near infrared spectroscopy in the response of stress and on-field monitoring of the growing oilseed rape..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3079 (2009)
Analysis of the Impact of Heparin on the Affinity of High Mobility Group Box-1 Protein and the Receptor of Advanced Glycation End Products by Surface Plasmon Resonance Technology
LING Yan, WANG Chun-you, and YANG Zhi-yong
To investigate the affinity constants of heparin with high mobility group protein 1(HMGB1) and HMGB1 with the receptor of advanced glycation end products (RAGE) and to analyze the impact of heparin on the affinity of HMGB1 and RAGE, the standard BIAcore amine coupling chemistry protocol using EDC and NHS was employed fTo investigate the affinity constants of heparin with high mobility group protein 1(HMGB1) and HMGB1 with the receptor of advanced glycation end products (RAGE) and to analyze the impact of heparin on the affinity of HMGB1 and RAGE, the standard BIAcore amine coupling chemistry protocol using EDC and NHS was employed for immobilizing. Surface plasmon resonance biosensor technology was used to detect the affinity constants of heparin/HMGB1, HMGB1/RAGE and heparin/RAGE. Binding analysis was used to investigate the impact of heparin on the affinity of HMGB1 and RAGE. After the immobilization, 9 000 and 5 000 RU rise of HMGB1 and RAGE respectively were obtained. These meant that the immobilized values of HMGB1 and RAGE were about 9 and 5 ng·mm-2 respectively. The kinetic constants were ka=1.78×105 L·mol-1·s-1, kd=8.02×10-4 s-1, and the affinity constants were KA=2.22×108 L·mol-1, the equilibrium dissociation constant KD=4.5×10-9 mol·L-1 for heparin and HMGB1; while the kinetic constants were ka=1.85×103 L·mol-1·s-1, kd=1.81×10-4 s-1, KA=1.02×107 L·mol-1, KD=9.77×10-8 mol·L-1 for HMGB1 and RAGE; there was very low affinity of heparin with RAGE. The highest concentration of 10 000 u·L-1 of heparin in this experiment did not reach the saturation with HMGB1. After 50 mg·L-1 of HMGB1 was mixed with heparin of 50, 100, 1 000, 10 000 u·L-1, the combining amount of HMGB1 and RAGE declined from 100 to 50 RU. But there were no significant differences between different concentrations of heparin. It was concluded that heparin can combine with HMGB1 and affect the affinity of HMGB1/RAGE. In addition, this impact was not in a dose-dependent manner..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3084 (2009)
Study on the Interaction of Tetrandrine and Bovine Serum Albumin
WU Qiu-hua, SONG Shuang-ju, WANG Chun, and WANG Zhi
The interaction of tetrandrine with bovine serum albumin was studied by fluorescence spectra and ultra-violet spectra. The results showed that tetrandrine could quench the intrinsic fluorescence of BSA. Both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The queThe interaction of tetrandrine with bovine serum albumin was studied by fluorescence spectra and ultra-violet spectra. The results showed that tetrandrine could quench the intrinsic fluorescence of BSA. Both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The quenching constants KSV at different temperatures were determined using Stern-Volmer equation. The KSV were 1.26×104 L·mol-1 (300 K), 1.17×104 L·mol-1 (310 K) and 1.12×104 L·mol-1 (320 K). According to the Frster theory of non-radiation energy transfer, the binding distances (r) were 3.24 nm (300 K), 3.31 nm (310 K) and 3.50 nm (320 K). The binding constants (KA) between tetrandrine and BSA (300 K: 1.52×105 L·mol-1; 310 K: 2.03×105 L·mol-1; 320 K: 2.89×105 L·mol-1) and thermodynamic parameters were also obtained. The thermodynamic parameters indicated that the interaction of tetrandrine and BSA was driven mainly by hydrophobic force. Results of synchronous fluorescence spectrum showed that the binding could cause conformational changes of BSA..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3088 (2009)
Study on Growth Mechanism and Crystallization Phase State of Pentacene Thin Films on p-Si Wafer
YUAN Guang-cai, XU Zheng, ZHAO Su-ling, ZHANG Fu-jun, XU Na, TIAN Xue-yan, SUN Qin-jun, XU Xu-rong, and WANG Yong-sheng
The growth mechanism and crystallization phase state were investigated by the methods of atomic force microscopy (AFM) and X-ray diffraction (XRD). The pentacene films were deposited with a self-assembling monolayer by thermal evaporation on p+-Si wafer substrates at room temperature and annealed at a constant temperatThe growth mechanism and crystallization phase state were investigated by the methods of atomic force microscopy (AFM) and X-ray diffraction (XRD). The pentacene films were deposited with a self-assembling monolayer by thermal evaporation on p+-Si wafer substrates at room temperature and annealed at a constant temperature (80 ℃) for 120 min. The experimental results show that pentacene films were grown with terraces island structure with the diameter of island of about 100 nm and constituted a layer consisting of faceted grains with a average step height between terraces of 1.54 nm·s-1, which were accord with the long axis length of pentacene molecule, and the film were vertically grown on the substrate surface. The crystallization of pentacene thin films is shown in XRD pattern. The increase in the thin film thickness introduced a second set of diffraction peaks, which were attributed to the pentacene triclinic bulk phase. The critical thickness of both phases is 150 and 80 nm, respectively. At a film thickness of 150 nm, the triclinic phase diffraction peaks become the dominant phase. This is contrast to the XRD spectrum of very thin film of 80 nm thickness, where the thin film phase is the only contribution..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3092 (2009)
A New Noise Filtering Method of the SPR Optical Fiber Sensor Spectrum
ZHAO Zhi-yuan, ZENG Jie, LIANG Da-kai, and ZHANG Xiao-li
According to the characters of SPR optical fiber sensor spectrum and the requirement of real-time monitoring, a new noise filtering method, mobile lifting wavelet analysis, is presented in this paper. This method is not based on Fourier transform, but on an algorithm of dividing a complicated noise filtering process inAccording to the characters of SPR optical fiber sensor spectrum and the requirement of real-time monitoring, a new noise filtering method, mobile lifting wavelet analysis, is presented in this paper. This method is not based on Fourier transform, but on an algorithm of dividing a complicated noise filtering process into a number of reversible simple processes. It is very fast, correct and does not use additional memory. A model of actual SPR optical fiber sensor spectrum is constructed by superposing a certain intensity of Gaussian white noise on the theoretical spectrum, of which the resonant wavelength is 557.70 nm. It applies noise filtering to the simulative spectrum with mobile lifting wavelet analysis based on Haar, CDF(3,1), DD(4,2) and 5/3 mother wavelet respectively and calculates the resonant wavelengths again. The results are 556.45, 564.06, 557.27 and 557.91 nm corresponding to each method listed. So a relative error of 0.037 7 percent, obtained after noise filtering with new method based on 5/3 mother wavelet, is the minimum one. It is also lower than 0.430 3 percent obtained after noise filtering with traditional symlet11 wavelet analysis that has been proved to be effective for SPR optical fiber sensor spectrum. At different time gather several spectra of one SPR optical fiber sensor detective system were gathered and mobile lifting wavelet analysis based on 5/3 mother wavelet was done. The result shows that, the standard deviation of resonant wavelengths is reduced to 1.560 8 from 4.186 7 nm, which is calculated before noise filtering. As expected, this result is better than doing the same experiment with traditional symlet11 wavelet analysis, which only reduces the standard deviation to 2.725 3 from 4.186 7 nm. The research shows that mobile lifting wavelet analysis significantly suppresses the system noises, reduces noise influence on the gathering of resonant wavelength information from SPR optical fiber sensor spectrum and gives a guarantee to actual accurate detection with SPR optical fiber sensor..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3096 (2009)
Periodic and Fractal Precipitation in ATP-Co2+-Decoxycholate Gel System
YIN Wen-xuan, LIU Yu-feng, ZHAO Ying, BAI Song-yan, ZHU Wei-wei, WENG Shi-fu, GAO Qing-yu, and WU Jin-guang
In the simulation experiments in vitro of the formation of gallstone, adenosine-triphosphate(ATP)-Co2+-deoxycholic acid(DC) gel system was chosen to study the periodic precipitation progress. The effect of ATP on the Co2+-DC gel system was also determined, and the structure of the periodic precipitation formed was charIn the simulation experiments in vitro of the formation of gallstone, adenosine-triphosphate(ATP)-Co2+-deoxycholic acid(DC) gel system was chosen to study the periodic precipitation progress. The effect of ATP on the Co2+-DC gel system was also determined, and the structure of the periodic precipitation formed was characterized by FTIR. The results show that the patterns formed in the systems with ATP are different, ATP affected the rate and structure of precipitation through its variable participation in the metal coordination complexes as judged by the phosphate PO bands and the deoxycholate COO- symmetric and asymmetric vibration bands as measured by FTIR. Theses spectroscopic differences were correlated with color and pattern differences in the precipitates. ATP has a more remarkable function than AMP to the modes of patterns, meanwhile the system patterns transform from fractal to periodic precipitation. There is a complex interaction among ATP, sodium deoxycholic and Co2+ with a transparent crystal produced. The crystal is deoxycholic acid and the periodic precipitation is composed of ATP and DC covalent to Co2+. These results indicate that stone formation and remodeling is a dynamic, nonlinear progress. Much of the precipitate, as judged by local differences in composition, is not in equilibrium with the general gel environment. The authors conclude that the formation of gallstone features complex and nonlinear chemical character, in which nucleotides as living material play a very important role..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3101 (2009)
Estimating Leaf Area Index by Fusing MODIS and MISR Data
WAN Hua-wei, WANG Jin-di, LIANG Shun-lin, and QIN Jun
Moderate-resolution imaging spectrometer (MODIS) and multi-angle imaging spectroradiometer (MISR) are two important sensors on TERRA satellite. The authors can have more spectral and multi-angular observations on the land surface objects by combining these two datasets. In the present paper, both MODIS and MISR observaModerate-resolution imaging spectrometer (MODIS) and multi-angle imaging spectroradiometer (MISR) are two important sensors on TERRA satellite. The authors can have more spectral and multi-angular observations on the land surface objects by combining these two datasets. In the present paper, both MODIS and MISR observations were combined to estimate leaf area index (LAI) of land surface. The adjoining model and trust-region optimal algorithm were introduced into the framework of physical model inversion to speed up the running of the model inversion algorithm. And the algorithm allows the prior knowledge on the retrieved parameters to be input into the inversion procedure. The uncertainty and sensitivity matrix (USM) based analysis is helpful for selecting the observed data subset with more information and less noise to retrieve LAI. The measured LAI in situ and estimated LAI from ETM data were scaling-up to MODIS/MISR LAI product scale, and were taken as the ground truth to evaluate the new approach. The result suggests that combining two sensors datasets can improve the accuracy of LAI estimation, and the developed inversion method in this paper can be applied to the large area remote sensed image data effectively..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3106 (2009)
Simultaneous Determination of Ten Active Components in Qingkailing Injection and Relationship with Quality Control
WU Yan-shu, JIN Cheng, ZHANG Qian, JIAO Yi, YAN Dan, XIAO Xiao-he, DU Xiao-xi, and WANG Jian
A method was established for simultaneous determination of ten active components in Qingkailing injection (QKL), and could be used as a feasible method for the quality control of QKL. HPLC-DAD-ELSD was employed for the determination at the optimal wavelength (255 nm). Fifteen samples of QKL at different batches from diA method was established for simultaneous determination of ten active components in Qingkailing injection (QKL), and could be used as a feasible method for the quality control of QKL. HPLC-DAD-ELSD was employed for the determination at the optimal wavelength (255 nm). Fifteen samples of QKL at different batches from different factories were analyzed by the means. The results show that the method is corresponding with specified standard. The contents from different samples (QKL from different factories and different batches) have great disparity (The RSD values range from 2.17% to 65.54%). It is concluded that the method is reliable and convenient for the quality control of QKL. The key point of QKL quality control is to control the chief activity components as much as possible..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3112 (2009)
Research on Pixel Decomposition of QuickBird Multi-Spectrum Band Images
CHEN Chun, LIU Cheng-yu, and ZHANG Shu-qing
In the condition that the DN(Digital Number) value images of ground-atmosphere system recorded by the QuickBird artificial satellite sensor were taken as the experimental datum, the equation of pixel decomposition was structured, abiding by energy conservation law and the proportional relationship between the sum of 1-In the condition that the DN(Digital Number) value images of ground-atmosphere system recorded by the QuickBird artificial satellite sensor were taken as the experimental datum, the equation of pixel decomposition was structured, abiding by energy conservation law and the proportional relationship between the sum of 1-4 band integral radiance and the panchromatic band (Pan) integral radiance. By using the equation gained above, every pixel of 1-4 band images was decomposed into sixteen pixels. So the high resolution 1-4 band radiance images with the resolution of 0.61 m were finally obtained in this experiment. Compared with the original 1-4 band images, the spatial resolution of the high resolution 1-4 band radiance images was raised by four times. The detailed characteristics of the surface features in the high resolution 1-4 band radiance images were more limpid than the original 1-4 band images. The optesthesia effect was also improved obviously in the high resolution 1-4 band radiance images. Therefore, the map with appropriate scale improved from 1∶10 000 to 1∶2 500 can be made based on the high resolution 1-4 band radiance images..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3117 (2009)
Experimental Investigation of Pb in Soil Slurries by Laser Induced Breakdown Spectroscopy
LU Yuan, WU Jiang-lai, LI Ying, GUO Jin-jia, CHENG Kai, HOU Hua-ming, and ZHENG Rong-er
Laser induced breakdown spectroscopy (LIBS) has been shown to be a promising technique for element analysis with many advantages including on-line, real time, standing off and multi-element detection capability. In the present paper, the LIBS experiments for Pb in slurry samples were carried out with the motivation of Laser induced breakdown spectroscopy (LIBS) has been shown to be a promising technique for element analysis with many advantages including on-line, real time, standing off and multi-element detection capability. In the present paper, the LIBS experiments for Pb in slurry samples were carried out with the motivation of developing an in-situ sensor for monitoring heavy metal. A Q-switched Nd∶YAG laser operating at 532 nm with repetition frequency of 10 Hz was utilized to generate plasma on the prepared slurry samples, which were doped with same weight manganese as reference and varied concentration of lead. The induced plasma emission was recorded by CCD. The LIBS signals at PbI 405.78 nm and MnI 403.07 nm from the slurry samples were investigated. It was found that the intensity ratio of IPb/IMn increased as a linear function of the concentration of Pb with correlation coefficient R2 of 0.994 9. The obtained results show that LIBS with conjunction of referent element could be developed as a potential technique for contamination analysis of soil slurries. The main influence factors in LIBS signal detection were also discussed..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3121 (2009)
Laser Induced Breakdown Spectroscopy for the Determination of Cr and Sr in Soil
HUANG Ji-song, CHEN Qiao-ling, and ZHAO Wei-dong
As a powerful and promising analytical technique, laser-induced breakdown spectroscopy (LIBS) has been undergoing a rapid development in the past years. LIBS technique allows for rapid, multi-elemental, in situ measurements, and has been proposed for real time soil analysis. Currently, a global effort is focused on howAs a powerful and promising analytical technique, laser-induced breakdown spectroscopy (LIBS) has been undergoing a rapid development in the past years. LIBS technique allows for rapid, multi-elemental, in situ measurements, and has been proposed for real time soil analysis. Currently, a global effort is focused on how to further improve the analytical accuracy and repeatability of this promising technique. In the present paper, a method of laser induced breakdown spectroscopy (LIBS) for the determination of Cr and Sr in soil was established. The experimental instrument was mainly equipped with a pulsed 1 064 nm Nd∶YAG laser and a portable spectrometer. The behavior of shot to shot variation in spectra line intensity emitted by the laser plasma was studied. Data acquisition and processing procedures were experimentally optimized. The precision of the method was, in terms of RSD, 9.02% for Cr 425.44 nm and 10.5% for Sr 460.73 nm respectively (n=8). Detection limits were 25.3 mg·g-1 for Cr and 15.2 mg·g-1 for Sr in soil respectively. These results are better than the data reported in literature, indicating that the established LIBS method is suitable for the determination of heavy metal in soil..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3126 (2009)
Research on SCB Discharge Behavior with Atomic Emission Spectroscopy
ZHANG Lin, FENG Hong-yan, ZHU Shun-guan, WU Rong, and ZHANG Wen-chao
Semiconductor bridge (SCB) was utilized to ignite energetic materials with thin film discharge and characterized of low input energy, high safety and logic control possibility. SCB discharge was diagnosticated with atomic emission spectroscopy. Firstly, discharge temperature was acquired with copper atom spectral linesSemiconductor bridge (SCB) was utilized to ignite energetic materials with thin film discharge and characterized of low input energy, high safety and logic control possibility. SCB discharge was diagnosticated with atomic emission spectroscopy. Firstly, discharge temperature was acquired with copper atom spectral lines 510.5 and 521.8 nm, and electron density was calculated with silicon atom spectral line 390.5 nm and corresponding ion line 413.0 nm. As for resistance 1.0 Ω of SCB with the discharge voltage of 20 V and capacity of 47 μF, its discharge temperature was about 2 500-4 300 K and electron density 1016 cm-3. Meanwhile, the temperature and density Vs time distributions were acquired simultaneously. And then with the diagnosis results, the discharge behaviors of two sorts of SCB were judged according to plasma space-dimension and time-dimension restrictions. This research set up an efficient technique for the diagnosis of transient small-size discharge behavior and provided instructions for the design of SCB and discharge condition..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3130 (2009)
Analysis of Optical Emission Spectra from ICP of Ar in the Vicinity of Plasma Sheath
ZHAO Wen-feng, CHEN Jun-fang, and MENG Ran
In order to control the ion density and energy distribution in the vicinity of plasma sheath independently, the inductively coupled plasma and its glow discharge mechanism in the vicinity of plasma sheath were studied by means of optical emission spectroscopy (OES) under different RF power, different discharge and diffIn order to control the ion density and energy distribution in the vicinity of plasma sheath independently, the inductively coupled plasma and its glow discharge mechanism in the vicinity of plasma sheath were studied by means of optical emission spectroscopy (OES) under different RF power, different discharge and different substrate DC bias voltage. It was shown that the ion density is higher and the electron temperature is lower in the vicinity of inductively coupled plasma sheath according to the ionic line and atomic line. With changing the discharge pressure and RF power, the spectral characteristics analysis shows that the ion density in the vicinity of plasma sheath linearly increases with the RF power and rises with the pressure under the low pressure. The atomic spectral intensity of low excitation states increases rapidly. The atomic spectral intensity of high excitation states rises slowly and the intensity of ion spectrum increases not obviously. By applying the DC bias voltage to substrate, the intensity of emission spectroscopy was analyzed. The result shows that the intensity of spectra rises with the increase in positive bias voltage, while first reduces then increases with the increase in negative bias voltage, and is the weakest in the case of DC bias at -30 V. This shows that the fast ions and the electrons are the main source of energy for Ar ionization and excitation..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3134 (2009)
Determination of 27 Inorganic Elements in Limonium bicolor by ICP-MS Using Microwave Digestion for Sample Preparation
WANG Bin, XU Yin-feng, LI Guo-qiang, and GUAN Hua-shi
An inductively coupled plasma mass spectrometry (ICP-MS) for determination of the contents of 27 inorganic elements in Limonium bicolor after microwave digestion of the sample was developed. The accuracy of the method was evaluated by the analysis of corresponding inorganic elements in standard reference materials (GBWAn inductively coupled plasma mass spectrometry (ICP-MS) for determination of the contents of 27 inorganic elements in Limonium bicolor after microwave digestion of the sample was developed. The accuracy of the method was evaluated by the analysis of corresponding inorganic elements in standard reference materials (GBW 07605), and matrix effect and signal drift were compensated by using the internal standard elements (Ge, In and Bi). By applying the proposed method, the contents of 27 inorganic elements in Limonium bicolor collected from Dongying (Shandong Province of China) were determined. The precision of measurement ranges from 1.5% to 9.7% in terms of relative standard deviation. The recoveries and the limits of detection are in the range of 92.4%-107.2% and 0.002-0.081 μg·L-1, respectively. It is indicated that the proposed method has the advantages of simplicity, speediness and sensitivity. The results showed that the Limonium bicolor are rich in major elements Na, K, Ca and Mg and trace elements Fe, Mn, Zn, Cr and Cu. This paper provides scientific basis for deeply studying the relation between the inorganic elements and the drug effects of Limonium bicolor..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3138 (2009)
Application of ICP-MS to Species Determination of Pb, As and Cd in Hoggery Waste
HUANG Ming-li, LI Li-na, WANG Juan, and HAN Wen-xuan
Distribution of heavy metal species in animal wastes needs to be monitored to control the heavy metal pollution during the utilization of wastes. Here, ICP-MS was applied to determine the speciation of Pb, As and Cd in the wastes from two hoggeries in the suburb of Beijing. The air-dried and finely ground samples were Distribution of heavy metal species in animal wastes needs to be monitored to control the heavy metal pollution during the utilization of wastes. Here, ICP-MS was applied to determine the speciation of Pb, As and Cd in the wastes from two hoggeries in the suburb of Beijing. The air-dried and finely ground samples were digested by HNO3-HClO4, or, sequentially extracted with BCR procedure before content determination of heavy metals. The total concentrations of Pb, As and Cd were 29.0, 28.2 and 0.288 mg·kg-1 dry weight (DW) in the fresh hoggery wastes respectively, and 19.7, 28.2 and 0.134 mg·kg-1 DW in the dry-cleaning waste, respectively. The concentrations of the three metals in both fresh and dry-cleaning wastes were all lower than the control standards for urban wastes for agricultural use promulgated by the national government, although As was close to the control value. Over 50% of Pb, As and Cd in the fresh waste were exchangeable/carbonate species, and less than 20% were organic/sulphide. However, species distributions of the heavy metals changed markedly after the process of dry-cleaning. The fraction of highly ecotoxic species (exchangeable/carbonate bound and Fe/Mn oxide bound) in the dry-cleaning waste decreases by 5%-25% for the three metals, indicating reduced risks of heavy metal pollutions when dry-cleaning wastes are applied to farmlands. This study contributes basic data for the resource utilization and ecological security assessment of hoggery wastes from Beijing..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3141 (2009)
Determination of Trace Mercury in Different Sorts of Chinese Herbs by Atomic Fluorescence Spectrometry with Microwave Digestion
LIU Chun-tao, HOU Hai-ge, YANG Jing-lin, LI Li, and LI Han-hui
A method for the determination of trace mercury in different sorts of Chinese herbs using hydride generation atomic fluorescence spectrometry under different microwave digestion conditions was developed. Under the optimized experimental conditions, the linear equation was IF=809.1X-3.327 5,the correlation coefficient wA method for the determination of trace mercury in different sorts of Chinese herbs using hydride generation atomic fluorescence spectrometry under different microwave digestion conditions was developed. Under the optimized experimental conditions, the linear equation was IF=809.1X-3.327 5,the correlation coefficient was 0.999 998,and the linear range for mercury was 0-80 ng·mL-1. The detection limit of mercury was 0.014 ng·mL-1(n=11) and the relative standard deviation was 2.03%. The recoveries for these samples were 96.8%-102.80% (n=6) while the detection limit of the method was 1.17 ng·g-1. The method’s accuracy and precision for different sorts of Chinese herbs using the standard reference standard substance of rice (GBW08508), poplar leaf (GBW07601), and mytilus edulis (GBW08571) was checked, and the results were found to be basically consistent with the reference values. This method has been proved to be sensitive, simple and rapid with satisfactory results..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3144 (2009)
Determination of Trace Elements in Hollyhock by Microwave Digestion-FAAS
LI Yin-ping, GAO Li, LI Jin, ZHOU Xiao-ying, and LIU Cong
Hollyhock powder was digested by microwave digestion before determination.The eight trace elements, Fe, Cu, Zn, Mn, K, Ni, Ca and Mg, in hollyhock were determined by microwave FAAS. Standard curves method was used for the determination. The samples were digested with HNO3. The conditions of digestion were optimized. ThHollyhock powder was digested by microwave digestion before determination.The eight trace elements, Fe, Cu, Zn, Mn, K, Ni, Ca and Mg, in hollyhock were determined by microwave FAAS. Standard curves method was used for the determination. The samples were digested with HNO3. The conditions of digestion were optimized. The effect of different microwave digestion conditions on the analysis results was reviewed, and the optimal condition for using atomic absorption spectrophotometry was determined. The experiments indicated that the content of trace elements of human needs, Mg, Ca, Fe, K etc. are highly enriched, the content of Mn and Zn is middling, and the content of Cu and Ni is low. The method is highly sensitive, convenient and speedy. The recovery (n=6) is 92.25%-110.50%, and the RSDs (n=6) are lower than 5%. The results are satisfactory..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3147 (2009)
Determination of Trace Extractable Lead in Artificial Acid Sweat from Ecological Textiles by GFAAS
LIU Chong-hua, FANG Han, LIN Xiao-yang, ZHANG Xiao-li, DENG Zhi-guang, and LI Yun-song
Extractable trace level lead in artificial sweat solution from ecological textiles is a key item limited by eco-textile standard. But the content of this extractable Pb is not so easy to determine for the strict limit of eco-textile standard, the complicatedness of extractable solution matrix and the strong background Extractable trace level lead in artificial sweat solution from ecological textiles is a key item limited by eco-textile standard. But the content of this extractable Pb is not so easy to determine for the strict limit of eco-textile standard, the complicatedness of extractable solution matrix and the strong background interference of NaCl. In the present paper a method for the determination of trace extractable lead in artificial acid sweat from ecological textiles by graphite furnace atomic absorption spectrometry (GFAAS) is described. Based on a number of experiments by using different single and mixed matrix modifiers including (NH4)2H2PO4, NH4NO3, Pd(NO3)2, Ni(NO3)2 and ascorbic acid, an effective modifier and its quantity were selected and the graphite furnace operating parameters were optimized. Experimental test results revealed that adding 5 mL (1∶1) mixed solution of 50 g·L-1 ammonium nitrate and 100 mg·L-1 palladium regent was an effective way to inhibit volatile lead and reduce background signals. The detection limit could reach a low level of 0.7 μg·L-1. The relative standard deviation was 3.2%. Under the optimum experimental conditions, the recoveries ranged between 95.5% and 105%..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3150 (2009)
Study on Terahertz Spectra of Multi-Walled Carbon Nanotubes
SU Tong-fu, YU Bin, HAN Peng-yu, LI Yong-liang, LI Wei, ZHAO Guo-zhong, and GONG Chang-rong
In the present paper, the authors report the characterization of multiwalled carbon nanotube at terahertz (THz) frequency range using terahertz time-domain spectroscopy. The surface appearances and microanalysis of multiwalled carbon nanotubes were measured by scanning electron microscope in order to fully understand tIn the present paper, the authors report the characterization of multiwalled carbon nanotube at terahertz (THz) frequency range using terahertz time-domain spectroscopy. The surface appearances and microanalysis of multiwalled carbon nanotubes were measured by scanning electron microscope in order to fully understand the unique features and applications of multiwalled carbon nanotube. The results show that the refractive indexes of the sample decrease with increasing frequency in the frequency range of 0.2 to 2 THz, while the absorption coefficients of the sample increase with increasing frequency. In addition, the curve of terahertz absorption coefficients can be fitted by a straight line with a slope of 1.92. From the results of scanning electron microscope, the ranges of inner diameter and outer diameters of the sample were from 5 to 15 nm and from 15 to 25 nm, respectively, and its length was in the order of micrometer. The results of microanalysis of its elemental composition showed that the content of element C was about 94% and the rest were O and Cl elements, which were impurity elements. Mathematical modes of terahertz absorption and refractive indexes in the frequency range of 0.2 to 2.0 THz were established after taking into account Taylor expansion and Maxwell’s equations, and the calculation was in relatively good agreement with the observed values of the sample in general. The terahertz refractive indexes and absorption properties of multiwalled carbon nanotube were mainly attributed to the chemical compositions and molecular weight, and carbon nanotubes with different content of carbon could show different terahertz absorption spectra and disclose different unique functions..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3154 (2009)
Experimental Study and Correction of the Absorption and Enhancement Effect between Ti, V and Fe
TUO Xian-guo, MU Ke-liang, LI Zhe, WANG Hong-hui, LUO Hui, and YANG Jian-bo
The absorption and enhancement effects in X-ray fluorescence analysis for Ti, V and Fe elements were studied in the present paper. Three bogus duality systems of Ti-V/Ti-Fe/V-Fe samples were confected and measured by X-ray fluorescence analysis technique using HPGe semiconductor detector, and the relation curve betweenThe absorption and enhancement effects in X-ray fluorescence analysis for Ti, V and Fe elements were studied in the present paper. Three bogus duality systems of Ti-V/Ti-Fe/V-Fe samples were confected and measured by X-ray fluorescence analysis technique using HPGe semiconductor detector, and the relation curve between unitary coefficient (RK) of element count rate and element content (WK) were obtained after the experiment. Having analyzed the degree of absorption and enhancement effect between every two elements, the authors get the result, and that is the absorption and enhancement effect between Ti and V is relatively distinctness, while it’s not so distinctness in Ti-Fe and V-Fe. After that, a mathematics correction method of exponential fitting was used to fit the RK-WK curve and get a function equation of X-ray fluorescence count rate and content. Three groups of Ti-V duality samples were used to test the fitting method and the relative errors of Ti and V were less than 0.2% as compared to the actual results..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3158 (2009)
Spatially Modulated Interference Hadamard Transform Spectral Imager
ZHOU Jin-song, XIANGLI Bin, and WEI Ru-yi
The principle and instrumental structure of dispersion Hadamard transform spectral imager were briefly described in the present paper, and the disadvantages of the imager both in dislocation of spatial and spectral information and in spectral resolution limited by the width of Hadamard encoding mask were pointed out. AThe principle and instrumental structure of dispersion Hadamard transform spectral imager were briefly described in the present paper, and the disadvantages of the imager both in dislocation of spatial and spectral information and in spectral resolution limited by the width of Hadamard encoding mask were pointed out. A new instrumental principle and design of spatially modulated interference Hadamard transform spectral imager was proposed. A lateral shearing interferometer was used to acquire interference signals of all the Hadamard encoding information at different optical path difference. Then the methods of Fourier transform and Hadamard transform for interferogram were performed to acquire the spectra of objectives. Theory analysis of this imager demonstrated that the modulation of interferogram would not be affected by some factors such as the form and size of Hadamard encoding mask, and the spectral resolution would not be influenced by the size of Hadamard encoding mask. Furthermore, such technique not only effectively eradicated the dislocation of spatial information and spectral information existing in dispersion Hadamard transform spectral imager, but also made it convenient to image with high-throughput, high spatial resolution and high spectral resolution..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 17, 2021
- Vol. 29, Issue 11, 3163 (2009)
Research Articles
Adsorption Characteristics and Mechanism of 2,4-D on Two Types of Humic Acid
CHANG Chun-ying, and LV Yi-zhong
This study mainly focused on the adsorption properties and adsorption mechanism of 2,4-D on two different humic acids. After the extraction of humic acid from the two different types of soil, the black soil and chestnut soil, adsorption experiments were carried out using the batch equilibrium techniques. Then FTIR and This study mainly focused on the adsorption properties and adsorption mechanism of 2,4-D on two different humic acids. After the extraction of humic acid from the two different types of soil, the black soil and chestnut soil, adsorption experiments were carried out using the batch equilibrium techniques. Then FTIR and ESR spectral analysis methods were employed to explain the functional mechanism between 2,4-D and humic acid. The results showed the relationship between the amount of 2,4-D sorbed by the two humic acids and the reaction time, with the adsorption process for both acids being very fast at the beginning, then becoming slower and finally reaching equilibrium. The adsorption capacity of 2,4-D on black soil humic acid and chestnut soil humic acid were 0.39 and 0.42 mg·kg-1 respectively. More carboxylic acid structure made the initial adsorption rate of 2,4-D on black soil humic acid much faster than on chestnut soil humic acid. Adsorption isotherm of 2,4-D on the two humic acids was both in accordance with the linear model and the Freundlich model. The interactions between humic acid and 2,4-D are mostly weak forces, such as the H-bond, proton transfer, charge transfer, van der Waals force and so on. In addition, ESR analysis found that covalent bond exists between humic acid and 2,4-D or its degradation product during the process of adsorption..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 20, 2021
- Vol. 29, Issue 11, 2926 (2009)
Purity Measurement of Hybrid Rice Seed Yixiang 725 with Visible-Near Infrared Reflectance Spectra
LIANG Liang, YANG Min-hua, LIU Zhi-xiao, XU Hai-wei, LIU Fu-hui, HE Qi-zhuang, and LUO Yun-fei
A rapid and non-invasive method was put forward to measure the purity of hybrid rice seed by visible-near infrared reflectance spectra. Ninety hybrid rice seed samples (Yixiang 725) with the purity of 90%-99% were collected using a FieldSpec3 visible-near infrared spectometer. All samples were divided randomly into twA rapid and non-invasive method was put forward to measure the purity of hybrid rice seed by visible-near infrared reflectance spectra. Ninety hybrid rice seed samples (Yixiang 725) with the purity of 90%-99% were collected using a FieldSpec3 visible-near infrared spectometer. All samples were divided randomly into two groups, one group with 75 samples used as calibrated set, and the other with 15 samples used as validated set. Based on the spectra in the range of 380-2 400 nm, the regression model was established using the PLS (partial least square), and different spectra pretreatment methods were compared. The study showed that spectra information can be extracted thoroughly by the pretreatment method of first derivative combined with standard normal variate, with the SEC (standard error of calibration) of 0.002 5, SEP (standard error of prediction) of 0.006 6, and determination coefficients of 0.988 4 (calibration set) and 0.922 7 (validation set) respectively. The spectra, which were pretreated with the method of first derivative combined standard normal variate, were analyzed by principal component analysis (PCA). The top 20 principal components, which were computed by PCA and accounted for 86.09% variation of the original spectral information, were used to build BP-ANN model for measuring the purity of hybrid rice seed as the new variables. The study showed that the SEC and SEP of BP-ANN model were 0.001 7 and 0.006 1, and the determination coefficients of that were 0.995 2 (calibration set) and 0.936 9 (validation set) respectively. Therefore, the predictive power of BP-ANN model was better than that of PLS model. Results indicated that it was feasible to measure the purity of the hybrid rice seed by visible-near reflectance spectra as a rapid and non-contact way, and PCA combined with BP-ANN was a preferred method..
Spectroscopy and Spectral Analysis
- Publication Date: Oct. 20, 2021
- Vol. 29, Issue 11, 2962 (2009)
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