Journals >Spectroscopy and Spectral Analysis
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2009
Volume: 29 Issue 5
68 Article(s)
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Research Article
[in Chinese]
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1 (2009)
New Method Study of Sites Vicarious Calibration for SZ-3/CMODIS
HU Xiu-qing, LIU Jing-jing, QIU Kang-mu, FAN Tian-xi, ZHANG Yu-xiang, RONG Zhi-guo, and ZHANG Li-jun
Chinese MODIS onboard ShenZhou-3 spacecraft (SZ-3/CMODIS)is the experiment instrument of next generation environmental and meteorological satellites. CMODIS can obtain the data of 30 bands in visible and near infrared region from the earth-atmosphere system. But the quantitative application of these data is limited by Chinese MODIS onboard ShenZhou-3 spacecraft (SZ-3/CMODIS)is the experiment instrument of next generation environmental and meteorological satellites. CMODIS can obtain the data of 30 bands in visible and near infrared region from the earth-atmosphere system. But the quantitative application of these data is limited by radiometric calibration. The present paper addresses a new concept of semi-synchronous measurements with satellite observation based on the traditional sites vicarious calibration. It can meet the expected calibration requirement under the condition of no enough ground measurements. In addition to this, the reflectance of Dunhuang Calibration site is very smooth on the Vis-NIR spectral region. A new cross-calibration was also conducted experimentally using the spectral interpolation of atmospheric correction reflectance from EOS/MODIS. The results of these two methods were compared and verified with each other and showed that they are effective and reliable. These new radiometric calibration methods provide good technique experiences for the next generation in-flight optical sensors..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1153 (2009)
Time Resolved Photoluminescence of ZnO Nanoparticles under Low Photon Energy Excitation
WANG Xiao-fang, XIE Ping-bo, ZHAO Fu-li, and WANG He-zhou
Time-resolved photoluminescence (TRPL)and time-integrated photoluminescence (TIPL)measurements were performed at ZnO nanoparticles with grain size from 17 nm to 110 nm prepared by homogenous precipitation method (HPM). With a quasi-continuous picoseconds laser excitation at a low photon energy of 2.33 eV (wavelength 53Time-resolved photoluminescence (TRPL)and time-integrated photoluminescence (TIPL)measurements were performed at ZnO nanoparticles with grain size from 17 nm to 110 nm prepared by homogenous precipitation method (HPM). With a quasi-continuous picoseconds laser excitation at a low photon energy of 2.33 eV (wavelength 532 nm)from a Vanguard 2000-HM532 laser, ultrafast emission with the wavelength ranging from 550 to 1 000 nm was detected. It was observed that the wavelength position of all the peaks of the samples regularly redshifted with the increase in the particle sizes. The PL spectra were fitted with Gaussian curves, in which a good fitting consisting of four Gaussian peaks was obtained. The Gaussian analysis indicates that the redshift in PL is due to the increased relative magnitude of the Gaussian combination in the low energy region. The analysis of the experiment suggests the existence of surface states in the bad gap near Fermi level of ZnO. At the same time, a strong dependence of the PL lifetime on grain size was found. Upon the increase in particle size, the decay of the emission shortened much, in which the PL intensity reveals bi-exponential decay for samples with small diameters while no identified decay of emission was observed within 2 nanoseconds for large particles. The dependence of the decay time on the grain size of nanoparticles can be suitably attributed to the surface related mechanism. Combined analysis of the lifetime dependence on particle size validates the model of surface states recombination in nanostructures due to large surface-to-volume ratio..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1160 (2009)
Spectroscopy Study of Rubidium Spectrum Lamps
WANG Fang, ZHAO Feng, QI Feng, WU Han-hua, ZHONG Da, and MEI Gang-hua
Rubidium spectral lamp is one of the critical parts in a rubidium atomic frequency standard (RAFS). The light emitted from the spectral lamp contains two components, one is the useful component, which contributes to the atomic transition signal, and the other is the useless component, which acts only as the light noiseRubidium spectral lamp is one of the critical parts in a rubidium atomic frequency standard (RAFS). The light emitted from the spectral lamp contains two components, one is the useful component, which contributes to the atomic transition signal, and the other is the useless component, which acts only as the light noise. In order to improve the signal-to-noise ratio of the frequency locking loop of a RAFS, and therefore to obtain a highly stable RAFS, it’s very important to enhance the useful light component and suppress the useless component. In the present work the light spectra of the three commonly used rubidium spectrum lamps with bulbs separately filled with buffer gases argon, krypton and xenon were obtained by means of a monochromator. The spectra were analyzed and the methods to enhance useful light intensity and reduce useless light intensity were discussed. Results showed that the useful light intensity strongly depends on the types of buffer gases and the bulb temperature. In the whole range of bulb temperature, the Xe lamp had the highest useful light intensity among the three lamps. The Kr lamp showed a higher useful light intensity than the Ar lamp at low bulb temperature, while at high bulb temperature the Ar lamp showed a higher useful light intensity than the Kr lamp. Analysis also indicates that the light noise of a rubidium spectrum lamp can be effectively minimized by adopting suitable light filtering technique..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1164 (2009)
Application of the Wavelet Transform in Terahertz Time-Domain Spectroscopy
CHEN Long-wang, MENG Kuo, and ZHANG Yan
With the development of ultrafast laser technique and deeper understanding of the terahertz (THz)electromagnetic wave, THz time domain spectroscopy (THz-TDS)has become a novel and rapidly developed technique. It has been applied in many fields such as biomedical diagnostics, semiconductor wafer diagnostics, and inspectWith the development of ultrafast laser technique and deeper understanding of the terahertz (THz)electromagnetic wave, THz time domain spectroscopy (THz-TDS)has become a novel and rapidly developed technique. It has been applied in many fields such as biomedical diagnostics, semiconductor wafer diagnostics, and inspection of artwork. However, the achieved spectrum will exhibit strong oscillations when it is measured in air environment due to the absorption of water vapor. In the present paper, spectra in the range of 0.2-1.9 THz for seven kinds of samples were measured by THz-TDs in both nitrogen and air environment. The wavelet transform was used to process the data measured in the air environment to eliminate the influence of water vapor. The feasibility of this method was demonstrated by the experimental results..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1168 (2009)
Experimental Evaluation of Cross Section for Rb(5DJ)+H2→RbH+H Reaction
ZHAO Yi-kun, CUI Xiu-hua, BAI Zhen-ao, DAI Kang, and SHEN Yi-fan
The Rb(5DJ)+H2→RbH［X １Σ＋(ｖ″＝０)］+H photochemical reaction was studied in a cell experiment applying a laser pump-absorption technique. Using two-photon excitation of the Rb5 2D atomic level in a Rb-H2 vapor mixture, the resulting fluorescence includes a direct component arising from the optically excited state and a senThe Rb(5DJ)+H2→RbH［X １Σ＋(ｖ″＝０)］+H photochemical reaction was studied in a cell experiment applying a laser pump-absorption technique. Using two-photon excitation of the Rb5 2D atomic level in a Rb-H2 vapor mixture, the resulting fluorescence includes a direct component arising from the optically excited state and a sensitized component due to the collisionally populated fine-structure state. The RbH molecules are formed in three-body reactive collisions between excited Rb5 2D atoms and ground state H2 molecules. Near-infrared absorption band RbH X 1Σ＋(v″＝０→ｖ′＝17) near 852 nm by using a diode laser was measured. The absorbed intensity of laser beam through a length L of the RbH vapor is defined as ΔΙ′ and ΔＩ″ where ΔＩ′ and ΔＩ″ are the absorbed intensity of pumping 5D3/2 and 5D5/2 levels, respectively. The ratio of ΔＩ′ to ΔＩ″ contains information on reactivity. ｗ５Ｄ３／２ and w５Ｄ３／２ are the production rates of Rb in the 5D5/2 and 5D3/2 levels by direct laser excitation from the 5S1/2 level. Using a second experiment in which pump laser is used to pump the 5D3/2 and 5D5/2 states in a pure Rb vapor (T=290 K), and the i′/i″ where ｉ′ and ｉ″ are measured intensities of the 5D3/2→5P1/2 and 5D5/2→5P3/2 transition, respectively, is determinined. At low density of Rb atoms, the 5D mixing rate is neglect. The rate of 5D3/2 and 5D5/2 fluorescence yields the ratio of 5D3/2 to 5D5/2 pump production rate. The rate equations were solved, and the authors estimate the value of the cross section at T=385 K and ＰＨ２＝400 Pa for collisional energy transfer from Rb5D3/2 to 5D5/2, from Rb(5D)to Rb states other than Rb(5D)to be 9.8×10-16 cm2 and 2.0×10-16 cm2, respectively. The reaction cross sections ［i.e., Rb(5DJ)+H2→RbH+H］ for J being 3/2 and 5/2 are 5.4×10-17 and 2.3×10-17 cm2, respectively. The relative reactivity with H2 for two studied atoms is in an order of Rb(5D3/2)＞Rb(5D5/2), and this is consistent with the result obtained from a laser pump-probe technique..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1172 (2009)
Study of Approaches to Spectral Reflectance Reconstruction Based on Digital Camera
YANG Ping, LIAO Ning-fang, and SONG Hong
It is still challenging to reconstruct the spectral reflectance of a surface using digital cameras under given luminance and observation conditions. A new approach to solving the problem which is based on neural network and basis vectors is proposed. At first, the spectral reflectance of the sample surface is measured It is still challenging to reconstruct the spectral reflectance of a surface using digital cameras under given luminance and observation conditions. A new approach to solving the problem which is based on neural network and basis vectors is proposed. At first, the spectral reflectance of the sample surface is measured by spectrometer and the response of an digital camera is recorded. Then the reflectance is represented as a linear combination of several basis vectors by singular value decomposition (SVD). After that, a neural network is trained so that it is able to approximate the relationship between the camera responses and the coefficients of basis vectors accurately. In the end, the spectral reflectance can be reconstructed based on the neural network and basis vectors.In the present paper, the authors reconstructed the spectrum reflectance based on neural network and basis vectors. Compared with other traditional methods, neural network expands the space of unknown function F(S) from linear functions to more general nonlinear functions, which gives more accurate estimation of the coefficients ak and better reflectance reconstruction. Results show that the reflectance of standard Munsell color patch (Matte)can be reconstructed successfully with mean of RMS which is 0.023 4. Compared with linear approximation method, reconstruction of standard Munsell color patch (Matte)using this approach reduces the reconstruction error by 67%. Since the neural network can be implemented by Matlab neural network toolbox, this method can be easily adopted in many other cases. Therefore we conclude that this approach has advantages of higher accuracy, easy implementation and adaptation, thus can be used in many applications..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1176 (2009)
Atmospheric Correction of Hyperion Hyperspectral Image Based on FLAASH
YUAN Jin-guo, NIU Zheng, and WANG Xi-ping
Atmospheric correction of remote sensing image is the premise of quantitative remote sensing. The present paper evaluated the capability of FLAASH (fast line-of-sight atmospheric analysis of spectral hypercubes)in ENVI software to make atmospheric correction for EO-1 Hyperion hyperspectral image. Hyperion hyperspecrealAtmospheric correction of remote sensing image is the premise of quantitative remote sensing. The present paper evaluated the capability of FLAASH (fast line-of-sight atmospheric analysis of spectral hypercubes)in ENVI software to make atmospheric correction for EO-1 Hyperion hyperspectral image. Hyperion hyperspecreal image of Zhangye city in Heihe River valley of Gansu province, China was acquired on September 10, 2007. Canopy spectra, biochemical component and GPS data of 41 plots were measured in near real-time during the satellite overpass. Hyperion hyperspectral image was geometrically corrected using Lansat-7 ETM+ image, then DN values were transformed to radiance and apparent reflectance, and atmospheric correction of Hyperion image was made using FLAASH. The resulting radiance, apparent reflectance and reflectance after FLAASH of four typical objects, including corn, water body, desert and building, were compared. ASD spectra of corn were resampled to Hyperion corresponding bands using Gaussian filter function. The comparison between ASD resampled spectra and Hyperion spectra after FLAASH demonstrated that the atmospheric correction using FLAASH is very effective and these two spectra are consistent with each other and the correlation coefficient reached 0.987..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1181 (2009)
Unique Optical Reflection Spectra of Bivalve Nacre and Its Origin
ZHANG Wei-gang, WANG Gang, YAN Jun, LI Hao-xuan, and ZHANG Gang-sheng
The structural color and microstructure of nacre in bivalve shells of Pinctada maxima were investigated by optical reflection spectra, scanning electron microscopy and theoretical simulation. The following results are obtained: (1)The thickness of aragonite tablets decreased significantly from growing to central regionThe structural color and microstructure of nacre in bivalve shells of Pinctada maxima were investigated by optical reflection spectra, scanning electron microscopy and theoretical simulation. The following results are obtained: (1)The thickness of aragonite tablets decreased significantly from growing to central region of nacre, which leads to a blue-shift of reflection peak wavelength with the same reflection order obviously; (2)The structural color of nacre in bivalve shells of Pinctada maxima is derived from the combination effects of aragonite-protein multilayer structure and yellow pigments in nacre..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1186 (2009)
Microelements in Potato and Lily Samples Studied by Laser-Induced Breakdown spectroscopy Technology
ZHANG Da-cheng, MA Xin-wen, ZHU Xiao-long, LI Bin, and ZU Kai-ling
A LIBS setup was built in the Institute of Modern Physics. In our experiments, LIBS spectra produced by infrared radiation of Nd∶YAG nanosecond laser with 100 and 150 mJ pulse energy, respectively, were measured by fiber optic spectrometer in the ranges of 230-430 nm and 430-1 080 nm with a delay time of 1.7 and gate wA LIBS setup was built in the Institute of Modern Physics. In our experiments, LIBS spectra produced by infrared radiation of Nd∶YAG nanosecond laser with 100 and 150 mJ pulse energy, respectively, were measured by fiber optic spectrometer in the ranges of 230-430 nm and 430-1 080 nm with a delay time of 1.7 and gate width of 2 ms for potato and lily samples prepared by vacuum freeze-dried technique. The lines from different metal elements such as K, Ca, Na, Mg, Fe, Al, Mn and Ti, and nonmetal elements such as C, N, O and H, and some molecular spectra from C2, CaO, and CN were identified according to their wavelengths. The relative content of the six microelements, Ca, Na, K, Fe, Al, and Mg in the samples were analyzed according to their representative line intensities. By comparison we found that there are higher relative content of Ca and Na in lily samples and higher relative content of Mg in potato samples. The experimental results showed that LIBS technique is a fast and effective means for measuring and comparing the contents of microelements in plant samples..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1189 (2009)
Study on Expert System of Infrared Spectral Characteristic of Combustible Smoke Agent
SONG Dong-ming, GUAN Hua, HOU Wei, and PAN Gong-pei
The present paper studied the application of expert system in prediction of infrared spectral characteristic of combustible anti-infrared smoke agent. The construction of the expert system was founded, based on the theory of minimum free energy and infrared spectral addition. After the direction of smoke agent was inpuThe present paper studied the application of expert system in prediction of infrared spectral characteristic of combustible anti-infrared smoke agent. The construction of the expert system was founded, based on the theory of minimum free energy and infrared spectral addition. After the direction of smoke agent was input, the expert system could figure out the final combustion products. Then infrared spectrogram of smoke could also be simulated by adding the spectra of all of the combustion products. Meanwhile, the screening index of smoke was provided in the wave bands of 3-5 μm and 8-14 μm. FTIR spectroscope was used to investigate the performance of one kind of HC smoke. The combustion products calculated by the expert system were coincident with the actual data, and the simulant infrared spectrum was also similar to the real one of the smoke. The screening index given by the system was consistent with the known facts. It was showed that a new approach was offered for the fast discrimination of varieties of directions of smoke agent..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1193 (2009)
Photoluminescence from Interface of SiO/SiO2 Superlattices
WANG Shen-wei, YI Li-xin, HE Zhen, HU Feng, and WANG Yong-sheng
SiO/SiO2 superlattices with different thickness of SiO and SiO2 films were deposited on the Si substrates at 200 ℃ by thermo-evaporation technology. The photoluminescence (PL)spectrum centers of the samples shifted from 400 nm to 600 nm with the increase in SiO films thickness. Similar phenomena were also found when inSiO/SiO2 superlattices with different thickness of SiO and SiO2 films were deposited on the Si substrates at 200 ℃ by thermo-evaporation technology. The photoluminescence (PL)spectrum centers of the samples shifted from 400 nm to 600 nm with the increase in SiO films thickness. Similar phenomena were also found when increasing the thickness of SiO2 film but forming SiO film. It was found that the PL was attributed to the defects located at the interfaces between SiO and SiO2 films. The deconvolution of the PL spectra showed that the WOB(O3≡Si—O—O·), NOV(O3≡Si—Si≡O3), the E′center(O≡Si·)and NBOHC (O3≡Si—O·)defects contributed to the PL spectra. A mass of Si—O dangling bonds formed on the interfaces of the SiO and SiO2 during the deposition process, could provide many free O atoms and intrinsic defects. When the SiO film was thin (such as 1 nm), most of the Si6 rings were broken, and more WOB defects(415 nm)would be formed because of the combination of the intrinsic NBOHC defects and the diffusing O atoms on the interfaces. With the increase in the SiO film thickness, more Si6 rings were formed in the SiO films, that is the number of the Si—O dangling bonds decreased, less of WOB defects could be formed as both of the free O atoms and intrinsic defects decreased, but the NOV defects(470 nm)increased because of more E′center defects would be combined in pairs. With increasing of the SiO film thickness, the combination of the intrinsic defects became more difficult, so the E′center defects(520 nm)and NBOHC defects(630 nm)would dominate the PL of the SiO/SiO2 superlattices in turn. In conclusion, the evolution of the defects located at the interfaces induced the red shift of the PL..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1197 (2009)
Characterization and Photoluminescence Properties of a Blue-Light-Emitting Material
CHEN Liu-qing, LIU Xu-guang, XU Hui-xia, WANG Hua, and XU Bing-she
Tris(2-methyl-8-hydroxyquinoline)aluminum (AlMeq3)was synthesized and purified by vacuum sublimation. The structure of the complex was characterized by 1H NMR, FTIR spectra and elemental analysis techniques. AlMeq3 consists of three 2-methyl-8-hydroxyquinoline ligands and one aluminum atom. Its thermal stability was stTris(2-methyl-8-hydroxyquinoline)aluminum (AlMeq3)was synthesized and purified by vacuum sublimation. The structure of the complex was characterized by 1H NMR, FTIR spectra and elemental analysis techniques. AlMeq3 consists of three 2-methyl-8-hydroxyquinoline ligands and one aluminum atom. Its thermal stability was studied by TG and DSC analysis and the result shows that AlMeq3 is a thermally stable material, with decomposition and crystalline transition temperature being 357 and 158 ℃, respectively. Energy band structure was investigated by UV-Vis absorption spectra and fluorescence emission spectra. Experimental results show that its UV absorption bands were at about 246 and 390 nm, and the absorption band at about 246 nm can be assigned to π—π* of phenyl ring. AlMeq3 displays 8-hydroxyquinoline-oriented photophysical properties. The optical gap of AlMeq3 was about 2.85 eV, as determined by intrinsic absorption band edge of the complex in ethanol solution. Under UV excitation at 365 nm, the complex in ethanol solution emitted intensive blue fluorescence with the maximum emission peak at 479 nm, while the effective energy-transfer from the ligand to the central Al3+ ion occurred in the complex. AlMeq3 with bright blue photoluminescence can be applied as luminescent material in OLEDs..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1201 (2009)
Preparation and Luminescence Properties of Eu3+-Doped Cadmium Aluminium Silicate Glass
CHEN Yue-e, and HOU Lan-tian
The growth and harvest of crops are closely related to photosynthesis and plants have strong absorption of red and blue light, in which red light has helminthic function. So it is very meaningful to transform the rest light in the vertical element of sunlight into red and blue light. The authors can simulate artificialThe growth and harvest of crops are closely related to photosynthesis and plants have strong absorption of red and blue light, in which red light has helminthic function. So it is very meaningful to transform the rest light in the vertical element of sunlight into red and blue light. The authors can simulate artificial light enviro nment in order to develop green agriculture and increase production of plants. As we all know, rare-earth doped Eu3+glass materials have wavelength conversion function. Based on the two views of the above, in this paper, the authors have prepared doped Eu3+cadmium aluminium silicate glasses by high temperature solid-state reaction method. The absorption spectra, excitation spectra, emission spectra are obtained by experiment at room temperature, in which have strong red and blue emissions. Gain the best concentration of doping corresponding to the strongest absorption peak. The charge-transfer band (CT band)is moved to 320 nm (red shift)due to the addition of Cd2+. By changing alkali metal ions, we can adjust and mix different intensity of blue light according to the demand. Based on J-O theory, we can gain the structure order of samples by calculating intensity parameter Ω2 and Ω4..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1205 (2009)
Micromachining of Au Film by Femtosecond Pulse Laser
YUAN Dong-qing, ZHOU Ming, CAI Lan, and SHEN Jian
Femtosecond laser micromachining of film is an emerging technology for fabrication of MEMS devices. A Ti: sapphire laser (130 fs, 1 000 Hz)was used to irradiate the thin film with variations in process parameters such as pulse energy. The film thickness is about 4 μm which was measured by AFM. When we used single pulseFemtosecond laser micromachining of film is an emerging technology for fabrication of MEMS devices. A Ti: sapphire laser (130 fs, 1 000 Hz)was used to irradiate the thin film with variations in process parameters such as pulse energy. The film thickness is about 4 μm which was measured by AFM. When we used single pulse to excite the film, the ablation diameter increased along with the energy ascending; when the energy of single pulse was invariable, the diameter had little change when altering the number of pulses. The single pulse threshold fluence of Au film was Ｆｔｈ＝0.7 J·cm-2 at this ultrashort pulse-length in air. By changing the energy of excitation pulse it was found that when the energy was lower than the threshold, the line on the film was heaved; when the energy was higher than the threshold, the line was concave, which was detected by AFM. It was also found that the width of line decreased along with the increase in process speed when the pulse energy remained unchanged; the width of line increased along with the pulse energy ascending when the process speed was fixed..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1209 (2009)
Field Measurement of Gobi Surface Emissivity Spectrum at Dunhuang Calibration Site of China
ZHANG Yong, LI Yuan, RONG Zhi-guo, HU Xiu-qing, ZHANG Li-jun, and LIU Jing-jing
Gobi surface emissivity spectrum of Dunhuang radiometric calibration site of China is one of the key factors to calibrate the thermal infrared remote sensors using land surface. Based on the iterative spectrally smooth temperature/emissivity separation (ISSTES)algorithm, Dunhuang Gobi surface emissivity spectrum was meGobi surface emissivity spectrum of Dunhuang radiometric calibration site of China is one of the key factors to calibrate the thermal infrared remote sensors using land surface. Based on the iterative spectrally smooth temperature/emissivity separation (ISSTES)algorithm, Dunhuang Gobi surface emissivity spectrum was measured using BOMEM MR154 Fourier transform spectroradiometer and Infrared Golden Board. Emissivity spectrum data were obtained at different time and locations. These spectrum data were convolved with the channel response function of CE312 radiometer and compared with the channel emissivity measured by the same instrument. The results showed that the difference between these two kinds of channel emissivity was within 0.012 and exhibited a good consistency. With these measured emissivity spectra, all of the mainstream thermal infrared remote sensors can be calibrated using Dunhuang Gobi surface at radiometric calibration site of China..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1213 (2009)
Study on Biosorption of Uranium by Rhodotorula Glutinis
BAI Jing, QIN Zhi, WANG Ju-fang, GUO Jun-sheng, ZHANG Li-na, FAN Fang-li, LIN Mao-sheng, DING Hua-jie, LEI Fu-an, WU Xiao-lei, and LI Xiao-fei
Characteristic of uranium biosorption in water solution by Rhodotorula glutinis was investigated in the present study and the optimal pH for uranium adsorption was found to be 6-7. At the same time, maximum adsorption capacity of 149.4 mgU/(g dry cell)was identified, and Langmuir adsorption models can be used to simulaCharacteristic of uranium biosorption in water solution by Rhodotorula glutinis was investigated in the present study and the optimal pH for uranium adsorption was found to be 6-7. At the same time, maximum adsorption capacity of 149.4 mgU/(g dry cell)was identified, and Langmuir adsorption models can be used to simulate the isothermal biosorption process with high correlation coefficient of 0.99. According to Fourier transform infrared spectra, a new peak at wave number of 904 cm-1, which can be assigned to the stretch vibration of UO2, was detected in the cell which was contacted by the uranium, indicated that uranium was really absorbed by Rhodotorula glutinis. Changes in the uranium-exposed yeast biomass were in the stretching vibrations of amino or hydroxyl groups, which shift from 3 309 to 3 287 cm-1, and in the stretching vibrations of C—O band, which shift from 1 068 to 1 080 cm-1, and these are all attributed to the important role that they may played in the binding of uranium. Hardly any changes can be found in the characteristic IR adsorbing peaks of protein at wave numbers of 1 653, 1 540 and 1 237 cm-1 before and after uranium adsorption, making it clear that the major component and the structure of the biomass remained intact. 96% of the absorbed uranium can be easily desorbed by 0.1 mol·L-1 NaHCO3. Obviously, the application potential of this yeast in the uranium wastewater treatment was very wide and expansive, and more more work should be done to realize its industrial use..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1218 (2009)
Size Dependent SERS Activity of Gold Nanoparticles Studied by 3D-FDTD Simulation
LI Li-mei, FANG Ping-ping, YANG Zhi-lin, HUANG Wen-da, WU De-yin, REN Bin, and TIAN Zhong-qun
By synthesizing Au nanoparticles with the controllable size from about 16 to 160 nm and measuring their SERS activity, the authors found that Au nanoparticles film with a size in the range of 120-135 nm showed the highest SERS activity with the 632.8 nm excitation, which is different from previous experimental results By synthesizing Au nanoparticles with the controllable size from about 16 to 160 nm and measuring their SERS activity, the authors found that Au nanoparticles film with a size in the range of 120-135 nm showed the highest SERS activity with the 632.8 nm excitation, which is different from previous experimental results and theoretical predictions. The three dimensional finite difference time domain (3D-FDTD)method was employed to simulate the size dependent SERS activity. At the 632.8 nm excitation, the particles with a size of 110 nm shows the highest enhancement under coupling condition and presents an enhancement as high as 109 at the hot site. If the enhancement is averaged over the whole surface, the enhancement can still be as high as 107, in good agreement with our experimental data. For Au nanoparticles with a larger size such as 220 nm, the multipolar effect leads to the appearance of the second maximum enhancement with the increase in particles size. The averaged enhancement for the excitation line of 325 nm is only 102..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1222 (2009)
In Situ Diffuse Reflectance FTIR Spectroscopy Study of CO Adsorption on Ni2P/Mesoporous Molecule Sieve Catalysts
LIU Qian-qian, JI Sheng-fu, WU Ping-yi, HU Lin-hua, HUANG Xiao-fan, ZHU Ji-qin, and LI Cheng-yue
The supported nickel phosphate precursors were prepared by incipient wetness impregnation using nickel nitrate as nickel source, diammonium hydrogen phosphate as phosphorus source, and MCM-41, MCM-48, SBA-15 and SBA-16 as supports, respectively. Then, the supported Ni2P catalysts were prepared by temperature-programmedThe supported nickel phosphate precursors were prepared by incipient wetness impregnation using nickel nitrate as nickel source, diammonium hydrogen phosphate as phosphorus source, and MCM-41, MCM-48, SBA-15 and SBA-16 as supports, respectively. Then, the supported Ni2P catalysts were prepared by temperature-programmed reduction in flowing H2 from their nickel phosphate precursors. The in situ diffuse reflectance FTIR spectroscopy (DRIFTS)analysis with the probe molecule CO was carried out to characterize the surface properties. The results indicated that there were significant differences in the spectral features of the samples. The νCO absorbances observed for adsorbed CO on mesoporous molecule sieve was attributed to weak physical adsorption. There are four different kinds of νCO absorbances observed for adsorbed CO on Ni2P/MCM-41 catalyst with the following assignments: (1)the formation of Ni(CO)4 at 2 055 cm-1. (2)CO terminally bonded to cus Niδ+(0<δ<1)sites at 2 091 cm-1. (3)CO terminally bonded to Ni+ sites at 2 127 cm-1. (4) CO terminally bonded to P and form PCO between 2 198 and 2 202 cm-1. There are two different kinds of νCO absorbances observed for adsorbed CO on Ni2P/MCM-48, Ni2P/SBA-15 and Ni2P/SBA-16 catalysts. The absorbance observed at 2 051-2 055 cm-1 for CO adsorption on Ni2P/MCM-48, Ni2P/SBA-15 and Ni2P/SBA-16 catalysts is due to the formation of Ni(CO)4 species. The other νCO absorbances observed at 2 093-2 096 cm-1 was attributed to CO terminally bonded to cus Niδ+(0<δ<1)sites..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1227 (2009)
FTIR-HATR to Identify β-Thalassemia and Its Mechanism Study
PENG Li-xin, WANG Gui-wen, YAO Hui-lu, HUANG Shu-shi, WANG Yi-bing, TAO Zhan-hua, and LI Yong-qing
Fourier transform infrared spectroscopy (FTIR)associated with horizontal attenuated total reflectance (HATR)was firstly used to diagnose β-thalassemia patients. With excellent linearity (r=0.997) and reproducibility (RSD＜4%), FTIR-HATR shows an order-of-magnitude increase in IR absorption bands over the single-path traFourier transform infrared spectroscopy (FTIR)associated with horizontal attenuated total reflectance (HATR)was firstly used to diagnose β-thalassemia patients. With excellent linearity (r=0.997) and reproducibility (RSD＜4%), FTIR-HATR shows an order-of-magnitude increase in IR absorption bands over the single-path transmission FTIR. Based on above, spectra from 37 patients’ and 68 health samples indicated several observable differences in IR vibrational spectra of the Hb lysates between the β-thalassemia major patients and control: (1)Because of decreasing hemoglobin, the peak intensities are obviously lower in β-thalassemia group that is consistent with index from routine hemoglobin diagnosis. (2)In 1 750-1 500 cm-1 region, slight decrease at 1 652 cm-1(α-helix), 1 638 and 1 628 cm-1 bands but mild increase at 1 682 cm-1 all demonstrate structure changes by both Fourier self-deconvolution and second derivative spectra. (3)More importantly, difference spectra substantially demonstrate decreased intensities at 1 440, 1 453, 1 479 cm-1 bands arising from CH2/CH3 deformation vibration of phospholipids but increased intensities at 1 150 cm-1 band originating from C—O stretching vibration of carbohydrate and at 1 081 and 1 053 cm-1 bands that are attributed to 2,3-diphosphoglycerate (DPG)in β-thalassemia major group. Statistical analysis demonstrates significant difference of DPG/phospholipids ratio between two groups. All the samples can be 100% correctly classified into groups on the basis of this ratio. These finding could help understand possible mechanism for diagnosing thalassemia. It makes large-scale screening of thalassemia by FTIR a possibility..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1232 (2009)
Effects of High Pressure on the Conformation of Freeze-Dried Soy Protein Isolate: A FTIR Spectroscopic Study
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The effect of high pressure (HP)treatment on the conformation of freeze-dried soy protein isolates (SPI)was investigated by Fourier transform infrared (FTIR) spectroscopy. Within the amide Ⅰ′ region (1 600-1 700 cm-1)of the deconvoluted FTIR curve of SPI, more than 10 bands associated with protein conformation were disThe effect of high pressure (HP)treatment on the conformation of freeze-dried soy protein isolates (SPI)was investigated by Fourier transform infrared (FTIR) spectroscopy. Within the amide Ⅰ′ region (1 600-1 700 cm-1)of the deconvoluted FTIR curve of SPI, more than 10 bands associated with protein conformation were distinctly observed, attributed to the CO stretching vibration and to a small extent to C—N stretching vibration of the peptide bonds, respectively. The secondary structure of native SPI is estimated to be composed of 15%-16% α-helix, 39%-44% extended strands, 17.5% random coils, and 21%-27% turns. The analyses of intensity and wavenumber of the bands showed that, HP treatment at pressures of 200-400 MPa resulted in the increases in intensity and a “red-shift” (about 2 cm-1)of these bands. HP treatment at 600 MPa further increased the band intensity of the amide Ⅰ′ region. The analyses of amide Ⅱ bands showed that HP treatment led to gradual increases in intensity and absolute area of amide Ⅱ bands, in a pressure-dependent manner. Thus, it is suggested that HP treatment resulted in gradual unfolding of secondary and tertiary structure of SPI, while the structure of denatured proteins underwent a “rebuilding” process after the release of high pressure. These results confirm that the HP-induced modification of SPI is by means of the HP-induced conformational changes..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1237 (2009)
A Denoising Algorithm for Absorption Spectra by Wavelet Transform Modulus Maxima Shift-Related Filter
TAO Wei-liang, WANG Xian-pei, LIU Yan, and YUAN Lei
In the present paper, a wavelet modulus maximum shift-related filter algorithm is proposed for denoising the absorption spectra. Firstly, using the wavelet transform modulus maxima theory, useful signal components and noise components of the binary wavelet coefficients of absorption spectra are identified. Then, the usIn the present paper, a wavelet modulus maximum shift-related filter algorithm is proposed for denoising the absorption spectra. Firstly, using the wavelet transform modulus maxima theory, useful signal components and noise components of the binary wavelet coefficients of absorption spectra are identified. Then, the useful signal components are aligned in the wave number domain to correct the “drifting” of modulus maximum across the scales, and the noise components are smoothed. Finally, according to the wavelet interscale dependencies obtained by multiplying the adjacent wavelet subbands preprocessed by the above procedure, important features of signal are enhanced while noises are attenuated further. Compared with the traditional spatially selective noise filtration technique proposed by Xu et al and adaptive multiscale products thresholding technique proposed by Paul Bao et al, the proposed wavelet modulus maximum shift-related filter algorithm has several advantages. First, it does not need estimate of the noise intensity, which could avoid the error introducing and the complex calculation. Meanwhile, there is not iterative calculation in the proposed algorithm, which could eliminate the risk of slow convergence or no convergence of the algorithm. Furthermore, the “drifting” of modulus maximum across the scales could be corrected in the proposed algorithm, which could make up for the loss of the spectrum information caused by the “drifting” phenomenon. Experiments show that the proposed scheme can effectively suppress noise and preserve the useful components in the infrared absorption spectra of SF6 gas..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1241 (2009)
Region Optimization of SSC Model for Pyrus Pyrifolia by Genetic Algorithm
PAN Lu, WANG Jia-hua, LI Peng-fei, SUN Qian, ZHANG Yong, and HAN Dong-hai
Genetic algorithm is widely used in NIRS data optimization, which is not limited by searching space. The region selecting by genetic algorithms (R-SGA)was applied in building calibration model of soluble solid content (SSC)of Pyrus pyrifolia, and the number of variables used to build calibration was further reduced froGenetic algorithm is widely used in NIRS data optimization, which is not limited by searching space. The region selecting by genetic algorithms (R-SGA)was applied in building calibration model of soluble solid content (SSC)of Pyrus pyrifolia, and the number of variables used to build calibration was further reduced from 2 075 to 690 in all of 3 models. Studies were performed to build GA-PLS models by different R-SGA latent variables, and the optimal R-SGA latent variables of Hosui, Wonhwang and Whangkeumbae pear were 10, 12 and 16, respectively. The R-SGA procedure was found to perform well (RMSEP=0.608 and 0.524 for Hosui and Whangkeumbae pear respectively), leading to calibration models that significantly outperform those based on full-spectrum analyses (RMSEP=0.632, 0.540). The prediction precision of GA-PLS models was similar to FULL-PLS for Wonhwang pear, with RMSEP of 0.610/0.595. In addition, the selected regions from R-SGA methods were used to build mixed model of 3 Pyrus pyrifolia varieties. The results indicated that the prediction precision of GA-PLS model was close to that of the full spectrum model, with RMSEP of 0.641 and 0.645, respectively. This work proved that the R-SGA could find optimal values for several disparate variables associated with the calibration model and that the PLS procedure could be integrated into the objective function driving the optimization, and it was feasible to build a universal model of different Pyrus pyrifolia varieties..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1246 (2009)
Identification of Xihu Longjing Tea by PLS Model Using Near-Infrared Spectroscopy
ZHOU Jian, CHENG Hao, HE Wei, WANG Li-yuan, and WU Di
Protection of geographical indication for Xihu longjing tea was necessary and an accurate method of identification of Xihu longjing tea ought to be developed to prevent Xihu longjing tea from being faked and protect the trade mark of Xihu longjing tea. Identification of Xihu longjing tea with near-infrared spectrum wasProtection of geographical indication for Xihu longjing tea was necessary and an accurate method of identification of Xihu longjing tea ought to be developed to prevent Xihu longjing tea from being faked and protect the trade mark of Xihu longjing tea. Identification of Xihu longjing tea with near-infrared spectrum was researched and a new method for identification of Xihu longjing tea by a quantitative model was developed. A new variance was first defined for Xihu longjing tea and other flat-shaped tea. And then the near-infrared spectrum without preprocess of tea was analyzed and partial least squares (PLS)was most suitably used to build the model (The number of PLS factors in this model is 9)for quantitative prediction. Compared with the critical numeral value, the result predicted by the PLS model was used to identify true Xihu longjing tea. The model was used to predict for 70 known samples which were used to build the quantitative model and 24 unknown samples. The recognition rate of 100% was achieved. So it is proved that the quantitative model by PLS was reliable and accurate to identify real Xihu longjing tea..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1251 (2009)
Identification of Papaver Somniferum L. and Papaver Rhoeas Using DSWT-FTIR-RBFNN
ZHANG Chang-jiang, and CHENG Cun-gui
Infrared spectra of Papaver somniferum L. and Papaver rhoeas were obtained directly, quickly and accurately by Fourier transform infrared spectroscopy (FTIR)with OMNI sampler. Discrete stationary wavelet transform was used to extrude local region of infrared spectra of Papaver somniferum L. and Papaver rhoeas. The diffInfrared spectra of Papaver somniferum L. and Papaver rhoeas were obtained directly, quickly and accurately by Fourier transform infrared spectroscopy (FTIR)with OMNI sampler. Discrete stationary wavelet transform was used to extrude local region of infrared spectra of Papaver somniferum L. and Papaver rhoeas. The difference of infrared spectra between Papaver somniferum L. and Papaver rhoeas was extruded. Accurate identification rate is improved greatly. One dimensional discrete stationary wavelet transform was implemented to the infrared spectra of Papaver somniferum L. and Papaver rhoeas. The difference between Papaver somniferum L. and Papaver rhoeas was observed at all scales in wavelet domain. Two scales, at which the difference between Papaver somniferum L. and Papaver rhoeas is the most obvious, were selected to extract the features of Papaver somniferum L. and Papaver rhoeas. A feature vector including eight feature parameters was constructed. The feature vector was input to RBFNN for training in order to accurately identify Papaver somniferum L. and Papaver rhoeas. In experiment, the authors used one hundred and twenty-eight couples of data of Papaver somniferum L. and Papaver rhoeas (including seventy-eight couples of training samples and fifty couples of testing samples). The experimental results show that it is effective to apply discrete stationary wavelet transform on the basis of FTIR to identify the Papaver somniferum L. and Papaver rhoeas. The accurate identification rate of Papaver somniferum L. and Papaver rhoeas is 99.8% and 99.9% respectively..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1255 (2009)
Deposition and Structures Analysis of Amorphous SiNx Films Prepared by Magnetron Sputtering
WU Yang, YI Li-xin, WANG Shen-wei, DU Yu-fan, HUANG Sheng, JI Guo-rui, and WANG Yong-sheng
Amorphous SiNx films were deposited on p-type Si(100)substrates by magnetron sputtering technology. The samples were then detected by a Bruker Tennsor 27 Fourier transform spectrometer. One intense absorption band of the SiNx films (from 812 to 892 cm-1)which was assigned to the stretching vibration mode of Si—N—Si bonAmorphous SiNx films were deposited on p-type Si(100)substrates by magnetron sputtering technology. The samples were then detected by a Bruker Tennsor 27 Fourier transform spectrometer. One intense absorption band of the SiNx films (from 812 to 892 cm-1)which was assigned to the stretching vibration mode of Si—N—Si bond was detected by Fourier transform infrared (FTIR)spectroscopy. Obviously, it was showed that a red shift of the absorption peak occurred in the FTIR spectrum with the sputtering power increasing; nevertheless, a blue shift of the absorption peak occurred after annealing with the temperature increasing. In the present paper, the deposition process and inner structures of the SiNx films were studied according to RBM (random bonding model)and CFM (central force model). With the increase in the ratio of N(Si)to N(N), the angle of the Si—N—Si changed and the different structures were formed correspondingly. Therefore the Si—Ny—Si4-y(0≤y≤4)models were set up to explain the inner structure of the SiNx films. The investigation showed that Si—N4 tetrahedron, Si—N—Si3, Si—N2—Si2, Si—N3—Si and Si—Si modes were formed accordingly in the SiNx films with the sputtering power increasing. And five models in total were formed during the deposition process. Different stretching vibration modes of Si—N—Si bond were corresponding to the different inner structures of thin films prepared by different sputtering power. With the temperature increasing, the activity of atoms increased which would let the angle of the Si—N—Si go to identical. As a result, Si3N4 and Si nanocrystals were formed with the phase separation of SiNx films during the annealing process with higher temperature, which would result in a blue shift to 870 cm-1 (the standard absorption peak of Si3N4)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1260 (2009)
Statistical Comparison of Independent Validation Results for Near Infrared Spectroscopy Models Predicting Calorific Value of Straw
HUANG Cai-jin, LIU Xian, YANG Zeng-ling, and HAN Lu-jia
Two hundred and twenty-two straw samples, consisting of 170 rice straw samples and 50 wheat straw samples, were collected from 24 provinces of China. Near infrared spectroscopy (NIRS)was applied to build quantitative models for calorific value of straw combining the use of principal component regression (PCR), partial Two hundred and twenty-two straw samples, consisting of 170 rice straw samples and 50 wheat straw samples, were collected from 24 provinces of China. Near infrared spectroscopy (NIRS)was applied to build quantitative models for calorific value of straw combining the use of principal component regression (PCR), partial least square regression (PLS)and modified partial least square regression (MPLS). Different scatter correction methods and derivative treatments were adopted to help improve the accuracy of NIRS models. A total of 54 NIRS models were obtained and independent validations were conducted using the same validation set of samples. A statistical comparison of independent validation results was then introduced to evaluate whether the models perform significantly. Bias and bias corrected standard error of prediction (SEP(C)), which are the mean and the standard deviation of the prediction residuals respectively, were compared by the proposed statistical procedures. It was concluded that near infrared spectroscopy was able to predict the calorific value of straw samples rapidly and accurately, with resulting SEP(C)s between 134 and 178 J·g-1; statistical comparison of biases and SEP(C)s was a reasonable and efficient way to compare spectral pre-processing methods, and select NIRS models predicting calorific value of straw..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1264 (2009)
Discrimination of Varieties of Dry Red Wines Based on Independent Component Analysis and BP Neural Network
WU Gui-fang, JIANG Yi-hong, WANG Yan-yan, and HE Yong
In order to achieve the rapid discrimination of the varieties of red wines, the authors selected 5 kinds of dry red wine for study with Vis/NIR spectroscopy. Firstly, Characteristics of the pattern were analyzed by independent component analysis (ICA). Through comparing the results of modeling performance by different In order to achieve the rapid discrimination of the varieties of red wines, the authors selected 5 kinds of dry red wine for study with Vis/NIR spectroscopy. Firstly, Characteristics of the pattern were analyzed by independent component analysis (ICA). Through comparing the results of modeling performance by different number of independent components, 20 principal components presenting important information of spectra were confirmed as the best number of principal components. The 20 independent components (ICs)extracted by ICA were employed as the inputs of the BP neural networks, and then a three layers of BP neural network was built, category analysis was performed, and the work of building mathematics model and optimizing the algorithm was completed. Five samples from each variety and a total of 25 samples were selected randomly as the prediction sets. The remaining 150 samples were used as the training sets to build the training model, which was validated by the samples of the prediction sets. The recognition rate was 100%. In addition, based on the independent component analysis, the authors selected two characteristic wave bands in reference to vector loading map of mixed matrix. So the pattern recognition methods developed in this paper not only played a good role in the classification and discrimination, but also had the capability to extract the finger feature of red wine, and offered a new way for detecting and developing red wines..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1268 (2009)
FTIR Spectroscopic Studies of the Photo-Discoloration of Chinese Fir
WANG Xiao-qing, FEI Ben-hua, and REN Hai-qing
Wood or wood products undergo rapid degradation of surface characteristics and quality indicated by changes in wood color during outdoor exposure owing to a combination of various weathering factors, which may result in significant reduction in utilization values of wood. In the present study, photodegradation of wood Wood or wood products undergo rapid degradation of surface characteristics and quality indicated by changes in wood color during outdoor exposure owing to a combination of various weathering factors, which may result in significant reduction in utilization values of wood. In the present study, photodegradation of wood surfaces of Chinese fir (Cunninghamia lanceolata)was carried out by a Xenon test chamber which can simulate sunlight irradiation. A Fourier transform infrared (FTIR)spectroscopy technique was used to study chemical changes caused by irradiation during photo-discoloration of wood surfaces, and the relationship between the changes in color and chemical composition was established. Results indicated that, during the process of irradiation, the intensity of absorption bands at 1 512, 1 462, 1 269 and 1 227 cm-1 decreased significantly, accompanied by a successive increase in the intensity of band at 1 720-1 735 cm-1. Lignin was the most sensitive component to the degradation process and underwent severe photodegradation during the process of irradiation. This was accompanied by formation of new carbonyl compounds, which indicated the photo-oxidation of wood surfaces. In the initial 80 h of irradiation, the degradation of lignin and formation of carbonyl groups were intense, and then became insignificant in longer exposure duration. Degradation of polysaccharides (cellulose and hemicellulose)also occurred during the process. Overall, color changes (ΔE*)were correlated well with the degradation of lignin and relative increase in the content of carbonyl groups during the process of irradiation..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1272 (2009)
Application of Particle Swarm Optimization Algorithm in Infrared Spectrum Quantitative Analysis of Gas Mixture
LI Yu-jun, TANG Xiao-jun, and LIU Jun-hua
An infrared spectrum quantitative analysis model was built based on particle swarm optimization algorithm (PSO)and backward propagation (BP)neural network. This model aimed at three components of gas mixture, with methane, ethane and propane gases included. The concentration of each component ranged from 0.01% to 0.1%.An infrared spectrum quantitative analysis model was built based on particle swarm optimization algorithm (PSO)and backward propagation (BP)neural network. This model aimed at three components of gas mixture, with methane, ethane and propane gases included. The concentration of each component ranged from 0.01% to 0.1%. Five features variables were abstracted from 1 866 infrared spectrum data by principal component analysis as the input of the BP network. The gas concentrations acted as the output. PSO was used to optimize the number of neural network hidden layer nodes. Then, the network was trained to construct models for quantitative analysis of these three kinds of gas. The experiment results show that the time taken for optimizing the prediction model by PSO, about 4 600 second, reduced to one fifth of that of ergodic optimizing, which is about 24 500 second. The precision of the model is corresponsive and the structure of the network is approximately the same. So the PSO has definite practical significance and application potential..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1276 (2009)
Application of Near-Infrared Spectroscopy to Quality Detection of Milk and Its Products
WANG Jing, WANG Jia-qi, BU Deng-pan, GUO Wei-jie, SHEN Jun-shi, WEI Hong-yang, ZHOU Ling-yun, and LIU Kai-lang
Milk and its products as a kind of ideal comprehensive nutritional food, has becoming an indispensable part of people’s daily life. But at the same time, the quality of dairy products has been also increasingly concerned by consumers. Real-time, rapid and accurate detection of milk and its products in terms of componenMilk and its products as a kind of ideal comprehensive nutritional food, has becoming an indispensable part of people’s daily life. But at the same time, the quality of dairy products has been also increasingly concerned by consumers. Real-time, rapid and accurate detection of milk and its products in terms of component, adulterants, residues and preservatives is the primary condition for improving the dairy products quality and controlling the production process. Quality predication of milk and its products was often completed by laboratory analysis in the past, which was complicated and time-consuming and could not satisfy the needs for evaluating the milk products quality and monitoring the production proceeding effectively. How to predict the quality of milk and its products quickly and accurately is a practical problem that needs to be resolved. Near-infrared spectroscopy (NIRS)is a rapid, convenient, highly efficient, non-destructive and low-cost analytical technique, which has been widely used in various fields for quantitative and qualitative analysis. As a new analysis technique, NIRS has great potential of application to milk and its products detection, owning to its quick, concise and non-destructive characteristics. The main nutrient components were the major index of milk and its products quality evaluation. Determining the main nutrient components of milk and its products rapidly can provide sound basis for evaluating the products quality. At the same time, adulterants, residues and preservatives were also distinct fingerprint characteristics in the NIR spectra just like the main nutrient components. So this new approaches could also be used in quality distinguishing and on-line detection of milk and its products. Many researches have also concluded that NIRS technology has good stability and high prediction ability on dairy products analysis, exhibites well correlation with the result by labor analysis method. In the present paper, the principles and advantages of NIRS were described. The research advancement of NIRS utilization for milk products nutrient component determination, quality estimation and on-line detection and the application prospect were comprehensively reviewed. With the development of spectral technique, the prediction model gained through NIRS will be more and more reliable and practicable, and the NIRS technique will be more widely used in milk and its products determination, quality estimation and on-line detection..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1281 (2009)
Analysis of the 4th Generation Scutellaria Baicalensis Georgi with Space Mutagenesis Via FTIR Spectroscopy
DING Xi-feng, GAO Hua-na, GUO Xi-hua, WANG Zhi-zhou, YANG La-hu, GUAN Ying, and SHI Jin-shan
Determination and analysis for the Scutellaria baicalensis Georgi with space mutagenesis and the ground group were carried out with FTIR for the first time in order to fully understand the quality changes of the 4th generation of space mutagenesis of Scutellaria baicalensis Georgi and do further research. The result shDetermination and analysis for the Scutellaria baicalensis Georgi with space mutagenesis and the ground group were carried out with FTIR for the first time in order to fully understand the quality changes of the 4th generation of space mutagenesis of Scutellaria baicalensis Georgi and do further research. The result shows that for the FTIR spectra of the two samples the position and shape of main absorption peaks are approximately the same, indicating that the major components and the structures of space group remain intact, but the intensities of the absorption peaks are obviously different, with the intensities of the space group significantly enhanced compared to the ground group, especially for the flavonoid compounds (baicalin, baicalein, wogonoside, wogonin and wogonoside etc), which are the main active components of the Scutellaria baicalensis Georgi, the absorption peak intensities at 3 391, 1 655 and 1 069 cm-1 are obviously stronger than those of the ground group, so the contents of flavonoid compounds and other components are higher, and the amorphous active components are optimized. Space mutation breeding is conducive to breeding new varieties of highly active components, and it is also one of the ways to innovate Chinese medicines germplasm resources efficiently..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1286 (2009)
Template Preparation of Metal-Molecule-Metal Junction and Its SERS Investigation
XU Min-min, WANG Mei, YAO Jian-lin, ZOU Wen-jun, LING Li, and GU Ren-ao
In the present paper, the authors reported the assembly and SERS studies of a simple device unit of a metal nanowire-molecule-metal nanoparticles junction in an anodic aluminum oxide (AAO)template. The AAO template was fabricated by two-step electrochemical oxidation. Metals were filled into the pores by AC deposition.In the present paper, the authors reported the assembly and SERS studies of a simple device unit of a metal nanowire-molecule-metal nanoparticles junction in an anodic aluminum oxide (AAO)template. The AAO template was fabricated by two-step electrochemical oxidation. Metals were filled into the pores by AC deposition. Then the AAO template with metal nanowires was immersed into the solution of 1,4-benzenedithiol (1,4-BDT), which was followed by the immersion into silver nanoparticles with appropriate diameter. 1,4-BDT served as the probe molecule for SERS detection as well as the molecule for linking the metal nanowires and metal nanoparticles. The simple junction of metal-molecule-metal embedded in AAO template was built successfully. The SERS effect of the junction was investigated through the dissolution of AAO template to expose the junctions in the same orientation (standing on the substrate vertically). The giant enhancement from the former junction might be attributed to the coupling effect in the junction. The authors’ preliminary results revealed that SERS might be a characteristic tool for the junction and the construction on the junction will be beneficial to the investigation of the complex SERS mechanism..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1289 (2009)
The Reseach on Raman Spectra of 1-Hexanol at High Pressure
LI Rui, and ZHANG Hai-fei
The present paper investigates Raman spectral characters of 1-hexanol by the SiC anvil cell at the pressure of 163.4-793.4 MPa and the temperature of 25 ℃. It was found that under the pressure of 163.4-767.6 MPa the character of 1-Hexanol is steady, and the frequencies of C—H symmetrical stretch vibration and antisymmeThe present paper investigates Raman spectral characters of 1-hexanol by the SiC anvil cell at the pressure of 163.4-793.4 MPa and the temperature of 25 ℃. It was found that under the pressure of 163.4-767.6 MPa the character of 1-Hexanol is steady, and the frequencies of C—H symmetrical stretch vibration and antisymmetric stretch vibration increase with increasing pressure, and the relations between the frequency and the pressure are given as follows: ν2 876=0.009 1P+2 875.1, ν2 931=0.005 7P+2 930.5. At 793.4 MPa there is transformation from liquid state to solid state. On the basis of former data, the authors contrasted the features of 1-hexanol, methanol and ethanol under high pressure. It was revealed that the relation between wave numbers of C—H symmetrical stretch vibration peaks and system pressure is independent of the C—C bond, that is the relation between wave numbers of C—H symmetrical stretch vibration peaks and system pressure is foreign to the number of the carbon atoms..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1292 (2009)
Solvent Effects on Raman Spectroscopy of 1,1,3,3-Tetramethylurea in Organic Solvents
ZHANG Liu-yang, LI Zuo-wei, LU Guo-hui, GAO Shu-qin, and JIANG Yong-heng
Raman spectra of 1,1,3,3-tetramethylurea in 20 solvents were obtained to investigate the solute-solvent interactions and to correlate solvent properties such as the Kirkwood-Bauer-Magat (KBM)equation, the solvent acceptor number (AN)and the linear solvation energy relationships (LSER), respectively, with the Raman shifRaman spectra of 1,1,3,3-tetramethylurea in 20 solvents were obtained to investigate the solute-solvent interactions and to correlate solvent properties such as the Kirkwood-Bauer-Magat (KBM)equation, the solvent acceptor number (AN)and the linear solvation energy relationships (LSER), respectively, with the Raman shifts of carbonyl group. There is little linear relation between dielectric constants and the Raman shift. These solvents were divided into two sections by the acceptor number. The two sections exhibit a good correlation with AN, respectively. These frequencies show a better correlation with LSER than the solvent AN. How the solvents interacts with the CO can be obtained from the regression coefficients..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1296 (2009)
Research on the Supersensitive Detecting Technology of Backward Raman Scattering Signal in Optic Fiber
ZHANG Yue, ZHANG Ji-long, LI Xiao, WANG Zhi-bin, and WANG Peng
Unlike the Brillouin scattering, the anti-Stokes Raman scattering in optic fiber is unrelated with the strain, but is only the function of the absolute temperature. The frequency shift caused by Raman scattering is about 13.95 Thz. So the Raman scattering is easier to be picked up than Brillouin scattering. It has certUnlike the Brillouin scattering, the anti-Stokes Raman scattering in optic fiber is unrelated with the strain, but is only the function of the absolute temperature. The frequency shift caused by Raman scattering is about 13.95 Thz. So the Raman scattering is easier to be picked up than Brillouin scattering. It has certain advantage while being used as the signal of the distributed optic-fiber temperature sensor. But it is weaker than the Brillouin scattering, the peak photocurrent produced in APD is of the order of nA,near or even lower than the noise current of the APD. The N/S after being photo-electric transformed is usually lower than 1. The means of Fourier transform and wavelet transform is not effective in dealing with such kind of signal. Through analyzing the feature of the anti-Stokes Raman scattering signal and using the wavelet, the anti-Stokes Raman scattering signal after being cumulated & averaged was picked up. The supersensitive detecting below the “noise current” of the APD was carried out with the senstivity: 0.104 nA·K-1,lower than the “noise current” of the APD 2 classes..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1300 (2009)
Measurement of Nasopharyngeal Carcinoma Tissue ex vivo by Raman Spectroscopy
HUANG Wei, PAN Jian-ji, CHEN Rong, LI Yong-zeng, FENG Shang-yuan, XIE Shu-sen, and ZENG Hai-shan
Raman spectroscopy has shown its potential and advantages in detecting molecular changes associated with tissue pathology, which makes it possible to diagnose with optical methods non-invasively and real-time. A compact and rapid near-infrared (NIR)Raman system was developed using 785 nm diode laser, volume phase technRaman spectroscopy has shown its potential and advantages in detecting molecular changes associated with tissue pathology, which makes it possible to diagnose with optical methods non-invasively and real-time. A compact and rapid near-infrared (NIR)Raman system was developed using 785 nm diode laser, volume phase technology (VPT)holographic grating system and NIR intensified charge-coupled device (CCD)with a specially designed Raman fibre probe which can effectively reduce the interference of fluorescence and Rayleigh scattering, maximize the ability of Raman collection as well as correct the image aberration of a planar grating diffraction. Adopting this method, signal-to-noise ratio has been greatly improved and human tissue signals can be acquired in a short time. Raman signals from fat and musculature of fresh pork were measured and referenced for further optimization, then Raman spectra of nasopharyngeal carcinoma in vitro and the effect of storage time on them were measured in 1-5 s and discussed. The sensitivities and performance of the system will be further enhanced and more Raman data will be acquired and compared between normal and cancerous nasopharyngeal tissue, expecting to discover the statistical characteristics, which will benefit the diagnosis and treatment of early nasopharyngeal carcinoma or other tumors..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1304 (2009)
Fluorescence Spectra and Protonation of Ofloxacin in Strong Acidic Solutions
LI Hui-zhen, ZHANG Cheng-feng, GAO Xiu-xiang, HUANG Kun, ZHAI Yu-jing, XU Yi-zhuang, and WU Jin-guang
Fluorescence and UV-Vis spectra of ofloxacin (OFL)in sulfuric acid were studied. In the present paper, a new protonation state of OFL was observed. In hydrochloric acid, OFL produced bright green fluorescence upon excitation by UV radiation. The maximal emission wavelength of OFL is about 505 nm. However, OFL produces Fluorescence and UV-Vis spectra of ofloxacin (OFL)in sulfuric acid were studied. In the present paper, a new protonation state of OFL was observed. In hydrochloric acid, OFL produced bright green fluorescence upon excitation by UV radiation. The maximal emission wavelength of OFL is about 505 nm. However, OFL produces violet fluorescence when dissolved in concentrated sulfuric acid. The maximal emission wavelength changes into 400 nm. Further analysis demonstrated that the above changes arise from the variation of protonation states of OFL molecule. In dilute sulfuric acid, OFL accepted one proton, resulting in a protonation state that is similar to the OFL molecule dissolved HCl solution. The corresponding fluorescence band occurs at 505 nm. In concentrated sulfuric acid solution, OFL might accept additional protons. As a result, the size of the conjugated system is reduced and the fluorescence band exhibits a blue shift. In sulfuric acid of moderate concentrations, two bands at 505 and 400 nm respectively were found in the fluorescence emission spectra, indicating that OFL in two different protonation states coexists in the solution. In addition, both excitation band in excitation spectra and absorption bands in UV-Vis spectra exhibit red-shifted with the decrease in the concentration of sulfuric acid. Based on the above result, OFL can be used as a spectral probe to reflect the variation of H+ in strong acid environment..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1308 (2009)
Three-Dimensional Excitation Emission Matrix Fluorescence Spectroscopic Characterization of Loosely Bound and Tightly Bound Extracellular Polymeric Substances of Sludge
OUYANG Er-ming, WANG Wei, LONG Neng, and LI Huai
Three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM)was applied to characterize the loosely bound extracellular polymeric substances (LB-EPS)and tightly bound extracellular polymeric substances (TB-EPS)extracted from aerobic sludge in wastewater treatment. The results showed that three fluoresThree-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM)was applied to characterize the loosely bound extracellular polymeric substances (LB-EPS)and tightly bound extracellular polymeric substances (TB-EPS)extracted from aerobic sludge in wastewater treatment. The results showed that three fluorescence peaks were identified in three-dimensional excitation emission matrix fluorescence spectra of the LB-EPS and TB-EPS: peak B (λex/λem=270-280 nm/345-360 nm), peak C (λex/λem=330-340 nm/410-430 nm)and peak D (λex/λem=390 nm/450-470 nm). The peak B was attributed to the protein-like fluorophores, peak C to the visible fulvic-like fluorophore and peak D to the humic-like fluorophore. Results of the peak intensity showed that the major component of the LB-EPS and TB-EPS is protein-like organic matter, then followed by (from high to low): fulvic-like organic matter and humic-like organic matter. The effects of both pH and concentration were significant to the 3DEEMs of LB-EPS and TB-EPS, but the degree is not the same. LB-EPS has the particular chemical structures which are different from the TB-EPS..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1313 (2009)
Study on Three-Dimensional Fluorescence Spectra of Phenanthrene
JIN Dan, ZHANG Yu-jun, LI Guo-gang, XIAO Xue, WANG Zhi-gang, YIN Gao-fang, and LIU Wen-qing
According to the high fluorescence quantum yields of polycyclic aromatic hydrocarbons (PAHs), the fluorescence spectra of phenanthrene were investigated by three dimensional fluorescence excitation-emission matrix(3DEEM). The results show that the three-dimensional fluorescence spectra of phenanthrene in aqueous solutiAccording to the high fluorescence quantum yields of polycyclic aromatic hydrocarbons (PAHs), the fluorescence spectra of phenanthrene were investigated by three dimensional fluorescence excitation-emission matrix(3DEEM). The results show that the three-dimensional fluorescence spectra of phenanthrene in aqueous solution mainly have two fluorescence peaks. On the basis of three-dimensional fluorescence spectrometry analysis of phenanthrene, the excitation wavelength of 255 nm and emission wavelength of 273 nm were chosen for the quantitative analysis of phenanthrene. The linear range for the determination of phenanthrene was 5.0-250.0 mg·mL-1, its detection limit was 3.88 ng·mL-1, and its relative standard deviation was 4.23% (n=5). It was a good precision. It has been tested satisfactorily for the determination of artificial sample in tap water. The recoveries are in the range of 90%-105%. The method provided basis for the rapid monitoring of trace PAHs in water..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1319 (2009)
Spectroscopic Analysis of Nd∶GGG Laser Crystal
ZENG Fan-ming, ZHANG Ying, SUN Jing, and LIU Jing-he
Neodymium-doped gadolinium gallium garnet (Nd∶GGG)crystal is the best operation material of solid-state heat-capacity laser. In the present paper, Nd∶GGG single crystal was grown by Czochralski (Cz)method. Fluorescence spectra and absorption spectra were measured. At the same time, the spectral parameters of Nd∶GGG lasNeodymium-doped gadolinium gallium garnet (Nd∶GGG)crystal is the best operation material of solid-state heat-capacity laser. In the present paper, Nd∶GGG single crystal was grown by Czochralski (Cz)method. Fluorescence spectra and absorption spectra were measured. At the same time, the spectral parameters of Nd∶GGG laser crystal were calculated by Judd-Ofelt theory, including absorption and emission cross-section, intensity parameters, radiative transition probability, fluorescence branch ratio and fluorescent lifetime. According to the measurement and calculation of absorption spectra, it is illustrated that the main absorption peak of Nd∶GGG crystal was at near 808 nm, the absorption cross section of the main peak at 808 nm σabs was equal to 4.35×10-20 cm2. The FWHM of absorption line-width was equal to 8 nm, and the absorption intensity became stronger with the increase in Nd3+ ions concentration. According to the measurement and calculation of fluorescence spectra, the fluorescence emission peak was at near 1 062 nm, which corresponds to 4F3/2-4I11/2 emission band of Nd3+ ions. The radiative transition probabilityof the main emission peak at 1 062 nm AJJ′ was equal to 1 832.01 s-1. The fluorescence branch ratio βJJ was equal to 45.07％. The fluorescence lifetime τ was equal to 250 μs. The stimulated emission cross section σ(λ) was equal to 21.58×10-20 cm2. The laser operation of 4F3/2-4I11/2 transition can be realized due to the larger fluorescence branch ratio and stimulated emission cross section..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1323 (2009)
Spectroscopic Investigation of Retrofluorescence in a Pure Optically Thick Rb Vapour Near the Surface
SHEN Xiao-yan, LIU Jing, GUO Qi-cun, DAI Kang, and SHEN Yi-fan
A low-power tunable laser was used to populate the Rb(5P3/2)hyperfine-structure levels in a pure optically thick vapour in the presence of a dissipative surface. The retrofluorescence intensities and spectrum profile for the 780 nm (5P3/2→5S1/2)and 795 nm (5P1/2→5S1/2)lines were measured and analyzed. The glass-vapor iA low-power tunable laser was used to populate the Rb(5P3/2)hyperfine-structure levels in a pure optically thick vapour in the presence of a dissipative surface. The retrofluorescence intensities and spectrum profile for the 780 nm (5P3/2→5S1/2)and 795 nm (5P1/2→5S1/2)lines were measured and analyzed. The glass-vapor interface was considered as two distinct regions, a wavelength-thickness vapor layer adjacent to the surface and a more remote vapor region. The first region was analyzed as a spectral filter that annihilated the absorbed photons and the second one as a rich spectral light source. The authors discussed two possible mechanisms for the 5P1/2 population in the cell［i.e., mechanism(1):collisions Rb(5P3/2)+Rb(5S1/2)→Rb(5P1/2)+Rb(5S1/2); mechanism(2): collisions Rb(5D)+Rb(5S)→Rb(5P)+Rb(5P)］. For each one of the possible mechanisms considered, the authors gave the theoretical formulation of the retrofluorescence integrated signal associated with 795 nm(5P1/2→5S1/2), which was compared with experiment. Two important characteristic aspects of retrofluorescence spectra must be taken into account when dealing with retrofluorescence signals for atomic process investigation: the retrofluorescence intensity dependence on laser power and sensitized laser retrofluorescence line shapes. When the laser frequency is scanned through the hyperfine resonance line, the sensitized retrofluorescence spectra signal corresponding to the 795 nm line has a profile similar to the profile of the retrofluorescence signal at the 780 nm. The authors have pointed out that mechanism(1)gives the linear dependence of the trtrofluorescence as a function of laser power and the spectrum profile. The population of the 5P1/2 atomic level in an optically thick vapour can be principally explained by the fine-structure excitation transfer process ［mechanism(1)］. It appears from our experimental and theoretical investigations that, the spectral properties of the laser-induced Rb 795 nm sensitized retrofluorescence in a pure optically thick vapour near a dissipative surface cannot be explained by the mechanism(2)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1327 (2009)
Research on the Autofluorescence Spectroscopy in Rats Doing Medium-Intensity Exercise
REN Wen-jun, XU Zheng-hong, ZHANG Zhen-xi, YANG Xu-dong, and LI Zheng
The laser-inducted fluorescence spectrum technology (LIF) was used for the first time to study the autofluorescence spectral characteristics of the heart, kidney, liver, fat, foreleg muscle, hind leg soleus muscle and musculus gastrocnemius of the rat performing motion exercises. The wavelength of the excitation light The laser-inducted fluorescence spectrum technology (LIF) was used for the first time to study the autofluorescence spectral characteristics of the heart, kidney, liver, fat, foreleg muscle, hind leg soleus muscle and musculus gastrocnemius of the rat performing motion exercises. The wavelength of the excitation light used during the measurement was in the range of 250-650 nm and the emission wavelength was 300-700 nm. When comparing the three-dimensional fluorescence spectra of the control group with those of the four groups of different motion states, a specific fluorescence peak related to the motion and located in the area where the excitation wavelength was (340±10) nm and the emission wavelength was (460±10) nm was found mainly in the spectra of the soleus muscle. From this fluorescence peak, it is possible to determine that its corresponding fluorescent substance is NADH (nicotinamide adenine dinucleotide reduced). When comparing the fluorescence spectra of the four groups of different motion modes, it was found that the motion mode has a conspicuous relativity with the peak intensity. The results show that the energy metabolism of the soleus muscle of the rat in motion is stronger than that of the foreleg, soleus muscle and other visceras, and the autofluorescence spectral characteristics of NADH form one of the effective indexes for determining the muscular metabolism degree..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1331 (2009)
Effect of the Change in Serum Concentration on Serum Fluorescence Spectrum
WANG Le-xin, ZHAO Zhi-min, CHEN Hui, LI Peng, and XIN Yu-jun
The spectral analysis technology applied to some blood diseases diagnosis is convenient and speedy. The experimental result shows that the line type and peak value of the fluorescence spectra of serum excited by ultraviolet radiation with different wavelength remain the same, but the fluorescence peak value changes witThe spectral analysis technology applied to some blood diseases diagnosis is convenient and speedy. The experimental result shows that the line type and peak value of the fluorescence spectra of serum excited by ultraviolet radiation with different wavelength remain the same, but the fluorescence peak value changes with the wavelength of the blazed light. The present paper studied how the serum fluorescence spectrum changes with the serum concentration, adopting Shimadzu Corporation (Japan) fluorescence photometer RF5301, and provided the experiment basis for disease diagnosis by hemanalysis. The experimental result shows that the fluorescence spectrum of serum is different under the excitation of different monochromatic light, the relative fluorescence intensity of serum increases with the serum concentration when excitated with 220, 230 and 310-420 nm monochromatic light, but the serum fluorescence intensity decreases while the serum concentration increases when the excitation monochromatic light is between 240 nm and 420 nm. The experimental research found that the serum concentration quenching and absorption effect is not obvious when the experimental sample is excitated by 220, 230 and 310 to 420 nm monochromatic light, and the fluorescence stimulation plays the main role. The serum concentration quenching and absorbing effect is obvious, so the fluorescence intensity becomes weaker and weaker with serum concentration increasing when the sample is excitated by 240 nm to 300 nm monochromatic light. This work provides the experimental basis for the choice of serum concentration in the study of serum fluorescence spectrum..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1336 (2009)
A Microplate Fluorimetric Assay for Sacchariase Activity Measurement
ZHANG Li-li, WU Zhi-jie, CHEN Li-jun, LI Dong-po, MA Xing-zhu, and SHI Yun-feng
With the fluorescent compound conjugates substrates, soil xylanase and cellulose in a free-air carbon dioxide enrichment (FACE) experiment were measured on the base of 96 microplate and fluorescence detection, aiming at testing its feasibility in sacchariase activity measurement. The results show that sacchariase activWith the fluorescent compound conjugates substrates, soil xylanase and cellulose in a free-air carbon dioxide enrichment (FACE) experiment were measured on the base of 96 microplate and fluorescence detection, aiming at testing its feasibility in sacchariase activity measurement. The results show that sacchariase activity can be tested and the data exhibit better repeatability（coefficient of variability≤4.879%）. Compared with spectrophotometric assay, this method allows a large number of soil samples and/or enzymes to be analyzed in a short time accurately and conveniently. Soil xylanase activity tends to be greater at elevated CO2 which significantly increases in jointing, heading and ripening stages of wheat and in heading and ripening stages of rice (P<0.05), and the crop metabolizes rapidly under FACE condition and soil microorganisms are affected, which causes elevation of xylanase acitivy. Compared with ambient CO2, soil cellulose activity decreased slightly under elevated CO2 but there was no significant difference between treatments, indicating the cellulose activity was not influenced intensively in a short time..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1341 (2009)
Fluorescence Characterization of Dissolved Organic Matter in East China Sea
WANG Jiang-tao, GUAN Ha-si-gao-wa, ZHAO Wei-hong, and WANG Xiu-lin
Sea water samples were collected in the East China Sea in March and April, 2005, and three-dimensional fluorescence of dissolved organic matter was measured by fluorescence excitation-emission matrix spectroscopy. The position, number and intensity of fluorescence peak in the spectra and the relations of the peaks wereSea water samples were collected in the East China Sea in March and April, 2005, and three-dimensional fluorescence of dissolved organic matter was measured by fluorescence excitation-emission matrix spectroscopy. The position, number and intensity of fluorescence peak in the spectra and the relations of the peaks were analyzed to determine the type, distribution and origin of the fluorescence dissolved organic matter. Seven types of fluorescence peaks were detected from the samples. There are protein-like fluorescence peaks B with Exmax/Emmax=275/300 nm, D with Exmax/Emmax=225/295-305 nm, T with Exmax/Emmax=280/345 nm, and S with Exmax/Emmax=225-240/320-350 nm, two humic-like peaks A with Exmax/Emmax=250-255/410-455 nm and C 335-345/410-440 nm, and marine humic peak M with Exmax/Emmax＝305 nm/400-420 nm. Peaks B, S and A appeared in all surveyed area. Peaks T and D appeared in the north of the surveyed area. Peaks M and C only appeared in a few stations. In the surface layer, the source of the fluorescence dissolved organic matter might be the fresh water outflow of the Yangtze River, while the fluorescence dissolved organic matter in the middle layer had double sources from the Yangtze River and the phytoplankton. The good correlationships of different fluorescence peaks showed the same source or some relationship between the protein-like and the humic-like fluorescence dissolved organic matter..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1345 (2009)
Fluorescence Characterization of Dissolved Organic Matter in the East China Sea after Diatom Red Tide Dispersion
ZHUO Peng-ji, and ZHAO Wei-hong
Fluorescence excitation-emission spectroscopy (EEMS) was employed to analyze the 3-dimensional fluorescence of dissolved organic matter in the East China Sea after diatom red tide dispersion. The relationships between fluorescence peak intensity, and salinity and chlorophyll-a were discussed. The centers of protein-likFluorescence excitation-emission spectroscopy (EEMS) was employed to analyze the 3-dimensional fluorescence of dissolved organic matter in the East China Sea after diatom red tide dispersion. The relationships between fluorescence peak intensity, and salinity and chlorophyll-a were discussed. The centers of protein-like fluorescence peaks dispersed at Exmax/Emmax=270-280/290-315 nm (Peak B), 220-230/290-305 nm (Peak D）, 230-240/335-350 nm（Peak S）and 280/320 nm（Peak T）. Two humic-like peaks appeared at 255-270/435-480 nm (Peak A）and 330-350/420-480 nm（Peak C）. High tyrosine-like intensity was observed in diatom red tide dispersion area, and tryptophan-like fluorescence was also found which was lower. High FIB/FIS showed that diatom red tide produced much tyrosine-like matter during dispersion. Peaks S, A and C had positive correlation with one another, and their distributions were similar, which decreased with distance increasing away from the shore. Good negative correlations between peaks S, A and C and salinity suggested that Jiangsu-Zhejiang coastal water was the same source of them. Correlations between fluorescence peak intensity and chlorophyll-a were not remarkable enough to clear the relationship between fluorescence and living algal matter. It was supposed that the living algal matter contributed little to the fluorescence intensity of algal dispersion seawater..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1349 (2009)
Study on UV-Vis Absorption Spectra and Fluorescence Emission Spectra of Sixteen Tetra-Substituted Metallophthalocyanine Complexes
HUANG Zi-yang, HUANG Jian-dong, CHEN Nai-sheng, and HUANG Jin-ling
The UV-Visible absorption spectra and the fluorescence emission spectra of sixteen tetra-substituted metallo-phthalocyanine complexes {R4PcM, where R=2-［4-(2-sulfonic ethyl)piperazin-1-］ ethoxyl (SPEO—), 2-(piperidin-1-yl)ethoxyl (PEO—); substitution position at α-position and β-position of phthalocyanine ring; M=Zn(Ⅱ)The UV-Visible absorption spectra and the fluorescence emission spectra of sixteen tetra-substituted metallo-phthalocyanine complexes {R4PcM, where R=2-［4-(2-sulfonic ethyl)piperazin-1-］ ethoxyl (SPEO—), 2-(piperidin-1-yl)ethoxyl (PEO—); substitution position at α-position and β-position of phthalocyanine ring; M=Zn(Ⅱ), Ni(Ⅱ), Co(Ⅱ)and Cu(Ⅱ)} were measured. The influence of different central ion, substituted group and its position, as well as different solvent on the Q-band of phthalocyanine complex in its UV-Vis absorption spectra was investigated. The influence of different central ion, substituted group and its position on the fluorescence emission spectra was discussed. Some properties of the UV-Vis absorption spectra such as the maximum absorption wavelength (λmax)of Q-band and its molar extinction coefficient (ε), and those of the fluorescence emission spectra such as fluorescence quantum yield (ΦF), fluorescence lifetime (τ) and excited state energy (Es)were studied. The results showed that the λmax of Q-band of all complexes were located at 681-718 nm, which had a distinct red shift in contrast with unsubstituted metallophthalocyanines (669-671 nm). All complexes of R4PcM possessed a very high molar extinction coefficient up to 105 L·mol－1·cm-1. And the UV-Vis absorption spectra and the fluorescence emission spectra of all complexes exhibited mirror shape concurrently. Two β-substituted zinc phthalocyanine complexes with formula β-(SPEO)4PcZn and β-(PEO)4PcZn possessed very high molar extinction coefficient, fluorescence quantum yield and fluorescence lifetime specially. Therefore, it is hoped that these two would be developing to be new photosensitizers for photodynamic therapy (PDT)and photodynamic diagnosis (PDD)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1354 (2009)
Synthesis and Spectral Properties of Polymer of Tis(5, 5′-Methylene-Bis(8-Hydroxy-Quinoline)Gallium with Orange-Red Light Emitting
GUO Hai-bo, HAO Yu-ying, FAN Wen-hao, ZHANG Zhi-qiang, GUO Xiao-xia, and XU Bing-she
A ligand 5,5′-methylene-bis(8-hydroxyquinoline)(Hqq)was synthesized by condensation reaction at low temperature and was subsequently coordinated to gallium ions to prepare the polymer of tis(5,5′-methylene-bis(8-hydroxyquinoline)gallium (Gaqq3)n. Both chemical structure and phase structure of the ligand and complexes wA ligand 5,5′-methylene-bis(8-hydroxyquinoline)(Hqq)was synthesized by condensation reaction at low temperature and was subsequently coordinated to gallium ions to prepare the polymer of tis(5,5′-methylene-bis(8-hydroxyquinoline)gallium (Gaqq3)n. Both chemical structure and phase structure of the ligand and complexes were characterized by Infrared absorption spectrum and X-ray diffraction (XRD). The thermal stability of the complexes was studied by thermogravimetry (TG). The photo-physical properties of the complexes were investigated by ultraviolet absorption spectrum (UV), fluorescence excitation spectrum and emission spectrum. The result indicated that (Gaqq3)n is a thermally stable material, whose decomposition temperature is 443.6 ℃. The ultraviolet absorption bands of (Gaqq3)n are in the range of 250-500 nm, with a relatively strong band tail absorption between 500 and 650 nm, which shows that the band-gap defect states exists in the forbidden band. The fluorescence excitation band of (Gaqq3)n is located at 380-456 nm, and (Gaqq3)n. emits orange-red fluorescence with the emission peak at 568 nm, which shows that the fluorescence emission of (Gaqq3)n is mainly attributed to the charge transfer transitions from phenol to ring pyridine ring, while the π→π* transition of benzene ring is deactivated by non-radiative transition, and makes no contribution to fluorescence emission. (Gaqq3)n optical band gap is 2.49 eV. Compared with the fluorescence emission peak of Gaq3, the fluorescence intensity of (Gaqq3)n decreases, which is attributed to the distortion of the two quinoline rings connected to the methylene, hence leads to the poor rigidity and coplanarity of (Gaqq3)n, thus affects fluorescence emission intensity. Because of the extending of the molecular conjugation system, π electron of (Gaqq3)n is more delocalized, resulting in the redshift of fluorescence emission peak. (Gaqq3)n is expected to be applied in organic light emitting display and organic photovoltaic devices..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1358 (2009)
Quantitative Retrieval of Soil Salinity Using Hyperspectral Data in the Region of Inner Mongolia Hetao Irrigation District
QU Yong-hua, DUAN Xiao-liang, GAO Hong-yong, CHEN Ai-ping, AN Yong-qing, SONG Jin-ling, ZHOU Hong-min, and HE Tao
In the present paper, to investigate the spectral property of salinized soil and the relationship between the soil salinity and the hyperspectral data, the field soil samples were collected in the region of Hetao irrigation, Neimeng in the northwest China from the end of July to the beginning of August. The partial leaIn the present paper, to investigate the spectral property of salinized soil and the relationship between the soil salinity and the hyperspectral data, the field soil samples were collected in the region of Hetao irrigation, Neimeng in the northwest China from the end of July to the beginning of August. The partial least squares regression (PLSR) model was established based on the statistical analysis of the soil ions and the reflectance of hyperspectra. The independent validation using data which are not included in the calibration model reveals that the proposed model can predicate the main soil components such as the content of total ions (S%), SO2+4, PH and K++Na+ with higher determination coefficients (R2) of 0.728, 0.801, 0.715 and 0.734 respectively. And the ratio of prediction to deviation (RPD) of the above predicted value is larger than 1.6, which indicates that the calibrated PLSR model can be used as a tool to retrieve soil salinity with accurate results. When the PLSR model’s regression coefficients were aggregated according to the wavelength of visual (blue, green and red) and near infrared bands of LandSat Thematic Mapper(TM) sensor, some significant response values were observed, which indicates that the proposed method in this paper can be used to analyse the remotely sensed data from the space-boarded platform..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1362 (2009)
Prediction of Total Nitrogen in Flue-Cured Tobacco with UV Spectrometry
XIN Rong, and TANG Yan-lin
Ultraviolet ( UV ) spectrum method was used to measure the spectra of flue-cured tobacco, and the spectra of different grades of flue-cured tobacco were compared. The samples were scanned in 210-360 nm with UV spectrometer. Further, the UV predicting models of total nitrogen of tobacco leaves were established by stepwiUltraviolet ( UV ) spectrum method was used to measure the spectra of flue-cured tobacco, and the spectra of different grades of flue-cured tobacco were compared. The samples were scanned in 210-360 nm with UV spectrometer. Further, the UV predicting models of total nitrogen of tobacco leaves were established by stepwise multiple regression method, principal components analytic method and partial least squares method. The results show that: (1) Predicting models of total nitrogen were established to adopt stepwise multiple regression method and principal components analytic method. (2) The models of total nitrogen of the different grade flue-cured tobacco established through scanning within the wavelength range of 230-290 nm were better for total nitrogen prediction. (3) The accuracy of total nitrogen prediction for flue-cured tobacco leaf with principal components analytic method was better than that of stepwise multiple regression method, and that of principal components analytic method is 78%. (4) The prediction model is different with different data treatment method. (5) The accuracy of prediction model could be improved by adopting fitting characteristic spectrum curve of total nitrogen. It is shown that the model of total nitrogen content prediction for flue-cured tobacco can be established by using UV spectrum. The model features good stability and can be used to determine accurately and speedily the total nitrogen content of flue-cured tobacco leaves without pollution..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1367 (2009)
Measurement Technology for Relative Spectral Responsivity of the Ultraviolet ICCD
ZHAO Yu-huan, YAN Feng, LOU Hong-wei, SUI Yong-xin, YANG Huai-jiang, and CAO Jian-lin
The spectral responsivity is one of the important parameters of detector. With the development of ultraviolet detect technique, accurate measure for the spectral responsivity of ultraviolet detector becomes more and more important. A measure principle which is based on the direct comparison measuring method for relativThe spectral responsivity is one of the important parameters of detector. With the development of ultraviolet detect technique, accurate measure for the spectral responsivity of ultraviolet detector becomes more and more important. A measure principle which is based on the direct comparison measuring method for relative spectral response measurement of the ultraviolet ICCD is introduced. Based on the scientific-grade spectrometer with ultraviolet responsivity, a measurement facility was built. The relative spectral responsivity curve of the ultraviolet ICCD was obtained. The curve indicates that the spectral response of UV-ICCD is from 220 to 300 nm and the peak response is near 270 nm, which indicates that the UV-ICCD is solar blind. The analysis of the uncertainty shows that the most largest uncertainty of measurement for relative spectral responsivity of the UV-ICCD is 7.79% and meets the requirement..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1371 (2009)
Spectral Response Measurement of FUV Image Intensifier
FU Li-ping, WANG Yong-mei, TAO Ye, LU Xiao-qing, ZHANG Zhong-mou, and WANG Yin-jian
It is possible to obtain some space weather parameters such as the electron flux and mean energy of the precipitating electrons from the far ultraviolet (FUV)radiance of the aurora observed in a nadir viewing geometry, and the FUV image intensifier is one of the key equipment that used for observation the FUV radiance It is possible to obtain some space weather parameters such as the electron flux and mean energy of the precipitating electrons from the far ultraviolet (FUV)radiance of the aurora observed in a nadir viewing geometry, and the FUV image intensifier is one of the key equipment that used for observation the FUV radiance of the aurora in a nadir viewing geometry. The capability of this equipment will affect the whole purpose of the detection. And the responsibility to the wavelength is the most important parameter of image intensifier. Using the VUV beamline from synchrotron radiation as optical source, with PMT and Si-photodiode to detect the optical signal from synchrotron radiation and image intensifier separately, the authors measured the relatively spectral response distribution of our FUV image intensifier from 135 to 250 nm. The measurement result shows that the equipment can work well between 140 and 190 nm and the peak response is near 160 nm, and it can be used for our FUV aurora camera..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1375 (2009)
Effects of Enhanced Solar UV-B Radiation on the Effective Photosynthetic Leaf Area and Milking Phase of Oat under Natural Field Condition in Qing Tibetan Plateau
WANG Sheng-yao, WANG Kun, ZHAO Yong-lai, and XIN You-jun
Stratospheric ozone depletion occurs mainly over polar regions during the spring when the solar ultraviolet B-band (280-315 nm, UV-B) radiation is most intense in a year,but over the Qing Tibetan Plateau region, the intensity is highest from June to September when the amount of UV-B radiation reaching the regions is moStratospheric ozone depletion occurs mainly over polar regions during the spring when the solar ultraviolet B-band (280-315 nm, UV-B) radiation is most intense in a year,but over the Qing Tibetan Plateau region, the intensity is highest from June to September when the amount of UV-B radiation reaching the regions is more than that in the adjacent areas lying in the same latitude by 10%. From June to September is just the time of plant’s germination, development, and reproduction in the alpine region. The enhanced UV-B radiation may alter the rate of senescence in the forage plant, oats (Avena sativa), which plays the vital role in developing indigenous herdsman’s animal husbandry industry. In the trial the authors enhanced the UV-B radiation by using lamp bank of florescent lights to increase the ambient levels of UV-B radiation in the field, we treated 3 groups under nature solar radiation, solar+0.50 W·m2, and solar+1.00 W·m2 respectively, and surveyed the rate of senescence by measuring the rate of lessening in the effective photosynthetic leaf area, the concentration of the chlorophyll, and the milking phase of oat phenology. The results proved that the effect of the enhanced UV-B radiation on the rate of senescence of oats is caused by reducing the effective photosynthetic leaf area per plant by 21.5%, accelerating the rate of the loss of the chlorophyll compared with that of the controlled by an average of 7.6% and shortening the milking phase by an average of 2 days in the treated groups compared with the rate in the controlled, but there were not statistically significant differences from those of the non-treated group in these index of oat’s senescence. All the results evidenced that the enhanced solar UV-B radiation has no significantly ominous consequence on the oat ecological characteristics concerning annual plant reproduction in Qing Tibetan plateau..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1378 (2009)
Application of Multispectral Image Texture to Discriminating Tea Categories Based on DCT and LS-SVM
WU Di, CHEN Xiao-jing, and HE Yong
Based on multispectral digital image texture feature, a new rapid and nondestructive method for discriminating tea categories was put forward. The new method combines the advantages of DCT (discrete cosine transform) and least squares-support vector machine (LS-SVM). In the present study, the images for each sample werBased on multispectral digital image texture feature, a new rapid and nondestructive method for discriminating tea categories was put forward. The new method combines the advantages of DCT (discrete cosine transform) and least squares-support vector machine (LS-SVM). In the present study, the images for each sample were captured using a red (R) waveband, near infrared (NIR) waveband and green (G) waveband multispectral digital imager. The three wavebands of image can be combined into one image, which contains more information than images captured by ordinary digital cameras, and the NIR image can catch more information than visible spectrum. Three images for one sample can be obtained simultaneously. Eighty filters were designed based on DCT. One hundred twenty images (twenty for each category) were used for calibration set and one hundred twenty mages (twenty for each category) were used as the prediction. Finally, tea category was classified by LS-SVM. The classification rate using Sd of NIR image was only 73.33%, while it reached 100% using 8 filtered images. The overall results show that the technique combining DCT and SVM can be efficiently utilized for texture recognition of multispectral image, and it also is an effective and simple discrimination way for the tea categories. The whole process is simple and easy to operate, and can be transferred to the industrial world for on-line application..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1382 (2009)
Studies on the Oxidation of LDL Induced by Cu2+ at Different Time by Spectroscopic Method
SUN Xia, LIU Qing-ping, ZHENG Xue-fang, LIU Zhe, WANG Ren-jun, HUANG Zhen-yu, and ZHANG Fan
Oxidized low density lipoprotein (oxLDL) is thought to be a key proatherogenic event. The oxidation of LDL induced by Cu2+ at different time was studied by UV-Vis absorption spectra and circular dichroism (CD) spectra. It was shown that long oxidation time is accompanied by an increased MDA content and fluorescence intOxidized low density lipoprotein (oxLDL) is thought to be a key proatherogenic event. The oxidation of LDL induced by Cu2+ at different time was studied by UV-Vis absorption spectra and circular dichroism (CD) spectra. It was shown that long oxidation time is accompanied by an increased MDA content and fluorescence intensity at 430 nm, which suggested new product. The intensity of UV absorption peak of LDL increased, while fluorescence and synchronous fluorescence intensities, which typified amino acids, decreased. CD data displayed that α-helical content of the protein decreased and the secondary structure changed. The results indicated that during the process of oxidation of LDL Cu2+ induced not only the product but also the change of the conformation of apoB-100..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1386 (2009)
Monitoring and Analysis of Air Pollutants Using DOAS in Winter of Beijing
ZHU Yan-wu, FU Qiang, XIE Pin-hua, LIU Wen-qing, PENG Fu-min, QIN Min, LIN Yi-hui, SI Fu-qi, and DOU Ke
Based on the differential optical absorption spectroscopy (DOAS) technology, the measurement of air pollutants (SO2, NO2, HONO and HCHO) was performed continuously from Jan 19, 2007 to Feb 8, 2007 in Peking University campus. The typical diurnal variation characteristic of SO2 concentration, the main source and the metBased on the differential optical absorption spectroscopy (DOAS) technology, the measurement of air pollutants (SO2, NO2, HONO and HCHO) was performed continuously from Jan 19, 2007 to Feb 8, 2007 in Peking University campus. The typical diurnal variation characteristic of SO2 concentration, the main source and the meteorological factors that influence the pollutants were analyzed. The results indicated that the typical diurnal variation of SO2 concentration has the same shape as the letter “V” when wind speed was low, and in the afternoon the SO2 concentration was the lowest, while in other time it was high. Coal-burning made prominent contribution to the concentration of atmospheric various pollutants in the heating period of Beijing. Wind speed played a leading role and other meteorological factors also have some effect, which resulted from the influence of the meteorology on diffusion, transmission, elimination of air pollutants..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1390 (2009)
Preparation, Spectral Analysis and Photocatalytic Activities of TiO2 Films Codoped with Iron and Nitrogen
LIU Wan-bing, DENG Jian, ZHAO Yu-bao, XU Jin-sheng, and ZHOU Liang
Using tetrabutyl titanate as the titanium source, and ammonia and ferric nitrate as the sources of nitrogen and ferrum respectively, iron and nitrogen-codoped nano-TiO2 gelatins were prepared by sol-gel method. The iron and nitrogen-codoped nano-TiO2 complex films were prepared with the obtained gelatins used to coat tUsing tetrabutyl titanate as the titanium source, and ammonia and ferric nitrate as the sources of nitrogen and ferrum respectively, iron and nitrogen-codoped nano-TiO2 gelatins were prepared by sol-gel method. The iron and nitrogen-codoped nano-TiO2 complex films were prepared with the obtained gelatins used to coat the surface of cleaned glass slides by several times of dipping-lifting procedure, followed by natural seasoning at room temperature and calcined at 450 ℃ for 3 hours, then the films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectrum (XPS) and ultraviolet-visible diffuse reflectance spectrum (UV-Vis). The XRD spectra of samples showed that the Fe-TiO2-xNx films were of anatase structure with a few of oxygen atoms in the lattice of anatase TiO2 substituted by nitrogen atoms, resulting in the distorsion of crystal lattice. The SEM image showed that the nanoparticles of the films have a good dispersion characteristic and uniform orbicular shape with an average diameter of about 19 nm. The absorption edges of UV-Vis spectra exhibited a red shift up to 740 nm when the TiO2 films were codoped with iron and nitrogen. The XPS of the Fe-TiO2-xNx film presented a lowering of Ti 2p3/2 electron binding energy because of the codoping of iron and nitrogen, which then resulted in the widening of the absorption of visible light range. The photocatalytic properties were studied by photocatalytical degradation of sudan Ⅰ as a model reaction in a self-assembled light-reactor. When the atomic ratio of Fe3+/Ti4+ reached 0.4%, the Fe-TiO2-xNx film showed the highest catalytic performance in degradation of sudan Ⅰ which was decomposed by up to 97% after 4 hours of photocatalytic reaction. Codoping of nitrogen and appropriate amount of iron in TiO2 enhances photoresponse and utilizing efficiency in visible light region, and then improves the performances of Fe-TiO2-xNx photocatalyst. The complex film catalyst prepared by this method will have potential application in areas of wastewater disposal..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1394 (2009)
Immobilization of Anti-Transferrin On Nano-Gold and Its Immune Recognition of Transferrin
YANG Pei-hui, WEI Wei, CAI Huai-hong, FENG Jing, and CAI Ji-ye
A novel strategy based on antigen-antibody interaction was developed by means of backfilling transferrin on antibody functionalized gold nanoparticles surfaces in the present study. Nano gold particles were immobilized with cysteamine layer by self-assembly, whose surfaces were chemically coupled with anti-transferrin A novel strategy based on antigen-antibody interaction was developed by means of backfilling transferrin on antibody functionalized gold nanoparticles surfaces in the present study. Nano gold particles were immobilized with cysteamine layer by self-assembly, whose surfaces were chemically coupled with anti-transferrin antibodies by using EDC, forming the anti-transferrin-Au immuno-probes. The particles and the nano-probes were characterized by the integrated tools of resonance Rayleigh scattering (RRS), UV-Vis absorption spectra, transmission electron microscopy (TEM) and laser light scattering. The result showed that the nano-probe with the ability of specific recognition of transferrin had good immune activity. The RRS peak at 470 nm was amplified obviously by using this signal amplification, and the antigen recognition was monitored via the enhancement of 470 nm RRS intensity when this binding event occurred. The result showed that the amplification strategy led to a dramatic improvement of the detection sensitivity of transferrin, and the detection of transferrin featured a linear range of 0.85 to 33.9×10-10 mol·L-1 with the detection limit of 8.5×10-11 mol·L-1..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1398 (2009)
Study of Fundamental Parameters of Inductively Coupled Plasma for Slurry Nebulization —— Electron Density Determination
WANG Zheng, QIU De-ren, TAO Guang-yi, and YANG Peng-yuan
The electron density of the plasma for slurry nebulization inductively coupled plasma emission spectrometry was determined and reported in the present paper. The Stark broadening method of Hβ line (486.1 nm) was chosen and used to determine the electron density of the plasma for nebulization into the inductively coupleThe electron density of the plasma for slurry nebulization inductively coupled plasma emission spectrometry was determined and reported in the present paper. The Stark broadening method of Hβ line (486.1 nm) was chosen and used to determine the electron density of the plasma for nebulization into the inductively coupled plasma with both the aqueous solution and different concentration titanium slurry. There are approximately the same plasma electron density results of 1015 cm-3 for the two nebulization ways. The experiment verified that the plasma electron density only shows a litter decrease with 10％ TiO2 suspension nebulization into the inductively coupled plasma. This means that the plasma electron density does not change remarkably with high content suspension nebulization into the inductively coupled plasma emission spectrometry instrument. It will help trace elements determination by using high concentration suspension nebulization into the inductively coupled plasma emission spectrometry instrument..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1402 (2009)
Convertibility of the Data Determined by ICP-AES and FAAS for Soil Available K and Na
ZHANG Jian-min, WANG Meng, GE Xiao-ping, WU Jian-zhi, GE Ying, LI Shi-peng, and CHANG Jie
In recent years, inductively coupled plasma atomic emission spectrometry (ICP-AES) have been commonly used to determine the soil available K and Na with the extraction solution of HCl-H2SO4, while previous data of soil available K and Na were measured by flame atomic absorption spectrometry (FAAS) with the extraction sIn recent years, inductively coupled plasma atomic emission spectrometry (ICP-AES) have been commonly used to determine the soil available K and Na with the extraction solution of HCl-H2SO4, while previous data of soil available K and Na were measured by flame atomic absorption spectrometry (FAAS) with the extraction solution of NH4OAc. In order to utilize previous data, quest for the convertibility of the data determined by ICP-AES and FAAS, and compare the data determined by both methods, the authors chose four types of soil to determine soil available K and Na by ICP-AES and FAAS, respectively. Four types of soil represent grit soil, clay, silt from river and silt from sea, respectively. Soil samples included four types of soil and these samples represent different soil nutrition. The authors analyzed the correlations of two kinds of measured data. The paired samples t-test proves that there was significantly positively correlation between these two methods. The correlation coefficient of the data between these two methods for measuring soil available K is 0.98. The results of soil available K determined by the two methods can be conversed through the formula, y=1.14x+6.53 (Ｒ2=0.91, n=24, p<0.001). As for Na, although there is a significantly positively correlation between these two methods, the slopes of single model of clay and grit soil were different from that of general model. And so the results determined by the two methods can be conversed through different formula according to the types of soil, that is, for clay: y=1.23x+10.03; for grit soil: y=3.12x-23.03; for silt: y=0.60x. In conclusion, the authors’ results showed that previous data of available K and Na measured by FAAS with the extraction solution of NH4OAc were available. And these data were comparable to the data measured by ICP-AES through definite formula. The authors’ results also suggested that ICP-AES was preferable when many elements were measured at the same time. Under this condition, ICP-AES was economical, efficient and reliable..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1405 (2009)
Analysis of Twenty Trace Elements in Ling Zhi by ICP-AES
HE Jin-zhe, KUI Xiao-yun, YANG Kai, SHAO Pin, and SUN Pei-long
Twenty trace elements, Al, As, Ca, Cd, Co, Cr, Cu, Fe, Ge, Hg, K, Mg, Mn, Na, Ni, P, Pb, S, Se and Zn were determined by ICP-AES with wet digestion from two kinds of different Ling Zhi fruitbody materials（Zhongzhi and Xianyuan）, Ling Zhi root, Ling Zhi mixture, unbroken and broken Ling Zhi spore powder. The common featTwenty trace elements, Al, As, Ca, Cd, Co, Cr, Cu, Fe, Ge, Hg, K, Mg, Mn, Na, Ni, P, Pb, S, Se and Zn were determined by ICP-AES with wet digestion from two kinds of different Ling Zhi fruitbody materials（Zhongzhi and Xianyuan）, Ling Zhi root, Ling Zhi mixture, unbroken and broken Ling Zhi spore powder. The common feature about the element content showed that there were rich trace elements in different Ling Zhi materials, and the concentrations of K, Ca, Mg, Fe, Zn, P and S in all kinds of Ling Zhi samples were relatively high. Besides, there were trace elements, Cu, Co, Cr and Ni, and potentially physiologically toxic elements, Al, As, Hg, Pb and Cd, in all samples. Elements Se and Ge with anticancer efficacy were not found in Ling Zhi samples. The concentrations of heavy metal elements were lower in spore powders than in other Ling Zhi samples. Trace element contents in the broken and unbroken spore powders showed minor difference, The concentrations of Fe and Se in Ling Zhi mixtures were obviously higher than in other kinds of Ling Zhi samples, due to factitious addition of these elements to Ling Zhi mixture sample. There was some difference between two kinds of Ling Zhi fruitbody from deferent plant places, which may have some relations with the soil and environment. The concentrations of Ca, Cu and Zn in Ling Zhi root were higher than in other Ling Zhi materials. According to the analyses, these elements in Ling Zhi were helpful to improving cardiovascular function..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1409 (2009)
Correlation of Mineral Elements Between Milled and Brown Rice and Soils in Yunnan Studied by ICP-AES
ZENG Ya-wen, WANG Lu-xiang, DU Juan, YANG Shu-ming, WANG Yu-chen, LI Qi-wan, SUN Zheng-hai, PU Xiao-ying, and DU Wei
In the present paper, the contents of 18 mineral elements in milled and brown rice of 55 accessions elite cultivars as well as corresponding soils were determined by ICP-AES technique. The method proves to be simple, rapid, highly sensitive and accurate, and can be used to determine many elements at the same time, its In the present paper, the contents of 18 mineral elements in milled and brown rice of 55 accessions elite cultivars as well as corresponding soils were determined by ICP-AES technique. The method proves to be simple, rapid, highly sensitive and accurate, and can be used to determine many elements at the same time, its recovery ratio obtained by standard addition method ranged between 93.1% and 110.2%, and its RSD was from 0.8% to 5.1%. The analytical results showed that 18 mineral elements (S, Mo, Ba, Ni, Fe, Cr, Na, Al, Cu, P, Sn, Zn, B, Mn, Mg, Ca, Sr and K) are the important active compositions of functional rice, and their mean contents in milled rice are in the order of P>K>S>Mg>Ca>Zn>Na>Al>Mn>Fe>Cu>B>Mo>Ni>Sn>Cr>Ba>Sr, in brown rice in the order of P>K>Mg>S>Ca>Zn>Mn>Al>Na>Fe>Cu>B>Mo>Sn>Ni>Cr>Ba>Sr, but in soil in the order of Fe> Al>Ca>K>Mg>P>S>Mn>B>Na>Ba>Zn>Cr>Cu>Ni>Sn>Mo>Sr; 16 mineral elements in milled and brown rice (except for S and P) are clearly lower than that in soils. The correlation of 8 microelements (Mo, Ni, Cr, Sr, Mn, Zn, Cu and Na) in milled and brown rice is closer than that of 6 macroelements (P, K, Mg, Ca, S and Al). There are rich Fe, Al and Ca in Yunnan soils, but 4 elements (P, K, Mg and S) are in high priority in milled and brown rice; The milled rice used for the staple is easier to place a premium on chronics than brown rice. The above results provided reliable data and theory bases for genetic breeding and production of functional rice, and for further solving the chronics and the malnourished problems with insufficient Fe, Zn and Ca for 4 billion people in the world..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1413 (2009)
Determination of Sulfur in Plant Using a High-Resolution Continuum Source Atomic Absorption Spectrometer
WANG Yu, and LI Jia-xi
A method for the analysis of sulfur (S) in plant by molecular absorption of carbon monosulfide (CS) using a high-resolution continuum source atomic absorption spectrometer (CS AAS) with a fuel-rich air/acetylene flame has been devised. The strong CS absorption band was found around 258 nm. The half-widths of some absorA method for the analysis of sulfur (S) in plant by molecular absorption of carbon monosulfide (CS) using a high-resolution continuum source atomic absorption spectrometer (CS AAS) with a fuel-rich air/acetylene flame has been devised. The strong CS absorption band was found around 258 nm. The half-widths of some absorption bands were of the order of picometers, the same as the common atomic absorption lines. The experimental procedure in this study provided optimized instrumental conditions (the ratio of acetylene to air, the burner height) and parameters, and researched the spectral interferences and chemical interferences. The influence of the organic solvents on the CS absorption signals and the different digestion procedures for the determination of sulfur were also investigated. The limit of detection achieved for sulfur was 14 mg·L-1, using the CS wavelength of 257.961 nm and a measurement time of 3 s. The accuracy and precision were verified by analysis of two plant standard reference materials. The major applications of this method have been used for the determination of sulfur in plant materials, such as leaves. Compared to the others, this method for the analysis of sulfur is rapid, easy and simple for sulfur determination in plant..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1418 (2009)
Crosslinked Carboxymethyl Konjac Glucomannan Microcolumn Preconcentration of Trace Lead, Cadmium and Copper in Water Samples and Determination by Graphite Furnace Atomic Absorption Spectrometry
CHEN Hao, SHEN Min, XUE Ai-fang, LI Sheng-qing, and PAN Si-yi
A novel solid phase extraction technique was developed for the determination of trace lead, cadmium and copper in environmental water samples based on separation and preconcentration with a microcolumn packed with crosslinked carboxymethyl konjac glucomannan (CCMKGM)prior to its determination by graphite furnace atomicA novel solid phase extraction technique was developed for the determination of trace lead, cadmium and copper in environmental water samples based on separation and preconcentration with a microcolumn packed with crosslinked carboxymethyl konjac glucomannan (CCMKGM)prior to its determination by graphite furnace atomic absorption spectrometry. Various influential factors on the separation and preconcentration of lead, cadmium and copper, such as the acidity of the aqueous solution, sample flow rate and volume, and eluent concentration and volume, were investigated systematically, and the optimized operation conditions were established. The analytes could be quantitatively retained by CCMKGM in the pH range of 5.0-7.0, then eluted completely with 1.0 mL 0.5 mol·L-1 HCl. The detection limits(3σ)for analyte ions were 0.038 μg·L-1 for Pb2+, 0.000 5 μg·L-1 for Cd2+ and 0.014 μg·L-1 for Cu2+ with an enrichment factor of 50, and the relative standard deviations were 3.5% for Pb2+, 9.2% for Cd2+ and 4.7% for Cu2+(cPb2+=cCu2+=1.0 μg·L-1; cCd2+=0.1 μg·L-1, n=11). The proposed method was successfully applied to the determination of trace lead, cadmium and copper in environmental water samples (local tap water and lake water). In order to validate the method, the developed method was applied to the determination of lead, cadmium and copper in environmental water reference materials (ERMs, GSBZ 50009-88, P.R. China), and the results obtained were in good agreement with the certified values..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1422 (2009)
Determination the Chemical Speciation of Cu, Zn, Fe and Mn in Radix Scutellariae by AAS
MIAO Shan, SUN Ji-yuan, XIE Yan-hua, WANG Jian-bo, SHI Xiao-peng, DING Yuan-yuan, BI Lin-lin, GAO Shuang-bin, and WANG Si-wang
An analysis method was developed to determine the chemical speciation of Cu, Zn, Fe and Mn in radix scutellariae decoction using atomic absorption spectroscopy(AAS). The decoction can be divided into suspension and soluble species by 0.45 μm filter membrane and the soluble species can be separated into organism and inoAn analysis method was developed to determine the chemical speciation of Cu, Zn, Fe and Mn in radix scutellariae decoction using atomic absorption spectroscopy(AAS). The decoction can be divided into suspension and soluble species by 0.45 μm filter membrane and the soluble species can be separated into organism and inorganic species by LSA-10 macroporous resin. These elements in water-soluble test samples can be divided into alcohol-soluble and water-soluble by adopting n-octyl alcohol-water allocation system in man-made gastric acidity. Then, the concentration of these elements was determined by AAS, which provided more chemical speciation information about these elements instead of the total amount of them only in radix scutellariae. Detection limit of Cu, Zn and Mn by using the method was all 0.01 μg·mL-1 and was 0.02 μg·mL-1 for Fe. The RSD was in the range of 1.5％-3.6％(n=11) and the recovery rate of soluble species and inorganic species were in range of 96.7％-105.0％. The method has been successfully applied to determine the chemical speciation of Cu, Zn, Fe and Mn in radix scutellariae, which was very important for overall study of radix scutellariae..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1427 (2009)
A Study on Decreasing the Instrument Detection Limit of Atomic Fluorescence Spectrometry(AFS-930)for Hg
YIN Xue-bin, LU Xiao-qi, YAO Chun-xia, SONG Jing, QIAN Wei, LUO Yong-ming, LIANG You-qing, and SUN Li-guang
In the present study, the detection limit of atomic fluorescence spectrometry (AFS-930) was decreased to 2 ng·L-1 (n=6) based on several optimizing modifications, including that the sub-high voltage of photomultiplier tube and the current of hollow-cathode lamp were elevated to 280 V and to 30 mA, respectively, anIn the present study, the detection limit of atomic fluorescence spectrometry (AFS-930) was decreased to 2 ng·L-1 (n=6) based on several optimizing modifications, including that the sub-high voltage of photomultiplier tube and the current of hollow-cathode lamp were elevated to 280 V and to 30 mA, respectively, and the height of atomization cell was set as 10 mm; In addition, the concentration of KBH4 was decreased to 0.5% (KOH 0.2%). With the optimized parameters, a good standard curve of Hg concentration versus intensity of fluorescence (If) could been obtained readily, after that, a 4-ng·L-1-Hg water samples was measured accurately with a little relative standard deviation (RSD) of <5%, while for approximately 2-ng·L-1-Hg waters the RSD varied within a wide range of 10.9%-27.2%, likely due to the absorption of Hg by polyethylene vessels used in this study and/or due to the contamination by analysis grade reagents used in this study. By using low-absorption polytetrafluoroethylene (PTFE) materials and the guaranteed reagents, the instrument detection limit was further decreased to 1 ng·L-1(n=10)..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1431 (2009)
Analysis of Lead in Soil with Partial Least Square Regression (PLS) Method and Field Portable X-Ray Fluorescence (FPXRF) Analyzer
HUANG Qi-ting, ZHOU Lian-qing, SHI Zhou, LI Zhen-yu, and GU Qun
In the present study, soil samples were scanned by NITON XLt920 field portable X-ray fluorescence (FPXRF)analyzer, and the relationship between the X-ray fluorescence spectra and the concentration of Pb in soil was studied. For predicating the Pb concentration in soil, a partial least square regression model (PLS)was eIn the present study, soil samples were scanned by NITON XLt920 field portable X-ray fluorescence (FPXRF)analyzer, and the relationship between the X-ray fluorescence spectra and the concentration of Pb in soil was studied. For predicating the Pb concentration in soil, a partial least square regression model (PLS)was established with 6 optimal factors and two closely relevant electron volt ranges: 10.40-10.70 keV and 12.41-12.80 keV. After cross-calibration, the correlation coefficient of value predicted by PLS model against that measured by ICP was 0.966 6, and the root mean square error of prediction (RMSEP)was 0.873 2. Meanwhile, the univariate linear regression and multivariate linear regression models were also built with the correlation coefficient of 0.680 5 and 0.730 2, respectively. Obviously, the PLS method was better than the other two methods for predication. Comparing to the conventional approach of atomic absorption spectroscopy（AAS）, FPXRF has the advantages of rapidness, non-destruction and relatively low cost with the acceptable accuracy. It would be a powerful tool to decide which sample is needs for further analysis..
Spectroscopy and Spectral Analysis
- Publication Date: Sep. 21, 2021
- Vol. 29, Issue 5, 1434 (2009)
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