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Self-Absorption Effects on Electron Temperature-Measurements Utilizing Laser Induced Breakdown Spectroscopy (LIBS)-Techniques 被引量:1
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作者 Shawqi A. M. Mansour 《Optics and Photonics Journal》 2015年第3期79-90,共12页
In the present work, we have studied the temporal evolution of aluminum alloy plasma produced by the fundamental (1064 nm) of a Q-switched Nd:YAG laser by placing the target material in air at atmospheric pressure. Th... In the present work, we have studied the temporal evolution of aluminum alloy plasma produced by the fundamental (1064 nm) of a Q-switched Nd:YAG laser by placing the target material in air at atmospheric pressure. The four Al I-neutral lines at 308.21, 309.27, 394.40 and 369.15 nm as well as Al II-ionic lines at 281.61, 385.64 and 466.30 nm are used for the determination of the electron temperature Te using Saha-Boltzmann plot method. The neutral aluminum lines were found to suffer from optical thickness which manifested itself on the form of scattered points around the Saha-Boltzmann line. The isolated optically thin hydrogen Hα-line at 656.27 nm appeared in the spectra under the same experimental conditions was used to correct the Al I-lines which contained some optical thickness. The measurements were repeated at different delay times ranging from 1 to 5 μs. The comparison between the deduced electron temperatures from aluminum neutral lines before correction against the effect self-absorption to that after correction revealed a precise value in temperature. The results sure that, in case of the presence of self-absorption effect the temperature varies from (1.4067 - 1.2548 eV) as the delay time is varied from 0 to 5 μs. Whereas, in the case of repairing against the effect, it varies from (1.2826 - 0.8961 eV) for the same delay time variation. 展开更多
关键词 Laser Induces Breakdown spectroscopy (LIBS) SELF-ABSORPTION (SA) Saha-Boltzmann PLOT Delay Time (Td) Electron Number Density (Ne) Plasma Temperature (Te)
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Poly(Acrylamide-Co-Acrylic Acid)-Zinc Acetate Polymer Electrolytes: Studies Based on Structural and Morphology and Electrical Spectroscopy
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作者 Mohd Faiz Hassan Siti Zulaikha Mohd Yusof 《Microscopy Research》 2014年第2期30-38,共9页
Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorp... Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA. 展开更多
关键词 Solution Cast Technique Solid Polymer Electrolyte Poly(Acrylamide-Co-Acrylic Acid) Zinc Acetate Ionic Conductivity Impedance spectroscopy Fourier Infrared spectroscopy Scanning Electron Microscopy
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Chemometric Feature Selection and Classification of <i>Ganoderma lucidum</i>Spores and Fruiting Body Using ATR-FTIR Spectroscopy 被引量:2
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作者 Ying Zhu Augustine Tuck Lee Tan 《American Journal of Analytical Chemistry》 2015年第10期830-840,共11页
Ganoderma lucidum(G. lucidum) spores as a valuable Chinese herbal medicine have vast marketable prospect for its bioactivities and medicinal efficacy. This study aims at the development of an effective and simple anal... Ganoderma lucidum(G. lucidum) spores as a valuable Chinese herbal medicine have vast marketable prospect for its bioactivities and medicinal efficacy. This study aims at the development of an effective and simple analytical method to distinguish G. lucidum spores from its fruiting body, which is of essential importance for the quality control and fast discrimination of raw materials of Chinese herbal medicine. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy combined with the appropriate chemometric methods including penalized discriminant analysis, principal component discriminant analysis and partial least squares discriminant analysis has been proven to be a rapid and powerful tool for discrimination of G. lucidum spores and its fruiting body with classification accuracy of 99%. The model leads to a well-performed selection of informative spectral absorption bands which improve the classification accuracy, reduce the model complexity and enhance the quantitative interpretations of the chemical constituents of G. lucidum spores regarding its anticancer effects. 展开更多
关键词 Feature Selection Attenuated Total Reflection Fourier Transform Infrared spectroscopy Penalized Linear DISCRIMINANT ANALYSIS Principal Component DISCRIMINANT ANALYSIS Partial Least Squares DISCRIMINANT ANALYSIS
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Use of Flame Atomic Absorption Spectroscopy and Multivariate Analysis for the Determination of Trace Elements in Human Scalp 被引量:1
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作者 Sayo O. Fakayode Sri Lanka Owen +1 位作者 David A. Pollard Mamudu Yakubu 《American Journal of Analytical Chemistry》 2013年第7期348-359,共12页
The analysis of trace elements in human hair for use as biomarkers continues to generate considerable interest in environmental and bioanalytical studies, medical diagnostics, and forensic science. This study investig... The analysis of trace elements in human hair for use as biomarkers continues to generate considerable interest in environmental and bioanalytical studies, medical diagnostics, and forensic science. This study investigated the concentrations of essential and toxic elements (Fe, Mg, Ca, Cu, Zn, Cr, Cd, and Pb) using flame atomic absorption spectroscopy (FAAS) in human scalp hair obtained from subjects living in Forsyth County, North Carolina, USA. The influence of age, sex, race, and smoking habits on the levels of trace elements in the hair samples were also investigated. Additionally, analyses were subjected to a statistical, regression, and principal component analysis to evaluate inter-elemental association and possible pattern recognition in hair samples. Furthermore, Ca/Mg and Zn/Cu ratios, which are often used to evaluate the degree of Ca and Cu utilization in humans and as markers for various health related issues including, atherosclerosis, hypertension, insulin sensitivity, and pancreatic cancer, were calculated. The overall mean concentrations of Fe (25 μg/g), Ca (710 μg/g), Mg (120 μg/g), Zn (190 μg/g), Cu (12 μg/g), and Cr (0.20 μg/g) were found in hair samples. The trace element concentrations varied widely in hair samples as demonstrated by large range of concentrations obtained for each element. However, levels of Cd and Pb elements of <0.030 μg/g were detected in hair sample. In general, the levels of the trace elements in hair samples were poorly correlated. However, significant correlations were found between Ca and Mg (r = 0.840, p = 0.05). The levels of Fe, Ca, Mg, Zn, Cu, and Cr in hair samples and the calculated Ca/Mg and Zn/Cu ratios were found to be largely correlated with age, race, sex, and smoking habits. 展开更多
关键词 HUMAN SCALP HAIR BIOMONITORING Trace ELEMENT Concentration Flame Atomic Absorption spectroscopy Regression and Principal Component Analysis Inter-Element Association
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Discrimination of Wild-Grown and Cultivated <i>Ganoderma lucidum</i>by Fourier Transform Infrared Spectroscopy and Chemometric Methods 被引量:1
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作者 Ying Zhu Augustine Tuck Lee Tan 《American Journal of Analytical Chemistry》 2015年第5期480-491,共12页
Wild-grown Ganoderma lucidum (G. lucidum), a traditional Chinese herbal medicine, is highly cherished and expensive for its medicinal efficiency. This study targets the development of an accurate and effective analyti... Wild-grown Ganoderma lucidum (G. lucidum), a traditional Chinese herbal medicine, is highly cherished and expensive for its medicinal efficiency. This study targets the development of an accurate and effective analytical method to distinguish wild-grown G. lucidum from cultivated ones, which are of essential importance for the quality assurance and estimation of its medicinal value. Furthermore, different parts of G. lucidum have been studied to examine the differences between wild-grown and cultivated ones. Fourier transform infrared (FTIR) diffuse reflectance spectroscopy combined with the appropriate chemometric method has been proven to be a rapid and powerful tool for discrimination of wild-grown and cultivated G. lucidum with classification accuracy of 98%. The informative spectral absorption bands for discrimination emphasized by the linear diagnostic rule have provided quantitative interpretations of the chemical constituents of wild-grown G. lucidum regarding its anticancer effects. 展开更多
关键词 GANODERMA lucidum Traditional Chinese Medicine Fourier Transform Infrared spectroscopy CHEMOMETRICS Principal Component DISCRIMINANT ANALYSIS Partial Least Squares DISCRIMINANT ANALYSIS
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Discriminant Analysis of Liquor Brands Based on Moving-Window Waveband Screening Using Near-Infrared Spectroscopy 被引量:6
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作者 Jie Zhong Jiemei Chen +1 位作者 Lijun Yao Tao Pan 《American Journal of Analytical Chemistry》 2018年第3期124-133,共10页
Partial least squares discriminant analysis (PLS-DA) with integrated moving-window (MW) waveband screening was applied to the discriminant analysis of liquor brands with near-infrared (NIR) spectroscopy. Luzhou Laojia... Partial least squares discriminant analysis (PLS-DA) with integrated moving-window (MW) waveband screening was applied to the discriminant analysis of liquor brands with near-infrared (NIR) spectroscopy. Luzhou Laojiao, a popular liquor with strong fragrant flavor, was used as the identified liquor brand (160 samples, negative, 52 vol alcoholicity). Liquors of 10 other brands with strong fragrant flavor were used as the interferential brands (200 samples, positive, 52 vol alcoholicity). The Kennard-Stone algorithm was used for the division of modeling samples to achieve uniformity and representativeness. Based on the MW-PLS-DA, a simplified optimal model set with 157 wavebands was further proposed. This set contained five types of wavebands corresponding to the NIR absorption bands of water, ethanol, and other micronutrients (i.e., acids, aldehydes, phenols, and aromatic compounds) in liquor for practical choice. Using five selected simple models with 4775 - 4239, 7804 - 6569, 6264 - 5844, 9435 - 7896, and 12066 - 10373 cm-1, the validation recognition rates were obtained as 99.3% or higher. Results show good prediction performance and low model complexity, and also provided a valuable reference for designing small dedicated instruments. The proposed method is a promising tool for large-scale inspection of liquor food safety. 展开更多
关键词 LIQUOR Brands NEAR-INFRARED spectroscopy PARTIAL Least SQUARES DISCRIMINANT Analysis Moving-Window Waveband SCREENING Simplified Optimal Model Set
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Tender energy spectroscopy beamline at the Shanghai Synchrotron Radiation Facility
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作者 Shu‑Min Yang Ling‑Ling Guo +12 位作者 Bing Nan Ying Zhao Yan‑Qing Wu Zhi Guo Chen Tian Bo Zhao Chao‑Fan Xue Jun Zhao Shuang Song Zhen‑Ye Liang Li‑Na Li Yong Wang Ren‑Zhong Tai 《Nuclear Science and Techniques》 2026年第1期94-106,共13页
This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source... This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline. 展开更多
关键词 Tender energy X-ray spectroscopy X-ray fluorescence SSRF X-ray absorption spectroscopy(XAS) MICROPROBE
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Body mass index and its effects on liver fat content in overweight and obese young adults by proton magnetic resonance spectroscopy technique 被引量:2
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作者 Duanghathai Pasanta Montree Tungjai +2 位作者 Sirirat Chancharunee Warayuth Sajomsang Suchart Kothan 《World Journal of Hepatology》 CAS 2018年第12期924-933,共10页
AIM To assess the association between liver fat content(LFC) and weight status in young adults using proton magnetic resonance spectroscopy(1H MRS) technique.METHODSSeventy-eight healthy young adults, between 19-30 ye... AIM To assess the association between liver fat content(LFC) and weight status in young adults using proton magnetic resonance spectroscopy(1H MRS) technique.METHODSSeventy-eight healthy young adults, between 19-30 years of age participated in this study. This group was then separated into a control of 39 subjects and an overweight/obese group(OW/OB group) consisting of 39 subjects. Blood biochemical quantity and 1 H MRS was performed for LFC assessment.RESULTS LFC was found to be almost three times higher in OW/OB group when compared to the control group. A 48.7% incidence of non-alcoholic fatty liver disease in the OW/OB group was found. Blood biochemical measurements showed statistically higher low-density lipoproteins and triglyceride, lower highdensity lipoproteins, and increased glycosylated hemoglobin and fasting glucose in the OW/OB group. Body mass index was a significant independent predictor for LFC after adjusting for age and sex(multiple linear regression; β = 0.459, P <0.001).CONCLUSION Due to the prevalence of high LFC in the OW/OB group, it can be proposed that weight gain and obesity are sensitive indicators of high hepatic fat content. 展开更多
关键词 Young ADULTS OVERWEIGHT Obesity Non-alcoholic FATTY liver disease Body mass index Proton magnetic resonance spectroscopy CHOLESTEROL
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Evaluation of Fourier Transform Infrared Spectroscopy for Diagnosis of Peroxisomal Diseases with Abnormal Very-Long-Chain Fatty Acid Metabolism
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作者 Minori Isogawa Satoshi Yoshida Nobuyuki Shimozawa 《American Journal of Analytical Chemistry》 2014年第6期359-366,共8页
Very long chain fatty acids (VLCFAs) are accumulated in cells and blood in patients with peroxisomal diseases, such as adrenoleukodystrophy (ALD) and Zellwger Syndrome (ZS). The purpose of this study is to investigate... Very long chain fatty acids (VLCFAs) are accumulated in cells and blood in patients with peroxisomal diseases, such as adrenoleukodystrophy (ALD) and Zellwger Syndrome (ZS). The purpose of this study is to investigate usefulness of Fourier transform infrared spectroscopy (FTIR) with attenuated total reflection (ATR) analysis method for clinical diagnosis of those diseases, thereby we measured the infrared spectra of the sera of patients and healthy controls. Correlation coefficients between 2nd derivative FTIR spectra of the serum samples and the VLCFA content ratio which is used as a clinical parameter to date were comprehensively calculated to investigate which wavenumber showed high correlation with the VLCFA ratio. Multiple regression analysis using the serum FTIR spectra showed that high correlations were observed with VLCFA ratios (C26:0/C22:0 ratio), and we could construct a suitable regression model (R2 = 0.97, p ﹣19). In addition, the model system using various VLCFAs in newborn bovine serum also showed that several FTIR peaks in 800 ~ 900 cm﹣1 region were found to have good correlation with VLCFA ratios. Our results support that FTIR analysis is useful for diagnosis of peroxisomal diseases. 展开更多
关键词 Fourier Transform Infrared spectroscopy ATTENUATED Total Reflection Very Long Chain FATTY ACIDS Peroxisomal DISEASES Multiple Regression Analysis
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Sensing of Moisture Content of In-Shell Peanuts by NIR Reflectance Spectroscopy 被引量:10
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作者 Jaya Sundaram Chari V. Kandala +1 位作者 Konda Naganathan Govindarajan Jeyam Subbiah 《Journal of Sensor Technology》 2012年第1期1-7,共7页
It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are ... It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are in their shells, it would save lot of labor and money spent in shelling and cleaning the nuts. Grain and nuts absorb low levels of NIR, and when NIR radiation is incident on them, a substantial portion of the radiation is reflected back. Thus, studying the NIR reflectance spectra emanating from in-shell peanuts, an attempt is made for the first time to determine the MC of in-shell peanuts. In-shell peanuts of two different market types, Virginia and Valencia, were conditioned to different moisture levels between 6% and 26% (wet basis), and separated into calibration and validation groups. NIR absorption spectral data from 1000 nm to 2500 nm in 1 nm intervals were collected from both groups. Measurements were obtained on 30 replicates within each moisture level. Reference MC values for each moisture level in these groups were obtained using standard air-oven method. Partial Least Square (PLS) analysis was performed on the calibration data, and prediction models were developed. The Standard Error of Calibration (SEC), and R2 of the calibration models were computed to select the best calibration model. The selected models were used to predict the moisture content of peanuts in the validation sets. Predicted MC values of the validation samples were compared with their standard air-oven moisture values. Goodness of fit was determined based on the lowest Standard Error of Prediction (SEP) and highest R2 value obtained for the prediction models. The model, with reflectance plus normalization spectral data with an SEP of 0.74 for Valencia and 1.57 for Virginia type in-shell peanuts was selected as the best model. The corresponding R2 values were 0.98 for both peanut types. This work establishes the possibility of sensing MC of intact in-shell peanuts by NIR reflectance method, and would be useful for the peanut and allied industries. 展开更多
关键词 In-Shell Peanuts NIR spectroscopy PRETREATMENTS Partial Least Square Standard Error of Prediction Relative PERCENT Deviation
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Endorectal Magnetic Resonance Imaging and Spectroscopy Are Useful for Selecting Candidates for Biopsy among Patients with Persistently Elevated Prostate Specific Antigen
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作者 Josep Comet-Batlle Carles Barceló-Vidal +6 位作者 Joan Carles Vilanova-Busquets Roger Boix-Orri Albert Maroto-Genover Joan Areal-Calama Margarita Osorio-Fernandez Ferran Perez-Bueno Nuria Fuertes-Izquierdo 《Open Journal of Urology》 2012年第3期198-205,共8页
Objective: To evaluate the efficacy of endorectal Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spetroscopic Imaging (MRSI) combined with total prostate-specific antigen (tPSA) and free prostate-specific ant... Objective: To evaluate the efficacy of endorectal Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spetroscopic Imaging (MRSI) combined with total prostate-specific antigen (tPSA) and free prostate-specific antigen (fPSA) in selecting candidates for biopsy. Subjects and Methods: 246 patients with elevated tPSA (median: 7.81 ng/ml) underwent endorectal MRI and MRSI before Transrectal Ultrasound (TRUS) biopsy (10 peripheral + 2 central cores);patients with positive biopsies were treated with radical intention;those with negative biopsies were followed up and underwent MRSI before each additional biopsy if tPSA rose persistently. Mean follow-up: 27.6 months. We compared MRI, MRSI, tPSA, and fPSA with histopathology by sextant and determined the association between the Gleason score and MRI and MRSI. We determined the most accurate combination to detect prostate cancer (PCa) using receiver operating curves;we estimated the odds ratios (OR) and calculated sensitivity, specificity, and positive and negative predictive values. Results: No difference in tPSA was found between patients with and without PCa (p = 0.551). In the peripheral zone, the risk of PCa increased with MRSI grade;patients with high-grade MRSI had the greatest risk of PCa over time (OR = 328.6);the model including MRI, MRSI, tPSA, and fPSA was more accurate (Area under Curve: AUC = 95.7%) than MRI alone (AUC = 85.1%) or fPSA alone (AUC = 78.1%), but not than MRSI alone (94.5%). In the transitional zone, the model was less accurate (AUC = 84.4%). The association (p = 0.005) between MRSI and Gleason score was significant in both zones. Conclusions: MRSI is useful in patients with elevated tPSA. High-grade MRSI lesions call for repeated biopsies. Men with negative MRSI may forgo further biopsies because a significantly high Gleason lesion is very unlikely. 展开更多
关键词 Endorectal MRI spectroscopy PROSTATE Cancer Diagnosis PROSTATE Specific ANTIGEN (PSA) Free to Total PSA Ratio (F/T PSA)
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Characterization of Vegetable Oils by Fluorescence Spectroscopy 被引量:1
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作者 Yvon Gilbert Mbesse Kongbonga Hassen Ghalila +4 位作者 Marthe Boyomo Onana Youssef Majdi Zohra Ben Lakhdar Houda Mezlini Sylvie Sevestre-Ghalila 《Food and Nutrition Sciences》 2011年第7期692-699,共8页
Results presented in this paper show the ability to analyze vegetable oils with very cheap and easy method based on fluorescence spectroscopy. We have recorded, with a very simple experimental set up, fluorescence spe... Results presented in this paper show the ability to analyze vegetable oils with very cheap and easy method based on fluorescence spectroscopy. We have recorded, with a very simple experimental set up, fluorescence spectra for several vegetable oils at excitation wavelength λex = 370 nm. After deconvolution, using a Lorentzian profile, and identification of the stripes forming the spectra, a normalization of the intensities was made with respect to the vitamin E band with λ= 525 nm taken as reference. A statistical method based on Principal Component Analysis (PCA) is used to emphasize differences between refined and unrefined oils. We also noticed a significant difference between fluorescence of the argan cosmetic oil and edible argan oil due to the heating of the second one during its preparation. Stability to thermal oxidation of high oleic sunflower oil compared to the extra virgin olive, argan cosmetic and refined corn oils is also shown. 展开更多
关键词 VEGETABLE OILS Oxidation Refined and Unrefined OILS UNSATURATED FATTY ACID FLUORESCENCE spectroscopy and Principal Component Analysis (PCA)
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An economical and flexible chip using surface-enhanced infrared absorption spectroscopy for pharmaceutical detection:Combining qualitative analysis and quantitative detection
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作者 Jikai Wang Pengfei Zeng +3 位作者 Haitao Xie Suisui He Xilin Xiao Cuiyun Yu 《Journal of Pharmaceutical Analysis》 2025年第2期474-476,共3页
Infrared(IR)spectroscopy,a technique within the realm of molecular vibrational spectroscopy,furnishes distinctive chemical signatures pivotal for both structural analysis and compound identification.A notable challeng... Infrared(IR)spectroscopy,a technique within the realm of molecular vibrational spectroscopy,furnishes distinctive chemical signatures pivotal for both structural analysis and compound identification.A notable challenge emerges from the misalignment between the mid-IR light wavelength range and molecular dimensions,culminating in a constrained absorption cross-section and diminished vibrational absorption coefficients(Supplementary data). 展开更多
关键词 pharmaceutical detection quantitative detection structural analysis surface enhanced infrared absorption spectroscopy qualitative analysis chemical signatures infrared spectroscopy molecular vibrational spectroscopyfurnishes
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Simultaneous Monitoring of Nitrogen Dioxide and Aerosol Concentrations with Dual Path Differential Optical Absorption Spectroscopy 被引量:1
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作者 Hayato Saito Yutaro Goto +9 位作者 Yusaku Mabuchi Ilham Alimuddin Gerry Bagtasa Naohiro Manago Hitoshi Irie Ippei Harada Toshihiko Ishibashi Kazunori Yashiro Shumpei Kameyama Hiroaki Kuze 《Open Journal of Air Pollution》 2014年第1期20-32,共13页
Differential optical absorption spectroscopy (DOAS) is a useful technique for measuring nitrogen dioxide (NO2) and aerosol, the most important species in urban environmental pollution. This paper reports on the result... Differential optical absorption spectroscopy (DOAS) is a useful technique for measuring nitrogen dioxide (NO2) and aerosol, the most important species in urban environmental pollution. This paper reports on the results of our dual path DOAS measurements recently conducted in Chiba City, Japan, using xenon flashlights equipped on tall constructions as aviation obstruction lights. Because of the proximity of the southern DOAS path to an industrial area, it is found that the level of air pollution generally increases with the dominance of westerly winds, from the plausible source area to the observation light path. This situation is consistent with the result of wind lidar measurement covering a sector of ±28? with the observation range of approximately 2.8 km. In spite of the fact that the two DOAS paths, having path lengths of 5.5 and 3.5 km each, are located in separated regions of Chiba City, the observed temporal behavior was similar for both nitrogen dioxide and aerosol, though the southern path tends to exhibit slightly higher pollution levels than the northern counterpart. Additionally it is confirmed that size information of aerosol particles can be derived from the DOAS data through the analysis of the wavelength dependence of the aerosol optical thickness, which shows fairly good correlation with the mass ratio between PM2.5 and suspended particulate matter (SPM) obtained from the in-situ sampling station measurement. Thus, the DOAS approach can also be utilized for obtaining information on PM2.5 that is considered to be more harmful to human health than SPM. 展开更多
关键词 Differential Optical Absorption spectroscopy (DOAS) WIND Lidar Urban Air POLLUTION Nitrogen Dioxide AEROSOL PM2.5 SPM
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A Review of Functional Near-Infrared Spectroscopy Studies of Motor and Cognitive Function in Preterm Infants 被引量:4
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作者 Quan Wang Guang-Pu Zhu +4 位作者 Li Yi Xin-Xin Cui Hui Wang Ru-Yi Wei Bing-Liang Hu 《Neuroscience Bulletin》 SCIE CAS CSCD 2020年第3期321-329,共9页
Preterm infants are vulnerable to brain injuries,and have a greater chance of experiencing neurodevelopmental disorders throughout development. Early screening for motor and cognitive functions is critical to assessin... Preterm infants are vulnerable to brain injuries,and have a greater chance of experiencing neurodevelopmental disorders throughout development. Early screening for motor and cognitive functions is critical to assessing the developmental trajectory in preterm infants, especially those who may have motor or cognitive deficits. The brain imaging technology functional near-infrared spectroscopy(fNIRS) is a portable and low-cost method of assessing cerebral hemodynamics, making it suitable for large-scale use even in remote and underdeveloped areas. In this article, we review peer-reviewed, scientific f NIRS studies of motor performance, speech perception, and facial recognition in preterm infants. f NIRS provides a link between hemodynamic activity and the development of brain functions in preterm infants. Research using fNIRS has shown different patterns of hemoglobin change during some behavioral tasks in early infancy. fNIRS helps to promote our understanding of the developmental mechanisms of brain function in preterm infants when performing motor or cognitive tasks in a less-restricted environment. 展开更多
关键词 Functional near infrared spectroscopy PRETERM INFANT MOTOR performance Speech perception FACIAL recognition CEREBRAL HEMODYNAMICS
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Near-Infrared Spectroscopy Combined with Partial Least Squares Discriminant Analysis Applied to Identification of Liquor Brands 被引量:6
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作者 Bin Yang Lijun Yao Tao Pan 《Engineering(科研)》 2017年第2期181-189,共9页
The identification of liquor brands is very important for food safety. Most of the fake liquors are usually made into the products with the same flavor and alcohol content as regular brand, so the identification for t... The identification of liquor brands is very important for food safety. Most of the fake liquors are usually made into the products with the same flavor and alcohol content as regular brand, so the identification for the liquor brands with the same flavor and the same alcohol content is essential. However, it is also difficult because the components of such liquor samples are very similar. Near-infrared (NIR) spectroscopy combined with partial least squares discriminant analysis (PLS-DA) was applied to identification of liquor brands with the same flavor and alcohol content. A total of 160 samples of Luzhou Laojiao liquor and 200 samples of non-Luzhou Laojiao liquor with the same flavor and alcohol content were used for identification. Samples of each type were randomly divided into the modeling and validation sets. The modeling samples were further divided into calibration and prediction sets using the Kennard-Stone algorithm to achieve uniformity and representativeness. In the modeling and validation processes based on PLS-DA method, the recognition rates of samples achieved 99.1% and 98.7%, respectively. The results show high prediction performance for the identification of liquor brands, and were obviously better than those obtained from the principal component linear discriminant analysis method. NIR spectroscopy combined with the PLS-DA method provides a quick and effective means of the discriminant analysis of liquor brands, and is also a promising tool for large-scale inspection of liquor food safety. 展开更多
关键词 IDENTIFICATION of LIQUOR Brands NEAR-INFRARED spectroscopy Partial Least SQUARES DISCRIMINANT ANALYSIS Principal Component Linear DISCRIMINANT ANALYSIS
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Metabonomic studies of pancreatic cancer response to radiotherapy in a mouse xenograft model using magnetic resonance spectroscopy and principal components analysis 被引量:1
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作者 Xin-Hong He Wen-Tao Li +4 位作者 Ya-Jia Gu Bao-Feng Yang Hui-Wen Deng Yi-Hua Yu Wei-Jun Peng 《World Journal of Gastroenterology》 SCIE CAS 2013年第26期4200-4208,共9页
AIM: To investigate the metabolic profiles of xenograft pancreatic cancer before and after radiotherapy by high-resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1H NMR) combined with princ... AIM: To investigate the metabolic profiles of xenograft pancreatic cancer before and after radiotherapy by high-resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1H NMR) combined with principal components analysis (PCA) and evaluate the radiotherapeutic effect. METHODS: The nude mouse xenograft model of human pancreatic cancer was established by injecting human pancreatic cancer cell SW1990 subcutaneously into the nude mice. When the tumors volume reached 800 mm3 , the mice received various radiation doses. Two weeks later, tumor tissue sections were prepared for running the NMR measurements. 1H NMR and PCA were used to determine the changes in the metabolic profiles of tumor tissues after radiotherapy. Metabolic profiles of normal pancreas, pancreatic tumor tissues, and radiationtreated pancreatic tumor tissues were compared. RESULTS: Compared with 1H NMR spectra of the normal nude mouse pancreas, the levels of choline, taurine, alanine, isoleucine, leucine, valine, lactate, and glutamic acid of the pancreatic cancer group were increased, whereas an opposite trend for phosphocholine, glycerophosphocholine, and betaine was observed. The ratio of phosphocholine to creatine, and glycerophosphocholine to creatine showed noticeable decrease in the pancreatic cancer group. After further evaluation of the tissue metabolic profile after treatment with three different radiation doses, no significant change in metabolites was observed in the 1H NMR spectra, while the inhibition of tumor growth was in proportion to the radiation doses. However, PCA results showed that the levels of choline and betaine were decreased with the increased radiation dose, and conversely, the level of acetic acid was dramatically increased. CONCLUSION: The combined methods were demonstrated to have the potential for allowing early diagnosis and assessment of pancreatic cancer response to radiotherapy. 展开更多
关键词 High-resolution MAGIC angle SPINNING PROTON magnetic resonance spectroscopy Principal components analysis PANCREATIC cancer RADIOTHERAPY
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Laser Induced Breakdown Spectroscopy for Comparative Quantitative Analysis of Betel Leaves from Pakistan 被引量:1
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作者 I Rehan K Rehan +1 位作者 S Sultana R Muhammad 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2018年第10期3295-3302,共8页
Laser induced breakdown Spectroscopy(LIBS)was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air.Pulsed Nd∶YAG(1064 nm)in conjunction with a suitable detector(LIBS 2000+,Ocean ... Laser induced breakdown Spectroscopy(LIBS)was applied for the elemental analysis and exposure of the heavy metals in betel leaves in air.Pulsed Nd∶YAG(1064 nm)in conjunction with a suitable detector(LIBS 2000+,Ocean Optics,Inc)having the optical resolution of 0.06 nm was used to record the emission spectra from 220 to 720 nm.Elements like Al,Ba,Ca,Cr,Cu,P,Fe,K,Mg,Mn,Na,P,S,Sr,and Zn were found to present in the samples.The relative abundances of the observed elements were calculated through standard calibration curve method,integrated intensity ratio method,and weight percentage LIBS approach.LIBS findings were validated by comparing its results with the results obtained using a typical analytical technique of Inductively Coupled plasma-optical emission spectroscopy(ICP-OES).Limit of detection(LOD)of the LIBS system was also estimated for heavy metals.The experience gain through this work implies that LIBS could be highly applicable for testing the quality and purity of food products. 展开更多
关键词 Laser induced BREAKDOWN spectroscopy(LIBS) Spectral analysis Inductively coupled plasma-optical emission SPECTROMETRY Limit of detection(LOD)
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Feasibility assessment of phenotyping cotton fiber maturity using infrared spectroscopy and algorithms for genotyping analyses 被引量:1
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作者 KIM Hee Jin LIU Yongliang +1 位作者 FANG David D. DELHOM Christopher D. 《Journal of Cotton Research》 2019年第1期44-55,共12页
Background:Cotton fiber maturity is an important property that partially determines the processing and performance of cotton.Due to difficulties of obtaining fiber maturity values accurately from every plant of a gene... Background:Cotton fiber maturity is an important property that partially determines the processing and performance of cotton.Due to difficulties of obtaining fiber maturity values accurately from every plant of a genetic population,cotton geneticists often use micronaire(MIC) and/or lint percentage for classifying immature phenotypes from mature fiber phenotyp es although they are complex fiber traits.The recent development of an algorithm for determining cotton fiber maturity(MIR)from Fourier transform infrared(FT-IR)spectra explores a novel way to measure fiber maturity efficiently and accurately.However,the algorithm has not been tested with a genetic population consisting of a large number of progeny pla,nts.Results:The merits and limits of the MIC-or lint percentage-bas ed phenotyping method were demonstrated by comparing the observed phenotypes with the predicted phenotypes based on their DNA marker genotypes in a genetic population consisting of 708 F2 plants with various fiber maturity.The observed MIC-based fiber phenotypes matched to the predicted phenotypes better than the observed lint percenta ge-based fiber phenotypes.The lint percentage was obtained from each of F2 plants,whereas the MIC values were unable to be obtained from the entire population since certain F2 plants produced insufficient fiber mass for their measurements.To test the feasibiility of cotton fiber infrared maturity(MIR)as a viable phenotyping tool for genetic analyses,we me asured FT-IR spectra from the second population composed of 80 F2 plants with various fiber maturities,determined MIR values using the algorithms,and compared them with their genotypes in addition to other fiber phenotypes.The results showed that MIR values were successfully obtained from each of the F2 plants,and the observed MIR-based phenotypes fit well to the predicted phenotypes based on their DNA marker genotypes as well as the observed phenotypes based on a combination of MIC and lint percentage.Conclusions:The M,R value obtained from FT-IR spectra of cotton fibers is able to accurately assess fiber maturity of all plants of a population in a quantitative way.The technique provides an option for cotton geneticists to determine fiber maturity rapidly and efficiently. 展开更多
关键词 Attenuated total reflection Fourier transform infrared spectroscopy Cotton FIBER MATURITY Crystallinity IMMATURE FIBER (im) mutant
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Titanium dioxide as an adsorbent to enhance the detection ability of near-infrared diffuse reflectance spectroscopy 被引量:4
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作者 Shuyu Wang Jin Zhang +1 位作者 Wensheng Cai Xueguang Shao 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第5期1024-1026,共3页
A method for quantitative determination of fish sperm deoxyribonucleic acid(fsDNA)was developed by using titanium dioxide(TiO2)as an adsorbent and near-infrared diffuse reflectance spectroscopy(NIRDRS).The selective e... A method for quantitative determination of fish sperm deoxyribonucleic acid(fsDNA)was developed by using titanium dioxide(TiO2)as an adsorbent and near-infrared diffuse reflectance spectroscopy(NIRDRS).The selective enrichment of fsDNA was proved by comparing the adsorption efficiency of bovine serum albumin,tyrosine and tryptophan,and the low adsorption background of TiO2 was illustrated by comparing the spectra of four commonly-used inorganic adsorbents(alkaline aluminium oxide,neutral aluminium oxide,nano-hydroxyapatite and silica).The spectral feature of fsDNA can be clearly observed in the spectrum of the sample.Partial least squares(PLS)model was built for quantitative determination of fsDNA using 28 solutions,and 13 solutions with interferences were used for validation of the model.The results showed that the correlation coefficient(R)between the predicted and the reference concentration is 0.9727 and the recoveries of the validation samples are in the range of 98.2%-100.7%. 展开更多
关键词 NEAR-INFRARED DIFFUSE reflectance spectroscopy Quantitative model DETECTION ABILITY Titanium dioxide Fish SPERM DNA
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