[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, ...[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, A. spinula, A. Caespitosa, A. sichuanensis, A. ebianensis, A. retusa, A. guizhouensis and A. liboensis were subjected to drying, pulverization and sieving and then directly determined for near- infrared reflectance spectrums; and the plants in this genus were classified by clus- ter analysis and principal component analysis （PCA）. [Result] The near-infrared re- flectance spectrums of the 23 batches of Guizhou Aspidistra plants showed very high similarity. The spectrums were processed by first derivative method, and the spectral range of 4 000-7 500 cm-1 was selected as the analytical range. Cluster analysis and PCA were employed to mass spectrum variables of plants in Aspidis- tra, fewer new variables became the linear combination of primary variables, and small differences between different varieties were enlarged, thereby facilitating intu- itive classification of plants in this genus. [Conclusion] Near-infrared diffuse re- flectance spectroscopy is nondestructive and rapid for determination of solid sam- pies, and provides a new method for the classification of Guizhou Aspidistra plants combined by information processing techniques.展开更多
[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were cho...[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were chosen and drought-tolerance degrees of wheat were graded and identified according to Winter-wheat Drought Tol- erance Evaluation Technical Standards （GB/T 21127-2007）, and harvest wheat grains underwent spectrum collection, with a full-spectrum analyzer, to establish a database. [Result] Based on qualitative analysis and full-spectrum correlation research, the coef- ficient of determination （RSQ） and cross-validation coefficient of determination （1-VR） were concluded at 0.697 5 and 0.600 2, showing near-infrared diffuse reflectance spectroscopy is of significant differences among wheat varieties and of significant or extremely significant correlation with drought-tolerance indices. [Conclusion] The re- search indicates that to evaluate drought-tolerance of wheat with near-infrared diffuse reflectance spectroscopy is a rapid and feasible way, which is simple, convenient without damages on grains, and of practical values for construction wheat drought-tol- erance evaluation index system and identification of breeding materials.展开更多
Partial least squares（PLS）,back-propagation neural network（BPNN）and radial basis function neural network（RBFNN）were respectively used for estalishing quantative analysis models with near infrared（NIR）diffuse r...Partial least squares（PLS）,back-propagation neural network（BPNN）and radial basis function neural network（RBFNN）were respectively used for estalishing quantative analysis models with near infrared（NIR）diffuse reflectance spectra for determining the contents of rifampincin（RMP）,isoniazid（INH）and pyrazinamide（PZA）in rifampicin isoniazid and pyrazinamide tablets.Savitzky-Golay smoothing,first derivative,second derivative,fast Fourier transform（FFT）and standard normal variate（SNV）transformation methods were applied to pretreating raw NIR diffuse reflectance spectra.The raw and pretreated spectra were divided into several regions,depending on the average spectrum and RSD spectrum.Principal component analysis（PCA）method was used for analyzing the raw and pretreated spectra in different regions in order to reduce the dimensions of input data.The optimum spectral regions and the models＇ parameters were chosen by comparing the root mean square error of cross-validation（RMSECV）values which were obtained by leave-one-out cross-validation method.The RMSECV values of the RBFNN models for determining the contents of RMP,INH and PZA were 0.00288,0.00226 and 0.00341,respectively.Using these models for predicting the contents of INH,RMP and PZA in prediction set,the RMSEP values were 0.00266,0.00227 and 0.00411,respectively.These results are better than those obtained from PLS models and BPNN models.With additional advantages of fast calculation speed and less dependence on the initial conditions,RBFNN is a suitable tool to model complex systems.展开更多
[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drou...[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drought resistance were selected and were classified according to their drought resistance grades determined by the Technical Specification of Identification and Evaluation for Drought Resistance in Wheat （GB/T 21127-2007）. In addition, the harvested wheat seed samples were spectrally analyzed with FOSS NIRSystems5000 near-infrared spectrum analyzer for grain quality （full spectrum analyzer） and then the forecasted regression equations were established. [Result] After the establishment of a database and validation, dis- criminated functions were obtained. The determination coefficient （RSQ） and coeffi- cients of determination for cross validation （1-VR） in the discriminant function built with seed samples from water stress area were 0.846 0 and 0.781 8, respectively, which indicated that the consistency between drought resistance and spectral charac- teristics in wheat varieties was good, and there was high correlation between the near-infrared diffuse reflectance spectra of seeds and the drought resistance in wheat. [Conclusiou] Under water stress condition, it is feasible to establish a conve- nient, rapid and no-damage identification system for the drought resistance in wheat by using the near-infrared diffuse reflectance spectrum technique to scan wheat seeds.展开更多
In this paper,the Fourier transform near-infrared(FTNIR)diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares(PLS)regression is successfully used as an ...In this paper,the Fourier transform near-infrared(FTNIR)diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares(PLS)regression is successfully used as an effective multivariate calibration technique.The calibration set is composed of 20 standard millet samples that the protein contents were determined by the traditional Kjeldahl method.The optimal model dimension is found to be 5 by cross-validation.22 millet samples were determined by the proposed FTNIR-PLS method.The correlation coefficient between the concentration values obtained by the FTNIR-PLS method and the traditional Kjeldahl method is 0.9805.The standard error of prediction(SEP)is 0.28% and the mean recovery is 100.2%.The proposed method has been successfully applied for the routine analysis of protein in about 10,000 grain samples.展开更多
In this study, we focused on diffuse reflectance spectroscopy, a rapid and noninvasive spectroscopy technique that has considerable potential for medical diagnosis. In order to better understand and analyze the signal...In this study, we focused on diffuse reflectance spectroscopy, a rapid and noninvasive spectroscopy technique that has considerable potential for medical diagnosis. In order to better understand and analyze the signals induced by this method, we performed a series of in vivo measurements on healthy and diseased skin. Measurement sites on a human hand and feet were chosen. Some preliminary results obtained on these sites show the feasibility of this technique in clinics.展开更多
In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive ...In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/1, respectively.展开更多
In the present study,we synthesized CeO2 catalysts doped with various transition metals(M=Co,Fe,or Cu)using a supercritical water hydrothermal route,which led to the incorporation of the metal ions in the CeO2 lattice...In the present study,we synthesized CeO2 catalysts doped with various transition metals(M=Co,Fe,or Cu)using a supercritical water hydrothermal route,which led to the incorporation of the metal ions in the CeO2 lattice,forming solid solutions.The catalysts were then used for the selective catalytic reduction(SCR)of NO by CO.The Cu‐doped catalyst exhibited the highest SCR activity;it had a T50(i.e.,50%NO conversion)of only 83°C and a T90(i.e.,90%NO conversion)of 126°C.Such an activity was also higher than in many state‐of‐the‐art catalysts.In situ diffuse reflectance Fourier transform infrared spectroscopy suggested that the MOx‐CeO2 catalysts(M=Co and Fe)mainly followed an Eley‐Rideal reaction mechanism for CO‐SCR.In contrast,a Langmuir‐Hinshelwood SCR reaction mechanism occurred in CuO‐CeO2 owing to the presence of Cu+species,which ensured effective adsorption of CO.This explains why CuO‐CeO2 exhibited the highest activity with regard to the SCR of NO by CO.展开更多
To develop near-infrared （NIR） reflectance spectroscopic methods for the quantitative analysis of cefoperazone sodium/ sulbactam sodium from different manufacturers for injection powder medicaments. Various powders ...To develop near-infrared （NIR） reflectance spectroscopic methods for the quantitative analysis of cefoperazone sodium/ sulbactam sodium from different manufacturers for injection powder medicaments. Various powders of cefoperazone sodium/ sulbactam sodium were directly analyzed by non-destructive NIR reflectance spectroscopy using the spectrometer EQUINOX55. Two quantitative methods via integrating sphere （IS） and fiberoptic probe （FOP） models were explored from 6 batches of commercial samples and 42 batches of laboratory samples at a content ranging from 30% to 70% for cefoperazone and 60% to 20% for sulbactam. The root mean square errors of cross validation （RMSECV） and the root mean square errors of prediction （RMSEP） of IS were 1.79% and 2.85%, respectively, for cefoperazone sodium, and were 1.86% and 3.08%, respectively, for sulbactam sodium; and those of FOP were 2.93% and 2.92%, respectively, for cefoperazone sodium, and were 2.23% and 3.01%, respectively, for sulbactam sodium. Based on the ICH guidelines and Ref. 12, the quantitative models were then evaluated in terms of specificity, linearity, accuracy, precision, robustness and model transferability. The non-destructive quantitative NIR methods used in this study are applicable for rapid analysis of injectable powdered drugs from different manufacturers.展开更多
This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This...This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This was achieved using diffuse reflectance visible （DRV） spectroscopy and dye deposition, using the pH sensitive dye, thymol blue （TB）. Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide （SFN） were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model （R2=0.992）, giving a rate constant of 2.43 × 10^- 2 s 1.展开更多
The non-linear relationships between the contents of ginsenoside Rg 1, Rb 1, Rd and Panax notoginseng saponins(PNS) in Panax notoginseng root herb and the near infrared(NIR) diffuse reflectance spectra of the herb wer...The non-linear relationships between the contents of ginsenoside Rg 1, Rb 1, Rd and Panax notoginseng saponins(PNS) in Panax notoginseng root herb and the near infrared(NIR) diffuse reflectance spectra of the herb were established by means of artificial neural networks(ANNs). Four three-layered perception feed-forward networks were trained with an error back-propagation algorithm. The significant principal components of the NIR spectral data matrix were utilized as the input of the networks. The networks architecture and parameters were selected so as to offer less prediction errors. Relative prediction errors for Rg 1, Rb 1, Rd and PNS obtained with the optimum ANN models were 8.99%, 6.54%, 8.29%, and 5.17%, respectively, which were superior to those obtained with PLSR methods. It is verified that ANN is a suitable approach to model this complex non-linearity. The developed method is fast, non-destructive and accurate and it provides a new efficient approach for determining the active components in the complex system of natural herbs.展开更多
This review report represents an overview of research and development on medical hyperspectral imaging technology and its applications.Spectral imaging technology is attracting attention as a new imaging modality for ...This review report represents an overview of research and development on medical hyperspectral imaging technology and its applications.Spectral imaging technology is attracting attention as a new imaging modality for medical applications,especially in disease diagnosis and image-guided surgery.Considering the recent advances in imaging,this technology provides an opportunity for twodimensional mapping of oxygen saturation(SatO2)of blood with high accuracy,spatial spectral imaging,and its analysis and provides detection and diagnostic information about the tissue physiology and morphology.Multispectral imaging also provides information about tissue oxygenation,perfusion,and potential function during surgery.Analytical algorithm has been examined,and indication of accurate map of relative hemoglobin concentration and SatO2 can be indicated with preferable resolution and frame rate.This technology is expected to provide promising biomedical information in practical use.Several studies suggested that blood flow and SatO2 are associated with gastrointestinal disorders,particularly malignant tumor conditions.The use and analysis of spectroscopic images are expected to potentially play a role in the detection and diagnosis of these diseases.展开更多
Macrovesicular Steatosis(MS)is an independent risk factor for adverse post-liver transplant(LT)outcomes.The degree of MS is intimately related to the viability of the liver graft,which in turn is crucial to the succes...Macrovesicular Steatosis(MS)is an independent risk factor for adverse post-liver transplant(LT)outcomes.The degree of MS is intimately related to the viability of the liver graft,which in turn is crucial to the success of the operation.An ideal liver graft should have no MS and most centres would find it unacceptable to use a donor liver with severe MS for LT.While a formal liver biopsy is the goldstandard diagnostic test for MS,given the logistical and time constraints it is not universally feasible.Other tests like a frozen section biopsy are plagued by issues of fallibility with reporting and sampling bias making them inferior to a liver biopsy.Hence,the development of an accurate,non-invasive,easy-to-use,handheld,real-time device for quantification of MS would fill this lacuna in the deceased donor selection process.We present the hypothesis,design and proof-ofconcept of a study,which aims to standardise and determine the feasibility and accuracy of a novel handheld device applying the principle of diffuse reflectance spectroscopy for real-time quantification of MS.展开更多
Activated carbon supported Mo-based catalysts were prepared and reduced under different activation atmospheres, including pure H2, syngas （H2/CO=2/1）, and pure CO. The cat- alysts structures were characterized by X-...Activated carbon supported Mo-based catalysts were prepared and reduced under different activation atmospheres, including pure H2, syngas （H2/CO=2/1）, and pure CO. The cat- alysts structures were characterized by X-ray diffraction , X-ray absorption fine structure, and in situ diffuse reflectance infrared Fourier transform spectroscopy. The catalytic per- formance for the higher alcohol synthesis from syngas was tested. The pure H2 treatment showed a high reduction capacity. The presence of a large amount of metallic CoO and low valence state Mo^φ＋ （0〈φ〈2） on the surface suggested a super activity for the CO dissoci- ation and hydrogenation, which promoted hydrocarbons formation and reduced the alcohol selectivity. In contrast, the pure CO-reduced catalyst had a low reduction degree. The Mo and Co species at the catalyst mainly existed in the form of Mo^4＋ and Co^2＋. The syngas- reduced catalyst showed the highest activity and selectivity for the higher alcohols synthesis. We suggest that the syngas treatment had an appropriate reduction capacity that is between those of pure H2 and pure CO and led to the coexistence of multivalent Co species as well as the enrichment of Mo~＋ on the catalyst＇s surface. The synergistic effects between these active species provided a better cooperativity and equilibrium between the CO dissociation, hydrogenation and CO insertion and thus contributed beneficially to the formation of higher alcohols.展开更多
Light illumination has been widely used to promote activity and selectivity of traditional thermal catalysts. Nevertheless, the role of light irradiation during catalytic reactions is not well understood. In this work...Light illumination has been widely used to promote activity and selectivity of traditional thermal catalysts. Nevertheless, the role of light irradiation during catalytic reactions is not well understood. In this work, Pt/Al2 O3 prepared by wet impregnation was used for photothermal CO2 hydrogenation, and it showed a photothermal effect. Hence, operando diffuse reflectance infrared Fourier-transform spectroscopy and density functional theory calculations were conducted on Pt/Al2 O3 to gain insights into the reaction mechanism. The results indicated that CO desorption from Pt sites including step sites(Ptstep) or/and terrace site(Ptterrace) is an important step during CO2 hydrogenation to free the active Pt sites. Notably, visible light illumination and temperature affected the CO desorption in different ways. The calculated adsorption energy of CO on Ptstep and Ptterrace sites was-1.24 and-1.43 e V, respectively. Hence, CO is more strongly bound to the Ptstep sites. During heating in the dark, CO preferentially desorbs from the Ptterrace site. However, the additional light irradiation facilitates transfer of CO from the Ptstep to Ptterrace sites and its subsequent desorption from the Ptterrace sites, thus promoting the CO2 hydrogenation.展开更多
In this work,a series of BiOBr nanoplates with oxygen vacancies(OVs)were synthesized by a solvothermal method using a water/ethylene glycol solution.The number of OVs and facets of BiOBr were tuned by changing the wat...In this work,a series of BiOBr nanoplates with oxygen vacancies(OVs)were synthesized by a solvothermal method using a water/ethylene glycol solution.The number of OVs and facets of BiOBr were tuned by changing the water/ethylene glycol ratio.Although the role of OVs in photocatalysis has been investigated,the underlying mechanisms of charge transfer and reactant activation remain unknown.To unravel the effect of OVs on the reactant activation and photocatalytic NO oxidation process,in situ diffuse reflectance infrared Fourier transform spectroscopy,so‐called DRIFTS,and theoretical calculations were performed and their results combined.The photocatalytic efficiency of the as‐prepared BiOBr was significantly increased by increasing the amount of OVs.The oxygen vacancies had several effects on the photocatalysts,including the introduction of intermediate energy levels that enhanced light absorption,promoted electron transfer,acted as active sites for catalytic reaction and the activation of oxygen molecules,and facilitated the conversion of the intermediate products to the final product,thus increasing the overall visible light photocatalysis efficiency.The present work provides new insights into the understanding of the role of OVs in photocatalysts and the mechanism of photocatalytic NO oxidation.展开更多
Bi12O17Br2and Bi4O5Br2visible‐light driven photocatalysts,were respectively fabricated by hydrothermal and room‐temperature deposition methods with the use of BiBr3and NaOH as precursors.Both Bi12O17Br2and Bi4O5Br2w...Bi12O17Br2and Bi4O5Br2visible‐light driven photocatalysts,were respectively fabricated by hydrothermal and room‐temperature deposition methods with the use of BiBr3and NaOH as precursors.Both Bi12O17Br2and Bi4O5Br2were composed of irregular nanosheets.The Bi4O5Br2nanosheets exhibited high and stable visible‐light photocatalytic efficiency for ppb‐level NO removal.The performance of Bi4O5Br2was markedly higher than that of the Bi12O17Br2nanosheets.The hydroxyl radical(?OH)was determined to be the main reactive oxygen species for the photo‐degradation processes of both Bi12O17Br2and Bi4O5Br2.However,in situ diffuse reflectance infrared Fourier transform spectroscopy analysis revealed that Bi12O17Br2and Bi4O5Br2featured different conversion pathways for visible light driven photocatalytic NO oxidation.The excellent photocatalytic activity of Bi4O5Br2resulted from a high surface area and large pore volumes,which facilitated the transport of reactants and intermediate products,and provided more active sites for photochemical reaction.Furthermore,the Bi4O5Br2nanosheets produced more?OH and presented stronger valence band holeoxidation.In addition,the oxygen atoms of NO could insert into oxygen‐vacancies of Bi4O5Br2,whichprovided more active sites for the reaction.This work gives insight into the photocatalytic pollutant‐degradation mechanism of bismuth oxyhalide.展开更多
The selective catalytic reduction reaction belongs to the gas-solid multiphase reaction, and the adsorption of NH3 and NO on CuO/γ-Al2O3 catalysts plays an important role in the reaction. Performance of the CuO/γ-Al...The selective catalytic reduction reaction belongs to the gas-solid multiphase reaction, and the adsorption of NH3 and NO on CuO/γ-Al2O3 catalysts plays an important role in the reaction. Performance of the CuO/γ-Al2O3 catalysts was explored in a fixed bed adsorption system. The catalysts maintain nearly 100% NO conversion efficiency at 350℃. Comprehensive tests were carried out to study the adsorption behavior of NH3 and NO over the catalysts. The desorption experiments prove that NH3 and NO are adsorbed on CuO/γ-Al2O3 catalysts. The adsorption behaviors of NH3 and NO were also studied with the in-situ diffusion reflectance infrared Fourier transform spectroscopy methods. The results show that NH3 could be strongly adsorbed on the catalysts, resulting in coordinated NH3 and NH4＋. NO adsorption leads to the formation of bridging bidentate nitrate, chelating bidentate nitrate, and chelating nitro. The interaction of NH3 and NO molecules with the Cu2＋ present on the CAl2O3 （100） surface was investigated by using a periodic density functional theory. The results show that the adsorption of all the molecules on the Cu2＋ site is energetically favorable, whereas NO bound is stronger than that of NH3 with the adsorption site, and key information about the structural and energetic properties was also addressed.展开更多
The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric materials.The polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-s...The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric materials.The polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-state reaction method.The single-phase formation of these compounds was confirmed by X-ray diffraction studies.It was found that the samples crystallized in tetragonal phase and the lattice parameters were calculated as a=1.0559(7) nm,c=1.0832(9) nm for Y1.9Fe0.1O3–y and a=1.0545(6) nm,c=1.0841(8)...展开更多
基金Supported by National Natural Science Foundation of China(81360623)~~
文摘[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, A. spinula, A. Caespitosa, A. sichuanensis, A. ebianensis, A. retusa, A. guizhouensis and A. liboensis were subjected to drying, pulverization and sieving and then directly determined for near- infrared reflectance spectrums; and the plants in this genus were classified by clus- ter analysis and principal component analysis （PCA）. [Result] The near-infrared re- flectance spectrums of the 23 batches of Guizhou Aspidistra plants showed very high similarity. The spectrums were processed by first derivative method, and the spectral range of 4 000-7 500 cm-1 was selected as the analytical range. Cluster analysis and PCA were employed to mass spectrum variables of plants in Aspidis- tra, fewer new variables became the linear combination of primary variables, and small differences between different varieties were enlarged, thereby facilitating intu- itive classification of plants in this genus. [Conclusion] Near-infrared diffuse re- flectance spectroscopy is nondestructive and rapid for determination of solid sam- pies, and provides a new method for the classification of Guizhou Aspidistra plants combined by information processing techniques.
基金Supported by National Wheat Industry System(CARS-E-2-36)Henan Wheat Industry System(S2010-10-02)National Science and Technology Support Plan(2011BAD35B-03)~~
文摘[Objective] The aim was to build an evaluation method rapidly identifying wheat drought tolerance with near infrared diffuse reflectance spectroscopy. [Method] In the research, 36 wheat varieties in 2007-2009 were chosen and drought-tolerance degrees of wheat were graded and identified according to Winter-wheat Drought Tol- erance Evaluation Technical Standards （GB/T 21127-2007）, and harvest wheat grains underwent spectrum collection, with a full-spectrum analyzer, to establish a database. [Result] Based on qualitative analysis and full-spectrum correlation research, the coef- ficient of determination （RSQ） and cross-validation coefficient of determination （1-VR） were concluded at 0.697 5 and 0.600 2, showing near-infrared diffuse reflectance spectroscopy is of significant differences among wheat varieties and of significant or extremely significant correlation with drought-tolerance indices. [Conclusion] The re- search indicates that to evaluate drought-tolerance of wheat with near-infrared diffuse reflectance spectroscopy is a rapid and feasible way, which is simple, convenient without damages on grains, and of practical values for construction wheat drought-tol- erance evaluation index system and identification of breeding materials.
基金Supported by the Science Technology Development Project of Jilin Province,China(No.20020503-2).
文摘Partial least squares（PLS）,back-propagation neural network（BPNN）and radial basis function neural network（RBFNN）were respectively used for estalishing quantative analysis models with near infrared（NIR）diffuse reflectance spectra for determining the contents of rifampincin（RMP）,isoniazid（INH）and pyrazinamide（PZA）in rifampicin isoniazid and pyrazinamide tablets.Savitzky-Golay smoothing,first derivative,second derivative,fast Fourier transform（FFT）and standard normal variate（SNV）transformation methods were applied to pretreating raw NIR diffuse reflectance spectra.The raw and pretreated spectra were divided into several regions,depending on the average spectrum and RSD spectrum.Principal component analysis（PCA）method was used for analyzing the raw and pretreated spectra in different regions in order to reduce the dimensions of input data.The optimum spectral regions and the models＇ parameters were chosen by comparing the root mean square error of cross-validation（RMSECV）values which were obtained by leave-one-out cross-validation method.The RMSECV values of the RBFNN models for determining the contents of RMP,INH and PZA were 0.00288,0.00226 and 0.00341,respectively.Using these models for predicting the contents of INH,RMP and PZA in prediction set,the RMSEP values were 0.00266,0.00227 and 0.00411,respectively.These results are better than those obtained from PLS models and BPNN models.With additional advantages of fast calculation speed and less dependence on the initial conditions,RBFNN is a suitable tool to model complex systems.
基金Supported by the Special Fund for the Industrial Technology System Construction of Modern Agriculture in Wheat(CARS-E-2-36)the Special Fund for Henan Industrial Technology System Construction of Modern Agriculture in Wheat(S2010-10-02)National Support Program for Science and Technology(2011BAD35B03)~~
文摘[Objective] This study aimed to establish an identification system for drought-resistance in wheat by using near-infrared diffuse reflectance spectroscopy. [Method] In 2006-2007, 36 wheat varieties with different drought resistance were selected and were classified according to their drought resistance grades determined by the Technical Specification of Identification and Evaluation for Drought Resistance in Wheat （GB/T 21127-2007）. In addition, the harvested wheat seed samples were spectrally analyzed with FOSS NIRSystems5000 near-infrared spectrum analyzer for grain quality （full spectrum analyzer） and then the forecasted regression equations were established. [Result] After the establishment of a database and validation, dis- criminated functions were obtained. The determination coefficient （RSQ） and coeffi- cients of determination for cross validation （1-VR） in the discriminant function built with seed samples from water stress area were 0.846 0 and 0.781 8, respectively, which indicated that the consistency between drought resistance and spectral charac- teristics in wheat varieties was good, and there was high correlation between the near-infrared diffuse reflectance spectra of seeds and the drought resistance in wheat. [Conclusiou] Under water stress condition, it is feasible to establish a conve- nient, rapid and no-damage identification system for the drought resistance in wheat by using the near-infrared diffuse reflectance spectrum technique to scan wheat seeds.
文摘In this paper,the Fourier transform near-infrared(FTNIR)diffuse reflectance spectroscopy is applied for the rapid determination of protein in millet.The partial least-squares(PLS)regression is successfully used as an effective multivariate calibration technique.The calibration set is composed of 20 standard millet samples that the protein contents were determined by the traditional Kjeldahl method.The optimal model dimension is found to be 5 by cross-validation.22 millet samples were determined by the proposed FTNIR-PLS method.The correlation coefficient between the concentration values obtained by the FTNIR-PLS method and the traditional Kjeldahl method is 0.9805.The standard error of prediction(SEP)is 0.28% and the mean recovery is 100.2%.The proposed method has been successfully applied for the routine analysis of protein in about 10,000 grain samples.
文摘In this study, we focused on diffuse reflectance spectroscopy, a rapid and noninvasive spectroscopy technique that has considerable potential for medical diagnosis. In order to better understand and analyze the signals induced by this method, we performed a series of in vivo measurements on healthy and diseased skin. Measurement sites on a human hand and feet were chosen. Some preliminary results obtained on these sites show the feasibility of this technique in clinics.
基金This work was supported by the National Natural Science Foundation of China (No. 30170261)the Natural Science Foundation of Tianjin (No. 023800411).
文摘In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/1, respectively.
文摘In the present study,we synthesized CeO2 catalysts doped with various transition metals(M=Co,Fe,or Cu)using a supercritical water hydrothermal route,which led to the incorporation of the metal ions in the CeO2 lattice,forming solid solutions.The catalysts were then used for the selective catalytic reduction(SCR)of NO by CO.The Cu‐doped catalyst exhibited the highest SCR activity;it had a T50(i.e.,50%NO conversion)of only 83°C and a T90(i.e.,90%NO conversion)of 126°C.Such an activity was also higher than in many state‐of‐the‐art catalysts.In situ diffuse reflectance Fourier transform infrared spectroscopy suggested that the MOx‐CeO2 catalysts(M=Co and Fe)mainly followed an Eley‐Rideal reaction mechanism for CO‐SCR.In contrast,a Langmuir‐Hinshelwood SCR reaction mechanism occurred in CuO‐CeO2 owing to the presence of Cu+species,which ensured effective adsorption of CO.This explains why CuO‐CeO2 exhibited the highest activity with regard to the SCR of NO by CO.
基金National Key Technologies R&D Program Foundation of China (Grant No. 2006BAK04A11)
文摘To develop near-infrared （NIR） reflectance spectroscopic methods for the quantitative analysis of cefoperazone sodium/ sulbactam sodium from different manufacturers for injection powder medicaments. Various powders of cefoperazone sodium/ sulbactam sodium were directly analyzed by non-destructive NIR reflectance spectroscopy using the spectrometer EQUINOX55. Two quantitative methods via integrating sphere （IS） and fiberoptic probe （FOP） models were explored from 6 batches of commercial samples and 42 batches of laboratory samples at a content ranging from 30% to 70% for cefoperazone and 60% to 20% for sulbactam. The root mean square errors of cross validation （RMSECV） and the root mean square errors of prediction （RMSEP） of IS were 1.79% and 2.85%, respectively, for cefoperazone sodium, and were 1.86% and 3.08%, respectively, for sulbactam sodium; and those of FOP were 2.93% and 2.92%, respectively, for cefoperazone sodium, and were 2.23% and 3.01%, respectively, for sulbactam sodium. Based on the ICH guidelines and Ref. 12, the quantitative models were then evaluated in terms of specificity, linearity, accuracy, precision, robustness and model transferability. The non-destructive quantitative NIR methods used in this study are applicable for rapid analysis of injectable powdered drugs from different manufacturers.
文摘This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This was achieved using diffuse reflectance visible （DRV） spectroscopy and dye deposition, using the pH sensitive dye, thymol blue （TB）. Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide （SFN） were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model （R2=0.992）, giving a rate constant of 2.43 × 10^- 2 s 1.
文摘The non-linear relationships between the contents of ginsenoside Rg 1, Rb 1, Rd and Panax notoginseng saponins(PNS) in Panax notoginseng root herb and the near infrared(NIR) diffuse reflectance spectra of the herb were established by means of artificial neural networks(ANNs). Four three-layered perception feed-forward networks were trained with an error back-propagation algorithm. The significant principal components of the NIR spectral data matrix were utilized as the input of the networks. The networks architecture and parameters were selected so as to offer less prediction errors. Relative prediction errors for Rg 1, Rb 1, Rd and PNS obtained with the optimum ANN models were 8.99%, 6.54%, 8.29%, and 5.17%, respectively, which were superior to those obtained with PLSR methods. It is verified that ANN is a suitable approach to model this complex non-linearity. The developed method is fast, non-destructive and accurate and it provides a new efficient approach for determining the active components in the complex system of natural herbs.
文摘This review report represents an overview of research and development on medical hyperspectral imaging technology and its applications.Spectral imaging technology is attracting attention as a new imaging modality for medical applications,especially in disease diagnosis and image-guided surgery.Considering the recent advances in imaging,this technology provides an opportunity for twodimensional mapping of oxygen saturation(SatO2)of blood with high accuracy,spatial spectral imaging,and its analysis and provides detection and diagnostic information about the tissue physiology and morphology.Multispectral imaging also provides information about tissue oxygenation,perfusion,and potential function during surgery.Analytical algorithm has been examined,and indication of accurate map of relative hemoglobin concentration and SatO2 can be indicated with preferable resolution and frame rate.This technology is expected to provide promising biomedical information in practical use.Several studies suggested that blood flow and SatO2 are associated with gastrointestinal disorders,particularly malignant tumor conditions.The use and analysis of spectroscopic images are expected to potentially play a role in the detection and diagnosis of these diseases.
文摘Macrovesicular Steatosis(MS)is an independent risk factor for adverse post-liver transplant(LT)outcomes.The degree of MS is intimately related to the viability of the liver graft,which in turn is crucial to the success of the operation.An ideal liver graft should have no MS and most centres would find it unacceptable to use a donor liver with severe MS for LT.While a formal liver biopsy is the goldstandard diagnostic test for MS,given the logistical and time constraints it is not universally feasible.Other tests like a frozen section biopsy are plagued by issues of fallibility with reporting and sampling bias making them inferior to a liver biopsy.Hence,the development of an accurate,non-invasive,easy-to-use,handheld,real-time device for quantification of MS would fill this lacuna in the deceased donor selection process.We present the hypothesis,design and proof-ofconcept of a study,which aims to standardise and determine the feasibility and accuracy of a novel handheld device applying the principle of diffuse reflectance spectroscopy for real-time quantification of MS.
文摘Activated carbon supported Mo-based catalysts were prepared and reduced under different activation atmospheres, including pure H2, syngas （H2/CO=2/1）, and pure CO. The cat- alysts structures were characterized by X-ray diffraction , X-ray absorption fine structure, and in situ diffuse reflectance infrared Fourier transform spectroscopy. The catalytic per- formance for the higher alcohol synthesis from syngas was tested. The pure H2 treatment showed a high reduction capacity. The presence of a large amount of metallic CoO and low valence state Mo^φ＋ （0〈φ〈2） on the surface suggested a super activity for the CO dissoci- ation and hydrogenation, which promoted hydrocarbons formation and reduced the alcohol selectivity. In contrast, the pure CO-reduced catalyst had a low reduction degree. The Mo and Co species at the catalyst mainly existed in the form of Mo^4＋ and Co^2＋. The syngas- reduced catalyst showed the highest activity and selectivity for the higher alcohols synthesis. We suggest that the syngas treatment had an appropriate reduction capacity that is between those of pure H2 and pure CO and led to the coexistence of multivalent Co species as well as the enrichment of Mo~＋ on the catalyst＇s surface. The synergistic effects between these active species provided a better cooperativity and equilibrium between the CO dissociation, hydrogenation and CO insertion and thus contributed beneficially to the formation of higher alcohols.
基金supported by the National Natural Science Foundation of China(U1862111,U1232119)Sichuan Provincial International Cooperation Project(2017HH0030)the Innovative Research Team of Sichuan Province(2016TD0011)~~
文摘Light illumination has been widely used to promote activity and selectivity of traditional thermal catalysts. Nevertheless, the role of light irradiation during catalytic reactions is not well understood. In this work, Pt/Al2 O3 prepared by wet impregnation was used for photothermal CO2 hydrogenation, and it showed a photothermal effect. Hence, operando diffuse reflectance infrared Fourier-transform spectroscopy and density functional theory calculations were conducted on Pt/Al2 O3 to gain insights into the reaction mechanism. The results indicated that CO desorption from Pt sites including step sites(Ptstep) or/and terrace site(Ptterrace) is an important step during CO2 hydrogenation to free the active Pt sites. Notably, visible light illumination and temperature affected the CO desorption in different ways. The calculated adsorption energy of CO on Ptstep and Ptterrace sites was-1.24 and-1.43 e V, respectively. Hence, CO is more strongly bound to the Ptstep sites. During heating in the dark, CO preferentially desorbs from the Ptterrace site. However, the additional light irradiation facilitates transfer of CO from the Ptstep to Ptterrace sites and its subsequent desorption from the Ptterrace sites, thus promoting the CO2 hydrogenation.
文摘In this work,a series of BiOBr nanoplates with oxygen vacancies(OVs)were synthesized by a solvothermal method using a water/ethylene glycol solution.The number of OVs and facets of BiOBr were tuned by changing the water/ethylene glycol ratio.Although the role of OVs in photocatalysis has been investigated,the underlying mechanisms of charge transfer and reactant activation remain unknown.To unravel the effect of OVs on the reactant activation and photocatalytic NO oxidation process,in situ diffuse reflectance infrared Fourier transform spectroscopy,so‐called DRIFTS,and theoretical calculations were performed and their results combined.The photocatalytic efficiency of the as‐prepared BiOBr was significantly increased by increasing the amount of OVs.The oxygen vacancies had several effects on the photocatalysts,including the introduction of intermediate energy levels that enhanced light absorption,promoted electron transfer,acted as active sites for catalytic reaction and the activation of oxygen molecules,and facilitated the conversion of the intermediate products to the final product,thus increasing the overall visible light photocatalysis efficiency.The present work provides new insights into the understanding of the role of OVs in photocatalysts and the mechanism of photocatalytic NO oxidation.
基金supported by the National Natural Science Foundation of China(51708078,21576034)Chongqing Postdoctoral Science Foundation funded project(Xm2016027)the Innovative Research Team of Chongqing(CXTDG201602014,CXTDX201601016)~~
文摘Bi12O17Br2and Bi4O5Br2visible‐light driven photocatalysts,were respectively fabricated by hydrothermal and room‐temperature deposition methods with the use of BiBr3and NaOH as precursors.Both Bi12O17Br2and Bi4O5Br2were composed of irregular nanosheets.The Bi4O5Br2nanosheets exhibited high and stable visible‐light photocatalytic efficiency for ppb‐level NO removal.The performance of Bi4O5Br2was markedly higher than that of the Bi12O17Br2nanosheets.The hydroxyl radical(?OH)was determined to be the main reactive oxygen species for the photo‐degradation processes of both Bi12O17Br2and Bi4O5Br2.However,in situ diffuse reflectance infrared Fourier transform spectroscopy analysis revealed that Bi12O17Br2and Bi4O5Br2featured different conversion pathways for visible light driven photocatalytic NO oxidation.The excellent photocatalytic activity of Bi4O5Br2resulted from a high surface area and large pore volumes,which facilitated the transport of reactants and intermediate products,and provided more active sites for photochemical reaction.Furthermore,the Bi4O5Br2nanosheets produced more?OH and presented stronger valence band holeoxidation.In addition,the oxygen atoms of NO could insert into oxygen‐vacancies of Bi4O5Br2,whichprovided more active sites for the reaction.This work gives insight into the photocatalytic pollutant‐degradation mechanism of bismuth oxyhalide.
基金Projects(50806025, 51021065, 50976038) supported by the National Natural Science Foundation of ChinaProject(20100480893) supported by the China Postdoctoral Science FoundationProject(1001022B) supported by the Postdoctoral Research Fund of Jiangsu Province, China
文摘The selective catalytic reduction reaction belongs to the gas-solid multiphase reaction, and the adsorption of NH3 and NO on CuO/γ-Al2O3 catalysts plays an important role in the reaction. Performance of the CuO/γ-Al2O3 catalysts was explored in a fixed bed adsorption system. The catalysts maintain nearly 100% NO conversion efficiency at 350℃. Comprehensive tests were carried out to study the adsorption behavior of NH3 and NO over the catalysts. The desorption experiments prove that NH3 and NO are adsorbed on CuO/γ-Al2O3 catalysts. The adsorption behaviors of NH3 and NO were also studied with the in-situ diffusion reflectance infrared Fourier transform spectroscopy methods. The results show that NH3 could be strongly adsorbed on the catalysts, resulting in coordinated NH3 and NH4＋. NO adsorption leads to the formation of bridging bidentate nitrate, chelating bidentate nitrate, and chelating nitro. The interaction of NH3 and NO molecules with the Cu2＋ present on the CAl2O3 （100） surface was investigated by using a periodic density functional theory. The results show that the adsorption of all the molecules on the Cu2＋ site is energetically favorable, whereas NO bound is stronger than that of NH3 with the adsorption site, and key information about the structural and energetic properties was also addressed.
文摘The compounds of iron substituted yttrium oxide systems have been prepared for the importance in the field of magneto electric materials.The polycrystalline samples of Y2–xFexO3–y(x=0.1,0.2) were prepared by solid-state reaction method.The single-phase formation of these compounds was confirmed by X-ray diffraction studies.It was found that the samples crystallized in tetragonal phase and the lattice parameters were calculated as a=1.0559(7) nm,c=1.0832(9) nm for Y1.9Fe0.1O3–y and a=1.0545(6) nm,c=1.0841(8)...
