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
The use of near infrared （NIR） spectroscopy was proved to be a useful tool for quality analysis of fruits. A bifurcated fiber type NIR spectrometer, with a detection range of 800-2500 nm by InGaAs detector, was used...The use of near infrared （NIR） spectroscopy was proved to be a useful tool for quality analysis of fruits. A bifurcated fiber type NIR spectrometer, with a detection range of 800-2500 nm by InGaAs detector, was used to evaluate the firmness of peaches. Anisotropy of NIR spectra and firmness of peaches in relation to detecting positions of different parts （including three latitudes and three longitudes） were investigated. Both spectra absorbency and firmness of peach were influenced by longitudes （i, ii, iii） and latitudes （A, B, C）. For modeling, two thirds of the samples were used as the calibration set and the remaining one third were used as the validation or prediction set. Partial least square regression （PLSR） models for different longitude and latitude spectra and for the whole fruit show that collecting several NIR spectra from different longitudes and latitudes of a fruit for NIR calibration modeling can improve the modeling performance. In addition, proper spectra pretreatments like scattering correction or derivative also can enhance the modeling performance. The best results obtained in this study were from the holistic model with multiplicative scattering correction （MSC） pretreatment, with correlation coefficient of cross-validation γcv=0.864, root mean square error of cross-validation RMSECV=6.71 N, correlation coefficient of calibration r=0.948, root mean square error of calibration RMSEC=4.21 N and root mean square error of prediction RMSEP=5.42 N. The results of this study are useful for further research and application that when applying NIR spectroscopy for objectives with anisotropic differences, spectra and quality indices are necessarily measured from several parts of each object to improve the modeling performance.展开更多
Near infrared reflectance （N1R） spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen （N） and organic ...Near infrared reflectance （N1R） spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen （N） and organic matter （OM） content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP （standard error of prediction） were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application.展开更多
Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064/μm were developed. High reflection mirrors for the Stokes wavelength have been used to gener...Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064/μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15 - 1.32/μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.展开更多
Coal has been used as an energy resource around the world, primarily for the generation of electricity. The cleaning of coal by removing its unwanted sulfur and mineral matter components is utmost essential before the...Coal has been used as an energy resource around the world, primarily for the generation of electricity. The cleaning of coal by removing its unwanted sulfur and mineral matter components is utmost essential before their gainful utilizations. The ionic liquids （ILs） are considered as non-toxic solvents for using in different industrial processes. The effect of two ILs namely, 1-n-butyl, 3-methylimidazolium tetrafluoro borate （ILl） and 1-n-butyl, 3-methylimidazolium chloride （IL2） in oxidative de-sulfurization and de-ashing of two industrially important high sulfur coal samples from Meghalaya （India） is discussed in this paper. The maximum removal of total sulfur, pyritic sulfur, sulfate sulfur and organic sulfur are observed to be 37.36 %, 62.50 %, 83.33 % and 31.63 % respectively during this oxidative process. The quantitative diffuse reflectance Fourier transform-infrared spectroscopy analysis supports the formation of sulfoxides （S--O） and sulfones （-SO2） and their subsequent removal during the oxidation of the coals in presence of ILs. The X-ray fluorescence combined with near edge X-ray absorption fine structure and scanning electron microscopic studies reveal the removal of mineral matters （ash yields） from the coal samples. The thermogravimetric analysis of the raw and clean coals indicates their high combustion efficiencies and suitability for using in thermal plants. The method is partially green and the ILs could be recovered and reused in the process.展开更多
To determine the refractive index of liquids in near infrared（lR）, a method is presented by measuring the output angle of the visible Cerenkov-radiation-mode when liquids are placed as the cover on a planar lithium ...To determine the refractive index of liquids in near infrared（lR）, a method is presented by measuring the output angle of the visible Cerenkov-radiation-mode when liquids are placed as the cover on a planar lithium niobate waveguide. The system configuration and the principle of the method are analyzed and some experimental results are given out. Both the experimental result and simulation show that this method is simple, rapid and of sufficient precision.展开更多
Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neu...Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neuromonitoring to objectively quantify the physiologic responses Methods In twenty two patients (all less than age 60) scheduled for repair of an aortic arch aneurysm, preoperative verification of effective collateral perfusion through both the carotid and vertebrobasilar arterial systems was documented with transcranial Doppler ultrasonography (TCD) During cardiopulmonary bypass, the sole arterial inflow from the pump was via the right subclavian artery The magnitude of ASCP was quantified by TCD using peak middle cerebral artery velocity, while flow adequacy was measured by continuous regional cerebrovenous oxygen saturation (rSO 2) using dual wavelength spatially resolved near infrared spectroscopy Results All patients experienced an uneventful recovery Flow in the middle cerebral artery became undetectable at ASCP < 5?ml·kg 1 ·min 1 , so adjustments from a 15-20?ml·kg 1 ·min 1 baseline were used to maintain rSO 2 above 50% Furthermore, ASCP flow was highly correlated ( P <0 01) with both peak middle cerebral artery velocity and rSO 2 ( r =0 86 and 0 96, respectively) Conclusion Neuromonitoring guided ASCP may be expected to extend the safe period and is at least partly responsible for the absence of neurologic complications in this patient cohort展开更多
Visible and near infrared spectroscopy is a non-destructive,green,and rapid technology that can be utilized to estimate the components of interest without conditioning it,as compared with classical analytical methods....Visible and near infrared spectroscopy is a non-destructive,green,and rapid technology that can be utilized to estimate the components of interest without conditioning it,as compared with classical analytical methods.The objective of this paper is to compare the performance of artificial neural network(ANN)(a nonlinear model)and principal component regression(PCR)(a linear model)based on visible and shortwave near infrared(VIS-SWNIR)(400-1000 nm)spectra in the non-destructive soluble solids content measurement of an apple.First,we used multiplicative scattering correction to pre-process the spectral data.Second,PCR was applied to estimate the optimal number of input variables.Third,the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models.The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN.Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.展开更多
A new dual-state emission(DSE) dye comprised of tetraphenylethene(TPE), triphenylamine(TPA), and indoline groups has been synthesized, which showed efficient fluorescence in both solution and solid. The dye is compris...A new dual-state emission(DSE) dye comprised of tetraphenylethene(TPE), triphenylamine(TPA), and indoline groups has been synthesized, which showed efficient fluorescence in both solution and solid. The dye is comprised of three parts and these parts show different fluorescence properties which can be very useful in some applications since the dye can produce information-rich responses. For example, the dye is p H-sensitive in both solution and solid states, and it emits yellow fluorescence in normal p H and red/NIR fluorescence in acidic condition. Cytotoxicity of the dye is low at concentration of 3 μM which was confirmed by a methyl thiazolyl tetrazolium(MTT) experiment, and in vitro experiments revealed that the p H responsive performance can be used in bioimaging. It provides a novel p H-sensitive DSE dye ever reported, which has potential application in many fields.展开更多
One polythiophene derivative PT3T and two low band gap copolymers,PBTT-T3T and PBTT,with different ratios of 5,6-dini-trobenzothiadiazole as the acceptor unit in the polymer backbone have been synthesized by Pd-cataly...One polythiophene derivative PT3T and two low band gap copolymers,PBTT-T3T and PBTT,with different ratios of 5,6-dini-trobenzothiadiazole as the acceptor unit in the polymer backbone have been synthesized by Pd-catalyzed Stille-coupling polymerizations.Thermal stability,X-ray diffraction analyses,UV-vis absorption spectra,photoluminescence spectra and electrochemical properties of the copolymers were investigated.The band gap estimated from UV-vis-NIR spectra of the copolymers films varied from 1.39 to 1.94 eV.Among these copolymers,the films of PBTT-T3T and PBTT,which contain the 5,6-dinitrobenzothiadiazole unit,cover a broad wavelength range in the visible and near-infrared region from 400 to 1000 nm with the maximal peak absorption around 700 nm,which is exactly matched with the maximum in the photon flux of the sun.展开更多
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.
基金the National Natural Science Foundation of China (No. 30671197)the Program for New Century Excellent Talents in University, China (No. NCET-04-0524)
文摘The use of near infrared （NIR） spectroscopy was proved to be a useful tool for quality analysis of fruits. A bifurcated fiber type NIR spectrometer, with a detection range of 800-2500 nm by InGaAs detector, was used to evaluate the firmness of peaches. Anisotropy of NIR spectra and firmness of peaches in relation to detecting positions of different parts （including three latitudes and three longitudes） were investigated. Both spectra absorbency and firmness of peach were influenced by longitudes （i, ii, iii） and latitudes （A, B, C）. For modeling, two thirds of the samples were used as the calibration set and the remaining one third were used as the validation or prediction set. Partial least square regression （PLSR） models for different longitude and latitude spectra and for the whole fruit show that collecting several NIR spectra from different longitudes and latitudes of a fruit for NIR calibration modeling can improve the modeling performance. In addition, proper spectra pretreatments like scattering correction or derivative also can enhance the modeling performance. The best results obtained in this study were from the holistic model with multiplicative scattering correction （MSC） pretreatment, with correlation coefficient of cross-validation γcv=0.864, root mean square error of cross-validation RMSECV=6.71 N, correlation coefficient of calibration r=0.948, root mean square error of calibration RMSEC=4.21 N and root mean square error of prediction RMSEP=5.42 N. The results of this study are useful for further research and application that when applying NIR spectroscopy for objectives with anisotropic differences, spectra and quality indices are necessarily measured from several parts of each object to improve the modeling performance.
基金Project supported by the National Natural Science Foundation of China (No. 30270773), and the Teaching and Research Award Pro-gram for Outstanding Young Teachers in Higher Education Institu-tions & the Specialized Research Fund for the Doctoral Program o
文摘Near infrared reflectance （N1R） spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen （N） and organic matter （OM） content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP （standard error of prediction） were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application.
文摘Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064/μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15 - 1.32/μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.
文摘Coal has been used as an energy resource around the world, primarily for the generation of electricity. The cleaning of coal by removing its unwanted sulfur and mineral matter components is utmost essential before their gainful utilizations. The ionic liquids （ILs） are considered as non-toxic solvents for using in different industrial processes. The effect of two ILs namely, 1-n-butyl, 3-methylimidazolium tetrafluoro borate （ILl） and 1-n-butyl, 3-methylimidazolium chloride （IL2） in oxidative de-sulfurization and de-ashing of two industrially important high sulfur coal samples from Meghalaya （India） is discussed in this paper. The maximum removal of total sulfur, pyritic sulfur, sulfate sulfur and organic sulfur are observed to be 37.36 %, 62.50 %, 83.33 % and 31.63 % respectively during this oxidative process. The quantitative diffuse reflectance Fourier transform-infrared spectroscopy analysis supports the formation of sulfoxides （S--O） and sulfones （-SO2） and their subsequent removal during the oxidation of the coals in presence of ILs. The X-ray fluorescence combined with near edge X-ray absorption fine structure and scanning electron microscopic studies reveal the removal of mineral matters （ash yields） from the coal samples. The thermogravimetric analysis of the raw and clean coals indicates their high combustion efficiencies and suitability for using in thermal plants. The method is partially green and the ILs could be recovered and reused in the process.
文摘To determine the refractive index of liquids in near infrared（lR）, a method is presented by measuring the output angle of the visible Cerenkov-radiation-mode when liquids are placed as the cover on a planar lithium niobate waveguide. The system configuration and the principle of the method are analyzed and some experimental results are given out. Both the experimental result and simulation show that this method is simple, rapid and of sufficient precision.
文摘Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neuromonitoring to objectively quantify the physiologic responses Methods In twenty two patients (all less than age 60) scheduled for repair of an aortic arch aneurysm, preoperative verification of effective collateral perfusion through both the carotid and vertebrobasilar arterial systems was documented with transcranial Doppler ultrasonography (TCD) During cardiopulmonary bypass, the sole arterial inflow from the pump was via the right subclavian artery The magnitude of ASCP was quantified by TCD using peak middle cerebral artery velocity, while flow adequacy was measured by continuous regional cerebrovenous oxygen saturation (rSO 2) using dual wavelength spatially resolved near infrared spectroscopy Results All patients experienced an uneventful recovery Flow in the middle cerebral artery became undetectable at ASCP < 5?ml·kg 1 ·min 1 , so adjustments from a 15-20?ml·kg 1 ·min 1 baseline were used to maintain rSO 2 above 50% Furthermore, ASCP flow was highly correlated ( P <0 01) with both peak middle cerebral artery velocity and rSO 2 ( r =0 86 and 0 96, respectively) Conclusion Neuromonitoring guided ASCP may be expected to extend the safe period and is at least partly responsible for the absence of neurologic complications in this patient cohort
基金Project(No.UTM.J.10.01/13.14/1/127/1 Jld 3(48))supported by the Zamalah Scholarship from the Universiti Teknologi Malaysia
文摘Visible and near infrared spectroscopy is a non-destructive,green,and rapid technology that can be utilized to estimate the components of interest without conditioning it,as compared with classical analytical methods.The objective of this paper is to compare the performance of artificial neural network(ANN)(a nonlinear model)and principal component regression(PCR)(a linear model)based on visible and shortwave near infrared(VIS-SWNIR)(400-1000 nm)spectra in the non-destructive soluble solids content measurement of an apple.First,we used multiplicative scattering correction to pre-process the spectral data.Second,PCR was applied to estimate the optimal number of input variables.Third,the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models.The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN.Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.
基金supported by the National Natural Science Foundation of China (51673180, 51373162)
文摘A new dual-state emission(DSE) dye comprised of tetraphenylethene(TPE), triphenylamine(TPA), and indoline groups has been synthesized, which showed efficient fluorescence in both solution and solid. The dye is comprised of three parts and these parts show different fluorescence properties which can be very useful in some applications since the dye can produce information-rich responses. For example, the dye is p H-sensitive in both solution and solid states, and it emits yellow fluorescence in normal p H and red/NIR fluorescence in acidic condition. Cytotoxicity of the dye is low at concentration of 3 μM which was confirmed by a methyl thiazolyl tetrazolium(MTT) experiment, and in vitro experiments revealed that the p H responsive performance can be used in bioimaging. It provides a novel p H-sensitive DSE dye ever reported, which has potential application in many fields.
基金support from the National Natural Science Foundation of China (50933003 & 50903044)MOST of China (2009AA032304)
文摘One polythiophene derivative PT3T and two low band gap copolymers,PBTT-T3T and PBTT,with different ratios of 5,6-dini-trobenzothiadiazole as the acceptor unit in the polymer backbone have been synthesized by Pd-catalyzed Stille-coupling polymerizations.Thermal stability,X-ray diffraction analyses,UV-vis absorption spectra,photoluminescence spectra and electrochemical properties of the copolymers were investigated.The band gap estimated from UV-vis-NIR spectra of the copolymers films varied from 1.39 to 1.94 eV.Among these copolymers,the films of PBTT-T3T and PBTT,which contain the 5,6-dinitrobenzothiadiazole unit,cover a broad wavelength range in the visible and near-infrared region from 400 to 1000 nm with the maximal peak absorption around 700 nm,which is exactly matched with the maximum in the photon flux of the sun.
