为了探究基于衰减全反射傅里叶变换红外光谱(attenuated total reflection Fourier transform infrared spectroscopy,ATR-FTIR)技术实施农药沉积量原位感知的可能性,该研究以含有不同量广谱性杀菌剂啶酰菌胺沉积的棉花叶片为试验材料,...为了探究基于衰减全反射傅里叶变换红外光谱(attenuated total reflection Fourier transform infrared spectroscopy,ATR-FTIR)技术实施农药沉积量原位感知的可能性,该研究以含有不同量广谱性杀菌剂啶酰菌胺沉积的棉花叶片为试验材料,结合化学计量学分析方法开展相关探索。首先使用棉花叶片制成140例已知农药沉积量的标准样品,并采用ATR-FTIR技术获取其光谱数据;然后借助区间偏最小二乘法、相关性分析等方法筛选到272个相关性强的波长变量;最后以优化后的变量及偏最小二乘回归算法建立定量预测模型。结果表明模型的预测性能优异,预测的均方根误差为1.18μg/cm^(2),最低检测限(limit of detection,LOD)低至3.54μg/cm^(2);利用概率神经网络判别样品中农药沉积量是否大于LOD的整体准确率高达95%。该研究结果证明ATR-FTIR技术可实现农药沉积量的高精度原位检测,为其在生产中的应用提供理论依据和数据支撑。展开更多
Comparison of the ATR-FITR spectra of nature and artificial leather shows that their feature peak positions do not overlap,By analysing their spectra and their corresponding second derivative infrared spectra we can d...Comparison of the ATR-FITR spectra of nature and artificial leather shows that their feature peak positions do not overlap,By analysing their spectra and their corresponding second derivative infrared spectra we can discriminate them easily.Analysis and discrimination of leather products by ATR-FTIR is an accurate,sensitive,quick method.展开更多
The mechanism of enhancers (methanol,chloroform,azone and thiozone) was studied in vitro in mouse stratum corneum (SC).Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) was applied ...The mechanism of enhancers (methanol,chloroform,azone and thiozone) was studied in vitro in mouse stratum corneum (SC).Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) was applied to monitor the wavenumber shifts of CH2 stretching absorbance as well as the lipid content in the SC,which were used as criteria to explain the effect of the enhancers on mouse SC.The FTIR spectra record that treatment with these four enhancers would result in significant shifts toward higher wavenumber at vasCH2 and vsCH2 and the integration areas of vasCH2 and vsCH2 decrease when treatment of methanol and choloroform.It is concluded that these four enhancers could increase the gauche conformational isomer content of lipid CH2,made the lipid in the SC a more fluid state,thus the resistance of drug transdermal delivery was reduced.展开更多
To consider the reliability and performance of electronic devices based on polyimide derivatives, dynamic water sorption and diffusion behavior in a polyimide derivative: poly(4'4 oxydiphenylene pyromellitimide) ...To consider the reliability and performance of electronic devices based on polyimide derivatives, dynamic water sorption and diffusion behavior in a polyimide derivative: poly(4'4 oxydiphenylene pyromellitimide) (PMDA-ODA)/silica nanocomposite was investigated by two-dimensional ATR-FTIR spectroscopy, by which three states of water molecules owning different H-bonding strength were distinguished. The amounts and strength of H-bonding also played a significant role in determining the diffusion rate of the different states of water molecules. The type of aggregated water molecules which also formed H-bonding with silicic acid (residues) or polyimide system was the last one diffusing to the polymer side in contact with the ATR crystal element because the polymeric matrix blocked their diffusion to a great extent. The diffusion coefficient was also estimated to gain the information of the dynamic diffusion behavior.展开更多
文摘为了探究基于衰减全反射傅里叶变换红外光谱(attenuated total reflection Fourier transform infrared spectroscopy,ATR-FTIR)技术实施农药沉积量原位感知的可能性,该研究以含有不同量广谱性杀菌剂啶酰菌胺沉积的棉花叶片为试验材料,结合化学计量学分析方法开展相关探索。首先使用棉花叶片制成140例已知农药沉积量的标准样品,并采用ATR-FTIR技术获取其光谱数据;然后借助区间偏最小二乘法、相关性分析等方法筛选到272个相关性强的波长变量;最后以优化后的变量及偏最小二乘回归算法建立定量预测模型。结果表明模型的预测性能优异,预测的均方根误差为1.18μg/cm^(2),最低检测限(limit of detection,LOD)低至3.54μg/cm^(2);利用概率神经网络判别样品中农药沉积量是否大于LOD的整体准确率高达95%。该研究结果证明ATR-FTIR技术可实现农药沉积量的高精度原位检测,为其在生产中的应用提供理论依据和数据支撑。
文摘Comparison of the ATR-FITR spectra of nature and artificial leather shows that their feature peak positions do not overlap,By analysing their spectra and their corresponding second derivative infrared spectra we can discriminate them easily.Analysis and discrimination of leather products by ATR-FTIR is an accurate,sensitive,quick method.
文摘The mechanism of enhancers (methanol,chloroform,azone and thiozone) was studied in vitro in mouse stratum corneum (SC).Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) was applied to monitor the wavenumber shifts of CH2 stretching absorbance as well as the lipid content in the SC,which were used as criteria to explain the effect of the enhancers on mouse SC.The FTIR spectra record that treatment with these four enhancers would result in significant shifts toward higher wavenumber at vasCH2 and vsCH2 and the integration areas of vasCH2 and vsCH2 decrease when treatment of methanol and choloroform.It is concluded that these four enhancers could increase the gauche conformational isomer content of lipid CH2,made the lipid in the SC a more fluid state,thus the resistance of drug transdermal delivery was reduced.
基金supported by the National Natural Science Foundation of China(No.20573022,No.20425415)the National Basic Research Pro-gram of China(2005CB623800),the PHD Program of M0E(20050246010)the"Qimingxing"Project(No.04QM1402)of Shanghai Municipal Science and Technology Commission,and the"Shuguang"Project(No.01SG05)of the Shanghai Municipal Education Commission and Shanghai Education Development Foundation.
文摘To consider the reliability and performance of electronic devices based on polyimide derivatives, dynamic water sorption and diffusion behavior in a polyimide derivative: poly(4'4 oxydiphenylene pyromellitimide) (PMDA-ODA)/silica nanocomposite was investigated by two-dimensional ATR-FTIR spectroscopy, by which three states of water molecules owning different H-bonding strength were distinguished. The amounts and strength of H-bonding also played a significant role in determining the diffusion rate of the different states of water molecules. The type of aggregated water molecules which also formed H-bonding with silicic acid (residues) or polyimide system was the last one diffusing to the polymer side in contact with the ATR crystal element because the polymeric matrix blocked their diffusion to a great extent. The diffusion coefficient was also estimated to gain the information of the dynamic diffusion behavior.