A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensi...A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensional(PCMW2D)and two-dimensional correlation(2DCOS)analyses were applied to the amideⅠband and thus the hydrogen bond interaction between SPI and Gly was systematically investigated.When Gly concentrations were in the range 0~35%,the hydrogen bond amongβ-sheets was replaced by the one between SPI chain and Gly molecule,which caused these protein chains being changed toα-helix.However,the transformation ofβ-sheet toα-helix was saturated and both of them tend to change to random coil when Gly concentrations were in the range 35%~60%.展开更多
以氘代氯仿为溶剂,以中药化学标准品厚朴酚为载体,采用二维相关光谱（Tow-dimensional correlation spectroscopy,2D-COS）技术,采集近红外光谱（near infrared spectroscopy,NIR）,由氘代氯仿纯溶剂与厚朴酚原始光谱的二维相关同步谱可...以氘代氯仿为溶剂,以中药化学标准品厚朴酚为载体,采用二维相关光谱（Tow-dimensional correlation spectroscopy,2D-COS）技术,采集近红外光谱（near infrared spectroscopy,NIR）,由氘代氯仿纯溶剂与厚朴酚原始光谱的二维相关同步谱可知,厚朴酚在1 365～1 455,1 600～1 720,2 000～2 181和2 275～2 465nm处有特征吸收,其中1 440nm为酚基O—H伸缩振动基频的一级倍频谱带,1 679nm为芳基C—H及与芳基相连的甲基C—H伸缩振动一级倍频谱带,2 117,2 304,2 339和2 370nm为芳基C—H伸缩振动、弯曲振动和变形振动的组合频,2 445nm为芳基相连的甲基C—H弯曲振动基频二级倍频谱带,这些波段为厚朴酚的特征归属。以藿香正气口服液复杂体系为载体,以厚朴酚光谱解析的特征波段与间隔偏最小二乘（interval partial least squares,iPLS）和组合间隔偏最小二乘（synergy interval partial least squares,SiPLS）筛选的特征波段分别建立偏最小二乘（partial least squares,PLS）定量模型,模型的决定系数R2cal和R2pre均大于0.99,校正均方根误差（root mean of square error of calibration,RMSEC）,交叉验证均方根误差（root mean of square error of cross validation,RMSECV）和预测均方根误差（root mean of square error of prediction,RMSEP）均较小。结果表明,2D-COS技术解析厚朴酚所得波段建立的定量模型与iPLS和SiPLS波段筛选的模型均相对稳定,这使定量模型的波段选择更具有解释性。该研究为中药化学成分NIR光谱解析特征波段的归属提供方法参考,同时为NIR建模波段筛选提供借鉴和指导。展开更多
采用二维相关光谱(2D-COS)技术,以氘代氯仿为溶剂,解析了丹参酮ⅡA和隐丹参酮标准品的近红外光谱(NIR)。丹参酮ⅡA和隐丹参酮二维相关切片谱在1600~1800,1900~2230和2300~2400 nm处有特征吸收,其中丹参酮ⅡA在1640和2140 nm处有不同于...采用二维相关光谱(2D-COS)技术,以氘代氯仿为溶剂,解析了丹参酮ⅡA和隐丹参酮标准品的近红外光谱(NIR)。丹参酮ⅡA和隐丹参酮二维相关切片谱在1600~1800,1900~2230和2300~2400 nm处有特征吸收,其中丹参酮ⅡA在1640和2140 nm处有不同于隐丹参酮的呋喃环双键一级倍频和组合频吸收,1696 nm为丹参酮ⅡA和隐丹参酮分子中甲基伸缩振动二级倍频,1726和1740 nm处吸收为丹参酮ⅡA和隐丹参酮环己烯亚甲基伸缩振动二级倍频,2146和2220 nm为丹参酮ⅡA和隐丹参酮苯环C-C伸缩振动与C-H伸缩振动的组合频,2300~2400 nm处一系列峰为丹参酮ⅡA和隐丹参酮甲基伸缩振动与弯曲振动组合频吸收。以丹参酮提取物为载体,以丹参酮ⅡA和隐丹参酮光谱解析特征波段及组合间隔偏最小二乘(SiPLS)筛选特征波段分别建立偏最小二乘(PLS)定量模型,模型的决定系数R^(2)均大于0.9,校正均方根误差(root mean of square error of calibration,RMSEC)和交叉验证均方根误差(RMSECV),预测均方根误差(RMSEP)均较小。结果表明,2D-COS技术解析特征波段与SiPLS波段筛选所建PLS模型均稳定。2D-COS技术使近红外定量模型更具解释性,可解析出结构差异特征吸收,同一波段可实现结构类似物的同时定量测定。展开更多
利用程序控温的水热合成法得到了两种含有2，2＇-bipy及[M003]簇骼的化合物：[（2，2＇-bipy）2（Mo03）3]。（工）和[（2，2＇-bipy）（M003）]n（11）。为了阐明这两个化合物结构与谱学的关系，通过XRD、FT-IR、热微扰2D-IR相关光谱...利用程序控温的水热合成法得到了两种含有2，2＇-bipy及[M003]簇骼的化合物：[（2，2＇-bipy）2（Mo03）3]。（工）和[（2，2＇-bipy）（M003）]n（11）。为了阐明这两个化合物结构与谱学的关系，通过XRD、FT-IR、热微扰2D-IR相关光谱、TG分析、SEM、高温红外分析、uV_visDRS光谱和固体荧光光谱研究手段进行研究，进而探讨结构与性能的关系。其XRD说明了化合物I和Ⅱ是纯物相；FTIR的特征振动频率和热微扰2D-IR相关光谱的响应峰与化合物I和Ⅱ的结构解析相一致，2D-IR的同步和异步相关光谱图还确定了化合物I和Ⅱ的钼氧簇骼振动强度随升温变化的先后顺序与高温红外解析相一致；通过TG分析和高温红外分析研究化合物I和Ⅱ的热稳定性；化合物I和Ⅱ的UV Vis DRS光谱显示在225～350 nm有宽的紫外吸收谱带；化合物I和Ⅱ的固体荧光光谱分别在277和295nm的激发下得到的最强发射峰值分别为460和480nm。本文阐明了化合物I和Ⅱ的配位情况，揭示了价电子在分子中相应能级间跃迁的内在规律；还验证了弱相互作用力在配合物的结构框架中不但起稳定作用，而且在耐热性扮演重要的角色。展开更多
为满足不同种类食品对大豆分离蛋白(soybean protein isolate,SPI)不同功能性的需求,本研究利用红外光谱快速采集70组不同pH值处理后SPI的数据,探讨pH值变化对SPI结构含量的影响。使用均值中心化、多元散射校正、标准正态变量变换和归...为满足不同种类食品对大豆分离蛋白(soybean protein isolate,SPI)不同功能性的需求,本研究利用红外光谱快速采集70组不同pH值处理后SPI的数据,探讨pH值变化对SPI结构含量的影响。使用均值中心化、多元散射校正、标准正态变量变换和归一化算法对红外光谱数据进行预处理,基于二维相关红外光谱提取特征波段,再利用偏最小二乘(partial least square,PLS)法和算术优化算法-随机森林(arithmetic optimization algorithm-random forests,AOA-RF)建立不同pH值条件下SPI结构及含量的预测模型。结果表明,经均值中心化和多元散射校正结合处理后,α-螺旋、β-折叠、β-转角和无规卷曲模型的相对标准偏差分别为1.29%、1.60%、1.37%、7.28%,两者结合对光谱数据的预处理效果最佳。预测α-螺旋和β-折叠含量最优模型为AOA-RF(特征波段),校正集决定系数为0.9350和0.9266,预测集决定系数为0.8568和0.8701;预测β-转角和无规卷曲含量最优模型为PLS(特征波段),校正集决定系数为0.9154和0.8817,预测集决定系数为0.8913和0.7843。本研究结果可为工业生产过程中产品质量快速检测和工艺条件控制提供理论支撑。展开更多
Aim:The fast and nondestructive identification of Cortex Periplocae and Cortex Acanthopanacis by Fourier transform near infrared spectroscopy and generalized two-dimensional（2D） correlation spectroscopy were perform...Aim:The fast and nondestructive identification of Cortex Periplocae and Cortex Acanthopanacis by Fourier transform near infrared spectroscopy and generalized two-dimensional（2D） correlation spectroscopy were performed.Methods:Near infrared spectra of Cortex Periplocae and Cortex Acanthopanacis was used for computation of the 2D correlation spectra and comparison of the synchronous and asynchronous 2D correlation spectra.Results:Two of the analytes had similar spectral characteristics in one-dimensional near infrared while quite different in 2D correlation spectra.Cortex Periplocae and Cortex Acanthopanacis were identified visually using the 2D correlation spectra in region 5 600～4 700 cm-1and 7 200～6 600 cm-1.Conclusion:The results prove that 2D correlation spectra could enhance the resolution of near infrared spectra and increase the capacity of identification.The combination of 2D correlation spectroscopy and near infrared spectroscopy allow a new and convenient approach for evaluating the medicinal herbs.展开更多
文摘A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensional(PCMW2D)and two-dimensional correlation(2DCOS)analyses were applied to the amideⅠband and thus the hydrogen bond interaction between SPI and Gly was systematically investigated.When Gly concentrations were in the range 0~35%,the hydrogen bond amongβ-sheets was replaced by the one between SPI chain and Gly molecule,which caused these protein chains being changed toα-helix.However,the transformation ofβ-sheet toα-helix was saturated and both of them tend to change to random coil when Gly concentrations were in the range 35%~60%.
文摘以氘代氯仿为溶剂,以中药化学标准品厚朴酚为载体,采用二维相关光谱（Tow-dimensional correlation spectroscopy,2D-COS）技术,采集近红外光谱（near infrared spectroscopy,NIR）,由氘代氯仿纯溶剂与厚朴酚原始光谱的二维相关同步谱可知,厚朴酚在1 365～1 455,1 600～1 720,2 000～2 181和2 275～2 465nm处有特征吸收,其中1 440nm为酚基O—H伸缩振动基频的一级倍频谱带,1 679nm为芳基C—H及与芳基相连的甲基C—H伸缩振动一级倍频谱带,2 117,2 304,2 339和2 370nm为芳基C—H伸缩振动、弯曲振动和变形振动的组合频,2 445nm为芳基相连的甲基C—H弯曲振动基频二级倍频谱带,这些波段为厚朴酚的特征归属。以藿香正气口服液复杂体系为载体,以厚朴酚光谱解析的特征波段与间隔偏最小二乘（interval partial least squares,iPLS）和组合间隔偏最小二乘（synergy interval partial least squares,SiPLS）筛选的特征波段分别建立偏最小二乘（partial least squares,PLS）定量模型,模型的决定系数R2cal和R2pre均大于0.99,校正均方根误差（root mean of square error of calibration,RMSEC）,交叉验证均方根误差（root mean of square error of cross validation,RMSECV）和预测均方根误差（root mean of square error of prediction,RMSEP）均较小。结果表明,2D-COS技术解析厚朴酚所得波段建立的定量模型与iPLS和SiPLS波段筛选的模型均相对稳定,这使定量模型的波段选择更具有解释性。该研究为中药化学成分NIR光谱解析特征波段的归属提供方法参考,同时为NIR建模波段筛选提供借鉴和指导。
文摘采用二维相关光谱(2D-COS)技术,以氘代氯仿为溶剂,解析了丹参酮ⅡA和隐丹参酮标准品的近红外光谱(NIR)。丹参酮ⅡA和隐丹参酮二维相关切片谱在1600~1800,1900~2230和2300~2400 nm处有特征吸收,其中丹参酮ⅡA在1640和2140 nm处有不同于隐丹参酮的呋喃环双键一级倍频和组合频吸收,1696 nm为丹参酮ⅡA和隐丹参酮分子中甲基伸缩振动二级倍频,1726和1740 nm处吸收为丹参酮ⅡA和隐丹参酮环己烯亚甲基伸缩振动二级倍频,2146和2220 nm为丹参酮ⅡA和隐丹参酮苯环C-C伸缩振动与C-H伸缩振动的组合频,2300~2400 nm处一系列峰为丹参酮ⅡA和隐丹参酮甲基伸缩振动与弯曲振动组合频吸收。以丹参酮提取物为载体,以丹参酮ⅡA和隐丹参酮光谱解析特征波段及组合间隔偏最小二乘(SiPLS)筛选特征波段分别建立偏最小二乘(PLS)定量模型,模型的决定系数R^(2)均大于0.9,校正均方根误差(root mean of square error of calibration,RMSEC)和交叉验证均方根误差(RMSECV),预测均方根误差(RMSEP)均较小。结果表明,2D-COS技术解析特征波段与SiPLS波段筛选所建PLS模型均稳定。2D-COS技术使近红外定量模型更具解释性,可解析出结构差异特征吸收,同一波段可实现结构类似物的同时定量测定。
文摘利用程序控温的水热合成法得到了两种含有2，2＇-bipy及[M003]簇骼的化合物：[（2，2＇-bipy）2（Mo03）3]。（工）和[（2，2＇-bipy）（M003）]n（11）。为了阐明这两个化合物结构与谱学的关系，通过XRD、FT-IR、热微扰2D-IR相关光谱、TG分析、SEM、高温红外分析、uV_visDRS光谱和固体荧光光谱研究手段进行研究，进而探讨结构与性能的关系。其XRD说明了化合物I和Ⅱ是纯物相；FTIR的特征振动频率和热微扰2D-IR相关光谱的响应峰与化合物I和Ⅱ的结构解析相一致，2D-IR的同步和异步相关光谱图还确定了化合物I和Ⅱ的钼氧簇骼振动强度随升温变化的先后顺序与高温红外解析相一致；通过TG分析和高温红外分析研究化合物I和Ⅱ的热稳定性；化合物I和Ⅱ的UV Vis DRS光谱显示在225～350 nm有宽的紫外吸收谱带；化合物I和Ⅱ的固体荧光光谱分别在277和295nm的激发下得到的最强发射峰值分别为460和480nm。本文阐明了化合物I和Ⅱ的配位情况，揭示了价电子在分子中相应能级间跃迁的内在规律；还验证了弱相互作用力在配合物的结构框架中不但起稳定作用，而且在耐热性扮演重要的角色。
文摘为满足不同种类食品对大豆分离蛋白(soybean protein isolate,SPI)不同功能性的需求,本研究利用红外光谱快速采集70组不同pH值处理后SPI的数据,探讨pH值变化对SPI结构含量的影响。使用均值中心化、多元散射校正、标准正态变量变换和归一化算法对红外光谱数据进行预处理,基于二维相关红外光谱提取特征波段,再利用偏最小二乘(partial least square,PLS)法和算术优化算法-随机森林(arithmetic optimization algorithm-random forests,AOA-RF)建立不同pH值条件下SPI结构及含量的预测模型。结果表明,经均值中心化和多元散射校正结合处理后,α-螺旋、β-折叠、β-转角和无规卷曲模型的相对标准偏差分别为1.29%、1.60%、1.37%、7.28%,两者结合对光谱数据的预处理效果最佳。预测α-螺旋和β-折叠含量最优模型为AOA-RF(特征波段),校正集决定系数为0.9350和0.9266,预测集决定系数为0.8568和0.8701;预测β-转角和无规卷曲含量最优模型为PLS(特征波段),校正集决定系数为0.9154和0.8817,预测集决定系数为0.8913和0.7843。本研究结果可为工业生产过程中产品质量快速检测和工艺条件控制提供理论支撑。
文摘Aim:The fast and nondestructive identification of Cortex Periplocae and Cortex Acanthopanacis by Fourier transform near infrared spectroscopy and generalized two-dimensional（2D） correlation spectroscopy were performed.Methods:Near infrared spectra of Cortex Periplocae and Cortex Acanthopanacis was used for computation of the 2D correlation spectra and comparison of the synchronous and asynchronous 2D correlation spectra.Results:Two of the analytes had similar spectral characteristics in one-dimensional near infrared while quite different in 2D correlation spectra.Cortex Periplocae and Cortex Acanthopanacis were identified visually using the 2D correlation spectra in region 5 600～4 700 cm-1and 7 200～6 600 cm-1.Conclusion:The results prove that 2D correlation spectra could enhance the resolution of near infrared spectra and increase the capacity of identification.The combination of 2D correlation spectroscopy and near infrared spectroscopy allow a new and convenient approach for evaluating the medicinal herbs.
