生物碱与一些特殊的试剂作用生成沉淀。这些反应可用于生物碱的检测和精制。本文分别在同步辐射装置和微聚焦 X 射线成像系统上用 X 射线相衬成像(XPCI)方法研究了三种不同类型的生物碱沉淀的结构。研究结果显示:在 Hager 试剂作用下,...生物碱与一些特殊的试剂作用生成沉淀。这些反应可用于生物碱的检测和精制。本文分别在同步辐射装置和微聚焦 X 射线成像系统上用 X 射线相衬成像(XPCI)方法研究了三种不同类型的生物碱沉淀的结构。研究结果显示:在 Hager 试剂作用下,有机胺类的秋水仙碱沉淀呈针状,吡啶类的槟榔碱沉淀呈胶团状,异喹啉类的小檗碱沉淀呈花瓣状。与目测或在光学显微镜下观察到的形态有很大差别。为今后用 XPCI 方法研究更复杂的化学反应体系提供参考和依据。展开更多
The propagation behaviour of terahertz （THz） pulses at an edge is characterized. The phenomenon that the amplitude oscillates periodically in the frequency spectrum is similar to Young＇s interference, if the absorp...The propagation behaviour of terahertz （THz） pulses at an edge is characterized. The phenomenon that the amplitude oscillates periodically in the frequency spectrum is similar to Young＇s interference, if the absorption effect is neglected. The oscillation cycle is shorter for a thicker sample. THz pulses at an edge are analyzed by the broadband Huygens-Fresnel diffraction integral. The experimental results are in agreement with the simulation results approximately. The simulation errors are also analyzed.展开更多
A facile microfocusing optical design is presented which is optimized for less slope error against the traditional tapered mirror. The essential idea of the innovation is based on the characteristics of the slope-erro...A facile microfocusing optical design is presented which is optimized for less slope error against the traditional tapered mirror. The essential idea of the innovation is based on the characteristics of the slope-error curve for the prototype. The relationship between the mirror shape of the improved model and the driving moments is established. Analytical results have been compared with the results of the prototype. The design demonstrates theoretically that smaller slope error is obtained with longer active length.展开更多
文摘生物碱与一些特殊的试剂作用生成沉淀。这些反应可用于生物碱的检测和精制。本文分别在同步辐射装置和微聚焦 X 射线成像系统上用 X 射线相衬成像(XPCI)方法研究了三种不同类型的生物碱沉淀的结构。研究结果显示:在 Hager 试剂作用下,有机胺类的秋水仙碱沉淀呈针状,吡啶类的槟榔碱沉淀呈胶团状,异喹啉类的小檗碱沉淀呈花瓣状。与目测或在光学显微镜下观察到的形态有很大差别。为今后用 XPCI 方法研究更复杂的化学反应体系提供参考和依据。
基金National Natural Science Foundation of China under Grant No.10574134.
文摘The propagation behaviour of terahertz （THz） pulses at an edge is characterized. The phenomenon that the amplitude oscillates periodically in the frequency spectrum is similar to Young＇s interference, if the absorption effect is neglected. The oscillation cycle is shorter for a thicker sample. THz pulses at an edge are analyzed by the broadband Huygens-Fresnel diffraction integral. The experimental results are in agreement with the simulation results approximately. The simulation errors are also analyzed.
文摘A facile microfocusing optical design is presented which is optimized for less slope error against the traditional tapered mirror. The essential idea of the innovation is based on the characteristics of the slope-error curve for the prototype. The relationship between the mirror shape of the improved model and the driving moments is established. Analytical results have been compared with the results of the prototype. The design demonstrates theoretically that smaller slope error is obtained with longer active length.
