Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer a...Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer and X-ray powder diffraction analyzer.Result,By analyzing the TG/DTA curves and XRD patterns of the free anthraquinones(Rhein,Emodin,Aloe-emodin,Chrysophanol and Physcion)from Rheum,the results showed that they had the similar TG curves,however,due to the substituents attached on the 1.8-dihydric anthraquinones are different,every sample had different weight lose.All the DTA curves of free anthraquinones had two obviously characteristic peaks,but there were obviously differences on curvilinear shapes,peak location and peak values.The X-ray powder diffraction patterns of free anthraquinones have their own characteristic and very obvious.Conclusion: According to the differences in the thermal and XRD properties of five free anthraquinones,the kind of free anthraquinones could be easily identified and they can be used as correspondence free anthraquinones’s characteristic fingerprint patterns.展开更多
X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0...X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.展开更多
文摘Objective,Used the TG/DTA curves and XRD patterns to identify five kinds of free anthraquinones.Method,The thermograms,differential thermograms and X-ray powder diffraction patterns were obtained by thermal analyzer and X-ray powder diffraction analyzer.Result,By analyzing the TG/DTA curves and XRD patterns of the free anthraquinones(Rhein,Emodin,Aloe-emodin,Chrysophanol and Physcion)from Rheum,the results showed that they had the similar TG curves,however,due to the substituents attached on the 1.8-dihydric anthraquinones are different,every sample had different weight lose.All the DTA curves of free anthraquinones had two obviously characteristic peaks,but there were obviously differences on curvilinear shapes,peak location and peak values.The X-ray powder diffraction patterns of free anthraquinones have their own characteristic and very obvious.Conclusion: According to the differences in the thermal and XRD properties of five free anthraquinones,the kind of free anthraquinones could be easily identified and they can be used as correspondence free anthraquinones’s characteristic fingerprint patterns.
基金supported in part by Program for New Century Excellent Talents in University of China (No. NCET-10-0133)Innovation Scientists and Technicians Troop Construction Projects of Henan Province (No. 114100510004)
文摘X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.
