Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms a...Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms and 0.00836° per step, 2θ range of 5°―80° and total scanning period of 8―10 min. Indexing of the crystal system and a search of the space group from the powder X-ray diffraction data were conducted by the computational crystallography method. The pilot crystal models of Jat were globally optimized with Monte Carlo method and then refined with the Rietveld method. In parallel with PXRD test, single crystals of Jat were cultured in an aqueous solution by a slow-decreasing temperature method, then its crystal structure was determined by single crystal X-ray diffraction (SCXRD). Both crystal structures from PXRD and SCXRD are identical. The results show that the crystal structure of Jat belongs to a monoclinic system and the space group P21/c. The parameters of cell dimensions from PXRD are a =7.69, b = 12.55 , c = 20.89 , β = 106.53°, Z = 4, and V = 1933.4 3, meanwhile the parameters from SCXRD are a = 7.72 , b = 12.61 , c =20.99 , β =106.38°, Z =4, and V =1961.3 3.展开更多
In this paper,a time of flight neutron reflectometer model is proposed.According to the original objective inputting physical parameters and expectations,computer simulation was done by McStas package.With the open sl...In this paper,a time of flight neutron reflectometer model is proposed.According to the original objective inputting physical parameters and expectations,computer simulation was done by McStas package.With the open slit, neutron flux at sample position was about 1×10~5 n·cm^(-2)·S^(-1),and the optimal resolution could reach 0.5%.The results show that the model has a good performance.The design of this model can be an instruction for neutron reflectometer construction or project analysis in the future.展开更多
文摘Optimum resolution data of powder X-ray diffraction (PXRD) for Jatrorrhizine (Jat) were collected by an X’ Pert Pro MPD diffractometer with an X’celerator detector under the stepwise scanning condition as 8.255 ms and 0.00836° per step, 2θ range of 5°―80° and total scanning period of 8―10 min. Indexing of the crystal system and a search of the space group from the powder X-ray diffraction data were conducted by the computational crystallography method. The pilot crystal models of Jat were globally optimized with Monte Carlo method and then refined with the Rietveld method. In parallel with PXRD test, single crystals of Jat were cultured in an aqueous solution by a slow-decreasing temperature method, then its crystal structure was determined by single crystal X-ray diffraction (SCXRD). Both crystal structures from PXRD and SCXRD are identical. The results show that the crystal structure of Jat belongs to a monoclinic system and the space group P21/c. The parameters of cell dimensions from PXRD are a =7.69, b = 12.55 , c = 20.89 , β = 106.53°, Z = 4, and V = 1933.4 3, meanwhile the parameters from SCXRD are a = 7.72 , b = 12.61 , c =20.99 , β =106.38°, Z =4, and V =1961.3 3.
基金Supported by grants from Science and Technology Development Foundation of CAEP(2007B02002)
文摘In this paper,a time of flight neutron reflectometer model is proposed.According to the original objective inputting physical parameters and expectations,computer simulation was done by McStas package.With the open slit, neutron flux at sample position was about 1×10~5 n·cm^(-2)·S^(-1),and the optimal resolution could reach 0.5%.The results show that the model has a good performance.The design of this model can be an instruction for neutron reflectometer construction or project analysis in the future.
