本文根据压水堆(Pressurized Water Reactor,PWR)堆芯燃料组件间定向横流与湍流交混等流动换热特性,提出了一种基于Sub栅元尺度的压水堆堆芯子通道计算分析方法,通过细致划分Sub栅元控制体,建立高分辨率三维动量源模型,自主开发了基于...本文根据压水堆(Pressurized Water Reactor,PWR)堆芯燃料组件间定向横流与湍流交混等流动换热特性,提出了一种基于Sub栅元尺度的压水堆堆芯子通道计算分析方法,通过细致划分Sub栅元控制体,建立高分辨率三维动量源模型,自主开发了基于此方法的压水堆堆芯精细栅元子通道分析程序CUNLUN。选取OECD/NEA MATiS-H和EPRI NESTOR国际基准题进行数值模拟验证。在MATiS-H国际基准题中,4个不同位置的轴向速度平均相对误差为9.07%,该程序可以准确评估压水堆堆芯的热工水力特性。在NESTOR国际基准题中,32个对比点内有24个点的计算精度提升69.08%,表明高分辨率三维动量源模型可以有效提高CUNLUN代码的计算精度。本代码能为压水堆堆芯热工水力分析提供有效的设计和研究手段,对反应堆堆芯热工水力分析程序的开发提供借鉴与参考。展开更多
Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE1...Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370039000000 -[3] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370036000000 . A redetermination of the structure using old but reliable photographic intensity data indicated the presence of additional split positions and reduced atomic occupancies. From the observed pattern of this “averaged” structure a consistent model of a superstructure with lattice parameters of a' = √13·a = 56.35(1) ?, c' = c, and a formula Bi5-x(Bi2S3)39I12S emerged, with 2 formula units in a cell of likewise P63 space group. Structural modulation may be provoked by the space the lone electron pair of Bi requires. When Bi on the 0, 0, z position of the “averaged” cell is transferred to two general six-fold sites and one unoccupied twofold one of the super-cell, more structural stability is guaranteed due to compensation of its basal plane dipole momentum. Owing to the limited intensity data available, more details of the superstructure are not accessible yet. Some physical properties and solar cell application are discussed together with suggestions of ambient temperature synthesis routes of c-axis oriented nano-rod sheets.展开更多
文摘本文根据压水堆(Pressurized Water Reactor,PWR)堆芯燃料组件间定向横流与湍流交混等流动换热特性,提出了一种基于Sub栅元尺度的压水堆堆芯子通道计算分析方法,通过细致划分Sub栅元控制体,建立高分辨率三维动量源模型,自主开发了基于此方法的压水堆堆芯精细栅元子通道分析程序CUNLUN。选取OECD/NEA MATiS-H和EPRI NESTOR国际基准题进行数值模拟验证。在MATiS-H国际基准题中,4个不同位置的轴向速度平均相对误差为9.07%,该程序可以准确评估压水堆堆芯的热工水力特性。在NESTOR国际基准题中,32个对比点内有24个点的计算精度提升69.08%,表明高分辨率三维动量源模型可以有效提高CUNLUN代码的计算精度。本代码能为压水堆堆芯热工水力分析提供有效的设计和研究手段,对反应堆堆芯热工水力分析程序的开发提供借鉴与参考。
文摘Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370039000000 -[3] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370036000000 . A redetermination of the structure using old but reliable photographic intensity data indicated the presence of additional split positions and reduced atomic occupancies. From the observed pattern of this “averaged” structure a consistent model of a superstructure with lattice parameters of a' = √13·a = 56.35(1) ?, c' = c, and a formula Bi5-x(Bi2S3)39I12S emerged, with 2 formula units in a cell of likewise P63 space group. Structural modulation may be provoked by the space the lone electron pair of Bi requires. When Bi on the 0, 0, z position of the “averaged” cell is transferred to two general six-fold sites and one unoccupied twofold one of the super-cell, more structural stability is guaranteed due to compensation of its basal plane dipole momentum. Owing to the limited intensity data available, more details of the superstructure are not accessible yet. Some physical properties and solar cell application are discussed together with suggestions of ambient temperature synthesis routes of c-axis oriented nano-rod sheets.
基金The National Natural Science Foundation for Young Scientists of China(21105027)he Fundamental Research Fundsfor the Central Universities(WK1014042)he Key Research Project from the Ministry of Public Security(201202ZDYJ005)
