在第四代反应堆中,核石墨作为慢化体和反射体材料服役于高温和高通量的快中子辐照环境中。快中子辐照会在核石墨中产生大量的弗伦克尔缺陷对。这些缺陷经过湮灭、扩散、最终形成更大的缺陷团簇,从而改变核石墨的微观结构,进而改变核石...在第四代反应堆中,核石墨作为慢化体和反射体材料服役于高温和高通量的快中子辐照环境中。快中子辐照会在核石墨中产生大量的弗伦克尔缺陷对。这些缺陷经过湮灭、扩散、最终形成更大的缺陷团簇,从而改变核石墨的微观结构,进而改变核石墨的宏观性能。因此,研究核石墨在高温辐照条件下的缺陷演化行为和机理对提高反应堆安全性具有重要意义。本研究采用30 MeV的^(107)Ag^(5+)离子在420℃下辐照IG-110核石墨来模拟核石墨在快中子辐照过程中的缺陷演化行为。通过微区拉曼光谱对IG-110核石墨截面结构进行表征,并对比不同深度处的拉曼光谱特征参数和辐照损伤剂量之间的关系,研究IG-110核石墨微观结构随辐照损伤剂量(Displacements Per Atom,DPA)的演化行为。研究结果表明,随着注量的增加,核石墨拉曼光谱的特征参数D峰高度与G峰高度比值(I_(D)/I_(G))、G峰半高宽(Full Width at Half Maximum of the G peak,FWHM(G))以及G峰的偏移量都显著增加。与^(58)Ni^(5+)辐照样品相比,相同辐照损伤剂量下,^(107)Ag^(5+)辐照的石墨拉曼光谱的I_(D)/I_(G)和FWHM(G)更大。相同的FWHM(G)下,^(107)Ag^(5+)辐照的石墨拉曼光谱的I_(D)/I_(G)比^(58)Ni^(5+)辐照样品大。这些结果说明更重的重离子辐照会在核石墨中引起更高速率的缺陷积累,从而更快地导致石墨晶粒尺寸变小,并促进纳米晶化进程。展开更多
While studying the flow of oil and gas in the reservoir, it is not realistic that capillary with circular section is only used to express the pores. It is more representative to simulate porous media pore with kinds o...While studying the flow of oil and gas in the reservoir, it is not realistic that capillary with circular section is only used to express the pores. It is more representative to simulate porous media pore with kinds of capillary with triangle or rectangle section etc. In the condition of the same diameter, when polymer for oil displacement flows in the porous medium, there only exists shear flow which can be expressed with power law model. Based on fluid flow-pressure drop equation in single capillary, this paper gives a calculation method of equivalent permeability of power law fluid of single capillary and capillary bundles with different sections.展开更多
Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and d...Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and diversity of the blade cross-section determine it impossible to establish an universal theoretical model for the rolling process. Finite element analysis(FEA) provides a perspective solution to the prediction. The FEA software DEFORM was applied to discovering the deformation, stress, strain and velocity field of the variable cross-section workpiece, and the effects of friction coefficient and rolling speed during the rolling process. which indicates that the average rolling force at friction coefficient of 0.4 is 6.5% higher than that at 0.12, and the rolling velocity has less effect on the equivalent stress and strain distribution, which would confer instructive significance on the theoretical study as well as the engineering practice.展开更多
The light propagation through system a polarizer-analyzer is investigated on the basis of quantum conceptions about the nature of light. It is shown, that Malus law based on principles of classical electrodynamics not...The light propagation through system a polarizer-analyzer is investigated on the basis of quantum conceptions about the nature of light. It is shown, that Malus law based on principles of classical electrodynamics not completely takes into account all effects which can occur at the light propagation through system a polarizer-analyzer. The phenomenon of possible change of frequency of light in particular drops out, for example in the region of X-ray radiation. The deduction of Malus law based on quantum principles is given. For comparison the differential effective section of interaction of a photon and electron with take into account of rotation of a plane of polarization of a photon in Compton’s effect is found.展开更多
针对桥梁墩柱和承台内的粘结滑移现象,基于fib混凝土规范(fib Model Code)推荐的混凝土粘结滑移模型,推导了纵筋滑移量的计算公式,并通过对墩柱塑性区域受拉纵筋的应力-应变本构进行修正,以引入墩柱塑性区域和承台内的纵筋滑移量,作为...针对桥梁墩柱和承台内的粘结滑移现象,基于fib混凝土规范(fib Model Code)推荐的混凝土粘结滑移模型,推导了纵筋滑移量的计算公式,并通过对墩柱塑性区域受拉纵筋的应力-应变本构进行修正,以引入墩柱塑性区域和承台内的纵筋滑移量,作为一种等效方法,以考虑粘结滑移对墩柱地震响应的影响,并用试验结果验证了该方法的合理性。此外,还对所提等效方法和零长度截面单元法的计算结果进行了对比。结果表明:未考虑粘结滑移会高估墩柱的侧向刚度、累计滞回耗能和残余位移,且无法客观反映滑移导致的墩柱强度退化问题;零长度截面单元法和所提等效方法均能考虑强度退化问题,但前者对粘结滑移的模拟效果受纵筋直径影响显著,后者则能合理捕捉滑移影响下的墩柱往复加载过程。展开更多
文摘在第四代反应堆中,核石墨作为慢化体和反射体材料服役于高温和高通量的快中子辐照环境中。快中子辐照会在核石墨中产生大量的弗伦克尔缺陷对。这些缺陷经过湮灭、扩散、最终形成更大的缺陷团簇,从而改变核石墨的微观结构,进而改变核石墨的宏观性能。因此,研究核石墨在高温辐照条件下的缺陷演化行为和机理对提高反应堆安全性具有重要意义。本研究采用30 MeV的^(107)Ag^(5+)离子在420℃下辐照IG-110核石墨来模拟核石墨在快中子辐照过程中的缺陷演化行为。通过微区拉曼光谱对IG-110核石墨截面结构进行表征,并对比不同深度处的拉曼光谱特征参数和辐照损伤剂量之间的关系,研究IG-110核石墨微观结构随辐照损伤剂量(Displacements Per Atom,DPA)的演化行为。研究结果表明,随着注量的增加,核石墨拉曼光谱的特征参数D峰高度与G峰高度比值(I_(D)/I_(G))、G峰半高宽(Full Width at Half Maximum of the G peak,FWHM(G))以及G峰的偏移量都显著增加。与^(58)Ni^(5+)辐照样品相比,相同辐照损伤剂量下,^(107)Ag^(5+)辐照的石墨拉曼光谱的I_(D)/I_(G)和FWHM(G)更大。相同的FWHM(G)下,^(107)Ag^(5+)辐照的石墨拉曼光谱的I_(D)/I_(G)比^(58)Ni^(5+)辐照样品大。这些结果说明更重的重离子辐照会在核石墨中引起更高速率的缺陷积累,从而更快地导致石墨晶粒尺寸变小,并促进纳米晶化进程。
基金Supported by the National Natural Science Foundation of China Youth Science Fund （51104030） Supported by the Science and Technology Research Project of Heilongjiang Province Department of Education（12521059） Supported by the China Postdoctoral Science Foundation（2014M561325）
文摘While studying the flow of oil and gas in the reservoir, it is not realistic that capillary with circular section is only used to express the pores. It is more representative to simulate porous media pore with kinds of capillary with triangle or rectangle section etc. In the condition of the same diameter, when polymer for oil displacement flows in the porous medium, there only exists shear flow which can be expressed with power law model. Based on fluid flow-pressure drop equation in single capillary, this paper gives a calculation method of equivalent permeability of power law fluid of single capillary and capillary bundles with different sections.
基金Project(F12-256-1-00)supported by the Key Laboratory Program of Shenyang City,ChinaProject(N090403006)supported by the Seed Cultivation Fund,ChinaProject supported by the Research Innovation Fund for Young Teachers,China
文摘Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and diversity of the blade cross-section determine it impossible to establish an universal theoretical model for the rolling process. Finite element analysis(FEA) provides a perspective solution to the prediction. The FEA software DEFORM was applied to discovering the deformation, stress, strain and velocity field of the variable cross-section workpiece, and the effects of friction coefficient and rolling speed during the rolling process. which indicates that the average rolling force at friction coefficient of 0.4 is 6.5% higher than that at 0.12, and the rolling velocity has less effect on the equivalent stress and strain distribution, which would confer instructive significance on the theoretical study as well as the engineering practice.
文摘The light propagation through system a polarizer-analyzer is investigated on the basis of quantum conceptions about the nature of light. It is shown, that Malus law based on principles of classical electrodynamics not completely takes into account all effects which can occur at the light propagation through system a polarizer-analyzer. The phenomenon of possible change of frequency of light in particular drops out, for example in the region of X-ray radiation. The deduction of Malus law based on quantum principles is given. For comparison the differential effective section of interaction of a photon and electron with take into account of rotation of a plane of polarization of a photon in Compton’s effect is found.
文摘针对桥梁墩柱和承台内的粘结滑移现象,基于fib混凝土规范(fib Model Code)推荐的混凝土粘结滑移模型,推导了纵筋滑移量的计算公式,并通过对墩柱塑性区域受拉纵筋的应力-应变本构进行修正,以引入墩柱塑性区域和承台内的纵筋滑移量,作为一种等效方法,以考虑粘结滑移对墩柱地震响应的影响,并用试验结果验证了该方法的合理性。此外,还对所提等效方法和零长度截面单元法的计算结果进行了对比。结果表明:未考虑粘结滑移会高估墩柱的侧向刚度、累计滞回耗能和残余位移,且无法客观反映滑移导致的墩柱强度退化问题;零长度截面单元法和所提等效方法均能考虑强度退化问题,但前者对粘结滑移的模拟效果受纵筋直径影响显著,后者则能合理捕捉滑移影响下的墩柱往复加载过程。
