报导了1.0~3.0MeV的Xe^(30+)离子与1.0MeV的Xe^(26+)离子入射Au表面发射的X射线谱,考虑到探测器Be窗对射线的非均匀衰减,还原了1.0MeV的Xe^(30+)离子产生X射线谱。通过用经典过垒模型及两体碰撞模型的分析表明:动能1.0~3.0MeV的Xe^(30+...报导了1.0~3.0MeV的Xe^(30+)离子与1.0MeV的Xe^(26+)离子入射Au表面发射的X射线谱,考虑到探测器Be窗对射线的非均匀衰减,还原了1.0MeV的Xe^(30+)离子产生X射线谱。通过用经典过垒模型及两体碰撞模型的分析表明:动能1.0~3.0MeV的Xe^(30+)离子入射Au靶,下表面空心原子M壳层空穴退激发射了能量0.7~1.75keV的Xe M X射线,下表面空心原子N壳层空穴退激发射了能量0.5~0.7keV的Xe N X射线。展开更多
The measurement of surface stresses in surrounding rocks with the use of a relief method of annular hole-drilling was studied by numerical analysis. The stress relief process by hole-drilling was then simulated with t...The measurement of surface stresses in surrounding rocks with the use of a relief method of annular hole-drilling was studied by numerical analysis. The stress relief process by hole-drilling was then simulated with the use of finite element method. The influences of the borehole diameter(d), the initial stresses and the ratio of the initial principle stresses on the variations of the remained stress and the released stress in function of the relief depth(h) were discussed. The relation between the non-dimensional ratio of the released principle strains and that of the initial principle stresses, and the effect of the elastic modulus and the Poisson ratio of the rock mass on the stress relief curves were studied. The results show that the stress relief behavior formulated with the non-dimensional ratio of the released stress and the ratio of h/d is only sensitive to the ratio of the initial principle stresses and the Poisson ratio. The stresses are completely released when h equals 1.6d, and the tensile stresses take place on the bore core surface in the relief measurement process. Finally, a non-complete relief method of annular hole-drilling for measuring surface stress in surrounding rocks is proposed and the procedure is presented.展开更多
Deformation behavior of slab at the straightening stage during continuous casting was simulated by the explicit dynamic finite element method,and the stress distribution along the width direction of the slab and its c...Deformation behavior of slab at the straightening stage during continuous casting was simulated by the explicit dynamic finite element method,and the stress distribution along the width direction of the slab and its change regularity at slab center during continuous casting were obtained.The influence of distribution and change of stress on the propagation of longitudinal cracks on slab surface was discussed.The results show that the tensional stress appears on slab surface at the inner arc side and the compressive stress appears on slab surface at the outer arc side at stages 6-8 in straightening zone during continuous casting.Longitudinal cracks generally appear on slab top surface and do not appear on slab bottom surface,which are also observed in industry.展开更多
文摘报导了1.0~3.0MeV的Xe^(30+)离子与1.0MeV的Xe^(26+)离子入射Au表面发射的X射线谱,考虑到探测器Be窗对射线的非均匀衰减,还原了1.0MeV的Xe^(30+)离子产生X射线谱。通过用经典过垒模型及两体碰撞模型的分析表明:动能1.0~3.0MeV的Xe^(30+)离子入射Au靶,下表面空心原子M壳层空穴退激发射了能量0.7~1.75keV的Xe M X射线,下表面空心原子N壳层空穴退激发射了能量0.5~0.7keV的Xe N X射线。
基金Projects(2013BAB02B01,2013BAB02B03)supported by the National Key Technology R&D Program of ChinaProject(N120801002)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(N20130042110010)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘The measurement of surface stresses in surrounding rocks with the use of a relief method of annular hole-drilling was studied by numerical analysis. The stress relief process by hole-drilling was then simulated with the use of finite element method. The influences of the borehole diameter(d), the initial stresses and the ratio of the initial principle stresses on the variations of the remained stress and the released stress in function of the relief depth(h) were discussed. The relation between the non-dimensional ratio of the released principle strains and that of the initial principle stresses, and the effect of the elastic modulus and the Poisson ratio of the rock mass on the stress relief curves were studied. The results show that the stress relief behavior formulated with the non-dimensional ratio of the released stress and the ratio of h/d is only sensitive to the ratio of the initial principle stresses and the Poisson ratio. The stresses are completely released when h equals 1.6d, and the tensile stresses take place on the bore core surface in the relief measurement process. Finally, a non-complete relief method of annular hole-drilling for measuring surface stress in surrounding rocks is proposed and the procedure is presented.
基金Project(50634030) supported by the National Natural Science Foundation of ChinaProject(20090042120005) supported by the Doctorate Foundation of the Ministry of Education of ChinaProject(2006CB605208-1) supported by the State Basic Research Program of China
文摘Deformation behavior of slab at the straightening stage during continuous casting was simulated by the explicit dynamic finite element method,and the stress distribution along the width direction of the slab and its change regularity at slab center during continuous casting were obtained.The influence of distribution and change of stress on the propagation of longitudinal cracks on slab surface was discussed.The results show that the tensional stress appears on slab surface at the inner arc side and the compressive stress appears on slab surface at the outer arc side at stages 6-8 in straightening zone during continuous casting.Longitudinal cracks generally appear on slab top surface and do not appear on slab bottom surface,which are also observed in industry.
