The molecular dynamics method is used to simulate microcrack healing during heating or/and under compressive stress.A centre microcrack in Cu crystal would be sealed under compressive stress or by heating.The role of ...The molecular dynamics method is used to simulate microcrack healing during heating or/and under compressive stress.A centre microcrack in Cu crystal would be sealed under compressive stress or by heating.The role of com- pressive stress and heating in crack healing was additive.During microcrack healing, dislocation generation and motion occurred.When there were pre-existing disloca- tions around the microcrack,the critical temperature or compressive stress necessary for microcrack healing would decrease,and,the higher the number of dislocations, the lower the critical temperature or compressive stress.The critical temperature necessary for microcrack healing depended upon the orientation of the crack plane. For example,the critical temperature for the crack along the(001)plane was the lowest,i.e.770K.展开更多
This article is devoted to the study of the propagations of the non- linear water waves on the shear flows. Assuming μ = kh is small and ε/μ~2 ～ 0 (1), and the base flow is uniformly sheared, the modified Boussine...This article is devoted to the study of the propagations of the non- linear water waves on the shear flows. Assuming μ = kh is small and ε/μ~2 ～ 0 (1), and the base flow is uniformly sheared, the modified Boussinesq equation is obtained. We calculate propagations of the single sohtary wave with vorticity Γ = 0, >0 and <0. The influences of the vorticity are manifested. At the end examples of the interactions of two solitary waves, moving in opposite and the same directions, are given. Besides the phase shift, there also occur second wavelets after head-on collision.展开更多
基金The project supported by the Special Fund for the Major State Basic Research Projects(No.G19990650)and by the National Natural Science Foundation of China(No.1989118059871010)
文摘The molecular dynamics method is used to simulate microcrack healing during heating or/and under compressive stress.A centre microcrack in Cu crystal would be sealed under compressive stress or by heating.The role of com- pressive stress and heating in crack healing was additive.During microcrack healing, dislocation generation and motion occurred.When there were pre-existing disloca- tions around the microcrack,the critical temperature or compressive stress necessary for microcrack healing would decrease,and,the higher the number of dislocations, the lower the critical temperature or compressive stress.The critical temperature necessary for microcrack healing depended upon the orientation of the crack plane. For example,the critical temperature for the crack along the(001)plane was the lowest,i.e.770K.
基金The project supported by the National Natural Science Foundation of China
文摘This article is devoted to the study of the propagations of the non- linear water waves on the shear flows. Assuming μ = kh is small and ε/μ~2 ～ 0 (1), and the base flow is uniformly sheared, the modified Boussinesq equation is obtained. We calculate propagations of the single sohtary wave with vorticity Γ = 0, >0 and <0. The influences of the vorticity are manifested. At the end examples of the interactions of two solitary waves, moving in opposite and the same directions, are given. Besides the phase shift, there also occur second wavelets after head-on collision.
