The effect of mold hardness on the microstructure of ductile iron and the contraction porosity was investigated.Molds with different hardnesses（0.41,0.48,0.55,0.62 MPa）and a sand mold prepared by Co2 method were use...The effect of mold hardness on the microstructure of ductile iron and the contraction porosity was investigated.Molds with different hardnesses（0.41,0.48,0.55,0.62 MPa）and a sand mold prepared by Co2 method were used.The influence of silicon content on the induced expansion pressure owing to the formation of graphite was also investigated.The contraction during solidification can be compensated by an induced expansion owing to the graphite relief when the hardness of mold increases;therefore,the possibility of achieving a sound product without using any riser increases.展开更多
A decoupled finite element algorithmis developed for simulating the vortex dynamics on an elastic superconductor which couples the time-dependent Ginzburg-Landau equation with the complex-valued superconducting order ...A decoupled finite element algorithmis developed for simulating the vortex dynamics on an elastic superconductor which couples the time-dependent Ginzburg-Landau equation with the complex-valued superconducting order parameter and the vector-valued magnetic potential,and the elasticity equation.We present an iterative algorithm for the decoupled system arising fromthe time and spatial discretization using a combination of preconditioner,algebraic multigrid method(AMG)and preconditioned conjugate gradient method(PCG).The iterative algorithm allows us to perform large-scale three-dimensional simulations of mesoscale pattern formation during superconducting phase transitions with arbitrary elastic boundary conditions.The performance and efficiency of the algorithm are numerically verified by several benchmark problems,exhibiting up to two orders of magnitude improvement depending on the scale of discrete system compared to the exact solver.展开更多
The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca＋ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms o...The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca＋ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms of symmetry energy. It is found that the neutron-rich system has smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It is indicated that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter.展开更多
文摘The effect of mold hardness on the microstructure of ductile iron and the contraction porosity was investigated.Molds with different hardnesses（0.41,0.48,0.55,0.62 MPa）and a sand mold prepared by Co2 method were used.The influence of silicon content on the induced expansion pressure owing to the formation of graphite was also investigated.The contraction during solidification can be compensated by an induced expansion owing to the graphite relief when the hardness of mold increases;therefore,the possibility of achieving a sound product without using any riser increases.
基金support by the Computational Materials Sciences Program funded by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,under Award No.DE-SC0020145support by NSFC project 12301523 and the Fundamental Research Funds for the Central Universities 413000117support by NSF Grant NSF DMS-2419033.The author Jinchao Xu is supported by KAUST Baseline Research Fund(BAS/1/1699-01-01).
文摘A decoupled finite element algorithmis developed for simulating the vortex dynamics on an elastic superconductor which couples the time-dependent Ginzburg-Landau equation with the complex-valued superconducting order parameter and the vector-valued magnetic potential,and the elasticity equation.We present an iterative algorithm for the decoupled system arising fromthe time and spatial discretization using a combination of preconditioner,algebraic multigrid method(AMG)and preconditioned conjugate gradient method(PCG).The iterative algorithm allows us to perform large-scale three-dimensional simulations of mesoscale pattern formation during superconducting phase transitions with arbitrary elastic boundary conditions.The performance and efficiency of the algorithm are numerically verified by several benchmark problems,exhibiting up to two orders of magnitude improvement depending on the scale of discrete system compared to the exact solver.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10575012 and 10435020, the Science Foundation of Beljlng, and the Science Foundation of Beijing Normal University.
文摘The threshold energies of radial flow in reactions of ^40 Ca-^40Ca and ^48Ca＋ ^48Ca in central collisions are investigated within an isospin dependent quantum molecular dynamics model by using three different forms of symmetry energy. It is found that the neutron-rich system has smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It is indicated that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter.
