Liquid metal embrittlement mechanism

Liquid metal embrittlement was studied in the following two aspects. First the first principle and ChenNanxian three-dimensional lattice reverse method were employed to obtain the effective potentials for Al-Ga and GaGa. Then with the molecular dynamics simulation, the influence of liquid metal adsorption on dislocation emission was studied. The simulated result shows that after Ga atoms are adsorbed on the crack plane in Al crystal, the critical stress intensity factor decreases, which changes from 0.5 MPam~(1/2) (without adsorption) to 0.4 MPam~(1/2) (with adsorption). The reason for the reduction in the critical intensity stress factor is that Ga adsorption reduces the surface energy of the crack plane. Moreover, 7075 Al alloy adsorbing liquid metal (Hg 3atm％Ga) was in-situ studied in TEM by using a special constant deflection device. The experimental result showed that liquid metal adsorption could facilitate emission, multiplication and motion of dislocations. When this process reached a critical     

均质圆形定压油藏不稳定渗流的数值解

为了解有水体压力供源的（或称有边水存在的）圆形油藏的压力动态变化，为小型断块边水油气藏的合理开发提供依据，利用网格自动或分技校。通过有限元计算解决了均质圆形定压油藏任意井位条件下的不稳定渗流问题，得到压力传播过程图，提出井位系数据的概念，计算出井在油藏任意位置时的井底压力随时间变化的理论曲线。通过井在圆形定压油藏中心位置的特殊情况数值解与解析解的对比，验证了数值解的正确性。     

Molecular dynamics simulation of hydrogen enhancing dislocation emission

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