AMY is a newly-developed code of handling neutron induced transmutation and activation in materials. The code is based on Chebyshev rational approximation method (CRAM) to solve Bateman equations and to deal with complex pattern of chains produced by sequences of neutron reaction processes.Varieties of material activation properties are provided in AMY, including activity, decay heat, biological hazard, dose rate, clearance index and gamma source spectra. In order to verify the code, basic nuclear database in handbook of activation data was selected for comparing with FISPACT-2007. It shows that results of AMY are in good agreement with FISPACT-2007, and calculation efficiency of AMY is slightly higher than FISPACT-2007.

Three-dimensional adjoint transport calculation module was integrated into S_N transport code ARES in which automated variance reduction parameters are generated based on consistent adjoint driven importance sampling method to accelerate calculation of MCNP5. It shows that automated variance reduction parameters are effective to improve MC calculational efficiency and to produce unbiased statistical results. Automated variance reduction technique with S_N function estimates particle importance more economically and accurately. It avoids obstacles of manual estimation and could be applied for MC simulation of large-scale, complicated shielding problems.

We solve Navier-Stokes equation with chemical source term, focusing on effect of three oxygen-hydrogen chemical reaction mechanisms on ignition, combustion efficiency and area compression ratio of reactive shock bubble interaction(RSBI). These chemical reaction mechanisms are Evans-Schexnayder(ES) model, Jachimowski(J) model, Ó Conaire(Ó) model, respectively. Results simulated with ES model show that subjected to shock wave,bubble has the largest ignition delay; the lowest balanced temperature and its ignition position is different from J model and Ó model.Dimensionless area is adopted to characterize shape of bubble under effect of shock and combustion. It shows that simulation of bubble area is closely related to chemical reaction model after stage of heat release,and J model has the highest dilation rate. In simulating combustion efficiency of long-term RSBI flow field, differences among chemical reaction models are relatively decreased. As ES model fails to reveal ignition position correctly, J model and Ó model are suitable for simulating RSBI.

A fluid model including two-temperature electrons was constructed for a collisionless plasma sheath. Effects of two-temperature electrons on sheath of stationary plasma were simulated. It is found that as temperature of cold electron is lower or density of cold electron at sheath adge is smaller critical ion Mach number decreases, sheath width becomes narrow and ion energy flow deposited on wall reduces. In addition, it is discussed that sheath thickness and ion energy flow deposited on wall are affected by cold electron in different plasma species.

A fluid model is developed in magnetized electronegative plasma sheath with two species of positive ions.It is shown that one-dimensional stationary plasma sheath is affected by ions-neutral collisions.The range of ion Mach numbers depends on density ratio of Ar⁺ to He⁺ and collision parameter. Collision efkct on charge density in the sheath is obvious as density of negative ions is small. Density of electron and negative ion decreases quickly.Two kinds of positive ion density present different fluctuations.Collision effect on ion velocitv distribution in the sheath is obvious as density of negative ions is great. In addition,collision paramcte affects density distribution of charge particles clearly as density ratio of two species of positive ions is great.

To keep interface fixed.we derive formula of smoothing parameter in level set re-initialization equation and form a implicit re-initialization method.It was proved that as the developed method is used to reinitialize the level set function for ensuring sign of level set function on nodes near interlace the time step need only to satisfy the original CFL condition.Finally,the improved method is combined with the original method to make an accurate and fast implicit re-initialization method. Numerical examples illustrate effectiveness of the methods.