We study parallel algorithms of Jacobi iteration and DRM based on GPU for separable elliptic equation. Two test cases are performed on GTX 570 platform to verify validity of parallel algorithms. It shows that the maximum speed-up ratio on DOUBLE reaches about 14. And efficiency reaches 53% for Jacobi iteration. Besides,the maximum speed-up ratio on DOUBLE reaches about 3.8. And efficiency reaches 15% for DRM algorithm.

The SIMPLE algorithm is used to solve the MHD equations and the solutions of MHD equations are presented for the whole free-burning arc, excluding the electrodes. The SIMPLE algorithm has been revised in order to solve MHD equations and the flow chart is showed. A self-consistent numerical solution of the MHD equations yields the temperature and velocity distributions. And different types of radiation term are examined on the numerical results and it is found that the radiation term redults in a small decrease on the temperature of the arc.

A new adaptive grid technique is proposed, which can redistribute grid points according to the equivalence of area under the curve of the weight function. So the iteration in the traditional technique through a variational approach is unnecessary here, and the efficiency is improved greatly. The new technique is applied to Burgers equation with analytic solutions. The results show that different weight functions have different distribution of grid points, and variational weight functions with time have variational distribution of grid points. Because the new technique can redistribute more grid points in the high gradient solution regions in response to the numerical solution, it can capture the shock efficiently.

A model for the fluorescence escape efficiency of CsI:Na(CsI:Tl) phosphor is proposed,and the converting factor of CsI:Na(CsI:Tl) to X-rays is discussed in detail.Calculated results show that the fluorescence escape efficiency,as well as the converting factor,strongly depends on the substrate reflectivity and 1/(σL)(σ is the absorption coefficient of CsI:Na(CsI:Tl) to fluorescence, and L is the phosphor layer thickness.).For a phosphor,1/(σL) should be above 10,and 30~40 is even better.In point of converting factor and spatial resolution,the reflection model is superior to the transmission model.The maximum converting factor can be obtained by optimizing the phosphor layer thickness.

It is known that there are sparse weather stations on the Tibetan Plateau,and the lack of real soil temperature data affects the understanding of surface thermodynamic structure over the Plateau.Clear sky T_BB data are employed,and the verified clear sky T_BB data in 1998 from May to August through variational techniques by real soil temperature can capture the distribution features of mean soil temperature of the Plateau.It turns out to be a kind of important data source to the central and western Plateau,and plays an important role in the Plateau underlying thermodynamic structure study.

A two dimensional kinematic frontogenesis process is studied for examing the use of adaptive grids in numerical model. From the comparison of the numerical results using fixed and adaptive grids and those with exact solution, it is found the adaptive runs with 1/3 fewer grid points has the same accuracy, and it can catch the structure of front because of its excellent redistribution of grid points. The results also show the adaptive runs can increase more than 10 hours for the forecasting of extratropical cyclone with the same accuracy comparison to fixed grids. There is an optimum value for grid smoothness and the error increases as the grid orthogonality is considered.