The multi-flow tube (MFT) method is mainly designed for two-dimensional (2-D) radiation hydrodynamic problems with multi-material, whose computational mesh is Lagrangian-Eulerian hybrid. Quality of the MFT quadrilateral mesh is usually higher than that of a general quadrilateral mesh. We consider a so-called nine-point diffusion scheme on this kind of meshes, in which the method of calculating vertex unknowns is improved by taking advantage of mesh features. Several methods for eliminating vertex unknowns are proposed by using harmonic averaging points or a gradient reconstruction method. Numerical experiments show that our methods obtain almost second order accuracy on MFT meshes.

High-speed impact problems are simulated with smoothed particle hydrodynamics method.Initial smoothing length and nonconforming space between particles in simulation are analyzed.A modified smoothing length approach is put forward.With increase of initial smoothing length, projectile rigidity decreases gradually.A rational range of initial smoothing length is d₀< h₀≤ 1.5d₀.With decrease of space between particles,rigidity of material decreases.With XSPH correction on velocity of a particle,results by nonconforming space between particles agree well with those from identical particle distribution.

We propose extrapolation boundary conditions(BCs) for blurring removal.They lead to C¹ continuity for one-dimensional signals and C⁰ continuity with normal derivative continuity for images.Two models and two kinds of blurring operators are used in the extrapolation BCs with Dirichlet,Neumann and antireflective BCs.We apply extrapolation BCs to fast algorithms for total variation-based image deblurring and denoising.Numerical results illustrate efficiency of the extrapolation BCs.

Considering the robustness and commonness, it uses the evolutionary algorithm to calculate the characteristic of H^- and He in outfield.The calculation for ground state energy of H^- and He can be converted to a problem of function optimization.At first the MCI method is adopted to deal with state wave functions of H^- and He, then the evolutionary algorithm calculates their ground state energies.Results show that it can obtain much more accurate results, and compared with other algorithms, it's more efficient.

It outlines the historical and current situations of monitoring of seismic events.According to the seismology characteristics of teleseismic signals from nuclear explosion,their P wave groups are analyzed by joint time-frequency analysis.It proves that,the time-frequency distributions of the NE teleseismic signals'P wave groups are most similar to each other.

The Modified Configuration Interaction method(MCI) is used to calculate the correlated energy of multi-electron systems.For obtaining the higher precision,it calls for huge computings.In order to handle this problem,which will cost much CPU time and memory room if only using one CPU to do it, the parallel multisection recurrence algorithm is adopted by using several CPUs to get the ground state energy of Helium atom at the same time.

Numerical computation to predict the pulverized-coal diffusion flame using Lagrangian treatment of the gas-solid flow and combustion is implemented. The authors analyse and discuss the gas-particle momemtum, mass and energy transfer processes. A modified scheme for existing computation model is proposed by the authors, which is effective in promoting two phase coupling process and can overcome divergency in computation for high pulverized-coal concentration combustion.

A Monte Carlo simulation code has been written for heavy-ion induced fission at sub-barrier energies with a simple model. The final properties of the heavy fragmemts such as mass, charge, energy, angular distribution and angular correlation have been simulated for complete fusion-fission and transfer-fission. The angles and velocities of the fragments relative to the recoil direction are given in the laboratory system. Consideration covers the combined kinematic effects of the distributions in mass energy and angular for the heavy fragments and pre-scission, post-scission neutron emission. The code can be used as a tool for experiment planning and analysis.

In the paper, the mathematical equations for the output signals of the stellar meridian observation are presented via analysing the processes of the observation. The output signals of the stellar meridian observation using a photon counter are obtained by means of combining the computed signals wiry recording noises. Two practical problems in meridian observation are dicussed and solved with the simulating method.