Structure stability, magnetism, electronic structure and elastic properties of (Mo,Fe,Mn)₃B₂ are determined with first-principles calculations. Density functional theory and ultrasoft pseudopotentials are used. Antiferromagnetic case has the lowest energy, indicating that it is ground state. DOS and population of (Mo,Mn,Fe)B₂ are similar to those of Mo₂FeB₂. From density of states and overlap populations, it is found that B-B and B-Mo are covalent bonding and they give positive contribution to shear modulus. According to analysis of magnetism, Fe and Mn atoms play the key point. However, Mn doping has weak effect on bonding and elastic properties of hard phase Mo₂FeB₂.

In the light of molecular dynamics simulation and bubble meshing a node placement method, called node placement method with bubble simulation, is presented. In the method nodes are bubbles and bubbles are moved by interacting forces. With dynamic simulation centers of bubbles form a good-quality node set in the domain. And this process doesn't need updating mesh connection constantly. Examples show that uniform point sets and non-uniform point sets generated by this method have good construction and gradualness. And this method is adaptable to complex regions. These placed nodes can be used in meshless method. And triangular meshes can also be generated from these placed nodes in finite element method. Furthermore, for locality of interacting forces, this method is similar to short-range molecular dynamics simulation, and is easy to parallelization. Experimental result shows that the parallelization of this method is feasible.

Based on the fuzzy theory, the fuzzy identification algorithm of the soil consolidation parameters is set up according to the measured pore water pressure posited in the inner soils. The subordinate functions are also built in accordance with the statistic charactersistics of the observed pore water pressure. The fuzzy objective functions and the subordinate functions with fuzzy restriction are established too. Based on the information theory, the influence of uncertainty of the observed information and the uncertainty load to the identified results is studied. The research makes known that the identified results are still uncertain by making use of the above proposed identification algorithm.

There are rich vortex phenomena presented in swirling circulation flow, such as secondary flow and vortex breakdown. For numerical simulation of such complicated recirculating flow, higher requirements are needed for grid density and calculation precision. With the increase of grid points, both convergence rate and calculation precision of traditional iterative numerical methods decrease. On the basis of finite control volume scheme and pressure correction method, the FAS multi staggered grid scheme is presented here for Navier Stokes equation in cylinder coordination. The axisymmetric swirling flow confined in cylindrical container is used as test problem. The results indicate that both convergence rate and calculation precision are highly improved.

Based upon the horizontal displacements data in-situ in the top of concrete gravity dam, the parameter identification problem is done with the regularizing least squares method for the elastic modulus of the concrete gravite dam. The iterative format and selecting algorithm of the regularizing parameters are set up. It is also put forward to identify material physical properties according to the priori information. The practical use of the parameter identification algorithm proposed shows that this algorithm has fast convergence speed and good stability.

The comparison between the experimental visualizations by Escudier and Hide S.Koyama and numerical simulations of the development procedure of vortex breakdown in laminar swirling flow induced from a rotating endwall is presented. The experimental visualizations by Escudier were the first to reveal the presence of vortex breakdown phenomena in closed cylindrical container with a rotating lid. Afterwards, much experimental and numerical work was done in this research field. The accurate experimental measurements for the recurrence and development of vortex breakdown by Hide S.Koyama then make clear this phenomena. With numerical solution of unsteady axisymmetric Navier Stokes equations, the author accurately reproduces these phenomena. The numerical results are given and compared with experiments.

The orientational transition,heat hysteresis and pressure induced transition in crystal C₆₀ have been simulated by the Monte-Carlo method.The numerical results are in agreement with those of experiment on the whole.

In this paper, two finite-difference methods for shallow-water equation in absolute coordinate-system are proposed, an iterative algorithm is given, then the algorithm is applied to multi-grid methoe.