We apply effective dipole approximation to investigate the equivalent dielectric constant of inclusion and the effective response and optical absorption in composites media of metal spherical particles.The dielectric constant varies along the radius of the particles.ε_e exhibits a monotonic decrease with the power index n while the dielectric constant shows a power law gradation.The presence of the gradation in metal particles yields a resonant optical absorption peak.It shows red-shift with m_ω and m_ν of the metal-dielectric composites.

Numerical calculations on Josephson junctions under microwave radiation are made by means of Runge-Kutta method in the RSJ model. The DC I-V curves of Josephson junctions reproduce experimental results very well.

Based on a combination of Monte Carlo models of fast electrons and species(N₂⁺,N⁺,N_r),Creation rates of atomic species(N⁺,N)and energy,density and angular distribution of species(N⁺,N_f)bombarding negative target in nitrogen dc discharge plasma-assisted nitriding of steel surface are investigated for e^-+N_2s→N⁺+N_s+2e^-及N₂¹+N_2s→N⁺+N_s+N₂.It is found that these is an optimum discharge temperature for the energy distribution of species(N⁺,N_f)at the cathode,creation rate and density of atomic species(N⁺,N)decreases with increasing temperature at steel surface,calculated results are generally in agreement with experimental ones.

Numerical method of the steady-state Fokker-planck equation is discussed.The numerical results are obtained by linear combination method and single step method based on Gauss node collection. Ratio frequency(RF) current density and power density of the steady state low hybrid wave(LHW) current drive are calculated numerically.

The oscillating solutions of the magnetic fields may arise on an axisymmetric model by using first order finite elements.In addtion,they may also occur for nonuniform grids.The paper analyses the cause of forming oscillating solutions and the behaviour of oscillating solutions.The methods of cancelling the oscillation are suggested.

This paper deals mainly with applications of the finite-element method in numerical simulation of neutron well-logging.In the frame of multigroup P₁ approximation the neutron transport equation is soluted by using finite-element method and the two-dimentional finite-element code FEMLOG is developed for the numerical simulation of neutron well-logging.The precision of numerical results of FEM-LOG is satisfactorily comparable to that of the international common code DOT4.2.However FEM-LOG is operated on the computer far faster than DOT4.2.

The effect of energetic trapped Particles on the stabilization of ballooning modes infinite-aspect-ratio tokamaks is numeically analyzed. The numerical solution of the corresponding integro-differential equation is obtained. Numerical results show that the instability domain of ballooning modes becomes smaller with the energetic particles pressure and the toroidal effect enhancing. The energetic trapped particles can Partially or completely stabilize the instability of ballooning modes.

A numerical method so called regularizing method applies for singular boundary value problem for ordinary differential equation with solutions that can be represented as series expansions on a subinterval near the singularity. A regular boundary value problem is derived on thd remaining interval, for which a difference method is used. Convergence results and numerical examples are given.

A set of nonlinear second order parabolic partial differential equations with initial-boundary values is approxinated by Crank-Nicholson difference method, and successfully solved by means of Loop-Iteration method. The computation of energy transport in tokamak plasma by ohmic heating provides numerical results in agreement with the theoretial analysis.