The static power and ground(P/G) network is analyzed by a combination of compressed equivalent circuit modeling and random wall algorithm.A model of power and ground network is obtained by parameter extraction and modeling over whole chips.The method builds an equivalent model for original network and uses random walk method to solve the simplified network.As a result,the improved compressed random walk algorithm saves CPU time greatly.The speed of the algorithm is more than two order of magnitude faster than the normal random walk algorithm.

The Boltzmann equation is applied for the CO₂ lasers excited by high frequency switching power,it has been solved numerically using cross-section-data available in the literature.The influences of frequency on the electron energy distributions and transport coefficients are also studied.

The coupling losses in planar waveguide resonators have been calculated and some results of the coupling losses for the EH₁₁ mode of different planar waveguide are given as a function of mirror curvature and position. It is shown that there exist two special geometries to provide low coupling losses.

The optical field distribution in wide planar-waveguide CO₂ gas laser satisfies Helmholtz equation.Under certain given conditions,expressions of the polarized modes EH_nm^x and EH_nm^y are obtained by solving optical field distribution equation.The present computation gives a normalized theoretical distribution curve of EH_1.16 polarized mode existed in 3×18mm² waveguide discharge area.The curve is consistent with the experimental results.

Two-dimensional magnetohydrodynamic behaviour of the plasma in co-axis of the plasma focus eguipment is studied in this paper. The two-step Lax-Wendroff scheme is applied to Eulerian cells of (r-z) plane in axial deuices. Applied special treatments are as follows. The complex diffusion terms have been treated by the forward time-defference method; The ion-electron equipartition terms are solved by a implicit iteration; The hapidus three-order smooth technics is used in all MHD equations; The mixed schame of Lax and Leapfrog schemes is used in the density equation and the momentum equation to eliminate the nonliear instabilities; The magneticfield of low-density region is treated as vacuum magnetic field, so that the calculations of magnetic field and fluids are decoupled,and the severe restriction in choosing the timestep is avoided.Each time-step of calculation takes 39 sec.on a DJS-8 (320), and approximately 370 timesteps are needed altogether. The steady dynamic structure is calculated.