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25 September 1985, Volume 2 Issue 3 Previous Issue    Next Issue

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THE DISTRIBUTION THEOREMS FOR PSEUDORANDOM POINTS Li Zuo-xin, Lu Qing-tang 1985, 2(3): 257-263.  Abstract ( )   PDF (419KB) ( )   This paper takes the large prime numbers as a module, the primitive roots of the module will be multiplicator and introduced concepts of Bands and Quasi-Symmetrical Distribution. Based on the distribution graphs of the pseudorandom points are generated by the multiplication congruential method gives nine distribution theorems and a deduction. Therefore, this paper will creat conditions for studies in connection with the pseudorandom points and get more simple and pricise deviation expression of the pseudorandom numbers.

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THE NUMERICAL SOLUTION OF THE ENERGETIC CHARGED PARTICLE FOKKER-PLANCK EQUATION Sun Yong-sheng, Liu Jun, Tian Yu-hong 1985, 2(3): 264-274.  Abstract ( )   PDF (613KB) ( )   The charged particle Fokker-Planck equation including the energy dispersion term is solved with "one-dimension difference method of both the space and the energy". On the basis of the results obtained, the total amount of energy transfer to background plasma and the fraction of energy transfer to the electrons and to the ions are computed. The results obtained are compard with that computed by the ether methods.

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ONE OF THE EVOLUTIONS FOR THE GALACTIC MAGNETIC FIELD AND GALACTIC SHOCK WAVES Hu Wen-Rui, Ao Chao 1985, 2(3): 275-279.  Abstract ( )   PDF (322KB) ( )   In the present paper, the unsteady and two-dimensional magnetohydrodyna-mical equations are solved to describe the origin and evolution processes of the galactic magnetic field and galactic shock waves. The initial uniform magnetic field will wind into the spiral structures in the galactic disk, in which the magnetic field and the interstellar gas are frozen together. The influence cf the galactic magnetic field on the formation of the galactic shock wave is analyzed. As the magnetic field is not very strong, the influence is weak.

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A NUMERICAL METHOD AND ITS APPLICATION TO ROTATING TWO PHASE FLOW Shi Qing-ping, Liu De-zhang 1985, 2(3): 280-292.  Abstract ( )   PDF (918KB) ( )   In this paper, we calculate the flow in an aircraft vapor-core pump that has been designed and manufactured in recent years. The physical and mathematical model of gas-liquid two phase flow are subjected by analyzing the flow,well known SIMPLE algorithm is used, but modified properly. The numerical method as well as the computer program that can be used in rotating two phase flow are presented. Results of numerical simulation are In agreement With our experiments, with difference less than 13-19%. The method is hopeful for two or single-phase flow calculation of other rotating systems.

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NUMERICAL CALCULATIONS OF THE PLASMA ENERGY DISTRIBUTIONS AND THE PLASMA POTENTIAL Cong Ye 1985, 2(3): 293-302.  Abstract ( )   PDF (574KB) ( )   The reduced Fokker-Planck equations are solved numerically under the assumptions that square well approximation, isotropic velocity distributions and lowest mode approximation. A number of the numerical solutions is obtained. Results show a good agreement with physical analysis In this paper numerical method is described in detail.

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A SMALL REGION MONTE CARLO METHOD FOR SOLVING DEEP PENETRATION PROBLEM Pei Lu-cheng 1985, 2(3): 303-312.  Abstract ( )   PDF (620KB) ( )   There exist some difficulties if the general Monte Carlo method is used for the deep penetration problem. In this paper,a new small region method in Monte Carlo calculation for the deep penetration problems is proposed. Based on this,two kinds of the small region methods are given, namely, the small region method for the plane geometry and the small region method for the spherical geometry. The practical calculation by examples indicates that the small region method is better and feasible. In this way, the difficalty of the general Monte Carlo method for solving deep penetration problem is overcome.

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A SMOOTHING TECHNIQUE IN METHOD SOLVED X-RAY SPECTRA IN LASER NUCLEAR FUSION Liu Cheng-hai, Lu Zhang-qiang 1985, 2(3): 313-320.  Abstract ( )   PDF (587KB) ( )   We have developed a method to solve X-ray spectra. The method includes a iterative with range limit and a periodic smoothing. Better resuts had been obtained by use the method to solve X-ray spectra in laser nuclear fusion. This paper places stress on introduction the smoothing technique in the method. A smoothing weigh fuction was formed and iterative spectra was treated periodically by the weigh fuction in iterative Course. Computational results show, Numerical structure producted in iterative course of X-ray spectra was eliminated and convergence of iterative was improved and level of solving spectra was raised by using the techn-ique. physics bases of smoothing are discussed, a theoretical analyses about smoothing and experiemental results on number of smoothing and weigh fuction are given in this Paper.

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NUMERICAL COMPUTATION OF THE ONE DIMENSIONAL DISCONTINUOUS FLOW Gu Guang-shu, Zhang Tian-shu 1985, 2(3): 321-326.  Abstract ( )   PDF (362KB) ( )   In this work, we Calculated numerically odiabatic expansion profile of ideal gas explosion product in homogeneous, Stationary and highpressure conditions for plane, Cylindrical and spherical symmetry without pseudo-viscosity method by treating the discontinuities as the boundaries of the flow region. We gave various discontinuities paths and the flow field parameters, and examined the effect of the geometrical convergingdiverging term in the continuum equation by Comparing the results computed in the three cases.

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A SELF-CONSISTENT METHOD FOR CALCULATING THE INTERNAL ELECTROMAGNETIC PULSE IN THE TWO-DIMENSIONAL CYLINDRICAL CAVITY (Ⅱ) Wang Tai-chun, Wang Yu-zhi 1985, 2(3): 327-336.  Abstract ( )   PDF (565KB) ( )   This paper is the coutinuity of the reference[1]. Under the case that the conditions of the Maxwell's equations, the equations of the rate, and corresponding to difference scheme are not varied, the equations of the primary electrons are solved by Euleran method. The difference scheme of the equations of the primary electrona are derived in the cne-dimensional plane and the two-dimensional cylindrical coordinate. At the same time, the model of the two-dimensional cylinder are numerically caltulated. Both the calculating results of this paper and the reference[1]are discussed in the reference[2].

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A DIMENSIONAL REDUCTION METHOD FOR INCOMPRESSIBLE FLUID DYNAMICS I. THE ESSENTIAL ALGORITHM Yu Xin 1985, 2(3): 337-346.  Abstract ( )   PDF (596KB) ( )   This paper is the first in a series of papers in which we present a new finite element method for incompressible fluid dynamics——a dimensional reductionmethod.We show that it saves a lot of computing time and storages using this method when a simple basis of Yh is available.in this paper, the essential algorithm is presented, and a very simpte basis of Vh is given for solving the homogeneous Navier-Stokes equations in a simply connected region in R2 using quadratic conforming triangular elements for the velocity field and piecewish constant triangular elements for the pressure[1].

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NUMERICAL CALCULATIONS OF A CLASS OF RESONANCE INTEGRALS RELATED WITH THE PLASMA DISPERSION FUNCTION Long Yong-xing, Shi Bing-ren 1985, 2(3): 347-352.  Abstract ( )   PDF (380KB) ( )   The resonance interaction of plasma waves with the toroidal drifts of particles leads to the occurence of a class of high order resonance integrals, which are related closed with the plasma dispersion function. Ordinary integral forms of them in finite region have been obtained by suitable complex transformation, that is very useful for their numerical calculation in case of the imaginary part of the complex parameter being small.

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NESTED DOUBLE DECOMPOSITION ALGORITHM FOR LARGE SCALE LINEAR PROGRAMMING PROBLEM WITH LOWER BLOCK TRIANGU LAR CONSTRAINTS Shun Yun-guang, Zheng Toug 1985, 2(3): 353-367.  Abstract ( )   PDF (927KB) ( )   A new linear programming decomposition algorithm, based upon the double decomposition, is developed. Firstly, teh basic double decomposition algorithm is introduced. Secondly, the basic idea of nested double decomncsition is discussed through the general triangular constrained linear programming problem. Thirdly, several available nested double decomposition algorithms are described. Finally, the application of the nested double decomposition algorithms are described. Finally, the application of the nested double decomposition algorithm to the structuref linear programming problems is briefly explaind and is shown that the algorithm presented here is effective on saving CPU time and memory.

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THE SPLIT COEFFICIENT MATRIX (SCM) FINIT DIFFERENT METHOD FOR HYPERBOLIC EQUATIONS Zhang Lu-min 1985, 2(3): 368-374.  Abstract ( )   PDF (415KB) ( )   SCM finite difference method for solving inviscid subsonic, transonic and supersonic flow over spherical cone is presented. This method is based on the mathematical theory of characteristics.In the SCM approach these coefficients are split according to the sign of the chara-oteristic slopes. The split coefficients are multiplied by appropriate one-sided. F orwardiffe-rences are associated with negative characteristic stopes, while baokward diflerchces are associated with positive slope values.In the SCM technique the governing Euler equations are solved by a secondorder accurate finit difference elgori thm in a predictor-corrector sequence. To maintain Secondorder spatial accuracy for the one-sided derivatives associated with the split coefficients the discretization formulas alternate between two-point and three -point approximation.The numerical example of the blunt spherecones have been worked in this paper and compared with Conventional finite difference to demonstrate good accuracy of SCM in rate mesh.

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ON THE NONLINEAR RESONANCE OF ELASTIC BEAM Zhao Yan-Hui, Yang Pan-Chi, Qu Xiao-Gang 1985, 2(3): 375-379.  Abstract ( )   PDF (270KB) ( )   The problem of nonlinear resonance of elastic beam is studied by finite element method using a nonlinear factor. It is discovered that the resonance can also take place in this case, the resonant frequency of this problem is given. The study given here shows a new way for engineering design.

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THE MONTE CARLO SIMULATION FOR THE STRUCTURE AND THE DEFECT STATES OF a-Si:H Lu Xian-ping, Wu Xiang 1985, 2(3): 380-385.  Abstract ( )   PDF (416KB) ( )   In this paper the function of dangling bound is considered and the structure of hydrogepated amorphous silicon is simulated by Monte Carlo Method. The radiai distrioution functions and other statistical quantities are agreement with experimental data. The incorporation form of hydrogen atom is also qualitative consitent with the knowledge from experiments.