Archive

25 March 1992, Volume 9 Issue 1 Previous Issue    Next Issue

---

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

NUMERICAL METHOD FOR SOLVING RELATIVISTIC HYDRODYNAMIC EQUATIONS Zhang Jiaju, He Zeijun 1992, 9(1): 1-5.  Abstract ( )   PDF (290KB) ( )   In this paper, the finite-difference Scheme is given to find numerical Solution of relativistic hydrodynamic equations including phase transition. Some computation results are illustrated.

Select

ON OPTIMIZATION OF ALGORITHMS ABOUT TWO-CENTER TWO-ELECTRON INTEGRALS OVER SLATER TYPE ORBITALS Li Yanxi, Dong Xialan, Pan Shoufu 1992, 9(1): 6-14.  Abstract ( )   PDF (549KB) ( )   The formulae of two-electron integrals are optimized by using complex Slater orbitals. Analysing both the formula structure and the instability of auxiliary functions, we obtain some approximate conditions of realizing the best balance between the required accuracy and the computational speed.

Select

FINITE-ELEMENT ALGORITHMS FOR SIMULATING WATER FLOW IN VARIABLY SATURATED POROUS MEDIA Duan Zhitian, Zhang Diming 1992, 9(1): 15-22.  Abstract ( )   PDF (468KB) ( )   The Galerkin finite element formulation is developed for the numerical simulation of water flow in variably saturated porous media. Both new Influence Cofficient techniques are proposed which can be used to compute element matrices in a simple and efficient manner. The new techniques avoid numerical integration and lead to a substantial saving of cost. Two examples are presented to verify the proposed techniques and show their computational characteristics.

Select

A NEW METHOD FOR THE SCATTERING FROM AN UNDERGROUND CONDUCTIVE CYLINDER Wang Zhengping, Yang Guang, Yang Jisheng 1992, 9(1): 23-28.  Abstract ( )   PDF (353KB) ( )   The scattering of waves from a cylindrical obstacle burried in the dielectric half-space can be investigated by many means. One of them is discrete method. But it is difficult to deal with the radiation conditions on the artificial boundaries of finite calculating region. To eliminate the effects of waves reflected from the artificial boudaries, an Artificial Transmitting Boundary Method was given by seismology circles and has been applied to some scattering problems successfully/In this paper, as a trial, the method mentioned above is combined with Finite Element Method and applied to give out the near-field solutions. Then, making use of the results, the far-field solutions are given with Green's function method. Finally, the results from the method used here are compared with those from the integral equations method. It is verified that the new method used here is feasible.

Select

COEFFICIENT INVERSION FOR A WAVE EQUATION WITH DIFFERENCE COMPUTATION ON TIME DOMAIN Liu Jijun, Zheng Jiamo 1992, 9(1): 29-34.  Abstract ( )   PDF (302KB) ( )   This paper considers the coefficient inverse problem of 1-D wave equation. Firstly we obtain the G-L equation which gives the relationship between assiatant information on time domain and the coefficient to be sought. Then both discrete scheme and numerical examples are given. Numerical results show our method is well-posed.

Select

NUMERICAL CALCULATION OF EOS AND PHASE DIAGRAM FOR TWO DIMENSIONAL HARD DISK SYSTEM Sun Fengguo, Hu Hongbo, Tang Rongqi 1992, 9(1): 35-39.  Abstract ( )   PDF (280KB) ( )   With numerical method we obtained the location of minimum value of Gibbs function in configuration space for two dimensional hard disk system, and the equation of state and phase diagram of the model, we found that only the 6-atom solid phase and liquid phase can be exist in the model. The wrong method and conclusion of previcus work have been corrected.

Select

NUMERICAL SOLUTION OF HADRON STRUCTURE FUNCTION Qian Lu 1992, 9(1): 40-44.  Abstract ( )   PDF (286KB) ( )   To avoid the dependence of hadron structure functions upon supposed function forms and to improve the accuracy, a new method to find the hadron structure fundtion at high Q2 is discussed in this paper to replace the commonly used moment method. The sturcture functions for gluon and valence quark and sea at high Q2 are obtained by discretizing the A-P evolution equations into ordinary simultaneous differential eqs. and then solving them with Runge-Kutta method.

Select

THE TRIANGULAR MESH-COLLOCATION METHOD FOR SOLVING THE TWO DIMENSIONAL TRANSPORT PROBLEM Fu Lianxiang, Du Mingsheng 1992, 9(1): 45-52.  Abstract ( )   PDF (455KB) ( )   A numerical method for solving the neutron transport problem (isotropic and anisotropic) in two-dimensional cylindrical geometry is presented. Results from numerical calculation are given. In comparision with SN and the discontinuous finite element method and the experiments the method is satisfactory.

Select

INFLUENCE OF LOW PRESSURE GLOW DISCHARGE PARAMETERS ON THE SECONDARY ELECTRON EMISSION COEFFICIENT Song Wendong, Liu Zuli, Li Zaiguang 1992, 9(1): 53-58.  Abstract ( )   PDF (354KB) ( )   The influence of the glow discharge total current density J and the gas pressure P on the secondary electron emission coefficient γ is studied by using the Runge-Kutta method. The variations of γ wity J, P and E/P (E is the electric field at the cathode) are obtained.

Select

DIAGNOSTIC OF THE STATE OF A LASER-PRODUCED Al PLASMA USING SPECTRAL LINES OF He-like Al ION Shao Yunfeng 1992, 9(1): 59-62.  Abstract ( )   PDF (249KB) ( )   In this paper, we explain the diagnostic method of electron temperature and density of a laser-produced plasma using spectral lines of He-like Al ion in detail; the intensity ratios of satellite to resonance line vs the electron temperature and resonance to combination line vs electron density have been given, respectively. Meanwhile, according to the line intensity ratios from experiment, the electron temperature and density for He-like Al ion have been determined.

Select

THE NUMERICAL SIMULATION OF ELASTIC WAVES Jin Baoxia, Wu Liangzi, Lu Lai 1992, 9(1): 63-67.  Abstract ( )   PDF (320KB) ( )   In this paper, an universial program for the simulation of elastic waves were developed by adding some treatment routines of artificial boundary conditions to the famous program of SAP5 and its micro-computer version SAP5P. The numerical results presented show that the program simulated the propagation of elastic waves in the uniformly elastic media quite well.

Select

EPM METHOD Yuan Guoxing, Duan Qingsheng, Zhang Yuhua, Wang Lihua 1992, 9(1): 68-78.  Abstract ( )   PDF (571KB) ( )   EPM method for two dimensional elastic-plastic hydrodynamic calculation, which couples Eulerian and Lagrangian methods, is presented in this paper. The difference scheme is constructed by means of contour integral. This method includes sliding interfaces treatment, several generating meshes technique, and so on. It can be widely applied to calculations of many hydrodynamic problems.

Select

PARALLEL BAORJ ALGORITHMS AND THEIR CONVERGENCE Liu Xingping 1992, 9(1): 79-86.  Abstract ( )   PDF (444KB) ( )   In this paper, a parallel block accelerated overralaxation Jacobi iterative method is proposed; the rate of convergence is analysed when the coefficient matrix A is symmetric positive definite and H-matrix, Numerical examples are given.

Select

MONTE-CARLO SIMULATION OF ATOM-STATE CHEMISORBED GAS DESORPTION CROSS SECTION BY LOW-ENERGY IONS INDUCTION Chen Yiping, Yu Shuyong 1992, 9(1): 87-92.  Abstract ( )   PDF (342KB) ( )   This paper simulates desorption phenomenon of atom-state chemisorbed gas on solid suface by low-energy ions bombardment based on collision theory of winters sigmund. In the simulation, line relevance between induced gas atom gields Y by ions and coverge density θ of gas atom on solid suface is obtained, on the basis of line relevance, ion induction desorption cross section σ is obtained rapidly.

Select

THE EXACT ANALYTIC SOLUTION OF POTENTIAL FLOW ABOUT MULTI-ELEMENT AIRFOILS Cao Jianfa 1992, 9(1): 93-98.  Abstract ( )   PDF (344KB) ( )   A new method is presented to calculate the exact analytic solution of potential flow about multi-element airfoils. The potential flow about multi-circles is calculated by the method of images, and multi-circles are transformed to multi-element airfoils by calculating the numerical solution of a partial differential system. This method can be applied to airfoils of arbitrary shape. Airfoils pressure distribution has been computed by this method and is in good agreement with independent results.

Select

THE MOST COMPACTLY-STORED FINITE ELEMENT METHOD IN GROUNDWATER SEEPAGE Zhang Shifeng, Zhang Huisheng 1992, 9(1): 99-105.  Abstract ( )   PDF (453KB) ( )   In the essay, the finite element algebraic equations by element assembling is replaced by node assembling, and the right term is dealt with by the idea of lumped mass, and the most compactly-stored finite element method is obtained.Thus, the total matrix elements are reduced to less than three times of unknown node, and the stored-units are even less than which the rectangle grid finite-difference method needs. The program structure is more rational and simpler, meanwhile the calculation quantity is reduced and the computational effciency is improded. All these become more obvious in process of solving nonlinear problems.

Select

MONTE-CARLO SIMULATION OF REB TRANSPORT IN THE MEDIUM IN THE PRESENCE OF THE EXTERNAL MAGNETIC FIELD Wu Shuxing, Li Yuanchen 1992, 9(1): 106-110.  Abstract ( )   PDF (307KB) ( )   This paper gives the relativity electron energy deposition simulated by Monte-Carlo method in Ne medium in the presence of the external magnetic field. Finally, the deposition energy pnofiles are given.