用于高压电容器的SrTiO3基陶瓷

报道ＳｒＴｉＯ３基陶瓷的制备方法和介电性质，给出了用此种陶瓷制成的高压电容器的试验结果，并对它位进行了讨论。     

A feasibility study of a direct-mapping parallel processing method to solve linear equations in load-flow calculation

With the growing size and complexity of power systems, system analysis—such as transients calculation—takes much time. Hence, fast calculation methods are required. Although parallel processing is a hopeful method, there have been difficulties in the parallel solution of linear equations which appear in power-flow calculations by the Newton-Raphson method. This paper aims at the fast calculation of the power-flow problem by means of parallel processing. In order to improve the suitability to the parallel solution of the differential equation in transients calculation, we assume the use of a direct-mapping parallel processing machine to map directly the network of a power system onto a network of processors. Under this assumption, we propose a new parallel-processing-oriented method in which the linear equation is solved by linear iterations between nodes with Aitken acceleration. We simulate the method on three model power systems and compare this Parallel Iterative Method (PIN) with a Parallel Direct Method (PDM) which uses the banded matrix according to the number of operations required. As a result, we can expect that PIM may solve linear equations faster than PDM with m processors, although the PIM might be inferior to the PDM with m × m processors, where m denotes the half-band width of the banded matrix.     

β—BBO晶体的电光性能

用干涉法测量了β－ＢＢＯ晶体的电光系数：γ２２＝２．６，γ３３＝０．２３，γ３１＝０．２５，γ５１＝－３．５×１０－１２ｍ／Ｖ。结果表明如果在Ｙ方向加电场，Ｚ方向通光，β—ＢＢＯ晶体可能制作成有应用价值的光开关。     

变结构变参数设计方法及其在机械CAD中的应用

提出了一种新颖的机械结构设计思想－变结构变参数设计方法，并结合实例，阐述了变结构变参数设计的概念、原则、实施措施和意义。由此对Ｉ－ｄｅａｓ软件包进行了二次开发，编制了发动机曲轴专用ＣＡＤ软件程序，并用某型号发动机曲轴进行了验证。     

A semi-analytic boundary element method for parabolic problems

A new semi-analytic solution method is proposed for solving linear parabolic problems using the boundary element method. This method constructs a solution as an eigenfunction expansion using separation of variables. The eigenfunctions are determined using the dual reciprocity boundary element method. This separation of variables-dual reciprocity method (SOV-DRM) allows a solution to be determined without requiring either time-stepping or domain discretisation. The accuracy and computational efficiency of the SOV-DRM is found to improve as time increases. These properties make the SOV-DRM an attractive technique for solving parabolic problems.     

Solution of temperature fields in hydrodynamics bearings by the numerical network method

Solution to the 2-D steady-state nonlinear heat conduction equation, involving cylindrical coordinates, applied to a plain bearing by a simple and versatile numerical technique based on network method is presented in this work. These advantages of the technique are necessary for the status evaluation of industrial machines during operation because time and computing resources are limited. The pressure field in the fluid is previously solved from the Reynolds equation by finite element method. The main difficulty is associated with the exponential dependency of the viscosity on temperature. The proposed model is very efficient and requires negligible computing times. Solutions are very close to the experimental and numerical results of other researchers.     

新产品——钢带增强聚乙烯螺旋波纹管

钢带增强聚乙烯螺旋波纹管是一种创新的埋地排水管,把钢材的高刚度、高强度和聚乙烯的柔韧、耐腐结合在一起,突出的优点是环刚度高和节约原材料.     

Displacement Discontinuity Method for Fracture Mechanics Analysis of Reissner Plates: Static and Dynamic

This paper is concerned with the displacement discontinuity method applied to the shear deformable plates (Reissner’s and Mindlin’s theories) with cracks subjected to static and dynamic loads. Fundamental solutions of dislocation are derived using the Fourier transform method and the Laplace transformation technique. Boundary integral equations are presented in terms of rotations/displacement on the crack surfaces. The Chebyshev polynomials of the second kind are used to evaluate the integral equations with hypersingular kernels on the crack boundaries and determine the stress intensity factors at the crack tips. Comparisons are made with other numerical solutions to demonstrate the proposed method is accurate both for static and dynamic problems.     

梯形断面水力计算的一种新方法

本文从梯形水力最优断面的基本思路出发，通过理论分析找到了梯形断面水力计算的一种新方法——即通过特征参数进行梯形断面的水力计算。     

压裂泵往复密封性能及机理研究

根据流体动压润滑理论，对压裂泵柱塞密封摩擦副的润滑机理进行了理论分析。在排出和吸入行程，柱塞密封摩擦副均能满足流体动压润滑的条件，即在柱塞与密封界面上能形成并保持一定厚度的油膜润滑密封，从而达到减小摩擦提高寿命的目的；建立了摩擦界面油膜厚度和泄漏量的计算公式。利用有限元法理论，对密封圈的压力沿轴向的分布规律、泄漏量与压力变化关系进行了模拟计算。对往复密封圈沿轴向压力分布、泄漏量随压力变化进行了测试；试验结果表明，建立的计算模型具有较高的计算精度，揭示了压裂泵的密封机理。