马歇尔-勒纳条件的实证研究

本文从人民币实际汇率变动是否会对我国贸易收支产生影响出发，基于马歇尔．勒纳条件，对计算贸易弹性常用的OLS回归模型进行了改进，建立了向量自回归误差修正模型来估算我国的国际贸易弹性。实证研究表明：我国进出口需求的价格弹性之和大于1。因此人民币贬值可改善贸易收支；反之升值将使贸易收支恶化。     

Effect of induced shielding current transmission in longitudinal direction on levitation force of melt grown single-domain YBa_2Cu_3O_(7-x) cylindrical superconductor

YBa2Cu3O7-x (YBCO) bulk is one of the most important high temperature superconducting materials for magnetic levitation applications, because it has a high magnetic irreversibility field Hirr at liquid nitrogen temperature, and can grow into large grains. The levitation force of YBCO bulk is proportional to the critical current density (Jc) and grain radius (r)[1], so higher Jc and r are appreciated for YBCO bulks to achieve higher levitation force. Now single-domain YBCO bulks up to s…     

Substructuring preconditioners for saddle-point problems arising from Maxwell's equations in three dimensions

This paper is concerned with the saddle-point problems arising from edge element discretizations of Maxwell's equations in a general three dimensional nonconvex polyhedral domain. A new augmented technique is first introduced to transform the problems into equivalent augmented saddle-point systems so that they can be solved by some existing preconditioned iterative methods. Then some substructuring preconditioners are proposed, with very simple coarse solvers, for the augmented saddle-point systems. With the preconditioners, the condition numbers of the preconditioned systems are nearly optimal; namely, they grow only as the logarithm of the ratio between the subdomain diameter and the finite element mesh size.

     

改善a-Si太阳电池界面特性的新方法

本文介绍一种用非晶金属硅化物改善a—Sipin太阳电池TCO/p界面特性的新方法.文章中详细讨论了载流子的传输模型并给出了一系列的实验数据.利用这种方法,用单反应室等离子体CVD装置使a—Si电池的短路电流提高了10%以上,并已获得10.6%的转换效率.     

偏振分束器对光学电流传感器稳定性的影响

采用偏振光学理论,详细分析了光学电流传感器中偏振分束器消光比的变化对传感器性能的影响,得到了偏振分束器消光比与传感器输出的关系式,并用系统实验进行了验证.理论及实验结果的吻合证明了光学电流传感器稳定性直接受偏振分束器两路消光比影响的结论.     

On a free boundary problem for the Reynolds equation derived from the Stokes system with Tresca boundary conditions

The asymptotic behaviour of a Stokes flow with Tresca free boundary friction conditions when one dimension of the fluid domain tends to zero is studied. A specific Reynolds equation associated with variational inequalities is obtained and uniqueness is proved.     

试析仲裁简易程序的适用条件

虽然我国各仲裁委员会在实践中大量适用仲裁简易程序,但我国法学理论界却很少对其时代内涵进行界定,对其适用条件也缺乏探讨,因而制约了仲裁简易程序的研究和发展。本文在分析仲裁简易程序时代内涵的基础上,从主观条件和客观条件两方面对仲裁简易程序的适用条件进行了探讨,建议规范我国仲裁简易程序的适用条件,实现仲裁简易程序的和谐价值取向。     

破解民族文字信息处理发展"瓶颈"

信息时代,民族文字信息处理对加速民族地区信息社会化进程,促进民族地区社会进步发挥了重要的作用.在信息文明强烈冲击下,探讨民族文字信息处理技术发展现状,提出促进民族文字信息处理发展的对策,具有独特的现实意义和研究价值,值得我们去审视和思考.本文简要介绍民族文字信息处理发展情况,分析了民族文字信息处理发展中出现的各种问题,对促进民族文字信息处理发展提出了几点对策.     

A non‐linear and non‐local boundary condition for a diffusion equation in petroleum engineering

This article deals with a boundary value problem for Laplace equation with a non‐linear and non‐local boundary condition. This problem comes from petroleum engineering and is used to obtain an estimation of well productivity. The non‐linear and non‐local boundary condition is written on the well boundary. On the outer reservoir boundaries, we have both Dirichlet and Neumann conditions. In this paper, we prove the existence and uniqueness of a solution to this problem. The existence is proved by Schauder theorem and the uniqueness is obtained under more restricted conditions, when the involved operator is a contraction. Copyright © 2005 John Wiley & Sons, Ltd.     

Minimum Distance Between the Faces of Two Convex Polyhedra: A Sufficient Condition

The problem of finding the Euclidean distance between two convex polyhedra can be reduced to the combinatorial optimization problem of finding the minimum distance between their faces. This paper presents a global optimality criterion for this problem. An algorithm (QLDPA) for the fast computation of the distance between convex and bounded polyhedra is proposed as an application of it. Computer experiments show its fast performance, especially when the total number of vertices is large.