含有非线性电阻的动态电路唯一稳态的范数判定方法

以矩阵范数为工具，得到了确定含有非线性电阻的动态电路唯一稳态的条件，并给出了一个算例，其结果与理论分析吻合．本文的结果表明，含有非线性电阻的动态电路的唯一稳态．可以用矩阵范数决定．而且这个方法可以应用于任意阶的非线性电路．判据适用范围更广，结果便于应用，在理论与实用两个方面，都有重要意义．     

隧道开挖中的应力旋转和裂隙塑性变形问题研究

通过对隧道开挖过程进行三维数值模拟,分析了隧道开挖过程中主应力方向的旋转变化,研究了主应力旋转与隧道裂隙塑性变形的关系,验证了"考虑应力主轴旋转的广义塑性原理"的正确性,并将数值模拟结果和相关试验成果进行了对比,得出了一致性的结论。研究结果表明,应力旋转基本在隧道开挖前后10 m左右的距离内完成,隧道开挖过程中的应力旋转可以引起裂隙塑性变形的突变,且对竖向和斜向裂隙的影响较大;可以根据应力旋转的变化规律合理地选择支护时机,依据应力旋转对裂隙的影响对隧道的重点部位进行超前加固。     

内河船舶法向接岸速度的数字模拟

文章根据内河船舶中较为典型的两种船型法向接岸速度实测子样，采用蒙特犬活法，通过计算机随机实验人法向接岸速度进行随机模拟，并经过统计检验求出法向接岸速度最大值的分布服从值Ｉ值分布和最大值的失效概率曲线，并与现行港口工程技术规范建议值及有关资料进行了比较。     

Tacoma 海峡桥的空气动力学—60年后

文中用一种新的方法来了解60年前对Tacoma海峡桥坍塌负有责任的空气动力破坏机理。证实了不稳定机理是与桥梁横截面上风边的巨大涡流形成和漂移相联系的。涡流形成和漂移过程的经验模型可用公式表达，以计算不稳定开始时的临界风速。模型为数字模拟和实验结果所证实。表明对Tacoma海峡桥横截面的结构改进可以消除涡流的形成，或抵抗空气动力的作用，因而给予桥梁较大的空气动力稳定。     

Information System for Land-Use Planning and Management

In order to maintain the overall social interest in land use and improve the level of land administration, an information system for land-use planning and management (ISLUPM) was established, which is composed of presentation layer, business logic layer and data layer in the general structure. The application support platform of the ISLUPM, built based on COM, COM and .NET standard components, includes data engine, data management, assemblies, components management, operation management, and interface. Then, an elaboration was made on major functions of the ISLUPM, such as planning revision scheme, planning operation flow, digital processing, thematic analysis and inquiry, and preparation of the chart of reserved land resources. The developed system has been successfully applied to the land-use planning and management work of Longquanyi District, Chengdu, China. It may provide a reference for development of geographic information system (GIS) for land and resources.     

数字模拟应对法国勒芒24小时赛

以虚拟的方式测试了完全由合成材料制成的新型C60汽车迎头撞击，从而将汽车的重量减少了四分之一。     

Steady state analysis of towed marine cables

Efficient numerical schemes were presented for the steady state solutions of towed marine cables. For most of towed systems, the steady state problem can be resolved into two-point boundary-value problem, or initial value problem in some special cases where the initial values are available directly. A new technique was proposed and attempted to solve the two-point boundary-value problem rather than the conventional shooting method due to its algorithm complexity and low efficiency. First, the boundary conditions are transformed into a set of nonlinear governing equations about the initial values, then bisection method is employed to solve these nonlinear equations with the aid of 4th order Runge-Kutta method. In common sense, non-uniform (sheared) current is assumed, which varies in magnitude and direction with depth. The schemes are validated through the DE Zoysa's example, then several numerical examples are also presented to illustrate the numerical schemes.     

模拟解决关键设计问题

制作塑料部件时节省重量和减少废品是非常重要的。采用数字模拟有助于达到这些目的     

Characteristics of new-type energy absorber for vehicle collision

A new type energy absorber was introduced, which is composed of thousands of thin ring plates with different diameters. Because it can switch the impact to thousands of shearing actions among thin ring plates inside the absorber, the impact energy is decentralized and dissipated gradually, the impact acting time is extended and the peak of acceleration is reduced obviously. Numerical simulations by finite element method (FEM) coupled with smoothed particle hydrodynamics (SPH) method were preformed to predict the energy absorption characteristics. Energy absorption ability with different impact velocities was studied and the effects of thickness and material of ring plates were discussed. The sled crash test was carried out to validate the result of simulations. The new type absorber is effective for collision that impact velocity is lower than 40 km/h.     

开发自主潜器控制软件工具

介绍由美国电子设备公司等开发的软件包的操作功能，目的是帮助设计人员对未来的自主潜器在勘察任务中的性能进行评估，其中包括对其高精度定位和速度及高度稳定性的评估。描述系统主要循环功能、AUV构造、环境、导航传感器和有关筛选器、执行使命航迹、制导及控制规则。对上述各条进行定义后，运用数字模拟来评估执行任务的效率，并以某些成功的AUV操纵设计为例说明软件包的功能。