Dynamic behavior of the He II-He I phase transition under gravity

The phase transition of superfluid helium (He II) to normal fluid helium (He I) is studied in this note. The He II -He I interface is found to move upwards under finite heat current. The temperature tracks are measured by four high resolution temperature sensors (HRTs). And the shifting of the λ　point temperature (phase transition temperature) along the cell is studied experimentally and theoretically. Under gravity, the shifting of the λ point temperature in creases with the pressure. The experimental results agree well with the theoretical ones.     

Controller Design for a 3 D.O.F Haptic Interface Device

This paper presents a novel 3 D.O.F haptic interface which is designed to meet the interaction requirement of teleoperation tasks and virtual reality applications. The mechanism design takes the operability into consideration such as adopting steel cables as transmission components and mass balances to eliminate the gravity effect and so on. The dynamics of haptic interface including actuating device is also studied. In order to provide operator with fidelity kinesthetic information, we design a force controller using self-learning fuzzy logic control. The simulation result verifies the effectiveness of the control method     

Determination of interface width value in phase-field simulation of dendritic growth into undercooled melt

The influence of the interface width value on the simulation results and its dependence upon thermo-physical parameters in the phase-field simulation of dendritic growth into undercooled melt are investigated. After choosing the reasonable interface width value, the tip velocities of dendritic growth in Ni melt under different undercoolings are calculated and compared with the experimental data in order to benchmark our results. It is shown that the reasonable interface width value， which is determined by the undercooling, anisotropy, interface kinetic, and thermal diffusivity， has to be taken low enough, and the agreement of our results with experimental data verifies that the credible results can be achieved as long as the interface width value is adequately low. This paper provides the basis of determining interface width value in simulating dendritic growth into undercooled melt by phase-field approach.     

ATM局域网仿真技术的应用

在对ATM局域网仿真技术进行简要概述的基础上，通过局域网的一个应用实例，提出了ATM局域网仿真技术的原理、构造及运行过程和目的，最后对ATM局域网仿真存在的问题进行了简述。     

智能温度测控仪高精度接口电路设计

研究了智能温度涵控仪内部接口电路存在的主要问题诸如温度漂移、线性度差、采样精度不理想等，针对这些问题提出了提高智能温度测控仪内部的微控制器压频接口电路性能与采样精度的几种方法，并在文中以V／F变换器为例，设计出了智能温度测控仪微控制器的几种接口电路，所设计的接口电路不仅适用于温度测控仪，也适用于其它由单片机构成的检测与控制系统之中。通过这种接口电路的应用，改善和提高了智能温度测控仪微控制器的性能。     

RMI在Mobile agent系统中的应用

在介绍RMI技术的基础上，提出利用RMI作为通信中间件，构建一个通用远程接口，实现Mobile agent作为客户机来调用远程对象的目的。     

图像采集过程中图像的存取及显示

在面向对象编程技术中 ,多媒体信息被统称大二进制对象 ,它们的存取方法与一般简单类型数据的存取不一样 .文章介绍了利用ODBC技术和MFC中CLongBinary类的结合以及使用COM接口 ,在VC ++中实现了对数据库中JPG图象的存取 .该方法同样也可以用于其它多媒体数据的访问 .     

跨国公司对外直接投资的博弈模型分析

构建跨国对外直接投资的二维信号博弈模型，并分析跨国公司选择不同的跨国经营战略对其产量及利润的影响．指出跨国公司可以战略性地选择其投资规模和融资方式，向其竞争对手传达关于成本类型和市场需求的信息，从而影响竞争对手的决策，实现利润最大化．     

基于STEP-NC标准的CAD/CAM集成接口的研究

在对STEP-NC进行介绍的基础上，阐述了采用对绘图软件Unigraphics二次开发的方法，开发基于STEP-NC的CAD/CAM集成接口的过程。该系统实现了CAD/CAM的集成，促进了CIMS的发展。     

Fe/ 硼酸盐缓冲溶液界面性质的交流阻抗研究

结合线性电位扫描、开路计时电位和交流阻抗技术研究了Fe在硼酸盐缓冲溶液(pH=8．4)中不同电位区间的界面性质．在氮气气氛下，电位低于-0．77V，界面发生析氢反应，反应受电子转移步骤控制。同时存在氢原子的表面吸附过程；-0．77V至0．60V间，Fe氧化成2价Fe而发生活性溶解，同时2价Fe进一步氧化成3价Fe，二步反应均受电子转移步骤控制；至0．60V，形成具有保护作用的单层Fe304；-0．60V至-0．50V间，Fe氧化成2价Fe的反应随电位升高而变慢，表现为负的反应电阻；-0．50V至0．90V间，Fe进入钝化区，较低电位下主要是Fe304转化成Fe2O3的过程，受电子转移步骤和0H^-在钝化膜中的扩散步骤混合控制，较高电位下Fe直接氧化成3价Fe。受电子转移步骤和3价Fe离子在钝化膜中的扩散步骤混合控制；电位高于0．90V，界面发生析氧反应和氧化膜溶解，反应受电子转移步骤控制，反应过程中有中间产物吸附．