如何优化维护局域网

为了排除局域网在构建和使用时出现的种种故障,从排除故障、优化性能的角度出发,简单归纳了一些局域网维护及优化的经验和技巧,其中着重讨论了网卡、网线的正确安装、合理设置等问题。实践证明,一般局域网经此方法维护及优化后,都起到了很好的效果。     

Comprehensive Warpage Analysis of Stacked Die MEMS Package in Accelerometer Application

<正>Packaging of MEMS ( micro-electro-mechanical system ) devices poses more challenges than conventional IC packaging, since the performance of the MEMS devices is highly dependent on packaging processes. A Land Grid Array ( LGA ) package is introduced for MEMS technology based linear multi-axis accelerometers. Finite element modeling is conducted to simulate the warpage behavior of the LGA packages. A method to correlate the package warpage to matrix block warpage has been developed. Warpage for both package and sensor substrate are obtained. Warpage predicted by simulation correlates very well with experimental measurements. Based on this validated method, detailed design analysis with different package geometrical variations are carried out to optimize the package design. With the optimized package structure, the packaging effect on accelerometer signal performance is well controlled.     

基于OLSR的QoS路由新方案

基于OLSR协议及扩展的最短路径算法,提出了综合折中跳数与带宽的一种路由计算新量度。组合MPR选择算法及路由计算新量度,设计了三种新的QoS路由方案。基于在NS-2环境中对新路由方案及OLSR原始协议进行的仿真,着重分析比较了它们的时延及分组递交率性能,探讨了带宽量度用于路由计算时对这两项性能产生的影响及主要原因,结果表明新量度能有效实现跳数少与带宽大之间的折中。     

Preparation and characterization of heteroepitaxial Zn2SnO4 single crystalline films prepared on MgO (100) substrates

Zinc stannate (Zn₂SnO₄) films were deposited on MgO (100) substrates by pulsed laser deposition, and Zn₂SnO₄ monocrystalline films were obtained by postannealing process. The structures, surface morphologies, and optical properties of the Zn₂SnO₄ films annealed at different temperatures were investigated in detail. Crystal structure analyses showed that the film annealed at 800°C was single crystal Zn₂SnO₄ with an inverse-spinel structure. The heteroepitaxial mechanism was further clarified by a schematic diagram, and the epitaxial relationships between the film and substrate were Zn₂SnO₄ (400) || MgO (200) with Zn₂SnO₄ [001] || MgO [001]. The obtained Zn₂SnO₄ films exhibited excellent transparency. The optical band gap of the 800°C-annealed Zn₂SnO₄ film was about 3.97 eV. The extinction coefficients and refractive indexes of the Zn₂SnO₄ films annealed at different temperatures as a function of wavelength were analyzed in detail.     

X60管线钢再结晶和过冷奥氏体连续冷却相变行为的研究

利用双道次压缩试验,在Gleeble-1500热模拟机上测定了X60管线钢的静态再结晶曲线.利用膨胀法,结合金相法,测定了X60不同冷却速度下连续冷却转变的膨胀曲线,获得了该钢的连续冷却转变曲线(动态CCT曲线);研究了X60管线钢的连续冷却过程中奥氏体转变过程及转变产物的组织;另外,通过对再结晶和CCT曲线的分析,为现场的控轧控冷工艺的制定提供了参考依据.     

甲醇－水溶液中反丁烯二酸二甲酯结晶介稳区宽度的测定

甲醇－水溶液中反丁烯二酸二甲酯结晶介稳区宽度的测定王留成，宋成盈，徐海升，栾亚非，于蕾，宁东刚（郑州工学院化学工程系）关键词反丁烯二酸二甲酯；结晶；介稳区宽度１前言反丁烯二酸二甲酯的合成是在甲醇过量的条件下完成的［１］，反应终了，溶液中含有甲醇、生成...     

基于景观要素的建筑设计——以采煤塌陷区建筑设计为例

建筑与人、建筑与城市、建筑与自然这三种关系一直是建筑设计的核心内容。在建筑设计过程中,建筑与自然之间关系的探讨需要通过"场地分析"完成,而其中的"自然环境"往往会影响设计成果。在很多特殊区域,设计需要借助对地质、地貌、水文、植被等景观要素的分析完成。采煤塌陷区是工业化进程中人类活动与自然环境矛盾冲突的产物,作为研究对象,可以较好地演示基于景观要素的建筑设计策略与方法,基地自身的"缺陷"可能会成为建筑空间组织的原点:建筑概念、结构、形态、空间组织均来自景观要素。     

钢渣水洗球磨污水的循环利用

重点介绍了钢渣水洗球污水处理的工艺过程。通过对主要设备选型的分析计算,、得到了选型最优参数、达到了污水处理的最佳效果,杜绝了污水外排、节约水资源。     

振动设备中振动轴转子系统及其振动传动研究

建立振动轴-转子系统振动微分方程,分析讨论系统中轴与转子的耦合效应。研究系统转子的稳定运动状态与各个运动参数的关系,阐明振动轴-转子系统的振动耦合,从理论上分析了转子的振动旋转与"失步"现象。结合理论分析与数值计算结果,为相关设备的设计提供理论依据。