如何快速掌握Auto CAD绘图软件

介绍了AutoCAD绘图软件最基本的使用方法.     

基于多属性决策的空间DTN网络路由算法研究

空间信息网絡是未来信息网络的重要发展方向,低轨卫星DTN网络是空间信息网络的重要组成部分,由于低轨卫星网络存在时延大、中断频繁、拓扑结构变化剧烈等特点,因此路由问题成为了制约该型网络发展的瓶颈。为推进路由问题的解决,提出了一种基于多属性决策理论的路由算法,利用卫星网络链路带宽、链路建立时延、节点剩余存储空间、节点数据转发率四个重要指标作为路由选择依据,通过计算各属性比例关系决定数据转发路径,从而实现DTN网络路由,同时,通过调整属性偏好,可以针对不同网络业务实现网络路径的优化,从而适应空间信息网路的多业务需求。仿真实验结果表明:该算法与Epidemic、PROPHET路由算法比较,在数据传输成功率、网络平均时延方面均有改进。     

BN-S刀片在切削高合金铸铁上的应用

随着工程材料的不断发展，一些行业产品所使用的材料向高硬度、高耐磨性和高耐腐蚀性发展。这类材料的使用，给切削加工造成很大的难度。文中介绍了一种在立方氮化硼复合刀片BN-A的基础上研制的立方氮化硼整体烧结型刀片BN-S，该刀片在切削高铬白口铸铁、硬镍铸铁、硼铸铁、冷硬铸铁、耐磨钢等高硬材料的生产实践中取得突破性进展，生产效率大幅提高。     

电阻应变式载荷传感器加工工艺中几个问题的探讨

本文报道了对电阻应变式拉压力传感器设计及加工工艺中关于弹性体尺寸误差对灵敏度的影响.电阻应变片粘贴在弹性体上后固化温度、固化时间,电阻应变片贴片固定工艺等进行探讨.     

Hydrogen cold plasma for synthesizing Pd/C catalysts: the effect of support-metal ion interaction

It has been found that cold plasma is a facile and environmentally benign method for synthesizing supported metal catalysts, and great efforts have been devoted to enlarging its applications. However, little work has been done to disclose the influence mechanism, which is significant for controllable synthesis. In this work, hydrogen cold plasma was adopted to synthesize a palladium catalyst supported on activated carbon(Pd/C-P) using H_2 PdCl_4 as a Pd precursor followed by calcination in hydrogen gas to remove the chlorine ions. The Pd/C-P catalyst was found to be made of larger Pd nanoparticles showing a decreased migration to the support outer surface than that prepared by the conventional thermal hydrogen reduction method(Pd/C-C). Meanwhile, the pore diameter of the activated carbon support is small(~4 nm).Therefore, Pd/C-P exhibits lower CO oxidation activity than Pd/C-C. It was proposed that the strong interaction between the activated carbon and PdCl_4~(2-)and the enhanced metal–support interaction caused by hydrogen cold plasma reduction made it difficult for Pd nanoparticles to migrate to the support outer surface. The larger-sized Pd nanoparticles for Pd/C-P may be due to the Coulomb interaction resulting in the disturbance of the metal–support interaction. This work has important guiding significance for the controllable synthesis of supported metal catalysts by hydrogen cold plasma.     

世界贸易格局出现新的变化

多边贸易谈判的时代已经结束了 随着世界贸易组织（WTO）多边框架下的谈判在过去的十多年停滞不前，世界主要经济体已展开新的贸易框架谈判。     

高速铁路岩溶地区钻孔桩溶洞处理措施研究

笔者结合武广客运专线老屋杨特大桥桩基的施工实践,深入研究岩溶地区钻孔桩施工技术,总结适合 客运专线的最优方案.     

中国共产党成立90周年暨人民兵工创建80周年·系列之九 大江南北 热血铸英魂 新四军军事工业(四)

本文第一、二、三部分介绍了新四军皖南军部及所属部队修械所、盐城军部军工部、新四军第1、2、3、4、5师军工部及第6师军实科的生产情况,第四部分将展示新四军第7师军工部、浙东纵队军工股的生产情况以及黄花塘会议后军工生产的大发展——