铝合金高速微小孔钻削工艺

铝合金微小孔钻削加工及其工艺难点 铝合金是以铝为主的合金总称,通过添加铜、硅、镁、锌、锰以及镍、铁、钛、铬、锂等合金元素,在保持纯铝质轻等优点的同时,其"比强度"可胜过很多合金钢,成为理想的结构材料,广泛用于机械制造、运输机械、动力机械及航空工业等方面.飞机的机身、蒙皮、压气机等常用铝合金制造,以减轻自重.     

从IP组播数据中断故障谈网络地址设计

首先描述了在IP网络环境中出现的组播数据偶断现象,分析定位了故障出现的原因。然后,详细阐述了组播维护机理,从组播管理协议的运行机制上进一步分析了组播数据偶断的过程。最后,给出了通过网络地址重新设计的方法解决问题的方案,并提出了交换机、路由器-VLAN（虚拟局域网）-主机的网络地址按顺序进行由小到大地分级分配的原则。     

基于三维模型定义技术应用的思考

MBD技术是一个新生事物,涉及到系统性问题,它的应用实施是一项长期、复杂而又艰巨的工作。需要考虑的问题不仅涉及技术方面,还有文化、管理、组织和生产方式等方面,只有解决好这些问题,才能充分发挥MBD技术的巨大效力,更好地为我国大飞机研制服务。     

一种实现实时多任务操作机制的方法

介绍一种实现实时多任务操作机制的方法和两个实例，这种方法可以用于嵌入式系统中。     

国产着色渗透探伤剂主要性能的普查

本文对国产大部分着色渗透剂、清洗剂、显像剂的主要性能进行了测试，提出了存在的问题，供用户在使用过程中，对探伤剂的性能要求及监督引起重视。     

Mutations in cauliflower and sprout broccoli grown from seeds flown in space

Cauliflower and sprout broccoli are widely planted vegetables particularly in Fujian Province, China. To study the mutation in these two types of vegetables induced from spaceflight, we flew the seeds on the 20th Chinese recoverable satellite which orbited the Earth for 18 days. After returning to the Earth, the cauliflower seeds were planted for two generations and the sprout broccoli seeds for one generation at the Xiamen Agriculture Research Institute. Of the 12 cauliflowers planted for the first generation, two showed significant phenotypical changes in both the size of the plant and the weight of the flower head. In addition, most of the space flown plants were found to be resistant to the black rot attack in the field. Cauliflowers planted for the second generation from the seeds in one of the two plants that displayed phenotypical changes in the first generation showed similar mutations. For the first generation of sprout broccoli, the rate of emergence from the flown seeds was lower than that of the control by 30%. No significant changes in the phenotype between the sprout broccolis planted from the flown seeds and the control were observed except one of the mutated sprout broccolis showed a change in the appearance in the lesser bud of the chief flower head. Results of the study demonstrated that DNA damages in some of the genes may have occurred in the seeds flown in space, and some of the changes in the genes may have inherited from the first to the second generation. The improved resistance to the black rot attack and increased size of the flower head are apparently beneficial.     

机载光电稳定平台常用材料的应用

介绍了2种机载光电稳定平台本体常用制造材料,利用有限元的方法对平台本体的强度和变形情况进行了分析.给出了不同材料在平台本体制造中的应用场合.     

整体叶盘片光饰抛光试验及发展应用探析

介绍了整体叶盘叶片利用机械光饰机进行的抛光试验,根据叶片试验取得的数据,分析了该种加工方法所具有的特点,以及应用时应采取的一些措施,为该种方法的应用提供了一定的借鉴经验.     

Relationship Between Corrosion Level of Steel Bar and Diameter of Corroded Sensing Steel Wire in Wireless Sensor

A kind of wireless sensor was previously developed,which is powered and transmit signals wirelessly instead of using an electrical connection to the embedded reinforcement.Based on this technique,the relationship between diameters of corroded sensing steel wires and corrosion levels of steel bars is established by experiments.Quadratic function is utilized to fit the experiment results,and the correlation coefficients are all larger than 0.95.Estimated corrosion levels of commonly used steel bars are given for different diameters of corroded sensing steel wires fractured due to corrosion.