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分布式虚拟环境资源管理系统的设计与实现 总被引:1,自引:1,他引:0
随着网络技术的发展,AFS(Anderw File System)成为网络资源定位和网络管理的有效实现技术。在大规模分布式虚拟环境中存在大量的仿真模型和动态数据,如何对他们进行有效的管理是构建分布式虚拟环境的关键技术之一。在LDAP(Light Directory Access Protocol,轻量目录访问协议)目录服务技术的基础上,使用AFS文件系统实现面向分布式虚拟环境的数据管理系统。首先分析其体系结构,然后介绍系统如何实现仿真模型及动态数据的统一命名、定位、安全操作和数据一致性。 相似文献
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十字轴径向挤压可分凹模设计 总被引:2,自引:0,他引:2
<正> 1 前言 图1为常用十字轴的结构。十字轴属典型的枝芽类锻件。采用以径向挤压力变形特征的闭式模锻同目前仍普遍采用的开式模锻和胎模锻相比,以EQ140十字轴(图1a)和EQ240(图1c)为例,分别可以节约钢材 相似文献
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粘性介质压力成形研究进展(上) 总被引:6,自引:0,他引:6
随着技术的发展,采用高强度难变形材料超薄板制成的板金零件越来越多,而且成形件的三维型面日趋复杂,对这些零件的尺寸精度及表面质量,尤其是厚度均匀性的要求越来越高,这就对成形技术提出更高的要求。而通常的软模成形技术以及常规冲压由于各自的特点构成了相应的适用范围,仍存在许多不足。而粘性介质压力成形(Viscous Pressure Forming,VPF)工艺由于采用粘性物质作为成形过程传力介质,具有独特的优点因而具有广阔的应用前景。 相似文献
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从有利于网络发展和充分利用现网资源的角度出发,通过对WiFi、WiMAX、2.5G/3G/4G等技术进行分析,认为无线城市应该采用WiFi和3G/4G混合组网,以3G/4G移动网络为主实现广域覆盖,以WiFi网络对流量较高的热点区域进行辅助覆盖。 相似文献
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The finite element analysis (FEA) software Ansys was employed to study the stress state of the dies of both plane and non-plane
parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference.
Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was
constructed. Four paths were defined to investigate the stress state at the bottom corner of the die where stress concentration
was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the
teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing
factor for the stress concentration at the bottom corner. When non-uniform interference is adopted the first principal stress
at the corner on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is
another important influencing factor for the corner stress concentration. The first principal stress at the corner of the
plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5
to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.
Foundation item: Project(2006BAF04B06) supported by the National Key Technology R & D Program of China; Project(2005AA101B19) supported by
the Key Technology R & D Program of Hubei Province, China 相似文献