高温结构陶瓷精密磨削塑性变质层的物理模型

用透射电镜观察发现了磨削表面微晶和非晶层的过渡行为。采用物相分析和Ｘ射线衍射谱线分析证实了变质层中微晶的存在,通过能谱分析确定了非晶层的化学成分,应用硅酸盐物理化学中的相平衡理论,在对玻璃相结构进行量化分析的基础上,研究证实了Ａｌ２Ｏ３陶瓷表面变质层是由微晶和玻璃态化合物组成的塑性变质层。在此基础上,建立了陶瓷镜面磨削塑性变质层的物理模型,并用微刃切削理论解释了表面晶粒的碎化机理。     

India’s emerging space assets and nuclear-weapons capabilities

ABSTRACT

Over the last five decades, India’s nuclear and space programs have gone through several phases, from collaboration to divorce to supportive. An interplay of two factors determined the nature of the relationship. One was the state of India’s nuclear-weapon program. The second was international conditions, especially India’s relationship with the nuclear-nonproliferation regime. In the early decades, because of the rudimentary nature of India’s nuclear and space programs, the relationship was collaborative, since the rocket technology being developed was a necessary adjunct to the nuclear-weapon program. Subsequently, as India’s rocketry capabilities and nuclear-weapon program began to mature and concerns about international sanctions under the non-proliferation regime began to grow, the two programs were separated. The Indian rocketry program was also divided, with the civilian-space and ballistic-missile programs clearly demarcated. After India declared itself a nuclear-weapon state in 1998 and the programs matured, the relationship has become more supportive. As the two programs mature further, this relationship is likely to deepen, as the nuclear-weapon program requires space assets to build a robust and survivable nuclear deterrent force.     

CSCW 协作支持平台 GZ-PCCS 的研究与设计

如何提供有效的协作机制是设计CSCW系统的关键技术。本文首次将CSCW的概念引入公安指挥中心系统的设计之中,全面介绍了一个基于CSCW的公安指挥中心系统的协作支持平台的设计和实现。在平台设计中,提出了一个层次的基于任务的快作支持方案,讨论了各种具体的协作支持方法,并在”集中一分布”混合式的体系结构的基础上实现了一个公安指挥中心系统的协作支持平台的原型GZ—PCCS。