通信卫星平台—来自东方的竞争

最近正在出现一些东方国家对通信卫星市场构成的威胁。尽管这些来自东方的竞争者无法与美国的休斯、洛·马、洛拉尔公司及欧洲的法国宇航公司和马特拉·马可尼公司相提并论，但它们的存在仍不容忽视。此前在其他领域低估日本、韩国和中国台湾实力的教训比比皆是。当前，亚太地区是通信卫星市场蓬勃发展的主要动力，西方主要卫星制造商在这一市场上的占有率不断提高，其主要原因是这些亚太国家不能自给自足。不过这一情况现已发生变化，预计在下个世纪初，这些刚刚在亚太市场立足的西方卫星制造商会发现他们的订单将逐渐被来自远东的竞争者夺…     

Human characteristics of pair assembly work in a microgravity environment

This research focuses on analyzing the human characteristics of pair assembly work in a microgravity environment. To obtain the necessary data, two groups of test subjects participated in an experiment in a pseudomicrogravity environment, and how such factors as work allotment, sizes of assembled objects, and conditions of parts influence the work efficiency were studied. The results show when the assembled object is smaller that it is easier to change the object's position and that workers can move it to an appropriate site and work easily. If the assembly object is attached to an object with very large mass, the work allotment does not result in a difference in work time. As for positioning the objects, step-saving processes can shorten the work time. For instance, if a part can be put so that both ends automatically touch the proper spots, time can be shortened.     

再入飞行器迎风面边界层转捩的数值预估

基于求解三维Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程,首先数值预估了高超声速三维流动的边界层特性;采用已有的高超声速三维边界层转捩准则,即在转捩位置Ｒｅθ／Ｍｅ＝常数,以及通过修正由ＯＮＥＲＡ提出的代数转捩模型,建立了预估三维边界层转捩的半经验数值技术并应用于三维Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程的求解。利用ＨＡＬＩＳ模型及相关的实验数据,首次进行了在Ｍ∞＝６时不同雷诺数及迎角的验证试验。预估结果表明：在不考虑     

面向制造物联环境下带有批量流的柔性流水车间调度问题研究

如何通过新一代信息技术进一步提升制造企业的生产效率是需要迫切解决的问题.结合当前物联网技术在制造业的发展趋势,以电容器制造车间为研究对象,首先搭建面向制造物联环境下的柔性流水车间调度系统多层次体系架构;在此架构下,建立多源制造信息驱动制造执行过程的基于批量流策略的调度优化模型;其次,设计了一种改进的分布估计算法,通过平...     

双轴载荷下孔边疲劳裂纹的扩展

 在AISI316奥氏体不锈钢制成的十字形带中心孔（圆孔和椭圆孔）试件上进行的双轴载荷疲劳裂纹扩展试验表明:应力双轴性对疲劳裂纹扩展的影响,仅发生在靠近开孔的局部区域内。等双轴应力较单轴应力状态下的裂纹扩展速率减慢,而纯剪切状态下的裂纹扩展速率加快。在孔的影响区之外,所有的结果服从Paris规律,与应力双轴性无关。     

In vitro edible muscle protein production system (MPPS): stage 1, fish

The working efficiency and state-of-mind of a Space vehicle crew on long-term missions is dependent on the suitability of living conditions including food. Our purpose was to establish the feasibility of an in vitro muscle protein production system (MPPS) for the fabrication of surrogate muscle protein constructs as food products for Space travelers. In the experimental treatments, we cultivated the adult dorsal abdominal skeletal muscle mass of Carassius (Gold fish). An ATCC fish fibroblast cell line was used for tissue engineering investigations. No antibiotics were used during any phase of the research. Our four treatments produced these results: a low contamination rate, self-healing, cell proliferation, a tissue engineered construct of non-homologous co-cultured cells with explants, an increase in tissue size in homologous co-cultures of explants with crude cell mixtures, maintenance of explants in media containing fetal bovine serum substitutes, and harvested explants which resembled fresh fish filets.

We feel that not only have we pointed the way to an innovative, viable means of supplying safe, healthy, nutritious food to Space voyagers on long journeys, but our research also points the way to means of alleviating food supply and safety problems in both the public and private sectors worldwide.