排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
Heilbronn L Frankel K Holabird K Zeitlin C McMahan MA Rathbun W Cronqvist M Gong W Madey R Htun M Elaasar M Anderson BD Baldwin AR Jiang J Keane D Scott A Shao Y Watson JW Zhang WM Galonsky A Ronningen R Zecher P Kruse J Wang J Cary R 《Acta Astronautica》1998,42(1-8):363-373
In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding of how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thicktarget neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations. 相似文献
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RUAG公司用HBM测量系统进行飞机全尺寸疲劳试验瑞士RUAG公司的研究人员对瑞士版F/A-18战斗机的加强结构进行了大规模的综合试验研究,以验证飞机结构是否能满足较高的要求,达到所需的5000个飞行小时的工作寿命。 相似文献
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北京航天测控技术开发公司 《航空制造技术》2010,(13)
<正>随着技术的发展,高技术产品和装备性能越来越先进、结构越来越复杂、产品维护维修技术水平要求逐渐增高,传统的产品维护手段和装备保障观念已经不能适应新的发展形势的需要,保障信息化技术已成为未来产品维护和装备保障的必然趋势。 相似文献
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GE能源集团检测控制技术 《航空制造技术》2011,(6):102-103
GE检测控制技术业务是一个行业领先创新者,业务涉及传感测量,无损检测技术,状态监测,与自动化优化控制领域,帮客户实现精确、高效和安全.旗下产品广泛应用于航空航天、石油天然气、电力、运输、医疗等行业. 相似文献
5.
2011年5月12日,GE检测控制技术宣布最新推出的新型phoenix x|aminer是一个微焦点X射线检测系统,有5个轴,主要用于电子元件分装的质量控制,并适用于焊点的可靠精确检测。 相似文献
6.
<正>未来几年内即将投入市场运营的新飞机、快速发展的客舱新技术,以及乘客对乘机舒适度和个性化要求的提升将极大地推动航空运输业对商用飞机客舱内饰升级改装的投资热潮。据波音2014年的商用飞机市场展望报告预测,未来20年全球将需要36770架新飞机。其中,42%的新交付飞机(即15500架)将会替换目前正在运营的机龄较老、效率较低的飞机,另外的21270架新飞机将会成为全球机队增长的部分。在一大批新飞机即将涌入 相似文献
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8.
Abdul-Baki B. Baldwin J. Rudel M.-P. 《Aerospace and Electronic Systems Magazine, IEEE》2000,15(8):3-21
This paper describes the specification-based testing, analysis tools, and associated processes used to independently validate, verify, and ultimately, provide for certifying safety-critical software developed for the Traffic Alert and Collision Avoidance System (TCAS II) program. These tools and processes comprise an effective and Independent Validation and Verification (IV and V) activity applied to the Collision Avoidance Subsystem (GAS) software development process. A requirements specification language called the Requirements State Machine Language (RSML), originally developed by the University of California, Irvine (UCI), was employed for the specification of GAS. The end result is the next generation of TCAS II collision avoidance logic, referred to as Version 7, that is of a higher quality than its predecessors, meets the certification requirements of DO-178B Level B (Ref. 1), and can be shown to satisfy the new operational requirements it was developed to address 相似文献
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英国威勤测量系统有限公司 《航空制造技术》2008,(24)
球栅尺是一种新颖的位移动态传感器,它采用电感测量原理,具有抗干扰、抗振动、抗污染和可靠耐用等优点。目前,球栅尺在国际上已被推广应用于各种机械加工行业中。但它在中国的使用普及程度还并不高,究其原因,价格是其中非常大的因素。 相似文献
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英国Newall公司 《航空制造技术》2008,(17)
球栅传感器是英国Newall公司发明的世界专利产品. 其主要特点是: (1)球栅尺和读数头全密封,防水、防油、防尘、防铁屑、耐振动,高可靠. 相似文献