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991.
992.
舰载导弹海上值班是导弹使用的重要任务之一,其值班可靠性是影响导弹舰上使用能力的关键因素。针对舰载导弹值班任务下的故障数据特点,基于随机截尾数据分析方法,建立了舰载导弹值班可靠性评估模型,给出了其值班可靠性计算方法,最后通过示例数据,验证了所给方法的有效性。 相似文献
993.
Lin Lu Haiyang Li Wanmeng Zhou Jianghui Liu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(3):1143-1154
A near rectilinear halo orbit (NRHO) is regarded as a potential orbit for a future deep space station that can effectively support sustainable crewed lunar exploration missions. In this paper, the L2 southern NRHOs are selected as the research object, and a direct transfer trajectory from an NRHO to a low lunar orbit (LLO) is designed and analyzed. First, based on the circular restricted three-body problem, the characteristics of NRHOs are discussed including geometric behaviour, stability and synodic resonance. Second, optimal direct transfer trajectories are obtained by combining a local gradient optimization with a numerical continuation strategy. A reachable domain calculation model is established. Finally, simulations are carried out to verify the feasibility of the trajectory design method. The relationship between the velocity change and the reachable domain is further analysed through simulation calculations. 相似文献
994.
Jiang Dongsheng Bu Xueqin Sun Bing Lin Guiping Zhao Hongtao Cai Yan Fang Ling 《中国航空学报》2016,(4):863-873
The ceramic membrane oxygen generation technology has advantages of high concentra-tion of produced oxygen and potential nuclear and biochemical protection capability. The present paper studies the ceramic membrane technology for onboard oxygen generation. Comparisons are made to have knowledge of the effects of two kinds of ceramic membrane separation technologies on oxygen generation, namely electricity driven ceramic membrane separation oxygen generation technology (EDCMSOGT) and pressure driven ceramic membrane separation oxygen generation technology (PDCMSOGT). Experiments were conducted under different temperatures, pressures of feed air and produced oxygen flow rates. On the basis of these experiments, the flow rate of feed air, electric power provided, oxygen recovery rate and concentration of produced oxygen are compared under each working condition. It is concluded that the EDCMSOGT is the oxygen generation means more suitable for onboard conditions. 相似文献
995.
InSight Mars Lander Robotics Instrument Deployment System 总被引:1,自引:0,他引:1
A. Trebi-Ollennu Won Kim Khaled Ali Omair Khan Cristina Sorice Philip Bailey Jeffrey Umland Robert Bonitz Constance Ciarleglio Jennifer Knight Nicolas Haddad Kerry Klein Scott Nowak Daniel Klein Nicholas Onufer Kenneth Glazebrook Brad Kobeissi Enrique Baez Felix Sarkissian Menooa Badalian Hallie Abarca Robert G. Deen Jeng Yen Steven Myint Justin Maki Ali Pourangi Jonathan Grinblat Brian Bone Noah Warner Jaime Singer Joan Ervin Justin Lin 《Space Science Reviews》2018,214(5):93
The InSight Mars Lander is equipped with an Instrument Deployment System (IDS) and science payload with accompanying auxiliary peripherals mounted on the Lander. The InSight science payload includes a seismometer (SEIS) and Wind and Thermal Shield (WTS), heat flow probe (Heat Flow and Physical Properties Package, HP3) and a precision tracking system (RISE) to measure the size and state of the core, mantle and crust of Mars. The InSight flight system is a close copy of the Mars Phoenix Lander and comprises a Lander, cruise stage, heatshield and backshell. The IDS comprises an Instrument Deployment Arm (IDA), scoop, five finger “claw” grapple, motor controller, arm-mounted Instrument Deployment Camera (IDC), lander-mounted Instrument Context Camera (ICC), and control software. IDS is responsible for the first precision robotic instrument placement and release of SEIS and HP3 on a planetary surface that will enable scientists to perform the first comprehensive surface-based geophysical investigation of Mars’ interior structure. This paper describes the design and operations of the Instrument Deployment Systems (IDS), a critical subsystem of the InSight Mars Lander necessary to achieve the primary scientific goals of the mission including robotic arm geology and physical properties (soil mechanics) investigations at the Landing site. In addition, we present test results of flight IDS Verification and Validation activities including thermal characterization and InSight 2017 Assembly, Test, and Launch Operations (ATLO), Deployment Scenario Test at Lockheed Martin, Denver, where all the flight payloads were successfully deployed with a balloon gravity offload fixture to compensate for Mars to Earth gravity. 相似文献
996.
在美育教育教学过程中提高学生的美术意识,是培养具有创新意识和创新能力的新型美术人才的关键环节,在美育教育过程中,通过改善教学条件与教学手段,促进学生的创新意识以及利用现代科学技术等措施来提高学生的意识水平。 相似文献
997.
杨琳 《西安航空技术高等专科学校学报》2008,26(2):11-13
为了弥补在文学语言中的不足,形成了以象寓意的话语蕴藉现象。本文运用了列举、分析等方式诠释话语蕴藉与文学词语、文学修辞、标点符号及文章结构之间的联系,揭示出文学话语蕴藉带给读者的丰富想象和再创造的审美空间。 相似文献
998.
999.
六点炉温追踪仪(BYKO-TRACK)能准确、科学的测试各种不同结构烘房的温度曲线。本文介绍了该仪器在烘房的工艺设计、工件烘烤质量及涂料选材等方面的应用。 相似文献
1000.