共查询到20条相似文献,搜索用时 656 毫秒
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现在,美国和俄罗斯的航天器之间的空间交会对接已经不算什么新鲜事了。为了建造国际空间站,1994~1998年,美国航天飞机曾9次与俄罗斯“和平”号空间站对接飞行,送美国航天员到“和平”号上工作,以取得航天飞机与空间站交会对接经验以及美国航天员在空间站上长期生活和工作能力,降低建造国际空间站的技术风险。 相似文献
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对于卫星型号的质量与可靠性而言,元器件结构分析技术至关重要,是促进元器件国产化的重要技术手段之一,是新型元器件型号应用的验证技术之一,对元器件研制方及使用方均有较大作用。元器件结构分析技术能够帮助使用方进行元器件比较、低等级元器件的升级筛选、空间环境适用性评估及可靠性与风险评估,能够帮助元器件制造方进行工艺结构改进等。元器件结构分析技术的关键环节为方案制定和方案实施,结构分析需逐层分解至结构最小单元,最后得出是否适合卫星型号应用的结论并提出合理化建议。 相似文献
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这一年国际空间站的组装工作比较少,主要进行了美国吊臂的安装。1999年5月27日,发现号航天飞机发射升空,为国际空间站运送人员和补给。 相似文献
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俄十年内需在国际空间站项目上投资62亿美元据俄罗斯航天局局长科普捷夫最近称,俄今后10年花在国际空间站俄罗斯部分的建设与维护上的费用将达62亿美元,其中建设工作将花去30亿美元,其余将用于维护工作。尽管俄近期在首批国际空间站组件的资金筹集上遇到了一些... 相似文献
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In this paper, we analyze the illumination conditions, the thermal regime, and the possibility of deposits of volatile compounds existing in the vicinity region (NSR S5 region) near the southern pole of the Moon. It has been found that there are no permanently shadowed zones near the Scott crater and the NSR S5 region, though the temperature conditions allow the of compounds such as CH3OH, SO2, NH3, CO2, H2S, C2H4, and water to remain stable relative to evaporation for a long time (≥1 Gyr). It has been also shown that compounds like CO and CH4 cannot stably exist in these regions. 相似文献
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A string moving with geostationary angular velocity in its radial relative equilibrium configuration around the Earth, reaching from the surface of the Earth far beyond the geostationary height, could be used as track for an Earth to space elevator. This is an old dream of mankind, originating about 100 years ago in Russia. Besides the question of feasibility from a technological point of view also the question concerning the stability of such a configuration has not yet been completely solved. Under the assumption that a proper material (carbon nanotubes) is available, making the connection possible technologically, we address the question of existence and stability of the radial relative equilibrium of a tapered string on a circular geosynchronous trajectory around the Earth, reaching from the surface of the Earth far beyond the geostationary height. 相似文献
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本文介绍了“三位一体”教育模式的内容,描述亍我们实施该模式所采取的措施及取得的成效。实践表明,“三位一体”教育模式能够提高学生的综合素质,为学生毕业后的发展打下坚实基础,对教育模式的改革具有一定的指导意义。 相似文献
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H Jijiwa N Watanabe T Hattori F Matuda M Hashiba Y Mizuno M Shindo S Watanabe 《Acta Astronautica》2001,49(3-10):365-369
Whether the endolymph of the semicircular canal passes the cupular partition or not was examined using the lateral semicircular canal system of adult pigeons (Columba livia). By applying various pressures by means of injection of a dye solution through the membranous canal, it was found that the dye solution, was seen to pass the cupula even under very low pressures when the pressure was increased gradually. When pulled by a magnet, the ultrafine particles of the dextran magnetite contained in the injected fluid were found to pass through the subcupular space without evident increase of the ampullary pressure. 相似文献
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李曙光 《北华航天工业学院学报》2005,15(1):35-37
本文以独特的视角,分析了高校学生欠费造成的危害及形成的原因,提出了解决该问题的若干对策,对指导高校学生欠费清理工作有一定参考价值. 相似文献
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对高校学生欠费问题的思考 总被引:2,自引:0,他引:2
李曙光 《华北航天工业学院学报》2005,15(1):35-37
本文以独特的视角,分析了高校学生欠费造成的危害及形成的原因,提出了解决该问题的若干对策,对指导高校学生欠费清理工作有一定参考价值。 相似文献
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电阻式传感器的核心部件——电阻应变计是目前最常用的应力分析的敏感元件。也常用于测量力、压力、扭矩和加速度等物理量。作者简要回顾了电阻应变计的发展历史,介绍了电阻应变计的结构、分类及现状,展望了电阻式传感器的前景。 相似文献
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混沌码用作测控扩频码的可行性研究 总被引:2,自引:0,他引:2
阐述了混沌码的基本特性,提出用混沌码作为测控扩频码的构想,并讨论了混沌码扩频测控体系构成,以及体系中的关键技术,从而论证混沌码扩频测控体制的可行性,研究表明混沌码比传统扩频码有更强的保密和抗多址干扰特性。 相似文献
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实施"三位一体"教育模式提高学生的综合素质 总被引:1,自引:0,他引:1
本文介绍了“三位一体”教育模式的内容,描述亍我们实施该模式所采取的措施及取得的成效。实践表明,“三位一体”教育模式能够提高学生的综合素质,为学生毕业后的发展打下坚实基础,对教育模式的改革具有一定的指导意义。 相似文献
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The results of an investigation of the distribution of plasma pressure, pressure gradients, and magnetic field near the equatorial plane in the plasma ring surrounding the Earth under magneto-quiet conditions are presented. Observational data obtained during the international THEMIS mission are used. The picture of the distribution of transverse-current density near the equatorial plane was obtained under assumption of observing the magnetostatic balance condition at geocentric distances from 6 to 12R E. In estimating the integral transverse current it was accepted that in daytime sector the magnetic-field minima on magnetic field lines are not localized in the equatorial plane. Estimates of the integral transverse current were obtained, which demonstrate the possibility of closing nighttime transverse currents at geocentric distances of up to ~12R E inside the magnetosphere, which form a high-latitudinal continuation of the ring current. 相似文献