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排序方式: 共有405条查询结果,搜索用时 906 毫秒
371.
月球探测器软着陆机构发展综述 总被引:15,自引:3,他引:12
综述了月球探测器软着陆机构的发展概况;分析了国际上月球探测器软着陆机构的结构组成、工作原理及特点。对不同展开机构和缓冲器特点进行了分析,预测了月球探测器软着陆机构的发展趋势。 相似文献
372.
环月卫星成像敏感器对月姿态确定算法 总被引:3,自引:0,他引:3
紫外月球敏感器是大视场成像式敏感器,针对姿态确定算法,以MOSAIC可见光成像敏感器为例分析了传统圆拟合模式的适用性与不足;推证出在低轨道情况下曲线拟合出的月像几何中心与真实月心(nadir)不能等同;依据成像几何分析通过泰勒展开公式推导并提出了新的姿态角运算方法,保证了低轨道姿态运算精度;仿真结果显示新算法的姿态运算是非常有效的。 相似文献
373.
T. Hashimoto T. HoshinoS. Tanaka H. OtakeM. Otsuki S. WakabayashiH. Morimoto K. Masuda 《Acta Astronautica》2014
The Japan Aerospace Exploration Agency (JAXA) views the lunar lander SELENE-2 as the successor to the SELENE mission. In this presentation, the mission objectives of SELENE-2 are shown together with the present design status of the spacecraft. JAXA launched the Kaguya (SELENE) lunar orbiter in September 2007, and the spacecraft observed the Moon and a couple of small satellites using 15 instruments. As the next step in lunar exploration, the lunar lander SELENE-2 is being considered. SELENE-2 will land on the lunar surface and perform in-situ scientific observations, environmental investigations, and research for future lunar utilization including human activity. At the same time, it will demonstrate key technologies for lunar and planetary exploration such as precise and safe landing, surface mobility, and overnight survival. The lander will carry laser altimeters, image sensors, and landing radars for precise and safe landing. Landing legs and a precisely controlled propulsion system will also be developed. A rover is being designed to be able to travel over a wide area and observe featured terrain using scientific instruments. Since some of the instruments require long-term observation on the lunar surface, technology for night survival over more than 2 weeks needs to be considered. The SELENE-2 technologies are expected to be one of the stepping stones towards future Japanese human activities on the moon and to expand the possibilities for deep space science. 相似文献
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为提高月球着陆器着陆可靠性,需识别潜在的故障模式对稳定性着陆带来的影响。建立了着陆器的动力学模型,给出了着陆器着陆时的七种极限工况,作为故障模式分析的基础;针对动力下降段三种典型故障模式,即主发动机延时关机、储箱残留液体着陆和触月信号延迟发出,建立与延时关机对应的上抛、平抛运动和数学关系,与残留液体着陆等效的单摆模型,施加触月信号延迟发出所产生的推力曲线,利用Adams软件进行动力学仿真;结果表明储箱残留液体着陆影响较小,另外两种故障模式使着陆时抗倾倒性能和缓冲性能恶化,增加着陆不稳定性。 相似文献
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Jonathan G. Metts 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012,49(1):204-212
Thermal control of a space suit during extravehicular activity (EVA) is typically accomplished by sublimating water to provide system cooling. Spacecraft, on the other hand, primarily rely on radiators to dissipate heat. Integrating a radiator into a space suit has been proposed as an alternative design that does not require mass consumption for heat transfer. While providing cooling without water loss offers potential benefits for EVA application, it is not currently practical to rely on a directional, fixed-emissivity radiator to maintain thermal equilibrium of a spacesuit where the radiator orientation, environmental temperature, and crew member metabolic heat load fluctuate unpredictably. One approach that might make this feasible, however, is the use of electrochromic devices that are capable of infrared emissivity modulation and can be actively controlled across the entire suit surface to regulate net heat flux for the system. Integrating these devices onto the irregular, compliant space suit material requires that they be fabricated on a flexible substrate, such as Kapton film. An initial assessment of whether or not this candidate technology presents a feasible design option was conducted by first characterizing the mass of water loss from sublimation that could theoretically be saved if an electrochromic suit radiator was employed for thermal control. This is particularly important for lunar surface exploration, where the expense of transporting water from Earth is excessive, but the technology is potentially beneficial for other space missions as well. In order to define a baseline for this analysis by comparison to actual data, historical documents from the Apollo missions were mined for comprehensive, detailed metabolic data from each lunar surface outing, and related data from NASA’s more recent “Advanced Lunar Walkback” tests were also analyzed. This metabolic database was then used to validate estimates for sublimator water consumption during surface EVAs, and solar elevation angles were added to predict the performance of an electrochromic space suit radiator under Apollo conditions. Then, using these actual data sets, the hypothetical water mass savings that would be expected had this technology been employed were calculated. The results indicate that electrochromic suit radiators would have reduced sublimator water consumption by 69.0% across the entire Apollo program, for a total mass savings of 68.5 kg to the lunar surface. Further analysis is needed to determine the net impact as a function of the complete system, taking into account both suit components and consumable mass, but the water mass reduction found in this study suggests a favorable system trade is likely. 相似文献
379.
模拟月尘对巡视器车轮轮轴材料的磨损试验研究 总被引:2,自引:2,他引:0
文章以CE-3巡视器车轮轮轴为研究对象,利用北京卫星环境工程研究所的月尘环境模拟器、摩擦磨损试验机以及自行研制的模拟月尘,对车轮轮轴主要材料进行了磨损试验研究。试验样品为轮轴常用的铝合金、聚四氟乙烯及轴承钢。文章分析了试验前后样品的表面形貌,采用测试系统获得了轮轴材料在不同试验条件下的摩擦系数曲线,采用电子天平测量了材料的质量损失;分析了真空、大气、有无月尘等试验条件以及材料本身在磨损试验中的效应。研究结果可为月面巡视器等月面应用设备的研制提供可借鉴的信息。 相似文献
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