全文获取类型
收费全文 | 85篇 |
免费 | 7篇 |
国内免费 | 5篇 |
专业分类
航空 | 10篇 |
航天技术 | 54篇 |
综合类 | 4篇 |
航天 | 29篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 13篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有97条查询结果,搜索用时 15 毫秒
61.
62.
63.
邓克绪 《南京航空航天大学学报》1990,(1)
本文在文[2]、[4]的基础上,研究了最优交会轨道,导出了在推力作用下最优交会轨道的解析表达式;并对最优交会轨道和最优控制规律作了数值计算,求得了最优解。结果表明,对于目标航天器绕圆形轨道运行的情况,要求最优空间交会轨道和最省燃料的控制规律,此法有较好的实用价值。 相似文献
64.
Resonance transitions associated to weak capture in the restricted three-body problem 总被引:1,自引:1,他引:0
Edward Belbruno Francesco Topputo Marian Gidea 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,42(8):1330-1351
An interesting dynamics is studied in the restricted three-body problem where a particle abruptly transitions between resonance states, called a resonance hop. It occurs in a region about the secondary mass point which supports weak capture. This region, called a weak stability boundary, was recently proven to give rise to chaotic dynamics. Although it was numerically known that the resonance hop was associated with this boundary, this process was not well understood. In addition, the dynamical structure of the weak stability boundary has not been well understood. In this paper, we give a way to reveal the global structure of the weak stability boundary associated to resonance motions. This structure is shown to be surprisingly rich in resonant periodic motions interconnected by invariant manifolds. In this case, nearly all the motions are approximately resonant in nature where resonance hops can occur. The correlation dimension of orbits undergoing resonant motions, associated to the weak stability boundary, is also examined. The dynamics analyzed in the present paper is related to that studied by J. Marsden et al. under the perspective of Lyapunov orbits and the associated invariant manifolds. Applications are discussed. 相似文献
65.
"闪晕"的电场结构和光辐射的时变模拟 总被引:1,自引:0,他引:1
用时变的2-D准静电场模型,研究了由雷暴放电产生的静电场在中间层-低电离层的空间结构、时延、持续时间、向下传播的速度以及静电场引起的大气电离和光辐射.研究表明,由静电场引起的氮分子第一个正波段光辐射的时空特征与观测到的“闪晕”时空特征基本一致. 相似文献
66.
共面圆轨道航天器在轨服务任务规划 总被引:1,自引:0,他引:1
为了降低"一对多"在轨服务的成本,以共面圆轨道卫星群为研究对象,开展了在轨服务任务规划问题的研究。首先,对"一对多"在轨服务任务场景进行了分析,建立了任务规划数学模型,将其简化为包含内层Lambert问题、外层最优时间分配问题的双层优化模型。然后,给出了任务规划求解方法及流程,提出采用工程图解法的思想求解内层多圈Lambert问题,采用遗传算法求解外层最优时间分配问题。最后,以三个目标航天器为例,针对限制和不限制在轨服务任务完成总时间这两种情况,采用上述方法进行求解,计算结果验证了方法的有效性。 相似文献
67.
本文研究了艳后星(216 Kleopatra)和爱神星(433 Eros)附近的周期轨道,在考虑太阳引力摄动的情况下,发现了以往所遗漏的216 Kleopatra轨道族和环绕433 Eros的12族周期轨道,并且给出了它们的特性。研究结果表明,太阳引力对小行星平衡点位置的影响很小,但是对平衡点上航天器运动的影响较大。同族不稳定轨道中,大Jacobi常数轨道更容易在摄动后保持轨道原来特性,这很好地解释了小行星卫星在较远轨道上长期存在的可能性。 相似文献
68.
J.P.S. Carvalho A. Elipe R. Vilhena de Moraes A.F.B.A. Prado 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The dynamics of orbits around planetary satellites, taking into account the gravitational attraction of a third-body and the non-uniform distribution of mass of the planetary satellite, is studied. The Hamiltonian considered is explicitly time-dependent. Conditions for frozen orbits are presented. Low-altitude, near-polar orbits, very desirable for scientific missions to study planetary satellites such as the Jupiter’s moon Europa, are analyzed. Lifetimes for these orbits are computed through the single and double averaged method. Comparison between the results obtained by the single and double averaged method is presented. The single-averaged model is more realistic, since it does not eliminate the term due to the equatorial ellipticity of the planetary satellite as done by the double-averaged problem. Considering the single-averaged method, we found unstable frozen orbits where the satellite does not impact with the surface of Europa for at least 200 days. We present an approach using the unaveraged disturbing potential to analyze the effects of these terms in the amplitude of the eccentricity. 相似文献
69.
为了研究波纹箔片和轴承壳之间的摩擦特性对转子-箔片轴承系统动力学特性的影响,设计了波箔型径向气体箔片轴承-转子试验台,通过在该试验台上对以两组不同轴承壳圆柱孔内表面粗糙度的箔片轴承支承的质量为0.458kg的转子进行转速为0~8000r/min的运行试验,对比分析了波纹箔片与轴承壳内壁之间的摩擦效应对系统转子动力学特性的影响.结果表明:直径为19.98mm的波箔型径向气体箔片轴承能够实现转子高速运行,在转子起飞后具有良好的运行稳定性,其轴承支承处的振动幅值一直维持在20μm附近,并且降低轴承壳内表面粗糙度(摩擦因数)能够让波纹箔片相对容易地在平箔片和轴承壳之间周向滑移,使其吸收并消除转子高频振动,提高转子系统运行稳定性. 相似文献
70.
Enrico Mai Robin Geyer 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
This article outlines necessary steps to perform numerical orbit integrations based on a Lie series approach. Its implementation requires an efficient evaluation of resulting series coefficients. As an example we treat the classical main problem in satellite orbit calculation (J2 only) and the case of a 4×4-gravity field. All calculations were performed in very high precision with up to 100 significant digits. In comparison to independent third party computations this approach led to superior results referring to the verifiable constancy of various integrals of motion. To achieve a performance similar to classical numerical integrations in terms of acceptable computing time, at least for non-Keplerian motion problems, we exploited parallel computing capabilities. For our examples, run times were improved by several orders of magnitude, depending on the actual chosen precision level (up to a factor of 50,000 in case of double precision). Here we present the mathematical framework of the proposed orbital integration scheme as well as the work flow for its application in a multi-core, parallel computing environment. 相似文献