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561.
空间交会中激光搜索跟踪系统的研究   总被引:1,自引:1,他引:1  
空间交会是航天领域里非常复杂的飞行过程之一。本文提出了一种用激光搜索跟踪技术实现空间交会的方法,它具有雷达、导航和通信的功能,基于此方法建立追踪航天器和目标航天器的激光搜索跟踪系统模型,并进行计算机仿真,能够完成系统指标的计算,此外仿真软件还能够根据设定的场景进行动画演示。  相似文献   
562.
航天器多功能结构传热特性的实验研究   总被引:1,自引:0,他引:1  
刘双  张博明 《宇航学报》2010,31(6):1656-1660
针对航天器结构高性能、轻质化和集成化的发展要求,设计了集电路控制,热管理功能和结构承载功能于一体的多功能结构。此种结构分别采用柔性电路板控制热仿真多芯片模块,作为多功能结构的热源;碳碳材料作为热倍增器;复合材料蒙皮和金属泡沫芯子的夹层结构作为承载结构,实现了结构和功能的集成。同时,为了研究多功能结构的传热特性,进行了热真空实验,实验测量了热流密度和温度梯度。结果表明这种新型的结构可以消散飞行器多芯片模块产生的热量,碳碳热倍增提供了一种减小温度梯度的新方法,同时这种多功能结构减少了结构的体积,降低了结构的质量。  相似文献   
563.
首次提出了一种多波段组合的孤立噪声去除方法.文章在对图像进行中值滤波处理之前,先进行门限法的孤立噪声初步定位,设定孤立噪声为候选点;然后结合多波段图像数据对候选孤立噪声进行最终定位,只有当像元判断为真实的孤立噪声时,进行中值滤波处理;最后以中国一颗传输型卫星图像为例,检验了算法的有效性.  相似文献   
564.
结合深空探测项目研制任务研究遥控数据接收处理电路FPGA片上容错设计技术。在研究航天器遥控数据接收处理电路数据模型的基础上,提出遥控数据接收处理电路FPGA片上小粒度自主备份容错设计方法;应用此新方法进行遥控指令通道FPGA设计优化;针对FPGA缺陷成团性,进行遥控指令通道FPGA布局优化,最终设计出能够自主容错,容错能力更强,可以应对缺陷成团性影响的新一代遥控指令通道FPGA。这一FPGA的实现,验证了文中提出的新方法,也为未来深空探测项目、微小卫星等提供新的遥控产品。  相似文献   
565.
为确保空间飞行器在轨安全,有必要搭载探测器对轨道空间环境进行实时监测,获取表面充电效应数据。在对轨道空间充电环境分析的基础上,确定探测器的任务目标并完成基于电位探头和电流探头的探测器方案设计,包括探头设计和电路设计。探测器设计方案在空间环境特殊效应测量领域迈出的关键一步,为更多空间效应参数的测量奠定了坚实基础。  相似文献   
566.
Rendezvous and docking (RVD) with a tumbling target is challenging. In this paper, a novel control scheme based on motion planning and pose (position and attitude) tracking is proposed to solve the pose control of a chaser docking with a tumbling target in the phase of close range rendezvous. Firstly, the current desired motion of the chaser is planned according to the motion of the target. In planning the desired motion, the “approach path constraint” is considered to avoid collisions between the chaser and the target, and the “field-of-view constraint” is considered to make sure the vision sensors on the chaser to obtain tight relative pose knowledge of the target with respect to the chaser. Then, the difference between the chaser’s motion and the desired motion is gradually reduced by a pose tracking controller. This controller is based on the non-singular terminal sliding mode (NTSM) method to make the tracking error converge to zero in finite time. Since the chaser nearly moves along the desired motion and the motion is reasonable, (1) it could safely arrive at the docking port of the target with a suitable relative attitude, (2) it will be always suitably oriented to observe the target well, and (3) the magnitude of the needed control inputs are less than that in existing literatures. The numerical results demonstrate the above three advantages of the proposed method.  相似文献   
567.
The CubeSail mission is a low-cost demonstration of the UltraSail solar sailing concept (, ,  and ), using two near-identical CubeSat satellites to deploy a 260 m-long, 20 m2 reflecting film. The two satellites are launched as a unit, detumbled, and separated, with the film unwinding symmetrically from motorized reels. The conformity to the CubeSat specification allows for reduction in launch costs as a secondary payload and utilization of the University of Illinois-developed spacecraft bus. The CubeSail demonstration is the first in a series of increasingly-complex missions aimed at validating several spacecraft subsystems, including attitude determination and control, the separation release unit, reel-based film deployment, as well as the dynamical behavior of the sail and on-orbit solar propulsion. The presented work describes dynamical behavior and control methods used during three main phases of the mission. The three phases include initial detumbling and stabilization using magnetic torque actuators, gravity-gradient-based deployment of the film, and steady-state film deformations in low Earth orbit in the presence of external forces of solar radiation pressure, aerodynamic drag, and gravity-gradient.  相似文献   
568.
Alexander Bolonkin   《Acta Astronautica》2008,62(10-11):577-591
The author offers a revolutionary method—non-rocket transfer of energy and thrust into Space with a distance of millions of kilometers. The author has developed the theory and made the computations. The method is more efficient than transmission of energy by high-frequency waves. The method may be used for space launch and for accelerating the spaceship and probes for very high speeds, up to a relativistic speed by the current technology. The research also contains prospective projects which illustrate the possibilities of the suggested method.  相似文献   
569.
The pace of scientific exploration of our solar system provides ever-increasing insights into potentially habitable environments, and associated concerns for their contamination by Earth organisms. Biological and organic-chemical contamination has been extensively considered by the COSPAR Panel on Planetary Protection (PPP) and has resulted in the internationally recognized regulations to which spacefaring nations adhere, and which have been in place for 40 years. The only successful Mars lander missions with system-level “sterilization” were the Viking landers in the 1970s. Since then different cleanliness requirements have been applied to spacecraft based on their destination, mission type, and scientific objectives. The Planetary Protection Subcommittee of the NASA Advisory Council has noted that a strategic Research & Technology Development (R&TD) roadmap would be very beneficial to encourage the timely availability of effective tools and methodologies to implement planetary protection requirements. New research avenues in planetary protection for ambitious future exploration missions can best be served by developing an over-arching program that integrates capability-driven developments with mission-driven implementation efforts. This paper analyzes the current status concerning microbial reduction and cleaning methods, recontamination control and bio-barriers, operational analysis methods, and addresses concepts for human exploration. Crosscutting research and support activities are discussed and a rationale for a Strategic Planetary Protection R&TD Roadmap is outlined. Such a roadmap for planetary protection provides a forum for strategic planning and will help to enable the next phases of solar system exploration.  相似文献   
570.
Thermal controllers equipped with phase-change materials are widely used for maintaining the moderate temperatures of various electric devices used in spacecraft. Yet, the structures of amounts of thermal controllers add up to such a large value that restricts the employment of scientific devices due to the limit of rocket capacity. A lightweight structure of phase-change thermal controllers has been one of the main focuses of spacecraft design engineering. In this work, we design a lightweight phase-change thermal controller structure based on lattice cells. The structure is manufactured entirely with AlSi10 Mg by direct metal laser melting. The dimensions of the structure are 230 mm × 170 mm × 15 mm, and the mass is 190 g, which is 60% lighter than most traditional structures(500–600 g) with the same dimensions. The 3 D-printed structure can reduce the risk of leakage at soldering manufacture by a welding process. Whether the strength of the designed structure is sufficient is determined through mechanical analysis and experiments. Thermal test results show that the thermal capacity of the lattice-based thermal controller is increased by50% compared to that of traditional controllers with the same volume.  相似文献   
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