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141.
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拟应用最优化理论中的投影定理,从理论上严格证明物体平行正投影的存在和唯一性,并在此基础上建立一个全新的平行正投影计算方法.内容包括:①应用数学语言阐明三维物体平行正投影的含义;②应用最优化理论中的相关理论依次论证与投影定理有关的几个命题,并在此基础上严格证明物体平行正投影的存在和唯一性,以及利用傅里叶级数形式建立平行正投影计算式;③简要分析这种计算方法的特点. 相似文献
143.
飞机装配型架标准接头定位器自动选取算法 总被引:3,自引:1,他引:3
在现代飞机结构中,整体结构件的应用导致了飞机装配型架结构中大量使用接头和工艺孔定位器.这些定位器一般由工作头和标准接头定位器两部分构成.为了缩短型架研制周期,在型架设计中开始推广应用CAD技术,包括开发型架专用设计系统.因此,研究接头定位器的自动设计,对进一步简化型架设计过程、提高设计效率具有重要的意义.标准接头定位器的自动选取是实现接头定位器自动设计的技术关键,就此提出了标准接头定位器自动选取的专门算法,其中包括提出并建立可定位域概念及其数据表示格式.该算法已应用于自行研制的飞机装配型架CAD系统中相关模块的开发,并取得了良好的应用效果。 相似文献
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G. De Franceschi A. De Santis S. Pau 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1994,14(12):61-64
The method of Spherical Cap Harmonic Analysis (SCHA) /1/ has been applied /2/ to the critical frequency of the F2 layer (f0F2) for mapping and modelling it over Europe. The model was based on longitudinal expansion in Fourier series, and fractional Legendre colatitudinal functions over a spherical cap including Europe. Here a new and simpler technique, previously developed for the regional modelling of the geomagnetic field /3/, is introduced and described. The basic improvement of the new method, called Adjusted Spherical Harmonic Analysis (ASHA), implies the use of conventional Spherical Harmonic (SH) functions after the colatitude interval is adjusted to that of a hemisphere. Examples are shown dealing with the application of ASHA to retrospective mapping and modelling of the monthly medians of f0F2 over Europe. 相似文献
147.
本文介绍了设计符合现代标准的智能大厦时应考虑的一些问题,阐述了在进行智能化设计时如何进行方案分析、系统设计的方法。 相似文献
148.
De Gaudenzi R. Lijphart E.E. Vassallo E. 《IEEE transactions on aerospace and electronic systems》1993,29(1):27-43
The European Space Agency's (ESA) multipurpose satellite tracking system is introduced. The system is able to perform accurate satellite ranging and Doppler measurements for a variety of mission types, i.e., from near-Earth satellites to deep space probes. The ranging signal is analyzed and described in an analytical manner from which the limits of the system performance are derived. A model of the overall system is presented and a few simulation results obtained thereby are compared with measurements performed with the ESA's Giotto and Hipparcos scientific missions 相似文献
149.
W G Sannita M Acquaviva S L Ball F Belli S Bisti V Bidoli S Carozzo M Casolino F Cucinotta M P De Pascale L Di Fino S Di Marco R Maccarone C Martello J Miller L Narici N S Peachey P Picozza A Rinaldi D Ruggieri M Saturno D Schardt M Vazquez 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2004,33(8):1347-1351
ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories [BNL] (Upton, NY, USA) and the Gesellschaft für Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, FRG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g. increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space. 相似文献
150.
Greene M. Walls J. Stensby J. 《IEEE transactions on aerospace and electronic systems》1988,24(6):817-820
A recently proposed method of reducing target glint errors in radar systems using extended Kalman filtering is further extended with the inclusion of and compensation for clutter effects. A discrete target model and discrete Kalman filter (DKF) are used. Simulation results demonstrating the DKF are presented, and the limits on the effectiveness of the method are investigated. The major advantage of the DKF is that it can be implemented in software in the digital processor of the radar, offering flexibility over continuous time filters. The ability of the filter to reduce clutter effects further demonstrates the usefulness of this technique for radar pointing error reduction 相似文献