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球载高能天文望远镜的超视距自动跟踪 总被引:1,自引:0,他引:1
本文在HAPI-4原有系统的基础上,利用80C196超16位单片机,首次实现了球载姿态指向控制系统的数字化;借助于全球卫星定位系统GPS,实现了气球位置的高精度定位和时间的绝对定标;采用小型高密度磁带机作为球载数据流存储器,利用海事卫星实现超视距测控,形成了新一代的球载高能望远镜控制系统. 相似文献
243.
Yinjie Yang Shin-ichi YokoboriAkihiko Yamagishi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
Earthly microorganisms might have contaminated Mars for millions of years by intellectual activities or natural transfer. Knowledge on the preservation of microorganisms may help our searching for life on outer planets, particularly Mars-contaminated earthly microorganisms at ancient time. Extreme dryness is one of the current Mars characteristics. However, a humid or watery Mars at earlier time was suggested by evidence accumulated in recent decades. It raises the question that whether water helps preservation of the microorganisms or not, particularly those with high possibility of interplanetary transfer like spores and Deinococci. In this study, we examined the effects of desiccation and high humidity on survival and DNA double strand breaks (DSB) of Escherichia coli, Deinococcus radiodurans and spores of Bacillus pumilus at 25, 4 and −70 °C. They exhibited different survival rates and DSB patterns under desiccation and high humidity. Higher survival and less DSB occurred at lower temperature. We suggest that some Mars-contaminated bacteria might have been viably preserved on cold Mars regions for long periods, regardless of water availability. It is more likely to find ancient spores than ancient Deinococci on Mars. In our search for preserved extraterrestrial life, priority should be given to the Mars Polar Regions. 相似文献
244.
Igor S. Veselovsky Serge Koutchmy 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
Several important issues are open in the field of solar variability and they wait their solution which up to now was attempted using critical ground-based instrumentations. However, accurate photometric data are attainable only from space. New observational material should be collected with high enough spatial and spectral resolution, covering the whole visible range of the electromagnetic spectrum as well infrared and ultraviolet to reconstruct the total solar irradiance: (1) the absolute contributions of different small-scale structural entities of the solar atmosphere from the white light flares and from micro-flares are still poorly known; (2) we do not know the absolute contributions of different structural elements of the solar atmosphere to the long-term and to the cyclic variations of the solar irradiance, including features of the polar regions of the Sun; (3) the variations of the chromospheric magnetic network are still poorly evaluated; (4) only scarce information is available about the spectral variations of different small-scale features in the high photosphere. Variability of the Sun in white light can be studied with higher spectral, spatial and time resolution using space-born telescopes, which are more appropriate for this purpose than ground based observatories because of better seeing conditions, no interference of the terrestrial atmosphere and a more precise calibration procedure. Scientific requirements for such observations and the possible experimental tools proposed for their solution. Suggested solar studies have broader astrophysical importance. 相似文献
245.
A. Zanini M. Storini O. Saavedra 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
The worldwide distribution of High Mountain Observatories provides a unique opportunity for performing contemporary measurements under different geomagnetic/altitude conditions and for collecting long-term data series. In this context, the history and some activities performed at two historical Research Stations are summarized: Chacaltaya Laboratory (Bolivia) and the Testa Grigia Research Station (Italy). 相似文献
246.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(4):1263-1278
Enhancing the dust storm detection is a key part for the environmental protection, human healthy and economic development. The goal of this paper is to propose a new Support Vector Machine (SVM)-based method to automatically detect dust storms using remote sensing data. Existing methods dealing with this problem are usually threshold-based that are of great complexity and uncertainty. In this paper we propose a simple and reliable method combining SVM with MODIS L1 data and explore the optimal band combinations used as the feature vectors of SVM. The developed method was evaluated by MODIS and OMI data qualitatively and quantitatively on three study sites located in the Arabian Desert, Gobi Desert and Taklimakan Desert, and it was also compared to three other traditional methods based on their accuracy, complexity, reliability and sensitivity to thresholds. The detection results demonstrated that the combination of (Band7 − Band3)/(Band7 + Band3) ((B7 − B3)/(B7 + B3)), Band20 − Band31 (B20 − B31), and Band31/Band32 (B31/B32) can detect the dust storms more precisely than other individual bands or their combination. The comparison among those cases indicated that the proposed automatic method exhibited an advantage of minimizing the uncertainty and complexity, which were the limits of defining thresholds based on the threshold-based methods. The conclusions can provide references for studies that focus on statistical-based dust storm detection. 相似文献
247.
文章结合高速时序工作的特点,从实现的角度提出了一种利用软件调整时序的新方法。在可编程逻辑器件中,利用数字时钟管理器(DCM),通过模块化和增量式设计思想达到对高速时序信号的精确调节。最终实现了一个20MHz速率的时序控制,调节精度达到100ps。 相似文献
248.
H.S. Ahluwalia R.C. Ygbuhay 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
For the last six decades the neutron monitors have provided a continuous string of very reliable data to the heliophysics community. Although neutron monitors are not the primary source of data for the galactic cosmic rays, these data serve as a baseline reference for the data collected by the detectors on board the satellites and deep space probes, far away from earth orbit. The pressure corrected hourly data are available from the World Data Centers. These data have been used to derive deep insights pertaining to the electromagnetic states of the heliosphere and the modes of transport of energetic charged particles in the tangled interplanetary magnetic fields. We present evidence that some of the high latitude neutron monitors are undergoing long-term drifts in their baselines. In particular, we argue that there is no physical basis to justify the observed long-term downward trend in the baseline of the South Pole neutron monitor. The real reason may have to do with its maintenance at a distant location with challenging logistics and an improper normalization of its data after the 26 months break in the 1970s. 相似文献
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