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951.
A body of techniques that have been developed and planned for use during the Earth Radiation Budget Experiment (ERBE), the International Satellite Cloud Climatology Project (ISCCP), and related climate experiments of the 1980's are reviewed. Validation and verification methods must apply for systems of satellites. They include: (1) use of a normalization or intercalibration satellite, (2) special intensive observation areas located over ground-truth sites, and (3) monitoring of sun and earth by several satellites and/or several instruments at the same time. Since each climate application area has a hierarchy of user communities, validation techniques vary from very detailed methods to those that simply assure high relative accuracy in detecting space and time variations for climate studies. It is shown that climate experiments generally require more emphasis on long-term stability and internal consistency of satellite data sets than high absolute accuracy.  相似文献   
952.
A survey is presented of the potential benefits, possible pitfalls, and anticipated testing needs of integrating inertial guidance systems with systems dependent on the availability of the electromagnetic spectrum. Commonly referred to as integrated communications, navigation, and identification avionics (ICNIA), these systems of the future offer the combined potential for superb positioning and secure communications. The general characteristics (if current development trends continue) of the next-generation inertial navigation systems (INS) are briefly presented, followed by key modular and conceptual issues in the synthesis of this INS with systems dependent on the EM spectrum. Modular issues as considered here are those related to detailed implementation and resulting efficiency. Conceptual issues are those related to overall military strategy and resulting effectiveness. An example of modular systems integration is given, and a few preparations which can be anticipated for the field testing of integrated systems are presented, followed by concluding comments  相似文献   
953.
Spectral measurements by the Solar Maximum Mission have been used to confirm the cyclotron lines in gamma-ray bursts reported from the Konus experiment. We present ISEE-3 data for the same burst (GB800419) during the same period of time which show no line. We discuss various problems in the analysis of scintillator spectra and point out that unfolded spectra are not necessarily unique and that the position of a data point in a deconvolved spectrum may vary depending on the assumed overall shape of the spectrum. As a result, if the analysis assumes a soft spectrum (such as optically thin thermal bremsstrahlung) an absorption feature might appear, whereas a harder spectrum (such as a Comptonized blackbody) would not require the feature. Since the continuum shape probably changes during the duration of a typical burst, the nonuniqueness of the spectral unfolding, combined with the assumption that the continuum is optically thin thermal bremsstrahlung, could give rise to spurious “absorption” features which vary on a time scale of seconds. Despite these problems, there is still some evidence for narrow spectral lines in the range 45 to 65 keV but not for the broad lines reported from the Konus experiment. Unfortunately, the range 45 to 65 keV is the most difficult spectral region to unfold.  相似文献   
954.
The Remote Sensing Centre of the Institute of Geodesy and Cartography in Warsaw has been operating since 1976. It has multi-disciplinary character; carries out scientific research, elaborates technologies of remote sensing investigations, applies remote sensing methods for solving various practical problems, coordinates national activities in this field, developes and disseminates remote sensing knowledge at both national and international levels offering various types of specialized training.The authors discuss the role of remote sensing investigations in the process of development planning. Examples of projects executed at the Remote Sensing Centre and concerning topographic and land use mapping, geological investigations, agricultural crop area determination, forest research, environmental monitoring and studies of climatic conditions in urban environment are described and extensively discussed in the paper. The authors emphasize these areas of the application of remote sensing and these interpretation techniques which are of potential interest for the developing countries.  相似文献   
955.
956.
We consider a nonstationary nonlinear integrodifferential equation describing the evolution of a disturbed plane flame front. The following two-dimensional problems are solved numerically: (i) The formation of a wrinkled noncellular laminar flame front under conditions of spontaneous hydrodynamic instability. (ii) The formation of a turbulent cellular flame front under conditions of spontaneous diffusional-thermal instability. (iii) The formation of a turbulent wrinkled-cellular flame front under conditions of spontaneous hydrodynamic and diffusional-thermal instability. We compute the flame front velocity in laminar and turbulent propagation.  相似文献   
957.
Preface     
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958.
We have investigated the use of real and synthetic stereo satellite images and stereo graphics in applications such as cloud-tracked winds, severe storm cloud analysis, and general meteorological interpretation. We have concluded that a stereo meteorological presentation is possible and desirable in an operational environment. Synthetic stereo could be used immediately in cloud-tracked wind operations. The presentation allows one to appreciate the interrelations between cloud motions and cloud structures, especially in multi-layered situations. Reprocessing of FGGE tropical wind sets with a synthetic stereo presentation showed some improved yields of low-level vectors, a significant increase in mid-level vectors, and very little change in the high-level vectors. Severe local storm real-stereo presentations are possible operationally because the 15 minute RISOP operations of GOES-East allow simultaneous scanning of both geosynchronous satellites twice per hour. The real-stereo height measurements of overshooting turrets are an improvement over infrared heights and can be used to monitor the strength of the thunderstorm updraft. Synthetic stereo presentations of thunderstorm tops can be presented in a non-linear fashion which stretches out the cloud top features. The synthetic stereo presentation is easier for most people to see. We recommend the use of a hybrid system where the viewing is done on the synthetic stereo image and the quantitative measurements are done on the real-stereo pairs.  相似文献   
959.
The results of a cross-spectral analysis between monthly mean temperatures at 100 mb, 50 mb and 30 mb over the equator and the corresponding monthly mean BUV total ozone at different latitude zones are presented for the period 1970–1977. Significant squared coherences between total ozone and 50 mb equatorial temperatures at 26 months are only found between 5 degrees on each side of the equator, between 45 deg N and 55 deg N and at 45 deg S. At latitudes were the QBO in stratospheric temperature diminishes so does the QBO in total ozone (i.e. close to 35 deg N and 15 deg S). Over subtropical latitudes there is a tendency towards a more biennial oscillation in total ozone (not correlated with the equatorial QBO in stratospheric temperatures) and at 65 deg N and 65 deg S total ozone oscillates at periods greater than the equatorial QBO.  相似文献   
960.
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