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821.
Klaus M. Meyer-Abich 《Climatic change》1980,2(4):373-385
Prevention of climatic change by changing human economic behaviour or compensation for climatically detrimental effects by technological fixes is not necessarily better than adaptation. In fact, there are good reasons to conclude that adaptation is the most rational political option, at the same time requiring least marginal action. The problems arising from CO2 all appear at present to be marginal ones which arise, and should be taken care of, for other reasons as well. With respect to CO2-induced changes we could not do better than do what should be done in any event for reasons of development policy.Editor's Note: This paper is, in part, a result of interactions at the U.S. Department of Energy's interdisciplinary workshop on Environmental and Societal Consequences of a Possible CO2-induced Climatic Change, Annapolis, Maryland, April, 1979. Although it is more of a discussion draft than a formal paper, it is being published rapidly and in its present form, for the reason it was written: to generate discussion, debate and exchange on the very important, yet hardly explored, question of societal response to CO2. Comments on this paper, or its subject, would be welcomed. 相似文献
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Klaus Keil Gayle Lux D.G. Brookins Elbert A. King Trude V.V. King Eugene Jarosewich 《Meteoritics & planetary science》1978,13(1):11-22
Inman (find, 1966) is a single, relatively unweathered stone of 7.25 kg that contains fresh metal and only few weathering products away from fractures. It has a pronounced chondritic texture, with 38 vol % of the meteorite being made up of chondrules of virtually all textural types. The recalculated bulk analysis, particularly the ratios of Fetotal/SiO2 (0.46), Fe°/Fetotal (0.35), and Fe°/Ni° (6.67) and the contents of Fetotal (19.45%) and metallic nickel-iron (7.94%), indicate that Inman is an L-group chondrite. The pronounced chondritic texture; the compositional variabilities of olivine, pyroxene, chromite, and ilmenite; the presence of a fine-grained, nearly opaque matrix, glass and twinned monoclinic low-Ca pyroxene indicate that the chondrite belongs to petrologic type 3. 相似文献
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In the following paper we argue that each wind-driving star in relative motion with respect to the ambient interstellar medium experiences a force exerted on its central wind-generating body. The exact magnitude of this force depends on the actual geometry of the counterflow configuration of stellar and interstellar winds for a particular kinematic situation which is especially sensitive to whether the interstellar flow is subsonic or supersonic. It will, however, be demonstrated here that this force is of an accelerating nature, i.e., it operates like a rocket-motor, as long as the peculiar motion of the wind-driving star with respect to the ambient interstellar medium remains subsonic.Here we use a specific analytical model to describe theoretically the specific counterflow configuration for the case of the solar system in a subsonic peculiar motion with respect to the local interstellar medium assuming irrotational and incompressible flows. We can work out a quantitative number for the accelerating force governing the Sun's motion at present. The net reaction force exerted on the solar body is then mediated by the asymmetric boundary conditions to which the distant solar wind field has to adapt.Next we study the indirect action of such a force on orbiting Keplerian objects like planets, planetesimals and comets. Since this force only influences the central solar body, but not the planets themselves, the problem is different from the treatment of a constant perturbation force perturbing the Keplerian orbits. We present a perturbation analysis treating the action of a corresponding position-dependent perturbation force resulting in secular changes of the orbital elements of Keplerian objects. It is found that changes are accumulating more rapidly in time the closer to the sun the orbiting bodies are. Main axis and perihelion distances are systematically increasing. Especially pronounced are changes in the perihelion position angle of the objects. For solar wind mass losses larger than the Sun's present value by a factor of 1000 (T-Tauri phase of the Sun,) the migration periods calculated for the planet Mercury are of the same order of magnitude as that for corresponding general relativistic migration. 相似文献
824.
Masahiko Honda Paul J. Sylvester Frank A. Podosek Klaus J. Schulz 《Precambrian Research》1985,27(4):301-306
The predominant 1480 Ma granites and rhyolites of the St. Francois Mountains, southeastern Missouri, are intruded by mafic rocks. A 40Ar—39Ar study of some of these, the Skrainka Mafic Group, indicates an age of ~ 1240 Ma, significantly younger than the host rocks, significantly older than Grenville/Keweenawan age, and close to the age of similar rocks in Labrador. 相似文献
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Highly non-linear seismic trace inversion problems can be solved efficiently by an implementation of Tabu Search, a meta-heuristic method related to artificial intelligence. The implementation under consideration is a deterministic, global search that combines the advantages ofa local search, giving a quick descent to local misfit minima, with an ability to cross misfit barriers in the model space. Once Tabu Search has found an area of low misfit, it performs an extensive exploration of its deepest points. This property makes it possible to use Tabu Search for a semiquantitative resolution and uncertainty analysis of the inverse problem. 相似文献