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411.
The effect of the oceans and sedimentary cover on global magnetovariational field distribution 总被引:1,自引:0,他引:1
Electromagnetic fields excited by long-period geomagnetic variations were calculated for spherical earth models with the realistic inhomogeneous surface layer. Calculations were also carried out for the model with the double inhomogeneous layer. The modelling results did not display the same level of distortions which had been observed experimentally. The revealed contradiction may be explained by a possible existence of significant inhomogeneities in the earth mantle. 相似文献
412.
Sh. Sh. Dolginov 《Earth, Moon, and Planets》1987,37(1):17-52
The evidence is presented for the existence of the magnetic field of the planet Mars and for the effectiveness of the dipolar part of the field as an obstacle to the solar wind at the most frequent parameters of the latter. The dipolar magnetic moment of Mars is (1.5–2.20 × 1022 G cm3. The dipole axis makes an angle i15 with the rotation axis of the panel. The magnetic north pole of Mars is located in its southern hemisphere.In terms of the precession dynamo model, the magnetic fields of the Earth and Mars are similar. This indicates that the Martian magnetic field is associated with the present-day dynamo-process in the Martian liquid core. 相似文献
413.
The system of a self-gravitating scalar field is frequently used in inflationary cosmological models. In the present paper we study a more complicated system containing an extra linear tensor field ik=ki with minimal coupling. We determine five of the six free parameters that occur in the most general expression for the actionS
of this field. In doing so we assume that in flat space-time the field ik must be invariant under gauge transformations. In a special case theS
found becomes a known expression for the action of a massless tensor field ik. We compute the metric energy-momentum tensor that determines the contribution of ik to the Einstein equations. We also exhibit the equations of motion of ik in curved space-time.Translated fromAstrofizika, Vol. 38, No. 3, 1995. 相似文献
414.
L. Sh. Grigoryan 《Astrophysics》1994,37(3):281-287
We study the bimetric theory of gravitation with background metric ik. In contrast to the accepted point of view, in which ik, is a metric given a priori, we assume that ik is a dynamic variable determined from the condition that the total action of the gravitating system must be an extremum. As a result it turns out that (1) ik can be described by the Einstein equation in space-time with the metric ik and (2) the energy-momentum tensor of the graviational field ik, is the source of ik. In this sense ik can be considered a secondary field in relation to gik. We determine the conditions for existence of integral covariant conservation laws. Two of the latter have no analogs in the theory with the background metric given a priori.Translated fromAstrofizika, Vol. 37, No. 3, 1994.The author is grateful to the participants in the seminar of the Department of Theoretical Physics at Erevan State University, and also to W. Bleier, K. A. Bronnikov, V. N. Mel'nikov, and G. Yu. Treder for discussions and valuable remarks. The investigations presented in this paper were partly financed by the International Scientific Fund, grant Ph1-262-0902. 相似文献
415.
A new method for bulk photographic photometry of stars is proposed. This method is based on the use of a new parameter
i proposed by the authors, which depends linearly on mv over the entire range of magnitudes.Translated fromAstrofizika, Vol. 39, No. 3, pp. 411–416, July–September, 1996. 相似文献
416.
A theory with variable gravitational constant, based on the bimetric formulation of general relativity, is suggested. It is in agreement with the Newtonian and post-Newtonian approximations of the theory of gravitation when the theory parameter ||4×10–6. The statical spherical-symmetric distribution of gravitating masses is investigated. It is shown that the total action (including the own gravitational field of the system)S=–M, where is the time in the remote system of reference, relative to which the celestial body is in rest. In the Brans-Dicke theory ||1 andS–M. The Tolman formula for the massM in the Einstein theory is also valid in the suggestedGeneralized Bimetric Theory of Gravitation. External analytical and internal numerical solutions of the field equations are found for the case of incompressible matter. It is shown that static and supermassive configurations may exist if –0.13<0. 相似文献
417.
结合水对海积软土流变性质的影响 总被引:7,自引:2,他引:7
海积软土的变形和强度性质与时间有明显的相关性,其原因之一是其中含量较多的结合水。土在一定压力下先排出自由水,然后是结合水,结合水膜厚度发生改变。压力改变结合水膜厚度,引起粘滞系数改变。通过剪切增变试验得到了粘滞系数与压力呈线性关系。研究粘滞系数与压力之间关系对修正或建立较为符合实际的本构模型有一定意义。 相似文献
418.
419.
The effective temperatures Teff, gravitational force g at the stellar surface, and Fe/H have been calculated for 50 components of 15 Trapezia of early spectral
types from electrophotometric observations in the six-color uvbyβ photometric system. The results of the calculation showed
that the log Teff of Trapezia components lie in the range 4.03–4.54, while their log g lie in the range 2.58–4.02. The atmospheric parameters
Teff and g were used to determine the stars’ masses and ages based on Hejlesen’s calculated evolutionary model sequences. All
the Trapezia components have several times more mass than the sun and almost half of them have over 10 times that mass. Over
70% of the components are less than 40.106 years old.
Translated from Astrofizika, Vol. 41. No. 2. pp. 235–244, April-June, 1998. 相似文献
420.