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451.
Laura Silva Gian Luigi Granato Alessandro Bressan Cedric Lacey Carlton M. Baugh Shaun Cole Carlos S. Frenk 《Astrophysics and Space Science》2001,276(2-4):1073-1078
We present the basic features and preliminary results of the interface between our spectrophotometric model GRASIL (which
calculates galactic SEDs from the UV to the submm with a detailed computation of dust extinction and thermal reemission) with
the semi-analytical galaxy formation model GALFORM (which computes galaxy formation and evolution in the hierarchical scenario,
providing the star formation history as an input to our model). With these two models we are able to synthesize simulated
samples of a few thousand galaxies for statistical studies of galaxy properties to investigate galaxy formation and evolution.
There is good agreement with the available SED and luminosity function data.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
452.
453.
454.
Jos M. García‐Ruiz Blas L. Valero‐Garcs Carlos Martí‐Bono Penlope Gonzlez‐Sampriz 《第四纪科学杂志》2003,18(1):61-72
The deglaciation history of the Escarra and Lana Mayor glaciers (Upper Gállego valley, central Spanish Pyrenees) had been reconstructed on the basis of detailed geomorphological studies of glacier deposits, sedimentological and palynological analyses of glacial lake sediments and an accelerator mass spectrometry (AMS) 14C chronology based on minimum ages from glacial lake deposits. The maximum extent of the Pyrenean glaciers during the last glaciation was before 30 000 yr BP and pre‐dated the maximum advances of the Scandinavian Ice Sheet and some Alpine glaciers. A later advance occurred during the coldest period (around 20 000 yr BP), synchronous with the maximum global ice extent, but in the Pyrenees it was less extensive than the previous one. Later, there were minor advances followed by a stage of debris‐covered glaciers and a phase of moraine formation near cirque backwalls. The deglaciation chronology of the Upper Gállego valley provides more examples of the general asynchroneity between mountain and continental glaciers. The asynchroneity of maximum advances may be explained by different regional responses to climatic forcing and by the southern latitude of the Pyrenees. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
455.
Darren S. Madgwick Ofer Lahav Ivan K. Baldry Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Carole Jackson Ian Lewis Stuart Lumsden Steve Maddox Peder Norberg John A. Peacock Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2002,333(1):133-144
We calculate the optical b J luminosity function (LF) of the 2dF Galaxy Redshift Survey (2dFGRS) for different subsets defined by their spectral properties. These spectrally selected subsets are defined using a new parameter, η , which is a linear combination of the first two projections derived from a Principal Component Analysis. This parameter η identifies the average emission- and absorption-line strength in the galaxy rest frame spectrum, and hence is a useful indicator of the present star formation. We use a total of 75 000 galaxies in our calculations, chosen from a sample of high signal-to-noise ratio, low-redshift galaxies observed before 2001 January. We find that there is a systematic steepening of the faint-end slope ( α ) as one moves from passive ( α =-0.54) to active ( α =-1.50) star-forming galaxies, and that there is also a corresponding faintening of the rest frame characteristic magnitude M *-5 log10 ( h ) (from −19.6 to −19.2). We also show that the Schechter function provides a poor fit to the quiescent (Type 1) LF for very faint galaxies [ M b J -5 log10 ( h ) fainter than −16.0], perhaps suggesting the presence of a significant dwarf population. The LFs presented here give a precise confirmation of the trends seen previously in a much smaller preliminary 2dFGRS sample, and in other surveys. We also present a new procedure for determining self-consistent k -corrections, and investigate possible fibre-aperture biases. 相似文献
456.
Parameter constraints for flat cosmologies from cosmic microwave background and 2dFGRS power spectra
Will J. Percival Will Sutherland John A. Peacock Carlton M. Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Carlos S. Frenk Karl Glazebrook Carole Jackson Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Stephen Moody Peder Norberg Bruce A. Peterson Keith Taylor 《Monthly notices of the Royal Astronomical Society》2002,337(3):1068-1080
457.
The 2dF Galaxy Redshift Survey: the dependence of galaxy clustering on luminosity and spectral type 总被引:1,自引:0,他引:1
Peder Norberg Carlton M. Baugh Ed Hawkins Steve Maddox Darren Madgwick Ofer Lahav Shaun Cole Carlos S. Frenk Ivan Baldry Joss Bland-Hawthorn Terry Bridges Russell Cannon Matthew Colless Chris Collins Warrick Couch Gavin Dalton Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Karl Glazebrook Carole Jackson Ian Lewis Stuart Lumsden John A. Peacock Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2002,332(4):827-838
We investigate the dependence of galaxy clustering on luminosity and spectral type using the 2dF Galaxy Redshift Survey (2dFGRS). Spectral types are assigned using the principal-component analysis of Madgwick et al. We divide the sample into two broad spectral classes: galaxies with strong emission lines ('late types') and more quiescent galaxies ('early types'). We measure the clustering in real space, free from any distortion of the clustering pattern owing to peculiar velocities, for a series of volume-limited samples. The projected correlation functions of both spectral types are well described by a power law for transverse separations in the range 2<( σ / h -1 Mpc)<15 , with a marginally steeper slope for early types than late types. Both early and late types have approximately the same dependence of clustering strength on luminosity, with the clustering amplitude increasing by a factor of ∼2.5 between L * and 4 L *. At all luminosities, however, the correlation function amplitude for the early types is ∼50 per cent higher than that of the late types. These results support the view that luminosity, and not type, is the dominant factor in determining how the clustering strength of the whole galaxy population varies with luminosity. 相似文献
458.
Rodrigo Leonardi Brian Williams Marco Bersanelli Ivan Ferreira Philip M. Lubin Peter R. Meinhold Hugh ONeill Nathan C. Stebor Fabrizio Villa Thyrso Villela Carlos A. Wuensche 《New Astronomy Reviews》2006,50(11-12):977
The COsmic Foreground Explorer (COFE) is a balloon-borne microwave polarimeter designed to measure the low-frequency and low-ℓ characteristics of dominant diffuse polarized foregrounds. Short duration balloon flights from the Northern and Southern Hemispheres will allow the telescope to cover up to 80% of the sky with an expected sensitivity per pixel better than 100 μK/deg2 from 10 GHz to 20 GHz. This is an important effort toward characterizing the polarized foregrounds for future CMB experiments, in particular the ones that aim to detect primordial gravity wave signatures in the CMB polarization angular power spectrum. 相似文献
459.
Carlos A. Altavista 《Celestial Mechanics and Dynamical Astronomy》1972,6(2):208-213
A new method for the development of the disturbing function of the three-body problem is outlined in this paper. A special process is devised to get the distance between two planetsP
1 andP
2 in terms of their heliocentric distances. It is then shown that the differential equations of relative motion of this problem can be brought in an homogeneous set of differential equations. 相似文献
460.
Vertical distributions of ozone in the stratosphere have been determined by means of u.v. differential absorption technique, using the Sun as a source. The filter radiometer and the data processing are described. Results obtained between altitudes of 22 and 32 km during the Intercomparison Ozone Campaign held in France in June 1981 are presented and discussed. 相似文献