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671.
《Monthly notices of the Royal Astronomical Society》2007,375(1):213-226
The First Data Release (DR1) of the United Kingdom Infrared Telescope Infrared Deep Sky Survey (UKIDSS) took place on 2006 July 21. The UKIDSS is a set of five large near-infrared surveys, covering a complementary range of areas, depths and Galactic latitudes. The DR1 is the first large release of survey-quality data from the UKIDSS and includes 320 deg2 of multicolour data to (Vega) K = 18 , complete (depending on the survey) in three to five bands from the set ZYJHK , together with 4 deg2 of deep JK data to an average depth K = 21 . In addition, the release includes a similar quantity of data with incomplete filter coverage. In JHK , in regions of low extinction, the photometric uniformity of the calibration is better than 0.02 mag in each band. The accuracy of the calibration in ZY remains to be quantified, and the same is true of JHK in regions of high extinction. The median image full width at half-maximum across the data set is 0.82 arcsec. We describe changes since the Early Data Release in the implementation, pipeline and calibration, quality control, and archive procedures. We provide maps of the areas surveyed, and summarize the contents of each of the five surveys in terms of filters, areas and depths. The DR1 marks completion of 7 per cent of the UKIDSS seven-year goals. 相似文献
672.
StephenSerjeant CarlottaGruppioni SebOliver 《Monthly notices of the Royal Astronomical Society》2002,330(3):621-624
We present a new determination of the local volume-averaged star formation rate from the 1.4-GHz luminosity function of star forming galaxies. Our sample, taken from the B ≤12 Revised Shapley–Ames catalogue (231 normal spiral galaxies over an effective area of 7.1 sr) has ≃100 per cent complete radio detections and is insensitive to dust obscuration and cirrus contamination. After removal of known active galaxies, the best-fitting Schechter function has a faint-end slope of −1.27±0.07 in agreement with the local H α luminosity function, characteristic luminosity L ∗=(2.6±0.7)×1022 W Hz−1 and density φ ∗=(4.8±1.1)×10−4 Mpc−3 . The inferred local radio luminosity density of (1.73±0.37±0.03)×1019 W Hz−1 Mpc−3 (Poisson noise, large-scale structure fluctuations) implies a volume-averaged star formation rate ∼2 times larger than the Gallego et al. H α estimate, i.e. ρ 1.4 GHz =(2.10±0.45±0.04)×10−2 M⊙ yr−1 Mpc−3 for a Salpeter initial mass function from 0.1–125 M⊙ and Hubble constant of 50 km s−1 Mpc−1 . We demonstrate that the Balmer decrement is a highly unreliable extinction estimator, and argue that optical–ultraviolet (UV) star formation rates (SFRs) are easily underestimated, particularly at high redshift. 相似文献
673.
K. V. K. Iyengar 《Journal of Astrophysics and Astronomy》1985,6(4):227-231
As dust emission in the far infrared (FIR) is a characteristic property of planetary nebulae we searched the Infrared Astronomical
Satellite (IRAS) point-source catalogue for confirmatory evidence on the two new possible planetary nebulae S 68 and 248 -
5 identified by Fesen, Gull & Heckathorn (1983) and the high-excitation planetary nebula 76 + 36 detected by Sanduleak (1983).
We identify the nebulae 248 - 5 and 76 + 36 with IRAS sources 07404 - 3240 and 17125 + 4919, respectively and have determined
their dust temperature, total FIR emission and optical depth. We also set a lower limit ranging in value from 1.2 × 10-6 to 3.7 × 10-5 forM
dust
/M
bd
of the nebula 248 - 5 depending on whether its grain material is silicate or graphite. S 68 could not be identified with
an IRAS source. 相似文献
674.
利用R(红)-I(近红外)两色照相测光方法,搜寻银道带天区的红外超天体,并证认IRAS点源的红外超对应体。本文是一组系列文章的第四篇。在矩尺天区发现了195个红外超天体,并证认出其中22个是IRAS点源的对应体。 相似文献
675.
Krishna M. V. Apparao S. P. Tarafdar R. P. Verma K. V. K. Iyengar K. K. Ghosh 《Journal of Astrophysics and Astronomy》1993,14(3-4):131-134
The observed infrared excess in Be stars is usually interpreted as free-free and free-bound emission from a hot gas envelope
around the Be star. This hot gas should also emit H-alpha line radiation. Earlier observations had suggested that the infrared
excess and Hα radiation were not consistent with models in which they arise from the same ionized region; however the observations
were made at different times. We have made simultaneous observation of infrared and H-alpha line radiation. Our observations
imply that either both these radiations cannot arise from the same hot gas or additional processes have to be invoked to account
for the observed excess infrared radiation. 相似文献
676.
In this panel discussion contributions were made by K. Strom, L. Nordh and H. Zinnecker on the contributions of surveys to the study of star formation regions, by B. Burton on a survey of galactic H I and by E. Dwek on the detection of galactic supernovae by infrared surveys. The contributions of K. Strom, L. Nordh and E. Dwek are summarized here. 相似文献
677.
N. Epchtein B. De Batz E. Copet P. Fouqué F. Lacombe T. Le Bertre G. Mamon D. Rouan D. Tiphène W. B. Burton E. Deul H. Habing J. Borsenberger M. Dennefeld A. Omont J. C. Renault B. Rocca Volmerange S. Kimeswenger I. Appenzeller R. Bender T. Forveille F. Garzon J. Hron P. Persi M. Ferrari-Toniolo I. Vauglin 《Astrophysics and Space Science》1994,217(1-2):3-9
The DENIS project is the first attempt to carry out a complete digitized survey of the southern sky in the range 1–2.5µm. The main objectives of the programme and the main specifications of the camera and of the data processing stream are briefly outlined 相似文献
678.
M. Magliocchetti L. Moscardini P. Panuzzo G.L. Granato G. De Zotti L. Danese 《Monthly notices of the Royal Astronomical Society》2001,325(4):1553-1558
This paper investigates the clustering properties of Submillimetre Common User Bolometric Array (SCUBA) selected galaxies within the framework of a unifying scheme relating the formation of quasi-stellar objects and spheroids. The theoretical angular correlation function is derived for different bias functions, corresponding to different values of the ratio M halo / M sph between the mass of the dark halo and the final mass in stars. SCUBA sources are predicted to be strongly clustered, with a clustering strength increasing with mass. We show that the model accounts for the clustering of Lyman-break galaxies, seen as the optical counterpart of low- to intermediate-mass primeval spheroidal galaxies, and is also consistent with the observed angular correlation function of extremely red objects. Best agreement is obtained for M halo / M sph =100 . We also consider the implications for small-scale fluctuations observed at submillimetre wavelengths by current or forthcoming experiments aimed at mapping the cosmic microwave background (CMB). The predicted amplitude of the clustering signal in the 350-GHz channel of the Planck mission strongly depends on the halo-to-bulge mass ratio and may be of comparable amplitude to primary CMB anisotropies for multipole numbers l ≳50 . 相似文献
679.
D. A. H. Buckley M. J. Coe J. B. Stevens K. van der Heyden L. Angelini N. White P. Giommi 《Monthly notices of the Royal Astronomical Society》2001,320(2):281-288
We report on two optical candidates for the counterpart to an X-ray source in the Small Magellanic Cloud , 1WGA J0053.8−7226, identified as a serendipitous X-ray source from the ROSAT Position Sensitive Proportional Counter (PSPC) archive, and also observed by the Einstein Imaging Proportional Counter . Its X-ray properties, namely the hard X-ray spectrum, flux variability and column density, indicate a hard, transient source, with a luminosity of ∼ XTE and ASCA observations have confirmed the source to be an X-ray pulsar, with a 46-s spin period. Our optical observations reveal two possible candidates within the error circle. Both exhibit strong H α and weaker H β emission. The optical colours indicate that both objects are Be-type stars. The Be nature of the stars implies that the counterpart is most likely a Be/X-ray binary system. Subsequent infrared (IR) photometry ( JHK ) of one of the objects shows that the source varies by at least 0.5 mag, while the measured nearly simultaneously with the UBVRI and spectroscopic observations indicate an IR excess of ∼0.3 mag. 相似文献
680.
Frank Przygodda O. Chesneau U. Graser Ch. Leinert S. Morel 《Astrophysics and Space Science》2003,286(1-2):85-91
MIDI, the MID-Infrared Interferometricnterferometric Instrument for ESO's Very Large Telescope Interferometer (VLTI), will be the first instrument for combining
mid-infrared light directly in order to obtain angular resolution up to 10 mas (assuming a 200 m baseline) in a wavelength
range from 8 to 13 μm. Currently in the phase of commissioning at Paranal, the start of its scientific operation is expected
for summer 2003. Direct interferometry at thermal infrared wavelengths demands special requirements on the instrument and
also on the procedures of preparation of data reduction. Hereafter MIDI's different observing modes are described and an example
for an interferometric observation is given.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献