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911.
It has been shown that the maximum of climate variations in the northern subpolar zone observable over the last three decades
conforms to the maximal methane and carbonic acid content in the atmosphere of the north latitudes. Statistical analysis of
long-term variations of ground air temperature, gas composition of atmosphere, depth of seasonal melting, temperature, and
distribution area of permafrost ground in the subpolar zone of the north hemisphere testifies to significant directional changes
of basic cryolitozone characteristics. Analysis of the latitudinal distribution of flux density of anthropogenic and natural
methane showed that the greatest methane emission is in the subpolar zone of the northern hemisphere, where anthropogenic
impact is minimal. In view of the estimations of methane emission during thawing of permafrost grounds, a new hypothesis explaining
the present climate conditions in northern latitudes has been proposed. The planetary maximum of climate warming in the arctic
zone is substantially caused by methane and carbonic acid outbreaks from thawing permafrost grounds, which, in turn, is an
additional reason for the greenhouse effect. This effect is materially analogous to the influence of technogenic discharge
of greenhouse gases in the temperate zone. 相似文献
912.
The authors describe results of a project involving intermediate-scale mapping of natural environmental complexes of an experimental area in central Belarus'. Three different cartographic models—of landscape dynamics, landscape-geochemical conditions, and composite ecological-landscape conditions—make it possible to organize and synthesize a large volume of material for the assessment of the ecological situation across a number of diverse natural complexes. Translated by Edward Torrey, Alexandria, VA 22308 from: Izvestiya Rossiyskogo Geograficheskogo Obshchestva, Vol. 127, No. 5, 1995, pp. 24-32. 相似文献
913.
Véronique Michel Guanjun Shen Patricia Valensi Henry de Lumley 《Quaternary Geochronology》2009,4(3):233-240
ESR dating was carried out on Cervus elaphus tooth enamel samples from the depositional sequence of Lazaret Cave, Nice, France. The deposits contain Anteneandertal hominid fossils associated with abundant lithic artefacts and faunal remains. Three samples from the Mousterian occupations in complex CIII (Fouille d'entrée) yielded early uptake (EU) ages between 108 and 125 ka and linear uptake (LU) ages between 133 and 160 ka. Seven samples from the Acheulian levels in the upper part of the complex CII (Fouille d'entrée and Fouille centre) gave EU ages between 113 and 165 ka and LU ages between 147 and 210 ka, with weighted means at 131 ± 7 and 165 ± 9 ka, respectively. The results of six enamel samples from the lower Acheulian levels at Locus VIII, another place in the cave, were discarded because of their decreasing tendency with depth. The US–ESR combination method was also applied and the CSUS–ESR dates were calculated using the ESR-DATA program. Altogether, the data suggest that the Lazaret Acheulian and Mousterian occupations were rapidly formed during OIS 6. 相似文献
914.
Currents and atmospheric parameters were measured in the East China Sea in February, 1975, as part of the AMTEX'75 program. These data were used to describe outbreaks of cold continental air over this warm and shallow sea. Particular emphasis was placed on describing the structure of mesoscale atmospheric cells embedded in the outbreaks and the effects of these cells on the water column.Two cold air outbreaks were recorded. Heat fluxes (latent plus sensible) as high as 1270 cal/cm2 day were calculated. Evidence of mesoscale atmospheric cells was found during outbreaks in satellite imagery and in solarimeter data. The development of mesoscale cells was described by correlating fluctuations in the air temperature and absolute humidity records. The cells were found to be best developed when satellite imagery showed that they were of the closed variety. The data suggest that cellular activity matures from open to closed cell types.During the period of greatest development, a representative closed cell was 24–30 km in diameter, moved at 8 m s-1 over the spar buoy, had a temperature fluctuation of 0.4 °C, an absolute humidity fluctuation of 0.4 g kg-1, and wind speed and heat flux fluctuations of - 12.5%.A non-dimensional index, formed from the fluctuations of the air temperature and absolute humidity records, was used to indicate the passage of mesoscale atmospheric cells over the measuring site. Using this index as input and the fluctuations in the oceanic parameters at a depth of 20 m as output, it was found that the passage of mature cells was significantly correlated with temperature fluctuations and current fluctuations aligned 25 ° to the right of the wind about 45 min later. 相似文献
915.
R. D. Kouznetsov V. F. Kramar F. Beyrich D. Engelbart 《Meteorology and Atmospheric Physics》2004,85(1-3):93-99
Summary A simple parameterization for the estimation of turbulent kinetic energy (TKE) and momentum flux profiles under near-neutral stratification based on sodar measurements of the vertical velocity variance has been tested using data from the LINEX-2000 experiment. Measurements included operation of a phased-array Doppler sodar DSDPA.90 and of a sonic anemometer USA-1 mounted at a meteorological tower at a height of 90m. Good agreement has been found between the TKE and momentum flux values derived from the sonic and sodar data (with correlation coefficients r>0.90 and a slope of the regression lines of about 1.01.1) suggesting the possible use of sodar measurements of w 2 to derive turbulence parameter profiles above the tower range. 相似文献
916.
The numerical modeling of the Archimedean upwelling of a salt bed predicts that, with mature diapirs (from the finger stage and later), an about 2-km-thick zone of inversion (mirror) folding, where the suprasalt diapirs correspond to the subsalt synclines while the suprasalt inter-diapir sags correspond to the anticlines in the subsalt, should be expected immediately below the bottom of the salt deposits. These deformations decay with depth. The development of the inversion folding is exceptionally due to the flow caused by the rising of the unstable layer. 相似文献
917.
D. J. Stom G. G. Ivanova G. V. Bashkatova T. P. Trubina O. M. Kozhova 《洁净——土壤、空气、水》1974,2(5):407-412
The concentration of phenols and quinones which stopped the protoplasmic movement in the Nitella cells after 15 min was determined. The quinones (β-naphthoquinone, α-naphthoquinone, p-benzoquinone, o-toluquinone, o-bromanil) stopped the protoplasmic movement in the concentration of (1 3) 10?4 M, phenols (m-cresol, p-cresol, hydroquinone, guaiacol, phenol, gallic acid, pyrogallic acid, resorcinol) in the concentration of (0.2 5) 10?2 M, except catechol – 2 10?3 M. Very high toxicity of catechol and in the prolonged experiments (3 hours) also of hydroquinone is connected with the action of quinonoid productions of its oxidation. This suggestion is confirmed by the experiments:
- – by adding the phenol solutions to Nitella shoots (catechol, hydroquinone, resorcinol) we observed the greatest increase of oxygen absorption in case of catechol (86%), less in case of hydroquinone (38%), and for resorcinol oxygen absorption practically remained on the control level;
- – the action of catechol, hydroquinone and p-benzoquinone did not take place in the presence of glutathione and cysteine (but not cystine and oxidated glutathione);
- – diethyldithiocarbamate as an inhibitor of o-diphenoloxidase reduced the ability of catechol solutions to stop the protoplasmic movement;
- – the low concentrations of benzoquinones were able to stop the protoplasmic movement;
- – for stopping the protoplasmic movement under the prolonged time of incubation from 15 min to 3 hours there was necessary a lower concentration of solutions of hydroquinone and catechol in comparison with resorcinol.
918.
G. A. Sobolev V. I. Vettegren S. M. Kireenkova V. B. Kulik Yu. A. Morozov A. I. Smul’skaya 《Izvestiya Physics of the Solid Earth》2007,43(6):447-454
Nanocrystals were detected and identified in rocks by the method of Raman spectroscopy. The experiments showed that the Raman scattering spectra of fine-lamellar arkosic sandstone exhibit bands corresponding to lattice vibrations of anatase, α-quartz, and plagioclase. In all spectra of the rock, the bands are displaced towards high frequencies as compared with their position in spectra of single crystals and widen on the same side. These results show that, in all of the studied places of the sample, the particles of anatase, quartz, and plagioclase have nanometer sizes, namely, of the order of 10 nm in anatase and quartz and about 20 nm in plagioclase. Moreover, in different places of the sample, not only the shape and position of the bands under study but also their intensity vary, the latter being directly proportional to the concentration of nanocrystals. 相似文献
919.
A spherical model of the Earth including a heterogeneous upper mantle and excited by the magnetic field of a magnetospheric ring current is constructed. The obtained synthetic data are used for testing a new approach to gradient geomagnetic sounding ensuring the immunity of the sought impedance to distortions caused by lateral heterogeneity of the Earth. It is shown that this approach significantly increases the informativeness of deep electromagnetic sounding. 相似文献
920.
V. G. Samylina 《Water Resources》2018,45(5):813-818
Objective analysis of water resources development in the territory of Vologda oblast in period from 2005 to 2014 is given. It was found that water withdrawal from water sources decreased by 22.4%, wastewater discharge into water bodies decreased by 22.6%, and the total volume of recycling and successive water use increased by 2.0%. The dynamics of the distribution of water resources between economic sectors is given. Unreasonable water losses were identified in water use systems and their extent was assessed. The main directions in water economy in the production and domestic sectors are determined. Steps for improving the efficiency of water resources development in the region are proposed. 相似文献