全文获取类型
收费全文 | 65180篇 |
免费 | 935篇 |
国内免费 | 611篇 |
专业分类
测绘学 | 1465篇 |
大气科学 | 4446篇 |
地球物理 | 12438篇 |
地质学 | 23421篇 |
海洋学 | 6287篇 |
天文学 | 14959篇 |
综合类 | 136篇 |
自然地理 | 3574篇 |
出版年
2022年 | 418篇 |
2021年 | 750篇 |
2020年 | 819篇 |
2019年 | 897篇 |
2018年 | 1798篇 |
2017年 | 1669篇 |
2016年 | 2028篇 |
2015年 | 1068篇 |
2014年 | 1856篇 |
2013年 | 3474篇 |
2012年 | 2066篇 |
2011年 | 2759篇 |
2010年 | 2503篇 |
2009年 | 3214篇 |
2008年 | 2710篇 |
2007年 | 2855篇 |
2006年 | 2611篇 |
2005年 | 1891篇 |
2004年 | 1833篇 |
2003年 | 1758篇 |
2002年 | 1744篇 |
2001年 | 1536篇 |
2000年 | 1442篇 |
1999年 | 1182篇 |
1998年 | 1206篇 |
1997年 | 1204篇 |
1996年 | 991篇 |
1995年 | 942篇 |
1994年 | 923篇 |
1993年 | 811篇 |
1992年 | 760篇 |
1991年 | 742篇 |
1990年 | 779篇 |
1989年 | 686篇 |
1988年 | 667篇 |
1987年 | 773篇 |
1986年 | 669篇 |
1985年 | 878篇 |
1984年 | 892篇 |
1983年 | 814篇 |
1982年 | 762篇 |
1981年 | 741篇 |
1980年 | 668篇 |
1979年 | 622篇 |
1978年 | 607篇 |
1977年 | 579篇 |
1976年 | 526篇 |
1975年 | 523篇 |
1974年 | 522篇 |
1973年 | 522篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
Krek A. V. Krek E. V. Ezhova E. E. Paka V. T. Kondrashov A. A. Danchenkov A. R. Bagirov N. E. Kudryavtzeva E. A. Bubnova E. S. Sergeev A. Yu. Aleksandrov S. V. 《Oceanology》2021,61(4):581-583
Oceanology - New data on the structure of the water column, upper layer of bottom sediments, and biological communities of the Gdansk and Gotland deeps and the Gulf of Finland in the Baltic Sea... 相似文献
932.
Demidov A. B. Gagarin V. I. Eremeeva E. V. Artemiev V. A. Polukhin A. A. Shchuka S. A. Grigoriev A. V. Khrapko A. N. Flint M. V. 《Oceanology》2021,61(5):645-661
Oceanology - Spatial and vertical variability of primary production (PP) and Chl a were studied in the framework of the 76th cruise of R/V Akademik Mstislav Keldysh to the Kara Sea from July 7 to... 相似文献
933.
Kuzmenko N. V. Tsyrlin V. A. Pliss M. G. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(10):1271-1292
Izvestiya, Atmospheric and Oceanic Physics - It is known that in mammals living in climates other than tropical, hemoconcentration is usually observed in winter. The average modern person actively... 相似文献
934.
Izvestiya, Atmospheric and Oceanic Physics - Zonally averaged characteristics of the North Atlantic (NA) thermohaline circulation are investigated in different phases of the Atlantic Multidecadal... 相似文献
935.
Gubanova D. P. Vinogradova A. A. Iordanskii M. A. Skorokhod A. I. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(3):297-309
Izvestiya, Atmospheric and Oceanic Physics - The results of an intensive complex experiment carried out from March 25 to May 3, 2020, to study the composition and time variability of urban aerosol... 相似文献
936.
Air–sea gas transfer velocities are estimated for one year using a 1-D upper-ocean model (GOTM) and a modified version of the NOAA–COARE transfer velocity parameterization. Tuning parameters are evaluated with the aim of bringing the physically based NOAA–COARE parameterization in line with current estimates, based on simple wind-speed dependent models derived from bomb-radiocarbon inventories and deliberate tracer release experiments. We suggest that A = 1.3 and B = 1.0, for the sub-layer scaling parameter and the bubble mediated exchange, respectively, are consistent with the global average CO2 transfer velocity k. Using these parameters and a simple 2nd order polynomial approximation, with respect to wind speed, we estimate a global annual average k for CO2 of 16.4 ± 5.6 cm h?1 when using global mean winds of 6.89 m s?1 from the NCEP/NCAR Reanalysis 1 1954–2000. The tuned model can be used to predict the transfer velocity of any gas, with appropriate treatment of the dependence on molecular properties including the strong solubility dependence of bubble-mediated transfer. For example, an initial estimate of the global average transfer velocity of DMS (a relatively soluble gas) is only 11.9 cm h?1 whilst for less soluble methane the estimate is 18.0 cm h?1. 相似文献
937.
Average concentrations of Pb, Zn, Cu, and other metals, as well as S and As, were calculated for the Aue granitic cupola,
the contact aureole of which hosts the large vein-type uranium deposit of Schlema-Alberoda and the Schneeberg uranium-base
metal deposit (Erzgebirge, Germany). The cupola was exposed by mine workings and boreholes, which provided an opportunity
to evaluate variations in the abundances of metals in the granites over a vertical interval of more than 2.5 km and estimate
their losses in the upper oxidized part of the investigated volume of the cupola (coefficient of iron oxidation, KO
Fe, increases in the granites from bottom to top from 7 to 70%) compared with the lower unaltered and unoxidized part (with
a KO
Fe plateau at about 5%). The average concentrations of metals in the upper part of the cupola are lower than those in the lower
part by a factor of 2.5 for Pb, 1.56 for Zn, 1.45 for Cu, 1.3 for Co, etc. A similar decrease in the abundances of ore elements
along the vertical section associating with the relative epigenetic alteration and oxidation of the granite was previously
described by us for U and Th and for the components of high-temperature ores, W, Sn, and Mo. The removal of ore elements from
the granite was accompanied by a decrease in the bulk contents of sulfur and arsenic by a factor of 1.35 and 1.65, respectively.
The leaching of trace metals from the granites of the upper part of the Aue cupola was followed by their partial redeposition
above the cupola in the ore veins of the Schlema and Schneeberg deposits.
Original Russian Text ? Vikt. L. Barsukov, N.T. Sokolova, O.M. Ivanitskii, 2006, published in Geokhimiya, 2006, No. 9, pp.
967–982. 相似文献
938.
939.
940.