全文获取类型
收费全文 | 85497篇 |
免费 | 1140篇 |
国内免费 | 526篇 |
专业分类
测绘学 | 1755篇 |
大气科学 | 5611篇 |
地球物理 | 16258篇 |
地质学 | 30802篇 |
海洋学 | 7869篇 |
天文学 | 19915篇 |
综合类 | 222篇 |
自然地理 | 4731篇 |
出版年
2022年 | 619篇 |
2021年 | 1048篇 |
2020年 | 1115篇 |
2019年 | 1247篇 |
2018年 | 2550篇 |
2017年 | 2361篇 |
2016年 | 2720篇 |
2015年 | 1356篇 |
2014年 | 2616篇 |
2013年 | 4488篇 |
2012年 | 2862篇 |
2011年 | 3694篇 |
2010年 | 3375篇 |
2009年 | 4264篇 |
2008年 | 3718篇 |
2007年 | 3832篇 |
2006年 | 3550篇 |
2005年 | 2526篇 |
2004年 | 2447篇 |
2003年 | 2283篇 |
2002年 | 2273篇 |
2001年 | 1970篇 |
2000年 | 1956篇 |
1999年 | 1535篇 |
1998年 | 1595篇 |
1997年 | 1465篇 |
1996年 | 1243篇 |
1995年 | 1243篇 |
1994年 | 1042篇 |
1993年 | 1007篇 |
1992年 | 935篇 |
1991年 | 967篇 |
1990年 | 935篇 |
1989年 | 817篇 |
1988年 | 751篇 |
1987年 | 883篇 |
1986年 | 774篇 |
1985年 | 946篇 |
1984年 | 1070篇 |
1983年 | 1033篇 |
1982年 | 950篇 |
1981年 | 891篇 |
1980年 | 792篇 |
1979年 | 748篇 |
1978年 | 726篇 |
1977年 | 618篇 |
1976年 | 626篇 |
1975年 | 615篇 |
1974年 | 589篇 |
1973年 | 657篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
D. A. Yarovaya 《Russian Meteorology and Hydrology》2016,41(8):535-543
The statistical study of intense mesoscale cyclones formed in the Black Sea region in 1979-2013 is carried out using the surface wind data of the RegCM climate model. Such cyclone parameters as intensity, lifetime, area, height, and trajectories over the sea as well as the place and time of origin are considered. The distribution of mesocyclones by months and times of day is considered. The obtained results are compared with the results of a statistical study on the Black Sea mesocyclones based on the PRECIS climate model. Possible causes for differences in data on the intensity and number of mesocyclones simulated by RegCM and PRECIS models are considered. 相似文献
992.
I. S. Sharygin A. V. Golovin A. V. Korsakov N. P. Pokhilenko 《Doklady Earth Sciences》2016,467(1):270-274
Tychite Na6Mg2(CO3)4(SO3) is a rare natural Na and Mg sulfatocarbonate. It is found only as minor mineral in deposits of saline lakes in the United States, Canada, Uganda, and China. In these continental evaporites tychite has sedimentary genesis. In this study, we report the first occurrence of tychite as a crystal phase in the melt inclusions in olivine from mantle xenoliths of the Udachnaya-East kimberlite pipe. This find provides an evidence for the probability of tychite crystallization from melts; i.e., this rare sulfatocarbonate may have a magmatic origin as well. 相似文献
993.
The first data on the chemical composition of dispersed matter from sedimentary traps are reported. The suspended components of sedimentary matter (amorphous silica, organic matter, carbonates, and lithogenic material, as well as Fe, Mn, and minor elements) are considered. As a result, it is shown that the intraannual variability in vertical fluxes of sedimentary matter is characterized by a seasonal increase in spring and autumn. The high fluxes of the components of sedimentary matter on the northern and southern slopes of the Derbent Basin in winter are explained by precipitation of material from the nepheloid layer that forms over the contour current. 相似文献
994.
A. N. Ovsuchenko M. Yu. Menshikov E. A. Rogozhin A. M. Korzhenkov 《Izvestiya Atmospheric and Oceanic Physics》2016,52(8):816-840
The results of comprehensive research into the area of the upper reach of the Mzymta River (Western Caucasus) are presented. The evidence of strong earthquakes that struck the study area throughout history is studied. The periods when mud flows and rockslides associated with the earthquakes are identified to fall between 3100–4000 and 700–1200 years ago. Paleoseismological results are correlated to the results of archeological excavations. As a result, it is revealed that the periods of tectonic disasters coincided with the onsets of the period when the area was uninhabited (abandoned) by people. The results of the present comprehensive research provide additional information to specify the seismic hazard and the chronology of human habitation in the region. 相似文献
995.
Issues of the formation and recording of the spatial and angular distributions of thermal radio radiation of rainfall in the microwave range are discussed. The thermal radio-frequency radiative transfer in a threedimensional rain cell is simulated numerically with a different rainfall rate, taking into account the nonspherical shape of falling raindrops and their size distribution. The role of the three-dimensional inhomogeneity of rainfall fields in the formation of a field of their inherent thermal radio radiation in the microwave range is revealed. 相似文献
996.
A numerical experiment has been carried out using a hydrodynamical model with nonlinear equations of motion and heat and salt advection to reconstruct the fields of hydrophysical parameters taking into account the real atmospheric forcing for the autumn season along the southern coast of the Crimean Peninsula. The studied part of the coast is situated at 44.25°N 33.95°E/44.72°N 34.55°E. High spatial resolution is used for modeling: 350 m in the horizontal plane with 38 layers in the vertical; the bottom topography is described in detail with ~500 m resolution. Detected and studied meso- and sub-mesoscale structures in the current field agree well with the observational data, which is impossible or hard to identify in numerical experiments with coarser resolution. Their kinematic characteristics and the lifetime are defined and some mechanisms of their origin are suggested. 相似文献
997.
The first find of srilankite (very rare Zr and Ti oxide, Ti2ZrO6) in the Urals and the third find in Russia is reported. Srilankite forms very small (0.5–20 μm) inclusions in some rutile grains. These minerals are observed in the rare rock variety, corundum-bearing spinel–saphirine hornblendite forming a block in serpentinized amphibolizied peridotite of the Ilmeny–Vishnevogorsk Complex, near the village of Taiginka, Chelyabinsk oblast. Srilankite has not been observed in such an association yet. The composition of the host rock provides evidence for its deep (the lowermost crust of the Earth) origin. Srilankites of the Urals are distinguished from all others by the high concentrations of UO2, ThO2, HfO2, and Nb2O5, which provides additional evidence for their crustal origin. Srilankite may indicate high-temperature and high-pressure conditions of rock formation. 相似文献
998.
The atmospheric disturbances caused by the first rocket launch from the Vostochnyi Cosmodrome on April 28, 2016, were registered 10–24 min after the launch using the signals of the GPS/GLONASS global navigation satellite systems. The analysis of the spatial distribution of the disturbances allowed the conclusion that the launch vehicle moved northwest from the cosmodrome, which corresponds to a trajectory of the satellite movement to the orbit with an inclination of 98º. 相似文献
999.
1000.