全文获取类型
收费全文 | 7888篇 |
免费 | 353篇 |
国内免费 | 40篇 |
专业分类
测绘学 | 248篇 |
大气科学 | 523篇 |
地球物理 | 2675篇 |
地质学 | 2673篇 |
海洋学 | 453篇 |
天文学 | 1328篇 |
综合类 | 35篇 |
自然地理 | 346篇 |
出版年
2022年 | 56篇 |
2021年 | 134篇 |
2020年 | 147篇 |
2019年 | 121篇 |
2018年 | 316篇 |
2017年 | 295篇 |
2016年 | 438篇 |
2015年 | 326篇 |
2014年 | 373篇 |
2013年 | 462篇 |
2012年 | 395篇 |
2011年 | 395篇 |
2010年 | 345篇 |
2009年 | 406篇 |
2008年 | 349篇 |
2007年 | 246篇 |
2006年 | 269篇 |
2005年 | 244篇 |
2004年 | 207篇 |
2003年 | 204篇 |
2002年 | 169篇 |
2001年 | 147篇 |
2000年 | 152篇 |
1999年 | 106篇 |
1998年 | 135篇 |
1997年 | 104篇 |
1996年 | 72篇 |
1995年 | 83篇 |
1994年 | 100篇 |
1993年 | 59篇 |
1992年 | 67篇 |
1991年 | 53篇 |
1990年 | 73篇 |
1989年 | 54篇 |
1988年 | 52篇 |
1987年 | 45篇 |
1986年 | 47篇 |
1985年 | 60篇 |
1984年 | 43篇 |
1983年 | 61篇 |
1982年 | 57篇 |
1981年 | 47篇 |
1980年 | 52篇 |
1979年 | 53篇 |
1978年 | 58篇 |
1977年 | 45篇 |
1975年 | 48篇 |
1974年 | 37篇 |
1973年 | 47篇 |
1971年 | 42篇 |
排序方式: 共有8281条查询结果,搜索用时 78 毫秒
711.
712.
Summary The meteorological microseisms recorded at Prague are found to be essentially independent of the occurrence of the major midwinter stratospheric warmings. This finding contributes to studying the downward propagation mechanism of some extraterrestrial influences. 相似文献
713.
Marcela Laštovičková Josef Pek Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1979,23(1):94-98
Summary A profile model of electric resistivity as a function of depth was compiled, the initial parameters being the values of the electric resistivity determined experimentally for basaltic and eclogitic rocks from the Bohemian Massif. The curves of the apparent resistivity were computed for this model and the measure of information evaluated for the various model layers. The dominant influence of the subsurface layer was proved. 相似文献
714.
František Blahák Vladimír Fiala Reviewer J. Prokop 《Studia Geophysica et Geodaetica》1979,23(4):388-392
Summary The current spectral density I() dependence on the width of the frequency band and sweep period is studied. The relation between the required accuracy of measurement an the optional parameters of the sweeping process is formulated. 相似文献
715.
Visiting professors Václav Hanuš Jiří Vaněk Reviewer M. Krs 《Studia Geophysica et Geodaetica》1979,23(3):218-234
Summary The morphology of the Wadati-Benioff zone in the region of Central America, based on the distribution of 1377 earthquake foci, verified the existence of an intermediate aseismic gap and its relation to active andesitic volcanism, and the non-uniformity of subduction due to the hampering effect of the main structural features of the subducting Cocos plate. Four deep seismically active fracture zones, genetically connected with the process of subduction, and three fracture zones manifesting the possible boundary between the Americas and Caribbean plates were identified in the continental wedge. 相似文献
716.
The orogenic belts encircling the present-day Adriatic Sea are the deformed Mesozoic continental margin of an area known as Adria, the outline of which began to take shape during Middle Triassic continental rifting. Early Jurassic oceanic rifting was usually close to, but not coincident with, sites of earlier continental rifting. The Triassic rifted zones were usually incorporated into the continental margin of Adria, profoundly influencing its subsequent development. The Mesozoic platform/basin morphology of this margin can be correlated along the length of the belt.Palaeomagnetic data from autochthonous outcrops of the foreland of Adria do not indicate relative rotation and moreover suggest that this foreland has moved in coordination with Africa since the Early Mesozoic. Seismic soundings indicate that thick Mesozoic sedimentary sequences which can be correlated with sections on the African platform are continuous beneath the eastern Mediterranean seas. The concept of Adria as having behaved as a promontory of the African plate is tested by correlation of the main tectonic events in the belt with the spreading history of the Atlantic. The simplest model which adequately accounts for available data comprises a continuous Mesozoic continental margin from the Magrebids of Tunisia, through the Apennines, Alps, Dinarides and Hellenides to the alpine belt of Turkey. This margin was the southern margin of the Mesozoic Tethys and its foreland was more or less continuous with the African platform. Some structural and geochemical features of the double ophiolitic belt on the eastern side of Adria may be explained in terms of more external oceanic branches giving a more diversified continental margin of Adria. The present undulations of the Periadriatic belt are mainly a product of Late Cretaceous to recent deformation, which severely modified the shape of this margin by continental collision and by subsequent development of back-arc features. 相似文献
717.
František Blahák Jan Laštovička Revievwer L. Křivský 《Studia Geophysica et Geodaetica》1980,24(1):60-64
¶rt;m uu n ¶rt;au m uu nu mau nam aum n. mu uu auam mmmuu uuu ¶rt;u u naam. a¶rt;am auu ¶rt; uuu n ¶rt;au m u u. a auu a¶rt;am nuu amm 245 . ¶rt;aam umnmau m a¶rt;a uu. 相似文献
718.
a mamumuu m, m n¶rt; u a¶rt;a au, um ¶rt;umuau. aam, m a au ¶rt;unu a¶rt;a au n ¶rt;umuauu u n¶rt; nu a an¶rt; a u uu aa
,¶rt; h a ¶rt;umuauu. 相似文献
719.
a u uma naau ¶rt; m¶rt; ¶rt; aaua ¶rt;auu uu. naau ¶rt; naam , ¶rt;mu mau a, m aa naau ¶rt;am n a au aauu uu auumu m amu m aaa um ¶rt;uam. m¶rt; m ¶rt;mam mu ¶rt;a nu auu u m mu, ma m nuu ma a a . 相似文献
720.
Jan Bednář Jaroslava Kalvová Reviewer K. Vaníček 《Studia Geophysica et Geodaetica》1980,24(4):400-413
Summary The statistical treatment of the dependence of monthly sums of global radiation on the monthly sums of sunshine at the stations of Hradec Králové, Bratislava — Koliba and Hurbanovo is presented. The parameters of linear and quadratic regression are derived for the said stations and for the individual months of the year. Drawing on the statistical analysis of the initial data sets, the accuracy and reliability of the mentioned regression relations are critically evaluated. 相似文献