全文获取类型
收费全文 | 345篇 |
免费 | 15篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 14篇 |
地球物理 | 100篇 |
地质学 | 171篇 |
海洋学 | 38篇 |
天文学 | 26篇 |
综合类 | 1篇 |
自然地理 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 14篇 |
2019年 | 13篇 |
2018年 | 22篇 |
2017年 | 20篇 |
2016年 | 20篇 |
2015年 | 12篇 |
2014年 | 19篇 |
2013年 | 20篇 |
2012年 | 17篇 |
2011年 | 16篇 |
2010年 | 20篇 |
2009年 | 19篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 13篇 |
2005年 | 20篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1973年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有362条查询结果,搜索用时 390 毫秒
71.
72.
N. V. Lubnina A. I. Slabunov A. V. Stepanova A. Yu. Bubnov N. I. Kosevich M. A. Novikova N. A. Tarasov 《Moscow University Geology Bulletin》2016,71(5):311-322
As a resulting of comprehensive studies of Paleoproterozoic igneous complexes a regular remagnetization trend is revealed. It is shown that the remagnetization front propagated from the northwest to southeast. The obtained remagnetization trend probably reflects the direction of the collision in the Paleoproterozoic. Correlation between remagnetization processes and rock compositions was found. The degree of conservation of secondary earlier and later magnetization components is likely associated to both the compositions of protoliths and different transformation conditions of rocks, including their fluid saturation. 相似文献
73.
74.
Maria V. Triantaphyllou Alexandra Gogou Margarita D. Dimiza Sofia Kostopoulou Constantine Parinos Grigoris Roussakis Maria Geraga Ioanna Bouloubassi Dominik Fleitmann Vassilis Zervakis Dimitris Velaoras Antonia Diamantopoulou Angeliki Sampatakaki Vassilis Lykousis 《Geo-Marine Letters》2016,36(1):51-66
75.
76.
Do the shallow‐water habitats of a hypersaline tropical estuary act as nursery grounds for fishes? 下载免费PDF全文
Natalice dos Santos Sales Alexandra Sofia Baptista Vicente Baeta Lidiane Gomes de Lima André Luiz Machado Pessanha 《Marine Ecology》2018,39(1)
Fish assemblages were studied in a hypersaline tropical estuary in Northeastern Brazil. A total of 104 species were collected by beach seine during the dry and rainy seasons of 2012. Two families, Atherinopsidae and Gerreidae, were numerically dominant in all zones of the estuary; juveniles of Atherinella brasiliensis, Eucinostomus argenteus, Lile piquitinga, Ulaema lefroyi, Lutjanus analis and Sphoeroides greeleyi contributed 77% of the total catch. The factors that best explained the fish abundance pattern were salinity and depth, which were related to spatial segregation. Species richness was lowest in the upper zone, an area with high salinity and shallow depth. The distinct roles of structurally different habitats (submerged macrophyte beds and mangrove prop‐roots) and the influence of physicochemical conditions in the middle zone of the estuary may influence taxonomic diversity. The middle zone of the estuary is the one most attractive to juveniles of reef species (Lutjanidae and Serranidae). The fish assemblages are clearly dominated by marine estuarine dependent species, highlighting the importance of the ecosystem as a nursery ground for marine species of the Brazilian coast. 相似文献
77.
E. A. Rogozhin A. V. Gorbatikov N. V. Larin M. Yu. Stepanova 《Izvestiya Atmospheric and Oceanic Physics》2010,46(8):973-981
Geological and geomorphological studies of the Moscow Aulacogene in the western part of Moscow suburbs have been conducted.
This deep structure has been studied by microseismic sounding. The resulting section presents the faults which frame the Teplostanskii
Graben in the south (Ramenskii or Butovskii, expressed on the surface as a ledge in the relief) and in the north (Pavlovo-Posadskii,
being traced on the surface as a series of lineaments and the valley of Setun’ River). The position of the surface Archean-Lower
Proterozoic crystalline basement within the limits of the graben and within the limits of buried elevated blocks (Krasnogorskii
and Tumsk-Shaturskii) frame it in the north and south, respectively. Additionally, another fault has been identified in the
central part of the graben: the Solntsevskii fault, which has a north-western course and which separates the deflection of
the basement in two blocks that are sunken in a slightly different degree. The low-velocity horizons of the Riphean-Vendian
complex which make up the graben at depths of 2 to 4.5 km have been found. Down to depths of 15 km, as a component of the
upper crust, the graben is underlain by a high-velocity material which also forms the upper part of the section of the crystalline
basement in the neighboring elevated block. A low-velocity block of the lithosphere is located in the larger (northern) part
of the graben deeper (down to 40 km) beneath the zones of Pavlovo-Posadskii and Solntsevskii faults; in the southern part
there is a high-velocity block. In the fault zones framing the graben in the north and south, the surface layer and soil displays
a flow of juvenile hydrogen and helium which exceeds several tenfold the background values. According to the collected data,
the Teplostanskii Graben has roots traceable through the entire crust and penetrating into the upper mantle. 相似文献
78.
Julien Némery Vincent Mano Alexandra Coynel Henri Etcheber Florentina Moatar Michel Meybeck Philippe Belleudy Alain Poirel 《水文研究》2013,27(17):2498-2508
Carbon and total suspended sediment (TSS) loads were investigated from April 2006 to March 2008 in the mountainous watershed of the Isère River, French Alps (5570 km2). The river bed has been highly impounded for hydroelectricity production during the last century. Hydraulic flushes are managed every year to prevent TSS storage within upstream dams. The Isère River has been instrumented for high‐frequency monitoring of water, TSS by turbidity and carbon (organic, inorganic, dissolved and particulate) in order to evaluate the impact of natural floods and hydraulic flushes on annual loads. Annual TSS load which was estimated between 1.3 and 2.3 MT y?1 (i.e. 233 to 413 T km?2 y?1) highlighted the high erodibility of the Isère watershed. Annual carbon load was estimated between 173 103 T y?1 and 199 103 T y?1 (i.e 31 to 36 T km?2 y?1). About 80% of the annual carbon loads were inorganic. The impact of hydraulic flushes on annual loads appeared limited (less than 3% for annual TSS load and about 1.5% for annual carbon load), whereas the most important natural flood event contributed to 20% of the annual TSS load and 10% of the annual carbon load. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
79.
We determined 15N/14N ratios of total nitrogen in surface sediments and dated sediment cores to reconstruct the history of N-loading of the North Sea. The isotopic N composition in modern surface sediments is equivalent to and reflects the isotopic mixture of oceanic nitrate on the one hand (δ15N = 5‰) and the imprint of river-borne nitrogen input into the SE North Sea (δ15N up to 12‰ in estuaries of the SE North Sea) on the other hand. We compare the results with δ15N records from pre-industrial sediment intervals in cores from the Skagerrak and Kattegat areas, which both constitute significant depositional centres for N in the North Sea and the Baltic Sea/North Sea transition. As expected, isotopically enriched anthropogenic nitrogen was found in the two records from the Kattegat area, which is close to eutrophication sources on land. Enrichment of δ15N in cores from the Skagerrak – the largest sediment sink for nitrogen in the entire North Sea – was not significant and values were similar to those found in sediment layers representing pre-industrial conditions. We interpret this isotopic uniformity as an indication that most riverine reactive nitrogen with its characteristic isotopic signature is removed by denitrification in shallow shallow-water sediments before reaching the main sedimentary basin of the North Sea. 相似文献
80.