全文获取类型
收费全文 | 13478篇 |
免费 | 2022篇 |
国内免费 | 2004篇 |
专业分类
测绘学 | 779篇 |
大气科学 | 2219篇 |
地球物理 | 4083篇 |
地质学 | 6133篇 |
海洋学 | 1299篇 |
天文学 | 721篇 |
综合类 | 1054篇 |
自然地理 | 1216篇 |
出版年
2024年 | 51篇 |
2023年 | 161篇 |
2022年 | 368篇 |
2021年 | 465篇 |
2020年 | 350篇 |
2019年 | 398篇 |
2018年 | 832篇 |
2017年 | 763篇 |
2016年 | 719篇 |
2015年 | 563篇 |
2014年 | 616篇 |
2013年 | 595篇 |
2012年 | 1086篇 |
2011年 | 914篇 |
2010年 | 591篇 |
2009年 | 632篇 |
2008年 | 612篇 |
2007年 | 578篇 |
2006年 | 474篇 |
2005年 | 1156篇 |
2004年 | 1110篇 |
2003年 | 866篇 |
2002年 | 422篇 |
2001年 | 306篇 |
2000年 | 285篇 |
1999年 | 365篇 |
1998年 | 306篇 |
1997年 | 297篇 |
1996年 | 280篇 |
1995年 | 222篇 |
1994年 | 195篇 |
1993年 | 210篇 |
1992年 | 177篇 |
1991年 | 113篇 |
1990年 | 79篇 |
1989年 | 71篇 |
1988年 | 64篇 |
1987年 | 39篇 |
1986年 | 41篇 |
1985年 | 20篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1965年 | 3篇 |
1958年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
61.
62.
63.
64.
65.
NotesEcologicalstudyofmacrobenthosinFuqingBay¥//INTRODUCTIONTheecologicalstudyOfmacrobenthoshasnotbeenrePOrtedthoughthemarine... 相似文献
66.
67.
68.
69.
70.
Riccardo?Geletti Emanuele?LodoloEmail author Anatoly?A.?Schreider Alina?Polonia 《Marine Geophysical Researches》2005,26(1):17-28
The structural framework of the southern part of the Shackleton Fracture Zone has been investigated through the analysis of
a 130-km-long multichannel seismic reflection profile acquired orthogonally to the fracture zone near 60° S. The Shackleton
Fracture Zone is a 800-km-long, mostly rectilinear and pronounced bathymetric lineation joining the westernmost South Scotia
Ridge to southern South America south of Cape Horn, separating the western Scotia Sea plate from the Antarctic plate. Conventional
processing applied to the seismic data outlines the main structures of the Shackleton Fracture Zone, but only the use of enhanced
techniques, such as accurate velocity analyses and pre-stack depth migration, provides a good definition of the acoustic basement
and the architecture of the sedimentary sequences. In particular, a strong and mostly continuous reflector found at about
8.0 s two-way traveltime is very clear across the entire section and is interpreted as the Moho discontinuity. Data show a
complex system of troughs developed along the eastern flank of the crustal ridge, containing tilted and rotated blocks, and
the presence of a prominent listric normal fault developed within the oceanic crust. Positive flower structures developed
within the oceanic basement indicate strike-slip tectonism and partial reactivation of pre-existing faults. Present-day tectonic
activity is found mostly in correspondence to the relief, whereas fault-induced deformation is negligible across the entire
trough system. This indicates that the E–W-directed stress regime present in the Drake Passage region is mainly dissipated
along a narrow zone within the Shackleton Ridge axis. A reappraisal of all available magnetic anomaly identifications in the
western Scotia Sea and in the former Phoenix plate, in conjunction with new magnetic profiles acquired to the east of the
Shackleton Fracture Zone off the Tierra del Fuego continental margin, has allowed us to propose a simple reconstruction of
Shackleton Fracture Zone development in the general context of the Drake Passage opening. 相似文献