全文获取类型
收费全文 | 1161篇 |
免费 | 175篇 |
国内免费 | 409篇 |
专业分类
测绘学 | 13篇 |
大气科学 | 9篇 |
地球物理 | 356篇 |
地质学 | 1063篇 |
海洋学 | 104篇 |
天文学 | 2篇 |
综合类 | 21篇 |
自然地理 | 177篇 |
出版年
2024年 | 14篇 |
2023年 | 29篇 |
2022年 | 61篇 |
2021年 | 72篇 |
2020年 | 60篇 |
2019年 | 62篇 |
2018年 | 71篇 |
2017年 | 75篇 |
2016年 | 54篇 |
2015年 | 61篇 |
2014年 | 48篇 |
2013年 | 63篇 |
2012年 | 76篇 |
2011年 | 52篇 |
2010年 | 48篇 |
2009年 | 72篇 |
2008年 | 56篇 |
2007年 | 83篇 |
2006年 | 75篇 |
2005年 | 58篇 |
2004年 | 74篇 |
2003年 | 60篇 |
2002年 | 48篇 |
2001年 | 40篇 |
2000年 | 43篇 |
1999年 | 35篇 |
1998年 | 31篇 |
1997年 | 36篇 |
1996年 | 37篇 |
1995年 | 24篇 |
1994年 | 25篇 |
1993年 | 29篇 |
1992年 | 20篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1983年 | 1篇 |
排序方式: 共有1745条查询结果,搜索用时 0 毫秒
1.
S. ENDO S.WALLIS T. HIRATA R. ANCZKIEWICZ J. PLATT M. THIRLWALL Y. ASAHARA 《Journal of Metamorphic Geology》2009,27(5):371-384
Two distinct age estimates for eclogite-facies metamorphism in the Sanbagawa belt have been proposed: (i) c. 120–110 Ma based on a zircon SHRIMP age for the Western Iratsu unit and (ii) c. 88–89 Ma based on a garnet–omphacite Lu–Hf isochron age from the Seba and Kotsu eclogite units. Despite the contrasting estimates of formation ages, petrological studies suggest the formation conditions of the Western Iratsu unit are indistinguishable from those of the other two units—all ∼20 kbar and 600–650 °C. Studies of the associated geological structures suggest the Seba and Western Iratsu units are parts of a larger semi-continuous eclogite unit. A combination of geochronological and petrological studies for the Western Iratsu eclogite offers a resolution to this discrepancy in age estimates. New Lu–Hf dating for the Western Iratsu eclogite yields an age of 115.9 ± 0.5 Ma that is compatible with the zircon SHRIMP age. However, petrological studies show that there was significant garnet growth in the Western Iratsu eclogite before eclogite facies metamorphism, and the early core growth is associated with a strong concentration of Lu. Pre-eclogite facies garnet (Grt1) includes epidote–amphibolite facies parageneses equilibrated at 550–650 °C and ∼10 kbar, and this is overgrown by prograde eclogite facies garnet (Grt2). The Lu–Hf age of c. 116 Ma is strongly skewed to the isotopic composition of Grt1 and is interpreted to reflect the age of the pre-eclogite phase. The considerable time gap ( c. 27 Myr) between the two Lu–Hf ages suggests they may be related to separate tectonic events or distinct phases in the evolution of the Sanbagawa subduction zone. 相似文献
2.
3.
4.
DONG Yunpeng ZHANG Guowei ZHAO Xia YAO Anping & LIU Xiaoming The Key Laboratory of Continental Dynamics Ministry of Education Department of Geology Northwest University Xi抋n China 《中国科学D辑(英文版)》2004,(4)
Being a composite collisional orogen between North China and South China blocks, the Qinling orogenic belt is the key to understand the composite combination, prolonged evolutionary history and their continental dynamics. The main suture between north and south Qinling, called Shangdan suture zone (SDSZ), had been studied in detail for about twenty years. Recently, another suture zone, called Mianl黣 suture zone (MLSZ), has been identified in the Qinling Mountains. It is characterized b… 相似文献
5.
6.
7.
Preseismic lithospheric deformation at a subduction zone can be modelled as dip-slip dislocation on an inclined fault or as
flexure of a thin plate. Both these models predict a region of positive topography known as forebulge or outer rise. By matching
the location and the magnitude of the forebulge, we derive useful relations between the dip-slip fault parameters and the
plate parameters. In particular, we determine the width of a long dip-slip fault of given dip corresponding to a semi-infinite
plate of given thickness. The displacement profiles of the two models are also compared. 相似文献
8.
In southern Taiwan the initial collision of the Luzon volcanic arc with the passive continental margin of China results in the emergence of an accretionary prism of, predominantly, turbidites in composition, thus providing an appropriate place to study the temporal and spatial variation of deformation during the transition of subduction to arc-continent collision. Field surveys have recently been carried out in slightly metamorphosed rocks along the well-exposed Jinlun-Taimali coast in southeastern Taiwan. Three folding phases are identified in the area. The first phase is characterized by gently dipping but widely distributed phyllitic cleavage (S1). The second phase is represented by sparsely distributed crenulation cleavage (S2) that folded the phyllitic cleavage. The third phase is characterized by E–W trending antiforms (F3) that involved both types of pre-existing cleavages. Restoration of such an antiform in the north using a method proposed in this paper reveals that phyllitic cleavage in the overturned beds dips gently towards the southeast or east-southeast before the antiform, in relation to the first-phase thrusting or folding under regional ESE-WNW compression. From the first to third phase, the maximum horizontal compression underwent an about 90° anticlockwise rotation from ESE-WNW to E–W or NE–SW to N–S, and the deformation depth seems to decrease drastically, in terms of the decreasing proportion of pervasive deformation. All these variations are attributed to the oblique arc-continent collision that exhumed the whole accretionary prism and induced a local stress perturbation in southeastern Taiwan. 相似文献
9.
中亚造山带是世界上最大的显生宙增生型造山带,是研究增生造山过程和大陆地壳生长的绝佳场所,其形成记录了新元古代—早中生代古亚洲洋发展演化历程,主要由一系列微陆块、岛弧、海山/大洋高原、增生杂岩及蛇绿混杂岩构成.中亚造山带西段蛇绿混杂岩物质组成基本一致,除了典型的蛇绿岩组分外,大多发育典型的海山岩石组合,即枕状玄武岩、火山... 相似文献
10.