全文获取类型
| 收费全文 | 163篇 |
| 免费 | 9篇 |
| 国内免费 | 3篇 |
专业分类
| 测绘学 | 3篇 |
| 大气科学 | 7篇 |
| 地球物理 | 72篇 |
| 地质学 | 50篇 |
| 海洋学 | 20篇 |
| 天文学 | 5篇 |
| 综合类 | 2篇 |
| 自然地理 | 16篇 |
出版年
| 2022年 | 1篇 |
| 2021年 | 8篇 |
| 2020年 | 3篇 |
| 2019年 | 2篇 |
| 2018年 | 9篇 |
| 2017年 | 8篇 |
| 2016年 | 12篇 |
| 2015年 | 12篇 |
| 2014年 | 8篇 |
| 2013年 | 8篇 |
| 2012年 | 2篇 |
| 2011年 | 7篇 |
| 2010年 | 10篇 |
| 2009年 | 6篇 |
| 2008年 | 4篇 |
| 2007年 | 3篇 |
| 2006年 | 2篇 |
| 2005年 | 7篇 |
| 2004年 | 11篇 |
| 2003年 | 5篇 |
| 2002年 | 8篇 |
| 2001年 | 2篇 |
| 2000年 | 4篇 |
| 1999年 | 2篇 |
| 1998年 | 3篇 |
| 1997年 | 1篇 |
| 1996年 | 1篇 |
| 1995年 | 1篇 |
| 1994年 | 4篇 |
| 1993年 | 1篇 |
| 1991年 | 5篇 |
| 1990年 | 3篇 |
| 1989年 | 1篇 |
| 1988年 | 3篇 |
| 1986年 | 3篇 |
| 1985年 | 1篇 |
| 1984年 | 1篇 |
| 1980年 | 1篇 |
| 1975年 | 1篇 |
| 1973年 | 1篇 |
排序方式： 共有175条查询结果，搜索用时 15 毫秒
41.
42.
Costa Rica is located geographically in the southern part of the Central American Volcanic Front, a zone where interaction between the Mesoamerican and South American cultures occurred in pre-Columbian times. Several volcanoes violently erupted during the Holocene, when the first nomadic human hunters and later settlers were present. Volcanic rocks were the most important geo-resource in making artifacts and as construction materials for pre-Columbian inhabitants. Some pottery products are believed to resemble smoking volcanoes, and the settlements around volcanoes would seem to indicate their influence on daily life. Undoubtedly, volcanic eruptions disrupted the life of early settlers, particularly in the vicinity of Arenal and Irazú volcanoes, where archaeological remains show transient effects and displacement caused by periodical eruptions, but later resilient occupations around the volcanoes. Most native languages are extinct, with the exception of those presently spoken in areas far away from active volcanoes, where no words are related to volcanic phenomena or structures. The preserved legends are ambiguous, suggesting that they were either produced during the early Spanish conquest or were altered following the pre-Columbian period. 相似文献
43.
The Quaternary evolution and the morpho-sedimentary features of some of the most important rivers in Spain (Ebro and Tagus rivers among others) have been controlled by subsidence due to alluvial karstification of the evaporitic bedrock. The subsidence mechanism may range from catastrophic collapse to slow sagging of the alluvium by passive bending. In the Ebro Basin, the mechanisms and processes involved in karstic subsidence were studied through the analysis of present-day closed depressions as well as through old subsidence depressions (palaeocollapses and solution-induced basins) and associated deformations recorded in the Quaternary alluvial sediments. The Gállego–Ebro river system is presented as a case study of channel adjustments and geomorphic and sedimentary evolution of fluvial systems in dissolution-induced subsidence areas. In this fluvial system, evaporite dissolution during particular Quaternary time intervals (namely early and middle Pleistocene) have lead to the development of a solution-induced basin, approximately 30 km-long by 8 km-wide, filled by Quaternary deposits with a total thickness in excess of 190 m. The main river response to balance the subsidence in the alluvial plain was aggradation in the central reach of the subsiding area, and degradation both in the upstream reach and in the valley sides where alluvial fans and covered pediments may prograde over the fluvial sediments. The main sinking areas are recognized in the sedimentary record by anomalous thickenings in the alluvial deposits and fine-grained sediments deposited in backswamp and ponded areas. 相似文献
44.
45.
Gerardo Grelle Laura Bonito Maresca Rosalba Silvia Iacurto Claudia Madiai Paola Revellino Giuseppe Sappa 《地震工程与工程振动(英文版)》2021,20(1):63-78
The estimate of seismic site effects by experimental approaches is based on different assumptions aimed at simplifying the complex actual site conditions and related uncertainties.However,the reliability of the results can increase if the experimental data is focused on quite strong seismic sequences and the on-site acquisition of a large number of signals is deemed strategic for the assessment of the expected phenomena.Based on these considerations,the ground motion at the Red Zone sector of Amatrice hill,violently struck by the 2016-2017 Central Italy seismic sequence,was analyzed via an observational approach.A large set of weak motions(moment magnitude Mw 2.5-3.9)was analyzed in this study by means of standard(SSR)and horizontal to vertical(HVSR)spectral ratio techniques.The results from the experimental analysis of the site effects by using weak motion and noise signals show a significant amplification at the top of Amatrice hill with a remarkable polarization of the motion and changes in spectral shapes according to the topographic setting of the relief. 相似文献
46.
47.
Anelastic Rayleigh Wave Attenuation In the Iberian Peninsula 总被引：1，自引：0，他引：1
48.
49.
50.