全文获取类型
| 收费全文 | 67篇 |
| 免费 | 1篇 |
专业分类
| 测绘学 | 2篇 |
| 地球物理 | 17篇 |
| 地质学 | 38篇 |
| 海洋学 | 2篇 |
| 天文学 | 6篇 |
| 自然地理 | 3篇 |
出版年
| 2022年 | 1篇 |
| 2021年 | 1篇 |
| 2020年 | 2篇 |
| 2019年 | 1篇 |
| 2018年 | 1篇 |
| 2017年 | 3篇 |
| 2016年 | 5篇 |
| 2015年 | 5篇 |
| 2014年 | 2篇 |
| 2013年 | 10篇 |
| 2012年 | 5篇 |
| 2011年 | 6篇 |
| 2010年 | 4篇 |
| 2009年 | 3篇 |
| 2008年 | 1篇 |
| 2007年 | 2篇 |
| 2005年 | 4篇 |
| 2004年 | 2篇 |
| 2003年 | 2篇 |
| 2002年 | 1篇 |
| 1999年 | 1篇 |
| 1996年 | 1篇 |
| 1994年 | 1篇 |
| 1990年 | 1篇 |
| 1989年 | 2篇 |
| 1970年 | 1篇 |
排序方式： 共有68条查询结果，搜索用时 15 毫秒
11.
12.
An earthquake of local magnitude 5.3 (duration magnitudeM
d
) on the Richter Scale occurred at Dahshour, 18 km south of Cairo, Egypt, on Monday, 12 October 1992 at 3:09 pm (local time). Numerous aftershocks followed the main event during the following weeks with magnitude up to 4.3. The earthquake occurred in an area that has had no recent seismic activity, and affected many cities in Egypt. Many buildings and monuments were severely damaged or collapsed. Modern concrete skeletal structures suffered minor nonstructural damage. Earthquake physical damage was estimated at about one billion U.S. Dollars. The severity of the damage was mainly due to poor construction materials and detailing, aging, inferior workmanship, and inadequate maintenance. Egypt was generally considered to be an area of moderate seismic activity. In 1989, earthquake provisions were first introduced in the Egyptian Code of Practice for Reinforced Concrete Structures only. The earthquake clearly showed the urgent need for an assessment and rehabilitation program to mitigate seismic risk hazard in existing structures. In addition, future development planning, and earthquake preparedness strategies should implement lessons learned from the event. In this paper, an overview discussion about the observations from the 12 October earthquake is presented. 相似文献
13.
The Albian–Maastrichtian seismic horizon analysis in central Tunisia (Gafsa–Sidi Bouzid area) using the reflection seismic sections calibrated to the well data, shows buried structures with deposit distributions and sedimentation geometries varying from the depressive to uplifted zones. Pinch outs, unconformities and hiatuses recognized on the folded high structures are caused by reactivation of the bordering faults. The Turonian–Maastrichtian unconformities correspond to the palaeogeographic limits that outline the Kasserine Islets and correspond to the N120, N180 major wrench-salt-intruded corridors and associated N90, N60 strike-slip faults. Formation of the different structures and evolution of the basins and platforms were controlled by conjugate dextral and sinistral strike-slip movements. These structures allow new palaeogeographic limits of the Kasserine Islets to be identified. To cite this article: T. Zouaghi et al., C. R. Geoscience 337 (2005). 相似文献
14.
Mourad Zeghal Ahmed-W. Elgamal Ender Parra 《Soil Dynamics and Earthquake Engineering》1996,15(8):523-547
Downhole records of seismically-induced soil liquefaction are a valuable source of information on the associated mechanisms of stiffness degradation and lateral spreading. In this paper, free-field downhole array seismic records are employed to identify and model the recorded response at Wildlife Refuge (California, USA) and Port Island (Kobe, Japan) sites. The Wildlife Refuge site was instrumented in 1982 with a two-accelerometer array and six piezometers that recorded a case of seismically induced site liquefaction. At Port Island, a four-accelerometer down-hole array recorded strong motion during the recent 1995 Hyogoken-Nanbu earthquake. This earthquake resulted in widespread liquefaction and major ground deformations at Port Island. Using the recorded downhole accelerations at these two sites, the actual seismic shear stress-strain histories are directly evaluated. These histories provide valuable insight into the mechanisms of site liquefaction and associated loss of stiffness and strength. Based on the identified dynamic soil behaviors, computational simulations of the observed seismic response are performed. Optimization techniques are employed to estimate the necessary computational modeling parameters. This document constitutes the second part of a set of two companion papers about site amplification and liquefaction. 相似文献
15.
Marco Langbroek Peter Jenniskens Leo M. Kriegsman Henk Nieuwenhuis Niek De Kort Jacob Kuiper Wim Van Westrenen Michael E. Zolensky Karen Ziegler Qing‐Zhu Yin Matthew E. Sanborn Josh Wimpenny Akane Yamakawa Sebastiaan J. De Vet Matthias M. M. Meier Kees C. Welten Kunihiko Nishiizumi Marc W. Caffee Aaron S. Burton Jason P. Dworkin Daniel P. Glavin Qinghao Wu Richard N. Zare Alexander Ruf Mourad Harir Philippe Schmitt‐Kopplin 《Meteoritics & planetary science》2019,54(7):1431-1461
A carbonaceous chondrite was recovered immediately after the fall near the village of Diepenveen in the Netherlands on October 27, 1873, but came to light only in 2012. Analysis of sodium and poly‐aromatic hydrocarbon content suggests little contamination from handling. Diepenveen is a regolith breccia with an overall petrology consistent with a CM classification. Unlike most other CM chondrites, the bulk oxygen isotopes are extremely 16O rich, apparently dominated by the signature of anhydrous minerals, distributed on a steep slope pointing to the domain of intrinsic CM water. A small subset plots closer to the normal CM regime, on a parallel line 2 ‰ lower in δ17O. Different lithologies in Diepenveen experienced varying levels of aqueous alteration processing, being less aqueously altered at places rather than more heated. The presence of an agglutinate grain and the properties of methanol‐soluble organic compounds point to active impact processing of some of the clasts. Diepenveen belongs to a CM clan with ~5 Ma CRE age, longer than most other CM chondrites, and has a relatively young K‐Ar resetting age of ~1.5 Ga. As a CM chondrite, Diepenveen may be representative of samples soon to be returned from the surface of asteroid (162173) Ryugu by the Hayabusa2 spacecraft. 相似文献
16.
Mourad Zeghal Ahmed-W. Elgamal Xiangwu Zeng Kandiah Arulmoli 《Soil Dynamics and Earthquake Engineering》1999,18(1):568
The process of dynamically induced liquefaction in two centrifuge soil models is analyzed. These models consist of saturated medium-dense sand overlain by a low permeability silt deposit, and represent prototypes of a level site and an embankment. The recorded lateral accelerations are employed to evaluate shear stress and strain histories at different elevations within the tested soil systems. These histories shed light on the involved liquefaction process, and the associated mechanisms of: (1) lateral deformation; (2) stiffness and strength degradation; and (3) possible densification and regain of stiffness, thereafter. The identified response patterns are found comparable to those documented by laboratory cyclic-loading tests. 相似文献
17.
Acta Geotechnica - In the last few decades, several empirical correlations of SPT-N with geotechnical parameters of sand have been developed based on conventional field and laboratory test results.... 相似文献
18.
19.
20.