首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1688篇
  免费   117篇
  国内免费   82篇
测绘学   90篇
大气科学   99篇
地球物理   452篇
地质学   882篇
海洋学   81篇
天文学   128篇
综合类   28篇
自然地理   127篇
  2024年   3篇
  2023年   13篇
  2022年   56篇
  2021年   59篇
  2020年   67篇
  2019年   78篇
  2018年   150篇
  2017年   130篇
  2016年   176篇
  2015年   81篇
  2014年   182篇
  2013年   173篇
  2012年   92篇
  2011年   103篇
  2010年   61篇
  2009年   74篇
  2008年   57篇
  2007年   39篇
  2006年   54篇
  2005年   30篇
  2004年   24篇
  2003年   25篇
  2002年   23篇
  2001年   18篇
  2000年   15篇
  1999年   6篇
  1998年   13篇
  1997年   7篇
  1996年   3篇
  1995年   5篇
  1994年   7篇
  1993年   7篇
  1992年   7篇
  1991年   2篇
  1990年   3篇
  1989年   2篇
  1988年   6篇
  1987年   3篇
  1986年   3篇
  1985年   4篇
  1984年   3篇
  1983年   3篇
  1982年   2篇
  1981年   3篇
  1978年   2篇
  1975年   3篇
  1974年   2篇
  1973年   1篇
  1972年   2篇
  1971年   1篇
排序方式: 共有1887条查询结果,搜索用时 15 毫秒
71.

A 6.8-magnitude earthquake that occurred on January 24, 2020, has been effective in Turkey’s eastern regions. The earthquake, with recorded peak ground acceleration (PGA) value of 0.292 g, caused the destruction or heavy damage of buildings, especially in the city center of Elaz?? province. The purpose of this paper was to share the results of detailed investigation in the earthquake-stricken area. Additionally, the causes of damages and failures observed in the buildings were compared to those that had occurred in previous earthquakes in Turkey. In this study, the damages observed in especially RC buildings as well as in masonry and rural buildings were summarized, the lessons learned were evaluated, and the results were interpreted with reference to Turkish earthquake codes. In the study, it was particularly emphasized why the building stock underwent such damage even though the buildings were exposed to earthquake acceleration well below the design acceleration values.

  相似文献   
72.

Excavation-induced ground movements and the resulting damages to adjacent structures and facilities is a source of concern for excavation projects in urban areas. The concern will be even higher if the adjacent structure is old or has low strength parameters like masonry building. Frame distortion and crack generation are predictors of building damage resulted from excavation-induced ground movements, which pose challenges to projects involving excavations. This study is aimed to investigate the relation between excavation-induced ground movements and damage probability of buildings in excavation affected distance. The main focus of this paper is on masonry buildings and excavations stabilized using soil nail wall method. To achieve this purpose, 21 masonry buildings adjacent to 12 excavation projects were studied. Parametric studies were performed by developing 3D FE models of brick walls and excavations stabilized using soil nail wall. Finally, probability evaluations were conducted to analyze the outputs obtained from case studies. Based on the obtained results, simple charts were established to estimate the damage of masonry structures in excavation affected distance with two key parameters including “Displacement Ratio” and “Normalized Distance”. The results also highlight the effects of building distance from excavation wall on its damage probability.

  相似文献   
73.
Geotechnical and Geological Engineering - The effects of diameter and location of drain pipes on the uplift force and exit hydraulic gradient for a gravity dam are investigated. A numerical model...  相似文献   
74.
Acta Geochimica - In the last five decades, Rare Earth Elements (REE) are mostly produced from carbonatite complexes and alkaline magmatic environments. In this respect, pyroclastic flows produced...  相似文献   
75.
Acta Geotechnica - A systematical testing program on frozen Onsøy clay under isotropic loading and undrained shearing at different temperatures...  相似文献   
76.
Acta Geotechnica - In this study, an analytical model is developed to establish a framework for predicting the coefficient of lateral soil pressure in unsaturated soils. To this end, the disturbed...  相似文献   
77.
古尔班通古特沙漠是中国最大的固定、半固定沙漠.利用2017年该沙漠克拉美丽站辐射资料,分析了古尔班通古特沙漠不同时间尺度和不同天气条件下的地表辐射变化特征.结果表明:(1)不同月份沙漠辐射收支各分量月平均日变化均呈单峰型,但极值大小及出现时间存在差异.各分量曝辐量季节变化明显:太阳总辐射表现为生长期(4-9月)>积雪期...  相似文献   
78.
Ali  Moamen  Abdelhady  A.  Abdelmaksoud  Ahmed  Darwish  M.  Essa  M. A. 《Natural Resources Research》2020,29(2):1259-1281
Natural Resources Research - The Albian/Cenomanian reservoir is one of the two main reservoirs composing the petroleum system in the Komombo Basin. However, these reservoirs have not previously...  相似文献   
79.
Natural Resources Research - In the present study, ground subsidence in the Aliabad plain (central Iran) was investigated using differential synthetic aperture radar interferometry. The data used...  相似文献   
80.
Natural Resources Research - The northwest of Iran is considered as a promising geothermal zone owing to its geographical properties, tectonic features, and thermal activities, particularly in...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号