全文获取类型
收费全文 | 264篇 |
免费 | 16篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 6篇 |
大气科学 | 17篇 |
地球物理 | 66篇 |
地质学 | 78篇 |
海洋学 | 26篇 |
天文学 | 74篇 |
综合类 | 2篇 |
自然地理 | 13篇 |
出版年
2024年 | 1篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 4篇 |
2016年 | 15篇 |
2015年 | 12篇 |
2014年 | 12篇 |
2013年 | 16篇 |
2012年 | 13篇 |
2011年 | 11篇 |
2010年 | 15篇 |
2009年 | 19篇 |
2008年 | 16篇 |
2007年 | 15篇 |
2006年 | 14篇 |
2005年 | 13篇 |
2004年 | 14篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有282条查询结果,搜索用时 0 毫秒
281.
The possibility of controlling the seismic response of tall buildings by use of a structural system consisting of a stiff and lightly damped external structure and a very flexible and moderately damped internal structure connected by stiff links at a few elevations is explored. Optimal damping values for the internal structure are obtained by consideration of the response on the composite structure in the vicinity of its fundamental mode. The resulting optimal damping values depend on the relative stiffness of both structures. Numerical results in the frequency and time domain are used to illustrate the advantages of such a system for seismic excitation. The possibility of using flexible links between the internal and external structures to moderate the required reduction of stiffness in the internal structure is also explored. © 1998 John Wiley & Sons, Ltd. 相似文献
282.
Mayra C. Robles-Montes Guillermo Martínez-Flores Michael K. Faught Enrique H. Nava-Sánchez 《Geoarchaeology》2024,39(2):106-121
When the first Americans inhabited the area now known as Isla Espiritu Santo, around 12.5 and 6 ka, the sea level continuously rose. This resulted in the loss of the coastal territory and the retreat of the human population further inland. Part of the archaeological evidence of this period currently lies over the seafloor and under the seabed. Therefore, reconstructing paleoshorelines is a necessary first step toward submerged precontact archaeology and a broad understanding of the spatial context in which those human populations interacted and how the landscapes changed. Isla Espiritu Santo is of prehistoric importance as it contains numerous Paleocoastal tradition sites as early as ~12,400 Cal B.P. This research aims to reconstruct the changing shoreline positions as sea levels rose around Isla Espiritu Santo between 12.5 and 6.5 ka. We apply numerical modeling to map digital elevation models at 1 ka intervals by estimating the changes in the morphology of the seafloor according to the deposition rates and global sea-level curve. The results show the evolution of coastal morphology and paleoshoreline's position. Three primary geoforms are proposed: (1) coastal plains, (2) tombolo, and (3) a coastal lagoon–island barrier system. This also offers insights into the physical aspect of submerged prehistoric landscapes and the possible resource exploitation options of early societies. In this research, the reconstruction of submerged landscapes seeks to contribute to the long-term goal of locating submerged precontact sites. 相似文献