全文获取类型
收费全文 | 912篇 |
免费 | 15篇 |
专业分类
927篇 |
出版年
2020年 | 26篇 |
2019年 | 37篇 |
2018年 | 36篇 |
2017年 | 45篇 |
2016年 | 35篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 240篇 |
2012年 | 21篇 |
2011年 | 25篇 |
2010年 | 22篇 |
2009年 | 25篇 |
2008年 | 22篇 |
2007年 | 25篇 |
2006年 | 23篇 |
2005年 | 17篇 |
2004年 | 21篇 |
2003年 | 17篇 |
2002年 | 8篇 |
2001年 | 15篇 |
2000年 | 6篇 |
1999年 | 12篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1970年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有927条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
95.
Behavioral ecology is the study of adaptive behavior in relation to social and environmental circumstances. Analysts working from this perspective hold that the reproductive strategies and decision-making capacities of all living organisms—including humans—are shaped by natural selection. Archaeologists have been using this proposition in the study of past human behavior for more than 30 years. Significant insights on variation in prehistoric human subsistence, life history, social organization, and their respective fossil and archaeological consequences have been among the more important results. 相似文献
96.
97.
98.
99.
Modern technology lends itself to holistic exploration and widely accessible outreach. New technology allows scientists studying
our planet either from space or deep under the seas, to explore and reveal both natural and cultural resources that have previously
escaped our scrutiny. However, the use of these new technologies is expensive and often the exclusive tool of industrial research.
Yet, these new technologies can lead the way to greater collaboration, better science and more public access. In 2003 and
2004, a landmark project, combining government agencies, industrial technology and outreach set new standards in collaborative
scientific exploration. The project focused on six shipwrecks at depth in the Gulf of Mexico. The questions posed by the project
illuminate how science and industry can collaborate to produce remarkable results. The papers presented in this issue form
a model for deepwater exploration. 相似文献
100.
This paper is an attempt to understand the changing characteristics of urban poverty in Turkey since 1980. First, it analyses how the urban poor in Turkey had adopted aggressive survival strategies by strengthening their solidarity networks on religious, ethnic and cultural bases until the 2000s. Then it sheds light on how those networks have dissolved later on thanks to a set of internal and external factors and concludes that Turkey now faces deepening poverty levels and engendering new forms and dynamics of poverty. This paper is based on the Sultanbeyli district of Istanbul, a district almost entirely composed of unauthorized houses whose population grew at an unprecedented rate after 1980; and it is a perfect case for the study of issues relating to migration, urbanization and poverty in Turkish cities. 相似文献