全文获取类型
收费全文 | 4543篇 |
免费 | 139篇 |
出版年
2020年 | 64篇 |
2019年 | 67篇 |
2018年 | 372篇 |
2017年 | 297篇 |
2016年 | 322篇 |
2015年 | 79篇 |
2014年 | 98篇 |
2013年 | 1074篇 |
2012年 | 101篇 |
2011年 | 256篇 |
2010年 | 247篇 |
2009年 | 99篇 |
2008年 | 133篇 |
2007年 | 138篇 |
2006年 | 48篇 |
2005年 | 62篇 |
2004年 | 42篇 |
2003年 | 30篇 |
2002年 | 38篇 |
2001年 | 35篇 |
2000年 | 46篇 |
1999年 | 45篇 |
1998年 | 37篇 |
1997年 | 30篇 |
1996年 | 34篇 |
1995年 | 30篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 20篇 |
1991年 | 28篇 |
1990年 | 19篇 |
1989年 | 33篇 |
1988年 | 23篇 |
1987年 | 25篇 |
1986年 | 30篇 |
1985年 | 40篇 |
1984年 | 29篇 |
1983年 | 35篇 |
1982年 | 24篇 |
1981年 | 38篇 |
1980年 | 35篇 |
1979年 | 34篇 |
1978年 | 36篇 |
1977年 | 26篇 |
1976年 | 32篇 |
1975年 | 25篇 |
1974年 | 19篇 |
1973年 | 28篇 |
1972年 | 22篇 |
1969年 | 22篇 |
排序方式: 共有4682条查询结果,搜索用时 265 毫秒
41.
42.
43.
Jamie B Kirkpatrick 《Geographical Research》2023,61(1):127-137
Isolation effects on the distributions of plant species in fragmented forests appear to be weak over tens to hundreds of years and strong over geological eras. The 250 km wide, 6.5 millennia old Bass Strait, and other millennium-scale disjunctions in the range of Eucalyptus regnans forests, were used to determine the effects of intermediate periods of isolation on plant species occurrence and composition. Three of six floristic communities were found on both sides of Bass Strait. The residuals from multiple regression models using climatic variables on the latitude vector were not explained by latitude, indicating negligible isolation effects from Bass Strait. However, there was a lesser compositional effect of disjunctions within land masses than between land masses, suggesting some effect of the larger barrier. No species that commonly occurred with E. regnans and were largely confined to wet forest exhibited absences from any region where the climate and soils were within their range. If areas isolated from each other for millennia can maintain their vascular plant biota, the expenditure of conservation funds on creating corridors to connect large areas separated by anthropogenic landscape modification might require more justification than it is currently afforded. 相似文献
44.
Matthias vom Hau Marc Helbling Maya Tudor Andreas Wimmer Daphne Halikiopoulou 《Nations & Nationalism》2023,29(3):810-830
The main thrust of the scholarship on nationalism has so far been concerned with its origins. But nationalism also has effects. Whether it underpins the nation-building efforts of states, is mobilised by counter-state forces or is used in everyday life, nationalism might implicate a wide range of substantive outcomes, including political regimes, public goods provision, citizenship and immigration laws, and different patterns of conflict. Yet—with a few notable exceptions—the consequences of nationalism have received significantly less scholarly attention. In response, the aim of this Exchange is to create a new dialogue between different strands of scholarship around what we know and do not know about the consequences of nationalism. We organise this Exchange around the following questions: (1) What is nationalism? (2) How can we measure nationalism? (3) What are the consequences of nationalism? (4) What are new research frontiers? 相似文献
45.
46.
47.
48.
49.
50.