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   72230篇
  免费   2831篇
  国内免费   37篇
  2020年   744篇
  2019年   906篇
  2018年   1327篇
  2017年   1337篇
  2016年   1396篇
  2015年   956篇
  2014年   1179篇
  2013年   5971篇
  2012年   2114篇
  2011年   2299篇
  2010年   1411篇
  2009年   1399篇
  2008年   2132篇
  2007年   2058篇
  2006年   1856篇
  2005年   1655篇
  2004年   1623篇
  2003年   1513篇
  2002年   1577篇
  2001年   2224篇
  2000年   2123篇
  1999年   1658篇
  1998年   876篇
  1997年   790篇
  1996年   741篇
  1995年   737篇
  1993年   685篇
  1992年   1391篇
  1991年   1312篇
  1990年   1277篇
  1989年   1160篇
  1988年   1154篇
  1987年   1112篇
  1986年   1168篇
  1985年   1207篇
  1984年   980篇
  1983年   854篇
  1979年   988篇
  1978年   765篇
  1976年   695篇
  1975年   878篇
  1974年   986篇
  1973年   978篇
  1972年   839篇
  1971年   782篇
  1970年   724篇
  1969年   751篇
  1968年   914篇
  1967年   864篇
  1966年   820篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
42.
In three experiments, successive negative contrast was examined in one-way avoidance learning. Reward magnitude in first (pre-shift) and second (post-shift) phases was manipulated by time spent in the safe compartment. Experiment 1 demonstrated that when time in the danger compartment was held constant, a group shifted from a large reward--30 sec spent in the safe compartment--to a small reward--1 sec--showed poor performance and longer response latency than a group conditioned with the small reward in both phases. Experiment 2 replicated this effect with a less intense shock and also demonstrated that a group shifted from large to small reward performed more poorly than a group exposed to large reward--30 sec--in both phases. Finally, Experiment 3 showed that changes in intertrial interval, defined as total time spent in the safe compartment and the danger compartment before the onset of the warning signal, were not responsible for this contrast effect. These results suggest that time spent in a safe place can act as appetitive incentive during one-way avoidance learning.  相似文献   
43.
44.
The essay examines intellectual virtue in the Summa theologiae, taking it as an interpretative key to the epistemology of the Summa theologiae as a whole. Because Aquinas blurs the line between the acquired and the theological virtues, and between virtues and the gifts of the Spirit, it becomes impossible to maintain the distinction between the realms of nature and grace, or between natural reason and revealed truth: grace permeates the most ordinary activities of human reasoning. This reading of the Summa theologiae raises questions about many contemporary debates, particularly those concerning natural law.  相似文献   
45.
46.
47.
48.
49.
50.
Gay marriages (as such) are not as yet allowed anywhere but the demand for them is increasing. Most countries take a liberal attitude towards marriage: few obstacles are put in its way. But objections to gay marriages continue to be raised. These objections are refuted and the case for gay marriage is assessed through the prism of various forms of liberalism. The normative argument for allowing gay marriage is shown to be both strong and consistent with many of the values upheld by the opponents of such unions.  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