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   59040篇
  免费   2392篇
  国内免费   18篇
  61450篇
  2020年   549篇
  2019年   737篇
  2018年   980篇
  2017年   1008篇
  2016年   1075篇
  2015年   782篇
  2014年   922篇
  2013年   4301篇
  2012年   1725篇
  2011年   1887篇
  2010年   1166篇
  2009年   1155篇
  2008年   1671篇
  2007年   1687篇
  2006年   1540篇
  2005年   1357篇
  2004年   1254篇
  2003年   1178篇
  2002年   1290篇
  2001年   1959篇
  2000年   1936篇
  1999年   1463篇
  1998年   681篇
  1997年   605篇
  1996年   605篇
  1993年   546篇
  1992年   1236篇
  1991年   1135篇
  1990年   1123篇
  1989年   1024篇
  1988年   1008篇
  1987年   963篇
  1986年   1039篇
  1985年   1046篇
  1984年   875篇
  1983年   797篇
  1982年   559篇
  1981年   557篇
  1979年   933篇
  1978年   665篇
  1975年   760篇
  1974年   814篇
  1973年   907篇
  1972年   766篇
  1971年   722篇
  1970年   642篇
  1969年   668篇
  1968年   855篇
  1967年   775篇
  1966年   651篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Public goods theories highlight an incentive system that rewards ‘free riding’ on the contributions of early contributors toward collective actions. However, because such theories focus on creation of the good, they may underestimate returns that accrue to early contributors subsequent to the good's realization. The concept of formative investment is introduced here to describe the extent to which organizations help to create public goods such as interorganizational linkages like participatory federations. Data from the CEOs of 48 organizations involved in a participatory federation were used to assess how an organization's level of formative investment is related to later patterns of dependency and interaction among federation members. Findings suggest that from a long‐term perspective, and for goods that involve communication and interaction, the incentive structure may not be so favorable for free riders. To the extent that organizations with high formative investment have the capability to envision the future and communicate that vision to potential federation partners, they may be able to both reduce free riding and secure for themselves advantageous positions in the subsequent network of relations.  相似文献   
42.
43.
44.
The token economy has been the primary model for the behavioral management of inpatient populations. However, this basically operant approach seldom emphasizes the development of cognitive-coping skills to help patients more effectively manage stressors that result in hospitalization. The Therapeutic Contract Program (TCP) is described as an inpatient-treatment strategy that is designed to help foster such cognitive-coping and self-control skills. While external structure is provided by components of this program, subprograms of the TCP have as their goal the development of internally-attributed coping skills and self-perceptions of competence. This preliminary report describes the structure of the TCP, as well as planned and in-progress measures of program participation and treatment outcome.  相似文献   
45.
Three factors that have transformed perceptual research in the last fifty years are the digital computer, single-unit electrophysiology, and molecular biology. Amongst the developments in which members of the Experimental Psychology Society have been central are: the recognition of the role of optic flow in spatial vision; the demonstration that our perceptual systems contain parallel pathways extracting different information from the sensory array; the identification of specific detectors that can be selectively adapted in psychophysical experiments; and the transfer of the concepts of fourier analysis from audition to vision. The history of Opponent Process Theory offers an example where experimental psychologists have been misled by too simple an interpretation of physiological recordings.  相似文献   
46.
47.
48.
49.
50.
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