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   86251篇
  免费   2792篇
  国内免费   23篇
  2020年   726篇
  2019年   933篇
  2018年   4331篇
  2017年   3684篇
  2016年   3340篇
  2015年   1157篇
  2014年   1255篇
  2013年   5408篇
  2012年   2633篇
  2011年   4385篇
  2010年   3697篇
  2009年   2791篇
  2008年   3599篇
  2007年   3947篇
  2006年   1936篇
  2005年   1856篇
  2004年   1746篇
  2003年   1604篇
  2002年   1647篇
  2001年   2129篇
  2000年   2144篇
  1999年   1619篇
  1998年   851篇
  1997年   742篇
  1996年   696篇
  1995年   651篇
  1993年   648篇
  1992年   1331篇
  1991年   1226篇
  1990年   1215篇
  1989年   1106篇
  1988年   1090篇
  1987年   1050篇
  1986年   1103篇
  1985年   1123篇
  1984年   965篇
  1983年   872篇
  1981年   651篇
  1979年   1017篇
  1978年   754篇
  1975年   813篇
  1974年   876篇
  1973年   958篇
  1972年   796篇
  1971年   756篇
  1970年   651篇
  1969年   684篇
  1968年   871篇
  1967年   785篇
  1966年   653篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
891.
892.
Handling time and choice in pigeons   总被引:2,自引:1,他引:1       下载免费PDF全文
According to optimal foraging theory, animals should prefer food items with the highest ratios of energy intake to handling time. When single items have negligible handling times, one large item should be preferred to a collection of small ones of equivalent total weight. However, when pigeons were offered such a choice on equal concurrent variable-interval schedules in a shuttlebox, they preferred the side offering many small items per reinforcement to that offering one or a few relatively large items. This preference was still evident on concurrent fixed-cumulative-duration schedules in which choosing the alternative with longer handling time substantially lowered the rate of food intake.  相似文献   
893.
Scores on the Beck Depression Inventory (BDI) were periodically obtained from the roommates of college students who exhibited a persistent mild depression over a 3-month period. For comparative purposes, BDI scores were also obtained from roommates of individuals who were transiently depressed and from subjects with nondepressed roommates. In comparison with control subjects, the roommates of persistently depressed persons displayed a progressive increase in BDI score over the course of the study.  相似文献   
894.
895.
896.
The foot is a highly cathected appendage that is commonly singled out as the brunt of humorous or derisive remarks, as if it embodies repugnance and disgust. Attitudes toward the foot are overdetermined, bearing the imprint of man's early linguistic patterns and individual dynamics. This article suggests that feet are symbolic because they bear the feelings derived from earlier separations, good and bad object representations, collective memories, and genital representations. The foot's role as symbol of both the male and female genitals, repository of badness, symbol of passivity, initiator of movement, and site of self-mutilation have been briefly reviewed. As Fats Waller rhapsodizes that the "feet's too big," he finds a convenient way to displace his symbiotic and erotic anxieties vis-à-vis women. Similarly, patients who come for psychiatric treatment and psychotherapy frequently make references to their feet or use them in specific ways. An understanding of this type of communication can often provide insight into individual dynamics and enhance treatment. The weight placed on these communications depends, of course, on the vicissitudes of the previous therapeutic work as well as on the particular problems of the patient.  相似文献   
897.
898.
Gender differences across age in motor performance a meta-analysis   总被引:3,自引:0,他引:3  
  相似文献   
899.
Two perspectives on the nature of the social group and psychological group formation are discussed. The traditional social cohesion approach traces group formation to processes of interpersonal attraction, while the social identity approach defines the group in cognitive terms and considers identification, or self-categorization, to be the mechanism of psychological group formation. On the basis of an experiment by Turner, Sachdev and Hogg (1983) it is hypothesized that interpersonal attraction (positive or negative) is related to group formation only in so far as it enhances intergroup distinctiveness. This hypothesis is experimentally tested in a 2 × 3 (interpersonal liking/disliking per se versus no explicit categorization/random categorization/criterial categorization on the basis of affect) factorial design employing the ‘minimal group’ paradigm. People who like each other and were not explicitly categorized formed a group. This effect was enhanced by criterial categorization but disappeared when categorization was random. Although the results do not support the hypothesis, they are not explicable in social cohesion terms. A social identity explanation is furnished—attraction influences group formation by acting, under certain specifiable conditions, as a cognitive criterion for common category membership. This explanation is located in current theorizing and is proposed as part of a reconceptualization of the relationship between interpersonal attraction and group formation.  相似文献   
900.
This paper seeks to offer an alternative approach to the study of prejudice than that based upon the notion of categorization which is currently influential in cognitive social psychology. It is argued that the categorization approach assumes the inevitability of prejudice and ignores the issue of tolerance. The assumptions of the categorization approach are criticized, and it is suggested that, by focusing on categorization as a cognitive process, it has overlooked an opposing process—that of particularization. The result has been a rather mechanical and bureaucratic model of cognition. A less mechanical view is possible if the relations between the two processes of categorization and particularization are considered from a rhetorical perspective, which examines the argumentative nature of thought. For theoretical and empirical reasons, this perspective does not equate prejudiced thinking with rigid categorization; instead a rhetorical approach permits a distinction between prejudice and tolerance on the basis of content, rather than form, and thereby avoids assuming the inevitability of prejudice.  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