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   63743篇
  免费   2618篇
  国内免费   23篇
  2020年   782篇
  2019年   901篇
  2018年   1304篇
  2017年   1303篇
  2016年   1355篇
  2015年   968篇
  2014年   1185篇
  2013年   5596篇
  2012年   2147篇
  2011年   2165篇
  2010年   1313篇
  2009年   1377篇
  2008年   1868篇
  2007年   1860篇
  2006年   1685篇
  2005年   1429篇
  2004年   1467篇
  2003年   1389篇
  2002年   1350篇
  2001年   2078篇
  2000年   1914篇
  1999年   1462篇
  1998年   724篇
  1997年   650篇
  1996年   702篇
  1995年   633篇
  1994年   635篇
  1993年   647篇
  1992年   1230篇
  1991年   1129篇
  1990年   1101篇
  1989年   1053篇
  1988年   1045篇
  1987年   977篇
  1986年   947篇
  1985年   1003篇
  1984年   845篇
  1983年   738篇
  1982年   598篇
  1979年   876篇
  1978年   706篇
  1977年   588篇
  1976年   587篇
  1975年   746篇
  1974年   804篇
  1973年   806篇
  1972年   699篇
  1971年   661篇
  1968年   677篇
  1967年   614篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
A psychomotor stimulant theory of addiction   总被引:64,自引:0,他引:64  
  相似文献   
942.
A model for stimulus generalization in Pavlovian conditioning   总被引:2,自引:0,他引:2  
  相似文献   
943.
Cognitive maps as orienting schemata   总被引:3,自引:0,他引:3  
A "point-to-unseen-targets" task was used to test two theories about the nature of cognitive mapping. The hypothesis that a cognitive map is like a "picture in the head" predicts that (a) the cognitive map should have a preferred orientation and (b) all coded locations should be equally available. These predictions were confirmed in Experiments 1 and 3 when targets were cities in the northeastern United States and learning was from a map. The theory that a cognitive map is an orienting schema predicts that the cognitive map should have no preferred orientation and that targets in front of the body should be localized faster than targets behind the body. These predictions were confirmed in Experiments 1 and 2 when targets were local landmarks that had been learned via direct experience. In Experiment 3, when cities in the Northeast were targets and geographical knowledge had been acquired, in part, by traveling in the Northeast, the observed latency profiles were not as predicted by either theory of cognitive mapping. The results suggest that orienting schemata direct orientation with respect to local environments, but that orientation with respect to large geographical regions is supported by a different type of cognitive structure.  相似文献   
944.
Stimulus categorization by brain-damaged patients   总被引:1,自引:0,他引:1  
Patients with localized insult to the right hemisphere, or to either the anterior or the posterior portion of the left hemisphere, as well as neurologically intact controls, evaluated stimuli on a seven-point rating scale for their degree of category membership. The stimuli were taken from one of two continua, one composed of fruit and vegetable items, and the other of items differing in hue and shape. Different subsets of stimuli provided different contexts for the judgments of category membership. The two left-hemisphere groups showed anomalies in categorizing the fruit and vegetable items but not the perceptual items, while the reverse was true for the right-hemisphere patients. Moreover, both left-hemisphere groups demonstrated context effects in their judgments of the representativeness of the fruit and vegetable items, but differed in the way in which they responded to changing contexts. Left posterior patients demonstrated weak category boundaries and even reclassified items. In contrast, patients with left anterior damage showed highly categorical responses and less differentiation of items within a category. All groups showed striking context effects in judgments of perceptual items in terms of changes in representativeness ratings and the location of a category boundary. Alternative interpretations of the results are offered.  相似文献   
945.
946.
Two left-handed siblings with developmental stuttering are comprehensively described. The methods of study included speech and language evaluation, neurological and neuropsychological examinations, dichotic listening, auditory evoked responses, electroencephalogram, and CT scan asymmetry measurements. The data from each sibling showed evidence of anomalous cerebral dominance on many of the variables investigated. The CT scan measurements showed atypical asymmetries, especially in the occipital regions. These findings support the theory that stuttering may be related to anomalous cerebral dominance, both on functional as well as structural bases. Implications of anomalous dominance and the resultant effect of hemispheric rivalry on speech fluency are discussed.  相似文献   
947.
The urban biases of empirical research on gay men, women, and families have resulted in minimal knowledge about gay people in rural settings. The diversity of lives of rural gay women and men and the variety of patterns of meeting the challenges of rural living are described. Processes of help-seeking and help-giving are discussed and the need for a helping community of family, friends, and caring others is affirmed. Collaboration between rural gay people and rural community psychologists is suggested to promote the development of helping communities for gay people and thereby initiate a process of change in rural settings.  相似文献   
948.
Impulsivity and anxiety are two dimensions of personality which have strong effects upon the efficiency of cognitive performance. The effects of these two variables depend upon characteristics of the task as well as upon four types of tradeoffs between psychological resources. Tasks may be characterized in terms of their relative requirements for sustained information transfer (SIT), short-term memory (STM), and long-term memory (LTM). Resource tradeoffs may be automatic, strategic, directional, or stylistic. Impulsivity effects on performance involve an automatic arousal-induced tradeoff between SIT and STM, strategic tradeoffs of speed for accuracy, and stylistic differences in persistence. Anxiety effects involve strategic, directional, and stylistic tradeoffs.  相似文献   
949.
950.
To be pertinent to democratic practice, collective choice functions need not apply to all possible constellations of individual preference, but only to those that are humanly possible in an appropriate sense. The present paper develops a theory of humanly possible preference within the context of the mathematical theory of learning. The theory of preference is then exploited in an attempt to resolve Arrow's voting paradox through restriction of the domain of majoritarian choice functions.  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