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   50885篇
  免费   1967篇
  国内免费   28篇
  2020年   475篇
  2019年   647篇
  2018年   888篇
  2017年   955篇
  2016年   956篇
  2015年   717篇
  2014年   797篇
  2013年   4003篇
  2012年   1410篇
  2011年   1544篇
  2010年   978篇
  2009年   956篇
  2008年   1326篇
  2007年   1314篇
  2006年   1188篇
  2005年   1045篇
  2004年   965篇
  2003年   1005篇
  2002年   974篇
  2001年   1801篇
  2000年   1744篇
  1999年   1278篇
  1998年   562篇
  1997年   478篇
  1996年   492篇
  1992年   1082篇
  1991年   1048篇
  1990年   1002篇
  1989年   943篇
  1988年   930篇
  1987年   895篇
  1986年   872篇
  1985年   941篇
  1984年   746篇
  1983年   615篇
  1981年   479篇
  1979年   769篇
  1978年   567篇
  1977年   510篇
  1976年   490篇
  1975年   654篇
  1974年   741篇
  1973年   795篇
  1972年   639篇
  1971年   577篇
  1970年   555篇
  1969年   548篇
  1968年   692篇
  1967年   616篇
  1966年   636篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
881.
882.
883.
Stress-processes and depressive symptomatology   总被引:5,自引:0,他引:5  
  相似文献   
884.
885.
A cross-cultural study of psychological differentiation of Canadian and Pakistani high school students was undertaken to examine the nature of psychological differentiation in relation to differences in age/grade, gender, and academic programs. The study involved 707 Canadian students from grades 6, 8, 10, and 12; and 349 Pakistani students from grades 8, 9, 10, and 12. The Group Embedded Figures Test was employed as a measure of the field-dependence-independence cognitive style. Analyses of data included two-way and three-way analyses of variance to determine the effects of grade, gender, and academic program upon GEFT scores. Differences in psychological differentiation between high school students in the two cultures were discussed in terms of Berry's eco-cultural model.  相似文献   
886.
A new test for measuring the ability to perceive pictorial depth was used with children of two remote Bushman populations (!Xu and Kxoe), as well as with a sample of adult Bushmen drawn from these populations and a sample of urban Zulu children. The results show that subjects of apparently little sophistication are capable of perceiving depth when confronted with a ‘geometric’ figure. They also show surprising inter-group differences which cannot be easily explained by differences of environmental experience.  相似文献   
887.
888.
Two studies were conducted to investigate the effects of perceived control in two men's prisons, one housing 181 inmates and the other housing 623 inmates. In both prisons, inmates' perceived control over the environment was found to be significantly related to their ratings of their living accommodations, experienced stress, and physical symptoms, even when type of cell was held constant.  相似文献   
889.
Pigeon's observational learning of successive visual discrimination was studied using within-subject comparisons of data from three experimental conditions. Two pairs of discriminative stimuli were used; each bird was exposed to two of the three experimental conditions, with different pairs of stimuli used in a given bird's two conditions. In one condition, observers were exposed to visual discriminative stimuli only. In a second condition, subjects were exposed to a randomly alternating sequence of two stimuli where the one that would subsequently be used as S+ was paired with the operation of the grain magazine. In a third experimental condition, subjects were exposed to the performance of a conspecific in the operant discrimination procedure. After exposures to conspecific performances, there was facilitation of discriminative learning, relative to that which followed exposures to stimulus and reinforcement sequences or exposures to stimulus sequences alone. Exposure to stimulus and food-delivery sequences enhanced performance relative to exposure to stimulus sequences alone. The differential effects of these three types of exposure were not attributable to order effects or to task difficulty; rather, they clearly were due to the type of exposure.  相似文献   
890.
Superimposition of response-independent reinforcement   总被引:6,自引:6,他引:0       下载免费PDF全文
Studies that have superimposed response-independent reinforcement (or reinforcers scheduled by contingencies placed on the absence of responding) upon conventional response-dependent schedules are reviewed. In general, providing alternative sources of reinforcement reduced response rates below the levels observed when alternative reinforcement was absent. However, response-rate elevation was sometimes found, particularly when rates of superimposed response-independent reinforcement were low. Superimposition of schedules providing reinforcers contingent on the absence of responding usually produced more severe response-rate decrements than superimposition of response-independent reinforcement. A variant of Herrnstein's equation, which assumes that some of the alternative reinforcers function as if they were delivered by baseline response-dependent source of reinforcement, is in qualitative agreement with the overall body of results obtained, and can predict both increases and decreases in response rate as resulting from superimposed reinforcers.  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