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   40300篇
  免费   1517篇
  国内免费   18篇
  2020年   415篇
  2019年   427篇
  2018年   570篇
  2017年   591篇
  2016年   679篇
  2015年   530篇
  2014年   598篇
  2013年   2920篇
  2012年   1097篇
  2011年   1081篇
  2010年   714篇
  2009年   711篇
  2008年   985篇
  2007年   962篇
  2006年   854篇
  2005年   828篇
  2004年   751篇
  2003年   711篇
  2002年   762篇
  2001年   1273篇
  2000年   1252篇
  1999年   885篇
  1998年   403篇
  1997年   388篇
  1992年   791篇
  1991年   755篇
  1990年   776篇
  1989年   728篇
  1988年   670篇
  1987年   672篇
  1986年   681篇
  1985年   714篇
  1984年   625篇
  1983年   556篇
  1982年   414篇
  1981年   435篇
  1979年   628篇
  1978年   481篇
  1977年   415篇
  1976年   396篇
  1975年   583篇
  1974年   673篇
  1973年   694篇
  1972年   573篇
  1971年   557篇
  1970年   513篇
  1969年   549篇
  1968年   680篇
  1967年   644篇
  1966年   586篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Experiment 1 replicated Yaniv and Meyer's (1987) finding that lexical decision and episodic recognition performance was better for words previously yielding high-accessibility levels (a combination of feeling-of-knowing and tip-of-the-tongue ratings) in comparison with those yielding low-accessibility levels in a rare word definition task. Experiment 2 yielded the same pattern even though lexical decisions preceded accessibility estimates by a full week. Experiment 3 dismissed the possibility that the Experiment 2 results may have been due to a long-term influence from the lexical decision task to the rare word judgment task. These results support a model in which Ss (a) retrieve topic familiarity information in making accessibility estimates in the rare word definition task and (b) use this information to modulate lexical decision performance.  相似文献   
22.
23.
OBJECTIVE: To test a theoretical model of how ethnic pride and self-control are related to risk and protective factors. DESIGN: A community sample of 670 African American youth (mean age = 11.2 years) were interviewed in households. MAIN OUTCOME MEASURES: Measures of cigarette smoking, alcohol use, and sexual behavior (lifetime to past month). RESULTS: Structural modeling analyses indicated parenting was related to self-control and self-esteem, and racial socialization was related to ethnic pride. Self-control and self-esteem variables were related to levels of deviance-prone attitudes and to perceptions of engagers in, or abstainers from, substance use and sexual behavior. The proximal factors (behavioral willingness, resistance efficacy, and peer behavior) had substantial relations to the criterion variables. Participant gender and parental education also had several paths in the model. Results were generally similar for the 2 outcome behaviors. CONCLUSIONS: In this population, self-esteem and self-control are related to parenting approaches and have pathways to attitudes and social perceptions that are significant factors for predisposing to, or protecting against, early involvement in substance use and sexual behavior.  相似文献   
24.
Most studies of suicide in younger patients have demonstrated significant alterations in the serotonin system. Although a high percentage of completed suicides occur in late-life, to date very few studies of the biology of suicide have focused on this age group. This chapter describes age-related changes in the central nervous system pertinent to the biology of suicide, then reviews post-mortem biological studies of the brains of suicides and suicide attempters. As suicide attempts in the elderly are characterized by the use of violent means, biologic studies of impulsive violence are discussed. Finally we describe data on the effect of degenerative diseases on the serotonin system and the possible link to increased suicidal behavior in affected patients. This review underscores the need for further study of the biology of suicide in the geriatric age group.  相似文献   
25.
26.
27.
This paper was not available at the time of going to press. It will be published in a future volume of the Proceedings of The Aristotelian Society.  相似文献   
28.
The three reliability and two construct validity studies presented here represent the first psychometric research on the commercially successful and popular Hartman Color Code Personality Profile. The reliability studies found high reliability after 3 and 6 weeks. The construct validity studies substantiated that the Color Code assesses some personality traits. The magnitude of the error variance suggests caution, however, in using the Color Code classifications at the individual level.  相似文献   
29.
It is widely assumed that reinforcers are biologically relevant stimuli, or stimuli that have been associated with biologically relevant stimuli. However, brief, arbitrary stimuli have also been reported to have reinforcement-like effects, despite being unrelated to biologically relevant stimuli like food. The present study explored the potential reinforcement-like effects of brief stimuli across 5 experiments. In Experiments 1 through 4, pigeon subjects responded for food reinforcement and brief stimulus presentations in a 2-component multiple schedule. Neither baseline response rates nor resistance to change during disruption tests were systematically greater in a component with versus without brief stimulus presentations. Increasing the rate and duration of brief stimulus presentations in Experiment 4 did not reveal reinforcement-like effects when compared directly with food. In Experiment 5, pigeons chose between independent terminal links in a concurrent-chains procedure. Across conditions, varying the location, duration, and rate of brief stimulus presentations in the terminal links had no systematic effects on preference. In contrast, varying rates of food reinforcers resulted in large and reliable shifts in preference. Therefore, the present study found no systematic evidence that brief stimuli unrelated to food reliably increase response rates, resistance to change, or preference. These data demonstrate the value of systematic replication, and a behavioral momentum approach to assessing potential reinforcement-like effects.  相似文献   
30.
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