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   24491篇
  免费   836篇
  国内免费   13篇
  2020年   235篇
  2019年   250篇
  2018年   354篇
  2017年   414篇
  2016年   400篇
  2015年   256篇
  2014年   339篇
  2013年   1872篇
  2012年   675篇
  2011年   749篇
  2010年   441篇
  2009年   428篇
  2008年   655篇
  2007年   618篇
  2006年   577篇
  2005年   510篇
  2004年   505篇
  2003年   454篇
  2002年   542篇
  2001年   740篇
  2000年   777篇
  1999年   589篇
  1998年   289篇
  1997年   244篇
  1992年   477篇
  1991年   434篇
  1990年   461篇
  1989年   449篇
  1988年   416篇
  1987年   431篇
  1986年   425篇
  1985年   452篇
  1984年   360篇
  1983年   329篇
  1982年   270篇
  1981年   246篇
  1979年   405篇
  1978年   310篇
  1977年   290篇
  1976年   248篇
  1975年   378篇
  1974年   397篇
  1973年   373篇
  1972年   342篇
  1971年   297篇
  1970年   276篇
  1969年   328篇
  1968年   373篇
  1967年   336篇
  1966年   343篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Much of what we need to plan for our survival is already known, but what we know, how we know, and who knows is divided up between disciplines. Thus much of the problem of ensuring our survival is a matter of learning across the disciplines. We identify four modes through which we bring disciplinary knowledge together: the unity of science, integrated assessment, heuristic models, and distributed learning networks. Although none of them are perfect, we can learn how to put our knowledge together across the disciplines much better than we do.  相似文献   
3.
Evaluated the effect of varied physician affect on subject recall, anxiety, and perceptions in a simulated tense and ambiguous medical situation. Forty women at risk for breast cancer viewed videotapes of an oncologist presenting--with either worried or nonworried affect--mammogram results. Although the mammogram results and the oncologist were the same in both presentation, analyses indicated that, compared to the women receiving the results from a nonworried physician, the women receiving the results from a worried physician recalled significantly less information, perceived the clinical situation as significantly more severe, reported significantly higher levels of state anxiety, and had significantly higher pulse rates. These results suggest that physician affect plays a critical role in patient reaction to medical information. Implications for compliance research, patient satisfaction, and physician training are discussed.  相似文献   
4.
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   
5.
6.
7.
8.
Subjects in five experiments read nine-digit memory lists from a cathode ray tube for immediate recall. Reading aloud always produced a localized and reliable advantage for the last item, compared to reading silently. Two experiments on whispered and mouthed lists, with or without simultaneous broadband noise, falsified expectations derived from the theory of precategorical acoustic storage. Three additional experiments showed no enhancement of recency in the silent conditions when the digits were drawn or spelled gradually on the screen, a result that is inconsistent with the changing-state hypothesis. The classic auditory-visual modality effect is large and reliable, but still poorly understood.  相似文献   
9.
10.
In three experiments we studied the relationship between contextual conditioning and the reinstatement of extinguished lever pressing that occurs when noncontingent food is introduced following extinction. In all three experiments the non-contingent food was presented off-baseline (with the response levers not present). On subsequent tests, with the response levers present, animals that had been exposed to food showed more reinstatement of lever pressing than control animals. This finding rules out alternative mechanisms for the reinstated responding that rely on the interaction of non-contingent food and responding, such as superstitious reinforcement or the discriminative after-effects of food. In addition, in each experiment we demonstrated that manipulations known to affect contextual conditioning (signalling the food in Experiment 1, context extinction in Experiment 2, and switching contexts in Experiment 3) reduced the reinstatement. These results are consistent with the claim that contextual conditioning is important in controlling instrumental conditioning and closely parallel findings concerning the reinstatement of Pavlovian responsing following extinction.  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