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   12154篇
  免费   508篇
  国内免费   6篇
  2023年   67篇
  2022年   61篇
  2021年   122篇
  2020年   218篇
  2019年   254篇
  2018年   337篇
  2017年   311篇
  2016年   375篇
  2015年   243篇
  2014年   335篇
  2013年   1330篇
  2012年   565篇
  2011年   559篇
  2010年   410篇
  2009年   418篇
  2008年   584篇
  2007年   569篇
  2006年   503篇
  2005年   434篇
  2004年   468篇
  2003年   424篇
  2002年   416篇
  2001年   182篇
  2000年   198篇
  1999年   185篇
  1998年   188篇
  1997年   158篇
  1996年   108篇
  1995年   147篇
  1994年   145篇
  1993年   132篇
  1992年   124篇
  1991年   115篇
  1990年   111篇
  1989年   110篇
  1988年   117篇
  1987年   112篇
  1986年   89篇
  1985年   104篇
  1984年   118篇
  1983年   99篇
  1982年   111篇
  1981年   115篇
  1980年   107篇
  1979年   103篇
  1978年   112篇
  1977年   91篇
  1976年   93篇
  1975年   66篇
  1974年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
This paper describes an amplifier for an electroencephalograph with gain of 1×104 to 1×106 and made entirely of commercially available IC components. The two-stage amplifier has a preamplifier stage with fixed gain of 1000, and a second stage with variable gain from 1 to 100. The final stage, an anti-aliasing filter, adds a gain of 10 to the signal. The circuit has high common mode rejection, low input bias current, very low noise characteristics, low offset voltages, and offset nulling capability built into the circuit.  相似文献   
45.
A unique relationship exists between physicians and philosophers — one that expands on the constructive potential of the liaison between physicians and, for example, theologians, on the one hand, or, social workers on the other. This liaison should focus in the scientific aspects of medicine, not just the ethical aspects. Philosophers can provide physicians with a perspective on both the philosophy and the history of medicine through the ages — a sense of how medicine has adapted to the social cultural and ethical needs of each period. This perspective, while emphasizing medicine asscience, should not be limited to matters of methodology, or to criteria for distinguishing science from other intellectual pursuits, but should be concerned also with the history, sociology and politics of science. Both physicians and philosophers stand to gain from a strengthening of their active liaison now as never before; but most of all, the public will be the beneficiary.  相似文献   
46.
Fear of Success (FOS) was originally conceived as a unidimensional motive. However, there is both theoretical and empirical support for the hypothesis that FOS is multidimensional. We factor analyzed the responses of 236 undergraduates to twenty-oneConcern Over the Negative Consequences of Success items and found four factors. Our four factors show considerable overlap with dimensions based on theoretical accounts of FOS etiology as well as with the factor structures obtained from two other factor analytic studies. Thus, there is converging evidence that FOS is multidimensional. The relationship between multidimensional FOS and a multidimensional approach to achievement motivation is discussed.  相似文献   
47.
A previous study (Leung, Bond, & Schwartz, 1990) established that an expectancy-valence model could be used effectively to explain behaviours in three social domains both within and across cultures. In this study the model was applied to the domains of resource allocation and conflict resolution in order to pinpoint which expectancies and which valences were carrying the explanatory weight of the respondents' behavioural strategies. For both Israeli and Hong Kong students the expectancies and, less strongly, the valences tapping harmony and performance quality were important for resource allocation; those tapping animosity reduction and process control, for conflict resolution. Suggestions were offered for broadening the net of explanatory constructs for future work aimed at specifying subjective factors associated with justice-related behaviours.  相似文献   
48.
Effects of persuasive messages, responsibility denial (RD), and attitude-accessing on blood-giving attitudes, intentions, moral obligations, and behavior were examined. In Study 1, participants (n= 84) who heard a message emphasizing moral reasons for donating indicated a more favorable postmessage attitude and stronger moral obligation to donate than participants exposed to a message aimed at reducing fear, a combined moral and fear- reduction message, or no message. Combined message participants showed greatest intent to donate, yet only 14% of all participants attended a campus drive. In Study 2, low (n= 52) and high (n= 60) RD individuals heard the message arguments and were asked to access their attitudes. Low compared to high RD individuals stated a stronger sense of moral obligation, particularly when they accessed their thoughts relevant to blood donating, and behavioral intention, especially in the combined message condition. Few participants attended a blood drive (12.5%), yet most were low RD individuals from the nonaccessed attitude condition (83%). Results suggest that few individuals will engage in the altruistic act of blood donating, despite the experimental use of persuasive messages and accessing issue-relevant attitudes.  相似文献   
49.
50.
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