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   52716篇
  免费   2104篇
  国内免费   30篇
  54850篇
  2020年   587篇
  2019年   745篇
  2018年   1075篇
  2017年   1082篇
  2016年   1130篇
  2015年   754篇
  2014年   938篇
  2013年   4584篇
  2012年   1694篇
  2011年   1829篇
  2010年   1059篇
  2009年   1094篇
  2008年   1671篇
  2007年   1645篇
  2006年   1437篇
  2005年   1306篇
  2004年   1282篇
  2003年   1161篇
  2002年   1203篇
  2001年   1757篇
  2000年   1660篇
  1999年   1273篇
  1998年   680篇
  1997年   583篇
  1996年   519篇
  1995年   528篇
  1994年   500篇
  1993年   520篇
  1992年   1012篇
  1991年   957篇
  1990年   946篇
  1989年   856篇
  1988年   820篇
  1987年   805篇
  1986年   805篇
  1985年   860篇
  1984年   676篇
  1983年   582篇
  1982年   473篇
  1979年   656篇
  1978年   489篇
  1976年   449篇
  1975年   590篇
  1974年   620篇
  1973年   595篇
  1972年   540篇
  1971年   473篇
  1968年   539篇
  1967年   540篇
  1966年   475篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
153.
This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here.  相似文献   
154.
155.
We prove that there are two involutions defined by monadic terms that characterize Monadic Algebras. We further prove that the variety of Monadic Algebras is the smallest variety of Interior Algebras where these involutions give rise to an interpretation from the variety of Bounded Distributive Lattices into it.Research funded by Fondecyt, project N 764-1987.  相似文献   
156.
We obtain in this paper a representation of the formulae of extensions ofL by generalized quantifiers through functors between categories of first-order structures and partial isomorphisms. The main tool in the proofs is the back-and-forth technique. As a corollary we obtain the Caicedo's version of Fraïssés theorem characterizing elementary equivalence for such languages. We also discuss informally some geometrical interpretations of our results.  相似文献   
157.
158.
The purpose of the present study was to determine whether the sex role orientations of male and female collegiate athletes were more similar in team sports than in individual sports. It was predicted that females in masculine-oriented team sports (basketball and volleyball) would exhibit sex role orientations more similar to those of their male counterparts than would females in individual sports (track/field and swimming). To test this notion the S. L. Bem (The Measurement of Psychological Androgyny, Journal of Consulting and Clinical Psychology, 1974, 42, 155–167) Sex Role Inventory was administered to 381 athletes from 37 National Collegiate Athletic Association institutions. The median-split procedure (S. L. Bem, On the Utility of Alternative Procedures for Assessing Psychology Androgyny, Journal of Consulting and Clinical Psychology, 1977, 45, 196–205) was used to classify subjects as masculine, feminine, androgynous, or undifferentiated. Separate Gender × Sex Role Orientation chi square tests were performed on the frequency data of team and individual sport athletes. The results indicated no significant differences in the sex role orientations of male and female team sport performers, with the greatest proportion (66%) having a masculine (33%) or androgynous (33%) orientation. For individual sports there was a significant difference in the sex role orientations of males and females. The highest proportion of females were classified as feminine (37%) and the lowest proportion were classified as masculine (11%). Individual sport males were somewhat evenly distributed among the four sex role orientation categories, with the highest proportion classified as undifferentiated (36%). It was concluded that sex role orientation of elite female athletes may be associated with the male appropriateness of the sport in which they participate.  相似文献   
159.
In the mind of many people chance and luck act as real but different causes of events. Even in strictly defined situations as casino gambling, people may perceive influences of luck that help to overcome the negative expectancy defined by the rules of chance. Interviews with gamblers in casinos confirmed this idea. In two experiments it was established that the distinction between chance and luck are also made by ordinary subjects in everyday situations. The results revealed that chance is perceived to operate when an event is surprising, an unexpected coincidence. Luck is perceived when an event implies the escape from negative consequences, or the achievement of something that is important and difficult. The distinction between chance and luck can explain why people are trapped by the illusion of control, even when it is clear that they have no influence on the physical causation determining the outcomes of events. They cannot change the outcome of the roulette wheel, but they can employ their luck, which helps them to place their bets on the winning number.  相似文献   
160.
Computerized career information and guidance systems, although now commonplace, have received little psychometric scrutiny. The authors argue for examining these systems in the same way in which paper and pencil instruments are assessed. Consideration is also given to issues related to programming, technical-service problems, and staffing.  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