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   42248篇
  免费   1861篇
  国内免费   726篇
  2020年   465篇
  2019年   511篇
  2018年   689篇
  2017年   706篇
  2016年   740篇
  2015年   578篇
  2014年   642篇
  2013年   2919篇
  2012年   1280篇
  2011年   1307篇
  2010年   862篇
  2009年   834篇
  2008年   1166篇
  2007年   1265篇
  2006年   1108篇
  2005年   1045篇
  2004年   912篇
  2003年   807篇
  2002年   784篇
  2001年   1365篇
  2000年   1300篇
  1999年   986篇
  1998年   446篇
  1997年   381篇
  1992年   877篇
  1991年   827篇
  1990年   847篇
  1989年   735篇
  1988年   732篇
  1987年   701篇
  1986年   738篇
  1985年   808篇
  1984年   606篇
  1983年   558篇
  1982年   383篇
  1981年   365篇
  1979年   696篇
  1978年   437篇
  1977年   421篇
  1976年   422篇
  1975年   593篇
  1974年   674篇
  1973年   723篇
  1972年   625篇
  1971年   582篇
  1970年   584篇
  1969年   572篇
  1968年   763篇
  1967年   673篇
  1966年   601篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
912.
913.
Is there a cell-biological alphabet for simple forms of learning?   总被引:5,自引:0,他引:5  
  相似文献   
914.
Redundancy analysis (also called principal components analysis of instrumental variables) is a technique for two sets of variables, one set being dependent of the other. Its aim is maximization of the explained variance of the dependent variables by a linear combination of the explanatory variables. The technique is generalized to qualitative variables; it then gives implicitly a simultaneous optimal scaling of the dependent, qualitative variables. Examples are taken from the Dutch Life Situation Survey 1977, using Satisfaction with Life and Happiness as dependent variables. The analysis leads to one well-being scale, defined by the explanatory variables Marital status, Schooling, Income and Activity.The views expressed in this paper are those of the author and do not necessarily reflect the policies of the Netherlands Central Bureau of Statistics.  相似文献   
915.
Programs,language understanding,and searle   总被引:1,自引:0,他引:1  
  相似文献   
916.
917.
Two experiments demonstrated the way in which musicians and nonmusicians process realistic music encountered for the first time. A set of tunes whose members were related to each other by a number of specific musical relationships was constructed. In Experiment 1, subjects gave similarity judgments of all pairs of tunes, which were analyzed by the ADDTREE clustering program. Musicians and nonmusicians gave essentially equivalent results: Tunes with different rhythms were rated as being very dissimilar, whereas tunes identical except for being in a major versus a minor mode were rated as being highly similar. In Experiment 2, subjects learned to identify the tunes, and their errors formed a confusion matrix. The matrix was submitted to a clustering analysis. Results from the two experiments corresponded better for the nonmusicians than for the musicians. Musicians presumably exceed nonmusicians in the ability to categorize music in multiple ways, but even nonmusicians extract considerable information from newly heard music.  相似文献   
918.
In their area of expertise experts know more potentially interfering facts than nonexperts do, yet their memory IS superior to that of nonexperts. This has been termed the “paradox of interference.” We proposed that the ability of experts to go beyond the information given allows them to infer the presence of items that might not otherwise be remembered. However, such inferences can also be detrimental to accurate recognition memory in that such inferences might become confused with actual targets. We examined the benefits and costs of expertise in two recognition memory experiments In which experts and nonexperts participated. Experts in Ex-penment 1 were knowledgeable about baseball; those in Experiment 2 were knowledgeable about Ohio geography. Distractors in both studies bore a synonymous, an inferential, or no special relation to the targets. In the last instance, experts had recognition memory superior to that of the nonexperts. When the distractors were related to the targets, however, the non-experts were superior. We proposed that experts' inferential behavior is a contributor to their generally superior memory, but that task demands can convert this asset into a liability.  相似文献   
919.
Research has demonstrated that on the path from a creative idea to a creative outcome, high creativity motivation and self-efficacy do not necessarily lead to creative behavior. The present study proposed and examined the notion that daily creativity planning could promote creative behavior and contribute to the cultivation of creativity. A total of 77 middle school students (39 students in the experimental group and 38 in the control group) participated in this study, for which a quasi-experimental design was administered. The experimental group conducted a two-week daily planning for creative activities, while the control group did not conduct any intervention. The results showed that students' creativity motivation and creative self-efficacy were at relatively high levels overall and were positively and moderately correlated with creative behavior. Daily planning could effectively facilitate students' creative behavior. These findings point to a promising and simple creativity enhancement strategy for cultivating students to develop the habit of making creative plans in their daily lives.  相似文献   
920.
Humeanism – the idea that there are no necessary connections between distinct existences – and Nomic Essentialism – the idea that properties essentially play the nomic roles that they do – are two of the most important and influential positions in the metaphysics of science. Traditionally, it has been thought that these positions were incompatible competitors. We disagree. We argue that there is an attractive version of Humeanism that captures the idea that, for example, mass essentially plays the role that it actually does in the laws of nature. In this paper we consider the arguments that have lead many to conclude that Humeanism cannot be combined with Nomic Essentialism; we identify the weaknesses in these arguments; and we argue in detail that a version of Humeanism based on a variant of the Best System account of laws captures the key intuitions behind nomic essentialism.  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