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   3754篇
  免费   34篇
教育   2570篇
科学研究   594篇
各国文化   8篇
体育   233篇
综合类   8篇
文化理论   79篇
信息传播   296篇
  2023年   4篇
  2022年   17篇
  2021年   37篇
  2020年   38篇
  2019年   60篇
  2018年   130篇
  2017年   166篇
  2016年   233篇
  2015年   145篇
  2014年   82篇
  2013年   214篇
  2012年   194篇
  2011年   189篇
  2010年   103篇
  2009年   51篇
  2008年   99篇
  2007年   77篇
  2006年   59篇
  2005年   704篇
  2004年   483篇
  2003年   307篇
  2002年   138篇
  2001年   68篇
  2000年   39篇
  1999年   27篇
  1998年   16篇
  1997年   11篇
  1996年   7篇
  1995年   8篇
  1994年   5篇
  1993年   5篇
  1992年   3篇
  1991年   2篇
  1990年   6篇
  1989年   5篇
  1988年   9篇
  1987年   5篇
  1985年   3篇
  1982年   2篇
  1981年   6篇
  1979年   2篇
  1978年   3篇
  1976年   4篇
  1974年   2篇
  1973年   2篇
  1972年   3篇
  1969年   2篇
  1968年   2篇
  1903年   1篇
  1870年   1篇
排序方式: 共有3788条查询结果,搜索用时 15 毫秒
41.
This paper presents an adaptive strategy for controlling chaotic systems. By employing the phase space reconstruction technique in nonlinear dynamical systems theory, the proposed strategy transforms the nonlinear system into canonical form, and employs a nonlinear observer to estimate the uncertainties and disturbances of the nonlinear system, and then establishes a state-error-like feedback law. The developed control scheme allows chaos control in spite of modeling errors and parametric variations. The effectiveness of the proposed approach has been demonstrated through its applications to two well-known chaotic systems: Duffing oscillator and Rössler chaos.  相似文献   
42.
43.
44.
In Japan, there has been an increased concern about family and community participation in the childs education. Traditionally, the role of parents and community in Japan has been one of support and less one of active involvement in school learning. Since the government commenced education reforms in the last quarter of the 20th century, a more active role for parents and the community in education has been encouraged. These reforms have been inspired by the need to tackle various problems that had arisen, such as the perceived harmful elements of societys preoccupation with academic achievement and the problematic behavior of young people. In this paper, the following issues are examined: (1) education policy and reform measures with regard to parent and community involvement in the childs education; (2) the state of parent and community involvement at the eve of the 20th century.  相似文献   
45.
46.
This study explored the role of student (e.g., age, language background, gender), home (e.g., parent/caregiver education), and school (e.g., school type, size) socio-demographic factors in students’ school (e.g., in-school arts tuition, arts engagement), home (e.g., parent/caregiver–child arts interaction), and community (e.g., arts attendance, arts tuition) arts participation. The sample comprised 1172 elementary and secondary school students from 15 schools. Findings revealed that student and home socio-demographic factors were the most salient in predicting arts participation across school, home, and community contexts. Age, gender, and prior achievement were the key student socio-demographic factors, while parent/caregiver education and occupation were also associated with students’ arts participation. Implications for practice and intervention pertinent to young people’s arts participation are discussed.  相似文献   
47.
This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional. The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs.  相似文献   
48.
European Journal of Psychology of Education - The purpose of this study was to test the relationships between critical thinking, prior topic knowledge and beliefs, and multiple-document...  相似文献   
49.
50.
This article examines the historical fantasy world created by Joan Aiken in the eleven volumes of her Wolves of Willoughby Chase series. In particular it looks at her subversion of historical reality by the creation of an alternative yet recognisable representation of our own world, using a wide range of events, and the remoulding of aspects of language and geography. It also discusses her reasons for writing in this form and explores the character of Dido Twite as heroine and major raison dtre of the series.This revised version was published online in May 2005 with corrections to the article title.  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