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   24426篇
  免费   388篇
  国内免费   16篇
教育   17579篇
科学研究   2058篇
各国文化   232篇
体育   1953篇
综合类   14篇
文化理论   180篇
信息传播   2814篇
  2022年   192篇
  2021年   277篇
  2020年   409篇
  2019年   663篇
  2018年   891篇
  2017年   868篇
  2016年   771篇
  2015年   453篇
  2014年   728篇
  2013年   4784篇
  2012年   680篇
  2011年   692篇
  2010年   501篇
  2009年   521篇
  2008年   617篇
  2007年   524篇
  2006年   476篇
  2005年   445篇
  2004年   405篇
  2003年   390篇
  2002年   361篇
  2001年   498篇
  2000年   416篇
  1999年   379篇
  1998年   221篇
  1997年   227篇
  1996年   259篇
  1995年   255篇
  1994年   204篇
  1993年   217篇
  1992年   337篇
  1991年   304篇
  1990年   306篇
  1989年   306篇
  1988年   264篇
  1987年   306篇
  1986年   269篇
  1985年   309篇
  1984年   252篇
  1983年   215篇
  1982年   197篇
  1981年   169篇
  1980年   159篇
  1979年   259篇
  1978年   183篇
  1977年   172篇
  1976年   154篇
  1975年   145篇
  1974年   150篇
  1971年   140篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Continuous observation of the physical activity of 56 preadolescent children was conducted in four regions of England from October 1988 to July 1989. Observations were undertaken during school break times, lunch times, and physical education lessons, as well as during the children's free time. Of total time observed, the children spent 32.4% of it engaged in moderate to vigorous physical activity (MVPA). Children were shown to be most active during school breaks and least active during free time at home. However, it is thought that cardiorespiratory benefits are best achieved by participation in sustained periods of MVPA. Only 8 (14%) of the 56 children were observed to participate in MVPA for sustained periods of 20 min or longer. A random sample of 55 physical education lessons was observed. Only 6 children engaged in MVPA for sustained periods of 5 min or more, and no children participated in MVPA for 10 min or longer. The implications of these results are that, although the children engaged in a reasonable amount of MVPA, it may not have been sustained for periods of sufficient length to produce a cardiovascular training response. Consideration is given to ways of promoting lifelong involvement in physical activity.  相似文献   
2.
3.
4.
Despite increased enrollment, outcomes such as grade point average (GPA), persistence, and graduation rates for college students with learning disabilities (LD) continue to lag behind those of their nondisabled peers. Reasons for the differences vary but may include academic and social integration, factors identified as important to the success of college students in general. This research investigated the relative influence of background characteristics, precollege achievement, and college integration variables on the academic success and intent to persist of college freshmen and sophomores with LD. While academic and social integration were not unique predictors of college GPA, both integration variables were unique predictors of intent to persist. The findings suggest that beyond high school achievement and background characteristics, college experiences as captured by academic and social integration are promising constructs to help explain the persistence of college students with LD. Implications for future research and practices for high school and college personnel are discussed.  相似文献   
5.
6.
7.
How accurate is the reported percent of students’reaching standards at the school level? How are standard errors for these statistics computed? How do estimates vary with choice of generalizability model?  相似文献   
8.
In recent years university presses have undergone some significant changes, such as expansion of their scope to include materials that may have appeal beyond the scholarly market. This article investigates, through the use of a survey of university libraries, the acquisition of university press products by libraries. In general, recent years have been changes in the relationship between university presses and libraries that have resulted in fewer items being purchased by the libraries.  相似文献   
9.
10.
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