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   24815篇
  免费   443篇
  国内免费   15篇
教育   17931篇
科学研究   2061篇
各国文化   254篇
体育   1988篇
综合类   14篇
文化理论   180篇
信息传播   2845篇
  2022年   197篇
  2021年   285篇
  2020年   440篇
  2019年   708篇
  2018年   942篇
  2017年   956篇
  2016年   824篇
  2015年   490篇
  2014年   751篇
  2013年   4881篇
  2012年   718篇
  2011年   723篇
  2010年   527篇
  2009年   546篇
  2008年   600篇
  2007年   529篇
  2006年   463篇
  2005年   440篇
  2004年   399篇
  2003年   395篇
  2002年   373篇
  2001年   490篇
  2000年   429篇
  1999年   378篇
  1998年   218篇
  1997年   223篇
  1996年   258篇
  1995年   247篇
  1994年   193篇
  1993年   206篇
  1992年   327篇
  1991年   305篇
  1990年   300篇
  1989年   302篇
  1988年   258篇
  1987年   304篇
  1986年   267篇
  1985年   310篇
  1984年   251篇
  1983年   211篇
  1982年   192篇
  1981年   166篇
  1980年   156篇
  1979年   258篇
  1978年   184篇
  1977年   169篇
  1976年   153篇
  1975年   141篇
  1974年   149篇
  1971年   140篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The purpose of this investigation was to describe the morphological parameters that characterize elite age group divers. Comparisons are made to normative age group data from the Coquitlam Growth Study and the constancy of important characteristics from age group to age group is examined. Data were collected on 27 male and 28 female elite divers who participated in the 1990 North American Age Group Diving Championships. Body build, body composition and skinfold corrected diameters were determined from 36 anthropometric parameters and analysed by ANOVA, t-test and Phantom z-scores procedures. All age groups except the 14- to 15-year-old males were significantly (P < or = 0.05) shorter than their norms but recorded higher androgyny index values. The estimated relative muscle mass increased significantly (P < or = 0.05) with age for males at all ages (40.8-46.3%). The 16- to 18-year-old females had a significantly (P < or = 0.05) larger relative muscle component compared to the younger age groups (40.1-38.4%). When normalized for height, active tissue development of the extremities was comparable between the sexes except in the forearm. The results indicate that at all age levels short stature is an important characteristic for divers. Analysis of regional active tissue development provides further insight into sport-specific prerequisites for success at elite levels.  相似文献   
32.
This article is a preliminary analysis of the first few years of the Computer Matching and Privacy Protection Act of 1988 (CMPPA). The act requires Federal agencies to establish Data Integrity Boards (DIBs) with responsibility to approve written agreements for computer matches in which their agencies are involved. Information for this analysis was collected from the annual reports on computer matching submitted by agencies to the Office of Management and Budget (OMB) for 1990 and 1991 and from 108 matching agreements. The secretaries of several DIBs were also interviewed. The effectiveness of DIBs and matching agreements are analyzed using McCubbins and Schwartz's distinction between “police-patrol” and “fire- alarm” oversight. The article concludes that more active and direct oversight, which would occur through an independent data protection or privacy board, is necessary.  相似文献   
33.
34.
35.
36.
37.
38.
39.
40.
Between 1880 and 1950, the role of women as authors of elementary readers flowered and faded. From 1880 to 1915, female authorship dominated. Over the next fifteen years female authorship withstood the challenge of the scientific movement in education. Women’s role as solo authors declined, however, during the Depression, World War II and the postwar years. These changes are explained by the deteriorating environment for female professionalism, changes in the concept of reading expertise, the expanded role of publishers in textbook development, and the differences between men and women in opportunities for graduate study. E. Jennifer is Monaghan a professor in the Department of Educational Services, Brooklyn College of the City University of New York. She is the founder of the History of Reading Special Interest Group of the International Reading Association and author ofA Common Heritage: Noah Webster’s Blue-Back Speller.  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