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   2852篇
  免费   59篇
  国内免费   1篇
教育   2367篇
科学研究   41篇
各国文化   43篇
体育   119篇
综合类   1篇
文化理论   11篇
信息传播   330篇
  2023年   9篇
  2022年   10篇
  2021年   43篇
  2020年   44篇
  2019年   81篇
  2018年   101篇
  2017年   105篇
  2016年   106篇
  2015年   72篇
  2014年   105篇
  2013年   619篇
  2012年   93篇
  2011年   89篇
  2010年   68篇
  2009年   90篇
  2008年   97篇
  2007年   86篇
  2006年   56篇
  2005年   73篇
  2004年   86篇
  2003年   58篇
  2002年   47篇
  2001年   47篇
  2000年   51篇
  1999年   52篇
  1998年   34篇
  1997年   38篇
  1996年   51篇
  1995年   37篇
  1994年   40篇
  1993年   33篇
  1992年   45篇
  1991年   32篇
  1990年   28篇
  1989年   20篇
  1988年   17篇
  1987年   14篇
  1986年   18篇
  1985年   19篇
  1984年   17篇
  1983年   21篇
  1982年   13篇
  1981年   19篇
  1980年   13篇
  1979年   15篇
  1978年   10篇
  1976年   10篇
  1975年   9篇
  1970年   13篇
  1968年   8篇
排序方式: 共有2912条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
Video market entry options available to telephone companies under the Telecommunications Act of 1996 have First Amendment implications that will affect the constitutional value of telephone video. These entry options impose regulatory constraints upon providers and differ in potentials for provider speech, speaker access, and content diversity. The author concludes that the Act's open video system option best advances First Amendment interests in increased diversity of and access to speech.  相似文献   
16.
17.
18.
Introduction     
  相似文献   
19.
The aims of this study were to describe normative values and seasonal variation of body composition in female cyclists comparing female road and track endurance cyclists, and to validate the use of anthropometry to monitor lean mass changes. Anthropometric profiles (seven site skinfolds) were measured over 16 years from 126 female cyclists. Lean mass index (LMI) was calculated as body weight?×?skinfolds?x. The exponent (x) was calculated as the slope of the natural logarithm of body weight and skinfolds. Percentage changes in LMI were compared to lean mass changes measured using dual-energy X-ray absorptiometry (DXA) in a subset of 25 road cyclists. Compared to sub-elite and elite cyclists, world class cyclists were (mean [95% CI]) 1.18?kg [0.46, 1.90] and 0.60?kg [0.05, 1.15] lighter and had skinfolds that were 7.4?mm [3.8, 11.0] and 4.6?mm [1.8, 7.4] lower, respectively. Body weight (0.41?kg [0.04, 0.77]) and skinfolds (4.0?mm [2.1, 6.0]) were higher in the off-season compared to the early-season. World class female road cyclists had lower body weight (6.04?kg [2.73, 9.35]) and skinfolds (11.5?mm [1.1, 21.9]) than track endurance cyclists. LMI (mean exponent 0.15 [0.13, 0.18]) explained 87% of the variance in DXA lean mass. In conclusion, higher performing female cyclists were lighter and leaner than their less successful peers, road cyclists were lighter and leaner than track endurance cyclists, and weight and skinfolds were lowest early in the season. LMI appears to be a reasonably valid tool for monitoring lean mass changes.  相似文献   
20.
Academic libraries are one of the most important sources of “on the job” training for future library instructors. Librarians who supervise and assess these future library instructors (often in graduate assistant positions) often choose to provide observations and feedback each semester to these instructors in training. Scholarly literature, however, provides little information on whether this system helps graduate assistants to develop as teachers. The authors of this article assessed graduate assistants’ performance as teachers over three semesters using a system of observation and self-assessment. They analyzed both patterns and areas of growth and discuss the strengths and weaknesses of this system.  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