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   22894篇
  免费   404篇
  国内免费   31篇
教育   16569篇
科学研究   1992篇
各国文化   212篇
体育   1738篇
综合类   35篇
文化理论   191篇
信息传播   2592篇
  2022年   128篇
  2021年   235篇
  2020年   374篇
  2019年   516篇
  2018年   725篇
  2017年   799篇
  2016年   750篇
  2015年   447篇
  2014年   606篇
  2013年   4398篇
  2012年   582篇
  2011年   646篇
  2010年   493篇
  2009年   476篇
  2008年   534篇
  2007年   526篇
  2006年   461篇
  2005年   402篇
  2004年   380篇
  2003年   339篇
  2002年   393篇
  2001年   440篇
  2000年   417篇
  1999年   414篇
  1998年   222篇
  1997年   251篇
  1996年   260篇
  1995年   225篇
  1994年   218篇
  1993年   202篇
  1992年   307篇
  1991年   306篇
  1990年   339篇
  1989年   323篇
  1988年   299篇
  1987年   255篇
  1986年   264篇
  1985年   328篇
  1984年   274篇
  1983年   256篇
  1982年   198篇
  1981年   169篇
  1980年   150篇
  1979年   221篇
  1978年   183篇
  1977年   169篇
  1976年   144篇
  1975年   119篇
  1974年   109篇
  1973年   136篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
Indexing consistency in MEDLINE   总被引:3,自引:0,他引:3  
The quality of indexing of periodicals in a bibliographic data base cannot be measured directly, as there is no one "correct" way to index an item. However, consistency can be used to measure the reliability of indexing. To measure consistency in MEDLINE, 760 twice-indexed articles from 42 periodical issues were identified in the data base, and their indexing compared. Consistency, expressed as a percentage, was measured using Hooper's equation. Overall, checktags had the highest consistency. Medical Subject Headings (MeSH) and subheadings were applied more consistently to central concepts than to peripheral points. When subheadings were added to a main heading, consistency was lowered. "Floating" subheadings were more consistent than were attached subheadings. Indexing consistency was not affected by journal indexing priority, language, or length of the article. Terms from MeSH Tree Structure categories A, B, and D appeared more often than expected in the high-consistency articles; whereas terms from categories E, F, H, and N appeared more often than expected in the low-consistency articles. MEDLINE, with its excellent controlled vocabulary, exemplary quality control, and highly trained indexers, probably represents the state of the art in manually indexed data bases.  相似文献   
94.
95.
A cooperative acquisition program for monographs for the twelve resource libraries in Region IX of the Regional Medical Library Network is described. Each of the participating libraries has agreed to purchase all books of an assigned publisher which fall within a prescribed subject-format profile. It is hoped that this will help to reduce unnecessary duplication and contribute toward the development of resources in the region.  相似文献   
96.
97.
98.
99.
100.
In recent years, the landscape for wireless technology has changed substantially, with profound implications for the evolution of last-mile access infrastructure. This paper provides a high-level introduction to emerging trends in wireless technology, with a special focus on how these are impacting municipal broadband deployments. Also discussed are some of the key architectural and design choices for wireless networking systems and their implications for cost and system performance. In addition, examples are provided regarding how the new wireless technologies are being deployed by municipalities in a variety of contexts, with reference to wireless technologies currently available from vendors. The policy implications of these trends are discussed further in a companion paper in this issue.  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