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   11540篇
  免费   161篇
  国内免费   7篇
教育   7855篇
科学研究   1286篇
各国文化   373篇
体育   819篇
综合类   8篇
文化理论   82篇
信息传播   1285篇
  2021年   135篇
  2020年   191篇
  2019年   276篇
  2018年   345篇
  2017年   379篇
  2016年   348篇
  2015年   237篇
  2014年   289篇
  2013年   2101篇
  2012年   283篇
  2011年   285篇
  2010年   248篇
  2009年   247篇
  2008年   283篇
  2007年   268篇
  2006年   240篇
  2005年   188篇
  2004年   222篇
  2003年   160篇
  2002年   140篇
  2001年   173篇
  2000年   208篇
  1999年   175篇
  1998年   104篇
  1997年   97篇
  1996年   88篇
  1995年   77篇
  1994年   78篇
  1993年   88篇
  1992年   151篇
  1991年   157篇
  1990年   156篇
  1989年   166篇
  1988年   125篇
  1987年   124篇
  1986年   130篇
  1985年   170篇
  1984年   139篇
  1983年   125篇
  1982年   110篇
  1981年   82篇
  1980年   94篇
  1979年   151篇
  1978年   99篇
  1977年   93篇
  1976年   80篇
  1975年   83篇
  1974年   94篇
  1973年   86篇
  1968年   76篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Libraries today, including most hospital-based patients' libraries, are involved only peripherally in providing patient health science information. Hospital libraries should collaborate with health professionals in getting health information to patients--along with the library's more traditional roles of providing recreational reading for patients and serving the informational needs of the physician and medical staff. The library should act as the center for educational materials and programs within the hospital. Many health agencies, health educators, physicians, and librarians have been discussing the need for patient health education, but there are few effectively organized or established education centers. This paper discusses an overview of patient health education and intellectural freedom, proposes a new role for the existing hospital library in patient health education, and suggests guidelines for establishing a patient education center.  相似文献   
42.
43.
44.
45.
46.
47.
This paper describes the procedures used at the Library of the College of Physicians of Philadelphia to divide its ninety-year-old dictionary card catalog. The division was necessitated by overcrowding, obsolete subject headings, and lack of a complete authority list which resulted in like materials being scattered throughout the catalog under several headings. Two catalogs were created: the historical-biographical catalog, representing all works published before 1950 and all works of historical or biographical nature; and the current catalog, containing all works published from 1950 on, excepting historical or biographical materials. The 1950- catalog was further divided into name and subject catalogs, and the subject section was revised according to MeSH. The project was completed in about two years. As a result, searching time has been much reduced, and the library is able to take advantage of the annual revisions of MeSH to update the subject catalog.  相似文献   
48.
A computer-generated catalog of nonprint media is described. Examples are given of four access points to the data base: (1) main entry, (2) title, (3) MeSH terms, and (4) broad subject categories. The data input procedure is summarized. The AV catalog as the basis for a union list is evaluated, and finally, the catalog in relation to certain local problems is discussed.  相似文献   
49.
In Information Retrieval, since it is hard to identify users’ information needs, many approaches have been tried to solve this problem by expanding initial queries and reweighting the terms in the expanded queries using users’ relevance judgments. Although relevance feedback is most effective when relevance information about retrieved documents is provided by users, it is not always available. Another solution is to use correlated terms for query expansion. The main problem with this approach is how to construct the term-term correlations that can be used effectively to improve retrieval performance. In this study, we try to construct query concepts that denote users’ information needs from a document space, rather than to reformulate initial queries using the term correlations and/or users’ relevance feedback. To form query concepts, we extract features from each document, and then cluster the features into primitive concepts that are then used to form query concepts. Experiments are performed on the Associated Press (AP) dataset taken from the TREC collection. The experimental evaluation shows that our proposed framework called QCM (Query Concept Method) outperforms baseline probabilistic retrieval model on TREC retrieval.  相似文献   
50.
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