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   16004篇
  免费   170篇
  国内免费   28篇
教育   11112篇
科学研究   1969篇
各国文化   79篇
体育   1029篇
综合类   9篇
文化理论   188篇
信息传播   1816篇
  2022年   79篇
  2021年   142篇
  2020年   215篇
  2019年   295篇
  2018年   1067篇
  2017年   1071篇
  2016年   829篇
  2015年   307篇
  2014年   423篇
  2013年   2126篇
  2012年   387篇
  2011年   616篇
  2010年   560篇
  2009年   416篇
  2008年   497篇
  2007年   569篇
  2006年   260篇
  2005年   291篇
  2004年   370篇
  2003年   261篇
  2002年   212篇
  2001年   284篇
  2000年   312篇
  1999年   259篇
  1998年   159篇
  1997年   188篇
  1996年   166篇
  1995年   113篇
  1994年   139篇
  1993年   97篇
  1992年   226篇
  1991年   180篇
  1990年   164篇
  1989年   192篇
  1988年   183篇
  1987年   146篇
  1986年   173篇
  1985年   160篇
  1984年   126篇
  1983年   147篇
  1982年   106篇
  1981年   92篇
  1980年   82篇
  1979年   145篇
  1978年   106篇
  1977年   92篇
  1976年   87篇
  1975年   71篇
  1974年   80篇
  1973年   83篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Acquiring both published and unpublished documents produced in Africa is, generally, a difficult task due to the existing poor state of bibliographic control and the publishing industry. It is even more difficult to obtain unpublished documents in a specialized area of study such as demography--a diffuse area which cuts across several disciplines. This paper discusses the problems encountered on acquisition trips to some African countries to acquire unpublished population material. To help solve the problems, the Population Association of Africa must persuade its members to send copies of their publications to population libraries and documentation centers in their individual countries for dissemination to the other users in Africa. The various organizations and institutions in Africa engaged in the teaching and research of population studies should have an agreement to exchange copies of their theses. The Economic Commission for Africa (ECA) and the Organization of African Unity (OAU) should make representations to the various African member countries on the need to disseminate the results of vital censuses and surveys conducted. Finally, the Population Information Network for Africa (POPIN-AFRICA) with its coordinating unit at the population division of ECA should ensure that all the nodes of the network have the financial and other resources to be able to acquire the relevant documents needed for their operations.  相似文献   
44.
Computers are integral to medical practice, education, and research. While medical students learn computer skills during their training, many practicing physicians do not have the same computer experience. To familiarize this group with the exciting developments in medical informatics, the Himmelfarb Health Sciences Library and Department of Computer Medicine at the George Washington University Medical Center organized a workshop "Introducing Your Office Computer!" for attending physicians. The workshop featured a short lecture/video presentation on computer applications in medicine followed by a "computer fair" of five computer applications. Eleven physicians attended the workshop. Feedback was very positive; many called later to request more detailed instructions on using the programs demonstrated. It was a valuable experience for the staff, and new bridges were built between departments and clients.  相似文献   
45.
The Alfred Taubman Medical Library at the University of Michigan has offered instruction in online literature searching to third-year pharmacy students as a component of the course "Drug Information and Scientific Literature Evaluation" since 1983. In the spring of 1989, a follow-up study was conducted to assess the impact of instruction on four classes of graduates. Of a pool of 151 graduates, 90 (60%) responded to a mailed questionnaire on their use of information and computerized literature searching. The respondents were divided into four subgroups: end-user searchers, users of intermediaries, end users who used intermediaries, and those who did not use computerized literature search systems. Seventy-two percent of the respondents used some type of computerized literature searching, and 42% performed their own searches. The four subgroups differed in general computer use, familiarity with MEDLINE search terminology, information use, reasons for using or not using literature searching, and characteristics of searches (i.e., type, time frame, amount, and frequency). Training in end-user search systems appears to have had an impact on the continued use of computerized literature searching several years after the formal educational program.  相似文献   
46.
47.
48.
49.
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