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   26771篇
  免费   301篇
  国内免费   64篇
教育   18677篇
科学研究   3157篇
各国文化   244篇
体育   1902篇
综合类   47篇
文化理论   150篇
信息传播   2959篇
  2021年   270篇
  2020年   353篇
  2019年   553篇
  2018年   742篇
  2017年   745篇
  2016年   665篇
  2015年   452篇
  2014年   619篇
  2013年   5119篇
  2012年   643篇
  2011年   638篇
  2010年   564篇
  2009年   537篇
  2008年   547篇
  2007年   544篇
  2006年   537篇
  2005年   493篇
  2004年   370篇
  2003年   371篇
  2002年   344篇
  2001年   503篇
  2000年   430篇
  1999年   371篇
  1998年   230篇
  1997年   236篇
  1996年   267篇
  1995年   212篇
  1994年   235篇
  1993年   220篇
  1992年   331篇
  1991年   333篇
  1990年   357篇
  1989年   354篇
  1988年   279篇
  1987年   285篇
  1986年   327篇
  1985年   311篇
  1984年   302篇
  1983年   289篇
  1982年   241篇
  1981年   224篇
  1980年   228篇
  1979年   318篇
  1978年   270篇
  1977年   210篇
  1976年   218篇
  1975年   184篇
  1974年   204篇
  1973年   192篇
  1971年   217篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
A cohort of 71 pairs of twins was studied in a project which started within the decade 1965 to 1975. The total level of intelligence (global IQ) and the level of particular intellectual components have been examined annually since the twins were two years of age. The data were analysed by comparing monozygotic and dizygotic twins. The results revealed that high intelligence is influenced much more by hereditary than exogenous factors. Furthermore, there is an irregularity in the development of intellectual level from childhood to adulthood. Consequently, decision making about children cannot be carried out on the basis of a single IQ evaluation. A cluster analysis demonstrated the importance of hereditary factors not only on intellectual level, but also on the pattern of intellectual development.  相似文献   
992.
The MELVYL MEDLINE project resulted in the addition of a full five-year subset of MEDLINE to the University of California's (UC) MELVYL online union catalog. As one of the nation's largest MEDLINE end-user searching systems, MELVYL MEDLINE provides online bibliographic access to the biomedical journal literature for all UC personnel at over seventy library sites or by remote access. This paper summarizes the project's accomplishments, reports MELVYL MEDLINE use and its impact on library services, and provides insights for other end-user search systems. The project serves as a model for adding databases to the MELVYL catalog and demonstrates the potential for use by other disciplines of a specialized database when readily accessible. Evaluation results report high user satisfaction and high usage. However, many advanced searching features of the interface are little used by searchers. Effects on library services include marked increases in reference transactions and interlibrary loans, with significant declines in mediated search services. Future MELVYL MEDLINE enhancements include matching search retrievals to journal locations, linkage to an online document delivery system, and consideration of building a superset of databases by combining MELVYL MEDLINE with citations from another database in the MELVYL catalog.  相似文献   
993.
994.
995.
This study analyzes publishing patterns of the staff of the University of Ibadan College of Medicine, Nigeria, based on a bibliography prepared by the authors. Data-gathering for the bibliography is described. An analysis is made of journals staff published in for the period 1961-1980, focusing on changes in journal order rank, publishing locations, and subject spread. A ranked list of the leading journals for the period 1976-1980 is given, showing the importance of local publishing and pointing to the need for local indexing.  相似文献   
996.
R V Sovrevinas  L Pasillas 《E-ITV》1984,16(10):56, 60-53, 66
  相似文献   
997.
Why is there an increased need for quantitative indicators of student socioeconomic status at the school level? What alternative approaches have been used to measure SES? Can principals accurately estimate the SES distribution of their student populations? How do their estimates correlate with other indexes o f family SES?  相似文献   
998.
999.
1000.
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