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   28739篇
  免费   405篇
  国内免费   20篇
教育   20577篇
科学研究   2258篇
各国文化   337篇
体育   2687篇
综合类   11篇
文化理论   302篇
信息传播   2992篇
  2021年   289篇
  2020年   494篇
  2019年   711篇
  2018年   906篇
  2017年   886篇
  2016年   868篇
  2015年   535篇
  2014年   685篇
  2013年   5356篇
  2012年   640篇
  2011年   704篇
  2010年   525篇
  2009年   554篇
  2008年   627篇
  2007年   599篇
  2006年   540篇
  2005年   496篇
  2004年   512篇
  2003年   433篇
  2002年   440篇
  2001年   546篇
  2000年   604篇
  1999年   498篇
  1998年   313篇
  1997年   324篇
  1996年   378篇
  1995年   296篇
  1994年   325篇
  1993年   273篇
  1992年   416篇
  1991年   416篇
  1990年   393篇
  1989年   407篇
  1988年   379篇
  1987年   358篇
  1986年   365篇
  1985年   417篇
  1984年   341篇
  1983年   351篇
  1982年   283篇
  1981年   280篇
  1980年   294篇
  1979年   384篇
  1978年   298篇
  1977年   261篇
  1976年   222篇
  1975年   197篇
  1974年   190篇
  1973年   182篇
  1971年   182篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
133.
134.
135.
136.
137.
138.
Museums are not usually seen to be agents of change. If they are to serve as important mechanisms for empowering local communities to define, recognize, and develop their own indigenous heritages, they should first consider a potential contradiction contained within this initiative: museums specialize in the representation of other peoples, while people have the sovereign right to represent themselves. Left unresolved, this contradiction could produce counterfeits of good intentions. The introduction of professionalized cultural management may mitigate the responsibilities of the citizenry to actively participate in the production and preservation of their own heritage.  相似文献   
139.
This study sought to determine if exposure to two communication-oriented activities, videotapes and public service announcements, accounts for changes in substance use among adolescents participating in the Drug Resistance Strategies Project's keepin' it REAL adolescent substance use prevention curriculum. Middle-school students (4,734, 72% Latino) responded to questionnaires related to these analyses. An analysis of covariance (ANCOVA) model was fit separately to six substance use outcomes. The results suggested that intervention students who saw four or five videos engaged in less substance use in the past month than did students who saw fewer videos. Having seen the PSAs one or more times did not predict the reported change in substance use.  相似文献   
140.
Search facilitated with agglomerative hierarchical clustering methods was studied in a collection of Finnish newspaper articles (N = 53,893). To allow quick experiments, clustering was applied to a sample (N = 5,000) that was reduced with principal components analysis. The dendrograms were heuristically cut to find an optimal partition, whose clusters were compared with each of the 30 queries to retrieve the best-matching cluster. The four-level relevance assessment was collapsed into a binary one by (A) considering all the relevant and (B) only the highly relevant documents relevant, respectively. Single linkage (SL) was the worst method. It created many tiny clusters, and, consequently, searches enabled with it had high precision and low recall. The complete linkage (CL), average linkage (AL), and Ward's methods (WM) returned reasonably-sized clusters typically of 18–32 documents. Their recall (A: 27–52%, B: 50–82%) and precision (A: 83–90%, B: 18–21%) was higher than and comparable to those of the SL clusters, respectively. The AL and WM clustering had 1–8% better effectiveness than nearest neighbor searching (NN), and SL and CL were 1–9% less efficient that NN. However, the differences were statistically insignificant. When evaluated with the liberal assessment A, the results suggest that the AL and WM clustering offer better retrieval ability than NN. Assessment B renders the AL and WM clustering better than NN, when recall is considered more important than precision. The results imply that collections in the highly inflectional and agglutinative languages, such as Finnish, may be clustered as the collections in English, provided that documents are appropriately preprocessed.  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