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   36862篇
  免费   426篇
  国内免费   18篇
教育   26780篇
科学研究   3537篇
各国文化   291篇
体育   2389篇
综合类   15篇
文化理论   604篇
信息传播   3690篇
  2022年   165篇
  2021年   276篇
  2020年   408篇
  2019年   654篇
  2018年   2960篇
  2017年   2856篇
  2016年   2303篇
  2015年   597篇
  2014年   817篇
  2013年   5404篇
  2012年   907篇
  2011年   1413篇
  2010年   1350篇
  2009年   953篇
  2008年   1218篇
  2007年   1668篇
  2006年   546篇
  2005年   827篇
  2004年   861篇
  2003年   754篇
  2002年   515篇
  2001年   523篇
  2000年   471篇
  1999年   396篇
  1998年   249篇
  1997年   264篇
  1996年   250篇
  1995年   264篇
  1994年   205篇
  1993年   221篇
  1992年   345篇
  1991年   319篇
  1990年   318篇
  1989年   312篇
  1988年   276篇
  1987年   328篇
  1986年   288篇
  1985年   340篇
  1984年   268篇
  1983年   227篇
  1982年   222篇
  1981年   179篇
  1980年   170篇
  1979年   278篇
  1978年   202篇
  1977年   174篇
  1976年   171篇
  1975年   158篇
  1974年   152篇
  1971年   131篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
1.
Research in Higher Education - Given the significant need to increase and diversify graduate enrollments within computing fields, it is vital to understand what shapes students’ pathways to...  相似文献   
2.
ABSTRACT

The aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8–18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time.  相似文献   
3.
David Kaldewey 《Minerva》2018,56(2):161-182
This article analyzes the concept of “grand challenges” as part of a shift in how scientists and policymakers frame and communicate their respective agendas. The history of the grand challenges discourse helps to understand how identity work in science and science policy has been transformed in recent decades. Furthermore, the question is raised whether this discourse is only an indicator, or also a factor in this transformation. Building on conceptual history and historical semantics, the two parts of the article reconstruct two discursive shifts. First, the observation that in scientific communication references to “problems” are increasingly substituted by references to “challenges” indicates a broader cultural trend of how attitudes towards what is problematic have shifted in the last decades. Second, as the grand challenges discourse is rooted in the sphere of sports and competition, it introduces a specific new set of societal values and practices into the spheres of science and technology. The article concludes that this process can be characterized as the sportification of science, which contributes to self-mobilization and, ultimately, to self-optimization of the participating scientists, engineers, and policymakers.  相似文献   
4.
5.
Letters     
  相似文献   
6.
Editorial     
B. Sury 《Resonance》2018,23(7):723-725
  相似文献   
7.
8.
9.
10.
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