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   34326篇
  免费   406篇
  国内免费   17篇
教育   25097篇
科学研究   3197篇
各国文化   236篇
体育   2252篇
综合类   15篇
文化理论   559篇
信息传播   3393篇
  2022年   156篇
  2021年   265篇
  2020年   399篇
  2019年   622篇
  2018年   2923篇
  2017年   2831篇
  2016年   2259篇
  2015年   565篇
  2014年   791篇
  2013年   4646篇
  2012年   887篇
  2011年   1390篇
  2010年   1332篇
  2009年   919篇
  2008年   1197篇
  2007年   1639篇
  2006年   501篇
  2005年   801篇
  2004年   835篇
  2003年   733篇
  2002年   510篇
  2001年   489篇
  2000年   423篇
  1999年   366篇
  1998年   209篇
  1997年   219篇
  1996年   211篇
  1995年   227篇
  1994年   171篇
  1993年   191篇
  1992年   302篇
  1991年   288篇
  1990年   289篇
  1989年   284篇
  1988年   247篇
  1987年   295篇
  1986年   255篇
  1985年   295篇
  1984年   239篇
  1983年   202篇
  1982年   176篇
  1981年   159篇
  1980年   138篇
  1979年   246篇
  1978年   177篇
  1977年   161篇
  1976年   145篇
  1975年   134篇
  1974年   133篇
  1971年   120篇
排序方式: 共有10000条查询结果,搜索用时 22 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