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   33836篇
  免费   398篇
  国内免费   15篇
教育   24652篇
科学研究   3192篇
各国文化   225篇
体育   2243篇
综合类   13篇
文化理论   566篇
信息传播   3358篇
  2022年   153篇
  2021年   259篇
  2020年   389篇
  2019年   610篇
  2018年   2910篇
  2017年   2814篇
  2016年   2247篇
  2015年   553篇
  2014年   777篇
  2013年   4544篇
  2012年   866篇
  2011年   1368篇
  2010年   1317篇
  2009年   903篇
  2008年   1176篇
  2007年   1629篇
  2006年   490篇
  2005年   793篇
  2004年   821篇
  2003年   719篇
  2002年   476篇
  2001年   480篇
  2000年   415篇
  1999年   360篇
  1998年   206篇
  1997年   211篇
  1996年   209篇
  1995年   221篇
  1994年   164篇
  1993年   184篇
  1992年   297篇
  1991年   280篇
  1990年   285篇
  1989年   281篇
  1988年   241篇
  1987年   286篇
  1986年   254篇
  1985年   290篇
  1984年   238篇
  1983年   201篇
  1982年   175篇
  1981年   155篇
  1980年   135篇
  1979年   244篇
  1978年   179篇
  1977年   154篇
  1976年   138篇
  1975年   131篇
  1974年   134篇
  1971年   119篇
排序方式: 共有10000条查询结果,搜索用时 625 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