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   38960篇
  免费   593篇
  国内免费   67篇
教育   28109篇
科学研究   3417篇
各国文化   382篇
体育   2879篇
综合类   52篇
文化理论   334篇
信息传播   4447篇
  2022年   219篇
  2021年   404篇
  2020年   561篇
  2019年   889篇
  2018年   1733篇
  2017年   1746篇
  2016年   1465篇
  2015年   731篇
  2014年   1041篇
  2013年   7357篇
  2012年   1079篇
  2011年   1274篇
  2010年   1056篇
  2009年   946篇
  2008年   1049篇
  2007年   1080篇
  2006年   797篇
  2005年   796篇
  2004年   700篇
  2003年   635篇
  2002年   549篇
  2001年   768篇
  2000年   640篇
  1999年   550篇
  1998年   342篇
  1997年   352篇
  1996年   378篇
  1995年   356篇
  1994年   311篇
  1993年   305篇
  1992年   461篇
  1991年   422篇
  1990年   468篇
  1989年   444篇
  1988年   363篇
  1987年   419篇
  1986年   393篇
  1985年   424篇
  1984年   362篇
  1983年   326篇
  1982年   276篇
  1981年   257篇
  1980年   236篇
  1979年   379篇
  1978年   299篇
  1977年   237篇
  1976年   234篇
  1975年   209篇
  1974年   210篇
  1971年   209篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Early childhood is a sensitive period for learning and social skill development. The maturation of cerebral regions underlying social processing lays the foundation for later social-emotional competence. This study explored myelin changes in social brain regions and their association with changes in parent-rated social-emotional development in a cohort of 129 children (64 females, 0–36 months, 77 White). Results reveal a steep increase in myelination throughout the social brain in the first 3 years of life that is significantly associated with social-emotional development scores. These findings add knowledge to the emerging picture of social brain development by describing neural underpinnings of human social behavior. They can contribute to identifying age-/stage-appropriate early life factors in this developmental domain.  相似文献   
2.
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   
3.
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   
4.
5.
Editorial     
B. Sury 《Resonance》2018,23(7):723-725
  相似文献   
6.
7.
8.
Cultural Studies of Science Education - The retention of underrepresented students remains a significant challenge in the STEM (Science, Technology, Engineering and Math) disciplines. A broad range...  相似文献   
9.
10.
In this digital ITEMS module, Dr. Jeffrey Harring and Ms. Tessa Johnson introduce the linear mixed effects (LME) model as a flexible general framework for simultaneously modeling continuous repeated measures data with a scientifically defensible function that adequately summarizes both individual change as well as the average response. The module begins with a nontechnical overview of longitudinal data analyses drawing distinctions with cross-sectional analyses in terms of research questions to be addressed. Nuances of longitudinal designs, timing of measurements, and the real possibility of missing data are then discussed. The three interconnected components of the LME model—(1) a model for individual and mean response profiles, (2) a model to characterize the covariation among the time-specific residuals, and (3) a set of models that summarize the extent that individual coefficients vary—are discussed in the context of the set of activities comprising an analysis. Finally, they demonstrate how to estimate the linear mixed effects model within an open-source environment (R). The digital module contains sample R code, diagnostic quiz questions, hands-on activities in R, curated resources, and a glossary.  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