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   24811篇
  免费   331篇
  国内免费   61篇
教育   18342篇
科学研究   1856篇
各国文化   315篇
体育   1683篇
综合类   49篇
文化理论   181篇
信息传播   2777篇
  2021年   232篇
  2020年   306篇
  2019年   495篇
  2018年   696篇
  2017年   760篇
  2016年   697篇
  2015年   489篇
  2014年   647篇
  2013年   5230篇
  2012年   601篇
  2011年   634篇
  2010年   575篇
  2009年   545篇
  2008年   593篇
  2007年   574篇
  2006年   581篇
  2005年   538篇
  2004年   412篇
  2003年   393篇
  2002年   360篇
  2001年   475篇
  2000年   413篇
  1999年   374篇
  1998年   264篇
  1997年   267篇
  1996年   274篇
  1995年   282篇
  1994年   271篇
  1993年   236篇
  1992年   319篇
  1991年   309篇
  1990年   336篇
  1989年   315篇
  1988年   264篇
  1987年   273篇
  1986年   267篇
  1985年   267篇
  1984年   276篇
  1983年   261篇
  1982年   232篇
  1981年   216篇
  1980年   188篇
  1979年   259篇
  1978年   233篇
  1977年   191篇
  1976年   181篇
  1975年   164篇
  1974年   155篇
  1973年   162篇
  1971年   155篇
排序方式: 共有10000条查询结果,搜索用时 125 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.
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.
4.
5.
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   
6.
7.
8.
9.
10.
With the exception of lecturing staff, research on occupational groups and cultures within the UK higher education system is relatively sparse. This paper focuses upon one specialist group, to-date under-researched but which plays a central role in contemporary higher education administration: graduate research administrators. This occupational group is of particular interest as its members administer and manage an increasing complex and key area of university life, which in many cases appears to span the putative occupational divide between 'academic' and 'administrative' work. Based upon qualitative interviews with 27 research administrators, and using some of Bourdieu's conceptual devices, the paper analyses particular kinds of informal occupational knowledge and practice, necessary in order effectively to 'do' the complex task of research administration in the pressurized environment of contemporary British higher education.  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