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   30438篇
  免费   376篇
  国内免费   72篇
教育   21821篇
科学研究   2792篇
各国文化   392篇
体育   2118篇
综合类   51篇
文化理论   218篇
信息传播   3494篇
  2021年   263篇
  2020年   369篇
  2019年   587篇
  2018年   766篇
  2017年   847篇
  2016年   795篇
  2015年   518篇
  2014年   721篇
  2013年   6249篇
  2012年   667篇
  2011年   716篇
  2010年   625篇
  2009年   624篇
  2008年   681篇
  2007年   638篇
  2006年   638篇
  2005年   587篇
  2004年   462篇
  2003年   430篇
  2002年   414篇
  2001年   543篇
  2000年   483篇
  1999年   430篇
  1998年   271篇
  1997年   279篇
  1996年   301篇
  1995年   261篇
  1994年   290篇
  1993年   276篇
  1992年   392篇
  1991年   411篇
  1990年   417篇
  1989年   400篇
  1988年   330篇
  1987年   356篇
  1986年   359篇
  1985年   371篇
  1984年   372篇
  1983年   360篇
  1982年   293篇
  1981年   302篇
  1980年   261篇
  1979年   378篇
  1978年   355篇
  1977年   247篇
  1976年   254篇
  1975年   238篇
  1974年   205篇
  1973年   223篇
  1971年   200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.
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.
Children are sensitive to a number of considerations influencing distributions of resources, including equality, equity, and reciprocity. We tested whether children use a specific type of reciprocity norm—market norms—in which resources are distributed differentially based strictly on amount offered in return. In two studies, 195 children 5–10 years and 60 adults distributed stickers to friends offering same or different amounts of money. Overall, participants distributed more equally when offers were the same and more unequally when offers were different. Although sensitive to why friends offered different amounts of money, children increasingly incorporated market norms into their distributions with age, as the oldest children and adults distributed more to those offering more, irrespective of the reasons provided.  相似文献   
7.
8.
This article describes the Engineering Professors' Conference (EPC) approach to quality assurance for Higher Education Institutions, which is currently the only formalized alternative to British Standard 5750 'Quality Systems'. The EPC approach is based on principles of quality assurance and Total Quality Management which have been developed in industry. These ideas are briefly outlined, and an opinion expressed on the interpretation and application of BSS7S0 for HE. The EPC model is explained, illustrated with example elements taken from the EPC Specification and Guidelines for Quality Assurance in Higher Education. A top-down approach to the development of an institutional quality system is described, based on a quality policy statement. Areas of activity which have an important impact on the quality of education are identified, emphasising the quality assurance requirements of academic departments. Supporting and administrative quality system requirements are also described, as these also play an important role in the quality of education. Formal quality procedures and documentation in key areas are proposed.  相似文献   
9.
As a group, students with learning disabilities (LD) have social difficulties. One possible explanation for these difficulties is the unique way they process social information. Although students with LD may differ from their nondisabled peers in their social cognition, investigators have suggested the presence of subgroups within the population of students with LD who may differ in their social competence and, thereby, shed light on the source of the difficulties. The present exploratory study examined how two subgroups of students with LD in inclusive settings, students with high and low social status, perceive social situations. Using a sociometric technique, three students with LD receiving high social‐status ratings and three students with LD receiving low social‐status ratings were identified. A qualitative approach was used to gather and evaluate data from the participants and their teachers. Results suggested differences between the two subgroups in their (1) sensitivity to cues in the environment, (2) interpretation of social situations in relation to their own experiences, and (3) levels of self‐control. Implications of these findings for practice and future research are discussed.  相似文献   
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