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   19228篇
  免费   292篇
  国内免费   57篇
教育   14133篇
科学研究   1352篇
各国文化   223篇
体育   1457篇
综合类   46篇
文化理论   118篇
信息传播   2248篇
  2021年   214篇
  2020年   282篇
  2019年   438篇
  2018年   644篇
  2017年   652篇
  2016年   605篇
  2015年   403篇
  2014年   550篇
  2013年   3901篇
  2012年   538篇
  2011年   544篇
  2010年   478篇
  2009年   467篇
  2008年   487篇
  2007年   447篇
  2006年   461篇
  2005年   413篇
  2004年   301篇
  2003年   294篇
  2002年   266篇
  2001年   392篇
  2000年   327篇
  1999年   267篇
  1998年   191篇
  1997年   181篇
  1996年   193篇
  1995年   169篇
  1994年   178篇
  1993年   170篇
  1992年   232篇
  1991年   217篇
  1990年   264篇
  1989年   230篇
  1988年   191篇
  1987年   202篇
  1986年   201篇
  1985年   195篇
  1984年   203篇
  1983年   182篇
  1982年   149篇
  1981年   154篇
  1980年   149篇
  1979年   202篇
  1978年   170篇
  1977年   122篇
  1976年   128篇
  1975年   117篇
  1974年   110篇
  1973年   116篇
  1971年   124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.
In this article we examine the complex relationship between care experience, mental health and exclusion from school and how young people (YP) negotiate these different experiences and identities. The study is a secondary analysis, informed by symbolic interactionist theory, of interviews conducted with 19 care experienced YP in Scotland. Not all of the YP were excluded and not all had a formal mental health diagnosis, as such our study design allows interrogation of the contexts and relationships which not only facilitate but also disrupt pathways to exclusion. It also allows reconsideration of assumptions of vulnerability which are often applied to care experienced YP. Our findings suggest that these YP are moving beyond ‘role playing’ the identities ascribed to them and actively seek out relationships which enable them to construct alternative identities.  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.
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.
Although there has been a great deal of research into Collaborative Information Retrieval (CIR) and Collaborative Information Seeking (CIS), the majority has assumed that team members have the same level of unrestricted access to underlying information. However, observations from different domains (e.g. healthcare, business, etc.) have suggested that collaboration sometimes involves people with differing levels of access to underlying information. This type of scenario has been referred to as Multi-Level Collaborative Information Retrieval (MLCIR). To the best of our knowledge, no studies have been conducted to investigate the effect of awareness, an existing CIR/CIS concept, on MLCIR. To address this gap in current knowledge, we conducted two separate user studies using a total of 5 different collaborative search interfaces and 3 information access scenarios. A number of Information Retrieval (IR), CIS and CIR evaluation metrics, as well as questionnaires were used to compare the interfaces. Design interviews were also conducted after evaluations to obtain qualitative feedback from participants. Results suggested that query properties such as time spent on query, query popularity and query effectiveness could allow users to obtain information about team's search performance and implicitly suggest better queries without disclosing sensitive data. Besides, having access to a history of intersecting viewed, relevant and bookmarked documents could provide similar positive effect as query properties. Also, it was found that being able to easily identify different team members and their actions is important for users in MLCIR. Based on our findings, we provide important design recommendations to help develop new CIR and MLCIR interfaces.  相似文献   
7.
8.
9.
Gordon  R. S.  Franklin  K. L.  Baker  J.  Davies  B. 《Sports Engineering》2004,7(3):131-138
Sports Engineering - A Monark cycle ergometer is a device globally used in physiological studies to measure the work and energy levels of exercising humans. In this paper a rope-braked cycle...  相似文献   
10.
Drawing distinctions on the basis of at least some case characteristics in making reporting decisions makes considerable sense. Using data from a national survey of mandated reporters that included vignettes in which case and personal characteristics were systematically varied, this paper examines the impact of selected characteristics while controlling for others. The data reveal that respondents noticed and responded to case characteristics. Abuse-relevant judgments and reporting intentions varied, often substantially, as a function of case characteristics. Three case characteristics--previous abuse, severity of abuse, and recantation--were powerful predictors of vignette outcomes. A history of previous abuse led to judgments of greater seriousness, a more salutary impact of a report, and greater likelihood of reporting. More severe abuse was more likely to be labelled as abuse, and was more likely to be reported. When the alleged victim retracted her accusation upon questioning by an authority figure, respondents were significantly less likely to intend a report. Child age, perpetrator intent and family socioeconomic status also influenced abuse-relevant judgments and reporting intentions. Respondents were more likely to intend a report when younger children, lazy or angry perpetrators and children from poorer families were portrayed.  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