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   2751篇
  免费   46篇
  国内免费   16篇
教育   1925篇
科学研究   280篇
各国文化   32篇
体育   336篇
综合类   29篇
文化理论   34篇
信息传播   177篇
  2023年   8篇
  2022年   38篇
  2021年   48篇
  2020年   86篇
  2019年   125篇
  2018年   169篇
  2017年   163篇
  2016年   128篇
  2015年   83篇
  2014年   92篇
  2013年   427篇
  2012年   104篇
  2011年   91篇
  2010年   61篇
  2009年   72篇
  2008年   64篇
  2007年   82篇
  2006年   68篇
  2005年   65篇
  2004年   58篇
  2003年   113篇
  2002年   131篇
  2001年   132篇
  2000年   75篇
  1999年   31篇
  1998年   20篇
  1997年   25篇
  1996年   13篇
  1995年   27篇
  1994年   13篇
  1993年   17篇
  1992年   14篇
  1991年   12篇
  1990年   14篇
  1989年   8篇
  1988年   7篇
  1987年   11篇
  1986年   4篇
  1985年   13篇
  1984年   10篇
  1983年   4篇
  1982年   8篇
  1981年   7篇
  1980年   5篇
  1978年   10篇
  1976年   4篇
  1974年   4篇
  1973年   4篇
  1967年   4篇
  1865年   4篇
排序方式: 共有2813条查询结果,搜索用时 31 毫秒
21.
Objective: To analyze the possible dose-response association between components of sports participation (intensity, volume and previous engagement) and 4-year mortality rates among Brazilian adults.

Methods: 679 males and females (mean age among men = 66.7 ± 9.3 years old and mean age among women = 64.8 ± 8.9 years old) composed the study sample. Sports participation was assessed using Baecke’s questionnaire, which considers intensity, duration and previous engagement. Medical records were used to identify the cause of the death. Cox regression analysis was performed to determine the independent associations of exercise components and mortality.

Results: Participants that reported exercising at moderate-vigorous intensity (Moderate/vigorous: 4.1% versus None/light: 10.3% [p-value = 0.012]; HR = 0.42 [0.1 to 0.94)] and for more than four months (≥4 months: 5.3% versus <4 months: 10.2% [p-value = 0.038]; HR = 0.47 [0.24 to 0.94]) had lower mortality risk. The percentage of survival according to all-cause mortality was significantly higher for participants engaged in sports at moderate-vigorous intensity (p-value = 0.014), as well as for those engaged in sports for periods superior than four months (p-value = 0.036).

Conclusion: We found higher percentage of survival among adults engaged in sports at moderate-vigorous intensity and with at least four months of previous engagement.  相似文献   

22.
23.
Abstract

Minority-serving institutions are important in the production of teachers of color. However, this formative process is not without limitations. This multisite, multistate study relied on network analysis techniques to unveil timely and relevant concerns that students, faculty, and administrators identified as critical toward the strengthening of teacher production.  相似文献   
24.
25.
This paper describes and analyses an attempt to introduce the public understanding of science as a subject in its own right to be taught to all students in upper secondary education in The Netherlands. The aim of this paper is to make some of the experiences gained in this attempt, especially those related to the development of curriculum content, available to others. As the large-scale implementation of the new subject is still in progress, we focus on the initial stages of the introduction, covering the period 1994-1998. This period includes: (i) the launching of the initiative by a departmental advisory committee; (ii) the subsequent formulation of attainment targets; (iii) a curriculum development project that produced four teaching units tested in classroom experiments and meant as specimens to guide and inspire the authors of schoolbooks; and (iv) the publication of the first schoolbooks on the new subject. We conclude that in spite of its status as a separate subject, the current version of the course does not yet have a clear identity that distinguishes it, in the eyes of students as well as teachers, unmistakably from the traditional science subjects in the school.  相似文献   
26.
研究假设是研究课题确定后依据一定的知识、事实和资料,对所研究问题的规律或原因做出的推测性论断和假定性说明,是研究之前预先设想的、暂时的理论,是对研究课题设想出的一种或几种可能的结论或答案。假设一般包括两个事件或概念之间的关系,用“如果……那么……”的句子来陈述。例如:如果教师对一名学生的评价越来越差,那么该生的自我评价也会变得越来越差。研究假设是我们在实施课题研究设计之前,必须明确的问题。在教育科学研究中,提出具体的研究假设具有非常重要的作用。一、为课题研究指明方向研究假设使研究目的更明确,研究范围更确…  相似文献   
27.
假日旅游经济是我国旅游经济发展中的一个新的增长点。本文对假日旅游经济的涵义、基本特征及产生的背景进行了论述,并提出了科学调控假日旅游经济的若干对策措施,以期有益于促使我国假日旅游经济持续、健康发展。  相似文献   
28.
农村劳动力的去留与农村职业教育   总被引:1,自引:0,他引:1  
农村劳动力的去留问题是影响农村经济发展的重要问题。当前,过低的劳动力素质已经成为制约农村经济发展的重要因素之一。在今后相当长时期内,职业教育的重点应放到农村,为农村劳动力的“去”与“留”服务。  相似文献   
29.
Background: In Self-Determination Theory (SDT), a well-validated macro-theory on human motivation, a distinction is made between internally controlling teaching practices (e.g. guilt-induction and shaming) and externally controlling practices (e.g. threats and punishments, commands). While both practices are said to undermine students’ motivation, they would do so through somewhat differential motivational processes. Unfortunately, the relevance of the conceptual distinction between internally and externally controlling strategies has not been examined systematically. In the context of sport and physical education (PE), most studies on controlling teaching have either measured controlling teaching in an undifferentiated way or have focused on one particular feature of controlling teaching.

Purpose: The purpose of this study was to provide a more fine-grained picture on the differential de-motivational effects of internally and externally controlling teaching strategies in the domain of PE.

Participants: A total of 925 students with an average age of 15.80 years (±1.99) coming out of 92 classes taught by 22 different PE teachers participated in the present study.

Data analysis: Data on perceived controlling teaching style and students’ motivation were analyzed within a multilevel framework from both a variable-centered (regression analyses) and person-centered approach (cluster analyses).

Results: We found evidence for a distinction between perceived internally and externally controlling teaching. Both teaching styles were strongly related to each other (r?=?.54). At the level of zero-order correlations, both internally and externally controlling teaching related negatively to students’ intrinsic motivation and identified regulation and related positively to introjected regulation, external regulation, and amotivation. However, when both teaching styles were included simultaneously as predictors of motivation in the regression analyses, only internally controlling teaching predicted poor quality and low quantity of motivation. A cluster analysis revealed different profiles of perceived controlling teaching style, with two profiles being characterized by either high or low levels of the two types of controlling teaching and other profiles displaying elevated or reduced levels of one of the types of controlling teaching. This person-centered analysis confirmed that particularly students who perceive their PE teacher as internally controlling are likely to report poor-quality motivation.

Conclusion: Controlling teaching (and internally controlling teaching in particular) is related to maladaptive motivational outcomes. As such, it can be advised to PE-practitioners to refrain from using controlling strategies when teaching students. More research is needed to identify the conditions under which teachers’ behavior is perceived as externally and/or internally controlling.  相似文献   
30.
The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30–15.07) and sex (female) (OR 4.62, 90% CI 1.15–18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.  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