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   46442篇
  免费   2767篇
  国内免费   4022篇
教育   29637篇
科学研究   8068篇
各国文化   360篇
体育   4492篇
综合类   1769篇
文化理论   284篇
信息传播   8621篇
  2022年   258篇
  2021年   355篇
  2020年   698篇
  2019年   1303篇
  2018年   1775篇
  2017年   1839篇
  2016年   1785篇
  2015年   1541篇
  2014年   1751篇
  2013年   7615篇
  2012年   2029篇
  2011年   2212篇
  2010年   2062篇
  2009年   1794篇
  2008年   2225篇
  2007年   1953篇
  2006年   1120篇
  2005年   1079篇
  2004年   1286篇
  2003年   1016篇
  2002年   1019篇
  2001年   910篇
  2000年   847篇
  1999年   713篇
  1998年   501篇
  1997年   541篇
  1996年   511篇
  1995年   447篇
  1994年   380篇
  1993年   407篇
  1992年   551篇
  1991年   510篇
  1990年   498篇
  1989年   498篇
  1988年   442篇
  1987年   470篇
  1986年   431篇
  1985年   493篇
  1984年   416篇
  1983年   383篇
  1982年   317篇
  1981年   296篇
  1980年   272篇
  1979年   402篇
  1978年   333篇
  1977年   283篇
  1976年   267篇
  1975年   242篇
  1974年   237篇
  1973年   227篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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   
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.
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   
5.
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.
A significant number of archaeological finds of the 13th–16th century from the Tuscan sites of Germagnana and Gambassi in Valdelsa—FI, was studied by different physico-chemical investigations (SEM–EDS, ICP, Mössbauer spectroscopy, XRD, XRF, TG-DTA) in order to contribute to clarify the production methodology and the pre-industrial glass manufacture technology. The studied samples are mainly non-vitreous finds as production waste, refractory materials, crucibles and raw materials; also vitreous finds as frits, skims, glasses (glass masses, glass working waste and finished products) have been taken into consideration. The obtained petrographic and physico-chemical data strongly suggest that both Gambassi and Germagnana glass manufactures were strictly connected with the sources of vitrifiable materials, situated in Tuscan sand quarries. In particular a comparison between sands from the neighbouring quarries and appropriate finds of the two archaeological sites evidences that the employed vitrifiable materials possibly belong to La Casina La Cava resort. The archaeological classification, based on macroscopic observation and stratigraphic position, was compared and verified with the scientific classification of the examined finds of Germagnana and Gambassi sites based on their composition, morphology and physico-chemical properties.  相似文献   
8.
中国竞技体育人力资源相关问题探讨   总被引:5,自引:0,他引:5  
对竞技体育人力资源的概念、特点等问题进行了探讨:研究表明,竞技体育人力资源是指竞技体育发展所需人员的现实及潜在禀赋的总和。处于不同层次、不同领域的众多人员组成了竞技体育人力资源系统:竞技人力资源具有稀缺性、目标性、整体性及调控性等特点.  相似文献   
9.
国内运动生物力学发展现状思考   总被引:5,自引:0,他引:5  
运动生物力学是一门新兴的边缘性科学,其定义、研究范畴、研究方法都有待商榷。从这三个角度出发,主要对大量资料进行归纳总结,综合、概括了目前国内运动生物力学发展状况。力求对我国的运动生物力学发展的状况勾勒出一个清晰的脉络图,以便在这门学科今后的研究中减少盲目性,具有更强的实用性。  相似文献   
10.
奥运会的经济价值分析以及对北京举办奥运会的借鉴意义   总被引:11,自引:1,他引:10  
2008年北京奥运会的举行将大大加快北京地区乃至我国的经济现代化建设的步伐。应用实证研究的方法,对历届奥运会的经济价值进行分析,指出举办奥运会对促进北京地区乃至全国的经济增长、改善劳动力就业,加快产业结构调整的积极作用。同时从资金筹措、场馆建设、产业可持续发展等方面对北京避免奥运会后可能出现的“经济低谷效应”,实现可持续发展提出了建议。  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