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   31799篇
  免费   509篇
  国内免费   22篇
教育   22625篇
科学研究   2984篇
各国文化   291篇
体育   2507篇
综合类   16篇
文化理论   235篇
信息传播   3672篇
  2022年   219篇
  2021年   358篇
  2020年   528篇
  2019年   811篇
  2018年   1162篇
  2017年   1116篇
  2016年   1013篇
  2015年   599篇
  2014年   942篇
  2013年   6132篇
  2012年   857篇
  2011年   917篇
  2010年   698篇
  2009年   700篇
  2008年   799篇
  2007年   708篇
  2006年   606篇
  2005年   591篇
  2004年   549篇
  2003年   493篇
  2002年   480篇
  2001年   628篇
  2000年   575篇
  1999年   514篇
  1998年   312篇
  1997年   344篇
  1996年   356篇
  1995年   315篇
  1994年   278篇
  1993年   288篇
  1992年   468篇
  1991年   411篇
  1990年   411篇
  1989年   431篇
  1988年   368篇
  1987年   393篇
  1986年   364篇
  1985年   404篇
  1984年   319篇
  1983年   298篇
  1982年   252篇
  1981年   229篇
  1980年   212篇
  1979年   358篇
  1978年   249篇
  1977年   231篇
  1976年   206篇
  1975年   188篇
  1974年   203篇
  1973年   160篇
排序方式: 共有10000条查询结果,搜索用时 328 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

In 2016, J. Murrey Atkins Library at the University of North Carolina at Charlotte opened a reservable study room where student parents and caregivers can study with their children on campus. In 2018, the library opened a second family-friendly study room to meet the needs of our growing campus community. To inform the room design, the library conducted a mixed methods research study that included a user survey, an examination of room reservation and usage data, and one-on-one user interviews. This paper focuses on the user-centered design process used to inform the development of the second, family-friendly, library study room.  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.
6.
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   
7.
8.
9.
ABSTRACT

This forum brings together food, (in)security, and communication. The authors participating in this forum center communication as both process and tool for understanding, mitigating, and making meaning of food (in)security. The nine authors together discuss the role of communication in food (in)security, the central challenges for scholars and practitioners working on food (in)security, and the creative possibilities and impacts influencing the future of food (in)security. The forum produces a call for applied scholars to re-imagine communication frameworks in order to make meaningful differences in their communities.  相似文献   
10.
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   
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