全文获取类型
收费全文 | 45143篇 |
免费 | 533篇 |
国内免费 | 21篇 |
专业分类
教育 | 33132篇 |
科学研究 | 4064篇 |
各国文化 | 298篇 |
体育 | 3073篇 |
综合类 | 18篇 |
文化理论 | 616篇 |
信息传播 | 4496篇 |
出版年
2021年 | 339篇 |
2020年 | 514篇 |
2019年 | 804篇 |
2018年 | 3089篇 |
2017年 | 3013篇 |
2016年 | 2423篇 |
2015年 | 691篇 |
2014年 | 991篇 |
2013年 | 6710篇 |
2012年 | 1088篇 |
2011年 | 1580篇 |
2010年 | 1426篇 |
2009年 | 1050篇 |
2008年 | 1405篇 |
2007年 | 1748篇 |
2006年 | 755篇 |
2005年 | 941篇 |
2004年 | 929篇 |
2003年 | 830篇 |
2002年 | 650篇 |
2001年 | 736篇 |
2000年 | 639篇 |
1999年 | 570篇 |
1998年 | 312篇 |
1997年 | 357篇 |
1996年 | 384篇 |
1995年 | 385篇 |
1994年 | 306篇 |
1993年 | 341篇 |
1992年 | 505篇 |
1991年 | 473篇 |
1990年 | 465篇 |
1989年 | 493篇 |
1988年 | 451篇 |
1987年 | 461篇 |
1986年 | 426篇 |
1985年 | 476篇 |
1984年 | 397篇 |
1983年 | 408篇 |
1982年 | 331篇 |
1981年 | 305篇 |
1980年 | 290篇 |
1979年 | 440篇 |
1978年 | 340篇 |
1977年 | 299篇 |
1976年 | 284篇 |
1975年 | 246篇 |
1974年 | 250篇 |
1973年 | 236篇 |
1971年 | 225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.
David Sánchez-Oliva Rebecca M. Leech Alberto Grao-Cruces Irene Esteban-Cornejo Carmen Padilla-Moledo Oscar L. Veiga 《Journal of sports sciences》2020,38(9):1062-1069
ABSTRACTThe 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.
Research in Higher Education - State financial aid grant programs are commonly categorized as either need-based, merit-based, or both, but their initial eligibility requirements include many more... 相似文献
4.
5.
6.
7.
8.
9.
Anthony J. Sadar 《Science & Education》2018,27(1-2):233-235
10.
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