全文获取类型
收费全文 | 29913篇 |
免费 | 543篇 |
国内免费 | 199篇 |
专业分类
教育 | 20378篇 |
科学研究 | 3415篇 |
各国文化 | 243篇 |
体育 | 2501篇 |
综合类 | 484篇 |
文化理论 | 212篇 |
信息传播 | 3422篇 |
出版年
2022年 | 252篇 |
2021年 | 468篇 |
2020年 | 507篇 |
2019年 | 699篇 |
2018年 | 901篇 |
2017年 | 904篇 |
2016年 | 789篇 |
2015年 | 662篇 |
2014年 | 1018篇 |
2013年 | 4921篇 |
2012年 | 1195篇 |
2011年 | 1201篇 |
2010年 | 977篇 |
2009年 | 980篇 |
2008年 | 1035篇 |
2007年 | 1019篇 |
2006年 | 940篇 |
2005年 | 834篇 |
2004年 | 638篇 |
2003年 | 606篇 |
2002年 | 587篇 |
2001年 | 699篇 |
2000年 | 548篇 |
1999年 | 459篇 |
1998年 | 292篇 |
1997年 | 270篇 |
1996年 | 286篇 |
1995年 | 261篇 |
1994年 | 205篇 |
1993年 | 217篇 |
1992年 | 336篇 |
1991年 | 309篇 |
1990年 | 306篇 |
1989年 | 307篇 |
1988年 | 260篇 |
1987年 | 303篇 |
1986年 | 266篇 |
1985年 | 311篇 |
1984年 | 249篇 |
1983年 | 214篇 |
1982年 | 190篇 |
1981年 | 165篇 |
1980年 | 153篇 |
1979年 | 259篇 |
1978年 | 183篇 |
1977年 | 160篇 |
1976年 | 137篇 |
1975年 | 130篇 |
1974年 | 133篇 |
1971年 | 120篇 |
排序方式: 共有10000条查询结果,搜索用时 453 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.
4.
顶岗实习是实现高职人才培养目标的重要途径。鉴于当前高职顶岗实习中学校、学生及教师各层面都存在的问题,重新设计了顶岗实习的流程体系,通过校、企、师、生、家五方联动,构建了五途径保障实习岗位、两维度驱动实习成效、四层次规范实习管理、三主体强化实习评价的“五二四三”顶岗实习模式,实现学生、企业、教师、家长、导师和学校的六方共赢。 相似文献
5.
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
6.
7.
8.
[目的/意义] 面对多学科领域、多类型用户的专题情报服务需求,建立专题情报数据管理与智能分析平台。实现专题情报分析的流程化和智能化,同时对融入专家智慧的专题情报分析过程数据进行管理,丰富服务模式,提升服务需求响应速度。[方法/过程] 在调研已有相关研究与实践分析基础上,提出平台设计思路、建设框架,对平台主要功能和关键技术进行剖析。[结果/结论] 专题情报数据管理与智能分析平台已建设完成。平台集成了多来源多类型数据,打通了从数据到分析的服务链条。嵌入了多种情报分析方法和深度学习算法,实现了多维多层次分析服务。能够对分析过程和情报分析人员历史积累数据进行管理,实现数据共享和重复利用。 相似文献
9.
10.
U. Casellato F. Fenzi P. Guerriero S. Sitran P. A. Vigato U. Russo M. Galgani M. Mendera A. Manasse 《Journal of Cultural Heritage》2003,4(4):337-353
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