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   10298篇
  免费   436篇
  国内免费   113篇
教育   5814篇
科学研究   2520篇
体育   554篇
综合类   497篇
文化理论   1篇
信息传播   1461篇
  2024年   11篇
  2023年   65篇
  2022年   186篇
  2021年   310篇
  2020年   327篇
  2019年   254篇
  2018年   184篇
  2017年   191篇
  2016年   261篇
  2015年   254篇
  2014年   453篇
  2013年   512篇
  2012年   695篇
  2011年   852篇
  2010年   712篇
  2009年   708篇
  2008年   701篇
  2007年   761篇
  2006年   826篇
  2005年   744篇
  2004年   562篇
  2003年   378篇
  2002年   313篇
  2001年   243篇
  2000年   133篇
  1999年   58篇
  1998年   51篇
  1997年   30篇
  1996年   17篇
  1995年   13篇
  1994年   20篇
  1993年   10篇
  1992年   3篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1957年   3篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
[目的/意义] 比较分析数据管理与数据治理差异与联系,为制定科学数据开放共享政策提供参考。[方法/过程] 运用比较分析法,解析数据管理与数据治理在定义与内涵、功能、目标、原则、焦点领域5个方面的异同,由此解析其对制定我国科学数据开放共享政策的启示。[结果/结论] 数据管理与数据治理在定义与内涵、功能、目标、原则、焦点领域上都有显著差异,但两者也有内在联系。数据治理是成功实施数据管理的关键。认清两者的关系有助于明晰目前我国科学数据管理政策的不足之处,为今后完善科学数据管理办法提供参考,从而规划与制定实用的科学数据开放共享细则。  相似文献   
2.
[目的/意义] 杰青基金实施25年来,资助者年龄呈大龄化趋势发展,深入分析该现象对完成杰青基金的影响,对未来杰青基金管理具有重要意义。[方法/过程] 研究以1994-2018年杰青基金地球科学项目为研究对象,构建科研论文产出效率、创新能力和学术影响力三个评价指标,提出"科技人力资本投入-科研产出"理论模型及假设,采用DID模型克服样本选择性偏误所导致的内生性问题,验证理论假设,实现对杰青基金资助年龄异质性的研究。[结果/结论] 实证结果表明:杰青科学家大龄化趋势日趋严重,存在明显的45岁现象;杰青基金实施20年中,支持"资助年龄越大,资助效应越好"假设的比例较低;三个评价指标维度,资助效应最大且资助年龄在39-42岁之间的年份在杰青基金实施20年中所占比例最大。因此,无论从杰青基金设立宗旨、还是从评估结果来看,都应该避免杰青科学家大龄化趋势,扩大对中低龄优秀青年人才的资助。  相似文献   
3.
科学数据共享研究现状与展望   总被引:2,自引:0,他引:2  
[目的/意义] 分析科学数据共享的研究现状及其发展趋势,为促进国内相关理论研究与实践进展提供参考。[方法/过程] 通过对国内外文献进行梳理和归纳,提炼出与科学数据共享研究相关的三大类主题:科学数据共享发展需求、科学数据管理共享模式与机制和科学数据服务共享度与服务效果,并构建科学数据共享管理分析框架,该框架体现上述三类主题之间的因果关联,强调科学数据共享管理与服务的合理面、重要度、关键性。[结果/结论] 国内外现有研究尚存不足,未来研究在加强实证研究、着眼管理机制完善的同时,还需注重共享服务模式的创新。  相似文献   
4.
医学统计学在科学研究中的重要性不容忽视。为培养本科生的医学科研素养,提升他们科学的统计思维和解决科研实际问题的能力,在医学统计学本科生课程教学中,有必要结合科研训练的课程。文章在分析医学统计学教学现状的基础上,提出了医学统计学结合科研训练教学的新模式,并结合实际教学经验就教学内容、教学模式、考核方式的改革提出了具体的思路和实践方法。希望通过加强对本科生的科研训练,提升他们的科研意识和科研创新能力。  相似文献   
5.
随着国家对武术发展的大力支持,近几年竞技武术赛事增多,对运动员提出了更高的要求。本文通过文献资料法、逻辑分析法、观察法等研究方法,从竞技武术套路训练现状的角度入手,分析了当今中国竞技武术套路训练现状,新规则对竞技武术套路及运动员的影响,并在此基础上提出了对策:加强竞技武术套路运动科学化训练,加强武术训练与科研的合作。  相似文献   
6.
Many studies have examined whether children’s gender influences their educational attainment. However, there are limited studies on both the impact of parents’ education on children’s education and the educational gender gap in rural China. This paper investigates the impact of parents’ education on their children’s education from a gender perspective in rural China using comprehensive rural household data. We find that the educational gender gap in rural China has been decreasing over the last several decades. Moreover, the educational gender gap decreases as parents’ education increases. Parents’ initial educational attainment plays an important role in narrowing the educational gender gap.  相似文献   
7.
IntroductionWhile early commenting on studies is seen as one of the advantages of preprints, the type of such comments, and the people who post them, have not been systematically explored.Materials and methodsWe analysed comments posted between 21 May 2015 and 9 September 2019 for 1983 bioRxiv preprints that received only one comment on the bioRxiv website. The comment types were classified by three coders independently, with all differences resolved by consensus.ResultsOur analysis showed that 69% of comments were posted by non-authors (N = 1366), and 31% by the preprints’ authors themselves (N = 617). Twelve percent of non-author comments (N = 168) were full review reports traditionally found during journal review, while the rest most commonly contained praises (N = 577, 42%), suggestions (N = 399, 29%), or criticisms (N = 226, 17%). Authors’ comments most commonly contained publication status updates (N = 354, 57%), additional study information (N = 158, 26%), or solicited feedback for the preprints (N = 65, 11%).ConclusionsOur results indicate that comments posted for bioRxiv preprints may have potential benefits for both the public and the scholarly community. Further research is needed to measure the direct impact of these comments on comments made by journal peer reviewers, subsequent preprint versions or journal publications.  相似文献   
8.
Despite seven decades of policy thrust, group-based educational inequalities persist in India. The tenacious social group-based stratification often proves to be a hurdle for educational participation policies to be effectively rolled out. Given these realities, this study reviews all major national education policy interventions since t 1950s. Using four rounds of National Sample Survey (NSS) data, we analysed the pattern of educational attainments in terms of Average Years of Schooling (AYS) and educational inequalities in India for the period 1994-2012. Three indices of inequality - Gini, Theil’s enttropy and Atkinson - have been constructed to study inequality by gender, place of residence and social groups. . We also empirically estimated the determinants of educational attainments in India by using OLS and Tobit Models. Further using the Oaxaca-Blinder Decomposition technique, we analysed the educational attainment gaps between groups. The study concludes that policy interventions have done little to reduce the group-based educational attainment gap and it’s time to place improved focus on secondary and higher education while continuing the efforts in primary education.  相似文献   
9.
Data from China demonstrate that the effect of the number of siblings on education is restricted by many factors, such as children’s gender, urban or rural household registration, whether there is only one child, the birth order of children within the family, and parents’ status. Chinese families have significant preferences for the eldest son and the youngest son. Moreover, research based on the natural experiment and instrumental variable approach suggests that market-oriented reform of education has increased the cost of family education expenditures since China’s reform and opening up, which further aggravates the negative impact on education of having many siblings in an urban setting.  相似文献   
10.
I examine the effects of a longer school year in Indonesia on grade repetition, educational attainment, employability, and earnings. I exploit an arbitrary rule that assigned students to a longer school year in Indonesia in 1978–1979, which fits a fuzzy regression discontinuity design. I find the longer school year decreases the probability of grade repetition and increases educational attainment; it also increases the probability of working in formal sectors and wages later in life. These results suggest the length of school years in Indonesia is not too long.  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