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   138167篇
  免费   2100篇
  国内免费   497篇
教育   93974篇
科学研究   16217篇
各国文化   2037篇
体育   10518篇
综合类   764篇
文化理论   1136篇
信息传播   16118篇
  2022年   668篇
  2021年   1307篇
  2020年   1906篇
  2019年   2715篇
  2018年   3317篇
  2017年   3595篇
  2016年   3602篇
  2015年   2731篇
  2014年   3760篇
  2013年   28094篇
  2012年   3385篇
  2011年   3863篇
  2010年   3291篇
  2009年   3485篇
  2008年   3340篇
  2007年   3155篇
  2006年   3368篇
  2005年   3244篇
  2004年   3517篇
  2003年   2816篇
  2002年   2610篇
  2001年   2513篇
  2000年   2028篇
  1999年   1887篇
  1998年   1623篇
  1997年   1640篇
  1996年   1791篇
  1995年   1542篇
  1994年   1513篇
  1993年   1519篇
  1992年   1625篇
  1991年   1495篇
  1990年   1488篇
  1989年   1428篇
  1988年   1267篇
  1987年   1208篇
  1986年   1212篇
  1985年   1502篇
  1984年   1346篇
  1983年   1303篇
  1982年   1272篇
  1981年   1190篇
  1980年   1174篇
  1979年   1309篇
  1978年   1231篇
  1977年   1137篇
  1976年   1014篇
  1975年   828篇
  1974年   844篇
  1973年   801篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
What If?     
  相似文献   
993.
With the rise of microfluidics for the past decade, there has come an ever more pressing need for a low-cost and rapid prototyping technology, especially for research and education purposes. In this article, we report a rapid prototyping process of chromed masks for various microfluidic applications. The process takes place out of a clean room, uses a commercially available video-projector, and can be completed in less than half an hour. We quantify the ranges of fields of view and of resolutions accessible through this video-projection system and report the fabrication of critical microfluidic components (junctions, straight channels, and curved channels). To exemplify the process, three common devices are produced using this method: a droplet generation device, a gradient generation device, and a neuro-engineering oriented device. The neuro-engineering oriented device is a compartmentalized microfluidic chip, and therefore, required the production and the precise alignment of two different masks.  相似文献   
994.
995.
The authors examined the relationship between stress, adaptive coping, and life satisfaction among college students who reported having a friend or family member with eating disorder symptomatology. A hierarchical regression confirmed the study's hypotheses. Higher stress was linked with less life satisfaction. After stress was controlled, plan coping had a beneficial influence on life satisfaction. College counselors can use these findings when choosing interventions for clients who are close to someone with an eating disorder.  相似文献   
996.
997.
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   
998.
Peer harassment is a major social problem affecting children and adolescents internationally. Much research has focused on student‐to‐student harassment from either an individual or a multilevel perspective. There is a paucity of multilevel research on students’ relationships with the classroom teacher. The purpose of this study was to use a socioecological perspective to examine the relationships between individual student‐level characteristics, problematic teacher–student relationships, and student‐reported peer harassment. A total of 1,864 children (50.7% female) aged 8 to 13 years (M = 9.82, SD = 1.24), nested in 27 schools (58.2% public) in Spain, participated in the study. Ninety‐four homeroom teachers reported on teacher–student relationships, and students completed self‐report measures related to peer harassment and teacher–student relationships. Multilevel models showed that relationships between students and teachers exerted a varying degree of influence on classroom levels of peer harassment. Specifically, student‐reported teacher support was associated with diminished student‐reported peer victimization, whereas direct and indirect student‐reported teacher‐to‐student aggression was associated with increased peer victimization. Additionally, student‐reported student‐to‐teacher aggression and teacher‐to‐student aggression were associated with increased student‐reported peer aggression. Teacher‐reported variables at the classroom level, however, contributed little to student‐reported outcomes. Results are discussed in the context of future research on relationships between teachers and students.  相似文献   
999.
1000.
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