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   11307篇
  免费   102篇
  国内免费   11篇
教育   7230篇
科学研究   2118篇
各国文化   81篇
体育   820篇
综合类   5篇
文化理论   74篇
信息传播   1092篇
  2021年   100篇
  2020年   152篇
  2019年   232篇
  2018年   295篇
  2017年   273篇
  2016年   213篇
  2015年   153篇
  2014年   215篇
  2013年   1983篇
  2012年   228篇
  2011年   216篇
  2010年   184篇
  2009年   167篇
  2008年   172篇
  2007年   182篇
  2006年   145篇
  2005年   145篇
  2004年   134篇
  2003年   135篇
  2002年   127篇
  2001年   168篇
  2000年   175篇
  1999年   155篇
  1998年   81篇
  1997年   90篇
  1996年   112篇
  1994年   94篇
  1993年   92篇
  1992年   131篇
  1991年   141篇
  1990年   143篇
  1989年   162篇
  1988年   119篇
  1987年   115篇
  1986年   158篇
  1985年   152篇
  1984年   127篇
  1983年   128篇
  1982年   113篇
  1981年   93篇
  1980年   103篇
  1979年   138篇
  1978年   119篇
  1977年   104篇
  1976年   101篇
  1974年   111篇
  1973年   92篇
  1972年   84篇
  1971年   109篇
  1970年   80篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
This study investigates the perceived impact of election polls,focusing on the hotly contested 2000 U.S. presidential election.Survey data from 558 individuals gathered during the final daysof the election campaign are analyzed to examine beliefs thatthe polls greatly affect other voters, general views of pollsas good or bad for the country, beliefs about whether pollstersinfluence their results to come out a certain way, and supportfor banning election-night projections. Results indicate thatmost respondents felt the polls had no influence on themselveswhile still affecting others. Respondents exhibiting these ‘third-person-effect’perceptions were significantly more likely than others to believethat election polls are a bad thing for the country. Negativeperceptions of polls and beliefs that pollsters try to influenceresults were also related to general distrust of the news media.Negative views of polls in turn were associated with increasedsupport for prohibiting election-night projections. In general,the results illustrate the dependency of negative views aboutpolling on fears of untoward effects on voters, in particularthe fear that polls and election projections might lend supportto candidates opposed by the respondent.  相似文献   
32.
The digital shift has provided easy access to academic library users, and yet, the usage of archival collections continues to be low. At the same time, the need for innovation in library services for cultural heritage scholarship and its advancement is emerging. This paper outlines a library-led service-learning program that connects students with lighthouse artifacts, archival collections, scholars in global academia, and wider communities. Student engagement cases are provided to illustrate the way in which the librarian utilizes the Framework of Information Literacy for Higher Education by ACRL to work closely with students. These cases also demonstrate how students can contribute to knowledge creation and preservation efforts for a specific cultural heritage topic that is not static, but which keeps receiving new contributions or additions to the depository. Thus, this paper is an answer to the ACRL's call for pilot projects to be assessed and shared with the wider community of academic librarians and support staff. It also builds on emerging roles for academic libraries like engaged learning. Librarians must move beyond simply seeing themselves as partners. Instead, librarians should see themselves as prime facilitators that co-create and co-develop cultural heritage research and historical projects by connecting actors and resources more effectively than any single actor can do alone.  相似文献   
33.
We have studied the efficiency of research in the EU by a percentile-based citation approach that analyzes the distribution of country papers among the world papers. Going up in the citation scale, the frequency of papers from efficient countries increases while the frequency from inefficient countries decreases. In the percentile-based approach, this trend, which is uniform at any citation level, is measured by the ep index that equals the Ptop 1%/Ptop 10% ratio. By using the ep index we demonstrate that EU research on fast-evolving technological topics is less efficient than the world average and that the EU is far from being able to compete with the most advanced countries. The ep index also shows that the USA is well ahead of the EU in both fast- and slow-evolving technologies, which suggests that the advantage of the USA over the EU in innovation is due to low research efficiency in the EU. In accord with some previous studies, our results show that the European Commission’s ongoing claims about the excellence of EU research are based on a wrong diagnosis. The EU must focus its research policy on the improvement of its inefficient research. Otherwise, the future of Europeans is at risk.  相似文献   
34.
35.
36.
37.
38.
39.
40.
Prior to the exhibition Portrait-making, Rodin and his models (2009), the Rodin museum wanted to restore two busts of Hanako and Clemenceau. Interestingly, these two sculptures contain pieces of modern modeling materials (MMMs) invented at the end of the nineteenth century as an alternative to clay or waxes. The poor state of conservation of the two portraits made any handling and exhibition impossible. Accordingly, the purpose of this article is twofold: to contribute to technical art history and conservation. Elemental and chemical analyses were done on samples from 12 sculptures (SEM–EDX, FTIR, GC–MS, GC–FID, XRD, synchrotron-based µXRF, µXANES, and µFTIR) aimed at identifying the composition of MMMs used by Rodin on plaster sculptures and establishing hypotheses about the origins of their degradation. This thorough study of their composition and degradation was necessary to implement an appropriate restoration plan. The development of conservation protocols adapted to such materials is rarely documented. Different tests were performed on mock-ups (pH, solubility, adhesion, consolidation, and cleaning). In particular, a protocol based on laser cleaning was developed and successfully applied to remove superficial dust and crusts so that the sculptures regained their original aspect.  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