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   4669篇
  免费   36篇
  国内免费   1篇
教育   3272篇
科学研究   600篇
各国文化   15篇
体育   320篇
综合类   8篇
文化理论   77篇
信息传播   414篇
  2023年   9篇
  2022年   10篇
  2021年   26篇
  2020年   35篇
  2019年   62篇
  2018年   107篇
  2017年   150篇
  2016年   228篇
  2015年   159篇
  2014年   96篇
  2013年   585篇
  2012年   186篇
  2011年   213篇
  2010年   124篇
  2009年   64篇
  2008年   108篇
  2007年   113篇
  2006年   83篇
  2005年   710篇
  2004年   493篇
  2003年   322篇
  2002年   158篇
  2001年   82篇
  2000年   64篇
  1999年   52篇
  1998年   19篇
  1997年   15篇
  1996年   16篇
  1995年   11篇
  1994年   16篇
  1993年   21篇
  1992年   21篇
  1991年   19篇
  1990年   14篇
  1989年   15篇
  1988年   12篇
  1987年   16篇
  1986年   22篇
  1985年   14篇
  1984年   18篇
  1983年   19篇
  1982年   20篇
  1981年   24篇
  1980年   12篇
  1979年   15篇
  1978年   8篇
  1977年   12篇
  1976年   8篇
  1975年   11篇
  1973年   11篇
排序方式: 共有4706条查询结果,搜索用时 15 毫秒
181.
This paper proposes a price index for artists adjusted for the quality of the paintings, based on the ratio between the average market price and the average pre-sale estimate for paintings. We apply this methodology to a group of selected artists and schools presented in auctions worldwide in the period 1990–2001. A comparison with quality unadjusted and hedonic indices is also conducted.JEL Classification: C10, Z11  相似文献   
182.
Conclusion In this paper we briefly described the current status of research in the field of digital libraries interoperability, mainly with respect to federated data processing such as permitted within the Open Archive Initiative framework. We then presented the CERN Document Server Software suite that is a free software package main-tained by CERN providing an online digital library solution for mid- to large-sized document repositories. The set of CDSware modules was described and the differ-ences with other existing tools briefly mentioned. Finally we have mentioned a typical usage statistics illustrating the scope of grey literature and networked con-ditions of the CERN Document Server. We pointed out that the current trend in grey literature management goes toward institutional repositories build upon the distributed and federated model. Further research is going on within the CDS collaboration in this area, focused particularly on (i) semantic interoperability using ontologies in distributed and federated data processing and (ii) ranking technologies when searching grey literature in OAI compliant repositories.  相似文献   
183.
Summary What will be the future of ONIX? Some argue that wider industry acceptance will lead to increased efficiencies in the transfer of book data, which will ultimately benefit book sales. ONIX still has to overcome many challenges: its implementation cost is high, whole-salers and aggregators are still using different spreadsheets and information sources. Furthermore, MS Excel as an alternative solution is widely available and accepted by the industry. Small publishers need more education and a straightforward demonstration of ONIX’s return on investment. An outreaching of the helping hand of professional organizations is strongly suggested to foster the adoption process among small players. It is the role of the AAP and BISG to get their memberships to think about what is good for all members as a whole throughout the industry. As an organization BISG can recommend, educate, and promote the standard. It cannot, however, bring pressure or demand organizations use it. Publishers, retailers, and wholesalers make those decisions for themselves and quite apparently the majority do not yet see the rewards. Market players need to determine the cost versus benefit and as long as distributors and retailers agree on receiving other formats, ONIX will never take a strong hold in the marketplace. After all, publishers should compete against each other with good books and not with multiple computer codes.  相似文献   
184.
185.
186.
187.
Conclusions We are living a deep change in the information transfer process involving the different actors of the editorial scene (from authors to editors, web-editors, e-publishers and readers), who occasionally play different roles at the same time (e.g., authors sometimes bypass the editor thus assuming direct responsibilities in the diffusion of documents in the Internet). Furthermore, information producers, managers or seekers often show twofold personalities like Dr. Jekyll and Mr. Hyde. They would like to find all documents free on the Internet and be able to read original, reliable, and high quality information, but they are sometimes reluctant to spread their papers through online nonofficial channels as they care for the impact factor, prestige, and career advancement. It is a revolutionary period in which new and alternative forms of scholarly communication live together with more traditional ones and the future is difficult to define. Recent initiatives of open access—such as Pubmed Central, Public Library of Science, Budapest Open Access Initiative—are contributing to define new trends in the editorial market, challenging the traditional distribution channels, mainly managed by commercial editors, and placing the authors’ role and publication copyrights under severe discussion. In this landscape, GL now has new dignity and becomes closer and closer to innovative scientific publications supported by researchers in view of a generalised movement towards open access. The nuances of grey are becoming lighter and lighter. The questions are many, the answers few, but, in any case, the ethical responsibility of producing and issuing quality documents can never be disregarded.  相似文献   
188.
189.
190.
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