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   23497篇
  免费   308篇
  国内免费   126篇
教育   16557篇
科学研究   2727篇
各国文化   251篇
体育   1826篇
综合类   17篇
文化理论   219篇
信息传播   2334篇
  2021年   149篇
  2020年   286篇
  2019年   449篇
  2018年   619篇
  2017年   598篇
  2016年   592篇
  2015年   404篇
  2014年   512篇
  2013年   4541篇
  2012年   460篇
  2011年   499篇
  2010年   410篇
  2009年   395篇
  2008年   438篇
  2007年   476篇
  2006年   449篇
  2005年   452篇
  2004年   421篇
  2003年   394篇
  2002年   373篇
  2001年   366篇
  2000年   386篇
  1999年   398篇
  1998年   251篇
  1997年   257篇
  1996年   292篇
  1995年   307篇
  1994年   244篇
  1993年   236篇
  1992年   322篇
  1991年   316篇
  1990年   326篇
  1989年   355篇
  1988年   300篇
  1987年   317篇
  1986年   294篇
  1985年   340篇
  1984年   307篇
  1983年   296篇
  1982年   279篇
  1981年   244篇
  1980年   214篇
  1979年   311篇
  1978年   257篇
  1977年   259篇
  1976年   210篇
  1975年   182篇
  1974年   199篇
  1973年   191篇
  1971年   159篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
In 1993, the Government of Austria passed legislation establishing a 'binary policy' in higher education. A new accrediting body the Fachhochschulrat was created, empowered to accredit vocationally oriented courses in any institution seeking to offer them. Institutions meeting certain conditions will be entitled to seek designation as Fachhochschulen. The policy marks an important departure from the traditionally highly regulated and centralized system of policymaking in Austria. The article offers an analysis of the factors leading to the policy and analyses the implications for the future. It draws on the author's experience as a member of a team of examiners from the Organization for Economic Co-operation and Development (OECD) undertaking a policy review of Austrian higher education, and points to lessons for Austria from the United Kingdom's experience over the last 25 years.  相似文献   
43.
44.
45.
Quantum algorithms are a field of growing interest within the theoretical computer science as well as the physics community. Surprisingly, although the number of researchers working on the subject is ever-increasing, the number of quantum algorithms found so far is quite small. In fact, the task of designing new quantum algorithms has been proven to be extremely difficult. In this paper we give an overview of the known quantum algorithms and briefly describe the underlying ideas. Roughly, the algorithms presented are divided into hidden subgroup type algorithms and in amplitude amplification type algorithms. While the former deal with problems of group-theoretical nature and have the promise to yield strong separations of classical and quantum algorithms, the latter have been proved to be a prolific source of algorithms in which a polynomial speed-up as compared to classical algorithms can be achieved. We also discuss quantum algorithms which do not fall under these two categories and give a survey of techniques of general interest in quantum computing such as adiabatic computing, lower bounds for quantum algorithms, and quantum interactive proofs.  相似文献   
46.
This article discusses the changing relationships of authors and publishers, the current trends and challenges they face, and the direction of these relationships in the future. As the STM publishing industry finds itself in the midst of significant technological and economic changes, this article provides background to these changes and looks at the key elements, including open access business development, institutional repository trends, and emerging public financing policies in the future.  相似文献   
47.
48.
49.
Medicine has made increasing use of meta-analysis, largely as a quantitative procedure for combining results of clinical trials. Meta-analysis begins with a comprehensive review of the literature. The next step is a systematic analysis of the quality and content of each study. Finally, results are combined statistically and conclusions are drawn from this new overview of the data. This paper presents a brief historical perspective on the use of meta-analysis in medicine with emphasis on the medical library. The authors conclude that in the future, medical librarians will play a significant role in the application of this useful technique.  相似文献   
50.
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