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   15846篇
  免费   256篇
  国内免费   14篇
教育   10998篇
科学研究   1856篇
各国文化   169篇
体育   1214篇
综合类   19篇
文化理论   196篇
信息传播   1664篇
  2022年   107篇
  2021年   162篇
  2020年   250篇
  2019年   342篇
  2018年   527篇
  2017年   536篇
  2016年   485篇
  2015年   328篇
  2014年   458篇
  2013年   2708篇
  2012年   412篇
  2011年   383篇
  2010年   366篇
  2009年   329篇
  2008年   348篇
  2007年   342篇
  2006年   317篇
  2005年   282篇
  2004年   309篇
  2003年   269篇
  2002年   276篇
  2001年   340篇
  2000年   377篇
  1999年   281篇
  1998年   169篇
  1997年   210篇
  1996年   204篇
  1995年   150篇
  1994年   157篇
  1993年   152篇
  1992年   216篇
  1991年   196篇
  1990年   242篇
  1989年   227篇
  1988年   199篇
  1987年   210篇
  1986年   185篇
  1985年   226篇
  1984年   173篇
  1983年   147篇
  1982年   140篇
  1981年   126篇
  1980年   130篇
  1979年   187篇
  1978年   139篇
  1977年   123篇
  1976年   99篇
  1975年   97篇
  1974年   103篇
  1973年   108篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
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   
32.
33.
34.
The roles of academic health sciences librarians are continually evolving as librarians initiate new programs and services in response to developments in computer technology and user demands. However, statistics currently collected by libraries do not accurately reflect or measure these new roles. It is essential for librarians to document, measure, and evaluate these new activities to continue to meet the needs of users and to ensure the viability of their professional role. To determine what new measures should be compiled, the authors examined current statistics, user demands, professional literature, and current activities of librarians as reported in abstracts of poster sessions at Medical Library Association annual meetings. Three new categories of services to be measured are proposed. The first, consultation, groups activities such as quality filtering and individual point-of-need instruction. The second, outreach, includes activities such as working as liaisons, participating in grand rounds or morning report, and providing continuing education. The third area, Web authoring, encompasses activities such as designing Web pages, creating online tutorials, and developing new products. Adding these three measures to those already being collected will provide a more accurate and complete depiction of the services offered by academic health sciences librarians.  相似文献   
35.
36.
The many challenges faced by health sciences libraries of all types and sizes often require innovative solutions. When an innovative solution involves calculated risk taking, the approach is called intrapreneurial. At the University of Miami School of Medicine, an intrapreneurial approach solved the fiscal problems of the biomedical communications unit. The Louis Calder Memorial Library inherited these problems when the Department of the Library and Biomedical Communications was created in the early 1980s. In this paper, two intrapreneurial programs are described, and the benefit and suitability of this management style to information services are demonstrated.  相似文献   
37.
38.
S. Ramasesha 《Resonance》2009,14(8):782-798
Efficient lighting and display have become important concerns in the energy-starved modern world. This has led to new paradigms in lighting and display technologies. Organic molecules provide a new class of active materials for such technologies. This article gives the basic science behind the design of such molecular materials used in displays and lighting.  相似文献   
39.
The most frequently requested accommodation among students with learning disabilities (LD) in postsecondary settings is extended test time. The frequency with which this accommodation is requested and granted compels disability service providers to become knowledgeable about the factors that influence the need for, and appropriateness of, the accommodation. Moreover, the synthesis of these factors becomes the basis for determining if the accommodation is reasonable under federal law. The purpose of this article is to present a step‐by‐step model to be used as a decision‐making process when considering the accommodation of extended test time for postsecondary students with LD. The model is designed to assist disability service providers in the analysis and synthesis of information collected from (1) the student's diagnostic evaluation, (2) the course or classroom test to be accommodated, and (3) student interviews. A list of diagnostic tests from the four most frequently administered test batteries used with adults is provided, along with a concise explanation of how characteristics of LD impact reading, writing, and math, and relate to the need for extended time. This information can be used to determine if extended test time is a reasonable accommodation and to estimate how much additional time to provide.  相似文献   
40.
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