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   39053篇
  免费   639篇
  国内免费   41篇
教育   27451篇
科学研究   3952篇
各国文化   383篇
体育   3209篇
综合类   19篇
文化理论   288篇
信息传播   4431篇
  2022年   252篇
  2021年   410篇
  2020年   623篇
  2019年   937篇
  2018年   1266篇
  2017年   1246篇
  2016年   1137篇
  2015年   697篇
  2014年   1022篇
  2013年   7316篇
  2012年   971篇
  2011年   1014篇
  2010年   789篇
  2009年   762篇
  2008年   867篇
  2007年   787篇
  2006年   705篇
  2005年   657篇
  2004年   624篇
  2003年   594篇
  2002年   558篇
  2001年   933篇
  2000年   710篇
  1999年   646篇
  1998年   348篇
  1997年   391篇
  1996年   410篇
  1995年   393篇
  1994年   359篇
  1993年   341篇
  1992年   539篇
  1991年   519篇
  1990年   520篇
  1989年   557篇
  1988年   448篇
  1987年   481篇
  1986年   468篇
  1985年   543篇
  1984年   417篇
  1983年   392篇
  1982年   366篇
  1981年   312篇
  1980年   294篇
  1979年   446篇
  1978年   354篇
  1977年   314篇
  1976年   285篇
  1975年   269篇
  1974年   273篇
  1973年   255篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Efforts to represent knowledge effectively have been central to progress in various aspects of medical informatics. These efforts range from relatively simple "electronic textbooks" to fairly sophisticated knowledge-based systems, which function as well as, or even better than, human experts faced with similar problems. Knowledge bases have been developed in many fields, but the relatively limited domains and structured language of medicine, as well as the importance of information in the provision of good medical care, have made research in medical knowledge representation an area of intense activity. This paper reviews representative knowledge bases and knowledge-based systems in medicine: electronic textbooks such as PDQ and the Hepatitis Knowledge Base (HKB), rule-based systems such as MYCIN, causal models (e.g., CASNET), and hypothesis- or frame-based systems, exemplified by PIP and INTERNIST-1. The paper describes the relationships among divergent approaches and provides a sense of current and future trends. It examines problems in knowledge-based systems, particularly in knowledge representation and acquisition, and the responses to these challenges. The latter include the use of domain-independent software shells for constructing knowledge bases, the adaptation and use of previously existing knowledge bases, and multiple uses of the same knowledge base for different purposes.  相似文献   
132.
133.
Serials, one of the more complicated areas of library technical endeavors, has lacked the benefit of standards for a long time. Even now, with standards beginning to be available, the majority of institutions are not working within standard serials formats. A survey to determine the use of serials standards in libraries was conducted in 1988 by the American Library Association, Resources and Technical Services Division, Serials Section, Committee to Study Serials Standards. In the spring of 1988 a survey was sent to a group encompassing the Association of Research Libraries members, CONSER participants, United States Newspaper Program participants, Microform Project libraries, and some vendors and librarians who attended the Committee meetings on a regular basis. The survey questionnaire assessed the current level of serials standards awareness of librarians and vendors. Topics included the type of serials systems used, standards relevant to serials control and union listing and whether or not they are implemented, types and levels of training staff received in the application of standards, benefits of the standards, and areas where standards are most needed.  相似文献   
134.
135.
136.
We theorize about the strategic alignment of computing with organizational mission, using the Commonwealth of Pennsylvania's efforts to pursue digital government initiatives as evidence. To do this we draw on a decade (1995–2004) of changes in Pennsylvania to characterize how a state government shifts from an organizational to an enterprise perspective regarding computing. We document and analyze the strategic and operational aspects of a series of information and communications technology (ICT) planning efforts to highlight the nature and roles of strategic alignment used to achieve this transition. Findings from this analysis mark the importance of combining several approaches to strategic planning regarding the adoption and application of ICT.  相似文献   
137.
Information access is central to library and information science, yet explorations of its conceptual nature have been limited. Given the importance of information access to the discipline, there is a need for research to create a better understanding of the concept and its many roles in all activities and behaviors related to information. Drawing on the theoretical work of Elfreda Chatman, this article proposes that the study of information access can be facilitated through the recognition and examination of the physical, intellectual, and social aspects of information access. These types of access are examined through three case studies in terms of different information behaviors and contexts, with a particular focus on the importance of social access. The article also discusses the future roles that considerations of social access can play in research and theory.  相似文献   
138.
139.
140.
彻底简化IT     
如何实现"简化IT"的战略,这是困扰很多企业,尤其是CIO的一个重要问题。本文以日本新生银行的例子来诠释如何彻底简化IT。中世纪哲人William of Ock- ham说过,理论应该尽可能的简单。同样的原则适用于企业IT系统:它们按照尽可能少的标准  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