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   23959篇
  免费   296篇
  国内免费   37篇
教育   16682篇
科学研究   2842篇
各国文化   185篇
体育   1738篇
综合类   10篇
文化理论   242篇
信息传播   2593篇
  2021年   231篇
  2020年   325篇
  2019年   437篇
  2018年   1238篇
  2017年   1210篇
  2016年   1020篇
  2015年   436篇
  2014年   582篇
  2013年   3649篇
  2012年   558篇
  2011年   803篇
  2010年   713篇
  2009年   528篇
  2008年   635篇
  2007年   659篇
  2006年   388篇
  2005年   416篇
  2004年   507篇
  2003年   388篇
  2002年   321篇
  2001年   610篇
  2000年   468篇
  1999年   399篇
  1998年   205篇
  1997年   286篇
  1996年   241篇
  1995年   190篇
  1994年   236篇
  1993年   172篇
  1992年   326篇
  1991年   288篇
  1990年   275篇
  1989年   305篇
  1988年   266篇
  1987年   245篇
  1986年   248篇
  1985年   287篇
  1984年   223篇
  1983年   209篇
  1982年   174篇
  1981年   165篇
  1980年   159篇
  1979年   239篇
  1978年   172篇
  1977年   159篇
  1976年   125篇
  1975年   146篇
  1974年   138篇
  1973年   146篇
  1971年   121篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
This study, an historical survey of medical journals in Louisiana before the outbreak of the Civil War in 1861, revealed that nine journals made an appearance during the period covered-all of them published in New Orleans. Of these, two were French language journals published by a French medical society. The others were all published by individuals rather than by professional societies. Medical practices, interests, and problems of the times were clearly reflected on the pages of the journals. It is evident that medical journalism reached a high plane in the era before the Civil War. Of the nine periodicals, only one emerged as a permanent publication after the War.  相似文献   
92.
The history of nursing education in America is briefly told, with the growth of education in institutions of higher learning emphasized. Two trends in nursing education are paralleled by similar developments in nursing literature. The growth of scholarship in nursing is also noted. It is pointed out that nursing is a discipline in its own right, and that training for leadership is required. Continuing education programs are mentioned, together with the increase in nursing literature. Integrated libraries for the health sciences are recommended.  相似文献   
93.
The American Hospital Association (AHA) Resource Center indexes journals for the Health Planning and Administration (HEALTH) database and Hospital Literature Index (HLI). These journals, designated special list health journals, are selected to provide access to a wide and balanced coverage of hospital and health care administration and health policy literature. This article provides background information on HEALTH and HLI and describes special list health journals in detail (including historical information, information sources, and broad subject divisions). It also discusses AHA policies relating to journal and article selection and current subject distribution of special list health journals.  相似文献   
94.
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   
95.
96.
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   
97.
98.
99.
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   
100.
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