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   34692篇
  免费   502篇
  国内免费   33篇
教育   24571篇
科学研究   3213篇
各国文化   369篇
体育   3162篇
综合类   12篇
文化理论   300篇
信息传播   3600篇
  2021年   342篇
  2020年   525篇
  2019年   749篇
  2018年   1044篇
  2017年   960篇
  2016年   969篇
  2015年   599篇
  2014年   786篇
  2013年   6255篇
  2012年   734篇
  2011年   807篇
  2010年   642篇
  2009年   622篇
  2008年   704篇
  2007年   637篇
  2006年   617篇
  2005年   544篇
  2004年   592篇
  2003年   483篇
  2002年   476篇
  2001年   840篇
  2000年   735篇
  1999年   623篇
  1998年   360篇
  1997年   385篇
  1996年   414篇
  1995年   350篇
  1994年   369篇
  1993年   312篇
  1992年   499篇
  1991年   509篇
  1990年   487篇
  1989年   514篇
  1988年   458篇
  1987年   449篇
  1986年   456篇
  1985年   530篇
  1984年   421篇
  1983年   427篇
  1982年   353篇
  1981年   339篇
  1980年   355篇
  1979年   466篇
  1978年   371篇
  1977年   334篇
  1976年   273篇
  1975年   275篇
  1974年   267篇
  1973年   267篇
  1971年   253篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
The successful delivery of health care involves a commitment to improved communication both with regard to health professionals and the public. The need for innovative educational patterns is implicit in the recommendations of the latest Carnegie Commission Report, Higher Education and the Nation's Health.The new technology of videorecording permits the learner to learn at a time and place of his own choosing. Information is transmitted through the cathode ray tube-a television set-the medium of our time. The videorecord is of significant value in the basic and clinical sciences, in training personnel for allied health professions, and in continuing education. It is thoroughly compatible with the new concept of the open university, an institution without walls.In addition to its unquestioned value in educational programs in the health sciences, the videorecord has major implications for the curriculum in librarianship and for increasing the professional competence of medical librarians and their ancillaries. The medical librarian has a major stake in its imaginative use for overcoming some of the barriers to individual and community health.  相似文献   
122.
Science Citation Index is one of a number of indexes based on the assumption that the papers cited by one author refer to work which is relevant to the subject discussed by the author citing them. Cleverdon, however, has questioned that assumption, and it was to test the assumption that this research was undertaken. An attempt was made to determine what percent of articles cited were related to the citing article. The conclusion reached was that in the field of medicine approximately 72 percent of the cited papers were considered related to the original paper by the authors of the original, thus apparently bearing out the assumption for citation indexing.  相似文献   
123.
The immediate circumstances of the new Broadcasting Act are discussed. The impact of this legislation on schools broadcasting is then considered in relation to the history of earlier legislation in the UK, and the early responses to the Television Act of 1954. The importance of the personnel involved in television production and their commitment to the values of public service is stressed, and placed against the gloomier forebodings of the pessimists of the past‐‐and of today. The article concludes with the assertion that it is the people in the television industry itself, and the values they hold, that will ensure the continued survival of good schools television.  相似文献   
124.
Time series analysis was used to investigate the hypothesis that during acquisition of a motor skill, knowledge of results (KR) information is used to generate a stable internal referent about which response errors are randomly distributed. Sixteen subjects completed 50 acquisition trials of each of three movements whose spatial-temporal characteristics differed. Acquisition trials were either blocked, with each movement being presented in series, or randomized, with the presentation of movements occurring in random order. Analysis of movement time data indicated the contextual interference effect reported in previous studies was replicated in the present experiment. Time series analysis of the acquisition trial data revealed the majority of individual subject response patterns during blocked trials were best described by a model with a temporarily stationary, internal reference of the criterion and systematic, trial-to-trial variation of response errors. During random trial conditions, response patterns were usually best described by a "White-noise" model. This model predicts a permanently stationary, internal reference associated with randomly distributed response errors that are unaffected by KR information. These results are not consistent with previous work using time series analysis to describe motor behavior (Spray & Newell, 1986).  相似文献   
125.
126.
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   
127.
128.
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   
129.
130.
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   
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