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   32993篇
  免费   490篇
  国内免费   35篇
教育   23392篇
科学研究   3299篇
各国文化   520篇
体育   2342篇
综合类   38篇
文化理论   325篇
信息传播   3602篇
  2021年   297篇
  2020年   463篇
  2019年   647篇
  2018年   1407篇
  2017年   1499篇
  2016年   1246篇
  2015年   573篇
  2014年   739篇
  2013年   5648篇
  2012年   774篇
  2011年   1030篇
  2010年   855篇
  2009年   731篇
  2008年   887篇
  2007年   929篇
  2006年   596篇
  2005年   585篇
  2004年   636篇
  2003年   497篇
  2002年   504篇
  2001年   543篇
  2000年   557篇
  1999年   531篇
  1998年   276篇
  1997年   310篇
  1996年   316篇
  1995年   271篇
  1994年   265篇
  1993年   261篇
  1992年   420篇
  1991年   422篇
  1990年   450篇
  1989年   433篇
  1988年   391篇
  1987年   348篇
  1986年   348篇
  1985年   451篇
  1984年   371篇
  1983年   362篇
  1982年   284篇
  1981年   274篇
  1980年   253篇
  1979年   358篇
  1978年   291篇
  1977年   272篇
  1976年   233篇
  1975年   194篇
  1974年   201篇
  1973年   214篇
  1972年   175篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
"Change" is a critical dimension of contemporary experience. Library associations are not exempt, and they change in ways similar to other organizations. According to some authorities, four phases typify the process: diagnosis, design, implementation, and incorporation. Focusing on changes in the Medical Library Association's longstanding program of continuing education, the authors utilize the "phase framework" to chart that association's movement from a management system depending primarily upon volunteers to one in which professional staff figure prominently. The historical review serves a heuristic purpose for individuals and institutions in identifying characteristic features of the change process.  相似文献   
92.
93.
94.
The preliminary building program suggested in this paper makes use of outlines, graphs, charts, and lists, rather than long-winded paragraphs, to describe the needs, objectives, and philosophy of the library. It is hoped that a short, concise, but detailed, report using these methods will save time and make the report more attractive to read, thereby encouraging the many people who will need to assist in the building planning to use the report.  相似文献   
95.
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   
96.
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   
97.
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   
98.
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   
99.
As a gatekeeper to medical literature and a critical link in the delivery of information to physicians, the librarian's role raises the issue of the librarian's professional liability. The paper suggests several ways in which liability may attach to the librarian or the librarian's employers. Although the librarian's personal risk is negligible, the physician's exposure due to ineffective library work is substantial since the courts have held that a physician must keep abreast of progress in his field. Librarians can also become associated with professional liability actions as part of a case against a physician or hospital through the legal doctrine of vicarious liability. The paper concludes by suggesting several proactive steps for health sciences librarians to pursue to insulate themselves from professional liability and to insulate physicians and institutions from vicarious liability.  相似文献   
100.
This article discusses HIV infection in terms of the risk manager's information needs in the health care environment. The malpractice problem, increasing workman's compensation suits, the greater role of the ombudsman, implementation of the National Practitioner Data Bank, and the Joint Commission on Accreditation of Health Care Organizations' (JCAHO) emphasis on clinical excellence are conditions which have given greater importance to the risk manager's position. Included in this article are hedges to retrieve various components of risk management and a select bibliography from AIDSLINE.  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