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   25337篇
  免费   354篇
  国内免费   18篇
教育   18045篇
科学研究   2172篇
各国文化   274篇
体育   2376篇
综合类   8篇
文化理论   242篇
信息传播   2592篇
  2021年   252篇
  2020年   386篇
  2019年   580篇
  2018年   786篇
  2017年   712篇
  2016年   708篇
  2015年   433篇
  2014年   562篇
  2013年   4737篇
  2012年   522篇
  2011年   574篇
  2010年   432篇
  2009年   452篇
  2008年   509篇
  2007年   462篇
  2006年   442篇
  2005年   382篇
  2004年   419篇
  2003年   335篇
  2002年   351篇
  2001年   475篇
  2000年   532篇
  1999年   456篇
  1998年   273篇
  1997年   267篇
  1996年   327篇
  1995年   260篇
  1994年   270篇
  1993年   241篇
  1992年   367篇
  1991年   382篇
  1990年   353篇
  1989年   383篇
  1988年   350篇
  1987年   347篇
  1986年   338篇
  1985年   382篇
  1984年   305篇
  1983年   319篇
  1982年   258篇
  1981年   263篇
  1980年   279篇
  1979年   367篇
  1978年   276篇
  1977年   246篇
  1976年   212篇
  1975年   189篇
  1974年   195篇
  1973年   187篇
  1971年   188篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
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   
82.
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   
83.
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   
84.
85.
86.
87.
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   
88.
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   
89.
Governments worldwide are increasingly using Web-based business models to enhance their service delivery. Yet the concept of the business model is unexplored within the context of e-government. Drawing upon the literature on e-commerce, we develop a taxonomy for analyzing Web-based business models for e-government. Based on a systematic survey of 59 e-government Web sites in the Netherlands, our findings indicate that most of the Web sites use the content provider or direct-to-customer business models, while only a few are using novel business models. Overall, the concept of business model is appealing and useful in the public sector. Specifically it compliments research on Web site quality by analyzing and describing Web sites using atomic e-government business models and suggesting improvements by using combinations of business models.  相似文献   
90.
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