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   1386篇
  免费   50篇
各国政治   121篇
工人农民   153篇
世界政治   121篇
外交国际关系   66篇
法律   518篇
中国政治   14篇
政治理论   435篇
综合类   8篇
  2021年   4篇
  2020年   17篇
  2019年   42篇
  2018年   47篇
  2017年   54篇
  2016年   39篇
  2015年   28篇
  2014年   46篇
  2013年   233篇
  2012年   35篇
  2011年   50篇
  2010年   26篇
  2009年   36篇
  2008年   51篇
  2007年   43篇
  2006年   52篇
  2005年   52篇
  2004年   58篇
  2003年   44篇
  2002年   45篇
  2001年   15篇
  2000年   26篇
  1999年   21篇
  1998年   24篇
  1997年   22篇
  1996年   18篇
  1995年   18篇
  1994年   24篇
  1993年   22篇
  1992年   15篇
  1991年   18篇
  1990年   15篇
  1989年   15篇
  1988年   11篇
  1987年   11篇
  1986年   9篇
  1985年   16篇
  1984年   9篇
  1983年   23篇
  1982年   10篇
  1981年   12篇
  1980年   10篇
  1979年   9篇
  1978年   4篇
  1977年   10篇
  1976年   4篇
  1974年   7篇
  1973年   4篇
  1971年   4篇
  1966年   4篇
排序方式: 共有1436条查询结果,搜索用时 0 毫秒
201.
202.
Reviews     
  相似文献   
203.
204.
205.
206.
Patrick Vaughan is Reader in health care epidemiology, Gill Walt is Lecturer in health policy and Anne Mills is Lecturer in health economics, at the Evaluation and Planning Centre for Health Care, London School of Hygiene and Tropical Medicine, Gower Street, London WC1, United Kingdom. A previous version of this paper was prepared for the Commonwealth Secretariat, London, for the Conference of Commonwealth Health Ministers held in Ottawa, Canada, in October 1983.  相似文献   
207.
Within the last 20 years, the fragile symbiotic relationship between physicians and hospitals has become increasingly strained. Physicians have created new healthcare delivery systems, including a host of for-profit, physician-owned specialty hospitals. Proponents of specialty hospitals argue that they provide high quality facilities and allow for innovative treatments. Opponents, however, contend that such hospitals "cherry pick" patients who otherwise would help to subsidize general hospitals, and point to the various fraud and abuse issues raised by physician-owned specialty hospitals. This Article examines the specialty hospital phenomenon and the arguments for and against such entities. It also analyzes whether an extension of the present federal moratorium on the construction of new physician-owned specialty hospitals is in the best interests of the country's healthcare system. The author concludes that the data are unclear as the overall impact of such hospitals and that they should not be further constrained until when and if the facts are clear.  相似文献   
208.
Improved detection of forensic evidence by combining narrow band photographic images taken at a range of wavelengths is dependent on the substance of interest having a significantly different spectrum from the underlying substrate. While some natural substances such as blood have distinctive spectral features which are readily distinguished from common colorants, this is not true for visualization agents commonly used in forensic science. We now show that it is possible to select reagents with narrow spectral features that lead to increased visibility using digital cameras and computer image enhancement programs even if their coloration is much less intense to the unaided eye than traditional reagents. The concept is illustrated by visualising latent fingermarks on paper with the zinc complex of Ruhemann's Purple, cyanoacrylate-fumed fingerprints with Eu(tta)(3)(phen), and soil prints with 2,6-bis(benzimidazol-2-yl)-4-[4'-(dimethylamino)phenyl]pyridine [BBIDMAPP]. In each case background correction is performed at one or two wavelengths bracketing the narrow absorption or emission band of these compounds. However, compounds with sharp spectral features would also lead to improved detection using more advanced algorithms such as principal component analysis.  相似文献   
209.
The good heart     
Underwood A 《Newsweek》2005,146(14):48-52, 54-5
  相似文献   
210.
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