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   26155篇
  免费   1251篇
各国政治   1065篇
工人农民   1760篇
世界政治   1355篇
外交国际关系   863篇
法律   17234篇
中国共产党   9篇
中国政治   114篇
政治理论   4909篇
综合类   97篇
  2023年   83篇
  2021年   105篇
  2020年   457篇
  2019年   477篇
  2018年   1794篇
  2017年   1737篇
  2016年   1648篇
  2015年   608篇
  2014年   582篇
  2013年   1925篇
  2012年   700篇
  2011年   1389篇
  2010年   1507篇
  2009年   1142篇
  2008年   1245篇
  2007年   1229篇
  2006年   596篇
  2005年   536篇
  2004年   638篇
  2003年   522篇
  2002年   473篇
  2001年   707篇
  2000年   631篇
  1999年   494篇
  1998年   259篇
  1997年   193篇
  1996年   214篇
  1995年   217篇
  1994年   195篇
  1993年   178篇
  1992年   313篇
  1991年   318篇
  1990年   302篇
  1989年   286篇
  1988年   312篇
  1987年   267篇
  1986年   326篇
  1985年   325篇
  1984年   257篇
  1983年   241篇
  1982年   184篇
  1981年   166篇
  1980年   144篇
  1979年   230篇
  1978年   127篇
  1977年   101篇
  1975年   94篇
  1974年   126篇
  1973年   82篇
  1972年   79篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
132.
A simple and rapid method is described for processing organ and water samples for the identification of diatoms so that they can be studied and recorded for taxonomic and diagnostic purposes. Samples are treated with concentrated nitric acid; the fluid obtained is centrifuged, and its sediment is dried, coated, and examined under the scanning electron microscope. The method does not alter the morphology of diatoms and allows the study of freshwater and seawater species present in the organs of bodies found in the water, making possible the diagnosis of drowning under specific conditions.  相似文献   
133.
134.
Book Reviews in This Article:
Getting Rid of Patients: Contradictions in the Socialization of Physicians . By Terry Mizrahi
Physicians and Social Change . By John Colombotos and Corinne Kirchner
Changing Values in Medicine . Edited by Eric J. Cassell and Mark Siegler
Professional Ethics and Primary Care Medicine: Beyond Dilemmas and Decorum . By Harmon L. Smith and Larry R. Churchill
Physician—Patient Decision-Making: A Study in Medical Ethics . By Douglas N. Walton
With Dignity: The Search for Medicare and Medicaid . By Sheri I. David
The Dismissal of Students with Mental Disorders. Legal Issues, Policy Considerations, and Alternative Responses .
Courtroom Toxicology . By Marshall Houts, Randall C. Baselt, and Robert H. Cravey  相似文献   
135.
136.
137.
138.
139.
In order to cooperate with voluntary screening programs aimed at the surveillance of the HIV epidemic in Finland, we have studied medicolegal autopsies for HIV antibodies since 1986 using an enzyme immunoassay on postmortem sera. The investigation covered 47.4% and 39.2%, respectively, of all deaths under the age of 65 years in the metropolitan areas of Helsinki and Turku--two cities on the densely populated southern coast of Finland from which most HIV infections have thus far been detected. Nine HIV-positive cases (0.12%) were detected among the 7305 medicolegal autopsies tested in 1986 to 1990. This figure is higher than the prevalence of 0.01 to 0.03% in voluntary screening programs for the general population would suggest. Seven of our cases had previously tested positive, and two were previously unknown cases, indicating that people at high risk are clustered in the medicolegal autopsy series. Of the six cases in an early stage of infection, three committed suicide suggesting the importance of HIV-screening in suicide cases in tracing symptomless HIV carriers. Five of the cases were detected in 1990, a year when the number of new HIV infections had more than doubled compared to the previous two years. This suggests that testing of medicolegal autopsies as surrogate tests for the population gives useful information even in low-prevalence areas like Finland. Such testing has none of the ethical problems of many other back-up surveys, and may be particularly sensitive to early changes in epidemiology.  相似文献   
140.
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