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   10950篇
  免费   321篇
各国政治   427篇
工人农民   438篇
世界政治   742篇
外交国际关系   304篇
法律   6881篇
中国政治   73篇
政治理论   2311篇
综合类   95篇
  2020年   122篇
  2019年   180篇
  2018年   211篇
  2017年   239篇
  2016年   235篇
  2015年   188篇
  2014年   205篇
  2013年   990篇
  2012年   234篇
  2011年   282篇
  2010年   222篇
  2009年   283篇
  2008年   288篇
  2007年   286篇
  2006年   275篇
  2005年   248篇
  2004年   241篇
  2003年   249篇
  2002年   250篇
  2001年   427篇
  2000年   372篇
  1999年   296篇
  1998年   161篇
  1997年   124篇
  1996年   140篇
  1995年   134篇
  1994年   135篇
  1993年   138篇
  1992年   234篇
  1991年   254篇
  1990年   241篇
  1989年   249篇
  1988年   226篇
  1987年   223篇
  1986年   264篇
  1985年   256篇
  1984年   230篇
  1983年   214篇
  1982年   151篇
  1981年   127篇
  1980年   113篇
  1979年   151篇
  1978年   85篇
  1977年   111篇
  1976年   95篇
  1975年   71篇
  1974年   89篇
  1973年   83篇
  1972年   78篇
  1971年   69篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
781.
Autopsy cases of deaths from handgun wounds were studied. Survival times were estimated from time of the incident until the time of pronouncement on police reports. Two groups were apparent--short-term and non-short-term survivors. These groups were compared statistically with respect to age, race, sex, Spanish surname, alcohol, drugs detected at autopsy, caliber of projectile, frequency of shots, and location of injury.  相似文献   
782.
A discrete nebulisation technique has been developed for the multi-element analysis of 100-μl solution droplets by inductively coupled plasma-optical emission spectrometry (ICP-OES). The technique increases analytical speed and uses very small solution volumes with only a slight degradation in detection limits when compared to continuous solution introduction.To evaluate its suitability in casework, small alloy fragments were produced by cutting with a hacksaw, sample division and filing. The analysis of fragments from two different brasses indicated that quantitative data could be obtained from fragments as small as 10 μg. The accurate determination of lead, a non-homogeneous constituent of leaded brasses, required sample sizes an order of magnitude greater. Analysis of an alloy of fine grain structure (copper-nickel) demonstrated that quantitative data could be obtained from samples weighing a few micrograms or less.  相似文献   
783.
784.
785.
786.
787.
Social security and private saving: theory and historical evidence   总被引:1,自引:0,他引:1  
This article is a nontechnical presentation of the debate that has gone on during the past decade over whether the U.S. social security system has depressed private saving in the economy. The heart of the article is an assessment of economist Martin Feldstein's original evidence, presentation of the alternative evidence that concluded that currently available historical data do not support the proposition that social security reduces private saving, and an evaluation of the contradictory evidence presented by Feldstein in response to the alternative evidence. The article concludes that, although the total body of evidence is inconclusive, the historical evidence fails to support the hypothesis that social security has reduced private saving. The Office of Research, Statistics, and International Policy, as part of its ongoing research mission, investigates the interrelationship between social security and the economy. This article presents an examination of one of several aspects of this relationship relevant to public policy considerations and is intended to make previously published technical papers available to a broader audience.  相似文献   
788.
789.
790.
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