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   11665篇
  免费   377篇
各国政治   594篇
工人农民   422篇
世界政治   910篇
外交国际关系   388篇
法律   7033篇
中国共产党   1篇
中国政治   65篇
政治理论   2533篇
综合类   96篇
  2020年   147篇
  2019年   177篇
  2018年   250篇
  2017年   269篇
  2016年   267篇
  2015年   209篇
  2014年   220篇
  2013年   1255篇
  2012年   295篇
  2011年   284篇
  2010年   259篇
  2009年   264篇
  2008年   305篇
  2007年   307篇
  2006年   316篇
  2005年   282篇
  2004年   292篇
  2003年   288篇
  2002年   275篇
  2001年   399篇
  2000年   341篇
  1999年   283篇
  1998年   162篇
  1997年   143篇
  1996年   110篇
  1995年   128篇
  1994年   124篇
  1993年   126篇
  1992年   203篇
  1991年   234篇
  1990年   229篇
  1989年   230篇
  1988年   205篇
  1987年   230篇
  1986年   235篇
  1985年   247篇
  1984年   206篇
  1983年   215篇
  1982年   145篇
  1981年   139篇
  1980年   128篇
  1979年   137篇
  1978年   130篇
  1977年   89篇
  1976年   98篇
  1975年   104篇
  1974年   127篇
  1973年   118篇
  1972年   96篇
  1969年   91篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
Telecommunications regulation has experienced a fundamentalshift from rate regulation to increased reliance on compelledaccess, perhaps best exemplified by the Telecommunications Actof 1996's imposition of no fewer than four new access requirements.Unfortunately, each access requirement is governed by a separateset of rules for determining both the scope and the price ofaccess. The resulting ad hoc regime has created difficult definitionalproblems and opportunities for regulatory arbitrage. In thisarticle we propose a system inspired by the discipline of mathematicsknown as graph theory that integrates all of the different formsof access into a single analytical framework. This system separatesdifferent access regimes into five categories: (1) retail access,(2) wholesale access, (3) interconnection access, (4) platformaccess, and (5) unbundled access. It also provides insightsinto how each type of access complicates the already difficultproblems of network configuration and management and introducesinefficient biases into decisions about network capacity anddesign. The approach we propose also provides insights intothe transaction cost implications of the different types ofaccess. Drawing on the Coasean theory of the firm, our approachexamines the tradeoffs between internal governance costs andthe external transaction costs of providing access to offera theory of network boundaries. This framework shows how accessregulation distorts networks' natural boundaries and providesa basis for evaluating whether private ordering through marketswould lead to more efficient network design.  相似文献   
93.
Eighteen external quality assessment (proficiency testing) samples were prepared from client specimens collected with the Intercept® oral fluid collection device and by spiking drug-free oral fluid. Samples were circulated in pairs at quarterly intervals to 13 UK and USA based laboratories for analysis by a panel of OraSure micro-plate Intercept® enzyme immunoassay kits and hyphenated mass spectrophotometric techniques. During the survey, there was a single case of non-specificity in a false report for methadone. The major errors were of lack of sensitivity relative to the concentration thresholds specified for the immunoassays. The sensitivity for overall ‘present’/‘not found’ reports calculated as true positives/(true positives + false negatives) were for the amfetamine specific assay 50%, methyl-amfetamines 93%, barbiturates 64%, cannabinoids 73%, cocaine and metabolites 100%, benzodiazepines 69%, methadone 95%, opiates 79% (opiates excluding oxycodone 93%), phencyclidine 93% and human gamma-globulin 97%. A small number of the sensitivity errors were attributable to errors in chromatographic confirmation techniques.  相似文献   
94.
95.
96.
Book Review     
Radical myths and superpower relations in the 1980s

A review of Mark Kaldor, Gerard Holden, and Richard Falk (eds), The New Detente: Rethinking East‐West Relations, Verso, London, 1989.

Paul Taylor and A.J.R. Groom, Global Issues in the United Nations Framework, Basingstoke, Hampshire, The MacMillan Press Ltd., 1989.

Roger A. Coate, Unilateralism, Ideology, and US Foreign Policy: The United States in and out of UNESCO, Lynne Reinner Publishers, London, 1988.

Bary Buzan, Morten Kelstnip, Pierre Lemaitre, Elzbieta Tromer, and Ole Weaver, The European Security Order Recast: Scenarios for the Post‐Cold War Era, Pinter Publishers, London & New York, 1990, pp.x. 282, £8.95 pbk, £30 hbk.  相似文献   

97.
98.
The authors present a method to separate and preserve stomach contents for forensic purpose. Analysis by "sieve tower" technique is simple and quickly done during autopsy. Solid phases of stomach content are arranged size up and can be stored for subsequent examinations. With the fluid phase drug analysis or microscopic analysis to confirm identy of the foodstuffs may be done. By adding alcohol (70%) enzymatic digestion and bacterial degradation of the stomach content are stopped.  相似文献   
99.
A definitive explanation of "crib" or "cot" death remains unknown. An unusual incidental autopsy finding of agenesis of the corpus callosum in a case presenting as "near miss" sudden infant death syndrome (SIDS) is discussed. Hitherto, only a single case associated with SIDS has been reported in the literature. The condition may be easily missed outside the interest in neuropathology.  相似文献   
100.
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