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   1021篇
  免费   46篇
各国政治   46篇
工人农民   29篇
世界政治   86篇
外交国际关系   56篇
法律   575篇
中国共产党   2篇
中国政治   11篇
政治理论   213篇
综合类   49篇
  2023年   8篇
  2022年   9篇
  2021年   8篇
  2020年   28篇
  2019年   23篇
  2018年   34篇
  2017年   30篇
  2016年   38篇
  2015年   28篇
  2014年   43篇
  2013年   132篇
  2012年   52篇
  2011年   44篇
  2010年   43篇
  2009年   42篇
  2008年   47篇
  2007年   37篇
  2006年   35篇
  2005年   44篇
  2004年   41篇
  2003年   35篇
  2002年   28篇
  2001年   28篇
  2000年   28篇
  1999年   15篇
  1998年   20篇
  1997年   12篇
  1996年   10篇
  1995年   12篇
  1994年   8篇
  1993年   6篇
  1992年   7篇
  1991年   6篇
  1990年   6篇
  1989年   7篇
  1988年   12篇
  1987年   3篇
  1986年   11篇
  1985年   3篇
  1984年   2篇
  1983年   7篇
  1982年   5篇
  1979年   2篇
  1978年   6篇
  1976年   2篇
  1974年   4篇
  1972年   3篇
  1969年   2篇
  1967年   4篇
  1963年   1篇
排序方式: 共有1067条查询结果,搜索用时 31 毫秒
31.
Indicators are currently being widely used in international policy making to substantiate analyses and justify decisions on the basis of their alleged scientific objectivity. This article analyses the role of indicators and statistics in the labelling and managing of ‘fragile states’, examining the powerful consequences of these classifications but also discussing the untraceable nature of numbers and the difficulties in attributing ownership of numerical claims and assigning responsibility for their many unforeseen impacts. Focusing on the education sector in Timor-Leste and on the World Bank’s Country Policy and Institutional Assessment (cpia) programme, the article shows how accountability and ownership are negotiated within the context of the g7+ group of self-labelled ‘fragile states’, encouraging an examination of the power relations involved.  相似文献   
32.
33.
This paper summarizes the results of previous work on the microscopic observation of linear dichroism found in dyed fibres (polyesters, polyamides, wool, silk, cotton, viscose, acrylics and acetates) and in pigmented fibres as well as the measurements on these fibre classes using microspectrophotometry with plane polarized light (MSP-PPL). The validation of this method is discussed and a practical tool is proposed for comparing fibre traces with control fibres. The limitations and strengths of this method are also revised.  相似文献   
34.
35.
Abstract: This study was based on a morphometric analysis of bite marks starting from the quantitative definition of the anterior teeth by the geometric acquisition of the “injuries,” using bite marks impressed on pig skin and plastic. Each mark was photographed and acquired. A dedicated program automatically supplied the values of the shape factors and the areas of the pattern geometric figures. The values obtained for the homologous samples were compared to the heterologous values. Statistical comparison was made of the sets by linear regression, determining the correlation coefficient and the determination coefficient for each value. Results showed only 4.8% and 2% of overlap between homologous and heterologous values. This study was carried out in attempting to quantitatively define the anterior teeth of the human dentition and the procedure described and the results obtained support the advantage of morphometric studies and computer‐aided programs in this study of bite marks.  相似文献   
36.
His many publications include Theories of Mass Communication; Understanding Mass Communication; Milestones in Mass Communication Research;and, with Otto N. Larsen, The Flow of Information.  相似文献   
37.
38.
39.
In a double-blind placebo controlled study on psychomotor skills important for car driving (Study 1), a 75 mg dose of +/- 3,4-methylenedioxymethamphetamine (MDMA) was administered orally to 12 healthy volunteers who were known to be recreational MDMA-users. Toxicokinetic data were gathered by analysis of blood, urine, oral fluid and sweat wipes collected during the first 5h after administration. Resultant plasma concentrations varied from 21 to 295 ng/ml, with an average peak concentration of 178 ng/ml observed between 2 and 4h after administration. MDA concentrations never exceeded 20 ng/ml. Corresponding MDMA concentrations in oral fluid, as measured with a specific LC-MS/MS method (which required only 50 microl of oral fluid), generally exceeded those in plasma and peaked at an average concentration of 1215 ng/ml. A substantial intra- and inter-subject variability was observed with this matrix, and values ranged from 50 to 6982 ng/ml MDMA. Somewhat surprisingly, even 4-5h after ingestion, the MDMA levels in sweat only averaged 25 ng/wipe. In addition to this controlled study, data were collected from 19 MDMA-users who participated in a driving simulator study (Study 2), comparing sober non-drug conditions with MDMA-only and multiple drug use conditions. In this particular study, urine samples were used for general drug screening and oral fluid was collected as an alternative to blood sampling. Analysis of oral fluid samples by LC-MS/MS revealed an average MDMA/MDEA concentration of 1121 ng/ml in the MDMA-only condition, with large inter-subject variability. This was also the case in the multiple drug condition, where generally, significantly higher concentrations of MDMA, MDEA and/or amphetamine were detected in the oral fluid samples. Urine screening revealed the presence of combinations such as MDMA, MDEA, amph, cannabis, cocaine, LSD and psilocine in the multiple-drug condition.  相似文献   
40.
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