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   11514篇
  免费   326篇
各国政治   380篇
工人农民   449篇
世界政治   775篇
外交国际关系   388篇
法律   7714篇
中国政治   69篇
政治理论   2006篇
综合类   59篇
  2020年   145篇
  2019年   183篇
  2018年   231篇
  2017年   251篇
  2016年   269篇
  2015年   175篇
  2014年   241篇
  2013年   1030篇
  2012年   278篇
  2011年   304篇
  2010年   246篇
  2009年   265篇
  2008年   294篇
  2007年   322篇
  2006年   332篇
  2005年   252篇
  2004年   272篇
  2003年   301篇
  2002年   242篇
  2001年   496篇
  2000年   467篇
  1999年   355篇
  1998年   145篇
  1997年   126篇
  1996年   122篇
  1995年   116篇
  1994年   132篇
  1993年   111篇
  1992年   253篇
  1991年   250篇
  1990年   255篇
  1989年   262篇
  1988年   261篇
  1987年   268篇
  1986年   231篇
  1985年   253篇
  1984年   197篇
  1983年   205篇
  1982年   140篇
  1981年   137篇
  1980年   105篇
  1979年   146篇
  1978年   107篇
  1977年   88篇
  1976年   86篇
  1975年   72篇
  1974年   92篇
  1973年   85篇
  1971年   70篇
  1970年   70篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
The recoveries of acidic, basic, and neutral drugs through buffered celite columns are reported. The methods are rapid, simple, clean, and efficient, especially with compounds having a high volatility.  相似文献   
922.
Samples of blue and red cotton fibres were examined using light and fluorescence microscopy as well as UV/VIS microspectrophotometry and fluorescence microspectroscopy. The degree of fluorescence and spectral variation was recorded. Particular attention was paid to the recurrence of certain spectral patterns. The importance of spectral information in the UV range is emphasized again. Colour plays a critical role in the comparison of cotton fibres in forensic sciences. Normally, fibres producing spectral patterns that are frequently seen will tend to have a lower evidential value in criminal cases as the choice of putative sources is theoretically greater and vice versa. Besides black cotton, blue and red cotton fibres are very frequent in fibre casework. The very high discriminating power using a combination of light microscopy, fluorescence microscopy and UV/VIS microspectrophotometry shows that even blue and red cotton fibres can provide excellent evidence when involved in fibre transfer cases.  相似文献   
923.
This article explores the potential evisceration of the deterrence function of punitive damages, one of the only economic incentives that deters insurance companies from opportunistically breaching their insurance policies. Readers will gain an understanding of why large punitive damages awards are essential in the insurance coverage field and how such awards may implicate due process standards. The article explains the constitutional limitations set forth by the U.S. Supreme Court in imposing punitive damages, and provides a roadmap of how lower courts and practitioners are presently applying these rules.  相似文献   
924.
Bite mark analysis involves comparison of individual dental characteristics between a dentition and the bite injury. A bite mark injury may result from sexual assault, or physical assault, and defensive injuries, and as such can be used to link a suspect to a victim or vice versa. Missing teeth are one of the characteristics that could implicate or exclude a suspected biter. However frequency data for use by forensic odontologists can only be collated from epidemiological studies. Therefore an audit was undertaken of missing anterior teeth in adult patients (n = 1010) attending for treatment, gathering data that could be more relevant to odontology. One in five of the sample presented with missing teeth that were either replaced with a denture (11%), not replaced (6%) or missing with the gap closed (2%).  相似文献   
925.
As the result of a previous study many laboratories have used XAM neutral medium-improved white mounting medium in textile fibre examination for more than 20 years. Due to European Directive 98/79/EC, XAM is no longer available and an alternative needed to be found. A list of desirable properties was formulated and a number of mounting media were tested against this. Entellan New was identified as the best mounting medium, and performed similarly to XAM in all aspects.  相似文献   
926.
927.
Endogenous and exogenous erythropoietin (EPO) present in urine can be distinguished according to their isoelectric profiles. This methodology requires urine samples to be concentrated about 200 to 1000 times with manipulations that should remove most of the cells occurring in the original sample. In this study, we tried to obtain DNA profiles from 10 ultrafiltered urines (retentates) in order to evaluate whether a formal genetic identification was technically feasible. No nuclear DNA profiles could be established from retentates, despite 34 PCR-cycles amplifications. Contrastingly, mitochondrial DNA (mtDNA) profiles were obtained for 9 out of the 10 retentates. Apart from some particularities, retentate mtDNA profiles were all distinct and matched mtDNA profiles of corresponding reference samples.  相似文献   
928.
929.
930.
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