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   365篇
  免费   7篇
各国政治   27篇
工人农民   7篇
世界政治   13篇
外交国际关系   18篇
法律   225篇
政治理论   82篇
  2023年   2篇
  2022年   3篇
  2021年   1篇
  2020年   4篇
  2019年   4篇
  2018年   7篇
  2017年   9篇
  2016年   7篇
  2015年   8篇
  2014年   13篇
  2013年   23篇
  2012年   13篇
  2011年   15篇
  2010年   14篇
  2009年   23篇
  2008年   24篇
  2007年   24篇
  2006年   22篇
  2005年   19篇
  2004年   5篇
  2003年   13篇
  2002年   26篇
  2001年   10篇
  2000年   12篇
  1999年   4篇
  1998年   2篇
  1997年   5篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1987年   3篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1983年   4篇
  1982年   2篇
  1981年   7篇
  1979年   3篇
  1978年   5篇
  1977年   3篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1970年   1篇
  1966年   1篇
排序方式: 共有372条查询结果,搜索用时 15 毫秒
21.
In this paper we suggest a model for an analysis of how newspapers and political parties determine their ideological orientation and how both decisions depend on each other. Quite naturally dissemination of information plays an important role. The model is set up as a two-stage game. Because elements of horizontal as well as vertical product differentiation are present in this model location patterns in ideology space exhibit in general neither maximal nor minimal differentiation, although we keep quite close to the Downs model, with information as the most important distinguishing feature. Furthermore, the model shows by way of example that economic theory can be a useful tool to investigate issues which are central to communication science.  相似文献   
22.
23.
The cause of drowning deaths in good swimmers may be difficult to solve. After homicide, suicide and other kinds of immersion deaths have been ruled out, not only alcohol and narcotics, but also other psychotropic substances such as thornapple and angel's trumpet should be taken into consideration--at least in adolescents and young adults. The article reports on an accidental death by drowning under the influence of tropane alkaloids after consumption of a decoction of the flowers of angel's trumpet.  相似文献   
24.
25.
26.
27.
Editorial     
Ohne Zusammenfassung
Editorial
  相似文献   
28.
29.
We present a case of an accidental autoerotic death involving the inhalation of a propane-butane gas mixture, also known as LPG (liquefied petroleum gas). A 19-year-old male was found dead in supine position in his bed in a residential accommodation one day after he was last seen alive. On a personal computer at the end of the bed, a pornographic movie was still running. On his left shoulder, an empty rubber balloon and on the bedside 2 empty "Kisag-Gas" cartridges were found. Toxicologic investigations revealed an intoxication with propane and butane, together with a recent consumption of cannabis. This case report compares the toxicologic findings with other recently published cases, and the theories of the toxic effects are discussed.  相似文献   
30.
Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.  相似文献   
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