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   1325篇
  免费   80篇
各国政治   105篇
工人农民   86篇
世界政治   136篇
外交国际关系   72篇
法律   742篇
中国政治   2篇
政治理论   259篇
综合类   3篇
  2023年   13篇
  2022年   15篇
  2021年   24篇
  2020年   39篇
  2019年   43篇
  2018年   67篇
  2017年   87篇
  2016年   86篇
  2015年   51篇
  2014年   66篇
  2013年   180篇
  2012年   62篇
  2011年   46篇
  2010年   25篇
  2009年   32篇
  2008年   42篇
  2007年   52篇
  2006年   43篇
  2005年   41篇
  2004年   48篇
  2003年   39篇
  2002年   40篇
  2001年   46篇
  2000年   22篇
  1999年   22篇
  1998年   11篇
  1997年   18篇
  1996年   10篇
  1995年   7篇
  1994年   5篇
  1993年   5篇
  1992年   8篇
  1991年   6篇
  1990年   9篇
  1989年   11篇
  1988年   7篇
  1987年   7篇
  1985年   4篇
  1984年   4篇
  1983年   4篇
  1982年   5篇
  1979年   4篇
  1978年   3篇
  1974年   3篇
  1973年   7篇
  1972年   6篇
  1971年   11篇
  1968年   3篇
  1966年   3篇
  1965年   2篇
排序方式: 共有1405条查询结果,搜索用时 15 毫秒
291.
Race is understudied in International Relations generally and International Security specifically. To mitigate this omission, this article provides a racial theory of threat perception. It argues that, under certain conditions, racial prejudices embedded in racial identities shape threat perceptions and generate behavioral dispositions. In the first step, racial similarity deflates threat perceptions, while racial difference inflates them. In the second step, deflated threat perceptions facilitate cooperation among racially similar agents, while inflated threat perceptions facilitate discord among racially different agents. Using extensive archival and secondary sources, the article illustrates the explanatory value of the theory in the case of the Anglo-Japanese Alliance (1902-23).  相似文献   
292.
293.
294.
295.
296.
297.
298.
299.
In recent years, there has been a renewed interest in forensic sciences about forensic age estimation in living subjects by means of radiological methods. This research was conducted on digital thorax X-rays to test the usefulness of some radiological changes in the clavicle and first rib. The sample consisted in a total of 123 subjects of Spanish origin (61 men and 62 women; age range: 5-75 years). From all subjects, a thorax posterior-anterior radiograph was obtained in digital format. Scoring for fusion of medial epiphyses of the clavicle was carried out by Schmeling's system and ossification of the costal cartilage of the first rib by Michelson's system. Degree of ossification and epiphyseal fusion were analyzed in relation with known age and sex of these subjects. The results give a minimum age of >20 years for full fusion of the medial epiphysis of the clavicle (Stages 4 and 5). Concerning the first rib, all subjects with the final Stage 3 of ossification were above 25 years of age. These results suggest that the first rib ossification might become an additional method to the ones so far recommended for forensic age estimation in subjects around 21. New research would be desirable to confirm this suggestion.  相似文献   
300.
During the analysis of "seized samples", suspected of containing 4-methylmethcathinone (mephedrone) and N-ethylcathinone (ethcathinone) additional compounds were observed in the GCMS chromatogram. These compounds were suspected to be the corresponding phenylacetone isomers of mephedrone and ethcathinone respectively. These isomers are referred to as iso-mephedrone and iso-ethcathinone, respectively. The identity of these compounds was verified by synthesising the isomers from known starting materials and comparing them with the compounds found in the seized samples. Analytical data, GCMS, NMR and IR on these compounds are provided. Possible explanations for the presence of these compounds in the seized samples are explored. Contaminated starting material is one suggestion. Rearrangement of the propiophenone based product to the phenylacetone based product is also suggested. The reaction of the α-bromopropiophenone with a primary amine can also lead to the phenylacetone based product. The presence of these isomeric compounds in seized samples could be used to compare different samples and attempt to establish a common origin.  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