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   355篇
  免费   10篇
各国政治   12篇
工人农民   23篇
世界政治   49篇
外交国际关系   44篇
法律   126篇
中国政治   4篇
政治理论   99篇
综合类   8篇
  2020年   5篇
  2019年   6篇
  2018年   9篇
  2017年   3篇
  2016年   6篇
  2015年   10篇
  2014年   7篇
  2013年   43篇
  2012年   5篇
  2011年   20篇
  2009年   7篇
  2008年   8篇
  2007年   12篇
  2006年   13篇
  2005年   12篇
  2004年   11篇
  2003年   12篇
  2002年   12篇
  2001年   7篇
  2000年   13篇
  1999年   5篇
  1998年   6篇
  1997年   4篇
  1996年   5篇
  1995年   7篇
  1994年   8篇
  1993年   5篇
  1992年   11篇
  1991年   5篇
  1990年   5篇
  1988年   3篇
  1987年   4篇
  1986年   3篇
  1985年   4篇
  1984年   4篇
  1983年   2篇
  1982年   5篇
  1981年   2篇
  1980年   3篇
  1979年   4篇
  1978年   8篇
  1976年   4篇
  1975年   2篇
  1974年   6篇
  1973年   6篇
  1971年   2篇
  1970年   3篇
  1968年   4篇
  1967年   3篇
  1966年   2篇
排序方式: 共有365条查询结果,搜索用时 15 毫秒
131.
This article explores the recent debate over the quality of Africa's growth episode of the past decade, specifically insofar as it pertains to the pitfalls of commodity-dependent growth and the hypothesised ‘resource curse’. In addition, the article focuses on why political and economic institutions are important, and why they are indicators for the likely development impacts of Africa's evident mineral and hydrocarbon wealth. Third, it suggests a useful theoretical framework for understanding these indicators, especially with regard to the differing constraints under which foreign investors operate and interact with host countries. Developing on the latter points, the article looks at the nature of Chinese foreign investment in Africa's extractive industries. Finally, the article suggests an agenda for future research that could better inform development policy for the purpose of promoting high-quality growth in Africa.  相似文献   
132.
Abstract: Larvae and pupae of blow fly species are frequently used in postmortem interval estimation, their age indicating minimum time since death. Most studies have considered age estimation of larvae, neglecting study of pupae. Relative development of external pupal features is useful, but there are also internal changes during metamorphosis that may be indicators of age, utilizing histological techniques. This study aimed to optimize preservation and histological analysis of blow fly pupae, specifically Calliphora vicina Robineau‐Desvoidy and Lucilia sericata (Meigen), and to examine internal features with potential for age estimation. Effect of hot‐water‐killing and different preservatives were examined. It was determined that blow fly pupae should be pierced through the three tagma, hot‐water‐killed, and preserved in 80% ethanol as the optimal preservation for subsequent analyses. Hematoxylin and eosin stained pupal sections revealed differences in brain and thoracic muscle development throughout the pupal stage with potential for age estimation.  相似文献   
133.
134.
Abstract:  We report a recent investigation into the death of a cat that was initially thought to involve intentionally burning the animal via the use of an ignitable liquid. The exposure of the animal to flame was ruled out. Instead, forensic investigation revealed the intentional mixing together of a common outdoor swimming pool chlorinator, trichlorocyanuric acid (TCCA), and 2-propanol (aka, isopropyl alcohol or rubbing alcohol). The reaction of these two chemicals resulted in the formation of cyanuric acid residue, hydrochloric acid, and the evolution of a significant volume of chlorine gas. Further α-chlorination side reactions also occurred between 2-propanol and TCCA to produce a variety of chlorinated 2-propanone species that were detected on the submitted evidence. The identification of the products of both the main reaction and the side reactions allowed the authors to determine what chemicals were originally mixed together by the culprit.  相似文献   
135.
Coase (Journal of Low and Economics 17(2):185–213, 1974) failed to appreciate that the construction and maintenance of nineteenth-century lighthouses were in part financed by British taxpayers. Bertrand (Cambridge Journal of Economics 30:389–402, 2006) rightly calls him to account. While agreeing with Bertrand’s conclusion, we dispute her reasoning and argue that lighthouses nevertheless could have been supplied by the private sector.  相似文献   
136.
137.
This article examines the relationship between fiscal year 1990 Fish and Wildlife Service spending on endangered species recovery and the priority ranking assigned by the Fish and Wildlife Service to particular species. The focus of the analysis is on the extent to which resources were allocated to species assigned higher priority rankings. The major conclusions are: species' recovery priority rank is not related to funding decisions by the Fish and Wildlife Service; some of the individual factors that make up the overall priority ranking—recovery potential and conflict with development—are correlated to funding decisions; and the likelihood of receiving some Fish and Wildlife Service recovery funding was greater for mammals, birds, and fish.  相似文献   
138.
139.
140.
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