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   65篇
  免费   2篇
各国政治   8篇
工人农民   3篇
世界政治   1篇
外交国际关系   7篇
法律   20篇
中国政治   1篇
政治理论   24篇
综合类   3篇
  2021年   3篇
  2019年   1篇
  2017年   2篇
  2016年   3篇
  2015年   1篇
  2014年   4篇
  2013年   5篇
  2012年   1篇
  2011年   1篇
  2010年   6篇
  2009年   5篇
  2008年   2篇
  2007年   2篇
  2006年   3篇
  2005年   2篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   8篇
  2000年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1991年   1篇
  1989年   1篇
  1988年   2篇
  1983年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有67条查询结果,搜索用时 0 毫秒
1.
Explanations for national success in science and technology typically focus on domestic institutions and policies. However, that line of research has yet to identify any particular set of institutions or policies that explain variation in national innovation rates across cases or over time. This article offers new evidence that the problem with domestic institutions approaches stems from their failure to consider international security factors. Specifically, this article finds a positive effect for U.S. security alliances on innovation. This finding is robust across different specifications and periods of analysis. While countries that ally militarily with the United States are found to realize benefits in economy‐wide, indigenous innovation, such an effect is not observed in military technologies. This suggests that alliances may substitute for being on the frontier in military technologies. Therefore, this article contributes not just to debates over S&T competitiveness, but also to alliance formation.  相似文献   
2.
Postmortem stability of DNA   总被引:11,自引:0,他引:11  
High-molecular-weight DNA was recovered postmortem in sufficient quantities from various human organ tissues as well as from blood, although not all organs were equally well suitable. Good DNA stability was found in brain cortex, lymph nodes and psoas muscle over a period of three weeks postmortem. Spleen and kidney showed good DNA stability up to five days postmortem but after longer periods, rapid degradation was observed. Yields of DNA from blood were not consistent because of the non homogeneity of samples. Blood clots were rich with DNA. Generally, the amount of degraded DNA correlated directly with the duration of the postmortem period. However in some cases, DNA degradation was already prominent after a short period. However in some cases, DNA degradation was already prominent after a short period. Case histories showed that high environmental temperature at the site of death and/or infectious diseases prior to death were the main factors for rapid autolysis. Gradual disappearance to complete loss of the long fragments (15-23 kb) was observed in DNA fingerprinting using the minisatellite probe 33.15. No extra-bands were noted, thus excluding erroneous conclusions. However, evidentiary value of older samples was lower.  相似文献   
3.
4.
5.
在证券市场国际化的趋势下,会计也在趋于国际协调,而海峡两岸关系密切,经济互动频繁,因此本文对海峡两岸在信息提供者、披露时点、财务预测更正更新、管理当局责任等财务预测制度的四个方面进行比较研究,指出差异,并提出中国大陆在财务预测制度改进的建议。  相似文献   
6.
7.
8.
曹静 《桂海论丛》2005,21(2):95-97
在高校教学过程中,选修课日益成为一道亮丽的风景,如何开设选修课以发挥其最大的教学功能,这是教育工作者普遍关注的问题.高校"音乐欣赏"选修课的开设一要明确教学目的,二要突破定向思维,三要设计课堂形式,四要增强师生交流.  相似文献   
9.
10.
Merton’s concept of “middle range theories” has been widely accepted as one of his most influential contributions to sociological terminology, even if there is no conclusive understanding of its semantic and methodological meaning. The article proposes to ignore the term. On the one hand, it cannot be logically clarified and, on the other, it restrains an appropriate judgement of the merits of Merton’s research programme.  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