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   3337篇
  免费   82篇
  国内免费   1篇
  3420篇
  2021年   37篇
  2019年   88篇
  2018年   51篇
  2017年   81篇
  2016年   79篇
  2015年   63篇
  2014年   64篇
  2013年   705篇
  2010年   36篇
  2009年   37篇
  2008年   48篇
  2007年   52篇
  2006年   36篇
  2005年   42篇
  2004年   56篇
  2003年   42篇
  2002年   57篇
  1999年   41篇
  1998年   46篇
  1997年   50篇
  1996年   62篇
  1995年   41篇
  1994年   59篇
  1993年   63篇
  1992年   58篇
  1991年   74篇
  1990年   39篇
  1989年   72篇
  1988年   78篇
  1987年   68篇
  1986年   72篇
  1985年   64篇
  1984年   36篇
  1983年   42篇
  1982年   43篇
  1981年   46篇
  1980年   51篇
  1979年   45篇
  1978年   49篇
  1977年   45篇
  1976年   45篇
  1975年   46篇
  1974年   52篇
  1973年   50篇
  1972年   52篇
  1971年   43篇
  1970年   40篇
  1969年   40篇
  1968年   34篇
  1967年   34篇
排序方式: 共有3420条查询结果,搜索用时 0 毫秒
871.
872.
This article argues that deterrence theory can be applied to counterterrorism. Doing so requires broadening the traditional concept of deterrence by punishment, expanding deterrence by denial to include defense, mitigation, and strategic hindrance, and developing deterrence by delegitimization to influence the political, ideological, and religious rationales informing terrorist behavior. In practice, deterring terrorism requires tailoring threats against state and individual facilitators, diffusing the intended consequences of terrorism, and manipulating terrorist self–restraints. When these and other deterrent leverages are applied simultaneously against various actors and processes involved in terrorism, coercion can be achieved.  相似文献   
873.
Conventional wisdom on the phenomenon of war is criticised for providing little relevant guidance to deal with the security challenges of our era. One reason is that this attitude uncritically assumes power as synonymous with force. In response, ‘productive war’ is here proposed as a re-conceptualisation of war based on Michel Foucault's alternative understanding of power. Productive war appreciates the role of violence but subordinates it to non-kinetic dynamics influencing the dimension of meaning in international security. This theoretical perspective provides a conceptual framework to deal with the dynamics of political mobilisation essential to create public support for nation-building abroad and for visions of world order.  相似文献   
874.
875.
876.
877.
878.
879.
880.
Compression and flexure members such as columns and beams are critical in a structure as its failure could lead to the collapse of the structure. In the present work, numerical analysis of square and circle short columns, and reinforced concrete (RC) beams reinforced withfiber reinforced polymer composites are carried out. This work is divided into two parts. In thefirst part, numerical study of axial behavior of square and circular concrete columns reinforced with Glass Fiber Reinforced Polymer (GFRP) and Basalt Fiber Reinforced Polymer (BFRP)bars and spiral, and Carbon Fiber Reinforced Polymer (CFRP) wraps is conducted. The results of the first part showed that the axial capacity of the circular RC columns rein-forced with GFRP increases with the increase of the longitudinal reinforcement ratio. In addition, the results of the numerical analysis showed good correlation with the experimental ones. An interaction diagram for BFRP RC columns is also developed with considering various eccentricities. The results of numerical modeling of RC columns strengthened with CFRP wraps revealed that the number and the spacing between the CFRP wraps provide different levels of ductility enhancement to the column. For the cases considered in this study, column with two middle closely spaced CFRP wraps demonstrated the best performance. In the second part of this research,flexural behavior of RC beams reinforced with BFRP, GFRP and CFRP bars is investigated along with validation of the numerical model with the experimental tests. The results resembled the experimental observations that indicate significant effect of the FRP bar diameter and type ont he flexural capacity of the RC beams. It was also shown that Increasing the number of bars while keeping the same reinforcement ratio enhanced the stiffness of the RC beam.  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