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   578篇
  免费   9篇
  2021年   5篇
  2020年   4篇
  2019年   6篇
  2017年   11篇
  2016年   15篇
  2015年   10篇
  2014年   12篇
  2013年   104篇
  2012年   22篇
  2011年   27篇
  2010年   23篇
  2009年   15篇
  2008年   30篇
  2007年   13篇
  2006年   15篇
  2005年   6篇
  2004年   4篇
  2002年   3篇
  2001年   4篇
  1998年   8篇
  1997年   7篇
  1996年   4篇
  1995年   7篇
  1994年   4篇
  1993年   13篇
  1992年   11篇
  1991年   9篇
  1990年   3篇
  1989年   13篇
  1988年   8篇
  1987年   12篇
  1986年   13篇
  1985年   9篇
  1983年   7篇
  1982年   6篇
  1981年   9篇
  1980年   10篇
  1979年   13篇
  1978年   5篇
  1977年   7篇
  1976年   9篇
  1975年   8篇
  1973年   4篇
  1972年   14篇
  1971年   3篇
  1970年   5篇
  1969年   11篇
  1968年   7篇
  1967年   4篇
  1966年   5篇
排序方式: 共有587条查询结果,搜索用时 15 毫秒
101.
102.
103.
针对空战目标威胁评估问题,提出了一种新的基于区间数理论的评估方法。在分析了现有的目标威胁评估方法中距离威胁模型存在不足的基础上,提出了改进的距离威胁模型。给出了区间数特征向量法求解威胁指标权重的计算步骤,建立了基于区间数理论的空战目标威胁评估的数学模型。最后给出了仿真算例,仿真结果表明该方法是合理和有效的。  相似文献   
104.
The EC's recognition of new states in former Yugoslavia is considered by most analysts to have seriously aggravated the conflict in the region. This article challenges the conventional wisdom and argues that the strategic effects of recognition have been largely overstated. The prospect of recognition played no significant role in the Slovene determination to sustain their campaign for independence and therefore bears little responsibility for the first phase of the war. In Croatia, recognition ‐ together with the deployment of UN peacekeepers ‐ may even have had a mitigating effect. Only in Bosnia is there any correlation between recognition and an intensification of hostilities but it is doubtful whether non‐recognition would have prevented the eruption of violence since Bosnian Serb aspirations for an ethnically homogeneous state entity could not be realised without resort to war. The real relevance of recognition lies with the opportunities for more effective international action which it created. It was the failure to seize these opportunities, rather than the strategic effects of recognition, which better explains the tragic events that ensued.  相似文献   
105.
Book reviews     
John Lawrence Tone, The Fatal Knot: The Guerrilla War in Navarre and the Defeat of Napoleon in Spain. Chapel Hill and London; The University of North Carolina Press 1994. Pp.vii + 239, 1 map, biblio., index. $34.95 (cloth). ISBN 0–8078–2169–1.

Robert Holland (ed), Emergencies and Disorder in the European Empires after 1945. London: Frank Cass, 1994. Pp.x + 256; index. £32 (cloth); £15 (paper). ISBN 0–7146–4516–8 and 4109 X

Deborah L. Norden, Military Rebellion in Argentina: Between Coups and Consolidation. Lincoln, NE: University of Nebraska Press, 1996. Pp.242, index, $35/$17.50 (paper). ISBN 0–8032–8369–5.

William M. Minter, Apartheid's Contras: An Inquiry into the Roots of War in Angola and Mozambique. London and Atlantic Highlands, NJ: Zed Books Ltd; Johannesburg: Witwatersrand University Press, 1994. Pp. xii +308, 3 maps, biblio., index. $69.95/£39.95 (cloth); $29.95/£16.95(paper). ISBN 1–85649–266–4 and 266–4.  相似文献   
106.
The Indian government has not made a public comment about the status of its nuclear weapon program since approving a nuclear doctrine in 2003. However, there is now enough information in the public domain to determine that the command-and-control system for the nuclear program has steadily matured in accordance with the intent of the approved nuclear doctrine. The Indian government has successfully mitigated many of the issues that plague the conventional military. The result is a basic command-and-control system that is focused only on the delivery, if ordered by the prime minister, of nuclear weapons. The system is not as robust as those of the United States and Russia, but is in place and ready as new Indian nuclear weapons enter into operation. The command-and-control system is developing to meet India's needs and political compulsions, but not necessarily as part of a more assertive nuclear policy.  相似文献   
107.
空投设备气囊缓冲系统的缓冲特性分析与匹配方法   总被引:1,自引:0,他引:1  
采用解析分析法,根据排气口流量方程和载荷运动方程建立了无量纲的空投设备气囊缓冲过程数学模型,并根据此模型构造了气囊的匹配设计图。讨论了排气口面积、气囊高度、着陆初速度、载荷质量、气囊底面积及排气口开启压力等参数对气囊缓冲性能的影响,提出了空投设备气囊缓冲系统的参数匹配设计方法,为空投设备气囊缓冲系统的匹配设计提供了技术支持。  相似文献   
108.
We present variants of a convergent Lagrangean relaxation algorithm for minimizing a strictly convex separable quadratic function over a transportation polytope. The algorithm alternately solves two “subproblems,” each of which has an objective function that is defined by using Lagrange multipliers derived from the other. Motivated by the natural separation of the subproblems into independent and very easily solved “subsubproblems,” the algorithm can be interpreted as the cyclic coordinate ascent method applied to the dual problem. We exhibit our computational results for different implementations of the algorithm applied to a set of large constrained matrix problems.  相似文献   
109.
110.
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