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   470篇
  免费   49篇
  国内免费   62篇
  2022年   3篇
  2021年   10篇
  2020年   13篇
  2019年   14篇
  2018年   28篇
  2017年   37篇
  2016年   30篇
  2015年   21篇
  2014年   34篇
  2013年   87篇
  2012年   36篇
  2011年   33篇
  2010年   19篇
  2009年   23篇
  2008年   19篇
  2007年   29篇
  2006年   44篇
  2005年   34篇
  2004年   21篇
  2003年   12篇
  2002年   4篇
  2001年   12篇
  2000年   6篇
  1999年   6篇
  1998年   1篇
  1997年   1篇
  1994年   2篇
  1993年   2篇
排序方式: 共有581条查询结果,搜索用时 15 毫秒
361.
The Arab Spring, a pro-democracy uprising that has been sweeping through North Africa and the entire Arab world since 2010, has been described as a cataclysmic revolutionary wave that has left the overthrow of political regimes in its wake. Studies have comprehensively x-rayed the political and socio-economic circumstances that gave rise to the uprising. Apart from the impact of the uprising on political developments and democratic governance in the Arab world in particular and the world in general, the circumstances that resulted in the revolutions constitute empirical security implications for Nigeria. This is the focus of this article. Using the Ibrahim Index of African Governance (IIAG) and other selected indicators, this article draws a comparative analysis of the key factors that led to the uprisings in Egypt, Libya and Tunisia, pointing out areas of social and security tensions in Nigeria. Based on these findings, it points out the urgency of and imperative for security sector reforms in Nigeria.  相似文献   
362.
In discussing China's January 2007 hit-to-kill intercept of the Chinese weather satellite FengYun-1C, most American analysts sought the “message” for the United States—either by asserting that China's test was a deliberate step toward a comprehensive counterspace capability to offset U.S. conventional military superiority or an attempt to force the United States to the negotiating table on “the prevention of an arms race in outer space.” Chinese officials, after a long silence, eventually claimed the test was an “experiment” that was “not targeted at any country.” We traveled to China several times in 2007 and had a series of conversations with Chinese individuals knowledgeable about the history of this particular antisatellite program and with access to information about the decision-making process prior to and after the final test. These discussions were off the record, not for attribution, given the sensitivity of the subject. They reflected the views of some of the key institutions involved in the test from the State, the Communist Party, the People's Liberation Army, and aerospace experts involved in debris calculations. The information conveyed to us suggests that American commentators tend to place much greater importance on the United States as a driver in China's decision to develop the technology and conduct the test than do the Chinese.  相似文献   
363.
Taiwan's international status is such that the country's ability to trade and to supply certain goods and technologies remains its primary means of practicing diplomacy and asserting international influence. U.S. pressure to conform to international nonproliferation standards has made the issue of export controls a troubling one for Taiwan. Limiting Taiwan's economic relations affects its ability to sustain itself economically and to maintain productive relations with other nations. On the other hand, as a recipient of U.S. high-technology transfers and security assurances, Taiwan cannot ignore the directives of the United States. The article focuses on this dilemma and how a shift in power to the Democratic Progressive Party is affecting Taiwan's choice between placing limitations on its global economic power or risking being cut off from U.S. technology and losing U.S. security assurances. In order to address this challenge properly, Taiwan will need to reassess its fundamental economic and security interests.  相似文献   
364.
This article analyzes the public side of the NH90 network consisting of four participating countries (Germany, France, Italy, and the Netherlands) and their industrial partners. Comparable to observations in earlier international projects in the defense sector, the development and production of the NH90 defense helicopter did not match original plans and costs estimates. On the basis of four mechanisms that were intended to facilitate the cooperation between the partnering countries (the General Memorandum of Understanding; coalition formation; the role of the central agency; and the process of vertical escalation) the question is posed whether or not there was a true alignment of national interests and “logics.” The lack of standardization, as well as program delays and issues concerning the division of the work-share, lead to the emerging alignment being characterized as “quasi-alignment” at best.  相似文献   
365.
针对网络国防的现实需求,文章就加强网络国防建设的战略运筹指出了需要强化的六种意识:忧患意识,全局意识,创新意识,主动意识,重点意识,优势意识。在分析了三个方面的忧患意识,归纳了服务于国家安全战略、加强全局筹划、强化长远效益的全局意识。总结了理论创新、法律创新、技术创新为主要领域的创新意识等基础上,提出了维护国家根本利益、聚力局部竞争优势、拓展综合防卫能力的重点意识,探讨了主动探索建设途径、主动加强机制建设、主动构建核心能力的主动意识.分析了尽快形成战斗力生成模式优势、尽快形成防御力量和人才优势、尽快形成军民融合发展体系的优势意识。  相似文献   
366.
为了分析了水面舰艇发射火箭悬浮深弹拦截潜射尾流自导鱼雷的作战使用问题,首先,概括了潜射尾流自导鱼雷的攻击原理。其次,介绍了水面舰艇针对尾流自导鱼雷的弹道预测原理以及鱼雷提前角估算数学模型,在此基础上,进一步建立了火箭悬浮深弹拦截鱼雷的射击要素求解模型。最后,进行了仿真检验,归纳了火箭悬浮深弹射击提前角随相关参数变化的分布规律。研究结果对火箭悬浮深弹拦截潜射尾流自导鱼雷的作战使用具有指导意义。  相似文献   
367.
针对防空指挥控制系统情报融合能力测试需要,重点研究了测试空情设计问题。具体论述了防空情报融合的目的和评判准则,基于提出的评判准则分析了测试空情设计策略和步骤,设计了测试空情基本用例,开发设计了测试系统。经仿真测试,测试系统能较好地满足空情设计需求,支持防空指挥控制系统情报融合能力测试。  相似文献   
368.
纯机动规避是水面舰艇防御潜射线导鱼雷的手段之一。首先,归纳了潜射线导鱼雷的攻击过程和导引规律。其次,分别针对线导导引状态和自导追踪状态的鱼雷分析了水面舰艇实施规避机动的目的。然后,结合具体装备性能仿真分析了不同影响因素对水面舰艇实际规避航向的影响效果。最后,根据规避目的和仿真结果提炼出水面舰艇纯机动规避潜射线导鱼雷实际航向的分布规律。研究结果对于提高水面舰艇的生存能力具有重要意义。  相似文献   
369.
作战体系具有层次高、规模大,各作战分系统间协调配合密切的特征。在作战任务中,这种多层次、多系统、多决策者、多目标的结构使得对各作战子系统的武器装备分配变得更为复杂。为解决此类复杂结构的优化问题,在层次化多目标分析方法基础之上,将层次系统的风险管理引入到模型中来,形成多目标多决策者资源分配模型多目标多决策者资源分配模型,用以解决在不确定风险环境下进行多目标资源分配的问题。利用MOMDRA模型建模空袭风险下防空反导体系的武器装备分配问题,在求解该模型的过程中采用系统分解的思路,利用权重法,站在不同决策者的角度得到该体系的Pareto最优资源分配方案,并通过一个实例来说明此方法的可行性。  相似文献   
370.
为提升舰载战斗机执行航母防空任务的作战效能,研究影响舰载战斗机防空效能发挥的关键因素,对舰载战斗机执行航母防空作战进行了仿真建模分析。首先对舰载战斗机执行航母防空作战任务问题进行了描述,推导出了舰载战斗机巡逻阵位与拦截距离的关系;其次分析了执行防空任务的舰载战斗机可能的作战状态,在此基础上构建了舰载战斗机执行航母防空作战的系统动态模型,并依据舰载战斗机空中巡逻阵位对模型中的关键参数进行了推导。最后应用实例,验证了模型的有效性与实用性。研究结果可为舰载战斗机执行防空作战任务提供量化依据和理论指导。  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