全文获取类型
收费全文 | 764篇 |
免费 | 230篇 |
国内免费 | 20篇 |
出版年
2024年 | 5篇 |
2023年 | 14篇 |
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 15篇 |
2019年 | 24篇 |
2018年 | 23篇 |
2017年 | 27篇 |
2016年 | 46篇 |
2015年 | 44篇 |
2014年 | 60篇 |
2013年 | 154篇 |
2012年 | 55篇 |
2011年 | 56篇 |
2010年 | 39篇 |
2009年 | 46篇 |
2008年 | 32篇 |
2007年 | 40篇 |
2006年 | 36篇 |
2005年 | 48篇 |
2004年 | 34篇 |
2003年 | 26篇 |
2002年 | 31篇 |
2001年 | 27篇 |
2000年 | 19篇 |
1999年 | 14篇 |
1998年 | 21篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有1014条查询结果,搜索用时 421 毫秒
921.
以自主武器为代表的人工智能正在掀起一场新的军事革命。保罗·沙瑞尔所著的《无人军队:自主武器与未来战争》一书通过技术概念解释、各路专家访谈与大量战场实例,深入浅出地探讨了自主武器的内涵、特点与影响。本文基于该书内容,结合相关文献、书籍、评论等资料,首先对自主武器与无人军队的内涵、现阶段的运用情况进行简要介绍;其次,通过对自主武器技术内核的分析,简要介绍自主武器在各类战争样式的运用、存在的反为敌方利用的可欺骗性风险和故障发生后产生更严重后果的不稳定性风险;最后从三方面总结自主武器对战争其他方面的影响,即对军队建设模式提出更高要求,对国际战略稳定的双重作用以及对战争法与战争伦理道德的挑战。 相似文献
922.
多种武器攻击下舰艇装备生命力的加权模糊综合评估 总被引:5,自引:1,他引:4
通过应用模糊数学理论中模糊评估法对舰艇装备系统生命力进行了模糊评判 ,建立多武器攻击下舰艇装备生命力加权模糊评估模型 ,并以某舰艇装备的主动力系统回路为例 ,运用所建立的评估模型对其生命力进行具体评估 ,结果分析表明根据加权模糊综合评判模型 ,选用合理的加权系数 ,就能把模糊性很强的装备生命力指标定量化 ,为设备系统设计方案选优提供依据。 相似文献
923.
Diana Wueger 《The Nonproliferation Review》2019,26(5-6):449-463
ABSTRACTIn 2019, the geostrategic landscape of South Asia significantly changed. A crisis between India and Pakistan involved air strikes across international boundaries for the first time since the 1971 war. Pakistan came close to economic collapse, while India re-elected hawkish Narendra Modi as prime minister in a landslide. These developments, alongside the United States’ efforts to strike a deal to leave Afghanistan and rapidly improving US-India relations, portend new challenges for Pakistan’s security managers—challenges that nuclear weapons are ill-suited to address. Despite the shifting security and political situation in the region, however, Pakistan’s nuclear posture and doctrine seem unlikely to change. This article explores the roots of Pakistan’s reliance on the traditional predictions of the nuclear revolution, most notably the notion that nuclear-armed states will not go to war with one another, and argues that this reliance on nuclear deterrence is a response both to Pakistan’s security environment and to serious constraints on moving away from nuclear weapons toward an improved conventional force posture. Pakistan’s central problems remain the same as when it first contemplated nuclear weapons: the threat from India, the absence of true allies, a weak state and a weaker economy, and few friends in the international system. While 2019 may have been a turning point for other states in the region, Pakistan is likely to stay the course. 相似文献
924.
为了实现Ku波段高功率微波的定向发射,研究并设计了新型高功率径向线连续横向枝节阵列天线。该天线采用圆极化同轴TE11模式进行馈电,经双层径向线波导传输后,通过连续横向枝节单元向外辐射。天线工作在驻波模式,相邻两圈缝隙的径向间距为一个波导波长,在上层径向线末端放置短路金属杆,金属杆表面到最内侧缝隙的径向间距为半个波导波长,整个天线具有较高的增益和功率容量。仿真研究了一个工作在14.25 GHz的天线,天线的高度为80 mm,半径为285 mm。仿真结果表明:该天线具有35.3 dBi的增益和47%的口径效率,反射系数小于-25 dB,辐射效率超过99.0%,同时具有吉瓦级的功率容量。 相似文献
925.
针对雷达对抗侦察装备综合作战能力对电磁环境的依赖性,提出一种基于网络层次分析法(Analytic Network Process,ANP)的雷达对抗侦察装备在不同电磁环境下作战能力的幂指数评估方法。通过对雷达对抗侦察装备作战任务及复杂电磁环境下的表现进行分析,确定装备作战能力指标;利用ANP分析各指标间的相互关系,计算出指标相对的权重;把该权重作为各指标的幂指数,计算雷达对抗侦察装备在不同电磁环境下的作战能力指数;最后结合某型装备多次不同环境下试验的数据,对该装备的综合作战能力进行评估。 相似文献
926.
927.
采用多功能SRV试验机考察了纳米SiO2在菜籽油中的高温摩擦学性能,利用表面轮廓仪观察磨损表面形貌。结果表明,在恒定负荷试验中,纳米SiO2能明显改善菜籽油的高温减摩抗磨性能,在500℃时,摩擦因数仅为0.16,磨损量降低了80%以上。在连续加载的高温试验中,当试验温度为200℃时,纳米SiO2对菜籽油的减摩抗磨性能没有明显的改善;而当试验温度达到500℃时,纳米SiO2能明显地改善菜籽油的减摩抗磨性能,在大负荷(500N)的情况下更为突出。 相似文献
928.
Rajeswari Pillai Rajagopalan 《The Nonproliferation Review》2019,26(5-6):465-479
ABSTRACTOver the last five decades, India’s nuclear and space programs have gone through several phases, from collaboration to divorce to supportive. An interplay of two factors determined the nature of the relationship. One was the state of India’s nuclear-weapon program. The second was international conditions, especially India’s relationship with the nuclear-nonproliferation regime. In the early decades, because of the rudimentary nature of India’s nuclear and space programs, the relationship was collaborative, since the rocket technology being developed was a necessary adjunct to the nuclear-weapon program. Subsequently, as India’s rocketry capabilities and nuclear-weapon program began to mature and concerns about international sanctions under the non-proliferation regime began to grow, the two programs were separated. The Indian rocketry program was also divided, with the civilian-space and ballistic-missile programs clearly demarcated. After India declared itself a nuclear-weapon state in 1998 and the programs matured, the relationship has become more supportive. As the two programs mature further, this relationship is likely to deepen, as the nuclear-weapon program requires space assets to build a robust and survivable nuclear deterrent force. 相似文献
929.
William T. Johnsen 《Defense & Security Analysis》2019,35(3):223-240
This essay outlines a theory of land power. After explaining the absence of such a theory, the article establishes the modern context for such a theory, specifically within the concept of joint interdependence. The analysis defines key terms and premises behind the theory, to include a definition of land power. The argument then outlines the national elements of power that contribute to a theory of land power. The analysis next applies the theory to the fundamental purposes of military power: defeat, deter, compel, assure, shape and support to the nation. The analysis then tests key definitions, supporting premises, and utility of the theory. The essay argues that historical experience validates the applicability and utility of the theory, and offers a solid basis for extrapolating the validity of the theory into the near future. 相似文献
930.
Doreen Horschig 《Defense & Security Analysis》2020,36(3):352-371
ABSTRACT Under what conditions are cyber-weapons effective in nuclear counter-proliferation? With continued interest in nuclear proliferation professed by Iran, North Korea, and Saudi Arabia, a discussion of the effectiveness of counter-proliferation measures remains relevant. Cyber-attacks as military option in a state-on-state conflict still requires additional corroborating evidence to make conclusions about its long-term effectiveness. This work analyses the general applicability of cyber-weapons and their usefulness in nuclear counter-proliferation. Through a comparative case study of Operation Orchard, Stuxnet, and recent “Left-of-Launch” operations against North Korea, the essay finds that cyber-operations are not particularly effective against nuclear programmes that are in the later stages of their development. They can disrupt and delay a nuclear programme temporarily, if the attack remains clandestine, but cannot halt nuclear proliferation all together. However, effectiveness increases if they are used in combination with conventional weapons. The article addresses a topic of interest to national-level decision-makers: whether cyber-operations can and should play a role in nuclear counter-proliferation. 相似文献