全文获取类型
收费全文 | 1102篇 |
免费 | 295篇 |
国内免费 | 97篇 |
出版年
2023年 | 1篇 |
2022年 | 13篇 |
2021年 | 24篇 |
2020年 | 22篇 |
2019年 | 34篇 |
2018年 | 18篇 |
2017年 | 69篇 |
2016年 | 64篇 |
2015年 | 41篇 |
2014年 | 80篇 |
2013年 | 146篇 |
2012年 | 127篇 |
2011年 | 141篇 |
2010年 | 48篇 |
2009年 | 44篇 |
2008年 | 53篇 |
2007年 | 77篇 |
2006年 | 81篇 |
2005年 | 95篇 |
2004年 | 77篇 |
2003年 | 58篇 |
2002年 | 25篇 |
2001年 | 39篇 |
2000年 | 35篇 |
1999年 | 19篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 4篇 |
排序方式: 共有1494条查询结果,搜索用时 15 毫秒
41.
分数阶傅立叶变换(FRFT)是傅立叶变换的广义形式,对线性调频(LFM)信号具有很好的能量积累作用.针对反辐射导弹(ARM)雷达回波信号的线性调频特性,提出了一种基于FRFT的反辐射导弹检测方法,并根据ARM信号的调频特性将FRFF局域化,缩小了峰值搜索区域,提高了检测效率.仿真实验表明该方法能够在高斯、非高斯分布杂波环境下有效地检测ARM信号. 相似文献
42.
研究了机动目标宽带线性调频脉冲回波全去斜率信号模型,根据速度和加速度的调频频谱展宽特点,提出了机动目标宽带一维距离像线性化调频回波模型,给出了Radon模糊图转换(RAT)法线性参数估计与运动补偿方法,并进一步分析了测速和测距误差.仿真实验验证了RAT法一维距离像线性化参数估计与补偿,表明该方法很好地解决了运动参数未知情况下机动目标的一维距离像频谱展宽问题. 相似文献
43.
Andrea Beccaro 《Small Wars & Insurgencies》2018,29(2):207-228
ISIS (the Islamic State of Iraq and Syria) has become a key political and military actor in the Middle East and in North Africa. This essay aims at outlining ISIS warfare through an analysis of its operations in the frame of hybrid warfare theory proposed by Frank Hoffman. Therefore, the paper deals with: the role of terrorist tactics in ISIS warfare and the relationship between terrorism and insurgency; ISIS use of technology, mainly with regard to suicide attacks and to drones; and the relevance of urban warfare. Finally, the paper highlights how ISIS operates and the most threatening features of its warfare. 相似文献
44.
45.
Per Marius Frost-Nielsen 《Journal of Military Ethics》2018,17(1):21-35
In this article, I outline a holistic approach to the military concept of “Rules of Engagement” (ROE), which complements the legal aspects of ROE with considerations of operational and political requirements for the use of military force. Drawing upon two illustrative cases from the US military experience with the use of ROE, I demonstrate that ROE for any particular military operation should be formulated to balance optimally, if not harmonize fully, the legal, operational and political concerns related to the use of force. In this task, political decision-makers and military practitioners alike are confronted with unavoidable and real-life dilemmas. How these dilemmas are handled has significant implications for how legal requirements concerning accountability and concerns for civilian lives in military combat can be preserved through ROE. 相似文献
46.
47.
George Joffé 《Small Wars & Insurgencies》2016,27(1):1-21
Although the Islamic State in Iraq and al-Sham (ISIS) is seen as a novel manifestation of Islamic extremism, it is in fact the latest, albeit perhaps the most effective, of a long line of revivalist movements in the Islamic and the Arab worlds. Its motivations – hisba and jihad – differ little from its predecessors and its ambitions – to create a state organised in accordance with the precepts of the Islamic caliphate – reflect a long-standing Islamic ambition. It differs, of course, in terms of the sophistication of its political and military strategies, which mirror the contemporary complexities of the world in which it operates, but its objectives recall long-standing Islamic ideals, even if articulated in radically brutal and extremist ways. More importantly, perhaps, ISIS or Da’ish, to give it its Arabic sobriquet, reflects the enormous degree of resentment inside the Middle East at the ways in which Western powers have intervened in regional affairs over recent years, particularly their support for regimes and economic systems there that have betrayed, in the popular imaginary, the essential principles of social justice that lie at the root of Islamic vision of ideal social order. Indeed, in many respects, its analysis of the world in which it operates and of the objectives it seeks differ little in essence from those any other resistance and rejectionist movement, whether religious or sectarian. More specifically, it has been the sectarian conflict that resulted from the reversal of political order in Iraq as a result of the 2003 American-led invasion that has driven the success of the movement in capturing widespread Sunni support. Whether it can manage the complexities of the administration of a state remains open to question. 相似文献
48.
Andreas Lutsch 《战略研究杂志》2016,39(4):535-558
ABSTRACTRecent nuclear-weapons-related consultation in NATO within the framework of the Defence and Deterrence Posture Review sheds light on historical experiences with nuclear consultation in NATO. In the early years of the Nuclear Planning Group (NPG), which became the main forum for multilateral nuclear consultation in the alliance, developing a nuclear weapons first use doctrine was of particular importance. This process led to the adoption of the Provisional Political Guidelines (PPGs) on the threat to initiate the use of nuclear weapons. With a focus on West Germany as the primary addressee of the NPG, it will be postulated that nuclear consultation functioned and may still be seen as an essential tool to manage the credibility of US extended nuclear deterrence in the framework of NATO. 相似文献
49.
50.