嫦蛾三号成功在月球虹湾软着陆

距月面15公里 1主减速段 利用7500牛发动机进行制动,将探测器的速度降至57米／秒。采用惯性导航并引入激光、微波测距和测速信息进行修正     

群时延傅里叶分解模型及其估计方法

建立了基于三角函数级数的群时延模型,并理论证明了仅采用有限阶数的三角函数群时延即可表征任意群时延对信号相关峰的影响。在此基础上,通过测量信号相关峰,并与不同三角函数群时延组合下的相关峰进行匹配搜索即可估计群时延的三角函数分解级数,从而估计得到相关峰影响等效的群时延特性。仿真中,采用该方法估计得到的群时延特性对滤波器进行修正后,信号相关峰与经过滤波器之前的信号相关峰高度吻合,时延估计偏差在0.1 ns之内。     

磁通门探测器的数值分析与仿真

给出了磁通门探测器的数学模型及其数值分析和计算机仿真的方法,并通过实例计算和模拟探测器内部各种物理量的波形、量值和相互关系,解决了电压源激励和非正弦波激励在传统分析计算中存在的难题,最后针对第Ⅱ类磁芯进行了分析.     

简论利用空中动目标确定火控网内探测器位置

火控空情共享可有效提高防空系统的抗击率 ,但前提是需要知道各探测器的相对位置坐标。本文研究了一种迅速准确、自主简便、费用低廉的定位方法 :利用空中动目标对火控网内探测器进行定位 ,主要分析了其定位原理与精度。     

点型火灾报警探测器保护范围对布置的影响

分析了点型火灾报警探测器＂保护半径＂与＂保护面积＂的内在关系,得出了以保护半径为主,保护面积及修正系数为辅新型计算方法,使其在不规则平面更有可操作性,能充分发挥探测器效能,给设置留下了宽裕的选择范围,使设置更趋合理;在安全性不受影响下,探测器用量最大可节省12%。     

HPGe多道γ谱仪测量煤灰的放射性

运用HPGe(高纯锗)多道γ谱仪对煤灰样品进行了放射性测量和核素分析,并与参考文献中的相关数据作了比较,讨论了燃煤对工作人员及公众的影响.结论:处理和利用此种煤灰必须慎重.     

利用空中动目标对火控网内探测器定位原理简介

介绍一种利用火控网内各探测器对空中动目标的探测记录数据,确定各探测器相对位置坐标并评估其精度的方法。介绍了定位系统的硬件结构、工作与信息流程、数学模型。应用实例表明,此定位方法具有定位迅速、准确、自主、廉价的特点。     

连续波金属探测器电磁场模型的理论分析

介绍了连续波金属探测器的工作原理,提出一种新的连续波金属探测器电磁场模型,采用基于电磁场和电路的混合方法对该模型进行了详细的理论分析,推导出在空气及海水中金属探测器接收感应电压的计算公式,并给出了简要的设计实例.文中理论分析结果对于连续波金属探测器设计与分析具有指导意义,对其它类型的金属探测器设计也有参考价值.     

基于多虚拟目标模型的榴弹炮炸偏修正方法

榴弹炮的传统射击修正方法是根据射击目标的高角距变及偏流不变原则完成的,该方法在通常情况下可以满足射击修正精度要求,但是在炮目距离接近最大射程,或因气象条件、弹药条件、火炮条件等数据不准确造成炸点偏离目标较远等情况下,高角距变和偏流均会产生剧烈变化,因此,传统修正方法存在较大误差.提出一种基于多虚拟目标模型的修正方法来改善这个问题,分析结果表明,该方法比传统方法修正精度更高.     

大椭圆停泊轨道月球探测器发射窗口运动学约束特性分析及转移轨道快速设计方法

通过分析大椭圆停泊轨道月球探测器发射窗口的运动学约束特性,给出了转移轨道运动学约束对发射窗口的影响规律,进一步明确了在该种情况下月球探测器的发射机会和增加窗口的可能性.并结合发射窗口运动学约束特性,提出了一种基于大椭圆停泊轨道的地月转移轨道快速设计方法.仿真结果验证了大椭圆停泊轨道下探测器发射窗口运动学约束特性分析的正确性,以及转移轨道设计方法的有效性.     

Insurgency in Afghanistan: implications for Pakistan's internal and external security

In the aftermath of 9/11, the USA embarked on a massive global hunt for terrorists and launched its “Operation Enduring Freedom” in Afghanistan. Its failure to control insurgency in Afghanistan spilled over into Pakistan, with disastrous consequences. The resurgence of the Taliban with more formidable tactics and maneuvering skills has become more troublesome for both Afghanistan and Pakistan and for the USA and its allied forces. The fierce comeback of the insurgents has challenged the political and territorial integrity of Pakistan, one that it cannot tolerate. This article analyzes the current situation and its implications for Pakistan's security. Moreover, it looks into the internal and external security complexities that Pakistan faces and the possible implications of the US exit strategy for Pakistan's security. It concludes that the security situation in Pakistan is continuously deteriorating and no part of her territory is immune from terrorists' attacks. To be successful, Pakistan must pursue a broad-based strategy that encompasses military, political, social, economic and informational domains aimed at accomplishing four major objectives: (1) elimination of foreign terrorists and their facilitators; (2) strengthening of the political and administrative institutions in the Federally Administered Tribal Areas (FATA); (3) establishing a safe and secure environment conducive for sustained development and the realization of real socio-economic progress and (4) integrating the FATA into the national mainstream. In the long term, a strategy based on the concept of “Enlightened Moderation” is the right solution, not only to the internal problems of Pakistan but also for the Muslim world and the international community.     

Terrorism,insurgency, kidnapping,and security in Africa's energy sector

Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).     

Helping hands: civil–military cooperation and Italy's military operation abroad

In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.     

A best practice for assessment in counterinsurgency

In September 2011, the Commander of the International Security Assistance Force (ISAF) in Afghanistan directed the Afghan Assessment Group to redesign the way in which ISAF was assessing the status of the war, and to be ‘revolutionary’ in so doing. The resulting assessment paradigm was novel, non-doctrinal, and effectively addressed the unique complexities of the counterinsurgency in Afghanistan and the needs of the ISAF Commander. It had a two-tier structure consisting of both strategic and campaign assessments. The former focused on answering a set of strategic questions in narrative, analytic form to address the strategic environment, while the latter used a set of standards and accompanying narrative responses to gauge accomplishment of campaign tasks. Both tiers captured the current state of the war while maintaining an eye on future challenges and opportunities. The two assessments and their associated processes were designed to stimulate discussions leading directly to decisions by senior leaders on actions they could take, direct, or request. While any assessment paradigm will have advantages and disadvantages, an examination of the pros and cons of this assessment paradigm makes clear that it should be considered a ‘best practice’ in the field of counterinsurgency assessment.     

Pakistan’s response to US foreign policy towards South Asia 1977–1993

Relations between the USA and Pakistan have been tenuous since the 1947 partition of British India and the subsequent creation of the former. The 1979 Soviet intervention in Afghanistan focused the attention of the international community on South Asia. This article will examine the foreign policies of three successive US Presidential Administrations between 1977 and 1993, and how their decisions and corresponding actions were interpreted by the Pakistani government and its people. The key finding is the trend of the ebb and flow of US interest in Pakistan. The primary research conducted for this article shows that Pakistanis recognize this trend and consider it hypocritical of the US government. The current conditions in South Asia are ominously similar to those of 1992 with the drawdown of US and NATO troops from Afghanistan. Policy-makers would be wise to review the events of 1977–1993 so that the cycle is not repeated again.     

ARMS CONTROL CONTINUUMS

In July 2001, member states will gather in New York for the UN Conference on the Illicit Trade in Arms in All its Aspects. It represents part of the effort to establish controls on small arms and light weapons. This article argues that it is possible that nuclear and conventional arms control represent two ends of a continuum, with common goals and a common set of mechanisms and processes at work. A decade after the end of the Cold War, it is not surprising that the international community is working on mechanisms to deal with conventional arms. The existence of a continuum and connections between conventional and nuclear arms control is less evident. The two arms control communities appear to function in isolation of each other. The return to the debate on small arms and light weapons echoes post-World War I and II periods. The fact that small arms control is back on the agenda within the context of the UN may signify recognition that any kind of arms control serves the same purpose—preventing and mitigating the effects and duration of, and bringing an end to conflict.     

基于神经网络的柴油机特征参数评价与选择

在设备故障诊断中,正确地提取与选择特征参数对于诊断结果的有效性和准确性具有关键性的意义,在提出评价判据时样本的概率分布往往难以确定,针对模式识别中特征量的选择方法,结合人工神经网络原理,提出了利用人工神经网络进行故障特征量评价与选择的方法,实现了对柴油机特征参数的提取及选择,有效地解决了柴油机状态监测与故障诊断中测试参数多而难以优化的问题。     

Kinetic responses to global terrorism: Lessons from Africa

This essay recalls the immediate and longer-term responses of the US and its allies to the events of 9/11. It contends that the die for contemporary developments in transnational terrorism was cast in the immediate aftermath of 9/11 – in particular the launching of sustained ‘anti-terrorist’ military combat operations in Afghanistan and Iraq, and more covert ‘kinetic’ operations elsewhere in the Middle East and Africa. The essay seeks specifically to expose the counter-productivity of using military operations as the primary antidote to transnational terrorism. Focusing on the African ‘laboratory’ and the spread of transnational terrorism and Islamic militancy, particularly in West and East Africa, the essay concludes that radical Islamists have mastered the ‘battle of the narrative’ and that the Western penchant for dispensing a kinetic brand of medication is feeding rather than fighting the virus of global terrorism.     

数字化战场指挥控制系统的发展

简要介绍了数字化战场指挥控制系统的定义,并探讨了未来高科技战争对作战指挥控制所提出的新要求和产生的影响;重点介绍数字化战场指挥控制系统的描述方法及其采用的关键技术;最后着重论述国外数字化战场指挥控制系统的现状和发展趋势,特别是对未来数字化战场指挥控制系统发展的四个方向进行了重点阐述.     

欲去明日 问道昨天——走出中国式建筑的困境

中国式建筑的困境在于附加意识形态性的起源和前因后果的关系倒置.近现代建筑进入中国后,曾经保持着与世界的同步发展,直至20世纪50年代初.中国式建筑是伴随着中西古今之争而产生的命题,建筑被赋予了意识形态的内容.在全球化背景下,重新认识中国式建筑产生和发展的局限性,其实质在于混淆了现代化与西方化之区别,将现代化等同于西方化...