太阳观测卫星的数传天线波束及其指向设计

针对三轴稳定对日指向姿态的太阳同步轨道卫星,提出为获得最大对地数据传输时间的天线波束设计及布局方案。根据某型太阳观测卫星的轨道姿态设计方案,建立数传天线对指定地面站的天线波束指向仿真模型;使用卫星工具包STK仿真软件,分析不同波束角方案及其可能的指向对数传时间的影响,发现了对日指向卫星与对地指向卫星在数传时间上的不同规律,找到最优的天线波束布局来获得最大的数传时间;根据星载数传能力与不同天线波束宽度之间的关系,获得传输数据的最佳天线波束宽度,为这类卫星数传天线的波束设计及其布局提供设计依据。     

某通信电台天线超宽带耦合效应研究

利用时域有限差分方法（FDTD）,结合端接负载模型,计算某指挥控制系统置于方舱上壁的鞭状天线的超宽带（UWB）耦合效应。计算结果表明：该天线在超宽带环境中耦合的最大电流在35 A左右;当入射波的电场方向与天线方向一致时,天线上可以感应更大的电流;由于方舱上壁反射电磁场的作用,当仰角在120°左右时,天线上的感应电流峰值最大;超宽带脉冲平行于车长方向入射该系统能比垂直入射该系统,感应出更大的电流。     

基于逆合成孔径成像激光雷达的自旋小目标成像系统

为了获得毫米级自旋小目标的清晰成像,采用逆合成孔径成像激光雷达技术设计了基于距离向数据与方位向数据相融合的图像重建系统。系统采用大带宽、窄线宽光纤激光器配合调制器实现激光脉冲的线性调频,利用光外差原理对回波信号进行采集处理。结合自旋目标的运动特性,给出了含有自旋分量的回波信号函数方程,并将该分量引入传统的R-D算法中实现了对自旋目标的ISAIL二维图像的重建。实验采用毫米级铝条构成被测小目标,通过步进电机及带倾角的转台完成运动及自旋模拟。实验结果显示,当目标固定时,可通过回波能量数据获得一维距离向图像,与被测目标的4个特征点位置一致。当目标运动时,通过数据压缩并代入自旋参量,最后通过R-D算法可以获得可识别的ISAIL二维图像,验证了系统符合自旋小目标成像的设计要求。     

农村小企业消防安全现状及对策研究

20世纪80年代兴起的农村工业小企业，为改革开放初期的经济发展发挥了显著作用，但由于在经济建设及发展过程中缺乏科学有效规划和消防安全管理，遗留了诸多火灾隐患。以福州市仓山区为例，深入分析了农村工业小企业存在的火灾隐患问题，并从火灾隐患的消防技术整改和强化消防管理两个方面提出具体对策。     

The structural origins of social cohesion: the dynamics of micro-solidarity in 1991–1995 Wars of Yugoslav Succession

This article explores the dynamics of social cohesion on the frontline. It attempts to show how micro-level solidarities largely depend on macro level organisational processes. I argue that frontline social cohesion is often the product of social development linked with the organisational structure. This general argument is applied to the case studies of two armed forces involved in the 1991–1995 Wars of Yugoslav Succession – the Croatian Army (HV) and the Bosnian Serb Army (VRS). Drawing on in-depth interviews with the former combatants I show how HV social cohesion played an important role in winning the war and how these networks of micro-level solidarity were shaped by long term organisational development.     

The strategic purpose of individual augmentee officers for junior partners in multinational military operations

ABSTRACT

This article examines the strategic purpose of Individual Augmentee Officers (IAOs) for junior partners in multinational military operations through an exploratory case study of Danish IAOs in Iraq and South Sudan between 2014 and 2017. IAOs are individual officers who are moved from their normal functions to be seconded to other units of the armed forces of their own or another country or an international institution. The study concludes that IAOs function as strategically important, yet not necessarily indispensable, supplements to military contingents in several ways: making tangible contributions to the overall mission (contributing), gaining access to information, knowledge, and experience (learning), and lobbying decision-making processes within mission headquarters (lobbying). The usefulness of IAOs depends on whether the junior partner has specific interests and a significant presence in the theatre and whether the mission is conducted as a UN mission, a NATO mission, or an ad hoc coalition.     

The ‘first’ surge: the repulse of the Easter Invasion in South Vietnam, 1972 – implications for Iraq and Afghanistan

In a military intervention, do surges work? I compare the failed ‘surge’ in Vietnam, the repulse of the Easter Invasion in 1972, as a means of assessing the more ambiguous surges in Iraq and Afghanistan. I identify four features of a surge for this analysis: the military dimensions and strategy of the surging forces, the military capabilities of the host forces, the political vitality and will of the host country, and the political commitment in the domestic politics of the intervener. I find that the last feature is the most critical; and, in all three surges, the American political commitment was lacking.     

小散远部队单位疫情防控工作思考【专题】

重大疫情具有突发性强、危害性大等特点，一旦发生，极易在防疫准备不充足的小散远部队单位造成爆发。加强基层疫情防控基础建设贵在平时，势在必行。本文首先对重大疫情的特点和小散远部队单位防疫工作面临的现实困难进行了分析，并对开展新时代基层单位疫情防控工作进行了思考，最后提出了应在思想政治教育、军地联动、心理辅导和防疫效果评估等方面予以加强的小散远部队单位疫情防控工作系统框架，以期为提高部队基层防疫效率提供参考。     

小子样多失效模式系统可靠性竞争模型

为解决小子样多失效模式系统可靠性模型参数的估计问题,首先应用支持向量积建立小子样条件下各故障模式的规律模型,其次利用模型将各故障模式的故障数据由小子样扩充成大样本,再次采用常规的参数估算方法估算各故障模式的分布参数,最后建立多失效模式系统的可靠性竞争模型。利用所提方法,建立了小子样条件下具有两种失效模式的柴油机汽缸套可靠性竞争模型,计算结果与大样本条件下的故障预测数据吻合度较高,说明了方法的有效性。     

基于圆锥扫描的卫星信号强度闭环控制方法

在车载卫星通讯系统中,常利用高精度速率陀螺仪作为稳定反馈器件构成天线稳定伺服控制系统,以抑制车体运动对卫星通讯天线的扰动.但由于陀螺仪自身存在的漂移特性,使得仅依靠速度闭环无法满足车载卫星"动中通"的要求.因此,采用圆锥扫描方法获取天线在空间扫过位置的卫星信号强度,再与伺服系统构成信号强度闭环,从而实现天线空间指向的稳定.介绍一种卫星信号强度闭环控制方法.该方法不仅能够很好地补偿由于陀螺飘移引起的系统稳定误差,而且对由其他原因引起的稳定误差和远距离移动引起的跟踪误差具有同样的补偿作用,达到有效锁定和高精度跟踪通信卫星的目的.