A Twin-CME Scenario for Ground Level Enhancement Events

Ground Level Enhancement (GLEs) events are extreme Solar Energetic Particle (SEP) events. Protons in these events often reach ～GeV/nucleon. Understanding the underlying particle acceleration mechanism in these events is a major goal for Space Weather studies. In Solar Cycle 23, a total of 16 GLEs have been identified. Most of them have preceding CMEs and in-situ energetic particle observations show some of them are enhanced in ICME or flare-like material. Motivated by this observation, we discuss here a scenario in which two CMEs erupt in sequence during a short period of time from the same Active Region (AR) with a pseudo-streamer-like pre-eruption magnetic field configuration. The first CME is narrower and slower and the second CME is wider and faster. We show that the magnetic field configuration in our proposed scenario can lead to magnetic reconnection between the open and closed field lines that drape and enclose the first CME and its driven shock. The combined effect of the presence of the first shock and the existence of the open close reconnection is that when the second CME erupts and drives a second shock, one finds both an excess of seed population and an enhanced turbulence level at the front of the second shock than the case of a single CME-driven shock. Therefore, a more efficient particle acceleration will occur. The implications of our proposed scenario are discussed.     

Study on Conceptual Selection for Provision of Trainers in Primary and Intermediate Training Stage

为了在初/中级教练机装备方案决策中体现出训练需求,选用质量功能展开的方法对其进行了分析.先利用比较矩阵确定训练需求重要度,建立训练需求与能力属性之间的QFD关系矩阵,得到不同能力属性的重要度,最后计算出个方案的能力属性值,通过线性加权计算将属性值反映到不同方案对于训练需求的满足程度上来,得出了量化分析的结果,为教练机装备决策方法研究提供了一个新思路.     

Track-before-detect for Infrared Maneuvering Dim Multi-target via MM-PHD

In this paper, we present a novel and efficient track-before-detect (TBD) algorithm based on multiple-model probability hypothesis density (MM-PHD) for tracking infrared maneuvering dim multi-target. Firstly, the standard sequential Monte Carlo probability hypothesis density (SMC-PHD) TBD-based algorithm is introduced and sequentially improved by the adaptive process noise and the importance re-sampling on particle likelihood, which result in the improvement in the algorithm robustness and convergence speed. Secondly, backward recursion of SMC-PHD is derived in order to ameliorate the tracking performance especially at the time of the multi-target arising. Finally, SMC-PHD is extended with multiple-model to track maneuvering dim multi-target. Extensive experiments have proved the efficiency of the presented algorithm in tracking infrared maneuvering dim multi-target, which produces better performance in track detection and tracking than other TBD-based algorithms including SMC-PHD, multiple-model particle filter (MM-PF), histogram probability multi-hypothesis tracking (H-PMHT) and Viterbi-like.     

双后掠鸭翼气动特性的数值模拟

首先针对具有中等前缘后掠角梯形鸭翼的缺点提出双后掠鸭翼概念,然后分别对安装梯形鸭翼和双后掠鸭翼的近距耦合鸭式布局的气动性能进行数值模拟研究,分析影响双后掠鸭翼气动性能的流动机理。研究表明：在大迎角时,对于双后掠鸭翼,具有较大前缘后掠角的外翼段可以使鸭翼涡在涡核破裂后仍能形成稳定集中涡并保持较高的强度,增加鸭翼本身的失速迎角,并通过诱导作用改善机翼外翼段流场,进而提高全机大迎角性能,但在小迎角时会破坏鸭翼附着流或前缘气泡涡的发展,造成略微的升力损失。拥有较大失速迎角的双后掠鸭翼在小迎角时具有较大的可用偏度,可以增强布局的抬头控制能力。双后掠鸭翼在满足隐身约束的前提下,超声速阻力较小,具有较好的超声速性能。     

加油机加油过程视频监控需求分析

通过对一般加油过程的分析,提出了空中加油机加油过程视频监控需求。将加油过程分为会合、编队、对接、解散四个部分对监控区域进行讨论,并对监控区域进行整理及优化,从功能、分辨率及显示等方面进行分析,给出适应性的视频监控需求,为机外摄像头布局,摄像头和显示器选型,机外照明布置提供有效支持。     

数字人感系统的研究

随着飞机模拟器技术的发展,电机伺服系统在人感系统中也得到了广泛的应用。本文着重讨论 了以DSP芯片为核心的数字人感系统组成和工作原理,并分析了系统的特点及功能。     

论航空产品质量改进

航空产品质量改进针对旧的质量标准．建立新的质量标准，可以不断提高产品技术水平，克服存在的缺陷,改善使用性能。为保证质量改进取得预期效果，应从程序、方法和管理控制等多方面着手。     

基于Petri网的建模方法在叶片制造流程重组中的应用

采用基于Petri网的流程建模方法,结合数字化条件下叶片工艺流程设计与评估的相关理论,对叶片制造流程进行重组,并绘制流程框图.利用可达树对Petri网模型进行死锁分析,从而减少流程重组的盲目性和风险.最后通过工程事例说明Petri网模型的死锁分析过程.     

ARM嵌入式处理器在智能仪器中的应用

介绍了一种基于ARM嵌入式处理器系统的智能仪器的硬件和软件设计方案,并结合uc/os-II嵌入式实时操作系统,给出了一套完整的任务调度和管理的方法,最后给出实例说明.     

利用压电驱动器改善飞机横滚性能的试验验证

利用分布粘帖在矩形机翼上下两面的压电驱动器,探索使用该类结构提高飞行器横滚能力的可能性。通过风洞模型设计、材料性能测试、模型固有特性测试、压电柔度矩阵测试等试验项目,保证了有限元模型的计算精度,最终通过模型的风洞试验验证了利用气动弹性效应,获得了附加升力与横滚力矩的方案。该原理性试验说明利用分布式压电驱动器改善横滚性能是可行的。