The origin of the prompt optical emission in GRB 060111B

The detection of a bright optical emission measured with good temporal resolution during the prompt phase makes GRB 060111B a rare event that is especially useful for constraining theories of the prompt optical emission. Comparing this burst with other GRBs with evidence of optical peaks, we find that the optical peak epoch (t_p) is anti-correlated with the high energy burst energetic assuming an isotropic energy release (E_iso) in agreement with Liang et al. (2009), and that the steeper is the post-peak afterglow decay, the less is the agreement with the correlation. GRB 060111B is among the latters and it does not match the correlation. The Cannonball scenario is also discussed and we find that this model cannot be excluded for GRB 060111B.     

空间冗余机械臂零反作用最优路径规划

自由漂浮空间机械臂运动通过力传递会对其载体航天器产生反作用力和力矩,从而影响基座和末端执行器的位置与方向。利用冗余机械臂的反作用零空间,求解对基座航天器姿态零干扰的机械臂运动规律的解析解。给定机械臂初始和终端状态,考虑最大关节角约束和最大关节角加速度约束,分别针对时间最优和沿整个运动路径关节加速度最小的问题,采用高斯伪谱法,在零反作用轨迹解集中寻找满足约束方程的最优解。所得最优解使得机械臂在达到期望构型的同时不影响基座姿态。将算法用于平面3自由度冗余机械臂系统中,仿真结果表明:算法在保证基座姿态稳定的同时,关节运动满足给定的约束条件,从而验证了算法的有效性。     

基于TEC的空间站末端回路温控系统建模及其热力学性能分析

针对空间站中间回路温度波动过大,高温时导致科学载荷工作温度超出允许范围的问题,设计了一种基于热电制冷器(TEC)的末端单向流体回路温控系统。该系统包含一个TEC温控模块,当中间回路温度过高,末端回路冷却功率不足时,该模块可提供额外的制冷量,降低流入冷板的工质温度,形成针对科学载荷的相对低温区域,恢复回路的冷却能力。分别建立了温控系统数学模型与数值仿真模型,并完成了热负载扰动、中间回路温度扰动、末端回路流量扰动和并联支路热扰动等4种扰动对系统热力学特性影响的仿真分析,验证了TEC模块的温控性能。结果表明:在科学载荷发热功率增加30%、中间回路的温度升高5K、末端回路流量减小至0.0015kg/s等多种工况下,所设计的温控系统能够将载荷温度控制在1K以内,实现科学载荷精确温控。      

火星表面热环境对航天器热控影响分析

火星大气对太阳辐射产生吸收和散射作用，同时还将与火星表面航天器发生对流换热。热设计时难以直接评估对流、辐射和导热三种换热对航天器的影响，从而确定主要的控温途径。在调研火星表面辐射、大气等热环境的基础上，从线性化传热系数和对流辐射比的角度对比分析了辐射、对流和导热对航天器的影响。器表辐射传热系数随光学属性和温度的变化范围为0.3～1.4W/(m2·℃)，对流传热系数随风速变化为0.2～1.5W/(m2·℃)，器内导热传热系数可控制在0.25W/(m2·℃)以下。结果表明，太阳辐射较火星表面和天空辐射而言是主要外热源，航天器表面的辐射和对流换热为两条并联换热途径，两者均可成为主要换热途径，器内导热传热是控制航天器内外隔热的主要可控因素。     

深空探测器无线电干涉测量开源数据处理系统构建及试验

为更好地开展深空无线电干涉测量试验,基于DiFX(Distributed FX,分布式FX型相关处理)、SPICE(Spacecraft Planet Instrument Camera-matrix Events,航天器行星仪器照相机矩阵事件)、HOPS(Haystack Observatory Postprocessing System,Haystack克天文台后处理系统)及AIPS(Astronomical Image Processing System,天文图像处理系统)等开源软件,搭建了一套可用于深空探测器信号相关处理的无线电干涉测量数据处理系统。首先介绍了该系统的整体架构及组成,然后介绍了系统各组成模块的功能及工作原理,最后利用该系统对嫦娥三号着陆器开展了观测试验,并对观测数据进行了处理。试验结果表明,该系统能成功实现深空航天器信号的相关处理、条纹拟合,以及时延解算等功能,有望为我国嫦娥五号任务及火星探测任务数据处理提供支持。     

多状态空间信息网络拓扑生成优化算法

依据空间信息网络（SIN）高动态性的特点，并考虑卫星工作的多状态特性，兼顾星间通信时延和拓扑抗毁性的要求，研究了多状态下空间信息网络拓扑生成及动态优化的问题。根据卫星星座的周期性，建立了一种卫星网络的拓扑周期表。综合卫星的可视性和连接度等约束条件，以网络平均和最大时延作为通信性能的优化目标，建立拓扑的多目标优化模型。提出一种改进的多目标模拟退火（IMOSA）算法，求解全局时延最优的卫星拓扑，并在考虑多状态情况下对链路进行优化，以满足网络高动态性。最后基于具有66颗低轨（LEO）的铱星星座进行仿真，研究表明：针对多状态条件下的铱星星座，该算法最大化减小了通信时延，得到抗毁性良好的拓扑结构，通信性能较之原有静态拓扑明显得到改善。     

空间压力容器可靠性定量设计方法研究

针对空间压力容器常规设计方法难以满足航天技术快速发展对轻质量、低成本、高可靠的需求,基于可靠性理论中应力-强度干涉模型,建立空间压力容器可靠性设计数学模型。结合某型号钛合金球形气瓶随机变量统计数据,开展了气瓶可靠性定量设计。计算结果表明,可靠性定量设计方法能够给出产品可靠度定量指标,并在一定程度上降低空间压力容器结构重量。     

宇航用双极器件和光电耦合器位移损伤试验研究

文章针对器件的位移损伤效应,利用质子加速器产生的质子及反应堆中子对化合物器件和硅器件位移损伤进行试验研究,得到了GaAs光电耦合器的电流传输比(CTR)和硅晶体管电流增益hFE的退化率随等效剂量的变化规律。研究结果表明,在质子70 MeV以上高能量范围,对于硅器件适用的位移损伤等效原理对于GaAs化合物器件则不再适用,需要修正。根据试验数据,给出了经验的修正系数。     

Prediction of shock-layer ultraviolet radiation for hypersonic vehicles in near space

A systemic and validated model was developed to predict ultraviolet spectra features from the shock layer of near-space hypersonic vehicles in the ‘‘solar blind" band region. Computational procedures were performed with 7-species thermal non-equilibrium fluid mechanics, finite rate chemistry, and radiation calculations. The thermal non-equilibrium flow field was calculated with a two-temperature model by the finite volume technique and verified against the bow-shock ultra-violet(BSUV) flight experiments. The absorption coefficient of the mixture gases was evaluated with a line-by-line method and validated through laboratory shock tube measurements. Using the line of sight(LOS) method, radiation was calculated from three BSUV flights at altitudes of 38,53.5 and 71 km. The investigation focused on the level and structure of ultraviolet spectra radiated from a NO band system in wavelengths of 200–400 nm. Results predicted by the current model show qualitative spatial agreement with the measured data. At a velocity of 3.5 km/s(about Mach11), the peak absolute intensity at an altitude of 38 km is two orders of magnitude higher than that at 53.5 km. Under the same flight conditions, the spectra structures have quite a similar distribution at different viewing angles. The present computational model performs well in the prediction of the ultraviolet spectra emitted from the shock layer and will contribute to the investigation and analysis of radiative features of hypersonic vehicles in near space.     

Coupled Stress-Electricity Model for Electromagnetic Emission Induced by Concrete Fracture

Electromagnetic emission induced during concrete fracturing is of great significance to health monitoring of concrete structures.A coupled stress-electricity model is established by analyzing the interaction between stress and electricity during concrete fracturing.And based on this model,the electromagnetic radiation parameters are calculated.The theoretical calculation is well coincident with experimental results.This work provides theoretical support for concrete testing system.