Marangoni heat pipe: An experiment on board MIOsat Italian microsatellite

This article summarizes the activities in preparation of a microgravity experiment to be carried out by using a small technological payload onboard a microsatellite developed by the Italian Space Agency. A dedicated hardware will be developed to investigate innovative heat pipes filled with self-rewetting fluids, i.e. dilute aqueous alcoholic solutions with unique surface tension properties. After a general introduction of the scientific background, the paper is focused on the main activities in preparation of the flight experiment, on the design of the flight hardware and on the experimental planned procedure. The laboratory results achieved on ground in preparation of a flight experiment are also presented, including measurements of fluids physical properties and preliminary heat pipes performances characterization test. From the engineering point of view, the activities dealing with heat pipes filling and sealing are included. The activities for heat pipe characterization conclude the paper.     

武器型号费用参数模型的数据处理

针对武器型号费用存在多重共线性及出现异常值的问题，讨论了武器型号费用参数模型的数据处理方法，采用岭回归法处理数据的多重共线性，采用库克距离测度法来识别异常值，并给出了应用实例。     

倾斜CCD光敏面以减小扩展像斑的分析

经理论推导，给出了倾斜ＣＣＤ光敏面以减小扩展像斑，从而减小激光三角法测量误差的理论根据，同时结合计算机模拟曲线，说明了它的缺点是限制了测量范围。     

Resistance welding of glass fiber reinforced thermoplastic composite: Experimental investigation and process parameter optimization

The utilization of fiber reinforced thermoplastics (FRTP) is expected to fulfill lightweight demand in mass-produced aerospace products. Facing the unavoidable assembly of FRTP parts, fusion bonding methods such as resistance welding are promising compared with mechanical joint and adhesive bonding. In this paper, a procedure has been brought out to understand the relationship between processing conditions and performance of the FRTP welding joints. The adherends were continuous glass fiber reinforced polypropylene (GF/PP) laminates fabricated by hot-pressing method. The influences of time, current and pressure on the bending strength of the resistance welding joints were investigated. A processing window was drawn based on the optical observation of welded surfaces. The quantitative relationship between process parameters and mechanical property of GF/PP welding joint was established by Response Surface Method (RSM) with high accuracy. It was found that bending strength of GF/PP welding joint was improved by 31% compared with hot-pressing benchmark.     

一种飞机操纵面驼峰型颤振随高度变化特性研究

飞机操纵面旋转和安定面弯曲模态频率较近时易耦合形成一种速度阻尼特性随高度显著变化的驼峰型颤振。某飞机垂尾颤振分析表明超过一定高度后驼峰型颤振分支阻尼峰值会超过结构阻尼系数,成为临界颤振型,并且随飞行高度增加阻尼峰值迅速增加。针对上述情况采用了三种方案抑制驼峰型颤振,算例表明降低30%安定面弯曲刚度,增加25%结构质量,操纵面旋转频率增加60%以上均能有效抑制高空驼峰型颤振。     

一种行星安全着陆点综合评估方法

随着精确着陆技术的发展,探测器在行星表面可到达的地区形貌状况越来越复杂。为了保障着陆的安全性,在下降过程中探测器需要结合敏感器信息对视野范围内的着陆区形貌进行评估分析,从而选取出最适宜着陆的地区。针对这一问题,本文提出一种行星安全着陆点选取思路,并设计出着陆点选取的参考指标,通过对形貌以及燃耗的评估,实时选取安全着陆点。MATLAB仿真结果表明,针对快速选取过程和遍历选取过程,该方法均能够在两种过程中有效选取出满足要求的着陆点,从而提高了任务的成功率与安全性。     

小行星形貌测绘与表征技术

小行星表面形貌测绘是深空小行星探测的首要任务。提出了一种适应探测器抵近观测的立体视觉在线测绘小行星形貌的方法,即先由立体相机获得所摄重叠区的三维地形,再用前后立体模型的连接点将各个独立模型连成一个完整地形信息,经整体最小二乘平差,确定小行星的形貌模型及特征;同时提出了一种基于等值线分析的撞击坑特征提取方法,即通过提取、分析地形等值线识别出地形中撞击坑特征。实验结果显示,本文所构建的原型系统能够快速重建出探测区域的三维地形,并识别出地形中撞击坑特征,证明了所提方法具有实用性。     

大型反射面天线温度分布规律及变形影响分析

针对高频段大型反射面天线对电性能的高要求,必须降低太阳热辐射对天线的影响。先计算一天中太阳入射角度的变化规律,再基于I\|DEAS软件仿真,得到一天中各时刻天线反射面上的温度、热应力场、热变形分布,然后针对阴影对天线结构的重要影响,以“分点分段”的形式给出不同时刻温度在反射面上的分布及其影响程度和规律,为工程人员进行天线的温度补偿和结构优化提供了依据。     

月面巡视探测器外场试验方法

首先对以Apollo月球车、MER火星车为代表的国外巡视探测器的研制试验进行调研,对它们的外场试验目的、试验工况的设置、外场选址的技术考虑进行了分析总结,认为外场试验对巡视探测器工作过程、遥操作过程的综合验证具有重要的意义,在实现对巡视探测器移动、导航能力考核的同时,还可以验证地面系统,训练操作人员;然后结合月面巡视探测器的任务特点,对其外场试验的目的和内容、外场选址要求、试验工况等进行研究;最后介绍了外场试验方法及任务规划试验、过夜停靠点试验、短距离移动探测试验、任务过程综合演练等4类试验的结果。     

Surface micro-texture on sapphire fabricated by laser ablation trajectory regulation

Fabrication of the surface micro-texture on the C-plane sapphire is undertaken by a355 nm Ultraviolet(UV) pulsed laser. The surface micro-textures of sapphire with different laser scanning line spacing ranging from 10 lm to 100 lm are obtained, where the selection range of scanning line spacing is controlled in the range of the groove width and plasma width to obtain a surface of high Peak-Valley(PV) value. A reasonable processing order is proposed to manufacture different types of surface micro...