地面附近的高空核爆电磁脉冲环境

 主要研究在高空核爆的双指数类型电磁脉冲平面波入射时，地面附近的电磁脉冲环境。计算给出了在不同入射波状态，不同地表介质电气特性和距地面不同高度等条件下的电磁脉冲环境参数，归纳了一些规律性认识。结果显示：地面附近的电场会随距地面高度的不同而发生显著的变化，对于水平场分量，其反射场总是试图抵消入射场，而对于垂直场分量，其反射场叠加在入射场上，使得地面附近的垂直场强幅值一般大于入射波场强幅值；当入射波仰角增大时，合成电场波形的脉冲宽度会变宽；地表介质的电气特性参数不同也会对地面附近电场的波形和幅值造成一定的影响。     

Near space radiation dosimetry in Australian outback using a balloon borne energy compensated PIN diode detector

This paper reports the near space ballooning experiment carried out at Australian outback town West Wyalong (33°51′S, 147°24′E) on 19 July 2015. Several dedicated electronic detectors including digital temperature and acceleration (vibration) sensors and an energy compensated PIN-diode gamma ray dosimeter were installed in a thermally insulated Styrofoam payload box. A 9 V Lithium-Polymer battery powered all the devices. The payload box was attached to a helium-filled latex weather balloon and set afloat. The balloon reached a peak burst altitude of 30 km and then soft-landed aided by a self-deploying parachute 66.2 km away form the launch site. The payload box was retrieved and data collected from the electronic sensors analysed. The integrated cosmic ray induced photon ambient dose equivalent recorded by the PIN diode detector was evaluated to be 0.36 ± 0.05 μSv. Furthermore, a high-altitude extended version of commercially available aviation dosimetry package EPCARD.Net (European Program package for the Calculation of Aviation Route Doses) was used to calculate the ambient dose equivalents during the balloon flight. The radiation environment originated from the secondary cosmic ray shower is composed of neutrons, protons, electrons, muons, pions and photons. The photon ambient dose equivalent estimated by the EPCARD.Net code found to be 0.47 ± 0.09 μSv. The important aspects of balloon based near-space radiation dosimetry are highlighted in this paper.     

高空无人机自动加油对接过程轨迹控制研究

针对无人机在高空自动加油对接过程中容易出现偏差的问题,提出了无人机空中自动加油精准对接的优化控制方案,研究并分析了影响加油锥管与受油接口快速准确对接的主要因素,通过运动轨迹生成器对浮锚加油锥套的运动轨迹进行模拟,无人机的自动飞行控制系统根据轨迹跟踪曲线对无人机的飞行姿态进行调整,引导无人机的受油接口与加油锥管进行精确对接,整个飞行轨迹跟踪控制过程优化了复杂高空环境中无人机加油对接的精准性。通过仿真实验表明,本高空无人机加油对接引导方法提高了空中管口对接的速度与抗干扰能力,可以满足各种复杂高空环境的无人机加油任务。     

高空缺氧条件下DPH对脑铁,锌及MDA含量的影响

和原子吸收法测定了高空缺氧条件下ＤＰＨ对大鼠脑组织铁、锌含量的影响，并测定了脑ＭＤＡ含量。结果显示：对照组在高空缺氧条件下，脑组织铁含量明显高于用药组，而脑锌含量明显低于用药组。脑组织ＭＤＡ一明显高于地面对照及用药组，这表明，在高空缺氧条件下，对照组脑组织过氧化反应增强，高于用药组：脑组织ＭＤＡ含量与锌含量成反比。     

Dust pollution during shotcrete process in high-altitude tunnel based on numerical simulation

The surrounding rock needs shotcrete support after drilling and blasting excavation in the tunnel; the high concentration of dust generated in the process will endanger workers’ occupational health. Therefore, to ensure the cleanness and safety of the tunnel construction process, a full-scale model of the tunnel was established based on field data of a high-altitude tunnel of the Sichuan-Tibet railway. The dust production mechanism is summarized by combing the whole process of shotcrete. The Computational Fluid Dynamics (CFD) method was used to study the diffusion and transport of dust under different conditions. The grey relational analysis was applied to investigate the correlation values of the influencing factors on dust diffusion in the shotcrete operation area. The results show that the dust generation mechanism of shotcrete includes the sudden change of particle velocity in the jet area leading to escape and particle impact dust generation, where fine dust is easily dispersed in the tunnel. During continuous dust production, the dust concentration is higher near the wet spraying machine and on the backflow side of the working face. Increasing the air supply volume and shortening the distance between the air duct and the working face is conducive to diluting the dust concentration in the tunnel. In the high-altitude environment, the dust concentration in the tunnel decreases, the diffusion distance becomes smaller, the settlement proportion of dust particles increases, and the risk of secondary pollution increases. The simulation results and the field measurement data are consistent, which can provide theoretical support for the construction site dust control.