光纤陀螺中保偏光纤60 Co辐照效应及光褪色特性

从光纤陀螺空间应用的角度出发,利用60Co辐照源模拟空间辐照,对光纤陀螺中的主要部件保偏光纤环进行了不同剂量率的辐照实验,得到了保偏光纤的辐照效应.并且利用大功率半导体激光器对保偏光纤环进行了光褪色实验.实验证明,辐照条件下,保偏光纤损耗增加;剂量率越大,损耗增加越快;总剂量越大,损耗越大;采用大功率半导体激光器对保偏光纤环进行光褪色,可以减缓辐照环境下光纤的损耗增加量,而且激光器功率越大,光褪色效果越明显,可将其用到光纤陀螺中作为其空间应用的抗辐射加固措施.      

利用随机森林算法的卫星控制系统故障诊

针对卫星姿态控制系统存在闭环控制，外部干扰强，进而影响故障诊断准确性和实时性的问题，提出了一种利用随机森林算法的卫星姿态控制系统姿态敏感器和执行器故障诊断方法。首先，采集不同故障情形下卫星姿态控制系统的输入输出数据，进行特征提取。随后通过随机有放回抽样划分训练集和测试集，建立基于随机森林算法的故障诊断模型。利用生成的随机森林模型，对实时输入输出数据进行分类，实现卫星姿态控制系统的故障诊断。利用卫星姿态控制系统半物理仿真平台的数据进行实验，对比实验结果表明：本文所提方法可以实现故障高精度分离，并具有更好的实时性，适用于卫星姿态控制系统的故障诊断问题。     

A multiple-CubeSat constellation for integrated earth observation and marine/air traffic monitoring

CubeSats has evolved from purely educational tools, to useful platforms for technology demonstration and many practical applications. This paper reviews a CubeSat constellation mission involving 3 CubeSats launched into orbit on Sep. 25th 2015, aiming to demonstrate the integrated application of low-cost CubeSat technologies with distributed payloads using a group of satellites, as well as to demonstrate several new technologies. The mission scenario, the satellite system design, the innovative technologies and instruments or devices used on the CubeSats and the in-orbit experimental results and the payload data analysis, as well as some experiences and lessons learned, are presented and summaried.     

Interseismic slip rate of the Garze–Yushu fault belt in the Tibetan Plateau from C-band InSAR observations between 2003 and 2010

InSAR time series techniques can provide high-spatial resolution deformation fields across an active fault belt, even for zones with heavy vegetation coverage. An interseismic deformation map across the Garze–Yushu fault belt in the Tibetan Plateau, ∼300 km by ∼100 km, is derived from C-band Envisat/ASAR imagery collected between 2003 and 2010. Unlike previous research, we obtain a lookup figure which relates the slip rate with the fault locking depth, the dip angle and the rake angle. The estimated slip rate changes significantly with the locking depth and the rake angle, but relatively little with the dip angle. When considering the focal mechanism solutions of historical earthquake along the Garze–Yushu fault, the interseismic slip rate of the Garze–Yushu fault is close to a value of 6.4 mm/yr, which is between the highest (18.2 mm/yr) and the lowest (3.1 mm/yr) slip rate from GPS estimations, but slightly less than the minimum value (∼ 7 mm/yr) from the geological estimations. The earthquake recurrence interval on the Yushu part of Garze–Yushu fault equals 272 yr, and the April 14, 2010 Mw 6.9 earthquake has not completely released the accumulated strain energy between 1738 and 2010.     

着陆作用下月尘激扬的三维离散元分析

基于模拟月尘的细观颗粒形状,采用刚性圆球单元重叠法建立了4种典型不规则模拟月尘颗粒的三维几何模型.根据月尘所处环境和颗粒间接触特性,建立了月尘离散元接触力学模型.通过三轴压缩实验离散元模拟的结果和模拟月尘的实际三轴压缩实验数据的对比,确定模拟月尘颗粒的三维离散元模型参数.采用建立的模型和获得的参数,进行了圆盘模拟体着陆...     

高校图书馆工作研究之我见

本文结合图书馆情报工作的实际经验，针对现代图书馆建设中面临的问题，提出了重视现代化图书馆工作研究，以全品质管理模式，深入开展各种载体文献的开发和利用工作，形成一支具有较高素质的管理人才、开放式的现代化图书馆。     

某跟踪雷达距离测量数据不稳定的研究

针对某跟踪雷达在试验中出现的距离测量数据不稳定的现象，进行了理论分析和试验，确认故障源于雷达的距离自动跟踪系统。通过进一步的研究，证明了原设计中的采样脉冲移动量化不正确，并从软件和硬件两个方面采取了相应的改进措施。飞行试验表明，改进后的雷达测距精度满足系统的要求。