Research on Feature Extraction of Remnant Particles of Aerospace Relays

The existence of remnant particles, which significantly reduce the reliability of relays, is a serious problem for aerospace relays. The traditional method for detecting remnant particles—particle impact noise detection (PIND)—can be used merely to detect the existence of the particle; it is not able to provide any information about the particles’ material. However, information on the material of the particles is very helpful for analyzing the causes of remnants. By analyzing the output acoustic signals from a PIND tester, this paper proposes three feature extraction methods: unit energy average pulse durative time, shape parameter of signal power spectral density (PSD), and pulse linear predictive coding coefficient sequence. These methods allow identified remnants to be classified into four categories based on their material. Furthermore, we prove the validity of this new method by processing PIND signals from actual tests.     

等维灰数递补动态预测在机场客运量预测中的应用

基于灰色系统等维灰数递补动态预测和残差GM（1，1）修正模型，对其应用的可行性进行了有益的探讨，并结合实例，对首都国际机场中短期客运量进行了预测。通过调整原始样本中的变异数据，得到比较理想的预测结果．经检验预测结果是可信的。该研究为机场客运量预测提供了一种方法，可供借鉴。     

磁悬浮反作用飞轮剩磁矩分析与补偿方法研究

为对磁悬浮反作用飞轮的剩磁矩(RMM)进行分析及最小化设计,提出一种基于等效磁偶极子模型的剩磁矩计算方法.利用有限元仿真空间磁场分布,通过选取3个特征平面的磁场反推得到剩磁矩.对不同工作状态下飞轮样机剩磁矩的大小及变化范围进行了分析,并在此基础上给出了磁悬浮反作用飞轮剩磁矩优化设计方法及补偿方法.分析结果表明.通过磁轴...     

VHE Gamma-ray supernova remnants

Increasing observational evidence gathered especially in X-rays and γ-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the “knee” in the energy spectrum of Cosmic rays. This review summarises the current status of γ-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with the upcoming GLAST satellite in the energy regime above 100 MeV are given.     

Magnetic and Optical Properties of the TiO2-Co-TiO2 Composite Films Grown by Magnetron Sputtering

The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction (XRD), Raman spectra and X-ray photoemission spectra (XPS). It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 nm, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.