Ka频段大口径测控天线无人机校相方法设计与验证

面向Ka频段航天测控设备天线标校工程应用需求,分析了大口径测控天线相位校准方法原理,论证设计了轻量化、模块化的组合式测控应答机无人机装载模式,提出了基于无人机的S频段天线自跟踪叠加偏置进行Ka频段天线快速校相的方法,并进行了跟踪精度分析.计算了在不同地面测控天线口径下进行相位标校的链路余量,规划了无人机飞行航路和试验步...     

声发射技术在复合材料结构无损检测中的应用

简述了复合材料AE技术的发展概况、AE特性和破坏类型;讨论了几种不同破坏机理的AE判据;着重介绍了AE技术在复合材料压力容器无损检测中的应用及压力容器水压试验时应注意的某些问题。     

复合材料裙用高性能树脂配方研究

主要介绍了复合材料裙用高性能树脂配方的研究。配方浇铸体的拉伸强度为 10 7.4MPa ,拉伸模量为4 .0 5GPa。配方的使用期为 7天。基体与纤维具有良好的相容性。NOL环的强度不低于 2 0 0 0MPa。     

航天器公路运输包装箱环境监测系统研制

为掌握运输过程中航天器的环境状态,确保过程受控,研制了一套运输环境监测系统,以NI cDAQ和LabVIEW为软硬件平台,设计软硬件架构与软件工作流程,能实现加速度、温湿度、车速多种类型信号的协同监测、实时超差警示与数据回放;并可利用北斗定位实现车速测量,针对高频采集的加速度信号,实现全程低速存储与触发高速存储。在实际运输道路上进行测试验证的结果表明,该监测系统功能完善,满足使用要求。     

Direct measurement of the composition and spectra of cosmic rays above 1 TeV/amu from Jacee

Direct measurements on cosmic ray protons through iron above about 1 TeV/amu have been performed in a series of balloon-borne experiments with emulsion chambers. The measured energy spectra of protons and helium are power laws with exponents of 2.77 ± 0.09 and 2.72 ± 0.11 in the energy range 5 to 500 TeV and 2 to 50 TeV/amu, respectively. The proton spectrum shows no evidence of the steepening near 2 TeV which was reported by other experiments. Helium has a slightly higher intensity compared to extrapolations from lower energy measurements. The heavier elements, carbon to sulfur, show a small tendency for intensity enhancement in the relative abundance above 10 TeV/amu.     

On Processing Optical Images Propagated Through the Atmosphere

The problem of how to process optical images that have propagated through a turbulent atmosphere is considered. It is assumed that either the object or its (free-space) scattered field at the receiving aperture is known, except for unknown parameters that are to be estimated. Isotropic and homogeneous turbulence as discussed by Tatarski and Chernov is assumed. It is assumed that a very short (in time) reception is made, that the turbulence-induced complex phase errors are either small or have a correlation distance short relative to the receiving aperture extent, and that the object is within an isoplanatic region. The method of maximum likelihood (ML) is used as a criterion; its applicability is discussed. The ML image-processing structure is found and is nonlinear. Asymptotic cases are examined; among other conclusions, it is shown that the ML processing of independent receptions is more complex than an ML processing of the sum of the receptions. A coherent optical system that realizes the ML image processor is described; it includes the capability to generate the scattered field. Simplifications are pointed out.     

Fine scale temporal structures in solar hard X-ray bursts observed by PHEBUS

We report here on preliminary results of a systematic study of fast temporal fluctuations in impulsive and extended solar X-ray bursts observed by PHEBUS at energies around 100 keV. Subsecond timescales are quite common in the impulsive events and are not observed in extended ones.     

Quantified EEG in different G situations

The electrical activity of the brain (EEG) has been recorded during parabolic flights in trained astronauts and non trained volunteers as well. The Fast Fourier analysis of the EEG activity evidenced more asymmetry between the two brain hemispheres in the subjects who suffered from motion sickness than in the others. However, such a FFT classification does not lead to a discrimination between deterministic and stochastic events. Therefore, a first attempt was made to calculate the dimensionality of "chaotic attractors" in the EEG patterns as a function of the different g-epochs of one parabola. Very preliminary results are given here.