Moment equation description of interstellar hydrogen

The flow of interstellar hydrogen in the heliosphere can be studied using the moment equation approach. The Boltzmann equation is integrated over the velocity space to obtain the moment equations, the moment equations are then solved directly for the flow conditions. We present a closed system of moment equations. This approach can include anisotropic pressure when the distribution function is distorted into skewed ellipsoid.     

涡轮叶栅叶型损失的数值模拟方法

给出了一个计算亚、跨音涡轮叶栅叶型损失的数值计算方法。主流采用时间推进有限体积法求解积分型欧拉方程,并采用了局部网格修正技术;附面层采用全隐格式求解有限差分方程;在叶栅出口与远后方均匀流之间进行了叶片尾迹与主流的掺混损失计算。算例表明本文的数值方法可准确地预测涡轮叶栅的叶型损失。     

THE WIDE-BAND PLASMA WAVE INVESTIGATION

As part of the Cluster Wave Experiment Consortium (WEC), the Wide-Band (WBD) Plasma Wave investigation is designed to provide high-resolution measurements of both electric and magnetic fields in selected frequency bands from 25 Hz to 577 kHz. Continuous waveforms are digitised and transmitted in either a 220 kbit s^-1 real-time mode or a 73 kbit s^-1 recorded mode. The real-time data are received directly by a NASA Deep-Space Network (DSN) receiving station, and the recorded data are stored in the spacecraft solid-state recorder for later playback. In both cases the waveforms are Fourier transformed on the ground to provide high-resolution frequency-time spectrograms. The WBD measurements complement those of the other WEC instruments and also provide a unique new capability for performing very-long-baseline interferometry (VLBI) measurements.     

Effects of polarization and resolution on SAR ATR

Lincoln Laboratory is investigating the detection and classification of stationary ground targets using high resolution, fully polarimetric, synthetic aperture radar (SAR) imagery. A study is summarized in which data collected by the Lincoln Laboratory 33 GHz SAR were used to perform a comprehensive comparison of automatic target recognition (ATR) performance for several polarization/resolution combinations. The Lincoln Laboratory baseline ATR algorithm suite was used, and was optimized for each polarization/resolution case. Both the HH polarization alone and the optimal combination of HH, HV, and VV were evaluated; the resolutions evaluated were 1 ft/spl times/1 ft and 1 m/spl times/1 m. The data set used for this study contained approximately 74 km/sup 2/ of clutter (56 km/sup 2/ of mixed clutter plus 18 km/sup 2/ of highly cultural clutter) and 136 tactical target images (divided equally between tanks and howitzers).     

空间环境下的有机热控涂层

本文综述了国外在空间有机热控涂层领域中的研究工作和试验，着重分析了空间极端环境中紫外光辐照和原子氧侵蚀这两大因素对有机热控涂层的影响。     

液体推进剂一甲肼与水二元物系汽液相平衡的研究

一甲肼是一种重要的液体推进剂,分离反应过程所生成的水是确保一甲肼质量的关键。测定了甲基肼－水（ＭＭＨ－Ｈ２Ｏ）物系在１０１．３３ｋＰａ下的汽液平衡,以及电解质对其汽液平衡的影响。采用盐效应和溶剂化的方法,研究了不同电解质对ＭＭＨ－Ｈ２Ｏ汽液平衡的盐效应。     

飞机结构环境谱初探

本文给出环境谱的定义及编谱的基本方法。对总体气候/化学环境因素的分布和随时间变化的规律进行了探讨。统计分析了我国各气候区和飞机典型使用地区的总体环境,提供了气温、湿度、太阳辐射、二气化硫,海水盐度及盐雾等国内实测数据。     

单室双推力固体火箭发动机两级推力的最佳选择

从理论上探讨了单室双推力固体火箭发动机中影响其两级推力的主要因素。建立了导弹/发动机一体化设计的优化模型,对一种推进剂实现双推力,双燃速推进剂实现双推力两种情况分别进行了计算和分析。求出了使导弹射程达到最大,又能够在设计中实现的最佳推力方案。     

Galileo Probe Nephelometer experiment

The objective of the Nephelometer Experient aboard the Probe of the Galileo mission is to explore the vertical structure and microphysical properties of the clouds and hazes in the atmosphere of Jupiter along the descent trajectory of the Probe (nominally from 0.1 to > 10 bars). The measurements, to be obtained at least every kilometer of the Probe descent, will provide the bases for inferences of mean particle sizes, particle number densities (and hence, opacities, mass densities, and columnar mass loading) and, for non-highly absorbing particles, for distinguishing between solid and liquid particles. These quantities, especially the location of the cloud bases, together with other quantities derived from this and other experiments aboard the Probe, will not only yield strong evidence for the composition of the particles, but, using thermochemical models, for species abundances as well. The measurements in the upper troposphere will provide ground truth data for correlation with remote sensing instruments aboard the Galileo Orbiter vehicle. The instrument is carefully designed and calibrated to measure the light scattering properties of the particulate clouds and hazes at scattering angles of 5.8°, 16°, 40°, 70°, and 178°. The measurement sensitivity and accuracy is such that useful estimates of mean particle radii in the range from about 0.2 to 20 can be inferred. The instrument will detect the presence of typical cloud particles with radii of about 1.0 , or larger, at concentrations of less than 1 cm³.Deceased.