原子氧对航天器表面的剥蚀效应及其预报研究

文章论述了一个航天器表面原子氧通量和遭遇量预报模式的建立,并对影响航天器表面原子氧遭遇量的主要因素进行了讨论。最后用模式计算了2003～2006年间太阳同步轨道卫星表面原子氧遭遇量的情况。     

Cyclicality or volatility? The satellite insurance market

The history of the satellite insurance market indicates that this market experiences crises and booms in profitability and prices that repeat in a manner suggestive of cycles. The purpose of this article is to rigorously investigate cyclicality of these and other features of the satellite insurance market and assess their volatility formally. Using data from 1968 to 2008, volatility and cyclicality are analyzed for satellite insurance market capacity, rates, and underwriting results, among other measures. The coefficient of variation for the various satellite insurance market metrics is used to assess volatility. Standard underwriting analysis is used to determine whether a cycle exists for various insurance metrics. The results indicate that some aspects of the satellite insurance market are volatile (e.g. claims) or cyclical (e.g. rates), while capacity is both volatile and cyclical.     

排气液化发动机高速液化装置研究

为简化涡轮排气液化发动机蒸汽液化装置的结构、缩小体积,提出了基于超声速汽液两相流升压原理的水蒸气液化方案,建立了考虑多因素的数学方程式,讨论了水蒸气喷嘴段结构参数、混合室参数、扩压段参数和混合室阻力等对升压能力的影响。计算结果表明：收敛-扩张式升压液化装置的升压系数大于3。     

柔性太阳能帆板振动变论域白适应模糊控制

研究了有压电智能结构的柔性太阳能帆板振动的模糊控制。建立了帆板的动力学方程,针对振动问题的特殊性,采用周期变论域设计了变论域自适应模糊控制器,提高了模糊控制的精度和自适应性能。仿真结果表明：变论域自适应模糊控制能有效抑制柔性太阳能帆板的振动,并明显优于简单模糊控制。     

全流量补燃循环液氧/甲烷发动机系统分析

对全流量补燃循环液氧,甲烷发动机系统进行了分析研究。确定了初步的发动机系统方案,对发动机的系统参数、结构质量进行了分析计算。     

空间飞行器快速高精度姿态控制技术研究

针对空间飞行器在某些情况下对姿态偏差及姿态稳定度的严格要求 ,采用了超前网络校正和开关反馈控制的复合控制方法 ,同时从工程应用角度出发 ,对开关反馈的信号进行了调整 ,仿真结果表明这种复合控制在一定程度上解决了采用单一控制方式时控制精度与响应速度之间的矛盾。     

Validation of University of New Brunswick Ionospheric Modeling Technique with ionosonde TEC estimation over South Africa

For more than a decade, ionospheric research over South Africa has been carried out using data from ionosondes geographically located at Madimbo (28.38°S, 30.88°E), Grahamstown (33.32°S, 26.50°E), and Louisvale (28.51°S, 21.24°E). The objective has been modelling the bottomside ionospheric characteristics using neural networks. The use of Global Navigation Satellite System (GNSS) data is described as a new technique to monitor the dynamics and variations of the ionosphere over South Africa, with possible future application in high frequency radio communication. For this task, the University of New Brunswick Ionospheric Modelling Technique (UNB-IMT) was applied to compute midday (10:00 UT) GNSS-derived total electron content (GTEC). GTEC values were computed using GNSS data for stations located near ionosondes for the years 2002 and 2005 near solar maximum and minimum, respectively. The GTEC was compared with the midday ionosonde-derived TEC (ITEC) measurements to validate the UNB-IMT results. It was found that the variation trends of GTEC and ITEC over all stations are in good agreement and show a pronounced seasonal variation for the period near solar maximum, with maximum values (∼80 TECU) around autumn and spring equinoxes, and minimum values (∼22 TECU) around winter and summer. Furthermore, the residual ΔTEC = GTEC − ITEC was computed. It was evident that ΔTEC, which is believed to correspond to plasmaspheric electron content, showed a pronounced seasonal variation with maximum values (∼20 TECU) around equinoxes and minimum (∼5 TECU) around winter near solar maximum. The equivalent ionospheric and total slab thicknesses were also computed and comprehensively discussed. The results verified the use of UNB-IMT as one of the tools for future ionospheric TEC research over South Africa.     

空间太阳能电站技术的可行性研究

简要介绍世界空间太阳能电站的太阳发电卫星／太阳能发电（ＳＰＳ／ＬＳＰ）系统两种设想及相关技术的可行性研究与发展情况。总体说，实现空间电站所需无线电能传输技术（ＷＰＴ）、太阳电池技术及空间技术已基本成熟，可望于下世纪初建立初步的空间太阳能发电系统。     

能源合理利用与人类住区的可持续发展

本文针对近期石油涨价以及全社会都在提倡节约的大气候,从现有能源的利用和新能源的开发两大方面谈能源合理利用与人类住区的可持续发展过程中应注意的问题,并提出相应的看法和建议。     

基于人工拉格朗日点太阳帆的导航卫星自主定轨技术

为提高导航星座的自主导航能力,提出一种基于人工拉格朗日点太阳帆的导航卫星自主定轨方法。在导航卫星星间测距的基础上,利用太阳帆提供的空间实时位置信息,来消除导航星座的整体旋转和漂移对自主定轨的影响。选用第一类无奇点根数作为状态变量,利用EKF滤波器融合卫星动力学信息及两类测距信息进行自主定轨。利用GPS导航星座的IGS精密星历进行了仿真试验,仿真结果表明了该方法不仅能够保证导航卫星自主定轨的长期稳定性,且与结合星间测距和星间测向的自主定轨方法相比,定轨精度更高。