基于CEI的航天器交会对接段的轨道监控

文章探讨了CEI技术在飞船交会对接远程导引段的实时监控的能力,采用单一绝对滤波器的方案进行实时轨道计算,仿真结果表明：采用滤波稳定后固定模糊度的方法可以提高轨道的滤波解精度,相对轨道位置精度可达十米级,速度精度可达厘米每秒级,满足远程导引段的精度指标。     

基于UG的虚拟制造

介绍了基于现代数控虚拟制造技术的基本内容,并以某零件为例进行了详细工艺分析与虚拟制造仿真技术研究,进行了该零件的切削仿真,开发了后置处理器,实现了机床碰撞系统的虚拟仿真。为解决此类复杂零件的高效数控加工提供了新的方法。     

C波段高增益平板微带天线的设计

文章以微带天线的基本电磁场理论为依据,对微带天线的结构进行了深入的研究。通过建模仿真,设计频带为4.5GHz～5.0GHz的天线,要求在该频段天线的驻波比VSWR〈1.6,平均增益为28～29.5dB。在设计中采用微带U_Slot矩形贴片作为单元,引入π结构,采用近邻耦合方式进行馈电,组成天线阵列来实现。设计结果通过实验室提供的天线测量设备进行测试,软件仿真结果与实际测量结果有较好的一致性。     

SHS/PHIP合成TiC-Al2O3-xFe金属陶瓷的工艺及性能

采用ＳＨＳ／ＰＨＩＰ工艺制轩出了致密的ＴｉＣ－Ａｌ２Ｏ３－ｘＦｅ金属陶瓷。研究子延迟时间、高压持续时间及压力等工艺参数对合成ＴｉＣ－Ａｌ２Ｏ３－２０Ｆｅ金属陶瓷密度的影响,并分析了Ｆｅ含量对ＴｉＣ－Ａｌ２Ｏ３－ｘＦｅ金属陶瓷材料性能的影响。     

高增塑聚乙二醇聚氨酯弹性体形态结构的研究

研究了高增塑聚乙二醇聚氨酯弹性体网络的形态结构,结果表明,由于极性增塑剂的存在,室温条件下,体系不存在结晶;常温条件下,不同增塑剂含量的聚乙二醇聚氨酯弹性体网络均不存在微相分离形态结构。     

真空羽流污染的数值模拟

姿控发动机真空环境下工作产生的喷流对航天器造成的污染非常严重.根据污染的性质,羽流污染又分为机械污染、热污染、沉积污染和化学污染.用直接模拟的蒙特卡罗(DSMC)法数值求解真空羽流场,在此基础上计算热污染和沉积污染,将对空间飞行器的设计和科学实验有参考价值.      

The relationship between ionospheric total electron content (TEC) over East Asia and the tropospheric circulation around the Qinghai-Tibet Plateau obtained with a partial correlation method

This paper reports a study on the relationship between ionospheric total electron content (TEC) over East Asia and the tropospheric circulation around the Qinghai-Tibet Plateau. Ionospheric TEC over East Asia are obtained from 25 observatories during 1996–2004. By applying a partial correlation method which can eliminate the influences of solar and geomagnetic activities, we find no significant correlation between TEC and the Asian zonal circulation index (Iz), but find a positive correlation between the day-to-day variability of TEC and Iz. We suggest that the positive correlation is closely related with the topography of the Qinghai-Tibet Plateau. The dynamical effect on airflow of the plateau can generate vortexes, and the vortexes may continuously excite internal gravity waves (IGWs) which transmit up to the ionosphere and cause regional wave disturbances. This study gives evidence for the dynamical mechanism of ionosphere–troposphere coupling and shows the importance of the Qinghai-Tibet Plateau in the ionosphere–troposphere coupling over East Asia.     

Effects of Contact Resistance on Heat Transfer Behaviors of Fibrous Insulation

In this article, a numerical model combining conduction and radiation is developed based on two flux approximation to predict the heat transfer behavior of fibrous insulation used in thermal protection systems. Monte Carlo method is utilized to determine the modified radiative properties with experimentally measured transient external temperature as high as 1 000 K. It is found that the estimated radiative properties become time-independent after about t = 3 000 s. By comparing the predicted to the measured results in transient state, the contact resistance exerts significant influences upon the temperature distribution in the specimen. Results show that the averaged absolute deviation is 3.25% when contact resistance is neglected in heat transfer model, while 1.82% with no contact resistance.     

利用多个相参脉冲回波估计目标径向速度和加速度

为从高加速度目标的多个相参脉冲回波中估计目标径向速度和加速度,首先对高加速度目标回波特点进行分析,其次提出采用FRFT(Fractional Fourier Transform)变换方法来提取目标径向速度、加速度,仿真结果验证了算法的有效性。     

飞机结构MSD失效概率的敏感性分析

考虑到飞机结构的多部位损伤（MSD,Multiple Site Damage）结构裂纹萌生位置的不同可能对结构的安全性能存在影响,分析结构失效概率对各应力集中部位裂纹萌生寿命和应力的敏感性,量化其对结构安全性能的影响.裂纹萌生寿命采用对数正态模型,通过定义核函数建立MSD结构失效的敏感性分析模型, 采用Monte-Carlo模拟计算概率敏感度.该方法利用Monte-Carlo概率分析的结果,只需增加少许计算量即可得到失效概率对参数的敏感度.将该方法应用于共线多孔板分析,得到了给定寿命下失效概率对各关键位置应力和裂纹萌生寿命对数均值的敏感度,从而确定了对结构安全影响最大的位置.