Statistical comparison of night-time NO2 observations in 2003–2006 from GOMOS and MIPAS instruments

GOMOS (Global Ozone Monitoring by Occultation of Stars) and MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) are remote sensing instruments on board the European Space Agency’s Envisat satellite. GOMOS and MIPAS have been designed for observations of stratospheric and mesospheric constituents, including ozone and nitrogen dioxide. Both instruments have a good global coverage of observations and can provide data also from the polar regions. In this paper, we compare night-time NO₂ data from GOMOS with those from MIPAS. We present statistics of selected sets of data spanning from the year 2003 to 2006. The results for low-to-mid latitudes show that the two instruments are in a good agreement in the middle stratosphere, the differences being typically less than 5%. In the upper stratosphere, GOMOS observations generally show 15% higher values than those from MIPAS. The bias is in virtually all cases smaller than the combined systematic error of the measurements, giving great confidence in the GOMOS and MIPAS data quality. The result for high mesospheric NO₂ mixing ratios observed in the polar regions during winter times indicate a good agreement between GOMOS and MIPAS. In the mesosphere, the difference is less than 35% and smaller than the systematic error. Due to the high mesospheric signal, MIPAS sensitivity decreases in the stratosphere which results in larger differences between the two instruments.     

关于太阳模拟器电源的理论和实践

文章回顾了太阳模拟器电源发展的三个阶段:碳弧灯和磁饱和电抗器阶段;氙灯和模拟量阶段;氙灯和数字量阶段.文章并阐述了KM6太阳模拟器电源的设计思路,详细地介绍了可选用元器件的优缺点,以及"PWM"变换器的选择.     

碳纤维对低特征信号XLDB推进剂力学性能影响的初步研究

初步研究了不同基的碳纤维(CF)及其加入工艺对XLDB推进剂力学性能的影响。结果表明,CF的加入提高了XLDB推进剂低温延伸率,电镜照片显示粘接剂与CF有良好的粘接能力,断裂是发生在粘接剂基体而不是发生在CF与粘接剂的接触面。     

热解炭含量对C/C复合材料性能的影响

研究了不同热解炭含量对C／C复合材料性能的影响。对采用CVD工艺致密到不同密度,具有不同热解炭含量的2D炭布针刺体试样,利用沥青高压浸渍炭化工艺增密至相同的最终密度,然后对其进行力学、热学性能及等离子烧蚀试验。试验结果表明,热解炭含量高的C／C试样具有较好的力学、烧蚀及导热性能。     

A generative deep learning framework for airfoil flow field prediction with sparse data

Deep learning has been probed for the airfoil performance prediction in recent years.Compared with the expensive CFD simulations and wind tunnel experiments, deep learning models can be leveraged to somewhat mitigate such expenses with proper means. Nevertheless, effective training of the data-driven models in deep learning severely hinges on the data in diversity and quantity. In this paper, we present a novel data augmented Generative Adversarial Network(GAN), da GAN, for rapid and accurate fl...     

固体火箭发动机复合材料技术的进展及其应用前景

综述了用于固体火箭发动机的聚合物基结构复合材料、聚合物基隔热烧蚀复合材料、C／C材料和陶瓷基复合材料的研究进展，也涉及了纳米复合材料、智能复合材料的研究现状与应用前景。     

Al2O3型碳/陶功能梯度材料烧蚀试验研究

Al2O3型影陶功能梯度材料作为一种新型喷管热防护材料，其具有导热系数较低及良好的隔热性能。在氧乙炔烧蚀试验条件下该材料有很好的耐烧蚀性，但由于发动机内的工作环境更为恶劣，为了更好地反映材料在固体火箭发动机中的烧蚀情况，该研究工作采用了试验发动机进行烧蚀试验。结果表明，试验发动机中获得的烧蚀率数据高于氧乙炔试验数据。文中在试验基础上分析了Al2O3型影陶功能梯度材料在发动机工作条件下的烧蚀性能及导热性能。     

高温热处理与C/C复合材料性能关系研究

采用整体炭毡为增强坯体,经过化学气相渗透(CVI)及树脂浸渍/炭化(PIC)工艺制备成整体毡C/C复合材料样品,对样品连续进行了3次2 500℃以上的高温热处理(HTT)。材料性能测试结果表明,3次HTT后材料z向抗拉强度由16.7MPa下降到8.87MPa,抗压强度由129.0MPa下降到72.7MPa,抗弯强度由35.7MPa下降到17.6MPa,抗剪强度由34.4MPa下降到18.7MPa;xy向室温(RT)~1 000℃的平均线膨胀系数由1.55×10-6K-1降低到1.13×10-6K-1;800℃的热导率由106.91 W/(m.K)降低到61.27 W/(m.K),比定压热容由2.56 kJ/(kg.K)下降到1.93 kJ/(kg.K);z向变化趋势基本相同。     

离子推进器C/C复合材料栅极研究

栅极是离子推进器的关键部件之一,直接影响推进器的可靠性和寿命。由于C/C复合材料栅极具有比较小的热膨胀系数和较强的耐溅射性,可以提高离子推进器的可靠性并延长其寿命。文章通过调研综述C/C复合材料栅极的研究和应用发展状况,针对目前我国离子推进器的研究发展水平,提出开展C/C复合材料栅极研究工作的初步思路。     

快速制备不同预制体C／C复合材料摩擦学性能研究

分别以短纤维模压毡和炭布叠层为预制体,采用快速CVI工艺制备C/C复合材料,测试了2种不同材料的干态静摩擦性能和干态动摩擦性能,分析了预制体结构及试验条件对其摩擦性能的影响,并探讨了该材料的摩擦磨损机理.结果表明,静摩擦系数随刹车比压增加而减小;快速制备C/C复合材料的磨损率非常低,具有良好的磨损性能,提高垂直取向(垂直于摩擦面)纤维的含量有利于减少磨屑量,降低磨损率.短纤维模压毡预制体制备的C/C复合材料的磨损率低于炭布叠层预制体.