着陆缓冲技术综述

着陆缓冲技术是空间飞行器返回技术的重要组成部分。利用着陆缓冲装置可以明显降低降落伞的面积、减小回收系统的重量,同时大幅度降低飞行器着陆时的冲击载荷。近些年来,着陆缓冲技术有了些新的发展。文中对已有的着陆缓冲装置进行了分类,对每种类型的技术性能、使用范围作了评述。     

多传感器数据融合与弹道落点的预报

为了更精确地对弹道落点进行预报，对多传感器数据融合技术进行了,分批人出了雷达、红外系统和光测系统与传感器融合子系统连用的实例，并得出结论：单传感器的精度是难以满足现代战争需要的，寻求一种较好的融合方法来提高落点预报精度虽是一个难题，但仍是可行的。     

Expectations for Infrared Spectroscopy of 9P/Tempel 1 from Deep Impact

The science payload on the Deep Impact mission includes a 1.05–4.8 μm infrared spectrometer with a spectral resolution ranging from R∼200–900. The Deep Impact IR spectrometer was designed to optimize, within engineering and cost constraints, observations of the dust, gas, and nucleus of 9P/Tempel 1. The wavelength range includes absorption and emission features from ices, silicates, organics, and many gases that are known to be, or anticipated to be, present on comets. The expected data will provide measurements at previously unseen spatial resolution before, during, and after our cratering experiment at the comet 9P/Tempel 1. This article explores the unique aspects of the Deep Impact IR spectrometer experiment, presents a range of expectations for spectral data of 9P/Tempel 1, and summarizes the specific science objectives at each phase of the mission.     

氟聚物基含能反应材料研究进展

对氟聚物基含能反应材料进行了概述,介绍了反应材料的组分、结构特点以及制备关键技术,并对反应材料各项性能指标进行了综述,对氟聚物基反应材料的应用现状和前景进行了归纳和展望.     

酚醛树脂基蒙脱土纳米复合材料的力学性能与增强增韧机理

利用三种蒙脱土(即S-MMT,TG-2,OLS,统称MMT)和一种短切纤维(Short-cutGlassFiber,简记为SGF),分别与酚醛树脂熔融混合,制得酚醛树脂基复合材料。通过缺口冲击实验和弯曲实验,对这些复合材料的力学性能和增强增韧机理进行了研究,取得了一些有规律性的结果。PF/NBR/SGF复合材料的缺口冲击强度、弯曲强度和弯曲模量都随SGF含量的增加而增大;PF/NBR基蒙脱土纳米复合材料的缺口冲击强度随纳米材料(即S-MMT,TG-2和OLS)含量的增加而增大,在含量为5份时达到最大值;弯曲强度和弯曲模量也随纳米材料含量的增加而增大,在含量为9份时达到最大值。其次,所有PF/NBR基复合材料的缺口冲击强度均在60℃取得最大值,PF/NBR/OLS,PF/NBR/TG-2,PF/NBR/S-MMT等三种纳米复合材料的力学性能与体系中蒙脱土的层间距密切相关。层间距越大,力学性能越好。最后,探讨了纳米蒙脱土增强增韧PF/NBR体系的机理,指出聚合物体系中的蒙脱土具有两种效应,并建立了模型。     

头盔硬衬用聚氨酯泡沫塑料的研究

介绍了聚氨酯泡沫塑料的发泡机理，设计了头盔硬衬用半硬质自结皮聚氨酯泡沫塑料配方，筛选出了高活性聚醚／TDI和高活性聚醚／PAPI两种聚氨酯发泡体系，穿透实验和碰撞实验表明，半硬质自结皮聚氨酯泡沫塑料完全可以取代传统的聚苯乙烯泡沫塑料作为头盔硬衬。     

电推进羽流粒子束溅射的蒙特卡罗模拟

为了研究电推进羽流对推力器及航天器造成的溅射腐蚀作用,采用蒙特卡罗方法对羽流等离子体对材料的溅射进行模拟,研究了溅射的级联碰撞机理,并开展了Xe离子正入射、斜入射Cu材料的溅射率、溅射产物的能量分布以及空间角分布的研究.结果显示,蒙特卡罗方法对溅射率和能量分布的计算结果与试验结果吻合较好,误差<30％,但是斜入射溅射率...     

The South Pole-Aitken basin region,Moon: GIS-based geologic investigation using Kaguya elemental information

Using Geographic Information Systems (GIS), we performed comparative analysis among stratigraphic information and the Kaguya (SELENE) GRS data of the ∼2500-km-diameter South Pole-Aitken (SPA) basin and its surroundings. Results indicate that the surface rock materials (including ancient crater materials, mare basalts, and possible SPA impact melt) are average to slightly elevated in K and Th with respect to the rest of the Moon. Also, this study demonstrates that K and Th have not significantly changed since the formation of SPA. The elemental signatures of the impact basin of Fe, Ti, Si, O through time include evidence for resurfacing by ejecta materials and late-stage volcanism. The oldest surfaces of SPA are found to be oxygen-depleted during the heavy bombardment period relative to later stages of geologic development, followed by both an increase in silicon and oxygen, possibly due to ejecta sourced from outside of SPA, and subsequent modification due to mare basaltic volcanism, which increased iron and titanium within SPA. The influence of the distinct geologic history of SPA and surroundings on the mineralogic and elemental abundances is evident as shown in our investigation.     

导流锥结构参数对燃气弹射筒内压力冲击平滑效果影响研究

针对导流锥结构参数对内弹道流场耦合影响问题,基于动态分层动网格技术,构建了含导弹运动和二次燃烧的内弹道数值模型,并验证了模型可靠性。解耦分析了导流锥半径、高度及冲击高度对内弹道流场特性和载荷的影响。结果表明：导流锥的结构直接决定燃气飞溅现象的产生和流场结构的紊乱程度,导流锥的半径、高度和冲击高度的改变会对燃气反射点的位置、二次燃烧的区域以及剧烈程度产生影响;结构优化后的导流锥,较大程度地缓解了冲击现象,获得了较好的平滑效果,筒底压力较实验装置降低了24.5%。     

S波自旋单态底夸克偶素衰变到粲夸克对

对S波自旋单态底夸克偶素衰变到粲夸克对进行了研究,同时还研究了S波自旋单态和自旋三重态底夸克偶素衰变到D介子对。利用BaBar实验组测量得到的自旋三重态底夸克偶素衰变到D介子分支比的数据,发现自旋三重态底夸克偶素的色八重态矩阵元远小于理论预言,理论预言要比实验上限大20倍以上;得到S波自旋单态底夸克偶素衰变到粲夸克对的分支比的理论预言,可以进行实验测量从而研究色八重态矩阵元;得到S波自旋单态底夸克偶素衰变到D介子对的分支比的理论预言,与其他理论预言差异较大。这些预言可以通过BelleⅡ的实验进行验证,从而得到更多强子化的信息。