飞机外露物隐身改进设计研究

外露物在一定程度上影响飞机隐身性能,而外露物的共形设计会增加成本。针对低成本准隐身飞机,本文探讨了一种外露物的隐身改进设计,主要采取优化外形,涂敷吸波材料、提升加工工艺等措施实现低成本飞机RCS值的缩减。经过隐身仿真、隐身测试等手段,获取了外露物在不同频点、不同极化下的RCS值,并通过仿真、测试数据对比验证采取隐身改进措施的有效性,并为其它外露物隐身设计提供了设计依据和手段。     

新型隐身材料吸收剂的研究进展

综述了国内外目前用于隐身技术的几种隐身材料,介绍了几种新型隐身材料的吸收剂.对纳米隐身材料进行了较为详细的描述,简述了其吸收机理.比较了各种吸收剂的特点,提出了雷达波吸收剂的发展趋势.     

吸波涂料的研究现状

重点对吸波涂料的种类进行了论述，并对吸波涂料的应用情况和发展趋势进行了简单描述。     

雷达吸波材料的隐身效果分析

从电磁场理论出发,推导出了电磁波以任意角入射时雷达吸波材料的反射系数公式。同时,给出了计算曲线的例子,通过实例计算分析了电磁波的入射角、极化状态等对隐身效果的影响。为雷达吸波材料的计算机辅助分析和设计提供了基础。     

A yeast antiviral protein,SKI8, shares a repeated amino acid sequence pattern with β-subunits of G proteins and several other proteins

SKI8 is a yeast antiviral gene, essential for controlling the propagation of M double-stranded RNA (dsRNA) and thus for preventing virus-induced cytopathology. Our DNA sequence of SKI8 shows that it encodes a 397 amino acid protein containing two copies of a 31 amino acid repeat pattern first identified in mammalian β-transducin and Cdc4p of yeast. There are also four copies of this repeat in yeast Mak11p, necessary for M dsRNA propagation, and three copies in the putative product of the Dictyostelium AAC3 gene. Analysis of 36 cases of the repeat unit shows they have a consensus predicted structure: N–helix–sheet–turn–sheet–turn–sheet–helix–C.     

闭式等离子体隐身技术及等离子体参数的优化

提出了一种等离子体隐身技术,即闭式等离子体隐身技术,从而解决了开放式的等离子体隐身技术的诸多问题.通过计算入射到覆盖闭式等离子体的金属平板上的电磁波的反射率,得出了在低温下,提高等离子体密度和温度,有利于更好的吸收电磁波结论.最后计算了未覆盖与覆盖闭式等离子体导体圆锥的雷达散射截面,结果表明:采用闭式等离子隐身技术有很好的隐身效果.     

Design of a Vivaldi antenna with wideband reduced radar cross section

In this paper, a low radar cross section (RCS) Vivaldi antenna is proposed. The main objective of this work is to achieve a reasonable RCS reduction without affecting the radiation performance of the antenna. With carefully inspecting the surface current distributions at different frequencies and realizing the critical role of the structural mode in reducing RCS, a simple and efficient object shaping method is employed by introducing a number of circular slots in the surface of the radiator to achieve the RCS reduction. These circular slots along the inner circular profile of the Vivaldi antenna can minimize the scattering along the surface of the radiator, which hence leads to a reduction in the monostatic RCS. Comparing the measured results between the reference antenna and the proposed antenna, a significant 11 dB RCS reduction is obtained while maintaining good radiation performance. Simulated and measured results including S-parameters, gain, RCS of the reference antenna and the proposed antenna are presented.     

低RCS选频滤波反射面天线技术

利用具有带阻选频特性的周期结构表面替代普通金属反射面构成的滤波反射面天线是一项克服天线散射的有效技术途径.本文给出了滤波反射面天线辐射特性和RCS的实测结果;分析讨论了此种天线的性能和可行性.     

Digital Doppelgängers: Future Scanscapes

Over the course of the last two years, ScanLAB Projects have explored various fragments of the natural and man-made world through the eyes of their forensic measuring machine. From surface mapping of Arctic ice floes in the Fram Strait (gateway to the Arctic) to the documentation of torture and detention sites in the Balkans, via the accidental editing of a Richard Long sculpture, to purposeful acts of detail theft from Foster and Wren. Here, Matthew Shaw and William Trossell discuss the capture, analysis and refabrication of their digital architectural doppelgängers.