共查询到19条相似文献,搜索用时 813 毫秒
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本文强调了在电子设备机壳材料的电磁屏蔽设计中,重视腐蚀防护对延长产品寿命及确保其电磁屏蔽效果长期有效性的重要性。遵循电化学腐蚀原理阐述了机壳防腐蚀设计的一般原理和方法。 相似文献
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电磁兼容设计中金属屏蔽镀(涂)层的选用 总被引:1,自引:0,他引:1
叙述了在电磁兼容设计中,在选用金属镀(涂)层作电磁屏蔽层时应考虑的因素。强调了屏蔽材料防气候环境条件腐蚀以确保电磁屏蔽性能长期可靠的重要性。分别介绍了针对各种材料制作的蜂窝屏蔽通风板、机壳、屏蔽网、垫片等电子仪器零部件选用的屏蔽镀(涂)层。 相似文献
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本文简要说明了全机电子综合试验电磁屏蔽暗室的必要性、优越性,电磁屏蔽暗室的用途以及电磁屏蔽暗室的技术要求和设计原理。 相似文献
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本文结合实际工作经验对民航VHF设备电磁屏蔽技术进行了探讨研究,总结VHF设备电磁屏蔽应注意的问题,以供同行参考。 相似文献
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《中国航空学报》2021,34(10):91-102
To meet the needs of preventing information leakage in space engineering and military industry, an efficient method was introduced to obtain layered electromagnetic shielding sealing rubber. The carbon fiber, Ni-Fe coating, and Carbon NanoTube (CNT) were combined by chemical plating and in-situ polymerization to obtain a lightweight (0.14 g/cm2) and thin (1 mm thick) Carbon fiber Fabric (CF)/Ni-Fe/CNT/silicone layered electromagnetic shielding composites. The layered material obtained by adjusting the electroless plating time exhibited a high Shielding Efficiency (SE) of 60.2–85.5 dB in the range of 0–4800 MHz, which can be used for aviation electromagnetic shielding. Carbon fibers and carbon nanotubes mainly attenuated electromagnetic waves through absorption loss, while the nickel-iron alloy coating through reflection loss interacted with the magnetic vector of incident ElectroMagnetic (EM) radiation and magnetic dipoles, therefore, the EM Interference (EMI) shielding composite attenuated EM waves with the “absorption-reflection-absorption” cooperative interaction. Moreover, the flexible fabric substrate adhered with silicone rubber possessed a breaking elongation of 52.3%, which can be utilized as a good sealing material. Simultaneously, the outstanding exothermicity (67.2 °C under the applied voltage of 5 V) makes it possible to be applied in electric heating area. The electromagnetic shielding composites prepared in this paper have good potential in the fields of precision electronic equipment and aviation systems. 相似文献
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在民用飞机电气线路互联系统(EWIS)设计中,通过物理隔离防止电弧和电磁干扰(EMI)是适航审定的重要内容。以隔离距离为研究对象,基于电磁仿真软件CST,构建多种模型,对不同类型线缆间、不同电信号线路进行了仿真,证明了物理隔离不但是防止电弧产生的有效方式,而且能够极大地降低电磁干扰,同时使用屏蔽线缆和多芯扭绞等防护方法,也是降低电磁干扰的有效措施。 相似文献
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高导热C/ C 复合材料具有高热导率、低密度、低热胀系数和高温下高强度等性能,成为近年来最
具发展前景的散热材料之一。本文综述了国内外高导热C/ C 复合材料的发展现状,分析了C/ C 复合材料的热
物理性能及影响其热导率的因素,介绍了C/ C 复合材料的导热机理、碳纤维、基体炭的导热性能,以及高导热
C/ C 复合材料的制备和改性等。 相似文献
具发展前景的散热材料之一。本文综述了国内外高导热C/ C 复合材料的发展现状,分析了C/ C 复合材料的热
物理性能及影响其热导率的因素,介绍了C/ C 复合材料的导热机理、碳纤维、基体炭的导热性能,以及高导热
C/ C 复合材料的制备和改性等。 相似文献
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将碳纳米管经过纯化、敏化、活化处理后,采用化学镀方法制备镀镍碳纳米管,利用DSC分析出合适的热处理温度,然后在惰性气体保护下进行退火处理.利用TEM、EDS、XRD对退火前后镀镍碳纳米管的形貌、元素组成、结构进行表征.结果表明:碳纳米管表面被成功镀上了一层镍磷合金,热处理后镀层更光滑,并发生晶化反应得到晶态镍,使得电磁性能得到较大提升.电性能测试表明,镀镍碳纳米管的电导率为450 S/m,热处理后提高到1400 S/m.磁性能测试表明,镀镍碳纳米管热处理前后均表现为软磁性,热处理前饱和磁化强度为2.753 emu/g,热处理后提高到11.254 emu/g. 相似文献
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电磁屏蔽抗干扰技术研究 总被引:2,自引:1,他引:1
从干扰源性质出发,将屏蔽分为电场屏蔽、磁场屏蔽和电磁场屏蔽,并对它们进行了分析研究。针对其特性提出其适用范围及注意事项,从而增强了抗干扰的效果。 相似文献
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具有电磁屏蔽性能的金属/织物复合材料 总被引:7,自引:0,他引:7
用化学镀铜和化学镀镍的方法对纤维织物进行改性,制备出有优良电磁波屏蔽性能的金属 /织物复合材料。该复合织物在 1 0 k Hz~ 1 2 GHz范围内可以获得 50~ 70 d B的优良屏蔽效果和良好的环境稳定性,成本低、结合力好,适用于丝绸、棉布、化纤布和玻璃纤维布等多种织物改性,有良好的应用前景。 相似文献
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S. V. Averin V. Yu. Kirillov E. V. Mashukov S. B. Reznikov D. A. Shevtsov 《Russian Aeronautics (Iz VUZ)》2017,60(3):442-446
The paper presents the results of studying the shielding efficiency for onboard cables of unmanned aerial vehicles (UAV). We specify the special features of studying the shielding efficiency for the onboard cables by means of a coaxial setup on frequencies more 3 MHz. The results presented in the paper experimentally verify that the shielding efficiency for onboard cables depends on the type of electromagnetic interference. 相似文献
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《中国航空学报》2015,(4)
Carbon nanotube(CNT) possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material.This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method.The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed.It is shown that CNT film exhibits anisotropic electromagnetic characteristic.Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film.For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases.The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 d B to78 d B in X-band.Stretching process induces the alignment of CNTs.When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity.Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness.This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials. 相似文献