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碳基/羰基铁复合吸波材料的研究进展 总被引:1,自引:0,他引:1
碳基/羰基铁复合吸波材料结合了各自优势,具有独特的物理化学特性和良好的吸波性能,成为近年来研究热点之一。本文结合国内外最新研究成果,介绍了羰基铁吸波剂自身改性的研究现状,将碳基/羰基铁复合吸波材料的研究成果系统归纳为6大类,即石墨烯/羰基铁复合吸波材料、碳纳米管/羰基铁复合吸波材料、碳纤维/羰基铁复合吸波材料、炭黑/羰基铁复合吸波材料、石墨/羰基铁复合吸波材料以及其他碳材料与羰基铁的复合吸波材料,并进行了详细介绍。最后,指出了碳基/羰基铁复合吸波材料未来研究亟待解决的性能调控和轻量化等问题,展望了其在宽频隐身等方面的发展前景。 相似文献
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碳化硅颗粒填充的碳纳米管/环氧树脂复合材料的吸波性能 总被引:1,自引:0,他引:1
以碳纳米管、碳化硅颗粒为原料制备环氧树脂复合吸波材料,并对其吸波性能进行测试,研究了碳纳米管、碳化硅颗粒含量与复合材料吸波性能的关系.结果表明碳纳米管、碳化硅颗粒的含量对复合材料的吸波性能有较大影响.随碳纳米管含量的增加,碳纳米管/环氧树脂复合材料的吸波性能先提高后降低,碳纳米管含量存在最佳值(12%,质量分数).将碳... 相似文献
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碳纳米管在聚合物基吸波隐身复合材料上的应用 总被引:16,自引:1,他引:16
针对新一代吸波隐身材料要求吸收强、宽频带、质量轻、厚度薄、功能多、红外微波吸收兼容以及具有优良的其他综合性能的要求,利用碳纳米管(CNTs)特殊的电磁吸波特性,以及聚合物优良的材料性能,研究开发碳纳米管聚合物基复合吸波功能材料是实现该技术的有效途径.从吸波材料的隐身机理出发,阐述了碳纳米管的电磁吸波特性,着重介绍了碳纳米管聚合物基吸波隐身复合材料的最新研究进展,并提出了该类材料今后发展着重应解决的技术问题. 相似文献
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新型电磁波吸收材料是国防科技中的研究热点和重点,碳材料作为一种轻质吸波材料受到研究者们的广泛重视.本研究利用浮动催化化学气相沉积法制备螺旋非晶碳纳米管,以螺旋非晶碳纳米管作为吸波剂,双马来酰亚胺树脂作为基体制备了螺旋非晶碳纳米管/双马来酰亚胺树脂吸波复合材料.采用扫描电子显微镜、透射电子显微镜、X射线衍射仪和拉曼光谱仪等设备对样品进行微观形貌和结构表征,通过矢量网络分析仪测试其电磁参数.实验结果表明,吸波剂含量的增加增强了螺旋非晶碳纳米管/双马来酰亚胺树脂复合材料的吸波性能,其最大吸收峰值可达-18.35 dB,最大吸波频宽(<-10 dB)为2.56 GHz(9.52~12.08 GHz),反射损耗超过97%,且吸收峰向低频方向移动.螺旋非晶碳纳米管因其特殊的螺旋型结构极大地增加了电磁波反射概率和散射波程,增大了入射电磁波能量损耗. 相似文献
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碳纳米管由于具有超高的强度、良好的韧性、导电性以及低密度等优异性能,是聚合物材料较为理想的增强填料。近年来,碳纳米管/环氧树脂复合材料的研究已成为碳纳米管应用研究的一个热点。本文介绍了碳纳米管/环氧树脂复合材料的力学性能、电性能、热性能、摩擦性能、吸波性能以及阻尼性能;并结合国内外研究现状,探讨了该复合材料存在的问题,对未来的发展方向进行了展望。 相似文献
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随着雷达探测技术的迅猛发展和电磁波辐射污染的日益加剧,新型吸波材料的研究和开发成为各国研究的热点。单一吸收剂存在吸波频带窄和吸收强度低等缺点,无法满足新型吸波材料频带宽、厚度薄、质量轻、吸收强的要求。碳材料具有密度低和吸波性能好等优点,通过与其他吸收剂的双组分、多组分复合,或对复合材料的微观结构进行设计,碳系复合材料表现出优异的吸波性能。简要介绍了吸波材料的工作机理,然后分别从炭黑、碳纤维、碳纳米管、石墨烯和其他碳系材料等5个方面综述了碳系材料在电磁波吸收中的应用和发展,归纳了碳系材料吸波性能的最新研究进展,最后提出了当前研究中存在的不足并明确了研究方向。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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Steffen Müller-Probandt 《材料科学与工程:中英文B版...》2018,(4):161-177
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di... 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Janet Lang 《Materials and Manufacturing Processes》2017,32(7-8):857-866
ABSTRACTThe production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them. 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill. 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献