共查询到20条相似文献,搜索用时 156 毫秒
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总结了高耐蚀镁合金、高温镁合金、阻燃镁合金、超轻Mg-Li合金的开发现状,综述了镁合金加工技术的研究进展及镁合金的应用状况.半固态射铸技术是一种自动化程度很高的新技术,有望成为生产镁合铸件的主流工艺.而近年来出现的许多新压铸方法,包括真空压铸、充氧压铸和半固态压铸等方法能够大大减少铸件气孔缺陷,提高铸件致密度,因而有很大的发展潜力. 相似文献
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通过对超轻EVA交联发泡材料特点的分析,探讨了这种材料的配方设计、生产工艺方面的关键技术,介绍了目前超轻EVA交联发泡材料的主要用途及其发展趋势. 相似文献
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镁合金将成为21世纪最重要的商用轻质结构材料。本文综述了变形镁合金的研究现状,介绍了改善镁合金塑性变形能力的途径。 相似文献
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镁合金由于具有质量轻、比强度和比刚度高以及良好的铸造性能等特点,在理论研究和实际应用上引起了人们极大的关注。近年来,世界各国纷纷致力于镁合金的研究开发。本文综述了国内外主要的变形镁合金材料的基本特性、力学性能和应用领域,介绍了目前变形镁合金材料的研究现状和进展,以及制备高性能变形镁合金材料的新工艺,探讨了镁合金的合金化原理和主要合金元素在变形镁舍金中的作用。 相似文献
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S. A. Gaikwad E. P. Samuel D. S. Patil D. K. Gautam 《Bulletin of Materials Science》2007,30(3):255-261
Temperature dependent analysis to achieve better performance by reducing threshold current requirements and field intensity
has been carried out for GaN/AlGaN heterostructure lasers. The mirror loss in the GaN cavity has been obtained as a function
of temperature and cavity length. The quantum efficiency has been deduced for different values of cavity length. Dependence
of recombination rate on band gap and temperature has been investigated. Threshold current density has been deduced for GaN
lasers and effect of temperature on it has been investigated. The near field intensity analysis has been carried out at different
temperatures for 10% aluminum mole fraction in GaN/AlGaN heterostructure lasers. Furthermore, the effective index and FWHM
of near field has been investigated as a function of temperature. It has been deduced from our analysis that temperature has
a dominant effect on the threshold conditions and near field intensity in the wide band gap GaN based lasers. 相似文献
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聚醚醚酮复合材料的摩擦学研究 总被引:1,自引:0,他引:1
采用模压方法制备了多元PEEK耐磨汽车材料。用环-块磨损实验机对复合材料进行了磨损试验,用SEM方法对复合材料的磨损表面进行了观察和分析,并利用DSC、FT-IR和SEM分析方法对复合材料的磨屑进行了研究,在上述基础上进行了复合材料的磨损机理探讨。结果表明,与PEEK相比,PEEK复合材料具有优良的摩擦学性能;PEEK复合材料磨屑的熔点比相应模压材料有所降低,且磨屑的熔限比相应的模压材料有所加宽;随着Ekonol含量的增加,复合材料的磨损机理发生了由粘着磨损为主向疲劳磨损为主的转变。 相似文献
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膜法提取大豆分离蛋白的研究 总被引:9,自引:0,他引:9
选用中空纤维聚砜膜提取大豆蛋白质。对膜分离过程的最优工艺条件进行了探讨,重点对膜污染规律进行了摸索。并通过对膜污染规律的动力分析,获得了克服生产过程中的膜污染的方法,通过工业化生产试验,取得较好的工艺效果和产品。 相似文献
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结合实际工程,对寒冷地区系统方案进行了比较。通过以天窗排风为主的自然通风和机械通风相结合的方式,解决屋顶风机过多带来的弊端,降低运行费用。利用热风系统作为中心区域补风,改善主生产区空气质量。采用置换通风形式,在地面上设置送风口,改善气流组织。并给出了运行效果及评价。 相似文献
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针对设计研制的512×512 CMOS APS图像传感器,采用聚焦脉冲激光束研究了其空间单粒子效应特性。试验结果表明,CMOS APS器件图像传感器存在单粒子翻转(SEU)和单粒子锁定(SEL)现象。验证了CMOS APS图像传感器抗单粒子锁定设计的有效性。当对图像传感器移位寄存器区进行照射时,同时发生单粒子翻转和单粒子锁定,器件其它区域也有类似现象。分析了器件单粒子效应的敏感性,获得了器件发生单粒子翻转和锁定的脉冲激光能量阈值及器件锁定电流大小。 相似文献
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Ronald L. Plaut Angelo F. Padilha N.B. Lima Clara Herrera Antenor Ferreira Filho Leandro H. Yoshimura 《Materials Science and Engineering: A》2009,499(1-2):337-341
Medium carbon steels are mostly used for simple applications; nevertheless new applications have been developed for which good sheet formability is required. This class of steels has an inherent low formability. A medium carbon hot rolled SAE 1050 steel has been selected for this study. It has been cold rolled with reductions in the 7–80% range. Samples have been used to assess the cold work hardening curve. For samples with a 50 and 80% thickness reduction, an annealing heat treatment has been performed to obtain recrystallization. The material has been characterized in the “as received”, cold rolled and annealed conditions, using several methods: optical microscopy, X-ray diffraction (texture), Vickers hardness and tensile testing. The 50% cold rolled and recrystallized material has been further studied in terms of sheet metal formability and texture evolution during the actual stamping of a steel toecap that has been used to validate the finite element simulations. 相似文献
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An inorgano-organic ion exchanger, Sn(IV) phenyl phosphonate, has been synthesized in amorphous form. Further, an attempt
has been made to synthesize Sn(IV) phenyl phosphonate in the nano form. The materials have been characterized for elemental
analysis (ICP-AES), thermal analysis (TGA), X-ray analysis and FTIR spectroscopy. Chemical resistivity of these materials
has been accessed in acidic, basic and organic solvent media. Catalytic activity has been studied and compared by using esterification
of ethylene glycol as a model reaction wherein glycoldiacetate has been prepared. The transport properties of these materials
have been explored by measuring specific proton conduction at different temperatures using SOLARTRON DATASET impedance analyser
over a frequency range 1 Hz-1 MHz. It has been observed that Sn(IV) phenyl phosphate in the nano form behaves as a better
Bronsted catalyst and proton conductor as compared to the amorphous form. 相似文献