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M. V. Peralta-Martinez M. J. Assael M. J. Dix L. Karagiannidis W. A. Wakeham 《International Journal of Thermophysics》2006,27(3):681-698
New measurements of the thermal conductivity of molten mercury, gallium, tin, and indium are reported up to 750 K. The measurements are performed in a novel transient hot-wire instrument described elsewhere. The present experimental technique overcomes problems of convection, and it is shown that it operates in an absolute way in accord with a theoretical model. The uncertainty of the thermal conductivity results is estimated to be ± 2%, which is superior to that achieved in most earlier work. The low uncertainty of the present experimental results has allowed us to test the only significant theory for the thermal conductivity of molten metals, which relates this property to the electrical conductivity. The pattern of results among the four metals indicates that further theoretical developments would be warranted. 相似文献
143.
Tarasankar Pal 《Materials and Manufacturing Processes》2006,21(3):315-317
Cetylpyridinium chloride (CPC)-stabilized gold organosol in toluene has been prepared by using a two-phase (water-toluene) extraction of AuCl4- followed by its reduction with sodium borohydride in the presence of the surfactant, CPC. The surfactant-stabilized gold nanoparticles were exploited to examine their optical properties when exposed to various solvent systems by measuring the changes in the localized surface plasmon resonance (LSPR) spectrum. 相似文献
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Steel in its various forms is the most widely utilized metallic alloy and comprises over 80 % by weight of all metallic alloys in industrial use.[1] The development of steel microstructures is based on manipulation of a very specific solid/solid state transformation called an eutectoid transformation (i.e. γaustenite → αferrite+ Fe3Ccementite). The control of this transformation is the primary factor resulting in wide variety of microstructures and resulting properties found in commercial steel alloys. However, the full benefit of its main constituent, iron has never been realized. Based on the metallic bonding in iron, the theoretical tensile strength has been calculated to be 13.2 GPa but ultra high strength steels, even today, only achieve maximum tensile strength levels from 1 to 1.5 GPa. Thus, our modern technological society has been established utilizing approximately only ~ 10 % strength level of iron. Here we demonstrate that a high level of strength (6.2 GPa) and strength to weight ratio of 8.3 × 104/m3 may be obtained in iron‐based alloys by their solidification into metallic glasses, as well as, by employing another solid state transformation called glass devitrification. 相似文献
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采用溶液还原法,以硫酸镍为原料,水合肼为还原剂制备了超细和纳米镍粉。研究了不同分散剂对镍粉粒度和粒度分布的影响。X射线衍射结果表明,所得粉末为纯Ni相,晶粒尺寸约13nm;激光粒度分布测试结果表明,Ni粉粒度分布较窄,中位径集中在0.7~0.8μm,最大粒径不超过2.0μm。透射电镜照片显示粉末近球形,一次颗粒粒径在50~100nm之间,有轻微团聚。改变分散剂种类(PVP、PEG1500、PEG20000、CTAC)和用量可使超细镍粉的比表面积在3.24~57.88m^2/g间变化。 相似文献
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世界再生金属生产现状与趋势 总被引:1,自引:0,他引:1
介绍了世界废钢铁、再生铝、再生铜、再生铅锌、再生贵金属等的生产现状,指出了再生金属产业的广阔前景。 相似文献