M. Wang
材料科学技术（英文）
The electrical resistivity of Cu/Ta multilayers deposited by radio-frequency magnetron sputtering on a polyimide substrate was investigated as a function of monolayer thickness. It is found that the resistivity of the multilayer increases with decreasing monolayer thickness from 500 nm to 10 nm. Two significant effects of layer interface
scattering and grain boundary scattering were identified to dominate electronic transportation behavior in the Cu/Ta multilayers at different length scales. The electrical resistivity of the multilayer with monolayer thickness ranging from nanometer to submicron scales can be well described by a newly-proposed Fuchs-Sandheimair
(F-S) and Mayadas-Shatzkes (M-S) combined model.
关键词:
Electrical resistivity
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A.A.Al-Aql
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M.S.Al-Salhi
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M.I.Ansari
材料科学技术（英文）
Precipitation study was carried out in Ni-35 at. pct Cr alloy by measuring electrical resistivity at different ageing temperatures and long ageing times. During ageing, it was observed that electrical resistivity initially rose with ageing time and then fell after very long ageing at a constant temperature. The initial increase in resistivity during ageing may be attributed to the formation of GP zones/Cr-rich precipitates at early stages by nucleation process and decrease in resistivity, and after attaining a maximum, is due to the growth of precipitate particles and subsequently by coarsening of these precipitates. The results of electrical resistivity measurements during ageing were confirmed by X-ray diffraction analysis indicating the formation of a Cr-rich phase and a Cr3Ni2 phase in the Ni matrix.
关键词:
Precipitation
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韩宝国
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欧进萍
新型炭材料
采用直流四端电极法测试炭纤维水泥基材料在不同烘干和泡水时间的电阻率,研究了炭纤维水泥基材料内部含水量对其电阻率的影响.结果表明:炭纤维水泥基材料的电阻率随烘干时间的增加而减少,随泡水时间的增加而增加.炭纤维水泥基材料的电阻率对材料内部含水量的变化较敏感:在温度为20℃、相对湿度为25%的情况下,烘干6d,电阻率变化率约为25%;而在温度为20℃的情况下,泡水4.5h,电阻率变化率约为100%.亦即炭纤维水泥基材料具有良好的湿敏性.
关键词:
水泥基材
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炭纤维
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炭黑
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湿敏性
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电阻率
