Nairong TAO
,
Weiping TONG
,
Zhenbo WANG
,
Wei WANG
,
Manling SUI
,
Jian LV
,
Ke LU
材料科学技术（英文）
A porosity-free and contamination-free surface layer with grain sizes ranging from nanometer to micrometer in Fe samples was obtained by surface mechanical attrition treatment (SMAT) technique. Mechanical and wear properties of the surface layer in the SMATed and annealed Fe samples were measured by means of nanoindentation and nanoscratch tests, respectively. Experimental results showed that the hardness of the surface layer in the SMATed Fe sample increased evidently due to the grain refinement. The elastic moduli of the surface layers in the SMATed and annealed Fe samples were unchanged, independent of grain size in the present grain size regime. Compared with the original Fe sample, the wear resistance enhanced and the coefficient of friction decreased in the surface layer of the SMATed Fe sample.
关键词:
Nanocrystallites
,
null
,
null
,
null
,
null
Jinghua HE
,
Wei WANG
,
Aimin WANG
,
Jianguo GUAN
金属学报(英文版)
The electromagnetic parameters were measured for the mixtures of mechanical milled carbonyl iron powders (CIPs) with different mass ratios of spheroid-like particles to flake-shape particles. The results indicate that mixing the sphere-like CIP particles with flake-shaped CIPs can be used to adjust effectively the electromagnetic parameters and enhance the absorption property in high frequency. In addition, a theoretic simulation based on the principle of superposition was carried out and compared with the microwave measurement results, indicating that the simple principle of superposition can not reflect truly the internal interaction mechanism in the composites with different particle shapes.
关键词:
Carbonyl iron
,
null
,
null
,
null
Kui LIANG
,
Ai CHEN
,
Li HE
,
Wei WANG
材料科学技术（英文）
The preparation of Ni oxide films and their capacitive mechanism are discussed in this paper. Nickel oxide film electrodes perform pseudocapacitance in aqueous KOH and NaOH but perform double layer capacitance in LiClO4/PC (propylence carbonate). The effect of increasing the specific capacitance was observed when Ni oxide film electrodes are doped with Co. A specific capacitance of around 70 F/g was achieved when using Ni oxide films doped with Co as electrodes and 1 mol/L aqueous KOH or NaOH as an electrolyte.
关键词:
Supercapacitor
,
null
,
null
,
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