X. He
材料科学技术（英）
Composited nanoparticles, consisting of Mn3O4, S-doped Mn3O4 and S, were synthesized by co-precipitation reaction and Mn3O4 nanoparticles were then obtained after removing the pure S from the composited nanoparticles. The Mn3O4-type phase with larger lattice constant a was formed by doping sulfur. At fixed temperatures below Curie temperature (TC), the magnetization of the S-doped Mn3O4/S composited nanoparticles was smaller than that of the Mn3O4 nanoparticles. The blocking temperature was 36.3 and 34.8 K for S-doped Mn3O4/S composite and Mn3O4 nanoparticles, respectively. The anisotropy field of S-doped Mn3O4/S composite was determined to be about 55.3 kOe.
关键词:
Nanostructured materials
Xiao Si
材料科学技术（英）
This study reports the significantly enhanced aluminizing behaviors of a low carbon steel at temperatures far below the austenitizing temperature, with a nanostructured surface layer produced by surface mechanical attrition treatment (SMAT). A much thicker iron aluminide compound layer with a much enhanced growth kinetics of η-Fe2Al5 in the SMAT sample has been observed relative to the coarse-grained steel sample. Compared to the coarse-grained sample, a weakened texture is formed in the aluminide layer in the SMAT sample. The aluminizing kinetics is analyzed in terms of promoted diffusivity and nucleation frequency in the nanostructured surface layer.
关键词:
Nanostructured materials
Wenge CHEN
材料科学技术（英）
Nanostructured (NS) W-Cu composite powder was prepared by mechanical alloying (MA), and nanostructured bulk of W-Cu contact material was fabricated by hot pressed sintering in an electrical vacuum furnace. The microstructure, electric conductivity, hardness, breakdown voltage and arcing time of NS W-Cu alloys were measured and compared to conventional W-Cu alloys prepared by powder metallurgy. The results show that microstructural refinement and uniformity can improve the breakdown behavior, the electric arc stability and the arc extinction ability of nanostructured W-Cu contacts materials. Also, the nanostructured W-Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.
关键词:
Nanostructured materials
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G.X.Wang
,
Steve Bewlay
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L.Yang
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J.Z.Wang
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Y.Chen
,
Jane Yao
,
H.K.Liu
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S.X.Dou
材料科学技术（英）
Nanocrystalline LiFePO4 and Si-C powders were prepared as electrode materials for lithium-ion batteries. Near full capacity (170 mAh/g) was achieved at the C/8 rate at room temperature for LiFePO4 electrodes. Nanosize Si-C composite anode materials demonstrated a reversible lithium storage capacity of 1450 mAh/g with good cyclability when used as anodes in lithium-ion cells. Nanostructured electrode materials have an important role to play in developing a new generation of lithium-ion batteries that will offer a dramatic improvement in power delivery.
关键词:
Lithium-ion battery
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