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排序方式: 共有7194条查询结果,搜索用时 15 毫秒
81.
D. Yadav 《Materials Science & Technology》2015,31(4):494-500
Copper particles were incorporated and retained in elemental state in an aluminium matrix by friction stir processing thereby producing a non-equilibrium particulate composite. The processed Al–Cup composite exhibited improved strength with significantly high ductility. The composite was stable up to a temperature of more than 300°C. Thermal exposure at 350°C for more than 10 min led to diffusion of Cu atoms into the Al matrix forming a core-shell type structure in the Cu particles and thus producing an Al–Cu core-shell composite. The shell consists of multiple layers, the thickness of which was controllable. 相似文献
82.
精炼吊瓜籽油的脂肪酸分析 总被引:1,自引:0,他引:1
对压榨吊瓜籽毛油进行了精炼,计算出得率为54%。采用GC分析、比较了吊瓜籽精油、橄榄油和菜籽油的脂肪酸组分,表明吊瓜籽油中油酸、亚油酸含量为8.48%、33.6%,亚油酸含量高于橄榄油(8.48%)和菜籽油(13.03%).经过GC-MS确证,吊瓜籽含有丰富的角鲨烯(22.7%),是营养保健物质的新型来源. 相似文献
83.
Chunyu Wang Volker Cimalla Genady Cherkashinin Henry Romanus Majdeddin Ali Oliver Ambacher 《Thin solid films》2007,515(5):2921-2925
We have grown indium oxide thin films on silicon substrates at low temperature by metal organic chemical vapor deposition. Polycrystalline film growth could only be obtained at temperatures below 400 °C. Above 400 °C, metallic indium deposition dominated. We have investigated the effect of substrate temperature and reactor pressure on the film growth and structural properties in the range of 250-350 °C and 5 ? 103-4 ? 104 Pa. The film grown at 300 °C exhibited a resistivity of about 3.6 × 10− 3 Ω cm and a maximal optical transmittance of more than 95% in the visible range. The film showed an optical band gap of about 3.6 eV. 相似文献
84.
《Materials Science & Technology》2013,29(12):1793-1797
AbstractThe microstructures and tensile properties of electrodeposited nanocrystalline Ni (nc-Ni) with a broad grain size distribution after annealing at 150, 200 and 300°C for 500 s were investigated. The as deposited broad grain size distribution nc-Ni sample exhibited a moderate strength σUTS of ~1107 MPa but a markedly enhanced ductility ?TEF of ~10%, compared with electrodeposited nc-Ni with a narrow grain size distribution. Annealing below 200°C increased the strength but caused a considerably reduction in tensile elongation. This behaviour is attributed to the grain boundary relaxation and the increased order of grain boundaries after annealing, which can make the grain boundary activities, such as the grain boundary sliding and grain rotations, more difficult. Further annealing at 300°C decreased both the yield strength and tensile elongation significantly due to significant grain growth. 相似文献
85.
Doped SrTiO3 capacitor-varistor multifunctional ceramics were fabricated by a single sintering process.AC complex impedance analysis was performed to investigate electrical features of grains and grain boundaries for both as-reduced ceramic and reoxidized ceramics.The results showed that the as-reduced ceramic exhibited inductive response at high frequencies above 2MHz,which is attributed to the contribution of electron behavior in semiconducting grains.The high frequency inductive response disappeared in impedance plots of reoxidized ceramics. 相似文献
86.
Grain growth during sintering of the polycrystalline high onset temperature superconductor YBa2Cu3O7−x has been examined by measuring grain sizes at various temperatures for different times above 900°C. The grain size distribution
is found to be predominately lognormal after some sintering time. The mean grain size increases with both temperature and
time. The standard deviation of the grain size distribution increases with temperature, but appears to be independent of time.
The grain growth law may have an exponent of five. The grain growth rate may be affected by the grain size of the calcined
powder. 相似文献
87.
88.
针对3种不同粒径的高煤级煤开展了甲烷高压等温吸附测试,并对不同粒径煤样甲烷吸附前后的孔隙结构特征进行了对比研究.结果 表明,不同粒径煤样的等温吸附曲线没有显著的差异,随着煤岩粒径的减小,煤岩的吸附速率和最大过剩吸附量呈逐渐增加的趋势.甲烷吸附前后,不同粒径煤样的孔隙结构发生了不同的变化.甲烷等温吸附前,随着煤岩粒径的减... 相似文献
89.
90.