铜铝合金中γ_2相沉淀的分析电镜研究

Cu-12.7(wt)%Al合金从900℃高温淬至365℃～500℃温度范围等温不同时间(30秒至15分钟)的试样中形成了大量树枝状的γ_2相沉淀粒子。应用配有X线能谱仪(XEDS)和电子能量损失谱仪(EELS)的分析电子显微镜(JEOL JEM-2000FX型)对上还试样研究,结果表明:这些γ_2相粒子具有富铝的“核心”,长大到粒子线度大于约800nm后以不稳定方式生长成“花朵”状。生长过程中伴随着溶质元素Al由基体向γ_2相内的富集。而且在γ_2相粒子内部呈现出Spinodal分解组织的形貌特征,表明γ_2粒子内形成了化学成分调幅。EELS分析表明试样含氧。     

Chiral Cu(II) complex catalyzed enantioselective addition of phenylacetylene to N-aryl arylimines

Chiral tridentate N-tosylated aminoimine ligands were used in the Cu(II)-catalyzed enantioselective addition of phenylacetylene to N-aryl arylimines, affording products up to 92% ee.     

Interactions of thiophenes and acidophilic,thermophilic bacteria

The growth and oxygen consumption of a variety of thermophilic, acidophilic bacteria in the presence of thiophene-2-carboxylate (T2C) and dibenzothiophene (DBT) have been determined. T2C was extremely toxic to the acidophiles in comparison with neutrophiles, but appeared to be degraded by a heterotrophicSulfolobus- like thermophile. DBT proved to be unstable at high temperatures, even in the absence of bacteria, and was not a substrate for the thermophiles.