María L. Faroppa
,
Juan J. Musci
,
María E. Chiosso
,
Claudia G. Caggiano
,
Hernán P. Bideberripe
,
José L. García Fierro
,
Guillermo J. Siri
,
Mónica L. Casella
催化学报
doi:10.1016/S1872-2067(16)62531-7
制备了Pd含量为1 wt%、不同Pb/Pd摩尔比的γ-Al2O3负载Pd-Pb双金属催化剂,并用于常压、45°C和pH =11条件下H2O2氧化甘油反应中.催化剂的形貌和分散度采用扫描电镜-X射线电子散射谱和透射电镜进行了表征；双金属催化剂中合金相用X射线光电子能谱进行了验证.单金属Pd催化剂上反应结束后甘油转化率为19%,但随着Pb的加入甘油转化率增大到约100%.所制四个不同Pb/Pd原子比的双金属催化剂PdPb0.25, PdPb0.50, PdPb1.00和PdPb1.60均可氧化甘油至二羟基丙酮(DIHA),反应结束后DIHA选择性分别可达59%,58%,34%和25%.
关键词:
钯
,
双金属钯-铅催化剂
,
过氧化氢
,
甘油氧化
,
甘油酸
,
羟基乙酸
高健
,
康健
,
吴学玲
,
徐競
,
李邦梅
,
邱冠周
中国有色金属学报
以分离于江西某铜矿的嗜铁钩端螺旋菌(L. ferriphilum YSK)菌株为研究对象,报道不同Fe2+浓度对 L. ferriphilum生长活性的影响.结果表明,YSK菌株生长最适宜的Fe2+浓度约为0.1 mol/L.当初始Fe2+浓度为0.4 mol/L时,进入对数生长期前很明显需要一个较长的延迟期,表明该Fe2+浓度对细胞的生长产生较强的抑制作用;当初始Fe2+浓度为0.6 mol/L时,YSK菌株的生长完全受到抑制.尽管高浓度的Fe2+抑制细胞的生长,但受到抑制而不生长繁殖的YSK细胞仍然具有氧化Fe2+的能力.
关键词:
L.ferriphilum YSK菌株
,
Fe2+
,
生长活性
J.H Lee
,
J. Chen
,
S.J. Choe
,
Y.T. Lee and H.M. Kim(High Temperature Materials Laboratory
,
Korea Institute of Machinery & Materials
,
66 Sangnam Dong
,
Changwon
,
Kyungnam
,
641010
,
Korea Manuscript received 26 August 1996)
金属学报(英文版)
The carbide growth behavior of MAR-M247 LC alloy was investigated by directional solidification and quench method. The carbide volume fraction, trapping and growth behavior were correlated with the growth rate.It was found that the carbide volume fraction decreased at slower growth rate.This decreasing was caused by lower solidliquid interface trapping ability at slower growth rate.
关键词:
:carbide
,
null
,
null
,
null
ZENON OPIEKUN
金属学报(英文版)
The manuscript presents changes of macrostructure and microstructure of plate and shaft castings made of cobalt alloy MAR-M509. They have different values of geometric module M within the range of 0.91-5.56 mm that have been created with multilayer ceramic shell moulds (MSC) of different initial temperatures of 200-1000℃ at the moment of pouring. It has been stated that decrease of initial temperature of MSC and value M causes increase in casting fine-granularity, distance reduction between dendrite branches λ2 and refinement of initial carbides in irregular ternary eutectic γ+$M23C6+MC.
关键词:
Multilayer ceramic shell mould (MSC)
