材料期刊网

Pb促进的Pd/γ-Al2O3催化剂上H2O2氧化甘油反应

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

Fe2+对嗜铁钩端螺旋菌L. ferriphilum生长活性的影响

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

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

关键词:

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

关键词:

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

关键词:

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

关键词:

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

关键词:

Distribution, Transportation and Cytolocalization of Neodymium in Oilseed Rape (Brassica napus L.)

魏幼璋

稀土学报(英文版)

关键词:

FeMoB Enhanced Sintering of P/M 316L Stainless Steel

YANG Xia , GUO Shiju

钢铁研究学报(英文版)

Liquidphase enhanced sintering of powder metallurgy (P/M) 316L stainless steel by addition of sintering aids was studied. 2%-8% of prealloyed FeMoB powder with two different particle sizes was added as sintering aids, and the specimens were sintered in vacuum at 1 200-1 350 ℃. The results show that the fine FeMoB powder (5-10 μm) has stronger activated effect. The sintered density increases with the increase in sintering aid content or sintering temperature. Warm compaction has a better effect on the control of dimensional precision of compacts. The prealloyed FeMoB powder deviated from Mo2FeB2 component can also be sintering aid of P/M 316L stainless steel.

关键词: P/M 316L stainless steel;liquidphase sintering;activated sintering;FeMoB;sintering aid

试棒的w_0/l_0值对Zn-5%Al合金超塑性m-δ关系的影响

刘勤 , 裔式珙

材料研究学报

在250℃以■=0.025min~(-1)测到的Zn-5%Al 合金的超塑性m-δ曲线均属式。w_0/l_0值加大使m_0,m_L 和δ_F 值增大,但对δ_L 和m_F 值无大影响。试样厚度的加大(由1增大到2mm)仅使δ_L 和δ_F 值增大,考虑w_0/l_0比值的影响,C_3~((m_0-m_L))-(m_L=m_(mas))型C.L.m-δ方程式规划为:或其中,m′_0(W_0/l_0)=m_0,m′_0>m_0;m′_L(w_0/l_0)=m_L,m′_L>m。w_0/l_0=0.15—0.39。当w_O/l_0=1时,缺口效应消失,δ(或δ_F)值为最大。

关键词: Zn-5%Al合金 , mechanics of superplasticity , C.L.m-δequation