段学志
,
周静红
,
钱刚
,
李平
,
周兴贵
,
陈德
催化学报
doi:10.1016/S1872-2067(10)60097-6
研究了鱼骨式碳纤维(CNFs)和管式碳纤维(CNTs)负载Ru催化剂的氨分解反应活性.结果表明,Ru/CNFs催化剂上氨分解活性高于Ru/CNTs催化剂.通过改变Ru负载量或载体表面的含氧基团来调节Ru的粒径.Ru的活性位随着Ru颗粒尺寸的增大而增加.CNFs上的含氧基团对Ru颗粒的氨分解活性影响很大.在相同粒径的Ru颗粒上,CNFs表面的含氧基团增加了Ru的活性.
关键词:
碳纤维
,
钉
,
负载型催化剂
,
氨分解
,
氢气
,
结构敏感性
张康侯
,
徐云
,
李曲波
贵金属
doi:10.3969/j.issn.1004-0676.2001.04.001
采用X-射线衍射、扫描电镜和显微金相分析等方法研究了Ag-Pd-Ru-Gd四元系相图的富Ag-Pd-Ru区域(Gd＜25at%).测定了Ag-Pd-Gd-20Ru和Ag-Pd-Gd-50Ru四元系相图的700℃部分等温截面.这两个等温截面上都分别含有3个二相区:Pd(Ag)+(Ru),(Ru)+Ag51Gd14,(Ru)+Pd3Gd;3个三相区:Pd(Ag)+Pd3Gd+(Ru),Pd(Ag)+Ag51Gd14+(Ru),Pd3Gd+Ag51Gd14+(Ru);1个四相区:Pd(Ag)+Pd3Gd+Ag51Gd14+(Ru).这2个截面上都不含有单相固溶区,也未发现新的四元中间相.
关键词:
银
,
钯
,
钌
,
钆
,
Ag-Pd-Ru-Gd四元系
,
相图
Applied Physics a-Materials Science & Processing
We investigate the effects of Ru-doping in polycrystalline TbMn1-x Ru (x) O-3 (xa parts per thousand currency sign0.10) on the multiferroicity. It is observed that the Ru substitution gradually melts away the dielectric anomaly at the ferroelectric transition point and the ferroelectricity by suppressing the polarization, accompanied with a surprising low-temperature dielectric plateau. While it is reasonable to observe the significant suppression of ferroelectricity, owing to the fact that the Ru-doping disrupts the Mn spiral spin ordering and reduces the Mn-Mn spin angle, quantum fluctuations associated with the Ru substitution, responsible for the low-temperature dielectric plateau, seems to be significant.
关键词:
polarization
Physica Status Solidi B-Basic Research
The embedded cluster model is used to study the electronic structure of Si chemisorption on Ru(001) surface, within the framework of local-density theory regime. The Kohn-Sham equation is solved self-consistently using the discrete variational method. The most possible adsorbed site of Si is obtained by calculating the adhesive energy for two positions. The distributions of Si 3s, Si 3p, and Ru 4d orbitals are clearly identified by our calculations, The interaction between Si adatom and Ru(001) surface and its influence on the d-d interatomic interaction of Ru atoms are also discussed.
关键词:
electronic-structure;silicon;photoemission;silicides;ruthenium;metal;cu
王秀云
,
王榕
,
倪军
,
林建新
,
魏可镁
催化学报
doi:10.3724/SP.J.1088.2010.00539
分别以K2RuO4,Ru(Ac)3和RuC13为Ru前驱体,制备了Ru/MgO-CeO2催化剂,并运用X射线衍射、X射线荧光光谱,CO吸附、N2物理吸附和H2程序升温还原等技术对催化剂进行了表征,考察了Ru前驱体对Ru/MgO-CeO2催化剂氨合成性能的影响.结果表明,Ru前驱体对载体MgO-CeO2和Ru的还原件能、氯残留量和催化剂比表面积的影响都很大,从而导致催化剂的氨合成性能的不同.其中以K2RuO4为Ru前驱体制备的催化剂的载体和Ru容易还原,无氯离子,且比表面积较高,因而催化剂活性和氨合成转换频率较高.在10MPa,425℃,10 000h-1条件下,K2RuO4,Ru(Ac)3和RuC13作前驱体制备的催化剂上氨合成转换频率比为1.33:1.05:1.
关键词:
前驱体
,
氨合成
,
氧化镁
,
二氧化铈
,
钌
耿魁伟
,
姚若河
稀有金属材料与工程
采用高分辨透射电镜结合振动样品磁强计研究了Fe/Ru多层膜,对不同层厚的Fe/Ru多层膜的界面结构及其对磁性能的影响进行了分析.Fe层很薄时薄膜不连续,岛状分布的Fe颗粒使多层膜显示超顺磁特性.Fe/Ru界面的高分辨电镜观察发现,界面存在粗糙度的不对称性,它是多层膜中产生正磁阻的重要原因.Fe/Ru多层膜的负磁阻在退火后得到较大的提高,表明Fe/Ru多层膜的负磁阻主要来源于界面的粗糙度.
关键词:
Fe/Ru多层膜
,
界面
,
磁性
,
磁阻
