材料期刊网

金掺杂对碳负载钯催化还原性能的促进作用

Yu-Lun Fang , Kimberly N. Heck , Zhun Zhao , Lori A. Pretzer , Neng Guo , Tianpin Wu , Jeffrey T. Miller , Michael S. Wong

催化学报 doi:10.1016/S1872-2067(16)62530-5

在许多催化应用中双金属的PdAu催化剂性能优于单金属催化剂.科研人员对具有可控纳米结构和高活性的PdAu催化剂进行了广泛的研究,但该催化剂的制备需要多步且通常步骤复杂.本文仅通过浸渍和焙烧制得了Au掺杂的负载型Pd催化剂,所得PdAu/C催化剂用于室温水相三氯乙烯加氢脱氯反应.当Pd和Au负载量分别为1.0 wt%和1.1 wt%时,在经过干燥、空气处理和H2还原的过程后，所制得的PdAu/C催化剂活性最高,初始转化频率(TOF)为34.0×10–2 molTCEmolPd–1 s–1,是单金属1.0 wt%Pd/C催化剂TOF (2.2×10–2 molTCEmolPd–1 s–1)的15倍以上. X射线吸收光谱结果表明,金的加入避免了400oC焙烧时Pd的氧化.本文还提出了可能的催化剂纳米结构演变路径,以解释所观察到的催化现象.

关键词: 双金属催化剂 , 钯 , 金 , 纳米结构 , X射线吸收光谱 , 扩展X射线吸收精细结构 , 加氢脱氯 , 三氯乙烯

Professor XU Zhong-yu and his research activities

新型炭材料

关键词:

Preface to Special Issue on Photocatalysis for celebrating the 20th anniversary of Professor Jimmy C. Yu’s return to Hong Kong and leading photocatalytic research there

催化学报 doi:10.1016/S1872-2067(15)61006-3

关键词:

Improved Nonlinear Equation Method for Numerical Prediction of Jominy EndQuench Curves

SONG Yuepeng , LIU Guoquan , LIU Shengxin , LIU Jiantao , FENG Chengming

钢铁研究学报(英文版)

Without considering the effects of alloying interaction on the Jominy endquench curves, the prediction results obtained by YU Baihai′s nonlinear equation method for multialloying steels were different from those experimental ones reported in literature. Some alloying elements have marked influence on Jominy endquench curves of steels. An improved mathematical model for simulating the Jominy endquench curves is proposed by introducing a parameter named alloying interactions equivalent (Le). With the improved model, the Jominy endquench curves of steels so obtained agree very well with the experimental ones.

关键词: Jominy endquench curve;nonlinear equation method;alloying interaction parameter;computer simulation

1998 COMPREHENSIVE TABLE OF CONTENTS

中国腐蚀与防护学报

N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....

关键词:

New criteria of glass forming ability, thermal stability and characteristic temperatures for various bulk metallic glass systems

Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing

Six mathematical criteria used for quantitatively measuring their glass forming ability, thermal stability and characteristic temperatures (temperature of glass transition T-g, crystallization onset T-x and liquidus T-l) of various bulk metallic glasses (BMGs) have been proposed in this article. It is found that the criteria are suitable for evaluating these quantities for BMGs. The estimated results are better than those calculated by Fang et al.'s models and Lu et al.'s gamma criterion, but our analyses indicate that these criteria, defined by the data (Pauling electronegativity xi, atomic radius ri, electron concentration ni and melting temperature T-mi) easily found in literatures, still need to be further refined in future research for shortcomings of the parameters. (C) 2007 Elsevier B.V. All rights reserved.

关键词: bulk metallic glasses;glass forming ability;thermal stability;supercooled liquid regions;mechanical-properties;amorphous-alloys;transition temperature;bond parameters;strength;binary;widths;ag

三维晶粒长大速率方程的大尺度Potts模型Monte Carlo仿真验证

王浩 , 刘国权 , 秦湘阁

金属学报

采用Potts模型Monte Carlo方法对3种现存的三维个体晶粒长大速率拓扑依赖性 方程进行了仿真验证. 结果表明, Rivier速率方程认为晶粒 体积变化率dVf/dt与晶粒面数f成线性关系, 与仿真 结果明显不符, 不适用于描述三维晶粒长大过程的动力 学. 当晶粒面数f≥8时, Yu-Liu速率方程和 MacPherson-Srolovitz速率方程均与仿真结果很好吻合, 表明这两者均可以用来定量描述三维晶粒长大过程的动力学；当 f＜8时, 这两个方程均与仿真结果有显著差异.

关键词: 三维晶粒长大 , topology-dependent grain growth rate equation

三维晶粒长大速率方程的大尺度Potts模型Monte Carlo仿真验证

王浩 , 刘国权 , 秦湘阁

金属学报 doi:10.3321/j.issn:0412-1961.2008.01.003

采用Potts模型Monte Carlo方法对3种现存的三维个体晶粒长大速率拓扑依赖性方程进行了仿真验证.结果表明,Rivier速率方程认为晶粒体积变化率dVf/dt与晶粒面数,成线性关系,与仿真结果明显不符,不适用于描述三维晶粒长大过程的动力学.当晶粒面数f≥8时,Yu-Liu速率方程和MacPherson-Srolovitz速率方程均与仿真结果很好吻合,表明这两者均可以用来定量描述三维晶粒长大过程的动力学;当f<8时,这两个方程均与仿真结果有显著差异.

关键词: 三维晶粒长大,拓扑依赖性长大速率方程,Potts模型,Monte Carlo仿真

环保型无卤素膜片开关银浆有机成份的选型研究

李文琳 , 李章炜 , 幸七四 , 张扬

贵金属

膜片开关用银浆制备使用的有机体系中，树脂、溶剂和添加剂对产品的性能和有害元素控制有重要的意义。经对比实悚，以热塑性聚酯为主体树脂，以MEA混合溶剂为溶剂，以YU-201、硅烷偶联剂以及自制增强塑性材料M-17材料为混合添加剂，制成有机载体。使用该载体制备出的浆料符合膜片开关银浆性能要求，且满足欧盟RoHS指标卤素控制要求。

关键词: 复合材料 , 环保型 , 无卤素 , 膜片开关 , 银浆

曳力和湍流对超临界水流化床传热特性的影响

吕友军 , 董旭斌 , 张天宁

工程热物理学报

本文采用基于颗粒动力学的欧拉双流体模型,对比研究了曳力和湍流对超临界水流化床传热特性的影响,选取了Gidaspow、Syamlal-O'Brien和Wen-Yu三种曳力模型以及标准κ-ε、RNG κ-ε、Realizable κ-ε湍流模型三种高Re数湍流模型及低Re数κ-ε湍流模型.研究结果表明,在三种曳力模型中,Gidaspow曳力模型在超临界水流化床中更为适用;对于所采用的四种κ-ε湍流模型,利用三种高雷诺数湍流模型模拟所得床层与壁面间传热系数基本一致且大于采用低雷诺数模型模拟所得传热系数,而综合考虑,RNGκ-s湍流模型更适于超临水流化床传热特性的研究.

关键词: 超临界水流化床 , 曳力 , 湍流 , 传热