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Mechanism of forming an ink-bottle-like pore structure based on SBA-15 by a novel MOCVD technique

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Chinese Science Bulletin 2010年第4期55卷 446-451页

作者： ZHANG Ying frank Leung-YUK lam YAN ZiFeng HU XiJun School of Chemistry & Chemical Engineering China University of Petroleum Dongying 257061 China Department of Chemical Engineering Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong China

Metallorganic chemical vapor deposition is used as a novel simple pore tailoring method to fine-tune the pore opening size of SBA-15 materials without significant loss in pore volume and surface area. By using acetylene as carbon source and copper (II) acetylacetonate as precursor, the poremouth of SBA-15 is effectively reduced from 5.78 nm to 3.67 nm while maintaining the pore body at 5.78 nm. The effect of four pore modification factors-the ratio of acetylene/nitrogen, the feeding time of carbon precursor, the ratio of SBA-C/Cu(acac)2 and the cycles of MOCVD on the final pore structure of the SBA-15/carbon/copper composite is studied. The morphology and microstructure of the resulting product SBA-C-Cu are characterized by XRD patterns, TEM images and EDS analysis. The XRD and TEM reveal that the SBA-C-Cu composite is highly hexagonally ordered and has similar particle morphology as the original SBA-15.

关键词：金属有机化学气相沉积化学气相沉积技术 SBA 分子筛孔结构铜复合材料化学气相沉积法透射电子显微镜

Fabrication of copper nanorods by low-temperature metal organic chemical vapor deposition

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Chinese Science Bulletin 2006年第21期51卷 2662-2668页

作者： ZHANG Ying frank Leung-Yuk lam HU Xijun YAN Zifeng State Key Laboratory for Heavy Oil Processing Key Laboratory of Catalysis CNPC University of Petroleum Dongying 257061 China Department of chemical Engineering The Hong Kong University of Science and Technology JiuLong Hong Kong China

Copper nanorods have been synthe-sized in mesoporous SBA-15 by a low-temperature metal organic chemical vapor deposition (MOCVD) employing copper (II) acetylacetonate, Cu(acac)2, and hydrogen as a precursor and reactant gas, re- spectively. The hydrogen plays an important role in chemical reduction of oganometallic precursor which enhances mass transfer in the interior of the SBA-15 porous substrate. Such copper nanostructures are of great potentials in the semiconductor due to their unusual optical, magnetic and electronic properties. In addition, it has been found that chemically modi- fying the substrate surface by carbon deposition is crucial to such synthesis of copper nanostructures in the interior of the SBA-15, which is able to change the surface properties of SBA-15 from hydrophilic to hydrophobic to promote the adsorption of organic cupric precursor. It has also been found that the copper nanoparticles deposited on the external sur- face are almost eliminated and the copper nanorods are more distinct while the product was treated with ammonia. This approach could be achieved under a mild condition: a low temperature (400℃) and vac-uum (2 kPa) which is extremely milder than the con- ventional method. It actually sounds as a foundation which is the first time to synthesize a copper nanorod at a mild condition of a low reaction temperature and pressure.

关键词：化学蒸气沉积法铜有机金属分解低温 MOCVD

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Mechanism of forming an ink-bottle-like pore structure based on SBA-15 by a novel MOCVD technique

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Science Bulletin 2010年第Z1期 446-451页

作者： frank Leung-YUK lam Department of Chemical Engineering Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong China

关键词： ink-bottle-like pore MOCVD SBA-15

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渗透测试技术在计算机网络安全中的应用

安防科技 2003年第3期 58-59页

作者： frank lam ,朴辉

一位著名的犯罪学家曾经这样讲过:如果要了解罪犯的想法,最好是用罪犯的思维去思考问题。这个原则用在计算机安全上面的话,就衍生出所谓的渗透测试技术。现在一些公司经常雇佣一些计算机专家对自己公司的网络进行善意的攻击,及时发现问... 详细信息

一位著名的犯罪学家曾经这样讲过:如果要了解罪犯的想法,最好是用罪犯的思维去思考问题。这个原则用在计算机安全上面的话,就衍生出所谓的渗透测试技术。现在一些公司经常雇佣一些计算机专家对自己公司的网络进行善意的攻击,及时发现问题并采取措

关键词：渗透测试计算机小组密码用户名邮件服务器目标网络域名远程系统

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北美“轻型木结构”住宅建筑的特点

结构工程师 2004年第1期20卷 1-5,10页

作者：何敏娟 frank lam 同济大学上海200092 不列颠哥伦比亚大学

“轻型木结构”是北美住宅建筑的主要结构形式。本文介绍了这种结构形式在经济性能、施工安装等方面的优点 ,阐述了其屋面、墙体及楼面等结构体系的特点和构造方法 ,介绍了结构传力体系、主要采用的设计方法、防腐防火处理等 ,以期对中... 详细信息

“轻型木结构”是北美住宅建筑的主要结构形式。本文介绍了这种结构形式在经济性能、施工安装等方面的优点 ,阐述了其屋面、墙体及楼面等结构体系的特点和构造方法 ,介绍了结构传力体系、主要采用的设计方法、防腐防火处理等 ,以期对中国“轻型木结构”

关键词：北美住宅建筑轻型木结构楼面防火防腐

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木材在北美建筑结构中的应用

特种结构 2003年第4期20卷 48-51页

作者：何敏娟 frank lam 同济大学建工系加拿大温哥华 V6T 1Z4 不列颠哥伦比亚大学上海 200092

本文描述了木材作为结构用材的一些重要特性,如各向异性的强度性能、吸湿性对承载能力的影响等;详细介绍了北美建筑中常用的各种锯材、工程木制品的类别、特点、应用等。对结构师了解材料、选用材料、提高结构可靠性能、降低成本、减少... 详细信息

本文描述了木材作为结构用材的一些重要特性,如各向异性的强度性能、吸湿性对承载能力的影响等;详细介绍了北美建筑中常用的各种锯材、工程木制品的类别、特点、应用等。对结构师了解材料、选用材料、提高结构可靠性能、降低成本、减少资源耗用等都具有重要的参考价值。

关键词：结构木材性能锯木工程木制品北美

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英属哥伦比亚大学的重型木构建筑创作解析

世界建筑 2020年第11期 38-43,130,131页

作者：李静徐洪澎林中法张超哈尔滨工业大学寒地城乡人居环境科学与技术工业和信息化部重点实验室英属哥伦比亚大学

英属哥伦比亚大学致力于为现代木构建筑的发展搭建一个开创性的实验平台。论文解析了其木构建筑的创作理念:开拓应用重木的现代木构建筑创作;建构校园建筑文化的木构空间设计;实证重型木构建筑的可持续性特征。并总结了其在木建造方面... 详细信息

英属哥伦比亚大学致力于为现代木构建筑的发展搭建一个开创性的实验平台。论文解析了其木构建筑的创作理念:开拓应用重木的现代木构建筑创作;建构校园建筑文化的木构空间设计;实证重型木构建筑的可持续性特征。并总结了其在木建造方面的引领思想。

关键词：英属哥伦比亚大学(UBC) 现代木构建筑重木木构技术创新木构空间设计可持续性

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Catalytically active interfaces in titania nanorod-supported copper catalysts for CO oxidation

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Nano Research 2020年第2期13卷 533-542页

作者： Wasim U.Khan Season S.Chen Daniel C.W.Tsang Wey Yang Teoh Xijun Hu frank L.Y.lam Alex C.K.Yip Department of Chemical and Process Engineering The University of Canterbury Christchurch 8041New Zealand Department of Civil and Environmental Engineering.The Hong Kong Polytechnic University Hong Kong.China School of Chemical Engineering The University of New South WalesSydneyNSW 2052Australia Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyHong KongChina

One-dimensional titanium dioxide nanorod(TNR)-supported Cu catalysts(2.5 wt.%-12.5 wt.%)were synthesized using deposition-precipitation.X-ray photoelectron spectroscopy,temperature programmed reduction and CO chemisorption measurements showed that Cu doping over TNR offered metal-support interactions and interfacial active sites that had a profound impact on the catalytic *** role of the Cu-TNR interface was investigated by comparing the catalytic activity of Cu-TNR catalysts with that of pure CuO nanoparticles in CO *** presence of highly dispersed copper species,a high number of interfacial active sites,CO adsorption capacity and surface/lattice oxygen were found to be responsible for the excellent activity of 7.5CU-TNR(ie,Cu loading of 7.5 wt.%on TNR).Moreover,the Cu-TNR catalysts followed the Langmuir-Hinshelwood reaction mechanism with 7.5CU-TNR,exhibiting an apparent activation energy of 44.7 kJ/*** TNR-supported Cu catalyst gave the highest interfacial catalytic activity in medium-temperature CO oxidation(120-240℃)compared to other commonly used supports,including titanium dioxide nanoparticles(TiO2-P25),silica(SiO2)and alumina(Al20g)in which copper species were nonhomogeneously *** study confirms that medium-temperature CO oxidation is highly sensitive to the morphology and structure of the supporting material.

关键词： supported catalysts nanorod oxygen species interfacial active sites CO oxidation

Sampled-data control through model-free reinforcement learning with effective experience replay

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Journal of Automation and Intelligence 2023年第1期2卷 20-30页

作者： Bo Xiao H.K.lam Xiaojie Su Ziwei Wang frank P.-W.Lo Shihong Chen Eric Yeatman Department of Electrical and Electronic Engineering Imperial College LondonLondon SW72AZUK Department of Engineering King’s College LondonLondon WC2B 4BGUK Department of Automation Chongqing UniversityShapingba DistrictChong QingChina School of Engineering Lancaster UniversityLA14YWUK Hamlyn Centre Imperial College LondonLondon SW72AZUK

Reinforcement Learning(RL)based control algorithms can learn the control strategies for nonlinear and uncertain environment during interacting with *** by the rewards generated by environment,a RL agent can learn the control strategy directly in a model-free way instead of investigating the dynamic model of the *** the paper,we propose the sampled-data RL control strategy to reduce the computational *** the sampled-data control strategy,the whole control system is of a hybrid structure,in which the plant is of continuous structure while the controller(RL agent)adopts a discrete *** that the continuous states of the plant will be the input of the agent,the state–action value function is approximated by the fully connected feed-forward neural networks(FCFFNN).Instead of learning the controller at every step during the interaction with the environment,the learning and acting stages are decoupled to learn the control strategy more effectively through experience *** the acting stage,the most effective experience obtained during the interaction with the environment will be stored and during the learning stage,the stored experience will be replayed to customized times,which helps enhance the experience replay *** effectiveness of proposed approach will be verified by simulation examples.

关键词： Reinforcement learning Neural networks Sampled-data control Model-free Effective experience replay