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Science China(Information Sciences) 2021年第6期64卷 172-187页

作者： Zhaolong NING Shouming SUN Xiaojie WANG Lei GUO Guoyin WANG Xinbo GAO ricky y.k.kwok School of Communication and Information Engineering Chongqing University of Posts and Telecommunications School of Software Dalian University of Technology State key Laboratory of Industrial Control Technology Zhejiang University Chongqing key Laboratory of Computational Intelligence Chongqing University of Posts and Telecommunications Chongqing key Laboratory of Image Cognition Chongqing University of Posts and Telecommunications Department of Electrical and Electronic Engineering University of Hong Kong

In order to protect the privacy and data security of mobile devices during the transactions in the industrial Internet of Things(IIoT), we propose a mobile edge computing(MEC)-based mobile blockchain framework by considering the limited bandwidth and computing power of small base stations(SBSs). First,we formulate a joint bandwidth and computing resource allocation problem to maximize the long-term utility of all mobile devices, and take into account the mobility of devices as well as the blockchain throughput. We decompose the formulated problem into two subproblems to decrease the dimension of action space. Then,we propose a deep reinforcement learning additional particle swarm optimization(DRPO) algorithm to solve the two subproblems, in which a particle swarm optimization algorithm is leveraged to avoid the unnecessary search of a deep deterministic policy gradient approach. Simulation results demonstrate the effectiveness of our method from various aspects.

关键词： mobile blockchain deep reinforcement learning mobile edge computing power allocation bandwidth allocation

Spatial Potential Distribution around Trench Target during Plasma Immersion Ion Implantation

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Journal of Materials Science & Technology 2003年第z1期19卷 94-96页

作者： Xiubo Tian Chunbei Wei Shiqin yang Paul k. Chu ricky k.y. Fu State key Lab. of Welding Production Technology School of Mater. Sci. & Eng. Harbin Institute of Technology Harbin 15001 China Department of Physics & Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong State Key Lab. of Welding Production Technology School of Mater. Sci. & Eng. Harbin Institute of Technology Harbin 15001 China Department of Physics & Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong State Key Lab. of Welding Production Technology School of Mater. Sci. & Eng. Harbin Institute of Technology Harbin 15001 China Department of Physics & Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong State Key Lab. of Welding Production Technology School of Mater. Sci. & Eng. Harbin Institute of Technology Harbin 15001 China Department of Physics & Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong State Key Lab. of Welding Production Technology School of Mater. Sci. & Eng. Harbin Institute of Technology Harbin 15001 China Department of Physics & Materials Science City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong

Plasma ion implantation, an alternative to conventional beam-line ion implantation, is a sheath-acceleration ionbombardment technique and the initial sheath is crucial to the process efficacy and surface properties. The initialspatial potential distribution in the plasma sheath around a trench-shaped target is simulated using a two-dimensionalmodel in this work. The results demonstrate that the sheath structure depends very much on the trench width. Thepotential drop in the trench may be quite small and the sheath expands outward if the width is small. This leadsto a smaller incident ion dose into the sidewalls of the trench. In contrast, the initial potential distribution in thecentral region is quite similar to that without a trench if the trench width is larger than twice the ion-matrix sheaththickness for an infinite plane. Consequently, a higher ion dose into the sidewalls is possible.

关键词： Plasma ion implantation, Trench target, Potential distribution

Uniformity of Plasma Density and Film Thickness of Coatings Deposited Inside a Cylindrical Tribe by Radio Frequency Sputtering

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Plasma Science and Technology 2008年第5期10卷 560-564页

作者：崔江涛田修波杨士勤胡涛 ricky k.y.FU Paul k.CHU School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Department of Physics and Material Science City University of Hong KongTat Chee AvenueKowloonHong KongChina

Plasma surface modification of the inner wall of a slender tube is quite difficult to achieve using conventional means. In the work described here, an inner coaxial radio frequency （RF） copper electrode is utilized to produce the plasma and also acts as the sputtered target to deposit copper films in a tube. The influence of RF power, gas pressure, and bias voltage on the distribution of plasma density and the uniformity of film thickness is investigated. The experimental results show that the plasma density is higher at the two ends and lower in the middle of the tube. A higher RF power and pressure as well as larger tube bias lead to a higher plasma density. Changes in the discharge parameter only affect the plasma density uniformity slightly. The variation in the film thickness is consistent with that of the plasma density along the tube axis for different RF power and pressure. Although the plasma density increases with higher tube biases, there is an optimal bias to obtain the highest deposition rate. It can be attributed to the reduction in self-sputtering of the copper electrode and re-sputtering effects of the deposited film at higher tube biases.

关键词： plasma distribution inner surface radio-frequency plasma

Spacing optimization of high power LED arrays for solid state lighting

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Journal of Semiconductors 2011年第1期32卷 45-49页

作者： y.Sing Chan S.W.ricky Lee Electronic Packaging Laboratory Center for Advanced Microsystems Packaging Hong Kong University of Science and Technology

This paper provides an analytical approach to determine the optimum pitch by utilizing a thermal resistance network, under the assumption of constant luminous efficiency. This work allows an LED array design which is mounted on a printed circuit board （PCB） attached with a heat sink subject to the natural convection cooling. Being validated by finite element （FE） models, the current approach can be shown as an effective method for the determination of optimal component spacing in an LED array assembly for SSL.

关键词： high power LED thermal resistance network finite element modeling

Novel method of separating macroporous arrays from p-type silicon substrate

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Journal of Semiconductors 2012年第4期33卷 28-31页

作者：彭波波王斐刘涛杨振亚王连卫 ricky k.y.Fu 朱剑豪 key Laboratory of Polar Materials and Devices Ministry of EducationDepartment of Electronic EngineeringEast China Normal UniversityShanghai 200241China Department of Physics and Material Sciences City University of Hong KongTat Chee AvenueKowloonHong KongChina

This paper presents a novel method to fabricate separated macroporous silicon using a single step of photo-assisted electrochemical etching. The method is applied to fabricate silicon microchannel plates in 1 O0 mm p-type silicon wafers, which can be used as electron multipliers and three-dimensional Li-ion microbatteries. Increasing the backside illumination intensity and decreasing the bias simultaneously can generate additional holes during the electrochemical etching which will create lateral etching at the pore tips. In this way the silicon microchannel can be separated from the substrate when the desired depth is reached, then it can be cut into the desired shape by using a laser cutting machine. Also, the mechanism of lateral etching is proposed.

关键词： electrochemical etching MCP macroporous silicon p-type silicon separation

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等离子体浸没离子注入绝缘材料的研究

核技术 2006年第5期29卷 335-338页

作者：田修波杨士勤 ricky k y Fu Paul k Chu 哈尔滨工业大学材料科学与工程学院哈尔滨150001 香港城市大学物理及材料科学系

等离子体浸没离子注入是一种新形式的离子注入技术,是利用负偏压工件周围形成的等离子体鞘层进行离子加速、进而获得离子注入。等离子体注入的前提条件是工件导电,因此对于绝缘材料的等离子体注入可能存在问题。本文从理论和实际处理的... 详细信息

等离子体浸没离子注入是一种新形式的离子注入技术,是利用负偏压工件周围形成的等离子体鞘层进行离子加速、进而获得离子注入。等离子体注入的前提条件是工件导电,因此对于绝缘材料的等离子体注入可能存在问题。本文从理论和实际处理的角度论证了绝缘材料等离子体注入的可能性、可操作性,并给出了一些实际例证。

关键词：等离子体离子注入绝缘材料鞘层表面充电

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高压耦合高功率脉冲磁控溅射的增强放电效应

物理学报 2014年第18期63卷 359-369页

作者：吴忠振田修波潘锋 ricky k.y.Fu 朱剑豪北京大学深圳研究生院新材料学院深圳518055 哈尔滨工业大学先进焊接与连接国家重点实验室哈尔滨150001 香港城市大学物理与材料科学系中国香港九龙

等离子体源离子注入与沉积技术作为一种可生产高结合力、高致密度涂层的真空镀膜技术,具有广阔的应用前景,尤其适用于高载荷工况下服役的功能涂层制备.该技术中金属等离子体源是关键,而现有的脉冲阴极弧源结构复杂,且由于伴随"金属液滴... 详细信息

等离子体源离子注入与沉积技术作为一种可生产高结合力、高致密度涂层的真空镀膜技术,具有广阔的应用前景,尤其适用于高载荷工况下服役的功能涂层制备.该技术中金属等离子体源是关键,而现有的脉冲阴极弧源结构复杂,且由于伴随"金属液滴"而需要增加过滤装置.本文研究了另一种简单结构的金属等离子体源备选一高功率脉冲磁控溅射源(HPPMS)的放电特性,采用等离子体发射光谱仪探索了不同的耦合高压对HPPMS放电靶电流特性和等离子体特性的作用.发现耦合高压对HPPMS放电有明显的促进作用,相同靶电压下的放电强度大幅增加,相对于金属放电,耦合高压对气体放电的促进作用更加明显,但在自溅射为主的高压放电阶段对金属放电的促进作用明显增强.讨论了耦合高压对HPPMS放电的增强机制,发现耦合高压自辉光放电、耦合高压和HPPMS电压构成双向负压形成的空心阴极效应,以及耦合高压鞘层改善的双极扩散效应都对HPPMS放电的增强有明显作用.

关键词：高功率脉冲磁控溅射耦合高压放电靶电流等离子体发射光谱

Optimization of the in vitro biodegradability,cytocompatibility,and wear resistance of the AZ31B alloy by micro-arc oxidation coatings doped with zinc phosphate

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Journal of Materials Science & Technology 2024年第12期179卷 224-239页

作者： Chao yang Suihan Cui ricky kyFu Liyuan Sheng Min Wen Daokui Xu ying Zhao yufeng Zheng Paul kChu Zhongzhen Wu School of Advanced Materials Peking University Shenzhen Graduate SchoolShenzhen 518055China Department of Physics Department of Materials Science&Engineeringand Department of Biomedical EngineeringCity University of Hong KongTat Chee AvenueKowloonHong Kong 999077China Shenzhen Institute Peking UniversityShenzhen 518057China PkU-HkUST Shenzhen–Hong kong Institution Shenzhen 518057China key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China National Engineering Research Center of Light Alloy Net Forming and State key Laboratory of Metal Matrix Composite Shanghai Jiao Tong UniversityShanghai 200240China

As implanted bone fixation materials,magnesium(Mg)alloys have significant advantages because the density and elastic modulus are closest to those of the human bone and they can bio-degrade in the physiological ***,Mg alloys degrade too rapidly and uncontrollably thus hampering clinical *** this study,a highly corrosion-resistant zinc-phosphate-doped micro-arc oxidation(MAO)coating is prepared on the AZ31B alloy,and the degradation process is assessed in *** increasing zinc phosphate concentrations,both the corrosion potentials and charge transfer resistance of the AZ31B alloy coated with MAO coatings increase gradually,while the corrosion current densities di-minish *** tests in the simulated body fluid(SBF)reveal that the increased zinc phos-phate concentration in MAO coating decreases the degradation rate,consequently reducing the release rates of Mg^(2+)and OH-in the physiological micro-environment,which obtains the lowest weight loss of only 5.22%after immersion for 56 *** regulation of degradation provides a weak alkaline environment that is suitable for long-term cell growth and subsequent promotion of bone proliferation,differentiation,mineralization,and *** addition,the zinc-phosphate-doped MAO coat-ings show an improved wear resistance as manifested by a wear rate of only 3.81 x 10^(-5) mm^(3) N^(-1) m^(-1).The results reveal a suitable strategy to improve the properties of biodegradable Mg alloys to balance tissue healing with mechanical degradation.

关键词： Mg alloys MAO coatings Degradation regulation Cytocompatibility Wear resistance

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高功率脉冲磁控溅射的阶段性放电特征

物理学报 2014年第17期63卷 196-204页

作者：吴忠振田修波李春伟 ricky k.y.Fu 潘锋朱剑豪北京大学深圳研究生院新材料学院深圳518055 哈尔滨工业大学先进焊接与连接国家重点实验室哈尔滨150001 香港城市大学物理与材料科学系

本文从放电靶电流出发,采用一种新的研究方法,即将靶电流分解为多个代表具体放电特性的特征参数,全面而系统的研究了不同的工作气压条件下,靶电流各特征参数随靶电压的增加而进行的演化.结果发现高功率脉冲磁控溅射技术(HPPMS)放电靶电... 详细信息

本文从放电靶电流出发,采用一种新的研究方法,即将靶电流分解为多个代表具体放电特性的特征参数,全面而系统的研究了不同的工作气压条件下,靶电流各特征参数随靶电压的增加而进行的演化.结果发现高功率脉冲磁控溅射技术(HPPMS)放电靶电流在靶电压由低向高增加的过程中,出现靶电流峰值和平台值的交替变化,体现出明显的阶段性放电特征,且不同的放电阶段在不同气压下出现一定的移动,会在测量范围内出现某些放电阶段的缺失.本文还通过等离子体发射光谱对HPPMS放电靶前等离子体测量发现五个不同的放电阶段分别主要对应氩原子、铬原子、氩离子、铬离子和氩、铬高价离子的放电,但不同的放电条件下相邻的阶段会出现一定程度的交叠.

关键词：高功率脉冲磁控溅射放电靶电流工作气压阶段性放电

System Integration in Radiation Oncology Through Networking

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临床医学工程 1998年第3期 107-110页

作者： k.y.Cheung ricky Chau Peter Choi Departmen of Clinical Oncology Hong kong Prince of Wales Hospital

This paper presents the basic system design and our initial experience on the operation and performance of a fully integrated radiotherapy treatment planning, treatment delivery and patient management network system at the Prince of Wales Hostpital, Hong kong, The aim of the project is to establish a suitable tool for easy and reliable implementation of routine conformal radiotherapy and to improve the effciency and quality of radiotherapy service through system integration

关键词： In System Integration in Radiation Oncology Through Networking 加心比切