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Stochastic Stability of FitzHugh-Nagumo Systems in Infinite Lattice Perturbed by Gaussian White Noise

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Acta Mathematica Sinica,English Series 2011年第11期27卷 2143-2152页

作者： Yan zheng Jian hua huaNG Department of Mathematics National University of Defense Technology Changsha 410073 P. R. China

The current paper is devoted to the study of stochastic stability of FitzHugh-Nagumo systems in infinite lattice perturbed by Gaussian white noise. We first study the dynamics of stochastic FitzHugh-Nagumo systems, then prove the existence and uniqueness of their equilibriums, which mix exponentially. Finally, we investigate asymptotic behavior of equilibriums when the size of noise gets to zero.

关键词： Stochastic stability Gaussian white noise equilibrium FitzHugh-Nagumo systems

Hybrid plasmon waveguide leveraging Bloch surface polaritons for sub-wavelength confinement

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Science China Technological Sciences 2013年第3期56卷 567-572页

作者： wan YuHang zheng zheng SHI XiaoGang BIAN YuSheng LIU JianSheng School of Electronic and Information Engineering Beihang University School of Instrument and Science and Optic-electronic Engineering Beihang University

A novel hybrid plasmonic waveguide based on a guided Bloch surface polariton structure is proposed and *** hybrid waveguide overcomes the weak confinement in the Bloch surface polariton structure caused by the diffraction *** introducing a metal stripe near the dielectric ridge located on the periodic multilayer structure that is designed to support a TM polarized Bloch surface polariton,a sub-wavelength scale electric field confinement is *** coupling of the Bloch surface polariton and the surface plasmon polariton results in a strong field distribution within the gap between the metal stripe and the dielectric *** variation of the characteristic of the hybrid mode is revealed via tuning the height of the ridge and the coupling ***-wavelength scale mode size is realized as well as a propagation length of about 100μm.

关键词： Bloch surface wave plasmonic waveguide

Corrosion resistance of benzotriazole passivated Cu-Zn-Alshape memory alloy in artificial Ringer's solution

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Rare Metals 2005年第3期24卷 252-256页

作者： LIANG Chenghao CHEN Bangyi CHEN wan wanG hua State Key laboratory of Fine Chemicals School of Chemical Engineering Dalian University of Technology Dalian 116012 China

The corrosion resistance of the Cu-Zn-Al shape memory alloy passivated by benzotriazole was investigated by salt spraying test and electrochemical methods in artificial Ringer＇s solution. The results showed that after benzotriazole passivation, the corrosion resistance of the Cu-Zn-Al shape memory alloy was improved evidently. The anodic polarization current density of the passivated alloy decreased, the mass loss reduced, the anodic passivation accelerated, the anodic active dissolution was inhibited effectively, and the surface tarnishing was reswained. Infrared reflection spectrum test showed that Cu（Ⅰ）-benzotriazole or Cu（Ⅱ）-benzotriazole complex layer was formed on the surface of the Cu-Zn-Al shape memory alloy after passivation. This layer appeared plane, well adhesion, and presented homogeneous golden metallic luster. The corrosion resistance of the Cu-Zn-Al shape memory alloy passivated by benzotriazole is improved for the formation of an electrochemical stable baffle layer on passivated surface. This layer separates the metal substrate from the outside corrosion medium effectively and retards the corrosion process of dezincification.

关键词： surface modification corrosion resistance electrochemical method Cu-Zn-Al shape memory alloy benzotriazole passivation

Electrochemical Properties of Poly (ethyl acrylate-co-lithium methacrylate) Latex Film Solid Electrolyte

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Chinese Chemical Letters 1999年第1期10卷 67-68页

作者： Yong Hong WU zheng hua DENG Guo Xiang wan(Chengdu Institute of Organic Chemistry, Academia Sinica, Chengdu 610041) Acad Sinica Chengdu Inst Organ Chem Chengdu 610041 Peoples R China

Poly (ethyl acrylate-co-lithium methacrylate) (PEM) latex film was synthesized by emulsion-free polymerization. The electrochemical window of plasticized PEM latex film is exceeding 5.0 V. LiCoO2/Li battery with PEM latex film as electrolyte exhibits excellent reversibility and when the discharge current density is 0.3 mA/cm(2), the specific discharge capacity achieves 4.4 mAh/cm(2).

关键词： interface layer polymer electrolyte lithium battery

Minimum wall pressure coefficient of orifice plate energy dissipater

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Water Science and Engineering 2015年第1期8卷 85-88页

作者： wan-zheng Ai Jia-hong wang School of Shipping and Ports Architecture Engineering Zhejiang Ocean University

Orifice plate energy dissipaters have been successfully used in large-scale hydropower projects due to their simple structure, convenient construction procedure, and high energy dissipation ratio. The minimum wall pressure coefficient of an orifice plate can indirectly reflect its cavitation characteristics： the lower the minimum wall pressure coefficient is, the better the ability of the orifice plate to resist cavitation damage is. Thus, it is important to study the minimum wall pressure coefficient of the orifice plate. In this study, this coefficient and related parameters, such as the contraction ratio, defined as the ratio of the orifice plate diameter to the flood-discharging tunnel diameter; the relative thickness, defined as the ratio of the orifice plate thickness to the tunnel diameter; and the Reynolds number of the flow through the orifice plate, were theoretically analyzed, and their relationships were obtained through physical model experiments. It can be concluded that the minimum wall pressure coefficient is mainly dominated by the contraction ratio and relative thickness. The lower the contraction ratio and relative thickness are, the larger the minimum wall pressure coefficient is. The effects of the Reynolds number on the minimum wall pressure coefficient can be neglected when it is larger than 10^5. An emoirical expression was presented to calculate the minimum wall oressure coefficient in this study.

关键词： Orifice plate Minimum wall pressure coefficient Cavitation Contraction ratio Relative thickness Energy dissipater

Structure Evolution and Electrochemical Performance of Al_2O_3-coated LiNi_(0.4)Co_(0.2)Mn_(0.4)O_2 During Charge-discharge Cycling

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Chemical Research in Chinese Universities 2012年第4期28卷 686-690页

作者： LIU Hao-han ZHANG Jian LOU Yu-wan YANG Chuan-zheng XIE Xiao-hua XIA Bao-jia Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 200050P.R.China

Several lithium-ion batteries of 18650-type were assembled with pristine or Al2O3-coated LiNi0.4Co0.2Mn0.4O2（NCM） as cathode material and mesocarbon microbeads（MCMB） as anode *** cycling performance of the batteries was examined under 25 °C at a 2C rate within a potential range of 2.75―4.20 *** changes of the crystal structure,the lattice parameter,the mean crystallite size,and the mean micro-strain of pristine NCM and Al2O3-coated NCM during the charge-discharge cycling were determined by X-ray diffraction（XRD）.The results indicate that the bulk structure of Al2O3-coated NCM is more stable than that of pristine NCM,which leads to the better cycling performance of Al2O3-coated NCM compared to that of pristine NCM.

关键词： LiNi0.4Co0.2Mn0.4O2 Al2O3-coated Cycling performance Bulk structure

Scale effects on bow wave breaking of KCS ship model:Insights from DDES investigations

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Journal of Hydrodynamics 2023年第4期35卷 668-678页

作者： Jian-hua wang Wen-tao wang De-cheng wan Computational Marine Hydrodynamics Laboratory(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China China Ship Scientific Research Center Wuxi214082China

Ship bow wave breaking is a common phenomenon during navigation,involving complex multi-scale flow ***,the understanding of this intense free surface flow issue is not sufficiently deep,especially regarding the lack of research on the impact of scale effects on bow wave *** paper focuses on the benchmark ship model KCS and conducts numerical simulations and comparative analyses of bow wave breaking for three model scales under the condition of Fr=*** numerical calculations were performed using the in-house computational fluid dynamics(CFD)solver naoe-FOAM-SJTU,which is developed on the open source platform *** detached eddy simulation(DDES)method is utilized to calculate the viscous flow field around the ship *** present method was validated through measurement data of wave profiles and wake flows obtained from model *** field results for three different scales,including bow wave profiles,vorticity at various sections,and wake distribution,were presented and *** results indicate that there is small difference in the bow wave overturning and breaking for the first two occurrences across different ***,considerable effects of scale are observed on the temporal and spatial variations of the free surface breaking pattern after the second *** findings of this study can serve as valuable data references for the analysis of scale effects in ship bow wave breaking phenomena.

关键词： Scale effects wave pattern bow wave breaking KRSIO Container Ship(KCS) delayed detached eddy simulation(DDES)approach

HCloud:A Trusted JointCloud Serverless Platform for IoT Systems with Blockchain

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China Communications 2020年第9期17卷 1-10页

作者： zheng huang Zeyu Mi Zhichao hua Institute of Parallel and Distributed Systems Shanghai Jiao Tong UniversityShanghai 200240China

Cloud computing has been exploited in managing large-scale IoT *** cloud servers usually handle a large number of requests from various IoT *** to the fluctuant and heavy workload,the servers require the cloud to provide high scalability,stable performance,low price and necessary ***,traditional clouds usually offer computing service with the abstraction of virtual machine(VM),which can hardly meet these ***,different cloud vendors provide different performance stabilities and price models,which fluctuate according to the dynamic workload.A single cloud cannot satisfy all the requirements of the IoT scenario *** JointCloud computing model empowers the cooperation among multiple public ***,it is still difficult to dynamically schedule the workload on different clouds based on the VM *** paper introduces HCloud,a trusted JointCloud platform for IoT systems using serverless computing *** allows an IoT server to be implemented with multiple serverless functions and schedules these functions on different clouds based on a schedule *** policy is specified by the client and includes the required functionalities,execution resources,latency,price and so *** collects the status of each cloud and dispatches serverless functions to the most suitable cloud based on the schedule *** leveraging the blockchain technology,we further enforce that our system can neither fake the cloud status nor wrongly dispatch the target *** have implemented a prototype of HCloud and evaluated it by simulating multiple cloud *** evaluation results show that HCloud can greatly improve the performance of serverless workloads with negligible costs.

关键词： IoT blockchain serverless jointcloud

Effects of initial grain size and strain on grain boundary engineering of high-nitrogen CrMn austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 922-929页

作者： Zhen-hua wang Jian-jun Qi wan-tang Fu School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China HBIS Group Technology Research Institute Shijiazhuang 050023China

18 Mn18 Cr0.5 N steel with an initial grain size of 28–177 μm was processed by 2.5%–20% cold rolling and annealing at 1000°C for 24 h,and the grain boundary character distribution was examined via electron backscatter *** strain(2.5%) favored the formation of low-Σ *** this strain,the fraction of low-Σ boundaries was insensitive to the initial grain ***,specimens with fine initial grains showed decreasing grain size after grain boundary engineering *** fraction of low-Σ boundaries and the(Σ9 + Σ27)/Σ3 value decreased with increasing strain; furthermore,the specimens with fine initial grain size were sensitive to the ***,the effects of the initial grain size and strain on the grain boundary engineering were discussed in detail.

关键词： grain boundary engineering grain boundary character distribution grain size strain austenitic stainless steel