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Communications and control co-design:a combined dynamic-static scheduling approach

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Science China(Information Sciences) 2012年第11期55卷 2495-2507页

作者： LU ZiBao & GUO Ge School of Information Sciences and Technology,dalian maritime university,dalian 116026,China School of Information Sciences and Technology Dalian Maritime University Dalian China

This paper investigates the problem of joint design of an output feedback controller and the medium access scheduling policy for networked control systems(NCSs).The capacity of communication networks on sensors side and actuators side are limited so that at any time the sensors and actuators cannot be accommodated simultaneously and that transmission delays are *** joint design problem is solved in three steps:determining communication sequences(called feasible sequences) for both sides that can preserve controllability and observability,respectively;designing output feedback controller without considering the effect of communication sequences;and setting up a rule that governs the switching between feasible communication ***,the first step is a static scheduling procedure that yields a set of feasible communication sequences for each *** third step is a dynamic scheduling process resulting in a switching policy in line of a stability criterion of the closed-loop switching delay *** show the effectiveness of the combined static and dynamic scheduling method,a numerical example is also provided.

关键词： controllability observability switching rule medium access scheduling communication sequence

Measurement and simulation of the two-phase velocity correlation in sudden-expansion gas-particle flows

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Acta Mechanica Sinica 2011年第4期27卷 494-501页

作者： Li-Xing Zhou.Yang Liu.Yi Xu Department of Engineering Mechanics,Tsinghua university,100084 Beijing,China Marine Engineering College,dalian maritime university,116026 dalian,China Department of Engineering Mechanics Tsinghua University Beijing China Marine Engineering College Dalian Maritime University Dalian China

In this paper the present authors measured the gas-particle two-phase velocity correlation in sudden expansion gas-particle flows with a phase Doppler particle anemometer （PDPA） and simulated the system behavior by using both a Reynolds-averaged Navier-Stokes （RANS） model and a large-eddy simulation （LES）. The results of the measurements yield the axial and radial time-averaged velocities as well as the fluctuation velocities of gas and three particle-size groups （30μm, 50μm, and 95μm） and the gasparticle velocity correlation for 30μm and 50μm particles. From the measurements, theoretical analysis, and simulation, it is found that the two-phase velocity correlation of sudden-expansion flows, like that of jet flows, is less than the gas and particle Reynolds stresses. What distinguishes the two-phase velocity correlations of sudden-expansion flow from those of jet and channel flows is the absence of a clear relationship between the two-phase velocity correlation and particle size in sudden-expansion flows. The measurements, theoretical analysis, and numerical simulation all lead to the above-stated conclusions. Quantitatively, the results of the LES are better than those of the RANS model.

关键词： PDPA measurement - Simulation Two-phasevelocity correlation Sudden expansion gas-particle flows

A New Approximate Iteration Solution ofBlasius Equation

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 91-94页

An approximate analytical solution of Blasius equation is obtained by theparameter iteration method. The comparison with Howarth’s numerical solution showsthat the accuracy of the proposed method is higher than other approximate analyticalsolutions. Further, we provide also a numerical iteration scheme which is simple, efficientand practical.

关键词： nonlinear problem parameter iteration method Blasius equation

Structure and photochromic properties of molybdenumphosphoric acid/TiO_2 composite films

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Science China Chemistry 2009年第2期52卷 169-173页

作者： QI He,LIU Yan,FENG Wei & ZHU YiMin College of Environmental Science and Engineering,dalian maritime university,dalian 116026,China College of Environmental Science and Engineering Dalian Maritime University Dalian China

TiO_2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel *** structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy(FT-IR),atomic force microscopy(AFM),and X-ray diffraction(XRD) patterns,*** photochromic behavior and mechanism of composite thin films were inves-tigated with ultraviolet-visible spectra(UV-vis) and electron spin resonance(ESR).FT-IR results showed that the Keggin geometry of PMoA was still preserved inside PMoA/TiO2 composite thin films,and a charge transfer bridge was built at the interface of PMoA and TiO2 through the Mo-O-Ti *** topography of the composite film showed obvious changes before/after adding PMoA,and the surface topography of composite films showed obvious changes before/after irradiating as *** thin film had reversible photochromic *** with UV light,transparent films changed from colorless to blue and they can bleach completely with ambient air in the *** re-sults showed that TiO_2 were excitated by UV light to produce electrons,which deoxidized PMoA to produce *** photochromic process of PMoA/TiO_2 system was carried through elec-tron transfer mechanism.

关键词： molybdenumphosphoric acid TiO_2 composite film photochromism

The Mechanism Analysis of IGBT Module Invalidation

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The Mechanism Analysis of IGBT Module Invalidation

Combinatorial　Method　of　Simulation　and　Optimization　and　Its　Application　on　Transportation　System

CES/IEEE 5th International Power Electronics and Motion Control Conference

作者： Xu Aide Fan Yinhai Wang Xinxin and Liu Yuanyuan dalian maritime university dalian China dalian maritime university Dalian China

ISBN: (纸本)1424404487;9781424404483

＜正＞The main purpose of this paper is to make a brief introduction of the applicable scope and the testing condition of IGBT module, to analyze the various reason causing IGBT module to be invalid which mainly involves drive part trouble, excessive heat, mechanical hurts, over voltage, over current and inductance that exists in the leads of circuit, and to make a general summary of the cautions which should be paid much attention to preventing IGBT module from being invalidated.

关键词： Insulated Gate Bipolar Transistor module invalidation gate drive voltage excessive heat mechanical hurts over voltage over current inductance exists in the leads of circuit

来源： cnki会议评论

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Systems Science and Systems Engineering 1995年第3期5卷 204-210页

作者： SUN Zhanshan(Institute of Systems Engineerjng,dalian maritime university,dalian 116024)

Combinatorial method of simulation and optimization can combine the merits of both methods, provide effectively simulation support for transportation decision *** tills paper, the simulation and optimization models for a transportation system of coal wharf are introduced, and their combination mechanism for constructing a simulation support system is presented.

关键词： cobinatorial method of simulation and optimization transportation system simulation support system combination mechanism

A New Navigation Strategy in Hypermedia Integral Ware Authoring System

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计算机工程 2002年第S1期28卷 141-144页

作者： FU Xianping1 , JIANG Jianping2(1. College of Computer Science and Technology, dalian maritime university, dalian 116026,China 2. College of Information Engineering, dalian maritime university, dalian 116026,China ) College of Computer Science and Technology Dalian Maritime University Dalian 116026China College of Information Engineering Dalian Maritime University Dalian 116026China

After analyzing the general navigation mechanisms and discussing the knowledge point card linking model which is the base of the navigation mechanism used in the Hypermedia Integral ware Authoring System(HIAS), the pa... 详细信息

关键词： Hypermedia Integral ware Navigation strategy

Surface stability and conductivity of a high Cr and Ni austenitic stainless steel plates for PEMFC

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Rare Metals 2006年第Z1期25卷 229-234页

作者： TIAN Rujin SUN Juncai WANG Jianli Institute of Materials and Technology Dalian Maritime University Dalian 116026 China Institute of Materials and Technology Dalian Maritime University Dalian 116026 China Institute of Materials and Technology Dalian Maritime University Dalian 116026 China

In order to use stainless steel as bipolar plate for PEMFC, electrochemical behavior of a high Cr and Ni austenitic stainless steel was studied in the solutions containing different concentration of H2SO4 and 2 mg·L-1 F-, and interfacial contact resistance was measured after corrosion tests. The experimental results show that the passive current density lowers with decreasing the concentration of H2SO4. The interfacial contact resistance between carbon paper and passive film formed in the simulated PEMFC environment is higher than the goal of bipolar plate for PEMFC. Surface conductivity should be further reduced by surface modification.

关键词： austenitic stainless steel bipolar plate passive film interfacial contact resistance

DC dielectrophoresis separation of marine algae and particles in a microfluidic chip

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Science China Chemistry 2012年第4期55卷 524-530页

作者： SONG YongXin1, YANG JianDong1, SHI XiaoFei4, JIANG Hai3, WU YanBin1, PENG Ran1, WANG Qi5, GONG Ning2, PAN XinXiang1, SUN YeQing2 & LI DongQing1,31Department of Marine Engineering, dalian maritime university, dalian 116026, China 2Institute of Environmental Systems Biology, dalian maritime university, dalian 116026, China 3Department of Mechanical and Mechatronics Engineering, university of Waterloo, Waterloo, ON, N2L 3G1, Canada 4College of Information Science and Technology, dalian maritime university, dalian 116026, China 5Department of Respiratory Medicine, the Second Hospital Affiliated to dalian Medical university, dalian 116026, China Department of Marine Engineering Dalian Maritime University Dalian China College of Information Science and Technology Dalian Maritime University Dalian China Department of Mechanical and Mechatronics Engineering University of Waterloo Waterloo Canada Department of Respiratory Medicine the Second Hospital Affiliated to Dalian Medical University Dalian China Institute of Environmental Systems Biology Dalian Maritime University Dalian China

This paper reports a microfluidic method of continuous separation of marine algae and particles by DC dielectrophoresis. The locally non-uniform electric field is generated by an insulating PDMS triangle hurdle fabricated within a PDMS microchannel. Both the particles and algae are subject to negative DEP forces at the hurdle where the gradient of local electric-field strength is the strongest. The DEP force acting on the particle or the algae depends on particles' or algae's volume, shape and dielectric properties. Thus the moving particles and algae will be repelled to different streamlines when passing the hurdle. In this way, combined with the electroosmotic flow, continuous separation of algae of two different sizes, and continuous separation of polystyrene particles and algae with similar volume but different shape were achieved. This first demonstration of DC DEP separation of polystyrene particles and algae with similar sizes illustrates the great influence of dielectric properties on particle separation and potentials for sample pretreatment.

关键词： DC dielectrophoresis – marine algae – particle – microfluidic chip – permittivity difference