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On the initial values of kinematic and dynamic free-surface boundary conditions for water wave problems

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Journal of Hydrodynamics 2020年第5期32卷 1024-1027页

作者： Dong-qiang lu Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

The kinematic and dynamic boundary conditions on the free surface of a fluid should be posed for water wave *** the framework of potential theory for an inviscid and incompressible fluid with an irrotational motion,the combined boundary condition,which involves the velocity potential only,is often used by eliminating the elevation terms *** a combination is correct for the solutions in the frequency domain,and is not feasible for an initial-boundary-value problem in the time domain since it leads to a totally different physical *** correct initial conditions for pure gravity waves and hydroelastic waves are presented.

关键词： Initial values boundary conditions water wave hydroelasticity

Analytical solutions for the interfacial viscous capillary-gravity waves due to an oscillating Stokeslet

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Journal of Hydrodynamics 2019年第6期31卷 1139-1147页

作者： Dong-qiang lu Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

The fundamental solutions of the Stokes/Oseen equations due to a point force in an unbounded viscous fluid are referred to as the Stokeslet/Oseenlet,for which a systematic derivation are analytically presented here in terms of a uniform *** means of integral transforms,the closed-form solutions are explicitly deduced in a formula which involves the Hamiltonian,Hessian,and Laplacian operators,and elementary ***,interfacial viscous capillary-gravity waves between two semi-infinite fluids due to oscillating singularities,including a simple source in the upper inviscid fluid and a Stokeslet in the low viscous fluid,were analytically studied by the Laplace-Fourier integral transform and asymptotic *** dynamics responses consist of the transient and steady-state components,which are dealt with by the method of stationary phase and the Cauchy residue theorem,*** transient response is made up of one short capillarity・dominated and one long gravity-dominated wave with the former riding on the *** steady-state wave has the same frequency as that of oscillating *** solutions for the wave profiles and the exact solution for the wave number are analytically derived,which show the combined effects of fluid viscosity,surface capillarity and an upper layer fluid.

关键词： Interfacial wave surface tension viscosity Stokeslet asymptotic solution singularity method

Relationship between the brain and the central pattern generator based on recurrent neural network

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第2期12卷 223-234页

作者： qiang lu College of Medical Information Engineering Shandong First Medical University Shandong Academy of Medical Sciences Taian Shandong Province 271000P.R.China

In animals,the command centers in the brain can drive the ***,it remains unclear how the brain modulates the locomotor central pattern generator(CPG).In this paper,a novel model is established to describe the relation between the brain and the CPG with time *** artificial recurrent neural network(RNN)consists of various computational modules that are used to model the *** brain synchronization under amplitude and frequency variations of the CPG and the effect of the RNN parameters variations on the CPG are *** the paper,the excitatory neuron probability and average connections number are parameter space of RNN and the parameter space of CPG,which include frequency and *** to the simulation results,the best RNN synchronization could be obtained by finding the optimum parameters space between the RNN and the CPG.I propose that the parameter space of some CPGs is related to the parameter space of the *** leads to a brain load decrement that facilities the control *** results are meaningful to investigate how to study the relationship between the brain and the locomotion.

关键词： Recurrent neural network central pattern generator brain parameters space

NECESSARY AND SUFFICIENT CONDITION FOR GLOBAL CONTROLLABILITY OF A CLASS OF AFFINE NONLINEAR SYSTEMS

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Journal of Systems Science & Complexity 2007年第4期20卷 492-500页

作者： Yimin SUN Shengwei MEI qiang lu Department of Electrical Engineering Tsinghua University Beijing 100084 China

In this paper, we investigate the global controllability of a class of n-dimensional affine nonlinear systems with n- 1 controls and constant control matrix. A necessary and sufficient condition for its global controllability has been obtained by using the methods recently developed. Furthermore, we generalize the above result to a class of affine nonlinear systems with a block-triangular-like structure. Finally, we will give three examples to show the applications of our results.

关键词： Affine nonlinear systems block-triangular-like structure global controllability vector field

Hypocalcemia: a reversible cause of T wave alternans and heart failure

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2014年第6期15卷 598-600页

作者： Yi-chen YANG Fa-rong SHEN Yuan-qiang lu Department of Clinical Medicine Graduate School Zhejiang Chinese Medical University Department of Emergency Medicine the First Affiliated HospitalSchool of Medicine Zhejiang University

We have read with great interest the recent article “Cellular mechanism of cardiac alternans： an unresolved chicken or egg problem” by Zang and Xia （2014）, published in Journal of Zhejiang University- SCIENCE B （Biomedicine ＆ Biotechnology）. The authors proposed that both calcium handling and electrical components of cardiac cells could be the cellular mechanism of cardiac alternans, and identifying the main mechanism of cardiac alternans could help to cure targeted patients with heart failure. Here,

关键词：低钙血症心力衰竭心律失常心性甲状旁腺功能减退症

Morphological features of anterior segment:factors influencing intraocular pressure after cataract surgery in nanophthalmos

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Eye and Vision 2020年第2期7卷 454-464页

作者： qiang lu Wenwen He Yi lu Xiangjia Zhu Department of Ophthalmology Eye and EarNoseand Throat HospitalFudan University83 Fenyang RoadShanghai 200031People’s Republic of China Eye Institute Eye and EarNoseand Throat Hospital of Fudan UniversityShanghai 200031People’s Republic of China Key Laboratory of Myopia Ministry of HealthShanghai 200031People’s Republic of China Shanghai Key Laboratory of Visual Impairment and Restoration Shanghai 200031People’s Republic of China

Purpose:To investigate the anterior segment in nanophthalmic eyes and their association with intraocular pressure after cataract ***:Thirty-two nanophthalmic eyes(axial length[AL]<18.5 mm)in 18 patients and 35 normal eyes(21≤AL≤24.5 mm)in 35 controls who had undergone uneventful cataract surgery were ***-source optical coherence tomography was used to compare the anterior segment structures between the two *** associations between the anterior segment characteristics of nanophthalmic eyes and postoperative intraocular pressure(IOP)were also ***:The IOP-lowering effect of cataract surgery was remarkably insufficient in nanophthalmic *** anterior synechiae(PAS)were observed in 56%(18/32)of nanophthalmic eyes,and a characteristic boomerangshaped iris was observed in 28%(9/32).The anterior surface of the iris seemed“smoother”in nanophthalmic eyes than in normal ***’s canal(SC)diameter,SC area,trabecular meshwork(TM)thickness,TM width,and TM area were generally smaller in the nanophthalmic *** age,higher preoperative IOP,broader PAS,and smaller SC area were main contributors to higher postoperative *** and SC diameter may also be of great importance in IOP prediction in patients without glaucoma surgery and ***:The morphological features of the anterior segment in nanophthalmic eyes are significantly different from those of normal *** factors such as age,AL,preoperative IOP,extent of PAS,SC and TM size could all be prognostic for IOP after cataract surgery in nanophthalmic eyes.

关键词： Nanophthalmos Anterior segment Intraocular pressure Catara

A Learning Particle Swarm Optimization Algorithm for Odor Source Localization

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International Journal of Automation and computing 2011年第3期8卷 371-380页

作者： qiang lu Ping luo School of Automation Hangzhou Dianzi University Hangzhou 310018 PRC

This paper is concerned with the problem of odor source localization using multi-robot system. A learning particle swarm optimization algorithm, which can coordinate a multi-robot system to locate the odor source, is proposed. First, in order to develop the proposed algorithm, a source probability map for a robot is built and updated by using concentration magnitude information, wind information, and swarm information. Based on the source probability map, the new position of the robot can be generated. Second, a distributed coordination architecture, by which the proposed algorithm can run on the multi-robot system, is designed. Specifically, the proposed algorithm is used on the group level to generate a new position for the robot. A consensus algorithm is then adopted on the robot level in order to control the robot to move from the current position to the new position. Finally, the effectiveness of the proposed algorithm is illustrated for the odor source localization problem.

关键词： Multi-robot system odor source localization particle swarm optimization source probability map distributed coordination architecture.

Waves propagating over a two-layer porous barrier on a seabed

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Journal of Hydrodynamics 2018年第3期30卷 453-462页

作者： qiang Lin Qing-rui Meng Dong-qiang lu China Ship Scientific Research Center Wuxi 214082China Shanghai Oriental Maritime Engineering Technology Company Limited Shanghai 200011China Shanghai Institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai 200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

A research of wave propagation over a two-layer porous barrier, each layer of which is with different values of porosity and friction, is conducted with a theoretical model in the frame of linear potential flow theory. The model is more appropriate when the seabed consists of two different properties, such as rocks and breakwaters. It is assumed that the fluid is inviscid and incompressible and the motion is irrotational. The wave numbers in the porous region are complex ones, which are related to the decaying and propagating behaviors of wave modes. With the aid of the eigenfunction expansions, a new inner product of the eigenfunctions in the two-layer porous region is proposed to simplify the calculation. The eigenfunctions, under this new definition, possess the orthogonality from which the expansion coefficients can be easily deduced. Selecting the optimum truncation of the series, we derive a closed system of simultaneous linear equations for the same number of the unknown reflection and transmission coefficients. The effects of several physical parameters, including the porosity, friction, width, and depth of the porous barrier, on the dispersion relation, reflection and transmission coefficients are discussed in detail through the graphical representations of the solutions. It is concluded that these parameters have certain impacts on the reflection and transmission energy.

关键词： Two-layer porous barrier inner product matched eigenfunction expansions

Conductive Au nanowires regulated by silk fibroin nanofibers

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Frontiers of Materials Science 2014年第1期8卷 102-105页

作者： Bo-Ju DONG qiang lu National Engineering Laboratory for Modern Silk College of Textile and Clothing Engineering Soochow University Suzhou 215123 China

Conductive Au-biopolymer composites have promising applications in tissue engineering such as nerve tissue regeneration. In this study, silk fibroin nanofibers were formed in aqueous solution by regulating silk self-assembly process and then used as template for Au nanowire fabrication. We performed the synthesis of Au seeds by repeating the seeding cycles for several times in order to increase the density of Au seeds on the nanofibers. After electroless plating, densely decorated Au seeds grew into irregularly shaped particles following silk nanofiber to fill the gaps between particles and finally form uniform continuous nanowires. The conductive property of the Au-silk fibroin nanowires was studied with current-voltage （I-V） measurement. A typical ohmic behavior was observed, which highlighted their potential applications in nerve tissue regeneration.

关键词： silk Au nanowire electrical conductivity biological device