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NONLINEAR DYNAMICS AND SYNCHRONIZATION OF TWO COUPLED PIPES CONVEYING PULSATING FLUID 被引量:6
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作者 Qiao Ni Zilong Zhang +2 位作者 Lin Wang Qin Qian Min Tang 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2014年第2期162-171,共10页
In this paper, the nonlinear dynamical behavior of two coupled pipes conveying pulsating fluid is studied. The connection between the two pipes is considered as a distributed linear spring. Based on this consideration... In this paper, the nonlinear dynamical behavior of two coupled pipes conveying pulsating fluid is studied. The connection between the two pipes is considered as a distributed linear spring. Based on this consideration, the equations of motion of the coupled two-pipe system are obtained. The two coupled nonlinear partial differential equations, discretized using the fourth- order Galerkin method, are solved by a fourth-order Runge-Kutta integration algorithm. Results show that the connection stiffness has a significant effect on the dynamical behavior of the coupled system. It is found that for some parameter values the motion types of the two pipes might be synchronous. 展开更多
关键词 pipe conveying pulsating fluid nonlinear dynamics coupled two-pipe system SYNCHRONIZATION
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An Analysis of the Invariance and Conservation Laws of Some Classes of Nonlinear Ostrovsky Equations and Related Systems
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作者 K. Fakhar A. H. Kara 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第1期1-4,共4页
A large class of partial differential equations in the modelling of ocean waves are due to Ostrovsky. We determine the invariance properties (through the Lie point symmetry generators) and construct classes of conse... A large class of partial differential equations in the modelling of ocean waves are due to Ostrovsky. We determine the invariance properties (through the Lie point symmetry generators) and construct classes of conservation laws for some of the models. In the latter case, the method involves finding the 'multipliers' associated with the conservation laws with a stronger emphasis on the 'higher-order' ones. The relationship between the symmetries and conservation laws is investigated by considering the invariance properties of the multipliers. 展开更多
关键词 Mathematical physics statistical physics and nonlinear systems
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One Specific State Variable for a Class of Fractional-Order Chaotic Systems and Its Applications
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作者 周平 程元明 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第12期52-55,共4页
We present a specific state variable for a class of fractional-order chaotic systems. By using a specific state variable and its (q-order, 2q-order, ..., and (n-1) q-order) time derivatives, all the state variable... We present a specific state variable for a class of fractional-order chaotic systems. By using a specific state variable and its (q-order, 2q-order, ..., and (n-1) q-order) time derivatives, all the state variables can be obtained. Several fractional-order chaotic systems are used to demonstrate this idea. A hybrid projective synchronization scheme is presented to show its applications. 展开更多
关键词 statistical physics and nonlinear systems
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Structure Identification of Nonlinearly Coupled Complex Networks with Non-Delayed and Delayed Coupling
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作者 郭万里 Francis Austin 陈士华 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期68-71,共4页
Topology identification is an important problem for complex networks because much information about networks in practice such as the topological structure is uncertain. We propose an adaptive control method for identi... Topology identification is an important problem for complex networks because much information about networks in practice such as the topological structure is uncertain. We propose an adaptive control method for identifying the topology of general nonlinearly-coupled complex network models that are either non-delayed or delayed coupled. Simulation results are also presented to illustrate the effectiveness of the method. 展开更多
关键词 Mathematical physics statistical physics and nonlinear systems
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Review of the Book “Non-Traditional Dynamics:Theory and Practice”
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作者 Gennadiy G. Goshin 《Engineering(科研)》 2012年第4期177-178,共2页
The offered book is devoted to theoretical and applied problems of nonlinear dynamics of radio physical systems. The main goal of this book is theoretical and experimental investigations of key principles and laws of ... The offered book is devoted to theoretical and applied problems of nonlinear dynamics of radio physical systems. The main goal of this book is theoretical and experimental investigations of key principles and laws of ra- dio physical system’s functioning with continuous and discrete time, in which both regular and chaotic oscillation types may occur. 展开更多
关键词 nonlinear dynamics RADIO PHYSICAL systems
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THE IMPROVED FOURIER SPLITTING METHOD AND DECAY ESTIMATES OF THE GLOBAL SOLUTIONS OF THE CAUCHY PROBLEMS FOR NONLINEAR SYSTEMS OF FLUID DYNAMICS EQUATIONS
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作者 Linghai Zhang 《Annals of Applied Mathematics》 2016年第4期396-417,共22页
Consider the Cauchy problems for an n-dimensional nonlinear system of fluid dynamics equations. The main purpose of this paper is to improve the Fourier splitting method to accomplish the decay estimates with sharp ra... Consider the Cauchy problems for an n-dimensional nonlinear system of fluid dynamics equations. The main purpose of this paper is to improve the Fourier splitting method to accomplish the decay estimates with sharp rates of the global weak solutions of the Cauchy problems. We will couple togeth- er the elementary uniform energy estimates of the global weak solutions and a well known Gronwall's inequality to improve the Fourier splitting method. This method was initiated by Maria Schonbek in the 1980's to study the op- timal long time asymptotic behaviours of the global weak solutions of the nonlinear system of fluid dynamics equations. As applications, the decay esti- mates with sharp rates of the global weak solutions of the Cauchy problems for n-dimensional incompressible Navier-Stokes equations, for the n-dimensional magnetohydrodynamics equations and for many other very interesting nonlin- ear evolution equations with dissipations can be established. 展开更多
关键词 nonlinear systems of fluid dynamics equations global weaksolutions decay estimates uniform energy estimates Fourier transformation Plancherel's identity Gronwall's inequality improved Fourier splitting method
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高速列车风荷载下接触网-隧道锚固端混凝土损伤分析
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作者 舒卓乐 王汉封 +2 位作者 何旭辉 李璋 邓朋儒 《工程力学》 北大核心 2025年第10期164-174,共11页
接触网作为隧道典型附属结构,日常承受高速列车过隧带来的列车风荷载反复冲击作用。为了准确评估其运营安全性,该研究对隧道接触网在列车风荷载作用下腕臂结构的动力放大效应和锚固端混凝土结构受力损伤进行了仿真分析。基于计算流体力... 接触网作为隧道典型附属结构,日常承受高速列车过隧带来的列车风荷载反复冲击作用。为了准确评估其运营安全性,该研究对隧道接触网在列车风荷载作用下腕臂结构的动力放大效应和锚固端混凝土结构受力损伤进行了仿真分析。基于计算流体力学(CFD)分析列车高速过隧时的列车风三维时空分布,开展隧道纵向风速与接触网所受列车风荷载相关性分析以确定最不利接触网位置并获得其风荷载时程。建立接触网腕臂结构有限元仿真分析模型,考虑不同定位管支撑水平连接角度、斜腕臂连接距离的接触网尺寸参数,开展最不利列车风荷载下腕臂结构的静、动力分析以计算结构动力放大系数。考虑列车风动力放大效应,利用非线性有限元(NFEA)方法对锚固端混凝土外荷载下的损伤情况进行了研究,结果表明:隧道纵向风速与接触网所受风荷载有强二次方关系,隧道出口附近接触网存在最不利风荷载;不同分析模型中列车风动力放大系数最小为1.358,最大为1.556。在螺栓预紧力、接触网自重及正常负载、列车风荷载作用下,各螺栓孔附近锚固混凝土在一定深度内存在微裂缝萌生;其中,迎风侧、腕臂伸出方向螺栓孔附近的混凝土存在拉伸损伤因子峰值0.769,压缩损伤因子峰值0.365。此外,列车风对锚固结构内力贡献不超过13.63%。研究结果为隧道接触网结构的设计、衬砌混凝土损伤分析及其维护加固提供参考。 展开更多
关键词 列车风 隧道 接触网 计算流体力学 非线性有限元
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基于物理约束并行网络的非线性系统辨识方法研究
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作者 赵尚宇 程长明 彭志科 《动力学与控制学报》 2025年第5期1-8,共8页
为解决非线性系统在带噪部分状态测量条件下的辨识问题,本文设计了一种新型物理约束并行网络.其核心思想是通过系统的隐式控制方程引导神经网络训练,以有效压缩网络求解空间,同时获得具备物理可解释性的动力学模型.首先,受稀疏回归方法... 为解决非线性系统在带噪部分状态测量条件下的辨识问题,本文设计了一种新型物理约束并行网络.其核心思想是通过系统的隐式控制方程引导神经网络训练,以有效压缩网络求解空间,同时获得具备物理可解释性的动力学模型.首先,受稀疏回归方法启发,设计了具备函数库的稀疏回归网络层,用于捕捉系统的非线性特性;其次,构建了状态约束并行网络架构,通过状态变量之间的导数关系对三个并行子网络的输出进行约束,实现在带噪部分状态测量的基础上重构系统的全状态输出;最后,将稀疏回归网络层与状态约束并行网络相结合,形成物理约束并行网络,实现全状态输出预测与显式动力学方程辨识的双重功能.为提升网络的优化效率,开发了一种轮换优化算法,交替优化稀疏回归网络层和状态约束并行网络.“物理约束”在此特指状态约束损失函数以及基于隐式控制方程构建的残差损失函数.通过上述融合策略,该方法能够在带噪部分状态测量条件下生成具有物理可解释性的非线性动力学模型.其有效性、鲁棒性和适用性通过数值模拟和实验研究得到验证. 展开更多
关键词 非线性动力系统 系统辨识 物理约束神经网络 稀疏回归 轮换优化
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Interest-Driven Model for Human Dynamics 被引量:12
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作者 尚明生 陈冠雄 +2 位作者 戴双星 汪秉宏 周涛 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期250-252,共3页
Empirical observations indicate that the interevent time distribution of human actions exhibits heavy-tailed features. The queuing model based on task priorities is to some extent successful in explaining the origin o... Empirical observations indicate that the interevent time distribution of human actions exhibits heavy-tailed features. The queuing model based on task priorities is to some extent successful in explaining the origin of such heavy tails, however, it cannot explain all the temporal statistics of human behavior especially for the daily entertainments. We propose an interest-driven model, which can reproduce the power-law distribution of interevent time. The exponent can be analytically obtained and is in good accordance with the simulations. This model well explains the observed relationship between activities and power-law exponents, as reported recently for web-based behavior and the instant message communications. 展开更多
关键词 Environmental and Earth science statistical physics and nonlinear systems
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Analysis of High Codimensional Bifurcation and Chaos for the Quad Bundle Conductor's Galloping 被引量:4
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作者 刘富豪 张琪昌 谭莹 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期171-174,共4页
A two-degree-of-freedom model of iced, electrical quad bundle conductor is developed to comprehensively describe the different galloping behaviors observed. By applying centre manifold and invertible linear transforma... A two-degree-of-freedom model of iced, electrical quad bundle conductor is developed to comprehensively describe the different galloping behaviors observed. By applying centre manifold and invertible linear transformation, the co-dimension-2 bifurcation is analyzed. The relationships of parameters between this system and the original system are obtained to analyze and to control the galloping of the quad iced bundle conductor. The space trajectory, Lyapunov exponent and Lyapunov dimension are investigated via numerical simulation to present a rigorous proof of existence of chaos. 展开更多
关键词 fluid dynamics Mathematical physics statistical physics and nonlinear systems
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Robustness of Complex Networks under Attack and Repair 被引量:6
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作者 胡斌 黎放 周厚顺 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第12期253-256,共4页
To study the robustness of complex networks under attack and repair, we introduce a repair model of complex networks. Based on the model, we introduce two new quantities, i.e. attack fraction fa and the maximum degree... To study the robustness of complex networks under attack and repair, we introduce a repair model of complex networks. Based on the model, we introduce two new quantities, i.e. attack fraction fa and the maximum degree of the nodes that have never been attacked ~Ka, to study analytically the critical attack fraction and the relative size of the giant component of complex networks under attack and repair, using the method of generating function. We show analytically and numerically that the repair strategy significantly enhances the robustness of the scale-free network and the effect of robustness improvement is better for the scale-free networks with a smaller degree exponent. We discuss the application of our theory in relation to theunderstanding of robustness of complex networks with reparability. 展开更多
关键词 statistical physics and nonlinear systems
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Effects of Slip on Unsteady Mixed Convective Flow and Heat Transfer Past a Stretching Surface 被引量:3
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作者 S. Mukhopadhyay 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第12期113-116,共4页
Unsteady mixed convective boundary layer flow and heat transfer over a stretching vertical surface in the presence of slip axe investigated. It is noted that fluid velocity decreases due to the increasing velocity sli... Unsteady mixed convective boundary layer flow and heat transfer over a stretching vertical surface in the presence of slip axe investigated. It is noted that fluid velocity decreases due to the increasing velocity slip parameter resulting in an increase in the temperature field. The rate of heat transfer decreases with the velocity slip parameter while it increases with unsteadiness parameter. The same feature is also noticed for thermal slip parameter. 展开更多
关键词 statistical physics and nonlinear systems
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Stochastic Resonance in a Time-Delayed Mono-Stable System with Multiplicative and Additive Noise 被引量:2
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作者 郭锋 黄志奇 +2 位作者 范勇 李少甫 张宇 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第10期53-56,共4页
The stochastic resonance (SR) in a time-delayed mono-stable system driven by multiplicative white noise, additive white noise, additive dichotomous noise as well as a periodic square-wave signal is considered from t... The stochastic resonance (SR) in a time-delayed mono-stable system driven by multiplicative white noise, additive white noise, additive dichotomous noise as well as a periodic square-wave signal is considered from the view of the signal-to-noise ratio (SNR). It is found that the SNR increases monotonically with the increase of the delay time. The SNR exhibits the SR behavior when it is plotted as a function of intensities of the noises, displaying the asymmetry of the dichotomous noise. The SNR varies non-monotonically with the increase of the system parameter and the amplitude of the input square-wave signal. 展开更多
关键词 Computational physics statistical physics and nonlinear systems
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Fuzzy Modeling and Impulsive Control of a Memristor-Based Chaotic System 被引量:2
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作者 钟其水 于永斌 虞厥邦 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第2期22-24,共3页
We mainly investigate the issues of fuzzy modeling and impulsive control of a memristor-based chaotic system and present a memristor-based chaotic system as the Takagi-Sugeno model-based fuzzy system. Then, based on t... We mainly investigate the issues of fuzzy modeling and impulsive control of a memristor-based chaotic system and present a memristor-based chaotic system as the Takagi-Sugeno model-based fuzzy system. Then, based on the impulsive control theory of dynamical systems, a criterion ensuring impulsive stabilization of the memristorbased chaotic system is derived for the first time. An illustrative example is given to verify the effectiveness of the control scheme. 展开更多
关键词 Mathematical physics statistical physics and nonlinear systems
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Analysis of Chaotic Dynamics in a Two-Dimensional Sine Square Map 被引量:1
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作者 徐杰 隆克平 +2 位作者 FOURNIER-PRUNARET Daniele TAHA Abdel-Kaddous CHARGE Pascal 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第2期33-36,共4页
We study an N-dimensional system based upon a sine map, which is related to the simplified model of an opto-electronic system. The system behavior is analyzed with the tools of nonlinear dynamics (bifurcations in the... We study an N-dimensional system based upon a sine map, which is related to the simplified model of an opto-electronic system. The system behavior is analyzed with the tools of nonlinear dynamics (bifurcations in the parameter plane, critical manifolds, basins of attraction, chaotic attractors). Our study relies on a two-dimensional system (N=2). It is interesting that this system shows the existence of bounded chaotic orbits, which can be considered for secure transmissions. 展开更多
关键词 statistical physics and nonlinear systems
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Statistical Mechanical Entropy of a (4 + n)-Dimensional Static Spherically Symmetric Black Hole
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作者 赵凡 贺锋 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第2期16-19,共4页
Considering corrections to all orders in the Planck length on the quantum state density from the generalized uncertainty principle and using the quantum state density to all degrees of freedom including extra dimensio... Considering corrections to all orders in the Planck length on the quantum state density from the generalized uncertainty principle and using the quantum state density to all degrees of freedom including extra dimensions, we calculate the statistical entropy of the scalar field in the higher-dimensional static spherically symmetric black hole spacetime without any artificial cutoff. Calculation shows that the entropy is proportional to the horizon area. The coefficient of proportionality is 1/4 when the minimal length parameter is selected appropriately. 展开更多
关键词 Quantum gases liquids and solids Mathematical physics Gravitation and cosmology statistical physics and nonlinear systems
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Statistical Interaction Term of One-Dimensional Anyon Models
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作者 朱仁贵 王安民 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期56-58,共3页
A form of statistical interaction term of one-dimensional anyons is introduced, based on which one-dimensional anyon models are theoretically realized, and the statistical transmutation between bosons (or fermions) ... A form of statistical interaction term of one-dimensional anyons is introduced, based on which one-dimensional anyon models are theoretically realized, and the statistical transmutation between bosons (or fermions) and anyons is established in quantum mechanics formalism. Two kinds of anyon models which are being studied are recovered and reexplained naturally in our formalism. 展开更多
关键词 Quantum gases liquids and solids Quantum information and quantum mechanics statistical physics and nonlinear systems
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Generalized Lorenz Equation Derived from Thermal Convection of Viscoelastic Fluids in a Loop
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作者 杨帆 朱克勤 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期196-199,共4页
A new generalized Lorenz system is presented based on the thermal convection of Oldroyd-B fluids in a circular loop. Two non-dimensional parameters De1 (a measure of the fluid relaxation) and De2 (a measure of the ... A new generalized Lorenz system is presented based on the thermal convection of Oldroyd-B fluids in a circular loop. Two non-dimensional parameters De1 (a measure of the fluid relaxation) and De2 (a measure of the fluid retardation) appear in the equation. Then we study this generalized Lorenz equation numerically and find that the values of De1 and De2 can greatly influence the behavior of the solution. The fluid relaxation De1 is found to precipitate the onset of periodic solution (limit cycle) in the system and impedes the onset of chaos while the fluid retardation (De2) tends to delay the onset of the periodic solution and precipitate the onset of chaos in the system. 展开更多
关键词 fluid dynamics Mathematical physics statistical physics and nonlinear systems
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A Simple Model of Interaction between Journals, Authors and Editorial Board Members
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作者 ZOU Sheng-Rong XU Ying-Ying +2 位作者 XU Xiu-Lian WANG Jian HE Da-Ren 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第1期222-225,共4页
Recently, quantitative study on complex systems has become an attractive research area for physicists. Human scientific activity, including scientific paper publication, is an important complex system and therefore de... Recently, quantitative study on complex systems has become an attractive research area for physicists. Human scientific activity, including scientific paper publication, is an important complex system and therefore deserves an investigation. We present a simple model to describe the interaction between journals, authors and editorial board members. In the model the probabilities, with which a journal accepts papers from an author or invites him as an editorial board member, obey normal distributions. However, the most probable value of the latter distribution shifts such that the journal can have higher level authors being its editorial board members. The analytic derivation by the model is in rather good agreement with the empirical observation from the selected fifteen worldwide journals with different impact factors. 展开更多
关键词 statistical physics and nonlinear systems
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Synchronization of Coupled Nonidentical Dynamical Systems
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作者 张刚 张伟 刘曾荣 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期56-59,共4页
Synchronization behavior of coupled dynamical systems is discussed. An equivalence relation is found between the diffeomorphic generalized synchronization and the complete synchronization of coupled nonidentical syste... Synchronization behavior of coupled dynamical systems is discussed. An equivalence relation is found between the diffeomorphic generalized synchronization and the complete synchronization of coupled nonidentical systems. Employing the method of the complete synchronization, the problem of the generalized synchronization can be unraveled. By constructing an appropriate coupling term, a sufficient condition is obtained for determining the complete synchronization of coupled nonidentical systems. Numerical simulations are also given to show the effectiveness of the proposed schemes. 展开更多
关键词 statistical physics and nonlinear systems
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