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Applied mathematics and Mechanics(English Edition) 2008年第1期29卷 75-87页

作者：孟新柱赵秋兰陈兰荪 college of science Shandong University of Science and Technology Department of Applied mathematics Dalian University of Technology

In this paper, we consider a new Monod type chemostat model with time delay and impulsive input concentration of the nutrient in a polluted environment. Using the discrete dynamical system determined by the stroboscopic map, we obtain a ＂microorganism-extinction＂ periodic solution. Further, we establish the sufficient conditions for the global attractivity of the microorganism-extinction periodic solution. Using new computational techniques for impulsive and delayed differential equation, we prove that the system is permanent under appropriate conditions. Our results show that time delay is ＂profitless＂.

关键词： permanence impulsive input chemostat model time delay for growth response extinction

A numerical simulation of the generation and evolution of nonlinear internal waves across the Kara Strait

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Acta Oceanologica Sinica 2019年第5期38卷 1-9页

作者： Qun Li Huiding Wu Hongwei Yang Zhanhai Zhang Polar Research Institute of China Ministry of Natural Resources college of mathematics and systems science Shandong University of Science and Technology

Nonlinear internal waves(NIWs) are ubiquitous around the Kara Sea, a part of the Arctic Ocean that is north of Siberia. Three hot spot sources for internal waves, one of which is the Kara Strait, have been identified based on Envisat ASAR. The generation and evolution of the NIWs through the interactions of the tide and topography across the strait is studied based on a nonhydrostatic numerical model. The model captures most wave characteristics shown by satellite data. A typical inter-packets distance on the Barents Sea side is about 25 km in summer, with a phase speed about 0.65 m/s. A northward background current may intensify the accumulation of energy during generation, but it has little influence on the other properties of the generated waves. The single internal solitary wave(ISW) structure is a special phenomenon that follows major wave trains, with a distance about 5–8 km. This wave is generated with the leading wave packets during the same tidal period. When a steady current toward the Kara Sea is included, the basic generation process is similar, but the waves toward the Kara Sea weaken and display an internal bore-like structure with smaller amplitude than in the control experiment. In winter, due to the growth of sea ice, stratification across the Kara Strait is mainly determined by the salinity, with an almost uniform temperature close to freezing. A pycnocline deepens near the middle of the water depth(Barents Sea side), and the NIWs process is not as important as the NIWs process in summer. There is no fission process during the simulation.

关键词： nonlinear internal wave nonhydrostatic numerical model Kara Sea synthetic aperture radar

Polymer-based smart fibers and textiles for wearable electronics

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science China Technological sciences 2025年第1期 85-120页

作者： Sanming HU Li WANG Zaixian YUAN Kun CHEN Wei PENG Hai YIN Zhijun SHI Guang YANG School of Biomedical Engineering and Imaging Xianning Medical CollegeHubei University of Science and Technology college of Life science and technology Huazhong University of Science and Technology Wuhan Branch of the National science Library Chinese Academy of Sciences

Smart fibers and textiles have attracted considerable interest for application in wearable devices because of their advantages of being human-friendly, lightweight, flexible, and comfortable. In addition, they are considered to have potential applications in health monitoring, energy management, and human-machine interaction systems. Polymers and polymer fibers,with excellent mechanical strength, wrinkle resistance, and heat resistance, are widely used to fabricate smart fibers and textiles. Herein, a comprehensive overview of polymer-based fibers and textiles is provided. First, we review the design principles of various polymer-based smart textiles, including textile-based sensors, energy capture and storage textiles, and computation and display textiles. Next, materials used for preparing polymer-based smart fibers, such as metals, carbon-based materials, and natural and synthetic polymers, particularly conductive polymers, are summarized. In addition, this review summarizes key technologies used for preparing smart fibers and the conventional structures of smart textiles. Furthermore, the applications of smart textiles in personal health monitoring, thermal management, energy capture and storage, and computation and displays are discussed. Finally, the current challenges, limitations, and future trends of smart fibers and textiles are discussed.

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Dynamical Analysis of Nonautonomous Trophic Cascade Chemostat Model with Regime Switching and Nonlinear Perturbations in a Polluted Environment

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Acta Mathematicae Applicatae Sinica 2023年第3期39卷 550-570页

作者： Ya-jie LI Hao-kun QI Zheng-bo CHANG Xin-zhu MENG college of mathematics and systems science Shandong University of Science and TechnologyQingdao 266590China Weifang Commercial college of shandong Weifang 261011China college of mathematics and Information science Anshan Normal UniversityAnshan 114007China

This paper investigates the stochastic dynamics of trophic cascade chemostat model perturbed by regime switching, Gaussian white noise and impulsive toxicant input. For the system with only white noise interference, sufficient conditions for stochastically ultimate boundedness and stochastically permanence are obtained, and we demonstrate that the stochastic system has at least one nontrivial positive periodic solution. For the system with Markov regime switching, sufficient conditions for extinction of the microorganisms are established. Then we prove the system is ergodic and has a stationary distribution. The results show that both impulsive toxins input and stochastic noise have great effects on the survival and extinction of the microorganisms. Finally, a series of numerical simulations are presented to illustrate the theoretical analysis.

关键词： stochastic trophic cascade chemostat model Markov chain extinction and stochastic permanence periodic solution ergodicity

Adaptive event-trigger-based sampled-data stabilization of complex-valued neural networks: a real and complex LMI approach

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science China(Information sciences) 2023年第4期66卷 297-298页

作者： Xiaohong WANG Zhen WANG Jianwei XIA Hao SHEN Yuxia LI college of Electrical Engineering and Automation Shandong University of Science and Technology college of mathematics and systems science Shandong University of Science and Technology School of Mathematical science Liaocheng University School of Electrical Engineering and Information Anhui University of Technology

Dear editor, With the popularization of digital techniques, practical control systems are usually implemented via embedded microprocessors, and sampled-data control is applied. The system state is sampled and received by the controller only at discrete sampling instants [1]. Sampled-data control is fundamentally time-triggered,

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An STP look at logical blocking of finite state machines: formulation, detection, and search

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science China(Information sciences) 2024年第10期67卷 332-342页

作者： Yongyi YAN Penglei HAO Jumei YUE Haitao LI Jun-E FENG college of Information Engineering Henan University of Science and Technology college of Agricultural Equipment Engineering Henan University of Science and Technology School of mathematics and Statistics Shandong Normal University School of mathematics Shandong University

The logical blocking of finite state machines(FSMs) is examined at the three levels of formulation,detection, and search from an STP viewpoint(semi-tensor product of matrices). The research idea regards an FSM as a logical system. The realizing method treats the event sequence exciting an FSM as the input signal of a logical system and treats the current states of an FSM as the states of a logical system. Based on a recently developed bilinear dynamic model of FSMs, a difference equation-like model is first proposed to describe the logical blocking. By defining a loop structure of FSMs and using the difference equation-like model, a criterion is built by which whether a given FSM is blocking can be easily judged. If it is, several algorithms are designed to find all the logical blocking of the FSM. Further, these results are extended to apply to the case of nondeterministic FSMs and, thus, to networks of FSMs. The proposed STP approach may provide a new angle for considering the problems of FSMs, and the presented results may strengthen the links between systems governed by human-designed rules and systems governed by natural laws.

关键词： semi-tensor product of matrices STP matrix approach finite-valued systems logical systems logical networks finite state machines

Asymptotic analysis of a nonlinear stochastic eco-epidemiological system with feedback control

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Applied mathematics(A Journal of Chinese Universities) 2022年第3期37卷 317-339页

作者： ZHANG Sheng-qiang MENG Xin-zhu college of mathematics and systems science Shandong University of Science and TechnologyQingdao 266590China Business School University of Shanghai for Science and TechnologyShanghai 200093China

This paper proposes a new stochastic eco-epidemiological model with nonlinear incidence rate and feedback ***,we prove that the stochastic system has a unique global positive ***,by constructing a series of appropriate stochastic Lyapunov functions,the asymptotic behaviors around the equilibria of deterministic model are obtained,and we demonstrate that the stochastic system exists a stationary Markov ***,the conditions for persistence in the mean and extinction of the stochastic system are ***,we carry out some numerical simulations with respect to different stochastic parameters to verify our analytical *** obtained results indicate that the stochastic perturbations and feedback controls have crucial effects on the survivability of system.

关键词： stochastic eco-epidemiological model stationary markov process feedback controls asymptotic behavior persistence in the mean

Generalizations of the finite nonperiodic Toda lattice and its Darboux transformation

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Communications in Theoretical Physics 2021年第8期73卷 18-30页

作者： Jian Li Chuanzhong Li School of mathematics and Statistics Ningbo UniversityNingbo315211China college of mathematics and systems science Shandong University of Science and TechnologyQingdao266590China

In this paper,we construct Hamiltonian systems for 2 N particles whose force depends on the distances between the *** obtain the generalized finite nonperiodic Toda equations via a symmetric group *** solutions of the generalized Toda equations are derived using the tau *** relationship between the generalized nonperiodic Toda lattices and Lie algebras is then be discussed and the generalized Kac-van Moerbeke hierarchy is split into generalized Toda lattices,whose integrability and Darboux transformation are studied.

关键词： Hamiltonian systems Toda lattices Darboux transformation Lie algebra Kac-van Moerbeke hierarchy

On limit fractional Volterra hierarchies

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Communications in Theoretical Physics 2024年第1期76卷 7-16页

作者： Lixiang Zhang Chuanzhong Li School of mathematics and Statistics Ningbo UniversityNingbo315211China college of mathematics and systems science Shandong University of Science and TechnologyQingdao266590China

For the limit fractional Volterra(LFV)hierarchy,we construct the n-fold Darboux transformation and the soliton ***,we extend the LFV hierarchy to the noncommutative LFV(NCLFV)hierarchy,and construct the Darboux transformation expressed by quasi determinant of the noncommutative ***,we establish the relationship between new and old solutions of the NCLFV ***,the quasi determinant solutions of the NCLFV hierarchy are obtained.

关键词： limit fractional Volterra hierarchy noncommutative limit fractional Volterra hierarchy Darboux transformation soliton solution quasi determinant solution

Formation control with obstacle avoidance of second-order multi-agent systems under directed communication topology

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science China(Information sciences) 2019年第9期62卷 144-157页

作者： Guoxing WEN C.L.Philip CHEN Hui DOU Hongli YANG Chunfang LIU college of science Binzhou University Department of Computer and Information science Faculty of Science and Technology University of Macau college of Navigation Dalian Maritime University State Key Laboratory of Management and Control for Complex systems Institute of AutomationChinese Academy of Sciences mathematics and systems science college Shandong University of Science and Technology

This paper addresses the obstacle avoidance problem of formation control for the multi-agent systems modeled by double integrator dynamics under a directed interconnection topology. The control task is finished by a leader-follower formation scheme combined with an artificial potential field(APF) *** leader-follower scheme is carried out by taking the desired trajectory with the desired velocity as virtual leader, while the APF method is carried out by dealing with the obstacles as the high potential points. When the obstacle avoidance tasks are finished, the artificial potential forces degrade the formation performance, so their undesired effects are treated as disturbances, which is analyzed by the robust H∞performance. Based on Lyapunov stability theory, it is proved that the proposed formation approach can realize the control objective. The result is also extended to the switching multi-agent formation. The effectiveness of the proposed formation scheme is further confirmed by simulation studies.

关键词： formation control obstacle avoidance artificial potential field method H_∞ performance second-order multi-agent system directed topology