Article
Chemistry, Physical
Mohammad Tauhidul Islam, Devika Nandwana, Jonathan Healy, Jenna K. Jaklich, Bowen Dong, Alexander Yu, Emily E. Moore, Yumi Ijiri, Scott K. McCall, Matthew A. Willard
Summary: (Fe1-xGax)92Zr8 amorphous and nanocrystalline alloys with x = 0.15 to x = 0.36 were investigated to improve the magnetic softness of Galfenol-type alloys and evaluate their magnetostrictive properties. It was found that annealing the rapidly solidified ribbons at 823 K for 1 h produced a nanocrystalline structure with body-centered cubic (BCC) Fe-Ga phase crystallization for x = 0.15 to x = 0.26. Beyond x = 0.26, the ribbons crystallized into BCC and a ternary intermetallic phase (ZrFe6Ga6) that negatively affected saturation magnetization, magnetic softness, and magnetostriction coefficient. The alloy with x = 0.26 annealed at 823 K for 1 h exhibited a peak magnetostriction of 10 ppm with saturation magnetization of 110 Am2/kg and coercivity of 260 A/m.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Review
Chemistry, Physical
Igor S. S. Golovin
Summary: This review focuses on the magneto-elastic properties of Fe-Ga alloys, particularly their magnetostriction in low saturation magnetic fields. The anelastic properties of these alloys, including frequency, amplitude and temperature dependencies, are analyzed. Special attention is paid to anelasticity caused by phase transitions, and comparison between Fe-Ga, Fe-Al alloys and the effect of RE elements is discussed.
Article
Mechanics
Zhouyu Hu, Yanling Yang, Congqing Zhang, Qiubao Wang
Summary: In this paper, the stability of a class of stochastic dynamical systems with fast time-varying periodic delays is studied, and a new definition of bifurcation is proposed. The effectiveness and reasonability of the methods presented in this paper are verified through numerical simulations.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
Article
Physics, Multidisciplinary
Qiubao Wang, Zhouyu Hu, Yanling Yang, Congqing Zhang, Zikun Han
Summary: This paper investigates the effects of different memory effects on the evolution of species population densities. A stochastic logistic model driven by non-Gaussian noise, with discrete and distributed time-delay, is considered. The results show a change in the population system from a single steady-state to a bi-periodic oscillation to a single steady-state again as memory intensity increased from weak to strong.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Mathematics, Interdisciplinary Applications
Hao Dai, Zikun Han, Qiubao Wang
Summary: In this paper, a stochastic time-delay mathematical model of the feedback system of glucose-insulin endocrine regulation with noise effects is proposed. The hopf bifurcation of the system is obtained with the delay as the parameter. Considering the influence of time delay and noise, the random bifurcation of the system is obtained, and the occurrence of bursting phenomenon is found more likely in a noise environment.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Mathematics
Genghong Lin, Lin Wang, Jianshe Yu
Summary: In this study, we investigate a class of delay differential equations with bistable nonlinearity, where the trivial equilibrium can coexist with two positive equilibria. Despite the challenges posed by delay and bistable nonlinearity, we provide a comprehensive description of the dynamics, including global stability, semi-stability, bistability, and Hopf bifurcation. We derive two delay-dependent intervals as subsets of basins of attraction for the case where the stable trivial equilibrium coexists with a stable positive equilibrium. Furthermore, using delay as the bifurcation parameter, we prove analytically that the number of local Hopf bifurcation values is finite and they are neatly paired. We use a Nicholson's blowflies equation with Allee effect to illustrate our general results, showing that delay can induce stability switches, symmetric transitions among multitype bistability, and robust phase transitions for long transients.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2023)
Article
Materials Science, Multidisciplinary
Tian Wang, Zhi-Wen Zhu
Summary: This paper proposes a new type of nonlinear hysteretic model for MRE and introduces natural frequency to offset the influence of the loading rate on the hysteresis loop. A developed multiscale method is used to solve the natural frequency under strong nonlinear conditions. The study discusses the dynamic characteristics of a simply supported MRE sandwich plate under in-plane stochastic load, showing that the new hysteretic model is hardly affected by the loading rate and exhibits abundant types of stochastic bifurcation in the system.
Article
Physics, Multidisciplinary
Zhouyu Hu, Qiubao Wang
Summary: This paper investigates the dynamic behavior and noise effects of semiconductor laser systems, focusing on the impact of time-delay parameters on laser stability. By manipulating the time-delay parameter, the dynamic performance of semiconductor lasers can be fine-tuned, enhancing stability and spectral purity.
Article
Mechanics
Xuan Hu, Qiduo Jin, Xinwei Fu
Summary: Research on the nonlinear parametric resonance of nanotubes in nanoelectromechanical systems is important. This study proposes a size-dependent nonlinear model considering various nonlinear factors and develops a two-step perturbation-incremental harmonic balance method to obtain the stability boundary and bifurcation diagram.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Physics, Multidisciplinary
Tiancai Liao
Summary: This paper studies the dynamics of a nutrient-phytoplankton-zooplankton model considering the factor of plankton body size in both deterministic and stochastic environments. Mathematically, the paper provides proofs of the existence, local and global stability of boundary and positive equilibria, and the existence of Hopf bifurcation for the model without stochastic environmental fluctuations. For the model with stochastic environmental fluctuations, the paper presents results related to stochastic extinction and persistence, as well as the existence of ergodic stationary distribution. Ecologically, numerical simulations show that plankton body size plays a crucial role in regulating the dynamics of interacting plankton in both deterministic and stochastic environments.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Zikun Han, Qiubao Wang, Hao Wu, Zhouyu Hu
Summary: This study focuses on the behavior of the Myc/E2F/miR-17-92 network under Gaussian white noise. The system exhibits bifurcation and a coexistence pattern of high and low protein concentrations. The research methods include stochastic center manifold theory, normal form theory, and stochastic averaging method.
INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS
(2022)
Article
Physics, Multidisciplinary
J. C. Zhang, Y. F. Hu, J. Wang, Z. Chen
Summary: In this study, a single degree of freedom dynamical model was established for a fractional differential-containing hysteretic nonlinear suspension system, and the approximate analytical solution of its forced vibration was obtained through the Krylov-Bogoliubov method. The stability of the system's stationary solution under the harmonic excitation of the pavement was analyzed, and it was found to be stable. Additionally, the accuracy of the approximate analytical solution was verified through a comparison with the numerical solution. The system's bifurcated structural characteristics were explored based on its amplitude-frequency response. Furthermore, the influences of the fractional coefficient and fractional order, as well as the stiffness and damping coefficient of hysteretic nonlinearity on the suspension system's resonance amplitude, resonance frequency, and nonlinearity degree were analyzed through numerical simulation.
INDIAN JOURNAL OF PHYSICS
(2023)
Article
Mathematics
Ivan Kipelkin, Svetlana Gerasimova, Davud Guseinov, Dmitry Pavlov, Vladislav Vorontsov, Alexey Mikhaylov, Victor Kazantsev
Summary: This article introduces a mathematical and experimental model of a neuronal oscillator with memristor-based nonlinearity. The mathematical model describes the dynamics of an electronic circuit implementing the FitzHugh-Nagumo neuron model. The nonlinear component of the circuit is the Au/Zr/ZrO2(Y)/TiN/Ti memristive device. This device is fabricated on an oxidized silicon substrate using magnetron sputtering. The circuit with this nonlinearity is described by a three-dimensional ordinary differential equation system. The article explores the effect of spontaneous self-oscillations, identifies a bifurcation scenario based on supercritical Andronov-Hopf bifurcation, and analyzes the dependence of the critical point on system parameters, particularly the size of the electrode area. Experimental demonstrations of self-oscillating and excitable modes are provided.
Article
Mathematics, Applied
Peng Wang, Shaopu Yang, Yongqiang Liu, Pengfei Liu, Xing Zhang, Yiwei Zhao
Summary: This paper establishes a stochastic wheelset model with a nonlinear wheel-rail contact relationship to investigate the stochastic stability and stochastic bifurcation of the wheelset system considering the stochastic parametric excitations of equivalent conicity and suspension stiffness. By using the stochastic average method, the wheelset system is transformed into a one-dimensional diffusion process, and the behavior of the singular boundary is analyzed to determine the hunting stability condition and critical speed of stochastic bifurcation. The effects of stochastic factors on hunting stability and bifurcation characteristics are analyzed, and the theoretical analysis is verified by simulation results.
APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION
(2023)
Article
Physics, Multidisciplinary
V. Vijayanarayanan, Himalay Basumatary, M. Manivel Raja, M. Mahendran
Summary: This study examines the effect of quenching on Fe-Ga alloys and found that quenching reduces the magnetostriction in the 25% Ga alloy but promotes a first-order transition in the production of the D0(3) structure in the 20% Ga alloy. Additionally, lowering the nonmagnetic element Ga enhances the saturation magnetization, while increasing Ga content and quenching temperature leads to more material flaws and dislocations.
INDIAN JOURNAL OF PURE & APPLIED PHYSICS
(2022)
