摘要：
A series of simulation experimentations are carried out on the overburden soil of the uranium tailings impoundment under the conditions of heat and insolation. The results show that: (1) The radon exhalation rate on the overburden soil of the uranium tailings impoundment increases rapidly at first and then slows down with the decrease of the moisture content. (2) The radon exhalation rate increases rapidly at first and then slows down with the increase of fractal dimension. The fitting formula of the influence of moisture content and fractal dimension on radon exhalation rate can be used to guide the radiation protection design and construction of the uranium tailings impoundment.
摘要：
Spreading speed of spatio-temporal nonlinear dynamical system can sometimes be determined either by its corresponding linear system with an explicit speed formula, or by the complicated nonlinear system itself with the existence of a pushed wavefront. In this paper, the spreading speed (the minimal speed of wavefronts) for a Lotka-Volterra competition model in spatially periodic habitats is investigated. We establish new results on the linear and nonlinear selections in terms of the spatio-periodic coefficient functions. In the case of nonlinear selection, lower and upper bound estimates of the minimal speed are provided. (C) 2020 Elsevier Inc. All rights reserved.
作者机构：
[You-Tian Zou; Xiao Pan; Hong-Ming Liu] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;[Xi-Jun Wu] School of Math and Physics, University of South China, Hengyang 421001, China;Cooperative Innovation Center for Nuclear Fuel Cycle Technology & Equipment, University of South China, Hengyang 421001, China;Key Laboratory of Low Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410081, China;[Biao He] College of Physics and Electronics, Central South University, Changsha 410083, China
摘要：
The precession effect of periastron for a massive test particle in the spacetime of a Janis–Newman–Winicour wormhole is studied in the weak field limit. Based on the metric of this static and spherically symmetric wormhole in harmonic coordinates, we derive the second post-Newtonian dynamics of the particle. The second-order orbital precession of periastron is then obtained via a post-Newtonian iterative technique under the Wagoner–Will–Epstein–Haugan representation. Our result is found to be consistent with the classical precession effect when the asymptotic scalar charge is dropped.
作者机构：
[Zhang, Dongrong] School of Mathematics and Physics, University of South China, Hengyang;421001, China;Continuum Physics Unit, Okinawa Institute of Science and Technology, Graduate University, Onna, Okinawa;904-0495, Japan;Fluid Mechanics Unit, Okinawa Institute of Science and Technology, Graduate University, Onna, Okinawa
通讯机构：
[Dongrong Zhang] S;School of Mathematics and Physics, University of South China, Hengyang 421001, People's Republic of China<&wdkj&>Continuum Physics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan<&wdkj&>Fluid Mechanics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
摘要：
In this paper, solutions of a Novikov equation are discussed based on the bifurcation method of dynamical systems. Through establishing a Hamiltonian function, the existence of a smooth soliton solution and a periodic cuspon solution are established for the corresponding traveling wave system of the Novikov equation. Numerical results are carried out to illustrate the feasibility of the main results. All these theories can be seen to fill the gap of the literatures Li (2014) and Pan and Li (2016). (C) 2020 Elsevier Ltd. All rights reserved.
摘要：
This article focuses on the finite-time and fixed-time synchronization of a class of coupled discontinuous neural networks, which can be viewed as a combination of the Hindmarsh-Rose model and the Kuramoto model. To this end, under the framework of Filippov solution, a new finite-time and fixed-time stable theorem is established for nonlinear systems whose right-hand sides may be discontinuous. Moreover, the high-precise settling time is given. Furthermore, by designing a discontinuous control law and using the theory of differential inclusions, some new sufficient conditions are derived to guarantee the synchronization of the addressed coupled networks achieved within a finite-time or fixed-time. These interesting results can be seemed as the supplement and expansion of the previous references. Finally, the derived theoretical results are supported by examples with numerical simulations.
期刊：
Journal of Dynamics and Differential Equations,2021年33(2):1153-1174 ISSN：1040-7294
通讯作者：
Ou, Chunhua
作者机构：
[Wang, Hongyong] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Ou, Chunhua] Mem Univ Newfoundland, Dept Math & Stat, St John, NF A1C 5S7, Canada.
通讯机构：
[Ou, Chunhua] M;Mem Univ Newfoundland, Dept Math & Stat, St John, NF A1C 5S7, Canada.
