We use molecular dynamics simulations to compute the Lyapunov spectra of many-particle systems resembling simple fluids in thermal equilibrium and in non-equilibrium stationary states. Here we review some of the most ...We use molecular dynamics simulations to compute the Lyapunov spectra of many-particle systems resembling simple fluids in thermal equilibrium and in non-equilibrium stationary states. Here we review some of the most interesting results and point to open questions.展开更多
We investigated exact traveling soliton solutions for the nonlinear electrical transmission line. By applying a concise and straightforward method, the variable-coefficient discrete（G /G）-expansion method, we solve ...We investigated exact traveling soliton solutions for the nonlinear electrical transmission line. By applying a concise and straightforward method, the variable-coefficient discrete（G /G）-expansion method, we solve the nonlinear differential–difference equations associated with the network. We obtain some exact traveling wave solutions which include hyperbolic function solution, trigonometric function solution, rational solutions with arbitrary function, bright as well as dark solutions.展开更多
In this paper,a way of building an electronic Parity Time(PT)-symmetric dimer without gain material is presented.This is achieved by capacitively coupling a pair of LZC circuits,each combining an inductance L,an imagi...In this paper,a way of building an electronic Parity Time(PT)-symmetric dimer without gain material is presented.This is achieved by capacitively coupling a pair of LZC circuits,each combining an inductance L,an imaginary resistance Z and a positive/negative capacitance C.We derive the effective Hamiltonian of the system,which commutes with the joint PT operator.The eigenspectrum displays spontaneous breaking points,where the system undergoes a transition from real to complex values.The transition points are imposed by the range value of the coupling thanks to the use of a negative capacitance.Temporal charge solutions and energy propagation are also analytically and numerically investigated,and the results are compatible.In the exact phase,these quantities oscillate,whereas in the broken phase,oscillations disappear,giving place to amplification.Our results pave the way to innovative PT-symmetric circuits.Applications could include,among others,optics,metamaterials,photonics and sensitive detection.展开更多
In this work, we investigate the dynamics of modulated waves non-identical coupled nonlinear transmission lines. Traditional methods for avoiding mode mixing in identical coupled nonlinear electrical lines consist of ...In this work, we investigate the dynamics of modulated waves non-identical coupled nonlinear transmission lines. Traditional methods for avoiding mode mixing in identical coupled nonlinear electrical lines consist of adding the same number of linear inductors in each branch. Adding linear inductors in a single line leads to asymmetric coupled nonlinear electrical transmission lines which propagate the signal and the mode mixing. On one hand, the difference between the two lines induced the fission for only one mode of propagation. This fission is influenced by the amplitude of the signal and the amount of the input energy as well; it also narrows the width of the input pulse soliton, leading to a possible increasing of the bit rate. On the other hand, the dissymmetry of the two lines converts the network into a good amplifier for the ω_ mode which corresponds to the regime admitting low frequencies.展开更多
This work investigates the dynamics of modulated waves in a coupled nonlinear LC transmission line. By means of a method based on the semi-discrete limit and in suitably scaled coordinates, we derive the two-dimension...This work investigates the dynamics of modulated waves in a coupled nonlinear LC transmission line. By means of a method based on the semi-discrete limit and in suitably scaled coordinates, we derive the two-dimensional NLS equation governing the propagation of slowly modulated waves in the network. The exact transverse solution is found and the analytical criteria of stability of this solution are derived. The condition for which the network can exhibit modulational instability is also determined. The exactness of this analytical analysis is confirmed by numerical simulations performed on the exact equation of the network.展开更多
Information dissemination and the associated change of individual behavior can significantly slow the spread of an epidemic.However,major social events which attract public attention will disturb information spread an...Information dissemination and the associated change of individual behavior can significantly slow the spread of an epidemic.However,major social events which attract public attention will disturb information spread and affect epidemic transmission in ways that have not been readily quantified.We investigate the interplay between disease spreading and diseaserelated information dissemination in a two-layer network.We employ the SIR-UAU model with a time dependent coefficient to denote information dissemination.We found that major social events are equivalent to perturbations of information dissemination in certain time intervals and will consequently weaken the effect of information dissemination,and increase prevalence of infection.Our simulation results agree well with the trends observed from real-world data sets.We found that two specific major events explain the trend of the coronavirus epidemic in the US:the online propaganda and international agenda setting of Donald Trump early in 2020 and the 2020 US Presidential Election.展开更多
文摘We use molecular dynamics simulations to compute the Lyapunov spectra of many-particle systems resembling simple fluids in thermal equilibrium and in non-equilibrium stationary states. Here we review some of the most interesting results and point to open questions.
基金supported by the Scientific Commission/ENS/University of Maroua 2013AM is grateful to the Abdus Salam International Center for Theoretical Physics(ICTP),Trieste,Italy through the Associate Program for financial support
文摘We investigated exact traveling soliton solutions for the nonlinear electrical transmission line. By applying a concise and straightforward method, the variable-coefficient discrete（G /G）-expansion method, we solve the nonlinear differential–difference equations associated with the network. We obtain some exact traveling wave solutions which include hyperbolic function solution, trigonometric function solution, rational solutions with arbitrary function, bright as well as dark solutions.
文摘In this paper,a way of building an electronic Parity Time(PT)-symmetric dimer without gain material is presented.This is achieved by capacitively coupling a pair of LZC circuits,each combining an inductance L,an imaginary resistance Z and a positive/negative capacitance C.We derive the effective Hamiltonian of the system,which commutes with the joint PT operator.The eigenspectrum displays spontaneous breaking points,where the system undergoes a transition from real to complex values.The transition points are imposed by the range value of the coupling thanks to the use of a negative capacitance.Temporal charge solutions and energy propagation are also analytically and numerically investigated,and the results are compatible.In the exact phase,these quantities oscillate,whereas in the broken phase,oscillations disappear,giving place to amplification.Our results pave the way to innovative PT-symmetric circuits.Applications could include,among others,optics,metamaterials,photonics and sensitive detection.
文摘In this work, we investigate the dynamics of modulated waves non-identical coupled nonlinear transmission lines. Traditional methods for avoiding mode mixing in identical coupled nonlinear electrical lines consist of adding the same number of linear inductors in each branch. Adding linear inductors in a single line leads to asymmetric coupled nonlinear electrical transmission lines which propagate the signal and the mode mixing. On one hand, the difference between the two lines induced the fission for only one mode of propagation. This fission is influenced by the amplitude of the signal and the amount of the input energy as well; it also narrows the width of the input pulse soliton, leading to a possible increasing of the bit rate. On the other hand, the dissymmetry of the two lines converts the network into a good amplifier for the ω_ mode which corresponds to the regime admitting low frequencies.
基金grateful to the Journal of Modern Physics for financial support in publication.
文摘This work investigates the dynamics of modulated waves in a coupled nonlinear LC transmission line. By means of a method based on the semi-discrete limit and in suitably scaled coordinates, we derive the two-dimensional NLS equation governing the propagation of slowly modulated waves in the network. The exact transverse solution is found and the analytical criteria of stability of this solution are derived. The condition for which the network can exhibit modulational instability is also determined. The exactness of this analytical analysis is confirmed by numerical simulations performed on the exact equation of the network.
基金supported by the National Natural Science Foundation of China(61803047)Major Project of the National Social Science Foundation of China(19ZDA149 and 19ZDA324)+1 种基金Fundamental Research Funds for the Central Universities(14370119 and 14390110)supported by ARC Discovery Project(DP20010296)
文摘Information dissemination and the associated change of individual behavior can significantly slow the spread of an epidemic.However,major social events which attract public attention will disturb information spread and affect epidemic transmission in ways that have not been readily quantified.We investigate the interplay between disease spreading and diseaserelated information dissemination in a two-layer network.We employ the SIR-UAU model with a time dependent coefficient to denote information dissemination.We found that major social events are equivalent to perturbations of information dissemination in certain time intervals and will consequently weaken the effect of information dissemination,and increase prevalence of infection.Our simulation results agree well with the trends observed from real-world data sets.We found that two specific major events explain the trend of the coronavirus epidemic in the US:the online propaganda and international agenda setting of Donald Trump early in 2020 and the 2020 US Presidential Election.
