The thermal decoherence of harmonic oscillators is investigated here.The quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental osci...The thermal decoherence of harmonic oscillators is investigated here.The quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental oscillators.There are various environmental oscillators with different angular frequency(below an ultraviolet cutoff).At the beginning,the quantum system is a pure state and the environmental oscillators are in thermodynamic equilibrium with temperature.After a period,the system-environment interactions inspire significant decoherence of the quantum state.Such decoherence is displayed by explicit calculations of the purity and von Neumann entropy of the quantum system.It is worth noting that the decoherence could be significant even in the weak coupling and low temperature case due to the large amount of environmental degrees of freedom.Since the decoherence process is inspired between the quantum system and an ordinary thermal environment here,the thermal decoherence result is quite general.展开更多
This paper examines the transport analysis,including both heat transfer and mass transfer,in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface.The influence of magnetic fi...This paper examines the transport analysis,including both heat transfer and mass transfer,in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface.The influence of magnetic fields is also inspected in terms of their physical characteristics.To depict the phenomena of transport,modified versions of both Fick's and Fourier's laws are used.Additionally,the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated.Utilizing a curvilinear coordinate system,the flow problem is formulated as partial differential equations(PDEs)for momentum,concentration,microorganism field,and energy.An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields,velocity,oscillation velocity,concentration,and temperature distributions are shown via graphs.Furthermore,the variations in skin friction,mass transfer rate,heat transfer rate,and local motile number due to different involved parameters are presented in tables and are analyzed in detail.Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables increase.It is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase,and it increases with the Schmidt number and the heterogeneous reaction strength parameter.Tabular outcomes show a favorable response of the motile number to advanced values of the Peclet number,the Schmidt number,the microorganism difference parameter,and the bio-convective Lewis number.展开更多
We propose a novel extension of quantum field theory by introducing Intrinsic Quantum Oscillators (IQuO) to describe the internal degrees of freedom of a particle. IQuO is composed of sub-oscillators with semi-quanta ...We propose a novel extension of quantum field theory by introducing Intrinsic Quantum Oscillators (IQuO) to describe the internal degrees of freedom of a particle. IQuO is composed of sub-oscillators with semi-quanta and are described by creation operators and annihilation with two components each. In the interaction between two particles, thanks to the structure with semi-quants of an IQuO, it is possible to show that in the initial phase of a coupling between two particle-fields, a non-dynamic process of reduction from a non-local to a local state takes place. Besides, IQuO allows us to demonstrate a direct correlation between the two directions of phase rotation of the wave function of a particle and the two signs of its electric charge. This connection provides a new understanding of particle-antiparticle pair creation and their associated virtual boson fields. Finally, two distinct IQuO configurations, B-IQuO and F-IQuO, explain the fundamental difference between fermions and bosons.展开更多
The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems.Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order...The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems.Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order interactions encoded with simplicial complexes.Previous works have shown that higher-order interactions promote coherent states.However, we uncover the fact that the introduced higher-order couplings can significantly enhance the emergence of the incoherent state.Remarkably, we identify that the chimera states arise as a result of multi-attractors in dynamic states.Importantly, we review that the increasing higher-order interactions can significantly shape the emergent probability of chimera states.All the observed results can be well described in terms of the dimension reduction method.This study is a step forward in highlighting the importance of nonlocal higher-order couplings, which might provide control strategies for the occurrence of spatial-temporal patterns in networked systems.展开更多
This study deals with the analytical investigation of oscillatory squeeze film flow through a Brinkman viscoelastic Oldroyd-B fluid-saturated porous layer subject to two vertically harmonically oscillatory disks.The v...This study deals with the analytical investigation of oscillatory squeeze film flow through a Brinkman viscoelastic Oldroyd-B fluid-saturated porous layer subject to two vertically harmonically oscillatory disks.The validity of the present proposed analytical solutions is first demonstrated for the Newtonian fluids when bothΛ_(1)andΛ_(2)tend to zero by comparison with the previous literature.Results demonstrate that an increase in the elasticity parameterΛ_(1)correlates with a rise in axial velocities,indicating that the relaxation timeΛ_(1)facilitates enhanced squeeze flow.In the case of squeeze film flow in porous layers,low oscillating frequencies exert minimal effects on axial velocities,independent of variations in the viscoelasticity parameterΛ_(1).However,at higher oscillating frequencies,axial velocities escalate with increasing the viscoelasticity parameterΛ_(1).Furthermore,the retardation timeΛ_(2)of the viscoelastic fluid shows no significant effect on the axial velocity,regardless of oscillating frequency changes in both pure fluids and porous layers.展开更多
The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied.It is shown that the oscillating liquid leads to the generati...The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied.It is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel segments.The intensity and direction of these flows depend on the dimensionless oscillating frequency.In the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each segment.For a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average position.It is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the channel.The quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless frequency.The behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in detail.Such findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.展开更多
We show that an intrinsically nonlinear oscillator can always be transformed into a linear or harmonic oscillator by addition of a constant force, which shifts the equilibrium position of the oscillator.
We study the dynamics of a quantum dissipative system. Besides its linear coupling with a harmonic bath modelling the dissipation, we suppose that it is coupled with an oscillator with an interaction of the form s 2 x...We study the dynamics of a quantum dissipative system. Besides its linear coupling with a harmonic bath modelling the dissipation, we suppose that it is coupled with an oscillator with an interaction of the form s 2 x 2 . In our study, we integrate over the bath and the oscillator, extract the corresponding influence functionals and then solve the system’s sign problem. We apply the theory to the case of a double well and study the time evolution of the expectation value of the position.展开更多
The generalized oscillator strengths (GOSs) of 2p63s0 (3p, 4p, 5p, 6p) states excited from sodium ground state in Debye plasma, are studied by two kinds of theoretical approaches: the restricted Hartree-Fock (RHF) met...The generalized oscillator strengths (GOSs) of 2p63s0 (3p, 4p, 5p, 6p) states excited from sodium ground state in Debye plasma, are studied by two kinds of theoretical approaches: the restricted Hartree-Fock (RHF) method and the random phase approximation with exchange (RPAE). Wavefunctions of the ground state and the excited states are calculated numerically from the RHF equation, employing the local density approach for exchange interaction including, in extension, plasma screening effects. The GOSs have been computed by using these wavefunctions. The results of RHF and RPAE calculations of the GOS for different Debye lengths have been reported for sodium dipole excitation to 3s0 (3p, 4p, 5p, 6p). We show, in this study, that RPAE results for values of Debye length D = 30, 100, ∞ are in excellent agreement with those found by other authors. The results of RPAE calculations show that correlation effects are quite significant around the maxima GOS for the excitations to 3s0 (4p, 5p, 6p) but are found to have no great influence in the GOS for the dipole excitation to 3s03p. We find that the amplitude of the GOS has noticeably been reduced in going from higher to lower Debye length. We’ve observed here that the peak of the GOS shifts towards a small momentum transfer when the value D = 20 a.u is taken. These results show an important influence of the Debye plasma screening interactions on the GOS as the screening Debye length is decreased.展开更多
In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f...In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f(x)≠0,the system is non-Hamiltonian,so we have to introduce some reversibility assumptions to apply a suitable twist theorem,for reversible maps with small twist.Moreover,when the nonnegative parameterαdecreases to 0,the system becomes discontinuous.In this case,we need to introduce some suitable transformations to overcome the lack of regularity.We will prove that for any nonnegative parameterα,when p(t)is an odd periodic function satisfying∣∣∫2π0p(t)sintdift∣∣<4,all the solutions are bounded;when p(t)satisfies∣∣∫2π0p(t)sintdift∣∣>4,the SD oscillator has unbounded solutions,and when p(t)satisfies∣∣∫_(0)^(2π)p(t)sintdift∣∣≥4+|F|_(∞),all the solutions are unbounded.展开更多
Background:Shear stress-induced erythrocyte damage,namely hemolysis,is an important problem in the development of blood-contacting medical devices such as mechanical circulatory support devices.Computational fluid dyn...Background:Shear stress-induced erythrocyte damage,namely hemolysis,is an important problem in the development of blood-contacting medical devices such as mechanical circulatory support devices.Computational fluid dynamics simulation combined with hemolysis prediction models have been widely used to predict hemolysis.With the development of hemolysis prediction models,the new hemolysis prediction model requires more experimental data to verify.In addition,the difference of in vitro blood-shearing device also affect the accuracy of hemolysis prediction.Methods:To address these problems,a new in vitro blood-shearing device(vortex oscillator)was used to further verify the accuracy of the hemolysis prediction models,and to guide the optimal design of blood-contacting medical devices such as mechanical circulatory support devices.Firstly,the flow field information such as wall stress and velocity of the vortex oscillator under different speeds was analyzed.Secondly,different hemolysis prediction models were used to calculate hemolysis,and the predicted data was compared with the experimental data.Results and Conclusion:In this study,the flow field information inside the vortex oscillator at high rotational speeds was systematically investigated,and the prediction of hemolysis was carried out.The results showed that the predicted data of hemolysis was significantly different from the experimental data,which indicated that it was urgent to establish a standardized in vitro blood-shearing platform to provide a reference for accurate hemolysis prediction.展开更多
The optoelectronic oscillator(OEO)is a typical time-delay system with rich nonlinear dynamical characteristics.Most of the previous research on OEOs has been focused on analyzing the properties of OEOs with a long tim...The optoelectronic oscillator(OEO)is a typical time-delay system with rich nonlinear dynamical characteristics.Most of the previous research on OEOs has been focused on analyzing the properties of OEOs with a long time delay,which makes it difficult to realize mode locking without additional phaselocking mechanisms.We have achieved,for the first time to our knowledge,a self-mode-locking OEO and generated stable microwave frequency combs by analyzing the characteristics of OEOs with an ultrashort time scale.In the experiment,the self-mode-locking OEOs with fundamental mode,second-order harmonic,and sixth-order harmonic were realized by adjusting the system parameters,all of which produced uniform square wave signals with tunable duty cycles,steep rising and falling edges,and periods of less than 20 ns.The self-fundamental-mode-locking OEOs with different time delays were also implemented and experimentally realized.Furthermore,the experiment revealed the self-hybrid mode-locking OEO,which is the coexistence and synchronization of the three measured self-locking modes in one OEO cavity,demonstrating the complex nonlinear dynamical behaviors of the OEO system and enabling the generation of periodic nonuniform hybrid square wave signals.The realization of the self-mode-locking OEO and the generation of flexible and stable square wave signals at ultrashort time scales enrich the study of OEO nonlinear dynamics in the realm of complex microwave waveform generation,offering promising applications in areas such as atomic clocks,radars,communications,and optoelectronic neural networks.展开更多
During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the s...During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis results.To elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget analysis.The findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern Pacific.This increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective instability.Such a process is pivotal in amplifying intraseasonal convection anomalies.The observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.展开更多
High-order Laguerre–Gaussian(LG)petal-like beams have become a topic of significant interest due to their potential application in next-generation optical trapping,quantum optics,and materials processing technologies...High-order Laguerre–Gaussian(LG)petal-like beams have become a topic of significant interest due to their potential application in next-generation optical trapping,quantum optics,and materials processing technologies.In this work,we demonstrate the generation of high-order LG beams with petal-like spatial profiles and tunable orbital angular momentum(OAM)in the mid-infrared wavelength region.These beams are generated using idler-resonant optical parametric oscillation(OPO)in a KTiOAsO_(4)(KTA)crystal.By adjusting the length of the resonant cavity,the OAM of the mid-infrared idler field can be tuned and we demonstrate tuning in the range of 0 to10.When using a maximum pump energy of 20.2 mJ,the maximum output energy of high-order modes LG_(0.45),LG_(0.48),and LG_(0.410) were 0.8,0.53,and 0.46 mJ,respectively.The means by which high-order LG modes with petal-like spatial profiles and tunable OAM were generated from the OPO is theoretically modeled by examining the spatial overlap efficiency of the beam waists of the pump and resonant idler fields within the center of the KTA crystal.The methodology presented in this work offers a simple and flexible method to wavelength-convert laser emission and generate high-order LG modes.展开更多
Chaos is a type of motion unique to nonlinear dynamical systems,characterized by extreme sensitivity to initial conditions and the randomness,which makes it potentially useful for secure communication.Chaos research r...Chaos is a type of motion unique to nonlinear dynamical systems,characterized by extreme sensitivity to initial conditions and the randomness,which makes it potentially useful for secure communication.Chaos research require a easily controllable chaotic oscillator.Chaotic behavior in optical bistability provides a simple theoretical model.Based on the theoretical model,a novel chaotic oscillator in frequency domain is proposed.The chaotic oscillator is composed of a tunable fiber laser,fiber Fabry⁃Perot interferometer(FFPI)and hybrid delayed feedback loop.The laser itself plays a part in delay time which is induced by PZT device.The chaotic oscillator is realized by experiments and chaos behaviors are observed.The chaos oscillator has the characteristic of simplicity and flexibility.It have potential application value in the field of fiber optical communication encryption.展开更多
Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Cu...Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.展开更多
A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary ...A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary patterns to asynchronous and synchronous oscillatory patterns are obtained.A novel method based on decomposing coupled systems into two associated subsystems has been proposed to elucidate the mechanism of formation of oscillating patterns.Linear stability analysis of the associated subsystems reveals that the Turing pattern in one layer induces the other layer locally,undergoes a supercritical Hopf bifurcation and gives rise to localized oscillations.It is found that the sizes and positions of oscillations are determined by the spatial distribution of the Turing patterns.When the size is large,localized traveling waves such as spirals and targets emerge.These results may be useful for deeper understanding of pattern formation in complex systems,particularly multilayered systems.展开更多
Sub-seasonal prediction of regional compound heatwaves and their predictability sources remain unclear.In this study,the underlying mechanisms for the long-lasting compound heatwave over Southern China during July 1–...Sub-seasonal prediction of regional compound heatwaves and their predictability sources remain unclear.In this study,the underlying mechanisms for the long-lasting compound heatwave over Southern China during July 1–18,2010,and the major sources of its sub-seasonal prediction skill are identified.The results show that both the development and decay of this compound heatwave are mainly dominated by atmospheric processes(i.e.,adiabatic heating associated with anticyclonic circulation),whereas land-atmosphere coupling processes play an important role in sustaining the heatwave.A further analysis indicates that by inducing anomalous anticyclonic circulations over Southern China,the tropical intraseasonal oscillations with periods of 30–60 days and 10–30 days facilitate the occurrence and maintenance of the heatwave during its entire and second half periods,respectively.The NCEP Climate Forecast System Version 2 shows a low skill in predicting the 2010 compound heatwave over Southern China when the lead time is longer than 2 pentads,which is largely attributed to the model’s bias in representing the intensity and phase of intra-seasonal oscillations.展开更多
The use of solar energy is today widely recognized for the green transition but also for addressing societal challenges associated with the rise in global surface temperature. The design of a photovoltaic solar panel ...The use of solar energy is today widely recognized for the green transition but also for addressing societal challenges associated with the rise in global surface temperature. The design of a photovoltaic solar panel field may require an understanding of how solar radiation oscillates with other variables or factors since multiple interactions occur during its transfer within the atmosphere. In this study, three years of the incoming shortwave radiation (SWin) and air temperature (Tair) data acquired within the “Institut de Mathématiques et de Sciences Physiques” were analyzed using the continuous wavelet transform to extract the inherent variability of these signals. The underlying characteristics meaning the timescale of these variabilities as well as the lead-lag relationship between SWin and Tair were also examined. With the wavelet power spectrum, the highest variability was evidenced at the 2 - 8 band period for the SWin, coinciding almost with that of Tair. This suggests that these two signals are well interconnected at this temporal scale. The results obtained with the phase (∅xy) difference analysis, reveal that SWin leads Tair by ~ 23.5˚ on average when (0 ∅xy∅xyi.e., periods ≤ 32 days), Tair increases with an increasing SWin since the lags between these two signals range between 0.09 - 2.30 days. However, when looking at their interdependence at a larger temporal scale (> 32 days), Tair lags SWin. An increase in SWin might not directly imply an increase in Tair. Overall, these findings give insight into complex relationships across scales between the incoming shortwave radiation and air temperature in a tropical humid region of Bénin.展开更多
An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation tech...An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation technique,the frequency tuning curves agree well with the experiment.At a 3.3V supply,the LC-VCO measures a phase noise of -82.2dBc/Hz at a 10kHz frequency offset while dissipating 3.1mA current.The chip size is 0.86mm×0.82mm.展开更多
文摘The thermal decoherence of harmonic oscillators is investigated here.The quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental oscillators.There are various environmental oscillators with different angular frequency(below an ultraviolet cutoff).At the beginning,the quantum system is a pure state and the environmental oscillators are in thermodynamic equilibrium with temperature.After a period,the system-environment interactions inspire significant decoherence of the quantum state.Such decoherence is displayed by explicit calculations of the purity and von Neumann entropy of the quantum system.It is worth noting that the decoherence could be significant even in the weak coupling and low temperature case due to the large amount of environmental degrees of freedom.Since the decoherence process is inspired between the quantum system and an ordinary thermal environment here,the thermal decoherence result is quite general.
文摘This paper examines the transport analysis,including both heat transfer and mass transfer,in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface.The influence of magnetic fields is also inspected in terms of their physical characteristics.To depict the phenomena of transport,modified versions of both Fick's and Fourier's laws are used.Additionally,the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated.Utilizing a curvilinear coordinate system,the flow problem is formulated as partial differential equations(PDEs)for momentum,concentration,microorganism field,and energy.An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields,velocity,oscillation velocity,concentration,and temperature distributions are shown via graphs.Furthermore,the variations in skin friction,mass transfer rate,heat transfer rate,and local motile number due to different involved parameters are presented in tables and are analyzed in detail.Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables increase.It is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase,and it increases with the Schmidt number and the heterogeneous reaction strength parameter.Tabular outcomes show a favorable response of the motile number to advanced values of the Peclet number,the Schmidt number,the microorganism difference parameter,and the bio-convective Lewis number.
文摘We propose a novel extension of quantum field theory by introducing Intrinsic Quantum Oscillators (IQuO) to describe the internal degrees of freedom of a particle. IQuO is composed of sub-oscillators with semi-quanta and are described by creation operators and annihilation with two components each. In the interaction between two particles, thanks to the structure with semi-quants of an IQuO, it is possible to show that in the initial phase of a coupling between two particle-fields, a non-dynamic process of reduction from a non-local to a local state takes place. Besides, IQuO allows us to demonstrate a direct correlation between the two directions of phase rotation of the wave function of a particle and the two signs of its electric charge. This connection provides a new understanding of particle-antiparticle pair creation and their associated virtual boson fields. Finally, two distinct IQuO configurations, B-IQuO and F-IQuO, explain the fundamental difference between fermions and bosons.
基金Project supported by the National Natural Science Foundation of China (Grants Nos.12375031 and 11905068)the Natural Science Foundation of Fujian Province, China (Grant No.2023J01113)the Scientific Research Funds of Huaqiao University (Grant No.ZQN-810)。
文摘The chimera states underlying many realistic dynamical processes have attracted ample attention in the area of dynamical systems.Here, we generalize the Kuramoto model with nonlocal coupling incorporating higher-order interactions encoded with simplicial complexes.Previous works have shown that higher-order interactions promote coherent states.However, we uncover the fact that the introduced higher-order couplings can significantly enhance the emergence of the incoherent state.Remarkably, we identify that the chimera states arise as a result of multi-attractors in dynamic states.Importantly, we review that the increasing higher-order interactions can significantly shape the emergent probability of chimera states.All the observed results can be well described in terms of the dimension reduction method.This study is a step forward in highlighting the importance of nonlocal higher-order couplings, which might provide control strategies for the occurrence of spatial-temporal patterns in networked systems.
基金Project supported by the National Natural Science Foundation of China(No.12262026)the Natural Science Foundation of the Inner Mongolia Autonomous Region of China(No.2021MS01007)+1 种基金the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region of China(No.NMGIRT2323)the Fundamental Research Funds for the Central Universities(Nos.2232022G-13,2232023G-13,and 2232024G-13)。
文摘This study deals with the analytical investigation of oscillatory squeeze film flow through a Brinkman viscoelastic Oldroyd-B fluid-saturated porous layer subject to two vertically harmonically oscillatory disks.The validity of the present proposed analytical solutions is first demonstrated for the Newtonian fluids when bothΛ_(1)andΛ_(2)tend to zero by comparison with the previous literature.Results demonstrate that an increase in the elasticity parameterΛ_(1)correlates with a rise in axial velocities,indicating that the relaxation timeΛ_(1)facilitates enhanced squeeze flow.In the case of squeeze film flow in porous layers,low oscillating frequencies exert minimal effects on axial velocities,independent of variations in the viscoelasticity parameterΛ_(1).However,at higher oscillating frequencies,axial velocities escalate with increasing the viscoelasticity parameterΛ_(1).Furthermore,the retardation timeΛ_(2)of the viscoelastic fluid shows no significant effect on the axial velocity,regardless of oscillating frequency changes in both pure fluids and porous layers.
文摘The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied.It is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel segments.The intensity and direction of these flows depend on the dimensionless oscillating frequency.In the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each segment.For a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average position.It is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the channel.The quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless frequency.The behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in detail.Such findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.
文摘We show that an intrinsically nonlinear oscillator can always be transformed into a linear or harmonic oscillator by addition of a constant force, which shifts the equilibrium position of the oscillator.
文摘We study the dynamics of a quantum dissipative system. Besides its linear coupling with a harmonic bath modelling the dissipation, we suppose that it is coupled with an oscillator with an interaction of the form s 2 x 2 . In our study, we integrate over the bath and the oscillator, extract the corresponding influence functionals and then solve the system’s sign problem. We apply the theory to the case of a double well and study the time evolution of the expectation value of the position.
文摘The generalized oscillator strengths (GOSs) of 2p63s0 (3p, 4p, 5p, 6p) states excited from sodium ground state in Debye plasma, are studied by two kinds of theoretical approaches: the restricted Hartree-Fock (RHF) method and the random phase approximation with exchange (RPAE). Wavefunctions of the ground state and the excited states are calculated numerically from the RHF equation, employing the local density approach for exchange interaction including, in extension, plasma screening effects. The GOSs have been computed by using these wavefunctions. The results of RHF and RPAE calculations of the GOS for different Debye lengths have been reported for sodium dipole excitation to 3s0 (3p, 4p, 5p, 6p). We show, in this study, that RPAE results for values of Debye length D = 30, 100, ∞ are in excellent agreement with those found by other authors. The results of RPAE calculations show that correlation effects are quite significant around the maxima GOS for the excitations to 3s0 (4p, 5p, 6p) but are found to have no great influence in the GOS for the dipole excitation to 3s03p. We find that the amplitude of the GOS has noticeably been reduced in going from higher to lower Debye length. We’ve observed here that the peak of the GOS shifts towards a small momentum transfer when the value D = 20 a.u is taken. These results show an important influence of the Debye plasma screening interactions on the GOS as the screening Debye length is decreased.
基金supported by the Key Research Funds for the Universities of Henan Province(No.19A110018)the Foundation for Key Teachers of Henan Polytechnic University(No.2022XQG-09)。
文摘In this paper we study the boundedness and unboundedness of the solutions of the smooth and discontinuous(SD)oscillatorbegin{equation*}x''+f(x)x'+x-frac{x}{sqrt{x^{2}+alpha^{2}}}=p(t).end{equation*}Since f(x)≠0,the system is non-Hamiltonian,so we have to introduce some reversibility assumptions to apply a suitable twist theorem,for reversible maps with small twist.Moreover,when the nonnegative parameterαdecreases to 0,the system becomes discontinuous.In this case,we need to introduce some suitable transformations to overcome the lack of regularity.We will prove that for any nonnegative parameterα,when p(t)is an odd periodic function satisfying∣∣∫2π0p(t)sintdift∣∣<4,all the solutions are bounded;when p(t)satisfies∣∣∫2π0p(t)sintdift∣∣>4,the SD oscillator has unbounded solutions,and when p(t)satisfies∣∣∫_(0)^(2π)p(t)sintdift∣∣≥4+|F|_(∞),all the solutions are unbounded.
基金supported by 2023 Kunshan Science and Technology Association youth science and technology talent lifting project(Project name:Mechanism study of mechanical damage of coagulation factor VWF based on in vitro blood-shearing experimental platform).
文摘Background:Shear stress-induced erythrocyte damage,namely hemolysis,is an important problem in the development of blood-contacting medical devices such as mechanical circulatory support devices.Computational fluid dynamics simulation combined with hemolysis prediction models have been widely used to predict hemolysis.With the development of hemolysis prediction models,the new hemolysis prediction model requires more experimental data to verify.In addition,the difference of in vitro blood-shearing device also affect the accuracy of hemolysis prediction.Methods:To address these problems,a new in vitro blood-shearing device(vortex oscillator)was used to further verify the accuracy of the hemolysis prediction models,and to guide the optimal design of blood-contacting medical devices such as mechanical circulatory support devices.Firstly,the flow field information such as wall stress and velocity of the vortex oscillator under different speeds was analyzed.Secondly,different hemolysis prediction models were used to calculate hemolysis,and the predicted data was compared with the experimental data.Results and Conclusion:In this study,the flow field information inside the vortex oscillator at high rotational speeds was systematically investigated,and the prediction of hemolysis was carried out.The results showed that the predicted data of hemolysis was significantly different from the experimental data,which indicated that it was urgent to establish a standardized in vitro blood-shearing platform to provide a reference for accurate hemolysis prediction.
基金supported by the National Natural Science Foundation of China(Grant No.62301495)the Project of the National Key Laboratory of Microwave Photonics(Nanjing University of Aeronautics and Astronautics),Ministry of Education(Grant No.NJ20220007).
文摘The optoelectronic oscillator(OEO)is a typical time-delay system with rich nonlinear dynamical characteristics.Most of the previous research on OEOs has been focused on analyzing the properties of OEOs with a long time delay,which makes it difficult to realize mode locking without additional phaselocking mechanisms.We have achieved,for the first time to our knowledge,a self-mode-locking OEO and generated stable microwave frequency combs by analyzing the characteristics of OEOs with an ultrashort time scale.In the experiment,the self-mode-locking OEOs with fundamental mode,second-order harmonic,and sixth-order harmonic were realized by adjusting the system parameters,all of which produced uniform square wave signals with tunable duty cycles,steep rising and falling edges,and periods of less than 20 ns.The self-fundamental-mode-locking OEOs with different time delays were also implemented and experimentally realized.Furthermore,the experiment revealed the self-hybrid mode-locking OEO,which is the coexistence and synchronization of the three measured self-locking modes in one OEO cavity,demonstrating the complex nonlinear dynamical behaviors of the OEO system and enabling the generation of periodic nonuniform hybrid square wave signals.The realization of the self-mode-locking OEO and the generation of flexible and stable square wave signals at ultrashort time scales enrich the study of OEO nonlinear dynamics in the realm of complex microwave waveform generation,offering promising applications in areas such as atomic clocks,radars,communications,and optoelectronic neural networks.
基金supported by the National Natural Science Foundation of China [grant number 42088101]。
文摘During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis results.To elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget analysis.The findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern Pacific.This increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective instability.Such a process is pivotal in amplifying intraseasonal convection anomalies.The observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.
基金supported by the National Natural Science Foundation of China(Grant Nos.12264049 and 11664041)the Xinjiang Normal University Young Outstanding Talent Programme(Grant No.XJNUQB2022-17).
文摘High-order Laguerre–Gaussian(LG)petal-like beams have become a topic of significant interest due to their potential application in next-generation optical trapping,quantum optics,and materials processing technologies.In this work,we demonstrate the generation of high-order LG beams with petal-like spatial profiles and tunable orbital angular momentum(OAM)in the mid-infrared wavelength region.These beams are generated using idler-resonant optical parametric oscillation(OPO)in a KTiOAsO_(4)(KTA)crystal.By adjusting the length of the resonant cavity,the OAM of the mid-infrared idler field can be tuned and we demonstrate tuning in the range of 0 to10.When using a maximum pump energy of 20.2 mJ,the maximum output energy of high-order modes LG_(0.45),LG_(0.48),and LG_(0.410) were 0.8,0.53,and 0.46 mJ,respectively.The means by which high-order LG modes with petal-like spatial profiles and tunable OAM were generated from the OPO is theoretically modeled by examining the spatial overlap efficiency of the beam waists of the pump and resonant idler fields within the center of the KTA crystal.The methodology presented in this work offers a simple and flexible method to wavelength-convert laser emission and generate high-order LG modes.
文摘Chaos is a type of motion unique to nonlinear dynamical systems,characterized by extreme sensitivity to initial conditions and the randomness,which makes it potentially useful for secure communication.Chaos research require a easily controllable chaotic oscillator.Chaotic behavior in optical bistability provides a simple theoretical model.Based on the theoretical model,a novel chaotic oscillator in frequency domain is proposed.The chaotic oscillator is composed of a tunable fiber laser,fiber Fabry⁃Perot interferometer(FFPI)and hybrid delayed feedback loop.The laser itself plays a part in delay time which is induced by PZT device.The chaotic oscillator is realized by experiments and chaos behaviors are observed.The chaos oscillator has the characteristic of simplicity and flexibility.It have potential application value in the field of fiber optical communication encryption.
基金supported by the National Natural Science Foundation of China,No.82071254(to WZ).
文摘Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275065,12275064,12475203)the Natural Science Foundation of Hebei Province(Grant Nos.A2021201010 and A2024201020)+3 种基金Interdisciplinary Research Program of Natural Science of Hebei University(Grant No.DXK202108)Hebei Provincial Central Government Guiding Local Science and Technology Development Funds(Grant No.236Z1501G)Scientific Research and Innovation Team Foundation of Hebei University(Grant No.IT2023B03)the Excellent Youth Research Innovation Team of Hebei University(Grant No.QNTD202402)。
文摘A new type of localized oscillatory pattern is presented in a two-layer coupled reaction-diffusion system under conditions in which no Hopf instability can be discerned in either layer.The transitions from stationary patterns to asynchronous and synchronous oscillatory patterns are obtained.A novel method based on decomposing coupled systems into two associated subsystems has been proposed to elucidate the mechanism of formation of oscillating patterns.Linear stability analysis of the associated subsystems reveals that the Turing pattern in one layer induces the other layer locally,undergoes a supercritical Hopf bifurcation and gives rise to localized oscillations.It is found that the sizes and positions of oscillations are determined by the spatial distribution of the Turing patterns.When the size is large,localized traveling waves such as spirals and targets emerge.These results may be useful for deeper understanding of pattern formation in complex systems,particularly multilayered systems.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)National Natural Science Foundation of China(42105015)+3 种基金Guangdong Basic and Applied Basic Research Foundation(2022A1515010659)Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP209)Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021001)Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies(2020B1212060025)。
文摘Sub-seasonal prediction of regional compound heatwaves and their predictability sources remain unclear.In this study,the underlying mechanisms for the long-lasting compound heatwave over Southern China during July 1–18,2010,and the major sources of its sub-seasonal prediction skill are identified.The results show that both the development and decay of this compound heatwave are mainly dominated by atmospheric processes(i.e.,adiabatic heating associated with anticyclonic circulation),whereas land-atmosphere coupling processes play an important role in sustaining the heatwave.A further analysis indicates that by inducing anomalous anticyclonic circulations over Southern China,the tropical intraseasonal oscillations with periods of 30–60 days and 10–30 days facilitate the occurrence and maintenance of the heatwave during its entire and second half periods,respectively.The NCEP Climate Forecast System Version 2 shows a low skill in predicting the 2010 compound heatwave over Southern China when the lead time is longer than 2 pentads,which is largely attributed to the model’s bias in representing the intensity and phase of intra-seasonal oscillations.
文摘The use of solar energy is today widely recognized for the green transition but also for addressing societal challenges associated with the rise in global surface temperature. The design of a photovoltaic solar panel field may require an understanding of how solar radiation oscillates with other variables or factors since multiple interactions occur during its transfer within the atmosphere. In this study, three years of the incoming shortwave radiation (SWin) and air temperature (Tair) data acquired within the “Institut de Mathématiques et de Sciences Physiques” were analyzed using the continuous wavelet transform to extract the inherent variability of these signals. The underlying characteristics meaning the timescale of these variabilities as well as the lead-lag relationship between SWin and Tair were also examined. With the wavelet power spectrum, the highest variability was evidenced at the 2 - 8 band period for the SWin, coinciding almost with that of Tair. This suggests that these two signals are well interconnected at this temporal scale. The results obtained with the phase (∅xy) difference analysis, reveal that SWin leads Tair by ~ 23.5˚ on average when (0 ∅xy∅xyi.e., periods ≤ 32 days), Tair increases with an increasing SWin since the lags between these two signals range between 0.09 - 2.30 days. However, when looking at their interdependence at a larger temporal scale (> 32 days), Tair lags SWin. An increase in SWin might not directly imply an increase in Tair. Overall, these findings give insight into complex relationships across scales between the incoming shortwave radiation and air temperature in a tropical humid region of Bénin.
文摘An accurate 1.08GHz CMOS LC voltage-controlled oscillator is implemented in a 0.35μm standard 2P4M CMOS process.A new convenient method of calculating oscillator period is presented.With this period calculation technique,the frequency tuning curves agree well with the experiment.At a 3.3V supply,the LC-VCO measures a phase noise of -82.2dBc/Hz at a 10kHz frequency offset while dissipating 3.1mA current.The chip size is 0.86mm×0.82mm.
