Catálogo de publicaciones - revistas

<jats:p>The spiral waves anchored to heterogeneous areas are more difficult to control and eliminate than freely rotating ones in homogenous mediums. To eliminate pinned spiral waves, the resistant force should be provided to resist the pinning force. Other than advection field, we introduce parametric wave to play the role of providing resistant force. It is found that the parametric wave with large enough amplitude and proper frequency can unpin and eliminate the spiral wave successfully. The capability of parametric wave in providing resistant force is dependent on its amplitude and frequency sensitively. On the basis of parametric wave, the dependence of pinning force on the size and level of heterogeneity is further confirmed.</jats:p>

<jats:p>Over the last few years, the interplay between contagion dynamics of social influences (e.g., human awareness, risk perception, and information dissemination) and biological infections has been extensively investigated within the framework of multiplex networks. The vast majority of existing multiplex network spreading models typically resort to heterogeneous mean-field approximation and microscopic Markov chain approaches. Such approaches usually manifest richer dynamical properties on multiplex networks than those on simplex networks; however, they fall short of a subtle analysis of the variations in connections between nodes of the network and fail to account for the adaptive behavioral changes among individuals in response to epidemic outbreaks. To transcend these limitations, in this paper we develop a highly integrated effective degree approach to modeling epidemic and awareness spreading processes on multiplex networks coupled with awareness-dependent adaptive rewiring. This approach keeps track of the number of nearest neighbors in each state of an individual; consequently, it allows for the integration of changes in local contacts into the multiplex network model. We derive a formula for the threshold condition of contagion outbreak. Also, we provide a lower bound for the threshold parameter to indicate the effect of adaptive rewiring. The threshold analysis is confirmed by extensive simulations. Our results show that awareness-dependent link rewiring plays an important role in enhancing the transmission threshold as well as lowering the epidemic prevalence. Moreover, it is revealed that intensified awareness diffusion in conjunction with enhanced link rewiring makes a greater contribution to disease prevention and control. In addition, the critical phenomenon is observed in the dependence of the epidemic threshold on the awareness diffusion rate, supporting the metacritical point previously reported in literature. This work may shed light on understanding of the interplay between epidemic dynamics and social contagion on adaptive networks.</jats:p>

<jats:p>We introduce a new integral scheme namely improved Kudryashov method for solving any nonlinear fractional differential model. Specifically, we apply the approach to the nonlinear space–time fractional model leading the wave to spread in electrical transmission lines (s-tfETL), the time fractional complex Schrödinger (tfcS), and the space–time M-fractional Schrödinger–Hirota (s-tM-fSH) models to verify the effectiveness of the proposed approach. The implementing of the introduced new technique based on the models provides us with periodic envelope, exponentially changeable soliton envelope, rational rogue wave, periodic rogue wave, combo periodic-soliton, and combo rational-soliton solutions, which are much interesting phenomena in nonlinear sciences. Thus the results disclose that the proposed technique is very effective and straight-forward, and such solutions of the models are much more fruitful than those from the generalized Kudryashov and the modified Kudryashov methods.</jats:p>

<jats:p>Non-Hermitian systems have observed numerous novel phenomena and might lead to various applications. Unlike standard quantum physics, the conservation of energy guaranteed by the closed system is broken in the non-Hermitian system, and the energy can be exchanged between the system and the environment. Here we present a scheme for simulating the dissipative phase transition with an open quantum optical system. The competition between the coherent interaction and dissipation leads to the second-order phase transition. Furthermore, the quantum correlation in terms of squeezing is studied around the critical point. Our work may provide a new route to explore the non-Hermitian quantum physics with feasible techniques in experiments.</jats:p>

<jats:p>The wave–particle duality relation derived by Englert sets an upper bound of the extractable information from wave and particle properties in a two-path interferometer. Surprisingly, previous studies demonstrated that the introduction of a quantum beamsplitter in the interferometer could break the limitation of this upper bound, due to interference between wave and particle states. Along the other line, a lot of efforts have been made to generalize this relation from the two-path setup to the <jats:italic>N</jats:italic>-path case. Thus, it is an interesting question that whether a quantum <jats:italic>N</jats:italic>-path beamsplitter can break the limitation as well. This paper systemically studies the model of a quantum <jats:italic>N</jats:italic>-path beamsplitter, and finds that the generalized wave–particle duality relation between interference visibility and path distinguishability is also broken in certain situations. We further study the maximal extractable information’s reliance on the interference between wave and particle properties, and derive a quantitative description. We then propose an experimental methodology to verify the break of the limitation. Our work reflects the effect of quantum superposition on wave–particle duality, and exhibits a new aspect of the relation between visibility and path distinguishability in <jats:italic>N</jats:italic>-path interference. Moreover, it implies the observer’s influence on wave–particle duality.</jats:p>

<jats:p>We explore the robustness of a network against failures of vertices or edges where a fraction <jats:italic>f</jats:italic> of vertices is removed and an overload model based on betweenness is constructed. It is assumed that the load and capacity of vertex <jats:italic>i</jats:italic> are correlated with its betweenness centrality <jats:italic>B<jats:sub>i</jats:sub> </jats:italic> as <jats:inline-formula> <jats:tex-math><?CDATA ${B}_{i}^{\theta }$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>i</mml:mi> <mml:mi>θ</mml:mi> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_5_050501_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $(1+\alpha){B}_{i}^{\theta }$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> <mml:mi>α</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:msubsup> <mml:mi>B</mml:mi> <mml:mi>i</mml:mi> <mml:mi>θ</mml:mi> </mml:msubsup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_5_050501_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> (<jats:italic>θ</jats:italic> is the strength parameter, <jats:italic>α</jats:italic> is the tolerance parameter). We model the cascading failures following a local load preferential sharing rule. It is found that there exists a minimal <jats:italic>α</jats:italic> <jats:sub>c</jats:sub> when <jats:italic>θ</jats:italic> is between 0 and 1, and its theoretical analysis is given. The minimal <jats:italic>α</jats:italic> <jats:sub>c</jats:sub> characterizes the strongest robustness of a network against cascading failures triggered by removing a random fraction <jats:italic>f</jats:italic> of vertices. It is realized that the minimal <jats:italic>α</jats:italic> <jats:sub>c</jats:sub> increases with the increase of the removal fraction <jats:italic>f</jats:italic> or the decrease of average degree. In addition, we compare the robustness of networks whose overload models are characterized by degree and betweenness, and find that the networks based on betweenness have stronger robustness against the random removal of a fraction <jats:italic>f</jats:italic> of vertices.</jats:p>

<jats:p>In traditional viewpoint, excitatory modulation always promotes neural firing activities. On contrary, the negative responses of complex bursting behaviors to excitatory self-feedback mediated by autapse with time delay are acquired in the present paper. Two representative bursting patterns which are identified respectively to be “Fold/Big Homoclinic” bursting and “Circle/Fold cycle” bursting with bifurcations are studied. For both burstings, excitatory modulation can induce less spikes per burst for suitable time delay and strength of the self-feedback/autapse, because the modulation can change the initial or termination phases of the burst. For the former bursting composed of quiescent state and burst, the mean firing frequency exhibits increase, due to that the quiescent state becomes much shorter than the burst. However, for the latter bursting pattern with more complex behavior which is depolarization block lying between burst and quiescent state, the firing frequency manifests decrease in a wide range of time delay and strength, because the duration of both depolarization block and quiescent state becomes long. Therefore, the decrease degree of spike number per burst is larger than that of the bursting period, which is the cause for the decrease of firing frequency. Such reduced bursting activity is explained with the relations between the bifurcation points of the fast subsystem and the bursting trajectory. The present paper provides novel examples of paradoxical phenomenon that the excitatory effect induces negative responses, which presents possible novel modulation measures and potential functions of excitatory self-feedback/autapse to reduce bursting activities.</jats:p>

<jats:p>It is shown that we can control spatiotemporal chaos in the Frenkel–Kontorova (FK) model by a model-free control method based on reinforcement learning. The method uses <jats:italic>Q</jats:italic>-learning to find optimal control strategies based on the reward feedback from the environment that maximizes its performance. The optimal control strategies are recorded in a <jats:italic>Q</jats:italic>-table and then employed to implement controllers. The advantage of the method is that it does not require an explicit knowledge of the system, target states, and unstable periodic orbits. All that we need is the parameters that we are trying to control and an unknown simulation model that represents the interactive environment. To control the FK model, we employ the perturbation policy on two different kinds of parameters, <jats:italic>i.e.</jats:italic>, the pendulum lengths and the phase angles. We show that both of the two perturbation techniques, <jats:italic>i.e.</jats:italic>, changing the lengths and changing their phase angles, can suppress chaos in the system and make it create the periodic patterns. The form of patterns depends on the initial values of the angular displacements and velocities. In particular, we show that the pinning control strategy, which only changes a small number of lengths or phase angles, can be put into effect.</jats:p>

<jats:p>Based on three-level exciton model, the enhanced photonic microwave signal generation by using a sole excited-state (ES) emitting quantum dot (QD) laser under both optical injection and optical feedback is numerically studied. Within the range of period-one (P1) dynamics caused by the optical injection, the variations of microwave frequency and microwave intensity with the parameters of frequency detuning and injection strength are demonstrated. It is found that the microwave frequency can be continuously tuned by adjusting the injection parameters, and the microwave intensity can be enhanced by changing the injection strength. Moreover, considering that the generated microwave has a wide linewidth, an optical feedback loop is further employed to compress the linewidth, and the effect of feedback parameters on the linewidth is investigated. It is found that with the increase of feedback strength or delay time, the linewidth is evidently decreased due to the locking effect. However, for the relatively large feedback strength or delay time, the linewidth compression effect becomes worse due to the gradually destroyed P1 dynamics. Besides, through optimizing the feedback parameters, the linewidth can be reduced by up to more than one order of magnitude for different microwave frequencies.</jats:p>

<jats:p>The 795 nm distributed feedback lasers have great application in pumping the Rb D1 transition. In this paper, in order to realize specific 795 nm lasing, we designed tilted ridge distributed feedback lasers based on purely gain coupled effect induced by periodic current injection windows through changing the angle of the tilted ridge. The fabricated devices were cleaved into 2 mm-cavity-length, including 5 tilted angles. The peak output powers of all devices were above 30 mW. Single longitudinal mode lasing was realized in all tilted Fabry–Perot cavities using periodic current injection windows, with side mode suppression ratio over 30 dB. The total wavelength range covered 8.656 nm at 20 °C. It was disclosed theoretically and experimentally that the output powers, threshold currents, and central wavelengths of the tilted ridge purely gain coupled DFB lasers were relevant to the tilted angles. The results will be instructive for future design of DFB laser arrays with different central wavelengths.</jats:p>