Catálogo de publicaciones - revistas

<jats:p>We studied quantum correlation and quantum entanglement of a quantum system in which a coherent state light field interacts with two qubits that are initially prepared in a separable and mixed state. The influence of mean photon number of the coherent field and distribution probability of the atom on the geometrical quantum discord and the negativity are discussed. Our results show that the mean photon number of light field and distribution function of the atom can regulate and control the quantum correlation and quantum entanglement.</jats:p>

<jats:p>A new Willis aneurysm system is proposed, which contains the Atangana–Baleanu(AB) fractional derivative. we obtain the numerical solution of the Atangana–Baleanu fractional Willis aneurysm system (ABWAS) with the AB fractional integral and the predictor–corrector scheme. Moreover, we research the chaotic properties of ABWAS with phase diagrams and Poincare sections. The different values of pulse pressure and system order are used to evaluate and compare their effects on ABWAS. The simulations verify that the changes of pulse pressure and system order are the significant reason for ABWAS’ states varying from chaotic to steady. In addition, compared with Caputo fractional WAS (FWAS), ABWAS shows less state that is chaotic. Furthermore, the results of bifurcation diagrams of blood flow damping coefficient and reciprocal heart rate show that the blood flow velocity tends to stabilize with the increase of blood flow damping coefficient or reciprocal heart rate, which is consistent with embolization therapy and drug therapy for clinical treatment of cerebral aneurysms. Finally, in view of the fact that ABWAS in chaotic state increases the possibility of rupture of cerebral aneurysms, a reasonable controller is designed to control ABWAS based on the stability theory. Compared with the control results of FWAS by the same method, the results show that the blood flow velocity in the ABWAS system varies in a smaller range. Therefore, the control effect of ABWAS is better and more stable. The new Willis aneurysm system with Atangana–Baleanu fractional derivative provides new information for the further study on treatment and control of brain aneurysms.</jats:p>

<jats:p>Extracting characteristic signal from a continuous signal can effectively reduce the difficulty of analyzing the running states of a single-variable nonlinear system. Whether the extracted characteristic signal can accurately reflect the running states of the system is very important. In this paper, a method called automatic sampling method (ASM) for extracting characteristic signals is investigated. The complete definition is described, the effectiveness is proved theoretically, and the general formulas of the extracted characteristic signals are derived for the first time. Furthermore, typical Chuaʼs circuit is used to accomplish a lot of experimental research on the aspect of frequency domain. The experimental results show that ASM is feasible and practical, and can automatically generate a characteristic signal with the change of the original signal.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>There has been much interest in studying quasi-periodic events on earthquake models. Here we investigate quasi-periodic events in the avalanche time series on structured earthquake models by the analysis of the autocorrelation function and the fast Fourier transform. For random spatial earthquake models, quasi-periodic events are robust and we obtain a simple rule for a period that is proportional to the choice of unit time and the dissipation of the system. Moreover, computer simulations validate this rule for two-dimensional lattice models and cycle graphs, but our simulation results also show that small-world models, scale-free models, and random rule graphs do not have periodic phenomena. Although the periodicity of avalanche does not depend on the criticality of the system or the average degree of the system or the size of the system, there is evidence that it depends on the time series of the average force of the system.</jats:p>

<jats:p>We propose a new approach to discuss the consensus problem of multi-agent systems with time-varying delayed control inputs, switching topologies, and stochastic cyber-attacks under hybrid-triggered mechanism. A Bernoulli variable is used to describe the hybrid-triggered scheme, which is introduced to alleviate the burden of the network. The mathematical model of the closed-loop control system is established by taking the influences of time-varying delayed control inputs, switching topologies, and stochastic cyber-attacks into account under the hybrid-triggered scheme. A theorem as the main result is given to make the system consistent based on the theory of Lyapunov stability and linear matrix inequality. Markov jumps with uncertain rates of transitions are applied to describe the switch of topologies. Finally, a simulation example demonstrates the feasibility of the theory in this paper.</jats:p>

<jats:p>The multi-walled carbon nanotubes (MWCNTs) studied in this work were synthesized by the catalytic chemical vapor deposition (CCVD) process, and were thermally annealed by the hot filament plasma enhanced (HF PE) method at 550 °C for two hours. The x-ray absorption near edge structure (XANES) technique was used to investigate the adsorption and desorption phenomena of the MWCNTs at normal and grazing incidence angles. The adsorbates were found to have different sensitivities to the thermal annealing. The geometry of the incident beam consistently gave information about the adsorption and desorption phenomena. In addition, the adsorption of non-intrinsic potassium quantitatively affected the intrinsic adsorbates and contributed to increase the conductivity of the MWCNTs. The desorption of potassium was almost 70% greater after the thermal annealing. The potassium non-intrinsic adsorbates are from a physisorption mechanism whereas the intrinsic adsorbates result from chemisorption.</jats:p>

<jats:p>The excited state intramolecular proton transfer of four derivatives (FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated. The geometries of different substituents are optimized to study the substituent effects on proton transfer. The mechanism of hydrogen bond enhancement is qualitatively elucidated by comparing the infrared spectra, the reduced density gradient, and the frontier molecular orbitals. The calculated electronic spectra are consistent with the experimental results. To quantify the proton transfer, the potential energy curves (PECs) of the four derivatives in S<jats:sub>0</jats:sub> and S<jats:sub>1</jats:sub> states are scanned. It is concluded that the ability of proton transfer follows the order: FM <jats:inline-formula> <jats:tex-math><?CDATA $\gt $?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>&gt;</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_9_093102_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> BFM <jats:inline-formula> <jats:tex-math><?CDATA $\gt $?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>&gt;</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_9_093102_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> BFBC <jats:inline-formula> <jats:tex-math><?CDATA $\gt $?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>&gt;</mml:mo> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_9_093102_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> CCM.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Bichromatic circularly polarized fields provide a useful tool to probe the ionization dynamics. In this work, we compare the photoelectron momentum distribution in few-cycle bichromatic field of different helicities. The spectral features are analyzed with semiclassical trajectories derived from the strong field approximation. In particular, the interference fringes in momentum distribution are investigated by tracking the ionization time and tunneling exits of released photoelectrons. Different types of trajectories that contribute to the interference fringes are elucidated.</jats:p>

<jats:p>We experimentally investigate Coulomb exploded directional double ionization of N<jats:sub>2</jats:sub>O molecules in elliptically polarized femtosecond laser pulses. The denitrogenation and deoxygenation channels are accessed via various pathways. It leads to distinct asymmetries in directional breaking of the doubly ionized N<jats:sub>2</jats:sub>O molecules versus the instantaneous laser field vector, which is revealed by tracing the sum-momentum spectra of the ionic fragments as a recoil of the ejected electrons. Our results demonstrate that the accessibility of the Coulomb exploded double ionization channels of N<jats:sub>2</jats:sub>O molecules are ruled by the detailed potential energy curves, and the directional emission of the fragments are governed by the joint effects of the electron localization-assisted enhanced ionization of the stretched molecules and the profiles of the molecular orbitals.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>An optical lattice could be produced either by splitting an input light (splitting scheme) or by reflecting the input light by a mirror (retro-reflected scheme). We study quantum dynamical properties of an atomic Bose–Einstein condensate (BEC) in the two schemes. Adopting a mean field theory and neglecting collision interactions between atoms, we find that the momentum and spatial distributions of BEC are always symmetric in the splitting scheme which, however, are asymmetric in the retro-reflected scheme. The reason for this difference is due to the local field effect. Furthermore, we propose an effective method to avoid asymmetric diffraction.</jats:p>