Modern Physics Letters B

In this work, a (2 + 1)-dimensional generalized Nizhnik–Novikov–Veselov (GNNV) equation, which can be reduced to several integrable equations, is under investigation. By virtue of Bell’s polynomials, an effective and straightforward way is presented to succinctly construct its two bilinear forms. Furthermore, based on the bilinear formalism and the extended homoclinic test, the breather wave solution, rogue-wave solution and solitary-wave solution of the equation are well constructed. The results can be used to enrich the dynamical behavior of the (2 + 1)-dimensional nonlinear wave fields.

High quality bus service is considered as an efficient way to mitigate traffic congestion in big cities. Global positioning system (GPS) data provide sufficient sources to evaluate the performance of bus vehicles that both passengers and operator concern about. This paper aims to propose a framework to assess the operational performance of bus routes based on the GPS trajectory data collected from Jinan, China. Several important indicators of bus operation including travel time of routes, section running time, dwell time and bus bunching have been studied. The results show that the travel time of routes follow right skewed distributions. Moreover, section running time between two consecutive stations varies in different time period and it is larger in evening peak hours. Additionally, the dwell time has been discussed and the results show that there is no big variation in most stations except some stations, which provides a help to identify the key stations. Furthermore, we propose an approach to detect the bunching points. The results indicate the bunching points are easy to occur in the peak hours and the congested road section.

${\mathrm{\text{MoO}}}_{2+x}$ has novel peculiarities and complexities due to multiple valence states of 4d molybdenum, but high carrier density impedes its thermoelectric (TE) application. Recent investigation has demonstrated that the TE performance of transition metal oxide films can be greatly enhanced by activating a parallel conduction channel in the perovskite substrates through reversible incorporation of oxygen. In this work, we report the TE properties of ${\mathrm{\text{MoO}}}_{2+x}$ thin films deposited on single crystalline Si and quartz glass substrates by magnetron sputtering. The TE power factor (PF) in the former is above 40 times bigger than that in the latter. Such a large enhancement originates mainly from the significantly enhanced Seebeck coefficient, correlated with the contribution of the Si substrate. The highest PF value 1.78 mW/(m⋅K²) at 700 K in this ${\mathrm{\text{MoO}}}_{2+x}$/Si system is comparable to the state-of-the-art in other TE thin films. Based on the preceding research, our experimental results suggest a more economic and scalable route to explore high-performance TE thin films.

In this paper, a refractive index and temperature sensor based on Fano resonance is realized. The proposed structure is composed of a MIM waveguide and a defect cavity which is filled with sealed ethanol. The Fano spectra and field distribution is numerically investigated by the two-dimensional finite-difference time-domain (FDTD) method. Due to the symmetry breaking, the sharp and asymmetric transmission spectra can be used as a sensor with high sensitivity. The sensitivity of the proposed structure can be up to 652 nm/RIU and $0.225\mathrm{\text{nm}}{/}^{\circ }\mathrm{\text{C}}$. Because of the high sensitivity, the proposed plasmonic structure may have potential application in nanosensing.

In this study, we acquire some new exact traveling wave solutions to the nonlinear Schrödinger’s equation in the presence of Hamiltonian perturbations. The compendious integration tool, generalized exponential rational function method (GERFM), is utilized in the presence of quadratic-cubic nonlinear media. The obtained results depict the efficiency of the proposed scheme and are being reported for the first time.

We present an analysis of Josephson effects in one quantum-dot-embedded junction with one s-wave superconductor (SC) and two topological superconductors (TSs). It is found that when superconducting phase difference is applied between the two TSs, the dot-SC coupling can efficiently modulate the fractional Josephson effect, including the changes of the supercurrent oscillation direction and period. Even though the polarization directions of the TSs are opposite, the dot-SC coupling enables to drive the fractional Josephson effect between the TSs. Next, as the superconducting phase difference is introduced between the TSs and SC, only the normal Josephson effect takes place.

This paper retrieves Jacobi elliptic, periodic, bright and singular solitons for paraxial nonlinear Schrödinger equation (NLSE) in Kerr media. We use extended trial equation method to obtain these solitons solutions. For the existence of the soliton solutions, constraint conditions are also presented.

The MgO/low-density polyethylene nanocomposite film and the sandwich-structure LDPE/MgO-LDPE/LDPE nanocomposite film were prepared by melt blending and hot pressing. Based on the Maxwell–Wagner effect, a theoretical model of the three-layer dielectric interface polarization was set up, and the charge density of the three layers of dielectric interface polarization is obtained. Then pulsed electro-acoustic (PEA) is used to study the charge distribution characteristics of the three-layer structure while the breakdown strength of the three-layer structure is tested. The formation and transmission mechanism of the interface charge is systematically analyzed through the above two methods. The results show that the formation of space charge at the interface of sandwich-structure film is likely to be the result of the interaction between the three-layer dielectric polarization effect and the capture charge mechanism at the interface. Compared with the single-layer composite film, the sandwich-structure nanocomposite film has higher breakdown strength, the reason may be that the charge is trapped by the charge trapping mechanism at the interface during the movement of the opposite electrode to form an interfacial space charge, and as the charge accumulates continuously to form a barrier at the interface, the barrier can effectively inhibit the formation of the conductive channel, and the material is improved. The breakdown field is strong.

A three-party quantum secret sharing scheme is proposed, in which the dealer uses the d-dimensional Bell state to distribute the secret, the participants perform the single-particle measurements to get their shares, and the dealer performs the Bell-basis measurements to check the eavesdropping. The main merit of our scheme is that the participants only need to measure the particles in one basis. Compared to the existing schemes in which the participants need to measure the particles in two bases, our scheme will be more practical.

In this work, we have studied the magnetocaloric effect (MCE) of a paramagnetic salt under the view of the Tsallis thermostatistics formalism. In order to model the paramagnetic salt we have used the simple two-level model. Within this model, it is possible to realize the role of the Tsallis parameter q for all thermodynamics variables calculated here, i.e. the internal energy, the specific heat, the entropy, and the magnetocaloric potential. The main result presented in this work is the relation between the total heat related to the MCE and the q-parameter of the Tsallis theory. There is a threshold value of q where, above this value, the total heat change is constant for all q while below this value, there is a quick decreasing.

Two-phase permanent magnets with soft and hard magnetic phases are suitable candidates for high energy product permanent magnets. To obtain enhanced energy product, the microstructure has to be optimum and the magnetization and nucleation field has to be as large as possible. The present studies suggest suitable combinations of soft–hard composites that could result in higher energy product. The role of microstructural parameter on the energy product is also presented.

This paper presents a new four-dimensional chaotic system with three nonlinearities and two equilibria. The most striking feature of the new system is that it has different types of asymmetric coexisting attractors. Simulation experiments are used to study the complex dynamic behaviors of the system. The chaos, period-doubling bifurcation, coexisting attractors with respect to system parameters and initial values are found in the system. It shows that the system has coexisting chaotic attractors, coexisting periodic attractors, coexisting chaotic and periodic attractors. The electronic circuit is applied to implement the chaotic attractor and coexisting attractors for studying the physical significance of the system. In addition, we consider the synchronization of the system by using the impulsive control method. Some synchronization criteria are established via theoretical analysis and simulation example.

The polycrystalline skutterudite ${\mathrm{\text{Ba}}}_{0.2}{\mathrm{\text{Co}}}_4{\mathrm{\text{Sb}}}_{11.5}{\mathrm{\text{Te}}}_{0.5}$ were successfully synthesized from 1.5 GPa to 3.5 GPa by the high pressure and high temperature (HPHT) method. Negative Seebeck coefficient confirmed the n-type conductivity of all samples. The phase compositions of samples were investigated by X-ray diffraction (XRD) and the microstructures were observed by scanning electron microscopy (SEM). It was found that the grains appeared smaller and the grain boundaries became more abundant when pressures were higher. We measured the electrical properties from room temperature to 723 K. Both the electrical resistivity and absolute value of Seebeck coefficient increase with the increasing synthetic pressure. At 723 K, the maximum power factor of $20.6\mu {\mathrm{\text{Wcm}}}^{-1}{\mathrm{\text{K}}}^{-2}$ was obtained for the sample synthesized under 3 GPa. The maximum ZT value of 0.61 was reached by ${\mathrm{\text{Ba}}}_{0.2}{\mathrm{\text{Co}}}_4{\mathrm{\text{Sb}}}_{11.5}{\mathrm{\text{Te}}}_{0.5}$ synthesized under 3 GPa and measured at 723 K.

An implicit symmetry constraint of the famous Toda lattice hierarchy is presented. Using this symmetry constraint, every lattice equation in the Toda hierarchy is decomposed by an integrable symplectic map and a completely integrable finite-dimensional Hamiltonian system.