Modern Physics Letters B

Aiming at improving the flexibility of designing the phosphorene-based nanodevices, we propose three kinds of Z-shaped phosphorene nanoribbons (ZPNRs), which are composed of two metallic nanoribbon electrodes and one semiconducting/metallic nanoribbon central region (CR). Many anomalous properties including the unexpected current increasing under the low bias voltage, the negative differential conductance, and the transition of the transport mechanism are found to be universal in different ZPNRs. Also, we find the current can be significantly suppressed by increasing the CR length, while no complete suppression can be induced by the increase of the CR width, indicating that the CR length and width will make different influences on the ZPNR transport. Moreover, the energy spectrums of two electrodes, the molecular energy levels of the CR, the transmission coefficients, and the transmission eigenstates are further calculated so as to clearly expound the anomalous properties and their universalities. We believe this research can provide a meaningful guidance for developing the phosphorene-based electronic devices.

A highly sensitive surface plasmon resonance (SPR) sensor composed of a photonic crystal fiber (PCF) with the D-type structure is designed and analyzed by the full-vector finite element method (FEM). Indium tin oxide (ITO) is adopted as the plasmonic substance on account of the low cost and controllable infrared range (1500–2600 nm). By optimizing the structural parameters, the sensor shows a maximum wavelength sensitivity of 46,000 nm/RIU and average sensitivity of 13,166.67 nm/RIU for analyte refractive indexes between 1.355 and 1.385. This PCF combining a circular layout and D-type structure offers excellent sensitivity while the deposition and manufacturing complexity can be reduced. This sensor will possess an extremely expansive development space in the field of chemical analysis and environmental safety.

Instantaneous cavitating turbulent flow in a two-stage centrifugal pump with diffuser was simulated using a hybrid RANS/LES model and rotating corrected-based cavitation model in this paper. The predicted results of numerical simulation were in good agreement with the experimental results. The mechanism of pressure pulsation in the two-stage centrifugal pump was discussed. Some representative main frequencies of pressure pulsation such as main blade passing frequency, sub-blade passing frequency and intersection frequency of impeller blade and diffuser blade were analyzed systematically. Uncertainty estimation was used to ensure the accuracy of experimental results and it was also used to analyze the variation of pressure pulsation and vibration signals at different positions with the intensification of cavitation degree in the centrifugal pump. According to the results of uncertainty estimation, the center frequency of 1/3 octave band and the root mean square method were used to evaluate the energy change of the pressure pulsation signals and vibration signals at different frequency bands as the cavitation number decreases. The characteristics of pressure pulsation and vibration signals at different positions were analyzed in different frequency bands.

This study is made to extract the exact solutions of Korteweg–de Vries–Burgers (KdVB) equation and Korteweg–de Vries (KdV) equation. The original idea of this work is to investigate KdV equation and KdVB equation for possible closed form solutions by employing the modified auxiliary equation (MAE) method. Exact traveling wave solutions of the considered equations are retrieved in the form of trigonometric and hyperbolic functions. Kink, periodic and singular wave patterns are obtained from the constructed solutions. The graphical illustration of the wave solutions is presented using 3D-surface plots to acquire the understanding of physical behavior of the obtained results up to possible extent.

In this paper, we examined four different forms of generalized (2+1)-dimensional Boussinesq–Kadomtsev–Petviashvili (B-KP)-like equations. In this connection, an accurate computational method based on the Riccati equation called sub-equation method and its Bäcklund transformation is employed. Using this method, numerous exact solutions that do not exist in the literature have been obtained in the form of trigonometric, hyperbolic, and rational. These solutions are of considerable importance in applied sciences, coastal, and ocean engineering, where the B–KP-like equations modeled for some significant physical phenomenon. The graph of the bright and dark solitons is presented in order to demonstrate the influence of different physical parameters on the solutions. All of the findings prove the stability, effectiveness, and accuracy of the proposed method.

In this paper, the physics-informed neural networks (PINNs) are applied to high-dimensional system to solve the $(N+1)$-dimensional initial-boundary value problem with $2N+1$ hyperplane boundaries. This method is used to solve the most classic (2+1)-dimensional integrable Kadomtsev–Petviashvili (KP) equation and (3+1)-dimensional reduced KP equation. The dynamics of (2+1)-dimensional local waves such as solitons, breathers, lump and resonance rogue are reproduced. Numerical results display that the magnitude of the error is much smaller than the wave height itself, so it is considered that the classical solutions in these integrable systems are well obtained based on the data-driven mechanism.

In this paper, the electrical and optical properties of single-layer MoS₂ and single-layer WS₂ in three strain states: biaxial tension, biaxial compression, biaxial tension and compression are systematically studied. All calculations are based on the first-principle of density functional theory. The results show that after biaxial tension strain, biaxial compression strain, and biaxial tension-compression strain are applied, the atomic structure, energy band structure, and optical absorption coefficient will show disparate changing trends. When the biaxial tension and compression strain intensity is less than 15%, the bond length, bond angle, and light absorption peak will have little fluctuation with the increase of strain intensity. However, compared with the other two strain states, these two crystal structures are the most volatile at this time. In addition, when 15% biaxial tensile strain is applied, the two crystals can still maintain their kinetic stability.

To further improve the properties of the Al–11.5Si–0.4Fe–0.35Mg, the effects of different reductions of hot-rolling (HR) Al–Si–Fe–Mg alloy on microstructure, thermal conductivity (TC), and mechanical properties were investigated in this paper. The results show that the eutectic silicon phases are broken and moved during the HR process. The average size of eutectic silicon phase decreases. Meanwhile, the aspect ratio of eutectic silicon phase closer to 1 and the distribution of that are more uniform with the increase of HR reduction. In addition, the ternary Al–Fe–Si phases are also broken after HR. It indicates that the action of shear force induced by the HR process is beneficial to promote refinement and spheroidization of the eutectic silicon phase, hence further improves the properties of the alloy. Apparently, the fine and dispersed distribution of spherical silicon particles can minimize the splitting of the $\alpha$-Al matrix, decrease the scattering effect on free electrons, and increase the number of free-electron transport channel. Therefore, the overall performance of HR Al–Si–Fe–Mg alloy with a reduction of 71.25% is the best with the TC of 170.24 W/m$\cdot$K, the tensile strength of 241.98 MPa and elongation of 8.73%, respectively.

In the applied research of nonlinear system, the low degree of chaos in the dynamical system leads to the limitation of using the chaos method to solve some practical problems. In this paper, we use the product trigonometric function and ternary polynomial to build a dynamical system, which has strong chaotic characteristics. The dynamical system is constructed by two product trigonometric functions and a ternary linear equation, and its chaotic properties are verified by bifurcation diagrams, Lyapunov exponents, fractal dimensions, etc. The system has many parameters and large parameter intervals and is not prone to cycles. The conditions for the non-divergence of this system are given by mathematical derivation, and it is found that the linear part of the system can be replaced by an arbitrary ternary polynomial system and still not diverge, and the bifurcation diagram is drawn to verify it. Finally, the chaotic sequence is distributed more uniformly in the value domain space by adding the modulo operation. Then, the bit matrix of multiple images is directly permuted by the above system, and the experiment confirms that the histogram, information entropy, and pixel correlation of its encrypted images are satisfactory, as well as a very large key space.

In this paper, we consider a model of an artificial neural network based on quantum-mechanical particles in $W$ potential. These particles play the role of neurons in our model. To simulate such a quantum-mechanical system, the Monte Carlo integration method is used. A form of the self-potential of a particle as well as two interaction potentials (exciting and inhibiting) are proposed. Examples of simplest logical elements (such as AND, OR and NOT) are shown. Further, we show an implementation of the simplest convolutional network in framework of our model.

Under the Vehicle-to-Vehicle (V2V) environment, connected vehicles (CVs) can share the traveling information with each other to keep the traffic flow stable. However, the open network cooperation environment makes CVs vulnerable to cyberattacks, which leads to changes in driving behavior. The existing theories divide cyberattacks into three types: bogus information, replay/delay and collusion cyberattacks. In addition, the mixed flow consisting of truck and car is a common form of road traffic. In order to clarify the potential impact of cyberattacks on mixed traffic flow, this paper proposes an extended car-following model considering cyberattacks under CVs environment. Subsequently, the stability of the model is analyzed theoretically, and the stability condition of the model is obtained. The numerical simulation is carried out and the result shows that the cyberattacks lead to different degrees of traffic behavior hazards such as queue time extension, congestion and even rear end collision. Among them, cooperative attack is the most serious.

This paper proposes an interesting autonomous chaotic system with hidden attractors and coexisting attractors. The system has no equilibrium, one equilibrium, three equilibria and line equilibria for different parameter regions. The existence of hidden attractors and coexisting attractors of the system has been revealed by using simulation analysis. The bifurcation diagram shows the period-doubling bifurcation route to chaos with the variation of parameters. The analog circuit and FPGA implementation of the system are presented. The synchronization for secure communication of the system is investigated. The synchronization conditions are established by using the adaptive control method.