Modern Physics Letters B

Community detection is of extraordinary significance in comprehending the structure and functions of complex networks. The particle competition algorithm is a quick and heuristic algorithm when applied to community detection. However, existing particle competition algorithms do not make full use of all information of networks and have several shortcomings such as poor robustness, weak stability, and low accuracy. In addition, it cannot be effectively applied to overlapping community detection. In this paper, a new particle propagation model with semi-supervised learning for community detection in social networks (SSPCO) is proposed. SSPCO divides the formation process of communities into the initialization phase, walking phase, restart phase, convergence phase and overlapping community detection phase. In the initialization phase, each team of labeled vertices generates a particle of this team. The domination level of each team particles at vertices and edges is also initialized in this phase. In the walking phase, the particle walks to one of the neighbors of the current vertex based on the proposed walking probability calculated by the proposed transfer acceptance probability and the proposed transfer proposal probability. In the process of particle walking, the particle has a possibility of entering the restart phase. The proposed restart probability determines whether the particle performs the restart mechanism. If the particle decides to restart, it will select a vertex for restart based on the domination level of this team particles at vertices. Otherwise, it continues to walk. After several particle walking and restart phases, the particle meets the convergence state. In the convergence phase, if all particles meet the proposed convergence condition, we will obtain community partition results based on the domination level of each team particles at the vertex. In the overlapping community detection phase, we can obtain overlapping community partition results based on the overlapping community detection mechanism. Experiment results reveal that SSPCO can improve the stability and accuracy of detecting communities. Moreover, SSPCO runs in near-linear time complexity, which allows it to be applied in large-sized networks.

Flexible electronics have gained attention with their unique ability to withstand stress deformations. However, stress makes significant impact on the electrical performance of the flexible devices. It is commonly believed that the stress imposed on the flexible device is only related to the bending curvature. Our study shows that the actual stress imposed on the device is not only related to the bending radius but also closely related to the device dimension. In this study, the effective stress of the device layer as well as the stress distributions are investigated, with the fundamental flexible diodes as representative examples. Flexible single-crystalline silicon $p$-$i$-$n$ diodes are fabricated and measured under different bending curvature conditions. Then the dominant affecting factor of the flexible diodes with bending stress is extracted. 3D finite-element method (3D-FEM) stress distribution modeling is also employed to analyze the stress distributions and demonstrate that the effective stress of the device layer is closely and proportionally related to the device dimension. Furthermore, theoretical calculations are conducted to verify the FEM results and quantitatively show the relation between the stress and the dimension of the flexible devices. The analysis provides a guideline in the design of flexible electronics under bending conditions.

The thermal conductivity of phase change materials (PCMs) during phase transitions is of great significance to the evaluation of the thermal performance of energy-saving buildings. Based on the transient plane source method, a method for measuring the effective thermal conductivity of PCM composites was proposed, by which the variations in effective thermal conductivity with liquid fraction and temperature during phase transitions can be obtained. The correctness of the proposed method was verified through matched simulation experiments. Three kinds of PCM samples were prepared for experimental measurement on the basis of the direct incorporation method, and the volume proportions of decanoic acid to gypsum were set to 10%, 12%, and 15%. The phase transition regions and latent heat values of these PCM samples were measured using the differential scanning calorimetry technique. Results showed that the effective thermal conductivity of the PCM first increased and then decreased during the phase transition. As the fraction of PCM content increased, the phase transition regions gradually expanded, and the effective thermal conductivity changed more drastically. The good measurement repeatability demonstrated the feasibility of this method for measuring the effective thermal conductivity of composites during phase transition.

In this paper, a constructive definition of entanglement for nonidentical particles is given. It is shown that particles arising in the process of inelastic scattering are entangled with each other. This property is a consequence of the symmetry of fundamental interactions. Considering detectors of elementary particles, it was concluded that only inelastic scattering can be the basis of a measuring instrument. In the process of inelastic scattering, the measuring instrument can acquire information about the particle (system), while in the case of elastic scattering, it cannot. The nonlinearity of inelastic scattering naturally solves the measurement problem in quantum mechanics.

In this paper, we will implement a comparison between three different perceptions to the behavior of the exact solution to the generalized Hirota–Satsuma coupling Korteweg–de Vries System (GHSCKDVS). The proposed model plays a vital role in different branches of physics and applied mathematics. Specially, this model describes dispersive waves as the shallow water waves in hydrodynamics and it has various types of solutions like soliton solutions and traveling wave solutions. These three various visions to the behavior of the exact solution are established via three various techniques that have three different mathematical analyses. These three important different techniques are the Paul–Painlevé approach method (PPAM) examined previously to extract the exact solutions for many nonlinear partial differential equations (NLPDE) and achieved good results, the Ricatti–Bernolli Sub-ODE method (RBSODM) which is one of the famous ansatze approaches that doesn’t surrender to the balance rule, treats the balance rule fails and realizes impressive forms of the exact solutions. Many new various types of soliton solutions as hyperbolic and trigonometric function solutions, represented by the M-shaped, W-shaped, kink, anti-kink and dark soliton solutions have been established via these two methods. Moreover, we will document the identical numerical solutions for all achieved exact solutions realized by the two methods mentioned above via the famous numerical variational iteration method (VIM) that usually gives good results. The powerful of our achieved numerical solutions related to that their initial conditions emerged from the extracted exact solutions.

This paper examines the three-dimensional nonlinear time-fractional water wave equations for their analytical wave solutions. These are the equations of the names $(3+1)$-Zakharov–Kuznetsov–Burgers equation and $(3+1)$-Yu–Toda–Sasa–Fukuyama equation. The obtained wave solutions are in the form of kink, periodic and singular waves by utilizing the $(G^{\prime }/G^2)$-expansion approach. The aforesaid solutions are verified and demonstrated graphically via symbolic soft computations.

We study the features of the evolution of a pulse in a dielectric medium (crystal) with optical anisotropic properties taking into account pumping. The medium contains semiconductor carbon nanotubes of a fixed orientation directed at an angle to one of the principal axes of the crystal. We analyze the influence of pumping and resistance to disturbances. Our study shows that the effects of pumping and nonlinear absorption suppress the dispersive pulse spreading caused by the optically anisotropic properties of the medium.

This paper presents the design of triple-band terahertz metamaterial absorber, whose surface structure is a nested-type metallic pattern composed of two pairs of splitting arcs, of which the inner two splitting arcs have the same but smaller size, while the outer two possess the same but larger dimension. The surface patterned structure can strongly interact with the incident terahertz beam, resulting in three narrow-band and discrete resonance peaks having higher than 94% absorption rates. Near-field patterns of the three absorption peaks are discussed to insight into the physical mechanism of these peaks, it is revealed that the first two absorption peaks result from the dipole resonance of the inner two splitting arcs and outer pair of splitting arcs, respectively, while the last absorption peak is caused by surface propagation resonance of the surface patterned resonator. The effect of structure parameters, including the sizes of splitting arcs and the spacing between two pairs of splitting arcs, on the absorption properties, is further analyzed. The absorber suggested here could provide guidance for the design of multiple-band metamaterial absorbers, and could find great application prospects in terahertz technology-related areas.

The reduction of the periodicity of phononic crystals (PnCs) usually leads to the decrease of band gap (BG) width. However, a systematic study of the relationship between the unit cell and the supercell in the proposed hybrid stepped PnCs shows that the BG width can be increased in special cases. How the periodicity of PnCs affects the final BG characteristics is important for the design of PnCs with high structural performance. Supercell of PnCs with imperfections from the rotation of the unit cell was used to demonstrate the relationship between the unit cell and the supercell, which was further used for the wave attenuations of the proposed hybrid stepped PnCs. The rotation angle and the number of the rotating scatterers can be controlled for better structural performance for the PnCs. The different changes of the equivalent stiffness corresponding to the starting and the end frequencies lead to the increase of the BG width when the ration angle of the unit cell is $35^{\circ }$ in the supercell composed of zigzag scatterers and cross scatterers. The rotation of the unit cell in the supercell leads to the decrease of the starting frequency.

A scheme for asymmetric controlled bidirectional remote state preparation by utilizing 15-qubit entangled state as quantum channel is proposed. In this paper, we present a new protocol that Alice prepares a three-qubit equatorial state for Bob and Bob prepares a four-qubit equatorial state for Alice at the same time under Charlie’s control. The success of this scheme cannot be separated from the controller Charlie. In addition, we give some analysis and conclusions by comparing with other schemes. The auxiliary qubits and operations are not required in our scheme. In particular, the success probability of the receivers restoring the prepared states can reach 100%. Thus, our scheme has better performance.

The shock waves and micro-jets generated by the bubble collapse will cause cavitation erosion on the solid surface. In this paper, a volume of fluid (VOF) method is used to simulate the bubble collapse process under different conditions. The protective effects of epoxy resin material with low hardness and toughness and tungsten carbide material with high stiffness and not easy to cause deformation affected by the pressure jump generated during the bubble collapse are studied. When the pressure jump caused by the bubble collapse impacts the surface of the two coating materials, the equivalent stress generated on the surface is in good agreement with the pressure distribution. The deformation and deformation velocity of tungsten carbide coating is smaller than that of epoxy resin coating. Tungsten carbide coating can effectively resist the impact pressure and prevent the formation of large stress in the substrate. Overall, tungsten carbide shows better protective performance on the substrate.

Hirota’s bilinear method (HBM) has been successfully applied to the $(2+1)$-dimensional Pavlov equation to analyze the different wave structures in this paper. The $(2+1)$-dimensional Pavlov equation is used for the study of integrated hydrodynamic chains and Einstein–Weyl manifolds. In our research, we find new solutions in the forms of lump solutions, breather waves, and two-wave solutions. The modulation instability (MI) of the governing model is also discussed. Moreover, a variety of 3D, 2D, and contour profiles are used to illustrate the physical behavior of the reported results. Acquired findings are useful in understanding nonlinear science and its related nonlinear higher-dimensional wave fields. Through the use of Mathematica, the obtained results are verified by inserting them into the governing equation. The strengthening of representative calculations we’ve made gives us a strong and effective mathematical framework for dealing with the most difficult nonlinear wave problems.