International Journal of Modern Physics B

In this paper, we review the theoretical analyses and simulations of the interactions between curvature-inducing proteins and biomembranes. Laterally isotropic proteins induce spherical budding, whereas anisotropic proteins such as Bin/Amphiphysin/Rvs (BAR) superfamily proteins, induce tubulation. Both types of proteins can sense the membrane curvature. We describe the theoretical analyzes of various transitions of protein binding accompanied by a change in various properties, such as the number of buds, the radius of membrane tubes, and the nematic order of anisotropic proteins. Moreover, we explain the membrane-mediated interactions and protein assembly. Many types of membrane shape transformations (spontaneous tubulation, formation of polyhedral vesicles, polygonal tubes, periodic bumps, network structures, etc.) have been demonstrated by coarse-grained simulations. Furthermore, traveling waves and turing patterns under the coupling of reaction-diffusion dynamics and membrane deformation are described.

This paper reviews some of the recent progresses in understanding the dynamical and statistical properties of anyons in fractional quantum Hall (FQH) systems. These are strongly interacting topological systems for electrons confined to a two-dimensional manifold, and anyons are fundamental particles emerging from the truncation of the Hilbert space as a result of both the kinetic and interaction energies. We introduce the concept of the conformal Hilbert spaces (CHS) from such Hilbert space truncation, and the hierarchy of these Hilbert spaces allows us to understand the internal structures of the anyons that can strongly affect their dynamics. The bulk-edge correspondence and the conformal mapping of the CHS also enable us to derive a rigorous bosonization scheme for anyons in these two-dimensional systems, and to capture the statistical interaction between anyons in the form of microscopic interaction Hamiltonians. Examples about the fractionalization of Laughlin quasiholes and a new family of bosonic FQH phases as the dual descriptions of the well-known fermionic FQH phases are given, as applications to the proposed theoretical constructions in this work.

Pendulum has recently been introduced into the field of elastic metamaterials because of its low-frequency vibration characteristic, which further expands the application value of such structure. However, the low-frequency and broadband performance of traditional pendulum (TB) metamaterials still need to be further improved. In this paper, a new low-frequency pendulum metamaterial is proposed, and the low-frequency elastic wave propagation characteristics of the metamaterial are studied. The study shows that compared with the TB metamaterial, it can effectively lower the bandgap (BG) of metamaterial, but greatly narrow the BG. To solve this problem, the negative inertial amplification mechanism is further proposed, and the variation law of the metamaterial BG under this mechanism is investigated. It is found that the mechanism can effectively broaden the metamaterial BG and in specific cases make it have infinite width. Meanwhile, the constraint relationship between the frequency response function of unit-cell structure and the wave vector of metamaterial is established, which is used to reveal the broadening rationale of the BGunder the negative inertial amplification mechanism. Finally, depending on the negative inertial amplification mechanism, a novel broadband pendulum metamaterial is designed based on the low-frequency pendulum metamaterial. The relationship between the broadband attenuation behavior of the metamaterial and the frequency response function of unit-cell structure is analyzed, the working mechanism of negative inertial amplification to broadband pendulum metamaterial is also discussed, and the relevant optimization design method is given at the end.

Pedestrian evacuation at the gate of primary school after school is always a tricky question bothering us. In order to improve the safety and efficiency of pedestrian evacuation at the gate of primary school, adult–child matching behavior after school is analyzed. We propose four adult–child matching strategies considering order or random of adults and children in the matching process. Fusing the matching strategy into a cellular automata (CA)-based pedestrian simulation model and taking the Linyi No. 40 middle school, China as the case study, the adult–child matching behavior is simulated on the platform of MATLAB software. The simulation results indicate that evacuation efficiency of the strategy (adults are orderly distributed in the first waiting area and children are orderly queuing up) reaches the maximum value among the four strategies. Effective matching strategies could reduce pedestrian conflicts. The randomly children and randomly adults are all the negative impacts for evacuation. Orderly evacuation process could reduce pedestrian conflicts. Compared with the randomly children, the effect on evacuation efficiency of the randomly adults is larger. A reasonable number of evacuated pedestrians at a time could improve the whole evacuation efficiency, and we advise the Linyi No. 40 middle school to evacuate three classes at a time.

In a quantum partially blind signature (QPBS) scheme, the contradiction between anonymity and controllability of completely blind signature (BS) schemes was better solved by adding common negotiated public information between the signer and the requester (the message holder). After reviewing the proposed scheme, we give an analysis about it and then propose a novel QPBS scheme without entanglement. The security without preconditions of this signature scheme is ensured by the secure quantum key distribution (QKD) protocol and quantum one-time pad (QOTP). Furthermore, in the process of security analysis, it proves that our scheme satisfies the foundational attribution of partially blind signature (PBS). Moreover, the scheme can solve the problem we put forward so as to allow it to have a wider application in the future.

Recently, problems related to structural balance have received widespread attention in the research fields of signed networks, such as signed network partition, community detection and correlation clustering. Structural balance problems aim to find a partition of a signed network such that the frustration index, the sum of positive edges between subsets and negative edges within subsets, is minimized, which is known to be nondeterministic polynomial-time (NP)-complete and remains an open challenge. Many heuristic and meta-heuristic algorithms are developed to minimize the frustration index. However, most extant algorithms require quite a few parameters and are not efficient enough for large signed networks. In this study, we present a simple and effective iterated greedy (IG) algorithm for solving the structural balance problems with the objective of frustration minimization. In the algorithm, a constructive greedy heuristic is proposed to generate and reconstruct solutions to the problem with high efficiency. A two-stage local search procedure is designed to exploit the search space at different levels of granularity. An adaptive destruction method is developed to enhance the exploitation ability of the algorithm in the early stage and maintain the exploration ability later. Additionally, two acceleration methods are proposed to help the algorithm get a better performance in large signed networks. The experimental results indicate that the proposed IG algorithm outperforms other meta-heuristics in the literature especially in terms of the computational time.

The thermal conductivity of the porous materials is dependent on the temperature in a range of applications, including nuclear reactors and fossil fuel sources. The LTNE (local thermal nonequilibrium) model is widely used to study the thermal interactions between solid and fluid phases inside the porous media. The majority of the prior LTNE models assumed the constant thermal conductivities of both the fluid and solid phases, but in actual practice, the thermal conductivities depend on the temperature variations. In the current study, the effective thermal conductivities of the fluid and solid phases in the porous channel are considered as the functions of the respective temperatures by implementing the LTNE model. The Biot number is assumed to vary linearly, quadratically and sinusoidally along with the channel height. The thermal conductivity variation parameter $(\delta )$, porosity $(𝜖),$ the ratio of fluid and solid phase thermal conductivities $(k=\frac{k_f}{k_s})$ and heat generation parameter $(\beta )$ are considered as the main operating parameters. A system of ordinary differential equations has been derived and solved numerically under the above-mentioned conditions which is the generalization of the constant thermal conductivities of both the phases. The present results are validated with the already published results for the constant thermal conductivity and variable Biot number with the LTNE model. The obtained results show that the maximum heat transfer between the two phases is observed by taking $\mathrm{\text{Bi}}$ as the linear increasing function of $\eta$ i.e., $\mathrm{\text{Bi}}(\eta )=50(1+\eta )$ and correspondingly, it provides the highest values of Nusselt number. The Nusselt number increases with the decrement in thermal conductivity variation parameter $(\delta )$, heat generation parameter $(\beta )$ and ratio of fluid to solid phase conductivities $(k).$ A complex relationship has been observed between the porosity and the Nusselt number.

In this paper, a new memristive chaotic system with a relatively simple structure and complex dynamic behavior is proposed by introducing an absolute memristor into the VB19 chaotic system as a positive feedback term. The analysis shows that the new system is a fractional dimensional dissipative system and is unstable at the line equilibrium point. The system’s dynamic characteristics are studied using a bifurcation diagram and Lyapunov exponent’s spectrum. The numerical simulation shows that the period-doubling bifurcation phenomenon occurs when changing the parameters and system change from period to chaos. When the initial condition changes, the dynamic evolution of the system indicates that the coexistence of multiple attractors and chaotic signals can be controlled by local amplitude. In addition, a new image encryption algorithm based on the system is designed and the performance of this algorithm is tested through numerical analyses. The system’s analog circuit is built using electronic components and also realized by the microprocessor. The circuit realization results consistent with the numerical simulation results are obtained to verify the physical existence of the system.

We investigate the photonic spin Hall effect (PSHE) of a Gaussian beam passing through a one-dimensional photonic crystal with a graphene defect film. We show that an epsilon singularity point and an epsilon-near-zero point of graphene emerge by varying its chemical potential. We find that the chemical potential of graphene significantly alters the transverse shifts of PSHE, while the temperature of graphene has a slight impact on the transverse shifts of PSHE. Moreover, we find that the behavior of PSHE near the singularity point considerably differs from that near the epsilon-near-zero point. Additionally, we further explore the different wavelengths of the incident Gaussian beam on the tunability of PSHE. We show that the considerable transverse shifts can be obtained simultaneously depending on the incident wavelength of the Gaussian beam and the chemical potential of graphene.

Since time delays are very vital and inevitable in the transmission of neurons, this paper is mainly concerned with the dynamic analysis of the magnetic flux e-HR neuron model with time delays. Specifically, the stability of the system at the equilibrium point and the conditions for bifurcations are analyzed to explore the impact of time delays on dynamics behavior. Results show that the system exhibits Hopf bifurcation within the specific range of time delay. Moreover, the increase of time delay can induce the tip discharge behavior. In addition, we investigate the stability and bifurcation behavior of the model with dual time delays. Our results indicate that the system displays rich dynamics performance under certain conditions. Furthermore, numerical simulations show time delays play a crucial role in the dynamics process for the magnetic flux e-HR neuron model.