A tunable narrowband metamaterial perfect absorber (NMPA) with single absorption peak at both normal incidence and oblique incidence is proposed. The spectral responses of the designed NMPA are calculated using finite-difference time-domain (FDTD) method. By using an Ag guided-mode resonance grating layer with great fill factor, the designed NMPA exhibits single resonance peak, which is converted to

In biological systems, gene expression is an important subject. In order to clarify the specific process of gene expression, mathematical tools are needed to simulate the process. The Boolean network (BN) is a good mathematical tool. In this paper, we study a Boolean network with intermittent perturbations. This is of great significance for studying genetic mutations in bioengineering. The expression

Based on the semi-continuum model, the effect of temperature on Young’s modulus in the presence of oxide layer in silicon nano-films was studied theoretically by using the anharmonic Keating deformation potential, and the effect of oxide layer on Young’s modulus was also studied. The results show that Young’s modulus of the nano-film is inversely proportional to its temperature, which decreases with

As a continuation of our previously published work, we propose a theoretical framework for the determination of steady-state kinetics in a spin-1 Ising model by the path probability method. The framework is based on the principles of non-equilibrium statistical physics and is quite different from the phenomenological approach. We construct a set of linear kinetic equations for the order parameters

Research study of volt-amperage properties (VAP) of Ca(Al0.1Ga0.9)2S4:EuF3 crystals determined the mechanism of current flow though the studied samples and this mechanism is based on barrier Schottky emission and emission of Franklin–Paul. The dielectric constant of the material, height of the potential barrier on metal–semiconductor border, concentration of the traps and the effective mass of electrons

With an advancement in wireless technologies, Internet of Things (IoT) are becoming popular in modern era because of its wide range of applications. In this paper, an IoT enable smart classroom is considered. However, IoT nodes are battery constrained, therefore, development and implementation of energy efficiency IoT based smart classroom turn out be more challenging issue. Recently, many clustering

Using first-principles calculations, we investigate the structural, electronic, thermal and optical properties of hexagonal ScAl3C3-type structure LaCd3P3 under high pressure. By calculating elastic constant, the mechanical stability of LaCd3P3 at high pressures was discussed. Then, by calculating the band gap and density of states, the pressure effect on electronic properties of LaCd3P3 was discussed

This study presents a partially averaged Navier–Stokes model, MSST PANS, based on a modified SST k−ω turbulence model to predict turbulent flows with large streamline curvature. The model was validated for turbulent flow in a 90∘ curved rectangular duct (Re = 224,000) to assess the MSST PANS capabilities. The predictions are compared against flow simulations for the same curved rectangular duct using

In this paper, we deduced a macroscopic traffic model on the uphill and downhill slopes by employing the transformation relation from microscopic variables to macroscopic ones based on a microscopic car-following model considering the velocity difference between adjacent vehicles. The angle 𝜃 of the uphill and downhill and the gravitational force have a great impact upon the stability of traffic flow

Generally, with the help of adding solid materials, the thermophysical behaviors of refrigerant can be modified. In this work, four kinds of organic refrigerants (i.e. ethane R170, 1-fluoroethane R161, 1,1-difluoroethane R152a, and 1,1,1-trifluoroethane R143a) mixed with metal–organic framework UIO-67 nanoparticles are selected as the objects, their thermodynamic energy, adsorption, desorption heat

In this paper, we investigate quantum manipulations in an open atom-molecule conversion system. Through the transformation for the basis of the system, a set of time-dependent equations are derived under mean field approximation. We find that transitions between different dynamic areas of the system can be realized through manipulating an external rotating magnetic field, which corresponds to the tunneling

Herein, we report the fabrication of UV-active NaNbO3/Al2O3 (30 wt.%) ferroelectric heterojunction photocatalyst with enhanced photoelectrochemical activity to Methylene Blue (MB). Pure NaNbO3 nanorods (NRs) were synthesized by a facile hydrothermal process and NaNbO3/Al2O3 composite was prepared by an ultrasonic vibration method. The heterostructures showed a remarkable increase in photocurrent density

To overcome the problems of poor structural reliability, high driving voltage and small scanning angle, a novel electromagnetic MOEMS scanning grating mirror (SGM) with folded torsion beam is reported in this work. Compared with the conventional straight torsion beam, the folded torsion beam has better elastic torsion property and can effectively improve the structural reliability of the MOEMS SGM

The effects of the synergy of pressure regulation and Eu substitution on the microstructure and thermoelectric (TE) properties are investigated for type-I clathrates EuxBa8−xCu6Si16Ge24 (x=0, 0.5, 1, 1.5). The rare-earth-substituted and high-pressure modulated samples show complicated morphologies composed of abundant grains and rich in lattice defects. The Seebeck coefficient and the electrical conductivity

By performing density functional theory (DFT) calculations, we demonstrate that periodically repeating heterostructures of zigzag borophene nanoribbons (BNR) of different widths can form stable borophene superlattice (BSL). The energy band structures of BSL can be modulated through modifying the width and length of the segments. A metal-semiconductor transition can be obtained when the length of each

The electronic and optical properties of the adsorption of alkali metals (Li, Na, K, Rb, Cs) on graphitic carbon nitride (g-C3N4) were calculated and studied based on the first principles of density functional theory. The results investigate that alkali metals adsorbed g-C3N4 has metallic properties, while intrinsic g-C3N4 was semiconducting. Importantly, the charge density differential investigated

The study of complex oxides and oxide heterostructures has dominated the field of experimental and theoretical condensed matter research for the better part of the last few decades. Powerful experimental techniques such as molecular beam epitaxy and pulsed laser deposition have made fabrication of oxide heterostructures with atomically sharp interfaces possible, whereas more and more sophisticated

Path planning has always been a hot topic in the field of mobile robot research. At present, the mainstream issues of the mobile robot path planning are combined with the swarm intelligence algorithms. Among them, the firefly algorithm is more typical. The firefly algorithm has the advantages of simple concepts and easy implementation, but it also has the disadvantages of being easily trapped into

The (3+1)-dimensional generalized Korteweg-de Vries (KdV)-type model equation is investigated based on the Hirota bilinear method. Diversity of exact solutions for this equation are obtained with the help of symbolic computation. We depicted the physical explanation of the extracted solutions with the free choice of the different parameters by plotting three-dimensional plots and contour plots. The

The deformation behavior of the nanocomposite structure under tension was studied by molecular dynamics (MDs) simulation. This nanocomposite structure is called as [email protected], which is a silicon nanowire (SiNW) embedded in carbon nanotube (CNT). The simulation results show that the insertion of the SiNW into CNT increases the tensile strength of zigzag CNT and the maximum tensile strain of the

We find a very simple scaling transformation method by which a kind of rank non-homogenous second order nonlinear ODEs is reduced to an integral form. Comparing with the canonical-like transformation method and the first integral method, our method provides a simple mechanism of reduction of such equations. As an application, a reaction–diffusion equation with variable coefficients is integrated, and

In this paper, we study the propagation of extremely short electromagnetic pulses in a medium with zig–zag carbon nanotubes taking into account pumping and nonlinear absorption introduced phenomenologically. Based on Maxwell’s equations, we obtain an effective equation for the vector potential of the electromagnetic field, which takes into account the dissipation of the pulse field under the conditions

Today in the age of advanced ceramic civilization, there are a variety of applications for modern ceramics materials with specific properties. Our up-to date research recognizes that ceramics have a fractal configuration nature on the basis of different phenomena. The key property of fractals is their scale-independence. The practical value is that the fractal objects’ interaction and energy is possible

We report on the fabrication of filament damages in Yb-doped phosphate glass by femtosecond laser pulses. The uneven index modification was obtained using a 20× optical microscope objective with 0.4 numerical apertures. The multimode fields of original channel waveguides were investigated and in good agreement with the simulation results, whose structures can be regarded as a kind of beam splitters

How to effectively control the trapping process in complex systems is of great importance in the study of trapping problem. Recently, the approach of delayed random walk has been introduced into several deterministic network models to steer trapping process. However, exploring delayed random walk on pseudo-fractal web with the co-evolution of topology and weight has remained out of reach. In this paper

We studied the influences of the inclusion of different geometrical defects (circle, triangle, and square) with different Ginzburg–Landau parameters κ on the vortex state of a mesoscopic superconducting square immersed in an external applied magnetic field. We calculated the magnetization, vorticity, and density of Cooper pairs for this system, solving the time-dependent Ginzburg–Landau equations.

In this review, the physics of Pfaffian paired states, in the context of fractional quantum Hall effect, is discussed using field-theoretical approaches. The Pfaffian states are prime examples of topological (p-wave) Cooper pairing and are characterized by non-Abelian statistics of their quasiparticles. Here we focus on conditions for their realization and competition among them at half-integer filling

Urban rail transit (URT) system plays a significant role in daily commuting. The main features of URT could be abstracted into two kinds of networks, topological network and transit network. The correlation between topological network and transit network could represent the service level of transportation which is also a main focus to some extent. In this study, static analysis based on one year or

Based on discrete-event dynamic system theory, train operation events in high-speed railway transportation systems are regarded as the basic elements of these dynamic systems. For non-periodic timetable railways in China, based on a max-plus algebra method, a delay propagation cellular automata model is proposed to evaluate the robustness of high-speed train operation plans. The cellular automata evolution

A general third order of linear partial differential equation in (3+1) dimensions is studied by using the ansätz method. The lump solutions which localize in all directions in the whole (x,y,z)-space are derived by the ansätz method. Diversity interactions including interacted lumps with periodic waves, interaction between lumps and multi-soliton, and interaction among lumps, multi-soliton and periodic

In this paper, a broadband metamaterial absorber (MA) based on multilayer structure is proposed in the terahertz region. Different from the general multilayer structure, the structure we designed superimposes with different resonators in the “horizontal direction” of the bottom metal plate. The unit of the absorber is composed of several different size metal and dielectric layers which are placed vertically

An extension of the KPII equation is studied. Adding a new fourth-order derivative term and some second-order derivative terms, we formulate an extended KPII equation. Different types of solutions of the extended equation are obtained by the Hirota bilinear method, and the presented solutions include soliton solutions, lump solutions and interaction solutions. Their dynamical behaviors are analyzed

In this work, by introducing a kind of parameters constraint to ensure that the well known formula of n-soliton solutions works well not only for integrable systems, but also for non-integrable systems. Then for the (4+1)-dimensional Fokas equation, based on this constraint and the modified n-soliton solutions, we further construct its different types of higher-order wave solutions, especially new

Thick-shell not only provides colloidal quantum dots (QDs) stability and workability, but also plays a significant role in passivation of QDs surface defects and change of electron transport characteristics of QDs. Here, the dedicated design and synthesis of high luminescence CdZnSe/CdSe/CdZnSe quantum wells are reported by precisely controlled shell growth. By tuning the thicknesses of the CdSe and

A model of twisted bilayer graphene has been offered on the base of developed quasi-relativistic approach with high energy k⋅p-Hamiltonian. Monolayer-graphene twist is accounted as a perturbation of monolayer-graphene Hamiltonian in such a way that at a given point of the Brillouin zone there exists an external non-Abelian gauge field of another monolayer. Majorana-like resonances have been revealed

The appearance of electron correlations–induced glassy state of low-energy phonons in the non-dimeric organic charge transfer salt in 𝜃-(BEDT-TTF)2CsZn(SCN)4 is considered as a strong evidence of charge lattice coupling in molecular charge transfer salts. We discuss the temperature and the magnetic field dependences of the heat capacity of this salt in terms of the soft potential model to describe

The transfer of the liquid from groove to plate is significantly affected by the breakup process of liquid bridge, which is the core problem of gravure. In this paper, many-body dissipative particle dynamics method (MDPD) is used to simulate the behaviors of the stretching liquid cylinder between the plate and the groove, and the influence of surface wettability, stretching velocity and groove structure

In this paper, a novel astrophysics-based prediction framework is developed for estimating the binding affinity of a glucose binder. The proposed framework utilizes the molecule properties for predicting the binding affinity. It also uses the astrophysics-learning strategy that incorporates the concepts of Kepler’s law during the prediction process. The proposed framework is compared with 10 regression

With both analytical and numerical methods, local dynamic behaviors including stability and Hopf bifurcation of a new four-dimensional hyper-chaotic system are studied in this paper. All the equilibrium points and their stability conditions are obtained with the Routh–Hurwitz criterion. It is shown that there may exist one, two, or three equilibrium points for different system parameters. Via Hopf

A micro-pressure sensor with an isosceles trapezoidal beam-membrane (ITBM) is proposed in this paper, consisting of a square silicon membrane, four isosceles trapezoidal beams (ITBs) and four piezoresistors. To investigate how the elastic silicon membrane affects pressure sensitive characteristics, simulation models based on ANSYS 15.0 software were used to analyze the effect of structural dimension

In Big data domain, platform dependency can alter the behavior of the business. It is because of the different kinds (Structured, Semi-structured and Unstructured) and characteristics of the data. By the traditional infrastructure, different kinds of data cannot be processed simultaneously due to their platform dependency for a particular task. Therefore, the responsibility of selecting suitable tools

Metasurfaces have recently emerged to realize flat optical components with various functions and providing potential capabilities in manufacturing active devices. In this paper, a doublet lens for mid-infrared wavelength with tunable focal length has been proposed. The designed metalens consists of two dielectric metalenses with different focal lengths patterned on a phase-change materials Ge2Sb1Te4

Spectral wavelength and bandwidth tunable mode-locking ultrafast fiber laser has widespread applications in the fields of optical telecommunication, spectroscopy, pump-probe measurements, and so on. Here, we report an single-wall carbon nanotube (SWCNT)-based wavelength and bandwidth tunable mode-locked fiber laser operation in the C+L band. The output spectral wavelength and bandwidth can be continuously

In this paper, a spring-mass system with impacts and frictions is formulated by the impulsive differential system. An energy-like Lyapunov function and an auxiliary step function are constructed to analyze the finite-time stability of such impact system with a time-varying external force and sliding friction as well as air resistance. We establish the sufficient conditions of finite-time stability

The spatial heterogeneity of land use patterns and residents’ corresponding economic activities give rise to urban mobility’s latent structure, which is of great importance for urban planning and transport infrastructure investment but cannot be readily captured using conventional data sources. We developed a methodological framework for detecting urban mobility structure at the transportation analysis

Fe-doped TiO2 films were prepared by sol–gel spin coating method. After annealing in vacuum, the structural and optical properties of the films were investigated. XRD patterns revealed that all diffraction peaks can be attributed to TiO2 with anatase phase structure. No segregated phases are present in the samples within XRD detection limit. XPS results indicated that iron element exists in a tervalent

In this paper, the first-passage behavior of under-damped asymmetric bistable system driven by Lévy noise is studied. The two aspects considered are the mean first-passage time (MFPT) and the distribution of first-passage time in two opposite directions. To begin with, using the Janicki–Weron algorithm to generate Lévy noise, the system driven by Lévy noise is simulated through the fourth-order Runge–Kutta

Aluminum alloy 6061(AA6061) sheets of 4 mm in thickness are joined by laser wire-filling welding (LWFW) using the ER4047 welding wire. Microstructure and alloy element distributions near the fusion line are characterized and are investigated by optical microscope, scanning electron microscope, energy dispersive spectrometer. The results showed that the well-formed welded joints are obtained with a

A new avalanche photodiode device applied to a visible light communication (VLC) system is designed using a standard 0.18 μm complementary metal oxide semiconductor process. Compared to regular CMOS APD devices, the proposed device adds a P-well layer above the deep N-well/P-substrate structure, and an N+/P+ layer is deposited upon it. The N+/P+ layer acts as an avalanche breakdown layer of the device

In this paper, we investigate the focusing Kundu–Eckhaus equation with non-zero boundary conditions. An appropriate two-sheeted Riemann surface is introduced to map the spectral parameter k into a single-valued parameter z. Starting from the Lax pair of Kundu–Eckhaus equation, two kinds of Jost solutions are constructed. Further, their asymptotic, analyticity, symmetries as well as spectral matrix

This work studies the temperature regime of the wall while up and down moving of the unsaturated liquid in the vertical tube at pressure below critical and influence of free convection on the heat transfer. The boundary of influence free convection on heat transfer is determined and summarized as a criterion equation.

Image captioning is a multidisciplinary artificial intelligence (AI) research task that has captures the interest of both image and natural language processing experts. Image captioning is a complex problem as it sometimes requires accessing the information that may not be directly visualized in a given scene. It possibly will require common sense interpretation or the detailed knowledge about the

The evolution of atomic structures and its correlation with the kinetic fragility of liquid tantalum (Ta) during cooling were investigated through molecular dynamics simulations. Pair distribution function, angular distribution function, and largest standard cluster analysis were used to characterize the atomic configurations in the Ta metal system. Results revealed that canonical Kasper clusters with

This paper reports two design thoughts about nano-scale waveguides including parallel slot structure and vertical slot structure. According to the simulation results of different schemes, the design of parallel slot structure is demonstrated to exhibit better performance. Thus, we further explore its typical characteristics based on this scheme, such as electric field distribution, effective refractive index

We report a quasi-semicircle GaN ultraviolet microcavity laser. Poincaré map of the quasi-semicircle cavity shows periodic, quasi-periodic and chaotic optical trajectories. Finite-element-method optical near-field distribution patterns of the periodic optical modes agree with the optical loops in the quasi-semicircle cavity. Based on the numerical results, optically pumped lasing experiment shows that

The reversible elementary reaction mechanism of six components and seven steps of H2/O2 are applied by using a CFD-DSMC coupling iteration method to study the impact of boundary on flow, heat transfer and chemical reaction in a microtube. The microtube consists of a converging section and a straight section, which represents the gap on the contact surface of the pellets in porous media. It shows that

Smart nonlinear circuits can be tamed to reproduce the main dynamical properties in neural activities and thus neural circuits are built to estimate the occurrence of multiple modes in electric activities. In the presence of electromagnetic radiation, the cardiac tissue, brain and neural circuits are influenced because field energy is injected and captured when induction field and current are generated

Link prediction in complex networks has always been a hot topic in statistical physics, sociology and information science. Since most works focus on undirected networks, how to predict missing links in directed complex networks remains a valuable and challenging problem. Many existing methods fail to differentiate the information provided by links with different orientations, nor do they consider the

This paper proposes a novel digital readout interface for capacitive MEMS accelerometer. The digitalization is fulfilled by incorporating a 1-bit ΣΔ (sigma-delta) modulator into the closed servo loop. It both realizes a direct digital output efficiently and linearizes the electrostatic feedback force. To maintain the stability and improve loop linearity, a discrete-time proportional integral and differential

There often exist behaviors of moving against the main direction of evacuation in order to rescue or find the important missing people in real situations. However, the traditional social force model (SFM) often lacks consideration of such “counter flow”. Motivated by this, we improve the traditional SFM to study the counter flow and its influence on evacuation out of multi-exit rooms. We call the person