Metaheuristic optimization-based identification of fractional-order systems under stable distribution noises
Publication date: 31 August 2018Source: Physics Letters A, Volume 382, Issue 34Author(s): Wei Du, Le Tong, Yang TangAbstractThis research investigates the identification problem of fractional-order chaotic systems under stable distribution noises. A powerful metaheuristic optimization method called composite differential evolution is used for the identification of the fractional-order Lorenz and Chen systems in the noisy environment, where the structure, parameters, orders and initial values of the systems are all unknown. The identification accuracy is examined when the noise follows the three special cases of stable dist...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Collisional radiative model for the M1 transition spectrum of the highly-charged W54+ ions
Publication date: 31 August 2018Source: Physics Letters A, Volume 382, Issue 34Author(s): Xiaobin Ding, Jiaoxia Yang, Linfan Zhu, Fumihiro Koike, Izumi Murakami, Daiji Kato, Hiroyuki A. Sakaue, Nobuyuki Nakamura, Chenzhong DongAbstractA detailed-level collisional-radiative model for the M1 transition spectrum of the Ca-like W54+ ion as observed in an electron beam ion trap (EBIT) was constructed based on atomic data calculated by the relativistic configuration interaction method and distorted wave theory. The present calculated transition energy, rate and intensity of W54+ M1 transitions are compared with previous theoreti...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Nonlinear statistical properties of fMRI signals in human visual cortex during resting-state
Publication date: 31 August 2018Source: Physics Letters A, Volume 382, Issue 34Author(s): Salim LahmiriAbstractThe purpose of the current work is to study nonlinear dynamics in neuronal activity within human brain visual cortex based on blood-oxygen-level dependent (BOLD) contrast imaging. In particular, based on functional magnetic resonance imaging (fMRI) signals, measures of fractality, complexity, and state disorder are estimated from central and peripheral eccentricity bands across three visual areas. Statistical results from analysis of 48750 resting-state fMRI signals show evidence that nonlinear dynamics of neurona...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Simultaneous investigation of MHD and convective phenomena on time-dependent flow of Carreau nanofluid with variable properties: Dual solutions
Publication date: 31 August 2018Source: Physics Letters A, Volume 382, Issue 34Author(s): M. Khan, M. Irfan, L. Ahmad, W.A. KhanAbstractIn countless applications, there is a thoughtful necessity for augmenting the poor thermal conductivity of conventional liquids to improve effectual heat transfer liquids. Nanofluids are fluids interruptions of nanoparticles and broad scrutiny have been presented on nanoliquid solicitations in heat transfer progressions. The intention of this exertion is to scrutinize the dual nature solutions of unsteady magnetite Carreau nanofluid influenced by porous stretching/shrinking surface. The ph...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Structural and magnetic properties of MoS2 monolayer zigzag nanoribbon doped by Ti, V, Cr, and Mn
This study provides a rational route of tuning the magnetic properties of ZZ-MoS2 NRs for their promising applications in nanoelectronics and spin electronic devices. (Source: Physics Letters A)
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Effect of dielectric layer on ferroelectric responses of P(VDF-TrFE) thin films
This study shows that the ferroelectric sandwich structure provides great potential towards low power negative capacitance devices. (Source: Physics Letters A)
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Quasi-invisible thermal cloak based on homogenous materials
Publication date: 31 August 2018Source: Physics Letters A, Volume 382, Issue 34Author(s): Quanwen Hou, Jianbo Yin, Xiaopeng Zhao, Yanqiang BiAbstractInvisible thermal cloak, which cancels distortions of temperature distribution caused by objects, has many potential applications in thermal engineering. In this letter, we theoretically proposed and simulatively verified a new design method for quasi-invisible thermal cloak. Different from conventional transformation thermodynamics that focus on complete invisibility, our method only decreases the effective scale of objects to small enough and realizes a quasi-invisible cloak...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Phase-dependent heat current of granular Josephson junction for different geometries
Publication date: 31 August 2018Source: Physics Letters A, Volume 382, Issue 34Author(s): Elaheh Afsaneh, Heshmatolah YavariAbstractWe theoretically investigate the phase-dependent heat transport of a temperature-biased granular Josephson junction in the presence of a perpendicular magnetic field. We illustrate the influence of geometry of the junction on the thermal current. The use of granular Josephson junction rather than bulk one makes significant changes in the heat current behavior. The heat current diffraction pattern of the rectangular, circular and annular geometries with no trapped fluxons demonstrates similar t...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

Describing intrinsic noise in Chua's circuit
Publication date: Available online 4 June 2018Source: Physics Letters AAuthor(s): Flavio Prebianca, Holokx A. Albuquerque, Marcus W. BeimsAbstractIn this Letter we demonstrate that intrinsic inevitable noise effects, existing in realistic experiments with electronic circuits, are properly described theoretically using a Gaussian noise. For this we integrate numerically the equations of motion from the Chua circuit using a fourth-order stochastic Runge–Kutta integrator. Periodic structures in parameter space, related to periodic motion, start to be destroyed when the noise intensity is increased and vanish at a critic...
Source: Physics Letters A - July 14, 2018 Category: Physics Source Type: research

First principles study of electronic structure and carrier mobility in β-armchair antimony nanotubes
Publication date: Available online 11 July 2018Source: Physics Letters AAuthor(s): Shilpa Singh, Sanjeev K. Gupta, Yogesh Sonvane, P.N. GajjarAbstractIn recent work, we have investigated the structure and stability of β-armchair antimony nanotubes (SbNT) using density functional theory (DFT). We studied electronic properties like electronic band structure, density of states (DOS) and mechanical properties such as stiffness constant, Poisson's ratio, and mechanical strength for these nanotubes. We found that these nanotubes are energetically stable and semiconducting in nature with band-gap varying between 1.32 eV to 1...
Source: Physics Letters A - July 12, 2018 Category: Physics Source Type: research

1-D harmonic oscillator in MONDified inertia
Publication date: Available online 4 June 2018Source: Physics Letters AAuthor(s): R. BonettoAbstractIn this paper we study the dynamics of a harmonic oscillator with laws of motion prescribed by MOND (Modified Newtonian Dynamics) in its modified inertia formulation. A differential equation for a 1D harmonic oscillator is obtained and several features of its solution are analyzed. Particular attention is given to the deep MOND limit regime, where the equations of motion are significantly different from the Newtonian one. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

A compendium of Hopf-like bifurcations in piecewise-smooth dynamical systems
Publication date: Available online 4 June 2018Source: Physics Letters AAuthor(s): D.J.W. SimpsonAbstractThis Letter outlines 20 geometric mechanisms by which limit cycles are created locally in two-dimensional piecewise-smooth systems of ODEs. These include boundary equilibrium bifurcations of hybrid systems, Filippov systems, and continuous systems, and limit cycles created from folds and by the addition of hysteresis or time-delay. In each case a stationary solution, such as a regular equilibrium, changes stability and possibly form and emits one limit cycle. Scaling laws for the amplitude and period of the limit cycles ...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Electro-mechanical behavior of single twisted high-temperature superconducting tape under transverse Lorentz force
This study helps understand the electro-mechanical properties of pre-twisted HTS tapes and provides theoretical reference for the design of novel HTS cable structures. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Stochastic resonance in time-delayed exponential monostable system driven by weak periodic signals
Publication date: Available online 5 June 2018Source: Physics Letters AAuthor(s): Lifang He, Xicheng Zhou, Gang Zhang, Tianqi ZhangAbstractBased on the exponential monostable potential, we study an exponential monostable system with time-delayed feedback driven by weak periodic signals and additive Gaussian white noises. The small delay approximation is used to deduce the steady-state probability distribution and the effective potential function is derived. The system parameters l and b, time delay τ, feedback strength β can change the shapes of the potential function. The mean first-passage time (MFPT) is calcula...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Analysis of repulsion states among pedestrians inflowing into a room
In this study, we deeply investigate the properties of proxemics defined for pedestrians, who inflow within a room. We analyzed two different cases: when some of the pedestrians are inactive and when no inactive people are present. In both cases the proxemics is characterized by a succession of upward step-like variations superimposed to an initial increasing behavior that tends to stabilize through time. The derivative of the proxemics, which indicates increase of repulsion (if positive) and decrease of repulsion (if negative) among pedestrians, is persistent; however, in case of absence of inactive persons, it increases ...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Atomistic simulations of effect of hydrogen atoms on mechanical behaviour of an α-Fe with symmetric tilt grain boundaries
Publication date: Available online 6 June 2018Source: Physics Letters AAuthor(s): H.Y. Song, C.F. Li, S.F. Geng, M.R. An, M.X. Xiao, L. WangAbstractThe effects of the hydrogen concentration, crystal orientation and grain size on the mechanical properties of an α-Fe bicrystal with symmetric tilt grain boundaries under tensile loading are investigated by molecular dynamics simulation. The results indicate that regardless of crystal orientation, the yield strength of bicrystal α-Fe decreases with the increase of hydrogen concentration. Hydrogen atoms have no influence on the primary dislocation (or twin) nucleatio...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Trivial and non-trivial superconductivity in dsDNA
Publication date: Available online 6 June 2018Source: Physics Letters AAuthor(s): H. SimchiAbstractA double-stranded DNA (dsDNA) is modeled by two coupled one-dimensional Kitaev's chain and the topological superconductivity is studied. It is shown that the zero energy mode exists under some specific conditions. The wave function of zero mode is calculated and it is shown that the Majorana quasi-particles exist on the ends of each strand. By calculating the winding number, we show that the topological phase transition can happen if the hopping integral between two strands is very smaller than the pairing potential between t...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Two-dimensional MTe2 (M = Co, Fe, Mn, Sc, Ti) transition metal tellurides as sodium ion battery anode materials: Density functional theory calculations
Publication date: Available online 7 June 2018Source: Physics Letters AAuthor(s): Yi-Xuang Li, Darwin Barayang Putungan, Shi-Hsin LinAbstractWe performed density functional theory calculations to probe sodium adsorption and diffusion properties on two-dimensional (2D) MTe2 (M = Co, Fe, Mn, Sc, Ti) first-row transition metal tellurides, and gauge their potentials as anode materials for sodium-ion batteries (NIBs). In this work, we found that all considered MTe2 possess strong sodium adsorption properties and excellent diffusion kinetics. Moreover, sodium atoms prefer to bind on sites that are farther apart rather than on ne...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Thickness-dependent of conduction mechanism and bias electric field modulation of transport properties for SrRuO3/PMN-PT heterostructures
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): L. Chen, X.K. Ning, C.D. Ren, M.J. ChenAbstractUltra-thin SrRuO3 (SRO) films have been grown on ferroelectric and piezoelectric PMN-PT substrates. The structural properties of these films have been characterized by atomic force microscopy, x-ray diffraction and cross-sectional transmission electron microscopy. The nature of electric transport was analyzed in detail and the conduction mechanism of SRO films evolves through three regimes: from a three-dimensional (3D) metallic through a weakly localized to a strongly localized behavior as film...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Temperature gradient driven Alfvén instability producing inward energy flux in stellarators
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Ya.I. Kolesnichenko, A.V. TykhyyAbstractDestabilizing influence of plasma inhomogeneity on Alfvén eigenmodes in stellarators is considered. It is found that the diamagnetic frequency can strongly increase due to the resonance interaction of particles and Alfvén eigenmodes. This occurs when the particle resonance velocity exceeds the thermal velocity, in which case the role of superthermal particles enlarges. Then Alfvén eigenmodes can be destabilized even in the absence of the energetic ion population. It is shown that i...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

The reassessment of the structural transition regions along the liquidus of Fe–Si alloys and a possible liquid–liquid structural transition in FeSi2 alloy
Discussions have been made on the materials phenomenon of several Fe–Si alloys based on the structural information. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Entropy generation (irreversibility) associated with flow and heat transport mechanism in Sisko nanomaterial
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): M. Ijaz Khan, Tasawar Hayat, Sumaira Qayyum, Muhammad Imran Khan, A. AlsaediAbstractHere a novel applications of entropy generation optimization is presented for nonlinear Sisko nanomaterial flow by rotating stretchable disk. Flow is examined in the absence of magnetohydrodynamics and Joule heating. Total irreversibility rate (entropy generation rate) is investigated for different flow parameters. Heat source/sink and viscous dissipation effects are considered. Impacts of Brownian motion and thermophoresis on irreversibility have been analyz...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Virial coefficients expressed by heat kernel coefficients
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Xia-Qing Xu, Mi XieAbstractIn this paper, we generally expressed the virial expansion of ideal quantum gases by the heat kernel coefficients for the corresponding Laplace type operator. As examples, we give the virial coefficients for quantum gases in d-dimensional confined space and spheres, respectively. Our results show that, the relative correction from the boundary to the second virial coefficient is independent of the dimension and it always enhances the quantum exchange interaction. In d-dimensional spheres, however, the influence of ...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Influence of sintering atmosphere and thermobaric treatment (TBT) on dielectric behaviors of CaCu3Ti4O12 ceramics
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Ling-Fang Xu, Cong Mao, Vyacheslav V. Marchenkov, Kang Sun, Tatyana V. Dyachkova, Alexander P. Tyutyunnik, Yurii G. Zainulin, Chang-Ping Yang, Shi-Heng LiangAbstractCopper titanate (CaCu3Ti4O12, or CCTO) ceramics sintered in oxygen and vacuum at 1100°C for 12 h have been treated by thermobaric treatment (TBT) at 9 GPa and 1000°C for 10 min and then quenched in liquid nitrogen (LN2). Pure cubic body-centered perovskite-related structure was confirmed from XRD results. Besides, after TBT and quenching, additional minor peaks of TiO2 an...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Spin transport properties in a non-uniform quantum wire modulated by both Rashba and Dresselhaus spin–orbit couplings
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Zhonghui Xu, Weishuai Lv, Mansoor B.A. Jalil, Jinsong Huang, Yangwan Zhong, Yuguang ChenAbstractSpin transport properties in a non-uniform quantum wire (QW) in the presence of both the Rashba and Dresselhaus spin–orbit couplings (SOCs) is investigated by using the non-equilibrium Green's function (NEGF) method combined with the Landauer Büttiker formalism. It is found that such a non-uniform quantum wire exhibits considerable spin polarization in its conductance in the influence of both the Rashba and Dresselhaus SOCs, and that th...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Macroscopic ground-state degeneracy and magnetocaloric effect in the exactly solvable spin-1/2 Ising–Heisenberg double-tetrahedral chain
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Lucia Gálisová, Dušan KnežoAbstractThe ground-state degeneracy and magnetocaloric effect in the spin-1/2 Ising–Heisenberg double-tetrahedral chain are exactly investigated. It is demonstrated that the zero-temperature phase diagram involves two classical and two quantum chiral phases with distinct degrees of the macroscopic degeneracy. Different macroscopic degeneracies observed in the latter phases and at individual ground-state phase transitions are confirmed by multiple-peak dependencies of the specific heat an...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Influence of Cr on microstructure and elastocaloric effect in Ni–Mn–In–Co–Cr polycrystalline alloys
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Ao Shen, Wen Sun, Dewei Zhao, Jian LiuAbstractNi–Mn-based metamagnetic shape memory alloys have been proposed as potential elastocaloric refrigerants. The intrinsic brittleness of the alloys has limited their cooling application. Introducing a soft second phase is an effective way to reduce the brittleness. From the viewpoint of application, the effect of second phase on elastocaloric effect should be illustrated. In this paper, we have investigated the microstructure, martensitic transformation and elastocaloric effect of Ni45Mn37-xIn...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Quantum effective potential from discarded degrees of freedom
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Luke M. ButcherAbstractI obtain the quantum correction ΔVeff=(ħ2/8m)[(1−4ξd+1d)(S′)2+2(1−4ξ)S″] that appears in the effective potential whenever a compact d-dimensional subspace (of volume ∝exp⁡[S(x)]) is discarded from the configuration space of a nonrelativistic particle of mass m and curvature coupling parameter ξ. This correction gives rise to a force −〈ΔVeff′〉 that pushes the expectation value 〈x〉 off its classical trajectory. Because ΔVeff does not depend on...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Ranking the spreading influence of nodes in complex networks: An extended weighted degree centrality based on a remaining minimum degree decomposition
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Fan Yang, Xiangwei Li, Yanqiang Xu, Xinhui Liu, Jundi Wang, Yi Zhang, Ruisheng Zhang, Yabing YaoAbstractRanking the spreading influence of nodes is crucial for developing strategies to control the spreading process on complex networks. In this letter, we define, for the first time, a remaining minimum degree (RMD) decomposition by removing the node(s) with the minimum degree iteratively. Based on the RMD decomposition, a weighted degree (WD) is presented by utilizing the RMD indices of the nearest neighbors of a node. WD assigns a weight to ...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Entangled trajectories during ionization of an H atom driven by n-cycle laser pulse
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Xianghe Ren, Yinan Wu, Lifei Wang, Yujun ZhengAbstractWe study the ionization of an H atom in a linearly polarized laser field with different optical cycle numbers by calculating the entangled trajectories in phase space. The results indicate that, for a two-cycle laser pulse, the entangled trajectory is simple owing to the simple laser electric distribution. As the number of optical cycles increases, the complexity of the laser electric field distribution, and subsequently, that of the entangled trajectories increase. From these entangled t...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

An optimal analysis for Darcy–Forchheimer 3D flow of nanofluid with convective condition and homogeneous–heterogeneous reactions
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): Tasawar Hayat, Arsalan Aziz, Taseer Muhammad, Ahmed AlsaediAbstractHere Darcy–Forchheimer 3D stretching flow of nanoliquid in the presence of convective condition and homogeneous–heterogeneous reactions is analyzed. Impacts of thermophoresis, Brownian diffusion and zero nanoparticles mass flux condition are considered. Adequate transformation procedure give rise to system in terms of ordinary differential equations. The governing mathematical system has been tackled by optimal homotopic technique. Graphical results have been pres...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Bogoliubov de Gennes equation on metric graphs
Publication date: Available online 14 June 2018Source: Physics Letters AAuthor(s): K. Sabirov, D. Jumanazarov, J. Yusupov, D. MatrasulovAbstractWe consider Bogoliubov de Gennes equation on metric graphs. The vertex boundary conditions providing self-adjoint realization of the Bogoliubov de Gennes operator on a metric star graph are derived. Secular equation providing quantization of the energy and the vertex transmission matrix are also obtained. Application of the model for Majorana wire networks is discussed. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

New exact solutions to the high dispersive cubic–quintic nonlinear Schrödinger equation
Publication date: Available online 15 June 2018Source: Physics Letters AAuthor(s): Yingying Xie, Zhaoyu Yang, Lingfei LiAbstractThe complete discrimination system method is employed to find exact solutions for a dispersive cubic–quintic nonlinear Schrödinger equation with third order and fourth order time derivatives. As a result, we derive a range of solutions which include triangular function solutions, kink solitary wave solutions, dark solitary wave solutions, Jacobian elliptic function solutions, rational function solutions and implicit analytical solutions. Numerical simulations are presented to visualize ...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Optimized configuration interaction approach for trapped multiparticle systems interacting via contact forces
We present calculations for model systems of identical bosons with harmonic and double-well potentials. Our results show promising potential for diminishing the computational cost of numerical simulations of various systems of trapped ultracold atoms. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Comparative study on transport properties and scattering mechanism of group III doped SiC nanotube
Publication date: Available online 15 June 2018Source: Physics Letters AAuthor(s): Pei Gong, Yan-Jing Li, Ya-Hui Jia, Ya-Lin Li, Shu-Long Li, Xiao-Yong Fang, Mao-Sheng CaoAbstractThe third group of elements is the acceptor of P-type silicon carbide (SiC). Therefore, studying the transport properties of group III doped SiC nanotube (SiCNTs) and revealing the carrier scattering mechanism have important scientific significance for improving the photoelectric properties and promoting the development of SiC nano-devices. In this article, the lattice structure and transport properties of IIIA-doped SiCNTs are investigated system...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Energy structure and electromagnetically induced transparency of neutral donor in a multi-hilled GaAs quantum ribbon
Publication date: Available online 18 June 2018Source: Physics Letters AAuthor(s): J.D. Salazar-Santa, D. Fonnegra, Y.A. Suaza, M.E. Mora-Ramos, J.H. MarinAbstractThe theoretical study of the energy spectrum and optical response of off-axis donor in a GaAs quantum ribbon with anisotropic rim height under the presence of constant crossed electric and magnetic fields is presented. The calculations are carried out within the effective mass and parabolic approximation, using an adiabatic approach combined with a diagonalization scheme. The rim height of the quantum ribbon has been modeled by including a phenomenological two-pa...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

An extended model for describing pedestrian evacuation under the threat of artificial attack
Publication date: Available online 18 June 2018Source: Physics Letters AAuthor(s): Changkun Chen, Yunhe Tong, Congling Shi, Wenlong QinAbstractAn extended floor field model was proposed to investigate evacuation behaviors of pedestrians under the threat of artificial attack. In this model, pedestrian movement governed by the static and dynamic floor field, and the motion and assault of artificial attacker were involved simultaneously. Further, injuries with lower velocity and deaths of pedestrians caused by the attacker during evacuation were considered. And a new parameter kt was introduced. It is the sensitivity coeffici...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Convective heat transfer flow of nanofluid in a porous medium over wavy surface
Publication date: Available online 19 June 2018Source: Physics Letters AAuthor(s): M. Hassan, M. Marin, Abdullah Alsharif, R. EllahiAbstractIn this letter, water base nanofluid flow over wavy surface in a porous medium of spherical packing beds is investigated. The copper oxides particles are taken into account. These properties are rehabilitated when fluid interacts with porous walls. For porous medium, Dupuit–Forchheimer model; an extension of Darcy's law model is utilized. The natures of velocity and temperature profiles of nanofluid are discussed graphically whereas the values of convection heat transfer coeffici...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

From quantum to classical without ħ → 0
Publication date: Available online 20 June 2018Source: Physics Letters AAuthor(s): E. GozziAbstractIn this paper we put forward some simple rules which can be used in order to pass from the quantum Moyal evolution operator to the classical one of Liouville without taking the limit of ħ→0. These rules involve the averaging over some auxiliary variables. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

First-principles predictions of the geometries and electronic structures of tungsten ditelluride nanoribbons
Publication date: Available online 20 June 2018Source: Physics Letters AAuthor(s): Jian-Hao Wang, Wei Yang, Mei Zhou, Yu Yang, Jie-Yun Yan, Ping ZhangAbstractFirst-principles calculations are carried out to predict the structures and electronic properties of 2H- and Td-WTe2 nanoribbons with different termination edges. It is found that the 2H-WTe2 nanoribbon along the armchair direction and the Td-WTe2 nanoribbon along the X direction show semiconducting characters with tunable band gaps. The 2H-WTe2 nanoribbon along the zigzag direction and the Td-WTe2 nanoribbon along the Y direction show metallic characters. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Reconfigurable topological phononic crystal slabs
Publication date: Available online 20 June 2018Source: Physics Letters AAuthor(s): Lu-yang Feng, Hong-bo Huang, Jian-cheng Zhang, Xiao-ping Xie, Jiu-jiu ChenAbstractWe propose two-dimensional reconfigurable phononic crystal slabs that support topologically protected edge states for Lamb waves. It consists of a triangular lattice of triangular-like air holes perforated in a slab and two sandwich cylinders are placed in the matrix of each unit cell. The pseudospin–orbit coupling is achieved by shifting the sandwich cylinders up or down. The robust transport of Lamb waves along reconfigurable interfaces is further demon...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Vacancy-defect scattering in Ag(111)-supported silicene interface
This study can contribute to the prediction of the electron mobility of other 2D graphene-like honeycomb-structure systems. (Source: Physics Letters A)
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Spectra in nested Mach–Zehnder interferometer experiments
Publication date: Available online 20 June 2018Source: Physics Letters AAuthor(s): Marcin WieśniakAbstractBy the means of the standard quantum mechanics formalism I present an explicit derivation of the structure of power spectra in Danan et al. and Zhou et al. experiments with nested dynamically changing Mach–Zehnder interferometers. The analysis confirms that we observe prominent, first-order peaks on frequencies related to some of the elements of the interferometer, but not on others. However, as I shall demonstrate, there are also other, weaker effects related to all relevant elements of the setup. In case of th...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Importance of Darcy–Forchheimer porous medium in 3D convective flow of carbon nanotubes
This article explores Darcy–Forchheimer 3D flow of water-based carbon nanomaterial (CNTs). A bi-directional linear stretchable surface has been used to create the flow. Flow in porous space is represented by Darcy–Forchheimer expression. Heat transfer mechanism is explored through convective heating. Results for single-wall (SWCNTs) and multi-wall (MWCNTs) carbon nanotubes have been presented and compared. The reduction of partial differential system into nonlinear ordinary differential system is made through suitable variables. Optimal homotopic scheme is used for solutions development of governing flow proble...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Compass-anisotropy-modulated helical states and skyrmion crystals in chiral magnets
Publication date: Available online 25 June 2018Source: Physics Letters AAuthor(s): J.P. Chen, Dan-Wei Zhang, Y. Chen, X.S. Gao, J.-M. LiuAbstractThe compass-type anisotropy appears naturally in chiral magnets with strong spin-orbit coupling. In this work, we investigate the critical roles of compass anisotropy in modulating various spin textures of chiral magnets, by Monte Carlo simulations. The simulated results reveal a gradual helical reorientation and varying symmetry of skyrmion crystal structures as a function of compass anisotropy. Furthermore, an extended continuum spin model with the lattice discretization anisotr...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Topological phases in Bi/Sb planar and buckled honeycomb monolayers
Publication date: Available online 25 June 2018Source: Physics Letters AAuthor(s): N. Nouri, M. Bieniek, M. Brzezińska, M. Modarresi, S. Zia Borujeni, Gh. Rashedi, A. Wójs, P. PotaszAbstractWe investigate topological phases in two-dimensional Bi/Sb honeycomb crystals considering planar and buckled structures, both freestanding and deposited on a substrate. We use the multi-orbital tight-binding model and compare results with density functional theory calculations. We distinguish topological phases by calculating topological invariants, analyzing edge states properties of systems in a ribbon geometry and studying th...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

High-pressure disproportionation phases of CO2 and CO
Publication date: Available online 26 June 2018Source: Physics Letters AAuthor(s): Anguang Hu, Nora Chan, Shiliang Wang, Fan ZhangAbstractFirst-principles enthalpy minimization simulations with target pressures suggest that dense-packed disproportionation phases of CO2 and CO can be transformed from selected molecular precursors under hydrostatic compression. In transformations, electrons are pushed from oxygen to carbon atoms to form electronic disproportionation phases with their chemical formulas of C−2O2+ and C−O+. Simulations indicate that the space packing properties of reactive groups in a molecular crys...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

The influences of the ionic channel conductances and kinetics on the phase-locking behaviors of modeled sinoatrial node cells and tissue
Publication date: Available online 26 June 2018Source: Physics Letters AAuthor(s): Xiaodong Huang, Zhikun Chu, Keming LiAbstractSinoatrial node (SAN) is the leading pacemaker of the heart, whose pathologies are closely associated to certain kinds of arrhythmias. Phase-locking is a characteristic behavior of the self-oscillatory SAN system, which is relevant to the heart rate modulation. It is known that the SAN phase-locking properties are influenced by the stimulating magnitude, the stimulated site in the tissue, the intercellular coupling strength and even the couplings from the atrial cells. Besides the above knowledge,...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

The difference of drivers' anticipation behaviors in a new macro model of traffic flow and numerical simulation
Publication date: Available online 26 June 2018Source: Physics Letters AAuthor(s): Guanghan Peng, Shuhong Yang, Hongzhuan ZhaoAbstractA valuable consideration is inserted into car-following theory to investigate the difference of drivers' anticipation. Furthermore, a fresh macro traffic model involving the difference of the drivers' anticipation is deduced from the car-following model by applying transformation relationship from micro to macro variables. And this effect resulted from the difference of the drivers' anticipation is observed via numerical simulation. The results show that the difference of drivers' anticipati...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research

Free energy and spatial periodicity of generalized cnoidal ion holes
Publication date: Available online 27 June 2018Source: Physics Letters AAuthor(s): Nilakshi Das, Prathana Borah, Hans SchamelAbstractThe free energy density of an ion hole excited coherent state plasma is calculated. The underlying ion trapping nonlinearity is shown to support expressions which appear one order earlier in the expansion scheme compared with conventional, linearly based derivations. This energy argument hence provides a further hint for the necessity of a full nonlinear Vlasov equation in describing coherent wave phenomena found ubiquitously in space, lab and fusion plasmas. The most prominent holes, the pri...
Source: Physics Letters A - July 10, 2018 Category: Physics Source Type: research