2017年, 第67卷, 第03期　
刊出日期：2017-03-01

  

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  Hypergeometric Series Solution to a Class of Second-Order Boundary Value Problems via Laplace Transform with Applications to Nanofluids

  Abdelhalim Ebaid, Abdul-Majid Wazwaz, Elham Alali, Basem S. Masaedeh

  理论物理通讯. 2017, 67(03): 231-234.

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  Very recently, it was observed that the temperature of nanofluids is finally governed by second-order ordinary differential equations with variable coefficients of exponential orders. Such coefficients were then transformed to polynomials type by using new independent variables. In this paper, a class of second-order ordinary differential equations with variable coefficients of polynomials type has been solved analytically. The analytical solution is expressed in terms of a hypergeometric function with generalized parameters. Moreover, applications of the present results have been applied on some selected nanofluids problems in the literature. The exact solutions in the literature were derived as special cases of our generalized analytical solution.
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  New Stability Criteria for High-Order Neural Networks with Proportional Delays

  徐昌进, 李培峦

  理论物理通讯. 2017, 67(03): 235-240.

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  This paper is concerned with high-order neural networks with proportional delays. The proportional delay is a time-varying unbounded delay which is different from the constant delay, bounded time-varying delay and distributed delay. By the nonlinear transformation y_i(t)=u_i(e^t) (i=1, 2,..., n), we transform a class of high-order neural networks with proportional delays into a class of high-order neural networks with constant delays and timevarying coefficients. With the aid of Brouwer fixed point theorem and constructing the delay differential inequality, we obtain some delay-independent and delay-dependent sufficient conditions to ensure the existence, uniqueness and global exponential stability of equilibrium of the network. Two examples with their simulations are given to illustrate the theoretical findings. Our results are new and complement previously known results.
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  Bound States Energies of a Harmonic Oscillator Perturbed by Point Interactions

  N. Ferkous, T. Boudjedaa

  理论物理通讯. 2017, 67(03): 241-249.

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  We determine explicitly the exact transcendental bound states energies equation for a one-dimensional harmonic oscillator perturbed by a single and a double point interactions via Green's function techniques using both momentum and position space representations. The even and odd solutions of the problem are discussed. The corresponding limiting cases are recovered. For the harmonic oscillator with a point interaction in more than one dimension, divergent series appear. We use to remove this divergence an exponential regulator and we obtain a transcendental equation for the energy bound states. The results obtained here are consistent with other investigations using different methods.
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  Investigation of Conformable Fractional Schrödinger Equation in Presence of Killingbeck and Hyperbolic Potentials

  Won Sang Chung, Soroush Zare, Hassan Hassanabadi

  理论物理通讯. 2017, 67(03): 250-254.

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  In this article, conformable fractional form of Schrödinger equation has been presented. Then in this formalism two different and well-known potential have been come in. Wave function of these potential are obtained in terms of Heun function and energy eigen values of each case is determined as well.
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  Non-Markovianity Measure Based on Brukner-Zeilinger Invariant Information for Unital Quantum Dynamical Maps

  贺志, 朱烈强, 李莉

  理论物理通讯. 2017, 67(03): 255-260.

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  A non-Markovianity measure based on Brukner-Zeilinger invariant information to characterize nonMarkovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner-Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner-Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information.
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  Quantum Fisher Information of Driven Multi-particle Systems in Structured Bosonic Reservoirs

  严凯, 谢燕青, 黄雨梦, 郝翔

  理论物理通讯. 2017, 67(03): 261-266.

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  We investigate the dynamics of the precision of the parameter estimation in many driven atoms, each of which interacts with a local structured bosonic reservoir respectively. The evolution of quantum states for single driven atom is described by the time local quantum master equation. The dynamics of the quantum Fisher information for many entangled atoms is obtained by means of the supreoperator mapping. The estimation limit is superior to the standard quantum limit during a characteristic interval. At a given time, the precision of parameter estimation can be improved to a maximal value if the number of entangled atoms is chosen to be an optimal value. The optimal number of entangled atoms is determined by the dynamical property. The decay of quantum Fisher information is accelerated with the increase of the number of entangled atoms.
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  Quantum Correlations Evolution Asymmetry in Quantum Channels

  李萌, 黄运锋, 郭光灿

  理论物理通讯. 2017, 67(03): 267-272.

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  It was demonstrated that the entanglement evolution of a specially designed quantum state in the bistochastic channel is asymmetric. In this work, we generalize the study of the quantum correlations, including entanglement and quantum discord, evolution asymmetry to various quantum channels. We found that the asymmetry of entanglement and quantum discord only occurs in some special quantum channels, and the behavior of the entanglement evolution may be quite different from the behavior of the quantum discord evolution. To quantum entanglement, in some channels it decreases monotonously with the increase of the quantum channel intensity. In some other channels, when we increase the intensity of the quantum channel, it decreases at first, then keeps zero for some time, and then rises up. To quantum discord, the evolution becomes more complex and you may find that it evolutes unsmoothly at some points. These results illustrate the strong dependence of the quantum correlations evolution on the property of the quantum channels.
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  Exact Soliton Solutions for the (2+1)-Dimensional Coupled Higher-Order Nonlinear Schrödinger Equations in Birefringent Optical-Fiber Communication

  蔡跃进, 白成林, 罗清龙

  理论物理通讯. 2017, 67(03): 273-279.

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  In birefringent optical fibers, the propagation of femtosecond soliton pulses is described by coupled higherorder nonlinear Schrödinger equations. In this paper, we will investigate the bright and dark soliton solutions of (2+1)-dimensional coupled higher-order nonlinear Schrödinger equations, with the aid of symbolic computation and the Hirota method. On the basis of soliton solutions, we test and discuss the interactions graphically between the solitons in the x-z, x-t, and z-t planes.
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  Two-Point Resistance of a Non-Regular Cylindrical Network with a Zero Resistor Axis and Two Arbitrary Boundaries

  谭志中

  理论物理通讯. 2017, 67(03): 280-288.

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  We study a problem of two-point resistance in a non-regular m×n cylindrical network with a zero resistor axis and two arbitrary boundaries by means of the Recursion-Transform method. This is a new problem never solved before, the Green's function technique and the Laplacian matrix approach are invalid in this case. A disordered network with arbitrary boundaries is a basic model in many physical systems or real world systems, however looking for the exact calculation of the resistance of a binary resistor network is important but difficult in the case of the arbitrary boundaries, the boundary is like a wall or trap which affects the behavior of finite network. In this paper we obtain a general resistance formula of a non-regular m×n cylindrical network, which is composed of a single summation. Further, the current distribution is given explicitly as a byproduct of the method. As applications, several interesting results are derived by making special cases from the general formula.
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  Accurate Structure Parameters for Tunneling Ionization Rates of Gas-Phase Linear Molecules

  赵松峰, 栗建科, 王国利, 李鹏程, 周效信

  理论物理通讯. 2017, 67(03): 289-300.

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  In the molecular Ammosov{Delone{Krainov (MO-ADK) model of Tong et al.[Phys. Rev. A 66 (2002) 033402], the ionization rate depends on the structure parameters of the molecular orbital from which the electron is removed. We determine systematically and tabulate accurate structure parameters of the highest occupied molecular orbital (HOMO) for 123 gas-phase linear molecules by solving time-independent Schrödinger equation with B-spline functions and molecular potentials which are constructed numerically using the modified Leeuwen{Baerends (LBα) model.
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  Advanced Study of Unsteady Heat and Chemical Reaction with Ramped Wall and Slip Effect on a Viscous Fluid

  Ayesha Sohail, K. Maqbool, Noreen Sher Akbar, Muhammad Younas

  理论物理通讯. 2017, 67(03): 301-308.

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  This paper investigate the effect of slip boundary condition, thermal radiation, heat source, Dufour number, chemical reaction and viscous dissipation on heat and mass transfer of unsteady free convective MHD flow of a viscous fluid past through a vertical plate embedded in a porous media. Numerical results are obtained for solving the nonlinear governing momentum, energy and concentration equations with slip boundary condition, ramped wall temperature and ramped wall concentration on the surface of the vertical plate. The influence of emerging parameters on velocity, temperature and concentration fields are shown graphically.
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  Solutions to Forced and Unforced Lin-Reissner-Tsien Equations for Transonic Gas Flows on Various Length Scales

  Kyle A. Theaker, Robert A. Van Gorder

  理论物理通讯. 2017, 67(03): 309-316.

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  The Lin-Reissner-Tsien equation is useful for studying transonic gas flows, and has appeared in both forced and unforced forms in the literature. Defining arbitrary spatial scalings, we are able to obtain a family of exact similarity solutions depending on one free parameter in addition to the model parameter holding the scalings. Numerical solutions compare favorably with the exact solutions in regions where the exact solutions are valid. Mixed wave-similarity solutions, which describe wave propagation in one variable and self-similar scaling of the entire solution, are also given, and we show that such solutions can only exist when the wave propagation is sufficiently slow. We also extend the Lin-Reissner-Tsien equation to have a forcing term, as such equations have entered the physics literature recently. We obtain both wave and self-similar solutions for the forced equations, and we are able to give conditions under which the force function allows for exact solutions. We then demonstrate how to obtain these exact solutions in both the traveling wave and self-similar cases. There results constitute new and potentially physically interesting exact solutions of the Lin-Reissner-Tsien equation and in particular suggest that the forced Lin-Reissner-Tsien equation warrants further study.
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  Electrostatic Surface Waves on Semi-Bounded Quantum Electron-Hole Semiconductor Plasmas

  Afshin Moradi

  理论物理通讯. 2017, 67(03): 317-321.

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  The electrostatic surface waves on semi-bounded quantum electron-hole semiconductor plasmas are studied within the framework of the quantum hydrodynamic model, including the electrons and holes quantum recoil effects, quantum statistical pressures of the plasma species, as well as exchange and correlation effects. The dispersion characteristics of surface electrostatic oscillations are investigated by using the typical values of GaAs, GaSb and GaN semiconductors. Numerical results show the existence of one low-frequency branch due to the mass difference between the electrons and holes in addition to one high-frequency branch due to charge-separation effects.
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  Proton Beam Generated by Multi-Lasers Interaction with Rear-Holed Target

  杨鹏, 范大鹏, 李玉晓

  理论物理通讯. 2017, 67(03): 322-326.

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  Multi-lasers are proposed to enhance the proton acceleration in laser plasma interaction. A rear-holed target is illuminated by three lasers from different directions. The scheme is demonstrated by two-dimensional particlein-cell simulations. The electron cloud shape is controlled well and the electron density is improved significantly. The electrons accelerated by the three lasers induce an enhanced target normal sheath acceleration (TNSA) which suppresses the proton beam divergence and improves the maximum proton energy. The maximum proton energy is 22.9 MeV, which increased significantly than that of a single-laser target interaction. Meanwhile, the average divergence angle (22:3°) is reduced. The dependence of the proton beam on the length of sidewall is investigated in detail and the optimal length is obtained.
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  Self-similar Solution of a Cylindrical Shock Wave under the Action of Monochromatic Radiation in a Rotational Axisymmetric Dusty Gas

  G. Nath, P. K. Sahu

  理论物理通讯. 2017, 67(03): 327-336.

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  A self-similar flow behind a cylindrical shock wave is studied under the action of monochromatic radiation in a rotational axisymmetric dusty gas. The dusty gas is taken to be a mixture of small solid particles and perfect gas, and solid particles are continuously distributed in the mixture. The similarity solutions are obtained and the effects of the variation of the radiation parameter, the ratio of the density of solid particles to the initial density of the gas, the mass concentration of solid particles in the mixture and the index for the time dependent energy law are investigated. It is observed that an increase in the radiation parameter has decaying effect on the shock waves; whereas the shock strength increases with an increase in the ratio of the density of solid particles to the initial density of the gas or the index for the time dependent energy law. Also, it is found that an increase in the radiation parameter has effect to decrease the flow variables except the density and the azimuthal component of fluid velocity. A comparison is also made between rotating and non-rotating cases.
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  Temperature Effects of Electric Field on the First Excited State of Strong Coupling Polaron in a CsI Quantum Pseudodot

  孙勇, 丁朝华, 肖景林

  理论物理通讯. 2017, 67(03): 337-340.

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  Employing variational method of Pekar type (VMPT), this paper investigates the first-excited state energy (FESE), excitation energy and transition frequency of the strongly-coupled polaron in the CsI quantum pseudodot (QPD) with electric field. The temperature effects on the strong-coupling polaron in electric field are calculated by using the quantum statistical theory (QST). The results from the present investigation show that the FESE, excitation energy and transition frequency increase (decrease) firstly and then at lower (higher) temperature regions. They are decreasing functions of the electric field strength.
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  Quantum Spin Transport in Rashba Spin-Orbit-Coupled Graphene Nanoflakes

  H. Nikoofard, M. Laghaei, E. Heidari Semiromi

  理论物理通讯. 2017, 67(03): 341-346.

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  We study the spin-resolved transport in a two-terminal graphene nanoflake device with a Rashba spinorbit coupling region in the center of the device. The Green's function method is applied to the system and the spin transmission probability and the spin polarization in x, y, and z directions are calculated. It is found that the components of the spin polarization are antisymmetric functions of Fermi energy, which oscillate and decay to the zero with increasing the energy for all values of the Rashba strength. It is shown that by tuning the Rashba strength via a gate voltage and/or changing the size of the system, it is possible to control the sign and magnitude of the spin polarization. The system represented here is a typical candidate for full electrical spintronic devices based on the carbon materials that are used for spin filtration.