理论物理通讯

Select

A KdV-Type Wronskian Formulation to Generalized KP,BKP and Jimbo-Miwa Equations

程丽, 张翼

理论物理通讯. 2017, 68(01): 1-5.

摘要 ( ) PDF全文 ( )

可视化

The purpose of this paper is to introduce a class of generalized nonlinear evolution equations,which can be widely applied to describing a variety of phenomena in nonlinear physical science.A KdV-type Wronskian formulation is constructed by employing the Wronskian conditions of the KdV equation.Applications are made for the (3+1)-dimensional generalized KP,BKP and Jimbo-Miwa equations,thereby presenting their Wronskian sufficient conditions.An N-soliton solution in terms of Wronskian determinant is obtained.Under a dimensional reduction,our results yield Wronskian solutions of the KdV equation.

Select

Interactions of Soliton Waves for a Generalized Discrete KdV Equation

周统, 朱佐农

理论物理通讯. 2017, 68(01): 6-12.

摘要 ( ) PDF全文 ( )

可视化

It is well known that soliton interactions in discrete integrable systems often possess new properties which are different from the continuous integrable systems,e.g.,we found that there are such discrete solitons in a semidiscrete integrable system (the time variable is continuous and the space one is discrete) that the shorter solitary waves travel faster than the taller ones.Very recently,this kind of soliton was also observed in a full discrete generalized KdV system (the both of time and space variables are discrete) introduced by Kanki et al.In this paper,for the generalized discrete KdV (gdKdV) equation,we describe its richer structures of one-soliton solutions.The interactions of two-soliton waves to the gdKdV equation are studied.Some new features of the soliton interactions are proposed by rigorous theoretical analysis.

Select

Classification of Dark Modified KdV Equation

熊娜, 楼森岳, 李彪, 陈勇

理论物理通讯. 2017, 68(01): 13-20.

摘要 ( ) PDF全文 ( )

可视化

The dark Korteweg-de Vries (KdV) systems are defined and classified by Kupershmidt sixteen years ago.However,there is no other classifications for other kinds of nonlinear systems.In this paper,a complete scalar classification for dark modified KdV (MKdV) systems is obtained by requiring the existence of higher order differential polynomial symmetries.Different to the nine classes of the dark KdV case,there exist twelve independent classes of the dark MKdV equations.Furthermore,for the every class of dark MKdV system,there is a free parameter.Only for a fixed parameter,the dark MKdV can be related to dark KdV via suitable Miura transformation.The recursion operators of two classes of dark MKdV systems are also given.

Select

Invariant Functions,Symmetries and Primary Branch Solutions of First Order Autonomous Systems

楼森岳, 姚若侠

理论物理通讯. 2017, 68(01): 21-28.

摘要 ( ) PDF全文 ( )

可视化

An invariant function (IF) is defined as a multiplier of a symmetry that means a symmetry multiplied by an IF is still a symmetry.Primary branch solutions of arbitrary first order scalar systems can be obtained by means of the IF and its related symmetry approach.Especially,one recursion operator and some sets of infinitely many high order symmetries are also explicitly given for arbitrary (1+1)-dimensional first order autonomous systems.Because of the intrusion of the arbitrary function,various implicit special exact solutions can be found by fixing the arbitrary functions and selecting different seed solutions.

Select

Enhancement of Quantum Correlations in Qubit-Qutrit Systems under the non-Markovian Environment

Abdul Basit, Hamad Ali, Fazal Badshah, 葛国勤

理论物理通讯. 2017, 68(01): 29-34.

摘要 ( ) PDF全文 ( )

可视化

We investigate the time evolution of quantum correlations of a hybrid qubit-qutrit system under the classical Ornstein-Uhlenbeck (OU) noise.Here we consider two different one-parameter families of qubit-qutrit states which independently interact with the non-Markovian reservoirs.A comparison with the Markovian dynamics reveals that for the same set of initial condition parameters,the non-Markovian behavior of the environment plays an important role in the enhancement of the survival time of quantum correlations.In addition,it is observed that the non-Markovian strength (γ/Γ) has a positive impact on the correlations time.For the initial separable states it is found that there is a finite time interval in which the geometric quantum discord is frozen despite the presence of a noisy environment and that interval can be further prolonged by using the non-Markovian property.Moreover,its decay can be significantly delayed.

Select

Time Operator in Relativistic Quantum Mechanics

Sina Khorasani

理论物理通讯. 2017, 68(01): 35-38.

摘要 ( ) PDF全文 ( )

可视化

It is first shown that the Dirac's equation in a relativistic frame could be modified to allow discrete time,in agreement to a recently published upper bound.Next,an exact self-adjoint 4×4 relativistic time operator for spin-1/2 particles is found and the time eigenstates for the non-relativistic case are obtained and discussed.Results confirm the quantum mechanical speculation that particles can indeed occupy negative energy levels with vanishingly small but non-zero probablity,contrary to the general expectation from classical physics.Hence,Wolfgang Pauli's objection regarding the existence of a self-adjoint time operator is fully resolved.It is shown that using the time operator,a bosonic field referred here to as energons may be created,whose number state representations in non-relativistic momentum space can be explicitly found.

Select

Static Axially Symmetric Models and Structure Scalars in Self-Interacting Brans-Dicke Gravity

M. Sharif, Rubab Manzoor

理论物理通讯. 2017, 68(01): 39-48.

摘要 ( ) PDF全文 ( )

可视化

This paper investigates static axially symmetric models in self-interacting Brans-Dicke gravity.We discuss physically feasible sources of models,derive field equations as well as evolution equations from Bianchi identities and construct structure scalars.Using these scalars and evolution equations,the inhomogeneity factors of the system are evaluated.It is found that structure scalars related to double dual of Riemann tensor control the density inhomogeneity.Finally,we obtain exact solutions of homogenous isotropic and inhomogeneous anisotropic spheroid models.It turns out that homogenous solutions reduce to Schwarzschild type interior solutions for a spherical case.We conclude that homogenous models involve homogenous distribution of scalar field whereas inhomogeneous correspond to inhomogeneous scalar field.

Select

Exact Solution of Space-Time Fractional Coupled EW and Coupled MEW Equations Using Modified Kudryashov Method

K. R. Raslan, Talaat S. EL-Danaf, Khalid K. Ali

理论物理通讯. 2017, 68(01): 49-56.

摘要 ( ) PDF全文 ( )

可视化

In the present paper,we established a traveling wave solution by using modified Kudryashov method for the space-time fractional nonlinear partial differential equations.The method is used to obtain the exact solutions for different types of the space-time fractional nonlinear partial differential equations such as,the space-time fractional coupled equal width wave equation (CEWE) and the space-time fractional coupled modified equal width wave equation (CMEW),which are the important soliton equations.Both equations are reduced to ordinary differential equations by the use of fractional complex transform and properties of modified Riemann-Liouville derivative.We plot the exact solutions for these equations at different time levels.

Select

Entanglment Concentration with Different Measurement in a 3-Mode Optomechanical System

李哲

理论物理通讯. 2017, 68(01): 57-63.

摘要 ( ) PDF全文 ( )

可视化

In this work,we perform a series of phonon counting measurement with different methods in a 3-mode optomechanical system,and we compare the difference of the Entanglment after measurement.In this article we focus on the three cases:prefect measurement,imperfect measurement and on-off measurement.We find that whatever measurement you take,the Entanglment will increase.The size of Entanglment enhancement is the largest in the perfect measurement,second in the imperfect measurement,and it is not obvious in the on-off measurement.We are sure that the more precise measurement information,the larger Entanglment concentration.

Select

Entropy of Schwarzschild-de Sitter Black Hole with Generalized Uncertainty Principle Revisited

唐浩, 孙成一, 岳瑞宏

理论物理通讯. 2017, 68(01): 64-66.

摘要 ( ) PDF全文 ( )

可视化

We study the entropy of Schwarzschild-de Sitter black holes based on generalized uncertainty principle with brick-wall method by counting degrees of freedom near the horizons and obtain the entropy proportional to the surface area at the horizons without cut-off.And reveal the possible value of the minimum length.

Select

On the Critical Behavior of Gapped Gravitational Collapse in Confined Spacetime

蔡荣根, 季力伟, 杨润秋

理论物理通讯. 2017, 68(01): 67-75.

摘要 ( ) PDF全文 ( )

可视化

The gravitational collapse of a massless scalar field enclosed with a perfectly reflecting wall in a spacetime with a cosmological constant Λ is investigated.The mass scaling for the gapped collapse M_AH-M_g ∝(ε_c-ε)^ξ is confirmed and a new time scaling for the gapped collapse T_AH-T_g∝(ε_c-ε)^ζ is found.For both the critical exponents,we find strong evidence to show that they are non-universal.Especially when Λ≠0,we find that both of these two critical exponents depend on the combination Λ R²,where R is the radial position of the reflecting wall.We find an evolution of the critical exponent ξ from 0.37 in the confined asymptotic dS case with Λ R²=1.75 to 0.68 in the confined asymptotic AdS case with Λ R²=-1.75,while the critical exponent ζ varies from 0.10 to 0.26,which shows that the new critical behavior for the gapped collapse is essentially different from the Choptuik's case.

Select

Approaching Quantum-Limited Amplification with Large Gain Catalyzed by Optical Parametric Amplifier Medium

郑强, 李凯

理论物理通讯. 2017, 68(01): 76-82.

摘要 ( ) PDF全文 ( )

可视化

Amplifier is at the heart of experiments carrying out the precise measurement of a weak signal.An idea quantum amplifier should have a large gain and minimum added noise simultaneously.Here,we consider the quantum measurement properties of the cavity with the OPA medium in the op-amp mode to amplify an input signal.We show that our nonlinear-cavity quantum amplifier has large gain in the single-value stable regime and achieves quantum limit unconditionally.

Select

Zero-Absorption Isolines in a 2-Photon 2-Level Atom Model

S. S. Hassan, R. A. Alharbey

理论物理通讯. 2017, 68(01): 83-90.

摘要 ( ) PDF全文 ( )

可视化

The c-number atomic Bloch equations modelling the coupling of a 2-photon 2-level single atom with a non-resonant (△≠0) squeezed vacuum (SV) radiation reservoir show that:(i) The quantum interference (QI) process,of parameter f≠0,between the 2-photon transition channels causes coupling of the atomic variables (inversion and polarisation),and,(ii) The SV reservoir parameters (N,M) induce periodic coefficients and hence inhibited oscillatory behaviour in the atomic variables.Perturbative analytical solutions of these non-autonomous Bloch equations are derived and used to calculate the absorption spectrum of a weak field probing the system.Of particular,the zero-absorption isolines in the relevant (N,f)-and (△,f)-planes of the system parameters are identified computationally.It is found that,the largest set of points,where absorption is zero,in the (△,f)-plane depends on the choice of the degree of squeezing parameter (M) of the SV reservoir.

Select

Analysis of Heat Transfer Phenomenon in Magnetohydrodynamic Casson Fluid Flow Through Cattaneo-Christov Heat Diffusion Theory

G. K. Ramesh, B. J. Gireesha, S. A. Shehzad, F. M. Abbasi

理论物理通讯. 2017, 68(01): 91-95.

摘要 ( ) PDF全文 ( )

可视化

Heat transport phenomenon of two-dimensional magnetohydrodynamic Casson fluid flow by employing Cattaneo-Christov heat diffusion theory is described in this work.The term of heat absorption/generation is incorporated in the mathematical modeling of present flow problem.The governing mathematical expressions are solved for velocity and temperature profiles using RKF 45 method along with shooting technique.The importance of arising nonlinear quantities namely velocity,temperature,skin-friction and temperature gradient are elaborated via plots.It is explored that the Casson parameter retarded the liquid velocity while it enhances the fluid temperature.Further,we noted that temperature and thickness of temperature boundary layer are weaker in case of Cattaneo-Christov heat diffusion model when matched with the profiles obtained for Fourier's theory of heat flux.

Select

Analytical Solution for Peristaltic Transport of Viscous Nanofluid in an Asymmetric Channel with Full Slip and Convective Conditions

Abdelhalim Ebaid, Emad H. Aly, K. Vajravelu

理论物理通讯. 2017, 68(01): 96-102.

摘要 ( ) PDF全文 ( )

可视化

The peristaltic flow of nanofluids is a relatively new area of research.Scientists are of the opinion that the no-slip conditions at the boundaries are no longer valid and consequently,the first and the second order slip conditions should be addressed.In this paper,the effects of slip conditions and the convective boundary conditions at the boundary walls on the peristaltic flow of a viscous nanofluid are investigated for.Also,the exact analytical solutions are obtained for the model.The obtained results are presented through graphs and discussed.The results reveal that the two slip parameters have strong effects on the temperature and the nanoparticles volume fraction profiles.Moreover,it has been seen that the temperature and nanoparticles volume fraction profiles attain certain values when the first slip condition exceeds a specified value.However,no limit value for the second slip parameter has been detected.Further,the effects of the various emerging parameters on the flow and heat transfer characteristics have been presented.

Select

Hydromagnetic Blood Flow of Sisko Fluid in a Non-uniform Channel Induced by Peristaltic Wave

A. Zeeshan, M. M. Bhatti, N. S. Akbar, Y. Sajjad

理论物理通讯. 2017, 68(01): 103-110.

摘要 ( ) PDF全文 ( )

可视化

In this paper,a smooth repetitive oscillating wave traveling down the elastic walls of a non-uniform two-dimensional channels is considered.It is assumed that the fluid is electrically conducting and a uniform magnetic field is perpendicular to flow.The Sisko fluid is grease thick non-Newtonian fluid can be considered equivalent to blood.Taking long wavelength and low Reynolds number,the equations are reduced.The analytical solution of the emerging non-linear differential equation is obtained by employing Homotopy Perturbation Method (HPM).The outcomes for dimensionless flow rate and dimensionless pressure rise have been computed numerically with respect to sundry concerning parameters amplitude ratio φ,Hartmann number M,and Sisko fluid parameter b₁.The behaviors for pressure rise and average friction have been discussed in details and displayed graphically.Numerical and graphical comparison of Newtonian and non-Newtonian has also been evaluated for velocity and pressure rise.It is observed that the magnitude of pressure rise is maximum in the middle of the channel whereas for higher values of fluid parameter it increases.Further,it is also found that the velocity profile shows converse behavior along the walls of the channel against multiple values of fluid parameter.

Select

Modified Potential Around a Moving Test Charge in Strongly Coupled Dusty Plasma

M. Shahmansouri, B. Farokhi, N. Khodabakhshi

理论物理通讯. 2017, 68(01): 111-116.

摘要 ( ) PDF全文 ( )

可视化

The theory of dynamical (wake) potential behind a moving test charge in a weakly coupled dusty plasma is extended to that including of strong interaction between dust grains.Such strong interaction is included in the dielectric response function by a generalized hydrodynamic (GH) fluid model.It is shown that the strong interaction between dusts including the lattice spacing correction has a significant effect on the wake potential in dusty plasma.This may be used to investigate basic features of phase transition and possibility of lattice formation of dusty plasma.

Select

Nonlinear Structures in an Ion-Beam Plasmas Including Dust Impurities with Nonthermal Nonextensive Electrons

Debjit Dutta, Biswajit Sahu

理论物理通讯. 2017, 68(01): 117-124.

摘要 ( ) PDF全文 ( )

可视化

The properties of dust ion acoustic waves are investigated in an unmagnetized multicomponent plasma system consisting of ion beam,charged positive and negative ions,electrons obeying nonthermal-Tsallis distribution and stationary negatively charged dust grains by the conventional Sagdeev pseudopotential method,through which the condition for existence of several nonlinear structures is analyzed theoretically.The dispersion relation for electrostatic waves is derived and analyzed and an expression of the energy integral equation is obtained.It is reported here that our plasma model supports solitions,double layers and supersoliton solutions for certain range of parameters.Finally,the effects of different physical plasma parameters on these nonlinear structures are studied numerically.The present theory should be helpful in understanding the salient features of the electrostatic waves in space and in laboratory plasmas where two distinct groups of ions and non-Maxwellian distributed electrons are present.

Select

Properties of Single-Layer Boron Sheets:First-Principle Study through MatCloud Platform

王宗国, 杨小渝, 覃绍京, 王垂林

理论物理通讯. 2017, 68(01): 125-130.

摘要 ( ) PDF全文 ( )

可视化

Electronic structures in two kinds of boron structures are investigated by the first-principle density functional theory (DFT) calculations.One structure is from theoretical prediction,and the other is from experimental investigation.Binding energy calculations suggest that the boron structure designed from theory is more stable than that made by experiment.Elastic constants calculations show that both structures are mechanically stable.The electronic structure results show that the theoretical designed structure exhibits semi-metal behavior,while the other structure exhibits metallic character.No magnetic phenomenal is discovered from them.All the calculations are carried out by the first principles calculation through the MatCloud platform,which is developed by our research group.

Select

Effect of Temperature on Topological States of Circular DNA

范洋涛, 李秀燕, 刘艳辉, 陈虎

理论物理通讯. 2017, 68(01): 131-136.

摘要 ( ) PDF全文 ( )

可视化

The different topological states of circular double-stranded DNA can be defined by their linking number.The equilibrium distribution of linking number can be obtained by circularizing a linear DNA into a circle by ligase.Based on the recent experimental results that the DNA bending rigidity and twist rigidity strongly depend on temperature,the reduced bending rigidity can be approximated by g=(3.19×10^-19-T·4.14×10^-22) erg·cm over the temperature interval (5~53)℃,and the temperature dependence of twist rigidity can be fitted by C (T)=(4588.89exp (-T/117.04)-251.33) nm.The temperature dependence of the linking number distribution of circular DNAs can be predicted by using Monte Carlo simulation.The variance of linking number distribution on temperature is in accordance with the previous experimental results.Compared with the temperature dependence of bending rigidity,the temperature dependence of twist rigidity causes a noticeable fluctuation in linking number distribution and mainly contribute towards the variance change of linking number distribution of circular DNA.The variance of the writhe number and twist number in the equation 〈(△ Lk)²〉=〈(△ Tw)²〉+〈(Wr)²〉 depends on the length of circular DNA.When the length of circular DNA is less than 230 nm,the variance of twist number 〈(△ Tw)²〉 is dominant over the variance of writhe number (〈(Wr)²〉),whereas for the condition that the length of the circular DNA is larger than 370 nm.

Select

Stabilities and Dynamics of Protein Folding Nuclei by Molecular Dynamics Simulation

宋永顺, 周昕, 郑伟谋, 王延颋

理论物理通讯. 2017, 68(01): 137-148.

摘要 ( ) PDF全文 ( )

可视化

To understand how the stabilities of key nuclei fragments affect protein folding dynamics,we simulate by molecular dynamics (MD) simulation in aqueous solution four fragments cut out of a protein G,including one α-helix (seqB:KVFKQYAN),two β-turns (seqA:LNGKTLKG and seqC:YDDATKTF),and one β-strand (seqD:DGEWTYDD).The Markov State Model clustering method combined with the coarse-grained conformation letters method are employed to analyze the data sampled from 2-μs equilibrium MD simulation trajectories.We find that seqA and seqB have more stable structures than their native structures which become metastable when cut out of the protein structure.As expected,seqD alone is flexible and does not have a stable structure.Throughout our simulations,the native structure of seqC is stable but cannot be reached if starting from a structure other than the native one,implying a funnel-shape free energy landscape of seqC in aqueous solution.All the above results suggest that different nuclei have different formation dynamics during protein folding,which may have a major contribution to the hierarchy of protein folding dynamics.

选择文件类型/文献管理软件名称

选择包含的内容

2017年, 第68卷, 第01期　
刊出日期：2017-07-01

模态框（Modal）标题

选择文件类型/文献管理软件名称

选择包含的内容

2017年, 第68卷, 第01期 刊出日期：2017-07-01

2017年, 第68卷, 第01期　
刊出日期：2017-07-01