Convective heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface with heat source

Heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface were addressed.Analysis was performed in the presence of internal heat generation/absorption. Concentration and thermal buoyancy effects were accounted. Convective boundary conditions for heat and mass transfer analysis were explored. Series solutions of the resulting problem were developed. Effects of mixed convection, internal heat generation/absorption parameter and Biot numbers on the dimensionless velocity, temperature and concentration distributions were illustrated graphically. Numerical values of local Nusselt and Sherwood numbers were obtained and analyzed for all the physical parameters. It is found that both thermal and concentration boundary layer thicknesses are decreasing functions of stretching ratio. Variations of mixed convection parameter and concentration buoyancy parameter on the velocity profiles and associated boundary layer thicknesses are enhanced. Velocity profiles and temperature increase in the case of internal heat generation while they reduce for heat absorption. Heat transfer Biot number increases the thermal boundary layer thickness and temperature. Also concentration and its associated boundary layer are enhanced with an increase in mass transfer Biot number. The local Nusselt and Sherwood numbers have quite similar behaviors for increasing values of mixed convection parameter, concentration buoyancy parameter and Deborah number.

Series Solution for Rotating Flow of an Upper Convected Maxwell Fluid over a Stretching Sheet

The equations for two-dimensional flow of an upper convected Maxwell （UCM） fluid in a rotating frame are modeled. The resulting equations are first simplified by a boundary layer approach and then solved by a homotopy analysis method （HAM）. Convergence of series solution is discussed through residual error curves. The results of the influence of viscoelastic and rotation parameters are plotted and discussed.

Boundary conditions: An effect of average of microscopic Maxwell’s equations

It is well known that the macroscopic Maxwell’s equations can be obtained from the corresponding microscopic or atomic equations by a proper averaging process. The purpose of this paper is to present the macroscopic Maxwell’s equations which are valid in all regions of space, including an interface between two different media; and the boundary conditions can naturally emerge from the macroscopic equations as an effect of average of the microscopic Maxwell’s equations. In addition, the application of the unit step functions and the Dirac delta function to our discussion not only permits great mathematical simplicity but also gives rise to convenient physical concepts for the description and representation of the actual fields in the vicinity of the interface.

Relationship Between Classical and Quantum Physics

Schrfdinger＇s equation is one the equations that mark the beginnings of the systematic quantum physics. It was shown that it follows from the Dirac＇s equation and the relationship with classical physics, i.e. with classical field theory was established. The subject of this work is the relationship between classical relativistic physics and the quantum physics. Investigation carded out in this work, shows that the free electromagnetic field, spinor Dirac＇s field without mass, spinor Dirac＇s field with mass, and some other fields are described by the same vibrational formulation. The conditions that a field be described by Maxwell＇s equations of motion are given in this work, and some solutions of these conditions are also given. Non-relativistic approximation of the equations of the non-quantified field are the Schrōdinger＇s equations. Dirac＇s equation as a special case, contains Maxwell＇s equations and the Schrōdinger＇s equation.

议程设置理论的研究范式与理论源流

议程设置理论兴起于20世纪70年代。经过三十多年的发展,不论在理论体系,还是研究方法上,都已经日渐成熟,成为当代西方学术界颇具影响力的主流理论之一。政治学与公共政策研究方面,议程设置理论已经占据重要的学术地位,并对政治体制、政策研究、制度变迁等政治学的基本问题提供了许多重要的解释理论和研究方法。中国学术界从20世纪90年代中期开始,对议程设置理论出现零星的介绍。但是到目前为止,该理论仅在新闻传媒领域偶有涉及。在政治学与政策研究领域,除了一两篇文章有所涉及外,基本还处于研究空白。

马克思主义中国化在青年大学生中的传播机制及跨文化应对

马克思主义中国化是个系统过程,其思想文化价值出场与青年大学生政治文化形成对接;而中国化在青年大学生中的有效传播需要理性的传播机制,包括传播中的出场路径、传播过程及要素结构、意识形态工作机制及"意见领袖"作用等问题。在传播过程中,全球化境遇所诉求的跨文化应当引起足够重视。

Convergence of Compressible Euler-Maxwell Equations to Compressible Euler-Poisson Equations

In this paper, the convergence compressible Euler-Poisson equations in a of time-dependent Euler-Maxwell equations to torus via the non-relativistic limit is studied. The local existence of smooth solutions to both systems is proved by using energy estimates for first order symmetrizable hyperbolic systems. For well prepared initial data the convergence of solutions is rigorously justified by an analysis of asymptotic expansions up to any order. The authors perform also an initial layer analysis for general initial data and prove the convergence of asymptotic expansions up to first order.

Zero dielectric constant limit to the non-isentropic compressible Euler-Maxwell system

We investigate the zero dielectric constant limit to the non-isentropic compressible Euler-Maxwell system.We justify this singular limit rigorously in the framework of smooth solutions and obtain the nonisentropic compressible magnetohydrodynamic equations as the dielectric constant tends to zero.