On Global Solvability of Nonlinear Equations with Parameters

Doklady Mathematics - We consider smooth mappings acting from one Banach space to another and depending on a parameter belonging to a topological space. Under various regularity assumptions,...     

Global Unique Solvability of an Initial-Boundary Value Problem for the One-Dimensional Barotropic Equations of Binary Mixtures of Viscous Compressible Fluids

Journal of Applied and Industrial Mathematics - We consider the equations of a multivelocity model of a binary mixture of viscous compressible fluids (the two-fluid medium) in the case of...     

Global Unique Solvability of Inhomogeneous Navier-Stokes Equations with Bounded Density

In this paper, we prove the global existence and uniqueness of solution to d-dimensional (for d = 2, 3) incompressible inhomogeneous Navier-Stokes equations with initial density being bounded from above and below by some positive constants, and with initial velocity u₀ ∈ H^s( R ²) for s > 0 in 2-D, or u₀ ∈ H¹( R ³) satisfying ‖u₀‖_L² ‖?u₀‖_L² being sufficiently small in 3-D. This in particular improves the most recent well-posedness result in [10 Danchin , R. , Mucha , P.B. ( 2013 ). Incompressible flows with piecewise constant density . Arch. Rat. Mech. Anal. 207 : 991 – 1023 .[Crossref], [Web of Science ®] , [Google Scholar]], which requires the initial velocity u₀ ∈ H²( R ^d) for the local well-posedness result, and a smallness condition on the fluctuation of the initial density for the global well-posedness result.     

Optimal Error Estimate of the Penalty Finite Element Method for the Micropolar Fluid Equations

We present an optimal error estimate of the numerical velocity, pressure, and angular velocity for the fully discrete penalty finite element method of the micropolar equations when the parameters ?, Δ t, and h are sufficiently small. In order to obtain this estimate, we present the time discretization of the penalty micropolar equation that is based on the backward Euler scheme; the spatial discretization of the time discretized penalty micropolar equation is based on a finite elements space pair (X _h , M _h ) that satisfies some approximations properties.     

Solvability of Control Problems for Stationary Equations of Magnetohydrodynamics of a Viscous Fluid

We consider the boundary-value problem for the stationary equations of magnetohydrodynamics of a viscous incompressible fluid with nonhomogeneous boundary conditions for the velocity and electromagnetic field. We study global solvability of this problem and establish some sufficient conditions for uniqueness of its solution. We state control problems for the model of magnetohydrodynamics under consideration, study their solvability, give and examine optimality systems for both arbitrary and particular quality functionals.     

Two Regularity Criteria Via the Logarithm of the Weak Solutions to the Micropolar Fluid Equations

In this note, a logarithmic improved regularity criteria for the micropolar fluid equations are established in terms of the velocity field or the pressure in the homogeneous Besov space.     

The Boundary Effects and Zero Angular and Micro-rotational Viscosities Limits of the Micropolar Fluid Equations

In this paper, we consider an initial-value problem to the two-dimensional incompressible micropolar fluid equations. Our main purpose is to study the boundary layer effects as the angular and micro-rotational viscosities go to zero. It is also shown that the boundary layer thickness is of the order \(O(\gamma^{\beta })\) with \((0<\beta <\frac{2}{3})\). In contrast with Chen et al. (Z. Angew. Math. Phys. 65:687–710, 2014), the BL-thickness we got is thinner than that in Chen et al. (Z. Angew. Math. Phys. 65:687–710, 2014). In addition, the convergence rates are also improved.     

微极流体方程组在Besov空间中弱解的正则性准则

In this paper,we investigate the regularity criterion via the pressure of weak solutions to the micropolar fluid equations in three dimensions.We obtain that for 0<α<1 if p€L^2/a(0,T;B^α∞,∞),then the weak solution(u,ω)is regular on(0,T).     

On the Global Solvability of the Cauchy Problem for Singular Functional Differential Equations

Sufficient conditions are found for the global solvability of the weighted Cauchy problem where f : C([a, b]; R ⁿ) L _loc([a, b]; R ⁿ) is a singular Volterra operator, c ₀ R ⁿ, h : [a, b] [0, +] is a function continuous and positive on [a, b], and · is the norm in R ⁿ.     

On Solvability of Integro-Differential Equations

A class of (possibly) degenerate integro-differential equations of parabolic type is considered, which includes the Kolmogorov equations for jump diffusions. Existence and uniqueness of the solutions are established in Bessel potential spaces and in Sobolev-Slobodeckij spaces. Generalisations to stochastic integro-differential equations, arising in filtering theory of jump diffusions, will be given in a forthcoming paper.

     

Neumann边界条件下强阻尼波动方程的一维全局吸引子

本文主要考虑齐次Neumann边界条件下强阻尼波动方程的全局吸引子的存在性．利用渐近时间周期微分方程的极限集的性质,证明了在一定的参数范围内,齐次Neumann边界条件下强阻尼波动方程存在一维全局吸引子,是一条水平曲线．     

Neumann边界条件下强阻尼波动方程的一维全局吸引子

本文主要考虑齐次Neumann边界条件下强阻尼波动方程的全局吸引子的存在性．利用渐近时间周期微分方程的极限集的性质，证明了在一定的参数范围内，齐次Neumann边界条件下强阻尼波动方程存在一维全局吸引子，是一条水平曲线．     

Global Weak Solutions to One-Dimensional Compressible Navier-Stokes Equations with Density-Dependent Viscosity Coefficients

We prove the global existence of weak solutions of the one-dimensional compressible Navier-stokes equations with density-dependent viscosity. In particular, we assume that the initial density belongs to L^1 and L^∞, module constant states at x = -∞ and x = ＋∞, which may be different. The initial vacuum is permitted in this paper and the results may apply to the one-dimensional Saint-Venant model for shallow water.     

Global Well-Posedness of the 2D Incompressible Micropolar Fluid Flows with Partial Viscosity and Angular Viscosity

This paper is concerned with the two-dimensional equations of incompressible micropolar fluid flows with mixed partial viscosity and angular viscosity. The global existence and uniqueness of smooth solution to the Cauchy problem is established.     

Global Existence of Strong Solutions of Navier-Stokes-Poisson Equations for One-Dimensional Isentropic Compressible Fluids

The authors prove two global existence results of strong solutions of the isentropic compressible Navier-Stokes-Poisson equations in one-dimensional bounded intervals. The first result shows only the existence. And the second one shows the existence and uniqueness result based on the first result, but the uniqueness requires some compatibility condition. In this paper the initial vacuum is allowed, and T is bounded.     

On Solvability of Some Chemotaxis Equations

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微极原弹性物质体理论和非局部微极弹性介质的本构方程

本文提出了微极原弹性物质体的定义并利用虚功率原理导出了该类物质体的变分原理.利用上述同样思想和这里给出的微极原势的定义很自然地导出了非局部微极弹性介质的本构方程.     

Solvability of Integral Equations with Endogenous Delays

This paper performs a systematic study of some nonlinear integral equations with unknown lower limits of integration, which arise in economics, operations research, population biology and environmental sciences. A general investigation technique is developed for systems of such equations and several theorems about the existence and uniqueness of a solution are proven. The links to other functional equations with state-dependent delays are discussed. Applied interpretation of the obtained results is provided.     

On the Solvability of Impulsive Differential-Algebraic Equations

We establish theorems on the existence and uniqueness of a solution of the impulsive differential-algebraic equation