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1.
In this article, we prove the local existence and uniqueness of the classical solution to the Cauchy problem of the 3-D compressible Navier-Stokes equations with large initial data and vacuum, if the shear viscosity μ is a positive constant and the bulk viscosity λ(ρ) = ρβwith β≥ 0. Note that the initial data can be arbitrarily large to contain vacuum states.  相似文献   

2.
We establish the global existence and uniqueness of classical solutions to the Cauchy problem for the two-dimensional isentropic compressible Navier-Stokes equations with smooth initial data under the assumption that the viscosity coefficient μ is large enough. Here we do not require that the initial data is small.  相似文献   

3.
The existence of spiral solution for the two-dimensional transport equations is considered in the present paper. Based on the notion of generalized solutions in the sense of Lebesgue-stieltjes integral, the global weak solution of transport equations which includes δ-shocks and vacuum is constructed for some special initial data.  相似文献   

4.
This article proves the logarithmically improved Serrin's criterion for solutions of the 3D generalized magneto-hydrodynamic equations in terms of the gradient of the velocity field, which can be regarded as improvement of results in [10](Luo Y W. On the regularity of generalized MHD equations. J Math Anal Appl, 2010, 365: 806–808) and [18](Zhang Z J.Remarks on the regularity criteria for generalized MHD equations. J Math Anal Appl, 2011,375: 799–802).  相似文献   

5.
In this paper we prove local well-posedness in critical Besov spaces for the full compressible MHD equations in R^N, N≥ 2, under the assumptions that the initialdensity is bounded away from zero. The proof relies on uniform estimates for a mixed hyperbolic/parabolic linear system with a convection term.  相似文献   

6.
We study the initial-boundary value problem of the Navier-Stokes equations for incompressible fluids in a general domain in R^n with compact and smooth boundary, subject to the kinematic and vorticity boundary conditions on the non-flat boundary. We observe that, under the nonhomogeneous boundary conditions, the pressure p can be still recovered by solving the Neumann problem for the Poisson equation. Then we establish the well-posedness of the unsteady Stokes equations and employ the solution to reduce our initial-boundary value problem into an initial-boundary value problem with absolute boundary conditions. Based on this, we first establish the well-posedness for an appropriate local linearized problem with the absolute boundary conditions and the initial condition (without the incompressibility condition), which establishes a velocity mapping. Then we develop apriori estimates for the velocity mapping, especially involving the Sobolev norm for the time-derivative of the mapping to deal with the complicated boundary conditions, which leads to the existence of the fixed point of the mapping and the existence of solutions to our initial-boundary value problem. Finally, we establish that, when the viscosity coefficient tends zero, the strong solutions of the initial-boundary value problem in R^n(n ≥ 3) with nonhomogeneous vorticity boundary condition converge in L^2 to the corresponding Euler equations satisfying the kinematic condition.  相似文献   

7.
In this paper, we investigate some new properties of the incompressible Euler and Navier-Stokes equations by studying a 3D model for axisymmetric 3D incompressible Euler and Navier-Stokes equations with swirl. The 3D model is derived by reformulating the axisymmetric 3D incompressible Euler and Navier-Stokes equations and then neglecting the convection term of the resulting equations. Some properties of this 3D model are reviewed. Finally, some potential features of the incompressible Euler and Navier-Stokes equations such as the stabilizing effect of the convection are presented.  相似文献   

8.
In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell's equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy.  相似文献   

9.
We propose and analyze a spectral Jacobi-collocation approximation for fractional order integro-differential equations of Volterra type. The fractional derivative is described in the Caputo sense. We provide a rigorous error analysis for the collection method,which shows that the errors of the approximate solution decay exponentially in L∞norm and weighted L2-norm. The numerical examples are given to illustrate the theoretical results.  相似文献   

10.
In this paper, we show the existence and uniqueness of solutions to a large class of SFDEs with the generalized local Lipschitzian coefficients. Some moment estima- tes of the solutions are given by establishing new Ito operator inequalities based on the Razumikhin technique. These estimates improve, extend and unify some related results including exponential stability of Mao (1997) [20], decay stability of Wu et al. (2010,2011) [32,33], Pavlovic et al. (2012) [24], asymptotic behavior of Luo et al. (2011) [18] and Song et al. (2013) [26]. Moreover, stochastic version of Wintner theorem in continuous space is established by the comparison principle, which improve and extend the main results of Xu et al. (2008 [39], 2013 [36]). When the methods presented are applied to the SFDEs with impulses and SFDEs in Hilbert spaces, we extend the related results of Govindana et al. (2013) [7], Liu et al. (2007) [15], Vinod- kumar (2010) [29] and Xu et al. (2012) [35]. Two examples are provided to illustrate the effectiveness of our results.  相似文献   

11.
In this article,we study the initial boundary value problem of generalized Pochhammer-Chree equation u_(tt)-u_(xx)-u_(xxt)-u_(xxtt)=f(u) xx,x ∈Ω,t 0,u(x,0) = u0(x),u t(x,0)=u1(x),x ∈Ω,u(0,t) = u(1,t) = 0,t≥0,where Ω=(0,1).First,we obtain the existence of local W k,p solutions.Then,we prove that,if f(s) ∈ΩC k+1(R) is nondecreasing,f(0) = 0 and |f(u)|≤C1|u| u 0 f(s)ds+C2,u 0(x),u 1(x) ∈ΩW k,p(Ω) ∩ W 1,p 0(Ω),k ≥ 1,1 p ≤∞,then for any T 0 the problem admits a unique solution u(x,t) ∈ W 2,∞(0,T;W k,p(Ω) ∩ W 1,p 0(Ω)).Finally,the finite time blow-up of solutions and global W k,p solution of generalized IMBq equations are discussed.  相似文献   

12.
Oscillation theorems for a second-order impulsive neutral differential equation are established, which extend the main results developed by Li et alLi et al, Oscillation of second order self-coajugate differential equation with impuls[es. J Comput Appl Math 197(2006): 78-88] to the considered equation. Two examples are also inserted to illustrate our main results.  相似文献   

13.
Scaffold proteins play an important role in the promotion of signal transmission and specificity during cell signaling. In cells, signaling proteins that make up a pathway are often physically orgnaized into complexes by scaffold proteins [1]. Previous work [2] has shown that spatial localization of scaffold can enhance signaling locally while simultaneously suppressing signaling at a distance, and the membrane confinement of scaffold proteins may result in a precipitous spatial gradient of the active product protein, high close to the membrane and low within the cell. However, cell-fate decisions critically depend on the temporal pattern of product protein close to the nucleus. In this paper, when phosphorylation signals cannot be transfered by diffusion only, two mechanisms have been proposed for long-range signaling within cells: multiple locations of scaffold proteins and dynamical movement of scaffold proteins. Thus, here we have unveiled how the spatial propagation of the phosphorylated product protein within a cell depends on the spatially and temporal localized scaffold proteins. A class of novel and fast numerical methods for solving stiff reaction diffusion equations with complex domains is briefly introduced.  相似文献   

14.
In this paper, we establish a few existence results of nonoscillatory solutions to second-order nonlinear neutral delay differential equations, construct several Manntype iterative approximation schemes for these nonoscillatory solutions, and give some error estimates between the approximate solutions and the nonoscillatory solutions. And finally we give an example to illustrate our results.  相似文献   

15.
In this paper we study the regularity theory of the solutions of a class of degenerate elliptic equations in divergence form. By introducing a proper distance and applying the compactness method we establish the HSlder type estimates for the weak solutions.  相似文献   

16.
In this article,we study the regularity of weak solutions and the blow-up criteria for smooth solutions to the magneto-micropolar fluid equations in R~3.We obtain the classical blow-up criteria for smooth solutions(u,ω,b),i.e.,u ∈ L q(0,T;L p(R 3)) for 2 q + 3 p ≤ 1 with 3p≤∞,u ∈ C([0,T);L 3(R 3)) or u ∈L q(0,T;L p) for 3 2p≤∞ satisfying 2 q + 3p≤2.Moreover,our results indicate that the regularity of weak solutions is dominated by the velocity u of the fluid.In the end-point case p = ∞,the blow-up criteria can be extended to more general spaces u∈ L~1(0,T;B_(∞,∞)~0(R~3)).  相似文献   

17.
The motion of the self-gravitational gaseous stars can be described by the Euler-Poisson equations. The main purpose of this paper is concerned with the existence of stationary solutions of Euler-Poisson equations for some velocity fields and entropy functions that solve the conservation of mass and energy. Under different restriction to the strength of velocity field, we get the existence and multiplicity of the stationary solutions of Euler-Poisson system.  相似文献   

18.
This paper is concerned with the system of Euler-Poisson equations as a model to describe the motion of the self-induced gravitational gaseous stars. When ~ 〈 7 〈 2, under the weak smoothness of entropy function, we find a sufficient condition to guarantee the existence of stationary solutions for some velocity fields and entropy function that solve the conservation of mass and energy.  相似文献   

19.
This paper concerns the oscillation of solutions of the second order nonlinear dynamic equation with p-Laplacian and damping(r(t)φ(x^△(t))^△+p(t)φα(x^△α(t)+q(t)f(xδ(t))=0on a time scale T which is unbounded above. Sign changes are allowed for the coefficient functions r, p and q. Several examples are given to illustrate the main results.  相似文献   

20.
In this paper, we prove that a kind of second order stochastic differential op-erator can be represented by the limit of solutions of BSDEs with uniformly continuous coe?cients. This result is a genera...  相似文献   

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