具临界Sobolev-Hardy指数的半线性椭圆方程的非平凡解

本文研究了如下问题：-div（｜x｜β△u）=｜x｜^a｜u｜^2（α,β）-2u＋λ｜x｜σ｜u｜^q-2,x∈Ω,u=0,x∈δΩ,这里Ω∪→R^N是有界光滑区域且0∈Ω，2（α，β）=2（N＋α）/N＋β-2，运用Sobolev-Hardy不等式和山路几何，证明了在一定的条件下方程至少存在一个非平凡解。     

Infinitely many solutions for a class of fourth order elliptic equations in <Emphasis Type="Italic">R</Emphasis><Superscript><Emphasis Type="Italic">N</Emphasis></Superscript>

With the aids of variational method and concentration-compactness principle, infinitely many solutions are obtained for a class of fourth order elliptic equations with singular potential
Δ^2u=μ｜u｜^2＊＊（s）-2u/｜x｜^s＋λk（x）｜u｜^r-2 u, u∈H^2,2（R^N） （P）     

A Note to the Cauchy Problem for the Degenerate Parabolic Equations with Strongly Nonlinear Sources

In this note we study the nonexistence of nontrivial global solutions on S = R^N × （0,∞） for the following inequalities：｜u｜t≥△（｜u｜^m-1u）＋｜u｜^q and ｜u｜t≥div（｜△u｜^p-2△｜u｜）＋｜u｜^q.When m,p,q satisfy some given conditions, the nonexistence of nontrivial global solution is proved, without taking their traces on the hyperplans t = 0 into account.     

On an Anisotropic Equation with Critical Exponent and Non-Standard Growth Condition

Using variational methods, we prove the existence of a nontrivial weak solution for the problem
{-∑i=1^Nδxi（｜δxiu｜pi-2δxiu）=λα（x）｜u｜q（x）-2u＋｜u｜p＊-2u,in Ω,
u=0 inδΩ,
where Ω R^N（N≥3） is a bounded domain with smooth boundary δΩ,2≤pi〈N,i=1,N,q：Ω→（1,p＊）is a continuous function, p＊ =N/∑i=1^N 1/pi-1 is the critical exponent for this class of problem, and λ is a parameter.     

Existence of positive solutions for a singular <Emphasis Type="Italic">p</Emphasis>-Laplacian differential equation

In this paper, we are concerned with the existence of positive solutions for a singular p-Laplacian differential equation
（φp（u＇））＇＋β/r φp（u＇）-γ ｜u＇｜^p/u ＋ g（r）=0,0〈r〈1,
subject to the Dirichlet boundary conditions： u（0） = u（1） =0, where φp（s） = ｜sl^P-2s,p 〉 2,β 〉0, γ〉（p-1）/p （β ＋ 1）, and g（r） ∈ C^1 [0, 1] with g（r） 〉 0 for all τ ∈ [0, 1]. We use the method of elliptic regularization, by carrying out two limit processes, to get a positive solution.     

Solutions to Some Open Problems in Fluid Dynamics

Let u=u（x,t,uo）represent the global solution of the initial value problem for the one-dimensional fluid dynamics equation ut-εuxxt＋δux＋γHuxx＋βuxxx＋f（u）x=αuxx,u（x,0）=uo（x）, whereα〉0,β〉0,γ〉0,δ〉0 andε〉0 are constants.This equation may be viewed as a one-dimensional reduction of n-dimensional incompressible Navier-Stokes equations. The nonlinear function satisfies the conditions f（0）=0,｜f（u）｜→∞as ｜u｜→∞,and f∈C^1（R）,and there exist the following limits Lo=lim sup/u→o f（u）/u^3 and L∞=lim sup/u→∞ f（u）/u^5 Suppose that the initial function u0∈L^I（R）∩H^2（R）.By using energy estimates,Fourier transform,Plancherel＇s identity,upper limit estimate,lower limit estimate and the results of the linear problem vt-εv（xxt）＋δvx＋γHv（xx）＋βv（xxx）=αv（xx）,v（x,0）=vo（x）, the author justifies the following limits（with sharp rates of decay） lim t→∞[（1＋t）^（m＋1/2）∫｜uxm（x,t）｜^2dx]=1/2π（π/2α）^（1/2）m!!/（4α）^m[∫R uo（x）dx]^2, if∫R uo（x）dx≠0, where 0!!=1,1!!=1 and m!!=1·3…（2m-3）…（2m-1）.Moreover lim t→∞[（1＋t）^（m＋3/2）∫R｜uxm（x,t）｜^2dx]=1/2π（x/2α）^（1/2）（m＋1）!!/（4α）^（m＋1）[∫Rρo（x）dx]^2, if the initial function uo（x）=ρo′（x）,for some functionρo∈C^1（R）∩L^1（R）and∫Rρo（x）dx≠0.     

Existence of Solutions for Schrodinger-Poisson Systems with Sign-Changing Weight

We study the existence of solutions for the SchrOdinger-Poisson system
{-△u＋u＋k（x）φu=a（x）｜u｜p-1u,in R3,
-△φ=k（x）u2, in R3,
where 3 G p 〈 5, a （x） is a sign-changing function such that both the supports of a＋ and a- may have infinite measure. We show that the problem has at least one nontrivial solution under some assumptions.     

MULTIPLE SOLUTIONS FOR SCHR(O)DINGER EQUATIONS WITH MAGNETIC FIELD

The authors consider the semilinear SchrSdinger equation
-△Au＋Vλ（x）u= Q（x）｜u｜γ-2u in R^N,
where 1 〈 γ 〈 2＊ and γ≠ 2, Vλ= V^＋ -λV^-. Exploiting the relation between the Nehari manifold and fibrering maps, the existence of nontrivial solutions for the problem is discussed.     

Traveling Waves and Capillarity Driven Spreading of Shear-Thinning Fluids

We study capillary spreadings of thin films of liquids of power-law rheology. These satisfy ut＋（u^λ＋2｜uxxx｜^λ-1uxxx）x=0,where u （x, t） represents the thickness of the one-dimensional liquid and λ 〉 1. We look for traveling wave solutions so that u（x,t） =g（x＋ct） and thus g satisfies g＇＇＇=｜g-ε｜^1/λ/g^1＋2/λ sgn（g-ε） We show that for each ε 〉 0 there is an infinitely oscillating solution, gε, such that limt→∞ gε=ε and that gε→ g0 as ε → O, where g0≡ 0 for t ≥ 0 and g0=cλ｜t｜3λ/2λ＋1 for t〈0 for some constant cλ.     

Quasilinear elliptic equations with Neumann boundary and singularity

Let Ω be a bounded domain with a smooth C2 boundary in RN（N ≥ 3）, 0 ∈Ω, and n denote the unit outward normal to ЭΩ.We are concerned with the Neumann boundary problems： -div（｜x｜α｜△u｜p-2△u）=｜x｜βup（α,β）-1-λ｜x｜γup-1,u（x）〉0,x∈Ω,Эu/Эn=0 on ЭΩ,where 1〈p〈N and α〈0,β〈0 such that p（α,β）△=p（N＋β）/N-p＋α〉p,y〉α-p.For various parameters α,βorγ,we establish certain existence results of the solutions in the case 0∈Ω or 0∈ЭΩ.     

A new hypothesis concerning children’s fractional knowledge

The basic hypothesis of the teaching experiment, The Child’s Construction of the Rational Numbers of Arithmetic (Steffe & Olive, 1990) was that children’s fractional schemes can emerge as accommodations in their numerical counting schemes. This hypothesis is referred to as the reorganization hypothesis because when a new scheme is established by using another scheme in a novel way, the new scheme can be regarded as a reorganization of the prior scheme. In that case where children’s fractional schemes do emerge as accommodations in their numerical counting schemes, I regard the fractional schemes as superseding their earlier numerical counting schemes. If one scheme supersedes another, that does not mean the earlier scheme is replaced by the superseding scheme. Rather, it means that the superseding scheme solves the problems the earlier scheme solved but solves them better, and it solves new problems the earlier scheme didn’t solve. It is in this sense that we hypothesized children’s fractional schemes can supersede their numerical counting schemes and it is the sense in which we regarded numerical schemes as constructive mechanisms in the production of fractional schemes (Kieren, 1980).     

NONLINEAR GALERKIN METHOD AND CRANK-NICOLSONMETHOD FOR VISCOUS INCOMPRESSIBLE FLOW

1.Introduction'NonlinearGalerkinmethodisnumericalmethodfordissipativeevolutionpartialdifferentialequationswherethespatialdiscretizationreliesonanonlinearmanifoldinsteadofalinearspaceasintheclassicalGalerkinmethod.Morepreciselygoneconsidersafinitedimension…     

A novel approach to construct numerical methods for stochastic differential equations

In this paper we propose a new numerical method for solving stochastic differential equations (SDEs). As an application of this method we propose an explicit numerical scheme for a super linear SDE for which the usual Euler scheme diverges.     

CONSTRAINT-PRESERVING ENERGY-STABLE SCHEME FOR THE 2D SIMPLIFIED ERICKSEN-LESLIE SYSTEM

Here we consider the numerical approximations of the 2D simplified Ericksen-Leslie system.We first rewrite the system and get a new system.For the new system,we propose an easy-to-implement time discretization scheme which preserves the sphere constraint at each node,enjoys a discrete energy law,and leads to linear and decoupled elliptic equations to be solved at each time step.A discrete maximum principle of the schemc in the finite element form is also proved.Some numerical simulations are performed to validate the scheme and simulate the dynamic motion of liquid crystals.     

一类非线性Schr dinger方程的高精度守恒数值格式

1引言本文讨论下面非线性Schr(?)dinger方程(NLS)方程的初边值问题:i(?)u/(?)t (?)~2u/(?)x~2 2|u~2|u=0,(1) u(x_l,t)=u(x_r,t)=0,t>0,(2) u(x,0)=u_0(x),x_l≤x≤x_r,(3)其中u(x,t)是复值函数,u_0(x)为已知的复值函数,i~2=-1.该问题有着如下的电荷与能量守恒关系:     

A new predictor-corrector scheme for valuing American puts

In this paper, we present a new numerical scheme, based on the finite difference method, to solve American put option pricing problems. Upon applying a Landau transform or the so-called front-fixing technique [19] to the Black-Scholes partial differential equation, a predictor-corrector finite difference scheme is proposed to numerically solve the nonlinear differential system. Through the comparison with Zhu’s analytical solution [35], we shall demonstrate that the numerical results obtained from the new scheme converge well to the exact optimal exercise boundary and option values. The results of our numerical examples suggest that this approach can be used as an accurate and efficient method even for pricing other types of financial derivative with American-style exercise.     

Numerical simulation of a Finite Moment Log Stable model for a European call option

Compared to the classical Black-Scholes model for pricing options, the Finite Moment Log Stable (FMLS) model can more accurately capture the dynamics of the stock prices including large movements or jumps over small time steps. In this paper, the FMLS model is written as a fractional partial differential equation and we will present a new numerical scheme for solving this model. We construct an implicit numerical scheme with second order accuracy for the FMLS and consider the stability and convergence of the scheme. In order to reduce the storage space and computational cost, we use a fast bi-conjugate gradient stabilized method (FBi-CGSTAB) to solve the discrete scheme. A numerical example is presented to show the efficiency of the numerical method and to demonstrate the order of convergence of the implicit numerical scheme. Finally, as an application, we use the above numerical technique to price a European call option. Furthermore, by comparing the FMLS model with the classical B-S model, the characteristics of the FMLS model are also analyzed.     

A multisymplectic explicit scheme for the modified regularized long-wave equation

In this paper, we derive a new 10-point multisymplectic scheme for the modified regularized long-wave equation. The new scheme is an explicit scheme in the sense that the third time level does not include nonlinear terms. Numerical results indicate that the new scheme not only provides satisfied numerical solutions, but also preserves three invariants of motion very well.     

带新熵函数的Entropy-Ultra-bee格式计算线性传输方程

本文研究了线性传输方程的数值解法.利用物理的熵函数得到了一种新的Entropy-Ultrabee格式.数值实验表明该格式长时间计算效果非常好,在间断附近有比较高的分辨率.