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1.
INITIALBOUNDARYVALUEPROBLEMSFORACLASSOFNONLINEARINTEGRO-PARTIALDIFFERENTIALEQUATIONSCuiShang-bin(崔尚斌)(Dept.ofMath.,LanzhouUni... 相似文献
2.
Iterative solution of nonlinear equations with strongly accretive operators in Banach spaces 总被引:1,自引:0,他引:1
周海云 《应用数学和力学(英文版)》1999,20(3):282-289
1IntroductionandPreliminariesLetXbearealBanachspacewithnormIJ'11andadualX'.ThenormalizeddualitymappingJ:X~ZxisdefinedbyJx={x'eX*I(x,x')=11x112=11x if'},where',')denotesthegeneralizeddualitypairing.Itiswell-knownthatifX isstrictlyconvex,Jissingle-valuedandJ(tx)=tjxforallt201xeX.IfX*isuniformlyconvex,thenJisuniformlycontinuousonanyboundedsubsetSofX(of.Browde,fljandBarbuL2]).AnoperatorTwithdomainD(T)andrangeR(T)inXissaidtobeaccretiveifforeveryx,y6D(T),thereexistsajeJ(x--y)suchthat(T… 相似文献
3.
Kang Lian-cheng 《应用数学和力学(英文版)》1992,13(2):149-157
In this paper, we consider a singularly perturbed problem of a kind of quasilinear hyperbolic-parabolic equations, subject
to initial-boundary value conditions with moving boundary:
When certain assumptions are satisfied and ε is sufficiently small, the solution of this problem has a generalized asymptotic
expansion (in the Van der Corput sense), which takes the sufficiently smooth solution of the reduced problem as the first
term, and is uniformly valid in domain Q where the sufficiently smooth solution exists. The layer exists in the neighborhood
of t=0. This paper is the development of references [3–5].
The Project supported by the National Natural Science Foundation of China. 相似文献
4.
谷安海 《应用数学和力学(英文版)》1987,8(10):991-1002
This paper is neither laudatory nor derogatory but it simply contrasts with what might be called elastostatic (or static topology),
a proposition of the famous six equations. The extension strains and the shearing strains
which were derived by A.L. Cauchy, are linearly expressed in terms of nine partial derivatives of the displacement function
(u
i
,u
j
,u
h
)=u(x
i
,x
j
,x
k
) and it is impossible for the inverse proposition to sep up a system of the above six equations in expressing the nine components
of matrix (∂(u
i
,u
j
,u
h
)/∂(x
i
,x
j
,x
k
)). This is due to the fact that our geometrical representations of deformation at a given point are as yet incomplete[1]. On the other hand, in more geometrical language this theorem is not true to any triangle, except orthogonal, for “squared
length” in space[2].
The purpose of this paper is to describe some mathematic laws of algebraic elastodynamics and the relationships between the
above-mentioned important questions. 相似文献
5.
郭艾 《应用数学和力学(英文版)》1999,20(6):683-689
1ProblemsandMainResultsInthispaper,westudythenonlinearvibrationsofinfiniterodswithviscoelasticity.Theconstitutionlawoftherods... 相似文献
6.
ITERATIVE PROCESS TO -HEMICONTRACTIVE OPERATOR AND-STRONGLY ACCRETIVE OPERATOR EQUATIONS 总被引:1,自引:0,他引:1
IntroductionLetEbeanarbitraryBanachspace ,E beitsdualspaceand〈x ,f 〉bethegeneralizeddualitypairingbetweenx∈Eandf ∈E .ThemappingJ :E→ 2 E definedbyJ(x) =f ∈E :〈x ,f 〉 =‖f ‖‖x‖ ,‖f ‖ =‖x‖iscalledthenormalizeddualitymapping .IfE isstrictlyconvex ,thenJissingle_valued .Wesh… 相似文献
7.
Peter Takáč 《Journal of Dynamics and Differential Equations》2006,18(3):693-765
We are concerned with the existence of a weak solution
to the degenerate quasi-linear Dirichlet boundary value problem
It is assumed that 1 < p < ∞, p ≠ 2, Ω is a bounded domain in
is a given function, and λ stands for the (real) spectral parameter near the first (smallest) eigenvalue λ1 of the positive p-Laplacian − Δ
p
, where
. Eigenvalue λ1 being simple, let φ1 denote the eigenfunction associated with it. We show the existence of a solution for problem (P) when f “nearly” satisfies the orthogonality condition ∫Ω
f φ1 dx = 0 and λ ≤ λ1 + δ (with δ > 0 small enough). Moreover, we obtain at least three distinct solutions if either p < 2 and λ1 − δ ≤ λ < λ1, or else p > 2 and λ1 < λ ≤ λ1 + δ. The proofs use a minimax principle for the corresponding energy functional performed in the orthogonal decomposition
induced by the inner product in L
2(Ω). First, the global minimum is taken over
, and then either a local minimum or a local maximum over lin {φ1}. If the latter is a local minimum, the local minimizer in
thus obtained provides a solution to problem (P). On the other hand, if it is a local maximum, one gets only a pair of sub- and supersolutions to problem (P), which is then used to obtain a solution by a topological degree argument. 相似文献
8.
This paper deals with connected branches of nonstationary periodic trajectories of Hamilton equations
emanating from the degenerate stationary point
for H being the generalized Hénon-Heiles (HH) Hamiltonian:
or the generalized Yang-Mills (YM) Hamiltonian:
The existence of such branches has been proved. Minimal periods of searched trajectories near x0 have been described. 相似文献
9.
曾文平 《应用数学和力学(英文版)》2000,21(9):1071-1078
IntroductionThispaperdealswiththeinitial_boundaryvalueproblemofthree_dimensionalheatconductionequationintheregionD :0≤x,y ,z≤L ,0 ≤t≤T u t= 2 u x2 2 u y2 2 u z2 ,u|x=0 =f1(y,z,t) , u|x=L =f2 (y ,z,t) ,u|y=0 =g1(z,x,t) , u|y=L =g2 (z,x,t) ,u|z=0 =h1(x ,y ,t) , u|z=L =h2 (x ,y ,t) ,u|t=0 =φ(x ,y,z) .(1 )(2 )… 相似文献
10.
ntroductionInrecentyears,chaosinnonlineardynamicsystemshasbenarousingmoreandmoreinterest[1~3].Thechaoticmotionisregardedasana... 相似文献
11.
蔡树棠 《应用数学和力学(英文版)》1983,4(5):681-697
In this article, as the velocity gradient is taken as a constant value, we obtain the solutions of the equation of fluctuation
velocity after Fourier transform. When the mean velocity gradient is small, they represent the picture of eddies, of which
the homogeneous turbulence (both isotropic and nonisotropic) of the final period is composed. By using the eddies of these
types at different times, we may compose the steady turbulent field with the constant velocity gradient and this field may
represent the turbulent field in the central part of the channel flow or pipe flow approximately. Then we may obtain the double
velocity correlation function of this turbulent field, which involves both longitudinal correlation coefficient
and the transversal correlation coefficient
. We compare these theoretical coefficients with the experimental data of these coefficients at initial period and final period
of isotropic homogeneous turbulence. And then we obtain the relationship between the turbulent double velocity correlation
coefficient
and the mean velocity gradient. Finally, we get the expressions of the Reynolds stress and the eddy viscosity coefficient. 相似文献
12.
Let X be a uniformly smooth real Banach space. Let T:X → X be continuos and strongly accretive operator. For a given f ε X,
define S: X → X by Sx =f−Tx+x, for all x ε X. Let {an}
n=0
∞
, {βn}
n=0
∞
be two real sequences in (0, 1) satisfying:
;
Assume that {un}
n=0
∞
and {υn}
n=0
∞
are two sequences in X satisfying ‖un‖ = 0(αn) and ‖υn‖ → 0 as n → ∞. For arbitrary x0 ε X, the iteration sequence {xn} is defined by
Moreover, suppose that {Sxn} and {Syn} are bounded, then {xn} converges strongly to the unique fixed point of S. 相似文献
((i)) |
((ii)) |
(1) |
13.
Let be an infinite cylinder of , n ≥ 3, with a bounded cross-section of C
1,1-class. We study resolvent estimates and maximal regularity of the Stokes operator in for 1 < q, r < ∞ and for arbitrary Muckenhoupt weights ω ∈ A
r
with respect to x′ ∈ Σ. The proofs use an operator-valued Fourier multiplier theorem and techniques of unconditional Schauder decompositions
based on the -boundedness of the family of solution operators for a system in Σ parametrized by the phase variable of the one-dimensional
partial Fourier transform.
Supported by the Gottlieb Daimler- und Karl Benz-Stiftung, grant no. S025/02-10/03. 相似文献
14.
IntroductionConsiderthefollowingdelaydifferenceequationxn 1=xn(a bxn)xn- 1, n=0 ,1 ,2 ,… ,(1 )wherea ,b∈ [0 ,∞ )witha b>0 (2 )andwheretheinitialvaluesx- 1andx0 arearbitrarypositivenumbers.Eq .(1 )isregardedasageneralizedLynessequationbyG .Ladasin [1 ] .Obviously ,undercondition (2 ) ,… 相似文献
15.
蒋星耀 《应用数学和力学(英文版)》1987,8(10):969-974
In this paper we generalize the Steiner problem on planes to general regular surfaces. The main result isTheorem 1 If A, B,C are three points on a regular surface Σ and if another point P on Σ such that the sum of the lengths of the smooth arcs AP+ BP + CP reaches the minimum, then the angles formed by every two arcs at P are all 120°. 相似文献
16.
S. M. Bruschi A. N. Carvalho J. W. Cholewa Tomasz Dlotko 《Journal of Dynamics and Differential Equations》2006,18(3):767-814
For
, we consider a family of damped wave equations
, where − Λ denotes the Laplacian with zero Dirichlet boundary condition in L
2(Ω). For a dissipative nonlinearity f satisfying a suitable growth restrictions these equations define on the phase space
semigroups
which have global attractors A
η,
. We show that the family
, behaves upper and lower semicontinuously as the parameter η tends to 0+. 相似文献
17.
陈松林 《应用数学和力学(英文版)》2001,22(11):1352-1356
1 IntroductionandLemmasTherearemanyresultsaboutexistence (globalorlocal)andasymptoticbehaviorofsolutionsforreaction_diffusionequations[1- 9].Bytheaidsofresults[2 ,3]ofequation u/ t=Δu-λ|u|γ- 1uwithinitial_boundaryvalues,paper [4 ]studiedtheproblemof u/ t=Δu-λ|eβtu|γ- … 相似文献
18.
Joel Avrin 《Journal of Dynamics and Differential Equations》2008,20(2):479-518
We obtain attractor and inertial-manifold results for a class of 3D turbulent flow models on a periodic spatial domain in
which hyperviscous terms are added spectrally to the standard incompressible Navier–Stokes equations (NSE). Let P
m
be the projection onto the first m eigenspaces of A =−Δ, let μ and α be positive constants with α ≥3/2, and let Q
m
=I − P
m
, then we add to the NSE operators μ A
φ in a general family such that A
φ≥Q
m
A
α in the sense of quadratic forms. The models are motivated by characteristics of spectral eddy-viscosity (SEV) and spectral
vanishing viscosity (SVV) models. A distinguished class of our models adds extra hyperviscosity terms only to high wavenumbers
past a cutoff λ
m0
where m
0 ≤ m, so that for large enough m
0 the inertial-range wavenumbers see only standard NSE viscosity.
We first obtain estimates on the Hausdorff and fractal dimensions of the attractor (respectively and ). For a constant K
α on the order of unity we show if μ ≥ ν that and if μ ≤ ν that where ν is the standard viscosity coefficient, l
0 = λ1−1/2 represents characteristic macroscopic length, and is the Kolmogorov length scale, i.e. where is Kolmogorov’s mean rate of dissipation of energy in turbulent flow. All bracketed constants and K
α are dimensionless and scale-invariant. The estimate grows in m due to the term λ
m
/λ1 but at a rate lower than m
3/5, and the estimate grows in μ as the relative size of ν to μ. The exponent on is significantly less than the Landau–Lifschitz predicted value of 3. If we impose the condition , the estimates become for μ ≥ ν and for μ ≤ ν. This result holds independently of α, with K
α and c
α independent of m. In an SVV example μ ≥ ν, and for μ ≤ ν aspects of SEV theory and observation suggest setting for 1/c within α orders of magnitude of unity, giving the estimate where c
α is within an order of magnitude of unity. These choices give straight-up or nearly straight-up agreement with the Landau–Lifschitz
predictions for the number of degrees of freedom in 3D turbulent flow with m so large that (e.g. in the distinguished-class case for m
0 large enough) we would expect our solutions to be very good if not virtually indistinguishable approximants to standard NSE
solutions. We would expect lower choices of λ
m
(e.g. with a > 1) to still give good NSE approximation with lower powers on l
0/l
ε, showing the potential of the model to reduce the number of degrees of freedom needed in practical simulations. For the choice
, motivated by the Chapman–Enskog expansion in the case m = 0, the condition becomes , giving agreement with Landau–Lifschitz for smaller values of λ
m
then as above but still large enough to suggest good NSE approximation. Our final results establish the existence of a inertial
manifold for reasonably wide classes of the above models using the Foias/Sell/Temam theory. The first of these results obtains such
an of dimension N > m for the general class of operators A
φ if α > 5/2.
The special class of A
φ such that P
m
A
φ = 0 and Q
m
A
φ ≥ Q
m
A
α has a unique spectral-gap property which we can use whenever α ≥ 3/2 to show that we have an inertial manifold of dimension m if m is large enough. As a corollary, for most of the cases of the operators A
φ in the distinguished-class case that we expect will be typically used in practice we also obtain an , now of dimension m
0 for m
0 large enough, though under conditions requiring generally larger m
0 than the m in the special class. In both cases, for large enough m (respectively m
0), we have an inertial manifold for a system in which the inertial range essentially behaves according to standard NSE physics,
and in particular trajectories on are controlled by essentially NSE dynamics.
相似文献
19.
Yoshihisa Morita Hirokazu Ninomiya 《Journal of Dynamics and Differential Equations》2006,18(4):841-861
We deal with a reaction–diffusion equation u
t
= u
xx
+ f(u) which has two stable constant equilibria, u = 0, 1 and a monotone increasing traveling front solution u = φ(x + ct) (c > 0) connecting those equilibria. Suppose that u = a (0 < a < 1) is an unstable equilibrium and that the equation allows monotone increasing traveling front solutions u = ψ1(x + c
1
t) (c
1 < 0) and ψ2(x + c
2
t) (c
2 > 0) connecting u = 0 with u = a and u = a with u = 1, respectively. We call by an entire solution a classical solution which is defined for all
. We prove that there exists an entire solution such that for t≈ − ∞ it behaves as two fronts ψ1(x + c
1
t) and ψ2(x + c
2
t) on the left and right x-axes, respectively, while it converges to φ(x + ct) as t→∞. In addition, if c > − c
1, we show the existence of an entire solution which behaves as ψ1( − x + c
1
t) in
and φ(x + ct) in
for t≈ − ∞. 相似文献
20.
Mike Cullen Wilfrid Gangbo Giovanni Pisante 《Archive for Rational Mechanics and Analysis》2007,185(2):341-363
We study the evolution of a system of n particles in . That system is a conservative system with a Hamiltonian of the form , where W
2 is the Wasserstein distance and μ is a discrete measure concentrated on the set . Typically, μ(0) is a discrete measure approximating an initial L
∞ density and can be chosen randomly. When d = 1, our results prove convergence of the discrete system to a variant of the semigeostrophic equations. We obtain that
the limiting densities are absolutely continuous with respect to the Lebesgue measure. When converges to a measure concentrated on a special d–dimensional set, we obtain the Vlasov–Monge–Ampère (VMA) system. When, d = 1 the VMA system coincides with the standard Vlasov–Poisson system. 相似文献