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931.
932.
.?AdimurthiEmail author G.?D.?Veerappa?Gowda 《NoDEA : Nonlinear Differential Equations and Applications》2004,11(3):335-348
We give an explicit formula for a solution of Hamilton-Jacobi equation ut+H(u,Du)=0 in
with initial condition u(x,0)=u0(x), where p H(u,p) is convex, positively homogeneous of degree one and the Hamiltonian H need not satisfy the monotonicity condition in u. 相似文献
933.
Pavol?QuittnerEmail author 《NoDEA : Nonlinear Differential Equations and Applications》2004,11(2):237-258
Consider the Dirichlet problem for the parabolic equation
in
, where
$\Omega$ is a bounded domain in
and f has superlinear subcritical growth in u.
If f is independent of t and satisfies some
additional conditions then using a dynamical method we find multiple (three, six or infinitely many) nontrivial
stationary solutions. If f has the form
where m is periodic, positive and m,g satisfy some technical
conditions then we prove the existence of a positive periodic solution and
we provide a locally uniform bound for all global solutions. 相似文献
934.
Alessio?PorrettaEmail author 《NoDEA : Nonlinear Differential Equations and Applications》2004,11(4):407-430
We consider here a class of nonlinear Dirichlet problems, in a bounded domain , of the form
investigating the problem of uniqueness of solutions. The functions (s) and
satisfy rather general assumptions of locally Lipschitz continuity (with possibly exponential growth) and the datum f is in L1(). Uniqueness of solutions is proved both for coercive a(x, s) and for the case of a(x, s) degenerating for s large. 相似文献
935.
Luigi?C.?BerselliEmail author Renato?ManfrinEmail author 《Journal of Evolution Equations》2004,4(2):193-211
In this paper we study some criteria for the full (space-time) regularity of weak
solutions to the Navier-Stokes equations. In particular, we generalize some
classical and very recent criteria involving the velocity, or its
derivatives. More specifically, we show with elementary tools that if a weak
solution, or its vorticity, is small in appropriate Marcinkiewicz spaces, then it
is regular. 相似文献
936.
The paper continues the authors work in measure and integration,
which is an attempt at unified systematization. It establishes projective limit
theorems of the Prokhorov and Kolmogorov types in terms of inner premeasures.
Then it specializes to obtain the (one-dimensional) Wiener measure
on the space of real-valued functions on the positive halfline as a probability
measure defined on an immense domain: In particular the subspace of continuous
functions will be measurable of full measure - and not merely of full
outer measure, as the usual projective limit theorems permit to conclude.
Dedicated to Professor Gustave Choquet 相似文献
937.
The purpose of this paper is to provide a careful and accessible exposition of static bifurcation theory for a class of degenerate boundary value problems for diffusive logistic equations with indefinite weights that model population dynamics in environments with spatial heterogeneity. We discuss the changes that occur in the structure of the positive solutions as a parameter varies near the first eigenvalue of the linearized problem, and prove that the most favorable situations will occur if there is a relatively large favorable region (with good resources and without crowding effects) located some distance away from the boundary of the environment.Dedicated to Professor Mitsuru Ikawa on the occasion of his 60th birthday 相似文献
938.
S. Bollanti F. Bonfigli E. Burattini P. Di Lazzaro F. Flora A. Grilli T. Letardi N. Lisi A. Marinai L. Mezi D. Murra C. Zheng 《Applied physics. B, Lasers and optics》2003,76(3):277-284
A long-pulse-width high-output energy (120 ns FWHM, 7 J) XeCl laser has been focused on thin tape targets (Cu and Ta) to generate
more than 100-ns-long (FWHM) EUV pulses in the 10–30 nm spectral region, suitable for projection microlithography. The conversion
efficiency was more than 20% over a 2π solid angle. We observed debris emission using a gated CCD camera, and measured the
debris speed for different irradiation conditions. We found irradiation conditions such that the measured velocities were
low enough that simple mechanical devices combined with krypton at low-pressure could efficiently stop both ionic debris and
cluster debris. Our results show that a suitable combination of driving-laser characteristics, target material and thickness,
environment gas and mechanical choppers can make clean and increase the power of EUV solid-target laser-plasma sources.
Received: 21 October 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax: +39-06/9400-5334, E-mail: bollanti@frascati.enea.it 相似文献
939.
A.F. Yaremchuk 《Applied Physics A: Materials Science & Processing》2003,76(3):405-411
The range of applicability of the mixed-boundary-value method for calculating spreading resistance for a homogeneous slab
with an effective contact-radius source and backed by a substrate of arbitrary but finite resistivity is investigated. Solutions
are presented in terms of the correction factor and the source current density distributions for a slab of varying thickness
and with various high-resistivity substrates. The correction factors for different schemes of calculation are correctly obtained
by means of introducing an additional current source of opposite sign, but with the same absolute value, located at the drain
point contact. This combination of source and drain currents gives the true value for the potential distribution along the
surface of the semiconductor. This, in turn, leads to new terms in the equations obtained for the correction factors, which
have been omitted in previously published works. A comparison between several schemes of calculation is presented. Within
the framework of “uniform” and “variable” current distributions underneath the contact probe, there are two limits for the
correction factor. A model based on a combination of these approaches is discussed, and a comparison between the proposed
method and the Schumann–Gardner formulation is made.
Received: 30 January 2002 / Accepted: 30 January 2002 / Published online: 28 October 2002
RID="*"
ID="*"Corresponding author. Fax: +7-095/531-83-54, E-mail: telkom@df.ru 相似文献
940.
Horst Osswald 《Advances in Mathematics》2003,176(1):1-37
Using infinitesimals, we develop Malliavin calculus on spaces which result from the classical Wiener space by replacing with any abstract Wiener space .We start from a Brownian motion b on a Loeb probability space Ω with values in the Banach space is the standard part of a ∗finite-dimensional Brownian motion B. Then we define iterated Itô integrals as standard parts of internal iterated Itô integrals. The integrator of the internal integrals is B and the values of the integrands are multilinear forms on , where is a ∗finite-dimensional linear space over between the Hilbert space and its ∗-extension .In the first part we prove a chaos decomposition theorem for L2-functionals on Ω that are measurable with respect to the σ-algebra generated by b. This result yields a chaos decomposition of L2-functionals with respect to the Wiener measure on the standard space of -valued continuous functions on [0,1]. In the second part we define the Malliavin derivative and the Skorohod integral as standard parts of internal operators defined on ∗finite-dimensional spaces. In an application we use the transformation rule for finite-dimensional Euclidean spaces to study time anticipating and non-anticipating shifts of Brownian motion by Bochner integrals (Girsanov transformations). 相似文献