40 research outputs found
On the symplectic phase space of KdV
We prove that the Birkhoff map \Om for KdV constructed on H^{-1}_0(\T)
can be interpolated between H^{-1}_0(\T) and L^2_0(\T). In particular, the
symplectic phase space H^{1/2}_0(\T) can be described in terms of Birkhoff
coordinates. As an application, we characterize the regularity of a potential
q\in H^{-1}(\T) in terms of the decay of the gap lengths of the periodic
spectrum of Hill's operator on the interval
Inverse spectral problems for energy-dependent Sturm-Liouville equations
We study the inverse spectral problem of reconstructing energy-dependent
Sturm-Liouville equations from their Dirichlet spectra and sequences of the
norming constants. For the class of problems under consideration, we give a
complete description of the corresponding spectral data, suggest a
reconstruction algorithm, and establish uniqueness of reconstruction. The
approach is based on connection between spectral problems for energy-dependent
Sturm-Liouville equations and for Dirac operators of special form.Comment: AMS-LaTeX, 28 page
Spectral Asymptotics for Perturbed Spherical Schr\"odinger Operators and Applications to Quantum Scattering
We find the high energy asymptotics for the singular Weyl--Titchmarsh
m-functions and the associated spectral measures of perturbed spherical
Schr\"odinger operators (also known as Bessel operators). We apply this result
to establish an improved local Borg-Marchenko theorem for Bessel operators as
well as uniqueness theorems for the radial quantum scattering problem with
nontrivial angular momentum.Comment: 20 page
Analysis of Thermal Residual Stresses Distribution in Circular and Elliptical Bonded Composite Repair of Metallic Cracked Structures
Studies of the Influence of Al Doping Agents Nature on the Physical Properties Al:ZnO Films Deposited by Spin-Coating Technique
Date du colloque : 09/2010International audienc
Influence of Al doping agents nature on the physical properties of Al: ZnO films deposited by spin-coating technique
cited By 14International audienceIn this paper we present the morphological,structural, optical and electrical properties of aluminium doped zinc oxide films prepared by spin coating technique from a zinc acetate dihydrate and 2-methoxyethanol (0.5M) solution. AlCl3and Al(NO3)3were used as doping agents in different concentrations (1at%, 4at% and 6at% in starting solution). After deposition, films were dried at 100°C and then annealed at temperatures between 400°C and 500°C. The characterization of deposited layer was performed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and UV-Vis spectroscopy. The results show that the optical and electrical properties of the structures strongly depend on the deposition conditions of ZnO:Al.In addition, the resistivity can be easily varied depending on ZnO:Al annealing temperatures and Al concentration