Search results for "resolve"
showing 10 items of 258 documents
Resolvent estimates for the magnetic Schrödinger operator in dimensions $$\ge 2$$
2019
It is well known that the resolvent of the free Schr\"odinger operator on weighted $L^2$ spaces has norm decaying like $\lambda^{-\frac{1}{2}}$ at energy $\lambda$. There are several works proving analogous high-frequency estimates for magnetic Schr\"odinger operators, with large long or short range potentials, in dimensions $n \geq 3$. We prove that the same estimates remain valid in all dimensions $n \geq 2$.
Femtosecond time resolved coherent anti-Stokes Raman spectroscopy: Experiment and modelization of speed memory effects on H2-N2 mixtures in the colli…
2005
194317; With the aim of temperature diagnostic, femtosecond time-resolved CARS (coherent anti-Stokes Raman spectroscopy) is applied to probe H2 in H2-N2 mixtures. In a first part, a Lorentzian profile is used to model the femtosecond CARS response. A difference between the experimental broadening and the expected one is observed in the collision regime. The observed broadening increases strongly in an inhomogeneous way with respect to the perturber concentration. This is of considerable importance for temperature measurements. In a second part, we show that in the collision regime, this inhomogeneous broadening is due to the speed dependence of the collisional parameters and the memory effe…
Monoclinic model shear zones
1998
Abstract Although many ductile shear zones are supposed to have developed by approximately simple shear flow, some must have formed under different conditions. A few types of such ‘non-simple shear zones’ have been proposed in the literature such as transpression-, transtension- and stretching-shear zones. This paper presents a full three-dimensional kinematic model of shear zones with monoclinic flow geometry. Monoclinic shear zone types can be classified according to flow parameters, and according to the geometry and orientation of accumulating finite strain. Modelling of finite strain accumulation shows that a number of unusual and potentially problematic structural features may develop …
Individual differences in adaptive choice strategies
2003
Abstract Individual differences in compensatory and non-compensatory choice processes remain an unresolved issue for decision process researchers. This study investigates the stability and nature of individual differences in choice processes when individuals adapt to changes in the structure of the choice environment, namely the correlation among the choice attributes. By means of process tracing techniques, between-subjects differences in choice processing (option-based or attribute based) were found to be stable across different tasks. Individuals with higher openness to experience and ability to solve reasoning tasks were found to be more adaptive, that is to switch more promptly their c…
On Lp resolvent estimates for Laplace–Beltrami operators on compact manifolds
2014
In this article we prove Lp estimates for resolvents of Laplace–Beltrami operators on compact Riemannian manifolds, generalizing results of Kenig, Ruiz and Sogge (1987) in the Euclidean case and Shen (2001) for the torus. We follow Sogge (1988) and construct Hadamard's parametrix, then use classical boundedness results on integral operators with oscillatory kernels related to the Carleson and Sjölin condition. Our initial motivation was to obtain Lp Carleman estimates with limiting Carleman weights generalizing those of Jerison and Kenig (1985); we illustrate the pertinence of Lp resolvent estimates by showing the relation with Carleman estimates. Such estimates are useful in the constructi…
High rate concentration measurement of molecular gas mixtures using a spatial detection technique
2010
International audience; Concentration measurement in molecular gas mixtures using a snapshot spatial imaging technique is reported. The approach consists of measuring the birefringence of the molecular sample when field-free alignment takes place, each molecular component producing a signal with an amplitude depending on the molecular density. The concentration measurement is obtained on a single-shot basis by probing the time-varying birefringence through femtosecond time-resolved optical polarigraphy (FTOP). The relevance of the method is assessed in air.
Oscillator strength reduction induced by external electric fields in self-assembled quantum dots and rings
2007
We have carried out continuous wave and time resolved photoluminescence experiments in self-assembled In(Ga)As quantum dots and quantum rings embedded in field effect structure devices. In both kinds of nanostructures, we find a noticeable increase of the exciton radiative lifetime with the external voltage bias that must be attributed to the field-induced polarizability of the confined electron hole pair. The interplay between the exciton radiative recombination and the electronic carrier tunneling in the presence of a stationary electric field is therefore investigated and compared with a numerical calculation based on the effective mass approximation.
The Pyridyl Functional Groups Guide the Formation of Pd Nanoparticles Inside A Porous Poly(4-Vinyl-Pyridine)
2015
The reactivity of palladium acetate inside a poly(4-vinylpyridine-co-divinylbenzene) polymer is strongly influenced by the establishment of interaction between the Pd precursor and the pyridyl functional group in the polymer. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and simultaneous X-ray absorption near edge structure (XANES) and small angle X-ray scattering (SAXS) techniques have been applied to monitor the reactivity of palladium acetate in the presence of H-2 and CO as a function of temperature. H-2 reduces palladium acetate to Pd nanoparticles and acetic acid. The pyridyl groups in the polymer play a vital role both in stabilizing the formed acetic acid, thu…
Concentration measurements in molecular gas mixtures with a two-pump pulse femtosecond polarization spectroscopy technique
2001
0021-9606; Recently, we have demonstrated the ability of the Raman-induced polarization spectroscopy (RIPS) technique to accurately determine concentration or polarizability anisotropy ratio in low-pressure binary molecular mixtures [E. Hertz, B. Lavorel, O. Faucher, and R. Chaux, J. Chem. Phys. 113, 6629 (2000)]. It has been also pointed out that macroscopic interference, occurring when two revivals associated to different molecules time overlap, can be used to achieve measurements with picosecond time resolution. The applicability of the technique is intrinsically limited to a concentration range where the signals of both molecules are of the same magnitude. In this paper, a two-pump puls…
Photoluminescence study of terbium-exchanged ultrastable Y zeolites: Number of species, photoluminescence decays and decay-associated spectra
2008
Terbium-exchanged ultrastable Y (USY) zeolites were investigated by using time-resolved photoluminescence spectroscopy techniques and methods. To determine the distribution of terbium species in USY zeolites together with their photoluminescence properties, several analysis methods for the time-resolved luminescence spectra were used such as the area normalization of time-resolved photoluminescence spectra, singular value decomposition, global nonlinear least squares, and the maximum entropy. Except for a questionable long lifetime, small contribution of a terbium species with lifetime of 1.9¿2.1 ms, all the experimental and analysis results converged to a two terbium species distribution w…