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81.
Lionel Santinacci Anne-Marie Gonçalves Muriel Bouttemy Arnaud Etcheberry 《Journal of Solid State Electrochemistry》2010,14(7):1177-1184
In this paper, we investigate the properties of porous structures anodically grown onto n-InP (100) in HCl. In situ electrochemical
characterizations show the pore morphology strongly influences the properties of the InP surfaces. Both dc- and ac-electrochemical
measurements reveal an enhancement of the capacitive current and a modification of the electronic distribution at the interface.
Photocurrent spectra performed during the pore growth are also strongly modified. For low anodic charges, an increase of the
photocurrent with a redshift of the absorption edge is measured. These evolutions can be respectively ascribed (i) to a reflection decrease due to a surface roughening and (ii) to the creation of surface states within the band gap. For higher anodic charges, the photocurrent drops with a narrowing
of the spectrum. Using a model based on the “dead” layer, the porous layer is considered as an absorbent film that progressively
attenuates the photocurrent of the bulk semiconductor. 相似文献
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85.
Véronique Dupuis Nils Blanc Luis E. Diaz-Sanchez Arnaud Hillion Alexandre Tamion Florent Tournus Gustavo M. Pastor Andrei Rogalev Fabrice Wilhelm 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2013,67(2):1-4
In this paper, the one-way absorption property in one-dimensional dielectric/metal photonic crystal structure with a dielectric defect layer is studied. The effects of incident angle and state of polarization on one-way absorption behaviour of the anti-resonant (AR) mode are investigated. The normally incident wave from left to right propagation is totally allowed to penetrate to the structure but right to left propagation totally reflected at the same wavelength. It is found that, with increasing of the incident angle, the AR mode shifts to the lower wavelengths and its intensity decreases. Simultaneously, another AR mode with reversed one-way property appears at higher wavelength. The one-way behaviour on absorption is observed at the both states of polarizations but is localized on different wavelengths. Those effects, are suggesting that the proposed structure can be used as a direction sense polarization splitter or reflector/antireflector device. 相似文献
86.
We study the relationship between two classical approaches for quantitative ergodic properties: the first one based on Lyapunov type controls and popularized by Meyn and Tweedie, the second one based on functional inequalities (of Poincaré type). We show that they can be linked through new inequalities (Lyapunov-Poincaré inequalities). Explicit examples for diffusion processes are studied, improving some results in the literature. The example of the kinetic Fokker-Planck equation recently studied by Hérau and Nier, Helffer and Nier, and Villani is in particular discussed in the final section. 相似文献
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S. Andrieu F. Ferrieu F. Arnaud d'Avitaya 《Applied Physics A: Materials Science & Processing》1989,49(6):719-722
In this paper, we present an analysis of antinomy deposition on silicon in the range of 0.1 to 1 monolayer by in situ spectroscopic ellipsometry. After a careful choice of viewpoint material, ellipsometric measurements are found to be sensitive to small surface perturbations, especially with antimony. In fact, less than a 0.1 monolayer of antimony on silicon at room temperature is detectable. Moreover, a linear dependence of the ellipsometric signal on Sb coverage is observed in the monolayer range. Consequently, the signal versus time variation directly gives the Sb adsorption kinetics on silicon. The saturation to one monolayer of compact antimony on silicon surface is used in order to calibrate the spectra. 相似文献
89.
Regis D. Gougeon Dr. Marianna Lucio Arnaud De Boel Moritz Frommberger Dr. Norbert Hertkorn Dr. Dominique Peyron Dr. David Chassagne Dr. François Feuillat Dr. Philippe Cayot Prof. Andrée Voilley Prof. Istvan Gebefügi Dr. Philippe Schmitt‐Kopplin Priv.‐Doz. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(3):600-611
A non‐targeted, ultra‐high‐resolution mass spectrometric, direct analysis of oak‐wood extracts from two species (Quercus robur L. and Quercus petraea Liebl.) from three French forests, and of a wine aged in barrels derived therefrom has been performed to identify families of metabolites that could discriminate both the species and the geographical origin of woods. From 12 T ultra‐high‐resolution Fourier transform ion cyclotron resonance mass spectra of wood extracts, hundreds of mass signals were identified as possible significant biomarkers of the two species, with phenolic and carbohydrate moieties leading the differentiation between Q. robur and Q. petraea, respectively, as corroborated by both FTMS and NMR data. For the first time, it is shown that oak woods can also be discriminated on the basis of hundreds of forest‐related compounds, and particular emphasis is put on sessile oaks from the Tronçais forest, for which sugars are significantly discriminant. Despite the higher complexity and diversity of wine metabolites, forest‐related compounds can also be detected in wines aged in related barrels. It is only by using these non‐targeted analyses that such innovative results, which reveal specific chemodiversities of natural materials, can be obtained. 相似文献
90.
A regio- and stereoselective iodination has been performed on vicinal diols located on ketopyranose templates using the controlled- Garegg conditions. 3-O-Benzyl-1,2-O-isopropylidene-β-d-fructo- or psicopyranoses (1 or 4) were selectively iodinated, respectively, at C-5 or C-4 of the ketoses to afford the l-sorbo or d-sorbo iodohydrins. 相似文献