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961.
Cecile Baudin Christophe Pean Bruno Pellizzari Andree Gadelle Florence Fauvelle Jean-Claude Debouzy Jean-Pierre Dalbiez Bruno Perly 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):287-296
We report on the synthesis,characterization and ionic complexation properties ofhexakis (2-O-acetyl-3,6-anhydro)cyclomaltohexaose and hexakis (2-O-methyl-3,6-anhydro) cyclomaltohexaose usingthin-layer chromatography and Nuclear MagneticResonance spectroscopy. The selectivity towardscations depends on chemical modification of thehydroxyl groups and a very high specificity can beobtained in the case of lead for methylatedderivatives. 相似文献
962.
Bruno Bassan Claudia Ceci 《Stochastics An International Journal of Probability and Stochastic Processes》2013,85(1-2):55-77
In this paper we show that the solution of a stochastic boundary value problem with additive noise and with a completely nonlinear drift is a Markov field if only if the boundary condition is an initial or a final type condition 相似文献
963.
Bruno Escribano Elena Akhmatskaya Jon I. Mujika 《Central European Journal of Mathematics》2013,11(4):787-799
Generalized Shadow Hybrid Monte Carlo (GSHMC) is a method for molecular simulations that rigorously alternates Monte Carlo sampling from a canonical ensemble with integration of trajectories using Molecular Dynamics (MD). While conventional hybrid Monte Carlo methods completely re-sample particle’s velocities between MD trajectories, our method suggests a partial velocity update procedure which keeps a part of the dynamic information throughout the simulation. We use shadow (modified) Hamiltonians, the asymptotic expansions in powers of the discretization parameter corresponding to timestep, which are conserved by symplectic integrators to higher accuracy than true Hamiltonians. We present the implementation of this method into the highly efficient MD code GROMACS and demonstrate its performance and accuracy on computationally expensive systems like proteins in comparison with the molecular dynamics techniques already available in GROMACS. We take advantage of the state-of-the-art algorithms adopted in the code, leading to an optimal implementation of the method. Our implementation introduces virtually no overhead and can accurately recreate complex biological processes, including rare event dynamics, saving much computational time compared with the conventional simulation methods. 相似文献
964.
Stefan Lautenschlaeger Sebastian Eisermann Michael N. Hofmann Udo Roemer Melanie Pinnisch Andreas Laufer Bruno K. Meyer Holger von Wenckstern Alexander Lajn Florian Schmidt Marius Grundmann Juergen Blaesing Alois Krost 《Journal of Crystal Growth》2010,312(14):2078-2082
We report on the growth of non-polar a-plane ZnO by CVD on r-plane-sapphire-wafers, a-plane GaN-templates and a-plane ZnO single-crystal substrates. Only the homoepitaxial growth approach leads to a Frank–van-der–Merwe growth mode, as shown by atomic force microscopy. The X-ray-diffraction spectra of the homoepitaxial thin films mirror the excellent crystalline quality of the ZnO substrate. The morphological and the structural quality of the homoepitaxial films is comparable to the best results for the growth on c-plane ZnO-substrates. The impurity incorporation, especially of group III elements, seems to be reduced when growing on the non-polar a-plane surface compared to the c-plane films as demonstrated by secondary ion mass spectrometry (SIMS). Optical properties have been investigated using low temperature photoluminescence measurements. We employed capacitance–voltage measurements (C–V) to measure the background carrier density and its profile from substrate/film interface throughout the film to the surface. In thermal admittance spectroscopy (TAS) specific traps could be distinguished, and their thermal activation energies and capture cross sections could be determined. 相似文献
965.
Lidia Caporossi Giovanna Tranfo Enrico Paci Mariangela De Rosa Silvia Capanna Felice Tidei Bruno Papaleo 《Chromatographia》2010,72(3-4):281-287
An LC–DAD method was developed to determine residues of oxamyl on greenhouse workers’ skin. The wipe test was used to obtain samples from hands, forearms, neck and gloves of workers taking cactus cuttings 48 h after pesticide treatment. It was validated in a concentration range 50–5,000 ng mL?1. The results on six workers and ten office employees indicated significant differences particularly in the hand samples. To avoid the overestimation owing to an interfering substance we proceeded to confirm these findings with LC–MS–MS, which found the pesticide only on the surface of the workers’ gloves, proving that there was indeed some UV interference. 相似文献
966.
967.
Marta Moraschi Giovanni Giulietti Federico Giove Manuela Guardati Girolamo Garreffa Nicola Modugno Claudio Colonnese Bruno Maraviglia 《Magnetic resonance imaging》2010
Parkinson's disease is a neurological disorder associated with the disfunction of dopaminergic pathways of the basal ganglia, mainly resulting in a progressive alteration in the execution of voluntary movements. We present a functional magnetic resonance imaging (fMRI) study on cortical activations during simple motor task performance, in six early–stage hemiparkinsonian patients and seven healthy volunteers. We acquired data in three sessions, during which subjects performed the task with right or left hand, or bimanually. We observed consistent bilateral activations in cingulate cortex and dorsolateral prefrontal cortex of Parkinsonian subjects during the execution of the task with the affected hand. In addition, patients showed both larger and stronger activations in motor cortex of the affected hemisphere with respect to the healthy hemisphere. Compared with the control group, patients showed a hyperactivation of the dorsolateral prefrontal cortex of the affected hemisphere. We concluded that a presymptomatic reorganization of the motor system is likely to occur in Parkinson's disease at earlier stages than previously hypothesized. Moreover, our results support fMRI as a sensitive technique for revealing the initial involvement of motor cortex areas at the debut of this degenerative disorder. 相似文献
968.
Bruno Bêche Arnaud Potel Véronique Vié Christian Godet David Pluchon 《Optics Communications》2010,283(1):164-2456
We have designed and realized an integrated photonic family of micro-resonators (MR) on multilayer SU8/lipidic film/glass materials. Such a family involves hybrid 3D-MR structures composed of spherical glass-MR arranged upon organic pair-SU8-waveguides, an efficient coupling being ensured with a Langmuir-Blodgett Dipalmitoylphosphatidylcholine (DPPC-lipid from Avanti Polar®) film whose thickness is ranging from 12 to 48 nm. We have characterized such add/drop filters, respectively, in intensity and spectral measurements, and experimentally achieved an evanescent resonant-photonic-coupling between the 3D-MR and the 4-ports structure through the DPPC-gap. Spectral resonances have been measured for 4-whispering gallery-modes (WGM) into such 3D-structures, respectively, characterized with a 0.97 nm free spectral range (FSR) and a high quality Q-factor up to 4.104. 相似文献
969.
Ana Paula D. Moreira Bruno S. Souza Ana Maria R. F. Teixeira 《Journal of Thermal Analysis and Calorimetry》2009,97(2):647-652
Naphthenates are produced when naphthenic acids present in crude oil are mixed with brine. They deposit at oil/water interface
and are insoluble in either of the phases causing a large problem to the oil industry. Generally, naphthenates precipitate
jointly with others compounds such as sulfates and carbonates. This fact makes difficult their characterization. In this study,
calcium stearate formation from stearic acid was investigated, under different conditions, as a previous model to understanding
of calcium naphthenate precipitation. Medium reactions distinct were studied and the results indicated that the ethanol medium
was the most efficient for the formation of solids because in this only case, the stearic acid was completely converted into
stearate. Monitoring of the conversion was performed by thermogravimetry in spite of this technique not be typical in salts
characterization. Nevertheless, the thermogravimetric analysis showed that is possible to identify differences between an
organic acid, a salt of this acid and an inorganic salt, in the same sample. Infrared spectra was used in order to confirm
the results obtained by thermogravimetry. However, this technique showed less efficiency and sensibility. 相似文献
970.
Eva Castillejos Dr. Pierre‐Jean Debouttière Dr. Lucian Roiban Abderrahim Solhy Dr. Victor Martinez Dr. Yolande Kihn Dr. Ovidiu Ersen Dr. Karine Philippot Dr. Bruno Chaudret Dr. Philippe Serp Dr. 《Angewandte Chemie (International ed. in English)》2009,48(14):2529-2533
Are you in? Bimetallic PtRu nanoparticles have been selectively confined inside or deposited outside carbon nanotubes (see picture). The confined nanoparticles display significantly higher selectivity and catalytic activity in hydrogenation reactions.