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361.
A phase-sensitive optical low-coherence reflectometry (OLCR) technique is demonstrated to simultaneously measure the absolute chromatic dispersion values of each guided LP mode of a few-mode fiber. We show that the OLCR technique requires only short samples of fiber (<1 m) and has no need for high-ratio mode converters to reach an accurate wavelength-dependent group delay evolution of every mode. As an example we present for the first time to our knowledge a direct and complete analysis of few-mode fibers with high, low, positive, and negative modal dispersion values, leading to chromatic dispersion parameters in good agreement with theoretical predictions. 相似文献
362.
Canon F Ballivian R Chirot F Antoine R Sarni-Manchado P Lemoine J Dugourd P 《Journal of the American Chemical Society》2011,133(20):7847-7852
We used ion mobility spectrometry to explore conformational adaptability of intrinsically disordered proteins bound to their targets in complex mixtures. We investigated the interactions between a human salivary proline-rich protein IB5 and a model of wine and tea tannin: epigallocatechin gallate (EgCG). Collisional cross sections of naked IB5 and IB5 complexed with N = 1-15 tannins were recorded. The data demonstrate that IB5 undergoes an unfolded to folded structural transition upon binding with EgCG. 相似文献
363.
Dr. Julien Rodriguez Dr. Isabelle Beurroies Dr. Thierry Loiseau Dr. Renaud Denoyel Dr. Philip L. Llewellyn 《Angewandte Chemie (International ed. in English)》2015,54(15):4626-4630
In any process, the heat exchanged is an essential property required in its development. Whilst the work related to structural transitions of some flexible metal–organic frameworks (MOFs) has been quantified and linked with potential applications such as molecular springs or shock absorbers, the heat related to such transitions has never been directly measured. This has now been carried out with MIL‐53(Al) using specifically devised calorimetry experiments. We project the importance of these heats in devices such as molecular springs or dampers. 相似文献
364.
Marie-Claude Bolduc Jacques Renaud Benoit Montreuil 《Central European Journal of Operations Research》2006,14(2):209-228
This paper presents a multi-period vehicle routing problem for a large-scale production and distribution network. The vehicles
must be routed in such a way as to minimize travel and inventory costs over a multi-period horizon, while also taking retailer
demands and the availability of products at a central production facility into account. The network is composed of one distribution
center and hundreds of retailers. Each retailer has its demand schedule representing the total number of units of a given
product that should have been received on a given day. Many high value products are distributed. Product availability is determined
by the production facility, whose production schedule determines how many units of each product must be available on a given
day. To distribute these products, the routes of a heterogeneous fleet must be determined for a multiple period horizon. The
objective of our research is to minimize the cost of distributing products to the retailers and the cost of maintaining inventory
at the facility. In addition to considering product availability, the routing schedule must respect many constraints, such
as capacity restrictions on the routes and the possibility of multiple vehicle trips over the time horizon. In the situation
studied, no more than 20 product units could be carried by a single vehicle, which generally limited the number of retailers
that could be supplied to one or two per route. This article proposes a mathematical formulation, as well as some heuristics,
for solving this single-retailer-route vehicle routing problem. Extensions are then proposed to deal with the multiple-retailer-route
situation. 相似文献
365.
366.
Tusche C Meyerheim HL Jedrecy N Renaud G Ernst A Henk J Bruno P Kirschner J 《Physical review letters》2005,95(17):176101
We present x-ray diffraction experiments and multiple-scattering calculations on the structure and transport properties of a Fe/MgO/Fe(001) magnetic tunnel junction (MTJ). Coherent growth of the top Fe electrode on the MgO spacer is observed only for Fe deposition in ambient oxygen atmosphere leading to a coherent and symmetric MTJ structure characterized by FeO layers at both interfaces. This goes in parallel with calculations indicating large positive tunnel magnetoresistance (TMR) values in such symmetric junctions. The results have important implications for achieving giant TMR values. 相似文献
367.
368.
Reactive organic polymer monoliths were prepared in fused-silica capillaries by UV-initiated free radical polymerization of N-acryloxysuccinimide (NAS) as reactive monomer, ethylene dimethacrylate as crosslinker, azobisisobutyronitrile as initiator, and toluene as porogen. In a second synthetic step, chemical derivatization of the activated-ester moieties was performed in situ through alkylation reaction with alkylamines to afford monolithic stationary phases with potential reversed-phase properties. A correlation between the synthesis conditions--composition of the reactive solution--chemical characteristics of the reactive polymer monoliths--nitrogen/NAS content--and the reversed-phase separation properties of the functionalized monolithic columns--selectivity towards homologous series of akylbenzenes--was clearly established. This finding offers the possibility of adjusting the experimental conditions with respect to the target applications. The monolithic stationary phases with optimized chemical and porous structures were used for the CEC separation of alkylbenzenes, phenols, anilines, organic acids, amino acids, and proteins. The data indicate that depending on the nature of the analytes (charge, hydrophobic/hydrophilic balance, size) reversed-phase or mixed modes may account for the observed separation. 相似文献
369.
Orio M Bochot C Dubois C Gellon G Hardré R Jamet H Luneau D Philouze C Réglier M Serratrice G Belle C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(48):13482-13494
We describe 2-mercaptopyridine-N-oxide (HSPNO) as a new and efficient competitive inhibitor of mushroom tyrosinase (K(IC) =3.7 μM). Binding studies of HSPNO and 2-hydroxypyridine-N-oxide (HOPNO) on dinuclear copper(II) complexes [Cu(2)(BPMP)(μ-OH)](ClO(4))(2) (1; HBPMP=2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol) and [Cu(2)(BPEP)(μ-OH)](ClO(4))(2)) (2; HBPEP=2,6-bis{bis[2-(2-pyridyl)ethyl]aminomethyl}-4-methylphenol), known to be functional models for the tyrosinase diphenolase activity, have been performed. A combination of structural data, spectroscopic studies, and DFT calculations evidenced the adaptable binding mode (bridging versus chelating) of HOPNO in relation to the geometry and chelate size of the dicopper center. For comparison, binding studies of HSPNO and kojic acid (5-hydroxy-2-(hydroxymethyl)-4-pyrone) on dinuclear complexes were performed. A theoretical approach has been developed and validated on HOPNO adducts to compare the binding mode on the model complexes. It has been applied for HSPNO and kojic acid. Although results for HSPNO were in line with those obtained with HOPNO, thus reflecting their chemical similarity, we showed that the bridging mode was the most preferential binding mode for kojic acid on both complexes. 相似文献
370.
Renaud Garrel Ronald Scherer Richard Nicollas Antoine Giovanni Maurice Ouaknine 《Journal of voice》2008,22(4):385-398
Well-known multimass models of vocal folds are useful to describe main behavior observed in human voicing but their principle of functioning, based on harmonic oscillation, may appear complex. This work is designed to show that a simple one-mass model ruled by laws of relaxation oscillation can also depict main behavior of glottis dynamic. Theory of relaxation oscillation is detailed. A relaxation oscillation model is assessed through a numerical simulation using conventional values for tissue characteristics and subglottal pressure. As expected, raising the mass decreases the fundamental frequency and increases the amplitude of vocal fold vibration: for a mass ranging from 0.01 to 0.4 g, F0 decreased from 297.5 to 42.5 Hz and vibrational amplitude increased from 1.26 to 3.25 mm (for stiffness k=10Nm(-1), damping r=0.015 N s m(-1), and subglottal pressure=1 kPa). Stiffness value has the opposite effect. The subglottal pressure controls the fundamental frequency with a rate ranging from 20 to 50 Hz/kPa. The vibrational amplitude is also controlled linearly by subglottal pressure from 0.22 to 0.26 mm/kPa. The range of phonation threshold pressure (PTP) is close to the values currently proposed, that is, 0.1 to 1 kPa and varies with the fundamental frequency. The relaxation oscillator is a simple and useful tool for modeling vocal fold vibration. 相似文献