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911.
Fabrice Béthuel Philippe Gravejat Jean-Claude Saut 《Communications in Mathematical Physics》2009,285(2):567-651
The purpose of this paper is to provide a rigorous mathematical proof of the existence of travelling wave solutions to the
Gross-Pitaevskii equation in dimensions two and three. Our arguments, based on minimization under constraints, yield a full
branch of solutions, and extend earlier results (see [3,4,8]) where only a part of the branch was built. In dimension three,
we also show that there are no travelling wave solutions of small energy. 相似文献
912.
Potential Analysis - The geometry of the quaternionic anti-de Sitter fibration is studied in details. As a consequence, we obtain formulas for the horizontal Laplacian and subelliptic heat kernel... 相似文献
913.
Basma Hasiaoui Ahmad Ibrahim Gildas L'Hostis Karine Gautier Xavier Allonas Cline Croutx‐Barghorn Bernard Durand Fabrice Laurent 《先进技术聚合物》2019,30(4):902-909
Glass–fiber‐reinforced polymers were manufactured either through a room temperature thermal curing or under ultraviolet (UV) light from a LED. The thermal system yields high performances when a post‐curing process at 65°C is applied. The photochemical curing leads to a composite in a faster timescale, albeit at the extent of the mechanical properties. It is found that in this case, impregnation and vacuum steps are too fast to allow a good wetting of the fibers, thereby leading to mechanical weaknesses and larger void volume. However, when applying longer vacuum and impregnation steps, the mechanical properties of the photochemically cured sample match the best thermally cured one. As a conclusion, it is shown that photochemical curing of glass–fiber‐reinforced polymer can lead to high performance composite provided that the preparation steps are well controlled. 相似文献
914.
Juliette Brunet Franck Collas Matthieu Humbert Lionel Perrin Fabrice Brunel Emmanuel Lacte Damien Montarnal Jean Raynaud 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12344-12350
Differential scanning calorimetry of high molar mass poly(4‐vinylphenylboronic acid, pinacol ester)s evidenced unusual reactive events above 120 °C, resulting in a high glass‐transition temperature of 220 °C. A reversible ring‐opening reactivity of pinacol boronates is proposed, involving a nucleophilic attack on the sp2 boron and subsequent bridging between boron atoms by interconnected pinacol moieties to form a densely crosslinked network with high Tg. FTIR, solid‐state NMR investigations, and rheology studies on the polymer as well as double‐tagging analyses on molecular model structures and theoretical calculations further support this hypothesis and indicate a ring‐opening inducing crosslinking. When diluted in an apolar solvent such as toluene, the polymer network can be resolubilized via ring closing, thus recovering the entropically favored linear chains featuring cyclic boronate esters. 相似文献
915.
Morgan Auffray Dae Hyeon Kim Jong Uk Kim Fatima Bencheikh David Kreher Qisheng Zhang Anthony D'Alo Jean‐Charles Ribierre Fabrice Mathevet Chihaya Adachi 《化学:亚洲杂志》2019,14(11):1921-1925
Thermally activated delayed fluorescence (TADF) based on through‐space donor and acceptor interactions constitute a recent and promising approach to develop efficient TADF emitters. Novel TADF isomers using a dithia[3.3]‐paracyclophane building block as a versatile 3D platform to promote through‐space interactions are presented. Such a 3D platform allows to bring together the D and A units into close proximity and to probe the effect of their orientation, contact site and distance on their TADF emission properties. This study provides evidence that the dithia[3.3]paracyclophane core is a promising platform to control intramolecular through‐space interactions and obtain an efficient TADF emission with short reverse‐intersystem crossing (RISC) lifetimes. In addition, this study demonstrates that this design can tune the energy levels of the triplet states and leads to an upconversion from 3CT to 3LE that promotes faster and more efficient RISC to the 1CT singlet state. 相似文献
916.
Rheological measurements were made on concrete and mortars to characterize the shear thickening behavior of certain concrete mix designs. Shear thickening reduction levers were found by selecting and designing admixtures. Since the shear-thickening phenomena occur at the scale of the finest particles, industrial limestone fillers were studied that behave like cementitious materials. Theories based on previous academic works were relevant. The shear stress-dependent effects of shear thickening and size scaling were very helpful to distinguish between surface interactions, such as lubrication and volumetric contributions and also including the packing effects. The suspension viscosity curves vary accordingly to the Newtonian viscosity of the solvent medium. In both the shear thinning and shear thickening regimes, viscosity is controlled by adjusting the amount of two specific admixtures. The reduction of friction between polymer-coated materials appears to be a key phenomenon to delay onset shear thickening in industrial processes. 相似文献
917.
Fabrice Barbe Romain Quey Andrei Musienko Georges Cailletaud 《Mechanics Research Communications》2009,36(7):762-768
In crystalline materials, the experimental observation of the localization of plastic strains in particular directions is generally restricted to the surface of a sample containing some hundreds of grains, because of the difficulties underlying microstructural analysis. In these conditions, the determination of the morphological characteristics of localization can be limited by the poor statistical representativity of the domain of observation. The purpose of this work is to extend the analysis of localization – localization bands or else – to the 3D elastoplastic strain fields of a high-resolution representative volume element of a polycrystal. 相似文献
918.
XMCD studies of magnetic polarization at Mo atoms in CoMo alloy and magnetically coupled Co/Mo multilayers 下载免费PDF全文
Andrzej Wawro Ewelina Milińska Zbigniew Kurant Aleksiej Pietruczik Jarosław Kanak Katharina Ollefs Fabrice Wilhelm Andrei Rogalev Andrzej Maziewski 《Journal of synchrotron radiation》2018,25(5):1400-1407
Magnetic polarization of Mo atoms in Co96Mo4 alloy film and Co/Mo multilayered structures has been studied by X‐ray magnetic circular dichroism. Samples with Mo spacers of two different thicknesses (0.9 nm and 1.8 nm) were investigated. Mo atoms receive a magnetic moment of ?0.21μB in the alloy. In the multilayer with the thinner Mo spacer (dMo = 0.9 nm) the magnetic moment is much smaller (?0.03μB). In both cases the measured induced moment at the Mo site is oriented antiparallel to the moment at the Co atoms. The presence of the induced moment in the Mo spacer coincides with antiferromagnetic coupling between the Co component slabs. In contrast, neither measurable induced moment at the Mo site nor interlayer coupling between the Co layers has been found for the multilayer with the thicker Mo spacer. Possible mechanisms of the coupling associated with the induced moment are discussed in detail. 相似文献
919.
Overview of Identification Methods of Mechanical Parameters Based on Full-field Measurements 总被引:6,自引:1,他引:5
Stéphane Avril Marc Bonnet Anne-Sophie Bretelle Michel Grédiac François Hild Patrick Ienny Félix Latourte Didier Lemosse Stéphane Pagano Emmanuel Pagnacco Fabrice Pierron 《Experimental Mechanics》2008,48(4):381-402
This article reviews recently developed methods for constitutive parameter identification based on kinematic full-field measurements,
namely the finite element model updating method (FEMU), the constitutive equation gap method (CEGM), the virtual fields method
(VFM), the equilibrium gap method (EGM) and the reciprocity gap method (RGM). Their formulation and underlying principles
are presented and discussed. These identification techniques are then applied to full-field experimental data obtained on
four different experiments, namely (i) a tensile test, (ii) the Brazilian test, (iii) a shear-flexural test, and (iv) a biaxial
test. Test (iv) features a non-uniform damage field, and hence non-uniform equivalent elastic properties, while tests (i),
(ii) and (iii) deal with the identification of uniform anisotropic elastic properties. Tests (ii), (iii) and (iv) involve
non-uniform strain fields in the region of interest.
Working group “Identification” of the French CNRS research network (GDR 2519) “Mesures de champs et identification en Mécanique
des Solides / Full-field Measurements and Identification in Solid Mechanics”. 相似文献
920.
We survey some recent work concerning the asymptotic dynamics of vortices in the 2-dimensional parabolic Ginzburg-Landau equation, the interaction of vortices with the phase field and the limiting initial value problem for both vortices and phase. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献