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11.
Abderrahim Jourani Emilio Vilches 《Journal of Optimization Theory and Applications》2017,173(1):91-116
The existence and the convergence (up to a subsequence) of the Moreau-Yosida regularization for the state-dependent sweeping process with nonregular (subsmooth and positively alpha-far) sets are established. Then, by a reparametrization technique, the existence of solutions for bounded variation continuous state-dependent sweeping processes with nonregular (subsmooth and positively alpha-far) sets is proved. An application to vector hysteresis is discussed, where it is shown that the Play operator with positively alpha-far sets is well defined for bounded variation continuous inputs. 相似文献
12.
Serdar Serdas Alexander Schwarz Jörg Schröder Stefan Turek Abderrahim Ouazzi Masoud Nickaeen 《PAMM》2014,14(1):623-624
In this contribution we present the least-squares finite element method (LSFEM) for the incompressible Navier-Stokes equations. In detail, we consider a non-Newtonian fluid flow, which is described by a power-law model, see [1]. The second-order problem is reformulated by introducing a first-order div-grad system consisting of the equilibrium condition, the incompressibility condition and the constitutive equation, which are written in residual forms, see [2]. Here, higher-order finite elements which are an important aspect regarding accuracy for the present formulation are investigated. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
13.
Raoudha Abderrahim Belgacem Baccar et Mohamed Lamine Benkhoud 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1033-1040
The reaction of hexamethylphosphotriamide or methylphosphonic bis(dimethylamide) compounds with amidines derived from N-Benzimidazoyl imidates 1 leads to (1,2a)benzimidazolo-1,3,5,2-tiazaphosphorine-2-oxides 4 in good yields. If the condensation is realized at room temperature, N-phosphonic amidines 3 can be isolated as intermediates. The isolated compounds 2 , 3 , and 4 are identified by spectroscopic methods: IR, 1 H, 13 C, 31 P, NMR, and M.S. 相似文献
14.
Raoudha Abderrahim Khaled Boujlel 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):995-999
The imidates derived from 3-aminotriazole 1 react with isocyanates and isothiocyanates to give corresponding 1,2,4-triazolo-1,3,5-triazin-4-ones and 1,2,4-triazolo-1,3,5-triazin-4-thiones in a 60–75% overall yield. If the condensation is realized at r.t., then the intermediate 2 can be isolated. 相似文献
15.
Abdelfetah Mounir Mohamed El Guendouzi Abderrahim Dinane 《Journal of solution chemistry》2002,31(10):793-799
Ternary aqueous solutions of MgSO4 and K2SO4 have been studied by the hygrometric method at 25°C. The relative humidity of this system is measured at total molalities from 0.35 mol-kg–1 to about saturation for three ionic-strength fractions (y = 0.25, 0.50, and 0.80 of MgSO4. The data allow calculation of water activities and osmotic coefficients. From these measurements, the Pitzer ionic mixing parameters are determined and used to predict the solute activity coefficients in the mixture. The results are used to calculate the excess Gibbs energy at total molalities for ionic-strength fraction y. 相似文献
16.
17.
The mechanisms for the reactions of AlF with HCl have been characterized in detail using DFT as well as the ab initio method, including zero-point corrections. From the potential energy profile it can be predicted that the reaction process of forming the new Al(III) hydride HAlFCl compound for this reaction is spontaneous with a low activation energy barrier. The reaction yielding to AlFCl2 and molecular hydrogen was calculated to be highly exothermic. The present calculations also show that the possible routes to the trihalides species start more favorable with the primary insertion products. 相似文献
18.
Guyon F Hameau A Khatyr A Knorr M Amrouche H Fortin D Harvey PD Strohmann C Ndiaye AL Huch V Veith M Avarvari N 《Inorganic chemistry》2008,47(17):7483-7492
The dinuclear gold complexes [{Au(PPh 3)} 2(mu- dmid)] ( 1) ( dmid = 1,3-dithiole-2-one-4,5-dithiolate) and [{Au(PPh 3)} 2(mu- dddt)] ( 2) ( dddt = 5,6-dihydro-1,4-dithiine-2,3-dithiolate) were synthesized and characterized by X-ray crystallography. Both complexes exhibit intramolecular aurophilic interactions with Au...Au distances of 3.1984(10) A for 1 and 3.1295(11) A for 2. A self-assembly reaction between 4,5-bis(2-hydroxyethylthio)-1,3-dithiole-2-thione ( (HOCH 2 CH 2 ) 2 dmit) and [AuCl(tht)] affords the complex [AuCl{ (HOCH 2 CH 2 ) 2 dmit}] 2 ( 4), which possesses an antiparallel dimeric arrangement resulting from a short aurophilic contact of 3.078(6) A. This motif is extended into two dimensions due to intra- and intermolecular hydrogen bonds via the hydroxyethyl groups, giving rise to a supramolecular network. Three compounds were investigated for their rich photophysical properties at 298 and 77 K in 2-MeTHF and in the solid state; [Au 2(mu- dmid)(PPh 3) 2] ( 1), [Au 2(mu- dddt)(PPh 3) 2] ( 2), and [AuCl{( HOCH 2 CH 2 ) 2 dmit}] ( 4). 1 exhibits relatively long-lived LMCT (ligand-to-metal charge transfer) emissions at 298 K in solution (370 nm; tau e approximately 17 ns, where M is a single gold not interacting with the other gold atom; i.e., the fluxional C-SAuPPh 3 units are away from each other) and in the solid state (410 nm; tau e approximately 70 mus). At 77 K, a new emission band is observed at 685 nm (tau e = 132 mus) and assigned to a LMCT emission where M is representative for two gold atoms interacting together consistent with the presence of Au...Au contacts as found in the crystal structure. In solution at 77 K, the LMCT emission is also red-shifted to 550 nm (tau e approximately 139 mus). It is believed to be associated to a given rotamer. 2 also exhibits LMCT emissions at 380 nm at 298 K in solution and at 470 nm in the solid state. 4 exhibits X/MLCT emission (halide/metal to ligand charge transfer) where M is a dimer in the solid state with obvious Au...Au interactions, resulting in red-shifted emission band, and is a monomer in solution in the 10 (-5) M concentration (i.e., no Au...Au interactions) resulting in blue-shifted luminescence. Both fluorescence and phosphorescence are observed for 4. 相似文献
19.
Tanguy Jousselin-Oba Masashi Mamada Atsushi Okazawa Jrome Marrot Takayuki Ishida Chihaya Adachi Abderrahim Yassar Michel Frigoli 《Chemical science》2020,11(44):12194
Biradicaloid compounds with an open-shell ground state have been the subject of intense research in the past decade. Although diindenoacenes are one of the most developed families, only a few examples have been reported as active layers in organic field-effect transistors (OFETs) with a charge mobility of around 10−3 cm2 V−1 s−1 due to a steric disadvantage of the mesityl group to kinetically stabilize compounds. Herein, we disclose our efforts to improve the charge transport of the diindenoacene family based on hexahydro-diindenopyrene (HDIP) derivatives with different annelation modes for which the most reactive position has been functionalized with (triisopropylsilyl)ethynyl (TIPS) groups. All the HDIP derivatives show remarkably higher stability than that of TIPS-pentacene, enduring for 2 days to more than 30 days, which depends on the oxidation potential, the contribution of the singlet biradical form in the ground state and the annelation mode. The annelation mode affects not only the band gap and the biradical character (y0) but also the value of the singlet–triplet energy gap (ΔES–T) that does not follow the reverse trend of y0. A method based on comparison between experimental and theoretical bond lengths has been disclosed to estimate y0 and shows that y0 computed at the projected unrestricted Hartree–Fock (PUHF) level is the most relevant among those reported by all other methods. Thanks to their high stability, thin-film OFETs were successfully fabricated. Well balanced ambipolar transport was obtained in the order of 10−3 cm2 V−1 s−1 in the bottom-gate/top-contact configuration, and unipolar transport in the top-gate/bottom-contact configuration was obtained in the order of 10−1 cm2 V−1 s−1 which is the highest value obtained for biradical compounds with a diindenoacene skeleton.Biradicaloid HDIP derivatives show that the ΔES–T gap does not follow the reverse trend of the biradical character but depends more on the delocalization of the radical centres at the outer rings. 相似文献
20.
Abderrahim A?t Adoubel Christophe J. Morin Nadine Mofaddel Georges Dupas Paul-Louis Desbène 《Analytical and bioanalytical chemistry》2009,394(2):597-608
Enantiomer separations of underivatised amino acids were carried out by using ligand exchange capillary electrophoresis (LECE).
Chiral discrimination is based on the formation of ternary complexes between copper(II), a chiral selector (L-proline or trans-4-hydroxy-L-proline) and an amino acid. All amino acids containing aromatic moieties or not were detected at 214 nm because
of their interactions with copper(II). In order to reduce copper(II) adsorption onto capillary walls, we used hexadimethrine
bromide to reverse the electroosmotic flow. Using this original strategy, the studied enantiomers migrated in the opposite
direction of the anodic electroosmosis. After optimising the analytical conditions taking into account the chiral resolution
and the detection sensitivity, we performed very satisfactory enantioseparations not only of aromatic amino acids (tryptophan,
tyrosine, phenylalanine and histidine) but also of aliphatic amino acids (threonine, serine, isoleucine and valine). These
enantioseparations were performed in a short analysis time at 35 °C. In order to rationalise the obtained results, we evaluated
the complexation constants corresponding to the formed ternary complexes by capillary electrophoresis and we used molecular
mechanics modelling. 相似文献