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91.
Moncef Aouadi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,57(6):1057-1074
The model of the equations of generalized linear micropolar thermoelasticity with two relaxation times in an isotropic medium
with temperature-dependent mechanical properties is established. The modulus of elasticity is taken as a linear function of
reference temperature. Laplace and exponential Fourier transform techniques are used to obtain the solution by a direct approach.
The integral transforms have been inverted by using a numerical technique to obtain the temperature, displacement, force and
couple stress in the physical domain. The results of these quantities are given and illustrated graphically. A comparison
is made with results obtained in case of temperature-independent modulus of elasticity. The problem of generalized thermoelasticity
has been reduced as a special case of our problem. 相似文献
92.
Consider a horizontal line in the plane and let γ(A) be a collection of n circles, possibly of different sizes all tangent to the line on the same side. We define the tangent circle graph associated to γ(A) as the intersection graph of the circles. We also define an irreflexive and asymmetric binary relation P on A; the pair (a,b) representing two circles of γ(A) is in P iff the circle associated to a lies to the right of the circle associated to b and does not intersect it. This defines a new nontransitive preference structure that generalizes the semi-order structure. We study its properties and relationships with other well-known order structures, provide a numerical representation and establish a sufficient condition implying that P is transitive. The tangent circle preference structure offers a geometric interpretation of a model of preference relations defined by means of a numerical representation with multiplicative threshold; this representation has appeared in several recently published papers. 相似文献
93.
94.
P. Mison R. Chaabouni Y. Diab A. Laurent R. Martino A. Lopez F. W. Wehrli T. Wirthlin 《Magnetic resonance in chemistry : MRC》1976,8(2):90-94
The configuration and favoured conformations of 1,2-dialkyl-(or alkyl-phenyl)-7-azabicyclo[4.1.0]heptane diastereoisomers have been determined by means of 13C NMR. The substituent in position-2 is ‘pseudo-axial’ in cis isomers and ‘pseudo-equatorial’ in trans isomers. 相似文献
95.
E Congiu H Chaabouni C Laffon P Parent S Baouche F Dulieu 《The Journal of chemical physics》2012,137(5):054713
Dust grains in the interstellar medium are known to serve as the first chemical laboratory where the rich inventory of interstellar molecules are synthesized. Here we present a study of the formation of hydroxylamine-NH(2)OH-via the non-energetic route NO + H (D) on crystalline H(2)O and amorphous silicate under conditions relevant to interstellar dense clouds. Formation of nitrous oxide (N(2)O) and water (H(2)O, D(2)O) is also observed and the reaction network is discussed. Hydroxylamine and water results are detected in temperature-programmed desorption (TPD) experiments, while N(2)O is detected by both reflection-absorption IR spectroscopy and TPD techniques. The solid state NO + H reaction channel proves to be a very efficient pathway to NH(2)OH formation in space and may be a potential starting point for prebiotic species in dark interstellar clouds. The present findings are an important step forward in understanding the inclusion of interstellar nitrogen into a non-volatile aminated species since NH(2)OH provides a solid state nitrogen reservoir along the whole evolutionary process of interstellar ices from dark clouds to planetary systems. 相似文献
96.
Naima?Yahyaoui Noureddine?SfinaEmail author Jean-Louis?Lazzari Arnaud?Bournel Moncef?Said 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(2):59
This paper presents the results of conduction band discontinuities calculation for strained/relaxed Si1?x Ge x /Si1?y Ge y heterointerfaces in Γ 15C , Γ 2′C and L upper bands minima, as well as the room-temperature strained (vs. relaxed) band gaps deduced from the classical model-solid theory. Based upon the obtained data, we propose a type-I W-like Si1?y Ge y /Si1?x Ge x /Ge/Si1?x Ge x /Si1?y Ge y quantum wells heterostructure optimized in terms of compositions and thicknesses. Electronic states and wave functions are found by solving Schrödinger equation without and under applied bias voltage. An accurate investigation of the optical properties of this heterostructure is done by calculating the energies of the interband transitions and their oscillator strengths. Moreover, a detailed computation of the bias-voltage evolution of the absorption spectra is presented. These calculations prove the existence of type-I band alignment at Γ 2′C point in compressively strained Ge quantum wells grown on relaxed Ge-rich Si1?y Ge y buffers. The strong absorption coefficient (> 8 × 103 cm-1) and the large Stark effect (0.1 eV @ 2 V) of the Γ 2′C transitions thresholds open up perspectives for application of these heterostructures for near-infrared optical modulators. 相似文献
97.
98.
Moncef Aouadi 《Applicable analysis》2013,92(9):1816-1828
In this article, we investigate the asymptotic behaviour of a one-dimensional problem of linear theory of nonsimple thermoelastic diffusion. We show that the corresponding semigroup is exponentially stable but not analytic. We conclude by showing the impossibility of localization in time of the solutions. 相似文献
99.
The synthesis of gamma-functionalized cyclopentenones was carried out in a few steps, starting firstly with the preparation of nitroketonic intermediates 2, which were readily transformed into 1,4-diketones using the Nef conversion. The intramolecular cyclization of the gamma-diketones 3 in a basic medium, led to the functionalized cyclopentenones 4. 相似文献
100.
The ethylenediammonium bis tetraiodobismuthate(III) tetrahydrate salt is monoclinic with the following unit cell dimensions:a=7.476(3)?,b=13.194(3)?,c=13.916(9)?, β=95.22(6)°, space groupP21
lc withZ=2. The structure consists of disordered ethylenediammonium cations, water molecules and polynuclear anions in which slightly
distored [BiI6]3− octahedra sharingcis edges are interconnected into chains. The [BiI4]− anions are connected through O(W2)−H...I hydrogen bonds, so that infinite two dimensional chains parallel to thea axis with anionic period [BiI4(H2O)]− are formed in the structure. These chains are themselves interconnected by means of the O−H...I and N...O(I) bonds originating
respectively from the water molecules and the ethylenediammonium entities, forming a three-dimensional network. 相似文献