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221.
In this paper, we investigate numerically the Susceptible–Infected–Recovered–Susceptible (SIRS) epidemic model on an exponential network generated by a preferential attachment procedure. The discrete SIRS model considers two main parameters: the duration τ0 of the complete infection–recovery cycle and the duration τI of infection. A permanent source of infection I0 has also been introduced in order to avoid the vanishing of the disease in the SIRS model. The fraction of infected agents is found to oscillate with a period T≥τ0. Simulations reveal that the average fraction of infected agents depends on I0 and τI/τ0. A maximum of synchronization of infected agents, i.e. a maximum amplitude of periodic spreading oscillations, is found to occur when the ratio τI/τ0 is slightly smaller than 1/2. The model is in agreement with the general observation that an outbreak corresponds to high τI/τ0 values. 相似文献
222.
Zazoua Hanane Touahra Fouzia Sehailia Moussa Chebout Redouane Lerari Djahida Bachari Khaldoun Saadi Adel 《Research on Chemical Intermediates》2019,45(5):3273-3290
Research on Chemical Intermediates - Delafossite mixed metal oxides of the form BaCuO2 and BaCu1M1?xO2 (M?=?Ni, Fe and Co) were successfully synthesized following a sol–gel... 相似文献
223.
224.
The Potential of the Diarsene Complex [(C5H5)2Mo2(CO)4(μ,η2-As2)] as a Connector Between Silver Ions
Dr. Mehdi Elsayed Moussa Jana Schiller Dr. Eugenia Peresypkina Dr. Michael Seidl Dr. Gábor Balázs Pavel Shelyganov Prof. Dr. Manfred Scheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(63):14315-14319
The reaction of the organometallic diarsene complex [Cp2Mo2(CO)4(μ,η2-As2)] ( B ) (Cp = C5H5) with Ag[FAl{OC6F10(C6F5)}3] (Ag[FAl]) and Ag[Al{OC(CF3)3}4] (Ag[TEF]), respectively, yields three unprecedented supramolecular assemblies [(η2- B )4Ag2][FAl]2 ( 4 ), [(μ,η1:η2- B )3(η2- B )2Ag3][TEF]3 ( 5 ) and [(μ,η1:η2- B )4Ag3][TEF]3 ( 6 ). These products are only composed of the complexes B and AgI. Moreover, compounds 5 and 6 are the only supramolecular assemblies featuring B as a linking unit, and the first examples of [AgI]3 units stabilized by organometallic bichelating ligands. According to DFT calculations, complex B coordinates to metal centers through both the As lone pair and the As−As σ-bond thus showing this unique feature of this diarsene ligand. 相似文献
225.
Using the machinery of Lie group analysis,the nonlinear system of coupled Burgers-type equations is studied.Using the infinitesimal generators in the optimal system of subalgebra of the said Lie algebras,it leads to two nonequivalent similarity transformations by using it we obtain two reductions in the form of system of nonlinear ordinary differential equations.The search for solutions of these systems by using the G'/G-method has yielded certain exact solutions expressed by rational functions,hyperbolic functions,and trigonometric functions.Some figures are given to show the properties of the solutions. 相似文献
226.
A. Abu-El Hassan M. Zidan M. M. Moussa 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,60(1):116-137
The present paper is concerned with non-isothermal spherical Couette flow of Oldroyd-B fluid in the annular region between
two concentric spheres. The inner sphere rotates with a constant angular velocity while the outer sphere is kept at rest.
The viscoelasticity of the fluid is assumed to dominate the inertia such that the latter can be neglected in the momentum
and energy equations. An approximate analytical solution is obtained through the expansion of the dynamical variable fields
in power series of Nahme number. Non-homogeneous, harmonic for axial- velocity and temperature equations and biharmonic for
stream function equations, have been solved up to second order approximation. In comparison of the present work with isothermal
case; [1,2], two additional terms; a first order velocity and a second order stream function are stem as a result of the interaction
between the fluid viscoelasticity and temperature profile. These contributions prove to be the most important results for
rheology in this work. 相似文献
227.
A neutral naphthyl methacrylate-phenylene diacrylate-based monolith (NPM) was introduced for RP-CEC of various neutral and charged solute probes via hydrophobic and π interactions. The NPM column was prepared by the in situ polymerization of naphthyl methacrylate as the functional monomer and 1,4-phenylene diacrylate (PDA) as the crosslinker in a ternary porogenic solvent containing cyclohexanol, dodecanol and water. The NPM column exhibited cathodal EOF despite the fact that it was devoid of any fixed charges. NPM exhibited stronger EOF than its counterpart naphthyl methacrylate monolith (NMM) made from the in situ polymerization of naphthyl methacrylate and trimethylolpropane trimethacrylate (TRIM). As for NMM, it is believed that the EOF arises from the adsorption of mobile phase ions onto the monolith surface. The higher EOF exhibited by NPM may be attributed to the acrylate nature of PDA as compared to the methacrylate nature of TRIM, and therefore PDA has a higher binding capacity for mobile phase ions due to its higher polarity than TRIM. The adsorption of mobile phase ions together with the additional π interactions offered by the aromatic rings of the NPM matrix modulated solute retention and separation selectivity. The applications of NPM were demonstrated by the separation of a wide range of small and large solutes including peptides, tryptic peptide maps and proteins. 相似文献
228.
Moussa Dicko Christophe Coquelet Carmen Jarne Scott Northrop Dominique Richon 《Fluid Phase Equilibria》2010
Aqueous amine solutions are widely used in the industry for acid gas removal. In order to treat natural gas or refinery process streams, an accurate knowledge of solubility data of carbon dioxide, hydrogen sulfide and other sulfur species in aqueous amine solutions is required. In this paper, new equilibrium measurements on 50 wt% aqueous methyldiethanolamine solution with CO2 and H2S have been produced. A simple way to correlate the data has been searched and found. First, a model proposed by Posey et al. in 1996, then a Deshmukh–Mather model are used to correlate “vapor–liquid” equilibria. The Posey et al. model lacks accuracy to represent the experimental data, especially for high loadings. The Deshmukh–Mather model shows good agreement as long as the total loading (H2S + CO2) does not reach 1.0. 相似文献
229.
Mostafa Bendahmane Moussa Chrif Said El Manouni 《Mathematical Methods in the Applied Sciences》2010,33(1):49-56
We deal with the existence and uniqueness of weak solutions for a class of strongly nonlinear boundary value problems of higher order with L1 data in anisotropic‐weighted Sobolev spaces of infinite order. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
230.
Sylvain Petit Stéphane Pailhès Xavier Fabrèges Martine Hennion Fernande Moussa Loreynne Pinsard Louis-Pierre Regnault Alexander Ivanov 《Pramana》2008,71(4):869-876
Aiming to shed light on the possible existence of hybrid phonon-magnon excitations in multiferroic manganites, neutron scattering
measurements have been undertaken at LLB and ILL on the particular case of hexagonal YMnO3. Our experiments focused on a transverse acoustic phonon mode polarized along the ferroelectric axis. The neutron data show
that below the magnetic transition, this particular phonon mode splits in two different branches. The upper branch is found
to coincide with a spin wave mode. This manifestation of a strong spin-lattice coupling is discussed in terms of a possible
hybridization between the two types of elementary excitations, the phonon and magnons.
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