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排序方式: 共有219条查询结果,搜索用时 31 毫秒
191.
Hani Ali 《Journal of Mathematical Fluid Mechanics》2013,15(2):303-316
In this paper, we establish the existence of a unique “regular” weak solution to turbulent flows governed by a general family of α models with critical regularizations. In particular this family contains the simplified Bardina model and the modified Leray-α model. When the regularizations are subcritical, we prove the existence of weak solutions and we establish an upper bound on the Hausdorff dimension of the time singular set of those weak solutions. The result is an interpolation between the bound proved by Scheffer for the Navier–Stokes equations and the regularity result in the critical case. 相似文献
192.
A Two-dimensional Full-wave Finite-difference Frequency-domain Analysis of Ferrite Loaded Structures
Hani Al-Barqawi Nihad Dib Majid Khodier 《International Journal of Infrared and Millimeter Waves》2008,29(5):443-456
A two-dimensional (2-D) full-wave finite-difference frequency-domain (FDFD) method is presented for analyzing the dispersion
characteristics of transversely magnetized ferrite loaded structures. Results for a number of different ferrite loaded structures
are presented. The accuracy of the FDFD formulation is verified by comparing the numerical results with analytical results
and those obtained using the FDTD method, and very good agreement is obtained. 相似文献
193.
In this work, we analyze the behavior of the particle phase in the flow of a particle-laden mixture through a porous medium. An attempt is made to model the diffusion and dispersion processes, and to quantify the deviation terms that arise when intrinsic volume averaging is used to derive the flow equations. 相似文献
194.
195.
196.
Hani Ali 《Applicable analysis》2013,92(2):339-355
We study a regularization of the rotational Navier–Stokes equations that we call the Rotational Approximate Deconvolution Model (RADM). We generalize the deconvolution model, studied by Berselli and Lewandowski in (Convergence of Approximate Deconvolution Models to the mean Navier- Stokes equations. Annales de l’Institut Henri Poincare (C), NonLinear Analysis. 2012;29:171–198), to the RADM with fractional regularization, where the convergence of the solution is studied with weaker conditions on the parameter regularization. 相似文献
197.
Nohra B El Moll H Rodriguez Albelo LM Mialane P Marrot J Mellot-Draznieks C O'Keeffe M Ngo Biboum R Lemaire J Keita B Nadjo L Dolbecq A 《Journal of the American Chemical Society》2011,133(34):13363-13374
The grafting of the triangular 1,3,5-benzene tricarboxylate linkers (denoted trim) on tetrahedral ε-Keggin polyoxometalates (POMs) capped by Zn(II) ions, formed in situ under hydrothermal conditions, has generated three novel POM-based metal organic frameworks (POMOFs). (TBA)(3)[PMo(V)(8)Mo(VI)(4)O(36)(OH)(4)Zn(4)][C(6)H(3)(COO)(3)](4/3)·6H(2)O (ε(trim)(4/3)) is a 3D open-framework built of molecular Keggin units connected by trim linkers, with channels occupied by tetrabutylammonium (TBA) counterions. ε(trim)(4/3) is a novel (3,4)-connected net, named ofp for open-framework polyoxometalate, and computer simulations have been used to evaluate its relative stability in comparison with ctn- and bor-like polymorphs, showing the stability of this novel phase directly related to its greatest density. A computational study was also undertaken with the aim of locating TBA molecules, the positions of which could not be deduced from single crystal X-ray diffraction, and further rationalizes their structure directing role. In (TBA)(3)[PMo(V)(8)Mo(VI)(4)O(37)(OH)(3)Zn(4)][C(6)H(3)(COO)(3)] (ε(2)(trim)(2)), the building unit is not the molecular Keggin but a dimerized form of this POM. Their connection via trim linkers generates a 3D framework with channels filled by TBA cations. In (TBA)(3)[PMo(V)(8)Mo(VI)(4)O(37)(OH)(3)Zn(4)][C(6)H(3)(COO)(3)]·8H(2)O ([ε(trim)](∞)), zigzag chains are connected via the organic linkers, forming 2D grids. Modified electrodes were fabricated by direct adsorption of the POMOFs on glassy carbon or entrapment in carbon paste (CPE). A remarkable electrocatalytic hydrogen evolution reaction (HER) was detected with a yield greater than 95%, and a turnover number as high as 1.2 × 10(5) was obtained after 5 h. The reported POMOF-based electrodes are more active than platinum, with a roughly 260 mV anodic shift. Finally, the electrocatalytic activities of ε(trim)(4/3)/CPE electrodes in various XCl (X = Li, Na, K, Cs) media have been studied. This allowed us to detect a cation effect and propose an electrocatalytic mechanistic pathway for the HER. 相似文献
198.
El Moll H Sémeril D Matt D Charbonnière L Toupet L 《Dalton transactions (Cambridge, England : 2003)》2011,40(17):4391-4393
Reaction of [Tb(III)(DMSO)(8)](CF(3)SO(3))(3) with a resorcinarene cavitand substituted by four -CH(2)P(O)Ph(2) pendant arms afforded an infinite 1D inorganic polymer, in which the consecutive resorcinarene units are linked through two terbium strands, this connection involves pairs of phosphoryl groups occupying adjacent positions of the resorcinarene units. 相似文献
199.
Hani KhallafChia-Ta Chen Liann-Be Chang Oleg Lupan Aniruddha Dutta Helge Heinrich A. ShenoudaLee Chow 《Applied Surface Science》2011,257(22):9237-9242
Chemical bath deposition of CdO thin films using three different complexing agents, namely ammonia, ethanolamine, and methylamine is investigated. CdSO4 is used as Cd precursor, while H2O2 is used as an oxidation agent. As-grown films are mainly cubic CdO2, with some Cd(OH)2 as well as CdO phases being detected. Annealing at 400 °C in air for 1 h transforms films into cubic CdO. The calculated optical band gap of as-grown films is in the range of 3.37-4.64 eV. Annealed films have a band gap of about 2.53 eV. Rutherford backscattering spectroscopy of as-grown films reveals cadmium to oxygen ratio of 1.00:1.74 ± 0.01 while much better stoichiometry is obtained after annealing, in accordance with the X-ray diffraction results. A carrier density as high as 1.89 × 1020 cm−3 and a resistivity as low as 1.04 × 10−2 Ω-cm are obtained. 相似文献
200.
Ahmed Abdelghany Khaled Abdelghany Hani Mahmassani Wael Alhalabi 《European Journal of Operational Research》2014
The paper presents a simulation–optimization modeling framework for the evacuation of large-scale pedestrian facilities with multiple exit gates. The framework integrates a genetic algorithm (GA) and a microscopic pedestrian simulation–assignment model. The GA searches for the optimal evacuation plan, while the simulation model guides the search through evaluating the quality of the generated evacuation plans. Evacuees are assumed to receive evacuation instructions in terms of the optimal exit gates and evacuation start times. The framework is applied to develop an optimal evacuation plan for a hypothetical crowded exhibition hall. The obtained results show that the model converges to a superior optimal evacuation plan within an acceptable number of iterations. In addition, the obtained evacuation plan outperforms conventional plans that implement nearest-gate immediate evacuation strategies. 相似文献