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91.
This paper examines the properties of the homentropic Euler equations when the characteristics of the equations have been spatially averaged. The new equations are referred to as the characteristically averaged homentropic Euler (CAHE) equations. An existence and uniqueness proof for the modified equations is given. The speed of shocks for the CAHE equations are determined. The Riemann problem is examined and a general form of the solutions is presented. Finally, numerically simulations on the homentropic Euler and CAHE equations are conducted and the behaviors of the two sets of equations are compared. 相似文献
92.
Michael Shusser Morteza Gharib Moshe Rosenfeld Kamran Mohseni 《Theoretical and Computational Fluid Dynamics》2002,15(5):303-316
The growth of a boundary layer at the nozzle wall during laminar vortex ring formation by a nozzle flow generator (piston/cylinder
arrangement) is analysed theoretically and numerically and used for modelling the formation of real vortex rings. The predictions
of the model are in good agreement with previous experimental and numerical results.
Received 19 January 2000 and accepted 17 August 2001 相似文献
93.
Damien Kudela Stephanie A. Smith Anna May‐Masnou Gary B. Braun Alessia Pallaoro Chi K. Nguyen Tracy T. Chuong Sara Nownes Riley Allen Nicholas R. Parker Prof. Hooman H. Rashidi Prof. James H. Morrissey Prof. Galen D. Stucky 《Angewandte Chemie (International ed. in English)》2015,54(13):4018-4022
We present a silica nanoparticle (SNP) functionalized with polyphosphate (polyP) that accelerates the natural clotting process of the body. SNPs initiate the contact pathway of the blood‐clotting system; short‐chain polyP accelerates the common pathway by the rapid formation of thrombin, which enhances the overall blood‐clotting system, both by accelerating fibrin generation and by facilitating the regulatory anticoagulation mechanisms essential for hemostasis. Analysis of the clotting properties of bare SNPs, bare polyP, and polyP‐functionalized SNPs in plasma demonstrated that the attachment of polyP to SNPs to form polyP‐SNPs creates a substantially enhanced synergistic effect that lowers clotting time and increases thrombin production at low concentrations. PolyP‐SNP even retains its clotting function at ambient temperature. The polyP‐SNP system has the potential to significantly improve trauma‐treatment protocols and outcomes in hospital and prehospital settings. 相似文献
94.
Mojtaba Bagherzadeh Hooman Karimi Mojtaba Amini 《Journal of Coordination Chemistry》2017,70(17):2986-2998
Graphene oxide was an effective supporting material for immobilizing a dioxomolybdenum Schiff base complex via covalent interaction. The large surface of graphene oxide plays important roles to obtain a good degree of catalytic reaction. Catalytic capacity of the graphene-bound dioxomolybdenum Schiff base complex was investigated for the oxidation of various sulfides to sulfoxide compounds using hydrogen peroxide urea as an oxidant. The catalyst was characterized by various techniques including XRD, FTIR, TGA, SEM, UV–vis, and ICP-AES. The immobilized complex was very efficient with the extra benefits of easy recovery and recycling of the heterogeneous catalyst. The graphene oxide bound dioxomolybdenum Schiff base complex was reused for several runs without meaningful loss in catalytic activity. 相似文献
95.
Davoudiasl H 《Physical review letters》2007,99(14):141301
It has recently been suggested that a scale-invariant "unparticle" sector with a nontrivial infrared fixed point may couple to the standard model (SM) via higher-dimensional operators. The weakness of such interactions hides the unparticle phenomena at low energies. We demonstrate how cosmology and astrophysics can place significant bounds on the strength of unparticle-SM interactions. We also discuss the possibility of a having a non-negligible unparticle relic density today. 相似文献
96.
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98.
This article examines the utilization of a spatial averaging technique to the nonlinear terms of the partial differential equations as an inviscid shock-regularization of hyperbolic conservation laws. A central motivation is to promote the idea of applying filtering techniques such as the observable divergence method, rather than viscous regularization, as an alternative to the simulation of shocks and turbulence in inviscid flows while, on the other hand, generalizing and unifying previous mathematical and numerical analysis of the method applied to the one-dimensional Burgers’ and Euler equations. This article primarily concerns the mathematical analysis of the technique and examines two fundamental issues. The first is on the global existence and uniqueness of classical solutions for the regularization under the more general setting of quasilinear, symmetric hyperbolic systems in higher dimensions. The second issue examines one-dimensional scalar conservation laws and shows that the inviscid regularization method captures the unique entropy or physically relevant solution of the original, non-averaged problem as filtering vanishes. 相似文献
99.
Ali Morsali S. Ali Beyramabadi S. Hooman Vahidi Maryam Ghorbani 《Molecular physics》2013,111(8):483-490
The curves of experimental heat capacity against density show a minimum around and below the critical temperature (Tc), but at higher temperatures, this minimum is not observed. In this study, the role of attractive and repulsive forces on excess heat capacity of Lennard–Jones (LJ) dense fluids has been investigated using a molecular dynamics simulation technique. LJ potential is divided into attractive and repulsive parts. From the molecular dynamics calculations, potential energy and heat capacities have been obtained for Argon at temperatures of 100–500?K. The repulsive forces play the main role in causing the heat capacities at temperatures greater than critical point. Around and below the critical temperature, the role of repulsion is dominant at high densities, but attraction has the main role at low densities, consequently at middle densities, a minimum is formed. 相似文献
100.
T.N. Anh Nguyen N. Benatmane V. Fallahi Yeyu Fang S.M. Mohseni R.K. Dumas Johan Åkerman 《Journal of magnetism and magnetic materials》2012
By varying the Pd thickness (tPd) from 0 to 8 nm in [Co/Pd]4/Co/Pd(tPd)/NiFe exchange springs, we demonstrate (i) continuous tailoring of the exchange coupling between a [Co/Pd]4/Co layer with perpendicular anisotropy, and a NiFe layer with an in-plane easy axis, (ii) tuning of the NiFe out-of-plane magnetization angle from 20○ to 80○, and (iii) an up to two-fold increase in the NiFe damping. The partial decoupling also results in a highly uniform NiFe magnetization. These properties make [Co/Pd]4/Co/Pd(tPd)/NiFe spring magnets ideal candidates for use as tilted polarizers, by combining stable and well-defined spin directions of its carriers with a high degree of angular freedom. 相似文献