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ENTrOPY FUNCTIONAL FOr CONTINUOUS SYSTEmS OF FINITE ENTrOPY

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Acta mathematica Scientia 2012年第2期32卷 775-782页

作者： m.rahimi A.riazi Depar.m.nt of mathematics Amirkabir University of TechnologyTehranIran

In this article, we introduce the concept of entropy functional for continuous systems on compact metric spaces, and prove some of its properties. We also extract the Kolmogorov entropy fr.m.the entropy functional.

关键词： Entropy entropy functional invaxiant

Hybrid LES/rANS Simulations of Compressible Flow in a Linear Cascade of Flat Blade Profiles

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Journal of Thermal Science 2024年第5期33卷 1839-1850页

作者： Jar.m.r PrIHODA Petr STrAKA David SImUrDA Petr SIDLOF Jan LEPICOVSKY Institute of Thermomechanics of the Czech Academy of Sciences Dolejskova 1402/518200 Prague 5Czech Republic Aerospace research and Test Centre Beranovych 13019905 PragueCzech Republic Technical University of Liberec Faculty of MechatronicsStudentska 246117 Liberec 1Czech Republic

The paper reports on 3D numerical simulations of unsteady compressible airflow in a blade cascade consisting of flat profiles using a hybrid LES/rANS approach including a transition *** a first step towards simulation of blade flutter in turbomachinery,various incidence angle offsets of the middle blade were *** simulations were run for the flow regime characterized by outlet isentropic mach number.m.(is)=0.5and zero *** results of the LES/rANS simulations(pressure and mach number distributions)were compared to a baseline rANS model,and to exper.m.ntal data measured in a high-speed wind *** numerical results show that both methods overpredict flow separation taking place at the leading *** this regard,the hybrid LES/rANS method does not provide superior results compared to the traditional rANS ***,the LES/rANS results also capture vortex shedding fr.m.the blunt trailing *** frequency of the trailing edge vortex shedding in CFD simulations matches perfectly the spectral peak recorded during wind tunnel measur.m.nts.

关键词： numerical simulation blade cascade hybrid LES/rANS

INVArIANCE AND STABILITY OF THE PrOFILE EQUATIONS OF GEOmETrIC OPTICS

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Acta mathematica Scientia 2011年第6期31卷 2141-2158页

作者： Guy mtivier Jeffrey rauch Institut de mathmatiques de Bordeaux Universit de Bordeaux Depar.m.nt of mathematics University of Michigan

The profile equations of geometric optics are described in a form invariant under the natural transformations of first order systems of partial differential equations. This allows us to prove that various strategies for computing profile equations are equivalent. We prove that if L generates an evolution on L2 the same is true of the profile equations. We prove that the characteristic polynomial of the profile equations is the localization of the characteristic polynomial of the background operator at （y, dφ（y）） where φ is the background phase. We prove that the propagation cones of the profile equations are subsets of the propagation cones of the background operator.

关键词： geometric optics profile equation localisation vector bundles propagation cones

Jungck's Common Fixed Point Theor.m.and E.A Property

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Acta mathematica Sinica,English Series 2008年第1期24卷 87-94页

作者： m.ImDAD Javid ALI Depar.m.nt of mathematics Aligarh Muslim University

We prove that （E.A） property buys the required containment of range of one mapping into the range of other in common fixed point considerations up to a pair of mappings. While proving our results, we utilize the ide... 详细信息

关键词： E.A property weak compatible mappings coincidence points fixed points and implicit functions

Ha Line Polarization in the 2B/X4.8 Flare of 2002 July 23

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Chinese Journal of Astronomy and Astrophysics 2003年第3期3卷 266-276页

作者： ZhiXu N.m.Firstova Depar.m.ntofAstronomy NanjingUniversityNanjing210093 InstituteofSolar-TerrestrialPhysics RussianAcademyofSciencesSiberianDivisionRussia

On 2002 July 23, a 2B/X4.8 flare was observed in the Hα line spec-tropolar.m.trically by the Large Solar Vacuum Telescope of Baikal AstrophysicalObservatory. Linear polarization of 3%-10% was detected in the Hα line, particu-larly where the line showed central reversal. The linear polarization is mainly radialon the solar disk and appears at the impulsive phase of the hard X-ray and γ-raybursts. It is limited to some relatively small regions of the flare. The polarizationin a limited small region (～ 4″ - 5″) changed its direction within a short period oftime (～ 10s).

关键词： Polarization - line: profile - Sun: flare

Size-manipulation,compaction and electrical properties of barium manganite nanorods synthesized via the CHm method

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Progress in Natural Science:materials International 2013年第4期23卷 388-394页

作者： Khizar Hayat m.A.rafiq Atta ur rahman Abid Ali Khan m.m.Hasan materials research Laboratory Institute of Physics and ElectronicsUniversity of PeshawarKhyber Pakhtunkhwa 25120Pakistan micro and Nano Devices Group Department of Metallurgy and Materials EngineeringPakistan Institute of Engineering and Applied SciencesP.O.NiloreIslamabad 45650Pakistan Centre of Biotechnology & microbiology University of PeshawarKhyber Pakhtunkhwa 25120Pakistan

A composite-hydroxide mediated method was employed to synthesize barium manganite ***,surface smoothness and uniformity of these nanorods were optimized by varying reaction temperature and reaction *** rods with an average diameter of 200 nm and length of1–1.5 μm were obtained at optimum conditions of 200 1C/48 *** dielectric study of these rods reveals that they have higher value of dielectric constant at lower frequencies which was attributed to the interfacial and rotational type ***,the increase in dielectric constant with temperature was attributed to the thermal activation of such ***,the analysis of ln(J) vs.E1/2characteristics in the temperature range of 300–400 K shows that possible operative conduction mechanism was of Poole–Frenkel *** value of βexp was found to be 4.85 times greater than the expected theoretical value of feld lowering coeffcient with an internal feld enhancement factor ofα2 *** high value of βexp may be due to some localized electric felds existing inside the sample.

关键词： BamnO3 nanorods Electrical properties Dielectric properties DC conduction mechanism

Evolution of Dissipative Anisotropic Expansion-Free Axial Fluids

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Communications in Theoretical Physics 2015年第8期64卷 139-144页

作者： m.Sharif Zunaira Nasir Depar.m.nt of mathematics University of the Punjab Quaid-i-Azam Campus

A general study of non-static restricted class of axial system with anisotropic dissipative expansion-free fluid under geodesic condition is carried out. It is found that expansion-free model must be dissipative under geodesic condition to preserve axial symmetry. We also investigate this system without geodesic condition. Finally, the role of dissipation is explored via transport equation.

关键词： general relativity dissipative systems analytical

Trivial and Simple Spectr.m.for SL(d,r) Cocycles with Free Base and Fiber Dynamics

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Acta mathematica Sinica,English Series 2015年第7期31卷 1113-1122页

作者： mrio BESSA Paulo VArANDAS Departamento de matemtica Universidade da Beira InteriorRua Marquês d'vila e Bolama6201-001 CovilhPortugal Departamento de matemtica Universidade Federal da BahiaAv.Ademar de Barros s/n40170-110 SalvadorBrazil

Let ACD（m, SL（d,r）） denote the pairs （f, A） so that f∈ A C Diff^1（m） is a C^1-Anosov transitive diffeomorphisms and A is an SL（d,r） cocycle dominated with respect to f. We prove that open and densely in ACD（m, SL（d,r））, in appropriate topologies, the pair （f,A） has simple spectr.m.with respect to the unique maximal entropy measure μf. Then, we prove prevalence of trivial spectr.m.near the dynamical cocycle of an area-preserving map and also for generic cocycles in AUtLeb（m） × LP（m, SL（d, r））.

关键词： Linear cocycles Lyapunov exponents Anosov diffeomorphisms topological conjugacy,maximal entropy measures

Effect of the Geometrical Par.m.ter of Openmicrochannel on Pool Boiling Enhancement

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Frontiers in Heat and mass Transfer 2024年第5期22卷 1421-1442页

作者： Ali m.H.Al-Obaidy Ekhlas m.Fayyadh Amer.m.Al-Dabagh mechanical Engineering Depar.m.nt University of Technology-IraqBaghdad10066Iraq

High heat dissipation is required for.m.niaturization and increasing the power of electronic *** boiling is a pr.m.sing option for achieving efficient heat dissipation at low wall superheat without the need for.m.ving *** studies have focused on improving heat transfer efficiency during boiling by modifying the surface of the heating *** paper presents an exper.m.ntal investigation on improving pool boiling heat transfer using an open *** pr.m.ry goal of this work is to investigate the impact of the channel geometry characteristics on boiling heat ***,rectangular.m.crochannels were prepared on a circular copper test piece with a diameter of 20 ***,the boiling characteristics of these microchannels were compared with those of a smooth surface under saturated conditions using deionized *** this investigation,a wire-cutting electrical discharge machine(EDm)machine was used to produce parallel microchannels with channel widths of 0.2,0.4,and 0.8 *** fin thicknesses were 0.2,0.4,and 0.6 mm,while the channel depth r.m.ined constant at 0.4 *** results manifested that the surface featuring narrower fins and broader channels achieved superior *** heat transfer coefficient(HTC)was enhanced by a maximum of 248%,and the critical heat flux(CHF)was enhanced by a maximum of 101%compared to a plain ***,the obtained results were compared with previous research and elucidated a good agreement.

关键词： Pool boiling microchannel surface geometrical par.m.ter heat transfer enhancement critical heat flux