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The quantum Hall's effect:A quantum electrodynamic phenomenon

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Chinese Physics B 2012年第12期21卷 444-450页

作者： A.i.Arbab Department of Physics Faculty of ScienceUniversity of Khartoum

We have applied Maxwell＇s equations to study the physics of quantum Hall＇s effect. The electromagnetic properties of this system are obtained. The Hall＇s voltage, VH ---- 27rh2ns/em, where ns is the electron number density, for a 2- dimensional system, and h ---- 27rh is the Planck＇s constant, is found to coincide with the voltage drop across the quantum capacitor. Consideration of the cyclotronic motion of electrons is found to give rise to Hall＇s resistance. Ohmic resistances in the horizontal and vertical directions have been found to exist before equilibrium state is reached. At a fundamental level, the Hall＇s effect is found to be equivalent to a resonant LCR circuit with LH = 2π m/e2ns and CH -= me2/π2h2ns satisfying the resonance condition with resonant frequency equal to the inverse of the scattering （relaxation） time, τs. The Hall＇s resistance is found to be RH = √LH/CH The Hall＇s resistance may be connected with the impedance that the electron wave experiences when it propagates in the 2-dimensional gas.

关键词： quantum Hall effect Maxwell equations electromagnetism

Optimal Combined Heat and Power Economic Dispatch Using Stochastic Fractal Search Algorithm

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Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 276-286页

作者： Muwaffaq i.Alomoush the Department of Electrical Power Engineering Hijjawi Faculty for Engineering TechnologyYarmouk UniversityIrbidJordan

Combined heat and power(CHP)generation is a valuable scheme for concurrent generation of electrical and thermal *** interdependency of power and heat productions in CHP units introduces complications and non-convexities in their modeling and *** paper uses the stochastic fractal search(SFS)optimization technique to treat the highly non-linear CHP economic dispatch(CHPED)problem,where the objective is to minimize the total operation cost of both power and heat from generation units while fulfilling several operation interdependent limits and *** CHPED problem has bounded feasible operation regions and many local *** SFS,which is a recent metaheuristic global optimization solver,outranks many current reputable *** constraints of the CHPED is achieved by employing external penalty parameters,which penalize infeasible solution during the iterative *** confirm the strength of this algorithm,it has been tested on two different test systems that are regularly *** obtained outcomes are compared with former outcomes achieved by many different methods reported in literature of *** results of this work affirm that the SFS algorithm can achieve improved near-global solution and compare favorably with other commonly used global optimization techniques in terms of the quality of solution,handling of constraints and computation time.

关键词： Combined heat and power(CHP) economic dispatch global optimization metaheuristic algorithms non-convex optimization problem power systems stochastic fractal search

Selective catalytic reduction of NOX with ethanol and other C1-4 oxygenates over Ag/Al2O3 catalysts: A review

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Frontiers of Chemical Science and Engineering 2020年第4期14卷 471-491页

作者： Pavlo i.Kyriienko L.V.Pisarzhevskii institute of Physical Chemistry of the NAS of Ukraine Kyiv 03028Ukraine

Research results regarding selective catalytic reduction(SCR)of NOx with ethanol and other C1-4 oxygenates as reductants over silver-alumina catalysts are *** aspects of the process mechanism,nature of active sites,role of alumina and silver(especially in the formation of bifunctional active sites),effects of reductants and reaction conditions are *** has been determined that key stages of the process include formation of reactive enolic species,their interaction with NOx and formation of nitroorganic compounds which transform to NCOads species and further to *** results obtained over various silver-alumina catalysts demonstrate the perspectives of their application for reducing the level of nitrogen oxides in engine emissions,including in the presence of water vapor and sulfur *** to improve the catalysts for the SCR of NOx with C1-4 oxygenates are outined.

关键词： SCR nitrogen oxides silver-alumina catalyst silver species ethanol oxygenates

Explosive-Emission Plasma Dynamics in ion Diode in Double-Pulse Mode

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Plasma Science and Technology 2011年第6期13卷 698-701页

作者： Alexander i.PUSHKAREV Yulia i.iSAKOVA Tomsk Polytechnic University

The results of an experimental investigation of explosive-emission plasma dynamics in an ion diode with self-magnetic insulation are presented. The investigations were accomplished at the TEMP-4M accelerator set in a mode of double pulse formation. Plasma behaviour in the anode-cathode gap was analyzed according to both the current-voltage characteristics of the diode （time resolution of 0.5 ns） and thermal imprints on a target （spatial resolution of 0.8 mm）. it was shown that when plasma formation at the potential electrode was complete, and up until the second （positive） pulse, the explosive-emission plasma expanded across the anode-cathode gap with a speed of 1.3±0.2 cm/μs. After the voltage polarity at the potential electrode was reversed （second pulse）, the plasma erosion in the anode-cathode gap （similar to the effect of a plasma opening switch） occurred. During the generation of an ion beam the size of the anode-cathode gap spacing was determined by the thickness of the plasma layer on the potential electrode and the layer thickness of the electrons drifting along the grounded electrode.

关键词： ion beams graphite cathodes plasma speed self-magnetic insulation

Optimized guided mode resonant structure as thermooptic sensor and liquid crystal tunable filter

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Chinese Optics Letters 2009年第8期7卷 667-670页

作者： i.Abdulhalim Department of Electrooptic Engineering Ben Gurion University of the Negev

Applicability of guided mode resonant structures to tunable optical filtering and sensing is demonstrated using nematic liquid crystals. As a sensor, a minimum refractive index detectivity of 10^-5 is demonstrated while as a tunable filter, tunability range of few tens of nanometers with 2-nm bandwidth is presented. The optimum design is achieved by maximizing the evanescent field region in the analyte which maximizes the overlap integral. The device can be operated in reflection or transmission modes at normal incidence. it can also be operated at a single wavelength by measuring the angular profile of the light beam.

关键词： mode Optimized guided mode resonant structure as thermooptic sensor and liquid crystal tunable filter

Transport Properties of the Universal Quantum Equation

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Chinese Physics Letters 2012年第3期29卷 21-24页

作者： A.i.Arbab Department of Physics Faculty of ScienceUniversity of KhartoumPO Box 321Khartoum 11115Sudan

The universal quantum equation(UQE)is found to describe the transport properties of the quantum *** equation describes a wave equation interacting with constant scalar and vector potentials propagating in spacetime.A new transformation that sends the Schr(o)dinger equation with a potential energy V=-1/2mc^(2)to Dirac's equation is *** Cattaneo telegraph equation as well as a one-dimensional UQE are compatible with our recently proposed generalized continuity ***,a new wave equation resulted from the invariance of the UQE under the post-Galilean transformations is *** equation is found to govern a Klein Gordon's particle interacting with a photon-like vector field(ether)whose magnitude is proportional to the particle's mass.

关键词： particles equation quantum

Test measurements for accuracy of absolute and relative GPS positioning

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中国有色金属学会会刊：英文版 2005年第S1期15卷 299-303页

作者： i. Havasi University of Miskolc Hungary

The paper, after the introduction, briefly outlines the principles of both absolute and relative GPS positioning. it deals with factors and error resources affecting the accuracy of these surveying procedures. it reviews the geodetic determination of a reference point and a base line used for the test measurements. The study describes the completed test measurements, and on the basis of results, it draws the conclusions for the accuracy of the investigated surveying methods. Finally, considering these accuracy measures, their possible application in mine surveying is also mentioned very shortly.

关键词： GPS surveying methods factors and errors test measurements accuracy

Comment on the paper “Hydromagnetic thin film flow of Casson fluid in non-Darcy porous medium with Joule dissipation and Navier's partial slip”

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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 1057-1058页

作者： i.POP Department of Mathematics Babes-Bolyai University

The present comment concerns some doubtful results included in the abovepaper.

关键词： local inertia parameter magnetic parameter Eckert number

Electro-tribological properties of diamond like carbon coatings

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Friction 2020年第2期8卷 451-461页

作者： iñigo BRACERAS iñigo iBÁNEZ Santiago DOMiNGUEZ-MEiSTER Xabier VELASCO Marta BRiZUELA iñaki GARMENDiA Tecnalia Research&innovation Mikeletegi Pasealekua 2Donostia-San Sebastian 20009Spain Mechanical Engineering Department University of the Basque Country UPV/EHUPlaza de Europa1Donostia-San Sebastian 20018Spain

Diamond like carbon(DLC)coatings typically present good self-lubricating tribological properties that could be of interest in sliding dielectric contacts in multiple electrical *** this work electro-tribological studies have been performed on several DLC coatings against aluminum in different humidity conditions,in which the coefficients of friction(CoFs)and electrical contact resistance(ECR)were continuously *** show that CoF and ECR data can be linked to the properties of the coatings(thickness,finishing,microstructure,residual stresses,and wettability)and the degradation modes of their tribological and electrical ***,electro-tribological data can provide valuable information about the performance of dielectric coatings,the reasons behind it,and assist in the development of the *** also shows potential for on-line monitoring of coated parts in operation.

关键词： DLC electro-tribology ECR-electrical contact resistance coefficient of friction