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简介：Cerenkovwakeamplificationcanbeusedasanacceleratingscheme,inwhichatriggerbunchofelectronspropagatinginsideacylindricalwaveguidefilledwithanactivemediumgeneratesaninitialwakefield.Duetothemultiplereflectionsinsidethewaveguide,thewakemaybeamplifiedsignificantlymorestronglythanwhenpropagatinginaboundlessmedium.Sufficientlyfarawayfromthetriggerbunchthewake,whichtravelswiththesamephasevelocityasthebunch,reachessaturationanditcanaccelerateasecondbunchofelectronstrailingbehind.ForaCO2gasmixtureournumericalandanalyticalcalculationsindicatethatashortsaturationlengthandahighgradientcanbeachievedwithalargewaveguideradiusfilledwithahighdensityofexcitedatomsandatriggerbunchthattravelsatavelocityslightlyabovetheCerenkovvelocity.Toobtainastablelevelofsaturatedwakethatwillbesuitableforparticleacceleration,itiscrucialtosatisfythesingle-moderesonancecondition,whichrequireshighaccuracyinthewaveguideradiusandtheratiobetweentheelectronphasevelocityandtheCerenkovvelocity.Forsingle-modepropagationourmodelindicatesthatitisfeasibletoobtaingradientsashighasGVm-1inawaveguidelengthofcm.

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简介：沿着在中等温度的以铜锌金焊接下面的典型的铝合金的深度方向的表面氧化物电影的进化借助于X光检查光电子光谱学(XPS)被调查。为有在2.0wt%下面的Mg内容的合金，是否在冷滚动状况下面或在中等温度的以铜锌金焊接期间处理，表面上的Mg元素的丰富没被检测，氧化物电影是纯Al2O3。然而，氧化物电影在中等温度的以铜锌金焊接的过程期间显然成长了，并且厚度是大约80nm。为有在2.0wt%上面的Mg内容的合金，在冷滚动状况下面，原来的表面氧化物电影是纯Al2O3。然而，Mg元素显著地在中等温度的以铜锌金焊接期间在最外面的表面上被充实过程，和与MgAl2O4的小数量混合的基于MgO的氧化物电影与大约130nm的厚度被形成。Mn和Si的alloying元素没既不在冷滚动状况下面也不在以铜锌金焊接的mediumtemperature期间在表面上被充实为所有选择的铝合金的过程，和表面氧化物电影几乎类似于纯铝的，它是全部Al2O3。

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简介：Extractionofthein-mediumpropertiesofstrangeparticlesfromheavy-ioncollisionsisverycomplicated,sincehenucleardensityvariesintheevolutionofnucleus-nucleuscollisions.Toavoidtheuncertaintiesofthebaryonensitiesduringthestageofstrangeparticleproduction,onecaninvestigateproton-nucleuscollisionswheretheucleardensityisdefinitearoundthesaturationdensity.DynamicsofstrangeparticlesproducedintheprotoninduceduclearthereactionsnearthethresholdenergieshasbeeninvestigatedwithintheLanzhouquantumoleculardynamics(LQMD)transportmodel.Thein-mediummodificationsonparticleproductionindensenuclearmatterareconsideredthroughthecorrectionstotheelementarycrosssectionsviatheeffectivemassandhemean-fieldpotentials[1].

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简介：Thispaperstudiesthethermal-diffusionanddiffusionthermo-effectsinthehydro-magneticunsteadyflowbyamixedconvectionboundarylayerpastanimpermeableverticalstretchingsheetinaporousmediuminthepresenceofchemicalreaction.Thevelocityofthestretchingsurface,thesurfacetemperature,andtheconcentrationareassumedtovarylinearlywiththedistancealongthesurface.Thegoverningpartialdifferentialequationsaretransformedintoself-similarunsteadyequationsusingsimilaritytransformationsandsolvednumericallybytheRunge-Kuttafourthorderschemeinassociationwiththeshootingmethodforthewholetransientdomainfromtheinitialstatetothefinalsteadystateflow.Numericalresultsforthevelocity,thetemperature,theconcentration,theskinfriction,andtheNusseltandSherwoodnumbersareshowngraphicallyforvariousflowparameters.Theresultsrevealthatthereisasmoothtransitionofflowfromunsteadystatetothefinalsteadystate.Aspecialcaseofourresultsisingoodagreementwithanearlierpublishedwork.

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