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简介：Thereciprocitymeasurementtheoryinanomalousreverberantsoundfieldswasinvestigated.AnimprovedmethodWasproposedduetotheinterrelatederrors.ThesourcevolumevelocityWascorrectedbyspatialaverageofmeasurementresultsandevaluationofthereverberantsoundfieldinfluenceonacousticenergydensity.Theresultwasvalidatedinunderwaterexperiment,correctedreciprocitymeasurementresultswerealmostthesameasdirectmeasurementresults.Itindicatesthatreverberantsoundfielddoesnotaffectthevaliditvoftheprinciple,butinfluencestheobtainmentofsourcevolumevelocity,theninfluencesthemeasurementoftransferfunctionswiththeprinciple.Theproposedmethodissimpleandeffectiveinanomalousreverberantsoundfields.Thestudymavbevaluablefortheapplicationswhicharebasedontheprinciple.

简介：Duetotheexistenceofspatialwalk-offand/orgroup-velocitymismatcheffects,pump-to-signalphasetransferbecomesinevitableduringparametricamplification.Weexperimentallydemonstratethatinhybridseededopticalparametricamplifiers(OPAs)thatincludetwoOPAstagesseededbythesignalandidlerwaves,respectively,thephaseoftheoutputsignalcanberestoredtoitsinitialvalue,althoughtherearespatialandtemporalphasefluctuationsonthepumpsource.Thismethodsignificantlyrelaxestherequirementforhighpumpbeamquality,whichisalwaysverystringentinparametricamplificationsystems.Withtheintroductionofthisschemeintobirefringentphase-matchingOPAsorchirped-pulseOPAs,itshouldbepromisingtoachieveintensefemtosecondlaserpulsesthatareclosetothediffractionlimitinspaceandultra-highcontrastintime,simultaneously.

简介：Anexperimentalstudyofheattransfercharacteristicsinsuperheatedsteamcooledrectangularchannelswithparallelribswasconducted.Thedistributionoftheheattransfercoefficientontherib-roughedchannelwasmeasuredbyIRcamera.Theblockageratio(e/Dh)ofthetestedchannelis0.078andtheaspectratio(W/H)isfixedat3.0.Influencesoftheribpitch-to-heightratio(P/e)andtheribangleonheattransferforsteamcoolingwereinvestigated.Inthispaper,theReynoldsnumber(Re)forsteamrangesfrom3070to14800,theribpitch-to-heightratioswere8,10and12,andribangleswere90°,75°,60°,and45°.Basedonresultsabove,wehaveconcludedthat:Incaseofchannelswith90°tranverseribs,forlargerribpitchmodels(theribpitch-to-heightratio=10and12),areaswithlowheattransfercoefficientinfrontofribislargeranditsminimumislower,whilethepositionoftheregionwithhighheattransfercoefficientnearlyremainsthesame,butitsmaximunofheattransfercoefficientbecomeshigher.Incaseofchannelswithinclinedribs,heattransfercoefficientsonthesurfacedecreasealongthedirectionofeachribandshowanapparentnonuniformity,consequentlytheregionswithlowNusseltnumbervaluescloselyfollowingeachribexpandalongtheaforementioneddirectionandthatofrelativehighNusseltnumbervaluesvaryinversely.Forasquarechannelwith90°ribsatRe=14800,widerspacingribconfigurations(theribpitch-to-heightratio=10and12)giveanarea-averagedheattransferontherib-roughenedsurfaceabout8.4%and11.4%morethanP/e=8model,respectively;forinclinedparallelribswithdifferentribanglesatRe=14800,thearea-averagedheattransfercoefficientsof75°,60°and45°ribbedsurfacesincreaseby20.1%,42.0%and44.4%incomparisonwith90°ribanglemodel.45°anglerib-roughenedchannelleadstoamaximalaugmentationofthearea-averagedheattransfercoefficientinallresearchobjectsinthispaper.

简介：同时的免费传送对流在上面并且在一个一致地激烈的水平盘子下面广泛地被调查了在等温的表面的情况中，并且一致地激烈的表面，但是总是作为液体(Pr=0.7)假定仅仅空气。不过，有工作，处理其结果证明Pr上的Nu依赖不能被一条幂定律简单地与Gr那的一样的代表表示的水平盘子。在等温的水平长带的情况中学习Prandtl数字影响因此被认为有用。，结果为长带的更低的表面显示出那在Gr的Nu依赖能被一条幂定律与代表结束表示到Gr那，为代表是的上面的表面聪明地不同。与调查状况有关的相关方程被建议。

简介：微尺寸的试管热exchanger(MTHE)被制作，并且它在转移和压力掉的发情的表演试验性地被学习。MTHE试管的方面上的单相的强迫的传送对流热转移关联被建议并且与在雷纳兹数字的以前的试验性的数据相比变化5001800。在计算Nusselt数字的关联的平均偏差是大约6.59%。在热入口区域的入口效果被讨论。在雷纳兹数字的一样的范围，压力落下和磨擦系数被发现比常规关联预言的那些更加高。磨擦因素和雷纳兹数字的产品也高是一个常数，而是大部分比常规。

简介：Topreparemanganese-containingspinelsulfurtransferagentwithacidpeptization,ultrasonicwaveisusedforthefirsttimetomodifythestructureofsulfurtransferagentinthiswork.Minifixedbedreactorwasusedtoinvestigatetheeffectofultrasonicpower,timeandtemperatureonthestructureandoxidationadsorptionperformanceofsulfurtransferagentandtheadsorptionkineticsandmechanismofSO2wereanalyzed.SEM,TEM,XRDandN2adsorption-desorptiontechniqueswereemployedtocharacterizeandanalysethefunctionofsulfurtransferagent.Theresultsindicatedthatmanganese-containingspinelisakindofpromisingsulfurtransferagentandexhibitshighersulfurcapacityanddesulfurizationdegreeundertheselectedconditionsoftheultrasonicwavepowerof60%,andwiththetreatmentperiodfor3hatatemperatureof60°C.

简介：Themainpurposeofthisstudyistosurveynumericallycomparisonoftwophaseandsinglephaseofheattransferandflowfieldofcopper-waternanofluidinawavychannel.Thecomputationalfluiddynamics(CFD)predictionisusedforheattransferandflowpredictionofthesinglephaseandthreedifferenttwo-phasemodels(mixture,volumeoffluid(VOF),andEulerian).Theheattransfercoefficient,temperature,andvelocitydistributionsareinvestigated.Theresultsshowthatthedifferencesbetweenthetemperaturefieldinthesinglephaseandtwo-phasemodelsaregreaterthanthoseinthehydrodynamicfield.Also,itisfoundthattheheattransfercoefficientpredictedbythesinglephasemodelisenhancedbyincreasingthevolumefractionofnanoparticlesforallReynoldsnumbers;whileforthetwo-phasemodels,whentheReynoldsnumberislow,increasingthevolumefractionofnanoparticleswillenhancetheheattransfercoefficientinthefrontandthemiddleofthewavychannel,butgraduallydecreasealongthewavychannel.

简介：这份现在的报纸处理对线性轴、扭力的颤动的数学描述。正常、正切的压力张肌部件在推进器和中间的柄由轴扭力的变丑和颤动生产了，在导致推进器的静电干扰的影响下面，可变水动力学刺激也被学习。与微分方程答案的经常的系数有关的转移矩阵方法被使用。当邻近的柄片断有一样的材料性质和直径时，作为与转移的一个著名方法相比，矩阵与州的向量联系了的后者的优点是减少乘的矩阵的数字的可能性。结果证明没有弄弯的风险并且证实轴线的强度取决于是应力张肌的最重要的部件的静态的正切的压力的价值。

简介：Thenaturalconvectionheattransferofa60%sucrosesolutioninaverticalconverging-divergingtube(CD)withregularly-spacedtwistedtapes(RSTT)hasbeeninvestigatednumericallyandexperimentally.TheeffectsofwalltemperatureandnumberofRSTTontheNusseltnumberwerestudiedindetail.Thedistributionsofvelocityandtemperatureinthe60%sucrosesolutionwerestudiedandthesimulatedresultsofCDwithRSTTwerecomparedwiththoseofthesmoothtube.TheinfluenceofRayleighnumberandRSTTontheNusseltnumberwasconductedexperimentally.TheresultsindicatethattheNusseltnumberofthe60%sucrosesolutionobviouslyincreasedwiththenumberofRSTTbutincreasedinconspicuouslywith2andmoretwistedtapes.Thesimulationshowsthatthedistanceforachievinganoptimalheattransferperformanceis46timesthediameterofthetube.Themechanismofthenaturalconvectionheattransferenhancementofthe60%sucrosesolutioninrelationshipwiththeCDandtheRSTTwasanalyzed,andthechangeofaveragetangentialvelocitywiththeaxialdistancewaspresentedtodemonstratethattheenhancementofheattransferwasrealizedmainlybecauseoftheincreaseintangentialvelocity.

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简介：Enhanced2.7μmemissionisobtainedinEr3+/Tm3+andEr3+/Ho3+codopedZBYAglasses.Absorptionandemissionspectraaretestedtocharacterizethe2.7μmemissionpropertiesofEr3+/Tm3+andEr3+/Ho3+dopedZBYAglassesandareasonableenergytransfermechanismof2.7μmemissionbetweenEr3+andTm3+Ho3+)ionisproposed.CodopingofTm3+orHo3+significantlyreducesthelifetimeoftheEr3+:4I13/2levelduetotheenergytransferofEr3+:4I13/2→Tm3+:3F4orEr3+:4I13/2→Ho3+:5I7.Thus,the2.7μmemissionisstrengthenedandthe1.5μmemissionisdecreasedaccordinglyespeciallyintheEr3+/Tm3+sample.TheupconversioneffectsbetweentheEr3+/Tm3+andEr3+/Ho3+dopedZBYAglassesaredifferentattributetothedifferentenergytransferefficiencies.Bothofthetwocodopedsamplespossessnearlyequallargeemissioncrosssection(16.6×10-21cm-2)around2.7μm.TheresultsindicatethatthisEr3+/Tm3+orEr3+/Ho3+dopedZBYAglasshaspotentialapplicationsin2.7μmlaser.