简介:从Baiyangdian异构的田间试验收集的热流动数据用脚印方法被分析。高分辨率(25m)Landsat-5卫星成像被用来作为四种表面类型之一决定土地覆盖:农田,湖,沼泽地,或村庄。从在2005年9月的二个观察地点的数据被使用。一个地点(Wangjiazhai)被高度异构的表面在Baiyangdian的中央区域描绘:湖/沼泽地。另外的地点(Xiongxian)在有更多的一致表面盖子的土地上。一个改进Eulerian分析流动脚印模型被用来决定“在从包围混合表面类型的风景在每个地点定位的塔测量的热流动的来源区域”。在相对术语,结果证明沼泽地和湖区域通常在Wangjiazhai最作出贡献到观察的热流动,当农田在Xiongxian贡献了大多数时。给表面类型贡献的真实分布,计算被做从湖,沼泽地和农田获得热流动的大小到观察流动和每表面的分配贡献打到理智、潜伏的热流动的总数。结果平均显示出那从沼泽地和农田的可感热流动是可比较的在上日报周期,当从农田的潜伏的热流动在白天期间由大约3050Wm−2是有点更大的时。分别地,从在白天的湖来源的潜伏、理智的流动比从沼泽地和农田少些是大约50Wm−2和100Wm−2。结果被判定合理并且服务在异构的表面上为流动分配表明潜力。
简介:Inthisstudy,Nocolokeutecticflux,usedwidelyintheprocessofthebrazingofaluminumanditsalloy,waspreparedbythereactionbetweenAl(OH)3/KOHresolutionandHF.AseriesofKF-AlF3eutecticproductionsatvariousreactiontemperatureswereprepared.Themeltingpointsoftheproductsweremeasuredbydifferentialthermalanalysis(DTA),andthecompositeswerecharacterizedbyX-raydiffraction(XRD).TheresultssuggestthatthetemperaturecontrolisimportanttoproduceanidealfluxconsistingofK2AlF5,H2OandKAlF4,withalowmeltingpointof560℃,whichissuitableforthebrazingofaluminumanditsalloyasthealuminumfluxes.
简介:YAGlaserweldingwithsurfaceactivatingfluxhasbeeninvestigated,andtheinfluencingfactorsandmechanismarediscussed.TheresultsshowthatbothsurfaceactivatingfluxandsurfaceactiveelementShavefantasticeffectsontheYAGlaserweldshape,thatistoobviouslyincreasetheweldpenetrationandD/Wratioinvariousweldingconditions.Themechanismisthoughttobethechangeofweldpoolsurfacetensiontemperaturecoefficient,thus,thechangeoffluidflowpatterninweldpoolduetotheflux.
简介:Reviewsonthecunentstudiesontheseatoairfluxofdimethylsulfide(DMS)havebeenmadeathomeandabroad,pointingoutthatthefluxofDMSisinfluencedbymanyfactors.Thereisgreatdifferencebetweentheresultscomingfiomdifferentmodels.Besides,thispaperfocusesontheoxidationmechanismsofDMSbyOHandNO3radicalsafteritenterstheatmosphere,theoxidationproducts'contributiontoacidrainandfogandtherelationshipsamongtheDMS,CCNandclimatesystem.
简介:Ignitionmodelsoftestedmaterialhaveimportantsignificancetofireprevention.Inordertoknowheattransferofthermalthinmaterialinfiredisaster,startingfromthelawofconservationofenergy,simplifyingheatcapacityintoaconstantaccordingtoDulong-Petitlaw,andthreecalculationformulasofignitiontimeofthermalthinmaterialinaconstantheatfluxwererespectivelyobtainedundertheconditionsofignoringheatloss,linearprocessingheatlossandconsideringthermalradiation.Therelationbetweentheignitiontimeandthethermalcurrentintensitywasdiscussed.
简介:变丑参数(DP)它被定义为产品砍变丑和潮湿流动循环的拉长的变丑,被介绍。DP的趋势方程在压力坐标被导出。而且,DP被用来在Bilis的圆周诊断潮湿流动循环的变丑特性。分析证明在Bilis登陆了以前,DP介绍了八个反常区域,它或者散布了并且仔细环绕了低压的中心。这显示在Bilis的圆周的潮湿流动发行量逆时针方向旋转了并且拉长了纵并且纬度地使变形。在Bilis登陆了以后,DP逐渐地变弱,它水平分发的常规模式松开了。在台风登陆了以后,shear和包围Bilis的潮湿流动循环的拉长的变丑变弱。在Bilis的圆周的潮湿流动循环的变丑主要出现在中间降低的对流层。在垂直纬度的生气的节的shear和拉长的变丑之间的在那里存在的1/2阶段差别和水平飞机上的他们之间的/4阶段差别。作为打的Bilis和中国的进一步的移动内陆,DP的紧张,砍并且拉长变丑减少了,同时,他们的垂直、水平的结构变得不规则。为在Bilis的圆周的潮湿流动循环的变丑负责的主要动态因素是与DP的三维的移流交通联系的三个术语,之间的方形的差别砍并且拉长在Bilis前结合geopotential高度的Coriolis参数,和水平坡度的变丑登陆了。二个动态因素在Bilis以后在潮湿流动循环的变丑上联合影响了的最后登陆了。
简介:Inthisstudy,adoptinguniformdesignmethodestablishedamathematicalmodeltopreparemulti-elementactiveflux.GHA\69superalloyplateswereweldedbytheNd:YAGlaserequipmentwiththepreparedactiveflux.Theresultsshowallkindsoffluxesincreasethedepthtowidthratioandthemulti-componentsystemsaremoresignificant.Thelargestincrementofthewelddepthtowidthratiois159%,obtainedbyusingoftheFI2seriesflux.Itisprovedthatbyusingoftheactivefluxtoincreasethedepthtowidthratioofmicrolaserweldingisfeasible.
简介:Thepresentstudyinvestigatesthecharacteristicsofturbulenttransferandtheconditionsfordustemis-sionandtransportusingthedustconcentrationandmicrometeorologicaldataobtainedduringdusteventsoccurringinthespringof2004overtheHuushandakedesertarea.Theturbulentexchangecoefficientsandturbulentfluxesofmomentumandheatarecalculated.Therelationshipsbetweendustflux,frictionvelocity,andwindspeedarealsoexplored.Theresultsshowthatthermalturbulenceisdominantduringdaytimeofnon-dnstydays.Thedynamicturbulenceincreasesobviouslyandthesensibleheatfluxreducesbydifferentdegreesduringdustevents.Thereisanefficientdownwardtransferofmomentumbeforeduststormoccur-rence,andboththedynamicturbulenceandthethermalturbulenceareimportantinthesurfacelayer.Thedynamicturbulenceevenexceedsthethermalturbulenceduringseverednststormevents.Thevaluesofdustfluxvaryintherangeof-5-5,-30-30,and-200-300μgm~(-2)s~(-1)duringnon-dustydays,blowingdust,andduststormevents,respectively.Aslightupwardtransportofdustisobservedduringnon-dnstydays.Thedustfluxgraduallyvariesfrompositivetonegativeduringdnststormperiods,whichindicatesthetimeevolutionofdusteventsfromdustrisingtostablysuspendingandthendeposition.Thedustfluxisfoundtobeproportionaltou_*~3.Thethresholdvaluesofwindspeedandfrictionvelocityareabout6and0.4ms~(-1),respectively.
简介:Internalwavesplayacrucialroleinoceanmixing,anddensityperturbationandenergyfluxareessentialquantitiestoinvestigatethegenerationandpropagationofinternalwaves.Thispaperpresentsamethodologyforcalculatingdensityperturbationandenergyfluxofinternalwavesonlyusingavelocityfieldthatisbasedonlinearizedequationsforinternalwaves.ThemethodwastestedbynumericalsimulationsofinternalwavesgeneratedbytidalflowingoveraGaussiantopographyinastratifiedfluid.Thedensityperturbationsandenergyfluxesdeterminedusingourmethodthatonlyusedvelocitydataagreedwithdensityperturbationsandenergyfluxesdeterminedbytheequationofstatebasedontemperaturedata.Themeanrelativeerror(MRE)androotmeansquareerror(RMSE)betweenthetwomethodswerelowerthan5%and10%respectively.Inaddition,anexperimentwasperformedtoexamourmethodusingthevelocityfieldmeasuredbyParticleImageVelocimetry(PIV),andthesetupoftheexperimentisconsistentwiththenumericalmodel.TheresultsoftheexperimentscalculatedbythemethodsusingPIVdatawerealsogenerallyequaltothoseofthenumericalmodel.
简介:SincethedesignstudiesofsolidtritiumbreederblanketmodelshavebeenperformedbyJapanandEUC,andtheirTBMdesignoptionsforITERhavebeenproposed.InordertodesignourTBMblanketoptionswithChineseresearchbasesandexperiences,wechoseliquidlithiumorlithium-leadasthetritiumbreedingmaterialsforourTBMblanketoptions.Howeverthethicknessoffirstwallisusuallyonlyafewcentimeters,
简介:这份报纸涉及为在逆的某未知分布式的流动的数字重建的一个有限元素方法的估计加热的一个priori错误传导问题。更精确,一些未知分布式的Neumann数据将在外部可存取的边界上用Dirichlet测量数据在内部无法接近的边界上被恢复。在这个工作的主要贡献是建立分别地,一个priori错误在领域并且在可存取/无法接近的边界上以网孔尺寸估计的一些因为温度u和伴随在最低整齐假设下面说p。集中率的更低的界限取决于领域的几何学,这被揭示。这些估计自己具有巨大的兴趣并且铺的一个priori错误为证明集中是适应技术的分析的方法把反的热传导问题的班用于一个将军。数字实验被介绍验证我们的理论预言。[从作者抽象]
简介:Boilingheattransferprocessisanalyzedinamoderatenarrowspaceconsistedoftwohorizontalplates,Themaindifferencebetweenthisprocessandtheconventionalunconfinedpoolboilingistheliquidsupplymechanismwhichisabsolutelypreventedbythegrowthofcoalescencebubblealongwiththeheatedsurfaceinthenarrowspace.Asaresult,themacrolayerbecomesthinnerduetotheevaporationoftheindividualbubbleswithinthemacrolayerduringtheperiodofbubblecoalescence,withorwithoutdryoutthatdependsonboththegapsizeofnarrowspaceandthesizeofheatedsurface.Foraspecifiedsizeoftheheatedsurface,theinitialthicknessoftheliquidlayerhasacriticalvaluewhichapproachesaconstantwhilethespaceheightislargerthanacriticalvalue.Theindividualbubblebehaviorsandtheheattransfercanbeconsideredasthesameasthatintheunconfinedpoolboiling,ifthespacegapislarge,However,theindividualbubblesdonotgenerateinthelastperiodofthebubblecoalescenceandalowermaximumheatfluxwillberesultedifthespacegapisreduced.Insuchacase,themacrolayerisdryout.