简介：Meso-scalestructuresexistingintheformofparticle-richclusters,streamersorstrandsincirculatingfluidizedbeds,andofascendingbubbleplumesanddescendingliquid-richvorticesinbubblecolumnsandslurry-bedreactors,ascommonlyobserved,haveplayedanimportantroleinthemacro-scalebehaviorofparticle-fluidsystems.Thesemeso-scalestructuresspanawiderangeoflengthandtimescales,andtheirorigin,evolutionandinfluencearestillfarfrombeingwellunderstood.Recentdecadeshavewitnessedtheemergenceofcomputersimulationofparticle-fluidsystemsbasedoncomputa-ionalfluiddynamic(CFD)models.However,strictlyspeakingthesemodelsarefarfrommatureandthecomplexnatureofparticle-fluidsystemsarisingfromthemeso-scalestructureshasbeenposinggreatchallengestoinvestigators.Thereasonmaybethatthecurrenttwo-fluidmodels(TFM)arederivedeitherfromcontinuummechanicsbyusingdifferentkindsofaveragingtechniquesfortheconservationequationsofsingle-phaseflow,orfromthekinetictheoryofgasesinwhichtheassumptionofmolecularchaosisemployed,therebylosingsightofthemeso-scaleheterogeneityatthescaleofcomputationalcellsandleadingtoinaccuratecalculationoftheinteractionforcebetweenparticlesandfluids.Forexample,theoveralldragforceforparticlesinacellisusuallycalculatedfromtheempiricalWen&Yu/Erguncorrelations,whichshouldbesuspectedsincethesecorrelationswereoriginallyderivedfromhomogeneoussystems.Schemestosolvethisproblemforgas-particlessystemsmaybeclassifiedintofourcategories.First,onecouldcapturethedetailedmeso-scalestructureinformationatthecellscalebyemployingtheso-calleddirectnumericalsimulation(DNS)(Hu,1996),thepseudo-particlemodeling(PPM)(Ge&Li,2003),ortheLattice-Boltzmannmethod(LBM)totracktheinterfacebetweengasandparticles.Second,refinementofthecomputationalmeshesmayreducetheheterogeneitytosomeextentandmaybe

简介：Theeffectsofdifferentconvectiveparameterization,explicitmoistureschemesandsurfaceheat-ingonthemeso-βscalestructureofasqualllinesystemareinvestigated,byusinganimprovedmesoscalemodel.Itisfoundthatthesuccessfulpredictionofmesoscaleconvectivesystemshingesup-onnotonlythesub-gridscaleconvection,butalsotheresolvablescalephasechangeprocessesandthediurnalvariationintheboundarylayer.ThesimultaneousoperationoftheFritsch-Chappellconvectiveschemewithparameterizedmoistdowndraftsandtheprognosticequationsforcloudwater(ice)andrainwater(snow)seemstobeessentialinsimulatingrealisticallyMCSsandreducingoreliminatingtheunrealisticdevelopmentoftheCISK-likeinstabilityassociatedwiththesqualllinesystem.

简介：Inthispaper,timeandspacedistributionregularityofmeso-scaleheavyrainsinfiveselectedtyphoonswhichlandedatFujianfrom1996to1998hasbeenanalyzed.Besides,withhourlydigitizedsatelliteinfraredimagery,thefeaturesofthemesoscalearerevealedforthegenesisandevolutionofmesoscaleconvectivesystemsintyphoons.Itindicatesthattheintensityofmesoscalestormsiscloselyconnectedwiththetemperatureandtheareaofthecoldestcloudcluster.Theheavyrainfallusuallyemergesontheeasternsideofthemesoscaleconvectivecloudclusters,wherethecloudmassisdevelopingandwithadensegradientandbigcurvatureofisolineofthecloudtoptemperature.

简介：在《英文角斗场》中,每篇文章都是精选自英美中小学生的读物和教材噢。想知道自己的英语水平有多高,就来试试吧。

简介：

简介：由灾害天气国家重点实验室数值预报研究部开发的区域中尺度数值预报系统（GRAPES_Meso）经过国家气象中心一年多的连续实时业务试验运行，达到了项目的指标要求，系统运行稳定，预报效果较现有的区域数值预报系统（HLAFS025）有明显改进。2006年7月，GRAPES_Meso通过了由中国气象局组织的业务运行专家评审。2006年7月26日，中国气象局正式批准GRAPES_Meso投入业务运行，同时停止运行HLAFS025业务系统，

简介：Longtermmorphologicalsimulationsusingcompletecoupledmodelsleadtoverytimeconsumingcomputations.Latteux(1995)presentedmodellingtechniquesdevelopedfortidalcurrentsituationsinordertoreducethecomputationaleffort.Inthispapertheapplicabilityofsuchmethodstosmallscaleproblemsisinvestigated.Itispointedoutthatthesemethodscanbetransferredtosmallscaleproblemsusingtheperiodicityofthevortexsheddingprocess.

简介：

简介：Frommethylpyropheophorbide-a(MPPa,1),thevinylgroupofmethylpyropheophorbide-awasconvertedintoalkylcarbonylgroupbyGrignardreactionandoxidizationtogivechlorins2,3and5.TheVilsmeierreactionofnickel3-substituent-3-devinylpyropheophorbide-a(6),whichwaspreparedbythemetallationwithnickelacetate,with3-dimethylamino-acrolein/phosphorylchloride(3-DMA/POCl3)wascarriedouttogiveδ-meso-formylvinylpyropheophorbide-a(7)ingoodyield.Thebenzoisobacterichlorin(8)wasobtainedbythetreatmentof7bwithconcentratedsulfuricacid.

简介：

简介：ＣｈｉｎｅｓｅＧｙｍｎａｓｔｓＳｃａｌｅＮｅｗＨｅｉｇｈｔｓＤｅｌｉｇｅｎｃｅｈａｓｉｔｓｒｅｗａｒｄｓ，ｔｈｅＣｈｉｎｅｓｅｔｅａｍｄｉｓｃｏｖｅｒｓ．ＴＨＥＣＨＥＮＥＳＥＮａｔｉｏｎａｌＧｙｍｎａｓｔｉｃｓＴｅａｍｈａｄｉｔｓｂｅｓｔｐｅｒｆｏｒ...

简介：合金(SMA)电线增强了的形状存储器的机械行为疼痛有损坏的结构通过变化原则被分析，为中央排水量域的为结构的一个管理方程被导出的、数学表达式，有损坏的典型元素的压力紧张地被介绍，并且为在SMA电线和矩阵之间的接口失败的一个失败标准在死了负担的二种使活动和温度下面被建立，在温度在有效免费恢复被包括的地方，拉紧。另外，在象接口性质那样的失败标准有一些另外的创作因素，SMA的动态性质，起始的debonding长度L-l等等。结果是重要的理解自我改编的控制和SMA电线的失败机制增强了的结构的力量有损坏的聪明的结构。

简介：Acombinedmethodofdensityfunctionaltheory(DFT)andstatisticsintegralequation(SIE)forthedeterminationoftheporesizedistribution(PSD)isdevelopedbasedontheexperimentaladsorptiondataofnitrogenonactivatedmesocarbonmicrobead(AMCMB)at77K.TheporesofAMCMBaredescribedasslit-shapedwithPSD.BasedonthePSD,methaneadsorptionandphasebehaviorarestudiedbytheDFTmethod.BothnitrogenandmethanemoleculesaremodeledasLennard-Jonessphericalmolecules,andthewell-knownSteele's10-4-3potentialisusedtorepresenttheinteractionbetweenthefluidmoleculeandthesolidwall.InordertotestthecombinedmethodandthePSDmodel,theIntelligentGravimetricAnalyzer(IGA-003)wasusedtomeasuretheadsorptionofmethaneontheAMCMB.TheDFTresultsareingoodagreementwiththeexperimentaldata.Basedonthesefacts,wepredicttheadsorptionamountofmethane,whichcanreach32.3ωat299Kand4MPa.TheresultsindicatethattheAMCMBsareagoodcandidateforadsorptivestorageofmethaneandnaturalgas.Inaddition,thecapillarycondensationandhysteresisphenomenonofmethanearealsoobservedat74.05K.

简介：IntroductionThesynthesesandcharacterizationofporphyrinsandmetalloporphyrinshavebeenstudiedextensively[1].Hemoglobin,myoglobinorcytochromeP450,hasbeenappliedasamodelcompound[2].WongC.P.etal.[3]synthesizedthefirstlanthanideporphyrin,acetylacetonatetetraphenylporphyrineuropium,in1974.

简介：ProblemsofChinaBuilding&SanitaryCeramicsindustrialclusters，Currentstatusanddevelopmentofbuildingceramicsindustryathomeandabroad，TheformationanddevelopmentofJiajiang'sbuildingceramicsindustrialclusters，Resourceismomentumforindustrialclusters'development

简介：Describedisanewtechniqueofdecade-scaleclimaticforecasting,presentedbyacombinationofwaveletanalysisandstochasticdynamics.ThetechniqueisalsoappliedtodiagnosingandforecastingthedurationtimeofdryandwetclimatesinthedecadalhierarchyofdifferentareasinChina.Resultsshowthatinthedecadalhierarchy,thenorth,southwest,andsoutheastofChinaareareaswherevariouskindsoffrequentclimatedisastersappear;droughtseasilyoccurinthenorthandnorthwest,whilefloodsoftenoccurinSouthChina.Becausethismodelingtechniqueisbasedontimeseriesdata,itcanalsobeappliedinthemodelingandforecastingofsuchtimeseriesashydrology,earthquakesandecology.

简介：A5－yearexperimentonwaterbalancehasbeenconductedinaflatrainfedwheatfieldwithanareaof66×100m^2inFengqiu,HenanProvinceinChina.Basedontheanalysisofsemi-variancefunctionsconductedwithsoilmoisturesamplestakenfrom77nodesofa10×10m^2grid,thesoilmoisturedistributioninthefieldwasstructuralwithatemporalstability.Accordingtotheautocorrelationrangeofthesemi-variancefunction,6siteswereselectedforthedeterminationofsoilwaterconditions.Thecharacteristicofprobabilitydensityfunctionofthedifferencesofwaterstorageintwosetsofmeasurementsshowedthatthedistributionofthesevariablesinthefieldwasanormalone.Theerrorintheestimationoftheaverageof5randomsampleswas14%(α=0.10),andtheerrorsofwaterconsumptionbywheatduringtheexperimentswereestimatedtobe6-13%.Simetheexperimentalfieldwaslargeenoughtoavoidanyedgeeffect,theresultsobtainedshouldtallywiththeactualsituation.Yetthesoilsystemwasheterogeneous,sowemustfollowtheprinciplesofstatisticsandgeostatisticswhendescribingthesystem'sstatuswiththeaverageofthesamples.

简介：Aclassoflarge-sealesystems,wheretheoverallobjectivefunctionisanonlinearfunctionofperformanceindexofeachsubsystem,isinvestigatedinthispaper.Thistypeoflarge-scalecontrolproblemisnon-separableinthesenseofconventionalhierarchicalcontrol.Hierarchicalcontrolisextendedinthepapertolarge-scalenon-separablecontrolproblems,wheremultiobjectiveoptimizationisusedasseparationstrategy.Thelarge-scalenon-separablecontrolproblemisembedded,under;ertainconditions,intoafamilyoftheweightedLagrangianformulation.TheweightedLagrangianformulationisseparablewithrespecttosubsystemsandcanbeeffectivelysolvedusingtheinteractionbalanceapproachatthetwolowerlevelsintheproposedthree-levelsolutionstructure.Atthethirdlevel,theweightingvectorfortheweightedLagrangianformulationisadjustediterativelytosearchtheoptimalweightingvectorwithwhichtheoptimaloftheoriginallarge-scalenon-separablecontrolproblemisobtained.Theoreticalbaseofthealgorithmisestablished.Simulationshowsthatthealgorithmiseffective.

简介：TheconstructionoftheGeologicTimeScale(GTS)isatitanicscientificchallengethathasbeenunderwayfortwocenturiesandwillrequiremuchdedicatedeffortinthefuture.ItalypreservesaparamountstratigraphicrecordofMesozoicandCenozoicmarinesedimentsthathavebeensignificantinthedevelopmentofthemodernGTS.TheItalianstratigraphicrecordhasbeenhistori-callyimportantinintroducinganddefiningthestandardChronostratigraphicUnits(CUs)oftheNeogeneandQuaternary.PelagicsuccessionsfromNorthernApen-ninesandSouthernAlpshavebeenusedintheseventiesforintegratingthelateCretaceous-PaleogeneGeomag-neticPolarityTimeScale(GPTS)withplanktonicmicrofossilbiostratieraohvandstandardCUs.Thiswasamajorcontributiontotheconstructionofanewgener-ationofGTSbasedonintegratedmagnetobiochronol-ogy.ThemiddleMiocenetoearlyPleistocenemarinerecordfromSicilyandsouthernItalyhasbeenfunda-mentalforestablishingtherecentlydevelopedAstro-nomicalTimeScale(ATS).Inprospect,therearemanypotentialsstilltobeexploitedintheItalianmarinestratigraphicrecordforimplementingtheGTSbydefin-ingGSSPsofvariousCUs,improvingmagneto-biochronologyandextendingdownwardstheATS.

简介：