简介:1Collectionstartingwithtwopiecesofembroidery.In1977,Chinawasunderagrayskyeverywhere.Ontheair,therewerenomorethan3to4radiostaions,whichemittedrevolutionarynewsandsongseveryday.Inmychildhood,justokeanyothersofthattime,Iwasalwayswearingclothesofamonotonouscolor.Momtiedmyhairintotwoponytailswithtwobrightredbowknots,whichbecametheonlybridhtcolorthatcouldbeseenonme.
简介:Comparedwithtraditionalsynchronousgenerators,windturbinegeneratorsaredifferentinelectricitygenerationprinciples,controlmodesandintegrationtopologies,whichmakestheirfaultcharacteristicschangealot.This,consequently,bringschallengesregardingthebehaviorofprotectionsforwindfarmcollectorsystems.Inthispaper,basedonapracticalwindfarm,configurationandsettingofrelayprotectionsforsuchacollectorsystemisanalyzedanddeterminedsystematicallyinconsiderationoftheselectivityandsensitivityoftheprotections.Resultsshowthatmisoperationofovercurrentrelayandzerosequenceovercurrentrelayofthenon-faultcollectorlineoccurs,andbusdifferentialrelayofcollectorbuscannotremovethesingle-phase-to-groundfault.Inordertosolvetheproblems,anovelsubstation-areaprotectionforcollectorsystemisproposedanditsoperationmechanismisdiscussed.
简介:ApoolcooledexperimentalmagnetbasedonthecopperstabilizedNbTisuperconductingwirewasdesigned,fabricatedandtested,inordertoevaluatetheengineeringdesignofthedipolesuperconductingmagnetforthecollectorring(CR)ofthefacilityforantiprotonandionresearch(FAIR)project.Inthispaper,theexperimentalsetupincludingquenchprotectionsystemwaspresented.Performanceoftheliquidheliumpoolcooledtestwasintroduced.Alloftheresultsindicateboththeperformanceofconductorandtheexperimentalsuperconductingmagnetunderlowtemperatureisstable,whichsuggeststheengineeringdesignarefeasiblefortheformalmagnetinCRoftheFAIRproject.
简介:EveninmyveryearlydaysinTibetanBuddhistartcircles,artauctionsandevenacademiccircles,IhadnotonlyheardthenameYesibutIalsoreadhisillustratedbooksonTibetanBuddhistart,whichwerewelldesignedandrichlyillustrated.Ialsobelievedtheywerequitevaluable.Nonetheless,whenIencounteredhimataBeijingSeminaronTibetanStudies,Iwasshocked.Hewasabout30yearsoldandayoung,handsome,elegantlydressedgentleman.
简介:Theflotabilityandmechanismofthecompositetantalite-niobitemineralswhichhavedifferentcontentoftheTa,Nb.Fe,Mnwithstyrenephosphonicacid(SPA)ascollectorareinvestigatedanddiscussed.Someimportantflotationparametersarefoundasfollows:SPAisabettercollectorforflotatingniobite-tantalitemineralthanother,theoptimumpHvalueinpulpislessthan5,theflotabilityofthosemineralsvarieswiththedifferentcontentofmineralcomposition,theflotabitityofthemineralswithhigherNb2O5contentisbetterthanthatwithhigherTa205content.HereweemphasizethatinwiderangeofpHinsolu-tiontheFe,Mnonthemineralsurfacesarethemainactivespeciesforflotationoftheseminerals.Inadditiontothis,someofre-searchworkbyusingAugerelectronspectroscopy,infraredspectroscopyandultravioletspectroscopyfordeterminingthesurfaceconditions,pretreatedbyacidornot,hasbeendone.ThecharacteristicsofadsorptionofSPAonthemineralsurfacesareexam-inedanddiscussed.ItisindicatedthattheSPAinteractswithFe,Mnionsonmineralsurfacesbythechemicalbondforce.Butonthewholeouterlayerofcollector,whichisnon-uniformmultilayer,itmaybesaidthattheadsorptionofSPAonthemineralsur-faceisbothchemico-adsorptionandphysico-adsorption,butthechemico-adsorptionispredominant.
简介:Thispaperpresentstheheatingperformanceandenergydistributionofasystemwiththecombinationofground-sourceheatpumpandsolarcollectororasolar-assistedground-sourceheatpumpsystem(SAGSHPS)bycalculationandexperiment.Theresultsshowthattheaverageabsoluteerrorislessthan0.6℃andtherelativeerrorislessthan5%underthepulseloadwhentheanalyticalsolutiontothe2-DsolidcylindricalsourcemodelisusedfortheSAGSHPS.Thecoefficientofperformance(COP)oftheSAGSHPSis2.95-4.70.Theaveragefluidtemperatureintheboreholeheatexchangercanincreaseby3℃withtheassistanceofsolarcollector,whichwillimprovetheCOPoftheheatpumpbyapproximately10%fromtheexperimentaldata.Theenergycontributionstothetotalheatingloadofsoil,electricityandsolarare56.30%,36.87%and6.83%,respectively.
简介:Inordertoestimatethecut-sizeXcandthemechanicallybalancedparticlesintheaxialflowcyclonewiththeslit-separationmethod,thetangentialvelocitydistributionswerecalculatedbythefinitedifferencemethod.Incomparisonofthecalculatedresultsofthetotalcollectioneffciencywiththeexperimentalresults,thecalculatedresultsshowedalittlehigherthantheexperimentalresultsduetothere-entrainmentofthecollectedparticlesbyturbulence.Theeffectoftheslitforpromotingthecollectionefficiencywasnotrecognized.
简介:ThispaperreportstheuseofAufilmstoimprovetheperformanceofthestackedsolidoxidefuelcell(SOFC)basedonthecharacterizationoftheinterfaceandtheadhesionbetweentheelectrodesoftheSOFCsandtheAgpaste.Thespecimensweremanufacturedtoperformtheexperimentasfollows.ASiO2waferwitha300mmnotchwasattachedtotheelectrodesofaSOFCbyaAgpasteandAufilm,whichweredepositedontheelectrodesbysputteringfor1minor5mindepositiontimeandannealedat300Cfor1h.Thefour-pointbendingtestwasperformed,whichresultedintheformationofanextendedcrackatthetiponthewafernotch,andthecrackpropagationwasobservedusingastereomicroscopeequippedwithacharge-coupleddevice(CCD).Consequently,theinterfacialadhesionenergyandtheeffectoftheAufilmbetweentheeachelectrodeandtheAgpastecanbeevaluated.Onthecathode,theinterfacialadhesionenergywithoutAufilmwas2.59J/m2(uppervalue)andtheadhesionenergyincreasedto11.59J/m2(uppervalue)and15.89J/m2(lowervalue)withtheAufilm.Ontheanode,theinterfacialadhesionenergywithoutAufilmwas1.74J/m2(uppervalue),whichincreasedto11.07J/m2(uppervalue)and14.74J/m2(lowervalue)withtheAufilm.Inaddition,theinterfaceareaswereanalyzedbyscanningelectronmicroscopy(SEM)andenergydispersivespectroscopy(EDS)toestimatetheinterfacedelamination.
简介:Heattransferintheevacuatedcollectortubeisathree-dimensionallaminarnaturalconvectionproblemdrivenbybuoyancy.Becauseofitscomplexity,noeffectivetheoreticalmodelisavailabledespiteoflimitedexperimentalworkwhichisconfinedtooneaspect.Thepresentworkaimstodepicttheconvectiveheattransferinsideatwo-endedinclinedtubewithEast-Westsymmetricheatinputusingnumericalmethods,Basedonreasonableassumptions,governingequationsoftheinsidefluidareestablished.Thecorrespondingdiscretizatedequationsaresolvedbyemplogyingnumericalmetholds.Thecalculatedresultsaredisplayedforvelocityandtemperatureprofilesondifferentcross-sectionalplasnes.whichpresenttheflowpatterncharacterizedbyupflowanddownflowalongtheaxialdirectionandadherentflowalongtheperipheraldirection,andtheheattransferrpocessfromthewalltothecenter,Furthermore,thetransientNusseltnumberandaveragetemperaturelevelareshownanddiscussed.Finally,theparametriceffectsofthetuberadiusandtheheatinputontheflowandheattransferarealsogiven.