简介:Blanketsandotherin-vesselcomponentsareeasilydamagedowingtotheircircumstanceofhighradiationandhighheat.Toprotectthem,firstwalldesignshouldbeconsidered.Owingtoitshighheatremovalndself-refreshingcapability,liquidmetalfirstwallhasbeenseenasapotentialfirstwallforafusionreactorinthefuture.Blanketliquidcurtainisactuallyaspecialliquidmetalwalltoprotectblanket.
简介:Heattransferinthethrustchamberisofgreatimportanceinthedesignofliquidpropellantrocketengines.Regenerativecoolingisandadvancedmethodwhichcanensurenotonlytheproperrunningbutalsohigherperformanceofarocketengine.Thetheoreticalmodeliscomplicated,itrelatestofluidbynamics,heattransfer,combustion.etc…,Inthispaper,aregenerativecoolingmodelispresented.Effectssuchasradiation,heattransfertoenvironment,variablethermalpropertiesandcokingareincludedinthemodel.Thismodelcanbeappliedtoallkindsofliquidpropellantrocketenginesaswellassimilarconstructions.Themodularizedcomputercodeiscompletedinthework.
简介:Weproposeadepolarizerbasedontheprincipleofacollectionofhalf-waveplateswithrandomlydistributedopticaxes.Thedesignisdemonstratedbymeansofdynamicallyphotopatterningliquidcrystalintorandomlyalignedhomogeneousdomains.Wecharacterizetheliquidcrystaldepolarizerfor1550nmandC-band(1520–1610nm).Adegreeofpolarizationoflessthan5%isobtainedforanylinearlypolarizedlight.Thisstudyprovidesapracticalcandidateforhigh-performancedepolarizers.
简介:Thisworkpresentsanumericalsimulationoftheflowfieldinaliquidpropellantrocketenginechamberandexitnozzleusingtechniquestoallowtheresultstobetakenasstartingpointsfordesigningthosepropulsivesystems.ThiswasdoneusingaFiniteVolumemethodsimulatingthedifferentflowregineswhichusuallytakeplaceinthosesystems.Astheflowfieldhasregionsrangingfromthelowsubsonictothesupersonicregimes,thenumericalcodeused,initiallydevelopedforcompressibleflowsonly,wasmodifiedtoworkproficientlyinthewholevelocityrange.ItiswellknownthatcodeshavebeendevelopedinCFD,foreithercompressibleofincompressibleflows,thejointtreatmentofbothtogetherbeingcomplexeventoday,giventhesmallnumberofreferencesavailableinthisarea.Hereanexistingcodeforcompressibleflowwasusedandprimitivevariables,thepressure,theCartesiancomponentsofthevelocityandthetemperatureinsteadoftheconservedvariableswereintroducedintheEulerandNavier-Stokesequations.ThiswasdonetopermitthetreatmentatanyMachnumber.Unstructuredmesheswithadaptiverefinementswereemployedhere.Theconvectivetermsweretreatedwithupwindfirstandsecondordermethods.ThenumericalstabilitywaskeptwithartificialdissipationandinthespatialcoverageoneusedafivestageRunge-KuttaschemefortheFluidMechanicsandtheVODE(ValueofOrdinaryDifferentialEquations)schemealongwiththeChemkinIIinthechemicalreactingsolution.Duringthedevelopmentofthiscodesimulatingtheflowinarocketengine,comparisontestsweremadewithseveraldifferenttypesofinternalandexternalflows,atdifferentvelocities,seekingtoestablishtheconfidencelevelofthetechniquesbeingused.ThesecomparisonsweredonewithexistingtheoreticalresultsandwithothercodesalreadyvalidatedandwellacceptedbytheCFDcommunity.
简介:Thispaperreportsthedopingeffectofcholestericliquidcrystal3β-Hydroxy-5-cholestene3-oleateonpolymersolarcellscomposedofthepoly3-hexylthiopheneandthefullerenederivative.Withadopingratioof0.3wt%,thedeviceachievesanidealimprovementontheshuntresistorandthefillfactor.Comparedwiththereferencecell,thepowerconversionefficiencyofthedopedcellisimproved24%.Thephotoelectricmeasurementandtheactivelayercharacterizationindicatethattheself-assemblyliquidcrystalcanimprovethefilmcrystallizationandreducethemembranedefect.
简介:Inthelightofφ-mappingmethodandtopologicalcurrenttheory,theeffectofdisclinationlinesonthefreeenergydensityofnematicliquidcrystalsisstudied.ItispointedoutthatthetotalFrankfreeenergydensitycanbedividedintotwoparts.Oneisthedistortedenergydensityofdirectorfieldaroundthedisclinationlines.Theotheristhesaddle-splayenergydensity,whichisshowntobecentralizedatthedisclinationlinesandtobetopologicallyquantizedintheunitofkπ/2whentheJacobiandeterminantofthedirectorfielddoesnotvanishatthesingularitiesofthedirectorfield.ThetopologicalquantumnumbersaredeterminedbytheHopfindicesandBrouwerdegreesofthedirectorfieldatthedisclinationlines,i.e.,thedisclinationstrengthes.WhentheJacobiandeterminantvanishes,thegeneration,annihilation,intersection,splittingandmergingprocessesofthesaddle-splayenergydensityaredetailedintheneighborhoodsofthelimitpointsandbifurcationpoints,respectively.Itisshownthatthedisclinationlinewithhightopologicalquantumnumberisunstableandwillevolvetothelowtopologicalquantumnumberstatesthroughthesplittingprocess.
简介:Thefinalgoaloffusionenergyresearchistomakeiteconomicallycompetitiveandthecostofelectricity(COE)aslowasacceptablebytheenergymarket.Thereforethefusionplasmahastobeoperatingwithhighpowerdensityandtheplasmafacingcomponents(PFC),suchasfirstwallanddivertor,havetosustainhighsurfaceheatloadandbombardmentwithhighparticleflux.SuchrigorousenvironmentsconsequentiallyleadtoseveredamageanderosionofPFCmaterials.Asaresult,thelifetimeofPFCwouldbeshortened.
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简介:Wereportthemicrostructureevolutionofcopper(Cu)nm-sizedatomicislandsonsiliconeoilsurfacesintheambientatmosphere.Theoriginofthesenearlyfreesustainingatomicislandsisexplainedbyathree-stagegrowthmodel.Thefirststageisthenucleationandgrowthofatomicgranules.Subsequently,thecompactatomicislandsgrowbytheaggregationoftheatomicgranules.Finally,theyadheretoeachotherandformbranchedatomicislands.Duringthecharacteristicevolution,theatomicgranulesreconstructandtheaverageheightoftheatomicislandsincreasesfrom7.0±1.0nmto13.0±1.0nm.ThedetailedevolutionmechanismoftheCuatomicislandsispresented.
简介:Helixunwindinginferroelectricliquidcrystalsinducedbyanelectricfieldistheoreticallystudiedonthebasisofthecontinuumtheory.Byapplyingaweakelectricfieldtiltedtothesmecticlayers,thecontributionofthedielectricinteractionenergydensitytothetotalfreeenergydensityisincreased.Approximationmethodsareusedtocalculatethefreeenergyfordifferenttiltanglesbetweentheelectricfieldandthesmecticlayers.Theobtainedresultssuggestselectingtheoptimalnumberofpitchesinthefilmthatmatchestotheminimumofthefreeenergy.
简介:Aliquidmodifiedphotoniccrystalfiber(PCF)integratedwithanembeddeddirectionalcouplerandmulti-modeinterferometerisfabricatedbyinfiltratingthreeadjacentairholesoftheinnermostlayerwithstandard1.48refractiveindexliquids.Therefractiveindexofthefilledliquidishigherthanthatofbackgroundsilica,whichcannotonlysupportthetransmittingrodmodesbutalsothe'liquidmodifiedcore'modespropagatingbetweenthePCFcoreandtheliquidrods.Hence,thelightpropagatingintheliquidmodifiedcorecanbeefficientlycoupledintothesatellitewaveguidesunderthephase-matchingconditions,resultinginadramaticdecreaseoftheresonantwavelengthintensity.Furthermore,thereisamulti-modeinterferenceproducedbymodifiedcoremodesandrodmodes.Suchacompact(~0.91cm)deviceintegratedwithanembeddedcouplerandinterferometerisdemonstratedforhigh-sensitivitysimultaneoustemperature(~14.72nm∕℃)andstrain(~13.01pm∕με)measurement.
简介:Experimentalresultsarepresentedforsuperfluid(HeⅡ)flowthroughporousplugliquid-vaporphaseseparators.Testshavebeenperformedonsevenporousplugswithdifferentthicknessesordifferentpermeabilities.Thetemperaturewasmeasuredfrom1.5Kto1.9K.Twoflowregionswereobservedinsmallandlargepressureandtemperaturedifferencesregionsrespectively.Theexperimentaldataarecomparedwiththeoreticalpredictions.Theperformanceandapplicabilityofthebasictheoryarediscussed.Hysteresisoftheflowrateisalsoobservedanddiscussed.