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简介:Intheexistingelectricitymarket,thetraditionalpowersuppliersandrenewableenergygeneratorscoexistinthepowersupplyside.Inthepowersupplyside,renewableenergygeneratorsgeneratepowerbywindandothernaturalconditions,leadingrenewableenergyoutputacertainrandomness.However,thelowmarginalgeneratingcostandthereductionofcarbonemissions,andthusbringsacertainadvantageforrenewableenergycomparedtoalternativeenergy.Electricity,asaspecialcommodity,stableandadequatepowersupplyisanecessaryguaranteeforeconomicandsocialdevelopment.Powershortagesituationisnotallowedinthepowersystem,andtheextrapowerneedstobehandledforthepurposeofsafety.Inthispaper,thehybridpowergeneratedbyrenewableenergygeneratorsandtraditionalenergygeneratorsisusedaspowersupply,andthentheelectricitymarketsellshybridpowertoelectricityconsumers,thehybridpowersystemdeterminestheoptimaldaytimeprice,nighttimeprice,andtheoptimalinstalledcapacityoftherenewableenergysuppliers.Wefindthattheinstalledcapacityofrenewableenergyincreasesfirstandthendecreaseswiththeincreaseofthepricesensitivitycoefficientoftraditionalenergysupply.Electricitydemandisnegativelyrelatedtoelectricitypriceinthecurrentperiod,andispositivelyrelatedtopriceintheotherperiod.Theaveragepriceofdayandnightisonlyrelatedtothetotalpotentialdemandofdayandnightandthetotalgenerationprobabilityofrenewableenergy.Thepricedifferencebetweendaytimeandnighttimeispositivelyrelatedtopotentialelectricitydemand,andnegativelyrelatedtothesensitivitycoefficientofelectricityprice.
简介:Quantumdots(QDs)canachievehighquantumyieldsclosetounityinliquidsolutions,whereastheyexhibitadecreasedconversionefficiencyafterbeingintegratedintosolid-statepolymermatricesforlight-emittingdiode(LED)devices,whichiscalledthehostmatrixeffect.Inthisstudy,weproposeasolid–liquidhybrid-stateQD-LEDtosolvethisissue.Theethylene-terminatedpolydimethylsiloxane(ethylene-PDMS)isusedtoestablishasolid-statecross-linkednetwork,whereasthemethyl-terminatedPDMS(methyl-PDMS)isusedinitsliquidstate.Fromamacroscopiclevel,thecuredsolid–liquidhybrid-statePDMS(SLHP)compositesreachasolidstate,whichisstableandflexibleenoughtobeusedinLEDdevices.ComparedwithLEDsusingconventionalQD/solidPDMScompositesatequalcolorconversionefficiencyrangingfrom40%to60%,theluminousfluxofLEDswithQD/SLHPcompositesisincreasedby13.0%usinganoptimizedmethyl-PDMSconcentrationof85wt.%.Asaresult,highefficiencyQD-LEDsusingQDsastheonlycolorconvertorwithluminousefficacyof89.6lm/W(0.19A)wereachieved,whichshowaworkingstabilitycomparablewiththatusingconventionalsolid-statestructuresataharshcondition.Consequently,thenovelapproachshowsgreatpotentialforachievinghighefficiencyandhighstabilityQD-LEDs,whichisalsocompatiblewithcurrentstructuresusedinilluminationanddisplayapplications.
简介:UnderType-IIprogressivelyhybridcensoring,thispaperdiscussesstatisticalinferenceandoptimaldesignonstepstresspartiallyacceleratedlifetestforhybridsysteminpresenceofmaskeddata.ItisassumedthatthelifetimeofthecomponentinhybridsystemsfollowsindependentandidenticalmodifiedWeibulldistributions.Themaximumlikelihoodestimations(MLEs)oftheunknownparameters,accelerationfactorandreliabilityindexesarederivedbyusingtheNewton-Raphsonalgorithm.Theasymptoticvariance-covariancematrixandtheapproximateconfidenceintervalsareobtainedbasedonnormalapproximationtotheasymptoticdistributionofMLEsofmodelparameters.Moreover,twobootstrapconfidenceintervalsareconstructedbyusingtheparametricbootstrapmethod.TheoptimaltimeofchangingstresslevelsisdeterminedunderD-optimalityandA-optimalitycriteria.Finally,theMonteCarlosimulationstudyiscarriedouttoillustratetheproposedprocedures.
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