简介:研究每个忙期中第一个顾客被拒绝服务的M/M/1排队模型的主算子在左半复平面中的特征值,证明对一切θ∈(0,1),(2√λμ-λ—μ)θ是该主算子的几何重数为1的特征值.
简介:ByapplyinghigherpowersoftheBogoliubovtransformationoperatorb^t=u^*a+μ^*a^ttothetwo-photoncoherentstates(orminimumuncertaintysqueezedstates)weconstructanewtypeofquantumstatewhichwecallthegeneralizedexcitedtwo-photoncoherentstates.Analyticexpressionsforthequantumstatisticalpropertiesarederived,andthroughnumericalcomputationthephasespacequasi-probabilitydistributionsarefound.Thesestatescanexhibithighlynonclassicalbehaviourdependingonthedegreeofexcitationmandotherparameters.ForparticularvaluesoftwoparametersAandp,thesegeneralizedstatesreducetootherclassesofcoherentstatesformerlyreported.Ourtheorythuspresentsamuchbroaderapproachtothesetypesofquantumstates.
简介:Recently,theL-modetoH-mode(L-H)transitionintokamakplasmaconfinementwasfoundtoberelatedtothepresenceofthepoloidalflowshearneartheplasmaedge.Animportantmechanismistheionorbitlosscausedbyinteractionwiththelimiter.AcomplementaryexplanationisthegenerationofpoloidalflowsbyplasmafluctuationsviatheReynoldsstressandthepoloidalspin-upofplasmasfrompoloidalasymmetryofparticleandmomentumsources.
简介:Inordertodeepentheunderstandingoftherelationshipbetweenfundamentalproperties(including:microstructureandcomposition)andphotocatalyticperformance,fourbismuthatecompounds,including:LiBiO3,NaBiO3,KBiO3,andAgBiO3,areregardedasresearchexamplesinthepresentwork,becausetheyhaveparticularcrystalstructuresandsimilarcompositions.Usingdensityfunctionaltheorycalculations,theirstructural,electronic,andopticalpropertiesareinvestigatedandcomparedsystematically.Firstofall,thecalculatedresultsofcrystalstructuresandopticalpropertiesareinagreementwithavailablepublishedexperimentaldata.Basedonthecalculatedresults,itisfoundthatthetunneledorlayeredmicro-structuralpropertiesleadtothestrongerinteractionbetweenbismuthandoxygen,andtheweakerinteractionbetweenalkaline-earthmetaland[BiO6]octahedron,resultinginthefeatureofmulti-bandgapsinthecasesofLiBiO3,NaBiO3,andKBiO3.ThisconclusionissupportedbythecaseofAgBiO3,inwhichthefeatureofmulti-bandgapsdisappears,duetothestrongerinteractionbetweenthenoblemetaland[BiO6]octahedron.Thesepropertieshavesignificantadvantagesinthephotocatalyticperformance:absorbinglowenergyphotons,rapidlytransferringenergycarriers.Furthermore,thefeaturesofelectronicstructuresofbismuthatecompoundsarewellreflectedbytheabsorptionspectra,whichcouldbeconfirmedbyexperimentalmeasurementsinpractice.Combinedwiththecalculatedresults,itcouldbeconsideredthatthecrystalstructuresandcompositionsofthephotocatalystdeterminetheelectronicstructuresandopticalproperties,andsubsequentlydeterminethecorrespondingphotocatalyticperformance.Thus,anovelBi-basedphotocatalystdrivenbyvisible-lightcouldbedesignedbyutilizingspecificcompositionstoformfavorableelectronicstructuresorspecificmicro-structurestoformabeneficialchannelforenergycarriers.
简介:ForthelowerboundaboutthedeterminantofHadamardproductofAandB,whereAisan×nrealpositivedefinitematrixandBisan×nM-matrix,JianzhouLiu[SLAMJ.MatrixAnal.Appl.,18(2)(1997):305-311]obtainedtheestimatedinequalityasfollowsdet(AoB)≥a11b11nⅡk=2(bkkdetAk/detAk-1+detBk/detBk-1(k-1Ei=1aikaki/aii))=Ln(A,B),whereAkiskthordersequentialprincipalsub-matrixofA.WeestablishanimprovedlowerboundoftheformYn(A,B)=a11baanⅡk=2(bkkdetAk/detAk-1+akkdetBk/detBk-1-detAdetBk/detak-1detBk-1)≥Ln(A,B).Formoreweakerandpracticallowerbound,Liugiventhatdet(AoB)≥(nⅡi=1bii)detA+(nⅡi=1aii)detB(nⅡk=2k-1Ei=1aikaki/aiiakk)=(L)n(A,B).WefurtherimproveitasYn(A,B)=(nⅡi=1bii)detA+(nⅡi=1aii)detB-(detA)(detB)+max1≤k≤nwn(A,B,k)≥(nⅡi=1bii)detA+(nⅡi=1aii)detB-(detA)(detB)≥(L)n(A,B).
简介:Wereportatype-ⅡGaSb-basedinterbandcascadelaseroperatingacontinuouswaveatroomtemperature.Thecascaderegionofinterbandcascadelaserwasdesignedusingthe‘W’configurationoftheactivequantumwellsandthe‘CarrierRebalancing’methodintheelectroninjector.Thedeviceswereprocessedintonarrowridgesandmountedepitaxialsidedownonacopperheatsink.The25-μm-wide,3-mm-longridgewithoutcoatedfacetsgenerated41.4mWofcontinuouswaveoutputpoweratT=15℃.Andalowthresholdcurrentdensityof267A/cm~2isachieved.TheemissionwavelengthoftheICLis3452.3nmat0.5A.
简介:WedemonstrateamonolithicsinglefrequencyTm-dopedfiberamplifierwithoutputpowerof51.5W.Asinglefrequencyfiberlaserat1.97μmisamplifiedbyacascadedmasteroscillatorpoweramplifier(MOPA)systemwithall-fiberconfiguration.Theoptical-to-opticalconversionefficiencyofthemainfiberamplifieris45%.Noamplifiedspontaneousemission(ASE)orstimulatedBrillouinscattering(SBS)effectisobservedinthefiberamplifier.Theoutputpowercouldbefurtherscaledbylaunchingmorepumppower.
简介:Thispaperprovesthattheoptimalquadratureformulasoftype(r1,…rn)forWm1isunique,andtheextremalfunctionischaracterizedbyitsoscillatoryproperty.Ontheotherhand,thefundamentaltheoremofalgebraforperiodicmonosplineswithoddmultiplicitiesissolvcd
简介:FifteennewabsorptionlinesareobservedwhenstudyingCO2absorptionspectroscopybywavelengthmodulation(WM)techniquewithadistributedfeedbacklaser.TheovertonespectraofCO2around1.31μmandthecorrespondingspectralparameters(i.e.positions,intensities,self-broadeningcoefficients)arepresented.Theintensityoftheweakestlinedetectedis2.25163×10^-27cm^-1/(molecule·cm^-2)atthepressureof5Tort,withacorrespondingabsorptionof3.88×10^-8.