简介:srzn2(PO4)2:在大气中的高温固相反应合成Sm3+荧光粉。srzn2(PO4)2:Sm3+荧光粉是通过紫外光有效激发(UV)和蓝色光,和发射峰被分配到2-6h54G5//2过渡(563nm),2-6h74G5//2(597nm和605nm)和2-6h94G5//2(644nm和653nm)。对srzn2发射强度(PO4)2:Sm3+的Sm3+浓度的影响,其浓度猝灭效应srzn2(PO4)2:钐也观察到。当掺杂离子(=Li,Na和K)离子的发光强度,srzn2(PO4)2:Sm3+可以明显增强。在国际照明委员会(CIE)的srzn2色坐标(PO4)2:Sm3+定位在橙红色的区域。结果表明,该荧光粉具有潜在的应用在白光发光二极管(LED)。
简介:Theoperationprincipleofanarrayedwaveguidegrating(AWG)multiplexerisintroducedandthe4×4AWGwithfollowingdesignparametersisdiscussedindetail,suchasthechoiceofwavelength,theneighboringarrayedwaveguidedistanceΔL,thechannelfrequencyintervalΔf,andthefreespectralrange.Thestructureof4×4AWGisdesignedandtheresultofstimulatedtestisalsogiven.Analysisshowsthatthe4×4AWGischaracterizedbyawidedynamicrange,lowcrosstalk,betterspectrumproperties,andacompactstructure.
简介:军用宽带移动通信技术与民用第三代移动通信(3G)和第四代移动通信(4G)技术相比,其发展缓慢。现有军用移动通信主要依靠短波、超短波及通信卫星等手段,对多媒体新型业务支持较弱,难以满足新一代指挥信息系统的需求。首先,介绍了4G宽带移动通信主流体制长期演进计划的后续演进(LTE—A)关键技术;然后,分析了4G技术的军事应用优势以及存在问题;最后,展望了未来4G移动通信军事应用。
简介:AnapproximationalgorithmispresentedforaugmentinganundirectedweightedgraphtoaK-edge-connectedgraph.Thealgorithmisusefulfordesigningareliablenetwork.
简介:InviewofK-faulttestability,thetopologicalconstructionofapracticalcircuitisfarfromideal.Inordertoimprovethetestabilityofacircuit,wemayincreasethenumberofaccessiblenodesorusethemulti-excitationmethod.Effectivenessofthesemethodsandthefeasibilityofchoosingaccessiblenodesarediscussedindetail.Theconditionsformulti-excitationtestabilityarepresented.
简介:Blindrecognitionofconvolutionalcodesisnotonlyessentialforcognitiveradio,butalsofornon-cooperativecontext.Thispaperisdedicatedtotheblindidentificationofratek/nconvolutionalencodersinanoisycontextbasedonWalsh-Hadamardtransformationandblockmatrix(WHT-BM).Theproposedalgorithmconstructsasystemofnoisylinearequationsandutilizesallitscoefficientstorecoverparitycheckmatrix.Itisabletomakeuseoffault-tolerantfeatureofWHT,thusprovidingmoreaccurateresultsandachievingbettererrorperformanceinhighrawbiterrorrate(BER)regions.Moreover,itismorecomputationallyefficientwiththeuseoftheblockmatrix(BM)method.
简介:Higher-orderalmostcyclostationarycomplexprocessesarecomplexrandomsignalswithalmostperiodicallytime-varyingstatistics,whichisimportanttotheresearchofnon-Gaussiansignalsininformationsystem.Intinspaper,smoothedpolyperiodogramsareproposedforrelatedtocyclicpolyspectralestimationandareshowntobeconsistentandasymptoticallycomplexnormal.Asymptoticcovarianceexpressionsarederivedalongwiththeircomputableforms.
简介:UsingdoublecrystalX-raysdiffraction(DCXRD)andatomicforcemicroscopy(AFM),theresultsofGexSi1-xgrownUHV/CVDfromSi2H6andSiH4areanalyzedandcompared.Adsorbatescanmigratetotheenergy-favoringpositionduetotheslowgrowthratefromSiH4.Inthiscase,aSibufferthatisolatestheeffectofsubstrateonepilayercouldnotbegrown,whichresultsinapitpenetratingintoepilayerandbuffer.TheFWHMis0.055°inDCXRDfromSiH4.Thepresenceofdiffractionfringesisanindicationofanexcellentcrystallinequality,TheroughnessofthesurfaceisimprovedifgrownbySi2H6:however,thecrystalqualityoftheGex2Si1-xmaterialbecameworsethanthatfromSiH4duetomuchlargergrowthratefromSi2H6.ThecontentofGeisobtainedfromDCXRD,whichindicatesthegrowthratefromSi2H6islargest,thenGeH4andthatfromSiH4isleast.