简介:W,N共同做TiO2nanoparticles被一个solgel方法综合。准备样品被X光检查衍射(XRD)描绘,域排放扫描电子显微镜学(FE-SEM),传播电子显微镜学(TEM),Fourier变换红外线的光谱学(英尺红外),X光检查光电子光谱学(XPS)和弥漫的反射spectrophotometry(医生)。结果证明共同做的光催化剂是有22.5nm的最小的粒子尺寸的实质上一致的球形的粒子。比作未做的TiO2,N-TiO2和P-25,W的吸收边,N共同做转移到更长的波长的TiO2和它为在Xe灯(350W)下面的甲基橘子(瞬间)的降级的photocatalytic活动更高。
简介:Westudytheleastsquaresestimationofdriftparametersforaclassofstochasticdifferentialequationsdrivenbysmallα-stablenoises,observedatnregularlyspacedtimepointsti=i/n,i=1,···,non[0,1].Undersomeregularityconditions,weobtaintheconsistencyandtherateofconvergenceoftheleastsquaresestimator(LSE)whenasmalldispersionparameterε→0andn→∞simultaneously.TheasymptoticdistributionoftheLSEinoursettingisshowntobestable,whichiscompletelydifferentfromtheclassicalcaseswhereasymptoticdistributionsarenormal.
简介:non-Gaussian噪音驾驶的一个随机的消散的动态系统被调查。系统的一个一般近似佛克普朗克常数方程通过一条路径积分途径被导出。基于香农的信息熵,熵流动的准确时间依赖和系统的熵生产的定义在缺席并且面对非平衡被计算限制。现在的计算能被用来在熵流动和熵生产上解释消散的常数和non-Gaussian噪音的相互影响。
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简介:Thispaperproposesanadaptiverotorcurrentcontrollerfordoubly-fedinductiongenerator(DFIG),whichconsistsofaproportional(P)controllerandtwoharmonicresonant(R)controllersimplementedintherotorrotatingreferenceframe.Thetworesonantcontrollersaretunedatslipfrequenciesωslip+andωslip-,respectively.Asaresult,thepositive-andnegative-sequencecomponentsoftherotorcurrentarefullyregulatedbythePRcontrollerwithoutinvolvingthepositive-andnegative-sequencedecomposition,whichineffectimprovesthefaultride-through(FRT)capabilityoftheDFIG-basedwindpowergenerationsystemduringtheperiodoflargetransientgridvoltageunbalance.Correctnessofthetheoreticalanalysisandfeasibilityoftheproposedunbalancedcontrolschemearevalidatedbysimulationona1.5-MWDFIGwindpowergenerationsystem.
简介:Theperiod-oneoscillationproducedbyanexternalopticalpulseinjectiondrivensemiconductorlaserisappliedtoclockrecoveryandfrequencydivision.Byadjustingtherepetitionrateorinjectionpoweroftheexternalinjectionopticalpulsestolockthedifferentharmonicfrequenciesoftheperiod-onestate,theclockrecoveryandthefrequencydivision(thesecondandthirdfrequencydivisions)areachievedexperimentally.Inaddition,infrequencylockingrangesof2GHzand1.9GHz,thesecondandthirdfrequencydivisionsareobtainedwiththephasenoiselowerthan-100dBc/Hz,respectively.Ourexperimentalresultsareconsistentwellwiththenumericalsimulations.
简介:Acouplednumericalmethodforthedirectnumericalsimulationofparticle-fluidsystemsisformulatedandimplemented,resolvinganorderofmagnitudesmallerthanparticlesize.Theparticlemotionisdescribedbythetime-drivenhard-spheremodel,whilethehydrodynamicequationsgoverningfluidflowaresolvedbythelatticeBoltzmannmethod(LBM).Particle-fluidcouplingisrealizedbyanimmersedboundarymethod(IBM),whichconsiderstheeffectofboundaryonsurroundingfluidasarestoringforceaddedtothegoverningequationsofthefluid.Theproposedschemeisvalidatedintheclassicalflow-around-cylindersimulations,andpreliminaryapplicationofthisschemetofluidizationisreported,demonstratingittobeapromisingcomputationalstrategyforbetterunderstandingcomplexbehaviorinparticle-fluidsystems.