简介:AbstractIntheparametertrackingoftime-varyingsystems,theordinarymethodisweightedleastsquareswiththerectangularwindowortheexponentialwindow.Inthispaperweproposeanewkindofslidingwindowcalledthemultipleexponentialwindow,andthenuseittofittime-varyingGaussianvectorautoregressivemodels.Theasymptoticbiasandcovarianceoftheestimatoroftheparameterfortime-invariantmodelsarealsoderived.Simulationresultsshowthatthemultipleexponentialwindowshavebetterparametertrackingeffectthanrectangularwindowsandexponentialones.
简介:Faraday-cupControlandMeasurementProgramBasedonMSWindows¥ZhangGuixuandLuXueqiuAnewfaraday-cupcontrolprogramwhichrunsonMSWindow...
简介:Li0.33MnO2cathodematerialwassynthesizedbysolidstatereaction.Thematerialshowedasmallcoherentdomainsizeabout10nmdeterminedbyX-raydiffractionandtransmissionelectronmicroscopy.Theelectrochemicalpropertiesofthematerialwerestudiedindifferentpotentialwindowsof3.5―2.0Vand4.3―2.0V.Anirreversibletransformationtospinelphasewasobservedintheinitialseveralcycles,whichwasmoreprominentoncyclingat4.3―2.0V.ElectrochemicalimpedancespectroscopyshowedthattheLi+diffusioncoefficientofthematerialwasabout2×10–9cm2/s.Li0.33MnO2showedareversibledischargecapacityof140and200mA·h/ginthepotentialwindowsof3.5―2.0Vand4.3―2.0V,respectively.Butthecapacityretentionat4.3―2.0Vwaspoorduetothethickerspinellayerformedonthematerialsurface.
简介:Whenmeasurementsareperformedinhighspeed,small-scalecompressors,theuseofcurvedglasswindowsisrequiredinordertoavoidanymismatchbetweenthemeasurementwindowandthecasing.However,theglasscurvatureleadstoopticaldistortions,whichhinderacceptablemeasurementsandcanevenpreventtheacquisitionofanydata.Thus,anoriginalopticalassembly,whichconsistsininsertingasimpleandinexpensivecorrectivewindowbetweenthefrontallensoftheanemometerandtheshroudwindow,isproposed.Thewayofdeterminingthegeometriccharacteristicsandthepositionofthiscorrectivewindow,whichrestoresveryacceptablefoci,ispresentedinthepaper.Thereliabilityofthiscorrectiveopticalassemblyishighlightedbycomparativemeasurementsinatestcase.Usingsuchanopticalsetting,L2Fmeasurementswererealisedalongasection,downstreamoftheinletguidevane(IGV)ofatransoniccompressorstage.Thespatialresolutionleadstoagooddescriptionoftheinteractionofthewakewiththeobliqueshockemanatingfromtheleadingedgeoftherotor.Aphenomenologicalstudyofthewake/shockinteractionwithachangeofframeisrealisedusingthestreamwiseequationofthetransportofvorticity.