简介：Afiniteelement-Helmholtzintegralhybridmethodhasbeendevelopedtocalculatetheelectro-acousticperformanceofafinitelengthcylindricaltransducerimmersedinwater.Thenumericalstudyconcernedwithelectricalimpedancesandbeampatternsofthetransducerispresented.Experimentaldataareshowntosupportthenumericalstudy.

简介：Thecreepeffectofsuspensionsinelectro-dynamicloudspeakerswasmodeledbasedonfractionalorderderivatives.Thefractionalstandardlinearsolid(FSLS)modelwaspresentedbysubstitutingtheAbeldashpotforNewtondashpotinStandardLinearSolid(SLS)model.TheelectricalimpedanceaswellasthetransferfunctionbetweendiaphragmdisplacementandinputvoltageofthetwotestedmidrangeloudspeakerswasmeasuredbyKlippellaseranalyzersystem,andthemodelparameterswereidentifiedbytheleast-mean-squaremethod.BycomparingthefittingresultsofFSLSmodelwiththeothertwoclassicalmodels-4ParameterLogarithmicmodelandSLSmodel,theresultsshowthattheFSLSmodelcanrightlypredictthefrequencydependentcompliancelossfactorandyieldhigheraccuracyformodelingthecreepeffectinloudspeakersuspensions.

简介：Anewapproachtodeterminealltheelectro-elasticconstantsofthepiezoelectriccrystalsinclass4mmhasbeenputforward.Asanexample,alltheconstantsofLithiumTetraborate（Li2B4O7）crystalhavebeenmeasuredbymeansoftheapproach.Theoutstandingadvantageoftheapproachisthatiton-lyneedstoemployinmeasurementthreecrystalplatesdifferentlyoriented.