简介：声学的散布从一沉没由一个事件飞机波浪的充满液体的有限的圆柱的壳insonified被学习。散布领域的分析答案与边界条件用有弹性的薄壳理论被导出。由于内部液体的效果，充满液体的阻抗必须增加系统的阻抗。结果证明在backscattering地里，僵硬散布仅仅在舷侧和有弹性的散布玩上有大贡献一个主要角色什么时候倾斜的发生。阶段速度的分散曲线显示出那与内部真空条件作比较，除了由纵的波浪的贡献并且砍舷侧附近的波浪一系列内部液体引起的另外的波浪被增加它有大贡献到散布领域。碗--形状回声曲线作为内部液体波浪的贡献在频率角度光谱被介绍。

简介：ThestatisticalpropertiesofthemodeconvertedSVwavespecklesinthebackscatteringspacewerestudiedasultrasonicPwaveswereincidentonastronglyscatteringinterface.BasedontheFrensel-Huygenstheoryandthecorrelationprinciple,theRayleighdistributionoftheSVwavespeckleamplitudeandtheformulaforcalculatingtheaveragelateralsizeoftheSVwavespeckleswereobtained.Besides,theprobabilitydensityfunctionofthenormalizedintensityoftheSVwavespecklesreceivedbyatransversewaveprobewithanapertureofsomesizewasdeduced.Theprobabilitydensityfunctionwasrelatedtotheaveragenumberofthespecklesreceivedbytheprobe.TwotransversewaveprobeswithaperturesindifferentsizewereemployedtomeasurethesoundintensityoftheSVwavespecklesintheexperiment.Aftertheexperimentaldataofthespeckleintensitywereanalyzedstatistically,itwasshownthattheexperimentalresultswereingoodagreementwiththetheoreticalones.Thus,thepresentedtheoreticalconclusionswereprovedtobecorrect.

简介：Thisstudyperformsthequantitativeanalysisandcomparisontoacousticsignalcharact,eristicsofLargcyellowcroaker(Pseudosciaenacrocea)attwodifferentages.Thesoundswercrecordedfromthefishesinanet-cage.Twoexponentialoscillationfunctionsarebuilttofittheacousticsignalofthefishes.Thesignalcharacteristicoftheoscillationfrequencyandattcnuationcoefficientwasdescribedquantitatively.Simulationcurvesofthefunctioncouldfitwellacousticsignals.Boththeaverageoscillationfrequencyandattenuationcoefficientofthefittedsignalsfromthe13-15-month-oldfishesarclowerthanthosefromthe7-8-month-oldfishes.Theresultssuggestthattheoscillationfrequencyandattenuationcoefficientoftheacollsi.icsignalfunctionmayberelevanttothephysicalproccssofsoundproductionandagecharacteristicsofLargeyellowcroaker.Thisstudymaybevaluablefortheacousticapplicationtotheartificialcultureofthespecies.