简介：Inthispaper,wegivethedistributionoftemperaturefie1dandpulsephotoacousticpressuregener-atedbypulsedlaserinliquid.Theeffectofpulsedurationandlaserbeamdimensiononthepres-suresignalisdiscussed.TheexperimentalresultsobtainedbytheGausslaserbeamdeflectiontech-niqueagreewiththetheoryqualitatively.Thistechniqueprovidesanovelopticalmethodforthecontactlessandrapidmeasurementofthermodynamicparameters.

简介：Animpulseresponsetechniquehasbeeninvestigatedbyapplicationtotheopenscreensforobtainingsoundtransmissionloss.ThemeasurementsofsuchscreensaccordingtoISO140werealsopresented.ThepredictedresultscalculatedbyamodelwhichisbasedonHuygen’sprincipleandKirchhoff’sformulationhaveshowngoodagreementswiththeresultsobtainedbyimpulsemethod.Themethodrequiresnospecialistacousticfacilitiesandmeasurementsystemscanbeportable.

简介：SeveralARMAmodelingapproachesareaddressed.Inthesemethodsonlypartofacorrelationsequenceisemployedforestimatingparameters.Itissatisfying,ifthegivencorrelationsequenceisofrealARMA,sinceanARMAprocesscanbecompletelydeterminedbypartofitscorrelationse-quence.Butforthecaseofameasuredcorrelationsequencethewholesequencemaybeusedtore-ducetheeffectoferroronmodelparameterestimation.Inaddition,thesemethodsnowdonotguar-anteeanonnegativespectralestimate.Inviewoftheabove-mentionedfact,aconstrainedleastsquaresfittingtechniqueisproposedwhichutilizesthewholemeasuredcorrelationsequenceandguar-anteesanonnegativespectralestimate.

简介：以便检测casing地上凿穿的损坏，有一个二维的超声的数组的一个声学的成像方法被介绍。数组的每个元素独立地在超声的波浪下面射出，所有元素收到的回响被取样并且在地面表面上传给一台计算机，动态移植方法在此被用来形成一2或在地上凿穿的状况的3-dimensional图象。数字模拟和实验被进行与在数组使用的元素的一个小数字表明高成像精确性。自从在传统的分阶段执行的数组成像使用的延期电路，系统不在这个系统被需要，并且所有数据进程能在地上凿穿在一个扎根的系统，复杂性和系统的卷被完成可以显著地被简化，它对地上凿穿仪器批评。

简介：在导致的震波和地雷之间的机械相互作用根据联合理论的acoustic-to-seismic被分析。并且一个地震检波器数组基于试验性的系统因为地雷察觉被开发。由作为一个集体春天的系统在矿上为一个顺从的矿和土壤建模，分析方法被采用学习系统的回声机制。一个扬声器作为精力来源被采用在土壤上使一个打扫正弦音调激动。我们也使用了一个地震检波器数组测量扎根的表面的颤动速度。以便分析表面颤动上的地雷效果，测量速度价值on-and-off矿的大小系列曲线被阴谋。结果证明在我的上测量的数据比那大得多离开目标，建议系统能被使用推进声学的地雷察觉的调查。

简介：以便减少磨擦力量并且在低速度消除一个技工系统的粘住滑倒现象，一个方法基于超声的微开车技术被建议改变摩擦特征。顺时针方向激动并且在超声的致动器的二个纵的夹钳门栓的震荡器上驾驶点的逆时针方向的显微镜的椭圆的运动将产生超声的润滑油行动；而且，磨擦能被调整震荡器的颤动的振幅活跃地控制。为磨擦控制的试验性的安装用航空的指南，力量传感器和一低速度时刻被设计motor.Fuzzy控制理论被使用进这个系统。实验显示磨擦力量大部分被减少了，试验性的系统的运动是稳定的。当超声的致动器和负担is3.8kg和马达的全部的团正在开车时，磨擦系数仅仅是大约0.0053速度是0.5mm/s。

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简介：Itisusuallydifficulttomeasureacousticvelocitiesthroughacasing,especiallywhenthecasingispoorlybondedwithformation.AnacousticloggingtechniqueusingthedualsourceofoppositepolarityisproposedtoenhancetheSignaltoNoiseRatiooftheformationsignalandtoreducethecasingwaveinthedataacquisitionprocess.Inwhatfollows,atheoreticalmodelingisusedtocaculatethewavefromsofcasedwells.Andthen,ascaledexperimentwasconductedinthe1:10scaledexperimentalwellusingtheproposedtechniqueinthepoorlybondedcondition.Theresultsshowthatthistechniquecaneffectivelysuppressthecasingwaveandenhancetheformationwave,eveninthepoorly-bondedcondition.Byanalyzingthemeasuredwavefroms,theamplitudeofcasingwaveisreducedto12%comparedtotheconventionalone-sourcetechnique,andthecompressionalwavevelocitycanbeeasilyobtainedbyusingthistechnique.Boththetheoreticalmodelingandexperimentresultsdemonstratethefeasibilityoftheproposedtechnique.Thisstudyestablishesthetheoreticalandexperimentalfoundationforthecased-hole,dualsourceofoppositepolarity,acousticloggingtooldevelopment.

简介：Onenearfieldacousticholography(NAH)techniqueisproposedforanalyzingcyclostationarysoundfield.Thesignalofthiskindofsoundfieldhasveryseriousmodulationphenomenongenerally,inspectrumofwhichobvioussidebandsexist.ItisdifficultforthetraditionalNAHtopossessdemodulationfunction,sovirtualpowerofsidebandsexistsinitshologram.ReplacingtheFourier'stransformwiththesecond-ordercyclicstatistics,theproposedNAHtechniqueusesthecyclicspectrumdensity(CSD)functionasreconstructedphysicalquantity,insteadofthespectrumorpowerspectrumdensityofsoundpressuresignal.TheCSDfunctioncandemodulatecyclostationarysignals,whichmakesnovirtualpowerofsidebandsinitshologram.TheresultsofsimulationandexperimentshowthattheproposedNAHcanextractmoreinformationaboutcyclostationarysoundfieldthantraditionalNAH,bywhichsoundfieldcanbeknownmoreclearly.

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