简介：由于到在二种尺寸的一极化的马方程的声学的方程的通讯，我们理论上利用最近建议的遥远的看不见外套的声学的对应物。外套与与各向异性的集体密度在壳内嵌入的设计体积moduli，和一个反目标由一个圆形的圆柱的核心组成。cloaking壳的材料参数被使用并列转变方法获得。外套的新设计的本质依靠cloaked目标被cloaking壳不再震聋的能力，它被两个验证在二种尺寸的远地、近地的完整波浪的有限元素的模拟。

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简介：在水下声学(UWA)通讯基于一个声学的向量传感器被学习。联合加权的健全压力并且速度处理的方法在高速度的UWA通讯系统与协调解调和适应均等算法相结合使解调并且译码的阶段调整被使用。而健全紧张能被使用而不是压力频率在频率调整UWA通讯系统译码。理论分析，模拟计算和湖试用的结果证明了在阶段调整或在频率调整UWA通讯系统，处理获得能显然被增加，以便BER(小点错误率)能有效地被减少，遥感勘测距离能被使用声学的向量传感器扩大。

简介：Consideringtheuncertaineffectsoftemporalandspatialchangesinthemarineenvironmentontheunderwateracousticenvironment,weestablishedanocean-acousticcouplednumericalmodelandperformedaparallelcalculation.Thismodelincorporatedacousticcalculationsintothedynamicocean,therebyachievingadynamicforecastingandassessmentoftheacousticenvironment.Furthermore,weadoptedtheensemblepredictionmethodtopredicttheverticalstructureoftemperatureinaclassiccross-section,thesoundspeedofthecross-sectionoftheinvestigatedseaarea,andtransmissionlosses.Wegavethepredictionerrorsofthesoundspeedprofileaswellasthe90%probabilityintervaloftransmissionlossesandtheuncertaintyhistogramsofthesoundspeeds,transmissionlosses,andsonarrangesatdifferentdepthsandfrequencies.Theresultsreflectedtheinfluenceofmarinetemporalandspacialvariationsontheuncertaintiesoftheunderwateracousticenvironment,andtheresultsalsoquantifiedtheuncertaintiesoftheunderwateracousticenvironmentparameters.Theexperimentalresultsindicatethatthemethodusedinthisstudyisabletodelineateandquantifytheuncertaintiesoftheunderwateracousticenvironmentcausedbymarinedynamicchanges.

简介：ThispaperdescribesanewphenomenonofacousticstreamingwhichtakesplacewhenaHelmholtzresonatorisexcitedbyaninsidesoundsourcewithresonantfrequency,andtakestheformofastrongturbulentjet.Theflowvisualizations,hotwireandLDVmeasurementsarecombinedtoinvestigatetheprocessofacousticstreaming.ItisfoundthatthiskindofacousticstreamingresultsfromthecontributionofReynoldsstress.

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简介：Anacousticbasedinstrument,theABSAcousticBubbleSpectrometer??(ABS),wasinvestigatedforthedetectionandquantificationofbubblesinbiologicalmedia.Theseincludeviscoelasticmedia(blood),materialsofvaryingdensity(boneintissue),non-homogenousdistributionofbubbles(intravenousbubblyflow),andbubblesmigratingintissue(decompressionsickness,DCS).TheperformanceoftheABSwasdemonstratedinaseriesoflaboratoryexperiments.Validationofthecodewasperformedusingaviscoelasticpolymersolution,Polyox,inwhichthebubblesizedistributionandvoidfractionweredeterminedbyABSmeasurementsandwithimageanalysisofhighspeedvideos.ThesetestsshowedthattheaccuracyoftheABSwasnotsignificantlyaffectedbyviscoelasticityforbubblessmallerthan200microns.TheABSdetectionandmeasurementofnon-homogenousbubbledistributionswasdemonstratedusingabubblyflowthroughasimulatedveinsurroundedbytissue.Thescatterofacousticsignalsduetobonesintheacousticpathwaywasalsoinvestigated.Thesein-vitroexperimentsweredoneusingmeat(beef)asatissuesimulant.Decompressionexperimentsweredoneusingbeefmeatwhichwasheldunderwaterathighpressure(9.9atm)thenrapidlydecompressed.Bubblesizedistributionsandvoidfractioncalculationsintheseexperimentswerethenvalidatedusingimageanalysisofhighspeedvideo.Inaddition,preliminaryexperimentswereperformedwiththeUSNavyMedicalResearchCenter,demonstratingtheutilityofthemodifiedABSsystemindetectingtheevolutionofbubblesinswineundergoingdecompressionsickness(DCS).TheseresultsindicatethattheABSmaybeusedtodetectandquantifytheevolutionofbubblesin-vivoandaidinthemonitoringofDCS.

简介：我们在一棵锯季度的白杨上使用了声学的测试在声学的波浪上学习木头anisotropy和洞缺点的效果的木材速度和旅行路径，和我们在木头调查了声学的波浪繁殖行为。木材标本首先处于未修改的状况被测试然后在在实验室的声学的波浪的播送时间调节的改变尺寸确定的洞缺点的介绍以后测试了。标本的光线的节上的二维的声学的波浪轮廓地图然后基于试验性的数据被模仿并且分析。当波浪通过木头在各种各样的方向过去了，我们测试了在木头谷物和声学的波浪速度之间的关系。伍德anisotropy在速度和通过超过的木材传递纵的波浪的声学的波浪，和速度的旅行路径上有重要效果光线的速度。而且，洞缺点在木材的光线的节上改变了声学的波浪时间轮廓。从刺激的声学的波浪运输比在未经触动的木头更慢慢地在有缺点的木头在一个洞后面指向这个区域。

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简介：<正>AcousticNeuroma(AN)arisesfromtheeighthcranialnerve.Itprimarilyinvolvesthevestibularbranchofthenerveandisthereforealsocalledvestibularschwannoma(VS).Tothedate,diagnosisandsurgicaltreatmentofANhaveadvancedsignificantly.Alongwithadvancesinaudiologyandimagingtechnologies,casesofdiagnosedANhavebeenincreasing,makingitacommon

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简介：声学的向量传感器同时，colocately并且直接在声学的地里在单个点象压力一样测量粒子速度的直角的部件以便是可能的改进性能传统在水下声学的测量设备或察觉系统并且为解决扩大新想法实际在水下的声学的设计问题。尽管出现在的声学的向量传感器历史在水下声学的区域不长，但是与巨大、潜在的军人一起要求声学的向量传感器在最后一十年有强壮的发展趋势，它正在演变为中的一一个重要在水下声学的技术。在这个背景下面，我们试着在声学的向量传感器信号处理上在学习考察最近的进步，例如信号察觉，DOA评价，beamforming等等。

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简介：Inordertoovercometheexistingdisadvantagesofofflinelasershockpeeningdetectionmethods,anonlinedetectionmethodbasedonacousticwavesignalsenergyisprovided.Duringthelasershockpeening,anacousticemissionsen-soratadefinedpositionisusedtocollecttheacousticwavesignalsthatpropagateintheair.Theacousticwavesignalissampled,stored,digitallyfilteredandanalyzedbytheonlinelasershockpeeningdetectionsystem.Thenthesystemgetstheacousticwavesignalenergytomeasurethequalityofthelasershockpeeningbyestablishingthecorrespondencebetweentheacousticwavesignalenergyandthelaserpulseenergy.ThesurfaceresidualstressesofthesamplesaremeasuredbyX-raystressanalysisinstrumenttoverifythereliability.Theresultsshowthatboththesurfaceresidualstressandacousticwavesignalenergyareincreasedwiththelaserpulseenergy,andtheirgrowthtrendsareconsistent.Finally,theempiricalformulabetweenthesurfaceresidualstressandtheacousticwavesignalenergyisestablishedbythecubicequationfitting,whichwillprovideatheoreticalbasisforthereal-timeonlinedetectionoflasershockpeening.

简介：Theacousticperformanceofthestructureformeasuringcavitationnoiseistheoreticallyanalysed,andtwojudgingcriteriaoftheacousticperformanceofSTW（soundtransmissionwindow）arepresentedinthispaper.OneisofimpedancematchingbetweenworkingliquidandSTW:ρ1C1=ρ2C2.Theotherisofmaximumfrequency（orminimumwavelength）ofcavitationnoisespectrum:fmax≤c/60D(orλmin/D≥60).Ifeitherofthecriteriaismetreliablemeasuredresultsofcavitationnoisewillbeobtained.Thetheoreticalresultsareverifiedthroughexperi-ments.Accordingtothecriteria,thepaperanalysestheacousticperformanceofroutinelyusedplexiglassSTW.Theresultsshowthatintheresearchofclearwatercavitationtheimpedanceratio,2.18,doesnotsatisfyρ1C1=ρ2C2,andfmax≤C/60Dhardlyholdsforactualcavitationnoisespectrum.Therefore,plexiglassSTWisnotgoodenoughforsoundtransmission.Fromthispointofview,polyethyleneisbettersoundtransmissionmaterialthanplexi-glass.

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简介：Eightsetsofcoastalacoustictomography(CAT)systemsweredeployedduringNovember29toDecember10,2002atthecoastsonbothsidesofTokyoBaytomeasuretidalcurrentstructuresat15-mininterval.SoundtransmissionacrosstheTokyoBay(betweenYokohamaandChiba)wassuccessfullytraced,evenundersevereinterferencefromshipgeneratedwakesandbubbles.Tidalcurrentfieldschangingfromnorthwardtosouthwardflowarewellreconstructedbytheinverseanalysisoftravel-timedifferencedataforaperiodwiththebestsoundtransmissioncondition.ItissuggestedthattheCATisthemostpowerfultooltocontinuouslymaptidalcurrentfieldsinthecoastalseaswithheavyshippingtrafficandfisheriesactivity.

简介：Thepresentreportsummarizesourexperienceusingendoscopesandneuronavigationaltechniquesasanassistanceinminimallyinvasivetoolinacousticneurinomasurgery.Basedontheexperienceinabout100casesdoneduringthelast5yearsusingtheseadditionaltechniquesthesignificantbenefitbyusingbothtechniquescouldbeprovenasabsolutelyhelpful.Inourpatientcollectiveuntilnownocomplicationscouldbeendetectedregardingtheuseoftheseoptionsaswellastheeffectivenesswasfromveryhighvalue.These,foronehandindetectingresidualtumoraswellasthepossibilityofcontrollingtheresultaftertheresectionusingrigidangledendoscopesandfortheotherhandbytheclearefficiencyinusingneuronavigationalsystemsinplanningandperformingtheapproachaswellasdoingsafetydrillingbyremovingtheposteriorpartoftheinnerauditorychannel.Specialremarksandrecommendationsofthetechnicalequipmentwhichhasbeenusedaregivenaswellaspersonalexperiencesintheoperatingroomsetup.Basedonourresultsandexperiencetheuseofthistwowellknowntechniquesinadditiontowelltrainedmicrosurgicaltechniquescanbehighlyrecommended.

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