简介：Inthispaper,propagationofsoundinpipesundertheinfluenceofagasflowofhightemperatureisinvestigated.Theanalysisinthepa-perisbasedonthefundamentalequationsoffluidmechanics.Approxi-mateformulasofthevariationofparameters,suchasthestatictempera-ture,thelocalvelocityofsound,theflowspeedandtheMachnumber,withdistanceareobtained.Thefourparameterstransmisionmatixwhichdeterminestheacousticalcharacterofthepipeisderivedanddiscussed.Theacousticalcharacterofapulsatinggasheaterisinvestigatedexperim-entallyandtheoretically.Thetheoreticalvaluesoftheresonantfrequenciesofthedeviceareingoodagreementwiththeexperimentalresults.

简介：直接模拟蒙特卡罗(DSMC)方法被介绍在多部件气体混合物为声学的繁殖建模。并且声学的变细的一个理论预兆的模型被建议，它不依靠经验的参数。各种各样的多部件气体混合物的声学的变细系列，由氮，氧，二氧化碳，甲烷和水组成，被DSMC方法估计。兴趣的健全频率范围从8MHz到232MHz。与基于DL，加古典变细的模型由Stokes-Kirchhoff公式计算了的松驰变细的结果相比，我们的模型的声学的变细的评价同意了他们。模型的精确取决于变细从产生的分子碰撞的物理机制的理解。另外，我们的模型的结果证明频率依赖者的人物声学的变细依靠煤气的混合物的作文。并且这能导致能够在各种各样的环境和进程决定煤气的作文的份量上的聪明的声学的煤气的传感器的开发。

简介：Simpleandefficientsurfaceacousticwave(SAW)two-portresonatorswithlowinsertionlossandhighQ-valuesonST-Xquartzsubstrateusingacorrosion-proofA1/Au-stripeelectrodestructurearedevelopedforgassensing.Itwascomposedoftwoshortedgratingreflectorsandadjacentintedigitaltransducers(IDT),andanactivemetalfilminthecavitybetweentheIDTsforthesensitivefilmcoating.Thedevicesareexpectedtoprovidegoodprotectiontowardsmetalelectrodeforgassensorsapplicationinchemicallyreactiveenvironments.Excellentdeviceperformanceaslowinsertionloss,highQfactorandsingle-modeareachievedbycarefullyselectingthemetallicelectrodethickness,cavitylengthandacousticaperture.Priortofabrication,thecouplingofmodes(COM)modelwasperformedfordevicesimulationtodeterminetheoptimaldesignparameters.Thefabricatedsingle-modeSAWresonatoratoperationfrequencyof300MHzrangeexhibitsmatchedinsertionlossof~6.5dBandloadedQfactorinthe3000range.Usingthefabricatedresonatorasthefeedbackelement,adualresonator-oscillatorwithexcellentfrequencystability(0.1ppm)wasdevelopedandevaluatedexperimentally,anditissignificantforperformanceimprovementofSAWgassensor.