学科分类
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2 个结果
  • 简介:Proceedingfromtheeigenvalueequationofthenormalmodeinhomogeneousshallowwater,wederiveseveralformulaecalculatingthemodeattenuationandgroupvelocity,andcomparetheiraccu-racybymeansofnumericalresults.Thepaperespeciallydiscussestheattenuationandthegroupve-locityofcriticalmodeinaPekerischannelandshowsthatingeneral,theattenuationandthegroupvelocityofthecriticalmoderespectivelyarelessthantheabsorptionandthesoundspeedinthebot-tom.Therefore.theKornhauser,Raney,WestonTindle‘sconclusionsaremodifiedthattheattenuationandthegroupvelocityofthecriticalmodeareexactlyequaltotheabsorptionandthesoundspeedinthebottom,respectively.

  • 标签: calculating EXACTLY ATTENUATION FORMULAE simplified EIGENVALUE
  • 简介:BasedonthenoisesurveyinChina,theformula(H′=H+N-HN/120)ofISO/DIS1999.2("Acous-tics-DeterminationofOccupationalnoiseexposureandestimationofnoise-inducedhearingimpairment,1985)wasappliedtothecalculationofthehearingthresholdlevelassociatedwithageandnoise(HTLAN)ofthenoise-impairedpeople.AccordingtotheGaussciandistribution,whenthenoise-exposurelevelLEX8hwas85,90,95,100dBandthehearingthresholdfrequencyisfrom0.5kto6kHz,theHTLANofnoise-exposedpeoplewithdifferentdurationofexposureanditsrelationvaluestothehearingthresholdfrequencyassociatedwithage(HTLA)wereobtained.TheISO/DIS1999.2hasbeenprovedtobeapplicableinChina.

  • 标签: HEARING NOISE IMPAIRED exposure EXPOSED Acous