简介：SpecimensofPbTesinglefilmaredepositedonGesubstratesbyvacuumthermalevaporation.Duringthetemperaturerangeof80–300K,thetransmittanceofaPbTefilmwithin2–15μmismeasuredevery20KbythePerkinElmerFouriertransforminfraredspectroscopycryogenictestingsystem.Then,therelationshipbetweentherefractiveindexandwavelengthwithin7–12μmatdifferenttemperaturesisreceivedbythefullspectruminversionmethodfitting.ItcanbeseenthattherelationshipconformstotheCauchyformula,whichcanbefitted.Then,therelationshipbetweentherefractiveindexofthePbTefilmandthetemperature/wavelengthcanbeexpressedasn(λ,T)=5.82840-0.00304T+4.61458×10~(-6)T~2+8.00280∕λ~2+0.21544∕λ~4,whichisobtainedbythefittingmethodbasedontheCauchyformula.Finally,thedesignedvalueobtainedbytheformulaandthemeasuredspectrumarecomparedtoverifytheaccuracyoftheformula.

简介：Thispaperpresentsastudyondragcoefficientsundertyphoonwindforcingbasedonobservationsandnumericalexperiments.ThefrictionvelocityandwindspeedaremeasuredatamarineobservationplatformintheSouthChinaSea.Threetyphoons:SOULIK(2013),TRAMI(2013)andFITOW(2013)areobservedatabuoystationinthenortheastseaareaofPingtanIsland.Anewparameterizationisformulatedforthewinddragcoefficientasafunctionofwindspeed.Itisfoundthatthedragcoefficient(Cd)increaseslinearlywiththeslopeof0.083?10?3forwindspeedlessthan24ms?1.Toinvestigatethedragcoefficientunderhigherwindconditions,threenumericalexperimentsareimplementedforthesethreetyphoonsusingSWANwavemodel.Thewindinputdataareobjectivereanalysisdatasets,whichareassimilatedwithmanysourcesandprovidedeverysixhourswiththeresolutionof0.125°×0.125°.Thenumericalsimulationresultsshowagoodagreementwithwaveobservationdataundertyphoonwindforcing.Theresultsindicatethatthedragcoefficientlevelsoffwiththelinearslopeof0.012?10?3forhigherwindspeeds(lessthan34ms?1)andthenewparameterizationimprovesethesimulationaccuracycomparedwiththeWu(1982)defaultusedinSWAN.

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简介：生物织物的吸收系数是在biomedicine的一个重要参数，但是它的决心仍然是挑战。在这份报纸，我们用集中photoacoustic成像技术和圆柱的扩散纤维(CDF)的内部轻照耀确定建议一个方法目标光吸收系数。为墨水吸收器的吸收系数第一在一样的刺激通过photoacoustic和spectrophotometric大小被决定，它表明这个方法的可行性。另外，有几集中的墨水吸收器的光吸收系数被测量。最后，二维的扫描photoacoustic图象被获得。光吸收系数测量和吸收器的同时的photoacoustic成像non-invasively是方法的典型特征。这个方法能为血氧浸透，基于吸收的成像和治疗的非侵略的决心起一个重要作用。

简介：Thispaperhadinvestigatedtheeffectsofsurfacewettabilityonthefrictionalresistanceofturbulenthorizontalflowfortapwaterinfivepipesmadeofvariousmaterialsandfourkindsofliquidsinapolytetrafluoroethylene(PTFE)pipe,withthesameinnerdiameterof14mm.Pressuredropsweremeasuredunderdifferentflowratesthroughanexperimentalflowloop.Thecontactanglesandadhesionworkofliquidsincontactwithpipesurfacesweredeterminedusingacontactanglemeter.Basedonthedimensionandregressionanalyses,twokindsofmodifiedrelationshipsbetweenthefrictionalcoefficientandthesurfacewettabilitywereestablishedaccordingtothemeasuredresultscorrespondingtotapwaterinfivepipesandfourliquidsinPTFEpipe.Theexperimentalresultsshowthatthesurfacewettabilityhassomeinfluenceonfrictionalcoefficientofthestudiedliquidsflowinginmacroscalepipes,andthefrictionalcoefficientdecreaseswiththeincreaseofthecontactangleatthesameReynoldsnumber.Meanwhiletheeffectofwettabilityonthehydrophobicsurfaceisgreaterthanthatonthehydrophilicone.Thefrictionalcoefficientspredictedbythemodifiedformulashaveverifiedtobeingoodagreementwiththeexperimentalvalues,therelativeerrorsofwhicharewithin±6%and±3%forthetapwaterflowinginfivedifferentpipesandfourkindsofliquidsflowinginPTFEpipe,respectively.

简介：Theexistingabsorptioncoefficientmeasurementinawatertubeislimitedinlowfrequencyduetothelimitationofthepulsetubelength.Awide-bandpulsetubemethodbasedonthepost-processinginversefilterisproposed.Afterobtainingtheresponseoftheentiresystem,thetransducerisexcitedwithwide-band,short-durationsignals.Then,thereceivedsignalsareprocessedwithinversefiltersandthe'blurred'reflectivesignalsofstandardreflectorandtestsamplearerecoveredrespectively,finally,thereflectioncoefficientandabsorptioncoefficientarecalculated.Simulationworkisimplementedtoverifytheadvantageofpostprocessinginversefilteroverpre-processinginversefilterintermsoflowfrequencymeasurement.Toverifytheproposedmethod,twodifferentwide-bandpulsesintheseparatefrequencyrangesareadoptedtomeasurethesamerubbermaterial.Theexperimentalresultsindicatethatthewide-bandpulsemethodandCW(ContinuousWave)pulsemethodhavegoodagreementinbothlowfrequencyrangeandhighfrequencyrange.Wide-bandpulsemethodisofhighefficiency,andthelowfrequencyreaches350Hz,whichisabletoextendthelowfrequencyrange.