简介：SEBSgrafted与的分子的结构缩苹果酸通过超声开始的酐(SEBS-g-MAH)被原子磁性的回声(NMR)调查。grafting组主要在超声的终点上存在，这能被证实开始的SEBS-g-MAH。然而，详细地证实MAH是通过描述的grafted的上SEBS的块是困难的<啜class=“a-plus-plus”>1H-NMR由于SEBS的复杂结构。而且，开始的SEBS-g-MAH也是的超声的红外线的系列由不安关联分析了的温度依赖者动人的窗户2D(PCMW2D)关联光谱学。它能证实破点在关节在之间存在poly(ethylene-co-1-butene)(EB块)并且聚苯乙烯块(S块)。因此，grafting组被纳入不仅S块而且EB块。另外，超声的聚集结构开始了SEBS-g-MAH，可能的grafting机制和在温度也是的空间的开始的SEBS-g-MAH建议了的超声的聚集模型以便很好理解。

简介：Ultrasoundsimulationforcarotidarteriesishelpfultotheperformanceassessmentsofvesselwalldetectionandsignalprocessingmethodsbyusingultrasoundtechniques.Anultrasoundsimulationmethodofcarotidarterywallwithathree-membranestructureisproposedinpresentstudy.Accordingtotheultrasoundspeckledistributionsvaryingwiththeshapesanddensitiesofscattererdistributions,aswellasthestatisticresultsoftheclinicalimages,theparametersofdistributions,densitiesandintensitiesofscatterersfordifferentkindsoftissuesinthecarotidarteryphantomsaredetermined.EachregionisacousticallycharacterizedusingFIELDIIsoftwaretoproducetheradiofrequencyechosignals,fromwhichultrasoundimagesarederived.Theresultsbasedon30simulationsshowthattheechodistributionsoftheintimae,mediae,adventitiasandbloodareconsistentwiththeclinicalones.Moreover,comparedwiththeresultsfromthecentralfrequencyof8MHz,themeanmeasurementsforthicknessesoftheintima,mediaandadventitiamembranes,aswellasthelumendiameterfromthesimulationimagesbasedon12MHzarethesameasthepresetones,andthemaximumrelativeerrorsarethe4.01%,1.25%,0.04%and0.15%,respectively.Thesimulationunderthisconditionismorerealistic.

简介：Acoherence-basedcorrectionmethodwasproposedinordertoimprovethelateralresolutionandenhancethecontrastofmedicalultrasoundimaginginthepresenceofphaseaberration.Theaveragedcoherencefactorwasproposedatfirstandusedasametrictoevaluatephaseaberrationcorrection.Bymaximizingtheaveragedcoherencefactor,thetimedelayparameterofeachchannelwasadjusted.AnewsetofcoherencefactorswascalculatedandthecorrecteddatawasoptimizedtoformthefinalB-modeimage.Thesimulationsonpointtargetsandacystphantomshowedthattheproposedmethodoutperformedthenearestneighboringcrosscorrelationmethodandconventionalcoherence-weightingmethod,andthelateralresolutionandcontrastratiowasimprovedbyapproximately0.24mmand18dBrespectively.Theproposedmethodcombinedtheadvantagesofphaseerrorcorrectionandcoherence-weighting,whichcouldimproveimagingqualitieseffectivelyinmedicalultrasound.