简介：

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

简介：Thedeformablemirrorwiththesizeof410mmstackswasdeveloped.Theresults×468mmcontrolledbythebimorphpiezoceramicplatesandmultilayerpiezoceramicofthemeasurementsoftheresponsefunctionsofalltheactuatorsandofthesurfaceshapeofthedeformablemirrorarepresentedinthispaper.ThestudyofthemirrorwithaFizeauinterferometerandaShack–Hartmannwavefrontsensorhasshownthatitwaspossibletoimprovetheflatnessofthesurfacedowntoaresidualroughnessof0.033μm(RMS).Thepossibilityofcorrectionoftheaberrationsinhigh-powerlaserswasnumericallydemonstrated.

简介：Lattice,charge,orbital,andspinarethefourfundamentaldegreesoffreedomincondensedmatter,ofwhichtheinteractivecouplingderivestremendousnovelphysicalphenomena,suchashigh-temperaturesuperconductivity(high-T_cSC)andcolossalmagnetoresistance(CMR)instronglycorrelatedelectronicsystem.Directexperimentalobservationofthesefreedomsisessentialtounderstandingthestructure-propertyrelationshipandthephysicsbehindit,andalsoindispensablefordesigningnewmaterialsanddevices.Scanningtransmissionelectronmicroscopy(STEM)integratingmultipletechniquesofstructureimagingandspectrumanalysis,isacomprehensiveplatformforprovidingstructural,chemicalandelectronicinformationofmaterialswithahighspatialresolution.Benefitingfromthedevelopmentofaberrationcorrectors,STEMhastakenabigbreakthroughtowardssub-angstromresolutioninlastdecadeandalwaysstepsforwardtoimprovethecapabilityofmaterialcharacterization;manyimprovementshavebeenachievedinrecentyears,therebygivinganindepthinsightintomaterialresearch.Here,wepresentabriefreviewoftherecentadvancesofSTEMbysomerepresentativeexamplesofperovskitetransitionmetaloxides;atomic-scalemappingofferroelectricpolarization,octahedraldistortionsandrotations,valencestate,coordinationandspinorderingarepresented.WeexpectthatthisbriefintroductionaboutthecurrentcapabilityofSTEMcouldfacilitatetheunderstandingoftherelationshipbetweenfunctionalpropertiesandthesefundamentaldegreesoffreedomincomplexoxides.

简介：Objectives:Facialnerveaberrationisthemosttroublesomesituationincongenitalmalformationsofmiddleear.Theaimofourstudyistoinvestigateitsimagingandclinicalfeaturesaswellasrelevantchoiceofsurgicaltechniquesforhearingimprovement.Methods:Aretrospectivestudyinvolvingreviewofclinicaldataof227patients(256ears)withcongenitalmiddleearanomalywasundertaken,includingpreoperativecomputedtomography(CT)data,surgicalrecordsandvideos.Results:Aberrationinvolvingintratemporalfacialnervewasfoundin82/256ears(32.03%)withcongenitalmiddleearanomaly.Themostcommonformsofaberrationincludedoverhangingovertheovalwindow(50/82ears,60.98%),bifurcation(3/82ears,3.66%)andtransverseoverthepromontory(3/82ears,3.66%),countingfor68.29%(56/82)ofthecaseswithfacialnerveaberration.Concomitantstapesmalformationwasfoundin76/82ears(92.68%)andatresiaorstenosisoftheovalwindowin27/82ears(32.93%).In9/82ears(10.98%)bothstapesandovalwindowwasabsent.Electivesurgeriesforthepurposeofhearingimprovementincludedstapodotomy+pistonimplantation,labyrinthotomy,labyrinthotomy+totalossicularreplacementprosthesis(TORP)implantationandVibrantSoundbridge(VSB)implantation.Conclusion:Themajorityoffacialnerveaberrationincongenitalmalformationofmiddleearinvolvesdisplacementoffacialnerve,inadditiontoconcomitantmalformationsofthestapesand/orovalwindow,whichmayinfluencethechoiceofsurgeryforhearingimprovement.VSBimplantationmaybeconsideredasausefuloption.

简介：AIM:Tocomparehigherorderaberrationsintwoasphericalintraocularlenses(IOLs):Akreosadvancedoptics(AO)andDr.SchmidtMicrocrystalline6125asphericanteriorsurface(MC6125AS)witheachother.METHODS:Fortyeyesof39patientsunderwentphacoemulsificationandAkreosAOandMC6125ASwereimplantedintheireyesinarandommanner.Threemonthspost-operatively,higherorderaberrationsincludingsphericalaberration,comaaberration,andtotalaberrationsweremeasuredandcompared.RESULTS:Thetotalaberrationwas0.24±0.17ineyeswithDr.Schmidtand0.20±0.01ineyeswithAkreosAO(P=0.361).Themeanofcomaaberrationwas0.17±0.21and0.09±0.86inDr.SchmidtandAkreoslenses,respectively(P=0.825).Totalsphericalaberrationwasalmostthesameinbothgroups(mean:0.05,P=0.933).BestcorrectedvisualacuityinAkreosAO(0.10±0.68)andDr.Schmidt(0.09±0.67)didnotdiffersignificantly(P=0.700).CONCLUSION:Thereisnostatisticallysignificantdifferenceinthehigherorderaberrationsbetweenthesetwoasphericallenses.