简介:Inmagneticresonanceelastography,oneseekstoreconstructtheshearmodulusfrommeasurementsofthedisplacementfieldinthewholebody.Inthispaper,wepresentanoptimizationapproachwhichsolvestheproblembysimplyminimizingadiscrepancyfunctional.Inordertorecoveracomplexanomalyinahomogenousmedium,wefirstobservethattheinformationcontainedinthewavefieldshouldbedecomposedintotwoparts,a'near-field'partintheregionaroundtheanomalyanda'far-field'partintheregionawayfromtheanomaly.Aswillbejustifiedboththeoreticallyandnumerically,separatingthesescalesprovidesalocalandprecisereconstruction.
简介:Inbiosciencepapers,besidestheotherscientificmisconductissues,replicationofthemethodsectionisacommonproblembecauseduplicationisalwaysbeingdetectedinthesectionMaterialsandMethods.Weeditorsoftenreceivecommentsandqueriesfromauthorswhothinkthatitisamatterofcoursetocopytheirownpublishedmaterialsasopposedtocopyingthoseofothers.Howshouldeditorshandlesuchpaperswithsimilarcontentinthemethodsectionandhowtoguideauthorsinwritingthemethodsectionwithoutbeingaccusedofplagiarism?Whatisright?Whatiswrong?Herewestudiedanexampletoexplainthisproblem.
简介:ThenucleiaroundmagicnumberN=126areinvestigatedinthedeformedrelativisticmeanfield(RMF)modelwitheffectiveinteractionsTMA.WefocusinvestigationsontheN=126isotonicchain.TheN=126shellevolutionisstudiedbyanalyzingthevariationsoftwo-neutron(proton)separationenergies,quadrupledeformations,singleparticlelevelsetc.Thegoodagreementoftwo-neutronseparationenergiesbetweenexperimentaldataandcalculatedvaluesisreached.TheRMFtheorypredictsthatthesizesofN=126shellbecomesmallerandsmallerwiththeincreasingofprotonnumberZ.However,theN=126shellexistsinourcalculatedregionallalong.Accordingtothecalculatedtwo-protonseparationenergies,theRMFtheorysuggests~(220)Puisatwo-protondrip-linenucleusintheN=126isotonicchain.
简介:Theobjectiveofthispaperistocomparetheperformancesoftheturbines,whichcouldbeusedforwaveenergyconversioninthenearfuture,undervariousirregularwaveconditions.Theturbinesincludedinthepaperareasfollows:(1)Wellsturbinewithguidevanes;(b)impulseturbinewithself-pitch-controlledguidevanes;(c)impulseturbinewithfixedguidevanes.Inthisstudy,experimentalinvestigationswerecarriedouttoclarifytheperformancesoftheturbinesundersteadyflowconditions,andthenanumericalsimulationwasusedforpredictingtheperformancesunderirregularwaveconditionswithvarioussignificantwaveheights.Asaresult,itwasfoundthattherunningandstartingcharacteristicsoftheimpulseturbinescouldbesuperiortothoseoftheWellsturbine.
简介:ThemeasurementresultsbyLaserDopplerVelocimetry(LDV)arecomparedwiththedirectnumericalsimulationresultbyEggelsetal.^[1]foracylindricalpipeflow.Inthecaseofapipeflow,thebiaserrorformeanvelocityisverysmall,becausethelocalturbulentintensityisverysmallalloverthepipecrosssection.Howeverthedifferenceofthecombinationofu'andv'haveconsiderableeffectsonReynoldsshearstress.Fromourinvestigation,itisfoundthattheselectionofcoincidencetimethatisanecessaryparameterforcombinationofu'andv'ismoreimportantinobtainingtheaccurateReynoldsshearstress.Thesuitablecoincidencetimeisselectedforajetflowandtheeffectivenessofcoincidenttimemethodorequaltimeintervalmethodwithcoincidencedataisshown.
简介:Inthepresentpaper,afour-stageperforationmodelthataccuratelypredictstheresidualvelocityisdevelopedbyadoptinganenergymethod.Thefourstagesareplugformation,dishingformation,petalformationandprojectileexit.Inaddition,someimportantexperimentalresultsarepresentedandanalyzedtovalidatethepresentperforationmodel.Intheexperiments,highspeedcamerasystemisusedtorecordtheperforationprocess.Observationsontargetdamageandmeasurementsofinitialvelocitiesandresidualvelocitieswiththeaidofthesystemarepresented.Numericalsimulationsarecarriedoutforprojectilesagainstsingleandlayeredplatesadoptedintheexperiments.Theperforationprocessisstudiedandthedeformationandfailuremodesareobtained.Thepredictionsofnumericalsimulationsandanalyticalmodelarefoundinreasonablygoodagreementwiththoseofexperiments,andcanbeusedtopredicttheballisticlimitandresidualvelocityofstiffenedplatesperforatedbyrigidprojectiles.
简介:Thispapercontainsadetailed,selfcontainedandmorestreamlinedproofofthel~2decouplingtheoremforhypersurfacesfromthepaperofBourgainandDemeterin2015.TheauthorshopethiswillserveasagoodwarmupforthereadersinterestedinunderstandingtheproofofVinogradov'smeanvaluetheoremfromthepaperofBourgain,DemeterandGuthin2015.
简介:Theheatofhydrationofdrysulfonicacidresinindifferentcomcentrationsofsulfuricacidhasbeendetermined.TheheatofhydrationoftheresininH2Ois143.4J/g(resin).Thegreatertheconcentrationofsulfuricacid,thelesstheheatwillbereleased.Thehydrateformedfromthreesulfonicacidgroupsandonewatermoleculeisthemoststableoneofallthehydratesofsulfonicacidresinandwater.
简介:Thefeasibilityofrecoveringglutamicacidbyionexchangemethodwithmacroporousresinswasinvestigated.Theiradsorptionpropertiesinstatistateandtheeffectivefactors,suchaspH,concentrationofeeedandtheratioofammoniumiontoglutamicacid,weresystematicallyexplored.Thebestconditionofseparatingglutamicacidfrommotherliquidwereobtained.
简介:TheinteractionsbetweenmetalionssuchasZn2+,Pb2+,Mn2+,Hg2+,Cd2+,Ni2+andchitosanhavebeeninvestigatedusingthemodelclustermodelmethodanddensityfunctionalmethod.FulloptimizationandfrequencyanalysisofallclustermodelshavebeenperformedemployingB3LYPhybridmethodat3-21Gbasissetlevelexceptmetalionswhichwereinvokedtouseeffectivecorepotential(ECP)method.Theenergychanges,andthemainstructuralparametershavebeenobtainedduringthetheoreticalstudyoftheadsorptionofmetalionsonthechitosan.Thecalculationsshowedthatthecoordinationmodesofmetalionswithchitosanmodelsweredifferent,thegeometriesofMn2+,Zn2+,Cd2+,Hg2+,Pb2+ionscoordinatedwithtwonitrogenatomsandtwooxygenatomsweredistortedtetrahedral,whilethesquareplanarstructureofNi2+coordinatedtwonitrogenatomsandtwooxygenatomswasobserved.Theheatofreactionbetweensixmetalionsandchitosanmodelsshowedtheorder:Mn2+>Ni2+>Zn2+>Pb2+>Hg2+>Cd2+,thissuggestedthatthecoordinationstrengthofMn2+>Ni2+>Zn2+>Pb2+>Hg2+>Cd2+.