简介：DellaVecchiaetal.(see[2])introducedakindofmodifiedBernsteinoperatorswhichcanbeusedtoapproximatefunctionswithsingularitiesatendpointson[0,1]Inthepresentpaper,weobtainakindofpointwiseStechkin-typeinequalitiesforweightedapproximationbythemodifiedBernsetinoperators.

简介：TheWahlquist-Estabrook(WE)prolongationstructuresofmodifiedBoussinesq(MB)systemarestudiedfromthecoveringspointofview.Therealizationsandclassificationsofone-dimensionalcoveringsofthissystemareobtainedcompletely.MoreoverthesufficientandnecessaryconditionsforavectorfieldtobeanonlocalsymmetryofthissystemarealsodemonstratedintheWEprolongationstructures.

简介：InthispaperweproposetheqanaloguesofmodifiedBaskakov-Sz′aszoperators.Weestimatethemomentsandestablisheddirectresultsintermofmodulusofcontinuity.Anestimatefortherateofconvergenceandweightedapproximationpropertiesoftheqoperatorsarealsoobtained.

简介：在使用micro-arc-oxidization(毛)并且随后在不同模仿的生理的环境与poly-L-lactic酸(PLLA)封上的表面修正以后的新奇高张力AZ31B镁合金电线的降级行为被调查。表面毛micropores能身体上是的结果表演由PLLA封上，因此为电线形成有效保护到腐蚀抵抗。在在低pH价值(1.5或2.5)的模仿的胃的液体(SGF)，对待的电线让高降级与质量，直径，机械性质和沉浸液体的pH价值的重要增加的快速的减少评价。然而，表面修正能有效地与上面的pH价值在SGF减少对待的电线的降级率4.0。为在在pH=的模仿的肠的液体的对待的电线8.5，他们的力量保留能力在强壮的酸的SGF比那高。并且质量的损失率比直径的快，当沉浸液体的pH价值减少时。在模仿的身体环境的修改电线有最好的力量保留能力，这应该被注意。电线显示出显示他们的不同降级机制的不同降级行为，它也在这个工作被建议。

简介：Amodifiedtorsionpendulumapparatusisdevelopedformeasuringtheshearmodulusofsinglefilamentswithuniformmicro-sizeddiameter.Asinglefilamentfixedatbothendsandwitharing-shapedmassattachedatthemiddleisusedasaclamped-clampedtorsionpendulum.Theshearmodulusofsinglefilamentscanbeexpressedasafunctionoftheoscillationfrequencyofthetorsionpendulum.TheoscillationmotionismeasuredwithaCCDlaserdisplacementsensor,anditsfrequencyisdeterminedbytheFastFourierTransform(FFT)method.Theshearmoduliofthreetypesoffilaments:copperwires,tungstenwiresandcarbonfibersareaccuratelymeasuredwiththistechnique.Itisfoundthatthesizeeffectinshearmoduliofbothcopperwiresandtungstenwiresisminor.Finally,theerroranalysisofourmeasurementtechniqueispresentedindetail.

简介：Weappliedthediscreteelementmethod(DEM)ofsimulationmodifiedbyanenlargedparticlemodeltosimulatebeadmotioninalargebeadmill.Thestainless-steelbeadmillhasinnerdiameterof102mmandmilllengthof198mm.Thebeaddiameterandfillingratiowerefixedrespectivelyat0.5mmand85%.Theagitatorrotationalspeedwaschangedfrom1863to3261rpm.Thebeadmotionwasmonitoredexperimentallyusingahigh-speedvideocamerathroughatransparentmillbody.Forthesimulation,enlargedparticlesizesweresetas3-6mmindiameter.WiththeDEMmodifiedbytheenlargedparticlemodel,themotionofenlargedparticlesinamillwassimulated.Thevelocitydataofthesimulatedenlargedparticleswerecomparedwiththoseobtainedintheexperiment.ThesimulatedvelocityoftheenlargedparticlesdependsonthevirtualfrictionalcoefficientintheDEMmodel.Theoptimizedvalueofthevirtualfrictionalcoefficientcanbedeterminedbyconsideringtheaccumulatedmeanvalue.Resultsshowthatthevelocityoftheenlargedparticlessimulatedincreaseswithanincreaseintheoptimumvirtualfrictionalcoefficient,butthesimulatedvelocityagreeswellwiththatdeterminedexperimentallybyoptimizingthevirtualfrictionalcoefficientinthesimulation.Thecomputingtimeinthesimulationdecreaseswithincreasedparticlesize.

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简介：Effectsofhydrochlorideaciddealuminationofmordenite(MOR)catalystsforthesynthesisof1-phenyl-1-xylylethane(PXE)wereinvestigated.ThestructureandacidityofcatalystswerecharacterizedbyXRD,BET,XRF,FT-IR,27AlNMRandNH3-TPDtechniques.Thecatalyticperformanceoftheacid-treatedMORzeoliteswasstudiedthroughusingthealkylationofo-xylenewithstyrene.ThetestresultsshowedthatthestrengthofremainingBr?nstedacidsitesincreaseddespitethereductionoftotalnumberofacidsitesafterdealumination,andthemicroporesofHMORwereslightlyenlargedcoupledwiththeformationofsecondarymesopores.Additionally,themodifiedHMORzeolitesshowedlongercatalystlifewiththestyreneconversionrateretained.Amongthecatalystsemployedinthisstudy,themodifiedmordenitethatwasdealuminatedbyHCl(2mol/L)couldbeusedrepeatedlywithoutsignificantlossofactivityandselectivityduringsixcatalyticruns,whichhavebeenascribedtoitsspecificacidityandstructuralproperties.

简介：Differentrareearth(RE=La,Ce,Pr,Nd,Sm,Y)andCumodifiednickelcatalystsforhydrogenproductionfrommethanedecompositionweresynthesizedbyasol-gelprocessandmethod.ThecatalystswerecharacterizedoranalyzedthroughBrumauer-Emmett-Teller(BET),X-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM)techniques.Andthehydrogenproductionperformancewasalsoevaluatedbyafixed-bedandmicro-reactiontechniquewithCH4→C+H2asaprobereaction.Theresultsshowedthatrareearthmodificationhadplayedagreatrolefornickelcatalysts,forexample,smallernickelparticles,goodthermalstability,highactivity,etc.Lawasthebestadditiveamongrareearthmodification.TheSEMofrareearthmodifiedcatalystsshowedorderedflower-likestructureandrareearthmodificationmadethenickelparticlesmovetothesurfaceofcatalysts.Inaddition,theSEMofnano-carbonswasalsochangedbyrareearthmodificationwithlong,narrownano-carbonfibersortubesobtained.Solidcarbonformationwaspreventedbyrareearthmodification.

简介：Anovelhydrophilicnanocompositeadditive(TiO2-g-PNIPAAm)wassynthesizedbythesurfacemodificationoftitaniumdioxide(TiO2)withN-isopropylacrylamide(NIPAAm)via"graft-from"technique.Andthenanocompositemembraneofpoly(vinylidenefluoride)(PVDF)/TiO2-g-PNIPAAmwasfabricatedbywetphaseinversion.Thegraftdegreewasobtainedbythermo-gravimetricanalysis(TGA).Fouriertransforminfraredattenuatedreflectionspectroscopy(FTIR-ATR)andX-rayphotoelectronicspectroscopy(XPS)characterizationresultssuggestedthatTiO2-g-PNIPAAmnanoparticlessegregatedonmembranesurfaceduringthephaseseparationprocess.Scanningelectronmicroscopy(SEM)wasconductedtoinvestigatethesurfaceandcross-sectionofthemodifiedmembranes.ThewatercontactanglemeasurementsconfirmedthatTiO2-g-PNIPAAmnanoparticlesendowedPVDFmembranesbetterhydrophlilicityandthermo-responsivepropertiescomparedwiththoseofthepristinePVDFmembrane.Thewatercontactangledecreasedfrom92.8°ofthePVDFmembraneto61.2°ofthenanocompostiemembrane.Bovineserumalbumin(BSA)staticanddynamicadsorptionexperimentssuggestedthatexcellentantifoulingpropertiesofmembraneswasacquiredafteraddingTiO2-gPNIPAAm.ThemaximumBSAadsorptionat40°Cwasabout3timesthanthatat23°C.ThepermeationexperimentsindicatedthewaterfluxrecoverratioandBSArejectionratiowereimprovedatdifferenttemperatures.

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简介：AmodifiedLindstedt-Poincaré(LP)methodforobtainingtheresonanceperiodicsolutionsofnonlinearnon-autonomousvibrationsystemsisproposedinthispaper.Inthemodifiedmethod,nonlinearnon-autonomousequationsareconvertedintoagroupoflinearordinarydifferentialequationsbyintroducingasetofsimpletransformations.Anapproximateresonancesolutionfortheoriginalequationcanthenbeobtained.Theperiodicsolutionsofprimary,super-harmonic,sub-harmonic,zero-frequencyandcombinationresonancescanbesolvedeffectivelyusingthemodifiedmethod.Someexamples,suchasdampedcubicnonlinearsystemsundersingleanddoublefrequencyexcitation,anddampedquadraticnonlinearsystemsunderdoublefrequencyexcitation,aregiventoillustrateitsconvenienceandeffectiveness.UsingthemodifiedLPmethod,thefirst-orderapproximatesolutionsforeachequationareobtained.Bycomparison,themodifiedmethodproposedinthispaperproducesthesameresultsasthemethodofmultiplescales.

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简介：BackgroundAnimalmodelsofmyocardialinfarction(MI)havebeenwidelyusedtostudythepathologicalandphysiologicalchangesthatoccurinMI,andtoobjectivelyevaluatetheefficacyofnewtreatments.Theyareanimportanttoolinthisprocedure.However,themortalityrateofMIanimalmodelshassofarbeenhigherthaninreal-lifesituations.Theaimofthisstudywastoexploretheuseofamodifiedretrogradetractiontrachealintubation(MRTI)methodforincreasingthesuccessrateofMImodelsinrats.MethodsSixtymaleSprague-Dawleyratswereusedintheexperiment.UsingtheMRTImethodofartificialairwaygeneration,weestablishedtheMImodelbyligationoftheleftanteriordescendingbranchofthecoronaryartery.WeanalyzedtheeffectsofMRTI,theuseoflidocaine,operativedetails,nursingconsiderationsduringtheoperation,andpost-operativefactorsonthesuccessrateoftheMImodelinrats.ResultsThesuccessrateofgeneratinganMImodelinratscanbesignificantlyincreasedusingthefollowingmethods:1)SettinguptheartificialairwaythroughtheuseofMRTIbyusingasingle-lumencentralvenouscatheter;2)Selectingaligationsite2mmbelowthemidpointoftheconnectionbetweentheleftatrialappendageandthepulmonarycone;3)Addingadropoflidocainetothesurfaceofthehearttoslowdowntheheartrate,maketheoperationeasiertoperform,andpreventarrhythmiaspostoperatively;4)Clearingupairwaysecretionstimelybothintraandpostoperatively;5)Makingsurethatratsareinawarmstatebothintraandpostoperatively;6)Preventingwoundinfection.ConclusionsUseoftheMRTImethodcanquicklyestablishanartificialairwayinrats.Intraoperativeuseoflidocaine,selectingaprecisevascularligationsite,andappropriatecarebothintraandpostoperativelycanincreasethesuccessrateofMImodelgeneration.更多还原

简介：Sm0.2Ce0.8O1.9(SDC)electrolytewaspreparedbyamodifiedsolidstatemethodatrelativelylowsinteringtemperatureswithoutanysinteringpromoters.ThephasecompositionandmicrostructureoftheelectrolyteswereinvestigatedbyX-raydiffraction(XRD)andfieldemissionscanningelectronmicroscopy(FESEM)technologies.ArelativedensityofSDCelectrolytesinteredat1300oCreached97.3%andthemeanSDCgrainsizewasabout770nm.Theirionicconductivityandthermalexpansioncoefficientwerealsomeasuredbyelectrochemicalworkstationanddilatometer.Theelectrolyteattainedahighconductivityof5×10–2S/cmat800oCwithanactivationenergyof1.03eVandaproperthermalexpansioncoefficientof12.6×10–6K–1.

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简介：InordertoimprovethecorrosionandmechanicalpropertiesofAM50magnesiumalloy,1wt.%GdwasusedtomodifytheAM50magnesiumalloy.Themicrostructure,corrosionandmechanicalpropertieswereevaluatedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),energydispersivespectroscopy(EDS),electrochemicalandmechanicalstretchmethods.Theresultsindicatedthatβ-Mg17Al12phasedecreasedandAl2Gd3andAl0.4GdMn1.6phaseexistedafterGdaddition.BecauseoftheGdaddition,thegrainofAM50magnesiumalloywasrefinedsignificantly,whichimprovedthetensilestrengthofAM50magnesiumalloy.Thedecreasingofβphaseimprovedthecorrosionresistanceofthemagnesiumalloy.ThefracturemechanismoftheGdmodifiedAM50magnesiumalloywasquasi-cleavagefracture.Thecorrosionresidualstrength(CRS)ofAM50magnesiumalloywasimprovedafter1wt.%Gdaddition.

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简介：Amorphouscarbonandgrapheneco-modifiedLiFePO4nanocompositehasbeensynthesizedviaafacilepolyolprocessinconnectionwithafollowingthermaltreatment.Variouscharacterizationtechniques,includingXRD.Mossbauerspectra,Ramanspectra,SEM,TEM,BET,O2-TPO,galvanocharge-discharge,CVandEISwereappliedtoinvestigatethephasecomposition,carboncontent,morphologicalstructureandelectrochemicalperformanceofthesynthesizedsamples.TheeffectofintroducingwayofcarbonsourcesonthepropertiesandperformanceofLiFePO4/C/graphenecompositewaspaidspecialattention.Underoptimizedsyntheticconditions,highlycrystalizedolivine-typeLiFePO4wassuccessfullyobtainedwithelectronconductiveFe2PandFePasthemainimpurityphases.SEMandTEManalysesdemonstratedthegraphenesheetswererandomlydistributedinsidethesampletocreateanopenstructuredLiFePO4withrespecttographene,whiletheglucosederivedcarbonmainlycoatedoverLiFeP04particleswhicheffectivelyconnectedthegraphenesheetsandLiFePO4particlestoresultinamoreefficientchargetransferprocess.Asaresult,favorableelectrochemicalperformancewasachieved.Theperformanceoftheamorphouscarbon-grapheneco-modifiedLiFePO4wasfurtherprogressivelyimproveduponcyclinginthefirst200cyclestoreachareversiblespecificcapacityashighas97mAh·g-1at10Crate.