简介：Effectsofself-coilingoforganicmoleculesonintramolecularexciplexformationofcompoundI,inwhichthecarbazolechromophoreandterephthalicacidmethylesteracceptorgrouparelinkedbyone(CH2)10chain,andthedecreaseofthefluorescenceintensitiesofcompoundsⅡ，Ⅲ，andⅣ,inwhichthecarbazolechromophoreand3,5-dinitrobenzoateareconnectedbyonealiphaticchainof(CH2)10(Ⅱ），（CH2）12（Ⅲ）,or(CH2)4(Ⅳ）,havebeenstudiedinthedioxane(DX)-H2Obinarysystem.Theresultsshowthatself-coilingoforganicmoleculesinDX-H2OfacilitatesintramolecularexciplexformationofIandinducesthedecreaseoffluorescenceintensitiesofⅡ,bacauseoftheproximityeffectbroughtaboutbyselfcoilingoforganicmoleculesunderhydrophobic-lipophilicinteraction(HLI)betweentheexcitedcarbazolechromophoreandtheacceptor.SincethesimilareffectsareobservedevenwhentheconcentrationoftheprobesarelessthantheirCAgCs(criticalaggregateconcentrations)intheDX-H2Omixturewiththesameφvalues,formationoftheintermolecularexciplexhasbeenexcluded.Theeffectsarefoundtobestronglydependedonφvalues,indicationthattheyaremainlydrivenbyHLI.Thepropertiesoftheacceptorscanalsoaffecttheintramolecularexciplexformation.Withterephthalicacidmethylestermoietyastheacceptor,thecarbazolechromophoreexhibitsthefluorescencespectraoftheexciplex,whilewith3,5-dinitrobenzoatemoietyastheacceptor,onlythefluorescencespectraofexcitedcarbazolylchromophoreareobserved.

简介：Thisstudyaimstoinvestigatetheeffectofthe1-stepquenchingandpartitioning(Q&P)processonthemicrostructureandtheresultingVicker’shardnessof0.3C-1.5Si-1.5Mnsteelbyusingin-situdilatometry,opticalmicroscopy(OM),scanningelectronmicroscopy(SEM),X-raydiffractometry(XRD),andVicker’shardnessmeasurement.Systematicanalysesindicatethatthemicrostructureofthespecimensquenchedandpartitionedat150℃,200℃,250℃,and300℃mainlycompriseslathmartensiteandretainedaustenite.Thedilatometrycurveofthespecimenpartitionedat150℃ispresumablyascribedtotheformationofisothermalmartensite.Intheearlystagesofpartitioningat200℃,thenearlyunchangeddilatationcurveiscloselyrelatedtothesynergisticeffectofisothermalmartensiteformationandtransitionalepsiloncarbideprecipitation.Inthelaterstagesofpartitioningat200℃,theslightincreaseinthedilatationcurveisduetothecontinuousisothermalmartensiteformation.Withfurtherincreaseinpartitioningtemperatureto250℃,thedilatationincreasesgraduallyupto3600s,whichisrelatedtocarbonpartitioningandlowerbainiteformation.Partitioningatahighertemperatureof300℃causesarapidincreaseinthedilatationcurveduringtheinitialstages,whichsubsequentlylevelsoffuponprolongingthepartitioningtime.Thisismainlyattributedtotherapiddiffusionofcarbonfromathermalmartensitetoretainedausteniteandcontinuousformationoflowerbainite.

简介：ThispaperdiscussestheglobalexistenceandquenchingofthesolutiontotheNewtonfiltrationequationwiththenonlinearboundarycondition.Theauthorsalsodiscusstheprofileofthequenchingsolutioninthequenchingtimeandobtainthequenchingrateofthequenchingsolution.

简介：Theinfluenceofingotsegregationonquenchingdistortionofgearsteelwasinvestigatedinthispaper.Theresultsshowthattheshapeofingotsegregationofrodsteeldependsontheshapeofcontinuouscasting(CC)molds,andthatthedistortionofgearsteelwithsquareingotsegregationisuniform,whilethatofgearsteelwithrectangularingotsegregationisanisotropic.Afterquenching,theoutercircleoftheringsamplewithalargerectangularsegregationareaisdistortedintoanovalshape.NoobviouselementsegregationhasbeenfoundintherodsteelproducedthroughtherectangularCCmold.Obviousdifferenceindensityhasbeendetectedatthecrosssectionofrodsteel.Itsuggeststhatcenterporositymaybethemainreasonforthestrongimpactofsegregationonheattreatmentdistortionofgearsteel.

简介：Onthebasisofthetheoryofthermalshockresistanceinthescienceofmaterialsandthetestmethodofairquenchingwhichisgenerallyrec-ognizedinternationally,especiallyinEurope,thepresenttestmethodsfordeterminationofthermalshockresistanceinChinahavebeenanalysed,Experimentstudyonthermalshockresis-tanceofsilicaandbasicrefractoryproductshasbeenconducted,andanewtestmethodofthermalshockresistance-airquenchingmethodhasbeenputforward.

简介：Sinceithasexcellenttensilestrength,thequenchingandpartitioning(Q&P)treatedsteelhasbeenwidelyacclaimed.SomeresearchediscurrentlybeingconductedonQ&Psteel,butQ&Ptechniquesandrelatedmechanismshavebeenmostlyresearchbasedonconventionaltransformation-inducedplasticity(TRIP)steel.ThisstudyresearchestheeffectofMnonthepropertiesofQ&Psheetsteel.TwokindsofsteelsheetwithdifferentlevelsofMncontent(1.46%Mnand2.75%Mn)areinvestigated.Afterbeingfullyannealed,thesteelsheetswerequenchedtoatemperaturebetweenMsandMf.Allocationtreatmentthencausedthecarbontobepartitionedintotheremainingaustenite.Themicrostructureandtensilepropertieswereanalyzed.TheresultsshowthattheincrementofMncontentcanincreasethestabilityofthesteelanddecreasethesensitivityofthequenchingtemperature(QT).TheresultsalsoindicatethatincreasingthelevelofMncaneffectivelysuppresstheformationofbainite.

简介：

简介：

简介：自尊是一种积极的心理品质，是勇于开拓进取者不可缺少的心理品质。

简介：

简介：

简介：

简介：Hello,mynameisLiuLinhan.MyEnglishnameisPeter.Iamelevenyearsold.NowIamstudyinginQingyunliprimaryschool.IaminGradefour,Classfive.IliveinQinhuangdao.Therearethreemembersinmyfamily:father,motherandI.TheylovemeandIlovethemverymuch.Inmysparetime,

简介：

简介：

简介：Bilayermembranesself-assembledfromamphiphilicmoleculessuchaslipids,surfactants,andblockcopolymersareubiquitousinbiologicalandphysiochemicalsystems.Theshapeandstructureofbilayermembranesdependcruciallyontheirmechanicalpropertiessuchassurfacetension,bendingmoduli,andlinetension.Understandinghowthemolecularpropertiesoftheamphiphilesdeterminethestructureandmechanicsoftheself-assembledbilayersrequiresamolecularlydetailedtheoreticalframework.Theself-consistentfieldtheoryprovidessuchatheoreticalframework,whichiscapableofaccuratelypredictingthemechanicalparametersofself-assembledbilayermembranes.Inthisminireviewwesummarizetheformulationoftheself-consistentfieldtheory,asexemplifiedbyamodelsystemcomposedofflexibleamphiphilicchainsdissolvedinhydrophilicpolymericsolvents,anditsapplicationtothestudyofself-assembledbilayermembranes.

简介：

简介：Self-assemblednanostructuresoflipidsandnanoparticlesholdgreatpromiseforapplicationsinsuchfieldsasnanomedicine.Thispaperusestheself-consistentfieldtheorytoinvestigatetheself-assemblybehavioroflipidmoleculesandnanoparticleswithdifferentshapesinanaqueoussolution.Itisfoundthatthelipidmoleculescanformmonolayeredandbilayerednanostructuresaroundthenanoparticleswithdifferentshapes(e.g.,triangular,square,hexagonalandoctangular).Withdecreasingthesizeofnanoparticlesorincreasingthenumberofpolygonedges,theshapeoflipidlayerswillapproachanapproximatelysphericalshape.Thesefindingsmayhelptopredictanddesignnoveldrugdeliverynanocarriers.

简介：Inthispaper,weconsiderthefollowingchemotaxismodelwithratio-dependentlogisticreactiontermu/t=D▽(▽u-u▽ω/ω)+u(α-bu/ω),(x,t)∈QT,ω/t=βu-δω,(x,t)∈QT,u▽㏑(u/w)·=0,x∈Ω,00,x∈,w(x,0)=w0(x)>0,x∈,Itisshownthatthesolutiontotheproblemexistsgloballyifb+β≥0andwillblowuporquenchifb+β<0bymeansoffunctiontransformationandcomparisonmethod.Variousasymptoticbehaviorrelatedtodifferentcoefficientsandinitialdataisalsodiscussed.

简介：Heptacyclo[6.6.0.02,6.03,13.04,11.05,9,010,14]tetradecaneisacage-shapedmoleculeofbothhighsymmetry(D2d)andhighrigidity.Inourpreviousreports,ithasbeenusedasanuniquespacergroupforelectrontransferprocessesbetweenadonor(D)andanacceptor(A)substituent.TheDandAchromophorescanbealignedalongastraightline,eithercoplanar(0°dihedralangle)orperpendicular(90°dihedralangle)withrespecttoeachother.Knowledgecollectedinthisworkmaybeusefulforthedesignofphoto-electronicdevices,suchaselectrochemicalsensors,photovoltaiccells,molecularrectifiersandswitches,etc.