简介：X-rayphotoelectronspectroscopyandRamanspectroscopywereusedtodeterminethechemicalchangeofpolyphenylsilsesquioxane(PPSQ)duringpyrolysisinflowingnitrogen.TwotemperaturerangeswerefoundforpyrolysedPPSQbelowandabove600℃,respectively.TheformerisrelatedtotherearrangementofPPSQbackboneandthelatterreflectsthatmostofbackbonestructureofPPSQmightbebrokendownandunorganized.CarbonformedincarbonizationofPPSQsamplepyrolysedat900℃shouldbesp3bondedcarbonwithcrystallitesizeeffectsordefects.

简介：Thephotophysicalpropertiesofaseriesofsulfonatedmicromolecule(paratoluenesulfonicacid,HPTS)andmacromolecules(linearandcrosslinkedpolystyrene)havebeenstudiedbysteady-statefluorescencespectra.Theresultsindicatethatthegroundsulfonatedringassociationscanforminboththemicromoleculesandthemacromolecules.Thefluorescencespectraofthesulfonatedcrosslinkedcopolymersappearared-shiftwhenthecopolymerschangefromhydrogen-typetosodium-type,andsomenewemissionbandsappearinthelong-wavelengthregion.Theseresultsareexplainedintermsofsynergeticeffectofhydrogenbond,π-πinteractionandcrosslinkingeffect.

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简介：Cryosurgeryisaneffectivewayofcuringmanydiseasesincludingtumorsandcancers.Itcanbeappliedusingavarietyofsystemsandcryogens.Cheap,convenient,reliableequipmentstillneedstobedevelopedsothatcryotherapymaybeacceptedbysurgeonsandhospitals.Thispaperpresentsacryosurgeryapparatusthatutilizesanauto-cascaderefrigerationsystem.RefrigerantmixtureR50/R23/R600awasselectedastheworkingfluid.Themixturecompositionwasalteredtoachievelowertemperaturesandhighercapacity.Thelowesttemperatureatthecryoprobecouldbeaslowas-100°C,and8Wrefrigerationcapacitycouldbeobtainedat-80°C.Aniceballof11.6mmdiametercouldbeformedwhenthecryoprobewasimmersedinawaterbathat37°C.

简介：Theelectrochemicaloxidationofdiphenylamineinacetonitrileproducesanadherentuniformpolymerfilmwhichexhibitsmutiplecolourvariation(yellow-green-blue)inawiderangeofpotentialscan.Thepolymerizationmechanismandthestructureofthepolymerwerestudiedbycyclicvoltammetry,FT-IRandinsituESR.Theresultsindicatethattheelectrochemicalpolymerizationofdiphenylaminebelongstoacationicradicalpolymerizationprocess.Duringelectrolysis,onlyoligomerswereinitialyproduced,thenpolymerfilmwasformedontheelectrodesurface.Theelectropolymerizationperformsviathe4,4’C-Cphenyl-phenylcouplingmechanism.

简介：ThesurfacecompositionandelectronicstructureoftungstencarbidespreparedbydirectsynthesisandcarburizationofwhitetungsticacidwerestudiedwithX-rayphotoelectronspectros-copy.TheexperimentalresultsshowthatWO3andfreecarbonarepresentonthesurfaceofthecarbides.Forthehighsurfaceareatungstencarbidepreparedfromwhitetungsticacidalargeextentofoxygeninsertionintothecrystallatticewasobserved.MeasurementsofthebindingenergiesoftheW47/2,C1sandO1scorelevelsindicatethatchargetransferisfromtheWtotheCandOatoms,formingW5d-C2pandW5d-O2pbonding.ThecatalyticbehaviorofthetungstencarbidesinhydrocarbonconversionreactionsismentionedandcomparedwithPtcatalysts.

简介：一、什么是STUDYGROUPSTUDYGROUP是牛津大学的A.B.Tayler博士和当时他的学生J.Ockendon等人在1968年创立的,它的原名是OxfordStudyGroupwithIndustry。这种活动历时一周,是由数学工作者和工业界人士参加的旨在解决实际问题的研讨会。在研讨会的第一天,由工业界代表陈述要解决的问题和目的要求,通常会有5~6个问题。后续2~3天按问题分组讨论,试图建立问题的数学模型和求解方法来解决问题。若问题比较

简介：［1］BASFUSP4479906［2］BASFBP1443541［3］BASFDE3618265［4］WangL.,WuZ.,ChinaLeather,26(8),11,(1997)［5］YuanL.,DinY.,ChineseChemistryBulletin,(2),19(1988)［6］KurokiH.,ChemistryofDyeingTheory(ChineseTranslation),TextileIndustryPress,Beijing,89(1982)［7］WangS.,LiP.,WuZ.DyestuffIndustry(Chinese),34(4),1,(1997)［8］Tian,Y.,Wu,Z.,Wang,G.,Zhang,S.J.ChineseChem.Eng.,46,156(1995)［9］Tian,Y.,Wang,G.,Wu,Z.,J.ChineseChem.Eng.,47,75(1996)［10］Lycka,A.,DyesandPigment,32,11(1996)［11］Griffith,J.,ColourandConstitutionofOrganicMolecules,AcademicPress,London,191(1976)

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简介：DiamondfromLiaoning,Chinawasstudiedbysynchrotronradiationandinfraredspectrum.Thedistributionofdislocationsinthespecimenthasbeenrevealed.Anewmethodtodeterminetheorientationofcrystaldefectshasbeenproposedandtheorientationindexesofthedislocationsinthespecimenwerecalculatedbythismethod.Ithasbeenfoundthatthedislocationsinthespecimentarenearbutnotpreciselyparallelto{111}planes,Themaximumanglebetweendislocationand{111}planeisabout16°.AlmostallthedislocationsinthespecimenthavethesameBurgersvector1/2[101]andimplythesamenessoftheirorigination.

简介：Toestablishthemechanismofsurfacechangeinacontinuouspolishingsystem,anidealmathematicalmodelisbuiltbasedonWinkler’shypothesisandthePrestonequation.Thebasicfeaturesofthemodelarethechangeratesinthesurfacepeak–valley(PV)valuesoftheworkpiece,conditioningdiskandpitchlap,ratherthanthespecificsurfaceshapes.Inaddition,anequilibriumstateexistsinthesystem,indicatingthatthesurfacechangeratesareallzero.Underequilibrium,thesurfaceofthelapcouldremainflat,anditisinsensitivetothesurfaceerroroftheworkpiece.Thesecharacteristicslaythetheoreticalfoundationsforhigh-efficiencyandhigh-precisionpolishing.Themethodstoobtainanequilibriumstatewithflatsurfacesarethenproposedandconfirmedexperimentally.High-precisionsurfacesbetterthanλ/10(λ=632.8nm)areconsistentlyproducedexperimentally.

简介：Let(X1,X2,…,Xn)and(Y1,Y2,…Yn)berealrandomvectorswiththesamemarginaldistributions,if(X1,X2,…,Xn)≤c(Y1,Y2,…Yn),itisshowedinthispaperthat∑i=1^nXi≤cx∑i=1^nYiandmax1≤k≤n∑i=1^kXi≤icxmax1≤k≤n∑i=1^kYihold.Basedonthisfact,amoregeneralcomparisontheoremisobtained.

简介：Ringinversionofeightsubstituted2-phenyl-4,4-dimethyloxazolidinesino-dichloro-benzene-d4wasstudiedbyHDNMR.Veryhighinversionbarriers(/nGc/n=86.7—93.4kJ·mol-1)werefoundfortheseoxazolidinerings.Themagnitudeoftheinversionbarrierisdependentonthepolarityofthesubstituentonthephenylgroup.Alinearcorrelationispresentbetweenthe/nGc/noftheinversionandthesubstituentconstant,σ+,ofthesubstituent.

简介：Blanketsandotherin-vesselcomponentsareeasilydamagedowingtotheircircumstanceofhighradiationandhighheat.Toprotectthem,firstwalldesignshouldbeconsidered.Owingtoitshighheatremovalndself-refreshingcapability,liquidmetalfirstwallhasbeenseenasapotentialfirstwallforafusionreactorinthefuture.Blanketliquidcurtainisactuallyaspecialliquidmetalwalltoprotectblanket.

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简介：Withcelluloseascarrier,immobilizedthermolysinHEIandHEⅡwerepreparedbydiazocouplingorglutaraldehydecrosslinkingreaction.Usingcaseinasasubstrate,theactivityrecoveryofimmobilizedthermolysinHEIandHEⅡreach34.5%and29%,respectively.Somefactorswhichaffecttheactivityoftheimmobilizedthermolysinsuchastemperature,mediumpH,EDTAandcalciumacetatewerestudied.Atthesametime,thethermalstabilityandstoragestabilityoftheimmobilizedthermolysinwerealsoinvestigated.

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简介：ExperimentalandtheoreticalinvestigationofpromptnitrogenoxidesemissioninflameofdifferentgaseousfuelswerecarriedoutwithpurposeofminimizingtotalNOxyield.Theeffectofthefollowingfactorswasdetermined:airexcessfrom0.3to1.1,flametemperature,heatingflamerate,fuelcontent,Itwasfoundthat,ifairexcesswaslessthan0.65,somepromptNOxconvertedtoN2inconsequenceofreactingwithhydrocarbonradicals.

简介：Stroma-freehemoglobin(SFHb)waspreparedfromfreshorout-datedwholebloodbylysingredcells.Atdifferenttemperatures,pyridoxal5-phosphate(PLP)wasaddedina4:1molar-ratiototheHbtetramerfollowedbyreductionwithNaBH4underN2for16hrssubsequentcrosslinkingbyglutaraldehydeinpresenceoflysinefor14-16hrs.Yieldedsolublepyridoxalatedpolyhemoglobin(PolyHb-P).5%-20%gradientSDS-PAGEshowedthechangeoftheHbmolecularweight(MW)aftercrosslinking.GelchromatographyshowedthatthepolyHb-Phadacontinuousdistributionofmolecularweightwiththerangefromabout65,000to600,000Dalton.ThepolyHb-Psolutionprovidedanornaloxygencarryingwith23.1ofP50atpH7.24or26.1ofP50atpH7.24.

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