简介:Threepolymericadsorbentswithhydrogenbondingacceptors,methylamine,N-methyl-acetamideandaminotri(hydroxymethyl)methanemodifiedresinsaresynthesizedfromchloromethylatedX-5resin.AdsorptionisothermsofphenolandtheophyllineontothethreemodifiedresinsandtheoriginalX-5resinfromaqueoussolutionaremeasured.TheresultsshowthatadsorptionofcompoundswithhydrogenbondingdonorontomethylamineandN-methylacetamidemodifiedresinsisenhancedascomparedwiththatontoX-5resin,andadsorptionmechanismbetweentheadsorbentsandtheadsorbatesismainlybasedonhydrogenbondingandhydrophobicinteraction.Whileadsorptionofcompoundswithhydrogenbondingdonorontoaminotri(hydroxymethyl)methanemodifiedresinisloweredascomparedwiththatontoX-5resin,andadsorptionmechanismbetweentheadsorbentandtheadsorbatesismainlybasedonhydrophobicinteraction.
简介:作为概念车,宝马Z07在1997年东京车展和1998年底特律车展一经亮相,立刻赢得了汽车鉴赏家们的好评,他们迫不及待地询问该车何时投产。今年1月份,宝马宣布这美仑美奂的汽车投入生产,最后定名为宝马Z8。去年,该车还成为007新片《末日帝国》中詹姆斯·邦德的座驾。Z8的外观设计独树一帜。颀长的发动机罩、宽大的车轮,还有车身两侧动感十足的排风口,无不令人回忆起那“美好的旧日时光”。很多人也许会从Z8联想到有史以来最漂亮的汽车-那款50年代的富于传奇色彩的宝马507。宝马507是当年的设计师高尔茨(AlbrechtGrafGoertz)的杰作,这款举世无双的经典车仅仅生产了252部。Z8把人们对宝马507的追念和激情变成了现实,然而和507一样,这款车是稀世珍品,狂热的车迷们并非每天都有机会向它致意。
简介:宝马汽车在马年到来之际,在新加坡推出全新的3系列宝马。新宝马在各方面都作了重大改进,在更省油的情况下输出更强劲的动力,不仅是同级车中的佼佼者其行驶性能获得行内人士一致好评。
简介:Thispaperderivesthephysicalmeaningsofpeakposition,peakwidthandheightofanX-raydiffractionpeakfromtheanalysesoftheBragg'sequation,theScherrer'sformulaandtheprincipleofpeakintensitycalculation.Thegeometriccharacteristicsofanasymmetricpeakareclarifiedbymeansofexperiment.Therelationshipsbetweenneakshapeanddomainsize/latticestrainhavebeenverifiedbygeologicalevents.Thereforethispaperintegratesthephysicalmeaningsofall5basicparametersforanX-raydiffractionpeak.Applicationsofthese5parame-tersareexemplified.
简介:ThemeasurementsoftemperaturedependenceofthemagneticsusceptibilityofLa1-xSrxCoO3perovskiteoxidesatdifferentSrdoping(0≤x≤0.5)andannealingtemperaturewerepresented.Forthesamplewithx=0.1,ashoulderwasobservedaround150K,andapeakwhichisonefeatureofspinglassappearedaround50Kinthecurveofsusceptibilityversustemperature.Thehigh-temperature(250~420K)susceptibilityfitswellwithCurie-Weisslawforallsamples.WeissconstantandeffectivemagneticmomentweredeterminedandtheirvariationswithSrdopingandoxygenannealingconditionwereobtained.TheWeissconstantincreasesmonotonouslywithSrcontentforx>0.2.Thevaluesofeffectivemomentswereinterpretedwiththespinstateofcobaltions.Studiesonthesusceptibilitiesofthesampleswithx=0.2underdifferentpreparationtemperaturesandannealingtemperaturesshowthattherisingofsinteringtemperatureandannealingtemperaturewillincreasethepara-ferromagnetictransitiontemperature,andreducetheeffectivemomenttonormalvalue.OurresultshowsthatbothCo3+andCo4+ionsshouldbeinISstateafterannealingandtheoxygenannealingcausesthetransitionofCo3+spinstatefromHStoIS.