简介:CuSmicrocrystalsweresuccessfullypreparedthroughamildsolvothermalreactioninethyleneglycol(EG)withtheassistanceofcationicsurfactantcetyltrimethylammoniumbromide(CTAB).Aninterestingmorphologyevolutionfromflower-likemicrospherestohollowmicrospheres,andfinallytosmoothnanoflakeswasobservedwhenincreasingtheamountofCTAB.TheproductswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),andUV—visspectroscopy.ItwasfoundthattheamountofCTABplayedanimportantroleindeterminingthemorphologyoftheCuSmicrocrystals.Electricalmeasurementrevealsthattheas-preparedCuSmicrosphereswereofhighconductivity,whichmightfavortheirdeviceapplications.ItisexpectedthatCuSmicrocrystalswithcontrolledmorphologiesandstructureswillhaveimportantapplicationsinsolarcells.Thissimplebuteffectivemethodcouldalsobeextendedtothecontrolledgrowthofotherinorganicmicrocrystals.
简介:Anewapproachtothesynthesisof2,2″-biflavanonesbythereductivedimerizationoffla-vonesisreported.Theproducts,theracemateandmesobiflavanones,havebeenseparatedandtheirstructureshavebeendeterminedonthebasisoftheirspectraldata.Theconfigurationof3bhasbeendeterminedbyX-raycrystallographyaswell.
简介:Thesolid-phasesynthesisofisoxazolineson2-polystyrylsulfonamidoethanolresinisreported.2-Polystyrylsuifonamidoethanolresin1wasreactedwithacryloylchloridetoafford2-polystyrylsulfonylamidoethylacrylateresin2,whichwasfurtherreactedwithbrominatedaldoximesby[3+2]cycioadditiontogiveisoxazolineresin4.Resin4wastreatedwithaqueous6mol/LHCIsolutiontoobtainisoxazolinesingoodyieldandpurity.
简介:IntroductionNanometer-scalecrystallitesofvariousmetalsandnonmetalshaveattractedagreatdealofattentionoverthepastdecade.Forsuchcrystallites,thephysicalandchemicalpropertiesareheavilydependentonparticlesizeandshape,and,asaresult,thesematerialshaveawiderangeofapplications(Ai&Kang,2003).Monodispersefinenickelparticlesarerequiredforhightechnologyapplicationsinalkalinerechargeablebatteries,magneticrecordingmediaandchemicalcatalysts,etc.,suchasconductingandmagneticinks,andferrofluids(Glicksman,1984).Amongthevariousmethodsforsynthesisofultrafinenickelpowdersincludingphysicalmethodssuchasballmilling,pulsedelectrodeposition(PED),thermalplasma,gasdepositionmethods(GDM),γ-radiation(Wangetal.,1988),andchemicalmethodssuchassonochemicaldecomposition(Gaoetal.,2001),chemicalreduction(Illy-Cherreyetal.,2002),microwavehydrothermalmethod(Komamenietal.,1992),mechanochemicalandpolyolprocessing(Baburajetal.,1997;Hegdeetal.,1997),chemicalreductioninanaqueoussolution(Lietal.,1999;Jungetal.,2003;Degen&Macek,1999;Syukrietal.,2003)ischoseninthepresentstudybecauseofeasycontrollingofthesizeandshapeofNinanocrystals.
简介:Thesynthesisofadamantanefromtetrahydrodicyclopentadieneonzeoliteswithdifferentframeworkstructureswasstudied.TheadamantaneyieldonHYzeolitesishigherthanonHMandHZSM-5zeolites.AmongvarioustypesofdealuminatedHYzeolitestheHEYandHUSYzeolitesgivehigheradamantaneyieldsthanconventionalHYzeolite.Thechangesinactivityandselectivityofthemainandsidereactionsarecorrelatedwiththeacidityandtheporestructureofthezeolites.Toion-exchangetheHYandHUSYzeoliteswithNi2+andLa3+cationsmayfurtherimprovetheactivityandselectivityofthezeolitecatalysts.
简介:THESYNTHESISOFSTEROID-OLIGOPEPTIDE¥XiaoZHANG;LingLingWENG;HuZHENG(DepartmentofBiochemistry,GuangdongMedicalCollege,Zhanjiang,...
简介:Thispaperintroducesaknowledgeconstructionmodelcalledthei-SystemforknowledgeintegrationandcreationanditsrelationtothenewconceptoftheCreativeSpace.Thefiveontologicalelementsofthei-SystemareIntelligence,Involvement,Imagination,Intervention,andIntegrationcorrespondingtofivediversedimensionsoftheCreativeSpace.Thepaperdiscussesthemeaningsandfunctionsofthesedimensionsinknowledgeintegrationandcreation,andpresentsapplicationsofthei-Systemtotechnologyroadmappingandarchiving.
简介:Hypericin是主要从属于节Euhypericum和凯勒的分类的Campylosporus的类Hypericum的工厂提取的最重要的phenanthoperylenequinones之一。普遍注意到抗病毒并且hypericin的反肿瘤性质刺激了化学合成的调查和这唯一的混合物的生合成。然而,合成策略为器官、生物的化学家是挑战性的。在这评论,在在过去的十年的全部的合成,半合成,和生合成的特定的重要进展被总结。
简介:Themonomerofphosphorylcholinederivative,O-(5-(2-methacryloxy)-3,3-dimethyl-3-azapentyl)-O’-(ω-hydroxy-octyl)-phosphatequaternaryammoniumsalt,wasdesignedandsynthesizedsuccessfully.Itwascharacterizedbythespectraof~1HNMRandMassspectra(ESI+),andeverysignalwasassigned.Thenthelubricatingcharacteristicsofthephosphorylcholinederivativewereinvestigatedonthetribologicalsetupofball-oh-flat.TheUltra-HighMolecularWeightPolyethylene(UHMWPE)flatwasrotatedagainstastainlesssteelballwith6mmdiameter.Theloadwas2.3N,whichcorrespondedtoamaximalHertzcontactpressureof29MPa.Water,phosphorylcholinederivative,andAcrylicAcid(AA)solutionwereusedaslubricants,respectively.ComparedwithAA,thephosphorylcholinederivativeshowssignificantlubrication.Itcanbestronglyhydratedunderwaterduetothechargedsegmentinchemicalstructure.Thethickwaterlayerswithinthechainsservesasboundarylubricants,andthisisthoughttobethemolecularoriginsoflubricatingbehavior.
简介:Nanoparticlescanprovideflameretardancetohostingpolymersandactasnanofireextinguishers.Hydroxyapatite(Ca5(OH)(PO4)3)(HA)isnothygroscopic,andisthermallystableupto800℃,with18.5wt%phosphorouscontent.ItisthishighphosphorouscontentthatcanprovideHAwithflameretardantproperties.Inthispaper,wereportonthecontinuoussynthesisofultrafineHAusingahydrothermalsynthesistechnique.TheHAsurfacepropertieswerechangedfromhydrophilictohydrophobicbypostsynthesissurfacemodification.TheratiooftheHAnanoparticlesandanintumescentagentknownasExolitAP750wasinvestigatedtoyieldaself-extinguishingmulti-componentepoxynanocompositeforextendedapplicationunderextremefireconditions.TheHA/AP750/epoxynanocompositewasabletoresistaflameat1700℃andself-extinguishaftertheflamehadbeenremoved.Thenanocompositeshowedanenhancedflammabilityperformanceinstandardconecalorimetrytestingandformedacompactandcohesiveprotectivecharlayerwitha50%decreaseinpeakheatreleasedcomparedwithvirginepoxy.OuraimwastoestablishtheuseofHAasaneffectivenanofillerwithphosphorous-basedflameretardantproperties.Thesurfaceofthisnanofireextinguisherwasmodifiedeffectivelywithdifferentsurfactantsforenhancedcompatibilitywithdifferentpolymericmatrices.
简介:4-Amino-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thiol1werecondensedwith2-bromo-1-(substitutedphenyl)ethanonetogivepyridinyltriazolothiadiazines2a~c,whichwerequaternarizedwithmethyliodideandoxidizedwith30%hydrogenperoxidetoaffordthecorrespondingmethylpyridiniumsalts3a~candpyridine-l-oxides4a~c,respectively.Thereductionofcompounds3and4withNaBH4inmethanolproducedthetargetcompounds1-methyl-1,2,5,6-tetrahydropyridin-3-yl)-6-aryl-s-triazolothiadiazines5a~cand3-(1-hydroxyl-1,2,5,6-tetrahydropyridin-3-yl)-6-aryls-triazolothiadiazines6a~c,respectively.Theendotheliumvascularrelaxingactivityofthetargetcompoundswasscreened.
简介:Fullysolublepoly[2-methoxy-5-(2’-ethylhexyl)-oxy)-p-phenylenevinylene](MEH-PPV)wassynthesizedbytheadditionofmolecularweightmodifiers(chainstopper,freeradicalscavengers)toapolymerizationsystemcontainingmonomer,catalystandasolvent.ThesePPVproductssynthesizedinthisworkwerecharacterizedbyIR,NMR,UV-visiblespectroscopyandGPC.ResultsshowthattheM_wofpolyphenylvinylene(PPV)canbecontrolledbytheadditionofchainstopper(benzylbromide)andradicalinhibitor(2,6-di-tert-butyl-4-methylphenol).Thepolymerizationmechanisminthepresenceoftheseadditiveswasalsodiscussed.AdualmechanisminvolvingcarbeneforPPVpolymerizationwasproposed.