学科分类
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51 个结果
  • 简介:Reactionofglycinewithphosphorustrichlorideinpresenceoftriethylaminehasurnishedtheovelspirohydridophosphorane.Itsstructurehasbeencharacterizedbyelementalanalysis,n.m.r.spectraandmassspectrum.Thecompoundreactedwithphenylisothiocyanatetogive2-phenyliminothiazolid-5-one.

  • 标签: phosphorus GLYCINE suspended FILTRATION NEUTRAL DRIED
  • 简介:在氧气体的处理以后,包含胺组的小分子能射出荧光。氧化被相信在荧光中心的形成起一个重要作用。比作以前的结果,小分子和大分子可能有一样的荧光中心。

  • 标签: 荧光发射 氧化作用 氧气 小分子 大分子
  • 简介:TheNb-bromomethylderivative(2)ofgelsemine,aquaternaryammoniumsalt,wasfoundtoberecalcitranttowardHofmanntypealkalinedegradationwhichhasbeensuccessfulinothercases.Instead,are-distributionoftheN-methylgrouptookplace,givingriseto3a,1,3band3c,indescendingorderofRfvalues.

  • 标签: DESCENDING hasbeen GIVING ALKALINE derivative toward
  • 简介:Sixnewcompounds,α,β-KaHb[GeW9M3(H2O)3O37].xH2O(M=Al,Ga,In;a+b=7)andα-K9H5[Ge2W18Ga6(H2O)3O74].20H2O,weresynthesizedfromthelacunaryprecursorsαandβ-GeW9O3410-andcharacterizedbyelementalanalysis,spectroscopyandelectrochemistry.Tungsten-183NMRspectraofthetitlecomplexesconsistoftwolineswithintensityratio2:1asexpectedfortrisubstitutedheteropolyanions.Theintensityratioofα-Gacompoundis1:2,whichisdifferentfromothers(2:1).WiththehelpofFABmassspectrum,weconcludedthatitisadimerwithD3h,structureinaqueous,andtheothersexistbymonomerswithC3cstructures.

  • 标签: Tungstogermanates 3A ELEMENTS trisubstituted HETEROPOLYANIONS 183W
  • 简介:TheelectrochemicalformationofMg-LialloyswasinvestigatedinamoltenLiCl-KCl(58-42mol%)eutecticmeltat723K.ThecyclicvoltammogramforaMoelectrodeshowedthattheelectroreductionofLi~+proceedsinasinglestepandthedepositionpotentialofLimetalwas-2.40V(vs.Ag/AgCl).ForMgelectrode,theelectroreductionofLi~+takesplaceatlesscathodicpotentialthanthatattheMoelectrodewhichwascausedbytheformationofMg-Lialloys.PhaseofthedepositedMg-Lialloyscouldbecontrolledbytheelectrolysispotential,andthesampleswerecharacterizedbyX-raydiffractionandscanningelectronmicroscopy.Theresultsshowedthatα-Mgandβ-Liphaseswereobtainedat-2.35and-2.55V,respectively.

  • 标签: LiCl-KCl MOLTEN SALT ELECTRODEPOSITION MG-LI alloy
  • 简介:Itwasfoundthatphosphorylationofsmallpeptidecouldimprovethesensitivityinmassspectrometry.DensityfunctionaltheorycalculationsshowedthattheenergyfortheprotonationofN-(O,O′-dimethyl)phosphorylglycylglycineislowerthanthatofglycylglycine.Thesecouldhelptounderstandingtheexperimentalresults.

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  • 简介:STUDIESONHETEROMACROCYCLICPOLYETHER(XIV)THESYNTHESISOFSELENACROWNETHERWITHHYDROXYGROUPANDDISELENA-AZA-CROWNETHERHanShengXu;Ju...

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  • 简介:Arapidandeffectivemethod,solidphaseextractioncoupledwithhighperformanceliquidchromatography(SPE-HPLC),wasappliedtotheseparationandanalysisofginsenosides.WatersOASISHLBwasusedforconcentratingandpurifyingsamplesandAlltimaC_(18)(53mm×7mm,3μm)chromatographycolumnwasusedforseparatingginsenosideRg_1,Re,Rb_1,Rc,Rb_2andRd.Theseginsenosideswereanalyzedwithin20mininourgradientelutionprocessandtheequilibriumtimeofthechromatographycolumncostonly5min.Moreover,therewasnoobviousbaselinedriftinourexperiment.Thismethodwasusedtoanalyzethecontentsofginsenosidesindifferentginsengproductsforqualitycontrol.Fourginsengproductswerestudied,includingtwokindsofcapsules,onekindoftabletandonekindofinjection.Theresultsshowthatthemethoddevelopedinthispaperhadgoodaccuracy,linearityandprecision.Therefore,thismethodcouldbeappliedinqualitycontrolofginsengproducts.

  • 标签: 高效液相色谱法 产品质量控制 人参皂甙 固相萃取 应用 人参皂苷RG1
  • 简介:TwospeciesofN-arylpyrazolescontainingactiveaminogroupweresynthesized.AndformylationsofN-arylpyazolescontainingaminoindifferentpositionofpyrazoleringsusingVilsmeier-Haackreactiongaveaseriesofusefulpyrazoleintermediates.Theimportantfeaturesofthisprotocolwerecheapmaterials,easyprocess,mildreactionconditionsandgoodyieldofproducts.

  • 标签: Vilsmeier-Haack反应 N-芳基吡唑 甲酰化 氨基 合成
  • 简介:THEREACTIONOFp-NITROPHENYLSULFONYLACETONITRILEWITHα,β-UNSATURATEDESTERSANDNITRILES¥GuoRenYUEandZhengZhang(DepartmentofChemist...

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  • 简介:Amain-chainliquidcrystallineionomer(MLCI)containingsulfonicgroupwassynthesizedbyaninterfacialcondensationreaction.TheMLCIwasblendedwithpolybutyleneterephthalate(PBT)andpolypropylene(PP).MLCIinteractedwithboththedispersed(PP)phaseandthematrix(PBT)phasetomodifytheinterfacialinteractionofPBTandPP.Differentialscanningcalorimetry(DSC),scanningelectronmicroscopy(SEM)andFTIRimagingsystemanalysisdemonstratedthesignificanceofinterfacialinteractioninthepolymerblends.MLCIbroughtaboutgoodadhesionattheinterfacial,whichreducedthedispersephasesizeandenabledafinePPphaseatmatrix.ThemechanicalpropertiesoftheternaryblendswereimprovedwhenaproperamountofMLCIwasadded.Thiswasattributedtoenhancedadhesionattheinterface,whichinvokedbettermechanicalpropertiesintheblends.

  • 标签: 界面相互作用 液晶离聚物 PBT 磺酸基 PP 共混改性
  • 简介:Condensationofmethyl7-methylcoumarin-4-acetate(2)withprimaryaminesandwithan-thranilicacidgave7-methyl-2-oxo-N-aryl-2H-[1]-benzopyran-4--acetamide(4a—d)and(7),respectively.Compound7underwentcyclizationtogive2-(7-methyl-2-oxo-2H-[1]-benzopyran-4-yl)-methyl-4H-3,1-benzoxazin-4-one(3).Thereactionof3witharomaticaminesgavethecorrespondingquinazolonederivatives5whichtautomerisestothethermodynamicallymorestableisomer6,whereasitsreactionwithGrignardreagentsandaromaticaldehydesgave8a,8b,and9a,9b,respectively.

  • 标签: LACTONE COUMARIN aromatic aldehydes AMINES CYCLIZATION
  • 简介:InanefforttoutilizeNMRtechniquefortheanalysisofthestructuralcomponentsofwoodandbiomassessuchaslignin,wemadeacomparativestudyoflignincontentsofseveraltypesoflignocellulosicmaterialsbothbeforeandafterenzymatichydrolyses.Tothisend,EucalyptusGlobulus,Norwaysprucethermomechanicalpulp(TMP)cornstoverandEucalyptuskraftpulpwereball-milledandtreatedwithcellulasetopreparematerialswithhighlignincontents.Thesematerialswereanalyzedvia31PNMRinionicliquids.Theresultsshowthatthecontentsofvariousfunctionalgroupsforthelignocellulosicmaterialsafterenzymatichydrolysesaregenerallyinagreementwiththosefromtheircorrespondingenzymaticmildacidolysisliginins(EMALs),indicatingthat31PNMRanalysisoflignocellulosicmaterialsinionicliquidsisapromisingmethodforquantitativecharacterizationoflignocellulosicmaterials.

  • 标签: 核磁共振分析 木质材料 离子液体 木质素含量 纤维素材料 核磁共振技术