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2554 个结果
  • 简介:Pr原子特殊的电子层结构使其具有多方面的催化特性.实验发现质量分数为0.7%的PrCl3就可使漆酚(U)于110℃固化成膜的时间从5h降低到1h.用可见分光光度法、电子能谱、紫外和红外光谱等方法研究U在PrCl3作用下的固化成膜历程.结果表明,在Pr(Ⅲ)催化U聚合的过程中首先是U与PrCl3发生配位作用,生成U镨配合物(UPr),然后该配合物分子中的Pr(Ⅲ)催化U聚合成体形结构的高分子化合物.

  • 标签: 漆酚 催化剂 氯化镨 配位作用 干燥成膜 交联聚合
  • 简介:以聚乙烯醇(PVA)作为络合剂与醋酸镁反应制得前驱体,采用静电纺丝法制得聚乙烯醇(PVA)/醋酸镁复合纤维,经焙烧后得到分布均匀、具有较高比表面积和多孔结构的MgO纳米纤维.对所制得的纳米纤维的结晶度、纯度和表面形貌,分别采用X射线粉末衍射、差热-热重分析(TG-DTA)、红外光谱(IR)、扫描电镜(SEM)等分析测试手段进行了表征.结果表明,煅烧温度对纳米纤维的结晶度和形貌有很大影响.

  • 标签: 氧化镁 纳米纤维 静电纺丝法 制备 煅烧温度 结晶度
  • 简介:用PCR方法扩增了人的BAF53全长cDNA序列,用酶切后的ΔBAF53cDNA片段构建了表达质粒.转化大肠杆菌后,经IPTG诱导表达,再经包涵体裂解、纯化,得到hBAF53抗原多肽.从免疫动物身上获得实验动物的抗血清.通过斑点印迹方法测得hBAF53抗血清的特异性和效价,又用已提取的HeLa细胞核蛋白(含有天然BAF53蛋白)进行免疫印迹分析,证明天然BAF53蛋白是该抗血清的抗原,说明获得的抗血清具有比较高的特异性,可用于染色体改构复合物各亚基间相互作用分析及调控基因转录机理方面的研究.

  • 标签: hBAF53 多克隆抗体 制备 活性 染色质改构复合物亚基 基因转录调控
  • 简介:合成了N,N′-亚水杨基皮考林酰肼(HL)及其铁配合物[FeL2](C26H20FeN6O4,Mr=536.33).X射线衍射实验结果表明,标题配合物晶体属于正交晶系,空间群为Pbcn,晶体学参数:a=1.4970(1)nm,b=1.51556(9)nm,c=2.0920(2)nm,V=4.7462(6)nm3,Z=8,Dc=1.501Mg·m-3,F(000)=2208,μ(MoKα)=0.682mm-1,R=0.0695,Rw=0.1502.在配合物[FeL2]中,铁(Ⅱ)原子具有扭曲的八面体配位构型,晶体通过分子间氢键作用形成缔合分子对.红外光谱表明,配体在形成配合物后,ν(CO)和ν(CN)红移.电子光谱表明存在π-π*和d-π*的跃迁;荧光光谱表明,配合物金属对配体n-π*激发引起的荧光发射峰有较大的影响.

  • 标签: N N′-亚水杨基皮考林酰肼 铁配合物 晶体结构 荧光性质 氢键
  • 简介:本文主要研究了炭化温度、升温速率以及碱处理浓度对稻壳制备锂离子电池负极材料结构及充放电性能的影响.通过差-热热重分析曲线(DT-TGA)、元素分析、X射线粉末衍射(XRD)以及电化学性能测试手段对材料进行了表征.结果表明:在最佳实验条件下,材料的首次充电容量为678mAh/g,首次放电容量为239mAh/g,循环10次的容量保持率为86.2%.

  • 标签: 锂离子电池 炭材料 稻壳 制备 充放电性能 结构
  • 简介:分别以不同的异羟肟酸为配体,合成了3个氧钒(Ⅳ)配合物,运用元素分析、红外光谱、核磁共振谱(1HNNR,13CNMR,51VNMR)、电子顺磁共振和电子吸收光谱等测试手段对配合物进行了表征.分别在不同的羟基醇中以氧钒(Ⅳ)配合物BHAOV为基础,合成了2个含烷氧基的五价氧钒(Ⅴ)化合物.在吡啶中合成了含吡啶的六配位氧钒(Ⅳ)配合物BHAOV(PY),V占据第6位置S原子,可使其不被氧原子进攻而氧化,要使V内层发生氧化,在四价钒上至少有一个空的配位位点是完全必要的.而且还研究了BHAOV在乙腈中的配位反应动力学.

  • 标签: 异羟肟酸氧钒化合物 合成 表征 配位化学性质 配位反应动力学 乙腈
  • 简介:建立了计算多环芳烃水中溶解度的数学表达式,用量子化学方法计算了7个多环芳烃的水中溶解度,计算结果与实验测定结果相符合.多环芳烃处于水体内体系状态能量愈高,其溶解度愈小,多环芳烃中的碳氢基团越多,溶解度越小.此时体系中的溶质呈单分子态,而不是聚集态.

  • 标签: 多环芳烃 水中溶解度 理论计算 数学表达式 量子化学方法 碳氢基团
  • 简介:用直接法合成了以锰为中心原子的过渡元素和钨的三元杂多配合物,经ICP和TG曲线确定其化学式为K5,6[MnM(OH2)W11O39]*xH2O(M=Mn2+,Fe3+,Co2+,Ni2+,Cu2+,Zn2+和Cd2+),采用IR,UV,XRD和XPS等手段对配合物结构进行了表征,用循环伏安测定了其系列配合物的氧化还原性质,得出系列配合物的氧化性顺序,同时讨论配合物的热稳定性.

  • 标签: 中心原子 三元杂多配合物 合成 氧化还原性 直接法
  • 简介:从猴头发酵菌丝体水提后残渣中用碱提出了水溶性粗多糖,对其分级纯化得到纯样HPP,SepharoseCL-6B柱层析测得其相对分子质量约为6.53×104,G.C.分析表明,其单糖组成为Glc;经部分酸水解、高碘酸氧化、Smith降解和甲基化分析确定此多糖为多分枝结构,其中(1→6)Glc构成主链的核心结构;分支点为O-3;支链部分由(1→3)Glc构成,并连接一端基Glc.

  • 标签: 猴头菌 水溶性多糖 提取 纯化 结构
  • 简介:采用密度泛函方法(B3LYP)优化了MX2(AsH3)2[M=Pd;X=Cl(1),Br(2),I(3)和M=Pt;X=Cl(4),Br(5),I(6)]的基态结构,得到的几何参数与实验结果符合.以基态几何为基础,将TD-DFT方法用于计算标题配合物的电子吸收光谱.研究结果表明,金属的dx2-y2与配体所组成的反键轨道为LUMO轨道,从而该类配合物具有d-d跃迁属性的吸收带;在多数跃迁过程中,配体也有较大的贡献.

  • 标签: 含时密度泛函方法 基态结构 电子吸收光谱 电荷转移 激发态性质 d^8金属配合物
  • 简介:Aself-assembledmonolayerfilm(SAM)ofrutheniumphthalocyanine(RuPc)fabricatedonasilversubstratepremodifiedwithanSAMofterephthalonitrile(TPN)wasstudiedbymeansofsurface-enhancedRamanscattering(SERS)andultraviolet-visible(UV-Vis)spectroscopies.TPNwasusedasaligandtolinkRuPcsinceitcannotonlymodifythesilversubstratebutalsodeliverthenitrilegroupsprotrudingfromthesilversurface.Therefore,wecanexploretherelationshipbetweenthestructureandtheorientationofRuPcandtheTPN-modifiedsubstrate.TheUV-VisspectraindicateastronginteractionbetweenRuPcandTPNinthecompositefilm.TheresultisfurtherconfirmedbytheSERSspectraofRuPc-TPNSAM,inwhichthevibrationalbandsarisingfromboththeRuPcandTPNmoietiesappearclearly,indicatingthattheRuPcissuccessfullyassembledontheTPNfilm.

  • 标签: 自组合装置 酞菁蓝 雷曼增强散射 光谱分析 苯二甲蓝染料 单层薄膜
  • 简介:Toinvestigatethetreatmenteffectof2-seleniumbridgedβ-cyclodextrin(2-SeCD),aGPXmimic,onthestrokeofstroke-pronespontaneouslyhypertensiverats(SHRSP),fifty-twoSHRSPof8-weekoldwererandomlydividedintofourgroupsA,B,CandcontrolgroupD.TheratsofgroupsA,B,CandDweregiven1.0%-1.5%NaClmassfractionasdrinkingfluid.Afteronsetofstroke,groupsA,BandCweregivenorally16.05,160.5and1605mg*kg-1*day-1of2-SeCD,respectively,andgroupDwasgivenwaterfor2weeks.Theclinicalscoreofstroke,systolicbloodpressure(SBP),survivaltimeofratswererecordedandthehistopathologicexaminationsoftheirbrainandcarotidarteryweremadeafterdecapitation.Theclinicalscoresofstrokeaftertreatmentwith160.5mg*kg-1*day-1(GroupB)and1605mg*kg-1*day-1(GroupC)of2-SeCDare2.55±0.98and1.98±0.79,respectively,thoseareobviouslylowerthanthatofgroupD(3.41±0.83,p<0.01).ThesurvivaldaysingroupB(10.0±8.6)andgroupC(14.4±7.9)arelongerthanthatforgroupD(4.7±2.9,p<0.01).TheelectronmicroscopestudyshowedthattheendotheliumofcarotidarterywasneartonormalingroupBandgroupC,whileitwasseriouslyinjuredincontrolgroupDandmildlyinjuredingroupA.2-SeCDmayeffectivelybeusedtotreatthestrokeforSHRSP.

  • 标签: 2-硒跨接β-环式糊精 谷胱甘肽过氧化物酶 酶模拟 高血压
  • 简介:Whenaproteinisencapsulatedintopoly(DL-lactide-co-glycolide)(PLGA)microspheresbymeansofthedouble-emulsionmethod,theharshmicrospheresformationprocessincludingultrasonification,exposuretoanorganicsolventandapolymermaycausethedenaturationoftheprotein.Inthisstudy,weinvestigatedtheenzymaticactivitychangeandtheeffectoftheexcipientsonthestabilityofrecombinanthumanCu,Zn-superoxidedismutase(rhCu,Zn-SOD)duringtheemulsification.ThespecificactivityrecoverywasfoundtobeconcentrationdependentandtheexcipientsinvolvedsuchasPEG600andTween20,andtrehalosewereshowntoincreasethestabilityofrhCu,Zn-SOD.TheproteinstructuralintegritywithinthemicrosphereswasanalyzedbyFTIR.ThestructureofrhCu,Zn-SODwithinPLGAmicrospherescontainingtrehalosewasfoundtobesimilartothatofthenativesolidstate,whereastheproteinencapsulatedduringthepreparationintheabsenceofanyexcipientchangedduetothepossiblehydrophobicinteractionwiththepolymer.Theresultssuggestthatarationalstabilitystrategyforproteintobeencapsulatedintomicrospheresshouldaimatdifferentprocesses.

  • 标签: DL-丙交酯-共-乙交酯 PLGA微球体 重组体 铜锌-超氧化物岐化酶 傅里叶变换红外光谱 蛋白质结构
  • 简介:TofindoptimalconditionsforexpressingthesolubleformofsFv-2F3andtostudythepurificationandpropertyofitsderivativeSe-sFv-2F3,thepreferredexpressionconditionswereinvestigatedbymeansoforthogonaldesign.Thesecultureconditionsincludedincubationtemperature,inducerconcentration,inductiontimeandcellconcentration.TheevaluationofexpressionwasaccomplishedbytheanalysisofwholecelllysatesandtheyieldofsolublesFv-2F3wascalculatedaccordingtotheanalysisofProfinder(FTI-500,Pharmacia).Thepurificationprocedurewascarriedoutviaatwo-steppurificationprocedureconsistingofion-exchangechromatography,followedbyimmobilizedmetalaffinitychromatography(IMAC).TheantioxidantefficacyofSe-sFv-2F3wasdemonstratedbythedeterminationofthecontentofthemainproductoflipidperoxidation,MDA,theviabilityofcellsandtheactivityofLDH.WeobtainedthepreferredcultureconditionstogrowtheengineeredbacteriaandtheprocedureforpreparingsolublesFv-2F3andconfirmedtheantioxidantefficacyofSe-sFv-2F3.

  • 标签: Se-sFv-2F3 可溶表示 谷胱甘肽过氧化物酶 抗氧化剂
  • 简介:Inanattempttofindnewantitumoragents,anovelclassofchromonecompoundswithabenzimidazoleorabenzoxazoleringinpositions2or6weresynthesizedviacondensationinpolyphosphoricacid(PPA)byusingchromoneacidsasthestartingmaterials.Duringthepreparationprocess,itwasfoundthatPPAcouldcleavethechromoneringtoproducearing-openingcompound(6).Themolarratioofthechromonecompound(5)tothering-openingcompound(6)variedwiththechangeofreactiontemperatureandtime.BasedonMTTprotocol,theantitumoractivityofeachofthecompoundsobtainedwasevaluatedagainstthreehumancancercelllines:KB(oralepidermal),A2780(ovary)andBel7402(liver).TheIC50variedfrom54.7μmol/Ltomorethan180μmol/L.

  • 标签: 2/6-取代色酮 抗癌试剂 多磷酸 开环效应
  • 简介:TakingthetransportoftotalphosphorpollutantsintheBeijingMiyunreservoirforexample,wehaveobtainedthreedimensionaldistributingregularityoftotalphosphorpollutantsbythecalculationofthelinearinterpolationvalueofeachpointbetweenhorizontallayers.Thecredibilityanalysisinallusiontothismethodwascarriedoutandtheprogrammingschemeforrealizingthismethodwassetforth.

  • 标签: 水域 荧光体 三维数学模型 蓄水池
  • 简介:Theanodicdischargeofwatertoproduceadsorbedhydroxylfreeradicals(*OH)isconsideredtobeaprerequisitetoanodicO-transferreactionsataPbO2electrode.Inthiswork,amethodwasstudiedbymeansofhigh-performanceliquidchromatography(HPLC)combinedwithelectrochemicaldetection(ED)soastoinvestigatetheproductionofhydroxylfreeradicals(*OH)intheprocessoftheanodicdischargeofH2OataPbO2electrode.ThevoltammetricdataobtainedatthePbO2electrodefortheoxidationofsalicylicacidtosalicylatehydroxylationproducts(DHBAs)andthedetectionofDHBAsbymeansofHPLC-EDconfirmtheproposedmechanism.

  • 标签: PbO2 氧化铅电极 电催化 羟基游离基 游离基 HPLC
  • 简介:Haloaceticacids(HAAs)areformedduringthechlorinationofdrinkingwater,whichareharmfultopeople′shealthduetotheircarcinogenicandmutageniceffects.Inthepresentstudy,adetectionmethodcombiningmethyltert-butylether(MtBE)extractionwithacidcatalysisandgaschromatographycoupledwithanelectroncapturedetector(GC/ECD)wasdevelopedfordeterminingHAAs.Thedetectionlimitofthismethod(MDL)andrelativestandarddeviation(RSD)werebelow0.37μg/Land6.2%,respectively.Thelaboratorychlorinationexperimentswereconductedwiththepurposeofinvestigatingtheinfluencesofreactiontime,temperature,UV254,bromideandammonia-nitrogenontheformationofHAAs.TheresultsshowthattheformationamountofHAAsincreaseswithincreasingreactiontimeandtemperature,respectively;andthereexistsalinearrelationshipbetweentheformationofHAAsandUV254.TheformationamountofHAAsdecreasesfirstandthenincreasesasthebromideionconcentrationincreases,andaddingNH+4isapossiblewaytocontroltheformationofHAAs.

  • 标签: 醋酸盐 HAA 饮用水 氯化
  • 简介:Inconsiderationoftheadsorptionofsolvent,diluentandsolutemoleculesonthesurfaceofastationaryphase,anewequationforsoluteretentioninliquidchromatographyispresented.Thisequationincludesthreeparameters:thedisplacementequilibriumconstant(Ksd)betweenthesolventanddiluentmoleculesonthesurfaceofthestationaryphase,thetotalnumber(N)ofthesolventanddiluentmoleculesreleasedfromthestationaryphaseafteronesolutemoleculebeingadsorbed,andtheparameter(I)relatedtothethermodynamicequilibriumconstantforthesoluteadsorptiononthestationaryphase.Overthewholeconcentrationrangeofthesolventinthemobilephase,theexperimentalretentiondatacanbewelldescribedbythisequation,parametersKsd,NandIcanbeobtainedbytheregressionanalysisoftheexperimentalretentiondata,andconsequentlythenumberofthesolventandthediluentmoleculesdisplacedbyonesolutemoleculefromthestationaryphasecanalsobederivedatdifferentsolventconcentrationsinthemobilephase.

  • 标签: 液相谱 保留参数 保留机理 方程式