学科分类
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31 个结果
  • 简介:一系列(p-phenylenevinylene)poly,有好溶解度的s(PPV)poly从先锋的热消除被综合(2,5-didodecyloxy-p-phenylenevinylene)在经由Wessling的不同温度方法。聚合物光物理学被热消除条件影响,它与NMR和红外描述一致。为在高消除温度获得的PPV,在在解决方案并且在电影的更长的波长和转移红的排放最大值的另外的吸收山峰在这些系统显示了更长结合的块的存在。为为PPV的落下演员组电影(436nm)的排放最大值下面获得了200

  • 标签: 聚合物链 热消除 苯乙烯 温度 物理方法 电影
  • 简介:基于密度泛函理论(DFT)的第一性原理平面超软赝势方法,计算了纯MgF2晶体、Co掺杂MgF2晶体、P掺杂MgF2晶体和(Co,P)双掺杂MgF2晶体的电子结构和光学特性.结果表明,掺杂后的MgF2晶体发生了畸变,原子之间的键长也有所变化.(Co,P)双掺杂后,由于非金属原子P态和金属原子d态之间的轨道杂化,在MgF:的导带与价带之间形成了新的杂质能级,这些杂质能级一方面减小了MgF2的带隙宽度,使光吸收曲线红移到可见光区,另一方面有利于光生电子一空穴对的分离,提高了MgF2光催化效率.(Co,P)双掺杂使位于禁带中的杂质能级的态密度明显增加,导致电子从价带跃迁到杂质能级和从杂质能级跃迁到导带的概率增加,从而使其对太阳能的利用率提高.并揭示了(Co,P)双掺杂MgF2在光学元器件方面的潜在应用.

  • 标签: 密度泛函理论 第一性原理 钴磷双掺杂MgF2 电子结构 光学性质
  • 简介:Theoptimalconditionsforthecomplexationreactionofmeso-tetra(3-methoxy-4-hy-droxyphenyl)porphineT(3-M-4HP)Pwithplatinumandrhodiumarepresented.Beer’sLawisobeyedwhentheconcentrationofrhodiumisintherangeof0.45-1.15μg/25mL.Themolarabsorptivityofrhodiumwasfoundtobe1.99×106L·mol-1·cm-1at460nm.ThevalueofεPtwasfoundtobe6.28×105L·mol-1·cm-1bylinearregressionmethod.TheKcoefficientmethodandcompensatingcoefficientwereusedtodetermineplatinumandrhodiumsimultaneoulywithoutremovalormaskingoftheinterferentsinthesample.Theresultsforthedeterminationofplatinumandrhodiuminthemixedsolutionofplatinumandrhodiumaresatisfactory.

  • 标签: PLATINUM RHODIUM Spectrophotonletry Meso-tetra(3-M-4HP)P.
  • 简介:RemanspectroscopyisusedasatooltomonitorthereactionbetweenN,N’-di(pmethyl)monothioxamidesand1,3-diaminetrimethyleneandtodetectthereactionintermediate.Byobservingchangesof1024cm-1C=Sbandandappearanceofanewbendataround1720cm-1,thereactionmechanismisdiscussed.

  • 标签: appearance monitor DIAMINE observing FIGURE minutes
  • 简介:SYNTHESIS AND 183W NMR CHARACTERIZATION OF P4W30Al4(H2O)2O11220- HETEROPOLYANIONSYNTHESISAND183WNMRCHARACTERIZ?..

  • 标签:
  • 简介:Theeffectandmechanismofcarmustine(BCNU)combinedwithall-transretinoicacid(ATRA)ontheapoptosisofhumanglioblastomaU251cellswereinvestigatedbymeansof3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazoliumbromide(MTT)assay,flowcytometry,reversetranscription-polymerasechainreaction(RT-PCR)andWesternblotanalysis.TheresultsshowthatBCNUorATRAshowstime-anddose-dependentinhibitioneffectsonhumanglioblastomaU251cellsandthecombinationofBCNUwithATRAshowsansynergisticinhibitioneffectonhumanglioblastomaU251cells,andthecombinedBCNUandATRAcansignificantlyinhibittheproliferationofhumanglioblastomaU251cells,andinducetheapoptosisofthem,makingthecellsarrestinthestageofG1phase,thestageofSandG2phasesdecline,therateoftheapoptosisofhumanglioblastomaU251cellsincrease,thecorrespondingmRNAexpressionofcyclinEandcyclin-dependentkinase2(CDK2)downregulatedandthecorrespon-dingmRNAexpressionofp27kip1unregulated.Inaddition,thecombinedBCNUandATRAreducedtheproteinexpressionofnuclearfactorkappaB(NF-κB).Takentogether,theseresultssuggestthatthetreatmentofhumanglioblastomaU251cellswithacombinationapplicationofATRAandBCNUcanexertsynergisticeffect,thecourseofthiskindofcombinationchemotherapymaylikelybeassociatedwithmultiplemolecularmechanismsforapoptosis,furthermore,thecyclinEandp27kip1shouldbeconsideredasnoveltargetsforcontrollingthegrowthofglioblastomacells.

  • 标签: 全反式维甲酸 脑胶质瘤 细胞凋亡 细胞周期素 卡莫司汀 细胞周期蛋白依赖性激酶
  • 简介:Anumberofnaphthalenedonorcompoundsthatpossessanadamantanaminebindingmoietyandan(OCH2CH2)n(nn1,2,3,4,6,8)spacerweresynthesized.Thefluorescencequenchingbetweenthesedonorsubstratesandmono-6-O-p-nitrobenzoyl-β-cyclodextrin(pNBCD)andmono-6-O-m-nitrobenzoyl-β-cyclodextrin(mNBCD)wasstudiedindetail.Itwasfoundthatveryefficientfluorescencequenchingcouldoccurinthesesupramolecularsystems.Thisquenchingwasattributedtothephotoinducedelectrontransferinsidethesupramolecularassemblybetweenthenaphthalenedonorsandcyclodextrinacceptors.DetailedStern-VolmerconstantsweremeasuredandtheywerepartitionedintodynamicStern-Volmerquenchingconstantsandstaticbindingconstants.Itwasdemonstratedthatthebindingconstantsbetweenallthenaphthalenecompoundsandcyclodextrinsarethesameastheypossessthesamebindingsite,i.e.,adamantanamine.

  • 标签: 光致电子转移 Host-Guest化合物 2-萘基-(乙烯氧基)n-金钢石 单-6-O-p-硝基苯甲酰基-β-环式糊精 单-6-O-m-硝基苯甲酰基-β-环式糊精
  • 简介:通过水热法合成了一维链状的磷钼氧酸盐(DETA)。NaNa(H5P4Mo6O31)2]·8H2O(DETA—Diethylenetriamine),采用x-射线单品衍射结构分析,元素分析和红外光谱等表征.该磷钼氧酸盐属于三斜晶系,空间群是P-1,晶胞参数a=1.2434(3)nm,6—1.2610(3)nm,c=1.3079(3)nm,a=85.418(3)°,β=73.399(2)°),γ=82.175(3)°,V=1.9450(8)Elm。,F(000)=1462,Z=:=2.标题化合物的结构是由Na(H5P4Mo6O31)2簇单元,二亚乙基三胺阳离子和结晶水分子组成.另外,Na(H5P4Mo6O31)2簇由钠离子连接形成了一维的链结构.一维链结构又由于二亚乙基三胺阳离子和结晶水分子形成的氢键进一步连接三维超分子结构.用标题化合物修饰的碳糊电极(APM—CPE)对AA氧化有很好的电催化活性.

  • 标签: 磷钼氧酸盐 一维链 三维结构 电催化
  • 简介:Tetrabutylammoniumorpotassiumsaltsoforganometalllicderivativesoflacunarypolyanion(RM)3P2W15O59^n-(RM=CpTi,CpZr,C4H7O2SnorC5H9O2Sn)havebeenpreparedandstructurallycharacterizedbyelementalanalysis,IR,UV-Vis,^1HNMRand^183WNMRspectroscopies.Thetitlecomplexesexhibitantitumoractivityinvitro.

  • 标签: 抗癌抗菌素 抗癌活性 合成 结构 多氧钨酸盐