简介：Theepoxideisakindofversatileintermediateformanufactureofawidevarietyoffinechemicals.Thegoalofmodemefficientcatalyticmethodsistoproducedesiredcompoundswithhighyield,selectivity,lowcost,safety,operationalsimplicityandmoreimportantlyenvironmentallybenignmanner.However,therearevariousoxidants,whichareoftenhazardousorexpensive,beingusedforbothlaboratoryandindustrialepoxidation.Hydrogenperoxide(30wt%)solutionisthoughtasoneoftheidealoxidantsbecausewaterisasoletheoreticalsideproduct.Meanwhiletheepoxidationofstyreneisatypicaloneamongolefins.Here,theperformanceofstyreneepoxidationwasstudiedwithhydrogenperoxidesolutioncatalyzedbyCo(Ⅱ)phenanthrolinecomplexencapsulatedinsupercagesofMCM-41.

简介：有spheres-within-a-sphere的合并Cu的订的六角形的mesoporous硅酸盐(Cu-MCM-41)凹陷结构作为合作模板用thermoreversible聚合物hydrogelmethylcellulose(MC)和cationic表面活化剂被综合了，它被扫描电子显微图(SEM)描绘了，X光检查衍射(XRD)，传播电子显微图(TEM)，并且N2吸附解吸附作用等温线。获得的结果显示合并Cu的MCM-41材料的形态学是“spheres-within-a-sphere”空组织，它很类似于的蜂窝状。在有H2O2的苯hydroxylation，空范围比Cu-MCM-41的粒子显示出许多更高催化的活动。

简介：1:介绍CCH近年来受到计算机、信息科学发展的冲击,国内外数学及教材的改革一直在进行中。本文介绍美国国家自然基金组资助的,以哈佛大学为首的微积分教材改革协作组所创新的微积分教材:《Calculus》ProducedbytheConsortiumbasedatHarvardandfundedbyaNational

简介：Wehaveinvestigatedthelow-lyingcollectivestatesandelectromagnetictransitionsin94Mowithintheframeworkoftheinteractingbosonmodel.Theinfluenceofmodelparametersontheenergylevelsandelectromagneticpropertieshasbeeninvestigated.Theanalysisoftheobtainedresultsandtheparametervaluespredictthatthe23+stateisthelowestmixedsymmetrystatewithpureF=Fmax-1inthisnucleus.Thecalculatedresultspredicatethatthe25+(two-Q-phonon)mixedsymmetrystateisclosedtotheJ=2+at2.870MeVintheexperimentaldata,andthe2.965MeVstateisthelowestmixedsymmetrywithJ=3+.

简介：首次在温和条件下，用在传统微孔沸石合成中常作为导向剂的乙二胺或1，6-己二胺替代NaOH作催化剂合成出SiO2基中孔MCM-41分子筛。合成样品用XRD和N2吸附等温线进行表征。实验结果表明，由于这种替代，使相应合成样品及焙烧样品的中孔骨架结构的有序度明显提高。在XRD图中四个衍射峰清晰可辨，是典型的六方紧密堆积，晶胞参数a0分别为4.11nm和3.75nm，且d100值随所用胺分子中碳链的增长逐渐从3．56nm减少到3．24nm，同时产物孔径由中孔转变为微孔。更多还原