简介:Bothenantiomersofdenopamineweresynthesizedusingmicrobial-chemicalapproachviabioreductionof1-(acetoxyphenyl)ketone4(R=CH2C1)and5(R=CO2Et)withfungusGeotrichumsp.G38.
简介:在哪儿在核物理学研究触发了一个新时代,在铁以外的重元素什么时候,并且怎么充实我们的宇宙的待研究的问题。所有相关核物理学输入,很充满中子的核种的团是为在铁以外揭示重元素的起源的关键数量。尽管这个性质的精确决心是大挑战,庞大的进步在最近的十年被取得了,并且它显著地作出贡献到原子结构和天体物理学的nucleosynthesis研究。在这评论,我们首先调查我们原子集体表面的现在的知识,强调在r过程计算的原子集体精确的重要性。我们然后与一些选择例子在原子集体测量的各种各样的方法讨论最近的进步。为每个方法,我们集中于最近的突破并且讨论改进称r过程核种的可能的方法。
简介:BasedupontheHellinger-Reissner(H-R)mixedvariationalprincipleforthree-dimensionalelasticbodies,themodifiedH-Rmixedvariationaltheoremformagnetoelectroelasticbodieswasestablished.Thestate-vectorequationofmagnetoelectroelasticplateswasderivedfromtheproposedtheorembyperformingthevariationaloperations.Tolayatheoreticalbasisofthesemi-analyticalsolutionappliedwiththemagnetoelectroelasticplates,thestate-vectorequationforthediscreteelementinplanewasproposedthroughtheuseoftheproposedprinciple.Finally,itispointedoutthatthemodifiedH-Rmixedvariationalprincipleforpureelastic,singlepiezoelectricorsinglepiezomagneticbodiesarethespecialcasesofthepresentvariationaltheorem.
简介:Veryrecently,BelleannouncedtheirobservationofΥ(5S)!bJ!(J=0;1;2),indicatingthattheΥ(5S)!bJ!decaysalsohavelargedecaywidths,i.e.,themeasuredbranchratiosofΥ(5S)!bJ!are<3:410??3,(1:640:23+0:30??0:22)10??3,and(0:570:220:07)10??3withJ=0;1;2,respectively[1].ItshouldbenoticedthateventhoughthetreelevelcontributionstoΥ(5S)!bJ!(J=0;1;2)shouldbestronglysuppressedduetotheOkubo-Zweig-Iizuka(OZI)rule,suchlargedecaywidthsareobserved,whichagaininspiresourinterestinunderstandingsuchquantities.Inthiswork,weproposethatthecontributionfromthehadronicloopshouldbeconsideredinstudyingΥ(5S)!bJ!.
简介:AnewlayeredCu-basedoxychalcogenideBa3Fe2O5Cu2S2hasbeensynthesizedanditsmagneticandelectronicpropertieswererevealed.Ba3Fe2O5Cu2S2isbuiltupbyalternativelystacking[Cu2S2]2-layersandironperovskiteoxide[(FeO2)(BaO)(FeO2)]2-layersalongthecaxisthatareseparatedbybariumionswithFe3+fivefoldcoordinatedbyasquare-pyramidalarrangementofoxygen.Fromthebondvalencearguments,weinferredthatinlayeredCuCh-based(Ch=S,Se,Te)compoundsthe+3cationinperovskiteoxidesheetprefersasquarepyramidalsite,whilethelowervalencecationprefersthesquareplanarsites.Thestudiesonsusceptibility,transport,andopticalreflectivityindicatethatBa3Fe2O5Cu2S2isanantiferromagneticsemiconductorwithaNe′eltemperatureof121Kandanopticalbandgapof1.03eV.Themeasurementofheatcapacityfrom10Ktoroomtemperatureshowsnoanomalyat121K.TheDebyetemperatureisdeterminedtobe113K.TheoreticalcalculationsindicatethattheconductionbandminimumispredominantlycontributedbyO2pand3dstatesofFeionsthatantiferromagneticallyarrangedinFeO2layers.TheFe3dstatesarelocatedatlowerenergyandresultinanarrowbandgapincomparisonwiththatoftheisostructuralSr3Sc2O5Cu2S2.
简介:基于图G的Mycielski图M(G),研究xb(G,TG)与xb(M(G),T’)之间的关系以及xb(G,TG)与xb(M(G),T")之间的关系,其中Tc为G的生成树,T’,T"分别为M(G)的两类特殊生成树.并给出当G为二部图,完全图以及Halin图时,Xb(M(G),T")的值.
简介:在计算机辅助工艺设计中,工序图的设计是工艺设计的一个重要组成部分,是否有一个好的工序图的设计环境,直接影响到CAPP系统能否广泛应用。我所CAPP系统已正式应用于科研生产中。该CAPP系统的工序图设计是在AutoCAD下绘制的,在试运行中发现,工序图的绘制还比较繁琐,究其原因有:(1)到现在为止还没有一种商业化的专用工序图设计软件;(2)工艺工序图设计中有一些专用特殊符号(如定位符号、夹紧符号及焊接符号等)特殊的线型以及一些专用的标注符号等,这些符号如让工艺人员在通用的CAD软件中绘制既费时又不规范;(3)由于工序图只是一个示意图,很多图形是可用以前绘制的或别人已绘制好的相似的图形稍作修改即可,然而在全所范围内没有一个集中统一管理的工序图图库以供所有的工艺人员实现资源共享,各自为政,重复劳动较多。为了解决这一问题,需开发一个适合CAPP中工序图设计的专用工序图CAD系统。
简介:NOVELOXIDATIONOFHEXABENZYLHEXAAZA-ISOWURTZITANEBYMe2CHNO2/CuCl/Py/O2XiaoPeiGUAN;HongYAN;JianGuangSUN;YongZhongYU(ScholofChe?..
简介:ThecharacteristicsofsuspendedsedimentimagecanbereflectedbythecoefficientsofbiorthogonalwavelettransformofCDF(2,2).Basedonthepowerdistributionindifferentscales,anadaptivealgorithmisproposedinthispaper,wherebythecoefficientsareadjustednon-linearly.Theparticleinformationcanbewellretainedwhiletheuselessbackgroundisremoved.Inthisway,satisfactorybinaryimagecanbeobtainedforfurtheranalysisofthesedimentparticle.