简介：(-)-(5R,6S)-6-Acetoxyhexadecan-5-olide1,anaturalmosquitoattractantpheromone,wassynthesizedfromreadilyavailablealdehyde2andcyclopentanone3usingL-proline-catalyzedasymmetricaldolreactionasthekeystep.

简介：利用Gaussian-94计算程序中的B3LYP方法,在6-311+G(2d)6d基组下,对Si5,Si5H3,Si5H6,Si5Li3和Si5Na3原子簇的几何结构进行优化和频率计算.结果表明,Si5原子簇中最稳定的具有D3h对称性的结构中,位于同一平面上的3个Si原子确实具有剩余的成键能力,可以与3个H,Li,Na原子和6个H原子形成稳定的化合物.研究还发现,虽然H,Li和Na都属同一主族,但它们与Si5原子簇中Si原子的键连方式却不同,而且它们的加入,对Si5原子簇的'三角双锥'结构也有不同的影响.

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简介：3,5,6,8-Tetrahydro-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4-ones(7)weresynthesizedviathebasecatalyticreactionsofaminesorphenolswithcarbodiimides(5),whichwereobtainedfromtheaza-Wittigreactionsofiminophosphoranes(4)witharomaticisocyanates.

简介：Thesynthesisandspectrophotometricpropertiesof2-(6-methyl-2-benzothiazolylazo)-5-diethylaminophenol(MBTAE),andtheuseofitasaprecolumnderivatizingreagenttoseparateCo(Ⅱ),Ni(Ⅱ),Rh(Ⅲ)andIr(Ⅳ)complexesbyHPLCarediscussed.Whenthemobilephaseconsistsofmethanol/water(90/10Ⅴ/Ⅴ),acetatebufferwithpH4.0and5×10-5mol/LEDTAsolution,thefourcomplexesCanbeseparatedwithin9minonODScolumn.Thedetectionlimits(20μLsamplesize)are0.059ppb,0.062ppb,0.053ppband0.049ppbforCo(Ⅱ),Rh(Ⅲ),Ni(Ⅱ)andlr(Ⅳ)respectivelyatasignal-to-noiseratioof3.

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简介：6,9,11-Trihydroxy-6a,12a-dehydrorotenoid1(coccineoneB)wassynthesizedfrom2-hydroxybenzaldehyde2andphloroglucinol.

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简介：ForagraphG,P(G,λ)denotesthechromaticpolynomialofG.TwographsGandHaresaidtobechromaticallyequivalent,denotedbyG-H,ifP(G,λ)=p(H,λ).Let[G]={H|H-G}.If[G]={G},thenGissaidtobechromaticallyunique.Foracomplete5-partitegraphGwith5nvertices,defineθ(G)=(a(G,6)-2^n+1-2^n-1+5)/2n-2,wherea(G,6)denotesthenumberof6-independentpartitionsofG.Inthispaper,theauthorsshowthatθ(G)≥0anddetermineallgraphswithθ(G)=0,1,2,5/2,7/2,4,17/4.Byusingtheseresultsthechromaticityof5-partitegraphsoftheformG-Swithθ(G)=0,1,2,5/2,7/2,4,17/4isinvestigated,whereSisasetofedgesofG.Manynewchromaticallyunique5-partitegraphsareobtained.

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简介：Quasiclassicaltrajectorycalculation(QCT)isusedfrequentlyforstudyingcollisionalenergytransferbetweenhighlyvibrationallyexcitedmoleculesandbathgases.Inthispaper,theQCToftheenergytransferbetweenhighlyvibrationallyexcitedC6F6andN2,O2andgroundstateC6F6wereperformed.TheresultsindicatethathighlyvibrationallyexcitedC6F6transferredvibrationalenergytovibrationaldistributionofN2,O2andgroundstateC6F6,sotheyareV-Venergytransfer.EspeciallyitismainlyV-VresonanceenergytransferbetweenexcitedC6F6andgroundstateC6F6,excitedC6F6transfersmorevibrationalenergytogroundstateC6F6thantoN2andO2.ThevaluesofQCT,-〈△Evib〉ofexcitedC6F6aresmallerthanthoseofexperiments.

简介：TheimportanceoftheInternettomodernHighEnergyPhysicsCollaboratorsisclearlyimmense,andunderstandinghownewdevelopmentsinnetworktechnologyimpactnetworksiscriticaltothefuturedesignofexperiments.ThenextgenerationInternetProtocol(IPv6)isbeingdeployedontestbedsandproductionnetworksthroughouttheworld.Theprotocolhasbeendesignedtosolvetodaysinternetproblems,andmanyofthefeatureswillbecoreInternetservicesinthefuture.Inthistalkthefeaturesoftheprotocolwillbedescribed.DetailswillbegivenonthedeploymentatsitesimportanttoHighEnergyPhysicsResearchandthenetworkservicesoperatingatthesesites,InparticularIPv6deploymentontheU.S.EnergySciencesNetwork(ESnet)willbereviewed.TheconnectivityandperformancebetweenHighEnergyPhysicsLaboratories,UniversitiesandInstituteswillbediscussed.

简介：Asurface-renewabletris(1,10-phenanthroline-5,6-dione)iron(Ⅱ）hexafluorophosphate(FePD)modifiedcarbonceramicelectrodewasconstructedbydispersingFePDandgraphitepowderinmethyltrimethoxysilane(MTMOS)basedgels.TheFePD-modifiedelectrodepresentedpH-dependentvoltannetricbehavior,anditspeakcurrentswerediffusion-controlledin0.1mol/LNa2SO4+H2SO4solution(pH=0.4).Inthepresenceofiodate,clearelectrocatalyticreductionwaveswereobservedandthusthechemicallymodiffiedelectrodewasusedasanamperometricsensorforiodatencommonsalt.Thelinearrange,sensitivity,detectionlimitandresponsetimeoftheiodatesensorwere5×10^-6-1×10^-2mol/L,7.448μA·L/mmol,1.2×10^-6mol/Land5s,respectively.Adistinctadvantageofthissensorisitsgoodreproducibilityofsurface-renewalbysimplemechanicalpolishing.

简介：通过水热合成方法合成了三维超分子化合物（C6H8N）6（PW12O40）（OH）3·5H2O,采用IR、单晶X射线衍射法、TG/DTG及循环伏安法对标题化合物进行结构、热稳定性和电化学性质研究.结构解析表明,化合物属于六方晶系,P-3空间群,晶胞参数a=1.39301（14）nm,b=1.39301（14）nm,c=1.02570（10）nm,V=1.7237（3）nm3,Z=1,Dc=3.452g/cm3,最终偏差因子R1=0.0683,wR2=0.1667.该化合物通过氢键作用形成3D超分子结构.

简介：Theneworganic-inorganiccompound,[C_6H_7N_2O_2]_3TeCl_5·2Clwassynthesizedanditsstructurewasdeterminedatroomtemperatureinthetriclinicsystem(P~-1)withthefollowingparameters:a=10.5330(11)?,b=10.6663(11)?,c=15.9751(16)?,α=82.090(2)°,β=71.193(2)°,γ=68.284(2)°andZ=2.ThefinalcycleofrefinementledtoR=0.057andRw=0.149.ThecrystalstructurewasstabilizedbyanextensivenetworkofN--H···Clandnon-classicalC--H···Clhydrogenbondsbetweenthecationandtheanionicgroup.Severalthermalanalysistechniquessuchasthermogravimetricanalysis,differentialscanningcalorimetricanalysisandevolvedgasanalysiswereused.Weusedisoconversionalkineticsmethodstodeterminethekineticsparameters.Weobservethatthedecompositionof[C_6H_7N_2O_2]_3TeCl_5·2Clentailstheformationhydrochloricacidofnitroanilineasvolatiles.Theinfraredspectrawererecordedinthe4000–400cm~(-1)frequencyregion.TheRamanspectrawererecordedintheexternalregionoftheanionicsublatticevibration50–1500cm~(-1).TheopticalbandgapwascalculatedfromtheUV-VisabsorbancespectrausingclassicalTaucrelationwhichwasfoundtobe3.12and3.67eV.

简介：隐藏的对称和一个无限的集合广告5S5上的格林Schwarz超弦的非局部的保存水流被Bena等指出了。在这篇论文，我们证明在MaurerCartan方程和运动的方程之间双的农夫在格林Schwarz超弦的moduli空格给隐藏的对称。因此由扭曲的转变vielbeins，我们能表示纸的水流[我。Bena，J。Polchinski，和R。Roiban，Phys。加快。D69(2004)046002]作为宽松的连接由一唯一光谱参数。

简介：为了满足我国正在建设的白光中子源（whiteneutronsource,WNS）需求,设计了具有共性化架构的C6D6谱仪读出电子学系统。该系统基于波形数字化技术和PXIe平台,实现对γ能谱和中子飞行时间的测量。介绍了系统设计方案,详细阐述了信号调理模块、时间测量、PXIe平台及相关软件的设计与实现,并开展了系统性能测试和联调实验。测量结果表明：该系统能够正确获得测量数据,满足了白光中子源的首批实验需求。

简介：合成了氰根桥联配合物Co[Fe(CN)5NO].5H2O,使用元素分析、热重分析、红外光谱、XRD对配合物进行了表征。红外光谱显示金属离子通过氰根桥联即FeII-CN-NiII传递磁相互作用,是属于桥式氰根配体的CN伸缩振动,而粉末XRD衍射图表明此化合物为面心立方体结构(FCC),空间群为Fm3m(225),晶格常数a=10.2856。通过对该配合物的直流变温磁化率和交流磁化率测定表明金属离子通过氰根传递弱反铁磁作用,根据Curie-Weiss定律,拟合数据获得居里常数C=1.55cm3·K/mol,顺磁居里温度θ=-1.87K。

简介：WeconsiderdiffusivelimitoftheBoltzmannequationinaperiodicbox.WeestablishL~6estimateforthehydrodynamicpartPfofparticledistributionfunction,whichleadstouniformboundsglobalintime.

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