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285 个结果
  • 简介:Theinsertionof1,1-bis(1′-naphthyl)ethylenemonomerunitintotheactivepolystyrenechainendgreatlydecreasedthereactivityoftheactivechainendtothecarbonylgroup,andallowedthepolymericchainendtoreactonlywiththedoublebondinN-methacryloylcaprolactam,resultinginN-acylcaprolactamfunctionalizedpolystyrenein100%conversion.Newdiblockcopolymerofpolystyrenewithpolycaprolactamwassynthesizedbydirectreactionofthefunctionalizedpolymerwithcaprolactamwithoutaddingadditionalalkalimetalortheircaprolactamsalts.

  • 标签: 1 1-bis (1’ -naphthyl) ETHYLENE N-methacryloylcaprolactam
  • 简介:<正>Inthispaper,weapplythesolitontheorytothecaseofisometricimmersionindifferentialgeometryandobtainafamilyofisometricimmersionsfromMn1(c1)×Mn2(c2)tospaceformsMn(c)byintroducing2-parameterloopalgebra.

  • 标签: SOLITON THEORY ISOMETRIC immersion Riemaniann product
  • 简介:Thehydrolysisreactionof(±)-2-acetamido-3-hydroxy-1-(4-nitrophenyl)-1-propanone[(±)-1],anintermediateofchloramphenicol,wasstudiedandthreedifferentproductswereobtainedrespectivelyunderdifferentreactionconditions.Theresolutionofhydrolysisproduct(±)-2-amino-3-hydroxy-1-(4-nitrophenyl)-1-propanone[(±)-3]wascarriedout.Aprocessofcrystallization-inducedasymmetrictransformationwasobservedandupto76%oftheopticallypureenantiomerwasobtainedintheresolutionof(±)-3.

  • 标签: Hydrolysis Resolution EPIMERIZATION
  • 简介:1-Ethoxycarbonylalkyldiphenylpolystyrylphosphoniumtriflatescanbeeasilypreparedbyquaternizingdiphenylpolystyrylphosphinewithethyl2-trifloxyalkanoates;basetreatmentofthesepolymer-supportedphosphoniumtriflatesaffords1-ethoxycarbonylalkylidenephosphoraneswhicharestableandundergosatisfactoryWittigreactions.

  • 标签: 制备 三苯基磷化氢 1-乙氧甲酰次烷基二苯基多苯乙烯基正膦
  • 简介:1.IntroductionLetRbethecollectionofallrealnumbers,andZthecollectionofallintegers.Iff1(x)andf2(x)aretwofunctionsinL2(R),theinnerproduct1,f2>isgivenbyWesayf1(x)andf2(x)arebiorthogonal,ifFirstletusdescribeaclassoffunctions(x)and(2)inL2(R)asfollows.Thr...

  • 标签: Biorthogonality
  • 简介:InthispaperitturnsoutthataBanachlatticeXisorderisomorphictol~1(Γ)forsomenonemptysetΓiffitisaSchurspaceandalltheinfinitelydimensional,separableandclosedidealsofXareorderisomorphic.

  • 标签: ISOMORPHIC nonempty INFINITELY SEPARABLE proof TURNS
  • 简介:The1,1'-binaphtholbasedoligomers3and7with3,3'-acetylene-phenylene-acetylenespacerwerepreparedfromBINOL1.ThehighopticalrotationvalueandCDspectrademonstratedthemainchainchiralityoftheoligomermolecule.TheUV-VISandfluorescentspectraevidencethecharacteristicsofconjugatedstructure.Incomparisonwitholigomer2bearing3,3'-acetylenespacer,theoligomers3and7havelongerefficientconjugationsegment,andtheirfluorescentquantumyields(φ)increased(0.60-0.65versus0.14).Extendingtheeffectiveconjugationsegmentwouldimprovethephotophysicalpropertiesofchiralconjugatedpolymers.``

  • 标签: CHIRAL CONJUGATED oligomer BINOL 3 3'-Acetylene-phenylene-acetylene SPACER
  • 简介:数列{(1+1/n)~2}的极限是数学上最重要的极限之一,关于它的存在性的证明方法已有多种,参见文[1]、[2]、[3],本文提供这个极限存在性的两种证法,并且给出用常用对数的工具计算e的近似值及进行误差估计的初等方法。

  • 标签: 证明方法 误差估计 证法 近似计算 初等方法 算术平均
  • 简介:WeinvestigateindetailtheeffectsofR-parityleptonnumberviolationonthedecay~↑b1→b~↑x1^0intheR-parityviolatingminimalsupersymmetricstandardmodel(Rp-MSSM)underthepresentexperimentalconstraintsonRpparameters.Inournumericalcalculationsweconsidertwocasesofinputparametersofthesquarkandsleptonsectors,MsquarkMslepton,forcomparison.TheresultsshowthattherelativeR-parityviolatingcorrectionisnotverysensitivetothemassofthelightestneutralino-0↑x1andthedegenerateR-parityviolatingcouplingparameterλ2′,butstronglydependsonMsquark,Mslepton,tanβandthedegenerateR-parityviolatingcouplingparameterλ1′.Therelativecorrectionisabout-4~3%andcanexceed-6%insomeregionofparameterspace.Therefore,preciseexperimentanalysesonthedecay~↑b1→b~↑x1^0mayprovideaprobeoftheR-parityviolation.

  • 标签: R-奇偶效应 最小超不对称模型 质子 稳定性 重子数
  • 简介:SYNTHESISANDANTI-HUMANIMMUNODEFICIENCYVIRUS-(HIV-)ACTIVITYOF9-(2-PHOSPHONYLMETHOXYETHYL)ADENINE()ANDITSREGIOISOMER3-(2-PHO...

  • 标签: HIV-1
  • 简介:ThispapershowsthattheC1-curvedfiniteelementdevelopedbyBernadoningeneralcannotsatisfytheessentialboundaryconditionsonapproximateboundary.Furthermore,amodifiedC1-curvedfiniteelementisgiven,whichiscompatiblewiththeelementofArgyristriangleandcansatisfythehomogeneousDirichletboundaryconditionsonapproximateboundary.

  • 标签: Curved boundary DOMAIN Argyris TRIANGLES C1-curved
  • 简介:TheCMSregionalcalorimetertriggersystemdetectssignaturesofelectrons/photons,taus,jets,andmissingandtotaltransverseenergyinadeadtinmesspipelinedarchitecture.Thissystemreceives7000calorimetertreggertowerenergieson1.2Gbanddigitalcoppercableseriallinksandprocessestheminalow-latencypipelineddesignusingcustom-builtelectronics.AttheheartofthesystemistheReceiverCardwhichusesthenewgenerationofgigabitethernetreceiverchipsonamezzaninecardtoconvertserialdatatoparalleldatabeforetransmissionona160MHzbackplaneforfurtherprocessingbycardsthatsumenergiesandidentifyelectronsandjets.Wedescribethealgorithmsandhardwareimplementation,andsummarizethesimulationresultsthatshowthatthissystemiscapableofhandlingtheraterequirementswhiletriggeringonphysicssignalswithhighefficiency.

  • 标签: CMS实验 热量计 解发系统
  • 简介:Fourteennew1-acyl-5-arylbiuretsweresynthesizedbythereactionofarylureaswithacylisocynantes.Thelatterwasobtainedfromacylchlorideandleadcyanateindichloromethane,usingpyridineascatalyst.Thestructuresofcompounds3a-nwereconfirmedbyIR,1HNMRandMSspectra.

  • 标签: 1-Acyl-5-aryl BIURET acylisocyanate arylurea SYNTHESIS
  • 简介:Itisoftenstatedthatevencleantokamakdischargesdisruptathighdensity.Onepossibilityisthatsuchdisruptionresultfromtheenergylossarisingfromhydrogenrecyclingattheedgeoftheplasma.thisenergylosscouldleadtoacontractionofthecurrentchannelandtheproductionofadisruptivelyunstableconfiguration.

  • 标签: 循环效应 HL-1M 托卡马克装置 放电分布 等离子体