简介：2-Phenyl-1,2,3-triazole-4-formylhydrazine(2)waspreparedbyhydrazinolysisofthecorrespondingester1.Reactionof2withCS2/KOHgavetheoxadiazolederivatives(3)whichvia,Mannichreactionwithdifferentdialkylaminesfurnished3-N,N-dialkylderivatives(4a-c).Also,condensationof2withappropriatearomaticacidinPOCl3yieldedoxadiazolederivatives(5a-c),orwithaldehydesandketonesaffordedhydrazones(6a-c).Cyclizationof(6a-c)withaceticanhydridegavethedesireddihydroxadiazolederivatives(7a-c).Ontheotherhand,reactionofdithiocarbazate(8)withhydrazinehydrategavethecorrespondingtriazolederivative(9)whichontreatmentwithcarboxylicacidsinrefluxingPOCl3yieldeds-triazole[3,4-b]-1,3,4-thiadiazolederivatives(10a-b).ThestructuresofalltheabovecompoundswereconfirmedbymeansofIR,1HNMR,MSandelementalanalysis.

简介：ThesynthesisofTs,T10andT12silsesquioxanecagesfromarangeofstartingmaterials:phenyl-cistetrol,1,3-divinyltetraethoxydisiloxaneandcyclopentylTresinsbyusingtetran-butylammoniumfluoride(TBAF)asthecatalystisdescribedinthispaper.Thereactionyieldsobtainedviathecurrentroutearebettercomparedtothoseviatheliteratureroutes.SomeofthecagecompoundshavebeencharacterizedbyX-raycrystallography.

简介：ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｙｅａｒｓ，Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔ（ＬＢ）ｆｉｌｍｓｈａｖｅａｔｒａｃｔｅｄｍｕｃｈａｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｓｉｂｉｌｉｔｉｅｓａｓｆｕｎｃｔｉｏｎａｌｍｏｌｅｃｕｌａｒｄｅｖ...

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简介：Inthispaper,thevariableseparationapproachisusedtoobtainlocalizedcoherentstructuresofthe(2+1)-dimensionalgeneralizedDavey-Stewarsonequations:iqt+1/2(qxx+qyy)+(R+S)q=O,Rx=-σ/2|q|2ySy=-σ/2|q|2/x.ApplyingaspecialBacklundtransformationandintroducingarbitraryfunctionsoftheseedsolutions,anabundanceofthelocalizedstructuresofthismodelisderived.Byselectingthearbitraryfunctionsappropriately,somespecialtypesoflocalizedexcitationssuchasdromions,dromionlattice,breathers,andinstantonsareconstructed.

简介：证明了M／G／1排队系统中(L(f)，θ(t))几何遍历的充分必要条件是服务时间分布函数B(x)∈g^+(r)，改进了文[2]的证明方法。

简介：MOS型功率场效应管具有大的脉冲开关电流(数十安培)、较高的漏源电压(达千伏)、小的导通内阻(欧姆量级)和较快的导通时间(数纳秒)。由于其输入输出电容大，故用其制作的脉冲源抗脉冲电磁干扰能力较强，也因此它的开关速度较慢。采用过驱动能提高MOS型功率场效应管的开关速度。就是使栅极驱动脉冲波形的前沿很快且上冲大大超过额定的栅源驱动电压。为此，在研制过程中，解决了用多个场效应管串、并联组合，形成具有纳秒级陡峭前沿的大电流开关；用多个脉冲变压器并联，对大电流开关输出的信号进行放大和成形；用脉冲变压器的技术解决了大功率脉冲功率合成等关键技术，采用稳定的开关器件等技术和工艺，解决低压电路抗高速高压强电干扰。实现了用固体器件—场效应管，替代国外氢闸流管部分用途的功能。

简介：TheCMSCollaborationof2000scientistsinvolves150institutionsfrom31nationsspreadallovertheworld.CMSsoftwaresystemintegrationandreleasemanagementisperformedatCERN.CodemanagementisbasedonCVS,withreadorwriteaccesstotherepositoryviaaCVSserver,Softwareconfiguration,releasemanagementtools(SCRAM)arebeingdevelopedatCERN.Softwarereleasesarethendistributedtoregionalcenters,wherethesoftwareisusedbyalocalcommunityforawidevarietyoftasks,suchassoftwaredevelopmentdetectorsimulationandreconstructionandphysicsanalysis.Dependingonspecificapplication,thesystemenvironmentandlocalhardwarerequirements,differentapproachesandtoolsareusedfortheCMSsoftwareinstallationatdifferentplaces.Thispresentationdescribesconceptsandreactialsolutionsforavarietyofwaysofsoftwaredistribution,withanemphasisontheCMSexperienceatFermilab,Installationandusageofdifferentmodelsusedfortheproductionfarm,forcodedevelopmentandforphysicsanalysisaredescribed.

简介：本文用三种方式给出计算队长L(t)的瞬时分布。

简介：设G是一个2—(v，11，1)设计的可解区传递但非旗传递自同构群，且G点一本原则，则v=p^n，G≤AГL(1，p^n)且p≠2。

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简介：DensityFunetionalTheory(DFT)methodwasusedinthispapertostudyone-carbontransferfrom1.10-tetrahydroquinoxalinc,ananalogucoftetrahydrofolicaeid,tomethylamine.Thisreaetioncanbecompletedviatwopaths.Fromthecomputationresultwecanconcludethaiageneral-aeidcatalysisexistsinthisreaction.BycomputationwefindDFThasitslimitationindeseribinganewlyincorporatedstructurewithaunitcharge.

简介：相对增益阵列(RGA)大多数应用的矩阵阶数都是较小的(n=2,3或4).我们从矩阵方程Φ(A)=1/2J2的实数解出发,应用矩阵方程Φ(A)=1/nJn的实数解在G-等价下的不变性和实数解的分块构造法,研究了Φ(A)=1/4J4的实数解的一些问题.

简介：Fluorescencespectraofladderlikepolyphenylsilsesquioxane(LPPS)andladderlike1,4-phenylene-bridgedpolyvinylsiloxane(LPPVS)havebeenmeasuredasafunctionoftemperature(4-55℃),indilutetetrahydrofuransolution.Theexcimer(IE)tomonomer(IM)intensityratio(IE/IM)ofLPPSdilutesolutionshowsadoublelinearArrheniusplotwithabreakpointascribabletoatransitiontemperatureTr.Thisbehaviorhasnotbeenfoundforsinglechainpolyorganosiloxanes.WhenIn/EofLPPSwasplottedagainst1/T,italsogaveadoublelinearplotwithonebreakpoint,whichwasfoundinsinglechainpolyorganosiloxanes.ThedifferentbehaviorsbetweenLPPSandsinglechainpolyorganosiloxanesmaybemainlyattributedtotherelativelyrigiddouble-chainmacromolecularbackboneofLPPS.However,theln(IE/IM)ofdiluteLPPVSsolutionversus1/Tshowsasimplelinearvariationwithapositiveslopewhichconfirmsourproposition.ThedifferencebetweenthefluorescenceresultsofLPPSandthoseofLPPVSmaypossiblyderivefromtheirstructuredifferencesandcooperativemotioninbackbonechainbonds.

简介：InfluenceoftheeffectivefermionhexadecapoleforcenewlyincorporatedinamicroscopicsdgIBM-1onspectra,reducedE2andE4transitionmatrixelements(T(E2)sandT(E4)s)intheeven-evenplatinumisotopes(A=192,194,196,198)isinvestigatedintermsofnumericalcalculations.ItisfoundthattheintroducedinteractioncausesonlylimitedmodificationtothespectrumandT(E2)s,apartfromafewexceptions.However,itplaysanessentialroleindescribingE4transitions.Thusinthecasethattheinteractionisincorporatedwithcertainstrength,areasonabledescriptionofalltheE4transitionsintheplatinumisotopesisreachedinthemicroscopicsdgIBM-1incomparingbothtoexperimentaldataandtheresultscalculatedinphenomenologicalbosonmodel.``

简介：DeoxybaccatinⅥ(4α,7β,9α,10β,13α-penta-acetoxy-2α-benzoyloxy-5β,20-epoxytax-11-ene)wasisolatedfromtherootsofTaxuschinensis,Rehd.var.mairei.Thestructuralassignmentsofthecompoundwerebasedontheirspectraldata,including2DNMRexperimentsandchemicalcorrelation.TheX-raycrystallographicanalysisof1-deoxybaccatinⅥprovidedunambiguouscharacterizationforthestructures.Inthestructure,thesix-memberedAringexhibitsboatconformation,theeight-memberedBringadoptsboat-chairconformation,andthesix-memberedCringexhibitsasofaconformation.

简介：Directasymmetricaldoladditionofmethylketonesto2,2,2-trifluoro-1-phenylethanoneanditsring-substitutedderivativeswasachievedusingL-prolineasachiralpromoter.Variousopticallyactiveβ-trifluoromethyl-β-hydroxyketoneswereobtainedinalmostquantitativeyieldswithmoderateenantioselectivitiesupto64%ee.

简介：在MengerPN空间中研究了一类非线性算子方程Tx=μx+p(μ≥1)的解,得到了几个新的定理.同时,改进和推广了若干个重要结论.

简介：<正>Inthefifties.Calderonestablishedaformalrelationbetweensvmbolandkerneldistribu-tion,butitisdifficulttoestablishanintrinsicrelation.TheCalderon-Zygmund（C-Z）schoolstudiedrheC-Zoperators,andHormander.KohnandNirenberg,etal.studiedthesymbolicoperators.HereweapplyarefinementoftheLittlewood-Paley（L-P）decomposition,analyseundernewwaveletbases.tocharacterizebothsymbolicoperatorsspacesOpS1,δmandkerneldistributionsspaceswithotherspacescomposedofsomeahnostdiagonalmatrices.thengetanisometricbetweenOpS1,δmandkerneldistri-butionspaces

简介：AseriesofRbxCs1-xAg4I5(x=0-1)thinfilmsweregrownbyvacuumevaporationonNaCIcrystalsubstratesat350K.Theabsorptionspectraofthesefilmsweremeasuredat80Kinthewavelengthrangefrom240nmto400nm.ItisshownthatsuperionicconductorthinfilmsofquaternarycompoundRb0.5Cs0.5Ag4I5andternarycompoundRbAg415canbeobtainedatx=0.5-0.6andx=0.7-1,respectively.Atx=0.65,thecombinedcompoundfilmofthemixtureof30mol%RbAg4I5and70mol%Rb0.5Cs0.5Ag4I5ispresented.Then,basedonthespectralpositionsoftheA1andA2peaks,wedeterminedthattheRb0.5Cs0.5Ag4I5excitoncouplingenergyRexis0.21eV,theforbiddenzonewidthEgis3.82eVandtheexcitonradiusaexis0.70hm.Furthermore,theionicconductivitiesofsuperionicconductorthinfilmsofRbAg4I5andRb0.5Cs0.5Ag4I5andtheirmixturefilmareinvestigated,respectively,inthetemperaturerange303K-393K.