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500 个结果
  • 简介:设α是正实数,[α0;α1,α2。…]是α的简单连分数;d是非平方整数,d1、d2是适合d1d2=d,1≤d11,d2)=1的正整数,本文证明了:当且仅当α=(d2/d1)(1/2)时,α=[α0α1,…αn-1,2α0],其中α0>0,αi=αn-1(i=1…,α-1).

  • 标签: 简单连分数 正整数 渐近分数 当且仅当 定理 引理
  • 简介:针对GM(1,1)模型的适用范围是近指数情况,提出了将优化灰导数与利用原始序列模拟的相对误差平方和最小估计预测系数c相结合的方法,从而得到一种简化计算的新GM(1,1)优化模型,该模型的预测公式x(0)(k)=ce-ak在形式上比较简洁,并且经严格指数序列从理论上验证了参数a具有白化指数律重合性,预测系数c具有白化系数重合性.

  • 标签: GM(1 1)模型 灰导数 预测系数 最小二乘法 白指数律 白化系数重合性
  • 简介:WeinvestigatethesensitivityoftheangularrotationmeasurementwiththemethodofhomodynedetectioninSU(2)andSU(1,1)interferometersbyemployingorbitalangularmomentum(OAM).BycombiningacoherentbeamwithavacuumbeaminanSU(2)interferometer,wegetthesensitivityoftheangularrotationmeasurementas1/(2N1/2l).WecansurpassthelimitoftheangularrotationmeasurementinanSU(1,1)interferometerbycombiningacoherentbeamwithavacuumbeamorasqueezedvacuumbeamwhentheprobebeamhasOAM.Withoutinjection,thesensitivitycanreach1/(2N1/2l).Inaddition,byemployinganotherconstructionofanSU(1,1)interferometerwherethepumpbeamhasOAM,withthesameinjectionofanSU(1,1)interferometer,thesensitivityoftheangularrotationmeasurementcanbeimprovedbyafactorof2,reaching1/(4Nl).Theresultsconfirmthepotentialofthistechnologyforprecisionmeasurementsinangularrotationmeasurements.

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  • 简介:利用Gaussian03软件包,采用多种方法和多种基组对CCl和CCl2分子的基态结构进行优化计算,优选出B3P86/6-311+G(3df)方法对CCl分子进行计算得到基态为X2Π、键长RCCl=0.16442nm,谐振频率ωe=886.3062cm-1;优选出B3P86/6-311G(2df)方法对CCl2分子进行计算得到基态为X1A1,平衡核间距RC—Cl=0.17194nm、键角βCl—C—Cl=109.2457°、离解能De=3.4635eV,并计算出了谐振频率和力常数,其结果与实验值符合很好.并采用多体展式理论推导出CCl2自由基的解析势能函数,其等值势能图准确呈现出CCl2分子的结构特征及能量变化曲线.由此讨论了Cl+CCl和C+ClCl分子反应的势能面特征.可用于研究该分子的微观反应动力学特性.

  • 标签: CCL CCl2 分子结构 势能函数
  • 简介:主要考虑11维Boussinesq系统的一个Darboux变换,反复利用该Darboux变换,可以从该系统的一个已知解出发,通过代数运算和求导运算得到系统的新解.

  • 标签: 1+1维Boussinesq系统 可积系统 DARBOUX变换
  • 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:Aseriesofnovel1H-benzimidazol-1-ylacetatesand1H-benzimidazol-1-ylpropionatescontaining1H-1,2,4-triazolemoietyweresynthesizedundermicrowaveirradiationbymulti-stepreactions,inyieldsof87-94%.TheirinvitroantifungalactivitiesagainstBotrytiscinereaandSclerotiniasclerotiorumwereevaluatedbymycelialgrowthratemethod.AllthetargetcompoundsexhibithighactivitiesagainstB.cinereawiththeEC50valuesof7.96-21.74μg/mL,higherthanthatofcarbendazim.

  • 标签: 抗真菌活性 苯并咪唑 乙酸酯 体外 合成 基团
  • 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:Therelativisticproblemofspin-1/2fermionssubjecttovectorhyperbolic(kink-like)potential(~tanhkx)isinvestigatedbyusingtheparametricNikiforov-Uvarovmethod.TheenergyeigenvalueequationandthecorrespondingnormalizedwavefunctionsareobtainedintermsoftheJacobipolynomialsintwocases.

  • 标签: 狄拉克方程 相互作用 向量 束缚态 三角 三维
  • 简介:本文研究E^n+1的中闭超曲面上的Lr(0≤r≤n)算子,得到其第一非零特征值心的两个上界估计,改进和推广了Alias等人的相应结论。

  • 标签: 第一非零特征值 闭超曲面 r-平均曲率
  • 简介:Onassumingthatweaksubstructurehasadynamicswhichissimilartoquantumchromodynamicsbutmuchstronger,weconcludethatunquenchingisindispensableforpredictionsonthespectrumofweak-substructureresonances[1].

  • 标签: Unquenching WEAK SUBSTRUCTURE
  • 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