学科分类
/ 2
39 个结果
  • 简介:以PbO,MgO,Nb2O5,TiO2为原料,采用两步固态反应法制备了纯钙钛矿相的0.92PMN-0.08PT陶瓷,并对其相的组成、微观形貌、电性能和储能性能进行了研究。在25℃,1kHz条件下,该陶瓷的相对介电常数高达27480,电损耗tan艿仅为4%,电滞回线形状细长,剩余极化很小,可释放的能量密度达0.31J·cm-3.结果表明:室温下该陶瓷具有优良的电和储能性能。

  • 标签: PMN—PT陶瓷 介电性能 介电常数 能量密度
  • 简介:Anewspectralproblemisproposed,andnonlineardifferentialequationsofthecorrespondinghierarchyareobtained.Withthehelpofthenonlinearizationapproachofeigenvalueproblems,anewfinite-dimensionalHamiltoniansystemonR2nisobtained.Ageneratingfunctionapproachisintroducedtoprovetheinvolutionofconservedintegralsanditsfunctionalindependence,andtheHamiltonianflowsarestraightenedbyintroducingtheAbel-Jacobicoordinates.Atlast,basedontheprinciplesofalgebracurve,thequasi-periodicsolutionsforthecorrespondingequationsareobtainedbysolvingtheordinarydifferentialequationsandinversingtheAbel-Jacobicoordinates.

  • 标签: 数学分析 数学理论 应用数学 函数
  • 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:Onassumingthatweaksubstructurehasadynamicswhichissimilartoquantumchromodynamicsbutmuchstronger,weconcludethatunquenchingisindispensableforpredictionsonthespectrumofweak-substructureresonances[1].

  • 标签: Unquenching WEAK SUBSTRUCTURE
  • 简介:这份报纸基于图1拉普拉斯算符为Cheeger切割论述理论和算法的详细评论。在可行集合的房间结构的优点,我们建议一个房间下降(CD)为完成Cheeger的框架切了。当插松驰在可行集合保证客观价值的减少时,从哪个反的力量(IP)方法和最陡峭的降下(SD)方法能也被恢复,我们能得到二个指定CD方法。所有这些方法的比较在几张典型的图上被进行。[从作者抽象]

  • 标签: 算法 细胞结构 最速下降法 可行集 功率法
  • 简介:Wereportonanunexplainedhighstatisticssignalthatmayindicatetheexistenceofasuperlightscalarboson[1].Thequestionwhetherthereexistsa(scalar)bosonwithamassofabout38MeVdoesnotdependexclusivelyontheexistenceofaresonance-likestructure(Fig.1)intheexperimentaldataofRef.[2],yetitisatpresenttheclearestsignalwehavefoundinmanyexperiments.

  • 标签: EXISTENCE Superlight SCALAR
  • 简介:Wecommunicatemanydifficultiesthatweencounterwhenattemptingtopinpointacommonoriginfortheseveralobservedanomalies[1;2]orassessingtheirtensionwithexistingexclusionlimits.Theseincludesystematicsaffectingtheoperationofthedetectors,ourknowledgeoftheirresponse,astrophysicaluncertainties,andthebroadrangeofparticlecouplingsthatcanmediatetheinteractionwithadetectortarget.Theinterestingastrophysicalevidence[2]thatmotivatesasearchfordark-photonandfocusesourattentiononaHiddenValleysmodelwithaGeV-scaledarksectorthatproducesexcitingsignatures.Resultsfromtherecentundergroundexperiments[1]arealsoconsidered.

  • 标签: RECENT PROGRESS SIGNATURES
  • 简介:TheGroupofNuclearStructureResearchatIMPhasdevotedmuchefforttothelifetimemeasurementsoflowlyingexcitedstatesvia??fasttimingcoincidence.Twoexperimentswereperformedin2015attheradioactivebeamlineRIBLL[1]andgas-filledrecoilseparatorSHANS[2].

  • 标签: STRUCTURE RESEARCH GROUP
  • 简介:Usingbi-spinorfieldswewritethepseudo-scalarandbi-spinorfieldsthatarecharacterizedbythefieldfunctionsofcoordinatesofseveralparticles,namelymulti-particlefields.Byapplyingthequantizationproceduretothesemulti-particlefields,hadroniccreationandannihilationoperatorshavebeenobtained.

  • 标签: MULTI-PARTICLE FIELD OPERATORS
  • 简介:纸的目的是估计Wasserstein测量的密度功能或分发功能公制的,统计距离的一种典型类型,它通常在统计学习被要求。基于古典伯恩斯坦近似,一个计划被介绍。得到计划的错误估计,到为单调C1功能估计伯恩斯坦近似的L1标准的问题拐弯,它是很少在古典近似理论讨论了。最后,我们由统计距离得到概率估计。

  • 标签: 伯恩斯坦 函数估计 公制 统计距离 分布函数 密度函数
  • 简介:AcarefulanalysisoftheAME2012[1]databaseintheframeworkoftheinverseproblemsusingthedynamicautoregularizationmethodor,moreprecisely,theREGNprogram[2],whichistheconstructivedevelopmentoftheTikhonovregularizationmethod[3],revealsphenomenologicalfunctionalfeaturesofpreviouslyunknownparametersoftheBethe-Weizs¨acker(BW)massformula.

  • 标签: Bethe-Weizsacker MASS FORMULA
  • 简介:运用荧光光谱、同步荧光光谱、紫外吸收光谱探讨了Co2+对槲皮(Quercetin,Que)与牛血清白蛋白(BovineSerumAlbumin,BSA)结合作用的影响,初步分析了影响二者结合作用减弱的因素.Co2+的存在使Que与BSA作用的猝灭常数、结合常数、结合位点数均减小,但Co2+没有改变二者的猝灭机制,仍为静态猝灭.Co2+与Que的竞争作用及BSA-Co和Que-Co复合物的形成,抑制了Que与BSA的结合.

  • 标签: 槲皮素 牛血清白蛋白 Co2+ 结合作用
  • 简介:Veryrecently,theBelleandBESIIIexperimentsobservedanewcharmonium-likestateX(3823),whichisagoodcandidatefortheD-wavecharmonium(13D2).BecausetheX(3823)isjustneartheDˉDthreshold,thedecayX(3823)!J=+??canbeagoldenchanneltotestthesignificanceofcoupled-channeleffects.Inthiswork[1],thisdecayisconsideredincludingboththehidden-charmdipionandtheusualquantumchromodynamicsmultipoleexpansion(QCDME)contributions.

  • 标签: IDENTIFY COUPLED-CHANNEL EFFECTS
  • 简介:UsingthestandardtruncatedPainlevexpansion,theresidualsymmetryofthe(2+1)-dimensionalmodifieddispersivewater-wavesystemislocalizedintheproperlyprolongedsystemwiththeLiepointsymmetryvector.Somedifferenttransformationinvariancesarederivedbyutilizingtheobtainedsymmetries.ThesymmetriesofthesystemarealsoderivedthroughtheClarkson-Kruskaldirectmethod,andseveraltypesofexplicitreductionsolutionsrelatetothetrigonometricorthehyperbolicfunctionsareobtained.Finally,somespecialsolitonsaredepictedfromoneofthesolutions.

  • 标签: DISPERSIVE water-wave system SYMMETRY reduction EX
  • 简介:综合运用密度泛函理论、分子力学、统计学及比较分子力场分析等方法研究了抗肿瘤药物5,8-二甲基乙酰紫草衍生物的二维(2D)、三维(3D)定量构效关系(QSAR).所建最优2D-QSAR方程的交叉验证系数(q^2)和拟合相关系数(R^2)分别为0.618和0.736.CoMFA模型的q^2和非交叉验证系数(r^2)分别为0.703和0.982,预测相关系数R^2pred为0.746.结果表明,所建立的2D/3D-QSAR模型都具有良好的统计学意义及合理、可信的预报能力,可以预测未知化合物的活性。基于此研究结果,设计了4个具有较高抗肿瘤活性的新化合物.

  • 标签: 紫草素衍生物 MCF-7 定量构效关系 比较分子力场分析 分子设计
  • 简介:Thermodynamicpropertiesandphasediagramsofamixedspin-(1,2)Isingferrimagneticsystemwithsingleionanisotropyonhexagonalnanowirearestudiedbyusingeffective-fieldtheorywithcorrelations.Thesusceptibility,internalenergyandspecificheatofthesystemarenumericallyexaminedandsomeinterestingphenomenainthesequantitiesarefound.TheeffectoftheHamiltonianparametersonphasediagramsareexaminedindetail.Besidessecond-orderphasetransition,linesoffirst-ordertransitionandtricriticalpointsarefound.Inparticular,wefoundthatforsomenegativevaluesofsingle-ionanisotropies,thereexistfirst-orderphasetransitions.

  • 标签: HEXAGONAL ISING NANOWIRE mixed spin-(1 2)