简介:利用电介质的平均能带模型计算了PrBa2Cu3O7的化学键参数,得到Cu(1)-O键的人价性为0.41,Cu(2)-O键的平均共价性为0.28,应用由共价性和要化率定义的化学环境因子计算了^57Fe在PrBa2Cu3O7中的Mossbauer同质异能位移,确定了^57Fe在PrBa2Cu3O7中的价态和占位情况。
简介:ZnOfilmscontainingErandGenanocrystals(nc-Ge)weresynthesizedandtheirphotoluminescence(PL)propertieswerestudied.Visibleandnear-infraredPLintensitiesarefoundtobegreatlyincreasedinnc-Ge-containingfilm.Er-related1.54μmemissionhasbeeninvestigatedunderseveralexcitationconditionsupondifferentkindsofGe,ErcodopedZnOthinfilms.1.54μmPLenhancementaccompaniedbytheappearanceofnc-Geimpliesasignificantcorrelationbetweennc-GeandPLemissionofEr3+.Theincreasedintensityof1.54μminGe:Er:ZnOfilmisconsideredtocomefromthejointeffectofthelocalpotentialdistortionaroundEr3+andthepossibleenergytransferfromnc-GetoEr3+.
简介:Theoptimalconditionsforthecomplexationreactionofmeso-tetra(3-methoxy-4-hy-droxyphenyl)porphineT(3-M-4HP)Pwithplatinumandrhodiumarepresented.Beer’sLawisobeyedwhentheconcentrationofrhodiumisintherangeof0.45-1.15μg/25mL.Themolarabsorptivityofrhodiumwasfoundtobe1.99×106L·mol-1·cm-1at460nm.ThevalueofεPtwasfoundtobe6.28×105L·mol-1·cm-1bylinearregressionmethod.TheKcoefficientmethodandcompensatingcoefficientwereusedtodetermineplatinumandrhodiumsimultaneoulywithoutremovalormaskingoftheinterferentsinthesample.Theresultsforthedeterminationofplatinumandrhodiuminthemixedsolutionofplatinumandrhodiumaresatisfactory.
简介:用构造法研究了路和圈的Mycielski图的点可区别均匀边染色,得到了路和圈的Mycielski图的点可区别均匀边色数,验证了它们满足点可区别均匀边染色猜想(VDEECC).
简介:ONM-IDEALSANDBESTAPPROXIMATIONHANDEGUANG(韩德广)(DepartmentofMathematics,QufuNormalUniversity,Qufu273165,China)Abstract:Inthispa...
简介:Byusingtheultrasound-assistedliquidphaseexfoliationmethod,Bi2Te3nanosheetsaresynthesizedanddepositedontoaquartzplatetoformakindofsaturableabsorber(SA),inwhichnonlinearabsorptionpropertiesaround2μmareanalyzedwithahome-mademode-lockedlaser.Withtheas-preparedBi2Te3SAemployed,astablepassivelyQ-switchedall-solid-state2μmlaserissuccessfullyrealized.Q-switchedpulseswithamaximumaverageoutputpowerof2.03Waregeneratedunderanoutputcouplingof5%,correspondingtothemaximumsingle-pulseenergyof18.4μJandpeakpowerof23W.Thedeliveredshortestpulsedurationandmaximumrepetitionrateare620nsand118kHzunderanoutputcouplingof2%,respectively.ItisthefirstpresentationofsuchBi2Te3SAemployedinasolid-stateQ-switchedcrystallinelaserat2μm,tothebestofourknowledge.Incomparisonwithother2Dmaterialssuitableforpulsed2μmlasers,thesaturableabsorptionperformanceofBi2Te3SAisprovedtobepromisingingeneratinghighpowerandhigh-repetition-rate2μmlaserpulses.
简介:Thetitlecomplex[NH_3CH_2CH(NH_2)CH_3]_2[M(Ⅵ)O_2(OC_6H_4O)_2](M=Mo_(0.6)W_(0.4))wassynthesizedviaasimplesolution-phasechemicalroute.ThedeterminationofsinglecrystalX-raydiffractionrevealedthatthetitlecompoundiscrystallizedinamonoclinicsystemwithP2(1)/nspacegroup,a=1.0913(10)nm,b=1.0442(10)nm,c=1.8842(19)nm,α=90°,β=96.530(17)°,γ=90°,Z=4,andV=2.133(4)nm3.Themononuclearanionicunit[M(Ⅵ)O2(OC6H4O)2]2-displayschiralpseudo-octahedral[MO_6]coordinationgeometryandislinkedbychiralcationsviahydrogenbondandπ…πstackinginteraction.Thetransmissionelectronmicroscopyimagesshowthatthetitlecomplexiscomprisedofnano-particleswithdiametersrangingfrom20to50nm.TheNMRstudyshowsthe1Hdownfieldchemicalshiftsof[NH_3CHaHbCH(NH_2)CH_3]+cationsinthetitlecomplexwhenitismixedwithadenosine-triphosphate(ATP),andthechemicalshiftdifferencebetweenHaandHbisincreasedgreatly,andmostofthecatecholateligandsdissociatefromthecentralmetalatoms.TheDNAcleavageactivityexperimentrevealsthatDNAcleavagepromotedbythetitlecomplexislowerthanthatbyNa_2MoO_4whichpossessesantitumorpro-perty,buthigherthanthatbyNa_2WO_4.