简介:Thetitlecomplex,[La(baec)1/2(H2btec)1/2(H2O)]n(H4btec=1,2,4,5-benzenetetracarboxylicacid)(1)wassynthesizedbythehydrothermalreactionof1,2,4,5-benzenetetracarboxylicdianhydridewithLa(NO3)3·6H2OinH2O,andcrystallizesinthetriclinicsystem,spacegroupP-1withα=0.64403(3)nm,b=0.94500(4)nm,c=0.96380(5)nm,α=88.535(2)°,β=100.314(2)°,γ=76.6470(10)°,V=1.69968(10)nm^3,Z=2,andfinalR=0.0274,Rw=0.0735.In1,eachLa(Ⅲ)ioniscoordinatedbyeightoxygenatomsfromsixcarboxylategroupsandonecoordinatedwatermolecule.TwodifferentcoordinstionmodesofH4btecwerePresentinthestructure,oneofwhichcontainstwoprotonatedcarboxylategrougpstobalancethecharge.
简介:上海市社会总抚养比受到诸多因素的影响,导致数据波动性较大,单纯地采用灰色预测模型无法更加准确地进行预测,因此文章提出了基于最小二乘法的改进GM(1,1)模型.首先文章介绍了普通GM(1,1)模型的建立方法与步骤;接着通过采用最小二乘法的原理弱化波动较大的数据,加强其规律性从而建立新的GM(1,1)模型;最后结合2007-2011年上海市社会总抚养比数据建立新的预测模型,并用2012年数据对模型进行验证合格,可以用来预测未来几年上海市社会总抚养比,便于该市对未来经济的发展宏观调控.结果表明该预测方法是合理可行的,为其他相关预测提供了理论依据.
简介:Inthispaper,theauthorsobtaintheBaecklundtransformationontime-likesurfaceswithconstantmeancurvatureinR^2,1.Usingthistransformation,familiesofsurfaceswithconstantmeancurvaturefromknownonescanbeconstructed.
简介:有CuBr2和CdI2催化的公司的1-bromo-6-chlorohexane的Photopromotedcarbonylation在周围的条件下面被执行了。结果显示carbonylation在CuBr2的催化作用下面继续chloroesterClCH2(CH2)5COOCH3的主要产品。而且,carbonylation的活动能被基本添加剂的增加改进(NaOAc,Na3PO4或(n-C4H9)3N)。在这些添加剂之中,(n-C4H9)3N以ClCH2(CH2)5COOCH3的收益是最有效的。然而,代替BrCH2(CH2)5COOCH3的氯产品的methoxycarbonyl没面对CdI2被获得。这与monochloroalkane的carbonylation相当不同。
简介:Thescalinglawsofenergyconfinementareverysignificantforconfinementimprovement.AtypicalscalinglawofohmicheatingwithloweffectivechargeandradiationpowerisgivenbyGoldston
简介:Morelocalizedenergydepositionisabletobeproducedinantiproton-nucleuscollisionsincomparisonwithheavy-ioncollisionsduetoannihilationreactions.Searchingforthecoldquark-gluonplasma(QGP)withantiprotonbeamshasbeenconsideredasahottopicbothinexperimentsandinthereticalcalculationsoverthepastseveraldecades.Strangenessproductionandhypernucleusformationinantiproton-inducednuclearreactionsareimportanceinexploringthehyperon(antihyperon)-nucleon(HN)potentialandtheantinucleon-nucleoninteraction,whichhavebeenhottopicsintheforthcomingexperimentsatPANDAinGermany.
简介:Thecomplexbandstructuresofa1Danisotropicgraphenephotoniccrystalareinvestigated,andthedispersionrelationsareconfirmedusingthetransfermatrixmethodandsimulationofcommercialsoftware.Itisfoundthattheresultofusingeffectivemediumtheorycanfitthederiveddispersioncurvesinthelowwavevector.Transmission,absorption,andreflectionatobliqueincidentanglesarestudiedforthestructure,respectively.Omni-gapsexistforanglesashighas80°fortwopolarizations.Physicalmechanismsofthetunabledispersionandtransmissionareexplainedbythepermittivityofgrapheneandtheeffectivepermittivityofthemultilayerstructure.
简介:Therearemanyacceleratingconvergencefactors(ACFs)forlimitperiodiccontinuedfractionK(an/1)(an→a≠0).Inthispaper,somecharacteristicsandcomparativetheoremsareobtainedonACFs.TworesultsaregivenformostfrequentlyusedACFs.
简介:Inthispaper,theL1-normestimatorsandtherandomweightedstatisticforasemiparametricregressionmodelareconstructed,thestrongconvergenceratesofestimatorsareobtainundercertainconditions,thestrongefficiencyoftherandomweightingmethodisshown.AsimulationstudyisconductedtocomparetheL1-normestimatorwiththeleastsquareestimatorintermofapproximateaccuracy,andsimulationresultsaregivenforcomparisonbetweentherandomweightingmethodandnormalapproximationmethod.