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500 个结果
  • 简介:<正>(a1/2)2和(a2)1/2兄妹俩,一来到花果山就受到众猴儿青睐,争相和他俩交朋友,哪知有的小猴对他俩不礼貌,有时还受到了委屈,于是他俩就到猴王那里去告状,兄妹俩来到猴王面前,深深行了个鞠躬礼说:“报告猴王,小猴儿常把我俩张冠李戴,用我俩来解题时,

  • 标签: 算术平方根 非负数 花果山 二次根式 彻底认识 彻底了解
  • 简介:Twonewdicyanamidecoordinationpolymers,{Mn(dmpz)[N(CN)2]2}2(1)and{Cu(dmpz)[N(CN)2]2}2(2)(dmpz=3,5-dimethylpyrazole),weresynthesizedandcharacterizedbysinglecrystalX-raydiffractionanalysisandIRspectroscopy.In1and2themetalionshavetwodifferentcoordinationmodes,whereoneiscoordinatedtofourdicyanamideanionsandtwomonodentatedmpzmoleculestoformaslightlydistortedoctahedralgeometry,whiletheotheradoptsoctahedralgeometry,surroundedbyfournitrileNatomsandtwoamideNatomsofthedicyanamideanions.Bothcomplexescontaintwoalternatingchainsthatareparalleltoeachother.

  • 标签: 氰氨基化合物 聚合体 晶体结构 3 5-二甲基吡唑
  • 简介:ThecrystalstructureofDi-nitratobis(ethylcaprolactam)uranyl(Ⅱ)UO2[CH2(CH2)4CONC2H5]2(NO3)2wasestablishedbyasingle-crystalX-raydiffractionstudy.Itistriclinie,spacegroupP1,witha=7.171(2),b=8.655(3),c=10.182(5)A,α=78.27(3),β=70.63(3),γ=81.76(3)°,V=581.7(4)A3,Z=l,Dc=1.94g.cm-3.FinalRvalueis0.0218.Theresultrevealsthaturanylioniscoordinatedtosixoxygenatoms,twoofthemarefromtwocarbonylgroupsofethylcaprolactamandtheotherfourarefromtwonitrategroups.

  • 标签: carbonyl coordinated nitrate NITRATOBIS NO3 ONC2H5
  • 简介:  Enantioimericallypure1,l'-bi-2-naphthol(BINOL)1anditsderivativesareimportantchiralligandsandauxiliariesforanumberofasymmetrictransformations1suchasaldolcondensations,alkylations,Diels-Alderreactions,Michaeladditions,epoxidations,etc.Opticallypure1andtheirderivativeshavealsobeenusedextensivelyinchiralrecognition,chiralseparationandintheconstructionoffunctionalisedmaterials2.Furthermore,(R)-and(S)-BINOLarealsofundamentalstartingmaterialsforthesynthesisofalargevarietyofotherchiralbinaphthylssuchasMOP(2c),NOBIN(2d)andBINAP(2e).Asaresultthedevelopmentofefficientandeconomicmethodsforthepreparationofopticallypure1hasattractedmuchattentioninrecentyears3andnovelmethodsfortheresolutionof(±)-1continuetobedeveloped.……

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  • 简介:Themononuclearcomplex,[NtCl2(trzCHzCHzCOPh)4]·6H2O(trz=1,2,4-triazole),wassynthesizedanditsstructurewasdeterminedbysinglecrystalX-raydetermination.Itcrystallizesinthemonoclinicsystem,spacegroupP21/c,withlatticepa-rameters:a=0.80391(2)nm,b=1.06215(2)nm,c=2.90133(2)nm,β=94.792(1)°andZ=2.EachnickelatomiscoordinatedbyfourNatomsoftriazolefromfourβ-(1,2,4-IriHole-1-yl)propiophenoneligandsandtwochlorideanionsinarrangementwithoctahedralcoordinationgeometry.Inadditiontothecoordinatingnickelcomplex,therearesixunco-ordinatedwatermolecules.TheNi—Ndistanceis0.24865(8)nmandtheNi—Ndistaneesareintherangeof0.2072(2)to0.2099(2)nm,respectively.Inthesolidstate,theUtiecom-poundformsthreedimensionalnetworkstructurethroughhy-drogenbonds.Theintermolecularhydrogenbondsconnectthe[NiCl2(C2H2N3CH2CH2COPh)4]andH2Omoieties.Thedeepgreencrystalswerealsoexaminedbyelementalanalysis,FT-IRandUVspectra,whichareinagreementwiththestructuralda-ta.

  • 标签: 单晶结构 二氯镍 镍(Ⅱ)配合物 六水配合物 ·6H2O 八面体
  • 简介:theAlternatingSegmentCrank-Nicolsonschemeforone-dimensionaldiffusionequationhasbeendevelopedin[1],andtheAlternatingBlockCrank-Nicolsonmethodfortwo-dimensionalproblemin[2].Themethodshavetheadvantagesofparallelcomputing,stabilityandgoodaccuracy.Inthispaperforthetwo-dimensionaldiffusionequation,thenetregionisdividedintobands,aspecialkindofblock.ThismethodiscalledthealternatingBandCrank-Nicolsonmethod.

  • 标签: 二维空间 分布函数 有限微分方程 边界条件
  • 简介:Thecopper(Ⅱ)complex[Cu3(nta)2(azpy)2(H2O2)]·6H2O(nta=nitrilotriacetate,azpy=4,4′-azobispyridine)hasbeensynthesizedandcharacterized.TheX-rayanalysisrevealsthattherearetwokindsofcopper(Ⅱ)coordinationenvironments.Cu(1)hasadistortedsquareplanesymmetryandCu(2)hasadistortedoctahedralsymmetry.Cu(1)islinkedtoCu(2)throughntaandboundtoCu(1C)byazpy,andCu(2)islinkedtoCu(2A)throughazpy,whichextendstotwo-dimensionalnetworkwithlargerhombus1.2nm×1.7nm.

  • 标签: 合成 结构 二(次氮基三乙酸酯)二(偶二嘧啶酰胺)二水三铜络合物
  • 简介:The2-Dheteronuclearcoordinationpolymer{[Ag4Fe2(SCN)12(H2O)2][(inaH)2(H2O)2]}n(1)(inaHistheabbreviationofprotonatedisonicotinicacid)withchemicalformulaC24H20Ag4Fe2N14O8S12hasbeensynthesizedandcharacterizedbysinglecrystalX-raydiffraction,elementalanalysisandIRspectroscopy.TheAgES2ringsconnecttwokindsofoctahedralgeometriesofFe(Ⅲ)ions,[Fe(NCS)6]^3-and[Fe(H2O)E(NCS)4]^-unitswithbridgingthiocyanateionsleadingto2-D[Ag4Fe2(SCN)12(H2O)2]^2-anionframework.Fourkindsofringsincludingtheunprecedentedthirty-twomemberedAg4Fe4(SCN)8ringssharecomersoredgesinthe2-Danionlayerstructure.AllthiocyanatescoordinatetothemetalionsaccordingtotheHSABprinciplewithNatomsbindingtotheFe(Ⅲ)ionsandwithSatomsbindingtoAg(I)ions.Pronoatedinacationsstabilizethelayerstructureascounterionsandhydrogenbondswereformedwithinthepronoatedinacationsdimerandbetweenthedimersandthelatticewaters.Crystaldata:Mr=1560.44,triclinic,P-↑1,a=0.76082(1)nm,b=0.9234nm,c=1.85611(4)nm,α=103.0170(10)°,β=93.7780(10)°,γ=97.4080(10)°,V=1.25385(3)nm^3,Z=1,μ(MoKα)=2.650mm^-1,Dc=2.067g·cm^-3,F(000)=758,R1=0.0412,wR2=0.1003.

  • 标签: 合成 晶体结构 异核核糖核酸 有机聚合物
  • 简介:运用G98W程序,采用Lan12dz基组,对茂金属配合物[2,5-(Me3Si)2MeC5H2FeI(CO)2]进行从头算研究,探讨了配合物结构单元稳定性、分子轨道能量、原子净电荷布居规律,以及一些前线分子轨道组成特征等.结果表明,标题配合物在能量上可作为结构单元而稳定存在.该结构单元为茂金属配合物合成、分子组装分析和催化活性研究提供理论依据.

  • 标签: 茂金属 从头算 电子结构
  • 简介:Thecanonicalandlocatizedmolecutarorbitersof[NCCuS2NoS2]2-clusterwerecalculatedbymeansofCNDOquantumchemistrymethod.Thentheenergyandpropertiesofcorrespondingchemicatbondswerediscussed,especially,Cu-Sb-NothreecenterconjugatedπbondsandNo-St-Noconjugatedπbondswereaccountedfor.

  • 标签: CONJUGATED BONDS accounted CANONICAL ORBITAL bonding
  • 简介:NOVELOXIDATIONOFHEXABENZYLHEXAAZA-ISOWURTZITANEBYMeCHNO/CuCl/Py/OXiaoPeiGUAN;HongYAN;JianGuangSUN;YongZhongYU(ScholofChe?..

  • 标签: CUCL
  • 简介:Theinteractionsof2,2’-bipyridylwiththelanthanidenitrateswerestudiedandcomplexesoftheformulaLn(NO8)8(bipy)8wereisolatedfromwater-ethanolmixedsolvent.Thecomplexeswerecharacterizedbyelementalanalysis,conductivitymeasurments,IRspectraandDAT-TGanalysis.

  • 标签: COMPLEXES LANTHANIDE ETHANOL 初场 卜山 洲口
  • 简介:ThecharacteristicsofsuspendedsedimentimagecanbereflectedbythecoefficientsofbiorthogonalwavelettransformofCDF(2,2).Basedonthepowerdistributionindifferentscales,anadaptivealgorithmisproposedinthispaper,wherebythecoefficientsareadjustednon-linearly.Theparticleinformationcanbewellretainedwhiletheuselessbackgroundisremoved.Inthisway,satisfactorybinaryimagecanbeobtainedforfurtheranalysisofthesedimentparticle.

  • 标签: 沉积物 悬浮图像 颗粒物 双正交微波 能量分布
  • 简介:Thecombinationofboth4,4′-bipyridine(4,4′-bipy)anddihydrogenphosphateanionligandswithcopper(Ⅱ)resultsintheformationofanovellayeredcompoundCu(4,4′-bipy)2(H2PO4)2(H2O)2.ThecrystalstructurecomprisesdiscreteneutralCu(4,4′-bipy)2(H2PO4)2(H2O)2units.Thecopperatom,locatedonthecrystallographictwofoldaxis,iscoordinatedwithtwonitrogenatomsofterminal4,4′-bipyligandsandtwowatermoleculesattheequatorialpositions,andtwodihydrogenphosphateoxygenatomsattheaxialpositions,forminganelongatedoctahedron.Thecomplexisatwo-dimensionaldistortedrhomboidalnetworkpossessingtwokindsofrhomboidswithdimensionsofca.1.6792nm×0.3203nmand1.2778nm×0.3198nm,respectively.Thetwo-dimensionalnetworksarestackedparallellyoneachotheralongc-axistogiveanextendedthree-dimensionalchannelnetworkwithaninterlayerdistanceofca.0.5030nm.Crystaldata:triclinic,spacegroupP-1,a=1.0253(2)nm,b=1.4501(3)nm,c=0.79715(16)nm,α=97.91(3)°,β=90.99(3)°,γ=85.54(3)°,V=1.1703(4)nm3,Z=2,R=0.0892,wR=0.2451.

  • 标签: 磷酸盐 4 4'-双吡啶 铜(Ⅱ)复合物 沟渠构造 热液合成
  • 简介:相对增益阵列(RGA)大多数应用矩阵阶数都是较小(n=2,3或4).我们从矩阵方程Φ(A)=1/2J2实数解出发,应用矩阵方程Φ(A)=1/nJn实数解在G-等价下不变性和实数解分块构造法,研究了Φ(A)=1/4J4实数解一些问题.

  • 标签: 相对增益阵列 HADAMARD乘积 G-等价 实数解
  • 简介:设α是正实数,[α0;α1,α2。…]是α简单连分数;d是非平方整数,d1、d2是适合d1d2=d,1≤d12,gcd(d1,d2)=1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:Thesolidaddofthefirstprotonatedzincoborophosphate,(H3O)Zn(H2O)2BP2O8·H2O(1),wassoventothermallysyn-thesizedbythereactionofZn(NO3)2·6H2OandH3BO3withH3PO4inamixedsolvent,andstructurallycharacterizedbysingle-ystalX-raydiffractionanalysis.ItcrystallizesinthehexagonalP6122,a=0.9604(4)nm,c=1.5297(6)nm,V=1.2218(8)nm^3,Dc=2.921g/cm^3,Z=6,F(000)=1080,μ=3.495mm^-1.Thestmchwefeaturesthatthetetrahedra-te-trahedrahdlcesinterconnectedbyoctahedraandstronghydro-gembondinteractionsformathree-dimensionalframework.Theprotonatedwatermoleculesarelocatedatuniquepositions.othercharacterizationsbyIRandthermalanalysisarealsode-scribed.

  • 标签: (H3O)Zn(H2O)2BP2O8·H2O 合成 结构 质子化 螺旋带状物 硼磷酸锌化合物
  • 简介:Theground-stateandthermodynamicpropertiesofquantummixed-spinchainsof1/2-1/2-1-1and3/2-3/2-1-1areinvestigatedbyaquantumMonteCarlosimulationwiththeloop-clusteralgorithm.For1/2-1/2-1-1chain,wefindithastwophasesseparatedbyanenergy-gapvanishingpointintheground-state.For3/2-3/2-1-1chain,thenumericalresultsshowtwoenergy-gapvanishingpointsisolatedbydifferentphasesinitsground-state.Ourcalculationsindicatethatallthesegroundstatephasescanbeunderstoodbymeansofvalence-bond-solidpicture,andthethermodynamicbehavioratfinitetemperaturesiscontinuousasafunctionofparameterα=J2/J1.

  • 标签: 蒙特卡罗模拟 混合自旋链 铁磁性 基态 热力学性质 能隙