简介：以乙酰丙酮和1R，2R-环己二胺进行缩合得到N，N＇-双（乙酰丙酮）-1R，2R-环己二胺的Schiff碱配体L’，以乙酰丙酮和1S，2S-环己二胺进行缩合得到N，N＇双（乙酰丙酮）-1S，2S-环己二胺的Schiff碱配体L^2，然后将L^1和L^2与AgClO4，AgBF4，AgSbF6进行配位反应，得到了3个配合物Ag2（L^1）（L^2）ClO4）2n（1），Ag2（L^1）（L^2）（BF4）2n（2）和Ag2（L^1）（L^2）（SbF6）2n（3），并用元素分析，FT—IR和X-射线单晶衍射进行了表征。结果表明，配合物1-3都属于单斜晶系，空间群P21/n，配合物1的中心Ag（I）离子采用扭曲四面体的配位构型，配合物2和3的中心Ag（I）离子都是近似平面三角形的配位构型。配合物1—3都通过配位作用向空间扩展形成2D网状结构。

简介：N-acetyl-D-methionine,NaAcandtheremainsofN-acetyl-L-methioninedramaticallyaffectthepurificationofL-methioninewhenpurifiedfromthemixtureofenzymaticallydeacylatedN-acetyl-DL-methionine,leadingtoalowyieldconventionally.Here,thispaperreportsasuccessfulseparationandpurificationofbothL-methionineandN-acetyl-D-methioninebyanHion-exchangecolumn.ThepH,L-Metconcentrationandtheratiobetweenthecontentofsodiumcationandtheion-exchangecapacitywereoptimizedtoobtainthemaximumyield.Experimentalresultsindicatethat,undertheoptimizedconditions,theyieldsofL-methionineandN-acetyl-D-methioninecanreachashighas85%and75%,respectively.

简介：证明了对于一个n-维赋范空间X，如果b#=2n-1，则它一定包含一个与（R^n-1，‖‖∞）等距同构的子空间．

简介：采用UMP2/6-311＋G（3df）方法研究了一系列化合物M_（n＋1）F_n（n=1,2;M=Na,K）体系的几何构型及非线性光学性质（NLO）.结果表明：这些体系均为超价化合物,均拥有较大的第一超极化率（β_0）.尤其是Na_3F_2体系中结构2c的β_0值为29.16×10~（-49）C~3·m~3·J~（-2）,是已知超价化合物Li_3F_2的2c结构的β_0值2.22×10~（-49）C~3·m~3·J~（-2）的13.1倍.

简介：Thecrystalandmolecularstructureofcopper(Ⅱ)dimericcomplexofS-methyl-B-N-(pyridineN-oxide-2-ylmethylidene)dithiocarbazatewithacetonitrile,[CuL(CH3CN)]2(ClO4)2,wasdeterminedbyX-raydiffraction.ThecomplexcrystalizesinmonoclinicsystemwithspacegroupP21/n,a=7.685(2),6=20.160(6),c=10.847(5)A,B=107.89(3),Z=2,Dc=1.788g/cm3,F(000)=835.8,u=18.17cm-1(Moka,R=0.057.EachCu(Ⅱ)ioninthecomplexissurroundedbyadistortedsquarepyramidal.ThebasalplaneiscomprisedofS,NandOatomsofoneligandtogetherwithaNatomofthesolvent--acetonitrile,whiletheaxialpositionisoccupiedbytheSatomoftheotherligand.ThebondlengthofCu-S(bridging)is3.038A.andCu-Cudistanceis3.700A.

简介：利用密度泛函理论（DFT）中的B3LYP方法,在6-311G（d）基组的水平上系统研究了CaSin（n=1-10）团簇的几何构型、稳定性与光谱（红外与拉曼）性质.研究结果表明,CaSin团簇构型是在CaSin-1构型上戴帽1个原子而形成的;当n≥4,CaSin团簇的最低能量结构均为立体构型;Ca原子的掺杂降低了体系的化学稳定性;CaSi3与CaSi5是幻数结构;在相同的观察频段内,CaSi3团簇的红外与拉曼活性在低频段均表现较好,而在高频段拉曼活性则表现较差,与之不同的是CaSi5团簇的红外与拉曼活性在整个频段内都表现的较好.

简介：合成了N,N′-亚水杨基皮考林酰肼(HL)及其铁配合物[FeL2](C26H20FeN6O4,Mr=536.33).X射线衍射实验结果表明,标题配合物晶体属于正交晶系,空间群为Pbcn,晶体学参数:a=1.4970(1)nm,b=1.51556(9)nm,c=2.0920(2)nm,V=4.7462(6)nm3,Z=8,Dc=1.501Mg·m-3,F(000)=2208,μ(MoKα)=0.682mm-1,R=0.0695,Rw=0.1502.在配合物[FeL2]中,铁(Ⅱ)原子具有扭曲的八面体配位构型,晶体通过分子间氢键作用形成缔合分子对.红外光谱表明,配体在形成配合物后,ν(CO)和ν(CN)红移.电子光谱表明存在π-π*和d-π*的跃迁;荧光光谱表明,配合物金属对配体n-π*激发引起的荧光发射峰有较大的影响.

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简介：Theinteractionsofoxidativeradicals(Br2,HOetc.)withN-phosphoryldipeptidederivatives(NDM-TrpOMeandNDT-MetOMe)havebeeninvestigatedbyusingpulseradiolysisatdifferentpHvalues.IthasbeenfoundthatBr2andHOradicalsoxidizetheMet-siteandTrp-siteinthedipeptidederivativesviaformationofthethree-electron-bondedintermediateandindolylradicalsimultaneously.Thentheintramolecularelectrontransferalongthepeptidebackboneoccurs.Therateconstantsofelectrontransfer,k,havebeendeterminedandthereactionmechanismhasbeendeduced.

简介：Difluorocarbenegeneratedfromthedecompositionoffluorosulfonyldifluoroaceticacid(2)reactedwithvarioussodiumsaltsofN-heterocycliccompounds(1)givingthecorrespondingdifluoro-methylatedproductsinacetonitrileat10—40℃.Benzotriazole(1a),benzimidazole(1b)andimidazole(1c)wereconvertedinto1-(difluoromethyl)benzotriazole(3a),1-(difluoromethyl)benzimidazole(3b)and1-(difluoromethyl)imidazole(3c)respectively.Indole(1d)reactedwith2togive-(fluorosulfonyldifluoro-acetate)indole(2d)ratherthantheexpecteddifluoromethylatedderivatives.

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简介：N-nitrosaminesarestrongcarcinogensforhumans.Thispapergivesanoverviewofthenitrosmainesincigarettesmokeincludingtheformation,theharmfulness,theanalyticalmethodsofthenitrosmainesandtheadsorptionsanddegradationsofN-nitrosamines.

简介：Inthispaper,therigiditytheoremsofthesubmanifoldsinS^n+pwithparallelMoebiusformandconstantMObiusscalarcurvaturearegiven.

简介：Aroutingtreeforasetoftasksisadecisiontreewhichassignsthetaskstotheirdestinationsaccordingtothefeaturesofthetasks.Aweightedroutingtreeisonewithcostsattachedtoeachlinkofthetree.Linksofthesamefeaturehavethesamecost.Itisprovedthattheproblemoffinding?routingtreeoftheminimumcostforagivensetoftasksoftwofeaturesisNP-complete.

简介：１－１７　Ｖｉｂｒａｔｉｏｎａｌ　Ｐｒｏｐｅｒｔｉｅｓ　ｏｆ　Ｎａ_ｎ１－１７ＶｉｂｒａｔｉｏｎａｌＰｒｏｐｅｒｔｉｅｓｏｆＮａ_ｎ￥ＺｈａｎｇＦｅｎｇｓｌｌｏｕ；Ｅ．ＳｕｒａｕｄｌａｎｄＲ．ＧｌｏｗｉｎｓｋｉＺＩｔｉｓｋｎｏｗｎｔｈａｔｓｍａｌｌｓｏ...

简介：对N阶电阻网络等效电阻进行了研究,应用虚拟电流法给出了这类问题的两个普适规律,并将所得结果与其它相关结果进行了比较

简介：Bythereactionofpoly(bromoacetylstyrene)(EBPS)withthiaurea(TU),akindofnovelchelatingresinwithheterocyaclicringofsulfurandnitrogen,poly[4-(2-amino)thiazoleyl-4-vinylben=ene],wassynthesized.ItsstructurewascharacterizedbyFTIRandelementalanalysis.Thefactorswhichhaveinfluenceonthereactionsuchasreactiontime,solvents,andmolarratioofreactantswereinvestigated.

简介：Inthispaper,theauthorsconstructaφ-groupfornsubmodules,whichgeneralizestheclassicalK-theoryandgivesmoreinformationthantheclassicalones.Thistheoryisrelatedtotheclassificationtheoryforindecomposablesystemsofnsubspaces.

简介：AnewchemilurninescencelabelN-(β-carboxypropionyl)luminol(CPL)wasusedtolabelsheepanti-humanIgG(SaHIgG).Thelabeledantibodywasstableandcouldbedetectedatleastdownto10-17~10-16mol.Themolarincorporationratiowasestimatedtobe0.26molofCPLpermolofSaHIgG.TherewerenoapparentchangesintheimmunoreactivityofthelabeledSaHIgGandinthequantumefficiencyoftheCPLafterlabeling.

简介：这篇文章处理考尔德的固定性质?慦桳潩吗？