学科分类
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8 个结果
Tb(
  • 简介:[1]C.H.Evans,BiochemistryofLanthanide,PlenumPress,NewYork,1990,391.[2]J.R.Duffield,F.Marsicano,D.R.Williams,Polyhedron,1991,10,1105.[3]G.E.Jackson,S.Wynchank,M.Woudenberg,Magn.Reson.Med.1990,16,57.[4]L.M.Webb,D.M.Taylor,D.R.Williams,J.AlloysandCompounds,1998,271-273,112.[5]P.M.May,P.W.Linder,J.C.S.Dalton,1977,588.[6]T.D.Luckey,B.Venugopal,D.Huntcheson,HeavyMetalToxicitySafetyandHormology,AcademicPress,NewYork,1975,27.[7]W.R.Harris,B.S.Yang,S.Abdollahi,Y.Hamada,J.Inorg.Biochem.,1999,76,231.[8]Y.Wang,Thesis,ChangchunInstituteofAppliedChemistry,AcademiaSinica,2000.[9]J.F.Han,Thesis,ChangchunInstituteofAppliedChemistry,AcademiaSinica,1999.[10]Y.M.Liu,Thesis,ChangchunInstituteofAppliedChemistry,AcademiaSinica,1997.[11]L.Meng,L.Ding,H.T.Chen,D.Q.Zhao,J.Z.Ni,ChemicalJ.ofChineseUniversities(inChinese),1999,20,5.

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  • 简介:利用C-O键上C原子电荷Qc和分子所含C原子个数Ⅳ作为醇分子结构描述符对其沸点巩、在水中的溶解度Sw及辛醇/水分配系数(k)进行了QSPR研究.Qc的计算采用Chemoffice8.0中的MOPAC-AM1量子化学法,容易获取,它表征了醇分子同分异构体之间的结构差异.多元回归分析结果表明醇分子的Tb,-lgSw,lgKow都随分子所含C原子数Ⅳ的增加而增加,随着C-O键上C原子电荷Qc的增大而减小,复相关系数均在0.99以上.MOPAC-AM1方法计算的量化参数Qc用于与脂肪醇的水溶解性关联优于分子连接性指数.

  • 标签: 量子化学参数 AM1 定量结构性质关系 辛醇/水分配系数
  • 简介:探讨了氨基酸结构与RNA中碱基三字密码间的关系,找到了与决定氨基酸相应碱基三字码的主要因素,指出决定氨基酸三字码的第1,2个码的碱基的亲水性要与氨基酸的亲水性相匹配,强亲水性的碱基与强亲水性的氨基酸相应;第2个码的碱基的亲水性是决定其亲水性的主要因素,而第1个码的碱基亲水必屯有相当的影响,每种氨基酸的碱基三字码个数的多少,以及三字码中第3个码为何种碱基,都与氨基酸的化学结构密切相关,特别是与R(R

  • 标签: 遗传密码 RNA 氨基酸 结构 碱基
  • 简介:建立了电感耦合等离子体原子发射光谱(ICP-AES)法快速测定TB6钛合金中Al、V的方法。对试样溶解酸浓度、元素分析谱线的选择、样品基体与待测元素间的干扰等因素进行了研究。结果表明,Al、V元素的加标回收率分别为97.5%-100%、98.4%-102%,相对标准偏差(RSD)分别为1.2%、0.45%,可用于TB6钛合金中Al、V含量的实际测定。

  • 标签: ICP-AES TB6合金 AL V
  • 简介:Thefluorescencequenchingofnaphthalene(2)and1,3-di(α-naphthyl)propane(1)byRNAandbasesinmethanol-water(v:v=1:1)binarysolventsinthepresenceorabsenceofcyclodex-trin(CD)hasbeeninvestigated.Theresultsshowthatboththemonomerandexcimerfluorescenceof1canbequenchedbythesequenchers.Thequenchingandratesdependonthequencherandtem-perature.Itisshownthatthereisacriticaltemperature(Tc)foreachquencher.BelowTc,theexcimerfluorescencespectrashowvibrationalstructuresandtheStern-Volmerplotsarestraightlines(forura-cilandcytosine);whileabovetheTc,thevibrationalstructuresdisappearandtheStern-Volmerplotsdeviatefromlinearityandcurveupward.Theformerisastaticprocess;whilethelatterisamixtureofbothstaticanddynamicprocesses.Theadditionofα-CDhasnoeffectonthefinestructure,whereasβ-CDpreventstheappearanceofthisstructureefficiently.Thequenchingratesbothforthemonomerandexcimerof1bybasesexceptcytosineinthepresenceofβ-CDatambienttemperaturearenotchanged;thequenchingoffluorescenceof1byRNAinthepresenceofβ-CD,however,ishindered.Time-resolvedfluorescencestudyshowsthattheexcimerfinestructuresappearfromthezerotime.Theintensityoffinestructuresdependonthefractionofwater(φ)inbinarysolvents,anditisindependentofthepHvalueofthesolvents.ItissuggestedthatbasesandRNAinducedaggregates(perhapsmicrocrystal)areformed,inwhichthemotionofmolecules1islimited.

  • 标签: METHANOL BASES NAPHTHYL quenching PROPANE monomer