简介:TheeffectofCdionsonsalmonspermDNAwasstudiedbymeansofcirculardichroism(CD),Ramanspectroscopy,X-rayphotoelectronspectroscopy(XPS)andfluorescencespectroscopy.TheCDspectralandfluorescentprobe-acriflavineresultsindicatethattheDNAunderwentaconformationchangeupontheadditionofCdions.XPSandRamanstudiesrevealthatthereexistedinteractionsbetweenCdionsandthephosphategroupsoftheDNA.Inaddition,anewbandappearedat803cm-1intheRamanspectra,whichcanbeattributedtocharacterizing"marker"bandofA-DNA.ItisconcludedthatCdionscanbecoordinatedbythephosphategroupsoftheDNAandinducetheconformationchangesoftheDNAfromB-DNAtoA-DNA.
简介:Naturalfreshwatersurfacecoatings(biofilmsandassociatedminerals),whichweredevelopedintheNanhuLake,Changchun,P.R.China,wereusedasanefficientbiosorbentfortheremovalofCd(Ⅱ)fromaqueoussolutions.ThebatchexperimentswerecarriedouttodeterminetheadsorptionpropertiesofCd(Ⅱ)ontothenaturalsurfacecoatings.TheclassicalLangmuiradsorptionisothermwasappliedtoestimatingtheequilibriumcoefficientsofCd(Ⅱ)adsorbedonthesurfacecoatings.Theresultsshowthatthemaximumadsorptioncapacityofthesurfacecoatingsis434.78μmolCd/m2(beingequalto0.17mmolCd/gofsurfacecoatingsor10.38mmolCd/gFe)andtheCd(Ⅱ)removalfromsolutionmediabythenaturalsurfacecoatingswasshowntobestronglyaffectedbysolutionpHandionstrength.TheresultedinformationalsoindicatesthatthemaximumCdremovalefficiency(CRE)wasdeterminedtobeapproximately90%atinitialCdmassconcentrationof0.1mg/L(theconcentrationlimitofCd(Ⅱ)inwastewatersfordischargeinaquaticmediainChineselegislation),andthekineticadsorptionofCd(Ⅱ)ontothesurfacecoatingsisfastwitharound70%ofthetotaladsorption-takingplacein150mininsolutionunderthecontrolledlaboratoryconditions(mineralsaltssolutionwithdefinedspeciation,ionicstrength0.05mol/L,and25℃).WiththeadvantageofhighCdadsorptioncapacity,thenaturalsurfacecoatingsappeartobeapotentiallyeffectivebiosorbentfortheremovalandrecoveryofCd(Ⅱ)frompollutedwater.
简介:新奇分子地印的合成nanofiber被一种简单electrospinning技术准备在哪个polyvinylbutyral(PVB)被选择为矩阵,-cyclodextrin(-CD)作为模板分子被用作功能的单体和naringin(NG)。在由hexamethylenediisocyanate(HMDI)的cross-linked以后,合成nanofiber展出了一个高特定的有约束力的能力。nanofibers的词法结构借助于红外线的光谱(红外)被学习,X光检查衍射(XRD),和扫描电子显微镜学(SEM)。没有形成阶段,CD分子同类地主要在PVBnanofiber以内被散布分开的水晶的总数。与传统的印的CD聚合物相比,有约束力的实验证明分子地印的合成nanofiber为NG显示出特定的有约束力的地点和选择有约束力的能力。没有任何损失,分子地印的nanofiber能在有约束力的能力被使用至少六次。
简介:Weperformfirst-principlecalculationsforthestudyoftheorthorhombicRb2Cd2(SO4)3structure.Electronicenergybands,totalandpartialdensitiesofstatesarereportedandanalysed.Itisfoundthatoxygenatomic2pelectronsstronglyhybridizewithRb/orCd4dandS2pstates,resultingintwo-typeionicgroupswithweakcouplings.Itisshownthatmacroscopicdomainwallsoriginatefromsuchweak-couplingionicgroups,arisingatthecellboundaries.Theasymmetriccationbonds(Rb-OandCd-O)andthesubsequentrotationsoftheS04tetrahedracanleadtothedrivingforceoftheferroelectricbehaviour.Thepredictedpyroelectriccurrenteffectsareobservedexperimentallyintheferroelectricphase.
简介:在这份报纸,CD衍生物的三种不同类型作为原子转移激进分子聚合(ATRP)被综合开始者或可逆增加破碎链转移聚合(木排)链转移。为每衍生物的替换的度小心地被描绘通过<啜class=“a-plus-plus”>1H-NMR,<啜class=“a-plus-plus”>13C-NMR光谱学和飞行团spectrometry(MALDI-TOF-MS)的帮助矩阵的激光解吸附作用/电离时间。影响替换的度的因素被讨论。而且,在ATRP和木排之间的比较在N-isopropylacrylamide(NIPAM)的聚合被显示出。
简介:新印离子的聚合物(IIP)被4-vinylpyridine(单体)的copolymerization综合,ethyleneglycoldimethacrylate(cross-linker)和2,2-azobis-isobutyronitrile(开始者)面对Cd2+和quinaldic酸(complexing代理人)。IIP和空白的聚合物的吸附能力分别地是45.0和6.2mgg1,这被发现。为不同二进制混合的印的聚合物的相对选择系数也是计算的。比作非印的聚合物(捏),IIP为Cd(II)有更高的选择。IIP被使用一个简单的批抽取过程从水样品为镉抽取用作吸着剂。从IIP的Cd2+抽取和它的恢复上的不同参数的效果被使用试验性的设计方法论评估并且优化。优化吸附/解吸附作用过程被申请从真实的水样品的镉移动。获得的恢复证明这IIP能从水样品被用于踪迹镉离子的移动。
简介:Toexaminetheeffectivenessofirondust-zeolitecompositeasanadsorbentfortheremovalofheavymetalionsfromaqueoussolutions,theadsorptionisotherms,thekinetic,thermodynamicandoptimumconditions,suchasinitialconcentration,pH,contacttime,adsorbentdosageandcompetitiveadsorptionconditionsofheavymetalswereinvestigated.ThecharacterizationofthecompositewascharacterizedviaFTIR,SEM,XRFandXRDmethods.Kineticresultsontheremovalofheavymetalionsfromaqueoussolutionshavebeenwelldescribedbythepseudo-second-ordermodel.TheadsorptiondataforCdandNiionswerefittedwellwiththeLangmuirandFretm-dlichisothermmodels,respectively.Themaximumadsorptioncapacitiesofirondust-zeoliteforCdandNiionswereequalto78.125and76.33mg/g,respectively.Thethermodynamicparameterssuchasenthalpy,entropyandfreeenergyofadsorptionofmetalionsweredetermined.Itwasfoundthattheprocessisendothermic,favorableandspontaneous.ThecompetitiveadsorptionabilityofheavymetalionsinthebinarysystemonthecompositeshowedthatCdionshadasynergisticeffectontheadsorotionofNiandNiionshadthenegativeeffectonCdadsorption.
简介:Thenovelcomplex[K(18-C-6)]2[Cd(mnt)2][18-C-6-18-crown-6,nmt=1,2-dicyanoethene-1,2-dithiolate,C2S2-(CN)2^2-]wassynthesizedandcharacterizedbyelementalanalysis,IRspectrumandX-raydiffractionanalysis.Thecomplexdisplaystwo-dimensionalnetworkstructureof[K(18-C-6)]complexsegmentsand[Cd(nmt)2]complexsegmentbridgedbyS-K-S,S-K-NandN-K-Ninteractionsbetweenadjacent[K(18-C-6)]and[Cd(mnt)2]units.
简介:利用水热方法制备了一个新的过渡金属镉配合物[Cd(1,3-BDC)(L)(H2O)2]·H2O(1,3-H2BDC=间苯二甲酸,L=2-(3-吡啶基)-1H-苯并咪唑),并通过元素分析、红外光谱和X-射线单晶衍射方法确定了该配合物的晶体结构.结构分析表明该配合物属于单斜晶系,P21/c空间群,晶胞参数a=1.01641(6)nm,b=2.08842(12)nm,C=1.00l38(6)nm,β=106.3360(10)°,V=2.0398(2)nm3,Z=4,R1=0.0207,wR2=0.494.配合物中CdⅡ“离子与L配体的1个吡啶N原子、1,3-BDC的4个氧原子和2个配位水的O原子配位,形成七配位的扭曲十面体结构.配体1,3-BDC的桥连相邻的CdⅡ离子形成一维聚合物链,相邻链间通过氢键和π…π作用形成三维超分子网络,并对该配合物的热稳定性和荧光性质进行了研究.
简介:研究了电感耦合等离子体原子发射光谱(ICP-AES)法测定南红玛瑙中As、Cd、Cr、Pb、Sb元素含量的分析方法。通过对前处理方法的选择、分析线的选择、基体干扰方面的研究,确定了分析条件,并对比研究了标准曲线法与标准加入法在测定方面的异同。标准加入法与标准曲线法的测定结果相近,但标准曲线法的测定结果总是比标准加入法的测定结果小。在标准加入法中,各元素加标回收率在93.6%~103%,测定值的相对标准偏差(RSD,n=6)小于10%;在标准曲线法中,各元素加标回收率在90.2%~103%,各元素的相对标准偏差(RSD,n=6)也均小于10%。基体效应对标准曲线法测定存在一定的影响,但不十分明显。标准加入法可以很好地减轻基体效应的干扰,但不可大批量测定样品。因此,在分析控制质量要求允许范围内,可采用标准曲线法对南红玛瑙中剧毒元素As、Cd、Cr、Pb、Sb的含量进行测定。