Macrocyclic compound as ionophores in lead(Ⅱ) ion-selective electrodes with excellent response characteristics

Macrocyclic compounds,such as crown ethers,azacrown ethers,thiacrown ethers,calixarenes and porphyrins,which act as ionophores in lead(Ⅱ) ion-selective electrodes,are systematically summarized based on the latest literatures.The molecular structure characteristics of the ionophores are general-ized.The modification regulations for the substituted ionophores are elaborated with the purpose of improving the response features of the lead(Ⅱ) ion-selective electrodes assembled by them.It is pointed out that the introduction of pendant moieties which contain soft base coordination centers like N,S and P atoms is in favor of adjusting the cavity size and conformation of the macrocyclic com-pounds.Furthermore,there is synergic effect between the cavity and the donor sites of the ligand and thus the selective complexation of lead ions is easily realized,resulting in significant avoidance of the interference from other metal ions.The macrocyclic ionophore having the best response characteris-tics thus far was found to be N,N'-dimethylcyanodiaza-18-crown-6 with the detection limit of 7.0×10-8(14.5 μg/L),which is one of the uncommon ionophores that can really eliminate the interference from silver and mercury ions.The selectivity coefficients of the ionophore for lead ions over other metal ions,such as alkali,alkaline earth and transition metal ions are in the order of 10-4 or smaller,where the se-lectivity coefficient of lead(Ⅱ) over mercury(Ⅱ) ions is much lower,down to 8.9×10-4.The structure de-sign idea for high-performance ionophore is proposed according to present results.The incorporation of nitrogen atom,especially cyano group or thiocyano group or amino/imino groups,rather than thio atom alone could result in new excellent lead ionophores.The aborative design for metacyclophanes containing aromatic nitrogen atoms with the aim of creating excellent ionophores would also become a potential research trend.The lead(Ⅱ) ion-selective electrodes have shown widely potential applications in the potentiometric titration,and flow injection potentiometry,and in the direct determination of lead in stack emissions of lead smelters,and assay of lead in rocks,particularly in the direct measurements of trace amount of lead(Ⅱ) in human hair,blood,edible oil,food,water,and air.     

对称矩阵力学模型

本文将Toda模型对应的3对角对称Lax矩阵L推广到任意p对角的情况，即将Toda模型推广到多体间不仅存在近邻相互作用而且存在次近邻及更长程相互作用的情形，推广后得到一个新的可积多体力学系统。     

复合营养液中N、K对边坡绿化植被生长的影响

选取3个不同浓度N、K含量的复合营养液进行交叉设计,施用于生长7个月的混种边坡绿化植被单体.从外观、叶绿素定量测定、抗逆性参数水平考察复合营养液中不同N、K含量对植被单体草坪草生长的影响,结果表明:复合营养液中施用(K2SO42.62 g,NH4NO34.97 g,CO(NH2)23.85 g)/m2N,K含量营养液对植被草坪的外观、抗逆性的提高有良好的效果.     

基于不同偏好信息的评价专家水平研究

针对不同偏好信息给出了一种分析方法.首先,给出有关效用值、序关系值、互反判断矩阵、互补判断矩阵和语言判断矩阵的定义及其相关性质;然后,通过定义不同偏好信息之间的转换公式,将不同偏好信息都转换为互补判断矩阵的偏好信息,得出各个专家的方案排序值向量,进而利用因子分析法,通过SPSS软件找出方案集相关系数矩阵的公共因子,计算出每个专家的因子得分及因子总得分.根据各个专家的因子总得分的大小,对各个专家的评价水平进行排序;最后,通过一个算例说明了本文提出的分析方法.     

铅的钨锰多金属氧酸盐K_(14)[Pb(MnW_(11)O_(39))_2]·49H_2O的合成与表征

采用直接法制备了主族金属元素铅取代的以锰为中心原子的杂多配合物,经ICP,TG曲线确定其化学式为K14[Pb(MnW11O39)2].49H2O,采用IR,XRD,183WNMR等手段对配合物结构进行了表征,表明配合物具有Keggin结构.同时对配合物的热稳定性进行了讨论。     

现代汉字字形研究三题

本文讨论了部件分析的三个问题(1)部件的定义;(2)独体字和合体字;(3)音符和意符.汉字现状的分析和溯源的分析,着眼点不同,只有摆脱传统"六书"理论的阴影才能构建起现代汉字字形分析的科学体系.     

复方理气中药对女自行车运动员内分泌的影响

目的　观察复方理气中药对女子自行车运动员血清生长激素(GH)水平及内分泌功能的影响。方法　采用自身前后对比方法,服药前做一次全面测试,4个月后再做一次复查。结果　大强度运动训练后即刻血清GH和血皮质醇(C)水平显著性升高(P<0.05),但与服药前相比无明显差异(P>0.05);安静时血睾酮(T)水平和血卵泡刺激素(FSH)水平与服药前相比显著性升高(P<0.05)。结论　复方理气中药可以促进女运动员的内分泌功能。     

信息集成算子加权向量的对称性研究

对信息集成算子加权向量的对称性进行了研究.提出了升序加权算术平均(AOWAA)算子和语言AOWAA算子,分别给出了降序加权算术平均(DOWAA)算子和升序加权算术平均(AOWAA)算子、降序加权几何平均(DOWGA)算子和升序加权几何平均(AOWGA)算子、以及语言DOWAA算子和语言AOWAA算子的一个等价条件,并证明了在加权向量是对称的情况下:1)利用DOWAA算子对若干个互补判断矩阵进行集成所得到的群判断矩阵仍为互补判断矩阵;2)利用DOWGA算子对若干个互反判断矩阵进行集成所得到的群判断矩阵仍为互反判断矩阵;3)利用语言DOWAA算子对若干个语言互补判断矩阵进行集成所得到的群判断矩阵仍为语言互补判断矩阵.最后探讨了一些常用加权向量的对称性问题.     

二元广义复合双Poisson风险模型下的破产概率

讨论了一类双险种风险模型,其中保费到达过程和索赔到达过程是相互独立的,且索赔过程均为广义复合Pois-son过程.得到了最终破产概率的一般表达式和破产概率的一个上界估计.     

A SIMPLE METHOD FOR CONSTRUCTING ORTHOGONAL ARRAYS BY THE KRONECKER SUM

In this article,we propose a new general approach to constructing asymmetrical orthogonalarrays,namely the Kronecker sum.It is interesting since a lot of new mixed-level orthogonal arrayscan be obtained by this method.