人体血浆中15种超痕量稀土元素的电感耦合等离子体质谱法测定

本文用电感耦合等离子体质谱法测定了人体血浆中的稀土元素。在优化的条件下 ,以内标法测得的各种纯水溶液的检测限在 0 .7(Eu)～ 5 .4(Gd) ng·L- 1范围内。研究了 K,Na,Ca,Fe等基体元素对稀土测定的影响。以 In为内标元素补偿样品基体效应以及灵敏度飘移。比较了直接稀释、HNO3- H2 O2 消解及 HNO3-HCl O4消解 3种样品处理方法 ,用 1% HNO3直接稀释样品可满足轻稀土元素的定量分析要求 ,方法的定量测定下限≤ 1μg·L- 1。

A rule to design high spin molecules with hetero-spin centers

The series of biradicals with m-phenylene coupling unit and hetero-spin centers were calculated compared with those possessing home-spin centers using AM1-CI method. A simple rule was proposed to design high spin molecules with ferromagnetic coupling unit and hetero-spin centers. Two neutral (or charged) hetero-spin centers resulted in high spin ground state, one neutral and another charged hetero-spin centers correspond to low spin ground state. The latter was ascribed to the huge splitting of two partially occupied molecular orbitals.

Synthesis and characterization of poly(amide imide)s containing cyclohexylidene moieties with bulky substituents

Novel poly(amide imide)s (PAI) containing alkyl-substituted cyclohexylidene moieties were synthesized by conventional polycondensation of trimellitic anhydride chloride with novel aromatic diamines followed by chemical imidization using acetic anhydride and pyridine. The inherent viscosities of the resulting PAIs are relatively high and range from 71 to 112 mt g(-1). The prepared PAIs show excellent thermal stability and good solubility. The glass transition temperatures (T-g) measured by DSC are observed in the range of 312-342 degrees C. Furthermore, all the polymers are readily soluble in less hygroscopic organic solvents like cyclohexanone, gamma-butyrolactone as well as aprotic polar solvents.

聚烯烃／极性聚合物界面的分子状态

为了克服高分子共混物界面不易表征的缺点，提出用溶剂选择性溶解方法使界面暴露．结合Ｘ－射线光电子能谱（ＸＰＳ）表征手段，研究了官能化聚合物，接枝型共聚物及带有反应性基团的聚合物作为共混物增容剂时在界面区域的分子状态．实验结果表明，作增容剂时，官能化聚合物在界面区内采取最有利的分子构象，充分发挥增容作用；接枝型共聚物主链、侧链向相应本体聚合物内扩散；而带有反应性基团的聚合物与某个本体聚合物发生反应之前存在反应基团在界面富集的过程

Preparation and characterization of polymer-supported rare earth complexes

The polymers containing different ligand groups of atoms (mainly O, N, and S) and their rare earth complexes were prepared, characterized and classified based on the type of metal-ligand tending. The catalytic activities of the complexes are briefly discussed. The polymer-supported rare earth complexes showed much greater activities than the corresponding complexes with a low molecular weight.

Synthesis and properties of thermotropic liquid crystalline copolyesters containing bis(4-hydroxyphenyl)methanone(IV)

A series of thermotropic liquid crystalline copolyesters were synthesized by thermal polycondensation of p-hydroxybenzoic acid, terephthalic acid, bis (4-hydroxyphenyl) methanone and diols. The resulting copolyesters were characterized by WAXD,DSC and PLM. All the copolyesters formed a nematic phase.

不对称取代钛茂/甲基铝氧烷催化体系丙烯聚合立构控制

利用一种新合成途径制备了单取代钛茂化合物(η~5-环戊二烯)[η~5-(1-(4-甲氧基苯基)环已烯基)环戊二烯]二氯化钛(Ⅰ),以衍射法确定其晶体结构属正交晶系,空间群P2_12_12_1,晶胞参数a=0.9680(5)nm,b=1.2846(5)nm,c=1.6944(6)nm,Z=4,R=0.066.详尽考察了不同聚合温度条件下Ⅰ/甲基铝氧烷(MAO)催化体系对丙烯聚合的立体化学控制,发现随着聚合温度的变化,能够生成等规、无规、间规三种不同立构取向的聚丙烯;其中等规、间规聚丙烯是由对映结构活性中心及链末端共同控制生成,而无规聚丙烯则受Bernoullian生成方式控制.

电化学扫描隧道显微镜的研制及银、镍的现场电沉积研究

本文报道电化学扫描隧道显微镜(ECSTM)的研制技术,包括电子线路及绝缘探针尖的制备。研制的ECSTM中,试样和探针的电位能同时控制。绝缘探针的制备包括先用电化学腐蚀形成针尖,然后再在光学显微镜下绝缘,用扫描电子显微镜评定了绝缘针尖的性能。最后用研制的ECSTM现场研究了银、镍在高定向裂解石墨(HOPG)上的电沉积。

BaLiF_3微晶辐照损伤的电子自旋共振研究

钙钛矿型复合氟化物ABF_3(A=Li,Na,K,Rb;B=Mg,Ba,Zn等)是固体可调谐激光的优良基质材料,人们对其辐照损伤已有较多研究,但其中关于BaLiF_3的研究相对较少,特别是用ESR方法研究BaLiF_3的辐照损伤尚未见报道.近年来,人们在适应新的高能粒子加速器需求的新型无机闪烁材料的过程中发现BaLiF_3具有一定的应用前景,在这一应用中对材料的抗辐照性能有很高的要求.本文报道了用ESR方法研究BaLiF_3微晶受X射线和γ射线

高氯酸铒与α-组氨酸络合物的合成和晶体结构

在水溶液中合成了标题络合物,其化学式为Er(His)_2(ClO_4)_5·6H_2O(His为质子化的α-组氨酸)。测定了该络合物的红外光谱。用X射线单晶衍射法测定了络合物的晶体结构,结果表明,其结构式为[Er_2(His)_4(H_2O)_(?)]·10ClO_4·4H_2O,属单斜晶系,空间群为Pī,每一个晶胞中有一个络合物分子,晶胞参数为:α=8.294(1)(?)、b=10.981(3)(?)、c=11.934(3)(?)、β=107.04(2)°。每两个中心离子铒由四个α-组氨酸的羧基桥连成双核络合物,两对对位的羧基组成两个平面,其夹角为91.9°。组氨酸中α-氨基和咪唑取代基上的N原子未参与配位。络合物中铒的配位数为8,八个氧原子取四方反棱柱体排布于饵的周围,络合物离子的配位多面体由两个四方反棱柱体组成。

A NEW KIND OF CONDUCTING POLYMER POLYPYRROLE (PPY) BR- ION CHEMICAL SENSOR

The modification of conducting polymer polypyrrole(PPy) on glassy carbon(GC)by electrcchemical technique, and the study on doping effect of Br anion and electrochemical behavior of PPy film electrode were reported.A new kind of Br~- ion selective electrode has been prepared successfully.The mechanism of the electrode potential response is based on the doping effect of anion in the conducting polymer.Effect of polymerization conditions on the potential response characteristic is investigated in dtail.The PPy...

高1,2-聚丁二烯及通用橡胶的流变性质

采用多速粘度计和Monsanto试验机联用,在表观剪切速率为3×10~(-8)—2.5×10~8s~(-1)时观察了高1,2-聚丁二烯(PB)生胶与顺式1,4-PB,EPDM,SBR 1500在流变性质上的差异。高1,2-PB虽在中等剪切速率下有较高的粘度,但在低、高剪切速率时的粘度均较低,这一特性有利于它的加工。高1,2-PB在低剪切速率下的流动活化能较其他橡胶高,故抗冷流性能优越,易于存放。

新型导电聚合物——聚吡咯溴离子化学传感器

本文用电化学方法把导电聚合物聚吡咯(PPy)修饰在玻碳(GC)电极上,研究了Br~-离子的掺杂效应和薄膜电极的电化学行为,研制一种新型Br~-离子选择电极,电极的响应机制是基于导电聚合物中阴离子的掺杂效应,详细研究了聚合条件对电极电位响应性能的影响,电极具有内阻小、响应快、抗毒化能力强、制备简便等优点,电极对1×10~(-1)—1×10~(-4)MBr~-呈能斯特响应,检测下限7×10~(-5)M,斜率61mV/PBr~-。本文结果是化学修饰电极技术在化学传感器方面应用的有意义的尝试。薄膜的良好导电性质使之更易于制备离子敏感电子学器件和生物电子学器件。