蒙脱土担载钴(Ⅱ)-邻菲罗啉金属配合物的制备与表征

本文首次合成了蒙脱土担载钻(Ⅱ)—邻菲罗啉金属配合物,并对其结构进行了IR、XRD、TEM及TG 的表征。     

双路及时锁存分时进入的快接口电路

在核物理实验中,常常需要对多路脉冲信号进行幅度分析及数据获取.通常使用多路模拟混合方式予以实现,也有采用DMA链的方式.本文介绍的接口电路不用模拟混合器,而采用对两路ADC变换的二进制码分别进行及时锁存、DMA分时进入的方式来实现两路数据获取,线路的组成比较简单而传送速率较快.本接口电路主要分为四个部份:顺序控制电路产生顺序控制信号,以保证两路数据代码按“先来先送,后来后送”的原则进入地址总线;地址形成电路将ADC变换的数据代码及予置的高位地址代码,变成对应两路数据存贮区的RAM 1所需的地址码;     

Measurement of trace lead (II) in water samples with biomacromolecule heparin modified electrode

A new method for electrode modification and accumulation with a biomacromolecule and subsequent voltammetric quantittion of metal ions is described. Heparin is used as the surface modifier, and the method is based on formation of the heparin complex of lead (II). The voltammetric responses were evaluated with respect to electrolyte, pH, preconcentration time, and lead concentration. The electrode composition, voltammetric wave form and other variables have also been taken into account. A detection limit of 3.0×10⁻⁹ mol/L has been obtained by preconcentration for 20 min. The method is sensitive, simple and relatively rapid, with a relative standard deviation of 5.2% at the 1.0×10⁻⁷ mol/L level. Supported by the Trants-Century Training Program Foundation for the Talents from the State Commission of Education of China: the national Natural Science Foundation of China and the Opening Laboratory Foundation of Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. Li Huiling: Born in July 14, 1972. Master of Science.     

Isolation and characterization of biologically active lectin from Korean mistletoe, Viscum album var. Coloratum

A mistletoe lectin was isolated from water extracts of Korean mistletoe, a subspecies of Viscum album, grown on Quercus mongolica using CM-Sepharose chromatography followed by an affinity chromatography on a concanavalin A-Sepharose column. The compound proved to be a mistletoe lectin II with D-galactose and N-acetyl-D-galactosamine specificity. Matrix-assisted laser desorption time-of-flight mass spectroscopy showed it to have an average molecular mass of 62.7 kDa and to consist of two subunits of 30.6 kDa and 32.5 kDa. It was a basic protein with isoelectric points of 9.4 and 9.6 by capillary isoelectric focusing and was cytotoxic to Molt4 cell. Received 17 November 1998; received after revision 3 March 1999; accepted 3 March 1999     

水合4-氧-1(4H)-吡啶乙酸锰配合物[Mn(H2O)6](4-OPA)2·2H2O的合成与晶体结构

利用氯化锰与4-氧-1(4H)-吡啶乙酸反应合成了一个新的配合物[Mn(H2O)6](4-OPA)2·2H2O(4-OPA-=4-氧-1(4H)-吡啶乙酸根),并对其进行了元素分析、IR光谱和单晶X射线的表征。配合物晶体属单斜晶系,空间群为P21/c,晶胞参数为a=1.2561(3)nm,b=1.2949(3)nm,c=0.68547(14)nm,β=98.68(3)°。V=1.1022(4)nm3,Z=2,Mr=503.32,最终R=0.0319,wR=0.0827。Mn(Ⅱ)原子与六个水分子配位形成八面体构型,4-氧-1(4H)-吡啶乙酸根作为抗衡阴离子,配阳离子与阴离子之间通过静电吸引和氢键作用形成了三维氢键超分子网络结构。     

海藻酸分子印迹聚合物的合成及其对锌离子的识别作用

将海藻酸钠与锌(II)配位形成配位聚合物膜,用FT-IR和DRS研究所得到的海藻酸-锌(II)配位聚合物(AA-Zn)的形成机理。将此配位聚合物与戊二醛(GA)进行交联,得到交联印迹聚合物前体,并用FT-IR光谱表征其结构。为了制备对Zn2+离子敏感的分子印迹聚合物(MIP),将前体聚合物浸入0.5 moL/L HCl溶液中48 h并搅拌,以洗脱Zn2+离子得到印迹聚合物(MIP-Zn)。洗脱液用UV-Vis光谱检测并验证,UV-Vis谱图显示Zn(II)的特征吸收峰在240 nm处,表明Zn2+离子已被洗脱。将制得的海藻酸钠-锌(II)印迹膜用于吸附Zn2+离子,结果表明印迹聚合物对Zn2+离子有较强的吸附能力。     

Chemiluminescence determination of tetracycline and oxytetracycline in pharmaceutical preparations using Ru (bipy)3 2+-cerium (IV) system

A new chemiluminescence (CL) method for the determination of tetracycline and oxytetracycline is developed, based on the CL reaction of tetracycline and oxytetracycline with Ru (bipy)₃ ²⁺ and Ce (IV). In sulfuric acid medium, the CL emission is generated upon continuous oxidtion of Ru(bipy)₃ ²⁺ by cerium (IV). The emission intensity is greatly enhanced when tetracycline and oxytetracycline are introduced into the reaction system after acid degradation. Under the optimum conditions, the calibration curves are linear over the range of 8.0×10⁻⁸∼4.0×10⁻⁶ mol/L for tetracycline and of 2.0×10⁻⁷∼4.0×10⁻⁵ mol/L for oxytetracycline, with the detection limits are 4.2×10⁻⁸ mol/L for tetracycline and 1.5×10⁻⁷ mol/L for oxytetracycline, respectively. The proposed method was used for the determination of tetracycline and oxytetracycline in pharmaceutical formulations with good results. Foundation item: Supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Province. Biography: HAH He-you (1962), male, Associate profeddor, Ph.D graduate candidate. Present address, Department of Chemistry, Huainan Teacher's College, Huainan.     

Multiple Type-II截尾样本的统计方法

Multiple Type-II截尾样本或称为带有缺失的定数截尾样本在实际中常会遇到 ,最近十多年来有关它的统计分析方法有了较多的研究结果 ,作者作了综述 ,并对进一步需要研究的问题提出一些看法     

Effect of Phosphatidylcholine on the Steady State Fluorescence of Chlorophyll in Photosystem Ⅱ Particles

Phosphatidylcholine (PC) accounts for less than 1% of the total lipids in plant photosystem II (PSII) particles.In this experiment, PSII particles were reconstituted with PC to construct PSII-PC vesicles.The effect of PC on the steady state fluorescence of chlorophyll (Chl) in PSII particles was studied.The results show that PC significantly affected the fluorescence intensity, but did not obviously affect the fluorescence emission band peak position.PC also did not obviously affect the absorbance at 436 nm or the amide I band peak position in FT-IR spectroscopy of PSII particles.The results suggest that PC may affect the light energy transfer from the antenna chlorophyll molecules to the reaction center chlorophyll molecule (P680).     

逐步增加II型截尾下Pareto分布参数的区间估计

基于逐步增加的Ⅱ型截尾,讨论了Pareto分布形状参数和尺度参数的区间估计。得到了两参数的区间估计和联合区间估计。最后以估计区间的最短长度为标准,通过数值模拟得到参数的最优区间估计方法。