四苯基卟啉在改性磷酸锆层间的插入及荧光增强

近年来,出于节约一次性能源的考虑,人们已经加大对太阳能等天然资源的利用,致力于模拟天然光合作用的研究[1￣3],而光合作用中的捕光复合物又称为光子天线。光子天线中往往存在一种或几种猝灭剂,猝灭剂吸收光子后产生激发态的能量可以在不同分子或者同一分子的不同生色团之间转移,转移出能量的一方为能量给体,另一方为能量受体。     

分光光度法快速测定毒鼠强的研究

本文将毒鼠强在酸性条件下分解,分解产生的甲醛用水蒸汽蒸馏使之与干扰物质分离,再根据Hantzsch反应原理,用乙酰丙酮-乙酸铵溶液作显色剂分光光度法测定甲醛,从而间接测定毒鼠强的含量。本法的线性范围为5~40 mg/kg。本法干扰少,操作简便、快速,可用于中毒样品的测定。     

固相膜萃取与GC/MS联用测定地下水中痕量半挥发性有机物的野外采样方法研究

C18固相萃取膜适宜处理大体积地下水样现场采样而且易于运输、贮存。利用C18固相膜萃取以及GC／MS联用的方法对地下水中痕量半挥发性有机污染物进行了萃取以及定性、定量分析。优化了固相膜萃取的地下水采样量和浓缩体积。有机氯农药和多环芳烃的平均回收率分别为85％～110．1％、90．3％～115．1％；方法检出限达到10^-9g／L；相对标准偏差均小于15％。本方法用于北京地区地下水中的有机污染物分析，并给出地下水样C18固相膜萃取的GC／MS测定结果。     

A New Diterpene Acid from the Flowers of Heteropappus altaicus

A new compound, named heteraltaic acid was isolated from the flowers of Heteropappus altaicus (willd) Novopokr. The compound was elucidated as (5R, 6S, 8aS) -5-[2-(3-furyl) ethyl-5, 6, 8a-trimethyl-4a, 5, 6, 7, 8, 8a -hexahydro-l-naphthalenecarboxylic acid] by the combination of 1D and 2D NMR techniques (HSQC, HMBC) and X-ray analysis.     

分数级反应热动力学研究—丙烯酰胺聚合反应动力学

应用n级等摩尔浓度反应的热动力学理论,在30℃和40℃下研究了丙烯酰胺在水溶液中和CTAB胶束溶液中由亚硫酸钠引发的聚合反应动力学.讨论了引发剂和CTAB的浓度对聚丙烯酰胺分子量的影响。     

氧化钡促进的Co/SiO2催化剂的还原性能和分解甲烷活性

 利用等体积浸渍法制备了氧化硅负载钴催化剂．通过程序升温还原、氢化学吸附、氧滴定和催化活性评价等手段研究了氧化钡对Co／SiO2的还原性能、钴分散度和颗粒度、分解甲烷活性及其稳定性等的影响．研究结果表明，氧化钡明显地影响Co／SiO2的还原性能；添加2％氧化钡提高了Co／SiO2在中温（450℃）条件下的还原度；氧化钡的还原对Co／SiO2还原的诱导、氧化钡与氧化硅及与氧化钴之间的相互作用是导致Co／SiO2还原性能变化的原因．氧化钡提高了Co／SiO2的初活性和钴的分散度，降低了钴的颗粒度；添加0．5％～1．5％氧化钡有利于提高Co／SiO2的稳定性．钴的分散度和颗粒度影响Co／SiO2的活性和稳定性；氧化钡的强供电效应也是提高Co／SiO2活性和稳定性的重要因素．甲烷分解生成的碳物种覆盖了钴活性中心，导致Co／SiO2初活性下降；但大部分碳物种并不沉积在钴活性中心上，可能形成了碳纤维生长在载体和钴活性中心之间．     

Tetra(μ3-hydroxo)hexa(μ2-carboxylato-O,O′)-bridged tetranuclear terbium(III) cubane complex

A novel tetranuclear terbium(III) complex [Tb₄(OH)₄(pybet)₆(H₂O)₈][Tb₄(OH)₄(pybet)₆(H₂O)₇ (NO₃)](ClO₄)₁₄·6H₂O has been synthesized and shown by X-ray crystallography to have a cubane-like Tb₄(μ₃-OH)₄(μ₂-carboxylato-O,O′)₆ core. The ligand pybet is pyridinoacetate, C₅H₅⁺N-CH₂CO₂⁻. Magnetic susceptibility data were measured for this Tb₄ complex in the range of 2.0–320 K and in fields of 1.0 G to 50.0 kG. It is concluded that either there is very weak antiferromagnetic exchange interaction (J = −0.015 cm⁻¹) or there is a small crystal-field splitting of the ⁷F₆ Tb^III ground state.     

周岁内幼儿头发中锌钙含量的动态分析

对合肥市16671名1－12个月幼儿的发锌，钙含量进行了测定，并对测定值进行了统计分析。结果表明，锌，钙的含量随着月龄的增加呈直线递减。并给出了发锌，钙含量的趋势线方程，丰富了目前文献给出的发锌，钙的标准值，为及时准确判断周岁内幼儿微量元素锌，钙缺乏程度提出依据。     

The Surface Imprinted Polystyrene Beads Prepared via Emulsion Templates

In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788),the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer,cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.     

THE NATURE AND SOURCE OF ESR SIGNAL IN BILIRUBIN

The ESR signals of bilirubin-IXα were studied including the samples treated with free radical generating and inhibiting systems, i.e.X-X0., Fe/EDTA, SOD, mannitol/ascorbate, DTPA, KCN et al.These stable signals all comprise those originated from a semiquinone radical(g=2.0012)and superoxide radical(g₁₁=2.041, g_⊥=2.0040).The latter is shown to be bound with metal ionsespecially iron, chelated by bilirubin.The iron probably comes from bilirubin precursor---hemootobin.Active oxygen free radical scavengers may destroy these radicals.Kinetic curves of regeneration of the bilirubin radicals have been determined.Bilirubin is discussed as"active oxygen trap"in mammatians.