铕离子探针研究Al2O3的相变过程

氧化铝具有许多重要的工业用途，而制备高热稳定活性氧化铝的技术也在不断地发展[1，2]，因此，研究其高温烧结下的相变过程很有意义．离子深法作为新型测试手段，已成功地用于生物大分子结构与功能研究方面［‘］，而在固体材料测试中的应用尚未见报道．我们以EU’“作为荧光探针，并结合＊＊D和＊nR研究了川对。在不同烧结温度下的相变过程．1实验部分样品的制备采用复盐分解法．先将Elf刀s用高纯硝酸溶解定容．以占AlzO。重量1％的量加入到硫酸铝锭溶液中，进行超声处理，冷冻干燥．再依次登于900”C、1000C、1100C、1200C的高温炉…     

STUDIES ON ION IMPLANTATION AND ELECTRICAL PROPERTIES OF POLYACETYLENE FILMS

The effects of ion implantation on ployacetylene films PA have been studied with Ar~+, Fe~+, C1~+, I~+, Na~+ and K~+ ions in the energy range of 15—30 keV. The changes of PA films in the electrical conductivity, due to chemical doping and ion implantation in relation to their structure and depth profiles of impurities, were measured through infrared (ATR/FTIK), Rutherford backscattering spectrometry (RBS) and the four probe technique. In all cases, ion implantation of active ions exhibits the same effects as chemical doping. The formation of p-n junction is observed at the interface of implanted region and chemical doped PA substrate. The mechanism of interaction process between ion beam and polymer is also discussed.     

Luminescence kinetic and association equilibria of lanthanide ions in aqueous solutions. II. Determination of the formation constant of Tb acetato complex by means of luminescence lifetime measurement

The association constant K of mono-acetato complex of Tb³⁺ has been determined at normal p and T conditions by measurement of its luminescence lifetime in aqueous solution containing increasing concentrations of acetate. Two experimental arrangements used for the measurement are described.     

氨基酸与钠离子非共价键相互作用的电喷雾质谱研究

实验研究中常常观察到钠离子与一些多肽或蛋白质有较强的非共价键结合能力,这种非共价键相互作用可能与生物的一些功能和活性有关。为了进一步了解这一结合作用,我们应用电喷雾质谱研究了常见的20种氨基酸与钠离子在溶液中的非共价键相互作用。实验研究中发现脯氨酸和苯丙胺酸与钠离子有较强的非共价键结合能力。     

罗丹明B-Mo(V)-SCN~--PVA体系荧光熄灭法测痕量钼

在聚乙烯醇存在下,用罗丹明B-Mo(V)-SCN~-荧光熄灭法测Mo,能消除过量的SCN-对罗丹明B的熄灭作用。加入聚乙烯醇后体系的荧光熄灭倍数比未加入时大14倍。此法灵敏度高、稳定性好、操作简便,检测下限0.12ng/ml Mo.可用于测水和头发中的钼。     

Separation of Anions of Organic Acids in Concentrated Solutions by Means of Capillary Isotachophoresis

The separation of a mixture containing anions of nine organic acids is investigated on an instrument for capillary isotachophoresis with an optical detector for the registration of boundaries. The separation is conducted in concentrated solutions of sodium salts. A counterflow is used during the separation.     

负载型纳米Ni催化剂用于对氯硝基苯选择加氢

以TiO2为载体,N iB为诱导剂,粉末化学镀法制备了负载型纳米N i催化剂.通过TEM、HRTEM、XRD和ICP技术对催化剂物性进行了表征.结果表明,碱性镀液可使载体表面均匀负载微晶结构纳米N i团簇,尺度为35nm左右.该负载型纳米N i在对氯硝基苯选择加氢反应中表现出很高催化加氢活性,并能有效抑制脱氯,达到了工业骨架镍水平.由酸性镀液得到的负载型非晶态纳米N i-P合金具有较弱的催化对氯硝基苯加氢活性.反应温度对反应时间和脱氯率有明显影响.     

熔融浸渍法制备锂离子电池正极材料LiMn2O4的研究

采用LiNO3和MnO2为原料,在650℃下制备了尖晶石型的LiMn2O4.通过X射线衍射、扫描电子显微镜、热重分析和电化学性能测试,发现该化合物具有很高的放电比容量和较好的循环性能,首次放电比容量可达到122 mA·h/g.并对循环性能衰减的各种因素进行了讨论.     

Dimerization of some substituted benzoic acids in aqueous solution from conductance measurements

Precision molar conductances of benzoic, o-toluic, 2,6-dimethylbenzoic, 2,3,6-trimethylbenzoic, and, o-fluorobenzoic acids have been determined in aqueous solution as a function of temperature and of concentration up to near saturation (<0.035 M). At the higher concentrations molar conductances are found to be less than anticipated for the simple dissociation of a 1-1 electrolyte. Although the deviations are only 1% or less they have been interpreted to show that these acids are dimerized in solution. The interpretation includes an assumption that the dimer ionizes to produce a triple ion. Increasing numbers of methyl groups lead to increasing dimerization. For those acids with two ortho groups the dimerization increases with increasing temperature while the other three show decreasing dimerization with increasing temperature. Temperature functions have been determined for the dimerization constants and from these functions standard changes in enthalpy, entropy, and heat capacity have been determined. Comparisons are made with dimerization studies in non-aqueous solvents. From these as well as the behavior of benzene in water it is concluded that a major factor driving the dimerization is hydrophobic interaction. To provide a limiting conductance of the triple ion needed in the dimerization calculations a conductance study was also made for o-Phenylbenzoic acid on the assumption that its anion provides an approximate model of the triple ion.     

四烷基锡中性载体推动亚硝酸根离子迁移穿透大块液膜

通过大块液膜体系研究了四烷基锡的碳链长度、载体浓度.NO_2~-浓度及抗衡离子等因素对NO_2~_穿透含四烷基锡的液膜的传质速率的影响,讨论了它们与四烷基锡为载体的离子电极性能间的关系。NO_2~-通过四烷基锡为载体的液膜的迁移规律符合离子对传输模式。