氨水介质中的原子吸收光度法测定铜精矿中的银量

试样经硝酸—氯酸钾溶解，在硫酸铵—氨水—乙醇介质中，将铜、锌、银等生成可溶性氨络合物与铁、铝、汞、铅、锰等元素分离。控制适量氨水，于原子吸收分光光度计，波长328．1nm处，以空气—乙炔火焰测定溶液中银的吸光度，扣除背景吸收。该法灵敏度为0．033μg/mL，1％吸收，检出限为0．004μg/mL，测量范围4～1500g/t。     

三核银穴合物的合成及其相应穴醚盐酸盐的电离喷雾质谱研究

在Ａｇ＾＋模板作用下，三（３－氨基丙基）胺与２，６－二甲酰基吡啶进行（２＋３）希夫碱缩合，合成了一个全新的三核银（Ｉ）穴合物，将此穴合物还原后得到一个新奇的穴醚。用电离喷雾质谱新技术研究了该穴醚盐酸盐的裂解机理。     

空心超顺磁性Fe3O4纳米微球的制备与表征

利用聚氧乙烯-聚氧丙烯-聚氧乙烯嵌段共聚物F127作为模板采用共沉淀法制备了空心超顺磁性Fe3O4纳米微球并用X射线衍射(XRD)和透射电子显微镜(TEM)进行了表征，纳米微球的大小为55-75nm，壳的厚度为7nm左右，颗粒大小均匀、在水溶液中分散良好．     

5-碘[杯(4)芳烃偶氮]氨基喹啉光度法测定银

合成了新试剂 5 碘 [杯 (4 )芳烃偶氮 ]氨基喹啉 (简称ICAQ ) ,并研究了该试剂与银显色反应条件。结果表明 ,在pH7 5的NaH2 PO4 -Na2 HPO4 缓冲介质中 ,在Tween 60存在下 ,试剂与银发生显色反应 ,生成 1:1稳定络合物。建立了测定银的光度法新体系 ,λmax=65 0nm ,ε =9 5 2× 10 4 ,在 2 5mL溶液中银的质量在 0～ 3 0 μg范围内符合比尔定律。方法用于显影液和工业废水中微量银的测定 ,结果令人满意。     

Sol-gel法在浮法玻璃表面镀制银胶粒着色涂层

以AgNO3、TEOS和KH550为原料，用溶胶凝胶法在浮法玻璃表面镀制了含银胶体粒子的二氧化硅涂层。所得到的溶胶中n(Ag)／n(Si)(原子比)为0．02～0．15。在热处理(≥500℃)之后，涂层的表面致密，无裂纹，并得到了淡黄-黄-棕黄系列样品。采用红外光谱仪、荧光光谱仪、紫外可见光分光光度计等仪器测试了涂层的微结构及光学性能。结果表明：浮法玻璃中的Na^ 与涂层中Ag^ 在热处理过程中进行交换，交换到基片中的Ag^ 与Sn^2 反应，使Ag^ 在较低的温度下即可被还原并形成银胶体粒子，从而获得银胶粒着色涂层。     

Fabrication of large area flexible and highly transparent film by a simple Ag nanowire alignment

This article describes the fabrication of a flexible polymer thin film incorporating a highly aligned Ag nanowire array, resulting in high transparency and polarisation that are useful for potential applications to optical filters, electronic and optical devices and negative refractive index materials.     

Enhancement of antibacterial properties of Ag nanorods by electric field

Abstract

The effect of an electric field on the antibacterial activity of columnar aligned silver nanorods was investigated. Silver nanorods with a polygonal cross section, a width of 20–60 nm and a length of 260–550 nm, were grown on a titanium interlayer by applying an electric field perpendicular to the surface of a Ag/Ti/Si(100) thin film during its heat treatment at 700 °C in an Ar+H₂ environment. The optical absorption spectrum of the silver nanorods exhibited two peaks at wavelengths of 350 and 395 nm corresponding to the main surface plasmon resonance bands of the one-dimensional silver nanostructures. It was found that the silver nanorods with an fcc structure were bounded mainly by {100} facets. The antibacterial activity of the silver nanorods against Escherichia coli bacteria was evaluated at various electric fields applied in the direction of the nanorods without any electrical connection between the nanorods and the capacitor plates producing the electric field. Increasing the electric field from 0 to 50 V cm^?1 resulted in an exponential increase in the relative rate of reduction of the bacteria from 3.9×10^?2 to 10.5×10^?2 min^?1. This indicates that the antibacterial activity of silver nanorods can be enhanced by applying an electric field, for application in medical and food-preserving fields.     

Magnetic Properties of Uranium Carbides after Neutron Irradiation

Fundamental investigations on valence control and solvent extraction of americium were carried out to develop a method for americium separation from reprocessing solution. In order to adjust americium valency from III to IV and VI, (NH₄)₁₀P₂W ₁₇O₆₁ synthesized was used as complexant stabilizing Am(IV). Oxidation behavior of americium was investigated as a function of (NH₄)₁₀P₂W ₁₇O₆₁ americium ratio. Using 0.1M (NH₄)₂S₂O₈ and 0.01M AgNO₃ as oxidation reagent, Am(IV) was obtained quantitatively at the ratio of 15. On decreasing the ratio to 0.6, 92% of americium was adjusted to Am(VI). The concentration of (NH₄)₂S₂O₈ could be reduced to 1/15 compared to the previously reported method in which no complexant was used. Americium(IV) was also prepared by reacting O₃ and AgNO₃ but no Am(VI) was obtained even at low (NH₄)₁₀P₂W ₁₇O₆₁ to americium ratio.

Americium(VI) could be extracted by tri-n-butyl phosphate stably without influence of (NH₄)₁₀P₂W ₁₇O₆₁. The distribution coefficient of Am(VI) was 4 between 100% tri-n-butyl phosphate and 1 M nitric acid, and separation factor from Nd(III) was 50.

With regard to the americium separation method which implemented valence control followed by extraction, adding (NH₄)₁₀P₂W ₁₇O₆₁ led to minimization of waste volume and improvement of extraction efficiency.