Investigation of mercury adsorption on gold films by STM

Scanning tunnelling microscopy, combined with complementary electrical and analytical measurements, provides a powerful method for examining the behaviour of mercury on gold-film sensors under actual sensor operating conditions. The films exhibit a linear increase in resistance upon adsorption of mercury, and this resistive change is accompanied by a decrease in measured barrier height at submonolayer coverages of mercury. STM studies of changes in the effective barrier height upon mercury adsorption provide evidence that mercury migrates to grain boundaries for films exposed at submonolayer coverages. Coverages in excess of a monolayer result in a nearly constant, reduced effective barrier height across the entire surface, which is indicative of a more uniform distribution of mercury over the surface. This behaviour is interpreted in terms of the adsorption of mercury onto defective, contaminated gold surfaces.     

蒸汽加热消解-电感耦合等离子体质谱法测定化探样品中痕量金

将样品焙烧后采用蒸汽加热王水消解,用两块聚氨酯泡塑分两次吸附消解后样品溶液中的痕量Au,将两块泡塑合并、灰化,用王水溶解,以Re为内标进行校正,实现了采用电感耦合等离子体质谱法(ICP-MS)对化探样品中痕量Au的测定。对消解条件、吸附条件和脱附条件进行了优化,结果表明:采用蒸汽加热消解所得到的Au测定结果与电热板消解相同,但蒸汽加热消解方法能够明显节约电力能源并能有效降低外来污染;选用化探金标准物质为试验对象,在吸附时间相同的条件下,分两次投入2块泡塑进行吸附,Au的回收率为97%~101%,比一次投入2块泡塑的Au回收率87%~92%更接近100%;采用先在180℃灰化20min,再经50min升温至700℃灰化1h的方法对载Au泡塑进行灰化,化探金标准物质中Au的回收率稳定在100%附近。在选定的实验条件下,校准曲线的线性相关系数为0.9996,方法检出限为0.13ng/g,测定下限为0.43ng/g,测定上限为120ng/g。应用实验方法对3件化探金标准物质、3件土壤样品和3件水系沉积物样品中Au进行了测定,结果表明:化探金标准物质的测定值与认定值相符;Au测定值的相对标准偏差(RSD,n=12)为2.9%~6.4%。按照实验方法对化探金标准物质进行加标回收试验,回收率为98%~104%。     

硫脲纤维素分离富集火焰原子吸收法测定地质样品中痕量金

在王水介质中，使用硫脲纤维素吸附以除去金矿中其他离子的干扰，被吸附的金用硫脲溶液解脱并用原子吸收光谱测定。本法研究了分离和测定的条件，方法已成功地应用于地质样品中痕量金的测定。     

采金船设计中几个主要外力的确定

总结出链斗式采金船设计中的挖掘阻力、横向挖掘阻力、风阻力、水阻力、斗架提升附加力、提锚力及锚柱所受的外力的计算方法，可供设计生产应用．     

用螯合树脂回收铅阳极泥中的金

对金含量较低（０￣１００ｇ／ｔ）的铅阳极泥，用ＳＯ２直接从其金浸出液中还的金，回收率和纯度均较低。本文用螯合树脂吸附法富集微量金（０￣４６ｍｇ／Ｌ）效果很好。吸附后溶液中金的浓度降至≤０．１ｍｇ／Ｌ，金的吸附率为９９．７％。经解吸与还原，金的真收率为９８％￣９９％。此外，从负阳极泥中回收银、锑、铋也取得较好结果。