火焰原子吸收法连续测定人发中铁、钙、锌、铜     

王觉吾  赖晓琦 《赣南师范学院学报》1993,(Z2)

本文应用空气——乙炔火焰原子吸收法连续测定人发中钙、铁、锌、铜的含量。在地区有关部门的帮助下,我们对我市100余名童发进行了上述元素的测定。测定方法的回收率为92％——107％,变异系数小于2％,结果令人满意。  相似文献   

Methyl–modified hybrid organic-inorganic coatings for the conservation of copper     

《Journal of Cultural Heritage》2014,15(3):242-249

A simple sol-gel technique for the preparation of methyl–modified silica coatings for the protection of the external surface of copper has been used in this study. Tetraethylorthosilicate (TEOS) has been used as a precursor to prepare nanosilica coatings on the surface of copper. The methyl–modified silica sols were obtained by mixing of 3% SiO₂ sol solution with trimethylchlorosilane (TMCS) or hexamethyldisilozane (HMDS) as basic materials. For comparison, the copper substrates were also coated with commercial polymers (Paraloid B 72, Plexisol P 550-40 and polyvinyl butyral (PVB)). The surface morphology changes of uncoated and coated specimens were investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The hydrophobicity of surfaces and photochemical ageing effects were evaluated by contact angle measurements. Potentiodynamic measurements were obtained in order to compare corrosion parameters of the coatings.  相似文献