Structure Refinement of the Icosahedral AIPdMn Quasicrystal Using Quantitative CBED

The atomic structure of the pcrfect AIPdMn icosahedral phase has been studied on a single crystal specimen by quantitative convergent beam electron diffraction (QCBED) technique in combination with describing the shape of atomic surface by symmetry adapted series of surface harmonics. The spherical model was used as the starting model for the refinement. By fitting the calculated electron diffraction intensities to the experimental line scan profile, the coefficients in the surface harmonics expansion of the boundaries of atomic surface are refined. The refined parameters show that the fluctuations of the external boundary of atomic surface for Pd at n0 can be as large as 0.2 nm. The boundaries of atomic surfaces for Mn show little fluctuation. In the present model. the number of unphysically short interatomic distances is significantly reduced in comparison with the spherical model.     

硅钼蓝光度法测定铅锰铁中硅的含量

试样经硝酸溶解后，在0．1-0．6mol／L的酸度下，使硅酸与钼酸形成黄色硅钼酸。然后加入草硫混酸消除磷的干扰，用硫酸亚铁铵将硅钼黄还原成硅钼蓝。通过采用配制与试样相同基体的办法，加入不同含量的硅标液来测定试样中硅的含量。     

N－乙烯基咔唑－丙烯酸共聚物的分析应用Ⅱ荧光熄灭法测定微量铅

Ｎ－乙烯基咔唑－丙烯酸共聚物的分析应用Ⅱ荧光熄灭法测定微量铅敖登高娃，赛音，盛显良，格日勒图（１．内蒙古大学化学系０１００２１，呼和浩特；２．内蒙古师范大学化学系０１００２０，呼和浩特；第一作者３７岁，女，讲师）关键词铅，Ｎ－乙烯基咔唑－丙烯酸共聚物...     

浅谈铅的污染及对人的危害

铅广泛应用于人们的生产、生活领域，但铅又是一种极具污染性的物质。它通过在环境和人体中的循环，对人体的神经系统、血液系统及其它方面产生毒害作用。铅对人体的危害主要有环境类、职业类、生活类、药物类、母源类五种方式。     

工业铅镉污染区动物慢性铅镉中毒的综合防治

本文报告了在工业铅镉污染区通过建立耐铅镉力强的母羊群、移场放牧、建立栅圈饲养、改善畜群结构、饲养短周期的畜禽品种和硒、铜颉颃铅镉毒性的综合防治措施进行防治效果的观察。结果表明，绵羊铅镉联合中毒的发病率由原来的３０％下降为５％以上，羔羊成活率由７４％提高至９３％，认为该综合防治措施在铅镉污染区是有效可行的。