扶弱助困 建立多层次的社会救助体系

我国正处于社会转型时期，作为改革开放和社会转型的代价，贫困人口问题逐渐凸现出来。形成了危及社会稳定，影响社会发展的巨大隐患。解决贫困人口问题的途径是建立多层次的社会救助体系。     

Synthesis and Characterization of Schiff Base Containing Thiocarbohydrazide

0 Introduction Symmetric and asymmetric derivatives of thiocarbohydrazide have broadly been studied due to their potential utility as analytical reagents. Symmetric Schiff base can be easily obtained by direct reaction. while there have many troubles in obtaining asymmetric Schiff base. The obvious difficulty in the synthesis of asymmetric Schiff base is that the straight condensation methodology used for symmetric Schiff base is no longer applicable when some symmetric dia mines were adopted as the parent reactants in the     

新显色剂偶氮氟胂-DBF的合成及与钍的显色反应

合成了新显色剂偶氮氟胂-DBF,并研究了其与钍的显色反应,在3.84 mol•L^-1的高氯酸介质中,钍与该显色剂形成紫红色配合物,最大吸收波长为630 nm,表观摩尔吸光系数为1.63×10⁵ L•mol^-1•cm^-1, 钍含量在每25 mL 0～40 μg范围内符合比尔定律,该方法简便,灵敏度高,选择性好,用于海产品中微量钍的测定,结果满意.     

含硫脲基Schiff碱的合成与表征(英)(简报)

Symmetric and asymmetric derivatives of thiocarbohydrazide have broadly been studied due to their potential utility as analytical reagents. Symmetric Schiff base can be easily obtained by direct reaction.while there have many troubles in obtaining asymmetric Schiff base. The obvious difficulty in the synthesis of asymmetric Schiff base is that the straight condensation methodology used for symmetric Schiffbase is no longer applicable when some symmetric dia mines were adopted as the parent reactants in the condensation reaction. As ketone has lower chemical activities than that of the aldehyde,