Flocculation and dispersion of clay particles in in vitro waterlogged soils at 8, 18, 28, and 380C were investigated with some indications of soil reduction. Above 280C, waterlogging for l-week in the six soils caused a significant decrease in the turbidity of their colloidal suspensions. The decrease in the turbidity, i.e., the flocculation of the clay particles, was evident with (i) a decrease of redox potential (Eh) of the soils, (ii) an increase in the values of electric conductivity (EC) and water-soluble cations (WSCs: Fe2+, Ca2+, Mg2+, NH4+ etc.) in the solutions, and (iii) an increase in the amounts of volatile fatty acids (VFAs: acetic, propionic, and n,-butyric acids) in the soils. Soilincutoation at 8℃ retarded the decrease in Eh, the increase in the values of EC, WSCs, and VFAs, and the decrease in the turbidity. At 380C, samples of four soils water-logged for 4 weeks showed a low turbidity with a low Eh, and high values of EC, WSCs, and VFAs. The samples of other two soils, however, exhibited a significant increase in the turbidity, viz. the dispersion of clay particles, with an increase in pH and decrease in the values of EC, WSCs, and VFAs under low Eh. The observed flocculation and dispersion of clay particles in the water-logged soils were discussed in relation to chemical changes under sequential reduction of soils, particularly change in ionic strength of soil solutions largely due to the (i) dissolution and precipitation reactions related to Fe2+ and Fe(III) and (ii) cation exchange reactions between Fe2+ and other exchangeable cations on clay surfaces.

The cause of the decrease in the Fe2+ concentration of the soil solution in the later period of soil waterlogging was investigated. After 7-d incubation of the soil solutions separated from previously waterlogged soils (PWdS), a greyish precipitate (PPT) was observed in the soil solutions. The color of the PPT became reddish brown after separation from the solutions and freeze-drying. The PPT observed in 14-d-PWdS contained 352.6 g Fe kg-1, 62.5g C kg-1, 22.6g P kg-1, 11.3g Si kg-l, 9.9 g N kg-1, 0.7 g AI kg-1, and a trace amount of Mn. However, Ca, Mg, K, and Na could not be detected. It was concluded that the separated PPT was dominated by amorphous ferric hydroxide based on the chemical analysis, broad IR absorption band at 585 cm-q, and exothermic peak at 301℃. The data of chemical analysis and the characteristic IR bands of the PPT suggested that organic substances and presumably alununosilicate anion were adsorbed onto the freshly-formed ferric hydroxide. The dominant phase of the greyish PPT in the reductive soil solution was considered to be ferrous PPT and was assumed to consist mainly of carbonate and/or hydroxide, and conconutantly of phosphate. The formation of the ferrous PPT in the soil solution in the later period of soil waterlogging was considered to (i) cause the decrease of concentration of Fe2+ ion and of other divalent cations such as Ca2+ due to the re-adsorption of Ca2+ on soil clays through the cation exchange reaction with Fe2+ ion, and consequently (ii) enhance the dispersion of the soil colloidal suspension.

以世界卫生组织和联合国粮农组织推荐的营养素供给量标准以及我国建议的营养素供给量标准为基准，以婴儿为对象．采用混合惩罚函数法，借助计算机技术．对婴儿经常食用的营养米粉进行了优化设计．获得了最佳配方．计算过程表明，该方飞可行结果可靠，该方法亦可用于各类营养保健食品的最忧设计。

以中性原子最高占据轨道能EHOAO、最低未充满轨道能ELUAO及价壳层轨道电子平均结合能EOEAC为基本参数，用下式定义了元素电负性：XL=0.063398-0.023110ELUAO-0.199659EOEAC+0.050572EHOAO用上式给出一个1-88号元素的电负性，结果表明，新电负性标度与目前流行的Pauling标度颇为一致，进一步确定了碳原子sp、sp2、sp3杂化轨道的电负性。

综述了渍水土壤还原过程中微生物代谢、化学变化、土壤结构和土壤胶体的稳定性的相关研究，在还原过程中，随着好氧细菌、兼性厌氧细菌、硫酸还原菌和甲烷菌的活动，相继形成氨、硝酸根离子、亚铁离子、硫化物、气体物质及有机酸，在渍水初期，水溶性阳离子浓度的增加导致土壤悬浊液凝集，在渍水后期，亚铁沉淀的形成致使二价水溶性阳离子浓度降低，使得土壤胶粒悬浊液分散，在还原条件下，土壤胶体稳定性的变化过程是一个动电机理.