Water and nitrogen transport characteristics of single-line interference infiltration under film hole irrigation with muddy water and fertilizer

Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.

聚乙二醇作致孔剂对聚氨酯微孔膜通透性能的影响

探讨了3种不同分子质量的聚乙二醇用量,对聚氨酯微孔膜透湿性和力学性能的影响。通过对聚氨酯微孔膜的透湿性能、力学性能、吸湿性能、孔隙率以及扫描电镜等表征手段的分析,结果表明:聚乙二醇分子质量为1000、加入量为3%时,透湿量和孔隙率都最高,分别为1407.38g·mm·m-2·24h-1和7.55%;加入量为2.5%时,聚氨酯微孔膜的透湿量和拉伸强度都比较高。

丁酮对聚氨酯微孔膜性能的影响

使用丁酮和二甲基甲酰胺配备混合溶剂,用于溶解稀释聚氨酯,并采用湿法成膜方法制备了聚氨酯微孔膜。通过调整溶剂的配比和凝固浴温度,研究了溶剂比例和凝固浴温度对成膜性能的影响。结果表明,随丁酮添加量的逐渐减少,凝固浴温度的增加,薄膜的孔隙率与透湿性呈现复杂的变换趋势,所以采用丁酮控制薄膜性能时,使用条件非常重要。