This is the tendency for water to pass through a membrane separating a weak solution from a strong one. 渗透是一种水通过膜的运动趋势，膜的两面分别是浓溶液和稀溶液。
However these troubles of concentrated urea liquor crystallizing and blocking pipe, as well as urea changing into biuret at high temperature should be avoided. 但在生产中要妥善解决尿素浓溶液易结晶堵塞管道以及尿素在高温下易生成缩二脲的问题。
