recession

The paper analyses the behaviors of surface water flow motion of film hole irrigation based on field experimental data, and studies the effects of discharge per unit width and holed ratio on the behaviors of water advance and recession, and presents that water flow advance curve of film hole irrigation accords with power function and water flow recession curve accords with quadratic function.

根据膜孔灌溉大田灌水试验资料 ,分析了膜孔灌溉田面水流运动特性 ,研究了单宽流量和开孔率对田面水流推进及消退特性的影响 ,提出了膜孔灌溉田面水流推进曲线符合幂函数规律 ,水流消退曲线符合一元二次函数规律。

As application of the spined product, we show that a perfect wrpp semigroup is a strong semilattice of R-left cancellative planks.

作为织积的应用,我们证明完备wrpp半群是R-左消板的强半格。