By means of variable substitution and iterative method, this paper puts forth some new higher-order differential equations, and gives their formulaofreduction of integrals to common denominator.
借助变量代换、迭代等方法，提出几类新的高阶常微分方程，给出其相应的通积分公式。
2
And base on the experiment, calculating formulaof cross section mean velocity's reduction after planting and bed shears stress of vegetation dam block are established.
同时在试验的基础上，推导得植树后断面平均流速减小值和植物坝段床面剪应力的计算公式。
3
The modified formula brings about obvious effect in reductionof equipment cost, decrease of power consumption.