second-order differential equation

Newton's second law can be expressed as a differential equation.

牛顿第二定律可表达成微分方程.

On the basis of Newton's second Law, a motion differential equation has been put forward, by which a formula to calculating instantaneous velocity has been obtained.

依据牛顿第二定律列出运动微分方程式，解方程式并求得计算瞬时速度的公式。

The existence and uniqueness about semilinear second-order differential equation are established by using global inverse function theorems.

本文利用整体反函数理论，研究了半线性二阶微分方程周期边值问题，给出了周期解存在唯一性的充分条件。

An important case is the linear homogeneous second-order differential equation with constant coefficients.

一种重要的情形是常系数二阶线性齐次微分方程.

The first one is solved by characteristic theory, the second one and equation of flow continuity are in triangular differential scheme, Which is suitable to not only mathematical characteristic, but alse arbitrary shape of flow domain.

对流算子用特征线求解，扩散算子和水流连续方程用三角形差分格式，既满足不同微商的数学性质，又适应不规则的边界形状。