Oscillation of a kind of second order nonlinear differential impulsive equation(The equation is abbreviated), is studied and some sufficient conditions are obtained.
用黎卡堤变换研究如下二阶非线性脉冲微分方程（ 方程式略）得到了两个判断方程振动的充分条件。
2
This article put forward some important integral formulas, such as baa (the equation is abbreviated), and performs to explain with examples.
文章提出几个形如(方程序略)的重要的积分公式，并加以举例说明。
3
An elementary proof of the Diophantine equation (the equationabbreviated) is given by using recursion sequence method.