说明：  一篇论文。主要利用特征和估计及三角和方法，研究了二次高斯和的均值性质，并通过初等方法给出了它的 次均值的两个精确的计算公式
(Paper. Mainly use features, and the estimates and the triangle and the method to study the quadratic Gaussian and mean nature, and given two precise formula it mean by elementary methods)