Results The surface roughness of the gradual composite materials was significantly higher than that of the control materials(P<0.01).
结果梯度复合材料的表面粗糙度明显高于对照材料（P＜0．01）；
2
The surface roughness and hydrophilicity of the PLLA-PDXB composite were obviously enhanced.
复合材料的亲水性和粗糙度明显增加。
3
Shanghai Composite Index is an important index for Chinese stock market, and we apply the Least Squares Method with roughness penalty to smooth its historical data, using spline functions.