Our Sprial series note book has color cover now. Click the above photo and you can go shop for them at our on-line store.

我们的旋圈本新出了彩色封面的版本，有兴趣购买的朋友可以点击上图到我们的网店选购。

Of all the gear frequency errors, the non-linear dynamic characteristics of gear tooth error, pressure angle error and sprial fluctuation error are compared with the results of the linear system.

在齿频误差中，分析了齿形误差、压力角误差和螺旋线波度误差激振下，转子系统的非线性振动特性，并与按线性模型计算的结果进行了对比。