本文将市区的浅层地下水硬度作为灰色量，用已有的硬度数据建立GM(1,1)灰色模型，预测其未来的变化趋势。
In this paper, the hardness of the shallow groundwater was treated as a grey variable and the GM (1, 1) grey model was created to predict the future trend of the change in hardness.
研究了稀土对电气铁路电车线用纯铜硬度、导电性、 耐磨性、耐蚀性的影响。结果表明，随稀土加入量的不同，上述性能都有一定程度的变化。
This paper studied the effects of rare earth elements on the properties(such as hardness, electrical conductivity and resistance to corrosion)of pure copper used in touching wire of electric railway.
其优点在于镀层中含磷量与硬度在纵向与镀层厚度方向两个方向上均有梯度变化。
Firstly, both the coating's phosphorus content and hardness have gradients in vertical and lateral directions.
应用推荐