Selection of ground current, comparison of isolation level and consideration of protective device in the resistance ground system are presented.
介绍了电阻接地系统中，接地电流的选取，绝缘水平比较，保护配置方面的考虑。
2
With excellent light reflectance and weather resistance, have to save energy, which makes protective layer can be.
具有优良的光线反射能力和耐候性，有利于建筑节能，其上可不做保护层。
3
They also show that water absorption could availably evaluate the waterproof ability and resistance to acid and alkali corrosion of concrete protective coatings.