Starting from the historical duty of developing new century's brick-tile industry, analysing the four couple contraction faced by the Guizhou brick-tile industry .
从新世纪砖瓦工业的历史责任出发，分析了贵州砖瓦工业面临的四组矛盾；
2
Describing the specialities of the starting motor brushes are of short-time duty system, big current density and the contact voltage drop must be as small as possible.
汽车启动机电刷具有短时工作制、电流密度大及接触压降小的特点。
3
This paper introduces duty type S4 of motor for crane and metallurgical applications and the test method to determine outputs of the motor at varied cyclic duration factor and starting times.