In some situations when the ranking difference between alternative decisions is too narrow a good strategy is to refine the scenarios into sub-scenarios and re-apply the method.
当候选方案的得分区别不大时，一个好的策略是把场景深化为子场景，并在子场景上应用该方法。
2
The results showed that sulphur and re can refine the microstructure of Cu-Pb alloy, but its fatigue strength decreases with the increase of sulphur, and increases with re.
结果表明，硫和稀土都能使铜铅合金组织细化，但硫降低其疲劳性能，而稀土能提高其疲劳性能。
3
The addition of rare earth (re) as trace elements to aluminum or magnesium alloys can purify the melts, refine and modify the microstructure, reduce the inclusion.