The curve of relationship between flame speeds and the primary air ratio is got, and when primary air ratio is about 0.

得出了二甲醚火焰传播速度与一次空气系数的关系曲线，并且在一次空气系数约为0。

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A new concept of achieving high temperature air by circulating fluidized bed combustion at high excess air ratio was proposed.

提出了借助循环流化床在高过剩空气系数下燃烧的技术提供高温空气的新构思。

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The results show that the best operating region of HCCI engine is related to the engine load, speed, and the mixture excess air ratio.

研究结果表明：均质充量压缩着火发动机的最佳工作范围与发动机转速混合气过量空气系数和负荷有密切的关系；

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But setting that aside, a 30-to-1 benefit ratio to keep our air clean sounds like a mighty wise investment to me.

FORBES: A Call to Arms on Climate Change

Though direct revenues alone would not make Galileo profitable, adding in the indirect economic gains resulting from better navigation of land, sea and air vehicles would produce a benefit-to-cost ratio of as much as 4.6 to 1.

ECONOMIST: Space race | The