Besides, the excess air or excess load will cause flame lift, combustion exacerbation and flame off, and that needs auxiliary flame and flame retention by inactive substance.

这就需要优化燃烧器的结构尺寸，再者，当空气量过多或超负荷下，发生离焰，导致燃烧恶化、火焰熄灭，需要有辅助火焰和钝体稳焰。

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Many companies sell the substance, along with claims that rivals’ preparations are inactive.

有许多公司在销售白藜芦醇，并声称竞争对手的产品没有活性。

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The other half received a placebo, an inactive substance.

VOA: special.2009.09.30

Here is the setup of these studies: Take people who have just had something very bad happen to them, like a motor vehicle accident or a rape, and within a few hours or a day or two at most, flip a coin and put half these people on a beta blocker and half on an inactive substance that looks the same (i.e. placebo).

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