在低水平放射性测量中，建议采用负二项式分布代替泊松分布来描述真实测量计数的几率分布。

In the measurement of low-level radioactivity, instead of Poisson distribution, a negative binomial distribution is proposed to denote the probability distribution of actual counts.

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该紧固件具有两个或三个切削松卷螺纹的刀状突起(5)，该刀状突起从实心的中轴(2)向外放射状延伸。

The fastener incorporates two or three loosely wound loosely wound thread-cutting blade-like helical projections (5) extending radially from a solid axial core (2).

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