two-dimensional normal distribution

Pollen fertility was observed in two successive selfing generations on a two-line sterility line, Zao S, which proved that the pollen fertility in the population showed a normal distribution.

通过早S连续两个世代花粉染黑率的观测，证实群体育性呈正态分布。

In our observation time window, the volume of cerebral infarction in rats brain of model group and EA group presented a basic normal distribution. The two peak appeared at I/ R48h both.

在我们设定的观察时间窗内（缺血／再灌注24h-72h），模型组和电针组大鼠脑梗死体积比呈现一个基本正态分布，都是在缺血／再灌注48h最大，处于峰值。

In this paper, we concretely design a fixed-width confidence interval for the variance σ 2 of a normal distribution N(μ,σ 2) by two-stage procedures and provide the optimal sample size of the first stage by numerical computations.

利用两阶段抽样，我们具体给出了正态总体方差的一个置信区间，它同时满足可靠度与精度，利用数值计算的方法，我们计算出第一阶段的最优抽样量。

The random process of two phase flow formed out of air entrained in the water by the aerator is an ergodic process, its amplitude distribution is in accord with the normal distribution.

利用掺气坎在水中强迫掺气形成水气两相流，其压力脉动属于平稳，各态历经随机过程。