等温区 meaning in English

isothermal region
zone of constant temperature

Within less than 1 millisecond the steep-fronted shock wave has traveled some distance ahead of the isothermal region .
在不到1毫秒的时间内，陡直的冲击波波阵面已比等温区领先一段距离了。
It includes the following aspects : adopting the partial differential equations and neighborhood average smoothing methods to reduce image noises . mapping the rgb three - color and gray scale histogram to study - 3 - the relationship of flame features and temperature field distribution . the methods of calculate important parameters about the average gray value , the flame area and the flame shape center coordinate are given
采用图象相加、偏微分、邻域平均等方法来消除图象噪声；绘制图象的r 、 g 、 b三色直方图来研究火焰幅度特征分布与温度分布的关系；给出计算平均灰度、火焰面积大小、火焰形心坐标等重要参数的方法；用彩色等温区或等温线重构温度场分布。