The authors want to deduce a brief formulation, and use all-purpose program to get exact result for echelon, rectangle and rotundity cross section.

作者想推导简短的公式，对梯形、矩形和圆形断面采用通用的程序，以得到准确的结果。

Bidders are shown only a cross section of the ribs.

投标者只能看到牛肋骨的横截面。

Prof Cheng agrees the Pisa results reflect a broad cross section.

程教授认为Pisa的测试结果能反映了大致情况。

Now this is a function of cross section, this is a function of energy on a log plot.

现在，这是横截面的函数，这是在坐标图的能量函数。

You take the flux, multiply it by the cross section, average it, integrate it over the whole volume.

你拿流量乘以横截面，平均它，乘以它除以总容积。