In this paper we derive the formula for computing the envelope of a bi-parametric familyofsurfaces, when they are expressed in parameters.
本文导出了双参数曲面族用参数形式表示时包络面的计算公式。
2
He moved his family to Gaithersburg, Maryland, to take a job with the Bureau of Standards, testing the skid resistance of various kinds of road surfaces.
他举家迁往马里兰州的盖瑟斯堡市,在标准局工作,测试各种路面的防滑性能。
3
Youngblood has built upon these materials to make a new familyof ready-to-use polymers that can be easily applied to a variety of surfaces.