... 2 0 0 d sin π 2 0 d r r v d d d sin d 2 M 二 曲面的面积(Area of surface) 1 设曲面S的方程为： ) , ( y x f z , D xoy 面上的投影区域为 在 , ) , ( 具有连续偏导数 上 在区域 函数 D y x f 下面通过微元...
Characterization and evaluation of machined surface topography has always being one of the most vital and appealing issues in the areaofsurface metrology and tribology.
机械加工表面形貌表征和评价一直都是表面计量学和摩擦学领域最重要的课题之一。
2
In an area where low temperatures are limiting to life, the importance of the additional heat near the surface is crucial.
在这样低温限制了生存的区域，近地表的额外热量至关重要。
3
Rainforests make up only a small part of the Earth's surface, about six percent, but there are more kinds of trees than any other area in the whole world.