| 摘要 |
<p>An elongated main panel portion has two opposite, bilaterally projecting flanges extending lengthwise. One curves in the shape of a surface of a truncated cone and the other curves in the shape of this surface's upper part. Specif., the main portion of the panel is a sector of the surface of a truncated cone. The connected panels form a stiff undulated surface for semi-cylindrical building structures.</p> |
