| 摘要 |
<p>Each longitudinal rib (3) is divided into partial ribs (7) by a series of openings (10) made through it near one edge (8). The partial ribs are each twisted relative to the longitudinal rib, through an angle of 3-135[deg]. The openings are constructed between free edges (8) of the partial ribs (7) in the main surface of the longitudinal rib.</p> |
