| 摘要 |
<p>The adjustable focussing mirror comprises a support on which there are mounted a set of small individual flat mirrors. The support comprises a cast concrete structure with a datum face to which the individual mirrors are glued close together but not touching. The structure is equipped with pre-stressing components by which the concavity of the datum face is adjusted. It can be honeycomb construction, with an external reinforced-concrete shell strengthened by concrete ribs sepg. the honeycomb compartments. Pref. the honeycomb structure is filled with expanded polystyrene, paper, etc.</p> |
