You don't need a waterproof outer layer, but it's good to have a significant degree of water resistance.

你并不需要密不透水的外套，但是它需要对水有一定的抗性。

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Plate side has the condensation process, prevent condensation water dripping. Both sides have UV resistant layer, has better corrosion resistance.

板材一面有抗冷凝处理，防止冷凝水滴落。板材两面均有抗UV层，具有更佳的耐侯性。

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Based on linear wave making resistance theory and on & technique of boundary layer separation control, the present paper gives an optimized study of hull form below the design water line.

本文基于线性兴波阻力理论，把控制尾流分离作为约束条件，利用优化计算方法对设计水线下船体外形进行优化研究。

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