However, the product has changed dramatically, from a single thickness of 6.8 mm to a range from sub-millimeter to 25 mm.

然而，玻璃制品在厚度上发生了巨大变化：从单一的6.8毫米变为亚毫米级至25毫米区间的任意厚度。

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For the case of hydrodynamic noise, in which the range of the frequency-thickness product of interest is relatively low, the symmetric zero-order mode dominates the noise radiation.

对于水动力噪声情况，感兴趣的频率厚度乘积相当低，这时零阶对称模式对噪声辐射起主要作用。

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