The low-frequencylimit in the parallel orientation was higher than that in the perpendicular orientation;
平行方向的低频极限量高于垂直方向的低频极限量;
2
The methods for calculating lowlimitfrequency and coupling capacitance are discussed in detail.
详细讨论了下限频率和耦合电容的计算方法。
3
Now most sound absorption layers are impedance transition constructs, which have been used widely, but their thickness is limit and cannot meet the need of absorbing sound at lowfrequency.