中文摘要：

特种泡沫云（SPS）是一种新型多波段无源干扰技术．在通过增加其气泡液层厚度（d）以提高对IR／MMW复合制导干扰效果的实验研究过程中，发现了干扰效果急剧下降的退化现象．本文对这一现象进行了理论研究，结果表明：SFS优良干扰效果的前提是保证其气泡干扰的多界面效应，而d超过一定限度（dmax）后必将使SFS的这一效应急剧退化，从而成为“退化泡沫”．文中还分析得出了dmax约为气泡半径的0．8882倍，实际应用中可以方便地通过控制施放条件来保证d不超过dmax．这些结论有利于防止SPS干扰效果的退化，对其作战使用直接具有重要的价值．

英文摘要：

Special foam screen （SFS） is a novel multi-band passive interference technique. During the processes of improving its interference effect against IR/MMW guidance by increasing the liquidthickness of air bubbles （d）, an abnormal phenomenon occurred so that the interference effect sharply declined. In order to solve this problem, the relevant phenomenon were studied. The results show that the air bubble＇s muhi-interface characteristic is the key factor for SFS to have high effective interference, and when d exceeds dmax （the upper limit of d ）, the muhi-interface characteristic will be severely bated and the SFS has become ＂degenerate SFS＂. The ratio of dmax to air bubbles＇radius was also calculated, and it is about 0. 8882. By controlling easily the working condition of the equipment to discharge SFS, the d won＇t exceed the dmax. These conclusions can offer the important basis for the tactics application of SFS.