Effect of electret membrane on activity of seeds and seedling drought resistance property of wheat and liquorice .
驻极体膜对小麦、甘草种子活力及幼苗抗旱性的影响。
The special noise cancelling electret or dynamic microphone guarantees clear communications in all conditions .
特殊的噪声消除电容或动圈麦克风保证了各种条件下的清晰通话。
Reviews the numerical simulation technology of gas-solid flow in the electret air filter , summarizes the research results , and points out the problems ought to be solved .