Double loop high speed vacuum suction system, spread to the surrounding air by the central.
双回路高速真空吸气系统，由中央向四周扩散吸气。
2
When the system close -loop controlling is realized for lower frequency perturbation, the approximate diffraction limited line spread function can again be achieved on the image plane.
对于低频扰动，当系统实现闭环控制后，像面上线扩散函数已接近衍射极限。
3
This paper discusses the despread of low signal to noise ratio of the direct sequence (DS) spread spectrum signals using intermediate-frequency recirculation summation loop (IFRSL).