Air bearings had been widely used in ultra-precision machine tools. In order to suppress the micro-vibration caused by air bearing, an effective way is keeping the air flow in laminar state. Porous bearing to control the micro-vibration was proposed in this paper, and the related experiments show that it can meet the requirement of decreasing the micro-vibration to less than 1nm, and the surface of diamond surface can be improved.

Underground mines have gradually entered the stage of deep mining with the consumption of shallow mineral resources, which makes mine ventilation networks generally complicated and the problem of unstable supply of branch airflow volume in deep-level ventilation networks increasingly serious. The scientific distribution of the airflow volume between operation areas has become an important problem in the optimization of mine ventilation systems. This study takes the ventilation system of the Xinli Submine of Sanshandao Gold Mine as an example to analyze the airflow volume regulation demand of the deep-level section stope to further improve the coordination of the airflow volume distribution in the underground mine. The drawing and equivalent simplification of the ventilation network diagram are completed according to the engineering parameters of the target level roadway, and the sensitivity matrix is calculated using a formula. The optimization of the adjustment branch and the formulation of the adjustment scheme are carried out based on the sensitivity matrix. By realizing the adjustment objective of the branch airflow volume via comparing the airflow volume of the ventilation network before and after adjustment, the adjustment scheme can make the airflow volume distribution in the level more balanced. The results of our study show that branch sensitivity theory is theoretically feasible for analyzing and solving the problem of the mine ventilation network, which has certain practical significance for the adjustment of airflow volume in mines.