Research and development on life ball system for mine disaster rescue 矿难救险生命球系统的研发
Test method for vertical rebound characteristics of sports surface ball systems ; acoustical measurement 球类运动场垂直回弹特性试验方法.声学测量
Standard test method for vertical rebound characteristics of sports surface ball systems ; acoustical measurement 球类运动场垂直回弹特性的标准试验方法.声学测量
The bias - ball system is the most aggressive , providing a highly consistent connection between the plunger and barrel by compressing a ball against an angled plunger 偏置球系统最有积极性,通过将球压到一个倾斜的顶杆,在顶针和客体之间提供极其一致的连接。