Worn surfaces of sliding pairs were characterized by scanning electron microscopy ( sem ) . chemical compositons on the worn surfaces were analyzed by energy dispersion x - ray analysis ( edax ) , and profiles and suface roughness of the worn surfaces were measured by stylus profilmetry 用扫描电子显微镜( sem )对磨痕表面形貌进行了分析，用能量色散x射线分析( edax )对磨痕表面进行化学成分分析，并用表面轮廓仪测定了磨痕表面粗糙度和磨痕表面轮廓曲线。
Touch screens employ one of three physics principles for detecting the point of touch . pressing a resistive design with a finger or other stylus raises a voltage . in capacitive models a finger draws a minute current this method is often used for cursor pads on notebook computers in other designs a finger or stylus interrupts a standing pattern of acoustic waves or infrared lights that blanket the surface 触控荧幕可依其侦测触控点的物理原理，分为三种：电阻式荧幕，用手指或其他触头轻按就会产生电压电容式荧幕，手指会吸取微小的电流常用于笔记型电脑的触控板。
The printer at present is used extensively in many fields . thus the higher request is put on the stylus printer quality and print speed which lies on the driving electric machinery of printer fast and placidly driving the movement of printer ’ s pin and the fast startup and stop and exact orientation of the driving paper electric machinery 打印机的应用非常普遍,同时人们对打印质量和速度的要求也越来越高,其中针式打印机的打印质量和速度主要依赖于打印机的驱动电机带动打印头运动的快速平稳以及走纸电机的启停快速、定位准确。
