The observation and analysis of microstructure obtained al2o3 ceramic microfiltration tube coated membrane were employed by modern test methods such as xrd , dta - tg , sem and epma . important performances of physics and chemistry of these membranes were measured . further , industrialized manufacture equipments of al2o3 ceramic microfiltration tube coated membranes has been designed compactly 采用现代测试手段如x射线衍射分析( xrd ) 、差热-热重分析( dta - tg ) 、扫描电子显微镜分析( sem ) 、电子探针分析( epma )对制得的al _ 2o _ 3微滤陶瓷管的微观结构、形貌等进行了观察和分析，并测试了其相关的理化性能。
The paper lays a strong emphasis on discussing the realization of the autocontrol of raster scanning of the scanner in x - y dimension , the " tapping " of the cantilever of the tappingmode afm by a direct digital synthesizer . then a method of parallel communication between dsp and pc in epp mode is given . finally , the author discussed the digital pid closed loop control of the scanner in z - direction , the automatic approaching of the tip using step - motor , and also some electro - magnetic interferences 论文首先简单介绍了扫描探针显微镜的发展、分类、工作原理及应用；接着对ti公司的tms320vc5402dsp的特点及外围扩展作了简单介绍；然后分章节重点讲述了利用vc5402dsp实现扫描探针显微镜的核心部件? ?压电陶瓷管的x向和y向的光栅扫描控制；借助直接数字集成器( dds )实现轻敲式原子力显微镜的微悬臂的“轻敲” ； vc5402dsp的主机接口( hpi )与pc机在增强并行口( epp )模式下的通信；论文最后还介绍了扫描管z向的数字pid闭环控制，步进电机的自动进针，并对实际出现的一些电磁干扰问题作了讨论。
