ra25粗糙度标注 RA25粗糙度标注是一种用来描述物体表面粗糙程度的方法。粗糙度是指物体表面的不均匀性,常用来评估物体表面的质量和功能。RA25粗糙度标注通常用于描述相对较粗糙的表面,其数值越大,表面越粗糙。 RA25粗糙度标注是由美国制造商协会(AMMA)提出的一种标准。该标准采用了一种特殊的仪器,称为粗糙度测量...
The present invention relates to a keyboard mounting structure of a portable computer. The present invention is the keyboard deck 33, the seating groove 35 is formed on the upper surface; The plurality of keys 43 are arranged on the base 41 to be seated in the seating groove 35, and at ...