The as-synthesized Mn-doped ZnO nanowires were characterized by field emission scanning electron microscopy and transmission electron microscopy (TEM). The well-aligned nanowires are single crystalline and are perpendicularly grown along thecaxis. Electron energy x-ray dispersive analysis, x-ray ...
如图所示,虚线MN下方存在竖直向上的匀强电场,场强E=2×103V/m,电场区域上方有一竖直放置长为l=0.5m的轻质绝缘细杆,细杆的上下两端分别固定一个带电小球A、B,它们的质量均为m=0.01kg,A带正电,电量为q1=2.5×10-4C;B带负电,电荷量q2=5×10-5C,B到MN的距离h=0.05m.现将轻杆由静止释放(g取10m/s2)...
射线AB和射线BA不是同一条射线,错误;②若AB=BC,点B在线段AC上时,则点B为线段AC的中点,错误;③同角的补角相等,正确;④点C在线段AB上,M,N分别是线段AC,CB的中点.若MN=5,则线段AB=10,正确, 选D. 点睛】本题考查了直线、射线、线段;两点间的距离;余角和补角等知识,注意基本概念的掌握是解题的关键....