是的，beam是可数名词。
N-COUNT（能量、放射线或粒子的）束，柱
Abeamisalineofenergy,radiation,orparticlessentinaparticulardirection.
N-COUNT（光）束；（光）线
Abeamoflightisalineoflightthatshinesfromanobjectsuchasalamp.
N-COUNT梁；横梁
Abeamisalongthickbarofwood,metal,orconcrete,especiallyoneusedtosupporttheroofofabuilding.
