[电] 线电荷密度 linear charge density: 电荷线密度; 线电荷密度; 线性荷密度electric charge density: 电荷密度electric charge surface density: 电荷表面密度electric charge volume density: 电荷体密度electric-charge density: 电荷密度下载手机词典可随时随地查词查翻译