vector field的用法和樣例：
例句
- The electric current density vector field also satisfies superposition principle, some applications thereof are introduced.
摘要電流密度矢量場也滿足疊加原理，給出了一些應用電流密度場疊加原理的例子。 - We shall use various schemes, none of them wholly satisfactory, to depict vector fields in this book.
在本書中我將用不同的圖樣畫出矢量場，但沒有一種是完全令人滿意的。
