The anion is one kind of airion with negative electric charge.
负离子是一种带负电荷的空气离子。
2
The results showed that negative airion concentrations increased gradually and ion polarity ratio decreased gradually from city center to suburb.
结果表明：从福州市中心向郊区空气负离子浓度逐渐增大，单极系数逐渐减小；
3
Though the negative airion concentration was sensitive to ambient environment, we found that rape and wheat crops can contribute to increase negative air ions in ambient air.