一般将小于1微米的粉末称为超细粉末。久保曾从理论上预计:当粒子变得非常微小时,金属微粒的电、磁性能及热效应等将发生显著的变化,已有实验证实了这一预计。近年来,对于小于100埃的微粒所引起的“久保效应”,颇为物理学者注意,感到很大的兴趣。超细金属粉末有许多特异的性能,用途很广,有的地方已显示出独特的效果。表1为目前实际应用的部分项目。 Generally less than 1 micron powder called ultrafine powder. Kubo had predicted theoretically: When the particles become very small, the electrical and magnetic properties of metal particles and thermal effects will change significantly, this experiment has confirmed this prediction. In recent years, “Kubo effect” caused by particles smaller than 100 angstroms has attracted the attention of the physicists and is very much interested. Ultra-fine metal powder has many unique properties, uses a very wide range, some places have shown a unique effect. Table 1 is currently part of the practical application.