中文摘要：

在超高真空（10^-6Pa）条件下，利用高速摄影机观测常规及纳米CuCr25合金的阴极斑点运动。实验结果显示，常规CuCr25合金的阴极斑点运动局限于阳极正下方的Cr相上，而纳米CuCr25合金的阴极斑点可以运动到偏离阳极正下方较远处。Cr粒子尺寸的减小及相应的晶界的增加是造成阴极斑点运动巨大差异的主要原因。

英文摘要：

The motion of cathode spots on coarse-grained and nanocrystalline CuCr25 under ultra-high vacuum condition were observed by a digital high speed video camera. The results show that the motion of spots on coarse-grained CuCr25 are restricted on Cr particle right opposed to the anode, while on nanocrystalline CuCr25, spots could reach places far from the position right opposed to the anode The novel difference of the motion of spots is due to the diminished particle size of Cr and the increase of the number of boundary.