up conversion

例句：

1. 1. The company has been undergoing a significant up conversion in its product line.
   该公司在其产品线上正在进行重大的向上转换。
2. 2. Up conversion is a process where the energy from a lower frequency is converted to a higher frequency.
   向上转换是一种过程，其中将较低频率的能量转换为较高频率。
3. 3. In this case, the up conversion of the signal can be used to enhance the quality of the image.
   在这种情况下，信号的向上转换可以用于提高图像的质量。