Several methods for quench correction-external standard channels ratio method, spectral index method and "H number" method are simply introduced.

Objective To observe the effects of different adjuvants on bispectral index (bis), spectral edge frequency (SEF) of electroencephalogram during lumbar anesthesia.

The result showed that the homogeneous degree of the soil nutrient was increased, the variability of spectral index and the yield were reduced in the management zone divided by soil data.