## 3 Results
### Analysis and Impact of Interactions on the R. solani Cell Damage Rate
When the voltage amplitude is 25 kV and the processing time is 3.83 min., the interaction between voltage amplitude and processing time is the most obvious. At this time, the cell membrane damage rate reaches 41.54%. \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Source**} & \multicolumn{2}{c}{**Cell Membrane Damage Rate**} & \multicolumn{2}{c}{**510 nm Absorbance**} \\ \cline{2-5}  & **F-Value** & \(p\)**-Value** & **F-Value** & \(p\)**-Value** \\ \hline Model & 5.39 & 0.0186 * & 4.05 & 0.0392 * \\ A-amplitude & 9.25 & 0.0188 * & 13.37 & 0.0081 ** \\ B-time & 14.40 & 0.0068 ** & 0.88 & 0.3788 \\ C-pulse duration & 3.60 & 0.0996 & 0.70 & 0.4293 \\ AB & 1.04 & 0.3407 & 0.58 & 0.4726 \\ AC & 0.22 & 0.6536 & 0.38 & 0.5569 \\ BC & 0.12 & 0.7433 & 0.32 & 0.5870 \\ A\({}^{2}\) & 12.68 & 0.0092 ** & 19.75 & 0.0030 ** \\ B\({}^{2}\) & 8.19 & 0.0243 * & 0.0002125 & 0.9888 \\ C\({}^{2}\) & 0.012 & 0.9161 & 0.83 & 0.3929 \\ Lack of Fit & 4.68 & 0.0851 & 13.65 & 0.0144 \\ R\({}^{2}\) & 0.8739 & & 0.8391 \\ \hline \end{tabular} Note: * in the table represents significance as \(p<0.05\); * in the table represents extremely significance as \(p<0.01\); V is pulsed voltage, kV; t is time, min; PW is pulse duration, \(\upmu\)s.  
\end{table} 
Table 4: Response surface variance analysis results. 3.2 Analysis of the Interaction between Voltage Amplitude and Pulse Duration, and Its Effect on the _R. solani_ Cell Membrane Damage Rate  
Figure 3 shows the response surface of the voltage amplitude and pulse duration vs. the _R. solani_ cell membrane damage rate at a processing time of 3 min. When the processing time is at an intermediate level, under different pulse durations, the effect of increasing the voltage amplitude on the _R. solani_ cell membrane damage rate was similar for different pulse durations, and the cell membrane damage rate first decreased from 23.26% to 17.49% and then increased with the voltage amplitude. At the same voltage amplitude, the effect of increasing the pulse duration on the _R. solani_ cell membrane damage rate was similar, and it slowly increased with the pulse duration, but the overall effect is not obvious. It can be seen from Table 4 that the change in the quadratic term of voltage amplitude has a significant effect on the _R. solani_ cell membrane damage rate (\(p<0.01\)). When the voltage amplitude is 25 kV and the pulse duration is 60 \(\upmu\)s, the interaction between the voltage amplitude and pulse duration is most obvious. At this time, the cell membrane damage rate reaches 43.48%. Figure 3: Response surface analysis of voltage amplitude and pulse duration. Figure 2: Response surface analysis of voltage amplitude and processing time. 3.3 Analysis of the Interaction between Processing Time and Pulse Duration, and Its Effect on the R. solani Cell Membrane Damage Rate  
Figure 4 shows the response surface of the processing time and pulse duration vs. the damage rate of _R. solani_ cells under the condition of voltage amplitude of 20 kV. It shows that, when the voltage amplitude is at the intermediate level, the effect of increasing the processing time on the cell membrane damage rate of _R. solani_ is similar under different pulse durations; and, it first increased from 26.64% to 28.1% and then slightly decreased with the processing time. Under different processing times, the effect of increasing pulse duration on the cell membrane damage rate of _R. solani_ was similar. As the pulse duration slowly increased, the effect was not obvious, and it can be seen from Table 4 that the change in the secondary term of processing time has a significant effect on the _R. solani_ cell membrane damage rate (\(p<0.05\)). When the processing time is 4.9 min., the pulse duration is 60 \(\upmu\)s. The interaction between the voltage amplitude and pulse duration is the most obvious. At this time, the cell membrane damage rate reaches 26.35%.