Energy spectra of the electrons/ions before and after acceleration/deceleration. (a) Number flux of electrons before (0748:16 UT) and after (0750:08 UT) acceleration. (b) Number flux of ions before (0748:16 UT) and after (0750:08 UT) deceleration. (c) Number flux of electrons before acceleration is shifted by +150 eV/q. (d) Number flux of ions before deceleration is shifted by −150 eV/q. The shifted lines of (c) and (d) correspond well with the number fluxes of electrons/ions after acceleration/deceleration.