(a) Energy variations of the six field components and the negative change of the total electron energy (−ΔE_k) for Case R (solid lines) and Case T (dashed lines); (b) energy variations of specific field components of various wave modes for Case R (BL for the beam-Langmuir mode, W for Whistler, O–F for the fundamental, and H for the harmonic PE); panels (c)–(e) illustrate the VDFs at three moments. Overplotted in panel (c) are two resonance curves of the W mode with the following (ω, k, θ) values: [0.1 Ω_ce, 4.5 Ω_ce/c, 30°] and [0.3 Ω_ce, 12.3 Ω_ce/c, 60°]. The two dashed lines in panels (a)–(b) represent ﹩t=80\ {\omega }_{\mathrm{pe}}^{-1}﹩ and ﹩t=300\ {\omega }_{\mathrm{pe}}^{-1}﹩.