Spectral parameter modulation with QPO phase for the combined total phase-resolved spectra under different models. The corresponding models are—left: tbabs*ztbabs*(powerlaw+thcomp*bbody); middle: tbabs*ztbabs*(powerlaw+bbody+nthcomp); and right: tbabs*ztbabs*(powerlaw+bbody+compTT). The blue and red lines represent the best fits with sinusoidal functions and horizontal straight lines, respectively, and the significance of the QPO modulation on the spectral parameters is assessed by an F-test between them.