Abstract: A positive electrode active material includes an active material A having a composition formula of Lix1Nia1Cob1Mnc1O2-y1Qy1, an active material B having a composition formula of Lix2Nia2Cob2Mnc2O2-y2Qy2, and an active material C having a composition formula of Lix3Nia3Cob3Mnc3O2-y3Qy3, where the subscripts in the formulae are as defined in the description. The active material A has an average particle size Dv50 greater than both an average particle size Dv50 of the active material B and an average particle size Dv50 of the active material C.

Abstract: A progressive photon mapping method based on statistical test includes launching rays from the viewpoint to each pixel on the image plane and intersecting the three-dimensional scene to be rendered. If an intersection with diffuse surface is found on the tracing path, it is recorded as the hit point; a photon pass is performed: 31) performing photon tracing step; 32) performing photon collection processing for each hit point; 33) if the current iteration of photon pass does not need chi-square test, then performing flux accumulation and keeping the collection radius unchanged; if chi-square is required, evaluating the photon distribution quality; computing a collection radius according to the estimated photon distribution, and performing the flux accumulation in the current photon pass; 34) if the photon collection radius is reduced, then performing distributed ray tracing, generating new hit points, and go to 31), otherwise go to 31), start a new iteration of photon pass.

Abstract: A progressive photon mapping method based on statistical test includes launching rays from the viewpoint to each pixel on the image plane and intersecting the three-dimensional scene to be rendered. If an intersection with diffuse surface is found on the tracing path, it is recorded as the hit point; a photon pass is performed: 31) performing photon tracing step; 32) performing photon collection processing for each hit point; 33) if the current iteration of photon pass does not need chi-square test, then performing flux accumulation and keeping the collection radius unchanged; if chi-square is required, evaluating the photon distribution quality; computing a collection radius according to the estimated photon distribution, and performing the flux accumulation in the current photon pass; 34) if the photon collection radius is reduced, then performing distributed ray tracing, generating new hit points, and go to 31), otherwise go to 31), start a new iteration of photon pass.