At 800, the speed of the strengthening slows down and the color deepens. On the surface of MoO3/SiO2 and MoO3/Al2O3, the EPR spectrum of S2- has g = 2. 047, 2.028, 1.998 branches.

• 在M_0O_3/Si0_2和M_0O_3/Al_2O_3表面上；S_2~-的FPR有g_1=2.；047；g_2=2