ESR spectrum with no superfine structure confirms the presence of V 4+ and the average valence of vanadium in the product is +4.30 on the basis of TG and XPS.

• 无明显精细结构的室温 ESR谱证明了 V4 +的存在 ；根据 TGA和 XPS求得产物中 V的平均化合价约为 + 4 .；3 0