$$\bex \int f^2g \leq C\sen{f}_{L^2}^\frac{5q-4}{3q-2} \sen{\p_3f}_{L^q}^\frac{q}{3q-2} \sen{g}_{L^2}^\frac{q-2}{3q-2} \sen{\n_hg}_{L^2}^\frac{2q}{3q-2},\quad 2\leq q<\infty. \eex$$ 不过发现没啥用. 嗨... 

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