About the $Q^2$ dependence of asymmetry $A_1$

We analyse the proton and deutron data on spin dependent asymmetry $A_1(x,Q^2)$ supposing the DIS structure functions $g_1(x,Q^2)$ and $F_3(x,Q^2)$ have the similar $Q^2$-dependence. As a result, we have obtained $\Gamma_1^p - \Gamma_1^n = 0.192$ at $Q^2= 10~{\rm GeV}^2$ and $\Gamma_1^p - \Gamma_1^n = 0.165$ at $Q^2= 3~{\rm GeV}^2$, in the best agreement with the Bjorken sum rule predictions.