Estimating the small-x exponent of the nonsinglet structure function g1   from the Bjorken Sum Rule
  We present a new estimate of the exponent governing the small-x behaviour of the nonsinglet structure function g_1(p-n) derived under the assumption that the Bjorken Sum Rule is valid. We use the world wide average of alpha_s and the NNNLO QCD corrections to the Bjorken Sum Rule. The structure function g_1(NS) is found to be clearly divergent for small x. 
Anke Knauf, Michael Meyer-Hermann, and Gerhard Soff