  Using the leading-twist approximation of the Wilson operator product
expansion with "frozen" and analytic versions of the strong-coupling constant,
we show that the Bessel-inspired behavior of the structure function F_2 and its
slope\break partial ln(F_2)/partial ln(1/x) at small values of x, obtained for
a flat initial condition in the DGLAP evolution equations, leads to good
agreement with experimental data of deep-inelastic scattering at DESY HERA.
