Turbulence is composed of hierarchical structures of various scales, various amplitude and various degree of coherence. At all length scales ranging from the integral scale to the dissipation scale, there exist the so-called most intermittent structures, which have the largest amplitudes and the strongest coherence. Structures of smaller amplitude airs related to the most intermittent structures according to a certain symmetry relation. This is the so-called Hierarchical Structures model of turbulence(She ...