  In this thesis, we consider some spin effects in QCD and recurrence lattices
with multi-site exchanges. Main topic of our manuscript are critical phenomena
in spin systems defined on the recurrence lattices. Main tool of our approach
is the method of recursive (hierarchical) lattices. We apply the method of
dynamical mapping (or recursive lattices) for investigation of magnetic
properties of the fluid and solid $^3$He, phase transitions in crystals and
macromolecules. First, we analyze the helix-coil phase transition for
polypeptides and proteins, and describe an quasi unfolding transition (like the
cold denaturation process) for the degree of helicity (the order parameter for
macromolecules). Next we consider the recurrent models of $^3$He defined on the
square, Husimi and hexagon lattices. Using the method of dynamical mapping, the
magnetization curves with plateaus, bifurcation point and one period doubling
are obtained. Then we investigate the model with cubic symmetry defined on the
Bethe lattice and containing both linear and quadratic spin-spin interactions.
The magnetization of the system is calculated, and a complex structure of the
phase transitions between the disordered, partially ordered and completely
ordered states is observed. In the framework of QCD, we consider the azimuthal
asymmetries in heavy flavor production in the lepton-nucleon deep inelastic
scattering (DIS). We calculate the azimuthal (or $\phi$-) dependence of the
next-to-leading order heavy-quark-initiated contributions to DIS. It is shown
that, contrary to the basic gluon-initiated component, the photon-quark
scattering mechanism is practically $\cos2\phi$-independent. We investigate the
possibility of measuring both nonperturbative (intrinsic) and perturbative
(CTEQ, MRST) charm distributions using the $\cos2\phi$ asymmetry.
