The Effect of Plastic Deformation on the Real Structure of ZnO Crystals during the Growth Process

The rotational model for ZnO plasticity under the action of concentraion stresses is given on the ground of the real structure analysis (the presence of two scales of the crystal lattice disorientation, a change of the ZnO crystal lattice parameter and the presence of disorientation boundaries of different types). Concentration stresses estimated at the T_gr. \documentclass{article}\pagestyle{empty}\begin{document}$ \tau = G\varepsilon = G\frac{{\Delta a}}{a} \approx 20 $\end{document} MPa exceed the yield point of crystals at T_gr. and may be the cause of rotational plasticity development.     

Mechanism of complexation of the phenothiazine dye methylene blue with fullerene C60

The complexation of fullerene C₆₀ with the aromatic dye methylene blue (MB) in aqueous solution was studied. Spectrophotometric titration revealed a reasonably strong interaction between C₆₀ and MB molecules with an equilibrium constant K = 2110 L/mol and the binding of up to five dye molecules with the surface of C₆₀. The energy analysis of the MB-C₆₀ system showed that the intermolecular and hydrophobic interactions were dominant in the energy profile of the complexation, and while the electrostatic factor played an insignificant role.     

New phosphonate-substituted tricarbocyanines and their interaction with bovine serum albumin

New tricarbocyanine dyes with phosphonate groups (2, 3) were synthesized and their binding constants to bovine serum albumin (BSA) were determined. The binding constants of the synthesized tricarbocyanines and cardiogreen (1) (K_b ~ 10⁵ M^–1) are similar, indicating an insignificant contribution of the Coulomb interaction to the complex formation, which is determined by the polymethine chain interaction with BSA. The fluorescence lifetimes attest to the formation of two types of complexes: the lifetime of the dye complex with BSA with a major contribution (~80%) is 740–800 ps, and a lifetime of ~210 ps corresponds to the complex of dye aggregates with BSA.     

Stochastic heating and stochastic outer ionization of an atomic cluster in a laser field

The dynamics of cluster electrons in a laser field is considered in the framework of the nonlinear oscillator model. The point map describing the motion of a cluster electron in the laser field is constructed. The critical value of the laser field, at which a transition to stochastic motion takes place, is determined. As a result of random walk in the energy space, an electron may accumulate an energy sufficient for overcoming the cluster potential barrier and for passing to the continuum. In this case, outer ionization of the cluster takes place. Estimates are obtained for the heating rate and the time of stochastic outer ionization of the cluster.     

Laser field absorption in self-generated electron-positron pair plasma

Recently, much attention has been attracted to the problem of limitations on the attainable intensity of high power lasers [A.?M. Fedotov et al., Phys. Rev. Lett. 105, 080402 (2010)]. The laser energy can be absorbed by electron-positron pair plasma produced from a seed by a strong laser field via the development of the electromagnetic cascades. The numerical model for a self-consistent study of electron-positron pair plasma dynamics is developed. Strong absorption of the laser energy in self-generated overdense electron-positron pair plasma is demonstrated. It is shown that the absorption becomes important for a not extremely high laser intensity I ～ 10(24) W/cm(2) achievable in the near future.