Bloch oscillations in a homogeneous nucleotide chain

It is shown that, at zero temperature, a hole placed in a homogeneous synthetic nucleotide chain with applied electric field demonstrates Bloch oscillations. The oscillations of the hole placed initially on one of the base pairs arise in response to disruption of the initial charge distribution caused by nucleotide vibrations. The finite temperature fluctuations result in degradation of coherent oscillations. The maximum permissible temperature for DNA “Bloch oscillator” occurrence is estimated.     

HSSH-model of Hole transfer in DNA

A method based on a selfconsistent solution of a quantum-mechanical system with temperature fluctuations described by Langevin equations is developed to calculate the charge carrier mobility in DNA. To model the charge transfer in DNA, a combined Holstein – SSH Hamiltonian is considered. As an example the hole mobility is calculated at room temperature for synthetic poly (G)/poly (C) duplex with regard to main structural fluctuations.     

A strongly attractive Fermi gas in an optical lattice

We study strongly attractive fermions in an optical lattice superimposed by a trapping potential. We calculate the densities of fermions and condensed bound molecules at zero temperature. There is a competition between dissociated fermions and molecules leading to a reduction of the density of fermions at the trap center.     

Solvation effects on hole mobility in the poly G/Poly C duplex

Theoretical calculations of solvation contribution to hole energy in a polynucleotide chain give very low hole mobility values at zero temperature, μ < 10⁻³ cm²/(V s). We calculated hole mobility at physiological temperature for the Poly G/Poly C DNA duplex, which gave substantially larger mobility values. Mobility over the temperature range 20–400 K was calculated. Taking stacking interaction into account substantially increased hole mobility.     

Natural Vibrations of Complex Bodies

The paper sets forth a modified preconditioned conjugate-gradient method with shifted aggregated multilevel preconditioning (MPCG_AMIS). The method is intended to solve large-scale natural-vibration problems. Such problems are typical for the finite-element analysis of buildings and other complex structures and bodies. Using a proper shift in preconditioning improves considerably the spectral properties of the preconditioner and, hence, improves convergence. Using the MPCG_AMIS allows us to avoid lock of convergence, which is the case in the conventional PCG method. The performance of the method is illustrated by examples     

Quantum tunneling of a vortex between two pinning potentials

A vortex can tunnel between two pinning potentials in an atomic Bose-Einstein condensate on a time scale of the order of 1s under typical experimental conditions. This makes it possible to detect the tunneling experimentally. We calculate the tunneling rate by phenomenologically treating vortices as charged particles moving in an inhomogeneous magnetic field. The obtained results are in close agreement with numerical simulations based on the stochastic c-field theory.     

Load-carrying capacity of flawed reinforced rectangular plates subjected to compressive end loads

UkrNIIproektstal' konstruktsii, Kiev. Translated from Prikladnaya Mekhanika, Vol. 27, No. 2, pp. 73–80, February, 1991.