Suspended semiconductor nanostructures: physics and technology.

The current state of research on quantum and ballistic electron transport in semiconductor nanostructures with a two-dimensional electron gas separated from the substrate and nanoelectromechanical systems is reviewed. These nanostructures fabricated using the surface nanomachining technique have certain unexpected features in comparison to their non-suspended counterparts, such as additional mechanical degrees of freedom, enhanced electron-electron interaction and weak heat sink. Moreover, their mechanical functionality can be used as an additional tool for studying the electron transport, complementary to the ordinary electrical measurements.

Universal behavior of magnetoresistance in quantum dot arrays with different degrees of disorder.

The magnetoresistance in a two-dimensional array of Ge/Si quantum dots was studied in a wide range of zero magnetic field conductances, where the transport regime changes from a hopping to a diffusive one. The behavior of the magnetoresistance is found to be similar for all samples--it is negative in weak fields and becomes positive with increasing magnetic field. The result apparently contradicts existing theories.

Computer simulation of nucleation in a gas-saturated liquid.

Molecular dynamics methods have been used to investigate the kinetics of the liquid-gas phase transition in a two-component Lennard-Jones system at negative pressures and elastic stretches of the liquid to values close to spinodal ones. The molecular dynamics system consists of 2048 interacting particles with parameters of the Lennard-Jones potential for argon and neon. Density dependences of pressure and internal energy have been calculated for stable and metastable states of the mixture at a temperature T* approximately 0.

[The use of depot phoresis of copper-calcium hydroxide for the treatment of impassable and hard to reach root canals].

Experience gained in the treatment of 100 patients by depot-phoresis of copper-calcium hydroxide is analyzed. The results of 6-month follow-up showed good results in 93.4% cases.