Phase Transitions in the Diluted Two-Dimensional Potts Model with the Number of Spin States q = 3 on a Square Lattice

Physics of the Solid State - The phase transitions in the two-dimensional diluted Potts model with the number of spin states q = 3 are studied by computer simulation method. The systems...     

Manifestation of the Sapphire Crystal Structure in the Surface Nanopattern and Its Application in the Nitride Film Growth

The “quenching” technique was used to investigate the initial stage of the formation of a terracestep nanostructure on the R-cut surface of sapphire crystal upon high-temperature annealing in air. The morphological features of the formation of A- and R-sapphire planes are experimentally shown in dependence on the misorientation direction and qualitatively interpreted with allowance for the surface energy density for the main sapphire faces. The possibilities of forming AlN layers on the R-sapphire surface with a terrace-step nanostructure under thermochemical effect and high-temperature substrate annealing in a mixture of nitrogen and reducing gases are considered.     

Theoretical and experimental study of the transformation of 2-pyridone-5-amide into nitrile

Molecular and crystal structures of 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxamide (1), 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carbonitrile (2), and 2-chloro-4,6-dimethylniсotinonitrile (3), which are the products of sequential transformations, are studied by means of single crystal diffraction. The procedure for synthesizing each compound is described. All of the compounds are characterized using IR and ¹H NMR spectra. Possible reaction pathways are simulated using the density functional theory (DFT).     

Electrochemical Generation of Pyrazolyl-Pyridyl N-Heterocyclic Carbene Complexes of Nickel

Russian Journal of Electrochemistry - By methods of cyclic voltammetry and preparative electrolysis, the electrochemical properties of sterically hindered imidazolium salt...     

Catalytic epitaxy of ZnO whiskers via the vapor–crystal mechanism

A model of oriented growth of (0001) ZnO whiskers on sapphire substrates via the vapor–crystal mechanism using the catalytic properties of gold islands is proposed. The morphological transition from the primary pyramidal ZnO structures to hexagonal ZnO whiskers is described in terms of the minimization of the free energy density of three-dimensional heteroepitaxial islands.     

Centrifugal enrichment of sulfur isotopes

This work contains the results of the research for the complete cycle of the centrifuge enrichment process of all sulfur isotopes. As a result of this work there was obtained, and made available (by centrifuge enrichment process), for the first time hundreds of grams of all the isotopes of sulfur to high enrichment.     

Identification of external load and control of deformed state of an asymmetric trimorphic beam in unsteady modes

We consider the problem of identifying the time-variation law of an external pulse load acting on an asymmetric trimorphic electroelastic beam with simultaneous minimization of the deformed state of the beam. In this problem, one of the trimorph layers operates in the direct piezoelectric effect mode and the other in the inverse piezoelectric effect mode. The control is performed by exciting the actuating piezoelectric layer by an electric signal determined according to one of the proposed criteria. The solution is obtained by using the Laplace integral transform with respect to time. The desired variables are determined from a system of Volterra integral equations after analytically passing to the space of transforms. The computations are based on special regularizing algorithms. Numerical results are presented and analyzed.