Finding the response matrix to the external action from a subspace for a discrete linear stochastic dynamical system

For a discrete linear stochastic dynamical system, computation of the response matrix to the external action from a subspace using given observational data is examined. An algorithm is proposed and substantiated that makes it possible to improve the numerical accuracy and to reduce the amount of observational data compared to the general case where an arbitrary external action is allowed. As an illustration, a discrete system arising in the analysis of a linear stochastic dynamical continuous-time system is considered more thoroughly. Some numerical results are presented.     

Arenesulfonylimines of methyl trifluoropyruvate in the cyclocondensation reactions with 1,3-C,N-and-N,N-binucleophiles

Reaction of arenesulfonylimines of methyl trifluoropyruvate with 1,3-C,N-and-N,N-binucleophiles led to a variety of N-sulfonylated fluorine-containing heterocycles, including the fused ones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2171–2175, November, 2007.     

Synthesis and structure of O-(arylcarbamoyl)butyrhydroximoyl chlorides

The O-(arylcarbamoyl)butyrhydroximoyl chlorides were synthesized, and the x-ray structural analysis (XSA) of one of them — O-(o-tolylcarbamoyl)butyrhydroximoyl chloride — was performed. It was established from the data of the XSA and the PMR spectra that all synthesized compounds are the Z isomers.Institute of Physiologically Active Substances, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 315–319, February, 1992.     

Interaction of CdSe/ZnS core-shell semiconductor nanocrystals in solid thin films

The optical properties of CdSe/ZnS semiconductor nanocrystals with the core-shell structure are studied upon visible-laser excitation in a wide range of flux densities. It is demonstrated that the dimensional quantization effect is preserved in the films with a limiting high concentration of nanocrystals. A strong bathochromic shift of the absorption and luminescence peaks relative to the peak positions in the corresponding spectra of nanocrystals in films with a relatively low concentration of nanocrystals and solutions is caused by a high concentration of nanocrystals and the dipole moment related to the asymmetry of the nanoparticles. The shift is varied from 35 to 50 nm depending on the film thickness. The luminescence spectra of the films remain unchanged upon an increase in the laser intensity to 1 × 10⁶ W/cm². The laser action on the nanoparticle films is studied at intensities (5 × 10⁶?1 × 10⁹ W/cm²) higher than the damage threshold.     

Organosilicon and organophosphorus compounds with pseudohalide groups. 2. Reactions of alkoxydimethylsilyl cyanides with chlorides of tricoordinated phosphorus

Reactions of alkoxydimethylsilyl cyanides with some chlorides of tricoordinated phosphorus (phosphorous chlorides) have been studied. It is shown that, depending on the nature of the phosphorous chloride, the chlorine atoms can either be substituted only for cyano groups, or for alkoxy and cyano groups simultaneously. The results obtained in this work clearly show that alkoxydimethylsilyl cyanides are more reactive reagents for attaching cyano groups to a phosphorus atom than trimethylsilyl cyanide.For Part 1, see [1].For a preliminary communication, see [2].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2847–2849, December, 1991.     

Statistical theory of the crystal state

A theory of the crystalline state of matter is constructed in the framework of the method of distribution functions. The system of two exact equations for the single- and two-particle distribution functions is solved by a series expansion in powers of the small parameter =(n-n _o)/n ₀, wheren is the density of the crystal andn ₀ is the density of the liquid at its crystallization point. In the zeroth order in , the theory leads to the Ornstein-Zernike equation, which determines all the properties of the molten state; in the first order, it leads to equations that determine the symmetry type of the crystal and the main lattice periods. Finally, in the second order in the theory makes it possible to calculate the jump in the density on crystallization of the molten state. The proposed method of solution is valid only at temperatures above the triple point, i.e., in the region in which the crystal can be in equilibrium with the molten matter.Institute of Physical Chemistry, USSR Academy of Sciences. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 90, No. 1, pp. 113–127, January, 1992.     

Properties of MOS-structures based on anode-oxidized CdSnAs2

The properties of metal (Al, Au)-anodic oxide-CdSnAs₂ monocrystal structures are studied. It is established that MOS-structures using undoped CdSnAs₂ crystals show a high positive fixed charge in the anodic oxide (N_S 5·10¹² cm^–2) and high surface state density on the oxide-CdSnAs₂ boundary surface (N_SS 2·10¹³ cm^–2·eV^–1). In MOS-structures using diffusion-doped (copper) crystals the sign of the fixed charge is negative (N_S 10¹¹ cm^–2, N_SS 2·10¹² cm^–2·eV^–1). The latter structures show a definite photosensitivity and photomemory. The possibility of effective control of the fixed charge value within the oxide by illumination is shown. The surface state distribution over energy, time constant, and capture section is determined.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 90–93, September, 1982.