(O-Si)-Chelate acetic and benzoic acid N-(fluorosilylmethyl)amides: synthesis and structure

Russian Chemical Bulletin - New representatives of (O-Si)-chelate compounds, N-(fluorosilyl)methyl derivatives of N-methylacetamide, N-methylbenzamide, N-phenylacetamide, and N-phenylbenzamide,...     

(Chloromethyl)alkoxyhalogenosilanes in Reaction with N-Trimethylsilyl-N-methylacetamide

Russian Journal of General Chemistry - The reaction of N-trimethylsilyl-N-methylacetamide with polyfunctional silanes, namely methyl(chloromethyl)alkoxychlorosilanes and...     

Silacyclophanones 3*. Cyclic organosilicon esters of ortho-phthalic acids

Chemistry of Heterocyclic Compounds - Reactions of dichlorodimethylsilane with 2,3,4,5-tetrafluorophthalic acid bis(trimethylsilyl) ether (1:1, 20°C, 24 h) without a solvent and...     

Structure-phase transformation in surface layers of hard alloy as a result of action of high-current electron beams

This work discusses the influence of pulse action by low-energy high-current electron beams on the structure-phase state of near-surface layers of T15K6 hard alloy. It is found that, upon an increase in energy density as a consequence of melting of the alloy carbides, there occurs formation of tungsten saturated hard alloy (Ti, W)C and the transformation WC → W₂C upon crystallization. Depending on the radiation mode, there occurs formation of a cellular (typical for “explosive” crystallization) or dendrite structure of the surface. These structure-phase transformations result in up to a threefold increase in the microhardness of the surface of the irradiated material.     

Unusual crystal and molecular structure of the 1-(1-silatranylmethyl)-3,5-dimethylpyrazole complex with zinc dichloride

The crystal and molecular structure of a 1-(1-silatranylmethyl)-3,5-dimethylpyrazole complex with zinc dichloride (I) is determined by XRD. The coordination polyhedron of the zinc atom is a tetrahedron formed by two covalent Zn-Cl bonds and coordination Zn ← N and Zn ← O bonds. Compound I is the first example of how an endocyclic oxygen atom of the silatranyl fragment participates in the coordination of the metal atom with the formation of a six-membered heterocycle.     

Group theoretical description of a spatial region of particle collisions

The complete set of states of a detected particle is discussed in which the role of quantum dynamic characteristics is played by the coordinates of the spatial region where this particle has been produced. The function of distribution over these coordinates is an important physical characteristic of the medium where the particle is produced. It is intimately related to the spatial structure of the colliding particles and nuclei, to the problem of deconfinement, if it happens, and also to the nature of the quark-gluon plasma. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 92–96, March, 2008.     

Interphase interaction at indium phosphide contacts with metals of group I

The interphase interaction at indium phosphide contacts with layers of metals of group I (Cu, Ag, Au) annealed in an atmosphere of oxygen is investigated using the method of Rutherford backscattering, x-ray structure analysis, and electrophysical measurements. The relation between the character of the interphase process and the behavior of the electrophysical parameters of the Schottky barriers is traced. The mechanism of degradation in the contacts mentioned is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 8–13, January, 1986.     

Spatial description of the particle production region in elastic and quasi-elastic processes on the <Emphasis Type="Italic">SO</Emphasis><Subscript>μ</Subscript> (2.1) group

The group-theoretical generalization of the impact parameter for elastic A + B → A + B processes is considered and analyzed in the work. The generalized impact parameter is identified with the vector of the closest approach of two particles. It is shown that after the procedure of standard quantization the components of the impact parameter’s vector, together with the components of the relative orbital’s angular momentum form SO(3.1) algebra from which we identify the SO(2.1) subalgebra. The spectrum of the Casimir operator for this subalgebra defines the allowed values of the impact parameter squared. The expansion coefficients of the elastic amplitude as a function on the SO(2.1) group define the profile function; an analogue of the partial wave on the O(3) group. The expansion itself is the generalization of the eikonal representation of the amplitude and is valid in the entire range of scattering angles. It also correctly describes the region of small impact parameters. The unitarity equation for the amplitude is solved and, as a consequence, the algebraic equation for the profile function, local in the impact parameter, is obtained. The simplest phenomenological models for cross sections (total, elastic, and inelastic) are analyzed in the framework of the solutions obtained. The next step in the development of the group-theoretical approach proposed in the work is associated with construction of a complete orthonormal basis in the one-particle Fock space where the particle is characterized by a particular energy and a particular value of its “impact parameter” relative to a point “O”. This point is related to the target particle’s coordinate (in the laboratory reference frame) or the beam’s collision point (center-of-mass system). This formalism allows for obtaining the relation between the escape parameter’s distribution function of particle C in the A + B → C + D process and the corresponding production amplitude of this particle in an angular interval. The resulting distribution function provides important physical information on the spatial structure of the production region of particle C.     

Formation of composite scaffolds based on chitosan and calcium phosphate

Composite materials based on chitosan and calcium phosphates with the structure and properties close to those of natural human tissues were developed. The possibility of formation of biological apatite, i.e., octacalcium phosphate, was demonstrated. The increase in the strength characteristics was caused by crystallization of the octacalcium phosphate phase on the surface of the material pore space. The materials resemble the extracellular matrix of the body in their structure and composition and can find wide use in the regenerative medicine as a scaffold for osteogenic factors.     

Thin films of palladium oxide for gas sensors

Thin films of PdO obtained by thermal oxidation of Pd films in air in the temperature range of 240–800°C were characterized using fast electron diffraction, transmission electron microscopy, and optical spectroscopy. The PdO films were found to be non-stoichiometric. With increasing oxidation temperature, the deviation of the PdO film composition from the stoichiometric component ratio becomes less pronounced. The resistivity response of PdO films to the presence of ozone in air was studied for the first time and good prospects for using this material for gas sensors are demonstrated.