Morphological Stability of the Solid–Liquid Interface during Melt Crystallization of Ca1–xSrxF2 Solid Solution

Crystallography Reports - Proceeding from the phase diagram of the CaF2–SrF2 system, the stability of crystal–melt interface of solid solution against constitutional supercooling has...     

Derivatives of Neopentanoic Acid Hydrazide as Reagents for Flotation Recovery of Non-Ferrous Metals

Russian Journal of Applied Chemistry - Five derivatives of neopentanoic acid hydrazide were studied and their physicochemical properties (solubility, protolytic equilibria, hydrolytic stability),...     

Synthesis and some properties of tetrakis-3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxybenzylated calix[4]resorcinols

A method for the synthesis of new calix[4]resorcinols tetra-3,5-di-tert-butyl-4-hydroxybenzyl derivatives is developed. Their interaction with methyldichlorophosphonate, dimethyldichlorosilane in the presence of a base leads to formation of organophosphorus-organosilicon cavitands. Acetylation of hydroxybenzylated calix[4]resorcinols with acetic anhydride leads to products of either incomplete or full acetylation depending on experimental conditions.     

Compositions of nanoparticles of hexagonal symmetry

The formulas for calculation of the number of atoms in nanoparticles with symmetry group D _6h are reported. The numbers of atoms are determined by six structurally invariant numbers and the “quantum number” of the group order n. Eight classes of nanostructures with symmetry group D _6h are revealed: C _{? + 12z} , where z = 0, 1, 2, …, and C _? is C ₂, C ₆, C ₈, or C ₁₄. The sum rule for the coordination numbers of all atoms of subshells related to symmetry elements is established. Two-dimensional nanoparticles are considered.     

Vyacheslav Isaakovich Vershinin (on his 60th birthday)

Chronicle

Vyacheslav Isaakovich Vershinin (on his 60th birthday)     

On the stability of a polling system with an adaptive service mechanism

We consider a single-server cyclic polling system with three queues where the server follows an adaptive rule: if it finds one of queues empty in a given cycle, it decides not to visit that queue in the next cycle. In the case of limited service policies, we prove stability and instability results under some conditions which are sufficient but not necessary, in general. Then we discuss open problems with identifying the exact stability region for models with limited service disciplines: we conjecture that a necessary and sufficient condition for the stability may depend on the whole distributions of the primitive sequences, and illustrate that by examples. We conclude the paper with a section on the stability analysis of a polling system with either gated or exhaustive service disciplines.     

Electroanalytical, dynamic, and transport properties of nonionic surfactant-selective membranes

It was found that electroanalytical properties of nonionic surfactant-selective membranes are determined by the stability, composition, solubility, and degree of dissociation of a metal-polyethoxylate-tetraphenylborate ionophore. The main trends in the potential formation in nonionic surfactant-selective electrodes were revealed based on the data on the dynamic, transport, and electrode properties of membranes. The main charge carriers at the membrane-solution interface and in the membrane phase were found. New, original, rapid, and selective methods were developed for determining nonionic surfactants in environmental samples and industrial compositions, for the separate determination of nonionic surfactants and polyethylene glycols, and for the determination of the average number of ethoxy groups in industrial samples of nonionic surfactants. Presented at the V All-Russian Conference with the Participation of CIS Countries on Electrochemical Methods of Analysis (EMA-99), Moscow, December 6–8, 1999.     

Two-fragment α-adrenolytics

A method for the synthesis of hypotensive alkyl(phenyl)[ω-(N-phenylpiperazino)alkyl]-phosphine oxides by reacting alkyl(ω-haloalkyl)phenylphosphine oxides withN-phenylpiperazine was elaborated. Phenyl[γ-(N-phenylpiperazino)propyl]propylphosphine oxide reacts with alkyl halides to give [γ-(N-alkyl-N′-phenylpiperazinio)propyl]phenyl(propyl)oxophosphine halides. For Part 1 see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 488–492, March, 2000.     

Synthesis of Copper Nanoparticles Using Hydrazine in Micellar Solutions of Sodium Dodecyl Sulfate

Moscow University Chemistry Bulletin - The influence of the synthesis conditions and composition of the reaction medium on the size and morphology of copper nanoparticles is studied for the...     

Photoelectric and electrophysical characteristics of In2S3-SiOx-Si Structures

Results are presented of the investigation of the effect of two oxidation methods of silicon (chemical and anodic) on the electrophysical properties of In₂1S₃-SiO_x-Si structures. It is shown that the change in the potential barrier height in silicon and the properties of the interface depend on the oxidation method. In the development of solar energy photoconverters, preference should be given to structures on n-type silicon with chemical oxide.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 3–6, July, 1985.