Alteration in the surface structure and properties of norbornene-ethylene copolymer films by direct-current discharge treatment

The effect of dc discharge on norbornene-ethylene copolymer films containing 30 and 60% norbornene was studied. It was found that plasma treatment leads to substantial changes in the surface properties of the copolymer, the enhancement of wettability, and an increase in the work of adhesion and surface energy, including its polar term. The change in the surface structure of the films was investigated by means of Fourier-transform IR spectroscopy. Transparent and colorless triplexes with a light transmission of 86–90% were prepared on the basis of the discharge-modified copolymer films and a cycloaliphatic epoxy resin.     

Critical parameters of tetraethyltin and its chlorine derivatives

Critical parameters of tetraethyltin and its chlorine derivatives were estimated by calculation methods. Reliability of the results obtained was confirmed by three independent methods.     

Polarization of block textured films of ferroelectric copolymers of vinylidene fluoride with tetrafluoroethylene in an external field

The polarization of oriented films of the ferroelectric copolymer of vinylidene fluoride and tetrafluoroethylene in a sinusoidal electric field is studied. In low fields, the copolymer behaves as a linear dielectric whose permittivity nonlinearly increases with the amplitude of the alternating field. This behavior is related to the preferential orientation of the dipole moment of the chain along the normal to the surface and to the monocrystal-structure formation. In higher fields, the hysteresis behaves formally coincidently with the behavior of an antiferroelectric. The important role of through stressed chains in the amorphous phase in the initiation of domains of a new direction in polar crystals is observed. Increased adsorption of water molecules on the surface of a polarized film is found and is attributed to the formation of the final density of the stable polarization charge on it.     

Role of the phase transition at GaN QDs formation on (0001)AlN surface by ammonia molecular beam epitaxy

Journal of Thermal Analysis and Calorimetry - We report an original method of GaN/AlN quantum dots (QDs) formation with low density by ammonia MBE on the (0001)AlN...     

Metallocenyl-containing and Unsaturated Fulleropyrrolidine Derivatives: Synthesis and Hydrogenation

Russian Journal of Coordination Chemistry - The possibility of Pd/C-catalyzed hydrogenation of ferrocenyl, cymantrenyl, and ruthenocenyl derivatives of N-methyl-2-(3-chlorovinyl)fulleropyrrolidine...     

Supersymmetric structure of Kadomtsev-Petviashvili equation: Connection between supersymmetry and Bäcklund transformations

Factorization of the Sato integrodifferential operator that gives the hierarchy of the Kadomtsev-Petviashvili equation is considered. The supersymmetric structure of this hierarchy is investigated by means of the factorization. A connection between the Miura transformations, Bäcklund transformations, and supersymmetry is established.P. N. Lebedev Physics Institute, Rossiskoi Akademii Nauk. Translated from Teorecheskaya i Matematicheskaya Fizika, Vol. 91, No. 3, pp. 426–432, June, 1992.     

Fronts,traveling fronts,and their stability in the generalized Swift-Hohenberg equation

The generalized Swift-Hohenberg equation with an additional quadratic term is studied. Time-stable localized stationary solutions of the pulse and front types are found. It is shown that stationary fronts give rise to traveling fronts, whose branches are also obtained. This study combines theoretical methods for dynamical systems (in particular, the theory of homo-and heteroclinic orbits) and numerical simulation.     

Heterocyclization of gem-dichlorocyclopropanes: “Fine tuning” of reactivity towards nitronium triflate

The heterocyclization of gem-dichlorocyclopropanes upon treatment with nitronium triflate in organic nitriles was studied and the influence of the medium on the reaction pathway was shown. While in anhydrous solvent 5-chloroisoxazole was the only product, the admixture with water promoted a three-component heterocyclization affording 4-chloropyrimidine N-oxides. This phenomenon was rationalized using DFT calculations.     

Sorption behavior and speciation of AmIII in orthophosphates of rare-earth elements

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