Dynamic elasticity of films formed by poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) microparticles on a water surface

Surface dilatational dynamic elasticity ε of films formed by cross-linked poly(N-isopropylacrylamide) microparticles on a water/air interface has been determined as a function of polymer surface concentration Γ. The experimental dependences exhibit two maxima of ε at surface pressures π of nearly 6 and 35 mN/m. In the region of the second maximum, the pattern of the dependence is governed by a method used to vary Γ. At π > 25 mN/m, film compression leads to the formation of a metastable monolayer, while the gradual addition of a microparticle dispersion results in the establishment of equilibrium between the monolayer and surface aggregates. In the region of π values corresponding to the second maximum of ε, slow relaxation processes with a characteristic time substantially longer than 10 s occur in the system. At π > 35 mN/m, the film collapses due to the displacement of microgel particles from the water surface.     

A luminescence immunoassay test method for determining benzo[a]pyrene in natural water

A test method is developed for determining benzo[a]pyrene in natural water, based on the use of a polyethylene filter (frit) with adsorbed specific antibodies, placed within a transparent column. In passing a test solution, the analyte is adsorbed on the frit similarly to the process implemented in immunoaffinity preconcentration. The added conjugate of a labeled analyte takes the remained vacant binding sites of antibodies. Luminescent semiconductor nanoparticles (quantum dots) CdSe/ZnS, used as labels, enable visual determination under irradiation with UV light. The limit of detection for benzo[a]pyrene in water is ~0.5 ng/mL.     

Na3V2(PO4)3/C/Ag nanocomposite materials for Na-ion batteries obtained by the modified Pechini method

Journal of Solid State Electrochemistry - Nanocomposite materials, Na3V2(PO4)3/C and Na3V2(PO4)3/C/Ag, were synthesized by a modified Pechini method. Their properties were characterized with the...     

Redox induced reactions of transition metal π- and σ,π-complexes

In this review, redox-induced reactions of π- and σ,π-complexes leading to the selective formation (or cleavage) of C–H, C–C, and C–O bonds have been summarized. To illustrate the synthetic potential of such methodology, the following representative reactions studied in our group are discussed: (1) oxidatively induced hydrogen elimination from “open” cyclic diene and dienyl complexes resulting in formation of “closed” dienyl and arene complexes, respectively; (2) reductive activation of C–H bonds in diene, vinylidene, and carbyne complexes forming new multiple C–C bonds; (3) oxidative dehydrodimerization of vinylidene complexes into binuclear μ-divinylidene species; and (4) oxidatively induced addition of oxygen nucleophiles to μ-divinylidene complexes affording cyclic μ-dicarbene derivatives. Oleg V. Gusev, deceased on October 31.     

Reactions of 1,3,2-dioxaphospholane derivatives with thiocyanatoalcohols

The reactions of 2-dimethylamino-, 2-methoxy-, 2-chloro-4,5-dimethyl-1,3,2-dioxaphos-pholanes with 4-thiocyanato-2-butanol in all cases yield 2-(1-methyl-3-thiocyanatopropoxy)-4,5-dimethyl-1,3,2-dioxaphospholane. The latter reacts with elemental sulfur to form the corresponding thiophosphate.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2130–2131, December, 1993.     

Algebra with polynomial commutation relations for the Zeeman effect in the Coulomb-Dirac field

We consider a model of particle motion in the field of an electromagnetic monopole (in the Coulomb-Dirac field) perturbed by homogeneous and inhomogeneous electric fields. After quantum averaging, we obtain an integrable system whose Hamiltonian can be expressed in terms of the generators of an algebra with polynomial commutation relations. We construct the irreducible representations of this algebra and its hypergeometric coherent states. We use these states to represent the eigenfunctions of the original problem in terms of the solutions of the model ordinary differential equation. We also present the asymptotic approximations of the eigenvalues in the leading term of the perturbation theory, where the degeneration of the spectrum is removed completely.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 142, No. 1, pp. 127–147, January, 2005.     

Synthesis of Phosphorus-substituted Amides of Acetic and Diethyl Phosphoric Acids Containing OCHN Fragments

Russian Journal of General Chemistry -     

Electrohydrodynamic instabilities inn-n +- andp-p +-junctions with a longitudinal drift current

We analyze convective instabilities of the free-carrier dynamics inn-n ⁺- andp-p ⁺-junctions with a longitudinal drift current in one of the contact layers using the hydrodynamic approximation which we formulated. State Technical University of Ul'yanovsk, Ul'yanovsk, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 11, pp. 1105–1111, November, 1999.