The spectral measure of a Jacobi matrix in terms of the Fourier transform of the perturbation

We study the spectral properties of Jacobi matrices. By combining Killip's technique [12] with the technique of Killip and Simon [13] we obtain a result relating the properties of the elements of Jacobi matrices and the corresponding spectral measures. This theorem is a natural extension of a recent result of Laptev-Naboko-Safronov [17]. The author thanks Sergei Naboko for useful discussions and Barry Simon for pointing out the conjecture.     

Synthesis and electrochemical applications of fluorinated vinylazole copolymers for monitoring NO in model and biological systems

Copolymers of 1-vinyl-1,2,4-triazole and 5-vinyltetrazole with 1,1,5-trihydrooctafluoropentyl methacrylate and 1,1,7-trihydrododecafluoroheptyl methacrylate were prepared under the conditions of radical initiation. These copolymers were used for modification of the surface of a glassy carbon electrode, and the effect of the modification on the electrochemical behavior of the electrode in anodic oxidation of dopamine and NO was studied. The possibility of enhancing the selectivity of the electrochemical sensor for monitoring NO in biological media was demonstrated.     

Electrochemical and spectral studies on the reductive nitrosylation of water-soluble iron porphyrin

The reaction of iron(III) (meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (Fe(III)TMPyP) with nitric oxide (NO) was studied by electronic absorption spectroscopy, ESR, and electrochemical and spectroelectrochemical techniques in aqueous solutions with pH from 2.2 to 12.0. Fe(III)TMPyP has been found to undergo a reductive nitrosylation in all pHs, and the product of nitric oxide binding to the porphyrin has been determined as iron(II) porphyrin nitrosyl complex ([Fe(II)(NO)TMPyP]). The rate of the reductive nitrosylation exhibits a tendency to get faster with increase in pH. An intermediate species was observed around neutral pH by spectroelectrochemical technique and was proposed to be the iron(II) nitrosyl complex of the mu-oxo dimeric form of FeTMPyP, which is known to be a predominant in neutral solutions.     

Facile one-pot synthesis of BINOL- and H8-BINOL-based aryl phosphites and their use in palladium catalysed asymmetric allylation

Novel P-monodentate aryl phosphite ligands have been synthesised in one step from (R)-BINOL, (R)-H₈-BINOL and (R)-H₈-3,3′-dibromo-BINOL. With the new aryl phosphites, up to 86% ee was observed in the asymmetric Pd-catalysed amination of 1,3-diphenyl-2-propenyl acetate with sodium diformylamide. In the enantioselective alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate, up to 97% enantioselectivity was achieved.     

Study of the stability of solid polyoxometalate Mo72Fe30 with a buckyball structure

Samples of polyoxometalate Mo₇₂Fe₃₀: [Mo₇₂Fe₃₀O₂₅₂(CH₃COO)₁₂{Mo₂O₇(H₂O)}₂ {H₂Mo₂O₈(H₂O)}(H₂O)₉₁] · ??150H₂O with a buckyball structure, which can be both crystalline and amorphous, were synthesized. It was shown that such samples can be studied by neutron diffraction. The stability of Mo₇₂Fe₃₀ to heating and UV light exposure (in poly(vinyl alcohol) and polyvinylpyrrolidone films) was studied by IR, EPR, and electronic absorption spectroscopy; thermal analysis; and mass spectrometry. Mo₇₂Fe₃₀ was found to be less stable to heating and irradiation in a poly(vinyl alcohol) film as compared with the related polyoxometallate Mo₁₃₂ free of iron. The sorption properties of Mo₇₂Fe₃₀ to organic vapors and its stability under sorption conditions were studied. It was demonstrated that, in addition to sorption, organic substances cause the destruction of buckyballs.     

Thermo-Oxidative Degradation of Hydroxypolychlorobiphenyls

Russian Journal of General Chemistry - The degradation of hydroxy derivatives synthesized from individual di-, tri-, tetra-, and pentachlorinated biphenyls as typical representatives of commercial...     

Use of Alternating-Current Plasma Torch for Processing Potentially Hazardous Substances

The decomposition of tetrachloromethane and tetrafluoromethane by air plasma in the presence of methane has been studied using an ac plasma torch of up to 500 kW power with rail electrodes. Methane reacts with air in the partial oxidation mode to form hydrogen, which reacts with a halogen to produce the hydrogen halide.     

Self-similar patterns of subsatellites formation at the capillary breakup of viscous jets

Formation of subsatellites at the capillary breakup of viscous liquid jets has been studied. The proposed analytical model qualitatively describes subsatellites formation. The obtained patterns for the formation of subsatellites’ nuclei and dynamics of their separation from a jet well agree with the results of numerical modeling.     

Synthesis of pharmacologically active hydrogels based on combined silicon and titanium polyolates

The target synthesis of new biologically active hydrogels based on combined silicon and titanium polyolates was carried out. The optimum conditions for hydrogel formation and their composition were determined. The type of hydrogels and mechanisms of gelation depend on the nature of polyols: gels based on combined silicon and titanium polyethylene glycolates are polymeric and formed via the polycondensation mechanism, whereas gels based on combined silicon and titanium glycerolates are colloidal and formed via the coagulation-condensation mechanism. The combined hydrogels based on silicon dimethyl glycerolates and titanium tetraglycerolate exhibit enhanced transcutaneous, wound healing, and regenerating activity.     

X-ray source based on a compact electron linear accelerator with a thin anode

An experiment confirming the possibility of extracting a narrow energy band from a wide spectrum produced by a compact electron linear accelerator with a thin transmission anode is described. A flat crystal of pyrolytic graphite was used as a monochromator.