Preparation method for noble metal-polymer matrix nanocomposites

A method is described for the preparation of new nanocomposites based on poly(ethylene terephthalate), poly(vinyl chloride), and polypropylene on the one hand and on noble metals (Ag and Pt) on the other. The method comprises the formation of nanoporous polymer matrices by crazing the polymers with simultaneous incorporation of noble metal precursors (AgNO₃ or H₂PtCl₆) into the matrices. Subsequent in situ reduction of the precursors yields the metal-polymer nanocomposites. Prospects for the practical application of the developed method for the production of metal-polymer nanocomposites are discussed.     

On the Gerber-Shiu function for a risk model with multi-layer dividend strategy

In this paper, we present a new approach to the study of the Gerber-Shiu discounted function for the risk model with multi-layer dividend strategy. The formulae for the Gerber-Shiu discounted function and ruin probability were obtained and the special case where the claim size distribution is a combination of exponentials is considered in detail.     

A Simple and Efficient Synthesis of Ethyl 1‐Aryl‐4‐formyl‐1H‐pyrazole‐3‐carboxylates

A new simple and convenient method of synthesis of ethyl 1‐aryl‐4‐formyl‐1H‐pyrazole‐3‐carboxylates from aromatic amines via diazonium salts has been developed. Hydrolysis and hydrazinolyization of these compounds has been investigated.     

Polymerization-induced phase separation in gradient copolymers

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Quasi-linearization and stability analysis of some self-dual,dark equations and a new dynamical system†

We describe a class of self-dual dark nonlinear dynamical systems a priori allowing their quasi-linearization, whose integrability can be effectively studied by means of a geometrically based gradient-holonomic approach. A special case of the self-dual dynamical system, parametrically dependent on a functional variable is considered, and the related integrability condition is formulated. Using this integrability scheme, we study a new self-dual, dark nonlinear dynamical system on a smooth functional manifold, which models the interaction of atmospheric magneto-sonic Alfvén plasma waves. We prove that this dynamical system possesses a Lax representation that allows its full direct linearization and compatible Poisson structures. Moreover, for this self-dual nonlinear dynamical system we construct an infinite hierarchy of mutually commuting conservation laws and prove its complete integrability.     

Novel Selected Tandem Transformations of the Amino and Carbonyl/Nitrile Groups in the Gewald Thiophenes

Novel transformations of the amino and carbonyl/nitrile groups in the Gewald thiophenes were studied for thienopyrimidine synthesis. It was found that 2-amino-thiophene-3-carboxamides and ethyl 2-(acetylamino)-4,5,6,7-tetrahydro-1-benzothiophene-3-carbo- xylate did not yield tetrazole derivatives, neither in the reaction with triethyl orthoformate and sodium azide, nor in the reaction with phosphorus oxychloride and sodium azide, correspondingly. On the contrary, derivatives of thieno[2,3-d]pyrimidin-4(3H)-one and thieno[2,3-d][1,3]oxazin-4-one were isolated. New 2-azidothiophenes [2-azido-4,5,6,7-tetra hydro-1-benzothiophene-3-carbonitrile and 2-azido-4,5,6,7-tetrahydro-1-benzothiophen-3-yl(phenyl)methanone] were synthesized and used in anionic domino reactions with activated acetonitriles to yield thieno[3,2-e][1,2,3]triazolo[1,5-a]pyrimidines and/or 2-(5-amino-1H-1,2,3-triazol-1-yl)thiophenes. Finally, a new ring system of thieno[3,2-e]pyrazolo[1,5-a]pyrimidine was synthesized via a domino reaction of ethyl 2-[(2Z)-2-(1-chloro-2-ethoxy-2-oxoethylidene)hydrazino]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate with activated acetonitriles.     

Adsorption of ammonia on graphite oxide/Al13 composites

Graphite oxide/Al₁₃ composites were prepared using graphite oxide and commercial solution of Chlorhydrol^®. Although surfactant was used to disperse of graphene-like layers, they were restacked together upon addition of Al₁₃ Keggin polycations. The crust of inorganic phase was deposited on the outer surface of GO platelets. The resulting materials were used as adsorbents of ammonia in dry or wet conditions either in an as received form or prehumidified for 2 h before the breakthrough test. It was shown that water in the system decreases the amount adsorbed, likely as a result of the competition with ammonia for adsorption centers. The highest and strongest adsorption was found in the dry conditions where interlayer space was partially available and the acidic centers of an inorganic phase played an enhancing role in the retention of ammonia.