Chemistry and thermal decomposition of trinitropyrazoles

New energetic compounds-3,4,5-1H-trinitropyrazole (TNP), 1-methyl-3,4,5-1H-trinitropyrazole (MTNP) and ammonium 3,4,5-1H-TNP have been synthesized and characterized by thermal analysis. These new compounds can be considered as promising since the high heat of formation for them. To estimate the process of their thermal decomposition, the original technique for computer simulation was used. We generated the models for the mechanisms of thermal decay of synthesized compounds which allowed obtaining comprehensive spectrum of transformations of intermediates on the way to the final products of thermolysis. The preferred pathways were determined based on the results of activation energy (E _a) calculations (DFT 6-311⁺⁺G** method) of thermal decay reactions for each generated pathways. The thermal decomposition has been studied also experimentally by thermogravimetry (TG) and differential scanning calorimetry. Kinetic parameters of thermolysis were evaluated by model-free and -fitting methods using TG data. Model-free method has given not reliable data for TNP and MTNP compounds, whereas model-fitting yields kinetic equations with the good correlation with experimental TG data.     

Preparation of Nanocomposites Based on PMMA and CdSe,CdSe/CdS Quantum Dots

Russian Physics Journal - Nanocomposites based on PMMA and CdSe, CdSe/CdS quantum dots were developed. Quantum dots (QD) of CdSe, CdSe/CdS with sizes from 2.0 nm to 4.0 nm were obtained by...     

p-adic Gibbs measures for the hard core model with three states on the Cayley tree

We study p-adic hard core models with three states on the Cayley tree. It is known that there are four types of such models. We find conditions that must be imposed on the order k of the Cayley tree and on the prime p for a translation-invariant p-adic Gibbs measure to exist.     

Weakly Periodic Gibbs Measures for HC-Models on Cayley Trees

We study hard-core (HC) models on Cayley trees. Given a 2-state HC-model, we prove that exactly two weakly periodic (aperiodic) Gibbs measures exist under certain conditions on the parameters. Moreover, we consider fertile 4-state HC-models with the activity parameter λ > 0. The three types of these models are known to exist. For one of the models we show that the translationinvariant Gibbs measure is not unique.     

Extremality of the Translation-Invariant Gibbs Measures for the Potts Model on the Cayley Tree

We study translation-invariant Gibbs measures for the ferromagnetic Potts model with q states on the Cayley tree of order k and generalize some earlier results. We consider the question of the extremality of the known translation-invariant Gibbs measures for the Potts model with three states on the Cayley tree of order k = 3.     

Solvability of nonlinear integral equations and surjectivity of nonlinear Markov operators

In the present paper, we consider integral equations, which are associated with nonlinear Markov operators acting on an infinite-dimensional space. The solvability of these equations is examined by investigating nonlinear Markov operators. Notions of orthogonal preserving and surjective nonlinear Markov operators defined on infinite dimension are introduced, and their relations are studied, which will be used to prove the main results. We show that orthogonal preserving nonlinear Markov operators are not necessarily satisfied surjective property (unlike finite case). Thus, sufficient conditions for the operators to be surjective are described. Using these notions and results, we prove the solvability of Hammerstein equations in terms of surjective nonlinear Markov operators.     

Excitation of magnetic field by Langumuir oscillations in a rotating plasma

Tadzhik State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 32, No. 4, pp. 405–410, April, 1989.     

Static Stability of a Pipeline

Technical Physics - Based on the assumption of the initial deformed shape of the pipeline without initial stresses, the critical compression force is determined. The pipeline was under the...     

Structure and complexation energy of benzotrifuroxan–benzene molecular complex

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