Shock waves in gas flows with nanoparticles

Journal of Thermal Analysis and Calorimetry - The paper focuses on the analytical analysis of the propagation of a normal shock wave in an adiabatic gas flow with nanoparticles. A modified...     

Model of Dynamics of the IBR-2M Pulsed Reactor with Temperature and Power Fast Feedback Effects

Physics of Atomic Nuclei - A model of dynamics with separate temperature feedback formed by average temperatures of the fuel and the coolant is constructed for the IBR-2M pulsed reactor of periodic...     

The Estimation of Parameters for the Tapered Pareto Distribution from Incomplete Data

Lithuanian Mathematical Journal - In this paper, we consider estimation of unknown parameters of the tapered Pareto distribution, which belongs to the class of semiheavy distributions, by a sample...     

Structural and phase characteristics of the diamond/matrix interfacial zone in high-resistant diamond composites

The structural-phase state of the contact zone and the factors that influence on the strength of diamond retention in the diamond carbide composites were determined. Composites were obtained by the new hybrid technology that eliminates the reheating of the metalized coating. The elaborated technology combines the thermal diffusion metallization of a diamond and the sintering by the scheme of self-dosed impregnation in a one-stage technological cycle. By the methods of electron microscopy, X-ray diffraction analysis, and Raman spectroscopy the structural and phase characteristics of the interphase boundary were investigated. The improvement of chemical and mechanical adhesion between the diamond and carbide matrix was obtained. It was shown that the specific productivity of the samples with a metalized diamond component is 39% higher than those without metallization.     

A generalization of Serre’s condition $$\mathrm {(F)}$$ ( F ) with applications to the finiteness of unramified cohomology

Mathematische Zeitschrift - In this paper, we introduce a condition ( $$\mathrm {F}_m'$$ ) on a field K, for a positive integer m, that generalizes Serre’s condition (F) and which still...     

Chromium complexes based on thiophene–imine ligands for ethylene oligomerization

A new set of Cr(III) complexes, {L}CrCl₃(THF), based on thiophene–imine ( 2a , L = PhOC₆H₄(N═CH)‐2‐SC₄H₃; 2b , L = PhOC₂H₄(N═CH)‐2‐SC₄H₃; 2c , L = Ph(NH)C₂H₄(N═CH)‐2‐SC₄H₃; 2d , L = PhOC₆H₄(N═CH)‐2‐SC₄H₂‐5‐Ph; 2e , L = Ph(NH)C₂H₄(N═CH)‐2‐SC₄H₂‐5‐Ph) have been prepared and characterized using elemental analysis and infrared spectroscopy. Upon activation with methylaluminoxane, all the chromium complexes generated active systems affording a nonselective distribution of α‐olefins with turnover frequencies in the range 9500–93 500 (mol ethylene) (mol Cr)^?1 h^?1, and producing mostly oligomers (95.0–99.3 wt% of total products). Small amounts of polymer were produced in these oligomerization reactions (0.8–8.2 wt%). The catalytic activities were quite sensitive to the ligand environment. Moreover, the effects of oligomerization parameters (temperature, [Al]/[Cr] molar ratio, time) on the activity and on the product distribution were examined.     

Exactly solvable chain of interacting electrons with correlated hopping and pairing

A generalization of the Mattis-Nam model Mattis and Nam (1972) [7], which takes into account a correlated hopping and pairing of electrons, is proposed, its exact solution is obtained. In the framework of the model the stability of the zero energy Majorana fermions localized at the boundaries is studied in the chain in which electrons interact through both the on-site Hubbard interaction and the correlated hopping and pairing. The ground-state phase diagram of the model is calculated, the region of existence of topological states is determined. It is shown that low-energy excitations destroy bonds between electrons in the chain, leading to an insulator state.     

Trimetallic NiCoM catalysts (M = Mn,Fe, Cu) for methane conversion into synthesis gas

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Structure,Spectral Properties,and Complexing Ability of 1-Phenyl-3-methylpyrazol-5-one Ferrocenoyl Hydrazone

A potentially tridentate coordinating chelating ligand system, 1-phenyl-3-methylpyrazol-5-one ferrocenoylhydrazone, has been synthesized. Structure of the obtained ligand and its equilibrium forms in the solution has been elucidated from the data of elemental analysis, IR, electronic absorption and NMR (1H, 13C, and 15N NMR including 1H–1H COSY, 1H–1H NOESY, 1H–13C HSQC, 1H–13C HMBC, and 1H–15N HMBC 2D correlation techniques) spectroscopy as well as quantum chemistry methods. The reactions of 1-phenyl-3-methylpyrazol-5-one ferrocenoylhydrazone with selected transition metal ions have afforded metal chelates, their composition, the mode of coordination, and type of tautomeric form of the coordinated ligand being dependent on the metal nature.