We prove that the upper general exponents of all systems in the
-class of a system of linear differential equations with conditionally periodic coefficients are the same. The relation between these ...exponents and the spectral radius of the monodromy operator of the original system is indicated.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This article considers the issues of resource conservation and integrated development of deposits, as well as their involvement in the processing of ore rocks, such as gabbro-diabase of the Bazhenov ...deposit, which has reduced the environmental burden and the costs of dumping and reclamation. Melting of gabbro-diabase of the Bazhenov deposit makes it possible to obtain a new product, i.e., basalt (rock) wool, which is a good heatproof, soundproof, and fireproof material for the construction industry. Based on this material, a unique hydroponic substrate is produced, which is widely used in agriculture. Increasing the complexity of processing mineral resources is an opportunity to obtain additional profit for the enterprise from new types of products.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•Conformations of the Cu(II) complex with chelating fluorinated ligands in a crystal and in acetonitrile solution are slightly different.•A phase transition α1 ↔ β1 in solid ...crystalline sample at 360 K occurs not instantly but during ca. 10–15 min.•Catalytic activity of the complex containing one ligand molecule is higher than activity of the initial complex with two ligands.
Structure of Cu(II) complex with chelating fluorinated ligands were studied at 298 K and 90 K using CW X-band electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT). Spin-Hamiltonian and structural parameters have been determined and the latter were compared with the X-ray data showing good similarity. A phase transition occurred at 360 K in solid crystalline sample was observed by EPR and discussed. Qualitative kinetic analysis of the catalytic behavior of Cu(II) complex upon H2O2 decomposition in acetonitrile-aqueous solutions at 313 K was studied using EPR and UV–visible spectroscopy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A high-voltage repetitively pulsed surface spark discharge propagating along the water–gas interface, when Ar is used as the gaseous medium, is studied. In the experiments, a generator with a storage ...capacitor energy of up to 1.6 J, a voltage of up to 20 kV, and a pulse duration of 2–3 μs is used. The energy characteristics of the discharge are measured as a function of its length from 40 to 140 mm. The UV radiation intensity is measured by actinometry in the wavelength range from 200 to 380 nm. It is established that the UV radiation yield along the discharge length is constant, almost independent of its length, and is directly proportional to the energy input into the discharge. The energy cost of a radiation photon is 150 eV. Quantitative estimates of the production of hydroxyl radicals depending on the length of the plasma channel and the energy input into the discharge are carried out.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Copper complex with 1,10-phenanthroline was synthesized by a partially modified method. This complex exhibited relatively high catalytic activity in the oxidation of cyclohexanol with
tert
-butyl ...hydroperoxide. The complex was characterized by CW EPR spectroscopy (X-band) at room temperature, and results were compared with calculations carried out by the density functional theory (DFT) method. Partial comparison of the EPR and DFT results with X-ray data proves our hypothesis that the structure and spectral properties of the same copper complex in solutions and in a crystalline state may be different.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The evolution of O2-producing cyanobacteria that use water as terminal reductant transformed Earth's atmosphere to one suitable for the evolution of aerobic metabolism and complex life. The ...innovation of water oxidation freed photosynthesis to invade new environments and visibly changed the face of the Earth. We offer a new hypothesis for how this process evolved, which identifies two critical roles for carbon dioxide in the Archean period. First, we present a thermodynamic analysis showing that bicarbonate (formed by dissolution of CO2) is a more efficient alternative substrate than water for O2 production by oxygenic phototrophs. This analysis clarifies the origin of the long debated "bicarbonate effect" on photosynthetic O2 production. We propose that bicarbonate was the thermodynamically preferred reductant before water in the evolution of oxygenic photosynthesis. Second, we have examined the speciation of manganese(II) and bicarbonate in water, and find that they form Mn-bicarbonate clusters as the major species under conditions that model the chemistry of the Archean sea. These clusters have been found to be highly efficient precursors for the assembly of the tetramanganese-oxide core of the water-oxidizing enzyme during biogenesis. We show that these clusters can be oxidized at electrochemical potentials that are accessible to anoxygenic phototrophs and thus the most likely building blocks for assembly of the first O2 evolving photoreaction center, most likely originating from green nonsulfur bacteria before the evolution of cyanobacteria.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
We study the existence of a conditionally periodic solution of a linear system with a Stepanov conditionally periodic inhomogeneity. We prove that if this system has a bounded solution, then almost ...every system in its
H
-class has a bounded Besicovitch conditionally periodic solution.
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CEKLJ, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The article discusses methodological problems that arise when assessing the availability indicators of NPP power units at the design stage. A description of the availability analysis process and ...indicators is provided. The downtimes of power units at NPPs with the VVER-1000 reactor in excess of the established standard are statistically evaluated. A computational model simulating the scheduled shutdown of the power unit is presented for assessing the downtime of the power unit in excess of the established repair schedule standard. The model is based on the vector-coordinate schedule synthesis method. The presented results indicate the possibility of using such a model for calculating the availability indicators of NPP power units at the design stage.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The “Operational Plan of the Baltic Sea Naval Forces in the event of the European War” dated 1912, with which the Russian Navy entered the First World War, is reviewed; the concept, operational ...structure, and tasks to the fleet units are analyzed. Strengths of the document include the principle of concentrating forces in a crucial line of action and complex use of heterogeneous forces; weaknesses are single-optionness, passive-expectant nature of actions, not quite rational operational formation of the fleet, lack of operational perspective, and poor coordination with ground forces and allies. The conclusion is made that the plan became a certain stage in the development of naval art and evidence of the creative approach to the search of forms and methods of “asymmetric” counteraction to a superior adversary. However, from the military and political point of view the document turned out to be untenable, as it was based on the only and, moreover, the least probable international political combination.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this work, we experimentally study intracavity frequency conversion of CO laser radiation in a nonlinear ZnGeP
2
crystal under noncritical phase matching. Various configurations of a laser cavity ...are considered, in one of which the nonlinear crystal itself was an output mirror. The spectrum of the converted radiation was shifted into the short-wavelength region owing to the temperature tuning of the phase matching in the nonlinear crystal. The maximum average lasing power was obtained at room temperature of the crystal and an output mirror with a transmission
T
~ 10% for the fundamental band and reached ~7.0 mW. The power ratio of sum frequency generation and the CO laser radiation was ~16%, which turned out to be higher than the value obtained earlier with the BaGa
2
GeSe
6
crystal (11.5%) at the same laser facility.
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