Russian Students’ Ideas About the Quality of Life: Transformation Under the COVID-19 Pandemic

The paper views change in Russian university students’ ideas about the quality of life during the pandemic. This empirical longitudinal study involved 107 first-year students of Kemerovo State University. To identify their ideas about the quality of life, R. S. Eliot’s Quality of Life Index was used in the Russian language adaptation by N. E. Vodopyanova. The students were surveyed at the beginning of the online learning mode (April 2020), after 8 months of online classes, and upon switching back from online learning (September 2021). The initial sampling demonstrated the students’ average extent of satisfaction with their quality of life during the lockdown. Among the problems they reported a poor ability to organize their own time, to act in difficult and changing circumstances, to control emotions. The students’ satisfaction with personal relations and studies, in general, remained high. In the autumn of 2020, a significant decrease in most indicators under study was found in the surveyed group. In September 2021, the students showed positive trends in the parameters in question

Demonstration of a parity-time symmetry breaking phase transition using superconducting and trapped-ion qutrits

Scalable quantum computers hold the promise to solve hard computational problems, such as prime factorization, combinatorial optimization, simulation of many-body physics, and quantum chemistry. While being key to understanding many real-world phenomena, simulation of non-conservative quantum dynamics presents a challenge for unitary quantum computation. In this work, we focus on simulating non-unitary parity-time symmetric systems, which exhibit a distinctive symmetry-breaking phase transition as well as other unique features that have no counterpart in closed systems. We show that a qutrit, a three-level quantum system, is capable of realizing this non-equilibrium phase transition. By using two physical platforms - an array of trapped ions and a superconducting transmon - and by controlling their three energy levels in a digital manner, we experimentally simulate the parity-time symmetry-breaking phase transition. Our results indicate the potential advantage of multi-level (qudit) processors in simulating physical effects, where additional accessible levels can play the role of a controlled environment.Comment: 14 pages, 9 figure

Characterization of collective ground states in single-layer NbSe2

Layered transition metal dichalcogenides (TMDs) are ideal systems for exploring the effects of dimensionality on correlated electronic phases such as charge density wave (CDW) order and superconductivity. In bulk NbSe2 a CDW sets in at TCDW = 33 K and superconductivity sets in at Tc = 7.2 K. Below Tc these electronic states coexist but their microscopic formation mechanisms remain controversial. Here we present an electronic characterization study of a single 2D layer of NbSe2 by means of low temperature scanning tunneling microscopy/spectroscopy (STM/STS), angle-resolved photoemission spectroscopy (ARPES), and electrical transport measurements. We demonstrate that 3x3 CDW order in NbSe2 remains intact in 2D. Superconductivity also still remains in the 2D limit, but its onset temperature is depressed to 1.9 K. Our STS measurements at 5 K reveal a CDW gap of {\Delta} = 4 meV at the Fermi energy, which is accessible via STS due to the removal of bands crossing the Fermi level for a single layer. Our observations are consistent with the simplified (compared to bulk) electronic structure of single-layer NbSe2, thus providing new insight into CDW formation and superconductivity in this model strongly-correlated system.Comment: Nature Physics (2015), DOI:10.1038/nphys352

Petrological implications of the Early Mesozoic lamprophyre dikes and related Tarkhata syenites (SE Altai and NW Mongolia)

This paper presents new data derived from field sampling and from a thorough description of lamprophyres located in southeastern Altai and northwestern Mongolia in terms of their mineralogy, textures, and chemical composition. The swarms of alkaline mafic dikes in the area coexist with granosyenite-monzodiorite and gabbro-dolerite intrusions and spatially coincide with an ore district of Sb-Hg, Ag-Sb, Ni-Co-As, Cu-Mo-W, and CaF2 hydrothermal mineralization. All lamprophyres belong to the Early Mesozoic Chuya complex formed in an intracontinental enviroment. Their distribution and orientation is controlled by two large fault zones. The Chuya dikes were investigated at two localities, namely, Yustyd and South-Chuya. The Yustyd lamprophyres intrude Middle-Upper Devonian black shale of the Yustyd depression. At South Chuya, lamprophyres, together with the Tarkhata granosyenite-monzodiorite complex, are hosted by Cambrian and Ordovician metamorphic rocks of the South-Chuya Range. Ar-Ar (phlogopite) and U-Pb (SHRIMP, zircon) ages of the lamprophyre dikes indicate long and continuous period of the formation of the Chuya complex (250-235 Ma). Major- and trace-element compositions of the lamprophyres from both localities and of the syenite indicate their origin from the same magma source. The textures and structures of the lamprophyre and plutonic rocks, their mineral assemblages and the chemistry of the rock-forming minerals provide clues to the evolution of the parental alkaline mafic magma and fluid regime

Petrological implications of the Early Mesozoic lamprophyre dikes and related Tarkhata syenites (SE Altai and NW Mongolia)

This paper presents new data derived from field sampling and from a thorough description of lamprophyres located in southeastern Altai and northwestern Mongolia in terms of their mineralogy, textures, and chemical composition. The swarms of alkaline mafic dikes in the area coexist with granosyenite-monzodiorite and gabbro-dolerite intrusions and spatially coincide with an ore district of Sb-Hg, Ag-Sb, Ni-Co-As, Cu-Mo-W, and CaF2 hydrothermal mineralization. All lamprophyres belong to the Early Mesozoic Chuya complex formed in an intracontinental enviroment. Their distribution and orientation is controlled by two large fault zones. The Chuya dikes were investigated at two localities, namely, Yustyd and South-Chuya. The Yustyd lamprophyres intrude Middle-Upper Devonian black shale of the Yustyd depression. At South Chuya, lamprophyres, together with the Tarkhata granosyenite-monzodiorite complex, are hosted by Cambrian and Ordovician metamorphic rocks of the South-Chuya Range. Ar-Ar (phlogopite) and U-Pb (SHRIMP, zircon) ages of the lamprophyre dikes indicate long and continuous period of the formation of the Chuya complex (250-235 Ma). Major- and trace-element compositions of the lamprophyres from both localities and of the syenite indicate their origin from the same magma source. The textures and structures of the lamprophyre and plutonic rocks, their mineral assemblages and the chemistry of the rock-forming minerals provide clues to the evolution of the parental alkaline mafic magma and fluid regime

Indium in cassiterite and ores of tin deposits

The results obtained with LA-ICP-MS by less abundant lighter 113In isotope and EPMA show that in cassiterite of cassiterite-quartz veins the indium contents do not exceed 160 ppm, while cassiterite from Sn-sulfide veins is characterized by higher indium contents from 40 to 485 ppm; sulfides of Sn-sulfide veins unlike sulfides of cassiterite-quartz veins also have the highest indium contents: Fe-sphalerite (100-25000 ppm), chalcopyrite (up to 1000 ppm), stannite (up to 60000 ppm). Indium contents in the Sn-sulfide ore of the Tigrinoe and Pravourmiiskoe deposits obtained using SR-XRF, ICP-MS and atomic absorption methods range from 10 to 433 ppm with average values of 56 - 65 ppm. Indium-rich Sn-sulfide mineralization in five large Sn-Ag ore districts of the Far East Russia (Khingansky, Badzhalsky, Komsomolsky, Arminsky, Kavalerovsky) provides the impetus for further exploration of deposits with Sn-sulfide mineralization as the most promising indium resources in Russia. Empirical observations from geology and geochronology of cassiterite-quartz and Sn-sulfide mineralization show that the combined contribution from granite and alkaline-subalkaline mafic sources and multistage oreforming processes doubled indium resources of deposits being the main factors in the formation of high grade indium mineralization

Indium in cassiterite and ores of tin deposits

The results obtained with LA-ICP-MS by less abundant lighter 113In isotope and EPMA show that in cassiterite of cassiterite-quartz veins the indium contents do not exceed 160 ppm, while cassiterite from Sn-sulfide veins is characterized by higher indium contents from 40 to 485 ppm; sulfides of Sn-sulfide veins unlike sulfides of cassiterite-quartz veins also have the highest indium contents: Fe-sphalerite (100-25000 ppm), chalcopyrite (up to 1000 ppm), stannite (up to 60000 ppm). Indium contents in the Sn-sulfide ore of the Tigrinoe and Pravourmiiskoe deposits obtained using SR-XRF, ICP-MS and atomic absorption methods range from 10 to 433 ppm with average values of 56 - 65 ppm. Indium-rich Sn-sulfide mineralization in five large Sn-Ag ore districts of the Far East Russia (Khingansky, Badzhalsky, Komsomolsky, Arminsky, Kavalerovsky) provides the impetus for further exploration of deposits with Sn-sulfide mineralization as the most promising indium resources in Russia. Empirical observations from geology and geochronology of cassiterite-quartz and Sn-sulfide mineralization show that the combined contribution from granite and alkaline-subalkaline mafic sources and multistage oreforming processes doubled indium resources of deposits being the main factors in the formation of high grade indium mineralization