443 research outputs found
Neural Mechanisms of Temporal and Rhythmic Structure Processing in Non-Musicians
Music is increasingly being used as a therapeutic tool in the field of
rehabilitation medicine and psychophysiology. One of the main key components of
music is its temporal organization. The characteristics of neurocognitive
processes during music perception of meter in different tempo variations
technique have been studied by using the event-related potentials technique.
The study involved 20 volunteers (6 men, the median age of the participants was
23 years). The participants were asked to listen to 4 experimental series that
differed in tempo (fast vs. slow) and meter (duple vs. triple). Each series
consisted of 625 audio stimuli, 85% of which were organized with a standard
metric structure (standard stimulus) while 15% included unexpected accents
(deviant stimulus). The results revealed that the type of metric structure
influences the detection of the change in stimuli. The analysis showed that the
N200 wave occurred significantly faster for stimuli with duple meter and fast
tempo and was the slowest for stimuli with triple meter and fast pace
Robust bifunctional aluminium-salen catalysts for the preparation of cyclic carbonates from carbon dioxide and epoxides
Abstract Two new one-component aluminium-based catalysts for the reaction between epoxides and carbon dioxide have been prepared. The catalysts are composed of aluminium-salen chloride complexes with trialkylammonium groups directly attached to the aromatic rings of the salen ligand. With terminal epoxides, the catalysts induced the formation of cyclic carbonates under mild reaction conditions (25-35 °C; 1-10 bar carbon dioxide pressure). However, with cyclohexene oxide under the same reaction conditions, the same catalysts induced the formation of polycarbonate. The catalysts could be recovered from the reaction mixture and reused. 161
Native and graphene-coated flat and stepped surfaces of TiC
Titanium carbide attracts growing interest as a substrate for graphene growth and as a component of the composite carbon materials for supercapacitors, an electrode material for metal-air batteries. For all these applications, the surface chemistry of titanium carbide is highly relevant and being, however, insufficiently explored especially at atomic level is a subject of our studies. Applying X-ray photoelectron spectroscopy (XPS) to clean (111) and (755) surfaces of TiC, we were able to obtain the detailed spectroscopic pattern containing information on the plasmon structure, shake up satellite, the peak asymmetry and, finally, surface core level shift (SCLS) in C 1s spectra. The latter is essential for further precise studies of chemical reactions. Later on, we studied interface between TiC (111) and (755) and graphene and found the SCLS variation due to strong chemical interaction between graphene and substrate. This interaction is also reflected in the peculiar band structure of graphene probed by angle-resolved photoelectron spectroscopy (ARPES). Based on LEED data the structure is close to (7√3 × 7√3)R30°, with graphene being slightly corrugated. We found that similarly to the graphene on metals, the chemical interaction between graphene and TiC can be weakened by means of intercalation of oxygen atoms underneath graphene.We thank Helmholtz-Zentrum Berlin (HZB) for the allocation of synchrotron radiation beamtimes at the Russian-German and UE112-PGM2 beamlines. The work was financially supported by the Russian Science Foundation (project 16-42-01093). DFT calculations were performed at “Lomonosov” MSU supercomputer.Peer reviewe
Construction and On-site Performance of the LHAASO WFCTA Camera
The focal plane camera is the core component of the Wide Field-of-view
Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air
Shower Observatory (LHAASO). Because of the capability of working under
moonlight without aging, silicon photomultipliers (SiPM) have been proven to be
not only an alternative but also an improvement to conventional photomultiplier
tubes (PMT) in this application. Eighteen SiPM-based cameras with square light
funnels have been built for WFCTA. The telescopes have collected more than 100
million cosmic ray events and preliminary results indicate that these cameras
are capable of working under moonlight. The characteristics of the light
funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate,
assembly techniques). In this paper, we present the design features,
manufacturing techniques and performances of these cameras. Finally, the test
facilities, the test methods and results of SiPMs in the cameras are reported
here.Comment: 45 pages, 21 figures, articl
Amidinate Aluminium Complexes as Catalysts for Carbon Dioxide Fixation into Cyclic Carbonates
A series of inexpensive and sustainable amidinate aluminium complexes has been developed as catalysts for the chemical fixation of carbon dioxide into cyclic carbonates. The reactions using terminal epoxides as substrates were carried out at room temperature and one bar of carbon dioxide pressure in the presence of tetrabutylammonium iodide as cocatalyst in the absence of solvent. Under these reaction conditions, excellent conversions and selectivities were achieved for a broad range of terminal epoxides. Moreover, the optimal catalyst could be used for the synthesis of disubstituted cyclic carbonates from internal epoxides and carbon dioxide, highlighting the potential of these amidinate aluminium complexes as catalysts
Features of the Soil Cover of the Semi-Desert Ecotone in the South of the Volga Upland
The semi-desert ecotone of the south of the Volga Upland is part of the zonal macroecotone bordering the Eastern European steppes from the southeast. Under strained hydrothermal conditions, the microrelief plays a decisive role in the redistribution of atmospheric moisture. This article contains materials from 10-year studies of the soil and landscape cover of the contact zone of the south of the Volga Upland and the northern end of Ergeni. The so-called three-membered complex described 100 years ago by N.A. Dimo and B.A. Keller is not traced in the soil cover. The methodology of landscape-catenary sections was used by laying soil-geomorphological profiles and drilling wells with subsequent sampling of soils at 5 test sites. The soil cover of the watersheds of the sites is represented by complexes of light chestnut low-humic weakly alkalinized medium- and heavy-loam soils. A smaller area is occupied by meadow-chestnut soils of cavities and solonets. The structure of the soil cover of the slopes includes combinations and variations that transform into mesocatenes. In the mesocatene of balkas, zonal light chestnut turn into metamorphosed meadow-chestnut soils or drift dark-colored soils of the bottom of balkas. The semi-desert ecotone is almost completely located within the boundaries of the spread of light chestnut soils in Volgograd region. The structure of the soil cover of the ecotone is dominated by a twofold complex, where zonal light chestnut soils in combination with meadow-chestnut soils of cavities and solonets.</jats:p
Ecological and Economic Aspects of Land Desertification
Agricultural lands of the Russian Federation are intensively subjected to degradation and desertification as a result of irrational economic activity, which, against the background of unfavorable climatic factors, led to the destruction of natural ecosystems, degradation of the soil cover and ultimately to the creation of the unfavorable ecological environment. About 65 % of 130 million hectares of arable land, are exposed to water and wind erosion. Only by water erosion, 10 % of arable land lost 30–60 % of fertility and almost 25 % lost 10–30 %. As a result of deflation 25million hectares of agricultural land in the European part of the Russian Federation are degraded to varying degrees. The concept of the anti-degradation arrangement proposes to use environmental-economic geoinformational monitoring. Within the framework of this approach, the development of cartographic and mathematical models in three time environments is proposed: pre-agricultural, modern degraded, and certainly improved condition. The ecological and economic analysis makes it possible to synthesize information flows and analyze the most important degradation processes. The most important tool for implementing ther adaptive-landscape anti-degradation arrangement of agricultural landscapes is precision farming, which consists of several subsystems: decision-making, monitoring, agronomic techniques, specialized equipment, etc. Computer technologies and telecommunications allow to speed up and optimize production by combining technology and people, which helps reduce costs. Precision agriculture is impossible without using modern advances in collecting, processing and storage of various, often heterogeneous, agricultural information.</jats:p
Assembly of Trifluoromethylated Morpholines through Cascade Reactions of Bromoenones with Secondary Amino Alcohols
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