•Critical points in charge density of Bi and Sb chalcogenides are found.•Premises for charge density fluctuations in Bi and Sb chalcogenides are revealed.•Charge density fluctuations are proposed to ...be the origin of anomalous properties.•Existence of local magnetic fields in Sb2S3 is found.
Electron band structure calculations and analysis of critical points parameters in the electron density distribution in Bi2Te3, Bi2Se3, Bi2S3, α-Bi2O3, Sb2Te3, Sb2Se3 and Sb2S3 at ambient and high pressures were performed to determine interrelations between the crystal structure, unusual physical (including magnetic and superconducting) properties and peculiarities in the electron density distribution. The programming code WIEN2k was used for band structure calculations. The previously found correlation between the superconducting transition temperature Tc and the electron density Laplacian value in the bond critical point with the highest electron density was confirmed by the calculations made for crystal structures under high pressure. The revealed parameters of bond critical points indicate the significant role of charge density fluctuations in the compounds studied.
The 121, 123Sb NQR spin echo envelopes assigned to the ν1 transition (Δm = 1/2–3/2) were measured for the two crystallographic positions of Sb atoms in the Sb2S3 structure. Unexpectedly deep oscillations of NQR spin echo envelopes were observed in very small (1–3 Oe) external magnetic fields, evidencing for the existence of local magnetic fields in Sb2S3 similar to those earlier observed in bismuth oxide compounds.
Male Wistar rats aged 10 months were assigned to groups according to the initial level of systolic BP: hypertensive (systolic BP >115 mm Hg) and normotensive (systolic BP <115 mm Hg). The animals ...were injected intraperitoneally with 100 μg/kg taxifolin daily for 7 days. Systolic BP and HR were measured on the next day after single taxifolin administration and on the next day after 7-day injection course. In the group of hypertensive animals, systolic BP markedly decreased on the next day after the first injection; this decrease became even more pronounced (to the level of normotensive animals) at the end of the taxifolin course. In the group of normotensive animals, systolic BP remained unchanged. Hence, we demonstrate the possibility of course administration of taxifolin for BP normalization in hypertensive patients.
The study of buried landforms during engineering–geological surveys is considered. The necessity of tracing and comprehensively studying Quaternary channels, troughs, and other cuttings, which may ...inherit lineament zones, is shown by the example of the Balakovo NPP site, which belongs to especially hazardous and complicated engineering objects. These zones show high water permeability and weak physicomechanical properties of soils. The structural geomorphological, geological, and hydrogeological conditions at the Balakovo NPP site were investigated. Most of the data were obtained from borehole cores. Ten lineament zones, following paleocuttings in the buried relief, were identified. On the Earth’s surface, they are marked by small depressions, which are interpreted as lineaments on satellite images. The long-term geodetic observations over deformations of ground bases of NPP buildings revealed uneven deformations and tilts at the compartment units 1–4 of the reactor. The tilting direction more or less fits the location of paleocuttings filled with deposits of different composition and structure. The groundwater and confined aquifers are redistributed there, and subsurface erosion may also occur. Thus, to predict the behavior of ground bases of buildings and engineering structures, it is necessary to consider buried landforms related to the specific structure of the Quaternary alluvial soils and local variability of their physical and mechanical properties.
The work was carried out in line with the current idea of the Internet as a global media that interacts with various sign systems and influences the structural and compositional features of the ...verbal text. The relevance of the study is due to the formation of the concept of intermediality in the context of a new cultural direction, called “metavirtualism”. The aim of the article is to characterize the principles underlying the structure and composition of the network poetic “book”. Russian-language poetic cycles are considered, the structural and compositional features and expressive means of which are associated with Internet technologies. Such aspects as the type of intermediality and ways of organizing the structure and composition of the network “book” are analyzed; the reader’s way of getting acquainted with the work and the degree of freedom of this way; manifestation of the category of ephemerality. It is concluded that technological poetry, paradoxically, strengthens traditional book forms, but also has an independent value, visualizing poetic images and metaphors. Internet technologies can be “embedded” into the structure and composition of a poetry book at various levels: it can be relative autonomy; interaction at the level of a conceptual metaphor explicated with the help of Internet media (Google maps); almost complete fusion of media.
The behavior of copper ion-exchange composites with metal particles of various sizes and contents in the electroreduction of oxygen dissolved in water have been studied. The primary size effect is ...significant for samples with low metal capacity: the smaller the metal particle size, the higher the process rate. At the same time, for samples with high metal capacity, the process occurs at approximately the same rate on copper particles obtained using different reducing agents due to the comparable size. A secondary size effect is observed due to the collective interaction of metal particles. The size effect was taken into account along with the effect of the content of metal particles using the proposed nanosized complex, which represents the ratio of capacity and size. At the level of electronic conductivity percolation, the nanosized complex reaches the limiting value corresponding to the highest degree of development of the reaction surface, which makes it possible to increase the current to the maximum current capacity. The reduction of oxygen occurs along several routes: electroreduction on copper particles, mainly on the surface of nanocomposite grains; and autocatalytic chemical reaction with electroregenerated metal nanoparticles in the nanocomposite grains. The electroreduction of oxygen generally reaches an intense steady-state mode.
in the Early Iron Age
Scientific information about the natives of Crimea, in spite of more than a century of investigations, is quite limited. Perhaps the least clear in the archaeological and ...cultural-historical constructions of the Crimean societies of the final Bronze Age — Early Iron Age is still the sphere of religion and cults.
The only thing that in any way indicates the religion of the population of Crimea — is a set of symbols on ceramics, which demonstrates the dynamics of change of signs. In addition to images of signs in the culture, images of faces are also known — on a vessel from Uch-Bash and on phallic-shaped ceramic figures from the pre-Greek layer of Chersonesos.
We assume that the social order of the tribes of the younger pre-Taurian period was destroyed due to the invasion of nomads. The old economic system in the northern Black Sea coast ceased to function, contacts collapsed, and the remnants of the local tribes formed a new society, in fact, on fire and together with the remnants of other tribes. In such a situation, the beginnings of a new ideology were probably destroyed along with their bearers. The tribes adopted a primitive ideology that was not characteristic of earlier Crimean societies. Why this happened and where this ideology was borrowed from, or whether it was characteristic of the tribal Bronze Age tribes living on the peninsula, remains unclear.
In general, characterizing the tribes that inhabited the Crimea during the metal ages, only in the final of Bronze Age and turn to Iron Age and later during the emergence of Greek centres we can talk about the tribes of farmers, where the cultivation of cereals accounts for a significant share in the economy. This is important because only the agricultural tribes have a common lunar calendar, which was determined by observations of celestial bodies, and therefore needed a sanctuary-observatory. There are no signs of such sanctuaries in the Crimea. The tribes of pastoralists had simpler ways of observing the sky, which probably occurred on the basis of the movement of the sun through the firmament, embodied in temples and sacred places on certain elevations — mountains, stone remains etc., or the construction of special structures — pyramids, ziggurats, mounds, obelisks, menhirs. We observe the simplest forms of worship in the Crimea — cemeteries under mountain ranges, mounds, menhirs. Sanctuaries and cults of the pre-Taurian periods of the Kyzyl-Koba culture are not known to us, except for a small set of signs on ceramic vessels. This antropomorthous signs have earlier analogies in Eastern Mediteranian and show features of changing in ideology of native population in different lends in process of transition from the Bronze to the Iron Age. This features appearances in anthropomorthous signs. All the known sanctuaries of the Crimean Mountains dated from the Roman time and they did not connect with Kyzyl-Koba culture. The burial custom of the tribes of the Taurian period is rows of stone cists, located under the ridges of the mountains; in some graves were installed menhirs. This custom is more in line with the population with the main component of livestock in the economy. The sanctuaries of the Crimean Mountains appear in the already formed form with an established custom and have nothing similar in the rites of Kyzyl-Koba tribes.
More and more evidence is now being gathered in favour of the emergence of a completely new phenomenon for Crimea — military cults, which may be associated with a new wave of people who found themselves in the Crimea in connection with the spread of Latin cultures to the east. Preconditions, in particular, the transition of the Tauri population to the customs of the Scythian tribes, developed on the peninsula in the late 4th — early 3rd century BC. Thus, nothing contradicts the formation of syncretic military cults in the barbarian population of Crimea in the 2nd century BC and the emergence of such phenomena as the sanctuary of Gurzufske Sidlo in Roman times.
One of the main limitations of capillary electrophoresis (CE) is the sorption of basic compounds on the walls of a quartz capillary. To prevent this phenomenon in CE, supporting electrolytes with ...various additives that prevent the sorption of analytes due to the formation of dynamic coatings are commonly used. Alternatively, covalent coatings, which have a number of advantages and expand the analytical capabilities of CE, are used. The main methods of the formation of coatings covalently bound to the walls of a quartz capillary are considered.
Display omitted
•Mononuclear and binuclear Cu(II) complexes with Phen and B10Cl102− as counterion are isolated.•Electronic structure of triply-bridged complex is studied by EPR.•Non-covalent ...interactions are revealed in the triply-bridged Cu(II) complex by 35Cl NQR.
The reaction between copper(II) acetate and Phen in the presence of B10Cl102− anion affords mononuclear copper(II) complex CuPhen2(CH3CO2)2B10Cl10·CuPhen(CH3CO2)2. Continuous heating of the latter in DMSO results in triply-bridged binuclear copper(II) complex Cu2Phen2(CH3CO2)2OH2B10Cl10 isolated from the reaction solution as a DMSO solvate hydrate Cu2Phen2(CH3CO2)2OH2B10Cl10·3DMSO·0.5H2O. Both complexes are studied by IR, 11B NMR, and X-ray diffraction; the binuclear complex is studied by 35Cl NQR and EPR spectroscopies as well as X-ray powder diffraction technique. Despite the short Cu−Cu distance revealed by X-ray diffraction analysis in the binuclear cationic complex (3.234 Å), no interactions between copper atoms are detected by EPR spectroscopy. According to 35Cl NQR studies, chlorine atoms bound with equatorial boron vertices of the boron cage participate in non-covalent interactions with H atoms of Phen molecules.
Synthesis of MOF-5 at room temperature was optimized. The phase-pure crystalline structure with high hydrogen capacity was prepared at room temperature and atmospheric pressure. The MOF-5 pressing ...and subsequent fractionation singificantly improves its operation properties. An adsorption apparatus was designed and assembled to study the adsorption properties of the synthesized materials under the conditions close to the real one. Experiments on studying the adsorption properties of MOF-5 under the conditions of cryogenic hydrogen adsorption showed that the samples adsorbed up 3.3 wt % H
2
at a 30 atm pressure and –196°С.
We study the process e + e − → e + e − η ′ in the double-tag mode and measure for the first time the γ * γ * → η ′ transition form factor F η′ ( Q 2 1 , Q 2 2 ) in the momentum-transfer range 2 < Q 2 ...1 , Q 2 2 < 60 GeV 2 . The analysis is based on a data sample corresponding to an integrated luminosity of around 469 fb − 1 collected at the PEP-II e + e − collider with the BABAR detector at center-of-mass energies near 10.6 GeV.
PDF