Explicit asymptotic velocity of the boundary between particles and antiparticles

On the real line initially there are infinite number of particles on the positive half-line., each having one of $K$ negative velocities $v_{1}^{(+)},...,v_{K}^{(+)}$. Similarly, there are infinite number of antiparticles on the negative half-line, each having one of $L$ positive velocities $v_{1}^{(-)},...,v_{L}^{(-)}$. Each particle moves with constant speed, initially prescribed to it. When particle and antiparticle collide, they both disappear. It is the only interaction in the system. We find explicitly the large time asymptotics of $\beta(t)$ - the coordinate of the last collision before $t$ between particle and antiparticle.Comment: 25 page

Raman spectroscopy of the low dimensional antiferromagnet with large Neel temperature SrRu2O6

We report results of the Raman measurements for SrRu$_2$O$_6$ having extraordinary high N$\acute{\textrm{e}}$el temperature for a layered material. No additional phonon modes were detected at the temperature of magnetic transition thus excluding lowering of the symmetry in the magnetically ordered phase. An unusual increase in softening and damping of some phonons as the temperature approaches $T_N$ indicate the appearance of a continuum of interacting electronic excitations at $T\geq300K$. We also observe an intensive Raman response at 2050 cm$^{-1}$. Analysis of the polarization dependence and comparison with available theoretical data shows that this peak likely originates from the transitions between molecular orbitals previously proposed to explain the magnetic properties of SrRu$_2$O$_6$

Effectiveness of mindfulness-based therapy, stress reduction in hypertension and prehypertension: a systematic review

Aim. To collect and analyze currently available clinical studies on the effectiveness of mindfulness-based stress reduction (MBSR) for lowering blood pressure in individuals with normal, high normal blood pressure and hypertension.Material and methods. The systematic review was prepared according to the PRISMA algorithm with minor modifications. The search algorithm included articles in Russian and English, indexed in the Pubmed/MEDLINE and Cochrane Library databases. The study included studies on the impact of mindfulness interventions on blood pressure levels in individuals aged ≥18 years with an established diagnosis of hypertension, with normal (120-129/80-84 mm Hg) and high normal office blood pressure (130-139/85-89 mm Hg).Results. A total of 4785 publications were identified and included in the study, of which, after a multistage sampling, including screening of articles, 6 studies were included in a qualitative systematic review.Conclusion. Qualitative synthesis of the results of clinical studies revealed that the evidence currently available indicates a possible positive effect of mindfulness interventions on blood pressure levels in individuals with normal, high normal blood pressure and hypertension. However, further studies with larger samples and measurement of more primary and secondary endpoints are required

Mobile applications for anxiety and stress reduction: potential for preventing noncommunicable diseases

The article discusses using mobile applications for smartphones as tools to reduce anxiety and stress. The modern views on pathogenesis of the relationship between stress, anxiety disorders and cardiovascular disease are considered. Based on a review of some representative studies, a methodology for evaluating the characteristics and functions of mobile applications for managing anxiety and stress symptoms is proposed. The applications selected for analysis were tested according to this methodology. There are following key features of the Russianlanguage field of mobile applications for anxiety and stress reduction: a small number of applications, high prevalence of using breathing exercises, meditations and sound therapy, an extremely low disease specificity and focus mainly on helping with general symptoms of anxiety

Zircon microstructures record deformation history of shock- And tectonically-generated pseudotachylites: A case study from the vredefort impact structure, South Africa

High-strain rate deformation can cause in situ melting of rocks, resulting in the formation of dark, micro- to nanocrystalline pseudotachylite veins. On Earth, pseudotachylite veins form during meteorite impacts, large landslides, and earthquakes. Within the Vredefort impact structure, both impact-generated and (pre-impact) tectonically-generated pseudotachylite veins have been described, but are challenging to distinguish. Here, we demonstrate a genetic distinction between two pseudotachylite veins from Vredefort by studying their petrography, degree of recrystallization and deformation, crosscutting relationships and the deformation microstructures in associated zircon. We conclude that Vein 1 is pre-impact and tectonically-generated, and Vein 2 is impact-generated. In agreement, zircon microstructures in Vein 1 contain planar deformation bands (PDBs), attributed to tectonic deformation, whereas zircon microstructures in Vein 2 reveal microtwin lamellae, indisputable evidence of shock metamorphism. Thus, deformation microstructures in zircon may provide a new criterion for distinguishing the genetic origin of pseudotachylite veins. Zircons that have been removed from their context (i.e., alluvial or detrital zircon, zircon from Lunar breccia) should be interpreted with caution in terms of their deformation history. For example, zircon with PDBs cannot reliably be used as a marker for shock deformation, because this feature has been shown to form in purely tectonic settings. © The Author(s) 2020.National Research Foundation, NRF: 106511, 111386, 98443This research is supported by the National Research Foundation (NRF) [grants number: 98443, 106511, and 111386, received by E.K]

Pressure-Induced Reversible Local Structural Disorder in Superconducting AuAgTe4

Here, we report results of the investigation of the lattice dynamics of the sylvanite mineral AuAgTe4 in a wide temperature and pressure range by Raman spectroscopy, together with the first-principle calculations. At ambient pressure, the experimental spectrum agrees well with the calculation data. The temperature behavior of the phonon self-energies (frequencies and linewidths) are described by an anharmonic mechanism and imply negligible contributions of electron–phonon interaction at low temperatures. A structural phase transition was recorded in the pressure range of 4–6 GPa, which is in accordance with theoretical predictions. At higher pressures, evidence of local structural disorder was found that made it possible to experimentally observe the spectrum of the density of vibrational states of AuAgTe4, which becomes superconducting under pressure. © 2023 by the authors.AAAA-A19-119071090011-6; Ministry of Education and Science of the Russian Federation, Minobrnauka: 122011300125-2, 122021000039-4This research was funded by the state assignment of the Ministry of Science and Higher Education of the Russian Federation (Theme “Electron” No. 122021000039-4). The Phonon spectra interpretation was funded within the framework of research project No. 122011300125-2. The SEM and EPMA analysis was funded within the framework of IGG UB RAS research project No. AAAA-A19-119071090011-6

THE APPROBATION OF JOINT ANALYSIS OF IMAGES (JPD-METHOD) TO STUDY THE MICRO-INHOMOGENEOUS MATERIALS

The study is devoted to approbation of the quantitative joint images analysis (JPD) for studying the micro-inhomogeneous minerals (zircon, diamond) and materials (active optical fibers, heterostructures) in order to deeper understand features of the texture, physical and chemical properties.Работа выполнена в ЦКП УрО РАН «Геоаналитик» при финансовой поддержке гранта РНФ № №19-77-00074. Авторы благодарны Киселеву П.Г. за обсуждение и реализацию JPD-метода в программном коде

A New Machine Learning Framework for Understanding the Link between Cannabis Use and First-Episode Psychosis

Lately, several studies started to investigate the existence of links between cannabis use and psychotic disorders. This work proposes a refined Machine Learning framework for understanding the links between cannabis use and 1st episode psychosis. The novel framework concerns extracting predictive patterns from clinical data using optimised and post-processed models based on Gaussian Processes, Support Vector Machines, and Neural Networks algorithms. The cannabis use attributes’ predictive power is investigated, and we demonstrate statistically and with ROC analysis that their presence in the dataset enhances the prediction performance of the models with respect to models built on data without these specific attributes

Visible light photoluminescence in TiO2/CdS nanopowders synthesized by sol-gel route: Effect of gel aging time

A series of sol-gel TiO2/CdS, TiO2 powders and coagulated CdS nanoparticles were studied by XRD, HRTEM and Raman spectroscopy to elucidate the effect of low-temperature gel aging time on visible photoluminescence (PL) emission of the TiO2/CdS composites. With an increase in aging time a content of amorphous titania and incorporated CdS nanoparticles decreases in composites. For all composites, visible PL emission includes bands attributed to surface oxygen vacancies and hydroxyl group of TiO2 nanocrystals, as well as yellow-green and red bands related to lattice defect states of CdS nanoparticles. It was found that gel aging time is a crucial parameter to influence visible PL emission in composites. This emission is suppressed with increasing aging time, and its evolution shows that healing of oxygen vacancy defects and hydroxyl group affect visible emission more significantly than improving crystallinity degree. The correlation between visible PL emission in TiO2/CdS and their visible-light photocatalytic activity was discussed. © 2020, ITMO University. All rights reserved.The research was carried out in accordance with the state assignment for ISSC UB RAS and financial support from ISSC UB RAS (theme AAAA-A19-119031890025-9). TEM study was supported by RFBR (grant No. 20-02-00906). The authors are grateful to Dr. Kozhevnikova N. S. and Dr. Gorbunova T. I. for the provided samples TiO2/CdS and CdS

Luminescence in anion-deficient hafnia nanotubes

Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronics devices. They possess a unique combination of physical and chemical properties such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric $HfO_2$ nanotubes. As-grown amorphous hafnia nanotubes and nanotubes annealed at 700{\deg}C with a monoclinic crystal lattice served as samples. It has been shown that the bandgap $E_g$ for direct allowed transitions amounts to $5.65\pm0.05$ eV for amorphous and $5.51\pm0.05$ eV for monoclinic nanotubes. For the first time, we have studied the features of the intrinsic cathodoluminescence and photoluminescence of the obtained nanotubular $HfO_2$ structures with an atomic deficiency in the anion sublattice at temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3-2.4 eV has been revealed. We have also conducted an analysis of the kinetic dependencies of the observed photoluminescence for synthesized $HfO_2$ samples in the millisecond range at room temperature. It showed that there are several types of optically active capture and emission centers based on vacancy states in the $O_{3f}$ and $O_{4f}$ positions with different coordination numbers and a varied number of localized charge carriers ($V^0$, $V^-$, and $V^{2-}$). The uncovered regularities can be used to optimize the functional characteristics of developed-surface luminescent media based on nanotubular and nanoporous modifications of hafnia.Comment: 15 pages, 6 figures, 3 tables, 50 reference