278 research outputs found

    Technical and tactical training of kickboxers and the results of performances at international tournaments in tatami

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    The popularization of various kickboxing disciplines in Russia has made it possible to obtain high results in this sport. However, high rates are absent in the least traumatic types tactical training of athletes - point fights and kick-lights, the fights of which take place on the tatami.For tatami disciplines are characterized by individual actions or their combinations, performed in the framework of attacks and counterattacks. The quality of an athlete's technical and tactical readiness is reflected in the overall performance of the athlete. In this regard, it is necessary to pay attention to the technical and tactical training of athletes-kickboxers for international competition

    Features of prevention of deviant behavior of students by means of sports and recreational activities

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    The results of the study showed the necessity and effectiveness of the use of means of physical culture and recreational activities in the prevention of students' deviant behavior. In the process of use of means of physical culture and recreational activities, attention was focused on getting pleasure from students in order to interrupt their destructive and stereotypical behavioral behavior programs, for which all forms of physical exercises were used aimed at emotionally active rest, entertainment, getting satisfaction from motor activity and comfortable psycho-emotional envi-ronment in the classroo

    Centrifugal quantum states of neutrons

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    We propose a method for observation of the quasi-stationary states of neutrons, localized near the curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror Fermi-potential. This phenomenon is an example of an exactly solvable "quantum bouncer" problem that could be studied experimentally. It could provide a promising tool for studying fundamental neutron-matter interactions, as well as quantum neutron optics and surface physics effects. We develop formalism, which describes quantitatively the neutron motion near the mirror surface. The effects of mirror roughness are taken into account.Comment: 13 pages, 10 figure

    REGULATION OF PERIPHERAL B-LYMPHOCYTE DIFFERENTIATION IN RECURRENT MISCARRIAGE

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    The important role of immune disorders in recurrent miscarriage has been proven. Clarification of the character of B-lymphocyte differentiation and its regulation factors in women with threatened miscarriage and recurrent miscarriage in history is an urgent problem, since it will reveal the immune mechanisms of the pathogenesis of this pathology. Purpose: to establish the features of B-lymphocyte differentiation and factors of its regulation in women with a history of recurrent miscarriage and threatening spontaneous miscarriage at the time of examination.Were examined pregnant women aged 18-40 years at a gestation period of 5-12 weeks. The main group consisted of 60 pregnant women with a threatening spontaneous miscarriage at the time of examination and a history of recurrent miscarriage. As a control, 35 pregnant women with uncomplicated pregnancy were examined. The comparison group consisted of 25 primary pregnant women with threatened spontaneous miscarriage at the time of examination. The material for the study was peripheral venous blood. Subpopulations of B-lymphocytes CD19+, CD19+ IgD+, CD20+IgM+, CD20+IgG+ were determined by flow cytometry; CD19+CD20- CD38+, CD19+CD27- , CD19+CD27+. Serum levels of BAFF and APRIL were assessed by enzyme-linked immunosorbent assay.In the main group, an increase in the proportion of B-cells, CD20+IgM+-lymphocytes and memory cells was recorded in the peripheral blood, along with a decrease in the level of naive cells and plasma cells. In the comparison group, an increase in the proportion of immature IgM+B-cells, circulating memory cells, along with a decrease in naive B-lymphocytes, was registered. in the main group there was a pronounced decrease in the serum BAFF level compared with the control and comparison groups. Analysis of the APRIL content showed a pronounced downward trend in groups with threatened miscarriage relative to healthy pregnant women. Thus, threatening habitual and sporadic miscarriages were associated with a shift in the differentiation of B-lymphocytes towards immature forms and a lack of regulatory influence of BAFF and APRIL, which is reflected in the disruption of B-cell homeostasis and weakening of humoral effector mechanisms at the systemic level. The revealed changes may indicate a single mechanism for the development of a threatening spontaneous miscarriage, the severity of which increases with repeated loss of pregnancy. These changes can lead to an increase in effector cytotoxic mechanisms and an increase in proinflammatory cytokines, which can lead to the development of damaging reactions in the fetoplacental complex, which can be reflected in the clinical picture of the threat of termination of pregnancy

    Quantum motion of a neutron in a wave-guide in the gravitational field

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    We study theoretically the quantum motion of a neutron in a horizontal wave-guide in the gravitational field of the Earth. The wave-guide in question is equipped with a mirror below and a rough absorber above. We show that such a system acts as a quantum filter, i.e. it effectively absorbs quantum states with sufficiently high transversal energy but transmits low-energy states. The states transmitted are mainly determined by the potential well formed by the gravitational field of the Earth and the mirror. The formalism developed for quantum motion in an absorbing wave-guide is applied to the description of the recent experiment on the observation of the quantum states of neutrons in the Earth's gravitational field

    Charm production nearby threshold in pA-interactions at 70 GeV

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    The results of the SERP-E-184 experiment at the U-70 accelerator (IHEP, Protvino) are presented. Interactions of the 70 GeV proton beam with C, Si and Pb targets were studied to detect decays of charmed D0D^0, D0\overline D^0, D+D^+, DD^- mesons and Λc+\Lambda _c^+ baryon near their production threshold. Measurements of lifetimes and masses are shown a good agreement with PDG data. The inclusive cross sections of charm production and their A-dependencies were obtained. The yields of these particles are compared with the theoretical predictions and the data of other experiments. The measured cross section of the total open charm production (σtot(cc)\sigma _{\mathrm {tot}}(c\overline c) = 7.1 ±\pm 2.3(stat) ±\pm 1.4(syst) μ\mu b/nucleon) at the collision c.m. energy s\sqrt {s} = 11.8 GeV is well above the QCD model predictions. The contributions of different species of charmed particles to the total cross section of the open charm production in proton-nucleus interactions vary with energy.Comment: 4 pages, 6 pages, 38th International Conference on High Energy Physics 3-10 August 2016, Chicago, US

    Synthesis, Structure and Electrical Properties of Li+-doped Pyrochlore Gd2Zr2O7

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    Received: 08.04.2020. Accepted: 20.05.2020. Published: 30.06.2020.The pyrochlore Gd1.55Li0.45Zr2O6.55 was prepared by the solution and solidstate methods. The introduction of lithium in the Gd-sublattice led to decrease in the lattice parameter a = 10.4830(8) Å in comparison with Gd2Zr2O7 (a =10.5346(2) Å). Monitoring of the lithium content in the sample during heat treatments showed a loss of lithium at temperatures above 1100 °C, so, to maintain the stoichiometry of lithium the low temperature sintering methods are required. The sample Gd1.55Li0.45Zr2O6.55 exhibited a predominant oxygen-ion transport over a wide range of temperatures. Although doping did not lead to an increase in the oxygen-ion conductivity compared to Gd2Zr2O7, it caused the suppression of the hole conductivity.The reported study was funded by RFBR and Sverdlovsk region, project number 20‑43‑660033a

    Properties of Neutral Charmed Mesons in Proton--Nucleus Interactions at 70 GeV

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    The results of treatment of data obtained in the SERP-E-184experiment "Investigation of mechanisms of the production of charmed particles in proton-nucleus interactions at 70 GeV and their decays" by irradiating the active target of the SVD-2 facility consisting of carbon, silicon, and lead plates, are presented. After separating a signal from the two-particle decay of neutral charmed mesons and estimating the cross section for charm production at a threshold energy {\sigma}(c\v{c})=7.1 \pm 2.4(stat.) \pm 1.4(syst.) \mub/nucleon, some properties of D mesons are investigated. These include the dependence of the cross section on the target mass number (its A dependence); the behavior of the differential cross sections d{\sigma}/dpt2 and d{\sigma}/dxF; and the dependence of the parameter {\alpha} on the kinematical variables xF, pt2, and plab. The experimental results in question are compared with predictions obtained on the basis of the FRITIOF7.02 code.Comment: 9 pages, 9 figures,3 table

    Resonant Phenomena in Antihydrogen-Hydrogen Scattering

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    We present a treatment of cold hydrogen-antihydrogen collisions based on the asymptotic properties of atom-antiatom interactions. We derive general formulas for the elastic and inelastic cross sections and for the scattering lengths and analyze their sensitivity to the parameters characterizing the inelasticity of the collision process. Given the inelasticity, we obtain bounds for the complex scattering length. We investigate the influence of strong nuclear forces and the isotope effects in HˉH\bar{\rm H}{\rm H} and HˉD\bar{\rm H}{\rm D} collisions and demonstrate enhancement of these effects due to the presence of the near-threshold narrow HHˉ{\rm H}\bar{\rm H} (HˉD\bar{\rm H}{\rm D}) states. The values of the elastic and inelastic cross-sections with simultaneous account of rearrangement and strong forces are presented. General expressions for the (complex) energies of the near-threshold HHˉ\rm{H}\bar{\rm H} states are obtained.Comment: 26 pages 7 figure
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