On automorphisms of a distance-regular graph with intersection array 44, 30, 5; 1, 3, 40

Prime divisors of orders of automorphisms and the fixed point subgraphs of automorphisms of prime orders are studied for a hypothetical distance-regular graph with intersection array 44, 30, 5; 1, 3, 40. Let G = Aut(Γ) is nonsolvable group. If Γ is arc-transitive then G is is an extension of some group P by PGL2(11), |P: O3(P)| = 2, |Ga: Pa| = 11 and |P: Pa| = 9. © 2019, Sobolev Institute of Mathematics

On graphs whose local subgraphs are strongly regular with parameters (144, 39, 6, 12)

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Measurement of Time Resolution of Scintillation Detectors with EQR-15 Silicon Photodetectors for the Time-of-Flight Neutron Detector of the BM@N Experiment

To study the dependence of the equation of state of high density nuclear matter on the term characterizing the isospin (proton-neutron) asymmetry of nuclear matter, it is necessary to measure azimuthal flow of neutrons as well as azimuthal flow of charged particles from a dense nuclear matter in the nuclear-nuclear collisions. For this purpose INR RAS is developing a new high-granular neutron detector which will be used in the BM@N experiment at the extracted beam of the Nuclotron accelerator at JINR (Dubna). This detector will identify neutrons and measure their energies in the heavy-ion collisions up to 4 GeV per nucleon. This article presents the results of measurements of the time resolution and light yields of samples of scintillation detectors with sizes 40$\times$40$\times$25 mm$^3$ that will be used in a neutron detector based on the currently available fast plastic scintillator manufactured by JINR using an EQR15 11-6060D-S photodetector for light readout. For comparison, the results of measurements for a detector of the same size with a fast scintillator EJ-230 and with the same type of photodetector are given. The measurements were made on cosmic muons as well as on the electron synchrotron "Pakhra" of the Lebedev Physical Institute of the Russian Academy of Sciences located in Troitsk, Moscow

Automorphisms of distance regular graph with intersection array 30, 27, 24; 1, 2, 10

Prime divisors of orders of automorphisms and the fixed point subgraphs of automorphisms of prime orders are studied for a hypothetical distance-regular graph with intersection array 30, 27, 24; 1, 2, 10. Let G = Aut(Γ) is nonsolvable group, G = G=S(G) and T is the socle of G. If Γ is vertex-symmetric then (G) is f2g-group, and T ≅= L2(11),M11,U5(2),M22,A11,HiS. © 2019, Sobolev Institute of Mathematics

Interplay of p-d and d-d charge transfer transitions in rare-earth perovskite manganites

We have performed both theoretical and experimental study of optical response of parent perovskite manganites RMnO_3 with a main goal to elucidate nature of clearly visible optical features. Starting with a simple cluster model approach we addressed the both one-center (p-d) and two-center (d-d) charge transfer (CT) transitions, their polarization properties, the role played by structural parameters, orbital mixing, and spin degree of freedom. Optical complex dielectric function of single crystalline samples of RMnO_3 (R=La, Pr, Nd, Sm, Eu) was measured by ellipsometric technique at room temperature in the spectral range from 1.0 to 5.0 eV for two light polarizations: E \parallel c and E \perp c. The comparative analysis of the spectral behavior of \varepsilon _1 and \varepsilon _2 is believed to provide a more reliable assignment of spectral features. We have found an overall agreement between experimental spectra and theoretical predictions based on the theory of one-center p-d CT transitions and inter-site d-d CT transitions. Our experimental data and theoretical analysis evidence a dual nature of the dielectric gap in nominally stoichiometric matrix of perovskite manganites RMnO_3, it is formed by a superposition of forbidden or weak dipole allowed p-d CT transitions and inter-site d-d CT transitions. In fact, the parent perovskite manganites RMnO_3 should rather be sorted neither into the CT insulator nor the Mott-Hubbard insulator in the Zaanen, Sawatzky, Allen scheme.Comment: 20 pages, 6 figure

Integrated approach to the treatment of primary brain tumors

This work is aimed to assess the variants and treatment effectiveness of the patients with primary brain tumors being hospitalized in Sverdlovsk regional oncologic dispensary, as well as factors determining the disease prognosis. The analysis of the survival rate reveals that it is greater in woman comparing to men, in younger patients to older ones, and in lower grade brain tumors to high grade tumors. Management of primary brain tumors requires complex approach and common algorithm for treatment taking prognostically significant factors (grade, spreading of the disease in brain, gender, age) into consideration.В данной работе оценены варианты и результаты лечения больных с первичными опухолями головного мозга, госпитализировавшихся в Свердловский областной онкологический диспансер. Определены факторы определяющие прогноз течения заболевания. При анализе выявлено, что выживаемость больше у женщин сравнительно с мужчинами, у молодых пациентов относительно более старших, и с меньшей степенью злокачественности опухолей. Лечение пациентов требует комплексного подхода и общий алгоритм, основанный на оценке прогностически значимых факторов (пол, возраст, степень злокачественности) совместно