3,203 research outputs found

    Упрочнение трибомодификацией вермикулитом

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    Приведены результаты исследований износостойкости трибосопряжения «коленчатый вал – вкладыш подшипника» судового дизеля после трибомодификации шеек вала (сталь 40Х твердостью 230 НВ) композитами на основе вермикулита. В результате модифицирования на поверхности стали формируется тонкопленочное износостойкое металлокерамическое покрытие.The results of researches of wear resistance of units of "cranked shaft – the bearing" marine diesel after tribomodification of the shaft (steel 40X with hardness 230 HB) composites based on vermiculite. In the result of the modification on the surface of the steel is formed thin-film wear-resistant ceramic-metal coating

    Nanostructural organization of naturally occurring composites - part II: silica-chitin-based biocomposites

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    Investigations of the micro- and nanostructures and chemical composition of the sponge skeletons as examples for natural structural biocomposites are of fundamental scientific relevance. Recently, we show that some demosponges (Verongula gigantea, Aplysina sp.) and glass sponges (Farrea occa, Euplectella aspergillum) possess chitin as a component of their skeletons. The main practical approach we used for chitin isolation was based on alkali treatment of corresponding external layers of spicules sponge material with the aim of obtaining alkali-resistant compounds for detailed analysis. Here, we present a detailed study of the structural and physicochemical properties of spicules of the glass sponge Rossella fibulata. The structural similarity of chitin derived from this sponge to invertebrate alpha chitin has been confirmed by us unambiguously using physicochemical and biochemical methods. This is the first report of a silica-chitin composite biomaterial found in Rossella species. Finally, the present work includes a discussion related to strategies for the practical application of silica-chitin-based composites as biomaterials

    Геопространственное распределение госпитальных ресурсов в региональных травматологических системах (обзор зарубежной литературы)

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    The review presents the results of foreign studies related to geospatial analysis and modeling of the distribution of trauma centers and helicopter emergency medical services in developed regional trauma systems. The optimal number and geographical location of the trauma centers in the region is determined taking into account the timing of the delivery of victims to the trauma centers of a high level, population density, hospitalization of patients with severe trauma, and the frequency of inter-hospital transfers. The distribution of hospital resources of the trauma system should be based on the needs of the population, and vary depending on the geographical and social characteristics of the region. В обзоре представлены результаты зарубежных исследований, касающихся геопространственного анализа и моделирования распределения травмоцентров и вертолетных баз скорой медицинской помощи в развитых региональных травматологических системах. Оптимальное количество и географическое расположение травмоцентров в регионе определяется с учетом сроков доставки пострадавших в травмоцентры высокого уровня, плотности населения, объема госпитализаций пациентов с тяжелой травмой, частоты межбольничных переводов. Распределение госпитальных ресурсов травматологической системы должно основываться на потребностях населения, варьировать в зависимости от географических и социальных особенностей региона.

    ПРЕИМУЩЕСТВА И ОПАСНОСТИ РАННЕГО ОСТЕОСИНТЕЗА БЕДРЕННОЙ КОСТИ ПРИ ПОЛИТРАВМЕ С ПОВРЕЖДЕНИЯМИ ГРУДИ

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    The review presents the results of experimental and clinical studies of the effect of early osteosynthesis in the femoral fracture on the development of systemic complications and the outcome of polytrauma with chest injuries. We explored the role of combination of thoracic injuries with a fracture of the femur, as well as its intramedullary osteosynthesis in the mechanisms of local and systemic inflammatory reaction formation, coagulopathy, fatty embolism and pulmonary embolism, respiratory failure. The concepts of “immediate total care” and “orthopedic damage control” are described with reference to fractures of the femur, combined with a chest trauma. The criteria for the relative safety of osteosynthesis of the femur in polytrauma with thoracic injuries are given.В обзоре представлены результаты экспериментальных и клинических исследований влияния раннего остеосинтеза при переломе бедренной кости на развитие системных осложнений и исхода политравмы с повреждениями груди. Рассмотрена роль сочетания торакальных повреждений с переломом бедренной кости, а также ее интрамедуллярного остеосинтеза в механизмах формирования местной и системной воспалительной реакции, коагулопатии, жировой и тромбоэмболии в легких, дыхательной недостаточности. Изложены концепции «немедленной тотальной помощи», «контроля ортопедических повреждений» применительно к переломам бедренной кости, сочетанных с травмой груди. Приведены критерии относительной безопасности выполнения окончательного остеосинтеза бедренной кости при политравме с торакальными повреждениям

    Measurement of the K+μ+νμγK^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma} decay form factors in the OKA experiment

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    A precise measurement of the vector and axial-vector form factors difference FVFAF_V-F_A in the K+μ+νμγK^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma} decay is presented. About 95K events of K+μ+νμγK^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma} are selected in the OKA experiment. The result is FVFA=0.134±0.021(stat)±0.027(syst)F_V-F_A=0.134\pm0.021(stat)\pm0.027(syst). Both errors are smaller than in the previous FVFAF_V-F_A measurements.Comment: 9 pages, 8 figure

    Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference \Delta\Gamma_s

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    We have made the first observation of Bs->Ds(*)+Ds(*)- decays using 23.6 fb-1 of data recorded by the Belle experiment running on the Upsilon(5S) resonance. The branching fractions are measured to be B(B^0_s\ra D^+_s D^-_s) = (1.0\,^{+0.4}_{-0.3}\,^{+0.3}_{-0.2})%, B(B^0_s\ra D^{*\pm}_s D^{\mp}_s) = (2.8\,^{+0.8}_{-0.7}\,\pm 0.7)%, and B(B^0_s\ra D^{*+}_s D^{*-}_s) = (3.1\,^{+1.2}_{-1.0}\,\pm 0.8)%; the sum is B(B^0_s\ra D^{(*)+}_s D^{(*)-}_s) = (6.9\,^{+1.5}_{-1.3}\,\pm 1.9)%. Assuming Bs->Ds(*)+Ds(*)- saturates decays to CP-even final states, the branching fraction determines the ratio \Delta\Gamma_s/cos(\phi), where \Delta\Gamma_s is the difference in widths between the two Bs-Bsbar mass eigenstates, and \phi is a CP-violating weak phase. Taking CP violation to be negligibly small, we obtain \Delta\Gamma_s/\Gamma_s = 0.147^{+0.036}_{-0.030}(stat.)^{+0.044}_{-0.042}(syst.), where \Gamma_s is the mean decay width.Comment: 13 pages, 2 figures, 2 tables. v2: text added for clarification, version published in Phys. Rev. Letter

    Measurement of CP violating asymmetries in B^0 -> K^+K^- K^0_S decays with a time-dependent Dalitz approach

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    We report a measurement of CPCP violating asymmetries in B0(B0)K+KKS0B^0(\overline{B}^0) \to K^+ K^- K^0_S decays with a time-dependent Dalitz approach. This analysis is based on a data sample of 657×106657\times 10^6 BBB\overline{B} pairs accumulated at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. As the result of an unbinned maximum likelihood fit to the selected candidates, the mixing-induced and direct CPCP violation parameters, ϕ1eff\phi^{\rm eff}_1 and ACP{\cal A}_{CP} are obtained for B0ϕ(1020)KS0B^0 \to \phi(1020) K^0_S, B0f0(980)KS0B^0 \to f_0(980) K^0_S and other B0K+KKS0B^0 \to K^+ K^- K^0_S decays. We find four solutions that describe the data. There are \{eqnarray*} \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (32.2 \pm 9.0 \pm 2.6 \pm 1.4)^{\circ}; \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (26.2 \pm 8.8 \pm 2.7 \pm 1.2)^{\circ};\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (27.3 \pm 8.6 \pm 2.8 \pm 1.3)^{\circ}\; {\rm and}\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (24.3 \pm 8.0 \pm 2.9 \pm 5.2)^{\circ}.{eqnarray*}\ The values for the CPCP violating phase in B0ϕ(1020)KS0B^0\to \phi(1020) K^0_S are similar but other properties of the Dalitz plot are quite different for the four solutions. These four solutions have consistent ϕ1eff\phi^{\rm eff}_1 values for all three BB meson decay channels and none of them deviates significantly from the values measured in B(ccˉ)K0B \to (c\bar{c}) K^0 decays with the currently available statistics. In addition, we find no significant direct CPCP violation.Comment: submitted to PR

    Search for CP violation in the decays D(s)+KS0π+D^+_{(s)} \to K_S^0\pi^+ and D(s)+KS0K+D^+_{(s)} \to K_S^0K^+

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    We have searched for CP violation in the charmed meson decays D(s)+KS0π+D^{+}_{(s)}\to K^0_S\pi^+ and D(s)+KS0K+D^{+}_{(s)}\to K^0_S K^+ using 673 fb1^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. No evidence for CP violation is observed. We report the most sensitive CP asymmetry measurements to date for these decays: ACPD+KS0π+=(0.71±0.19±0.20)A_{CP}^{D^+\to K^0_S\pi^+}=(-0.71\pm0.19\pm0.20)%, ACPDs+KS0π+=(+5.45±2.50±0.33)A_{CP}^{D^+_s\to K^0_S\pi^+}=(+5.45\pm2.50\pm0.33)%, ACPD+KS0K+=(0.16±0.58±0.25)A_{CP}^{D^+\to K^0_S K^+}=(-0.16\pm0.58\pm0.25)%, and ACPDs+KS0K+=(+0.12±0.36±0.22)A_{CP}^{D^+_s\to K^0_S K^+}=(+0.12\pm0.36\pm0.22)%, where the first uncertainties are statistical and the second are systematic

    Measurement of CP violating asymmetries in B^0 -> K^+K^- K^0_S decays with a time-dependent Dalitz approach

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    We report a measurement of CPCP violating asymmetries in B0(B0)K+KKS0B^0(\overline{B}^0) \to K^+ K^- K^0_S decays with a time-dependent Dalitz approach. This analysis is based on a data sample of 657×106657\times 10^6 BBB\overline{B} pairs accumulated at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. As the result of an unbinned maximum likelihood fit to the selected candidates, the mixing-induced and direct CPCP violation parameters, ϕ1eff\phi^{\rm eff}_1 and ACP{\cal A}_{CP} are obtained for B0ϕ(1020)KS0B^0 \to \phi(1020) K^0_S, B0f0(980)KS0B^0 \to f_0(980) K^0_S and other B0K+KKS0B^0 \to K^+ K^- K^0_S decays. We find four solutions that describe the data. There are \{eqnarray*} \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (32.2 \pm 9.0 \pm 2.6 \pm 1.4)^{\circ}; \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (26.2 \pm 8.8 \pm 2.7 \pm 1.2)^{\circ};\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (27.3 \pm 8.6 \pm 2.8 \pm 1.3)^{\circ}\; {\rm and}\\ \phi_1^{\rm eff}(B^0\to \phi(1020) K^0_S) & = & (24.3 \pm 8.0 \pm 2.9 \pm 5.2)^{\circ}.{eqnarray*}\ The values for the CPCP violating phase in B0ϕ(1020)KS0B^0\to \phi(1020) K^0_S are similar but other properties of the Dalitz plot are quite different for the four solutions. These four solutions have consistent ϕ1eff\phi^{\rm eff}_1 values for all three BB meson decay channels and none of them deviates significantly from the values measured in B(ccˉ)K0B \to (c\bar{c}) K^0 decays with the currently available statistics. In addition, we find no significant direct CPCP violation.Comment: submitted to PR
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