3,203 research outputs found
Упрочнение трибомодификацией вермикулитом
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
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)
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
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 decay form factors in the OKA experiment
A precise measurement of the vector and axial-vector form factors difference
in the decay is presented.
About 95K events of are selected in
the OKA experiment. The result is .
Both errors are smaller than in the previous 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
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
We report a measurement of violating asymmetries in decays with a time-dependent Dalitz approach. This analysis
is based on a data sample of pairs accumulated
at the resonance with the Belle detector at the KEKB
asymmetric-energy collider. As the result of an unbinned maximum
likelihood fit to the selected candidates, the mixing-induced and direct
violation parameters, and are obtained for
, and other 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 violating phase in are similar
but other properties of the Dalitz plot are quite different for the four
solutions. These four solutions have consistent values for
all three meson decay channels and none of them deviates significantly from
the values measured in decays with the currently
available statistics. In addition, we find no significant direct
violation.Comment: submitted to PR
Search for CP violation in the decays and
We have searched for CP violation in the charmed meson decays and using 673 fb of data
collected with the Belle detector at the KEKB asymmetric-energy
collider. No evidence for CP violation is observed. We report the most
sensitive CP asymmetry measurements to date for these decays: , , , and , 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
We report a measurement of violating asymmetries in decays with a time-dependent Dalitz approach. This analysis
is based on a data sample of pairs accumulated
at the resonance with the Belle detector at the KEKB
asymmetric-energy collider. As the result of an unbinned maximum
likelihood fit to the selected candidates, the mixing-induced and direct
violation parameters, and are obtained for
, and other 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 violating phase in are similar
but other properties of the Dalitz plot are quite different for the four
solutions. These four solutions have consistent values for
all three meson decay channels and none of them deviates significantly from
the values measured in decays with the currently
available statistics. In addition, we find no significant direct
violation.Comment: submitted to PR
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