332 research outputs found

    The magnetic field influence on magnetostructural phase transition in Ni2.19Mn0.81Ga

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    Magnetic properties of a polycrystalline alloy Ni2.19_{2.19}Mn0.81_{0.81}Ga, which undergoes a first-order magnetostructural phase transition from cubic paramagnetic to tetragonal ferromagnetic phase, are studied. Hysteretic behavior of isothermal magnetization M(H)M(H) has been observed in a temperature interval of the magnetostructural transition in magnetic fields from 20 to 100 kOe. Temperature dependencies of magnetization MM, measured in magnetic fields H=400H = 400 and 60 kOe, indicate that the temperature of the magnetostructural transition increases with increasing magnetic field.Comment: Presented at the Second Moscow International Symposium on Magnetism (Moscow-2002

    Особенности выделения передних большеберцовых сосудов при формировании костных васкуляризированных трансплантатов

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    Background. The currently existing techniques for dissection the anterior tibial vascular bundle in the proximal third of the lower leg do not provide sufficient length of the vascular pedicle to rotate the tibial bone graft to the level of the middle third of the thigh. The aim of the study to substantiate the possibility of pedicled transfer to the level of the thigh middle third of two blood-supplied bone autografts on a common permanent pedicle, including the anterior tibial vascular bundle. Material and Methods. The study was conducted on 62 lower limbs of non-fixed (native) corpses. We studied the topographic and anatomical relationship between the anterior tibial vascular bundle and the deep peroneal nerve at the level of the proximal third of the leg. Results. The distance between the tip of the greater trochanter of the femur and the distal edge of the anterior tibial bone graft using a combination of grafts at the same level in men was Me 176.7 [173.7; 193.9] mm, in women Me = 151.6 [146.9; 159.9] mm. An analysis of limb lengths ratios in men and women indicates standard level that can be achieved with graft rotation in each person. Conclusion. Dissection of the anterior tibial vascular bundle at the level of the proximal third of the lower leg allows rotation of the complex of the anterior tibial bone autograft and the autograft of the second metatarsal bone into the area of the middle third of the femur on a single vascular bundle. Prevention of injury to the deep peroneal nerve branches during dissection of the vascular pedicle requires the use of microsurgical techniques and preoperative preparation.Актуальность. Существующие в настоящее время методики выделения переднего большеберцового сосудистого пучка (ПББСП) в проксимальной трети голени не обеспечивают достаточной длины сосудистой ножки для ротации костного трансплантата большеберцовой кости до уровня средней трети бедра. Цель исследования обосновать возможность выполнения операций несвободной пересадки на уровень средней трети бедра двух кровоснабжаемых костных аутотрансплантатов на общей постоянной питающей ножке, включающей ПББСП. Материал и методы. Исследование проведено на 62 нижних конечностях нефиксированных (нативных) трупов людей. Изучали топографо-анатомические взаимоотношения ПББСП и глубокого малоберцового нерва на уровне проксимальной трети голени. Результаты. Расстояние между верхушкой большого вертела бедренной кости и дистальным краем костного переднего большеберцового трансплантата при использовании комбинации трансплантатов на одном уровне составило: у мужчин Ме = 176,7 [173,7; 193,9] мм, у женщин Ме = 151,6 [146,9; 159,9] мм. Анализ соотношений длины конечностей у мужчин и женщин свидетельствует о стандартном уровне, который можно достичь при ротации трансплантатов у каждого человека. Заключение. Выделение ПББСП на уровне проксимальной трети голени позволяет ротировать на едином сосудистом пучке комплекс переднего большеберцового костного аутотрансплантата и аутотрансплантата второй плюсневой кости в зону средней трети бедренной кости. Предотвращение повреждения ветвей глубокого малоберцового нерва в ходе выделения сосудистой ножки требует использования микрохирургической техники и предоперационной подготовки

    Один из способов управления технологическим процессом дуговой сталеплавильной печи

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    В статье приводится описание комплексной математической модели, используемой для рационального управления работой дуговых электросталеплавильных печей.In article the description of the complex mathematical model used for rational management by work of arc electrosteel-smelting furnaces is resulted

    The Stress-Energy Tensor in Soluble Models of Spherically Symmetric Charged Black Hole Evaporation

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    We study the decay of a near-extremal black hole in AdS2_2, related to the near-horizon region of 3+1-dimensional Reissner-Nordstr\"om spacetime, following Fabbri, Navarro, and Navarro-Salas. Back-reaction is included in a semiclassical approximation. Calculations of the stress-energy tensor of matter coupled to the physical spacetime for an affine null observer demonstrate that the black hole evaporation proceeds smoothly and the near-extremal black hole evolves back to an extremal ground state, until this approximation breaks down.Comment: 19 pages, 14 figure

    Inhomogeneous Magnetism in La-doped CaMnO3. (II) Mesoscopic Phase Separation due to Lattice-coupled FM Interactions

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    A detailed investigation of mesoscopic magnetic and crystallographic phase separation in Ca(1-x)La(x)MnO3, 0.00<=x<=0.20, is reported. Neutron powder diffraction and DC-magnetization techniques have been used to isolate the different roles played by electrons doped into the eg level as a function of their concentration x. The presence of multiple low-temperature magnetic and crystallographic phases within individual polycrystalline samples is argued to be an intrinsic feature of the system that follows from the shifting balance between competing FM and AFM interactions as a function of temperature. FM double-exchange interactions associated with doped eg electrons are favored over competing AFM interactions at higher temperatures, and couple more strongly with the lattice via orbital polarization. These FM interactions thereby play a privileged role, even at low eg electron concentrations, by virtue of structural modifications induced above the AFM transition temperatures.Comment: 8 pages, 7 figure

    Coronal Shock Waves, EUV waves, and Their Relation to CMEs. I. Reconciliation of "EIT waves", Type II Radio Bursts, and Leading Edges of CMEs

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    We show examples of excitation of coronal waves by flare-related abrupt eruptions of magnetic rope structures. The waves presumably rapidly steepened into shocks and freely propagated afterwards like decelerating blast waves that showed up as Moreton waves and EUV waves. We propose a simple quantitative description for such shock waves to reconcile their observed propagation with drift rates of metric type II bursts and kinematics of leading edges of coronal mass ejections (CMEs). Taking account of different plasma density falloffs for propagation of a wave up and along the solar surface, we demonstrate a close correspondence between drift rates of type II bursts and speeds of EUV waves, Moreton waves, and CMEs observed in a few known events.Comment: 30 pages, 15 figures. Solar Physics, published online. The final publication is available at http://www.springerlink.co

    Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

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    A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

    Search for the lepton-flavor-violating decays Bs0→e±μ∓ and B0→e±μ∓

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    A search for the lepton-flavor-violating decays Bs0→e±μ∓ and B0→e±μ∓ is performed with a data sample, corresponding to an integrated luminosity of 1.0  fb-1 of pp collisions at √s=7  TeV, collected by the LHCb experiment. The observed number of Bs0→e±μ∓ and B0→e±μ∓ candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(Bs0→e±μ∓)101  TeV/c2 and MLQ(B0→e±μ∓)>126  TeV/c2 at 95% C.L., and are a factor of 2 higher than the previous bounds

    Measurement of the Bs0J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

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    The Bs0J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction is measured in a data sample corresponding to 0.41fb1fb^{-1} of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2β\beta measurement from B0J/ψKS0B^0\to J/\psi K_S^0 The time-integrated branching fraction is measured to be BF(Bs0J/ψKS0)=(1.83±0.28)×105BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}. This is the most precise measurement to date

    Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+

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    An analysis of B+ → K0 Sπ+ and B+ → K0 S K+ decays is performed with the LHCb experiment. The pp collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass energies of √ s = 7 TeV and √ s = 8 TeV, respectively. The ratio of branching fractions and the direct CP asymmetries are measured to be B(B+ → K0 S K+ )/B(B+ → K0 Sπ+ ) = 0.064 ± 0.009 (stat.) ± 0.004 (syst.), ACP(B+ → K0 Sπ+ ) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0 S K+ ) = −0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at √ s = 7 TeV is used to search for B+ c → K0 S K+ decays and results in the upper limit ( fc · B(B+ c → K0 S K+ ))/( fu · B(B+ → K0 Sπ+ )) < 5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b quark into a B+ c or a B+ meson, respectively
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