165 research outputs found

    Metals from the ritual site of Shaitanskoye Ozero II (Sverdlovsk Oblast, Russia) [Metales del yacimiento ritual de Shaitanskoye Ozero II (provincia de Sverdlovsk Oblast, Rusia)]

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    The present article describes materials from the ritual site of Shaitanskoye Ozero II, Sverdlovsk Oblast. Few excavations carried out at the site measuring less than 240 sq. m in size, yielded more than 160 bronze artifacts: utensils, weapons, rolled copper ornaments, and abundant smelting and casting waste. Apart from Seima-Turbino (celts and laminar knives) and Eurasian types (daggers with cast hilts, truncated knives with guards, fluted bracelets and rings), several metal artifacts were revealed manufactured in the style of the Samus-Kizhirovo tradition. Bronze artifacts, stone knives and scrapers, and numerous arrowheads are accompanied by ceramics of the Koptyaki type. Metals use mainly a copper-tin alloy. This assemblage is shown to be relevant to the local tradition of metalworking, which, in this particular region, was comparatively ancient having been left uninterrupted by the rapid migrations of the Seima-Turbino people. In addition, the assemblage indicates the sources from which post-Seima artifacts reached the Alakul people. These artifacts may also have been linked with a large metalworking center located in the Middle Urals

    Смешанная задача для одномерного волнового уравнения с условиями сопряжения и производными второго порядка в граничных условиях

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    In this paper, we consider the boundary problem for the half-strip on the plane for the case of two independent variables. This mixed problem is solved for a one-dimensional wave equation with Cauchy conditions on the basis of the half-strip and boundary conditions for lateral parts of the area border containing second-order derivatives. Moreover, the conjugation conditions are specified for the required function and its derivatives for the case when the homogeneous matching conditions are not satisfied. A classical solution to this problem is found in an analytical form by the characteristics method. This solution is approved to be unique if the relevant conditions are fulfilled.В полуполосе на плоскости в случае двух независимых переменных рассмотрена смешанная задача для одномерного волнового уравнения с условиями Коши на основании полуполосы и граничными условиями на боковых частях границы области, в которые входят производные второго порядка. Кроме того, на характеристиках, на которых не выполняются однородные условия согласования, задаются условия сопряжения для искомой функции и ее производных. Методом характеристик найдено классическое решение указанной задачи в аналитическом виде. Доказана его единственность при выполнении соответствующих условий

    Crossing the Dripline to 11N Using Elastic Resonance Scattering

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    The level structure of the unbound nucleus 11N has been studied by 10C+p elastic resonance scattering in inverse geometry with the LISE3 spectrometer at GANIL, using a 10C beam with an energy of 9.0 MeV/u. An additional measurement was done at the A1200 spectrometer at MSU. The excitation function above the 10C+p threshold has been determined up to 5 MeV. A potential-model analysis revealed three resonance states at energies 1.27 (+0.18-0.05) MeV (Gamma=1.44 +-0.2 MeV), 2.01(+0.15-0.05) MeV, (Gamma=0.84 +-$0.2 MeV) and 3.75(+-0.05) MeV, (Gamma=0.60 +-0.05 MeV) with the spin-parity assignments I(pi) =1/2+, 1/2- and 5/2+, respectively. Hence, 11N is shown to have a ground state parity inversion completely analogous to its mirror partner, 11Be. A narrow resonance in the excitation function at 4.33 (+-0.05) MeV was also observed and assigned spin-parity 3/2-.Comment: 14 pages, 9 figures, twocolumn Accepted for publication in PR

    Study of the unbound nucleus N-11 by elastic resonance scattering

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    4 pages, 4 figures, 2 tables.-- PACS nrs.: 21.10.Pc, 25.40.Ny, 27.20.+n.Resonances in the unbound nucleus N-11 have been studied, using the resonance scattering reaction C-10+p. The data give evidence for three states above the C-10+p threshold with energies 1.30, 2.04, and 3.72 MeV. These states can be interpreted, in a potential-model analysis, as the ground state and the first two excited states with spin-parity 1/2(+), 1/2(-), and 5/2(+) arising from the shell-model orbitals 1s(1/2), Op(1/2), and Od(5/2). A narrow state superposed on a broad structure found at higher energy could be interpreted as the mirror state of the 3/2(-) in Be-11 shifted down in energy. This shift would suggest a large radius of the potential.We acknowledge financial support from the European Community under Contract No. CHGE-CT94-0056 (Human Capital and Mobility, Access to the GANIL large scale facility) and from the Russian Foundation RFFI.Peer reviewe

    Four-dimensional distribution of the 2010 Eyjafjallajökull volcanic cloud over Europe observed by EARLINET

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    © Author(s) 2013. This work is distributed under the Creative Commons Attribution 3.0 License.The eruption of the Icelandic volcano Eyjafjallaj ökull in April-May 2010 represents a "natural experiment" to study the impact of volcanic emissions on a continental scale. For the first time, quantitative data about the presence, altitude, and layering of the volcanic cloud, in conjunction with optical information, are available for most parts of Europe derived from the observations by the European Aerosol Research Lidar NETwork (EARLINET). Based on multi-wavelength Raman lidar systems, EARLINET is the only instrument worldwide that is able to provide dense time series of high-quality optical data to be used for aerosol typing and for the retrieval of particle microphysical properties as a function of altitude. In this work we show the four-dimensional (4-D) distribution of the Eyjafjallajökull volcanic cloud in the troposphere over Europe as observed by EARLINET during the entire volcanic event (15 April-26 May 2010). All optical properties directly measured (backscatter, extinction, and particle linear depolarization ratio) are stored in the EARLINET database available at www.earlinet.org. A specific relational database providing the volcanic mask over Europe, realized ad hoc for this specific event, has been developed and is available on request at www.earlinet.org. During the first days after the eruption, volcanic particles were detected over Central Europe within a wide range of altitudes, from the upper troposphere down to the local planetary boundary layer (PBL). After 19 April 2010, volcanic particles were detected over southern and south-eastern Europe. During the first half of May (5-15 May), material emitted by the Eyjafjallajökull volcano was detected over Spain and Portugal and then over the Mediterranean and the Balkans. The last observations of the event were recorded until 25 May in Central Europe and in the Eastern Mediterranean area. The 4-D distribution of volcanic aerosol layering and optical properties on European scale reported here provides an unprecedented data set for evaluating satellite data and aerosol dispersion models for this kind of volcanic events.Peer reviewe

    The 6^{6}H states studied in the d(8He,α)d(^8\text{He},\alpha) reaction and evidence of extremely correlated character of the 5^{5}H ground state

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    The extremely neutron-rich system 6^{6}H was studied in the direct 2H(8He,4He)6^2\text{H}(^8\text{He},{^4\text{He}})^{6}H transfer reaction with a 26 AA MeV secondary 8^{8}He beam. The measured missing mass spectrum shows a resonant state in 6^{6}H at 6.8(3)6.8(3) MeV relative to the 3^3H+3n3n threshold. The population cross section of the presumably pp-wave states in the energy range from 4 to 8 MeV is dσ/dΩc.m.190(40)d\sigma/d\Omega_{\text{c.m.}} \simeq 190(40) μ\mub/sr in the angular range 5<θc.m.<165^{\circ}<\theta_{\text{c.m.}}<16^{\circ}. The obtained missing mass spectrum is free of the 6^{6}H events below 3.5 MeV (dσ/dΩc.m.3d\sigma/d\Omega_{\text{c.m.}} \lesssim 3 μ\mub/sr in the same angular range). The steep rise of the 6^{6}H missing mass spectrum at 3 MeV allows to show that 4.5(3)4.5(3) MeV is the lower limit for the possible resonant state energy in 6^{6}H tolerated by our data. According to paring energy estimates, such a 4.5(3)4.5(3) MeV resonance is a realistic candidate for the 6^{6}H ground state (g.s.). The obtained results confirm that the decay mechanism of the 7^{7}H g.s.\ (located at 2.2 MeV above the 3^{3}H+4n4n threshold) is the ``true'' (or simultaneous) 4n4n emission. The resonance energy profiles and the momentum distributions of the sequential 6^{6}H \,\rightarrow \, ^5H(g.s.)+n\, \rightarrow \, ^3H+3n3n decay fragments were analyzed by the theoretically-updated direct four-body-decay and sequential-emission mechanisms. The measured momentum distributions of the 3^{3}H fragments in the 6^{6}H rest frame indicate very strong ``dineutron-type'' correlations in the 5^{5}H ground state decay.Comment: 9 pages, 11 figure

    Study of Proton and Deuteron Pickup Reactions 2H(10Be,3He)9Li an 2H(10Be,4He)8Li with 44 A MeV 10Be Radioactive Beam at ACCULINNA-2 Fragment Separator

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    The proton and deuteron pickup reactions 2H(10Be,3He)9Li and\\ 2H(10Be,4He)8Li radioactive beam produced by the new fragment separator ACCULINNA-2 at FLNR, JINR\@. These measurements were initially motivated as test reactions intended for the elucidation of results obtained in the study of the extremely neutron-rich 7H and 6H systems created in the 2H(10Be,3He)9Li and 2H(10Be,4He)8Li reactions using the same setup. In the 2H(10Be,3He)9Li reaction the 9Li ground-state (3/23/2^-) and its first excited state (2.69~MeV, 1/21/2^-) were identified in the low-energy region of its excitation spectrum. The differential cross sections for the 9Li g.~s.) population were extracted at forward center-of-mass angles (3133^\circ-13^\circ) and compared with the FRESCO calculations. Spectroscopic factor of 1.7\sim 1.7, derived by a model for the 10Be=p+ = p +9Li(g.s.) clustering was found in accord with the experimental data. The energy spectrum of 8Li populated in the 2H(10Be,4He)8Li reaction shows the strong peak which corresponds to excitation of the second excited state of 8Li (2.25 MeV, 3+3^+). The fact that the ground and the first excited states of 8Li were not observed is fully consistent with Shell-Model calculations carried out for the 10Be g.\,s. and 8Li level structure applying momentum selection rules

    Increased Expression of the Auxiliary β(2)-subunit of Ventricular L-type Ca(2+) Channels Leads to Single-Channel Activity Characteristic of Heart Failure

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    BACKGROUND: Increased activity of single ventricular L-type Ca(2+)-channels (L-VDCC) is a hallmark in human heart failure. Recent findings suggest differential modulation by several auxiliary β-subunits as a possible explanation. METHODS AND RESULTS: By molecular and functional analyses of human and murine ventricles, we find that enhanced L-VDCC activity is accompanied by altered expression pattern of auxiliary L-VDCC β-subunit gene products. In HEK293-cells we show differential modulation of single L-VDCC activity by coexpression of several human cardiac β-subunits: Unlike β(1) or β(3) isoforms, β(2a) and β(2b) induce a high-activity channel behavior typical of failing myocytes. In accordance, β(2)-subunit mRNA and protein are up-regulated in failing human myocardium. In a model of heart failure we find that mice overexpressing the human cardiac Ca(V)1.2 also reveal increased single-channel activity and sarcolemmal β(2) expression when entering into the maladaptive stage of heart failure. Interestingly, these animals, when still young and non-failing (“Adaptive Phase”), reveal the opposite phenotype, viz : reduced single-channel activity accompanied by lowered β(2) expression. Additional evidence for the cause-effect relationship between β(2)-subunit expression and single L-VDCC activity is provided by newly engineered, double-transgenic mice bearing both constitutive Ca(V)1.2 and inducible β(2) cardiac overexpression. Here in non-failing hearts induction of β(2)-subunit overexpression mimicked the increase of single L-VDCC activity observed in murine and human chronic heart failure. CONCLUSIONS: Our study presents evidence of the pathobiochemical relevance of β(2)-subunits for the electrophysiological phenotype of cardiac L-VDCC and thus provides an explanation for the single L-VDCC gating observed in human and murine heart failure
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