1,754 research outputs found
Латинська Америка в дослідженнях російських етнографів за останні тридцять років
Статья посвящена истории исследований в области латиноамериканистики российскими и советскими учёными на примере научной деятельности сотрудников Института этнографии им. Н. Н. Миклухо-Маклая АН СССР (московское и ленинградское отделения).The article is dedicated to the Latin American researches provided by the Russian and Soviet scientists illustrated with the scientific activities of the representatives of the Soviet Academy of Science’s Myklukho-Maklai Ethnographical Institute (Moscow and Leningrad branches)
Титульні сторінки та зміст
Sr and Nd isotopes were determined using new thermal ionisation mass spectrometry (TIMS) techniques for a suite of 21 olivine-hosted (85-92mol% Fo) melt inclusions selected from potassic and ultra-potassic lavas from the Italian peninsula. Sr isotopes were measured using default 1
Термопружний стан шаруватих термочутливих циліндрів і куль за конвективно-променевого теплообміну
Розроблено методику розв’язування одновимірних статичних задач термопружності для шаруватих циліндрів і куль за конвективно-променевого нагрівання з урахуванням лінійної залежності коефіцієнтів теплопровідності та довільного характеру залежності інших фізико-механічних характеристик від температури. Задачі теплопровідності зведено, незалежно від кількості шарів, до розв’язування системи двох нелінійних алгебричних рівнянь. У задачах термопружності неперервні в межах кожного шару коефіцієнти рівнянь апроксимовано кусково-сталими функціями. Проведено числовий аналіз температурних полів і напружень у двошарових тілах.The method for solving one-dimensional static thermoelasticity problems is developed for layered cylinders and spheres under convective and radiation heating, taking into account linear dependence of heat conductivity coefficients and arbitrary character of dependence of other physical and mechanical characteristics on a temperature. Problems of heat conductivity have been reduced to the system of two nonlinear algebraic equations regardless of the number of layers. In the thermoelasticity problems the continuous within every layer coefficients of equations are approximated by piecewise constant functions. The numerical analysis of the temperature fields and stresses is conducted for two-layered bodies.Разработана методика решения одномерных статических задач термоупругости для слоистых цилиндров и сфер при конвективно-лучевом нагреве с учетом линейной зависимости коэффициентов теплопроводности и произвольного характера зависимости других физико-механических характеристик от температуры. Задачи теплопроводности сведены, независимо от количества слоев, к решению системы двух нелинейных алгебраических уравнений. В задачах термоупругости непрерывные в пределах каждого слоя коэффициенты уравнений аппроксимированы кусочно-постоянными функциями. Проведен численный анализ температурных полей и напряжений в двухслойных телах
Etched Glass Surfaces, Atomic Force Microscopy and Stochastic Analysis
The effect of etching time scale of glass surface on its statistical
properties has been studied using atomic force microscopy technique. We have
characterized the complexity of the height fluctuation of a etched surface by
the stochastic parameters such as intermittency exponents, roughness, roughness
exponents, drift and diffusion coefficients and find their variations in terms
of the etching time.Comment: 5 pages, 6 figures
Time-of-arrival distributions from position-momentum and energy-time joint measurements
The position-momentum quasi-distribution obtained from an Arthurs and Kelly
joint measurement model is used to obtain indirectly an ``operational''
time-of-arrival (TOA) distribution following a quantization procedure proposed
by Kocha\'nski and W\'odkiewicz [Phys. Rev. A 60, 2689 (1999)]. This TOA
distribution is not time covariant. The procedure is generalized by using other
phase-space quasi-distributions, and sufficient conditions are provided for
time covariance that limit the possible phase-space quasi-distributions
essentially to the Wigner function, which, however, provides a non-positive TOA
quasi-distribution. These problems are remedied with a different quantization
procedure which, on the other hand, does not guarantee normalization. Finally
an Arthurs and Kelly measurement model for TOA and energy (valid also for
arbitrary conjugate variables when one of the variables is bounded from below)
is worked out. The marginal TOA distribution so obtained, a distorted version
of Kijowski's distribution, is time covariant, positive, and normalized
A Note on Domain Walls and the Parameter Space of N=1 Gauge Theories
We study the spectrum of BPS domain walls within the parameter space of N=1
U(N) gauge theories with adjoint matter and a cubic superpotential. Using a low
energy description obtained by compactifying the theory on R^3 x S^1, we
examine the wall spectrum by combining direct calculations at special points in
the parameter space with insight drawn from the leading order potential between
minimal walls, i.e those interpolating between adjacent vacua. We show that the
multiplicity of composite BPS walls -- as characterised by the CFIV index --
exhibits discontinuities on marginal stability curves within the parameter
space of the maximally confining branch. The structure of these marginal
stability curves for large N appears tied to certain singularities within the
matrix model description of the confining vacua.Comment: 33 pages, LaTeX, 6 eps figures; v2: references adde
Generalised second law of thermodynamics for interacting dark energy in the DGP brane world
In this paper, we investigate the validity of the generalized second law of
thermodynamics (GSLT) in the DGP brane world when universe is filled with
interacting two fluid system: one in the form of cold dark matter and other is
holographic dark energy. The boundary of the universe is assumed to be enclosed
by the dynamical apparent horizon or the event horizon. The universe is chosen
to be homogeneous and isotropic FRW model and the validity of the first law has
been assumed here
The increasing burden of tuberculosis in rural South Africa - impact of the HIV epidemic
Objective. To determine the impact of the HIV epidemic on tuberculosis caseload in rural South Africa.Setting. Hlabisa health district, Kwazulu-Natal.Methods. Demographic and clinical data were extracted from the tuberculosis database for the period, May 1991 June 1995. The attributable fraction of HIV-infected tuberculosis cases was estimated from the prevalence of HIV infection in tuberculosis cases and the prevalence of HIV infection in women attending antenatal clinics.Results. Between 1991 and 1995, the annual tuberculosis caseload increased from 301 to 839 cases. Tuberculosis accounted for 4.7% of all admissions in 1989 and 8.3% in 1995 (P < 0.0001). The incidence of tuberculosis increased from 154/1 00 000 in 1991, to 413/100 000 in 1995. The proportion with smear-positive pulmonary disease fell from 65% to 56% (P = 0.04), and pleural tuberculosis accounted for 7.5% of disease in 1991 and 18% in 1995 (P = 0.002). The minimum HIV prevalence in patients with tuberculosis increased from 8.7% in 1991 to 28.3% in 1995, and the proportion of tuberculosis cases attributable to HIV infection was estimated to be at least 44% in 1995.Conclusion. The burden of HIV-related tuberculosis is increasing rapidly in rural South Africa and is exerting a negative impact. Innovative approaches to control will be needed to cope with it effectively
Распределение металлической фазы в синтетических алмазах типа «карбонадо»
Studying of a structural structure synthetic «carbonado» is spent by a method of electronic scanning
microscopy. It is established, that the surface «carbonado» is covered by the large diamond crystals
reaching 200 microns, having obviously expressed structure of growth. On a surface of these crystals observed
drops of metal-catalyst (nickel) of a submicronic range. It is established, that the structure synthetic
«carbonado» represents interpenetrating skeletons from diamond and ceramic-metal phases
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