2,672 research outputs found
Procesos de incorporación y preservación de bioclastos en flujos piroclásticos subacuáticos: dos ejemplis y un modelo genético
Se ofrecen dos ejemplos de incorporación de bioclastos por parte de coladas piroclásticas en ambiente subacuático. Estos ejemplos proceden del Ordovicico Superior-Silúrico inferior del Sarrabus (Sureste de Cerdeña, Italia) y el Mioceno del Arcuentu (Suroeste de Cerdeña, Italia). Los bioclastos aparecen en ambos casos en el frente de coladas piroclásticas, y se han preservádo en forma de moldes. Tras una exposición detallada de los materiales se propone un modelo genético común para ambos ejemplos, en el que tras la asimilación de los bioclastos en el frente de la colada éstos sufren disolución y se preservan en los raros casos en los que la colada piroclástica se enfrió rápidamente
Procesos de incorporación y preservación de bioclastos en flujos piroclásticos subacuáticos: dos ejemplis y un modelo genético
Se ofrecen dos ejemplos de incorporación de bioclastos por parte de coladas piroclásticas en ambiente subacuático. Estos ejemplos proceden del Ordovicico Superior-Silúrico inferior del Sarrabus (Sureste de Cerdeña, Italia) y el Mioceno del Arcuentu (Suroeste de Cerdeña, Italia). Los bioclastos aparecen en ambos casos en el frente de coladas piroclásticas, y se han preservádo en forma de moldes. Tras una exposición detallada de los materiales se propone un modelo genético común para ambos ejemplos, en el que tras la asimilación de los bioclastos en el frente de la colada éstos sufren disolución y se preservan en los raros casos en los que la colada piroclástica se enfrió rápidamente
Inscripciones del norte y suroeste de la provincia de Cáceres: revisión y nuevas aportaciones II
En el presente trabajo se revisan y se dan a conocer varias inscripciones procedentes de algunas localidades de las zonas norte y suroeste de la provincia de Cáceres. Entre ellas, tres de augustobriga que, aunque ya conocidas, se encontraban en paradero desconocido o de las que no se tenia reproducción gráfica
Green functions and the Dirichlet spectrum
This article has results of four types. We show that the firsteigenvalueλ1(Ω) of the weighted Laplacian of a bounded domain withsmooth boundary can be obtained by S. Sato’s iteration scheme of theGreen operator, taking the limitλ1(Ω) = limk→∞‖Gk(f)‖L2/‖Gk+1(f)‖L2for anyf∈L2(Ω,μ),f >0, (Theorems 2.1 & 2.2). Then, we study theL1(Ω,μ)-moment spectrum of Ω in terms of iterates of the Green oper-atorG, (Theorem 3.2), extendind the work of MacDonald-Meyers [29]to the weighted setting. As corollary, we obtain the first eigenvalue ofa weighted bounded domain in terms of theL1(Ω,μ)-moment spectrum,generalizing the work of Hurtado-Markvorsen-Palmer [25]. Finally, westudy the radial spectrumσrad(Bh(o,r)) of rotationally invariant geodesicballsBh(o,r) of model manifolds. In Theorems 5.4 & 5.6, we prove anidentity relating the radial eigenvalues ofσrad(Bh(o,r)) to an isoperimet-ric quotient, i.e.∑1/λradi=∫V(s)/S(s)ds,V(s) = vol(Bh(o,s)) andS(s) = vol(∂Bh(o,s)). We then consider a proper minimal surfaceM⊂R3and the extrinsic ball Ω =M∩BR3(o,r). We obtain upper and lower es-timates for the series∑λ−2i(Ω) in terms of the volume vol(Ω) and theradiusrof the extrinsic ball Ω, (Theorem 6.1)
Relative multiplexing for minimizing switching in linear-optical quantum computing
Many existing schemes for linear-optical quantum computing (LOQC) depend on
multiplexing (MUX), which uses dynamic routing to enable near-deterministic
gates and sources to be constructed using heralded, probabilistic primitives.
MUXing accounts for the overwhelming majority of active switching demands in
current LOQC architectures. In this manuscript, we introduce relative
multiplexing (RMUX), a general-purpose optimization which can dramatically
reduce the active switching requirements for MUX in LOQC, and thereby reduce
hardware complexity and energy consumption, as well as relaxing demands on
performance for various photonic components. We discuss the application of RMUX
to the generation of entangled states from probabilistic single-photon sources,
and argue that an order of magnitude improvement in the rate of generation of
Bell states can be achieved. In addition, we apply RMUX to the proposal for
percolation of a 3D cluster state in [PRL 115, 020502 (2015)], and we find that
RMUX allows a 2.4x increase in loss tolerance for this architecture.Comment: Published version, New Journal of Physics, Volume 19, June 201
Asymptotically Extrinsic Tamed Submanifolds
We study, from the extrinsic point of view, the structure at infinity of open
submanifolds, ϕ : Mm → Mn(κ) isometrically immersed in the real space forms of
constant sectional curvature κ ≤ 0.We shall use the decay of the second fundamental
form of the so-called tamed immersions to obtain a description at infinity of the
submanifold in the line of the structural results in Greene et al. (Int Math Res Not
1994:364–377, 1994) and Petrunin and Tuschmann (Math Ann 321:775–788, 2001)
and an estimation from below of the number of its ends in terms of the volume growth
of a special class of extrinsic domains, the extrinsic balls.Vicent Gimeno: Work partially supported by the Research Program of University Jaume I Project UJI-B2016-07, and DGI -MINECO Grant (FEDER) MTM2013-48371-C2-2-P. Vicente Palmer: Work partially supported by the Research Program of University Jaume I Project UJI-B2016-07, DGI -MINECO Grant (FEDER) MTM2013-48371-C2-2-P, and Generalitat Valenciana Grant PrometeoII/2014/064. G. Pacelli Bessa: Work partially supported by CNPq- Brazil grant # 301581/2013-4
Near infrared nadir retrieval of vertical column densities: methodology and application to SCIAMACHY
Nadir observations with the shortwave infrared channels of SCIAMACHY on-board the ENVISAT satellite can be used to derive information on atmospheric gases such as CO, CH<sub>4</sub>, N<sub>2</sub>O, CO<sub>2</sub>, and H<sub>2</sub>O. For the operational level 1b-2 processing of SCIAMACHY data, a new retrieval code BIRRA (Beer InfraRed Retrieval Algorithm) has been developed. BIRRA performs a nonlinear or separable least squares fit (with bound constraints optional) of the measured radiance, where molecular concentration vertical profiles are scaled to fit the observed data. Here we present the forward modeling (radiative transfer) and inversion (least squares optimization) fundamentals of the code along with the further processing steps required to generate higher level products such as global distributions and time series. Moreover, various aspects of level 1 (observed spectra) and auxiliary input data relevant for successful retrievals are discussed. BIRRA is currently used for operational analysis of carbon monoxide vertical column densities from SCIAMACHY channel 8 observations, and is being prepared for methane retrievals using channel 6 spectra. A set of representative CO retrievals and first CH<sub>4</sub> results are presented to demonstrate BIRRA's capabilities
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