5,599 research outputs found
Detailed analysis of radiation data from the Gemini 4 and Gemini 7 proton-electron spectrometer experiments Final report, 13 Jun. 1967 - 30 Dec. 1968
Detailed analysis of radiation data from Gemini 4 and 7 proton-electron spectrometer experiment
Proton-electron spectrometer experiments on Gemini-4 and Gemini-7 Final report, 27 May 1963 - 30 Sep. 1966
Fluxes and spectra of electrons and protons in atmosphere measured by spectrometer experiments on Gemini spacecraf
Zoneamento de riscos climáticos para a consorciação feijão e milho no Estado do Mato Grosso.
Esse estudo teve a finalidade de subsidiar um zoneamento de risco climático para o sistema de cultivo consorciado feijão e milho.bitstream/CNPAF-2010/29717/1/comt-178.pd
Zoneamento agroclimático para a consorciação arroz e braquiária no Estado de Goiás.
O objetivo desse trabalho foi determinar as áreas e períodos mais apropriados para a consorciação de arroz com braquiária em Goiás.bitstream/item/58176/1/comunicadotecnico-168.pd
Coronal heating distribution due to low-frequency wave-driven turbulence
The heating of the lower solar corona is examined using numerical simulations
and theoretical models of magnetohydrodynamic turbulence in open magnetic
regions. A turbulent energy cascade to small length scales perpendicular to the
mean magnetic field can be sustained by driving with low-frequency Alfven waves
reflected from mean density and magnetic field gradients. This mechanism
deposits energy efficiently in the lower corona, and we show that the spatial
distribution of the heating is determined by the mean density through the
Alfven speed profile. This provides a robust heating mechanism that can explain
observed high coronal temperatures and accounts for the significant heating
(per unit volume) distribution below two solar radius needed in models of the
origin of the solar wind. The obtained heating per unit mass on the other hand
is much more extended indicating that the heating on a per particle basis
persists throughout all the lower coronal region considered here.Comment: 19 pages, 5 figures. Accepted for publication in Ap
Implementation of the LDA+U method using the full potential linearized augmented plane wave basis
We provide a straightforward and efficient procedure to combine LDA+U total
energy functional with the full potential linearized augmented plane wave
method. A detailed derivation of the LDA+U Kohn-Sham type equations is
presented for the augmented plane wave basis set, and a simple
``second-variation'' based procedure for self-consistent LDA+U calculations is
given. The method is applied to calculate electronic structure and magnetic
properties of NiO and Gd. The magnetic moments and band eigenvalues obtained
are in very good quantitative agreement with previous full potential LMTO
calculations. We point out that LDA+U reduces the total d charge on Ni by 0.1
in NiO
Robust metastable skyrmions with tunable size in the chiral magnet FePtMoN
Synthesis of new materials that can host magnetic skyrmions and their
thorough experimental and theoretical characterization are essential for future
technological applications. The -Mn-type compound FePtMoN is one
such novel material that belongs to the chiral space group , where the
antisymmetric Dzyaloshinkii-Moriya interaction is allowed due to the absence of
inversion symmetry. We report the results of small-angle neutron scattering
(SANS) measurements of FePtMoN and demonstrate that its magnetic ground
state is a long-period spin helix with a Curie temperature of 222~K. The
magnetic field-induced redistribution of the SANS intensity showed that the
helical structure transforms to a lattice of skyrmions at 13~mT at
temperatures just below . Our key observation is that the skyrmion
state in FePtMoN is robust against field cooling down to the lowest
temperatures. Moreover, once the metastable state is prepared by field cooling,
the skyrmion lattice exists even in zero field. Furthermore, we show that the
skyrmion size in FePtMoN exhibits high sensitivity to the sample
temperature and can be continuously tuned between 120 and 210~nm. This offers
new prospects in the control of topological properties of chiral magnets.Comment: 6 pages, 4 figure
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