6,713 research outputs found
Investigation of environmental change pattern in Japan. Investigation of the ecological environment index from observation of the regional vegetation cover and their growing condition
There are no author-identified significant results in this report
Manganite charge and orbitally ordered and disordered states probed by Fe substitution into Mn site in LnBaMn1.96Fe0.04O5, LnBaMn1.96Fe0.04O6 and LnBaMn1.96Fe0.04O5.5 (Ln=Y, Gd, Sm, Nd, Pr, La)
The layered manganese oxides LnBaMn1.96Fe0.04Oy (Ln=Y, Gd, Sm, Nd, Pr, La)
have been synthesized for y=5, 5.5 and 6. In the oxygen-saturated state (y=6)
they exhibit the charge and orbital order at ambient temperature for Ln=Y, Gd,
Sm, but unordered eg-electronic system for Ln=La,Pr,Nd. Fourfold increase of
quadrupole splitting was observed owing to the charge and orbital ordering.
This is in agreement with the jumplike increase in distortion of the reduced
perovskite-like cell for the charge and orbitally ordered manganites compared
to the unordered ones. Substitution of 2 percents of Mn by Fe suppresses the
temperatures of structural and magnetic transitions by 20 to 50 K. Parameters
of the crystal lattices and the room-temperature M\"{o}ssbauer spectra were
studied on forty samples whose structures were refined within five symmetry
groups: P4/mmm, P4/nmm, Pm-3m, Icma and P2/m. Overwhelming majority of the Fe
species are undifferentiated in the M\"{o}ssbauer spectra for most of the
samples. Such the single-component spectra in the two-site structures are
explained by the preference of Fe towards the site of Mn(III) and by the
segmentation of the charge and orbitally ordered domains.Comment: 8 figures; figures 2 and 3 were revise
Geometric and combinatorial realizations of crystal graphs
For irreducible integrable highest weight modules of the finite and affine
Lie algebras of type A and D, we define an isomorphism between the geometric
realization of the crystal graphs in terms of irreducible components of
Nakajima quiver varieties and the combinatorial realizations in terms of Young
tableaux and Young walls. For affine type A, we extend the Young wall
construction to arbitrary level, describing a combinatorial realization of the
crystals in terms of new objects which we call Young pyramids.Comment: 34 pages, 17 figures; v2: minor typos corrected; v3: corrections to
section 8; v4: minor typos correcte
Energy gaps and roton structure above the nu=1/2 Laughlin state of a rotating dilute Bose-Einstein condensate
Exact diagonalization study of a rotating dilute Bose-Einstein condensate
reveals that as the first vortex enters the system the degeneracy of the
low-energy yrast spectrum is lifted and a large energy gap emerges. As more
vortices enter with faster rotation, the energy gap decreases towards zero, but
eventually the spectrum exhibits a rotonlike structure above the nu=1/2
Laughlin state without having a phonon branch despite the short-range nature of
the interaction.Comment: 4 pages, 4 figures, 1 tabl
Josephson Effects in Double-Layer Quantum Hall States
Under quite plausible assumptions on double-layer quantum Hall states with
strong interlayer correlation, we show in general framwork that coherent
tunneling of a single electron between two layers is possible. It yields
Josephson effects with unit charge tunneling. The origin is that Halperin
states in the quantum Hall states are highly degenerate in electron number
difference between two layers in the absence of electrons tunneling.Comment: 9 Pages, Revtex Inpress Int.J.Mod.Phys.
High-Symmetry Polarization Domains in Low-Symmetry Ferroelectrics
We present experimental evidence for hexagonal domain faceting in the
ferroelectric polymer PVDF-TrFE films having the lower orthorhombic
crystallographic symmetry. This effect can arise from purely electrostatic
depolarizing forces. We show that in contrast to magnetic bubble shape domains
where such type of deformation instability has a predominantly elliptical
character, the emergence of more symmetrical circular harmonics is favored in
ferroelectrics with high dielectric constant
Somatic embryogenesis from filaments of Vitis vinifera L. and Vitis labruscana Bailey
Research NoteSomatic embryogenesis from filaments of grape was investigated. The combination of 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 μM N-(1,2,3-thiadiazol-5-yl)-N’-phenylurea (TDZ) or 10 μM 2,4-D and 10 μM TDZ was suitable for somatic embryogenesis from filaments. The filaments of 8 grape cultivars including recalcitrant genotypes were cultured on a half strength MS basal medium supplemented with 1 μM 2,4-D and 1 μM TDZ. Two-step culture (liquid medium followed by solid medium) gave better results for somatic embryogenesis than one-step culture (solid medium only). Induction of embryogenic callus (EC) was achieved with 5 of 8 cultivars including recalcitrant ones by the two-step culture method, indicating that the filament culture enlarges the number of the EC inducible cultivars.
Effect of viscosities of dispersed and continuous phases in microchannel oil-in-water emulsification
Although many aspects of microchannel emulsification have been covered in literature, one major uncharted area is the effect of viscosity of both phases on droplet size in the stable droplet generation regime. It is expected that for droplet formation to take place, the inflow of the continuous phase should be sufficiently fast compared to the outflow of the liquid that is forming the droplet. The ratio of the viscosities was therefore varied by using a range of continuous and dispersed phases, both experimentally and computationally. At high viscosity ratio (eta (d)/eta (c)), the droplet size is constant; the inflow of the continuous phase is fast compared to the outflow of the dispersed phase. At lower ratios, the droplet diameter increases, until a viscosity ratio is reached at which droplet formation is no longer possible (the minimal ratio). This was confirmed and elucidated through CFD simulations. The limiting value is shown to be a function of the microchannel design, and this should be adapted to the viscosity of the two fluids that need to be emulsified
Weight Vectors of the Basic A_1^(1)-Module and the Littlewood-Richardson Rule
The basic representation of \A is studied. The weight vectors are
represented in terms of Schur functions. A suitable base of any weight space is
given. Littlewood-Richardson rule appears in the linear relations among weight
vectors.Comment: February 1995, 7pages, Using AMS-Te
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