3,350 research outputs found
Young Wall Realization of Crystal Bases for Classical Lie Algebras
In this paper, we give a new realization of crystal bases for finite
dimensional irreducible modules over classical Lie algebras. The basis vectors
are parameterized by certain Young walls lying between highest weight and
lowest weight vectors.Comment: 27page
Exploring wide bandgap metal oxides for perovskite solar cells
The heterojunction formed when wide bandgap oxides come into contact with perovskite solar cells is essential for high efficiency as it minimizes charge leakage along with charge separation and charge transfer. Therefore, the electrical and optical properties of wide bandgap oxides, including the bandgap, charge mobility, and energy level, directly determine the efficiency of perovskite solar cells. In addition, the surface properties of the wide bandgap oxide act as an important factor that determines the efficiency through the wettability and penetration of the precursor solution during perovskite layer deposition and long-term stability through the intimate interfacial bonding with the perovskite. Although a great variety of wide bandgap oxides are known, the number that can be used for perovskite solar cells is considerably reduced in view of the limitations that the light absorber (here, perovskite) for solar cells is fixed, and the oxides must be uniformly coated at low temperature onto the substrate. Herein, a review of the results from several broad bandgap oxides used in perovskite solar cells is presented, and a direction for discovering new photoelectrodes is proposed
Double resonance of Raman transitions in a degenerate Fermi gas
We measure momentum-resolved Raman spectra of a spin-polarized degenerate
Fermi gas of Yb atoms for a wide range of magnetic fields, where the
atoms are irradiated by a pair of counterpropagating Raman laser beams as in
the conventional spin-orbit coupling scheme. Double resonance of first- and
second-order Raman transitions occurs at a certain magnetic field and the
spectrum exhibits a doublet splitting for high laser intensities. The measured
spectral splitting is quantitatively accounted for by the Autler-Townes effect.
We show that our measurement results are consistent with the spinful band
structure of a Fermi gas in the spatially oscillating effective magnetic field
generated by the Raman laser fields.Comment: 7 pages, 6 figure
Estimating Net Operating Income Growth for Modeling U.S. Apartment Property Capitalization Rates
The properties of income-to-price ratios in asset markets have potentially far reaching implications for understanding investor behavior. Prevailing levels of commercial real estate (CRE) capitalization rates, similar to price / earnings ratios for stocks and owner equivalent rent-to-price relatives for houses, may foretell future investment returns and income growth rates. In CRE capitalization rate models, rent growth rates often proxy for the net operating income (NOI) growth rates. Empirical studies of capitalization rate predictive powers produce inconsistent results that may be due either to the use of these rent growth proxies, model misspecification, or both. We use a novel approach for generating NOI growth rate estimates that involves combining survey rent and the expense growth rates for U.S. apartments. Our GARCH analysis of the capitalization rate spread process using the estimated NOI growth rate produces theoretically consistent results. Importantly, we demonstrate efficiency gains from using our NOI growth rate estimates relative to traditional rent growth rate
The complete mitochondrial genome of the sea spider Achelia bituberculata (Pycnogonida, Ammotheidae): arthropod ground pattern of gene arrangement
<p>Abstract</p> <p>Background</p> <p>The phylogenetic position of pycnogonids is a long-standing and controversial issue in arthropod phylogeny. This controversy has recently been rekindled by differences in the conclusions based on neuroanatomical data concerning the chelifore and the patterns of <it>Hox </it>expression. The mitochondrial genome of a sea spider, <it>Nymphon gracile </it>(Pycnogonida, Nymphonidae), was recently reported in an attempt to address this issue. However, <it>N. gracile </it>appears to be a long-branch taxon on the phylogenetic tree and exhibits a number of peculiar features, such as 10 tRNA translocations and even an inversion of several protein-coding genes. Sequences of other pycnogonid mitochondrial genomes are needed if the position of pycnogonids is to be elucidated on this basis.</p> <p>Results</p> <p>The complete mitochondrial genome (15,474 bp) of a sea spider (<it>Achelia bituberculata</it>) belonging to the family Ammotheidae, which combines a number of anatomical features considered plesiomorphic with respect to other pycnogonids, was sequenced and characterized. The genome organization shows the features typical of most metazoan animal genomes (37 tightly-packed genes). The overall gene arrangement is completely identical to the arthropod ground pattern, with one exception: the position of the <it>trnQ </it>gene between the <it>rrnS </it>gene and the control region. Maximum likelihood and Bayesian inference trees inferred from the amino acid sequences of mitochondrial protein-coding genes consistently indicate that the pycnogonids (<it>A. bituberculata </it>and <it>N. gracile</it>) may be closely related to the clade of Acari and Araneae.</p> <p>Conclusion</p> <p>The complete mitochondrial genome sequence of <it>A. bituberculata </it>(Family Ammotheidae) and the previously-reported partial sequence of <it>Endeis spinosa </it>show the gene arrangement patterns typical of arthropods (<it>Limulus</it>-like), but they differ markedly from that of <it>N. gracile</it>. Phylogenetic analyses based on mitochondrial protein-coding genes showed that Pycnogonida may be authentic arachnids (= aquatic arachnids) within Chelicerata <it>sensu lato</it>, as indicated by the name 'sea spider,' and suggest that the Cormogonida theory – that the pycnogonids are a sister group of all other arthropods – should be rejected. However, in view of the relatively weak node confidence, strand-biased nucleotide composition and long-branch attraction artifact, further more intensive studies seem necessary to resolve the exact position of the pycnogonids.</p
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