8,940 research outputs found
Ab Initio Study of Phase Stability in Doped TiO2
Ab-initio density functional theory (DFT) calculations of the relative
stability of anatase and rutile polymorphs of TiO2 were carried using
all-electron atomic orbitals methods with local density approximation (LDA).
The rutile phase exhibited a moderate margin of stability of ~ 3 meV relative
to the anatase phase in pristine material. From computational analysis of the
formation energies of Si, Al, Fe and F dopants of various charge states across
different Fermi level energies in anatase and in rutile, it was found that the
cationic dopants are most stable in Ti substitutional lattice positions while
formation energy is minimised for F- doping in interstitial positions. All
dopants were found to considerably stabilise anatase relative to the rutile
phase, suggesting the anatase to rutile phase transformation is inhibited in
such systems with the dopants ranked F>Si>Fe>Al in order of anatase
stabilisation strength. Al and Fe dopants were found to act as shallow
acceptors with charge compensation achieved through the formation of mobile
carriers rather than the formation of anion vacancies
A dictionary of Eastern Bonan
Eastern Bonan is a Mongolic language spoken on the upper reaches of the Yellow River, Gansu province in Amdo (northern) Tibet. Of the Eastern and Western varieties of Bonan [Bao'an äżćź, Bonang; ISO 639-3: peh; Glottocode: bona1250], Eastern Bonan is the officially-recognized variety. Unpublished Eastern Bonan data collected by Charles Li from 1982 to 1984 forms the basis of this dictionary; Arienne Dwyer digitized and analyzed these data, adding lemmatized headwords, etymological sources, parts of speech, Chinese glosses, and forms from other published sources.
Charles N. Li is an Emeritus Professor of Linguistics at the University of California - Santa Barbara
Arienne M. Dwyer is a Professor of Linguistic Anthropology at the University of KansasU.S. National Science Foundation (BCS-8308220 Baonan: Languages in Contact & Language Change
Propagation characteristics of guided waves in stratified metallic optical waveguides
An eigenvalue equation is derived for stratified metallic optical slab waveguides with any number of layers. The equation is solved using the numerical zoom analysis (NZA) method. The analysis is applied to various metallic optical slabs and the propagation characteristics of the guided waves are determined, which may be useful for optimizing the design parameters. It is found possible, with proper optimization, to design a polarizer having hundreds of decibels of extinction ratio at the cost of a fraction of a decibel of insertion loss. Examples of optimizations with respect to wavelength, relative refractive indices, core/clad geometries, etc. are demonstrated for slabs with single or double metal layers. Guidelines for determining the metal film thickness have been formulated and tabulated for many useful metals
The Rise and Fall of Tones Through Diffusion
Proceedings of the Twelfth Annual Meeting of the Berkeley Linguistics
Society (1986), pp. 173-18
From Verb-Medial Analytic Language to Verb-Final Synthetic Language: A Case of Typological Change
Proceedings of the Tenth Annual Meeting of the Berkeley Linguistics
Society (1984), pp. 307-32
Identification of the Red Supergiant Progenitor of Supernova 2005cs: Do the Progenitors of Type II-P Supernovae Have Low Mass?
The stars that end their lives as supernovae (SNe) have been directly
observed in only a handful of cases, due mainly to the extreme difficulty in
identifying them in images obtained prior to the SN explosions. Here we report
the identification of the progenitor for the recent Type II-plateau
(core-collapse) SN 2005cs in pre-explosion archival images of the Whirlpool
Galaxy (M51) obtained with the Hubble Space Telescope (HST) Advanced Camera for
Surveys (ACS). From high-quality ground-based images of the SN from the
Canada-France-Hawaii Telescope, we precisely determine the position of the SN
and are able to isolate the SN progenitor to within 0".04 in the HST/ACS
optical images. We further pinpoint the SN location to within 0".005 from
HST/ACS ultraviolet images of the SN, confirming our progenitor identification.
From photometry of the SN progenitor obtained with the pre-SN ACS images, and
also limits to its brightness in pre-SN HST/NICMOS images, we infer that the
progenitor is a red supergiant star of spectral type K0--M3, with initial mass
7--9 Msun. We also discuss the implications of the SN 2005cs progenitor
identification and its mass estimate. There is an emerging trend that the most
common Type II-plateau SNe originate from low-mass supergiants 8--15 Msun.Comment: Submitted to ApJ. A high resolution version can be found at
http://astron.berkeley.edu/~weidong/sn05cs.p
Nonfactorizable contributions to decays
While the factorization assumption works well for many two-body nonleptonic
meson decay modes, the recent measurement of with
, and shows large deviation from this assumption. We
analyze the decays in the perturbative QCD approach based on
factorization theorem, in which both factorizable and nonfactorizable
contributions can be calculated in the same framework. Our predictions for the
Bauer-Stech-Wirbel parameters, and and and , are
consistent with the observed and branching ratios,
respectively. It is found that the large magnitude and the large
relative phase between and come from color-suppressed
nonfactorizable amplitudes. Our predictions for the , branching ratios can be confronted with
future experimental data.Comment: 25 pages with Latex, axodraw.sty, 6 figures and 5 tables, Version
published in PRD, Added new section 5 and reference
Influence of Crohnâs disease related polymorphisms in innate immune function on ileal microbiome
We have previously identified NOD2 genotype and inflammatory bowel diseases (IBD) phenotype, as associated with shifts in the ileal microbiome (âdysbiosisâ) in a patient cohort. Here we report an integrative analysis of an expanded number of Crohn's disease (CD) related genetic defects in innate immune function (NOD2, ATG16L1, IRGM, CARD9, XBP1, ORMDL3) and composition of the ileal microbiome by combining the initial patient cohort (Batch 1, 2005â2010, n = 165) with a second consecutive patient cohort (Batch 2, 2010â2012, n = 118). These combined patient cohorts were composed of three non-overlapping phenotypes: 1.) 106 ileal CD subjects undergoing initial ileocolic resection for diseased ileum, 2.) 88 IBD colitis subjects without ileal disease (predominantly ulcerative colitis but also Crohnâs colitis and indeterminate colitis, and 3.) 89 non-IBD subjects. Significant differences (FDR C. difficile infection, and NOD2 genotype on ileal dysbiosis in the expanded analysis. The relative abundance of the Proteobacteria phylum was positively associated with ileal CD and colitis phenotypes, but negatively associated with NOD2R genotype. Additional associations with ORMDL3 and XBP1 were detected at the phylum/subphylum level. IBD medications, such as immunomodulators and anti-TNFα agents, may have a beneficial effect on reversing dysbiosis associated with the IBD phenotype. Exploratory analysis comparing microbial composition of the disease unaffected region of the resected ileum between 27 ileal CD patients who subsequently developed endoscopic recurrence within 6â12 months versus 34 patients who did not, suggested that microbial biomarkers in the resected specimen helped stratify patients with respect to risk of post-surgical recurrence.</div
Off-shell effects in dilepton production from hot interacting mesons
The production of dielectrons in reactions involving a_1 mesons and pions is
studied. We compare results obtained with different phenomenological
Lagrangians that have been used in connection with hadronic matter and finite
nuclei. We insist on the necessity for those interactions to satisfy known
empirical properties of the strong interaction. Large off-shell effects in
dielectron production are found and some consequences for the interpretation of
heavy ion data are outlined. We also compare with results obtained using
experimentally-extracted spectral functions.Comment: 14 pages, LaTeX2e, 2 figure
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