San Francisco State University

About: San Francisco State University is a education organization based out in San Francisco, California, United States. It is known for research contribution in the topics: Population & Planet. The organization has 5669 authors who have published 11433 publications receiving 408075 citations. The organization is also known as: San Francisco State & San Francisco State Normal School.

Observation of superluminal and slow light propagation in erbium-doped optical fiber

Abstract: We observe both extremely slow and superluminal pulse propagation speeds at room temperature in an erbium-doped fiber (EDF). A signal at 1550 nm is sent through an erbium-doped fiber with varying powers of a 980 nm pump. The degree of signal delay or advancement is found to depend significantly on the pump intensity. We observe a maximum fractional advancement of 0.124 and a maximum fractional delay of 0.089. The effect is demonstrated both for a sinusoidally modulated signal and for Gaussian pulses. The ability to control the sign and magnitude of the pulse velocity could have important implications for applications in photonics.

Sociolinguistics and Language Education

Abstract: Introduction: Sociolinguistics and Language Education - Nancy H. Hornberger and Sandra Lee McKayLANGUAGE AND IDEOLOGYLanguage and Ideologies - Mary E. McGroartyLanguage, Power and Pedagogies - Hilary JanksNationalism, Identity and Popular Culture - Alastair PennycookLANGUAGE AND SOCIETYEnglish as an International Language - Sandra Lee McKayMultilingualism and Codeswitching in Education - Nkonko M. KamwangamaluLanguage Policy and Planning - Joseph Lo BiancoLANGUAGE AND VARIATIONStyle and Styling - Jurgen JaspersCritical Language Awareness - H. Samy Alim Pidgins and Creoles - Jeff SiegelLANGUAGE AND LITERACYCross-cultural Perspectives on Writing: Contrastive Rhetoric - Ryuko KubotaSociolinguistics, Language Teaching and New Literacy Studies - Brian Street and Constant LeungMultimodal Literacy in Language Classrooms - Viniti Vaish and Phillip A. Towndrow LANGUAGE AND IDENTITYLanguage and Identity - Bonny NortonGender Identities in Language Education - Christina HigginsLanguage and Ethnicity - Angela ReyesLanguage Socialization - Patricia A. DuffLANGUAGE AND INTERACTIONLanguage and Culture - Gabriele Kasper and Makoto OmoriConversation Analysis - Jack Sidnell Classroom Discourse Analysis: A Focus on Communicative Repertoires - Betsy RymesLANGUAGE AND EDUCATIONLanguage and Education: A Limpopo Lens - Nancy H. Hornberger

A theory of reparameterizations for AdS3 gravity

Abstract: We rewrite the Chern-Simons description of pure gravity on global AdS3 and on Euclidean BTZ black holes as a quantum field theory on the AdS boundary. The resulting theory is (two copies of) the path integral quantization of a certain coadjoint orbit of the Virasoro group, and it should be regarded as the quantum field theory of the boundary gravitons. This theory respects all of the conformal field theory axioms except one: it is not modular invariant. The coupling constant is 1/c with c the central charge, and perturbation theory in 1/c encodes loop contributions in the gravity dual. The QFT is a theory of reparametrizations analogous to the Schwarzian description of nearly AdS2 gravity, and has several features including: (i) it is ultraviolet-complete; (ii) the torus partition function is the vacuum Virasoro character, which is one-loop exact by a localization argument; (iii) it reduces to the Schwarzian theory upon compactification; (iv) it provides a powerful new tool for computing Virasoro blocks at large c via a diagrammatic expansion. We use the theory to compute several observables to one-loop order in the bulk, including the “heavy-light” limit of the identity block. We also work out some generalizations of this theory, including the boundary theory which describes fluctuations around two-sided eternal black holes.

Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

Abstract: The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron backscattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on undercoordinated titanium atoms,...

Workplace fun: the moderating effects of generational differences

Abstract: Purpose – This paper aims to investigate how generational differences moderate the relationship between workplace fun and individual workplace outcomes.Design/methodology/approach – The authors review and integrate the literatures on workplace fun and generational theory and empirically test the interaction effects of generation membership and workplace fun with job satisfaction, task performance, and OCB using a sample of 701 workers.Findings – The findings suggest that not only do members of different generational cohorts respond differently to workplace fun, but cohort membership moderates the relationship between workplace fun and some individual workplace outcomes.Research limitations/implications – Snowball sampling and cross‐sectional data limit the generalisability of the study's findings.Practical implications – The authors provide managerial implications for promoting workplace fun.Originality/value – The paper contributes to the workplace fun conversation by addressing the overlooked question o...