Tunability of the optical absorption in small silver cluster-polymer hybrid systems

We have calculated the absorption characteristics of different hybrid systems consisting of Ag, Ag2 or Ag3 atomic clusters and poly(methacrylic acid) (PMAA) using the time-dependent density-functional theory. The polymer is found to have an extensive structural-dependency on the spectral patterns of the hybrid systems relative to the bare clusters. The absorption spectrum can be `tuned' to the visible range for hybrid systems with an odd number of electrons per silver cluster, whereas for hybrid systems comprising an even number of electrons, the leading absorption edge can be shifted up to about 4.5 eV. The results give theoretical support to the experimental observations on the absorption in the visible range in metal cluster-polymer hybrid structures.Comment: Updated layout and minor changes in versions 2 and

Inelastic X-ray scattering from valence electrons near absorption edges of FeTe and TiSe2_2

We study resonant inelastic x-ray scattering (RIXS) peaks corresponding to low energy particle-hole excited states of metallic FeTe and semi-metallic TiSe$_2$ for photon incident energy tuned near the $L_{3}$ absorption edge of Fe and Ti respectively. We show that the cross section amplitudes are well described within a renormalization group theory where the effect of the core electrons is captured by effective dielectric functions expressed in terms of the the atomic scattering parameters $f_1$ of Fe and Ti. This method can be used to extract the dynamical structure factor from experimental RIXS spectra in metallic systems.Comment: 6 pages, 4 figure

Design of Channels Against Distortional Buckling

Thin-walled lip-stiffened channel columns composed of high strength steel may fail in a distortional mode involving movement of the lip stiffener perpendicular to the flange plate it supports. In this report, test results for a simple lipped channel section(CH1) and an intermediate stiffened channel section (CH2) of thickness of approximately 1.1 mm (0.043 in) and 550 MPa (79.8 ksi) steel and undergoing distortional or mixed local-distortional buckling failure are compared with different design methods. The design methods compared are Australian Standard AS1538, EC3 Partl/ Annexe A, the ECCS Recommendations and the AISI Specification. In addition, new methods based on a modified Winter formula for effective width are presented and compared with the tests

Perceptions towards risks involved in off-site construction in the integrated design & construction project delivery

This study aimed to address the gap in research regarding the application of integrated design and construction (IDC) project delivery into off-site construction Projects (OSC) within China. A questionnaire survey was designed and delivered to reach Chinese professionals in Architecture, Engineering, and Construction (AEC) disciplines to assess their risk perceptions

Learning Backtrackless Aligned-Spatial Graph Convolutional Networks for Graph Classification.

In this paper, we develop a novel Backtrackless Aligned-Spatial Graph Convolutional Network (BASGCN) model to learn effective features for graph classification. Our idea is to transform arbitrary-sized graphs into fixed-sized backtrackless aligned grid structures and define a new spatial graph convolution operation associated with the grid structures. We show that the proposed BASGCN model not only reduces the problems of information loss and imprecise information representation arising in existing spatially-based Graph Convolutional Network (GCN) models, but also bridges the theoretical gap between traditional Convolutional Neural Network (CNN) models and spatially-based GCN models. Furthermore, the proposed BASGCN model can both adaptively discriminate the importance between specified vertices during the convolution process and reduce the notorious tottering problem of existing spatially-based GCNs related to the Weisfeiler-Lehman algorithm, explaining the effectiveness of the proposed model. Experiments on standard graph datasets demonstrate the effectiveness of the proposed model

Generalized tight-binding transport model for graphene nanoribbon-based systems

An extended tight-binding model that includes up to third-nearest-neighbor hopping and a Hubbard mean-field interaction term is tested against ab initio local spin-density approximation results of band structures for armchair- and zigzag-edged graphene nanoribbons. A single tight-binding parameter set is found to accurately reproduce the ab initio results for both the armchair and zigzag cases. Transport calculations based on the extended tight-binding model faithfully reproduce the results of ab initio transport calculations of graphene nanoribbon-based systems.Peer reviewe

Use of IU parallel computing resources and high performance file systems July 2013 to Dec 2014

The paper discusses the contributions of Big Red II and Data Capacitor II and their impact on IU's research and creative output