Evidence for very strong electron-phonon coupling in YBa_{2}Cu_{3}O_{6}

From the observed oxygen-isotope shift of the mid-infrared two-magnon absorption peak of YBa$_{2}$Cu$_{3}$O$_{6}$, we evaluate the oxygen-isotope effect on the in-plane antiferromagnetic exchange energy $J$. The exchange energy $J$ in YBa$_{2}$Cu$_{3}$O$_{6}$ is found to decrease by about 0.9% upon replacing $^{16}$O by $^{18}$O, which is slightly larger than that (0.6%) in La$_{2}$CuO$_{4}$. From the oxygen-isotope effects, we determine the lower limit of the polaron binding energy, which is about 1.7 eV for YBa$_{2}$Cu$_{3}$O$_{6}$ and 1.5 eV for La$_{2}$CuO$_{4}$, in quantitative agreement with angle-resolved photoemission data, optical conductivity data, and the parameter-free theoretical estimate. The large polaron binding energies in the insulating parent compounds suggest that electron-phonon coupling should also be strong in doped superconducting cuprates and may play an essential role in high-temperature superconductivity.Comment: 4 pages, 1 figur

Spontaneous Raman scattering for simultaneous measurements of in-cylinder species

A technique for multi-species mole fraction measurement in internal combustion engines is described. The technique is based on the spontaneous Raman scattering. It can simultaneously provide the mole fractions of several species of N-2, O-2, H2O, CO2 and fuel. Using the system, simultaneous measurement of air/fuel ratio and burnt residual gas are carried out during the mixture process in a Controlled Auto Ignition (CAI) combustion engine. The accuracy and consistency of the measured results were confirmed by the measured air fuel ratio using an exhaust gas analyzer and independently calculated mole fraction values. Measurement of species mole fractions during combustion process has also been demonstrated. It shows that the SRS can provide valuable data on this process in a CAI combustion engine

Inclusion agglomeration in electrified molten metal: thermodynamic consideration

The effect of electric current on inclusion agglomeration in molten metal has been investigated. It is found that the agglomeration is dependent on the electric current density, distance between inclusions and orientation of electric field. Electric current retards the agglomeration unless two inclusions are aligned along or closely to the current flow streamlines and the distance between inclusions is less than a critical value. The mechanism is also validated in the computation of cluster agglomeration. The numerical results provide a comprehensive indication for the current-induced inclusion removal and current-induced inclusion elongation. When the inclusions are in long-thin shape, the calculation predicts the current-induced microstructure alignment and current-induced microstructure refinement phenomena

Information technology and marketing performance within international market-entry alliances: a review and an integrated conceptual framework

The purpose of our paper is to engage in a comprehensive review of the research on Information Technology (IT)-mediated international market-entry alliances.This paper provides a theory-informed conceptual framework of IT-enabled cross-border interfirm relationships and performance outcomes. It integrates perspectives of Resource-based View (RBV) and Transaction Cost Economics (TCE) to argue that the establishment of interfirm IT capabilities enhances the marketing performance of the foreign partner in the host location by improving interfirm relationship governance. Furthermore, IT-related risks and contextual restrictions are identified as important moderators. Conceptualisations of IT capabilities, IT-enhanced interfirm governance, and IT-led marketing performance improvement are suggested. Drawing on RBV and TCE, IT resources, related human resources, and IT integration between partner firms in combination enhances the ability of firms to manage the relationship more effectively through shared control, interfirm coordination, cross-firm formalisation, and hybrid centralisation. These benefits then bring about better upstream and downstream marketing performance in the host location. Additionally, IT capabilities help to mitigate possible contextual limitations and risks. The paper offers a number of theory- and literature- informed research propositions which can be empirically tested in future studies.Top managers of firms currently in or planning to enter international alliances for market entry should carefully consider effective development of interfirm IT capabilities in terms of readiness of hardware and software, human resources, and organisational resources. Our paper provides an integrated framework and propositions which contribute to limited understanding and appreciation of IT value in international market-entry alliances

Managing five paradoxes of knowledge exchange in networked organizations: new priorities for HRM?

The life-blood of most organizations is knowledge. Too often, the very mechanisms set up to facilitate knowledge-flow militate against it. This is because they are instituted in a top-down way, they are cumbersome to manage and the bridges of trust fail to get built. In their thirst for innovation, the tendency is for firms to set up elaborate transmission channels and governance systems. As a result, staff are drowned in a deluge of mundane intranet messages and bewildered by matrix structures, while off-the-wall ideas and mold-breaking insights are routinely missed. Added to this is the challenge of operating across professional, cultural, regional and linguistic boundaries, where ways of sharing knowledge differ markedly, even within the same project team. Drawing upon extensive research with scientists in the ATLAS collaboration (a high-energy particle physics experiment comprising 3,500 scientists from 38 countries) we explore five paradoxes associated with knowledge exchange in global networks. Each paradox leads to a proposition which takes the theory and practice of knowledge management in a fresh direction. We conclude by outlining a number of HRM priorities for international knowledge-intensive organizations