31,659 research outputs found
New Terms for the Compact Form of Electroweak Chiral Lagrangian
The compact form of the electroweak chiral Lagrangian is a reformulation of
its original form and is expressed in terms of chiral rotated electroweak gauge
fields, which is crucial for relating the information of underlying theories to
the coefficients of the low-energy effective Lagrangian. However the compact
form obtained in previous works is not complete. In this letter we add several
new chiral invariant terms to it and discuss the contributions of these terms
to the original electroweak chiral Lagrangian.Comment: 3 pages, references adde
Quantum Spin Hall and Quantum Anomalous Hall States Realized in Junction Quantum Wells
Both quantum spin Hall and quantum anomalous Hall states are novel states of
quantum matter with promising applications. We propose junction quantum wells
comprising II-VI, III-V or IV semiconductors as a large class of new materials
realizing the quantum spin Hall state. Especially, we find that the bulk band
gap for the quantum spin Hall state can be as large as 0.1 eV. Further more,
magnetic doping would induce the ferromagnetism in these junction quantum wells
due to band edge singularities in the band-inversion regime and to realize the
quantum anomalous Hall state.Comment: 5 pages, 4 figure
Post-MH370 Incident: A Comparative Study of Social Media Users' Perception in China and Malaysia
The flow of information experienced complexity uncertainty and ambiguity in terms
of information adequacy when Malaysia Airlines flight MH370 went missing. This
incident demonstrated an unprecedented international humanitarian response
from the technology sector. This study discovered that most respondents from
Mainland China and Malaysia access information about Malaysia Airlines flight
MH370 during and after the tragic incident through social media. This study revealed
significant difference of active social media users' perceptions on this incident in
these two countries. On one hand, social networking sites such as Facebook (in
Malaysia), Weibo and Wechat (in China), become the public opinion field that
illustrates sorts of openness and negotiation in Malaysia and China. This study,
instead of conventional crisis communication approach, specifically examined
active online users in both countries, as it aims to make a valuable contribution
by synthesizing current research and identifying areas for investigation for each
aspect of the survey process. Two hundred questionnaires had been collected
from respondents in China and Malaysia respectively. The survey results
contributed to mechanism of crisis communication for henceforth similar incident
in the future. There is no doubt that the portrait of Malaysia Airlines on social
media in these two countries affected its organizational reputation. However, the
participants from Malaysia and China showed a very average level of confidence
to empower themselves to enhance dialog capacity among various stakeholders
for this inciden
Hydrothermal synthesis of α-MnO<inf>2</inf> and β-MnO <inf>2</inf> nanorods as high capacity cathode materials for sodium ion batteries
Two types of MnO2 polymorphs, α-MnO2 and β-MnO2 nanorods, have been synthesized by a hydrothermal method. Their crystallographic phases, morphologies, and crystal structures were characterized by XRD, FESEM and TEM analysis. Different exposed crystal planes have been identified by TEM. The electrochemical properties of α-MnO 2 and β-MnO2 nanorods as cathode materials in Na-ion batteries were evaluated by galvanostatic charge/discharge testing. Both α-MnO2 and β-MnO2 nanorods achieved high initial sodium ion storage capacities of 278 mA h g-1 and 298 mA h g-1, respectively. β-MnO2 nanorods exhibited a better electrochemical performance such as good rate capability and cyclability than that of α-MnO2 nanorods, which could be ascribed to a more compact tunnel structure of β-MnO2 nanorods. Furthermore, the one-dimensional architecture of nanorods could also contribute to facile sodium ion diffusion in the charge and discharge process. © The Royal Society of Chemistry 2013
SnO<inf>2</inf>@graphene nanocomposites as anode materials for Na-ion batteries with superior electrochemical performance
An in situ hydrothermal synthesis approach has been developed to prepare SnO2@graphene nanocomposites. The nanocomposites exhibited a high reversible sodium storage capacity of above 700 mA h g-1 and excellent cyclability for Na-ion batteries. In particular, they also demonstrated a good high rate capability for reversible sodium storage. © 2013 The Royal Society of Chemistry
The challenge of acute-stroke management: does telemedicine offer a solution?
<p><b>Background:</b> Several studies have described successful experiences with the use of telemedicine in acute stroke. The objective of this study was to assess the feasibility, acceptability, and treatment delivery reliability, of telemedicine systems for the clinical and radiological assessment, and management of acute-stroke patients.</p>
<p><b>Summary of Review:</b> A systematic review of the literature was carried out. Studies were included if they met the following criteria: (1) study population included participants with a diagnosis of suspected acute stroke, (2) intervention included the use of telemedicine systems to aid assessment, diagnosis, or treatment in acute stroke, and (3) outcomes measured related to feasibility in clinical practice, acceptability to patients, carers, and staff, reliability of telemedicine systems, and effectiveness in delivering treatment, especially tissue plasminogen activator (tPA). Overall, 17 relevant non-randomised studies reported that telemedicine systems were feasible and acceptable. Interrater reliability was excellent for global clinical assessments and decisions on radiological exclusion criteria although agreement for individual assessment items was more variable. Telemedicine systems were associated with increased use of tPA.</p>
<p><b>Conclusion:</b> Although there is limited reliable evidence, observational studies have indicated that telemedicine systems can be feasible, acceptable, and reliable in acute-stroke management. In addition, telemedicine consultations were associated with improved delivery of tPA.</p>
Hydrothermal synthesis of I?-MnO2 and I?-MnO2 nanorods as high capacity cathode materials for sodium ion batteries
Two types of MnO2 polymorphs, I?-MnO2 and I?-MnO2 nanorods, have been synthesized by a hydrothermal method. Their crystallographic phases, morphologies, and crystal structures were characterized by XRD, FESEM and TEM analysis. Different exposed crystal planes have been identified by TEM. The electrochemical properties of I?-MnO2 and I?-MnO2 nanorods as cathode materials in Na-ion batteries were evaluated by galvanostatic charge/discharge testing. Both I?-MnO2 and I?-MnO2 nanorods achieved high initial sodium ion storage capacities of 278 mA h ga??1 and 298 mA h ga??1, respectively. I?-MnO2 nanorods exhibited a better electrochemical performance such as good rate capability and cyclability than that of I?-MnO2 nanorods, which could be ascribed to a more compact tunnel structure of I?-MnO2 nanorods. Furthermore, the one-dimensional architecture of nanorods could also contribute to facile sodium ion diffusion in the charge and discharge process
4D dynamic management for construction planning and resource utilization
Author name used in this publication: K. W. Chau2003-2004 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Crystal growth and quantum oscillations in the topological chiral semimetal CoSi
We survey the electrical transport properties of the single-crystalline,
topological chiral semimetal CoSi which was grown via different methods.
High-quality CoSi single crystals were found in the growth from tellurium
solution. The sample's high carrier mobility enables us to observe, for the
first time, quantum oscillations (QOs) in its thermoelectrical signals. Our
analysis of QOs reveals two spherical Fermi surfaces around the R point in the
Brillouin zone corner. The extracted Berry phases of these electron orbits are
consistent with the -2 chiral charge as reported in DFT calculations. Detailed
analysis on the QOs reveals that the spin-orbit coupling induced band-splitting
is less than 2 meV near the Fermi level, one order of magnitude smaller than
our DFT calculation result. We also report the phonon-drag induced large Nernst
effect in CoSi at intermediate temperatures
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