8,683 research outputs found
XPS characterization of silver electrodes and catalyst for oxygen reduction
The combined analysis of the silver GDE using an ex-situ surface sensitive technique (XPS) and in-situ electrochemical measurements (EIS, CV) show that the performance of the silver GDE is significantly influenced by the degree of degradation of the electrodes, e. g., the reduction of the active surface due to the decomposition of the PTFE. These findings indicate a different degree of decomposition of the PTFE on the on the GDE
Tunable multi-photon Rabi oscillations in an electronic spin system
We report on multi-photon Rabi oscillations and controlled tuning of a
multi-level system at room temperature (S=5/2 for Mn2+:MgO) in and out of a
quasi-harmonic level configuration. The anisotropy is much smaller than the
Zeeman splittings, such as the six level scheme shows only a small deviation
from an equidistant diagram. This allows us to tune the spin dynamics by either
compensating the cubic anisotropy with a precise static field orientation, or
by microwave field intensity. Using the rotating frame approximation, the
experiments are very well explained by both an analytical model and a
generalized numerical model. The calculated multi-photon Rabi frequencies are
in excellent agreement with the experimental data
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What happens post-deportation? The experience of deported Afghans
Deportation, understood as the physical removal of someone against their will from the territory of one state to that of another, has moved to the forefront of academic and policy agendas. Although there is a growing literature on legislation and policy, there is very little in-depth data on what happens post-deportation. In this article, we examine possible post-deportation outcomes. We argue that, whatever reasons existed for people to migrate in the first place, deportation adds to these and creates at least three additional reasons that make adjustment, integration, or reintegration difficult, if not impossible. These include the impossibility of repaying debts incurred by migration, the existence of transnational and local ties, the shame of failure, and the perceptions of ‘contamination’. We draw on a mixture of quantitative and qualitative data gathered in Europe and Afghanistan to argue that many deported Afghans at- tempt and succeed in re-migrating
Multi-photon Rabi oscillations in high spin paramagnetic impurity
We report on multiple photon monochromatic quantum oscillations (Rabi
oscillations) observed by pulsed EPR (Electron Paramagnetic Resonance) of
Mn (S=5/2) impurities in MgO. We find that when the microwave magnetic
field is similar or large than the anisotropy splitting, the Rabi oscillations
have a spectrum made of many frequencies not predicted by the S=1/2 Rabi model.
We show that these new frequencies come from multiple photon coherent
manipulation of the multi-level spin impurity. We develop a model based on the
crystal field theory and the rotating frame approximation, describing the
observed phenomenon with a very good agreement.Comment: International Conference: Resonance in Condensed Matter Altshuler 10
On Multilingual Training of Neural Dependency Parsers
We show that a recently proposed neural dependency parser can be improved by
joint training on multiple languages from the same family. The parser is
implemented as a deep neural network whose only input is orthographic
representations of words. In order to successfully parse, the network has to
discover how linguistically relevant concepts can be inferred from word
spellings. We analyze the representations of characters and words that are
learned by the network to establish which properties of languages were
accounted for. In particular we show that the parser has approximately learned
to associate Latin characters with their Cyrillic counterparts and that it can
group Polish and Russian words that have a similar grammatical function.
Finally, we evaluate the parser on selected languages from the Universal
Dependencies dataset and show that it is competitive with other recently
proposed state-of-the art methods, while having a simple structure.Comment: preprint accepted into the TSD201
Using Constructive Alignment to Support Metaliteracy in International Classrooms
This paper discusses strategies for promoting literacy and metaliteracy development in international and multicultural classrooms. Drawing on the first author’s observational research and the second author’s expertise in metaliteracy, we present a case study of international postgraduate students in an interdisciplinary department. The authors synthesize their different areas of work to describe how a fusion of metaliteracy, constructive alignment, and learning oriented assessments (LOA) facilitates student engagement with theories of knowledge organization and extensible markup language (XML) data-encoding standards. Our discussion describes curriculum design and redesign strategies and contextualizes observations about student success. The authors’ observations provide a basis for proposing methods for using metaliteracy to implement constructive alignment and LOA methods for promoting collaborative and truly diverse learning
Random access quantum information processors
Qubit connectivity is an important property of a quantum processor, with an
ideal processor having random access -- the ability of arbitrary qubit pairs to
interact directly. Here, we implement a random access superconducting quantum
information processor, demonstrating universal operations on a nine-bit quantum
memory, with a single transmon serving as the central processor. The quantum
memory uses the eigenmodes of a linear array of coupled superconducting
resonators. The memory bits are superpositions of vacuum and single-photon
states, controlled by a single superconducting transmon coupled to the edge of
the array. We selectively stimulate single-photon vacuum Rabi oscillations
between the transmon and individual eigenmodes through parametric flux
modulation of the transmon frequency, producing sidebands resonant with the
modes. Utilizing these oscillations for state transfer, we perform a universal
set of single- and two-qubit gates between arbitrary pairs of modes, using only
the charge and flux bias of the transmon. Further, we prepare multimode
entangled Bell and GHZ states of arbitrary modes. The fast and flexible
control, achieved with efficient use of cryogenic resources and control
electronics, in a scalable architecture compatible with state-of-the-art
quantum memories is promising for quantum computation and simulation.Comment: 7 pages, 5 figures, supplementary information ancillary file, 21
page
The rise of global policy networks in education: analyzing Twitter debates on inclusive education using social network analysis
With the Convention on the Rights of Persons with Disabilities (CRPD), inclusive education has become the main alternative to special schools for the schooling of children with disabilities. In order to promote the global implementation of inclusive education, a variety of stakeholders form networks to transmit and exchange information and knowledge concerning political strategies. However, little is known about the actors and actor groups involved in these networks. In the present paper, we draw on general network theory and policy network theory to examine the Twitter communication network that has formed around the topic of inclusive education. Using exploratory and inferential social network analysis, we show that disabled persons’ organizations and international organizations, such as the United Nations, hold a particularly central position in the network. This position enables them to potentially exert influence on the content and flow of information within the network. Aside from that, business actors are active participants in the network. Moreover, the Twitter network shows some structural patterns that can also be found in policy networks. Our findings help to map the global sphere of inclusive education promotion and can contribute to a broader understanding of global processes in inclusive education policy.info:eu-repo/semantics/acceptedVersio
Normal-mode spectroscopy of a single bound atom-cavity system
The energy-level structure of a single atom strongly coupled to the mode of a
high-finesse optical cavity is investigated. The atom is stored in an
intracavity dipole trap and cavity cooling is used to compensate for inevitable
heating. Two well-resolved normal modes are observed both in the cavity
transmission and the trap lifetime. The experiment is in good agreement with a
Monte Carlo simulation, demonstrating our ability to localize the atom to
within at a cavity antinode.Comment: 4 pages, 4 figure
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