21,941 research outputs found
Electromechanical tuning of vertically-coupled photonic crystal nanobeams
We present the design, the fabrication and the characterization of a tunable
one-dimensional (1D) photonic crystal cavity (PCC) etched on two
vertically-coupled GaAs nanobeams. A novel fabrication method which prevents
their adhesion under capillary forces is introduced. We discuss a design to
increase the flexibility of the structure and we demonstrate a large reversible
and controllable electromechanical wavelength tuning (> 15 nm) of the cavity
modes.Comment: 11 pages, 4 figure
Measurements of the Rate Capability of Various Resistive Plate Chambers
Resistive Plate Chambers (RPCs) exhibit a significant loss of efficiency for
the detection of particles, when subjected to high particle fluxes. This rate
limitation is related to the usually high resistivity of the resistive plates
used in their construction. This paper reports on measurements of the
performance of three different glass RPC designs featuring a different total
resistance of the resistive plates. The measurements were performed with 120
GeV protons at varying beam intensitie
Fermi surface topology and low-lying quasiparticle structure of magnetically ordered Fe1+xTe
We report the first photoemission study of Fe1+xTe - the host compound of the
newly discovered iron-chalcogenide superconductors. Our results reveal a pair
of nearly electron- hole compensated Fermi pockets, strong Fermi velocity
renormalization and an absence of a spin-density-wave gap. A shadow hole pocket
is observed at the "X"-point of the Brillouin zone which is consistent with a
long-range ordered magneto-structural groundstate. No signature of Fermi
surface nesting instability associated with Q= pi(1/2, 1/2) is observed. Our
results collectively reveal that the Fe1+xTe series is dramatically different
from the undoped phases of the high Tc pnictides and likely harbor unusual
mechanism for superconductivity and quantum magnetic order.Comment: 5 pages, 4 Figures; Submitted to Phys. Rev. Lett. (2009
Moderate deviation principle for ergodic Markov chain. Lipschitz summands
For , we propose the MDP analysis for family where
be a homogeneous ergodic Markov chain, ,
when the spectrum of operator is continuous. The vector-valued function
is not assumed to be bounded but the Lipschitz continuity of is
required. The main helpful tools in our approach are Poisson's equation and
Stochastic Exponential; the first enables to replace the original family by
with a martingale while the second to avoid the
direct Laplace transform analysis
Prediction of Postchemotherapy Ovarian Function Using Markers of Ovarian Reserve
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140040/1/onco0068.pd
RIS-Assisted Integrated Sensing and Backscatter Communications for Future IoT Networks
Reconfigurable intelligent surface (RIS), by intelligently manipulating the incident waveform, offers a spectral and energy efficient capability for improving sensing and communication performance. In this article, we introduce a novel concept of RIS-assisted integrated sensing and backscatter communication (ISABC) system, by introducing RIS as either helper or transceiver to resolve the energy constraint of devices in internet of things (IoT) network and enable non line-of-sight (NLoS) sensing. We first introduce the RIS-assisted ISABC framework, including the system architecture and realization of RIS. Three potential applications are then discussed, with the analysis on their requirements. The research on several critical techniques for the RIS-assisted ISABC system is then discussed. Finally, we provide our vision of the challenges and future research directions to facilitate the development of the RIS-assisted ISABC systems
Cyclic cosmology from Lagrange-multiplier modified gravity
We investigate cyclic and singularity-free evolutions in a universe governed
by Lagrange-multiplier modified gravity, either in scalar-field cosmology, as
well as in one. In the scalar case, cyclicity can be induced by a
suitably reconstructed simple potential, and the matter content of the universe
can be successfully incorporated. In the case of -gravity, cyclicity can
be induced by a suitable reconstructed second function of a very
simple form, however the matter evolution cannot be analytically handled.
Furthermore, we study the evolution of cosmological perturbations for the two
scenarios. For the scalar case the system possesses no wavelike modes due to a
dust-like sound speed, while for the case there exist an oscillation
mode of perturbations which indicates a dynamical degree of freedom. Both
scenarios allow for stable parameter spaces of cosmological perturbations
through the bouncing point.Comment: 8 pages, 3 figures, references added, accepted for publicatio
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