20,493 research outputs found
Hadronic Molecular States Composed of Spin- Singly Charmed Baryons
We investigate the possible deuteron-like molecules composed of a pair of
charmed spin- baryons, or one charmed baryon and one charmed
antibaryon within the one-boson-exchange (OBE) model. For the spin singlet and
triplet systems, we consider the couple channel effect between systems with
different orbital angular momentum. Most of the systems have binding solutions.
The couple channel effect plays a significant role in the formation of some
loosely bound states. The possible molecular states of
and might be stable once produced.Comment: 18 pages, 7 figure
Development of high resolution arrayed waveguide grating spectrometers for astronomical applications: first results
Astrophotonics is the next-generation approach that provides the means to
miniaturize near-infrared (NIR) spectrometers for upcoming large telescopes and
make them more robust and inexpensive. The target requirements for our
spectrograph are: a resolving power of about 3000, wide spectral range (J and H
bands), free spectral range of about 30 nm, high on-chip throughput of about
80% (-1dB) and low crosstalk (high contrast ratio) between adjacent on-chip
wavelength channels of less than 1% (-20dB). A promising photonic technology to
achieve these requirements is Arrayed Waveguide Gratings (AWGs). We have
developed our first generation of AWG devices using a silica-on-silicon
substrate with a very thin layer of silicon-nitride in the core of our
waveguides. The waveguide bending losses are minimized by optimizing the
geometry of the waveguides. Our first generation of AWG devices are designed
for H band and have a resolving power of around 1500 and free spectral range of
about 10 nm around a central wavelength of 1600 nm. The devices have a
footprint of only 12 mm x 6 mm. They are broadband (1450-1650 nm), have a peak
on-chip throughput of about 80% (-1 dB) and contrast ratio of about 1.5% (-18
dB). These results confirm the robustness of our design, fabrication and
simulation methods. Currently, the devices are designed for Transverse Electric
(TE) polarization and all the results are for TE mode. We are developing
separate J- and H-band AWGs with higher resolving power, higher throughput and
lower crosstalk over a wider free spectral range to make them better suited for
astronomical applications.Comment: 12 pages, 13 figures, 3 tables. SPIE Astronomical Telescopes and
Instrumentation, Edinburgh (26 June - 1 July, 2016
Dynamics of Quincke Particles with Tunable Memory
Memory can remarkably modify the collective behaviors of active particles. In
Quincke systems driven by electric fields, the memory of particles, in the form
of relaxation of polarization, has been taken to account for the run-and-tumble
behaviors under periodical driving. However, we show that the memory of Quincke
particles is generally a product of multiple mechanisms including inertia and
depolarization. The memory of Quincke particles can be tuned and enhanced by
the parameters of electric fields. Moreover, the interplay between inertia and
propulsion results in a frequency-dependent mobility such that a balance
between activity and attraction can be reached, giving rise to the formation of
dense active clusters. The memory in dense clusters becomes even more
significant because of the strong electrostatic interactions. Combining the
tunable memory and the adjustable mobility, a rich variety of collective
motions can be realized. These findings offer new insights into the dynamics of
active matter and have broad interests in periodically driven active systems.Comment: 14 pages,6 figures, 3 movie
Integrable Open Spin Chains from Flavored ABJM Theory
We compute the two-loop anomalous dimension matrix in the scalar sector of
planar flavored ABJM theory. Using coordinate Bethe ansatz, we
obtain the reflection matrix and confirm that the boundary Yang-Baxter
equations are satisfied. This establishes the integrability of this theory in
the scalar sector at the two-loop order.Comment: v2, 25 pages, 2 figures, minor corrections, references adde
A mutual authentication and key update protocol in satellite communication network
Satellite communication networks have been widely used to provide essential communication services, including voice communication, global positioning, message communication, etc. However, sorts of network attacks are easy to be launched in these networks due to the limited computation capability and communication width, long communication delay, and intermittent link connection. In this paper, we first propose a new [E]ncryption-based [M]utual [A]uthentication and [K]ey [U]pdate (EMAKU) protocol in satellite communication networks. Next we analyze the security of the EMAKU protocol under two classic network attacks which are replay attack and man-in-the-middle attack. Finally, experiments show that the EMAKU protocol is 21.5% faster than the traditional encryption-based authentication protocols, and the average time of key update of the EMAKU protocol is about 450.01 ms
Using Artificial Neural Networks to Produce High-Resolution Soil Property Maps
High-resolution maps of soil property are considered as the most important inputs for decision support and policy-making in agriculture, forestry, flood control, and environmental protection. Commonly, soil properties are mainly obtained from field surveys. Field soil surveys are generally time-consuming and expensive, with a limitation of application throughout a large area. As such, high-resolution soil property maps are only available for small areas, very often, being obtained for research purposes. In the chapter, artificial neural network (ANN) models were introduced to produce high-resolution maps of soil property. It was found that ANNs can be used to predict high-resolution soil texture, soil drainage classes, and soil organic content across landscape with reasonable accuracy and low cost. Expanding applications of the ANNs were also presented
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