5,008 research outputs found
Possible open-charmed pentaquark molecule --- the bound state --- in the Bethe-Salpeter formalism
We study the -wave bound state in the Bethe-Salpeter formalism in
the ladder and instantaneous approximations. With the kernel generated by the
hadronic effective Lagrangian, two open-charmed bound states, which quantum
numbers are , and , ,
respectively, are predicted as new candidates of hadronic pentaquark molecules
in our formalism. If existing, they could contribute to the broad 3188 eV
structure near the five new narrow states observed recently by the
LHCb Collaboration.Comment: 8 pages, 4 figures, accepted by Eur. Phys. J.
A Dependency-Based Neural Network for Relation Classification
Previous research on relation classification has verified the effectiveness
of using dependency shortest paths or subtrees. In this paper, we further
explore how to make full use of the combination of these dependency
information. We first propose a new structure, termed augmented dependency path
(ADP), which is composed of the shortest dependency path between two entities
and the subtrees attached to the shortest path. To exploit the semantic
representation behind the ADP structure, we develop dependency-based neural
networks (DepNN): a recursive neural network designed to model the subtrees,
and a convolutional neural network to capture the most important features on
the shortest path. Experiments on the SemEval-2010 dataset show that our
proposed method achieves state-of-art results.Comment: This preprint is the full version of a short paper accepted in the
annual meeting of the Association for Computational Linguistics (ACL) 2015
(Beijing, China
Bis(4,4′-methylenedianilinium) naphthalene-1,5-disulfonate dihydrate
The asymmetric unit of the title salt, C13H16N2
2+·C10H6O6S2
2−·2H2O, consists of one dication located on a general position, half each of two centrosymmetric dianions, and two uncoordinated water molecules in general positions. In the dication, the dihedral angle between the benzene rings is 74.67 (6)°. The cations and anions interact through N—H⋯O hydrogen bonds. The NH3
+ functional groups are also involved in N—H⋯O hydrogen bonds with the water molecules, forming an infinite three-dimensional framework in the crystal structure
Monolayer Molybdenum Disulfide Nanoribbons with High Optical Anisotropy
Two-dimensional Molybdenum Disulfide (MoS2) has shown promising prospects for
the next generation electronics and optoelectronics devices. The monolayer MoS2
can be patterned into quasi-one-dimensional anisotropic MoS2 nanoribbons
(MNRs), in which theoretical calculations have predicted novel properties.
However, little work has been carried out in the experimental exploration of
MNRs with a width of less than 20 nm where the geometrical confinement can lead
to interesting phenomenon. Here, we prepared MNRs with width between 5 nm to 15
nm by direct helium ion beam milling. High optical anisotropy of these MNRs is
revealed by the systematic study of optical contrast and Raman spectroscopy.
The Raman modes in MNRs show strong polarization dependence. Besides that the
E' and A'1 peaks are broadened by the phonon-confinement effect, the modes
corresponding to singularities of vibrational density of states are activated
by edges. The peculiar polarization behavior of Raman modes can be explained by
the anisotropy of light absorption in MNRs, which is evidenced by the polarized
optical contrast. The study opens the possibility to explore
quasione-dimensional materials with high optical anisotropy from isotropic 2D
family of transition metal dichalcogenides
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