4,909 research outputs found
New integrable boundary conditions for the q-deformed supersymmetric U model and Bethe ansatz equations
New classes of integrable boundary conditions for the q-deformed (or
two-parameter) supersymmetric U model are presented. The boundary systems are
solved by using the coordinate space Bethe ansatz technique and Bethe ansatz
equations are derived.Comment: A few words added; the version to appear in Phys. Lett.
Reflection K-Matrices of the 19-Vertex Model and XXZ Spin-1 Chain with General Boundary Terms
We derive and classify all solutions of the boundary Yang-Baxter equation (or
the reflection equation) for the 19-vertex model associated with
. Integrable spin-1 chain hamiltonian with general
boundary interactions is also obtained.Comment: 14 pages, LaTeX, no figur
A Study on SSVEP-Based BCI
Abstract⎯Brain-computer interface (BCI) can help the deformity person finish some basic activities. In this paper, we concern some critical aspects of SSVEP based BCI, including stimulator selection, method of SSVEP extracting in a short time, stimulating frequency selection, and signal electrode selection. The conclusion is that the stimulator type should be based on the complexity of the BCI system, the method based on wavelet analysis is more valid than the power spectrum method in extracting the SSVEP in a short period, and the selections of stimulating frequency and electrode are important in designing a BCI system. These contents are meaningful for implementing a real SSVEP-based BCI. Index Terms⎯Brain-computer interface, electroencephalogram, steady-state visual evoked potential
Non-diagonal solutions of the reflection equation for the trigonometric vertex model
We obtain a class of non-diagonal solutions of the reflection equation for
the trigonometric vertex model. The solutions can be expressed
in terms of intertwinner matrix and its inverse, which intertwine two
trigonometric R-matrices. In addition to a {\it discrete} (positive integer)
parameter , , the solution contains {\it continuous}
boundary parameters.Comment: Latex file, 14 pages; V2, minor typos corrected and a reference adde
Drinfeld Twists and Algebraic Bethe Ansatz of the Supersymmetric t-J Model
We construct the Drinfeld twists (factorizing -matrices) for the
supersymmetric t-J model. Working in the basis provided by the -matrix (i.e.
the so-called -basis), we obtain completely symmetric representations of the
monodromy matrix and the pseudo-particle creation operators of the model. These
enable us to resolve the hierarchy of the nested Bethe vectors for the
invariant t-J model.Comment: 23 pages, no figure, Latex file, minor misprints are correcte
On the second reference state and complete eigenstates of the open XXZ chain
The second reference state of the open XXZ spin chain with non-diagonal
boundary terms is studied. The associated Bethe states exactly yield the second
set of eigenvalues proposed recently by functional Bethe Ansatz. In the
quasi-classical limit, two sets of Bethe states give the complete eigenstates
of the associated Gaudin model.Comment: Latex file, 12 pages; New version appears in JHE
Exact solution of the trigonometric vertex model with non-diagonal open boundaries
The trigonometric vertex model with {\it generic
non-diagonal} boundaries is studied. The double-row transfer matrix of the
model is diagonalized by algebraic Bethe ansatz method in terms of the
intertwiner and the corresponding face-vertex relation. The eigenvalues and the
corresponding Bethe ansatz equations are obtained.Comment: Latex file, 25 pages; V2: minor typos corrected, the version appears
in JHE
Isospin dependence of projectile-like fragment production at intermediate energies
The cross sections of fragments produced in 140 MeV Ca + Be
and Ni + Be reactions are calculated by the statistical
abration-ablation(SAA) model and compared to the experimental results measured
at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State
University. The fragment isotopic and isotonic cross section distributions of
Ca and Ca, Ni and Ni, Ca and Ni, and
Ca and Ni are compared and the isospin dependence of the
projectile fragmentation is studied. It is found that the isospin dependence
decreases and disappears in the central collisions. The shapes of the fragment
isotopic and isotonic cross section distributions are found to be very similar
for symmetric projectile nuclei. The shapes of the fragment isotopic and
isotonic distributions of different asymmetric projectiles produced in
peripheral reactions are found very similar. The similarity of the
distributions are related to the similar proton and neutron density
distributions inside the nucleus in framework of the SAA model.Comment: 7 pages, 4 figures; to be published in Phys Rev
A strategy to tailor the mechanical and degradation properties of PCL-PEG-PCL based copolymers for biomedical application
Biodegradable and biocompatible 3D printable biomaterials with tunable
mechanical properties and degradation rate adapted to target tissues were
urgently required to manufacture scaffolds for tissue regeneration. Herein, a
strategy based on a series of copolymers are proposed where the mechanical and
degradation properties can be optimized regarding the specific biological
application. With this purpose, poly(-caprolactone)-poly(ethylene
glycol)-poly(-caprolactone) (PCL-PEG-PCL, PCEC) triblock co-polymers
with high molecular weight were synthesized by using PEG with a wide range of
molecular weight (from 0.6 kg/mol to 35 kg/mol) as macroinitiators. PCEC
copolymers exhibited tunable mechanical properties with an elastic modulus in
the range 338-705 MPa and a degradation rate from 60% mass loss after 8 h to
70% mass loss after 23 days in accelerated tests, as well as excellent
cytocompatibility and cell attachment after culture with mouse fibroblast L929
cells. The mechanisms responsible for these properties were ascertained by
means of different techniques to ascertain the structure-property relationship
in PCEC copolymers. Furthermore, it was shown that it is possible to
manufacture PCEC scaffolds by 3D printing with excellent dimensional accuracy
and controlled microporosity. This study provides a promising strategy to
design, select, and fabricate copolymers with tunable mechanical properties and
degradation rate for tissue engineering applications
Drinfeld twists of the open XXZ chain with non-diagonal boundary terms
The Drinfeld twists or factorizing F-matrices for the open XXZ spin chain
with non-diagonal boundary terms are constructed. It is shown that in the
F-basis the two sets of pseudo-particle creation operators simultaneously take
completely symmetric and polarization free form. The explicit and completely
symmetric expressions of the two sets of Bethe states of the model are
obtained.Comment: Latex file, 25 page
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