702 research outputs found
Technical note: Characterization of key volatile odorants in rabbit meat using gas chromatography mass spectrometry with simultaneous distillation extraction
[EN] This study explored the key volatile compounds in both male and female rabbit meat. Simultaneous distillation extraction with dichloromethane was adopted to extract the volatile compounds in Hyla rabbit meat. A total of 35 volatile compounds were identified by gas chromatography–mass spectrometry and quantified with 2, 4, 6-thimethylpyridine as internal standard. Seventeen volatile aldehydes, 4 alcohols, 2 ketones, 2 acids, 1 heterocyclic compound, 2 alkanes and 7 esters were detected. Hexanal, heptanal, octanal, nonanal, (E, E)-2, 4-decadienal, 1-octen-3-ol and (Z)-2-decenal were the key odorant compounds, with high relative odour activity value. Furthermore, the concentration of volatile compounds in male rabbit meat was higher than that in female rabbit meat.This work was supported by the National Natural Science Foundation of China (31671787), the Chinese
Rabbit Industry System of Education Ministry (100030-40305411) and Fundamental Research Funds for the Central Universities
(XDJK2014D042).Xie, Y.; He, Z.; Zhang, E.; Li, H. (2016). Technical note: Characterization of key volatile odorants in rabbit meat using gas chromatography mass spectrometry with simultaneous distillation extraction. World Rabbit Science. 24(4):313-320. https://doi.org/10.4995/wrs.2016.4464SWORD31332024
Interlayer Exchange Interactions, SU(4) Soft Waves and Skyrmions in Bilayer Quantum Hall Ferromagnets
The Coulomb exchange interaction is the driving force for quantum coherence
in quantum Hall systems. We construct a microscopic Landau-site Hamiltonian for
the exchange interaction in bilayer quantum Hall ferromagnets, which is
characterized by the SU(4) isospin structure. By taking a continuous limit, the
Hamiltonian gives rise to the SU(4) nonlinear sigma model in the
von-Neumann-lattice formulation. The ground-state energy is evaluated at
filling factors . It is shown at that there are 3
independent soft waves, where only one soft wave is responsible for the
coherent tunneling of electrons between the two layers. It is also shown at
that there are 3 independent skyrmion states apart from the
translational degree of freedom. They are CP skyrmions enjoying the
spin-charge entanglement confined within the \LLL.Comment: 12 pages, 2 figure
Statistics of skyrmions in Quantum Hall systems
We analyze statistical interactions of skyrmions in the quantum Hall system
near a critical filling fraction in the framework of the Ginzburg-Landau model.
The phase picked up by the wave-function during an exchange of two skyrmions
close to is , where is the skyrmion's
spin. In the same setting an exchange of two fully polarized vortices gives
rise to the phase . Skyrmions with odd and even numbers of reversed
spins have different quantum statistics. Condensation of skyrmions with an even
number of reversed spins leads to filling fractions with odd denominators,
while condensation of those with an odd number of reversed spins gives rise to
filling fractions with even denominators.Comment: 6 pages in Latex. addendum - skyrmions with odd or even number of
reversed spins have different quantum statistics. They condense to form
respectively even or odd denominator filling fraction state
Quantum Coherence and W_infty*SU(2) Algebra in Bilayer Quantum Hall Systems
We analyze the bilayer quantum Hall (QH) system by mapping it to the
monolayer QH system with spin degrees of freedom. By this mapping the tunneling
interaction term is identified with the Zeeman term. We clarify the mechanism
of a spontaneous development of quantum coherence based on the Chern-Simons
gauge theory with the lowest-Landau-Level projection taken into account. The
symmetry group is found to be W_infty*SU(2), which says that the spin rotation
affects the total electron density nearby. Using it extensively we construct
the Landau-Ginzburg theory of the coherent mode. Skyrmion excitations are
topological solitons in this coherent mode. We point out that they are
detectable by measuring the Hall current distribution.Comment: 15pages, Phys. Lett. A (in press
Electromagnetic characteristics of bilayer quantum Hall systems in the presence of interlayer coherence and tunneling
The electromagnetic characteristics of bilayer quantum Hall systems in the
presence of interlayer coherence and tunneling are studied by means of a
pseudospin-texture effective theory and an algebraic framework of the
single-mode approximation, with emphasis on clarifying the nature of the
low-lying neutral collective mode responsible for interlayer tunneling
phenomena. A long-wavelength effective theory, consisting of the collective
mode as well as the cyclotron modes, is constructed. It is seen explicitly from
the electromagnetic response that gauge invariance is kept exact, this
implying, in particular, the absence of the Meissner effect in bilayer systems.
Special emphasis is placed on exploring the advantage of looking into quantum
Hall systems through their response; in particular, subtleties inherent to the
standard Chern-Simons theories are critically examined.Comment: 9 pages, Revtex, to appear in Phys. Rev.
Improved Composite-Boson Theory of Monolayer and Bilayer Quantum Hall Ferromagnets
An improved composite-boson theory of quantum Hall ferromagnets is formulated
both for the monolayer and bilayer systems. In this scheme the field operator
describes solely the physical degrees of freedom representing the deviation
from the ground state. Skyrmions are charged excitations confined to the lowest
Landau level. By evaluating the excitation energy of one skyrmion in the
interlayer-coherent phase it is shown that the bilayer QH state becomes stabler
as the interlayer density difference becomes larger.Comment: 14 pages including 1 figure; Physics Letters A (to be published
Charged bottomonium-like structures and
The observation of two charged bottomonium-like structures and
has stimulated extensive studies of the properties of
and . In this talk, we briefly introduce the research status of
and combined with our theoretical progress.Comment: 6 pages, 1 table, 5 figures. Plenary talk given at the international
conference The Fifth Asia-Pacific Conference on Few-Body Systems in Physics
2011 (APFB2011), Seoul, Republic of Korea, 22-26 August 201
Quantum Ferromagnetism and Phase Transitions in Double-Layer Quantum Hall Systems
Double layer quantum Hall systems have interesting properties associated with
interlayer correlations. At where is an odd integer they exhibit
spontaneous symmetry breaking equivalent to that of spin easy-plane
ferromagnets, with the layer degree of freedom playing the role of spin. We
explore the rich variety of quantum and finite temperature phase transitions in
these systems. In particular, we show that a magnetic field oriented parallel
to the layers induces a highly collective commensurate-incommensurate phase
transition in the magnetic order.Comment: 4 pages, REVTEX 3.0, IUCM93-013, 1 FIGURE, hardcopy available from:
[email protected]
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