697 research outputs found

    Technical note: Characterization of key volatile odorants in rabbit meat using gas chromatography mass spectrometry with simultaneous distillation extraction

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    [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

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    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 ν=1,2,3,4\nu =1,2,3,4. It is shown at ν=1\nu =1 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 ν=1\nu =1 that there are 3 independent skyrmion states apart from the translational degree of freedom. They are CP3^{3} skyrmions enjoying the spin-charge entanglement confined within the \LLL.Comment: 12 pages, 2 figure

    Statistics of skyrmions in Quantum Hall systems

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    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 ν=1/(2n+1)\nu=1/(2n+1) is π[S+1/2(2n+1)]\pi[S+1/2(2n+1)], where SS is the skyrmion's spin. In the same setting an exchange of two fully polarized vortices gives rise to the phase π/(2n+1)\pi/(2n+1). 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

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    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

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    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

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    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 Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650)

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    The observation of two charged bottomonium-like structures Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650) has stimulated extensive studies of the properties of Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650). In this talk, we briefly introduce the research status of Zb(10610)Z_b(10610) and Zb(10650)Z_b(10650) 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

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    Double layer quantum Hall systems have interesting properties associated with interlayer correlations. At ν=1/m\nu =1/m where mm is an odd integer they exhibit spontaneous symmetry breaking equivalent to that of spin 1/21/2 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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