31,636 research outputs found

    δ\delta meson effects on neutron stars in the modified quark-meson coupling model

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    The properties of neutron stars are investigated by including δ\delta meson field in the Lagrangian density of modified quark-meson coupling model. The Σ\Sigma^- population with δ\delta meson is larger than that without δ\delta meson at the beginning, but it becomes smaller than that without δ\delta meson as the appearance of Ξ\Xi^-. The δ\delta meson has opposite effects on hadronic matter with or without hyperons: it softens the EOSes of hadronic matter with hyperons, while it stiffens the EOSes of pure nucleonic matter. Furthermore, the leptons and the hyperons have the similar influence on δ\delta meson effects. The δ\delta meson increases the maximum masses of neutron stars. The influence of (σ,ϕ)(\sigma^*,\phi) on the δ\delta meson effects are also investigated.Comment: 10 pages, 6 figures, 4 table

    A Simultaneous Quantum Secure Direct Communication Scheme between the Central Party and Other M Parties

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    We propose a simultaneous quantum secure direct communication scheme between one party and other three parties via four-particle GHZ states and swapping quantum entanglement. In the scheme, three spatially separated senders, Alice, Bob and Charlie, transmit their secret messages to a remote receiver Diana by performing a series local operations on their respective particles according to the quadripartite stipulation. From Alice, Bob, Charlie and Diana's Bell measurement results, Diana can infer the secret messages. If a perfect quantum channel is used, the secret messages are faithfully transmitted from Alice, Bob and Charlie to Diana via initially shared pairs of four-particle GHZ states without revealing any information to a potential eavesdropper. As there is no transmission of the qubits carrying the secret message in the public channel, it is completely secure for the direct secret communication. This scheme can be considered as a network of communication parties where each party wants to communicate secretly with a central party or server.Comment: 4 pages, no figur

    The trispectrum in ghost inflation

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    We calculate the trispectrum in ghost inflation where both the contact diagram and scale-exchange diagram are taken into account. The shape of trispectrum is discussed carefully and we find that the local form is absent in ghost inflation. In general, for the non-local shape trispectrum there are not analogous parameters to τNLloc.\tau_{NL}^{loc.} and gNLloc.g_{NL}^{loc.} which can completely characterize the size of local form trispectrum.Comment: 19 pages, 8 figures; clarifications and corrections added, version accepted for publication in JCA

    Probabilistic teleportation of unknown two-particle state via POVM

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    We propose a scheme for probabilistic teleportation of unknown two-particle state with partly entangled four-particle state via POVM. In this scheme the teleportation of unknown two-particle state can be realized with certain probability by performing two Bell state measurements, a proper POVM and a unitary transformation.Comment: 5 pages, no figur

    Consistency of shared reference frames should be reexamined

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    In a recent Letter [G. Chiribella et al., Phys. Rev. Lett. 98, 120501 (2007)], four protocols were proposed to secretly transmit a reference frame. Here We point out that in these protocols an eavesdropper can change the transmitted reference frame without being detected, which means the consistency of the shared reference frames should be reexamined. The way to check the above consistency is discussed. It is shown that this problem is quite different from that in previous protocols of quantum cryptography.Comment: 3 pages, 1 figure, comments are welcom

    Nonlinear alternating current responses of graded materials

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    When a composite of nonlinear particles suspended in a host medium is subjected to a sinusoidal electric field, the electrical response in the composite will generally consist of alternating current (AC) fields at frequencies of higher-order harmonics. The situation becomes more interesting when the suspended particles are graded, with a spatial variation in the dielectric properties. The local electric field inside the graded particles can be calculated by the differential effective dipole approximation, which agrees very well with a first-principles approach. In this work, a nonlinear differential effective dipole approximation and a perturbation expansion method have been employed to investigate the effect of gradation on the nonlinear AC responses of these composites. The results showed that the fundamental and third-harmonic AC responses are sensitive to the dielectric-constant and/or nonlinear-susceptibility gradation profiles within the particles. Thus, by measuring the AC responses of the graded composites, it is possible to perform a real-time monitoring of the fabrication process of the gradation profiles within the graded particles.Comment: 18 pages, 4 figure

    Co-pyrolysis kinetics analysis of stone coal and biomass for vanadium extraction

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    In this paper, co-pyrolysis of stone coal and biomass was performed. The activation energy of pyrolysis was analyzed, and the mechanism of biomass on the stone coal pyrolysis was discussed. The results show that biomass contributed to the pyrolysis of stone coal. The optimum pyrolysis heating rate of the biomass and stone coal was 25 °C/min and 20 °C/min respectively. The alkaline and alkaline earth metals derived from biomass pyrolysis improved thermal decompose of stone coal, yet stone coal inhibited biomass pyrolysis under co-pyrolysis conditions. The promotion of corn stalk on the stone coal pyrolysis was better than that of sawdust

    Co-pyrolysis kinetics analysis of stone coal and biomass for vanadium extraction

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    In this paper, co-pyrolysis of stone coal and biomass was performed. The activation energy of pyrolysis was analyzed, and the mechanism of biomass on the stone coal pyrolysis was discussed. The results show that biomass contributed to the pyrolysis of stone coal. The optimum pyrolysis heating rate of the biomass and stone coal was 25 °C/min and 20 °C/min respectively. The alkaline and alkaline earth metals derived from biomass pyrolysis improved thermal decompose of stone coal, yet stone coal inhibited biomass pyrolysis under co-pyrolysis conditions. The promotion of corn stalk on the stone coal pyrolysis was better than that of sawdust

    The 7-channel FIR HCN Interferometer on J-TEXT Tokamak

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    A seven-channel far-infrared hydrogen cyanide (HCN) laser interferometer has been established aiming to provide the line integrated plasma density for the J-TEXT experimental scenarios. A continuous wave glow discharge HCN laser designed with a cavity length 3.4 m is used as the laser source with a wavelength of 337 {\mu}m and an output power up to 100 mW. The system is configured as a Mach-Zehnder type interferometer. Phase modulation is achieved by a rotating grating, with a modulation frequency of 10 kHz which corresponds to the temporal resolution of 0.1 ms. The beat signal is detected by TGS detector. The phase shift induced by the plasma is derived by the comparator with a phase sensitivity of 0.06 fringe. The experimental results measured by the J-TEXT interferometer are presented in details. In addition, the inversed electron density profile done by a conventional approach is also given. The kinematic viscosity of dimethyl silicone and vibration control is key issues for the system performance. The laser power stability under different kinematic viscosity of silicone oil is presented. A visible improvement of measured result on vibration reduction is shown in the paper.Comment: conference (15th-International Symposium on Laser-Aided Plasma Diagnostics
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