A universal symplectic structure for a Newtonian system including nonconservative cases can be constructed in the framework of Birkhoffian generalization of Hamiltonian mechanics. In this paper the symplectic geometry...A universal symplectic structure for a Newtonian system including nonconservative cases can be constructed in the framework of Birkhoffian generalization of Hamiltonian mechanics. In this paper the symplectic geometry structure of Birkhoffian system is discussed, then the symplecticity of Birkhoffian phase flow is presented. Based on these properties we give a way to construct symplectic schemes for Birkhoffian systems by using the generating function method.展开更多
By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson-Kolb model has been previously studied by several groups. Some physicists argued that, a...By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson-Kolb model has been previously studied by several groups. Some physicists argued that, as far as the existence of superconductivity in this model is concerned, it is canonically equivalent to the negative-U Hubbard model.However, others did not agree. In the present paper, we shall investigate this model by an independent and rigorous approach. We show that the ground state of the Penson-Kolb model is nondegenerate and has a nonvanishing overlap with the ground state of the negative-U Hubbard model. Furthermore, we also show that the ground states of both the models have the same good quantum numbers and may have superconducting long-range order at the same momentum q ＝ 0. Our results support the equivalence between these models.展开更多
By using the density matrix renormalization group technique, the phase diagram of the half-tilting extended Hubbard model is investigated. The conventional order parameter, the two-site entanglement entropy, and the b...By using the density matrix renormalization group technique, the phase diagram of the half-tilting extended Hubbard model is investigated. The conventional order parameter, the two-site entanglement entropy, and the block- block entanglement entropy are analyzed in detail. According to the numerical results, in the weak coupling region, an intermediate bond-order-wave （BOW） phase is shown to exist indeed between the charge-density-wave （CDW） and the spin-density-wave （SDW） phases. The critical phase transition points are determined by the singularity of the first order derivative of two-site entanglement entropy. In strong coupling region, a direct phase transition occurs from SDW phase to CDW phase, and shows discontinuous （first order） character accompanied with energy level crossing. The numerical results support the phase diagram proposed previously by some authors Sengupta et al., （2002）; Sandvik et al., （2004）; Zhang, （2004）. Therefore, the quantum entanglement is a sensitive tool to describe quantum phase transitions in strongly correlated electron systems.展开更多
A method, named XHJ-method, is proposed in this letter to determine the number of clusters of a data set, which incorporates with the Fuzzy Reinforced Learning Vector Quantization (FRLVQ) technique. The simulation res...A method, named XHJ-method, is proposed in this letter to determine the number of clusters of a data set, which incorporates with the Fuzzy Reinforced Learning Vector Quantization (FRLVQ) technique. The simulation results show that this new method works well for the traditional iris data and an artificial data set, which contains un-equally sized and spaced clusters.展开更多
To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperatu...To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China： No.4 by volume 3,200 m3 of “Jinan Iron ＆ Steel Company” in Jinan （683 thermocouples）, No.2 by volume 1,080 m3 of “Henan Jiyuan Iron ＆ Steel （Group） Company” in Jiyuan （212 thermocouples）, No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron ＆ Steel （Group） Company” in Liuzhou （383 thermocouples）, No.3 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）; No.1 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）.展开更多
In this paper,we investigate the spontaneously generated coherence(SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system.By using a strong control...In this paper,we investigate the spontaneously generated coherence(SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system.By using a strong control field, in the absense of SGC effects,strong correlation and anticorrelation fluorescence photons can be produced from two ladder transitions in this system respectively.However,in the presence of SGC effects,the fluorescence fields correlation properties are reversed for the two transitions.The above phenomena can be traced to the quantum destructive or constructive interference in terms of dressed states.展开更多
Numerous candidates for exotic hadrons have been detected experimentally in the past two decades,predominantly near the threshold of a pair of hadrons.This study aims to investigate the overall behavior of nearthresho...Numerous candidates for exotic hadrons have been detected experimentally in the past two decades,predominantly near the threshold of a pair of hadrons.This study aims to investigate the overall behavior of nearthreshold line shapes in invariant mass distributions.It is noteworthy that the threshold cusp might manifest as a peak only in channels with attractive interaction.The assertion is made that there should be near-threshold structures for any heavy-quark and heavy-antiquark hadron pairs exhibiting attractive interaction at the threshold,as observed in the invariant mass distribution of heavy quarkonium and light hadrons that couple to the open-flavor hadron pair.Furthermore,we have conducted an analysis of potential hadronic molecules comprising pairs of heavy hadrons,utilizing the Bethe-Salpeter equation with constant interactions derived from the one-boson-exchange model.Observed candidates for these hadronic molecules are in good agreement with our predicted spectrum.展开更多
基金supported by National Key Projects for Research and Development of China with Grant No. 2021YFA1400400the National Natural Science Foundation of China with Grants No. 12225407 and 12074174+2 种基金China Postdoctoral Science Foundation with Grants No. 2022M711569 and 2022T150315Jiangsu Province Excellent Postdoctoral Program with Grant No. 20220ZB5Fundamental Research Funds for the Central Universities
基金The project supported by the Special Funds for State Key Basic Research Projects under Grant No.G1999,032800
文摘A universal symplectic structure for a Newtonian system including nonconservative cases can be constructed in the framework of Birkhoffian generalization of Hamiltonian mechanics. In this paper the symplectic geometry structure of Birkhoffian system is discussed, then the symplecticity of Birkhoffian phase flow is presented. Based on these properties we give a way to construct symplectic schemes for Birkhoffian systems by using the generating function method.
文摘By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson-Kolb model has been previously studied by several groups. Some physicists argued that, as far as the existence of superconductivity in this model is concerned, it is canonically equivalent to the negative-U Hubbard model.However, others did not agree. In the present paper, we shall investigate this model by an independent and rigorous approach. We show that the ground state of the Penson-Kolb model is nondegenerate and has a nonvanishing overlap with the ground state of the negative-U Hubbard model. Furthermore, we also show that the ground states of both the models have the same good quantum numbers and may have superconducting long-range order at the same momentum q ＝ 0. Our results support the equivalence between these models.
基金Supported by the National Natural Science Foundation of China under Grant No.11047160the National Basic Research Program of China under Grant No.2009CB939901the Foundation of Tianjin Polytechnic University under Grant No.029289
文摘By using the density matrix renormalization group technique, the phase diagram of the half-tilting extended Hubbard model is investigated. The conventional order parameter, the two-site entanglement entropy, and the block- block entanglement entropy are analyzed in detail. According to the numerical results, in the weak coupling region, an intermediate bond-order-wave （BOW） phase is shown to exist indeed between the charge-density-wave （CDW） and the spin-density-wave （SDW） phases. The critical phase transition points are determined by the singularity of the first order derivative of two-site entanglement entropy. In strong coupling region, a direct phase transition occurs from SDW phase to CDW phase, and shows discontinuous （first order） character accompanied with energy level crossing. The numerical results support the phase diagram proposed previously by some authors Sengupta et al., （2002）; Sandvik et al., （2004）; Zhang, （2004）. Therefore, the quantum entanglement is a sensitive tool to describe quantum phase transitions in strongly correlated electron systems.
基金Supported by the National Natural Science Foundation of China (No.60172065).
文摘A method, named XHJ-method, is proposed in this letter to determine the number of clusters of a data set, which incorporates with the Fuzzy Reinforced Learning Vector Quantization (FRLVQ) technique. The simulation results show that this new method works well for the traditional iris data and an artificial data set, which contains un-equally sized and spaced clusters.
文摘To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China： No.4 by volume 3,200 m3 of “Jinan Iron ＆ Steel Company” in Jinan （683 thermocouples）, No.2 by volume 1,080 m3 of “Henan Jiyuan Iron ＆ Steel （Group） Company” in Jiyuan （212 thermocouples）, No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron ＆ Steel （Group） Company” in Liuzhou （383 thermocouples）, No.3 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）; No.1 by volume 1,750 m3 of “Jinan Iron ＆ Steel Company” in Jinan （524 thermocouples）.
基金Supported by the National Natural Science Foundation of China under Grant No.11104163
文摘In this paper,we investigate the spontaneously generated coherence(SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system.By using a strong control field, in the absense of SGC effects,strong correlation and anticorrelation fluorescence photons can be produced from two ladder transitions in this system respectively.However,in the presence of SGC effects,the fluorescence fields correlation properties are reversed for the two transitions.The above phenomena can be traced to the quantum destructive or constructive interference in terms of dressed states.
文摘Numerous candidates for exotic hadrons have been detected experimentally in the past two decades,predominantly near the threshold of a pair of hadrons.This study aims to investigate the overall behavior of nearthreshold line shapes in invariant mass distributions.It is noteworthy that the threshold cusp might manifest as a peak only in channels with attractive interaction.The assertion is made that there should be near-threshold structures for any heavy-quark and heavy-antiquark hadron pairs exhibiting attractive interaction at the threshold,as observed in the invariant mass distribution of heavy quarkonium and light hadrons that couple to the open-flavor hadron pair.Furthermore,we have conducted an analysis of potential hadronic molecules comprising pairs of heavy hadrons,utilizing the Bethe-Salpeter equation with constant interactions derived from the one-boson-exchange model.Observed candidates for these hadronic molecules are in good agreement with our predicted spectrum.
