We discuss a particular four-dimensional cosmology based on non-minimal scalar tensor theories characterized by a supersymmetric loop corrected potential and a Hubble parameter defined as a function of the scalar fiel...We discuss a particular four-dimensional cosmology based on non-minimal scalar tensor theories characterized by a supersymmetric loop corrected potential and a Hubble parameter defined as a function of the scalar field.Power-law solutions are obtained in the FRW background giving rise to acceleratedly expanding universe characterized by a scale factor and a scalar field depending both on the non-minimal coupling parameterξ.Based on SNeIa data and on Hubble data X-ray gas mass fraction measurements,we find 0.116<ξ<0.225 which results on a universe dominated by vacuum energy.展开更多
Theω-andρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are investigated.The influences of the tensor couplings on the binding energies per nucleon,the root-mean-square c...Theω-andρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are investigated.The influences of the tensor couplings on the binding energies per nucleon,the root-mean-square charge radii,spin-orbit splittings and single particle energies are discussed.The obtained results show that the spin-orbit splittings for finite nuclei are more sensitive to theω-meson tensor coupling.展开更多
The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor...The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor couplings of vector mesons ω and ρ on the nucleonic direct URCA processes. It is found that the inclusion of the tensor couplings of vector mesons w and p can slightly increase the maximum mass of neutron stars. In addition, the results indicate that the tensor couplings of vector mesons ω and ρ lead to obvious enhancement of the total neutrino emissivity for the nucleonic direct URCA processes, which must accelerate the cooling rate of the non- superfluid neutron star matter. However, when considering only the tensor coupling of vector meson ρ, the neutrino emissivity for the nucleonic direct URCA processes slightly declines at low densities and significantly increases at high densities. That is, the tensor coupling of vector meson ρ leads to the slow cooling rate of a low-mass neutron star and rapid cooling rate of a massive neutron star.展开更多
Subcortical vascular mild cognitive impairment(svMCI)is a common prodromal stage of vascular dementia.Although mounting evidence has suggested abnormalities in several single brain network metrics,few studies have exp...Subcortical vascular mild cognitive impairment(svMCI)is a common prodromal stage of vascular dementia.Although mounting evidence has suggested abnormalities in several single brain network metrics,few studies have explored the consistency between functional and structural connectivity networks in svMCI.Here,we constructed such networks using resting-state f MRI for functional connectivity and diffusion tensor imaging for structural connectivity in 30 patients with svMCI and 30 normal controls.The functional networks were then parcellated into topological modules,corresponding to several well-defined functional domains.The coupling between the functional and structural networks was finally estimated and compared at the multiscale network level(whole brain and modular level).We found no significant intergroup differences in the functional–structural coupling within the whole brain;however,there was significantly increased functional–structural coupling within the dorsal attention module and decreased functional–structural coupling within the ventral attention module in the svMCI group.In addition,the svMCI patients demonstrated decreased intramodular connectivity strength in the visual,somatomotor,and dorsal attention modules as well as decreased intermodular connectivity strength between several modules in the functional network,mainly linking the visual,somatomotor,dorsal attention,ventral attention,and frontoparietal control modules.There was no significant correlation between the altered module-level functional–structural coupling and cognitive performance in patients with svMCI.These findings demonstrate for the first time that svMCI is reflected in a selective aberrant topological organization in multiscale brain networks and may improve our understanding of the pathophysiological mechanisms underlying svMCI.展开更多
Based on the charge conjugation invariance and the vazuum property of the Pomeron, we point out that the commonly used vector vertex of the Pomeron coupling to quarkis incorrect since it contradicts with the Pomeron p...Based on the charge conjugation invariance and the vazuum property of the Pomeron, we point out that the commonly used vector vertex of the Pomeron coupling to quarkis incorrect since it contradicts with the Pomeron property. We also claim that the soft Pomeron could be a tensor glueball ξ（2230） with quantum numbers I^GJ^PC = 0^＋2^＋＋ and total decay width Гtot ≌ 100 MeV, which lies on the soft Pomeron trajectory αp = 1.08＋ 0.20t. Therefore, the coupling vertex of the soft Pomeron to quark should be tensorial which is invariant under the charge conjugation and can explaIn why the inadequate vector coupling, γ^μ, of the soft Pomeron to quark is successful in dealing with Pomeron physics.展开更多
We study a general class of holographic superconductor models via the Stiickelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein＇s tenso...We study a general class of holographic superconductor models via the Stiickelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein＇s tensor. We explore the effects of the coupling parameter on the critical temperature, the order of phase transitions and the critical expo- nents near the second-order phase transition point. Moreover, we compute the electrical conductivity using the probe approximation and check the ratios wg/Tc for the different coupling parameters.展开更多
The mechanical properties of stratified rocks are closely related not only to the stress state but also to the inherent structural anisotropy,which can be represented by the occurrence of bedding planes.This research ...The mechanical properties of stratified rocks are closely related not only to the stress state but also to the inherent structural anisotropy,which can be represented by the occurrence of bedding planes.This research aims to enhance the understanding of the anisotropic deformation and failure behaviors of stratified rocks by proposing a novel coupled elastoplastic-damage constitutive model.In this constitutive model,a scalar anisotropic parameter(stress-structure mixed invariant)based on the Pietruszczak–Mroz anisotropic theory is incorporated into a nonlinear yield surface,which accounts for the combined effects of the stress state and bedding structure on the anisotropic strength behaviors of stratified rocks.A damage-driven function governs the expansion and contraction of the anisotropic yield surface in the pre-peak strain hardening and post-peak strain-softening regions.The strength and deformation characteristics under multiaxial stress conditions are represented by incorporating the Lode's angle into the yield and plastic potential functions.Numerical simulations are conducted to facilitate a comparison with the conventional and true triaxial compression test data for several stratified rocks.The simulation results demonstrate good agreement with the test data,validating the effectiveness of the proposed constitutive model.This study provides theoretical and technical support for addressing engineering challenges involving stratified rocks.展开更多
文摘We discuss a particular four-dimensional cosmology based on non-minimal scalar tensor theories characterized by a supersymmetric loop corrected potential and a Hubble parameter defined as a function of the scalar field.Power-law solutions are obtained in the FRW background giving rise to acceleratedly expanding universe characterized by a scale factor and a scalar field depending both on the non-minimal coupling parameterξ.Based on SNeIa data and on Hubble data X-ray gas mass fraction measurements,we find 0.116<ξ<0.225 which results on a universe dominated by vacuum energy.
基金Supported in part by the Major State Basic Research Developing Program under Grant No.G2000077400.
文摘Theω-andρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are investigated.The influences of the tensor couplings on the binding energies per nucleon,the root-mean-square charge radii,spin-orbit splittings and single particle energies are discussed.The obtained results show that the spin-orbit splittings for finite nuclei are more sensitive to theω-meson tensor coupling.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11447165,11373047 and 11265009the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2016056
文摘The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor couplings of vector mesons ω and ρ on the nucleonic direct URCA processes. It is found that the inclusion of the tensor couplings of vector mesons w and p can slightly increase the maximum mass of neutron stars. In addition, the results indicate that the tensor couplings of vector mesons ω and ρ lead to obvious enhancement of the total neutrino emissivity for the nucleonic direct URCA processes, which must accelerate the cooling rate of the non- superfluid neutron star matter. However, when considering only the tensor coupling of vector meson ρ, the neutrino emissivity for the nucleonic direct URCA processes slightly declines at low densities and significantly increases at high densities. That is, the tensor coupling of vector meson ρ leads to the slow cooling rate of a low-mass neutron star and rapid cooling rate of a massive neutron star.
基金supported by the Natural Science Foundation of Tianjin Municipal Science and Technology Commission(18JCQNJC10900)Tianjin Natural Science Foundation(17JCZDJC36300)。
文摘Subcortical vascular mild cognitive impairment(svMCI)is a common prodromal stage of vascular dementia.Although mounting evidence has suggested abnormalities in several single brain network metrics,few studies have explored the consistency between functional and structural connectivity networks in svMCI.Here,we constructed such networks using resting-state f MRI for functional connectivity and diffusion tensor imaging for structural connectivity in 30 patients with svMCI and 30 normal controls.The functional networks were then parcellated into topological modules,corresponding to several well-defined functional domains.The coupling between the functional and structural networks was finally estimated and compared at the multiscale network level(whole brain and modular level).We found no significant intergroup differences in the functional–structural coupling within the whole brain;however,there was significantly increased functional–structural coupling within the dorsal attention module and decreased functional–structural coupling within the ventral attention module in the svMCI group.In addition,the svMCI patients demonstrated decreased intramodular connectivity strength in the visual,somatomotor,and dorsal attention modules as well as decreased intermodular connectivity strength between several modules in the functional network,mainly linking the visual,somatomotor,dorsal attention,ventral attention,and frontoparietal control modules.There was no significant correlation between the altered module-level functional–structural coupling and cognitive performance in patients with svMCI.These findings demonstrate for the first time that svMCI is reflected in a selective aberrant topological organization in multiscale brain networks and may improve our understanding of the pathophysiological mechanisms underlying svMCI.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10247004 and 10565001 and the Natural Science Fotindation of Guangxi Province of China under Grant Nos. 0481030, 0542042, and 0575020.
文摘Based on the charge conjugation invariance and the vazuum property of the Pomeron, we point out that the commonly used vector vertex of the Pomeron coupling to quarkis incorrect since it contradicts with the Pomeron property. We also claim that the soft Pomeron could be a tensor glueball ξ（2230） with quantum numbers I^GJ^PC = 0^＋2^＋＋ and total decay width Гtot ≌ 100 MeV, which lies on the soft Pomeron trajectory αp = 1.08＋ 0.20t. Therefore, the coupling vertex of the soft Pomeron to quark should be tensorial which is invariant under the charge conjugation and can explaIn why the inadequate vector coupling, γ^μ, of the soft Pomeron to quark is successful in dealing with Pomeron physics.
基金supported by the National Natural Science Foundation of China (Grant No. 10875041)the Program for New Century Excellent Talents in University (Grant No. 10-0165)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT0964)the Construct Program of Key Disciplines in Hunan Provincethe Project of Knowledge Innovation Program of Chinese Academy of Sciences (Grant No. KJCX2.YW.W10)
文摘We study a general class of holographic superconductor models via the Stiickelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein＇s tensor. We explore the effects of the coupling parameter on the critical temperature, the order of phase transitions and the critical expo- nents near the second-order phase transition point. Moreover, we compute the electrical conductivity using the probe approximation and check the ratios wg/Tc for the different coupling parameters.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52109143 and 12062026)the Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin(China Institute of Water Resources and Hydropower Research)(Grant No.IWHRSKL-KF202305).
文摘The mechanical properties of stratified rocks are closely related not only to the stress state but also to the inherent structural anisotropy,which can be represented by the occurrence of bedding planes.This research aims to enhance the understanding of the anisotropic deformation and failure behaviors of stratified rocks by proposing a novel coupled elastoplastic-damage constitutive model.In this constitutive model,a scalar anisotropic parameter(stress-structure mixed invariant)based on the Pietruszczak–Mroz anisotropic theory is incorporated into a nonlinear yield surface,which accounts for the combined effects of the stress state and bedding structure on the anisotropic strength behaviors of stratified rocks.A damage-driven function governs the expansion and contraction of the anisotropic yield surface in the pre-peak strain hardening and post-peak strain-softening regions.The strength and deformation characteristics under multiaxial stress conditions are represented by incorporating the Lode's angle into the yield and plastic potential functions.Numerical simulations are conducted to facilitate a comparison with the conventional and true triaxial compression test data for several stratified rocks.The simulation results demonstrate good agreement with the test data,validating the effectiveness of the proposed constitutive model.This study provides theoretical and technical support for addressing engineering challenges involving stratified rocks.
