The octupole deformation and collectivity in octupole double-magic nucleus 144Ba are investigated using the Cranking covariant density functional theory in a three-dimensional lattice space.The reduced B(E3)transition...The octupole deformation and collectivity in octupole double-magic nucleus 144Ba are investigated using the Cranking covariant density functional theory in a three-dimensional lattice space.The reduced B(E3)transition probability is implemented for the first time in semiclassical approximation based on the microscopically calculated electric octupole moments.The available data,including the I-ωrelation and electric transitional probabilities B(E2)and B(E3)are well reproduced.Furthermore,it is shown that the ground state of 144Ba exhibits axial octupole and quadrupole deformations that persist up to high spins(I≈24h).展开更多
The back bending phenomenon observed in ^(87)Nb is interpreted very well within the approach of the triaxial cranking shell model(CSM)with the deformations determined by a total routhian surface calculation which incl...The back bending phenomenon observed in ^(87)Nb is interpreted very well within the approach of the triaxial cranking shell model(CSM)with the deformations determined by a total routhian surface calculation which includes the deformation drive of the high j quasiparticle orbits.It is suggested that the CSM is still valid for slightly deformed transitional nuclei if the configuration dependence of deformations is taken into account properly.展开更多
Some serious difficulties encountered in the usual Cranking Shell Model may he overcome in the Particle-tlumber-Conserving treatment for the cranking hamiltonian.The variation of the K-structure of low-lying hands wit...Some serious difficulties encountered in the usual Cranking Shell Model may he overcome in the Particle-tlumber-Conserving treatment for the cranking hamiltonian.The variation of the K-structure of low-lying hands with the rotational frequency is investigated.展开更多
Based on tilted axis cranking relativistic mean-field theory within point-coupling interaction PC-PK1, the rotational structure and the characteristic features of antimagnetic rotation for AI = 2 bands in 108,110In ar...Based on tilted axis cranking relativistic mean-field theory within point-coupling interaction PC-PK1, the rotational structure and the characteristic features of antimagnetic rotation for AI = 2 bands in 108,110In are studied. Tilted axis cranking relativistic mean-field calculations reproduce the experimental energy spectrum well and are in agreement with the experimental I -w plot, although the calculated spin overestimates the experimental values. In addition, the two-shears-like mechanism in candidate antimagnetic rotation bands is clearly illustrated and the contributions from two-shears-like orbits, neutron （gd） orbits above Z = 50 shell and Z = 50, N = 50 core are investigated microscopically. The predicted B（E2）, dynamic moment of inertia ■ （2）, deformation parametersβ and γ, and ■ （2）/B（E2） ratios in tilted axis cranking relativistic mean-field calculations are discussed and the characteristic features of antimagnetic rotation for the bands before and after alignment are shown.展开更多
In this paper,a new finite element and finite difference(FE-FD)method has been developed for anisotropic parabolic interface problems with a known moving interface using Cartesian meshes.In the spatial discretization,...In this paper,a new finite element and finite difference(FE-FD)method has been developed for anisotropic parabolic interface problems with a known moving interface using Cartesian meshes.In the spatial discretization,the standard P,FE discretization is applied so that the part of the coefficient matrix is symmetric positive definite,while near the interface,the maximum principle preserving immersed interface discretization is applied.In the time discretization,a modified Crank-Nicolson discretization is employed so that the hybrid FE-FD is stable and second order accurate.Correction terms are needed when the interface crosses grid lines.The moving interface is represented by the zero level set of a Lipschitz continuous function.Numerical experiments presented in this paper confirm second orderconvergence.展开更多
Based on the basic theory of mechanics,kinematic and dynamic analysis for a slider-crank mechanism with a balance mechanism is performed.The theoretical formula of the load spectrum for the interaction between the cra...Based on the basic theory of mechanics,kinematic and dynamic analysis for a slider-crank mechanism with a balance mechanism is performed.The theoretical formula of the load spectrum for the interaction between the crank shaft and the bearing seat of the upper beam is achieved by approximately simplifying the mechanical model of the crank shaft.The simulation for the load spectrum data of combined frame under the operating conditions of blanking or piling is performed using Matlab and the law of the load spectrum curves under these two conditions is analyzed.The simulation results show that under a no-load condition,the load spectrum curves of the interaction between the crank shaft and the bearing seat of the upper beam present a form of periodic sine wave and under the piling condition,the load spectrum curves of the interaction between the crank shaft and the bearing seat of the upper beam present a form of periodic pulse wave.The simulation results can provide a theoretical foundation for the load determination during the process of analyzing the dynamic characteristics on the combined frame of a closed high-speed press through the finite element method.展开更多
The dynamical moment of inertia is estimated with its even-power expansion of the rotational frequency and in accordance we determine the intermediate spins of the superdeformed(SD)rotational bands.Using Marquardt met...The dynamical moment of inertia is estimated with its even-power expansion of the rotational frequency and in accordance we determine the intermediate spins of the superdeformed(SD)rotational bands.Using Marquardt method of nonlinear least-squares routines,we determine the expansion coefficients by fitting the proposed dynamical moment of inertia with its recent experimental data of the SD nuclei in the A=190 mass region.The comparison between our theoretical and available experimental data for the dynamic moment of inertia and spin shows good agreements. Also,we have calculated the static moment of inertia at three alternative values of spin.The value of spin at which the two moments of inertia are nearly equals is to be regarded as a bandhead spin of the corresponding band.These studies are carried out for eighteen bands of odd-A nuclei of the superdeformed region 190,namely ~(189)Hg(b1),~(191)Hg(b1,b2, b3,b4),~(193)Hg(b2,b3,b5),~(195)Hg(b1,b2,b3,b4),~(193)Tl(b1,b2,b3,b5),~(189)Tl(b1),and~(197)Bi(b1).We also notice the occurrence of identical SD bands with near identical transition energies among the considered SD bands.展开更多
Understanding muscle hemodynamics using near-infrared spectroscopy is increasingly evident in the recent spinal disorders-related literature.However,none of these human studies addressed the issue of physiological lim...Understanding muscle hemodynamics using near-infrared spectroscopy is increasingly evident in the recent spinal disorders-related literature.However,none of these human studies addressed the issue of physiological limits for the lumbar muscle within the same participants during various exercise modes.The purpose of this study is to evaluate physiological limits for the lumbar muscle during dynamic and static endurance tests.On three separate days,22 healthy men and women performed three endurance protocols(static prone trunk extension,arm cranking,and pushingpulling)until volitional exhaustion.For each protocol,minimum and maximum oxygenation and blood volume responses from the right lumbar erector spinae were obtained using a continuous dual wavelength near-infrared spectroscopy(Micro-Runman,NIM Inc.,PA,USA).Statistical analysis showed that greatest reduction in oxygenation(minimum)were obtained during dynamic exercises:pushingpulling(2.1 times)and arm cranking(2.03 times)versus static test (P<0:05).Physiological change(calculated as the difference between maximum during recovery and minimum at the point of volitional exhaustion)during static test was lower[(66-75%for oxygenation)and(34-46%for blood volume)]than dynamic exercises (P<0:05).Contrary to the theory that sufficient occlusion of bloodflow to the lumbar muscle is possible with static trunk extension,it was concluded that a dynamic protocol until volitional exhaustion might be a good alternative in establishing near-infrared spectroscopy-derived physiological limits to the lumbar muscle.Further research is essential to identify an optimal calibration procedure for establishing true hypoxic values for the human lumbar muscle.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(No.12205097)the Fundamental Research Funds for the Central Universities(No.2024MS071)。
文摘The octupole deformation and collectivity in octupole double-magic nucleus 144Ba are investigated using the Cranking covariant density functional theory in a three-dimensional lattice space.The reduced B(E3)transition probability is implemented for the first time in semiclassical approximation based on the microscopically calculated electric octupole moments.The available data,including the I-ωrelation and electric transitional probabilities B(E2)and B(E3)are well reproduced.Furthermore,it is shown that the ground state of 144Ba exhibits axial octupole and quadrupole deformations that persist up to high spins(I≈24h).
基金Supported by the National Natural Science Foundation of China.
文摘The back bending phenomenon observed in ^(87)Nb is interpreted very well within the approach of the triaxial cranking shell model(CSM)with the deformations determined by a total routhian surface calculation which includes the deformation drive of the high j quasiparticle orbits.It is suggested that the CSM is still valid for slightly deformed transitional nuclei if the configuration dependence of deformations is taken into account properly.
文摘Some serious difficulties encountered in the usual Cranking Shell Model may he overcome in the Particle-tlumber-Conserving treatment for the cranking hamiltonian.The variation of the K-structure of low-lying hands with the rotational frequency is investigated.
基金Supported by National Natural Science Foundation of China(11205068,11205069,11405072,11475072,11547308)China Postdoctoral Science Foundation(2012M520667)
文摘Based on tilted axis cranking relativistic mean-field theory within point-coupling interaction PC-PK1, the rotational structure and the characteristic features of antimagnetic rotation for AI = 2 bands in 108,110In are studied. Tilted axis cranking relativistic mean-field calculations reproduce the experimental energy spectrum well and are in agreement with the experimental I -w plot, although the calculated spin overestimates the experimental values. In addition, the two-shears-like mechanism in candidate antimagnetic rotation bands is clearly illustrated and the contributions from two-shears-like orbits, neutron （gd） orbits above Z = 50 shell and Z = 50, N = 50 core are investigated microscopically. The predicted B（E2）, dynamic moment of inertia ■ （2）, deformation parametersβ and γ, and ■ （2）/B（E2） ratios in tilted axis cranking relativistic mean-field calculations are discussed and the characteristic features of antimagnetic rotation for the bands before and after alignment are shown.
基金partially supported by the National Natural Science Foundation of China(Grant No.12261070)the Ningxia Key Research and Development Project of China(Grant No.2022BSB03048)+2 种基金partially supported by the Simons(Grant No.633724)and by Fundacion Seneca grant 21760/IV/22partially supported by the Spanish national research project PID2019-108336GB-I00by Fundacion Séneca grant 21728/EE/22.Este trabajo es resultado de las estancias(21760/IV/22)y(21728/EE/22)financiadas por la Fundacion Séneca-Agencia de Ciencia y Tecnologia de la Region de Murcia con cargo al Programa Regional de Movilidad,Colaboracion Internacional e Intercambio de Conocimiento"Jimenez de la Espada".(Plan de Actuacion 2022).
文摘In this paper,a new finite element and finite difference(FE-FD)method has been developed for anisotropic parabolic interface problems with a known moving interface using Cartesian meshes.In the spatial discretization,the standard P,FE discretization is applied so that the part of the coefficient matrix is symmetric positive definite,while near the interface,the maximum principle preserving immersed interface discretization is applied.In the time discretization,a modified Crank-Nicolson discretization is employed so that the hybrid FE-FD is stable and second order accurate.Correction terms are needed when the interface crosses grid lines.The moving interface is represented by the zero level set of a Lipschitz continuous function.Numerical experiments presented in this paper confirm second orderconvergence.
基金The Key Technologies R& D Program of Jiangsu Province(No. BE2006036)Transformation Program of Science and Technology Achievements of Jiangsu Province (No. BA2008030)
文摘Based on the basic theory of mechanics,kinematic and dynamic analysis for a slider-crank mechanism with a balance mechanism is performed.The theoretical formula of the load spectrum for the interaction between the crank shaft and the bearing seat of the upper beam is achieved by approximately simplifying the mechanical model of the crank shaft.The simulation for the load spectrum data of combined frame under the operating conditions of blanking or piling is performed using Matlab and the law of the load spectrum curves under these two conditions is analyzed.The simulation results show that under a no-load condition,the load spectrum curves of the interaction between the crank shaft and the bearing seat of the upper beam present a form of periodic sine wave and under the piling condition,the load spectrum curves of the interaction between the crank shaft and the bearing seat of the upper beam present a form of periodic pulse wave.The simulation results can provide a theoretical foundation for the load determination during the process of analyzing the dynamic characteristics on the combined frame of a closed high-speed press through the finite element method.
文摘The dynamical moment of inertia is estimated with its even-power expansion of the rotational frequency and in accordance we determine the intermediate spins of the superdeformed(SD)rotational bands.Using Marquardt method of nonlinear least-squares routines,we determine the expansion coefficients by fitting the proposed dynamical moment of inertia with its recent experimental data of the SD nuclei in the A=190 mass region.The comparison between our theoretical and available experimental data for the dynamic moment of inertia and spin shows good agreements. Also,we have calculated the static moment of inertia at three alternative values of spin.The value of spin at which the two moments of inertia are nearly equals is to be regarded as a bandhead spin of the corresponding band.These studies are carried out for eighteen bands of odd-A nuclei of the superdeformed region 190,namely ~(189)Hg(b1),~(191)Hg(b1,b2, b3,b4),~(193)Hg(b2,b3,b5),~(195)Hg(b1,b2,b3,b4),~(193)Tl(b1,b2,b3,b5),~(189)Tl(b1),and~(197)Bi(b1).We also notice the occurrence of identical SD bands with near identical transition energies among the considered SD bands.
文摘Understanding muscle hemodynamics using near-infrared spectroscopy is increasingly evident in the recent spinal disorders-related literature.However,none of these human studies addressed the issue of physiological limits for the lumbar muscle within the same participants during various exercise modes.The purpose of this study is to evaluate physiological limits for the lumbar muscle during dynamic and static endurance tests.On three separate days,22 healthy men and women performed three endurance protocols(static prone trunk extension,arm cranking,and pushingpulling)until volitional exhaustion.For each protocol,minimum and maximum oxygenation and blood volume responses from the right lumbar erector spinae were obtained using a continuous dual wavelength near-infrared spectroscopy(Micro-Runman,NIM Inc.,PA,USA).Statistical analysis showed that greatest reduction in oxygenation(minimum)were obtained during dynamic exercises:pushingpulling(2.1 times)and arm cranking(2.03 times)versus static test (P<0:05).Physiological change(calculated as the difference between maximum during recovery and minimum at the point of volitional exhaustion)during static test was lower[(66-75%for oxygenation)and(34-46%for blood volume)]than dynamic exercises (P<0:05).Contrary to the theory that sufficient occlusion of bloodflow to the lumbar muscle is possible with static trunk extension,it was concluded that a dynamic protocol until volitional exhaustion might be a good alternative in establishing near-infrared spectroscopy-derived physiological limits to the lumbar muscle.Further research is essential to identify an optimal calibration procedure for establishing true hypoxic values for the human lumbar muscle.
