A probabilistic teleportation scheme for atomic stats via cavity QED [Phys. Rev. A 70 （2004） 054303] is revisited and accordingly some improvements are made.
This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stres...This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Appling the Hamilton's principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method the discrete equations can be deduced, which can be solved easily by Runge-Kutta method. The dynamic buckling loads of the stiffened plates are obtained form Budiansky-Roth criterion.展开更多
Relativistic mean-field theory and phase-shift analysis are combined together to investigate the elasticCoulomb scattering between electrons and unstable nuclei.Electron scattering at several different energies is stu...Relativistic mean-field theory and phase-shift analysis are combined together to investigate the elasticCoulomb scattering between electrons and unstable nuclei.Electron scattering at several different energies is studiedand compared,in order to see the energy dependence of electron-nucleus scattering.It is shown that electron scattering at200 MeV or 300 MeV can be used to reveal electron-nucleus scattering information around the first diffraction minimum-Shiftsin opposite directions are obtained for the first diffraction minima of the electron scattering off the ground andfirst excited states of ^(17)F with ^(16)O as reference,and similar effects are obtained for ^(18)Ne.Besides,some neutron-richN = 8 isotones are also studied.Results show that electron scattering will be very useful and important in studyingboth proton- and neutron-rich nuclei in the future.展开更多
During rapid urbanization and industrialization process, non-farm employment of rural laborers has emerged as a prevalent phenomenon in rural areas of China and become an important driving factor for changes in agricu...During rapid urbanization and industrialization process, non-farm employment of rural laborers has emerged as a prevalent phenomenon in rural areas of China and become an important driving factor for changes in agricultural land use. This article attempts to theoretically analyze the impacts of non-farm employment of rural laborers on agricultural land use based on economic frameworks. As rational agents, farmers aim to maximize their income and follow equilibrium principles when they decide how to allocate their labor forces（or working time） in two departments（farm and non-farm） and how to use their agricultural land with different quality and location. The income earned by non-farm employment is higher, and there exists a comparative advantage between labors, as a result the quantity and quality of labor input in agricultural land use decreases. With the limitation of labor input during agricultural land use decision-making of farm households, on the one hand, land with higher quality is still utilized by farmers. On the other hand, poor quality land will be less well managed and is more likely to be abandoned. Non-farm employment of rural laborers and the rising of opportunity costs will result in abandonment of poor quality land, and great importance should be attached to this by policy makers.展开更多
Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here,...Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here, we present a novel method of probing quantum many-body correlation by ramping dynamics. We ramp a Hamiltonian parameter to the same target value from different initial values and with different velocities, and we show that the first-order correction on the finite ramping velocity is universal and path-independent, revealing a novel quantum many-body correlation function of the equilibrium phases at the target values. We term this method as the non-adiabatic linear response since this is the leading order correction beyond the adiabatic limit. We demonstrate this method experimentally by studying the Bose-Hubbard model with ultracold atoms in three-dimensional optical lattices.Unlike the conventional linear response that reveals whether the quasi-particle dispersion of a quantum phase is gapped or gapless, this probe is more sensitive to whether the quasi-particle lifetime is long enough such that the quantum phase possesses a well-defined quasi-particle description. In the BoseHubbard model, this non-adiabatic linear response is significant in the quantum critical regime where well-defined quasi-particles are absent. And in contrast, this response is vanishingly small in both superfluid and Mott insulators which possess well-defined quasi-particles. Because our proposal uses the most common experimental protocol, we envision that our method can find broad applications in probing various quantum systems.展开更多
This paper presents a novel stiffness prediction method for periodic beam-like structures based on the two-scale equivalence at different strain states.The macroscopic fields are achieved within the framework of Timos...This paper presents a novel stiffness prediction method for periodic beam-like structures based on the two-scale equivalence at different strain states.The macroscopic fields are achieved within the framework of Timoshenko beam theory,while the microscopic fields are obtained by the newly constructed displacement form within the framework of three-dimensional(3D)elasticity theory.The new displacement form draws lessons from that in the asymptotic homogenization method(AHM),but the present field governing equations or boundary conditions for the first two order influence functions are constructed and very different from the way they were defined in the AHM.The constructed displacement form,composed of one homogenized and two warping terms,can accurately describe the deformation mode of beam-like structures.Then,with the new displacement form,the effective stiffness is achieved by the equivalence principle of macro-and microscopic fields.The finite element formulations of the proposed method are presented,which are easy to implement.Numerical examples validate that the present method can well predict both diagonal and coupling stiffness of periodic composite beams.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 10304022, the Science-Technology Fund of Anhui Province for 0utstanding Youth under Grant No. 06042087, the General Fund of the Educational Committee of Anhui Province under Grant No. 2006KJ260B, and the Key Fund of the Ministry of Education of China under Grant No. 206063
文摘A probabilistic teleportation scheme for atomic stats via cavity QED [Phys. Rev. A 70 （2004） 054303] is revisited and accordingly some improvements are made.
文摘This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Appling the Hamilton's principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method the discrete equations can be deduced, which can be solved easily by Runge-Kutta method. The dynamic buckling loads of the stiffened plates are obtained form Budiansky-Roth criterion.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10535010,10675090,10775068,and 10975072the 973 National Major State Basic Research and Development of China under Grant No.2007CB815004+1 种基金CAS Knowledge Innovation Project KJCX2-SW-N02the Research Fund of Doctoral Point (RFDP) under Grant No.20070284016
文摘Relativistic mean-field theory and phase-shift analysis are combined together to investigate the elasticCoulomb scattering between electrons and unstable nuclei.Electron scattering at several different energies is studiedand compared,in order to see the energy dependence of electron-nucleus scattering.It is shown that electron scattering at200 MeV or 300 MeV can be used to reveal electron-nucleus scattering information around the first diffraction minimum-Shiftsin opposite directions are obtained for the first diffraction minima of the electron scattering off the ground andfirst excited states of ^(17)F with ^(16)O as reference,and similar effects are obtained for ^(18)Ne.Besides,some neutron-richN = 8 isotones are also studied.Results show that electron scattering will be very useful and important in studyingboth proton- and neutron-rich nuclei in the future.
基金National Natural Science Foundation of China(41501095)
文摘During rapid urbanization and industrialization process, non-farm employment of rural laborers has emerged as a prevalent phenomenon in rural areas of China and become an important driving factor for changes in agricultural land use. This article attempts to theoretically analyze the impacts of non-farm employment of rural laborers on agricultural land use based on economic frameworks. As rational agents, farmers aim to maximize their income and follow equilibrium principles when they decide how to allocate their labor forces（or working time） in two departments（farm and non-farm） and how to use their agricultural land with different quality and location. The income earned by non-farm employment is higher, and there exists a comparative advantage between labors, as a result the quantity and quality of labor input in agricultural land use decreases. With the limitation of labor input during agricultural land use decision-making of farm households, on the one hand, land with higher quality is still utilized by farmers. On the other hand, poor quality land will be less well managed and is more likely to be abandoned. Non-farm employment of rural laborers and the rising of opportunity costs will result in abandonment of poor quality land, and great importance should be attached to this by policy makers.
基金supported by Beijing Outstanding Young Scholar Programthe National Key Research and Development Program of China (2021YFA0718303, 2021YFA1400904, and 2016YFA0301501)+1 种基金the National Natural Science Foundation of China (91736208, 11974202, 61975092, 11920101004,61727819, 11934002, 11734010, and 92165203)the XPLORER Prize。
文摘Ramping a physical parameter is one of the most common experimental protocols in studying a quantum system, and ramping dynamics has been widely used in preparing a quantum state and probing physical properties. Here, we present a novel method of probing quantum many-body correlation by ramping dynamics. We ramp a Hamiltonian parameter to the same target value from different initial values and with different velocities, and we show that the first-order correction on the finite ramping velocity is universal and path-independent, revealing a novel quantum many-body correlation function of the equilibrium phases at the target values. We term this method as the non-adiabatic linear response since this is the leading order correction beyond the adiabatic limit. We demonstrate this method experimentally by studying the Bose-Hubbard model with ultracold atoms in three-dimensional optical lattices.Unlike the conventional linear response that reveals whether the quasi-particle dispersion of a quantum phase is gapped or gapless, this probe is more sensitive to whether the quasi-particle lifetime is long enough such that the quantum phase possesses a well-defined quasi-particle description. In the BoseHubbard model, this non-adiabatic linear response is significant in the quantum critical regime where well-defined quasi-particles are absent. And in contrast, this response is vanishingly small in both superfluid and Mott insulators which possess well-defined quasi-particles. Because our proposal uses the most common experimental protocol, we envision that our method can find broad applications in probing various quantum systems.
基金supported by the China Postdoctoral Science Foundation(Grant No.2021T140040)the National Natural Science Foundation of China(Grant Nos.12002019 and 11872090).
文摘This paper presents a novel stiffness prediction method for periodic beam-like structures based on the two-scale equivalence at different strain states.The macroscopic fields are achieved within the framework of Timoshenko beam theory,while the microscopic fields are obtained by the newly constructed displacement form within the framework of three-dimensional(3D)elasticity theory.The new displacement form draws lessons from that in the asymptotic homogenization method(AHM),but the present field governing equations or boundary conditions for the first two order influence functions are constructed and very different from the way they were defined in the AHM.The constructed displacement form,composed of one homogenized and two warping terms,can accurately describe the deformation mode of beam-like structures.Then,with the new displacement form,the effective stiffness is achieved by the equivalence principle of macro-and microscopic fields.The finite element formulations of the proposed method are presented,which are easy to implement.Numerical examples validate that the present method can well predict both diagonal and coupling stiffness of periodic composite beams.
