Under the CES production technology, an improved Cass Coopmans model with solvable endogenous fertility is given. We prove that there are multiple growth paths and multiple steady states when CES 0<σ<1 ...Under the CES production technology, an improved Cass Coopmans model with solvable endogenous fertility is given. We prove that there are multiple growth paths and multiple steady states when CES 0<σ<1 and the technology level is high enough; the growth path and the steady state is unique when σ>1 and the ratio of capital is smaller than a constant. So, the dynamic system which describes the model undergoes a bifurcation when σ=1 . We discuss the economic sense of the main results we give.展开更多
-A truncated shell model approach is presented for studying the properties oflow-lying states as well as the high-spin states in even-even nuclei with the help of thegeneralized boson-fermion expansion technique.The p...-A truncated shell model approach is presented for studying the properties oflow-lying states as well as the high-spin states in even-even nuclei with the help of thegeneralized boson-fermion expansion technique.The primary fermion state space isspanned by the interacting valence protons and neutrons with effective nucleon-nucleonforce.The truncated model space is considered as a direct sum of two subspaces corre-sponding to the configurations of（sd）<sup>N</sup> and（sd）<sup>N-1</sup>,respectively,plus a broken fermionpair.Numerical calculations are carried out for <sup>130～134</sup>Ce isotopes.The calculated spec-trum reproduces the experimental data quite well,especially the backbending appearingin these nuclei.The results suggest that the approach is able to describe the spectroscopyof states with angular momenta up to J≈20.展开更多
文摘Under the CES production technology, an improved Cass Coopmans model with solvable endogenous fertility is given. We prove that there are multiple growth paths and multiple steady states when CES 0<σ<1 and the technology level is high enough; the growth path and the steady state is unique when σ>1 and the ratio of capital is smaller than a constant. So, the dynamic system which describes the model undergoes a bifurcation when σ=1 . We discuss the economic sense of the main results we give.
文摘-A truncated shell model approach is presented for studying the properties oflow-lying states as well as the high-spin states in even-even nuclei with the help of thegeneralized boson-fermion expansion technique.The primary fermion state space isspanned by the interacting valence protons and neutrons with effective nucleon-nucleonforce.The truncated model space is considered as a direct sum of two subspaces corre-sponding to the configurations of（sd）<sup>N</sup> and（sd）<sup>N-1</sup>,respectively,plus a broken fermionpair.Numerical calculations are carried out for <sup>130～134</sup>Ce isotopes.The calculated spec-trum reproduces the experimental data quite well,especially the backbending appearingin these nuclei.The results suggest that the approach is able to describe the spectroscopyof states with angular momenta up to J≈20.
