we study entanglement and squeezing of a cluster of spin systems under the influence of the two-axis countertwisting hamiltonian. the squeezing parameters given by wineland et al and also by kitagawa et al. are chosen as the criteria of spin squeezing. the criterion of pairwise entanglement is chosen to be the concurrence and that of the bipartite entanglement the linear entropy. we also define...

A gradient-extended two-surface damage-plasticity model based on a von Mises yield criterion has been proposed by [1, 2], which can be flexibly adapted to (quasi-)brittle-like, ductile-like, or various material behaviors in between. However, the does not take into account effect of hydrostatic pressure, therefore it hardly failure behavior pressure-sensitive materials such as geomaterials and s...