Becoming American: The Hmong American Experience

Hmong Americans, who came from a pre-literate society and rural background, went through many acculturation barriers and have had many successes between the time they first arrived in 1975 and the year 2000. Their first decade was preoccupied with their struggle to overcome cultural shock and acculturation difficulties. The second decade is their turning point to be new Americans, beginning to run for political office, establish business enterprises, achieve in education, and reduce their high rate of unemployment and welfare participation. Hmong Americans in 2000 appeared to have achieved much, yet have some serious challenges still ahead

The weakly coupled polaron

The Green\u27s Function technique has been used to investigate the properties of weakly coupled longitudinal optical polarons. By taking into consideration the contribution of the multi-phonon and the phonon-cross-exchange diagrams in the self-energy, a vertex correction has been made to the lowest order diagram. The real part and the imaginary part of the self-energy are obtained. The dispersion relationship obtained by this approximation gives the ground state energy which is lower than the upper bound obtained from the variational method. Also, the spectral weight function for several momentum values has been calculated. It shows that the quasi-particle description is good for polarons with small momentum while for polarons with momentum values near the phonon emission threshold, the quasi-particle description is not adequate