Publications by authors named "Ji-wei Geng"
We theoretically investigate the nonadiabatic subcycle electron dynamics in orthogonally polarized two-color laser fields with comparable intensities. The photoelectron dynamics is simulated by exact solution to the 3D time-dependent Schrödinger equation, and also by two other semiclassical methods, i.e.
View Article and Find Full Text PDFMost previous studies have focused on high-order harmonic generation beyond the ionization threshold; mechanisms of below-threshold harmonics are less understood. We schematically study the harmonic emission process in this region by numerically solving the time-dependent Schrödinger equation of an atom in laser fields. We show that, besides the quantum path interference mechanism recently identified, the effects induced by the Coulomb potential also have a critical impact on these harmonics.
View Article and Find Full Text PDFWe measure high resolution photoelectron angular distributions (PADs) for above-threshold ionization of xenon atoms in infrared laser fields. Based on the Ammosov-Delone-Krainov theory, we develop an intuitive quantum-trajectory Monte Carlo model encoded with Feynman's path-integral approach, in which the Coulomb effect on electron trajectories and interference patterns are fully considered. We achieve a good agreement with the measured PADs of atoms for above-threshold ionization.
View Article and Find Full Text PDFObjective: To investigate the relationship between methylation of the CDH1 gene promoter on the expression of E-cadherin and β-catenin, and to evaluate the correlation with clinicopathological characteristics of the colonic carcinoma.
Methods: Methylation specific PCR (MSP) was used to detect CDH1 gene promoter methylation in the cancer tissue, adjacent tissues and normal tissues in 68 patients. The expression of E-cadherin and β-catenin was determined by immunohistochemistry staining.