Sr2CuO2Cl2. Represents a nearly perfect situation of the two-D antiferromagnetic CuO2-airplane and so is of individual fascination while in the context with the origins of large TC superconductivity. We've measured experimentally and analyzed theoretically the Ti 2p X-ray photoemission spectra (XPS) and also the resonant improvement of valence photoemissionat the https://okada4dsg.com/