Investigation on Exciton Relaxation Kinetics of ZnCulnS/ZnSe/ZnS Quantum Dots by Time-Resolved Spectroscopy Techniques

The exciton relaxation kinetics of ZnCuInS/ZnSe/ZnS quantum dots （QDs） is investigated by time-resolved spectroscopy techniques in detail. Based on the rate distribution model, the wavelength-dependent emission dynamics shows that the intrinsic exciton, the exciton in the interface defect state and that in donor-acceptor pair state （DAPS） together participate in the photoluminescence process of QDs, and the whole emission process is mainly dependent on the DAPS emission. Transient absorption data show that the intrinsic exciton and the interface defect species maybe together appear after excitation and the intensity-dependent Auger recombination process also exists in QDs at high excitation intensity.

三杨庄遗址出土石磙浅识

三杨庄汉代聚落遗址出土了一件形制呈鼓形的石磙,作为一件农业生产工具,这件鼓形石磙的功能可能具有多样性。根据文献记载和现今农村仍在使用的传统农具——砘子推测,它是一件镇压器,主要功能是覆种,以达到令种、土相亲的效果,从而有利于农作物发芽与生长。