镱的奇宇称自电离谱

本文报道用激光分步激发技术测定镱的奇宇称自电离谱的实验方法及其结果。文中给出了测得的30余个自电离能级,并与前人用单光子吸收和电子碰撞激发技术等所得的结果进行了比较与分析。 关键词：     

Compositional change in human enamel irradiated with MIR free electron laser

The purpose of this study was to investigate compositional changes in human enamel irradiated with the free electron laser (FEL).The exposure on dental enamel at the wavelength of 9.64μm was observed with the Beijing free electron laser.The distribution of elements in the irradiated or non-irradiated enamel was measured by scanning electron microscope (SEM) with energy-dispersive spectroscopy and synchrotron radiation X-ray fluorescence(SRXRF) in Beijing Synchrotron Radiation Facility (BSRF).The results showed that the P/Ca ratio in the ablation region of enamel at the maximum wavelength of infrared absorption of enalmel at the maximum wavelength of infrared absorption was obviously smaller than that at the non-maximum wavelength.In the ablation region the ratios of P/Ca and Ca/Sr were smaller than those in the non-ablation region.The distribution of P,Ca and Sr in the ablation region were heterogeneous due to the element change caused by FEL irradiation.     

激光打标记

激光打标记是有显著经济效益的,发展前景良好的激光应用之一.这方面最早的应用是60年代中开始的硅片刻划.用激光束代替金刚石刀,在硅片上划上刻痕,然后加力使之分为所需的小片. 60年代末和70年代初,美国和联邦德国生产出商品调 QYAG激光打标记系统,可以在金属上刻文字、图案,然而,因为新技术需要一个发展过程。新技术为人们所认识也需要一个过程,所以固体激光打标记系统为工业界采用,作为一种生产工具,是1975年以后的事. 几乎同时,国外还发展了 TEA CO2激光打标记系统.这使以前主要用于科学研究的TEACO2激光器走进了工业应用领域.由于…