报告题目：A Rapid Cosmic-ray Increase in BC 3372-3371 from Ancient Buried Tree Rings in China

　　报告人简介：王发印，南京大学教授，分别于2005年和2010年获得南京大学学士和博士学位。先后获得全国优秀博士学位论文奖，国家优秀青年科学基金和“万人计划”青年拔尖人才计划资助等。主要研究方向为高能天体物理、宇宙学等。

　　报告摘要：Cosmic rays interact with the Earth's atmosphere to produce 14C, which can be absorbed by trees. Therefore, rapid increases of 14C in tree rings can be used to probe previous cosmic-ray events. By this method, three 14C rapidly increasing events have been found. Plausible causes of these events include large solar proton events, supernovae or short gamma-ray bursts. However, due to the lack of measurements of 14C by year, the occurrence frequency of such 14C rapidly increasing events is poorly known. In addition, rapid increases may be hidden in the IntCal13 data with five-year resolution. Here we report the result of 14C measurements using an ancient buried tree during the period between BC 3388 and 3358. We find a rapid increase of about 9‰ in the 14C content from BC 3372 to BC 3371. We suggest that this event could originate from a large solar proton event.

　　时间：11月30日（周四）中午12：00—13：00

　　地点：仙林园区3号楼402会议室

　　联系人：孙玮（83332162）、魏俊杰（83332042）