标题： 太阳活动周期23-25期间的DH型II类射电爆发：起源及其与太阳爆发事件的相关性 显示英文标题

标题： DH type II radio bursts during solar cycles 23-25: Origin and association with solar eruptive events

摘要： 我们分析了跨越太阳活动周期23至25的DH型II类太阳射电爆发，期间共报告了590次DH型II类爆发，其中确认了568次与日冕物质抛射和462次与耀斑相关的情况。 当我们根据事件数量及其持续时间来检查数据时，发现DH型II活动存在短期但重要的差异，例如在第24个太阳活动周期中峰值活动的时间偏移，以及在第25个太阳活动周期中活动水平增长速率的变化。 为了深入探索，根据其结束频率将DH型II爆发分为三类：低频组（LFG）、中频组（MFG）和高频组（HFG）。 HFG类别最为常见（约47%），而LFG类别约占事件的四分之一（约24%）。 LFG事件明显倾向于最快的日冕物质抛射和X级耀斑，四分之一的事件显示结束频率低于50 MHz。 显示英文摘要

摘要： We analyses occurrence of DH type II solar radio bursts spanning over solar cycles 23-25 during which a total of 590 DH type II bursts are reported with confirmed 568 and 462 cases of associated CME and flares, respectively. We find short-term yet important differences in DH type II activity when the data is examined in terms of event counts and their durations, e.g., temporal shift in the peak activity during cycle 24 and variation in the growth rate of the activity level during cycle 25. For an in-depth exploration, DH type II bursts are classified in 3 categories based on their end-frequencies: Low-, Medium-, and High- Frequency Groups (LFG, MFG, and HFG, respectively). The HFG category is the most populous (~47 %) while the LFG category occupy about a quarter of the events (~24 %). The LFG events show a clear inclination toward fastest CMEs and X-class flares with a quarter of events exhibiting end frequency below 50 MHz.