郯庐断裂带中段安丘-莒县断裂(F_(5))为中国东部重要的地震活动断裂,其最南段展布于淮河—女山湖之间,长约20km,最新活动时代为全新世早期。针对F_(5)断裂淮河—女山湖段的前期工作侧重于在不同地段开挖探槽以揭示断裂的最新活动时代、...郯庐断裂带中段安丘-莒县断裂(F_(5))为中国东部重要的地震活动断裂,其最南段展布于淮河—女山湖之间,长约20km,最新活动时代为全新世早期。针对F_(5)断裂淮河—女山湖段的前期工作侧重于在不同地段开挖探槽以揭示断裂的最新活动时代、结构特征及运动性质,并报道了零星的古地震事件。本次在该段选取关键地段开挖探槽并结合前期探槽资料,开展了古地震事件的综合对比研究;通过测量探槽附近断层陡坎的高度,并结合相关地层测年数据,计算了断裂的垂直滑动速率;基于该段古地震研究成果,结合其他学科资料,分析了苏皖交界地区的地震危险性。研究表明:(1)F_(5)断裂淮河—女山湖段中更新世晚期以来至少发生过5次古地震事件,厘定的最近2次事件的年代为20.36~(18.7±0.3) ka BP和10.92~7.83ka BP;(2)F_(5)断裂淮河—女山湖段紫阳山一带的垂直滑动速率约为0.05mm/a,陡山一带的垂直滑动速率约为0.07mm/a,该段整体属于弱活动断层;(3)F_(5)断裂泗洪—明光段为历史地震地表破裂空段,最近1次古地震的离逝时间较长,现今小地震不活跃,闭锁程度较高,易于应力积累,存在发生7级及以上强震的危险性。展开更多
For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chie...For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chief approach to improve their thermoelectric performance. Herein, we report the multiple effects of Se doping on thermoelectric performance of p-type Bi0.5Sb1,5Te3-xSex ＋ 3 wt% Te ZM ingots, which increases carrier concentration, reduces lattice thermal conductivity and deteriorates the carrier mobility. As a result, the peak figure of merit （ZT） is shifted to a higher temperature and a high ZT 1.2 at 350 K is obtained, due to the reduced thermal conductivity and suppressed intrinsic conduction. Further, decreasing Sb content is followed to optimize the room temperature performance and a ZT - 1.1 at 300 K is obtained. These results are significant for designing and optimizing the thermoelectric performance of commercial Bi0.5Sb1.5Te3＋ 3 wt% Te ZM alloys.展开更多
文摘郯庐断裂带中段安丘-莒县断裂(F_(5))为中国东部重要的地震活动断裂,其最南段展布于淮河—女山湖之间,长约20km,最新活动时代为全新世早期。针对F_(5)断裂淮河—女山湖段的前期工作侧重于在不同地段开挖探槽以揭示断裂的最新活动时代、结构特征及运动性质,并报道了零星的古地震事件。本次在该段选取关键地段开挖探槽并结合前期探槽资料,开展了古地震事件的综合对比研究;通过测量探槽附近断层陡坎的高度,并结合相关地层测年数据,计算了断裂的垂直滑动速率;基于该段古地震研究成果,结合其他学科资料,分析了苏皖交界地区的地震危险性。研究表明:(1)F_(5)断裂淮河—女山湖段中更新世晚期以来至少发生过5次古地震事件,厘定的最近2次事件的年代为20.36~(18.7±0.3) ka BP和10.92~7.83ka BP;(2)F_(5)断裂淮河—女山湖段紫阳山一带的垂直滑动速率约为0.05mm/a,陡山一带的垂直滑动速率约为0.07mm/a,该段整体属于弱活动断层;(3)F_(5)断裂泗洪—明光段为历史地震地表破裂空段,最近1次古地震的离逝时间较长,现今小地震不活跃,闭锁程度较高,易于应力积累,存在发生7级及以上强震的危险性。
基金supported by the National Natural Science Foundation of China (Nos. 61534001 and 11574267)the National Science Fund for Distinguished Young Scholars (No.51725102)
文摘For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chief approach to improve their thermoelectric performance. Herein, we report the multiple effects of Se doping on thermoelectric performance of p-type Bi0.5Sb1,5Te3-xSex ＋ 3 wt% Te ZM ingots, which increases carrier concentration, reduces lattice thermal conductivity and deteriorates the carrier mobility. As a result, the peak figure of merit （ZT） is shifted to a higher temperature and a high ZT 1.2 at 350 K is obtained, due to the reduced thermal conductivity and suppressed intrinsic conduction. Further, decreasing Sb content is followed to optimize the room temperature performance and a ZT - 1.1 at 300 K is obtained. These results are significant for designing and optimizing the thermoelectric performance of commercial Bi0.5Sb1.5Te3＋ 3 wt% Te ZM alloys.
