Studies on the shape-controlled nano-scale silver

[中文文摘]在聚乙烯吡咯烷酮(PVP)保护下,以乙二醇(EG)为还原剂制备银纳米粒子。探讨了反应物浓度、反应温度对制备的纳米银粒子形貌的影响。采用X射线衍射(XRD)和透射电镜(TEM)来表征纳米银粒子的结构和形貌。结果表明,AgNO3和PVP的浓度,AgNO3和PVP的比例以及反应温度对纳米银粒子有较大影响,反应温度控制在140℃至160℃之间,易于控制纳米银粒子的形貌。[英文文摘]Nano-scale silver was prepared using the reduction reaction of silver nitrate by ethylene glycol with polyvinyl pyrrolidone(PVP) as the capping agent.The effect of reaction temperature and the concentration of AgNO3 and PVP on the shape of the nano-scale silver were studied.The nano-scale silver was characterized by XRD and TEM.The results indicated that certain shape nano-scale silver can be obtained by controlling the concentration of AgNO3 and PVP under the certain reaction temperature.厦门大学预研基金(Y07027)资助项

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^