影响SmCo_5@FeCo软磁相包覆效果的关键因素

为获得良好磁性耦合和高磁能积的纳米复合永磁粉,系统研究了化学法包覆软磁相FeCo的关键影响因素。研究发现,在制备纳米复合磁粉SmCo_5@FeCo过程中表面活性剂的分子量、反应的加热方式、SmCo_5磁粉的预处理时间以及化学包覆反应的时间等对软磁相的形貌、尺寸、分布,以及对复合粉体的磁性能都有重要影响。表面活性剂分子量的调控和加热方式的改善可使相同量软磁相前躯物投入时形成更致密的高含量包覆层。经过酸洗预处理的SmCo_5粉更有利于软磁相包覆,酸洗时间0.5 h为佳。此结果对制备超高性能纳米复合永磁粉体及块体材料具有重要意义

应用于聚光光伏模组的全反射式二次聚光器的设计与性能分析

<span>当前聚光光伏系统存在很多问题,比如跟踪器的跟踪精度偏低、聚焦光斑强度分布不均匀、聚焦光斑的形状跟太阳电池不匹配等,二次聚光器可以解决这些问题,从而提高高倍聚光光伏系统的光电转换效率。对高倍聚光光伏系统中的菲涅耳透镜和二次聚光器的聚光原理进行了简要分析,重点对全反射式二次聚光器进行了二维聚光的理论分析,并配合非成像光学的光线追迹方法,设计并加工了应用于某高倍聚光光伏系统的全反射式二次聚光器。对该二次聚光器的主要性能进行了仿真分析及评价,结果表明:该聚光器能提高高倍聚光光伏系统的整体性能。&nbsp;</span

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies