Preparation and Characterization of the HA/MWCNTs Composites

为了赋予碳纳米管(CnTS)表面良好的生物性能,拓展CnTS在硬组织生物材料及组织工程支架材料中的应用,采用化学共沉淀和水热后处理法宏量制备了羟基磷灰石(HA)/多壁碳纳米管(MWCnTS)复合材料,通过调节制备过程中浓硝酸纯化的MWCnTS加入量,考察不同MWCnTS含量的HA/MWCnTS复合材料的结合形式.扫描电子显微镜(SEM)和透射电镜(TEM)表征结果表明,当ω(MWCnTS)=15%时,MWCnTS表面均匀地包覆了一层由纳米HA晶粒紧密相连的膜层,在此情况下MWCnTS与纳米HA形成最佳结合状态.体外细胞培养实验表明,制备的HA/MWCnTS复合材料具有良好的生物相容性.In order to get a good biological performance for carbon nanotubes,in this work,multi-walled carbon nano-tubes(MWCNTs) were purified by the nitric acid,and purified MWCNTs were treated by a chemical coprecipitation of hydroxyapatite(HA) under the hydrothermal reaction.By changing the content of MWCNTs,a series of HA/MWCNTs composites with various percentages of MWCNTs were successfully prepared.The results characterized by SEM,TEM and spectroscopic measurements revealed that the MWCNTs could be well coated with a dense nano-hydroxyapatite coating when the content of MWCNTs was about 15%(by mass).In this case,the optimal combination between HA and MWCNTs can be achieved.In vitro cell culture demonstrates that the prepared HA/MWCNTs nano-composites with 15%(by mass) MWCNTs exhibit a good biocompatibility.国家自然科学基金(20773100)资

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