Study on corrosion resistance and chroma of the deposit from sulfate trivalent chromium plating bath

以厦门大学研发的XTC-硫酸盐三价铬镀铬工艺进行中试试验,利用扫描电子显微镜(SEM)、能谱仪(EdS)和CM-2600dlAb值测试仪分别对镀层的表面形貌、组分和色度进行表征,考察了电流密度和导电盐浓度对镀层抗腐蚀能力和色度的影响。结果表明,镀件外观均匀一致,色度白亮、略偏黄;镀层形貌平整、致密,为微裂纹结构;当电流密度为3~6A/dM2,导电盐质量浓度为170g/l时,所得镀层能够通过CASS16H测试。A pilot-scale test for XTC-sulfate trivalent chromium electroplating process developed by Xiamen University was carried out.The surface morphology,composition and chroma of the deposit were characterized by scanning electron microscope(SEM),energy-dispersive spectrometer(EDS) and CM-2600d Lab values tester.The effects of current density and concentration of conductive salt on the corrosion resistance and chroma of deposit were studied.The results indicated that the deposit features a uniform,bright and white appearance with a bit yellowish color,as well as a level and compact morphology with a micro-crack structure.The deposit prepared with conductive salt 170 g/L at current density 3-6 A/dm2 can pass 16-h CASS test.福建省产业技术开发项目(闽发改高技[2010]299号);福建省科技计划重点项目(2008H0086

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