A Photoelectrochemical Investigation of A.C.Modulated Passive Films on 304 Stainless Steel in Weak-alkaline and Neutral Solution

采用光电化学方法—恒电位光电流测量技术研究了ＡＩＳＩ３０４不锈钢在０．ｌｍｏｌ／ＬＮａ＿２Ｂ＿４Ｏ＿７及０．５ｍｏｌ／ＬＮａ＿２ＳＯ＿４介质中载波钝化膜，光电流测量结果表明：光电流大小与电极电势、成膜条件及测量介质有关．载波钝化膜基本上是高度无序的非晶态膜．A photoelectrochemical investigation has been carried out on AISI 304 stainlesssteeI AV modulated passive film in 0.1mol/L Na_2B_4O_7 and 0.5 mol/L Na_2SO_4 solution.Photocurrentcurve depends on the potential、passive condition and testing solutions. The results of the measurementsindicate that the photoresponse is determined by the defects in the electronic structure of the films whenthe defects lead to localized states in the bandgap region. It is concluded that the passive film on AISI304 stainless steel is in a highly disordered amorphous state.作者联系地址：中国科学院金属腐蚀与防护研究所，金属腐蚀与防护国家重点实验室Author's Address: State Key Laboratory for Corrosion and Protection,Institute of Corrosion and Protection of Metals,Chinese Academy of Sciences,Shenyang 11001

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