LDPC码在军用光纤通信系统中的应用研究

低密度奇偶校验（LDPC）码可降低信号在光纤信道传输过程中产生的误码,可应用于对信号传输的准确性和实时性都具有特殊要求的军事光纤通信系统中。文章针对军用光纤通信系统的性能要求,分析了LDPC码的结构,使用准下三角校验矩阵方法实现LDPC码的编码,采用直线近似置信传播迭代译码（LLR-BP）算法进行译码,并在单片现场可编程门阵列（FP-GA）上实现了编译码器设计。结果表明,该设计具有较强的纠错功能,能满足军用光纤通信系统对信息传输的准确性与可靠性的高要求

Sulfonated-Graphene/Nafion Composite Membrane for All Vanadium Redox Flow Batteries

本文通过磺化石墨烯对Nafion膜进行改性，研究了磺化石墨烯/Nafion复合膜（GRS-Nafion复合膜）的吸水率、电阻率和钒离子迁移数. 结果表明，经磺化石墨烯改性之后，GRS-Nafion复合膜的面电阻和钒离子渗透率显著降低. 全钒液流电池的测试结果表明，GRS-Nafion复合膜有着更加优异的电化学性能，展示出GRS-Nafion复合膜在液流电池中的应用潜力.Nafion membrane has been widely used in fuel cells due to its good proton conductivity, chemical and mechanical stabilities. However, the well-developed water channels in Nafion membrane have restricted its application in all vanadium redox flow batteries owing to the high permeation of vanadium ions and the cost. In this work, the water adsorption rate, resistivity and transference number of vanadium ions of sulfonated-graphene/Nafion composite membrane were investigated and compared with those of Nafion membrane in an effort to overcome the abovementioned drawbacks. It was found that the area resistivity and permeation rate of sulfonated-graphene/Nafion composite membrane were significantly reduced after the modification of Nation membrane by sulfonated grapheme. The results from the all vanadium redox flow battery indicated that the sulfonated-graphene/Nafion composite membrane exhibited better electrochemical performance, demonstrating potential application in all vanadium redox flow batteries.江苏省科技厅项目（No. BE2013084，No. BA2014117）作者联系地址：1. 淮安科润膜材料有限公司，江苏 淮安 211600；2. 厦门大学化学化工学院化学系，福建 厦门 361005Author's Address: 1. Huai An Kerun Film Material Co., Ltd, Huai'an 211600, Jiangsu, China; 2. Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China通讯作者E-mail：[email protected]

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