光分配网故障诊断技术研究与应用

网络管理和维护一直是保证网络正常运行、提高客户感知的重要手段。PON（无源光网络）作为宽带接入的主流技术正被各大运营商广泛采用,如何对PON进行有效的管理维护成为各方关注的重点,而ODN（光分配网）的管理和维护也就成为重中之重。文章从ODN存在的故障及运维中面临的问题出发,介绍现有ODN的总体情况,并讨论现有的各种故障诊断技术,分析了各技术方案的优缺点,以及适用的组网模式、定位效果等

中科1号羊草在陕西佳县引种试验成功

中科1号羊草(Leymus chinensis "Zhongke No. 1")是由中国科学院植物研究所选育的国审育成品种,该品种市场需求大,种源远远不能满足需求。陕西省佳县是国贫县,根据其土壤气候资源,适合开展羊草种子繁殖,在收获良种的同时,饲草可用于饲喂牲畜,发展草畜加产业链。因此,本文采用三年引种试验数据评价了中科1号羊草品种引种到榆林佳县的适应性。结果表明:该品种田间发芽率56%,保苗率95%以上;第二年越冬率保持在98%以上,完成了从播种到新种子形成的有性生活史。进入生殖期的群体,抽穗率65. 51%,结实率76. 63%,千粒重2. 34g,发芽率76. 29%,种子产量426kg/hm~2;第一茬鲜草和干草产量分别为15 100 kg/hm~2和5 301 kg/hm~2。综上所述,中科1号羊草新品种适宜在佳县及同类地区种植,具有建设我国"黄土高原羊草种子繁殖基地"的巨大潜力,为我国农牧交错带和草原区生态修复提供乡土草种种源

Identification of degradation mechanisms of blue InGaN/GaN laser diodes

A comprehensive analysis of the degradation mechanism of blue InGaN/GaN laser diodes (LDs) is carried out by investigating the electrical and optical characteristics. The increase in the leakage current as well as decrease in the slope efficiency is observed. The luminescence properties of the active region at different aging stages are studied by means of cathodoluminescence. Significant degradation of the active region is observed on the room temperature cathodoluminescence while the low temperature cathodoluminescence shows almost no degradation, indicating that the degradation of the LDs is due to generation of low temperature frozen point defects. Furthermore, the generation of the defects follows a kinetic mechanism enhanced by electron-hole non-radiative recombination which explains the acceleration of time degradation in our LDs

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