几种天然产物在海洋防污涂料中的应用研究

将天然产物齐墩果酸、蛇床子素和鱼藤酮作为防污剂,分别制备海洋防污涂料,在厦门海域检验其海区防污效能,并与已报道在厦门海域具防污效能的天然产物喜树碱进行比较,发现蛇床子素和鱼藤酮在海区挂板2个月内显示出一定的防污效能,齐墩果酸没有呈现出防污效能,而喜树碱的海区防污效能明显优于上述3种天然产物。另外,将喜树碱与鱼藤酮进行1∶1复配,并将这2种天然产物与氧化亚铜、N-(2,4,6-三氯苯基)马来酰亚胺(TCPM)和吡啶硫铜锌(ZPT)这3种防污(助)剂分别进行1∶1复配,共获得7种复配防污剂,制备相应的海洋防污涂料以检测其防污效能,发现喜树碱-TCPM、喜树碱-ZPT以及喜树碱-鱼藤酮这3种复配防污剂具良好的防污效能。进一步在上述涂料中选取了防污效能最优的含喜树碱涂料,在福建东山海域和海南陵水海域分别进行了海区挂板试验,结果表明含喜树碱涂料在这2个海域均显示出稳定、优异的防污效能,且期效可达13个月以上。文中研究为推进天然防污产物在海洋防污涂料中的应用进程提供了重要资料。厦门市海洋经济创新发展示范产业链协同创新类项目(16CZB023SF12);;海洋(赤潮)灾害立体监测技术与应用国家海洋局重点实验室开放研究基金(MATHAB201808);;福建省海洋经济发展补助资金项目(FJHJF-L-2018-2

不同上方来水模式下工程堆积体坡面的植被调控

为揭示植被格局对工程堆积体坡面水沙调控的影响，采用野外模拟径流冲刷试验，分析了 4 种上方来水模式（均 匀型、峰值前型、峰值中型和峰值后型）下坡面 5 种覆草格局（裸坡、坡顶聚集、坡中聚集、坡底聚集和带状格局）的 侵蚀特征。结果表明：水流功率与土壤剥蚀率之间相关性最高且呈极显著幂函数关系（R2 =0.47～0.72，P&lt;0.01），是描述 堆积体侵蚀动力机制的最优参数。植被格局的减流效益在 12.23%～49.62%之间，减沙效益在 12.92%～80.54%之间，减 沙效益高于减流效益；带状和坡顶聚集格局的平均减流减沙效益分别为 43.87%、58.09%和 30.55%、54.41%，显著优于 其他植被格局，在治理堆积体水土流失时应优先考虑这两种植被格局。植被格局下侵蚀泥沙中砂粒含量较对照小区减小 了 18.79%～35.80%，黏粒含量增加了 3.56%～10.69%，表明植被对砂粒的拦截效果显著；侵蚀泥沙颗粒体积分形维数主 要由黏粒体积分数决定，两者呈极显著线性相关关系（R2 =0.90，P&lt;0.01）。植被格局的砂粒富集率较对照小区相对减小， 黏粒富集率相对增加，体积分形维数增大；侵蚀泥沙中黏粒和砂粒迁移方式以团粒为主，粉粒则以单粒为主。该研究可 为工程堆积体水土流失植被防控措施的配置提供参考。</div

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

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

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^