波动方程反演问题的一种新的逼近方法

本文给出了一种求解波动方程反演问题的“多目标函数法”.这种方法简单、有效,并具有明确的物理意义.对于三维问题的程序化它有很强的优越性

Optimal Conditions on the Production of Deltamethrin-degrading Enzyme from Pseudomonas sp.P1-1-B3 Strain

农药降解酶对去除农药残留污染具有良好的应用前景.从海洋沉积物中筛选到一株高产溴氰菊酯降解酶的菌株PSEudOMOnAS SP.P1-1-b3,研究了碳源、氮源、PH值、培养温度、培养时间、接种量及溴氰菊酯对菌株产酶的影响.结果表明,降解菌产酶的最适条件为:以可溶性淀粉作为碳源,M(蛋白胨):M(酵母浸膏)=2:1为氮源,PH 7.5,温度30℃,培养时间2 d,接种量3%,溴氰菊酯含量15μMOl/l.在此条件下,菌株产酶的比活力最大为113.3 u/Mg.该降解酶对溴氰菊酯的降解,在12 H内降解率达54.6%.The pesticide-degrading enzyme shows good prospective application for the removal of pesticide residues.Some optimal conditions were studied on producing deltamethrin-degrading enzyme from Pseudomonas sp.P1-1-B3 strain,which obtained from marine sediment and showed high degradation efficiency on deltamethrin.These conditions consisted of carbon sources,nitrogen sources,pH value,temperature,cultivation time,inoculation amount of bacteria and concentration of deltamethrin.The results showed that the maxium enzymatic activity 113.3 U/mg when the strain was cultured under the following conditions:soluble starch as carbon source,the mass ratio of peptone to yeast extract(2:1),pH 7.5,30℃,3%inoculation amount of bacteria,2 d of cultivation time,15μmol/L of deltamethrin in media.Meanwhile,the degrading enzyme showed good degradation efficiency on deltamethrin with the degradation rate of 54.6%in 12 h.福建省青年科技人才创新项目(2007F3094);厦门大学引进人才科研启动费项目(0000-X071C3);细胞生物学与肿瘤细胞工程教育部重点实验室(厦门大学)开放基金(2007110);近海海洋环境科学国家重点实验室(厦门大学)开放基金(MEL0603);国家海洋局第三海洋研究所海洋生物遗传资源重点实验室开放研究基金(HY200601);国家海洋局近岸海域生态环境重点实验室开放基金(200702

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