Analysis of contents and sources of pesticides in cultured shellfish of Fujian coastal areas

对福建省15个缢蛏和牡蛎样品中的有机氯农药(六六六、DDTs)、PCBs、及有机磷农药残留进行了监测,并对其污染来源进行了探讨。结果表明,有机磷农药敌敌畏、甲胺磷和有机氯农药滴滴涕的检出率较高,敌敌畏和甲胺磷的平均含量分别为0.80和2.58×10-9(湿重),滴滴涕平均质量分数为8.84×10-9(湿重)。六六六和多氯联苯未检出。福建省内的闽江口和泉州湾的污染程度相对较高,但贝类体内污染物的含量均在食用卫生标准的控制下。The concentrations of organophosphorous pesticides, HCHs, DDTs and PCBs in 15 cultured shellfish samples (Ostrea gigas Thumberg and Sinonovacula constricta) collected from Fujian coastal areas were determined. The possible sources of these pollutants were discussed. The results showed that the shellfish samples were polluted mostly by organophosphorous pesticides, dichlorvos and methamidophos, as well as organochlorine pesticides DDTs. The average concentrations of dichlorvos and methamidophos in the shellfish were 0.80 and 2.58×10~(-9)(ww), respectively, while DDTs were 8.84×10~(-9) (ww). HCHs and PCBs were not detected. The water column in the Minjiang Estuary and Quanzhou Bay were more polluted than other coastal areas in Fujian. However, the pollutants in the cultured shellfish were still controled

基于切向超滤技术的胶体有机碳和无机氮分离及物源初探

利用切向超滤技术对九龙江口天然水体中胶体相(1 kDa～0. 45μm)、真溶解相(<1 kDa)和\"溶解相\"(<0. 45μm)的溶解有机碳和无机氮进行了分离与提取,初步探讨了水环境因子对其理化特性的影响机制,进而探讨了它们的来源和转化.结果表明,切向超滤过程的膜空白和质量平衡符合技术要求;溶解有机碳、亚硝酸盐氮、氨氮、硝酸盐氮和无机氮存在形式以真溶液相(<1 kDa)为主,其在胶体相中的质量浓度分别为0. 207～0. 810 mg/dm3、0. 001～1. 870μg/dm3、ND～2. 08μg/dm3、0. 62～79. 30μg/dm3和1. 07～81. 10μg/dm3;胶体态溶解有机碳(COC)含量主要受陆源输入控制.国家海洋局海洋公益性行业科研专项资助项目(201505034-4);;福建省科学技术厅公益专项资助项目(2015R1003-12

Determination of Peptide Antibiotics Residues in Sediment From Aquaculture Environment by High Performance Liquid Chromatography-Tandem Mass Spectrometry

建立了测定水产养殖环境沉积物中多肽类抗生素残留量的高效液相色谱串联质谱法。沉积物经10 m L甲醇-柠檬酸-Na_2HPO_4溶液(3∶4,V/V)超声提取2次,0.5 g乙二胺四乙酸二钠络合除杂,5 m L甲基异丁基甲酮净化,HLB固相萃取柱进一步富集净化,MGII C18色谱柱分离,0.1%甲酸与0.1%甲酸-乙腈梯度洗脱,ESI+电离,多反应监测模式(MRM)监测,外标法定量。粘菌素和杆菌肽在10~10000μg/L范围内,维吉尼霉素M1在4~4000μg/L范围内,线性回归系数均大于0.999,方法检出限为2~5μg/kg,方法定量限为4~10μg/kg。在3个浓度添加水平下,多肽类抗生素回收率79.7%~91.6%,相对标准偏差1.9%~10.8%。本方法具有良好的精密度和准确度,灵敏度高,适用范围广。A new method for the determination of peptide antibiotics in sediment from aquaculture environment by high performance liquid chromatography-tandem mass spectrometry was developed.The target analytes in sediments were ultrasonically extracted twice with citrate buffer solution and methol mixture( 3∶ 4,V/V),followed by complexation with 0.5 g of Na2 EDTA,purification with 5 m L of methyl isobutyl ketone,and clean-up with HLB-SPE column.The analytes were separated on a MGII C18 column by gradient elution with 0.1% formaic acid-0.1% formaic acid acetonitrile as mobile phase,detected in multiple reaction monitoring( MRM) with electrospray ionization( ESI) under positive ion mode,and quantified by external standard method.The calibration curves were linear( R~2> 0.999) over a concentration range of 10- 10000μg /L for colistin and bacitracin and 4-4000 μg /L for virginiamycin M1.The limits of detection( S/N = 3)were 5 μg/kg for colistin and bacitracin and 2 μg/kg for virginiamycin M1.The limits of quantification( S /N=10) was 10 μg /kg for colistin and bacitracin and 4 μg /kg for virginiamycin M1.At three spiked levels,the recoveries ranged from 79.7% to 91.6%( RSD = 1.9%-10.8%),showing high sensitivity,good reproducibility and wide applicability.国家海洋局海洋公益性行业科研专项(No.201305043-4);; 福建省省属公益类科研院所基本科研专项(No.2015R1003-7);; 福建省海洋高新产业发展专项(闽海洋高新[2014]18号);; 2014年第一批福建省地方标准制修订项目(闽质监标[2014]137号)资

Remote sensingdetected mariculture changes in Dongshan Bay

运用lAndSAT卫星序列遥感数据的监督分类方法,识别与分析了东山湾网箱养殖和延绳式养殖两种海水养殖类型的时空变化。1999—2012年间东山湾海水养殖面积扩大了10倍,大型海藻养殖为主的延绳式养殖面积约为以鱼类与贝类养殖为主的网箱养殖面积的5.6倍。东山湾的养殖布局为适应海湾水质特点而逐年调整,网箱养殖区主要集中在水交换能力较强的湾口,延绳式养殖主要集中在营养盐高、水交换能力略弱的湾内。以大型海藻养殖为主的海水养殖大规模扩展,对海湾富营养化趋势起到缓解作用,但规模过大的海水养殖介入可能诱发主要表现在氮循环上的海湾生态系统不稳定。Using supervised classification method of Landsat satellite sequence remote sensing data,historical changes both cage and longline culture method types of aquaculture farming of Dongshan Bay were identified and analyzed.From 1999 to 2012,the mariculture area expanded ten times while the longline culture-based is5.6times the area of cages culture-based.Reasonable mariculture pattern were adjusted year and year to fit the water quality distribution within the bay.Cage culture zones of the bay were mainly concentrated in waters near tidal inlet with strong exchange capacity,while longline culture zones were mainly distributed in the area far away from the bay mouth where the water exchange capacity was a litter poor but nutrient was rich.Massive expansion of seaweed farming dominated aquaculture structure in the bay had played an important role in mitigation eutrophic tendency in bay.However as its nitrogen circulation revealed,excessive intervention process of mariculture may induce instability in the ecosystem.国家海洋公益性行业科研专项经费项目资助(201005012

Research of nitrification in coastal water of Meizhou Bay—— [~(15)N]ammonium oxidation method

本文利用15n-nH4+氧化法对湄洲湾近岸水体的硝化作用进行深入研究。结果表明,湄洲湾近岸水体硝化速率范围在0.51~4.60μMOl·l-1·d-1。养殖区附近较高的硝化速率,有利于海水对nH4+-n污染物的自净作用,当水体硝化作用强烈时,水中的nO-3的浓度也随之升高,表明海水中nO-3主要来自于细菌的硝化作用。湄洲湾海水nH4+-n的周转时间在1~9 d,表层水体的nH4+-n转化时间高于底层水。硝化作用转化nH4+为nO-2,并最终转化为nO-3,减少了nH3-n及nH4+-n对近岸养殖系统中生物的危害。These studies were conducted to estimate nitrification in coastal water of Meizhou Bay by [15N]ammonium oxidation method.The nitrification rate of 0.51 ～ 4.60 μmol·L-1·d-1were recorded,and the higher nitrification rate in water close to aquaculture area were propitious to ammonium self-purification.Higher nitrification rate was observed at high NO-3concentration water column,which showed NO-3 produced mostly from nitrification.The biological turnover times for NH+4 were short( 1 ～ 9 d) in coastal water of Meizhou Bay with the longer turnover times in surface seawater.Nitrification transformed NH+4 to NO-2,final to NO-3,reducing the harm to organisms of coastal aquaculture system resulted from NH3-N and NH+4-N.福建省专项基金(2005021477); 福建省自然科学基金(D0610020

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

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