Denitrification and anammox in marine water columns using 15N technique

通过系列方法实验建立了海洋水体反硝化速率和厌氧氨氧化速率测定的15N示踪方法，将该方法运用于厦门筼筜湖、黄海、东海的反硝化作用和厌氧氨氧化作用研究，以及白令海和西北冰洋的反硝化作用研究，获得主要结果如下： 夏季厦门筼筜湖水体的反硝化速率和厌氧氨氧化速率分别为0~49.45μmolN2/L/d和0~2.83μmolN2/L/d。秋季水体反硝化速率和厌氧氨氧化速率的变化范围分别为0.023~0.43μmolN2/L/d和0~0.33μmolN2/L/d。夏季的反硝化速率和厌氧氨氧化速率比秋季高出1~2个数量级，与该季节水体温度较高、缺氧程度较大有关。两个季节反硝化作用和厌氧氨氧化作用对N2总产生...15N tracer method was established for measuring denitrification rates and anammox rates simultaneously in seawater, and used to evaluate denitrification and anammox in the Yundang Lagoon, Xiamen, the Yellow Sea and the East China Sea. Besides, denitrification in the Bering Sea and the western Arctic Ocean were also studied. In summer, denitrification rates and anammox rates in the water column o...学位：理学硕士院系专业：海洋与环境学院海洋学系_海洋化学学号：2242007115087

Gasbench Ⅱ-IRMS升级NO预富集装置测定海水硝酸盐的氮氧同位素

本研究研制了由气压棒、气体控制阀、不锈钢管冷阱、石英毛细管冷阱、杜瓦瓶、化学阱等构成的NO预富集装置,通过扩展GasbenchⅡ功能控制冷阱的升降,改造气体回路、进样针和样品盘,实现NO的预富集以及GasbenchⅡ自动进样与IRMS联机测定.通过将海水中的硝酸盐经化学方法转化成NO,建立了海水硝酸盐氮、氧同位素的分析方法.研究表明,所建立方法对海水硝酸盐氮、氧同位素的分析具有很好的精度,硝酸盐δN、δO及峰面积的相对标准偏差分别小于1%、3%和5%.对采自南极普里兹湾海水样品中硝酸盐氮、氧同位素的分析结果与文献报道值吻合,也与海水硝酸盐氮、氧同位素组成的变化规律相一致,证明所建立的技术方法可成功运用于海水硝酸盐氮、氧同位素的分析.高等学校仪器设备和优质资源共享系统大型仪器示范机组建设资助项目(CERS-1-76)；国家重点基础研究发展计划资助项目(2015CB452903)；南北极环境综合考察与评估专项资助项目(CHINARE2016-01-04-03)；国家自然科学基金杰出青年基金资助项目(41125020)

Effects of benzo[a]pyrene and DDT subacute co-exposure on ALT, AST and γ-GT in mice

目的:探讨不同剂量的苯并[A]芘(b[A]P)和滴滴涕(ddT)联合暴露对小鼠血清中谷丙转氨酶(AlT)、谷草转氨酶(AST)和γ-谷胺酰转移酶(γ-gT)的影响及作用形式。方法:成年雄性昆明种小鼠50只,随机分为10组即空白对照组(正常饲养)、溶剂对照组(食用油和二甲基亚砜处理)、低和高浓度b[A]P染毒组[1.0和10 Mg/(kg·d)]、低和高浓度ddT染毒组[0.6和6 Mg/(kg·d)]、低浓度ddT+低浓度b[A]P染毒组、低浓度ddT+高浓度b[A]P染毒组、高浓度ddT+低浓度b[A]P染毒组、高浓度ddT+高浓度b[A]P染毒组。染毒组各受试物经腹腔注射染毒,每日注射1次,连续31 d。末次染毒24 H后通过眼球摘除取血,自动生化仪检测血清中AlT、AST、γ-gT的活性;并制作肝脏HE切片,观察肝细胞形态。采用两因素三水平析因设计的方差分析对数据进行统计分析。结果:与对照组比较,b[A]P和ddT单独染毒时,均能诱导AlT和AST活性升高(f=41.308,P=0.000;f=20.083,P=0.000),随各自染毒剂量的增加,AlT和AST活性升高,但二者联合暴露对AlT和AST活性均不存在交互作用(分别为P=0.258,P=0.264)。b[A]P和ddT单独染毒对γ-gT活性均未产生明显影响,联合暴露也不存在交互作用(P=0.816)。HE染色观察到肝细胞膜界限模糊,发生水样变性,肝细胞中出现小空泡,呈蜂窝状,随染毒剂量增加,肝细胞质水样变性加剧,部分肝细胞质溶解,并且细胞核肿大,形状不规则。结论:在本实验条件下,b[A]P和ddT单独染毒均能诱导小鼠血清AlT和AST活性升高,不同剂量的b[A]P和ddT联合暴露对小鼠血清AlT、AST活性的作用形式主要表现为单独作用,而非交互作用。b[A]P和ddT的单独和联合暴露均未观察到对γ-gT的活性产生明显影响。OBJECTIVE: To explore the effects of benzo[a] pyrene and DDT exposure alone or in combination on ALT,AST and γ-GT in mice.METHODS:Fifty healthy male Kunming mice were divided into 10 groups at random:blank control group(normal feed);solvent control group(equal volume of oil);1,10 mg/(kg·d) B[a]P groups;0.6,6 mg/(kg·d) DDT groups;1 mg/(kg·d) B[a]P+0.6 mg/(kg·d) DDT group;1 mg/(kg·d) B[a]P+6 mg/(kg·d) DDT group;10 mg/(kg·d) B[a]P+0.6 mg/(kg·d) DDT group and 10 mg/(kg·d) B[a]P+6 mg/(kg·d) DDT group.Exposure groups were treated with oil contained B[a]P and DDT once a day.After 31 days of intraperitoneal injection,eyeballs were extracted and ALT,AST and γ-GT were examined in blood.HE slices were made to confirm the liver damage.Using two factors and three levels factorial ANOVA design for data analysis.RESULTS:The levels of ALT and AST in all B[a]P or DDT alone exposure groups were significantly higher than that of the control groups(F=41.308,P=0.000;F=20.083,P=0.000),showing dose-effect relationships in both.But no interaction was observed in co-exposure groups(P=0.258,P=0.264).No significant changes in γ-GT were observed in all B[a]P or DDT alone exposure groups.Neither was there any interactive effect in co-exposure groups(P=0.816).This was in accordance with the observation in HE slice:hydropic degeneration,endolysis and nuclear enlargement in liver cell.CONCLUSION:Under this experimental condition,increasing levels of ALT and AST could be detected in B[a]P or DDT separate exposure groups.But neither could affect γ-GT level.No interactive effects of ALT,AST and γ-GT could be induced in co-exposure groups.福建省自然科学基金项目(2013J01354); 厦门市科技计划项目(3502Z20123003); 中央高校基本科研业务费专项资金(2011121006

Biological nitrogen fixation in the upper water column in the south Taiwan Strait during summer 2011

2011年6—7月,利用15n2示踪法实测了台湾海峡南部海域的生物固氮速率,结合温度、盐度、天然颗粒物氮同位素组成的分布,分析并讨论了影响研究海域生物固氮速率的环境因素。结果表明,夏季台湾海峡南部海域的生物固氮速率介于168—1080 nMOl M-3d-1之间,平均为537 nMOl M-3d-1,较高的生物固氮速率大多出现在次表层水体中。研究站位的积分固氮速率变化范围为11—40μMOl M-2d-1,平均为23μMOl M-2d-1。积分固氮速率的空间变化与不同水团的影响有关,在受黑潮水影响的海域,生物固氮速率较高,而在上升流和受河流冲淡水影响的海域,生物固氮速率较低,说明较低的水温及较高的无机氮营养盐可能会抑制研究海域的生物固氮作用。研究海域天然颗粒物δ15n与生物固氮速率之间呈现良好的负相关关系,表明天然颗粒物氮同位素组成可定性指征研究海域生物固氮作用的强弱。Biological N2fixation in marine environments is a major component in the ocean nitrogen budget and plays an important role in global carbon cycles through the sequestration of atmospheric carbon dioxide and production of marine organic matter.N2fixation could be regulated by the abundance and chemical speciation of nutrients and many trace elements in seawater.Recent studies have revealed that N2fixation is much more widespread in marine environments than previously thought.However,little is known about the N2fixation in the Taiwan Strait,especially on N2fixation rates,and their relationship with environmental parameters.The major objectives of this study were to determine the N2fixation rates and their spatial distributions and to explore major physicochemical controlling factors in the south Taiwan Strait.During June and July 2011,seawater samples were collected from ten stations at two transects in the south Taiwan Strait for the measurements of N2fixation rate using the15N2tracer assay.Particulate nitrogen and its isotopic composition were measured with an elemental analyzer(Carlo Erba NC 2500) coupled with a Finnigan MAT DeltaplusXP isotope ratio mass spectrometer.Reproducibility of nitrogen isotope measurements(in terms of δ15N) was within 0.2‰.Our results showed that N2fixation rates in the south Taiwan Strait ranged from 168—1080 nmol m-3d-1with an average of 537 nmol m-3d-1.Most of the high rates were observed at subsurface layers.The depth-integrated N2fixation rates were 11—40 μmol m-2d-1with an average of(23±10) μmol m-2d-1.The distribution of the N2fixation rates showed regional variations with influence from water masses with distinctive temperature and salinity.Higher N2fixation rates were mostly observed in the regions influenced by the Kuroshio,with an average of 31 μmol m-2d-1,while lower rates occurred in the upwelling and river plume regions with an average of 15 μmol m-2d-1.This spatial distribution pattern indicated that biological N2fixation was largely impeded by the low temperature and the high concentration of dissolved inorganic nitrogen in the south Taiwan Strait.The contribution of N2fixation in the study area could be further quantified based on the δ15N signatures of suspended particles which could be significantly depleted during N2fixation.Indeed,a negative correlation between the δ15N signatures of suspended particles and N2fixation rates was observed regardless of using all data points or depth-averaged values within the water column.This indicated that15N-depleted particles were largely derived from the enhanced N2fixation,supporting the use of nitrogen isotopic composition(δ15N) of suspended particles as a potential indicator of N2fixation in the south Taiwan Strait.Further studies are needed to better elucidate the relationship between N2fixation rates and limiting elements and their chemical speciation,and thus the physical and biogeochemical controls on N2fixation in the south Taiwan Strait.国家自然科学基金资助项目(41125020;41076043;41206062); 国际海域资源调查与开发“十二五”项目(DY125-13-E-01

Loop-Mediated Isothermal Amplification(LAMP) for Detection of Alicyclobacillus acidoterrestris in Foods

目的:利用环介导等温扩增技术建立食品中酸土环脂芽孢杆菌快速检测方法。方法:针对酸土环脂芽孢杆菌16S序列设计特异引物,再优选反应体系,用显色法检测实验结果。结果:该方法能够在63℃条件下1 H内检出食品中酸土环脂芽孢杆菌,所设计的引物有良好的特异性;灵敏度达6.7 Cfu/M l(弱阳性)。结论:该方法具有高效、特异性强和敏感性高等特点,可满足酸土环脂芽孢杆菌快速检测筛选的要求。Purpose: A loop-mediated isothermal amplification(LAMP) method was established for the detection of Alicyclobacillus acidoterrestris in foods.Methods: After optimization of the reaction conditions of LAMP including the concentrations of primers, reaction time and amplification temperature, the LAMP method was developed, and its sensitivity and specificity were evaluated.Results: The method was capable of rapidly and specifically detecting A.acidoterrestris in foods within 1 hour at a constant temperature of 63 ℃.The sensitivity of the method was 6.7 CFU/m L and the specificity was 100%.Conclusions: The LAMP method is efficient, highly sensitive and specific, and suitable for the rapid detection of A.acidoterrestris in various food samples.福建省漳州市自然科学基金项目(ZZ2012J16

Accurately quantification of ~(29)N_2 concentration in ~(15)N tracer derived marine denitrificaiton rates

利用15 n示踪法实测南海水体反硝化速率的研究发现,培养水样在长时间密闭放置过程中也会受到外界空气的污染,且其29n2/28n2比值恒定为0.007 35。根据空气背景中29n2/28n2比值恒定的特征,提出基于质量平衡关系校正空气n2污染的方法,通过将样品实测29n2浓度扣除由外界空气贡献的29n2浓度,可获得由生物反硝化作用所产生的29n2准确浓度,进而可计算出准确的反硝化速率。经空气29n2背景校正后,29n2浓度的偏差明显小于未经校正的结果,且29n2浓度与培养时间之间的线性相关性显著加强,凸显出空气29n2背景校正是获取准确反硝化速率的关键。鉴于15 n示踪法已被广泛应用于海洋水体与沉积物反硝化速率的测定中,所提出的空气29n2背景校正方法具有重要的意义。15 N tracer technique was widely applicated in measuring water column denitrification rate in water samples,however,the sealed samples could be contaminated by air during a long time storage.Our study suggested that N2in air has a constant 29N2/28N2ratio of 0.007 35.According to this feature,a mass-balance calculation was proposed to calibrate the interference from air background.It helps obtain more accurately 29N2concentrations produced by biological activity and further the denitrification rates.After the calibration,the deviations of 29N2concentrations were much less than those of the raw data,and the linear correlation between 29N2concentration and the incubation time was more significant.It is important to calibrate extra 29N2signals from air contamination for accurately quantification of denitrification rate,considering the 15 N technique has been widely used in pelagic and beneath denitrification rate measurements.国家自然科学基金杰出青年基金项目(41125020); 国际海域资源调查与开发“十二五”课题(DY125-13-E-01); 科技基础性工作专项(2008FY110100

N_2O preconcentration device upgraded for GasbenchⅡ-IRMS analyzing N and O isotopes of seawater nitrate

本研究研制了由气压棒、气体控制阀、不锈钢管冷阱、石英毛细管冷阱、杜瓦瓶、化学阱等构成的N_2O预富集装置,通过扩展Gasbench; Ⅱ功能控制冷阱的升降,改造气体回路、进样针和样品盘,实现N_2O的预富集以及Gasbench; Ⅱ自动进样与IRMS联机测定.通过将海水中的硝酸盐经化学方法转化成N_2O,建立了海水硝酸盐氮、氧同位素的分析方法.研究表明,所建立方法对海水硝; 酸盐氮、氧同位素的分析具有很好的精度,硝酸盐delta~(15)N、delta~(18)O及峰面积的相对标准偏差分别小于1%、3%和5%.对采自; 南极普里兹湾海水样品中硝酸盐氮、氧同位素的分析结果与文献报道值吻合,也与海水硝酸盐氮、氧同位素组成的变化规律相一致,证明所建立的技术方法可成功运; 用于海水硝酸盐氮、氧同位素的分析.The preconcentration device for N_2O analysis was upgraded and assembled; by a series of components, including air pressure bar, gas control; valve, stainless steel cyro trap, fused silica capillary cyro trap,; dewar, chemical trap and etc. The function of Gasbench Ⅱ was extended to; control the lifting of cyro traps while the gas circuit, sampling; syringe, and sample plate were altered to realize the on-line; determination with N_2O preconcentration device, Gasbench Ⅱ and IRMS.; Nitrate was chemically converted to N_2O to build the method for; analysis of N and O isotope in seawater nitrate. Our results showed that; the developed method has a very good precision. The standard deviation; of delta~(15)N, delta~(18)O and peak area of nitrate was less than 1%,; 3% and 5%, respectively. The N and O isotopes of nitrate in seawater; collected from the Prydz Bay, Antarctica, were measured with this; method. The values of delta~(15)N, delta~(18)O of nitrate obtained were; agreed well with literature reports. The profiles of delta~(15)N,; delta~(18)O of nitrate in the Prydz Bay showed the typical; characteristics of the ocean. The developed technique for analyzing N; and O isotopes of seawater nitrate was feasible.高等学校仪器设备和优质资源共享系统大型仪器示范机组建设资助项目; 国家重点基础研究发展计划资助项目; 南北极环境综合考察与评估专项资助项目;; 国家自然科学基金杰出青年基金资助项

球壳的变形计算和能量准则

本文是用近似计祘的方法,通过球壳自由胀形问题的具体计祘,来得出球壳在爆炸载荷作用下的变形过程,以及球壳半径R,料厚δ,半径增加量y和药量w之间的关系。从理论上论述了爆炸成形能量准则的准确性。另外本文提出了球壳爆炸成形的近似计祘公式和方法。根据球壳的最终变形量归纳出一个简单的药量计祘公式

Simultaneous determination of denitrification and anammox rates in seawater using ~(15)N tracer assay and its application

反硝化与厌氧氨氧化作用是海洋结合态氮迁出的主要途径,15n示踪法是定量反硝化和厌氧氨氧化作用的新方法,它具有灵敏度高、可同步测量反硝化与厌氧氨氧化速率的优点.本研究开展了一系列方法学实验,以确定高纯氦气驱赶水样所含气体的时间、超声赶气时间、同位素比值质谱仪测量n2含量的精度、n2含量及其同位素组成测定的工作曲线以及示踪剂的最佳添加量等,从而确立起15n示踪同步测定海水反硝化和厌氧氨氧化速率的方法.所建立方法测量n2含量的相对标准偏差小于8%,可满足海洋反硝化与厌氧氨氧化速率测定的需要.应用该方法实测了厦门筼筜湖富氧与缺氧水体的反硝化与厌氧氨氧化速率,结果表明,缺氧底层水的反硝化速率[4.10~5.47μMOl/(dM3·d)]比富氧表层水[0.43~0.46μMOl/(dM3·d)]明显来得高,但缺氧底层水的厌氧氨氧化速率[0.00~0.12μMOl/(dM3·d)]则比富氧表层水的速率[0.52~0.67μMOl/(dM3·d)]低得多.Denitrification and anammox are two pathways for removal of fixed nitrogen from marine environments.15N tracer assay was a new method for simultaneously measuring denitrification and anammox rates in seawater with high sensitivity.In this study,a series of experiments were conducted to assess the purge time for removing natural dissolved N2,the blowing time for N2concentrated in bottle headspace,the measurement accuracy of N2determination,the standard curve for calculation of N2content,and the effect of tracer amounts on the measured denitrification rate.The established method measured N2content with an accuracy of less than 8%,which met the need for measurements of denitrification and anammox rates.The measured denitrification and anammox rates in the Yundang lagoon,Xiamen,indicated that the denitrification rates in the anoxic bottom water[4.10 ~ 5.47 μmol /(dm3·d)] were much higher than those in the aerobic surface water[0.43 ~ 0.46 μmol /(dm3·d)],while the anammox rates in the bottom water[0.00 ~ 0.12 μmol /( dm3·d)]were lower than those in the surface water[0.52 ~ 0.67μmol/(dm3·d)].国家自然科学基金杰出青年基金资助项目(41125020); 国家海洋局大洋专项资助项目(DY125-13-E-01); 科技部海洋公益性行业科研专项资助项目(2010050012-3

Effects of Nature Colloids on the Growth of Nature Bacteria Community

利用错流超滤技术提取厦门湾东南部海域、九龙江河口及九龙江水体中的胶体,研究了胶体的来源和胶体有机碳浓度(COC)对天然菌群生长的影响.结果表明,海洋胶体、河口胶体及河流胶体在不同程度上对天然菌群的生长均有促进作用.海洋胶体中的天然菌群相对增长率y为54.0%~96.1%,相对增长率的平均值Y为76.7%;河口胶体中的天然菌群的y为20.0%~97.3%,Y为72.2%;而河流胶体中天然菌群的y为8.3%~112.4%,Y为69.8%.胶体对外加菌群的促进作用与COC浓度没有相关关系.Colloids were abstracted by cross-flow ultrafiltration technique from Xiamen Bay,Jiulongjiang Estuary and Jiulongjiang River respectively.The effects of colloids with different sources and different concentrations of colloidal organic carbon(COC)on the growth of nature bacteria community were studied.The results showed that colloids could apparently improve the growth of nature bacteria community,and the improving effects varied with the different source of colloids,in the colloids from Xiamen Bay,Jiulongjiang estuary and Jiulongjiang River,the raletive increacing rate(y) of nature bacteria community were respectively 54.0%～96.1%,20.0%～97.3% and 8.3%～112.4%,the avarage of raletive increacing rate(Y) were respectively 76.7%,72.2%and 69.8%.The results also showed that there was no correlativity between the avarage of raletive increacing rate(Y) and the concentrations of colloidal organic carbon(COC).国家自然科学基金重大研究计划重大项目(904111016);; 国家教育部高等学校骨干教师计划基金资