夏季珠江口水体中多环芳烃的分布、组成及来源   总被引：2，自引：0，他引：2  

金海燕  陈建芳  潘建明  周怀阳  李炎 《海洋学研究》2006,24(3):32-40

利用1999年7月对珠江口海域的调查资料,对该区表层海水中优控多环芳烃的分布、组成及来源进行了分析和讨论,结果表明:(1)夏季珠江口海域表层海水中14种溶解态多环芳烃[苊、芴、菲、蒽、荧蒽、芘、苯并(a)蒽、艹屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、二苯并(a,h)蒽、苯并(g,h,i)艹北、茚并(1,2,3-cd)艹比]的质量浓度为63.8~171.7 ng/L,且沿着冲淡水流向呈降低趋势;(2)颗粒态中15种多环芳烃[萘、苊、芴、菲、蒽、荧蒽、芘、苯并(a)蒽、艹屈、苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、二苯并(a,h)蒽、苯并(g,h,i)艹北、茚并(1,2,3-cd)艹比]的质量浓度为60.7~186.7 ng/L,其分布与水体载沙量及悬浮颗粒物的性质、粒径有关,具有从河口内向外海降低的分布特征;(3)多环芳烃组成和特征参数比值的分析表明,珠江口海域高温裂解来源的多环芳烃在伶仃洋海区输入最多,且主要为人类活动中煤燃烧排放的,而在香港岛周围海区的输入则相对较少,且主要为油燃烧排放的;(4)与法国塞纳河及长江口等河口相比,珠江三角洲海域水体中存在高菲含量排放源。  相似文献   

Mass fluxes in the Canary Basin   总被引：1，自引：1，他引：0  

F. Machín  A. Hernndez-Guerra  J.L. Pelegrí 《Progress in Oceanography》2006,70(2-4):416

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浙江秀山海泥营养物质对环境生物抗氧化性能的影响   总被引：1，自引：0，他引：1  

罗红宇  吴辉辉  解延海  桑卫国  张骏 《海洋与湖沼》2008,39(1):8-13

将浙江秀山海泥样品通过水浸提、离心沉降处理得到水溶相体系海泥提取液,按照20%(体积分数)加入到抗氧化性能评价体系中,采用BCS-Trolox法测定体系的总抗氧化性能,研究了温度、pH和时间对水溶相体系抗氧化性能的影响;分析了含水量为50%的浙江秀山海泥的营养成分,测定了生长于秀山滩涂海泥的菲律宾蛤仔和泥螺肌肉的SOD和GSH-Px的活力。结果表明,与已经开发成保健或泥疗产品的对照泥样相比,秀山海泥富含抗氧化活性营养成分V_A、V_E、V_C、Ge、Fe、Mg、Zn、Sr、Ca,总蛋白酶活性较强;该水溶相体系的抗氧化性能显著,20%的海泥提取液的抗氧化性能与(3.68±0.25)μmol/L的Trolox相当;温度对水溶相体系的抗氧化性能影响显著,pH、时间没有显著影响,因此确定最佳的水溶相体系制备条件为温度60℃、pH 5.6、时间10min;与对照组相比,秀山滩涂海泥能够激活菲律宾蛤仔和泥螺肌肉的SOD、GSH-Px的活性,提高机体的抗氧化性能。  相似文献   

Summer phytoplankton blooms in the oligotrophic North Pacific Subtropical Gyre: Historical perspective and recent observations     

John E. Dore  Ricardo M. Letelier  Roger Lukas 《Progress in Oceanography》2008,76(1):2-38

The export of organic matter from the oceanic euphotic zone is a critical process in the global biogeochemical cycling of bioelements (C, N, P, Si). Much of this export occurs in the form of sinking particles, which rain down into the unlit waters of the deep sea. Classical models of oceanic production and export balance this gravitational loss of particulate bioelements with an upward flux of dissolved nutrients, and they describe reasonably well those areas of the ocean where deep winter mixing occurs. The surface waters of the North Pacific Subtropical Gyre (NPSG), however, are strongly stratified and chronically nutrient-depleted, especially in summer. Nevertheless, there is ample evidence that blooms of phytoplankton and subsequent pulses of particle export occur during the height of summer stratification in these waters, especially to the northeast of the Hawaiian Islands. These blooms impact regional bioelemental cycling and act as a food source to the deep-sea benthos. We review here numerous published observations of these events in the NPSG, and present new data collected at Station ALOHA (22.75°N, 158°W) during the first 176 cruises of the Hawaii Ocean Time-series program (1988-2005), along with results from transect cruises conducted in the region in 1996 and 2005. We suggest that the summer phytoplankton bloom can be considered a frequent, perhaps annual feature in the northeastern NPSG, and that its perceived stochastic nature is a manifestation of chronic undersampling in time and space. The bloom is typically dominated by only a few genera of large diatoms and the cyanobacterium Trichodesmium. It appears to be consistently supported by dinitrogen fixation, but the fate of the organic matter produced during the summer depends critically on the species composition of the responsible diazotrophs. We estimate that the summer bloom is responsible for up to 38% of N₂ fixation and up to 18% of N-based new production annually at Station ALOHA. We hypothesize that the spatial distribution, timing and magnitude of the bloom may be determined largely by the physical and biological processes controlling new phosphorus delivery into the euphotic zone during the summer and the preceding winter.  相似文献   

Evaluation of anthropogenic carbon in the Nordic Seas using observed relationships of N, P and C versus CFCs     

Sara Jutterström  Emil Jeansson  Leif G. Anderson  E. Peter Jones  James H. Swift 《Progress in Oceanography》2008,78(1):78-84

Several methods to compute the anthropogenic component of total dissolved inorganic carbon () in the ocean have been reported, all in some way deducing (a) the effect by the natural processes, and (b) the background concentration in the pre-industrial scenario. In this work we present a method of calculating using nutrient and CFC data, which takes advantage of the linear relationships found between nitrate (N), phosphate (P) and CFC-11 in the Nordic Seas sub-surface waters. The basis of the method is that older water has lower CFC-11 concentration and also has been exposed to more sinking organic matter that has decayed, resulting in the slopes of P versus CFC-11 and N versus CFC-11 being close to the classic Redfield ratio of 1:16. Combining this with the slope in total alkalinity (A_T) versus CFC-11 to correct for the dissolution of metal carbonates gives us the possibility to deduce the concentration of anthropogenic C_T in the Nordic Seas. This further allowed us to compute the inventory of anthropogenic C_T below 250 m in the Nordic Seas in spring 2002, to ∼1.2 Gt C.  相似文献   

长江口崇明东滩水域悬沙粒径组成和再悬浮作用特征   总被引：6，自引：2，他引：4  

李占海  陈沈良  张国安 《海洋学报》2008,30(6):154-163

根据2006年10月在崇明东滩潮间带和潮下带两个站位的大小潮水文泥沙观测资料和悬沙水样的室内粒度分析资料,对悬沙粒径的时空分布特征及其与流速等的关系进行了分析,并对再悬浮特点进行了探讨,结果表明,大小潮期间的悬沙颗粒组成较细,平均粒径的均值仅为6μm;大潮时的悬沙粒径略粗于小潮的,潮间带的略粗于潮下带的;由底床向上悬沙粒径趋于减小。悬沙粒径与流速、悬沙含量无明显的统计学关系,底质粒径、再悬浮强度和再悬浮泥沙粒径的空间变化以及浮泥的悬浮作用等是主要的影响因素。由于底质粒径的空间分布复杂,在东滩水域再悬浮具有明显的空间变化。在底质平均粒径大于60μm的粗颗粒沉积区,大小潮的再悬浮作用微小,底质以推移质运动为主。在底质平均粒径介于5~11μm的细颗粒沉积区上,悬沙级配与底质级配基本相同,该区域是再悬浮的主要发生源地;悬沙级配的变化过程揭示,再悬浮对底层悬沙的贡献率平均为8%~20%,大潮时的再悬浮强度是小潮的5~10倍,由底质再悬浮产生的悬沙在底部水层中的平均含量约为0.03~0.47 kg/m3。  相似文献   

利用MODTRAN 3计算我国太阳直接辐射和散射辐射          下载免费PDF全文

傅炳珊  陈渭民  马丽 《大气科学学报》2001,24(1):51-58

根据光的多次散射理论——离散纵标法,利用我国国家一级辐射测站的大气廓线,计算出晴空大气观测波段不同高度上的太阳直接辐射和向下散射辐射。将模式输出的地面辐射值与地面辐射观测资料进行比较,对不同高度的太阳直接辐射和向下散射辐射以及日变化进行了讨论。最终目的是直接由MODTRAN3计算我国辐射空白站的地面辐射值,以弥补我国辐射站稀少,时空分布短缺的不足。  相似文献