厦门湾溶解有机物的三维荧光光谱特征及其来源解析

利用三维荧光光谱-平行因子分析(EEM-PARAFAC)技术,研究了2009年春、秋季厦门湾有色溶解有机物(CDOM)的荧光组分特征,并利用主成分分析方法对影响该海域CDOM分布的主控因素及其相对贡献进行了解析。厦门湾CDOM中含有3个类腐殖质荧光组分(C1,C2和C5)及2个类蛋白质组分(C3和C4)。所有类腐殖质组分之间、以及所有类蛋白质组分之间均有很好的相关性,表明同一类型的荧光组分具有相似的来源属性及地球化学行为。类腐殖质组分的高值区分布在九龙江河口区上游,而类蛋白质组分的高值区则位于厦门西海域北部,低值区都位于东部的厦金海域。排污口附近的局部海域存在污染输入的贡献。对荧光组分进行的主成分分析结果显示,陆源径流输入是厦门湾水体中CDOM荧光组分的主要来源;海区现场生物活动的贡献不大。这表明对PARAFAC识别的荧光组分进行主成分分析,有助于实现对水环境中CDOM的不同来源及其相对贡献率的定量解析。     

胶州湾海水溶解有机物三维荧光特征研究

应用三维荧光光谱(excitation-emission matrix spectroscopy, EEMs)研究了不同河流输入有机物对胶州湾海水中溶解有机物荧光特征的影响。结果表明,生活污水和工业废水的排放使附近海水中类腐殖质荧光位置发生红移;类蛋白荧光在海泊河附近最强,类腐殖质荧光在李村河附近最强,中心海区荧光强度最弱,表明沿岸河流输入是胶州湾海水中有机物的主要来源,而中心海区有机物主要来源于现场生物活动。不同河口附近区域样品中有机物的类蛋白和类腐殖质荧光强度之间相关性不同,表明河流输入有机物的影响。胶州湾大部分海水中有机物的类蛋白与类腐殖质荧光强度之间的比值较大,表明可能受到了人类活动产生类蛋白有机物的污染。研究结果对于分析海水中有机物来源以及河流排放污染物的迁移等过程具有一定的指导意义。     

杭州湾跨海大桥道路交通流的建模与模拟

在杭州湾跨海大桥道路交通流实测数据统计分析的基础上, 提出了开放式边界的单向三车道元胞自动机交通流模型, 考虑了小车和大车的不同运动性能, 并区分激进型司机与谨慎型司机的不同驾驶特征, 根据杭州湾跨海大桥不同时段的实测车流量, 对模型中开放式边界的进车率进行了识别. 依据提出的模型模拟得到杭州湾跨海大桥路段不同密度时的车流量, 经与实测数据比较, 两者吻合良好, 表明本文提出的交通流模型符合杭州湾跨海大桥交通流的实际情况. 同时, 通过展示车辆的时空演化图, 从微观的角度分析了杭州湾跨海大桥路面交通流所表现出的宏观特征, 有望为杭州湾跨海大桥的交通优化与管理提供理论依据.     

Variations of δ15N-Values and Hydrolyzable Amino Acids in Settling Particles in the Ocean

Abstract

The modification of nitrogen isotopic signals during particle sedimentation in the sea is of great interest for the use of sedimentary δ¹⁵N-values as a paleoceanographic tool. The effect of organic matter degradation on such modification was studied by analyzing nitrogen, hydrolyzable amino acids (THAA) and δ¹⁵N-values in a suit of marine settling particles collected from the Bay of Bengal, Indian Ocean, by using time-series sediment traps, and in underlying sediments. The flux of settling particles showed temporal variations which are related to the monsoons, the major climatic feature of this marine region. During high flux periods settling particles are enriched in nitrogenous material that is less degraded and exhibit higher δ¹⁵N-values than particles showing characteristics of degradation. At the sediment surface more than 95% of the settling particulate nitrogen is lost and the δ¹⁵N-values of the residual sedimentary nitrogen are higher than those of settling particles. The observed increase is interpreted to be due to fractionation during degradation of organic matter.     

Chlorinated Hydrocarbons: Pollutants or Indicators of Fish Stock Structure

Abstract

Chlorinated hydrocarbons are used in industry for many purposes. They are ubiquitous in the environment. Being soluble in lipids, they tend to accumulate in living organisms and consequently in the food chain. In an attempt to identify the herring stock units (Clupea harengus harengus) present in the St. Lawrence Estuary and the Chaleur Bay, we have measured the degree of contamination by some organochlorinated compounds, of herrings fished in both locations. The purpose of the study is to establish the presence of many discrete stocks units or of only one homogeneous stock brought about by large scale straying of individuals from one group to another. Adult herrings are thought to migrate to spawning areas in spring or autumn depending on whether they were born in spring or autumn. The juveniles are believed to remain close to where they were born for about three years before they join their parent stock migrations. If one area is contaminated by chlorinated pesticides, these products will accumulate in the herring fat and could possibly be used for fingerprinting if straying is negligible. The data obtained indicate that the populations studied are marked by their environment and that they probably have their own life cycle and their own migration pattern. A study of the genetic structure of these herring populations is being concurrently made.     

固相微萃取-气质联用测定胶州湾海水中有机锡化合物

采用顶空固相微萃取-气质联用(HS-SPME-GC-MS)技术测定了胶州湾海水中有机锡的含量.样品用4%的四乙基硼化钠(NaBEt4)进行衍生,同时用PDMS纤维进行萃取,萃取富集后,用气质联用仪进行测定.通过分析,该方法中MBT的线性范围为10～1000ng/L,DBT和TBT的线性范围为50～1000ng/L,相对标准偏差低于14.0%,回收率在70.0%～125.0%之间,检出限低于12.5ng/L;通过所建立的方法对胶州湾海水中有机锡的污染现状进行了调查,发现胶州湾海水中存在不同程度的有机锡污染.     

Effect of open boundary condition on numerical simulation of three-dimensional hydrothermal behavior of Biscayne Bay,Florida

A three-dimensional time dependent free-surface model has been used to simulate the velocity and temperature distributions in Biscayne Bay, an estuarine basin in South Florida. Comparisons with tide gauge data and airborne infrared temperature data have been made. Analyses of three-dimensional velocity structure, phase relationships of velocity with depth and horizontal location have been conducted. One of the major concerns with three-dimensional models is the specification of conditions at open-boundaries, since it is rare that complete time dependent variations of variables at these boundaries are available. Two sets of approximate boundary conditions at the Biscayne Bay-Atlantic Ocean interface have been used for computations. It was found that specification of averaged surface height variation at open boundaries yield significantly better results than specification of estimated values of velocity.     

A numerical modelling study of the flow and salinity structure in the Godavari Estuary,east coast of India

The Godavari Estuary in Andhra Pradesh (a state bordering the east coast of India) communicates with the Bay of Bengal. Conditions in the estuary are characterized by a seasonally varying freshwater discharge and an intrusion of salt water from the bay dependent upon the flow associated with the semi-diurnal component of the astronomical tide. A numerical model is applied to simulate the flow and salinity structures, which in the case of the Godavari Estuary have also been determined observationally and are documented in the literature. Observational data on the flow and salinity structure during two seasons are used in a comparison with theoretical results derived using a turbulent energy equation. Reasonable agreement is obtained between the model results and the observational data; in particular, streamlines are computed for the tidally averaged (or mean) component of the density-controlled flow.