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1.
用邻苯二甲醛(OPA)-3-巯基丙酸(3-MPA)柱前衍生高效液相色谱法测定了采自大亚湾近岸海域的一个长60cm的沉积物柱样W0中15种游离氨基酸(FAA)的含量,结果表明,W0中FAA总量在0.83-2.69mmol/kg之间,15种FAA以及FAA总量均随深度而以指数曲线降低,对氨基酸组成的分析表明,天冬氨酸,甘氨酸,组氨酸和苯丙氨酸的摩尔分数随深度而上升,苏氨酸,精氨酸,缬氨酸和异亮氨酸的摩尔分数随浓度而下降,其他氨基酸的摩尔分数随深度无显著变化,甘氨酸,丙氨酸,天冬氨酸,谷氨酸,丝氨酸是W0中含量最丰富的氨基酸,其摩尔数依次为28.1%,16.0%,14.7%,10.6%和7.2%。  相似文献   
2.
根据湄洲湾海域2005年丰、平、枯三个水期的海水监测及2005年9月的湄洲湾表层沉积物监测数据对湄洲湾的环境质量进行评价。结果显示,湄洲湾海域水质综合指数(WQI)全年平均为0.69,除了F1站位枯水期为1.04,轻度污染,其余的均小于1.0,全年综合评价为清洁,但受气候及水文条件的影响,丰水期和枯水期有两个站位呈富营养化状态;表层沉积物综合质量指标平均值为0.52,综合评价为清洁,但铜、砷、镉的单因子污染指数平均值介于0.5~1.0之间,说明表层沉积物已被这三个因子玷污。  相似文献   
3.
The solution-phase photodecomposition of l, l-dichloro-2,2-bis(5′-chloro-2′-methoxy-phenyl)ethylene (MPE) has been studied at an excitation wavelength of 313 nm in the presence of O2 as well as in vacuum-degassed solutions. Only two non-volatile compounds are produced: 2,5-dichloro-3-(5′-chloro-2′-methoxyphenyl)benzofuran (BFD) and a minor product which was not identified. The BFD represents approximately 90% of the total non-volatiles. The volatile products were identified as CH3Cl, CH4 and HC1, with CH3C1 being approximately 99.9 % of the total volatiles. Photolyses were carried out in C6H12 and CCI4 solvents, the same products being observed in both solvents. Variation of MPE concentration has little or no effect on the relative quantum yield of decomposition. The photodecomposition of MPE does not follow the same pathway as the photodecomposition of DDE.  相似文献   
4.
Temporal patterns of pesticide inputs to San Francisco Bay were identified and correlated with timing of application and transport mechanism. Fluxes were calculated from measured concentrations and estimated flow. Persistence of the pesticides under typical riverine or estuarine conditions were estimated from laboratory experiments. Simazine was detected most frequently and had the highest flux into the Bay, which could be explained by its continuous use and long half-life. In comparison, diazinon was detected at lower concentrations and had a lower flux which corresponded to its lower use and shorter half-life. The order-of-magnitude lower fluxes of carbofuran and methidathion corresponded to their lower use and expected hydrolysis. Molinate was detected at the highest concentration but its flux was lower than expected, considering its very high use and persistence in the laboratory experiments. Additional loss of molinate is likely to occur from volatilization and photodegradation on the rice fields. Although thiobencarb had the second highest use, it had the lowest flux of the six pesticides, which can be attributed to its loss via hydrolysis, photodegradation, volatilization, and sorption to sediments. Fluxes into San Francisco Bay were equal to or greater than those reported for other estuaries, except for the Gulf of Mexico.  相似文献   
5.
2006年7月至2007年11月采集了大亚湾10个采样点春、夏、秋和冬4季表层沉积物样品,分析了沉积物中的生物硅(BSi)、有机碳(TOC)、总氮(TN)和总磷(TP)含量。结果表明:大亚湾生源要素含量与国内外港湾相比属于中等水平;春季BSi、TP的平均含量分别为1.09%、0.043%;夏季BSi、TOC、TN、TP的平均含量分别为1.21%、1.05%、0.37%、0.043%;秋季BSi、TP的平均含量分别为0.99%、0.038%;冬季BSi、TOC、TN、TP的平均含量分别为1.09%、0.84%、0.11%、0.039%。根据TN/TP和TOC/TN比值判断,大亚湾沉积物为磷限制;夏季TOC主要来源于水生有机碳,冬季为混合来源。夏季表层沉积物中BSi、TOC、TN和TP的平均含量均高于其他季节;其中夏季各站位TN的含量较冬季要高,反映了夏季较高的硅藻生产力以及较丰富的地表径流。大亚湾大部分采样点TOC和TN的污染基本属于Ⅱ类,TP属于Ⅰ类,可能对底栖生物群落具有一定毒害作用。  相似文献   
6.
A finite element method for the analysis of a one level and a multiple level current flow is presented. The basic equations can be derived from the three-dimensional Navier-Stokes equations under the shallow water assumptions. The standard finite element method has been introduced using the linear interpolation function based on a triangular finite element. For each level, the finite element subdivisions are not required to be coincident. To integrate the discretized equations numerically in time, an improved two step explicit scheme is employed. The multiple level finite element method is applied to a tidal flow analysis of Tokyo Bay.The multiple level tidal flow analysis is performed at the entrance channel of Tokyo Bay. The density of water is assumed to be constant for each level. The vertical profiles of the numerical velocity are compared with those of the observed velocity. The flow directions and the order of velocity are both well in agreement with the observed data. The tidal flow pattern in Tokyo Bay has been shown to be expressed by the multiple level flow assuming that the density of seawater is levelwise constant.The numerical tidal flow computation of Tokyo Bay carried out using a one level model is compared with observed data. The one level numerical values will be used to specify the boundary conditions for the multiple level analysis. Both numerical and observed results correspond extremely well in this computation. The two dominant circulated residual flows have been computed, and they coincide with the observed facts.  相似文献   
7.
The composition and abundance of phytoplankton in Suruga Bay, Japan, were investigated to evaluate the photosynthetic production structure and population dynamics from surface to oligotrophic layers seasonally for a four-year period. High-performance liquid chromatography analyses separated more than 80 peaks of pigments, and about 50 pigment species were identified. The main chlorophylls (Chls) and carotenoids were mostly found up to 100 m deep, while small amounts of a limited number of species of pigments such as Chl a, Chl c2, and fucoxanthin, which are markers of diatoms, were also detected even in the oligotrophic region, in addition to degradation products of Chl a, such as pheophorbide a and pheophytin a.  相似文献   
8.
根据2013年5月(春季)和8月(夏季)莱州湾海水环境要素的调查资料,通过主成分分析提取了3个主成分,累计表达原数据矩阵78.57%的信息,然后分别利用监测要素和主成分综合得分的层次聚类分析筛选出监控指标,并确定了水质污染状况及主要污染区域.结果表明,2013年莱州湾水质春季和夏季较差,导致水质状况恶化的主要要素是溶解无机氮,水质污染程度在时间和空间上存在较大差异,总体上春季海水污染程度高于夏季,莱州湾西侧和南侧处于严重污染或中度污染水平,因此常规监测中应重点关注化学需氧量、无机氮、叶绿素a和石油类这4个指标.  相似文献   
9.
以南海三亚湾鹿回头海域八种常见造礁石珊瑚优势种的反射率光谱为代表,用光谱仪测量它们和此海域常见底质石莼以及碎石的反射率光谱。通过反射率、导数光谱法研究了三亚鹿回头海域造礁石珊瑚、石莼和碎石的光谱差异。石莼于561.4 nm处出现反射率高达48%左右的显著波峰,在500~700 nm波长范围和造礁石珊瑚反射率差异较大;碎石反射率明显高于造礁石珊瑚反射率,整体差异显著。导数分析结果表明造礁石珊瑚、石莼和碎石可区分波段为:造礁石珊瑚与石莼主要为一阶导数在485~487,505~510,515~529,559~578,587~593,598~603和667~670 nm等波段。二阶导数在494.4~505.7,524~534.5,543.6~561.4和567.2~579.7 nm波段。四阶导数在515.8~430,621~627.1,628.8~635.6,639.3~645,661.8~669.8和678.4~682.4 nm等波段。造礁石珊瑚与碎石一阶导数反射光谱,主要为400~413.7,414~418,484.8~486.9,506~509.6,514.5~528.9,576.9~587.6和602.7~653.4 nm波段。二阶导数主要为,451.6~461.6,564.5~570.7和677~685 nm。四阶导数主要为,412.6~425.3,459.8~467,467.7~470.6,535.6~540.8,583.8~591.4,654.4~659.8和670.8~680 nm等波段。  相似文献   
10.
以大亚湾核电站附近海域为研究区,基于HJ-1B卫星热红外遥感数据IRS4,对核电站温排水空间分布特征进行了识别与验证。首先利用时空插值后的NCEP大气廓线数据,结合近地面气象观测信息对IRS4数据进行大气订正;其次查找表数据建立IRS4宽通道辐亮度与辐射温度转换公式,完成研究区海表温度反演。利用温盐深测量仪,与卫星同步采集了84个离散点的水温,经空间插值获得地面调查海水“体温度”(bulk temperature, BT)的分布,并与海表温度(sea surface temperature, SST)反演结果进行了对比。结果表明,调查区平均BT比平均SST高0.47 ℃。在远离热排放口区域,SST高于BT,两者差异在1.0 ℃以内;在靠近热排放口区域,SST低于BT,并且越接近排放口两者之间差距越大。遥感与地面调查两种手段获得的温升分布基本一致,总温升区域面积相近。遥感手段获得的温升等级较少(小于4级),地面调查获得温升等级较多(大于5级);后者高温升等级(2级以上)区域面积较大,但对于1级温升区面积而言,两种手段差异较小。上午10时左右海表BT与SST差异较小,“肤-体”温差效应可以忽略,在IRS4业务化SST应用中,这一时段的卫星遥感可以作为核电站温排水分布监测的常规手段。  相似文献   
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