共查询到20条相似文献，搜索用时 562 毫秒
1.
2.
东海沿岸不同区域贝类体内石油烃含量的分布特征及其评价 总被引：4，自引：0，他引：4
根据 2006 年 5 月对东海沿岸 9 个区域贝类的监测结果,探讨分析了调查海域的6种贝类体内石油烃含量的分布特征,采用单因子污染指数法按照海洋生物质量 ( GB 18421 - 2001 ) 评价标准评价了监测海域贝类的石油烃污染状况.结果表明,东海沿岸的9 个海域的 6 种受测贝类体内石油烃含量分布范围1.28 ～ 37.6 mg / kg ( 湿重 ),平均含量10.78 mg / kg,总体上符合<海洋生物质量>一类标准 ( 15.0 mg / kg );6 种贝类体内种间石油烃平均含量分布从大到小依次是:牡蛎＞毛蚶＞四角蛤蜊＞文蛤＞贻贝＞泥蚶,其中牡蛎平均含量达到 15.62 mg / kg,超出海洋生物质量一类标准.从区域分布看,长江口和江苏如东沿岸海域的牡蛎石油烃的平均污染指数较高,分别为 1.91 和 1.19,受到重度污染. 相似文献
3.
根据2005年4月和10月厦门市贝类生产环境区划调查资料,着重对僧帽牡蛎(Saccostrea cacullata)、菲律宾蛤仔(Rudita Pesphilippin adams)、泥蚶(Tegillarca grannosa)和缢蛏(Sinonvacula cucullata)的软体部、胃含物、外套膜、卵、肌肉和外套腔液中的重金属含量进行探讨和研究.结果表明,厦门4种养殖贝类体内Cu,Pb,Cd和Zn的湿质量比分别为0.88～60.3 mg/kg,0.12～0.48 mg/kg、0.04～0.72 mg/kg和12.4～163.5 mg/kg,平均湿质量比分别为16.3,0.24,0.38,63.9 mg/kg.在不同养殖水域,同种贝类体内重金属的含量差异较大,在相同养殖水域贝类体内重金属的平均含量种间差异也较大.4种贝类的胃舍物中重金属的平均含量最高,外套膜和软体部次之,外套腔液含量最低.根据<无公害食品水产品中有毒有害物质限量的标准,对4种贝类体重金属的污染程度进行评价,结果表明,僧帽牡蛎、菲律宾蛤仔和缢蛏体中重金属的含量均未超标,但泥蚶体内Cd的含量略微超标. 相似文献
4.
福建沿海养殖贝类体石油烃总量水平的分布特征 总被引：9，自引：1，他引：8
对福建沿海6种主要养殖贝类体石油烃总量水平的分布特征进行了探讨.结果表明：福建沿海6种养殖贝类体石油烃总量水平范围在2.57 mg/kg.wet～61.5 mg/kg.wet之间,总平均10.5 mg/kg.wet其受测样品石油烃总量水平的频率分布,含量在5.00mg/kg～15.0mg/kg范围的样品占81.3%;其石油烃污染指数范围在0.2～4.0之间,总平均0.7,总体属轻度污染.福建沿海6种养殖贝类体石油烃总量水平的种间分布,缢蛏〉僧帽牡蛎〉翡翠贻贝〉太平洋牡蛎〉泥蚶〉菲律宾蛤子.其石油烃总量水平的空间分布,由闽南海区向闽中海区和闽东海区呈明显递减之势;其石油烃总量水平的时空分布,在2002-2004年间总体呈微弱上升之势,但缢蛏和僧帽牡蛎体石油烃含量的年际升幅比其它4种养殖贝类体的升幅大且较明显. 相似文献
5.
砷在贝类养殖区表层沉积物及贝类体中的积累和分布 总被引：2，自引：0，他引：2
2003—2004年福建近岸海域海洋环境和海洋生物质量的监测资料表明,福建沿海主要贝类养殖区表层沉积物和4种养殖贝类(僧帽牡蛎、太平洋牡蛎、缢蛏和泥蚶)体中砷含量分别为(4.15—13.7)×10-6(干重)和(1.28—3.56)×10-6(湿重),总平均值分别为9.06×10-6(干重)和2.22×10-6(湿重),均低于海洋环境污染评价标准限值。总体上看,福建沿海潮间带滩涂贝类养殖区表层沉积物和养殖贝类体中砷含量高于浅海贝类养殖区的含量,且呈闽东和闽南贝类养殖区高、闽中养殖区低的格局。贝类养殖区表层沉积物中砷含量的多寡与表层沉积物的类型密切相关,并与僧帽牡蛎、缢蛏体砷含量之间总体成正相关。 相似文献
6.
在实验室条件下对厦门海域4种主要养殖贝类,僧帽牡蛎、菲律宾蛤仔、缢蛏和翡翠贻贝的滤水率进行研究.结果表明:(1)这4种贝类的滤水率范围为54～74.8cm3/(g·min),滤水率大小顺序依次为僧帽牡蛎、缢蛏、翡翠贻贝、菲律宾蛤仔;(2)单位体重滤水率与个体大小之间呈负幂函数关系(FR=aWb,FR'=aWb-1),b-1值范围在-0.435 6～-0.392之间;(3)僧帽牡蛎和菲律宾蛤仔对中肋骨条藻的滤水率高于对塔马亚历山大藻和锥状施克里普藻的滤水率;(4)僧帽牡蛎和菲律宾蛤仔滤水率与藻类密度之间呈现负幂函数关系(FR'=aDb-1),其b-1值分别为-0.143和-0.215 2. 相似文献
7.
泥蚶、缢蛏和僧帽牡蛎呼吸与排泄的周年变化 总被引：1，自引：1，他引：0
于2005年5月至2006年3月对浙江沿岸重要的3种经济贝类泥蚶、缢蛏和僧帽牡蛎的呼吸率与排泄率进行了周年研究。结果表明:泥蚶、缢蛏和僧帽牡蛎耗氧率的变化范围分别为0.11~5.05 mg/（g·h）、0.77~5.97 mg/（g·h）和0.33~5.47 mg/（g·h）,排氨率的变化范围分别为21.51~1 078.63 μg/（g·h）,26.97~990.73 μg/（g·h）和32.12~1 378.67 μg/（g·h）;耗氧率与排氨率9月份最高,1月份最低。经单因素方差分析发现,3种实验贝类月际间的耗氧率与排氨率均存在极显著差异（p<0.01）,经配对T检验发现,缢蛏（SC）和僧帽牡蛎（SCA）之间的耗氧率存在着显著差异T（SC-SCA）=3.184,p=0.024）,泥蚶（TG）与缢蛏、僧帽牡蛎的耗氧率之间都不存在差异（T（TG-SC）=1.887,p=0.118;T（TG-SCA）=0.246,p=0.815）,泥蚶、缢蛏和僧帽牡蛎之间的排氨率的差异均不显著（T（TG-SC）=0.977,p=0.373;T（TG-SCA）=2.369,p=0.064;T（SC-SCA）=1.002,p=0.362）。3种贝类的耗氧率与排氨率均随温度的升高而升高,经回归分析发现,耗氧率和排氨率与温度的变化均呈较显著的幂指数性相关lnY=lna+blnT（Y=aebT）。泥蚶呼吸排泄O:N变化范围为4.69~28.55,缢蛏和僧帽牡蛎的O:N变化范围分别为:4.68~37.89和3.04~10.27。 相似文献
8.
在室内可控条件下,比较和分析了青岛大扁藻Tetrasemis helgolandica、球等鞭金藻Isochrysis galbana、角毛藻Chaetoceros calcitrans、微绿球藻Nannochloropsis oculata和绿色巴夫藻Pavlovaviridis5种微藻对泥蚶Tegillarca granosa、缢蛏Sinonovacula constricta、青蛤Cyclina sinensis和彩虹明樱蛤Moerella iridescens4种滩涂贝类稚贝生长的影响。结果显示,在培养初期(5~6 d),投喂不同微藻的稚贝实验样品生长速度差异并不明显,但培养9~10 d后,各实验组稚贝实验样品的生长速度开始出现明显差异:投喂角毛藻、球等鞭金藻的泥蚶和缢蛏稚贝实验样品及投喂角毛藻、青岛大扁藻的青蛤和彩虹明樱蛤稚贝实验样品,运动能力强,生长迅速、整齐,经过15~18 d的培养,成活率达85%以上;投喂微绿球藻的4种稚贝实验样品,运动能力弱,生长缓慢、不整齐,成活率低于20%。投喂角毛藻的泥蚶、缢蛏和青蛤稚贝实验样品的生长速度最快;投喂青岛大扁藻的彩虹明樱蛤稚贝实验样品的生长速度最快,而投喂角毛藻的彩虹明樱蛤稚贝实验样品的生长速度与之非常接近。角毛藻对泥蚶、缢蛏和彩虹明樱蛤稚贝实验样品的饵料效果最好,球等鞭金藻次之;青岛大扁藻对青蛤和彩虹明樱蛤稚贝实验样品的饵料效果与角毛藻非常接近,而青岛大扁藻对泥蚶和缢蛏稚贝实验样品的饵料效果较差;绿色巴夫藻的饵料效果与球等鞭金藻类似但均比球等鞭金藻差;微绿球藻的饵料效果最差。用颗粒粒度计数分析仪分析泥蚶和青蛤稚贝实验样品对5种微藻的选择性滤食后发现,最先被泥蚶稚贝实验样品滤食干净的是角毛藻,其后是球等鞭金藻;泥蚶稚贝实验样品开始滤食青岛大扁藻时的速度较慢,但当角毛藻和球等鞭金藻被滤尽后,青岛大扁藻也被迅速滤食,泥蚶稚贝实验样品滤食微绿球藻的速度最慢;最先被青蛤稚贝实验样品滤净的也是角毛藻,其后是青岛大扁藻,在角毛藻和青岛大扁藻被滤尽后,球等鞭金藻也迅速被滤食干净,微绿球藻同样是最慢被滤食的。可见,贝类稚贝总是优先滤食饵料效果好的微藻,饵料效果最差的微藻被贝类稚贝滤食的速度最慢。 相似文献
9.
利用扫描电镜技术、X-射线粉末衍射技术和弱酸去钙法, 对菲律宾蛤仔、文蛤、厚壳贻贝、泥蚶、缢蛏5种习见海洋经济贝类贝壳的断面微观结构、物相组成、有机基质和蛋白质含量等进行了观察和分析。电镜观察结果显示, 5种贝壳的微观结构主要包含棱柱层和珍珠层; 棱柱层晶体结构有斜棱柱层、球棱柱层、棱柱层、均质层和交错板状层5种类型, 其中缢蛏只有斜棱柱层, 而泥蚶除球棱柱层外, 其他4种晶体类型均存在, 此复杂结构可能与其贝壳强度大有关; 珍珠层晶体结构有珍珠层和肌棱柱层2种类型, 其中厚壳贻贝的珍珠层呈典型的“砖-泥”结构, 具有明显的层状结构, 其余4种贝壳珍珠层均由不规则块状结构组成。X-射线衍射结果显示, 菲律宾蛤仔、文蛤、缢蛏和泥蚶4种贝壳都属于文石质壳体, 无机相几乎由文石组成, 而厚壳贻贝属于混合质壳体, 无机相由文石和方解石组成; 贝壳化学成分分析显示, 5种贝壳有机质含量均为3%左右, 而总蛋白含量占有机质的2.98%~7.21%, 其中可溶性蛋白是不可溶蛋白含量的5.55~20.31倍。上述结果为贝壳形成机理的研究积累了基础资料。 相似文献
10.
11.
稠油黏度高,流动性差,常规测试难以正确评价储层的真实产能。随着多元热流体热采技术在海上油田生产平台的成功应用,提出了在探井测试中应用多元热流体热采技术。通过对支撑平台的适应性分析研究,运用数值模拟方法预测多元热流体热采测试的开采效果,并对相应的井口、供给方式等进行了优化研究。通过现场实施,多元热流体热采测试的日产油量可达常规冷采测试产油量的2倍以上,实际效果与数值模拟的结果基本相当。该技术的应用更能准确反映油田的真实产能,为海上稠油油田的探井测试提供了一个新方法。 相似文献
12.
13.
14.
15.
The reflectance of chitinozoa (%ChR0) was investigated as an alternative technique of determining the level of thermal maturity of organic-rich Palaeozoic rocks in southern Ontario. These sedimentary strata, which include the Ordovician Collingwood Member and the Blue Mountain Formation, as well as the Devonian Marcellus Formation, lack vitrinite precluding the application of a standard vitrinite reflectance (%VR0) technique. ChR0 shows a proportional increase at marginal to moderate maturities, being on average 20 to 25% higher than expected vitrinite reflectance. The reflectance data fall into a very narrow range showing a high degree of consistency for each lithostratigraphic unit. The average ChR0 are as follows: Collingwood Mbr 0.63% (Georgian Bay area) and 0.88% (Toronto area), Blue Mountain Fm 0.92%, Marcellus Fm 0.68%. Correlation with more conventional optical and geochemical maturity parameters obtained from the same set of samples (fluorescence of Tasmanites, Leiosphaeridia and Gloeocapsomorpha alginite, Rock-Eval Tmax, extract data, distribution of terpanes and steranes in extracts) indicates that, within the area of study, the beginning of the catagenetic stage corresponds to ChR0=0.65% (equivalent VR=0.50%) whereas the threshold of significant oil generation is reached at ChR0=0.9% (equivalent VR=0.70%). Therefore the Blue Mountain Formation is thermally mature with respect to hydrocarbon generation throughout the whole area of study. The Collingwood shales are mature only in the Toronto area while those occurring in the Georgian Bay area as well as the Marcellus shales have yet to enter the main stage of hydrocarbon generation. This integrated approach of assessing thermal maturity shows that ChR0, when constrained with other maturity parameters, is a very reliable indicator of thermal maturity in Lower to Middle Palaeozoic sedimentary rocks. 相似文献
16.
Heat flow data provide constraints on the thermal structure and evolution of the oceanic lithosphere. Because precise determination of the heat flux requires that both the thermal gradient and the thermal conductivity be well determined we have examined the thermal conductivities used in a new Pacific Basin heat flow data set. 43% of the 1600 heat flow determinations rely on values estimated by various methods, rather than directly measured. Although the measured and estimated conductivities have comparable means, the measured conductivities have a standard deviation 50% larger than the estimated, suggesting that the estimated values underestimate the actual variation. We investigate the limitations of using such estimates by examining factors controlling the variations of measured conductivity values. We find that the variation between the closest adjacent sites increases with increasing separation, such that sites within 200 km are on average noticeably closer in conductivity than sites further apart. Contributing to this effect may be the variation of conductivity with lithology (with mean conductivity highest for carbonate oozes, intermediate for deep-sea clays, and least for siliceous oozes) and a possible trend of decreasing conductivity with increasing seafloor depth. Tests with the measured data suggest that the best method for estimating conductivity is using the mean value measured within 200 km. The mean of a larger geographical region is a somewhat poorer predictor, and using the oceanwide mean and the value at the nearest site are poorer still. Approximately 29% of the estimated values were not based on measurements from a reference site. For most others, the reference site was the nearest measurement from the same cruise, typically a large distance away. For those sites where conductivity was not measured, 78% had measured conductivity within 200 km and were reestimated using the local mean, whereas the remaining 22% were reestimated using the regional mean. The resulting change in the estimated conductivity averaged 9% using the local mean and 6% using the regional mean. We suggest that such a procedure be used to improve the utility of the heat flow data set, as an alternative to discarding the large fraction of the available data that does not incorporate measured conductivities. 相似文献
17.
对大亚湾3种重要经济鱼类包括黑鲷Sparusmacrocephalus、平鲷Rhabdosargussarba和细鳞Theraponjarbua的多项温度指标进行室内热效应模拟研究。结果表明：在驯化温度为25—33℃条件下,黑鲷、平鲷和细鳞3种鱼类的起始致死温度分别为34．96─36．42,34．78─35.62,38．75─39.39℃;最高起始致死温度分别为36.35,35.52℃和39.32℃;临界热最大值分别为38．08─40.50,38．28─40.40℃和42.40─43.64℃;最适生长温度分别为28,28℃和32℃;生长的最高周平均温度分别为30．78,30.51℃和34．44℃;短期暴露最高温度分别为34.04,33.57℃和37．90℃。根据黑鲷、平鲷和细鳞的多项温度指标,结合这些鱼类的生活习性分析和大亚湾基本环境特征的调查资料,就大亚湾核电站温排水对渔业资源影响的热效应问题进行初步探讨。 相似文献
18.
本研究采用Landsat 8热红外数据反演后石电厂营运期的排水口区域水体温度,并尝试采用无人机携带热红外传感器对该区域的水温分布细节特征进行遥感探测。结果表明,后石电厂排水口区域水温自北向南递减,温水团自排水口排出后沿岸南下,向南扩散约3500 m,东西扩散约1000 m。利用Pix4Dmapper软件对无人机航拍热红外照片进行拼接并绘制排水口区域温度剖面图可知,后石电厂排水口南侧300~500 m处的水温呈现西岸较低、东岸较高的特点,温水团从排水口排出后并不是均匀向南扩散,而是先沿东岸向南扩散,然后部分从东岸向西扩散后再向南扩散。 相似文献
19.
Four surveys of airborne expendable bathythermograph with horizontal spacing of about 35 km and vertical spacing of 1 m extending
from the surface down to 400 m deep are used to analyze thermal finestructures and their seasonality in frontal zones of the
southern Yellow Sea and the East China Sea. Finestructure characteristics are different not only among fronts but also along
the same front, implying different mixing mechanisms. Summer thermocline intrusions with thickness from few to 40 meters,
generated by the vertically-sheared advection, are identified along the southern tongue of the Cheju-Yangtze Front (especially
south of Cheju Island). The finestructures south of the Yangtze Bank (i.e. the western tip of the southern tongue) produced
by strong along-frontal currents are not as rich as elsewhere in the southern tongue. The Cheju-Tsushima Front presents mixed
finestructures due to confluent currents from various origins. The irregular-staircase finestructures in the Kuroshio region
(below the seasonal thermocline), driven by double-diffusive mixing, show seasonal invariance and vertical/horizontal coherence.
The strength of mixing related to finestructure is weaker in the Kuroshio region than in the Cheju-Tsushima Front or south
of Cheju Island. The profiles in the Tsushima Warm Current branching area show large (∼50 m thick), irregular-staircase structures
at the upper 230 m depth, which coincides roughly with the lower boundary of the maximum salinity layer. The finestructure
at depths deeper 230 m is similar to that in the Kuroshio region. The possible mechanisms for generating the finestructures
are also discussed. 相似文献
20.
Short-Term Thermal Effects of a Power-Generating Plant on Zooplankton in the Swartkops Estuary, South Africa 总被引：1，自引：0，他引：1
Abstract. The short-term effect of elevated water temperatures (Δ t = 5–10°C after passing through the cooling circuit of an electricity generating plant) on plankton in a warm temperate estuary. South Africa, was investigated. Phytoplankton entrained on the flood tide was more severely affected than that entrained on the ebb, but chlorination of cooling water was probably a major factor affecting phytoplankton assemblages. Abundance of zooplankton of marine origin was significantly reduced after passing through the cooling circuit. The effect of thermal stress on the curyhalinc zooplankton was not clear, as the origin of the water canal to the generators is located at the extreme seaward limit of spatial distribution of cstuarinc plankton at low tide. Estuarinc species of zooplankton were therefore infrequently sampled and in low numbers only. Other factors which increase mortality are discussed. 相似文献