浅海声信道信号时间相关特性研究

水声信道中信号的时间相关特性是水声微弱信号相关检测的理论基础和具体参数选择依据。文中以厦门港典型的浅海声信道中信号的时间自相关和互相关特性进行实验研究。结果指出,信号有强的时间相关性,无论自相关或互相关性均比海洋环境噪声强得多,因此在水声信道中采用时间相关检测可望达到优良的抗噪声效果。     

虹鳟(Oncorhynchus mykiss)选育群体主要体尺性状表型和遗传相关分析

以虹鳟(Oncorhynchus mykiss)优良品系选育群体作为试验群体,采用单性状动物模型估计头长、体长、体高、体厚、尾柄长、尾柄高、背吻距、背鳍基长等8个主要体尺性状的遗传力。结果显示,上述8个性状的遗传力在0.131—0.313之间,多为中等或偏低遗传力,其中背鳍基长遗传力最低,为0.131±0.039,体高遗传力最高,为0.313±0.086。采用皮尔逊相关法估计上述性状之间的表型相关,结果显示,上述性状间表型相关变化范围为0.016—0.815。采用两性状动物模型估计上述性状间的遗传相关,结果表明,上述性状间遗传相关变化范围为0.065—0.866。在本研究中,比较分析表型和遗传相关结果发现,虽然体厚与尾柄长的表型相关最低,仅为0.016,相关性不显著(P0.05),但是遗传相关为0.247,似然比检验(likelihood ratio test,LRT)统计分析达到显著水平(P0.05)。体厚与背鳍基长的表型相关为0.647,t检验达到显著水平(P0.05);但遗传相关仅为0.305,LRT统计分析未达到显著水平(P0.05)。上述结果说明,在该群体中各体尺性状的表型相关和遗传相关水平不完全相同,在设计育种方案时应综合考虑各个性状间的表型相关及遗传相关。     

东亚七地区台风频数与北太平洋海表面温度相关关系的长期变化

本文计算了西沙、广州、厦门、上海、那霸、鹿儿岛、名古屋七地区台风频数与北太平洋海表面温度之间的相关关系。从海温超前2年到落后1年逐月进行了计算,发现最好的相关期是海温超前2年的夏季到超前1年的夏季,大约持续1年左右的长时间的最优相关期。在此期间,北太平洋西北部为负相关;东南部为正相关。海温超前的相关在秋冬季最好;同年及落后1年在春夏季最好。同年的相关场,赤道东太平洋由前期的正相关转为负相关,落后1年最好的相关区是阿拉斯加海流区,并且还发现这种相关关系强弱的变化,大约具有1年、1年半、2年的长周期。     

P-J遥相关型位置的年际变化特征与ENSO的关系ZXF

本文利用ERA-40再分析资料对太平洋-日本(Pacific-Japan)遥相关型(简称P-J)在不同ENSO(El Ni?o-Southern Oscillation)事件时的位置特征进行了分析研究,并评估了第五次耦合模式比较计划(CMIP5)各模式对P-J遥相关型的模拟能力,利用CMIP5模式数据验证P-J遥相关型与赤道中东太平洋海温异常之间的相关性。结果表明,ENSO对P-J遥相关型的位置有影响:El Ni?o年,P-J遥相关型位置相对偏西偏南;La Ni?a年,P-J遥相关型位置则相对偏东偏北。ENSO对P-J遥相关型强度有影响:ENSO事件年赤道中东太平洋海温与次年夏季P-J遥相关型强度相关明显,正常年两者没有相关性。本文评估了CMIP5中24个耦合模式,发现大多数模式能很好得模拟出P-J型,并且全球变暖对PJ型位置变化的影响较小,而赤道中东太平洋海温异常对P-J遥相关型强度影响较大。     

北大西洋海温场与东亚温带气旋的关系

本文分析了北大西洋海温场与东亚各月温带气旋个数的相关。发现相关区的分布特点是大西洋西部、南部以正相关为主,东北部以负相关为主。相关的季节分布特点是大西洋海温对东亚温带气旋的影响从秋季开始增大,到2月达到最大。相关区有很强的持续性,有的有系统性位移的现象。     

安邦河湿地浮游植物数量与环境因子相关性研究

2005年7月-2006年5月,对安邦河湿地浮游植物数量及其环境因子监测,运用相关分析和灰关联分析对其浮游植物数量与环境因子关系进行研究.相关分析结果显示,浮游植物数量与水温呈显著正相关(p<0.01);与DIN在春季呈显著正相关(p<0.01),在夏、秋季呈显著负相关(p<0.05,p<0.01);与DIP在各个季节均呈显著正相关(p<0.01,p<0.05);与溶解氧呈正相关,在春季和秋季相关显著(p<0.05,p<0.01),在夏季相关不显著(p>0.05);与透明度呈正相关,但相关均不显著(p>0.05);与pH值呈负相关,且在春季、夏季呈显著相关(p<0.01);灰关联分析结果表明,对安邦河湿地浮游植物数量影响最大的DIP,因此控制外源性的DIP的输入对于维持安邦河湿地生态系统的健康是非常重要的.     

我国海域立体开发相关法律问题研究综述

海域立体开发能够使海域开发利用利益最大化,减少对海洋资源的损耗。目前我国对于海域立体开发缺乏相关法律依据。文章梳理国内外关于海域立体开发的研究重点,指出我国可借鉴的研究成果;提出我国现阶段海域立体开发存在的法律问题,包括缺乏法律法规依据、相关规定较宽泛、缺乏海域分层开发利用时序统筹以及缺乏海洋基础数据调查等,并提出加速制定相关法律法规、具体化相关规定、明确海域立体开发时序和明确海洋资源环境承载能力的建议,以期为相关部门提供理论参考。     

海面温度对西北太平洋副热带高压的影响

本文在两次相关分析的基础上,讨论了海流区海温与副高特征量相关的特点及高相关区的时空演变特征。发现大部分高相关区的演变可分成移动型和准静止型两种。相关区移动或摆动的起点多集中在黑潮区、洪堡德海流区和热带东太平洋海区。同时对几个相关现象的可能物理原因做了初步分析,表明海温影响副高的途径是多种多样的;有下垫面的直接加热的影响;有下垫面加热影响其它环流系统,再通过此系统与副高的相互制约进而影响副高;还有通过经向垂直环流影响等等。     

印度洋和北太平洋海温与夏季西太平洋副热带高压长期变动的关系

本文通过对印度洋、北太平洋海表温度与夏季西太平洋副高特征量进行相关分析来研究两大洋海温与西太平洋副高长期变动的关系。分析得出,海温和夏季西太平洋副高的强度关系十分密切。空间上表现为相关敏感区位于洋流区和季风流区;时间上海温变化超前于副高,且两大洋超前的时间有差异。海温与副高位置变动的关系在两大洋亦有不同。北太平洋海温与副高南北位置变动有较好相关,相关区主要分布在洋流区,而印度洋没有明显相关。对副高东西位置变动,印度洋海温的作用强于北太平洋海温,相关区主要都分布在冷暖海流交汇处附近。两大洋与副高长期变动的相关敏感区的起迄时间大体上与大洋上空大气环流的转换期相对应。     

利用卫星遥感SST估算海表流场

介绍了利用遥感资料得到的海表温度图估算海表流场的最大相关系数和相关松弛法。比较二种方法在不同参数条例下的矢量图，相关松弛法明显地优于最大相关系数法。在用相关松弛法时，模板大小和搜索距离这二个参数对计算结果影响很大，选择１６×１６像元数的模板和１５像元数的搜索距离计算１９８９年１２月３月－１２月６日台湾海峡这一组资料时比较理想，结果表明用相关松弛法计算海表流场有一定的可靠性和实用性。     

南海北部春季网采浮游植物群落结构初步研究

报道了2005年春季南海北部23个大面站网采浮游植物的调查结果,对浮游植物的群落结构进行了初步研究.共鉴定浮游植物3门73种,硅藻种类最多(50种),其次为甲藻(22种)和金藻(1种);浮游植物细胞丰度平均为3.07×104cells/m3,以硅藻为主(相对丰度平均93.8%),其次为甲藻(相对丰度平均6.16%)和金...     

A model study on carbon cycle and phytoplankton dynamical processes in the Bohai Sea

The carbon cycle of lower trophic level in the Bohai Sea is studied with a three-dimensional biological and physical coupled model. The influences of the processes (including horizontal advection, river nutrient load, active transport etc. ) on the phytoplankton biomass and its evolution are estimated. The Bohai Sea is a weak sink of the CO2 in the atmosphere. During the cycle, 13.7% of the gross production of the phytoplankton enter the higher trophic level and 76.8 % of it are consumed by the respiration itself. The nutrient reproduction comes mainly from the internal biogeochemical loop and the rem-ineralization is an important mechanism of the nutrient transfer from organic form to inorganic. Horizontal advection decreases the total biomass and the eutrophication in some sea areas. Change in the nutrient load of a river can only adjust the local system near its estuary. Controlling the input of the nutrient, which limits the alga growth, can be very useful in lessening the phytoplankton biomass.     

鸭绿江口浮游植物群落特征及与环境因子的关系

于2009年3月对鸭绿江河口进行了10个站的浮游植物生态调查,分析了该海域浮游植物的种类组成、优势种类、群落结构以及水平分布等特征参数.本次调查共鉴定浮游植物48种,其中硅藻种类最多,达41种,甲藻其次,为6种,金藻1种.浮游植物可划分为广温类群、暖水类群和暖温类群3个生态类群,以广温类群为主.浮游植物细胞数量平均4.67×108个/m3,细胞数量自河口向外海逐渐降低.其中,中肋骨条藻(Skeletonema costatum)占据绝对优势.浮游植物群落优势种单一且优势度较大,群落结构相对简单.相关性分析表明温度和盐度是浮游植物细胞数量的主要限制性因子.浮游植物数量受鸭绿江径流的影响较大.     

浮游植物生物量研究Ⅱ.胶州湾网采浮游植物细胞体积转换生物量

基于浮游植物细胞体积转换法获得的胶州湾浮游植物细胞生物量,计算了胶州湾水体中同采浮游植物生物量,并与浮游植物细胞计数结果进行了周年变化的比较和优势种分析。研究结果表明,调查期内,浮游植物细胞数量出现两次高峰(主峰1月份,次峰9月份),转换生物量仅出现一次高峰(8月份);优势种分析表明,上述峰值期的不同,与浮游植物群落结构及不同种群细胞的个体大小密切相关。浮游植物细胞体积转换生物量不仅能较客观地反映浮游植物现存量,又能从群落、种群结构角度解释能量分布及不同种群对浮游植物生物量的各自贡献。     

1996年春季副热带环流区浮游植物生态的初步研究

鉴定浮游植物种类54属184种(含变种和变型),其中暖水种为140种(占76.5%).硅藻类和甲藻类等浮游植物的平均总细胞密度为198.71×102个/m3;蓝藻类藻丝体平均密度为44.55×102条/m3.浮游植物各类别的分布与水域的磷酸盐含量、黑潮以及其他水系(涌升水和沿岸水等)等相关;蓝藻类的束毛藻(Trichodesmium)的分布还与50m以浅水体的平均水温关系密切.     

Response of a benthic suspension feeder (Crassostrea virginica Gmelin) to three centuries of anthropogenic eutrophication in Chesapeake Bay

Biogenic reefs built by oysters and other suspension feeders are vital components of estuarine ecosystems. By consuming phytoplankton, suspension feeders act to suppress accumulation of organic matter in the water column. Nutrient loading increases the rate of primary production, thereby causing eutrophication. As suspension feeders consume more organic matter from increasing abundance of phytoplankton, their rate of growth should also increase if they are food limited. We show here that the eastern oyster, Crassostrea virginica (Gmelin), from St. Mary's and Patuxent rivers, Chesapeake Bay, grew faster during anthropogenic eutrophication relative to C. virginica before eutrophication. Growth of shell height, shell thickness and adductor muscle increased after eutrophication began in the late 18th century. After 1860, growth decreased, perhaps reflecting the negative effects of hypoxia, harmful algal blooms, disease and fishing on oyster growth. These results are consistent with the view that an increasing supply of phytoplankton resulting from eutrophication enhanced growth of C. virginica between 1760 and 1860, before oyster reefs were degraded by destructive fishing practices between 1870 and 1930. Alternative factors, such as changes in water temperature, salinity, and fishing are less likely to be responsible for this pattern. These results have implications for restoration of oyster reefs in order to mitigate the effects of eutrophication in estuaries, as well as the paleoecological relationship between suspension feeders and paleoproductivity.     

东海陆架水文浊度要素自动采集系统设计

提出了一种利用四脚架体原位观测东海陆架区域水文、浊度要素的方法,通过数据采集单元,实现对测量要素的采集和存储。通过对获取数据的分析,表明该方法安全可靠,可为揭示东海内陆架沉积过程研究提供数据来源。     

泉州湾水域浮游植物群落的昼夜变化

对福建省泉州湾口、大坠岛以北水域的浮游植物群落作了准同步昼夜连续观测,观测时间分别在2001年11月至2002年8月内的秋(11月)、冬(2月)、春(5月)、夏(8月)季大潮期.结果表明,该水域的叶绿素a生物量(以下简称生物量)受湾内高生物量的影响在潮汐作用下出现波动,高潮期出现低生物量,低潮期出现高生物量.靠近内湾的站位生物量大于湾外的站位;底层水体中的生物量普遍大于表层,底栖硅藻成为生物量变化的重要部分.调查海区生物量呈现昼夜节律变化,生物量白天高于夜间.进一步的分析表明,在潮汐和昼夜变化综合作用下,浮游植物的群落结构发生相应变化,白天的多样性指数低于夜间,浮游植物昼夜群落的不相似度很高.群落中一些种类如中肋骨条藻白天大量增殖,出现较高的优势度,昼夜平均密度比值达到9,变化节律明显.研究认为,尽管海区潮汐和流向左右着生物量变化,浮游植物的生态学过程如细胞增殖、再悬浮、扩散等过程在昼夜生物量变化中仍产生较大作用.     

Photoinduced toxicity single and binary mixtures of four polycyclic aromatic hydrocarbons to the marine diatom Skeletonema costatum

Diatom Skeletonema costatum Cleve is one of the main predominant phytoplankton species in the Changjiang Estuary in China. In order to provide some basic information for future assessment of the potential risk on phytoplankton communities in this estuary caused by polycyclic aromatic hydrocarbons(PAHs), this alga was selected as a representative to investigate the photoinduced toxicity of PAHs, in single and mixture. Four PAHs including three-ring phenanthrene and anthracene, four-ring fluoranthene and pyrene were tested in the laboratory. The single toxicity of each PAH on this microalga was compared with and without the simulated solar UV radiation. The results showed that this microalga was sensitive to PAH's photoinduced toxicity. Ratios of the 72 h median effect concentration obtained for fluorescent and UV light tests were about 8.4 for phenanthrene, 13.0 for anthracene, 6.5 for fluoranthene, and 5.7 for pyrene, indicating that UV light enhanced the PAH toxicity to this alga significantly. Under the fluorescent radiation (lacking UV), the dose-response curves based on chemical concentrations revealed that the order of toxic strength was fluoranthene greater than pyrene greater than anthracene greater than phenanthrene; while under the UV radiation (476 μW/cm2 for UVA, 6.5 μW/cm2 for UVB) it became fluoranthene approximately equaling anthracene greater than pyrene greater than phenanthrene, indicating that the UV light also changed its relative toxicity to this alga. The photoinduced toxicity of PAHs to the marine diatom S. costatum might be a synergistic effect of photosensitization reactions (e.g., generation of single-state oxygen) and photomodification (photooxidation and/or photolysis).The combined effects of six binary mixtures on the marine diatom S. costatum were investigated using the additive-index method. Four binary-mixtures (phenanthrene plus anthracene; phenanthrene plus pyrene; anthracene plus fluoranthene; anthracene plus pyrene) were found to be synergistic joint action mode, while two binary-mixtures (phenanthrene plus fluoranthene; fluoranthene plus pyrene) displayed antagonist, revealing a complex pattern of possible interactions. The combined action mode of PAHs might be related to various factors such as the mixture compounds, mixture ratios and test conditions, etc.     

Zooplankton Feeding Ecology: Contents of Fecal Pellets of the Copepod Undinula vulgaris from Continental Shelf Waters of the Gulf of Mexico

Abstract. The in situ diet of the copepod Undinula vulgaris was examined by comparing contents of fecal pellets produced on natural food with assemblages of available phytoplankton. Samples were collected in continental shelf waters of the northern Gulf of Mexico. U. vulgaris was an indiscrimi-nant suspension feeder, ingesting a broad size, shape, and taxonomic array of phytoplankters. Contents of fecal pellets generally matched those of available phytoplankton assemblages. The presence within the same fecal pellets of remains of microplankters ranging over two orders of magnitude in longest dimension suggests that feeding is nonselective, and that U. vulgaris may rapidly switch between several modes of feeding.