快速筑堤技术——鲎式轻质堤坝的结构和筑堤方法     

陶松垒  傅晓航 《海洋学研究》2006,24(Z1):83-90

针对软基堤坝稳定性差,容易沉陷滑移,土石方堆不上,工期长,无法快速施工等问题,提出了鲎式轻质堤坝结构和筑堤方法,又称"松垒筑堤法".它减轻了易沉陷部位的质量,均衡堤坝荷重,增强整体稳定性,提高强度,使堤坝与地基溶为一体,消除了堤坝的不均匀沉降;是一种在软弱地基上应用仿生结构的筑堤方法.  相似文献   

东海大陆架海域经济蟹类种类组成和数量分布   总被引：16，自引：1，他引：16  

俞存根  宋海棠  姚光展  吕华庆 《海洋与湖沼》2006,37(1):53-60

根据1998年5月、8月、11月和1999年2月东海区虾蟹类资源调查结果,用重量资源密度作为经济蟹类数量分布的数量指标,对东海区经济蟹类的种类组成、数量分布、季节变化趋势以及数量与环境的关系作了定量分析。结果表明,在东海调查海区,经济蟹类主要有细点圆趾蟹Ovalipes punctatus、三疣梭子蟹Portunus trituberculatus、日本蟳Charybdis japonica、锈斑蟳Charybdis feriatus、武士蟳Charybdis miles、光掌蟳Charybdis riversandersoni和红星梭子蟹Portunus sanguinolentus等。经济蟹类渔获量约占蟹类总渔获量的62.8%,渔获量的季节变化明显,年间有二个汛期,一个出现在春夏季,以细点圆趾蟹为主要捕捞对象,兼捕光掌蟳、日本蟳等,渔场的主体分布在东海北部近海,渔场范围较小,蟹群集中,是捕捞生产条件较为理想的渔场;另一个出现在秋冬季,以三疣梭子蟹为主要捕捞对象,兼捕武士蟳、日本蟳、锈斑蟳、红星梭子蟹等。高生物量分布区主要出现在长江口、大沙、舟山渔场20—60m水深海域,是东海三疣梭子蟹和日本蟳的主要渔场,该渔场也是捕捞条件较为理想的渔场。在长江口以南的东海南部海域也有经济蟹类的较高生物量分布区,是武士蟳和锈斑蟳的渔场,该渔场具有范围较大,蟹群较分散的特征,所捕捞的品种往往只能作为兼捕对象。  相似文献   

雷州半岛红树林滩涂底栖生物多样性的初步研究   总被引：10，自引：0，他引：10       下载免费PDF全文

梁超愉  张汉华  颉晓勇  邹发生 《海洋科学》2005,29(2):15-28

分析了广东省雷州半岛红树林滩涂底栖生物种类组成与数量分布特点，用Shan non-Wiener多样性指数(H′)、Pielous种类均匀度(J)、种类丰度(D)、Berger-Parker优势度指数(I)4个测定红树林群落种类多样性指标进行数值分析。结果表明，调查所采获的底栖生物种类共有68科165种，种类组成以软体动物和甲壳类动物为主。红树林滩涂全年平均生物量为223．25g／m^2，平均栖息密度为2lO．97个／m^2。H′甚高，2个季度平均为2．2633～2.7411，J平均为0．6407～0．6411，D平均达到1．4910～2．6232。全年各类群生物组成中，生物量及栖息密度以软体动物居首位。红树林滩涂底栖生物主要经济种类有中国绿螂(Glauconome chinensis)、四角蛤蜊(Mactrar Mactra) veneriformis)、青蛤(Cyclinasinensis)等20多种。  相似文献   

东海西湖凹陷平湖构造带油气运聚特征   总被引：9，自引：0，他引：9  

胡芬  叶加仁  刘俊海 《海洋地质与第四纪地质》2003,23(1):95-102

平湖构造带是东海西湖凹陷的一个次级构造单元，是油气勘探的重点区域之一，应用流体包裹体及碳同位素组成等研究了构造带内的油气运聚特征，并与凹陷内的另一个主要油气聚集带－浙东中央背斜带的油气运聚特征进行对比。研究表明，平湖构造带经历了2期油气充注过程，其中第1期主要充注液态烃，第2期主要充注气态烃，充注时间相对较晚，且第1期古地温低于第2期；构造带内油气运移以侧向运移为主，该区是有利于的油气运移指向区。  相似文献   

Properties of sea ice and overlying snow in the Southern Sea of Okhotsk     

Takenobu Toyota  Shinya Takatsuji  Kazutaka Tateyama  Kazuhiro Naoki  Kay I. Ohshima 《Journal of Oceanography》2007,63(3):393-411

The general properties of sea ice and overlying snow in the southern Sea of Okhotsk were examined during early February of 2003 to 2005 with the P/V “Soya”. Thin section analysis of crystal structure revealed that frazil ice (48% of total core length) was more prevalent than columnar ice (39%) and that stratigraphic layering was prominent with a mean layer thickness of 12 cm, indicating that dynamic processes are essential to ice growth. The mean thickness of ice blocks and visual observations suggest that ridging dominates the deformation process above thicknesses of 30 to 40 cm. As for snow, it was found that faceted crystals and depth hoar are dominant (78%), as which is also common in the Antarctic sea ice, and is indicative of the strong vertical temperature gradients within the snow. Stable isotope measurements (δ¹⁸O) indicate that snow ice occupies 9% of total core length and that the mass fraction of meteoric ice accounts for 1 to 2% of total ice volume, which is lower than the Antarctic sea ice. Associated with this, the effective fractionation coefficient during the freezing of seawater was also derived. Snow ice was characterized by lower density, higher salinity, and nearly twice the gas content of ice of seawater origin. In addition, it is shown that the surface brine volume fraction and freeboard are well correlated with ice thickness, indicating some promise for remote sensing approaches to the estimation of ice thickness.  相似文献   

台湾南湾区秋末冬初海樽类的种类组成和数量分布   总被引：6，自引：0，他引：6  

张金标  黄将修  连光山 《海洋通报》2003,22(6):9-16

根据2001年11月2--3日和12月8--10日在台湾南湾12个测站分别用2种圆锥形浮游生物网(长180cm，网口直径45cm，网目333μm或200μm)采集表层和底层的浮游动物样品，分析了南湾浮游海樽类的种类组成和数量分布，其鉴定海樽类16利，其中7种为台湾周围海域新记录。东方双尾纽鳃樽和小齿海樽为优势种。南湾海樽类的种类数及个体数量均以12月多于11月。讨论了水文条件与海樽类时空分布的关系，认为外海高盐水团足南湾冬季海樽类生态特征的主要制约因子。典型的高温高盐种大西洋火体虫、长吻纽鳃樽、安纽鳃樽、多手纽鳃樽、书氏纽鳃樽、羽环纽鳃樽和斑点纽鳃樽等可以作为外海高温高盐水入侵南湾的指标种。与邻近海域比较，秋冬季南湾与台湾岛以东海域海樽类的区系特征比与台湾海峡和南海北部更加相似。  相似文献   

Embryonic exposure to environmentally relevant concentrations of PCB126 affect prey capture ability of Fundulus heteroclitus larvae     

Couillard CM  Légaré B  Bernier A  Dionne Z 《Marine environmental research》2011,71(4):257-265

Early life stages from a marine fish species, Fundulus heteroclitus, were exposed to sublethal doses of 3,3',4,4',5 pentachlorobiphenyl (PCB126) to evaluate its effects on ecologically relevant responses: growth and behavior. A few hours after fertilisation, eggs were treated topically with PCB126 (2.5-50 pg egg?1). Four days post-hatching (dph), morphological changes (body length and malformations), spontaneous locomotor activity (active swimming speed, rate of travel, % inactivity), prey capture ability (Artemia franciscana nauplii) and whole body EROD activity were evaluated in larvae. Untreated larvae collected at 0.5, 1, 2, 3, 4 dph were also examined. PCB126 did not increase the mortality or malformation rates. Body length and spontaneous locomotor activity were altered only in larvae treated with the highest dose. Treatment with PCB126 caused a dose-responsive reduction in prey capture ability (rate of decline in the number of Artemia) and induction of EROD activity. The lowest observed effective dose for both of these responses was 5.0 pg PCB126 egg?1 or 5.0 TCDD-toxic equivalents pg g?1 egg, using a TCDD-toxic equivalent factor of 0.005 and an egg mass of 5 mg. Prey capture efficiency (number of Artemia captured per feeding strike) was reduced at ≥ 10.0 pg egg?1. In untreated developing larvae, prey capture ability and efficiency increased as post-hatching development progressed and EROD activity remained low. The pattern of behavioral responses observed in PCB126-exposed Fundulus larvae differed from that observed in less-developed larvae indicating that other mechanisms than retarded development were involved. Behavioral dysfunction was a more sensitive response to PCB126 than morphological alterations and it occurred at environmentally relevant concentrations.  相似文献   

东山岛周围海域各类水母的分布   总被引：5，自引：0，他引：5  

黄加祺  许振祖 《台湾海峡》1996,15(4):363-365

本文分析了１９９０年春至１９９１年冬采自东山岛周围海域的浮游动物样本。共鉴定６０种水线，水螅水母类在种数和数量上的均占优势。拟细浅室水母，球型侧腕水母和半口壮丽水母为优势种。  相似文献   

厦门浔江海域棘皮动物若干生态特点     

吕小梅 《台湾海峡》1995,14(2):150-154

本文报道了厦门浔江海域棘皮动物调查的结果：初步鉴定棘皮动物46种，年平均生物量23.02g/m^2，栖息密度127个/m^2。对浔江海域棘皮动物的种类组成、数量分布等生态特点进行初步研究。  相似文献   

山东省大中型水库浮游生物研究──Ⅱ．浮游植物构成及其特点     

卢敬让  李德尚  周春生 《中国海洋大学学报(自然科学版)》1994,(3)

报道１９８９～１９９０年山东省大中型水库浮游植物种类组成百分数和生物量、种类频级和主要种类，提出代表性水库的种类多样性指数和均匀性指数、微型浮游植物和小型浮游植物组成、优势类群或优势种以及它们与各水库总浮游植物生物量之间的关系。  相似文献