潮汐对瞬态气候响应模拟的影响研究

In this study, the impact of oceanic processes on the sensitivity of transient climate change is investigated using two sets of coupled experiments with and without tidal forcing, which are termed Exp_Tide and Exp_Control,respectively. After introducing tidal forcing, the transient climate response(TCR) decreases from 2.32 K to 1.90 K,and the surface air temperature warming at high latitudes decreases by 29%. Large ocean heat uptake efficiency and heat storage can explain the low TCR in Exp_Tide. Approximately 21% more heat is stored in the ocean in Exp_Tide(1.10×10~(24) J) than in Exp_Control(0.91×10~(24) J). Most of the large ocean warming occurs in the upper 1 000 m between 60°S and 60°N, primarily in the Atlantic and Southern Oceans. This ocean warming is closely related to the Atlantic Meridional Overturning Circulation(AMOC). The initial transport at mid-and high latitudes and the decline in the AMOC observed in Exp_Tide are both larger than those observed in Exp_Control. The spatial structures of AMOC are also different with and without tidal forcing in present experiments. The AMOC in Exp_Tide has a large northward extension. We also investigated the relationship between AMOC and TCR suggested by previous studies using the present experiments.     

翘嘴红鲌(Erythroculter ilishaeformis Bleeker)种群遗传多样性的RAPD分析

采用RAPD技术对翘嘴红鲌养殖群体进行了DNA多态性检测.共采用40个随机引物进行扩增,其中14个引物可获得清晰且重复性好的扩增图谱,共扩增出121个RAPD位点,具有多态现象的位点为40个,多态位点比例为33.06%.翘嘴红鲌群体的遗传相似系数为 0.8878-0.9600,平均为0.9201,遗传变异度为0.0799.Shannon多样性指数为10.8824,Shannon多样性值为0.0899.研究表明,翘嘴红鲌目前的种质资源状况令人堪忧,改变目前人工繁育模式,建立原种、良种场,丰富物种遗传多样性是资源保护的基础.     

黄河三角洲潮滩剖面特征

利用验潮、潮滩水准测量、沉积物分析和遥感资料,分析了黄河三角洲不同岸段潮滩的特征。水准测量表明,侵蚀潮滩剖面形态为下凹,而淤积潮滩则上凸,由高潮线至低潮线,潮滩沉积物均变粗,这种变粗趋势在北部侵蚀岸段和河口侧缘明显,在河口南侧稳定海岸则不明显。潮滩沉积物含水量为12.2%~32.2%,平均为21%,海滩表层沉积物不排水剪切强度在0.1~0.35 kg/cm2之间。受局限岸滩的平面形态和剖面形态受到周围大坝地形影响,具有和砂质海滩类似的形态,显示波浪对该潮滩的作用强烈,根据剖面测量结果与遥感图像,发现河口北侧有一个小的冲积扇。     

三角帆蚌对水体悬浮物和叶绿素a消除量的研究

本研究在不同温度条件下分别测定了一龄(△1)和三龄(△3)三角帆蚌对水体中悬浮物和叶绿素a的消除量;研究了三角帆蚌对叶绿素消除效果与水体中藻类生物量之间的关系,并在池塘中挂养1200只三角帆蚌四个月。结果表明:三角帆蚌对水体中悬浮物和叶绿素a的消除率均随水温升高而提高,其中消除效果在总重量相同时△3>△1,较高水温条件下三角帆蚌在悬浮物中优先利用藻类;同一温度下,水体中藻类量增大时,三角帆蚌对叶绿素a的消除量增大而消除率却降低;在池塘挂养测试中与对照池塘比较,四个月后三角帆蚌因大量消除了池塘水中的悬浮物和叶绿素a,使池塘水体透明度提高从26cm提高到了80cm。     

PSEUDO-STATIC ANALYSIS FOR DYNAMIC DEFORMATION BEHAVIORS OF OFFSHORE GRAVITY PLATFORM FOUNDATIONS

Based on the analysis of cyclic triaxial test for the South-Sea sand, a comprehensive normalized model of soil stress-strain relationship is presented herein, which includes effects of not only initial stress states but also loading cycles. Consequently, a pseudo-static procedure to analyse the deformation behavior of foundations is suggested. Example of calculations shows that the suggested procedure is convenient in application.     

海水温度和盐度对泥蚶幼虫和稚贝生长及存活的影响

1996～1997和1999年在浙江省乐清市东发水产育苗场和福建省宁德市四海水产育苗场分别研究了海水温度和盐度对泥蚶浮游幼虫和稚贝生长及存活的影响,结果表明,泥蚶浮游幼虫的适宜温度为25～33℃,最适生长温度为28～30℃.稚贝的适宜温度为15～35℃,最适生长温度为25～30℃.浮游幼虫的适宜盐度为16.54～30.02,最适生长盐度为1654～23.38;稚贝的适宜盐度为10.01～30.02,最适生长盐度为10.01～23.38.泥蚶幼虫和稚贝对高温和低盐海水有较强的适应能力,这与它们夏季的繁殖期和自然分布于内湾河口区是相适应的.     

中国多金属结核开辟区东、西两小区小型底栖动物的空间分布

利用 1 998年“大洋一号”调查船 DY95 - 8航次在中国多金属结核开辟区东、西两小区用多管取样器采集的沉积物样品 ,对小型底栖动物的组成、分布及其与环境因子的关系进行了研究。结果表明 :(1 )东、西两小区共有 1 6个类群的小型底栖动物 ,其中线虫类占居显著优势 ,在东、西两小区各占总栖息密度的 71 %和 6 4 %,其次为猛水蚤类和蜱螨类。 (2 )东、西两小区小型底栖动物类群平均栖息密度分别为 3 2 .47ind/1 0 cm2 和 1 8.0 5 ind/1 0 cm2 ,东小区高于西小区。小区各站位间的栖息密度平面分布差异显著。 (3 )东、西两小区小型底栖动物类群栖息密度的垂直分布趋势明显 ,由表层向底层 ,栖息密度逐渐降低。 (4)东、西两小区小型底栖动物空间分布与底质沉积物、结核覆盖率和底层流等环境因子密切相关 ,底质较硬、结核覆盖率较高以及底层流较强都不利于小型底栖动物的栖息。     

细菌、病毒与浮游植物相互关系及其对海洋地球化学循环的作用

本文综述了近年来国内外在海洋地球化学循环，特别是微生物环研究方面的发展现状，探讨了浮游植物，细菌，病毒相互之间的关系及其对海洋地球化学循环的影响。     

化学物质对硬壳蛤幼虫变态的诱导

用KCl、肾上腺素（EPI）、去甲肾上腺素（NE）、L—DOPA和GABA（γ-氨基丁酸）进行了不同浓度不同处理时间对硬壳蛤（Mercenaria mercenaria L ）幼虫变态诱导实验。结果表明，KCl、肾上腺素、去甲肾上腺素和DDOPA对硬壳蛤幼虫的变态均有诱导作用，而GABA的诱导作用不显著。KCl的最佳诱导浓度随处理时间不同而有所不同。处理时间为1～24，48，72h时KCl的最佳诱导浓度分别为33．56，20．13～26．85，13．42mmol／L。肾上腺素和去甲肾上腺素的诱导作用与浓度和处理时间均有关。肾上腺素的最佳处理浓度为100μmol／L，最佳处理时间均为8h，此时幼虫变态率提高最大，为36．97个百分点。当去甲肾上腺素的诱导浓度为100μmol／L，处理时间为8～16h时，幼虫变态率提高也较大，均大于18个百分点，死亡率增加，但均低于30个百分点，当去甲肾上腺素诱导浓度为500μmol／L时，虽然在8～16h的处理时间范围内，幼虫变态提高率也较大，均大于18个百分点，但当处理时间超过8h，在16～48h范围内，幼虫死亡率提高明显增大，均大于50个百分点。L-DOPA的适宜诱导浓度为10～50μmol／L，适宜处理时间为8～24h，此时幼虫变态率均提高30个百分点以上，最高可提高79．43个百分点。GABA的诱导作用较弱，最佳诱导浓度随处理时间的不同而有所不同，处理时间为24h和48h时，最佳诱导浓度为0．1μmol／L；处理时间为0．5～16h时，最佳诱导浓度为100μmol／L。     

In-Situ Observation of Fluid Mud in the North Passage of Yangtze Estuary, China

Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary.