近海污损生物生态研究进展

污损生物是影响海洋设施安全与使用寿命的重要因素之一。由于地理位置和环境因素的差异,各近海海区污损生物群落的种类组成和结构特点会出现不同,但基本上均由双壳类和无柄蔓足类构成污损生物群落的主要框架。开展数学生态模型研究是准确预测污损生物群落形成和发展过程的关键,但这需以大量的实海调查资料及数据库的构建为基础。此外,探讨污损生物群落的演替变化机制还可为海洋恢复生态学的发展提供借鉴。因此,开展近海污损生物研究不仅在海洋产业具有极高的应用价值,而且在基础研究领域也具有重要的科学意义。     

After UNCLOS: the future of international marine research

The April 1984 special issue of Marine Policy included an overview article on international marine research in the post-UNCLOS era: ‘Marine science: organizing the study of the oceans’ by Henry Charnock. We sent a galley proof of the article to Dr Hans Tambs-Lyche, formerly of ICES, for comment and we are pleased to publish his remarks.     

天津近海海底地质灾害类型及声学特征

作者利用浅地层剖面资料研究了天津近海海域存在的主要海底地质灾害.研究发现:浅层气、埋藏三角洲前缘、水下潮流沙脊、陡坎、沙波等地质灾害发育.浅层气主要分布在研究区北部海域的近岸附近,南部海域远离海岸浅层气逐渐增多;埋藏三角洲前缘分布区北至涧河口,南至南港工业区东部海域;水下沙脊分布于北部海域5 m～7 m水深的近岸带,地...     

多源卫星高度计海浪资料在中国近海的验证及应用

Studies of offshore wave climate based on satellite altimeter significant wave height(SWH) have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate characteristics in the offshore areas of China. First, the SWH measurements from 28 buoys located in China's coastal seas were compared with an Ifremer calibrated altimeter SWH dataset. Although the altimeter dataset tended to slightly overestimate SWH, it was in good agreement with the in situ data in general. The correlation coefficient was 0.97 and the root-mean-square(RMS) of differences was 0.30 m. The validation results showed a slight difference in different areas. The correlation coefficient was the maximum(0.97) and the RMS difference was the minimum(0.28 m) in the area from the East China Sea to the north of the South China Sea.The correlation coefficient of approximately 0.95 was relatively low in the seas off the Changjiang(Yangtze River) Estuary. The RMS difference was the maximum(0.32 m) in the seas off the Changjiang Estuary and was0.30 m in the Bohai Sea and the Yellow Sea. Based on the above evidence, it is confirmed that the multialtimeter wave data are reliable in China's offshore areas. Then, the characteristics of the wave field, including the frequency of huge waves and the multi-year return SWH in China's offshore seas were analyzed using the23-year altimeter wave dataset. The 23-year mean SWH generally ranged from 0.6–2.2 m. The greatest SWH appeared in the southeast of the China East Sea, the Taiwan Strait and the northeast of the South China Sea.Obvious seasonal variation of SWH was found in most areas; SWH was greater in winter and autumn than in summer and spring. Extreme waves greater than 4 m in height mainly occurred in the following areas: the southeast of the East China Sea, the south of the Ryukyu Islands, the east of Taiwan-Luzon Island, and the Dongsha Islands extending to the Zhongsha Islands, and the frequency of extreme waves was 3%–6%. Extreme waves occurred most frequently in autumn and rarely in spring. The 100-year return wave height was greatest from the northwest Pacific seas extending to southeast of the Ryukyu Islands(9–12 m), and the northeast of the South China Sea and the East China Sea had the second largest wave heights(7–11 m). For inshore areas, the100-year return wave height was the greatest in the waters off the east coast of Guangdong Province and the south coast of Zhejiang Province(7–8 m), whereas it was at a minimum in the area from the Changjiang Estuary to the Bohai Sea(4–6 m). An investigation of sampling effects indicates that when using the 1°×1°grid dataset, although the combination of nine altimeters obviously enhanced the time and space coverage of sampling, the accuracy of statistical results, particularly extreme values obtained from the dataset, still suffered from undersampling problems because the time sampling percent in each 1°×1°grid cell was always less than33%.     

台湾近海热液体系独特的生物及地球化学特征

台湾地处西太平洋构造活动带,近海发育了多处热液活动,其中最典型的为龟山岛和绿岛热液体系。本文对海峡两岸在龟山岛和绿岛热液的地球化学特征以及周边生物体的响应的研究进展进行了综述。龟山岛热液喷出流体具有全球最低的pH(1.52),富含重金属元素和CO₂等酸性气体,是周围海水中有色溶解有机质的来源;绿岛具有全球热液中最低的溶解有机碳浓度(14 μmol /L),且具有特殊的动力学特性。喷口周边分布了较为罕见的自然硫烟囱体和硫磺球。喷口的高毒性、高酸性热液改变了热液区生物体如螃蟹的生活习性和解毒机制。热液区的主要活跃菌群为参与碳、硫和氮代谢途径的γ-和ε-变形菌。主要生物质合成以硫还原和硫氧化的化能无机自养型生物为主,微生物硫代谢促进了热液系统中的微生物能量流动和元素循环作用。某些热液生物采用繁殖期迁徙的机制应对高毒性、高酸性热液环境。在热液活动的胁迫下,这些微生物产生了新颖独特的代谢产物。此外,龟山岛和绿岛热液体系还受到了潮汐、台风和地震等灾害性事件的影响。台湾近海热液体系的研究对认识热液地球化学循环、探讨热液的生态环境效应等具有重要的意义。     

An offshore eddy in the California current system part III: Chemical structure

From January 9 to 17, 1981, detailed physical, chemical and biological measurements were made through the historical surface signature (Berstein, Breaker and Whritner, 1977; Burkov and Pavlova, 1980; Simpson, 1982) of a warm-core eddy in the California Current System. The data show a three-layer system: surface layer to 75 m, intermediate cold-core region to about 200 m, and the physically dominant subsurface warm-core eddy to about 1400 m. The chemical structure simultaneously possesses characteristics of both warm- and cold-core eddies. This structure results from a complex interplay among non-local eddy generation processes at the time the three-layer system was formed and a continuous set of interactions within the three-layer system, both inshore (cold) and offshore (warm) waters of the California Current and coastal and local biological processes (e.g. this California Current System eddy is $\text{not}$ an isolated structure like some Gulf Stream rings). The dominant biological/chemical process in the euphotic zone is phytoplankton photosynthesis; photosynthetic alteration of the chemical structure below 100 m is much reduced. The effects of heterotrophic activity on the deeper-lying chemical structure, however are not as significant as those of autotrophs on the chemical structure of the euphotic zone. Hence, below 100 m, the distribution and structure of chemical properties is controlled primarily by physical processes. The continuous set of interactions of the three-layer system with coastal and oceanic waters of the California Current make this offshore eddy in the California Current System fundamentally different chemically and biologically from cold-core Gulf Stream rings and rather similar to some of the warm-core eddies found in the East Australian Current.     

广东流沙湾近岸和离岸育珠海区养殖环境的调查

2011年2月~2012年1月对广东流沙湾近岸和离岸育珠海区6个航次11个指标进行了调查。结果表明,近岸和离岸育珠海区水温、透明度、盐度和pH周年变化范围相似,水温呈现明显季节性变化,透明度、盐度和pH周年比较稳定,揭示目前流沙湾近岸和离岸育珠海区水流交换较好。近岸和离岸育珠海区叶绿素a和浮游植物细胞密度具有类似的周年变化规律,夏秋季高于冬春季。在4~7月份和9~10月份,近岸海区叶绿素a和浮游植物细胞密度呈现显著递增趋势,而10月份之后,显著递减。2~4月份,以及12月份至次年1月份,叶绿素a值和浮游植物细胞密度均较低。5~11月份,离岸海区叶绿素a和浮游植物细胞密度均显著低于近岸海区。近岸和离岸育珠海区COD含量周年变化范围分别为0.2~0.7 mg/L和0.1~0.8 mg/L,均达到国家一类水质标准。近岸海区和离岸海区无机氮(inorganic nitrogen,IN)含量周年变化范围分别为1.9~8.0μmol/L和3.4~8.7μmol/L,均达到国家第二类水质标准。两个海区IN含量的周年变化趋势与叶绿素a值和浮游植物细胞密度的周年变化趋势相反,冬春季高于夏秋季。无机磷(inorganic phosphorus,IP)在流沙湾近岸和离岸海区含量具有相似的周年变化趋势,其季节性变化与无机氮恰好相反,表现为夏、秋季含量高于冬、春季。6~8月份,近岸海区IP超出国家二类水质标准分别达44.67%、96.33%和210%,离岸海区在相同的月份超出国家二类标准分别达75.67%、86%和230.67%。揭示在夏、秋季节应合理控制贝类养殖密度和流沙湾周边环境的污染。     

Methods for ultimate limit state assessment of ships and ship-shaped offshore structures: Part III hull girders

The present paper is Part III of a series of three papers on the methods useful for ultimate limit state assessment of ships and ship-shaped offshore structures. It is focused on the methods for the progressive collapse analysis of hull girders under bending moments, in contrast to the previous two papers (Parts I and II), respectively, dealing with methods for the ultimate limit state assessment of unstiffened plates and stiffened panels. An AFRAMAX-class hypothetical double hull oil tanker structure designed by IACS common structural rules (CSR) method is studied as an illustrative example. The ultimate vertical bending moment capacity of the hull structure is then analyzed by ANSYS FEA, ALPS/HULL, and IACS CSR methods, and their resulting computations are compared.     

上海邻近海域风暴潮数据同化与特征分析

风暴潮是一种复杂的对众多因素敏感又备受关注的海洋现象。本文基于协方差局地化的集合卡尔曼滤波方法（EnKF）,选择201810号台风“安比”登陆上海的风暴潮过程,首次将海洋站和FVCOM数值模拟的不同来源、不同误差信息、不同时空分辨率的风暴潮进行数据同化融合,获得了逐72 h的上海海域风暴潮的最优解,进行了同化结果评估验证,并给出了集合样本数和Schur半径设置范围。结果表明,实测计算和数值模拟的风暴增减水之间均方根误差为0.20 m,实测和同化计算的风暴增减水之间均方根误差为0.07 m,准确度提高了65%;独立观测和同化计算的风暴增减水均方根误差为0.09 m,集合离散度与均方根误差比值为0.90,同化效果较好且可信;同化后的风暴增减水能够较好地刻画双峰增水、台风眼增水、增水锋面等特征,对于风暴潮研究、数值模拟结果订正、海洋防灾减灾等有重要意义。     

SMAP卫星辐射计在中国近海及沿岸的RFI特征分析

射频干扰RFI(Radio-Frequency Interference)的校正和抑制一直是微波遥感研究领域的重要问题之一。本文基于SMAP卫星2015年5月1日至5日L波段辐射计亮温数据对中国近海及沿岸的射频干扰进行了特征分析。研究发现RFI分布不均匀,主要集中在城市群及其周边地区;通过对比辐射计天线接收的亮温数据与射频干扰校正和抑制后的数据,发现研究区域主要的射频干扰(95%)的平均值为1.4 K,整体射频干扰平均值为2.5 K,标准差为6.5;研究区域中不同波段和极化的数据受到射频干扰影响较为相似,受射频干扰影响最大的是升轨的垂直极化数据,受影响最小的是升轨的水平极化数据。     

浅析UNCLOS海洋争端解决机制的强制性及我国的对策

<联合国海洋法公约>(UNCLOS)作为国际海洋法的重要组成部分,在处理国际海洋争端方面发挥着重要的作用.为适应国际海洋活动的不断发展,公约规定了一套全新的争端解决机制.而这一新机制具有的强制性特点,区别于其他一般的争端解决机制.中国作为世界海洋大国之一,在处理海洋争端方面亦受到这一争端解决机制的影响.     

Plate tectonics and offshore boundary delimitation: Tunisia-Libya case at the International Court of Justice

The first major offshore boundary dispute where plate tectonics constituted a significant argument was recently brought before the International Court of Justice by Libya and Tunisia concerning the delimitation of their continental shelves. Libya placed emphasis on this concept to determine natural prolongation of its land territory under the sea. Tunisia contested use of the entire African continental landmass as a reference unit and views geography, geomorphology and bathymetry as relevant as geology. The Court pronounced that “It is the outcome, not the evolution in the long-distant past, which is of importance.” Moreover, it is the present-day configuration of coasts and seabed that are the main factors, not geology.     

冰区海上风机支撑结构疲劳评估方法研究

采用谱分析的方法,对冰区作业的海上风机支撑结构进行疲劳损伤评估。基于风冰散布图,将海上风机所受的风载荷和连续挤压冰载荷作为系统输入,热点应力作为输出,运用随机振动理论与主应力线性化方法,对冰区海上风机支撑结构进行疲劳评估。以某2 MV海上风机支撑结构为计算实例,验证频域疲劳评估方法的准确性。频域方法与时域方法计算结果吻合较好,证明了频域方法的快速有效,可用于快速评估风机支撑结构的疲劳损伤。     

A new look at the phenomenon of offshore pile plugging

Abstract

Open‐pipe piles are widely used for offshore structures. During the initial stage of installation, soil enters the pile at a rate equal to the pile penetration. As penetration continues, the inner soil cylinder may develop sufficient frictional resistance to prevent further soil intrusion, causing the pile to become plugged. The open‐ended pile then assumes the penetration characteristics of a closed‐ended pile. The mode of pile penetration significantly alters the soil‐pile interaction during and after installation. This affects the ultimate static bearing capacity (mainly in granular materials), the time‐dependent pile capacity (in clays), and the dynamic behavior and analysis of the piles.

Following a summary demonstrating the effects of pile plugging, a review of the common view of offshore pile plugging is undertaken. The interpretation of plugging by referring to the average plug length has led to the erroneous conclusion that in most piles significant plugging action does not occur.

Establishment of an analogy between soil samplers and open‐ended piles enabled correct identification of plugging by referring to the incremental changes in plug length. Examination of case histories of plugging of offshore piles revealed that beyond a certain penetration depth‐to‐diameter ratio, most piles are plugged.