海底管线冲刷悬空及其抑制技术研究综述

海底管线作为海洋工程的重要组成部分,其安全性受到广泛关注。本文简单回顾了国内外学者通过物理实验、理论分析与数值模拟等方法研究海底管线冲刷悬空及防护问题的成果,并对工程中应用较广泛的防护方法的优缺点进行了简单对比,为该领域的进一步研究提供参考。     

Seasonal variations of phytoplankton diversity in the Coleroon coastal waters, southeast coast of India

The results of an investigation carried out during June 2005 to May 2007 on physico-chemical parameters,species composition and community structure of phytoplankton including Chlorophyll a(Chl-a) at the Coleroon coastal waters(Southeast coast of India) are reported.Air and surface water temperatures(°C) varied from 25.1 to 30.1 and from 24.5 to 28.5 respectively.Salinity values varied from 6 to 28.5 and the pH ranged between 7.0 and 8.3.Variation in dissolved oxygen content was from 3.1 to 7.5 mg/dm-3 while the light extinction coefficient values(LEC) ranged between 3.1 and 10.1 cm.The ranges of inorganic nutrients(μmol/dm-3) viz.,nitrate,nitrite,phosphate and silicate were 10.1-23.4,1.2-8.9,0.2-3.1 and 55-125,respectively.The ranges of Chlorophyll a(μg/dm-3) values was 2.0-7.5.Presently,124 phytoplankton species representing different classes viz:Bacillariophyceae(77),Dinophyceae(19),Cyanophyceae(15),Chlorophyceae(10) and Chrysophyceae(3) were recorded.The phytoplankton cell abundance varied from 0.290 to 111.662 cells/cm-3,with peak diversity(3.38 bits/ind.) during summer season.The maximum abundance was found during summer season coinciding with the stable hydrographical conditions.The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters.Canonical Correspondence Analysis(CCA) was applied in this paper for discriminating environmental factors having effect on phytoplankton community at species level.Coleroon coastal water is subjected to long term fluctuations in physico-chemical parameters depending upon the seasonal tidal amplitude and freshwater influx resulting in a continuous exchange of organic,inorganic,plant and animal matters.     

厦门同安湾鳄鱼屿海岸侵蚀与防护对策

在2009年3月对鳄鱼海岸线测量的基础上,利用ArcGIS软件分析比较了现有海岸线与厦门市集美区地形图（1988年版,图号：7-50-129甲-）中鳄鱼屿海岸线位置的变化.结果表明21a来,鳄鱼屿海岸最大侵蚀率为2.0 m/a,东南侧最大侵蚀宽度达42 m,侵蚀总面积达14 000 m2;其东北侧海岸侵蚀后退约35 m,侵蚀总面积达4 100 m2;其西北侧海岸最大侵蚀宽度达30 m,侵蚀面积达12 000 m2.文中就厦门市鳄鱼屿海岸侵蚀的成因进行了分析,提出了工程防护、人工补沙、红树林修复以及加强海岛及其周边海域资源综合管理等方面的防护对策.这可为我国其他无居民海岛的海岸侵蚀防护提供经验借鉴.     

徐闻南山镇红树林沉积物及红树植物中重金属的累积特征与迁移规律

为探究重金属在红树林沉积物及红树植物中的分布累积及迁移规律,选取了徐闻南山镇红树林为研究对象,通过测定红树林沉积物及红树植物不同部位（根、茎、叶）的重金属质量分数,运用富集因子、生物富集系数、转移系数及相关性分析等方法进行分析。结果表明：1）红树林沉积物重金属质量分数表现为铬（Cr）＞锌（Zn）＞镍（Ni）＞铜（Cu）＞铅（Pb）＞砷（As）＞汞（Hg）＞镉（Cd）,为中等变异程度;除了镍（Ni）元素外,其余7种重金属未超过国家一级标准,除了铅（Pb）元素外,其余7种重金属均超过广东省土壤环境背景值,说明研究区沉积物中重金属具有一定的积累效应。2）沉积物中砷（As）、铜（Cu）、锌（Zn）、汞（Hg）、镍（Ni）、铬（Cr）富集因子值均＞1.5,说明受到轻微人为活动影响;各站位镍（Ni）富集因子值均＞5,结合研究区背景,反映了镍（Ni）受到自然和人为输入的共同影响。3）白骨壤体内重金属主要集中在根部,而红海榄体内重金属在根茎叶中分布相对均匀。白骨壤根茎叶部位的大多数重金属质量分数远高于红海榄,说明白骨壤对重金属的吸附能力比红海榄强。汞（Hg）集中分布在植物的叶片部位,且与其他重金属之间相关性不明显;推测汞（Hg）主要通过叶片吸收进入植物体内,与交通运输污染有关。4）不同红树植物对不同重金属富集能力各异,白骨壤对重金属的富集能力表现为：镉（Cd）＞砷（As）＞铜（Cu）＞锌（Zn）＞汞（Hg）＞铅（Pb）＞镍（Ni）＞铬（Cr）,红海榄表现为：镉（Cd）＞铜（Cu）＞汞（Hg）＞锌（Zn）＞铅（Pb）＞砷（As）＞镍（Ni）＞铬（Cr）。白骨壤和红海榄对汞（Hg）的运移能力都较强;红海榄对镉（Cd）的富集能力和转运能力都较强,而白骨壤对镉（Cd）富集能力较强,转运能力却较弱,这说明红树植物对重金属元素的富集能力与转运能力不存在正比关系。     

Micromorphology of solonetzic horizons as related to environmental events in the Caspian Lowland

Micromorphology of solonetz species with special attention to natric horizon was studied in microcatenas at the Dzhanybek Research Station （northwestern Caspian Lowland）. The solonetzic （natric） horizon is easily identified, and it occurs at varying depths, which are the criteria for subdividing solonetzes into 4 species, namely, crusty, shallow, medium and deep. In this sequence, the depth of humus-accumulative horizons increases, and the upper boundary of salinity manifestations goes down. The following micromorphological features are assumed as typical for natric horizons： angular blocky microstructures with partially accommodated aggregates having sharp boundaries and narrow plane-like packing voids; b-fabric speckled in the aggregates＇ centers and monostriated at their peripheries merging into stress coatings; very few interpedal voids; organo-clay coatings; humus- enriched infillings; no calcite and gypsum pedofeatures. A complete set of ＂natric＂ features was found only in the crusty solonetz; the shallow solonetz lacks only illuviation coatings, while the medium and deep species have several modifications of fabric elements： blocky aggregates have a rounded shape and are penetrated by biogenic channels favoring their further biogenic reworking; plant residues became more abundant and diverse, and blackened tissues occur; illuviation clay coatings evolved into papules; stress coatings gave birth to striated bfabrics, thus maintaining a high plasma orientation. The thin sections of natric horizons made 50 and 20 years ago were examined to study the influence of environmental changes （increase in precipitation and rise of ground water table） on micropedofeatures. The following processes took place： （i） in the topsoil： humus accumulation and biogenic structurization; （ii） in the natric horizon - re-arrangement of clay coatings into micromass b-fabrics; and （iii） in the lower part of the natric horizon - development of pseudosand fabric, calcite and gypsum formation. The trends revealed are in good agreement with the environmental events.     

必需脂肪酸在海洋食物链中的作用

"硅藻-桡足类-鱼类"是海洋生态系统中物质循环和能量流动的主要环节[1].在海洋食物链中,饵料的数量和营养价值是各营养级海洋动物生长和繁殖的主要制约因素[2].影响饵料营养价值的化学组分包括蛋白质、脂类、糖类、矿物质、维生素等,其中脂类物质作为浮游植物营养成分的重要组成部分,在动物的细胞膜、视网膜、脑、神经组织和某些激素的合成中具有不可替代的作用[3].     

甘肃省重要古植物化石产地区划及保护利用

古植物化石是地质历史时期各类植物实体或遗迹的残留.对古植物化石产地进行系统的调查和区划研究是开展古生物化石保护和利用工作的基础.在资料研究和实地调查的基础上,对甘肃省24处重要古植物化石产地进行了评价和区划研究.甘肃省古植物化石产地可划分为北山地区、祁连山——河西走廊地区、鄂尔多斯和秦岭地区4个古生物化石大区以及6个古...     

Stress Responses to Rapid Temperature Changes of the Juvenile Sea Cucumber （Apostichopusjaponicus Selenka）

Activities of hexokinase （HK）, pyruvate kinase （PK）, superoxide dismutase （SOD） and catalase （CAT） and Hsp70 level were measured to evaluate the response of the commercially important sea cucumber （Apostichopus japonicus Selenka） to rapid temperature changes in laboratory. Animals were subjected to a higher temperature （from 10 to 20℃） （Tinc treatment） or to a lower temperature （from 20 to 10℃） （Tddec treatment） for 72 h. At 1, 3, 12, 24, 72 h of exposure, animals were removed and prepared for further analysis. Results showed that the effect of acute temperature changes on enzyme activities was significant. In Tinc treatment, activities of SOD and CAT increased immediately. The significant enhancement of SOD and CAT activities suggested that oxidative stress increases significantly when ambient temperature increasing from 10 to 20℃. The up-regulation of Flsp70 in Tinc and Tdec treatments indicated that Hsp70 was a bioindicator of thermal stress in the sea cucumber, and the expression pattern depended on the thermal treatment.     

淹没植物对河道糙率的影响

基于河道水动力及植物柔性变形分析,建立淹没状态下的植物河道糙率计算的理论关系,同时,利用试验资料及理论分析成果,进一步获得了植物河道糙率的附加值,借此可以分析与评价河道植物对水流阻力的影响程度.     

张家港市绿岩生态技术有限公司

绿岩生态 矿山、公路边坡、土壤（沙）荒漠化等生态防护治理,恢复绿化,本着诚信创新理念,以适合国内各地区生长的植物为主,一年半以后免养护,植物自然生长。