环境化学因子对单胞藻生长和代谢产物络合容量的影响

通过一次培养、极谱滴定测定研究一次培养过程中叉边金藻细胞渗出物对铜、镉的络合容量及常数的变化;培养介质的营养水平;加入微量营养元素铁、锰和重金属铜对细胞生长和渗出物释放的影响。结果表明,在一次培养过程中,从接种到稳定生长期细胞渗出物的铜络合容量从1.49×10~(-7)mol/dm~3增加到8.34×10~(-7)mol/dm~3,条件稳定常数LgK′_(CuL)从7.57变化到7.11。培养介质的营养水平愈高,单个细胞渗出的有机物量增加,铁明显抑制细胞渗出物的释放,铜在细胞中可容忍的浓度范围内刺激细胞渗出物的释放。     

牟氏角毛藻的有机渗出物及其对铜的络合作用

对牟氏角毛藻(chaetoceros muelleri)进行一次性的培养过程,不同时间取藻培养液过滤,测定滤液中的COD及铜络合容量CC_(cu)值。结果表明,牟氏角毛藻在生长过程中向体外渗出有机物,在指数生长期渗出的有机物量很少;细胞渗出有机物明显增加;出现在静止期之后。牟氏角毛藻的细胞渗出物对铜具有络合能力,CCcu值从初始到192小时,由1.65×10~(-7)mol/dm~3增加到2.20×10~(-7)mol/dm~3。铜络合物的条件稳定常数在整个培养过程中无明显改变,logKcuL变化范围从7.27到7.74。过滤藻液的COD值从初始到192小时由0.81mg/dm~3增加到1.58mg/dm~3。     

极谱法测定海水介质的铜络合容量

采用新极谱技术(1.5次微分)的阳极溶出伏安滴定方法测定天然海水的铜络合容量和条件稳定常数。对测试条件、EDTA回收率和有关问题进行了探讨。青岛近岸水样的九次平行测定表明,铜的表现络合容量为3.01×10~(-7)mol/dm~3,条件稳定常数为7.34×10~7,相对标准偏差分别为9.2％和13.8％。     

三角褐指藻对汞吸收富集作用的研究——汞与浮游植物相互作用(Ⅱ)

采用连续培养方法,研究三角褐指藻对汞(HgCl_2)的吸附富集作用。结果表明,藻体对汞有较大的富集能力,加入培养瓶中的汞被藻体富集率在95％以上,富集因子的变化范围在3×10~4—2×10~5之间。三角褐指藻的吸附符合Freundlich吸附公式,其动力学过程是一级反应。并讨论了胶州湾水体中浮游植物与汞含量间的关系。     

浮游植物生物法测定海水铜络合容量

采用牟氏角毛藻通过生物法测定青岛多处近岸水的铜络合容量CC_(cu)。此法测定的CC_(cu)值范围在1.6×10~(-7)～6.7×10~(-7)mol/dm~3之间。测定了4个经紫外线消解的海水中不同含量EDTA,结果表明,此法可较好反映水体中配位体的含量。使用1.5次微分ASV法也测定了这些样品的CC_(cu),两种方法测定结果比较,表明生物法测得的CC_(cu)值大于ASV法。这样差异可能与两种方法测定铜的形态不同有关。     

几种污染物对草鱼细胞SCE的影响

1987年10月—1988年6月期间,以草鱼(Ctenopharyngodon idellus)ZC-7901细胞株和1龄稚鱼作实验材料,选5种金属盐和4种农药作水体环境的污染物,对培养细胞和稚鱼进行处理,观察培养细胞和鱼体内肾细胞SCE的变化。结果表明:在每毫升培养基中分别含有104×10~(-7)mg的Cr~(6+),112×10~(-7)mg的Cd~(2+),74.9×10~(-7)mg的As~(3+),20l×l0~(-6)mg的Hg~(2+),207×10~(-4)mg的Pb~(2+)及216×10~(-4)mg的敌百虫等污染物,都能诱使培养细胞的SCE明显增加;稚鱼在每升分别含有15×10~(-7)g的Cr~(6+),15×10~(-7)g的Cd~(2+),13×10~(-7)g的Hg~(2+)的池水中喂养40天后,体内肾细胞的SCE也见增加;但是三环唑、甲胺磷、呋喃丹对细胞的SCE没有影响。本文认为,能够引起草鱼SCE变化的污染物的浓度,应该作为今后制定水质标准的参考;同时,草鱼培养细胞和体内肾细胞SCE的检测技术,可以发展成为一种监测水体环境污染的检测系统。     

大气压下磁力浮沉子法测量中国标准海水的密度

用自行设计安装的磁力浮沉子法密度装置测量溶液密度具有±3×10~(-3)kgm~(-3)的灵敏度,±3.5×10~(-3)kgm~(-3)的精密度。25℃时测定Nacl溶液的密度与Millero测量值平均偏差为2.6×10~(-3)kgm~(-3),求得NaCl的φ_v~0值为16.61(cm)~3mol~(-1)。 对12批中国标准海水及24个稀释中国标准海水的密度测量值(温度在15～25℃之间)与1980年国际海水状态方程计算值之间平均偏差为3.4×10~(-3)kgm~(-3)。实验结果表明中国标准海水及其稀释海水的密度与盐度及温度的关系遵从1980年国际海水状态方程。为中国标准海水作为溶液密度测量标准提供实验依据。     

环雷州半岛海域表层沉积物与鲬鱼汞污染研究

对2018年1月在广东环雷州半岛近海海域采集的海底表层沉积物、鲬鱼(Platycephalus indicus)进行汞含量的测定,分析比较了鲬鱼不同部位汞含量的差异,并采用单因子污染指数法对沉积物和鲬鱼的汞污染状况进行了风险评价。结果表明,环雷州半岛海域表层沉积物中汞含量范围为0.005×10^-6～0.359×10^-6,平均值为0.081×10^-6,雷州半岛东部海域表层沉积物汞含量高于南部和西部海域。鲬鱼的鳃中汞含量范围为0.032×10^-6～0.034×10^-6,平均值为0.033×10^-6;肌肉中的汞含量范围为0.065×10^-6～0.080×10^-6,平均值为0.073×10^-6;肝脏中的汞含量范围为0.228×10^-6～0.270×10^-6,平均值为0.249×10^-6。鲬鱼样品的汞含量都呈现出肝脏＞肌肉＞鳃。单因子污染指数评价结果显示,雷州半岛海域鲬鱼受到汞的轻微污染,雷州半岛东部海域表层沉积物存在汞污染生态风险,而其南部、西部海域尚未受到汞污染的威胁。     

冬夏季南海西部固氮蓝藻

本研究分析了冬季东北季风期(2006年11月27日-12月16日)及夏季西南季风期(2007年8月11日-9月16日)南海西部越南沿岸区域(10°~17°N,108°~115°E)的网采浮游植物样品,探讨了冬夏两季南海西部固氮蓝藻的物种、丰度及分布特征,以及影响固氮蓝藻丰度与分布的环境因素。冬夏两季南海西部固氮蓝藻主要有束毛藻(Trichodesmium)和胞内植生藻(Richelia intracellularis),束毛藻物种包括铁氏束毛藻(Trichodesmium thiebaultii)、红海束毛藻(Trichodesmium erythraeum)以及汉氏束毛藻(Trichodesmium hildebrandtii),其中铁氏束毛藻为优势种,胞内植生藻主要与根管藻(Rhizosolenia sp.)共生。冬季时束毛藻藻丝体平均丰度为0.194×104 filaments/L,束毛藻细胞平均丰度为0.172×106 cells/L,胞内植生藻细胞平均丰度为0.255×104 cells/L,与笔尖形根管藻(Rhizosolenia styliformis)共生的胞内植生藻居多;蓝藻主要分布在调查海域的北部。夏季时束毛藻藻丝体平均丰度为2.995×104 filaments/L,束毛藻细胞平均丰度为6.007×106 cells/L,胞内植生藻细胞平均丰度为2.198×104 cells/L,与笔尖根管藻共生的胞内植生藻占优势。夏季时固氮蓝藻丰度高于冬季,胞内植生藻宿主更为多样化。本研究中温度及冷窝对蓝藻的分布有重要影响,而盐度单独对蓝藻分布的影响不大,与温度结合时表现出一定的限制作用。     

铬(VI)对浮游植物生长率的影响(英文)

本工作使用一次培养法初步研究了Cr(VI)对菱形硅藻和隐藻的毒性,实验结果表明,当Cr(VI)浓度大于16ppb时,则对其生长率产生抑制作用,其72小时EC_(50)值分别为260ppb和230ppb.根据活性点位模式计算了Cr(VI)与藻体的结合常数,约为2×10~5藻体中Cr含量与培养液中Cr浓度有关,两者近似指数关系,根据藻体中Cr含量和溶液中Cr的浓度,估计每个硅藻细胞与Cr最大结合容量约为5×10~(-17)mol/cell.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.     

A Tidal Flow Model for the Gulf of Kachchh, India

A vertically integrated model has been used to study the tidal circulation and currents in the Gulf of Kachchh along the west coast of India. The model is fully nonlinear and uses a semiexplicit finite difference scheme to solve the basic hydrodynamic equations on a staggered grid. The model is forced by prescribing the tides along the open boundary of the model domain. The flow is simulated both with and without the presence of the proposed tidal barrage across the Hansthal Creek in the Gulf of Kachchh. The results show a considerable change in the behavior of the tidal flow in the presence of the barrage.     

利用中国GF-3卫星SAR和HY-2A卫星微波散射计的首次台风联合定量观测

<正>The typhoon,as a mature tropical cyclone that develops in the western part of the North Pacific Ocean with high wind speed and heavy rainfall,is one of the most lethal and costly of natural disasters for the densely populated countries of East Asia.It can be easily detected by space-borne sensors operated at microwave,visible or infrared bands(Liu et al.,2014).Synthetic Aperture Radar(SAR)is     

离子交换—原子吸收光谱法测定海水中痕量铜、铅、锌、镉、铁、锰

本文介绍了用国产D401型螯合树脂分离富集海水中铜、铅、锌、镉、铁、锰等痕量元素,并用原子吸收光谱仪测定其含量的方法。讨论了各元素的分离条件选择及干扰元素的影响,并与溶剂萃取法的结果作了比较。各元素检测的定量下限为:铜0.5μg/L、铅0.1μg/L、锌1.0μg/L、镉0.01μg/L、铁2.0μg/L、锰2.0μg/L。方法精密度在4—8％之间,回收率为90—102％。     

Biogeochemistry of Mangrove Soil Organic Matter: a Comparison BetweenRhizophoraandAvicenniaSoils in South-eastern Brazil

Soil core samples fromRhizophora mangleL. andAvicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher inAvicenniathan inRhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth inRhizophorasoils whereas inAvicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter inRhizophorasoils and a continuing degradation of organic matter inAvicenniasoils. The latter may thus release more nutrients to adjacent ecosystems thanRhizophorasoils.     

A review of orange roughy Hoplostethus atlanticus fisheries,estimation methods,biology and stock structure

Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at 22 – 40 years), and to have exceptionally low natural mortality (M = 0.045–0.064 year^?1) and slow growth rates (K = 0.055–0.070 year^?1). In addition, they spawn large eggs and have low fecundity. These factors combine to make orange roughy highly susceptible to overfishing; most stocks are below 30% of pristine levels. Assessments are obtained from indices of catch rate and trawl, acoustic and egg surveys. Acoustic estimates are the most direct, but are confounded by the species' low target strength (?50 to ?53 dB)–attributable to the wax-filled swim bladder. Extracellular wax esters are stored in abundance and comprise mostly mono-unsaturated fatty acids, with low concentrations of the ω-3 fatty acid family. This unusual composition (resultant from the species' diet) ensures neutral buoyancy. Stock separation has been inferred mainly from biological studies, but genetic studies have also found differences among stocks within New Zealand and Australia. Deep-water habitat may be damaged by trawling operations and may take many years to recover, so in some quarters there is a call for a portion of suitable habitat to be set aside for preservation. Although Namibian orange roughy are shallower, smaller and younger than those in other stocks, the Namibian fishery sustained high catches for only a few years before quotas were reduced, from 12 000 to 1 875 tons. Three management lessons are suggested for developing orange roughy fisheries based on the Namibian experience: (1) imposition of catch limits during exploratory fishing; (2) starting the acoustic surveys earlier in the fishery, if possible; (3) greater reliance on trends in catch rate until a survey series has been established.