长江口海水的密度

为了核对1980年国际海水状态方程应用于中国近岸海水的可靠性,高精度的磁力浮沉子密度计在15—25℃,盐度5—35,一个大气压条件下,测量了长江口附近海水及其人工稀释海水的相对密度。结果表明,海水密度直接测量值系统地偏高于状态方程计算值,二者之间的偏差随水样盐度值降低而增大,且与海水[Ca~(2+))/s比值成明显正相关关系。经计算机拟合,导出了长江口附近海水及其稀释海水的状态方程,该方程计算值与实验值的平均标准偏差为±3.9×10~(-3)kg/m~3。     

一个大气压国际海水状态方程

用米勒罗(Millero),罔萨雷斯(Gonzalez),沃德(Ward)(1976,Journal of Marine Research,34,61—93)还有波伊森(Poisson),布律内(Brunet),布伦—科坦(Brun—Cottan)(1980,Deep Sea Research,27,1013—1028)在温度0—40℃,盐度0.5—43时进行的密度测量值来确定新的一个大气压海水状态方程。方程的形式如下(t℃;S;ρkgm~(-3)) ρ=ρ_o AS BS~(3/2) CS~2 式中:A=8.24493×10~(-1)-4.0899×10~(-3)t 7.6438×10~(-5)t~2-8.2467×10~(-7)t~3 5.3875×10~(-9)t~4 B=-5.72466×10~(-3) 1.0227×10~(-4)t-1.6546×10~(-6)t~2 C=4.8314×10~(-4) ρ_o是水的密度(Bigg,1967,British Jonrnal fo Applied physics 8,521—537) ρ_o=999.842594 6.793952×10~(-2)t-9.095290×10~(-3)t~2 1.001685×10~(-4)t~3-1.120083×10~(-6)t~4 6.536332×10~(-9)t~5 方程的标准误差为3.6×10~(-3)kgm~(-3)。联合国教科文组织海洋学常用表及标准联合专家小组已推荐该方程为新的一个大气压海水状态方程。     

一种高精密的溶液密度测量装置：—磁力浮沉子密度计

本文介绍了一种改进的、原理简单的溶液密度测量装置——磁浮密度计,讨论了影响精密度和准确度的因素。该装置简单,操作简便,速度快,精密度、灵敏度分别为±2×10~(-6)、0.3×10~(-6),其准确度通过测定19.89℃时国际标准海水P105的密度得到了验证,我们的测定结果和别人的极好地一致。     

黄河口及渤海湾海水的密度

用磁力浮沉子法溶液密度测量装置,在15—25℃之间的三个温度下测定了黄河口渤海湾36个站位海水样品(于1989年7月和1990年7月采集)的密度,发现所有实验测定值与根据其盐度和温度由1980年国际海水状态方程的计算值比较,均有明显的正偏差,此正偏差随海水盐度降低而增大。在黄河口渤海湾海水样品全部盐度范围内,已发现其海水密度正偏差与海水[Ca~(2+)]/s,[Mg~(2+)]/s,[SO_4~(2-)]/s之间呈指数曲线相关,而与碱度之间呈S形曲线相关,但在盐度25.72—31.57范围内都可近似看作直线相关。黄河口渤海湾海水的高碱度、高[Ca~(2+)]/s为其特征,这也是其密度正偏差的主要影响因素。本文还给出了计算黄河口及渤海湾海水密度的公式。     

1980年国际标准海水状态方程应用于低盐海水的可能性

为了考察１９８０ 年国际标准海水状态方程在盐度小于０ ．５ 条件下的适用性,测定了０ ．０３９～２ ．０００ 盐度范围内的稀释大洋水的密度,并与状态方程的计算值作了比较。测定值与计算值之间的平均偏差为±０．６×１０－ ３ｋｇ／ｍ３ ,小于状态方程的标准偏差３．６ ×１０－ ３ｋｇ／ｍ３ 。结果认为１９８０ 年国际标准海水状态方程的低盐范围可以从现在的０．５ 继续扩展到０．０３９ 。     

胶州湾海水中的钙和镁

于1989年10月28日在胶州湾的23个站位采集表层水样,对Ca、Mg及盐度、氯度、碱度等化学要素进行了测定,并用崂山水库水进行了稀释实验。结果表明,Ca/s,Mg/s均高于大洋水,其值分别为0.01250±7×10~(-4)和0.03728±1×10~(-4)。湾东北部的Ca,Mg均高于中部及湾口海域,这是湾东北部的工业废水及高盐卤水排放所致;CaCO_3(20℃)呈现过饱和状态。认为,ca,Mg有良好的保守性,低盐混合水样在放置过程中pH的下降可能与空气中CO_2的溶解有关,从而将引起ca,Mg含量的相对增高。     

固体吸附剂吸硼研究概况

Ⅰ.硼的存在形式及去硼意义 据文献报道自来水中硼的含量为7×10~(-9)～0.2×10~(-6)g/L,海水中的含量为5×10~(-6)g/L,河水中的含量为13×10~(-6)g/L,地下水和卤水中的含量随各地而有所不同。在一般的水溶液中,硼以H_3BO_3,B(OH)_4~(-)形式存在,以H_3BO_3为主。硼酸是一元弱酸,是一种路     

1980年高压国际海水状态方程定义

高压海水密度(ρ,kgm~(-3))可根据实用盐度(S)、温度(t,℃)和所加压力(P,bar)按下列方程计算得出: ρ(S,t,P)=ρ(S,t,O)/(1-P/K(S,P)) 式中ρ(S,t,O)为如上所述的1980年一个大气压下的国际海水状态方程,K(S,t,P)为正割体积模量,由下式给出 K(S,t,P)=K(S,t,O) AP BP~2     

东山湾海水盐度,温度和溶解氧的分布特征

1988年5月、8月、11月和1989年2月东山湾海水的盐度范围分别为20.81～33.89、30.43～34.24、26.76～30.59和30.27～31.57;水温范围分别为23.4～25.0、22.5～30.8、18.1～20.7和14.5～17.3℃;溶解氧体积分数分别为(4.12～4.91)×10~(-3)、(3.50～5.10)×10~(-3)、(5.21～6.68)×10~(-3)和(5.64～6.00)×10~(-3);氧饱和度分别为85.1%～104%、73.3%～116%、99.6%～124%和102%～104%。春、夏季东山湾受高盐外海水的影响明显,其中夏季可能还受到上升流的影响.秋季浮游植物大量生长和繁殖,成为溶解氧含量和氧饱和度的主要影响因素。     

1980年一个大气压下国际海水状态方程定义

在一个标准大气压(P=0)下,海水密度(ρ,kgm~(-3))根据实用盐度(S)和温度(t,℃)按下列方程计算得出: ρ(s,t,o)=ρ_W (8.24493×10~(-1)-4.0899×10~(-3)t 7.6438×10~(-5)t~2-8.2467×10~(-7)t~3 5.3875×10~(-9)t~4)S (-5.72466×10~(-3) 1.0227×10~(-4)t-1.6546×10~(-6)t~2)S~(3/2) 4.8314×10~(-4)S~2     

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.