自容式海洋仪器用微处理机

在海洋仪器中应用微处理机有助于改进仪器的性能和降低其成本。在这种情况下,把仪器测得的资料存放在微处理机的内存中是一个记录资料的好办法。要用这种办法构成自容式海洋仪器,就要求所用微处理机的功耗很低才行。本文介绍了一个低功耗的处理机。所用的微处理器片子MC146805E2具有一个很低功耗的“WAIT”状态和一个功耗极低的“STOP”状态。电路中还采用了其他降低功耗的措施。这台尺寸为95×150mm的单板微处理机具有8K字节的内存容量,一个外部定时器和一个标准接口RS-232。作者曾以此微处理机为主体研制了一台自容式温度记录器。这项工作曾得到了伍兹霍尔海洋研究所A.Bradley博士的指导,特致谢意。     

海洋测温仪器的校准

海洋测温仪器的测温范围一般为0～32℃,很多海洋测温仪器使用前都要进行校准。其校准点选为零度左右和室温两点,零度左右这一点一般在水三相点瓶中进行。水三相点是国际实用温标——68定义的一个固定点,有其固定的标准值。而室温一点只能在一般水槽中进行,精确度低,而且每次所控的温度不一致,若能引进镓三相点温度,将给仪器调试带来很大方便。现把水三相点温度、镓三相点温度及其设备介绍如下:     

UECM—2000型磁泡存储器电磁海流计

该型仪器是由日本联合工程有限公司制造的一种新型测流仪器。该仪器采用磁泡存储记录器,适于在近海或波浪区长期测海流。磁泡存储记录器是一种非常可靠的数据收集系统,它与MT数据记录器完全不同,不产生由测量介质引起的误差。该记录器没有机械部分,使用时不需要维修,因此使用寿命长。该仪器的标准传感器技术指标如下: 1.流速传感器:     

关于SYY1-1盐度计的温度订正值的微机处理方法

SYY1-1盐度计是济南光学仪器厂生产的。该仪器在测量海水盐度时,同一个样品海水在不同的温度下所测得的盐度值却不同,因此对于仪器所测得的盐度值,要进行温度修正,为此厂方提供了一本盐度的温度修正表。该表的盐度读数范围为0—50S,且每隔5S给出一组值,这样共分11组,温度范围是0—40℃,每0.2℃给出一组值,共分201组。由此可知,该表共有修正值数据2211个。虽然该表如此繁杂,但仍不能满足实际工作的需要。在使用该仪器的实际工作中,其盐度读数精确到0.1‰,温度精确到0.1℃,这样就不     

温度对不同地理种群萱藻孢子附着、萌发及幼配子体早期发育的影响

为比较中国南北方不同地理种群萱藻繁殖生物学特性的差异,本研究应用实验生态学方法,以实验室保存的野生萱藻种质为材料,比较了温度对中国北方(大连)、南方(温州)不同地理种群萱藻孢子附着、萌发及幼配子体早期发育的影响。结果显示,大连萱藻孢子附着的适宜温度范围为14～18℃,最适温度为16℃,而温州萱藻孢子附着的适宜温度范围为16～20℃,最适温度为18℃;大连萱藻孢子萌发的适宜温度范围为10～18℃,14℃下孢子萌发率最高,实验第9天萌发率达到(19.62±0.78)%,温州萱藻孢子萌发的适宜温度范围为12～18℃,16℃下孢子萌发率最高,实验第9天萌发率达到(19.94±1.45)%;大连萱藻幼配子体生长的适宜温度范围为10～16℃,最适温度为12℃,该温度下培养30 d幼配子体长度为(0.50±0.03) mm,温州萱藻幼配子体生长的适宜温度范围为12～16℃,最适温度为14℃,该温度下培养30 d幼配子体长度为(0.41±0.01) mm。     

高精度温度记录仪

本文介绍了一种能满足海洋调查要求的高精确度数字式温度记录仪，其量程为－３￣＋３７℃，精确度为±０．０５℃，分辨率±０．０１℃。它以低功耗单片微计算机、液晶显示器和Ｖ／Ｆ变换接口为基础，采用干电池供电。仪器适于在室内、野外和海上多种用途的精密测温及自动记录；具有标准的并行打印接口和Ｒ５－２３２串行接口。这种仪器已在一些项目中实际应用。     

用航空红外测温仪速报大面积海表面温度

为速报大面积海表面温度,SWH1—1型航空红外测温仪参加了一九八四年十二月十八日至十二月二十九日在东海海域进行的航空测温试验,它和投掷浮标组成系统,提供海表面温度数据。该仪器的原理及其性能详见文献,在此仅列出其主要技术指标并将仪器的工作情况及试验结果作一介绍。一、仪器的主要技术指标测温范围:-2℃—— 35℃;分四档。测温精度:±0.5℃(均方根值); 温度分辨率:0.1℃; 工作波段:8——12微米; 视场角:2°; 使用的环境条件:温度:-10℃— 40℃;相对湿度:小于80％; 电源:27V±10％,110VA。     

温度、盐度对斑点鳟发眼卵孵化的影响

为了确定斑点鳟(Oncorhynchus mykiss)发眼卵孵化的适宜温度、盐度条件,作者通过设置不同的孵化温度和盐度,研究了温度、盐度对斑点鳟发眼卵孵化的影响。结果表明,发眼卵孵化的适宜温度范围为8~16℃,孵化率都在(73.33±2.04)%以上,最适温度为10℃,孵化率达(87.77±1.23)%。温度高于24℃时发眼卵不能孵化。温度在6~22℃内,斑点鳟发眼卵孵化时间与温度成负相关关系。斑点鳟胚胎发育的平均积温值为343℃?d。发眼卵孵化的适宜盐度范围为0~15,孵化率都在(85.33±1.92)%以上,最适盐度为0,孵化率达(97±1.13)%。盐度高于15时的孵化率为0。盐度在0~15内,发眼卵孵化时间与盐度成正相关关系。     

漂浮铜藻室内保存及海上越冬试验

在我国南北海区经常能观察到聚集的漂浮铜藻,为有效利用铜藻资源,设计了铜藻室内保存及海上越冬试验。结果显示,铜藻在室温3℃～15℃下藻的鲜重均有不同程度下降,80μmol·m^-2·s^-2强光比20μmol·m^-2·s^-2弱光保存铜藻效果好,低温比高温保存效果好,但低于5℃后的铜藻保存效果变差。在温度5℃～17℃左右时,海上筏养铜藻特定生长率随温度升高而升高,而且藻体健壮,在冬季海水温度降到℃以下时,铜藻基本停止生长,但是藻体仍保持较好的活力,因此漂浮铜藻可在黄海南部海上顺利越冬。     

温度及其波动对潮间带海藻生长及光合作用的影响

研究了青岛潮间带地区的四种海藻在不同恒温(5～35℃)、不同变温(23±3,26±3,29±3℃)及不同变温幅度下(25±0,25±2,25±3,25±4,25±5℃)的生长和光合作用。实验结果表明:(1)每种海藻均能在较宽的温度范围生长,且最适生长温度为25℃左右。(2)在给定的温度范围(20～30℃)内,适宜的变温(23±3℃和/或26±3℃)可提高海藻的光合作用速率,从而促进海藻生长,但当变温超出适温范围时(29±3℃),海藻生长受到抑制。(3)与25℃恒温相比,高潮带的叉枝藻随着变温幅度的增大,生长率和光合作用速率显著下降。中潮带的孔石莼和缘管浒苔则对不同变温幅度显示出一定的适应性。低潮带的扁江蓠在不同变温幅度下的生长和光合作用速率均有所提高。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

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。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

A Review of Some Environmental Issues Affecting Marine Mining

This article reviews information recently available from existing marine and coastal mining for responses to environmental issues affecting marine mining at different depths. It is particularly but not exclusively concerned with those issues affecting seabed biodiversity impact and recovery. Much information has been gathered in the past 10 years from shallow mining operations for construction aggregate, diamonds, and gold, from coastal mines discharging tailings to shallow and deep water, and from experimental deep mining tests. The responses to issues identified are summarized in a series of eight tables intended to facilitate site-specific consideration. Since impacts can spread widely in the surface mixing layer SML, and can affect the biologically productive euphotic zone, the main issues considered arise from the depth of mining relative to the SML of the sea. Where mining is below the SML, the issue is whether it is environmentally better to bring the extraction products to the surface vessel for processing (and waste discharge), or to process the extraction products as much as possible on the seabed. Responses to the issues need to be sitespecific, and dependent on adequate preoperational environmental impact and recovery prediction. For deep tailings disposal from a surface vessel, there are four important environmental unknowns: (1) the possible growth of "marine snow" (bacterial flocs) utilizing the enormous quantities of fine tailings particles (hundreds or thousands of metric tons per day) as nuclei for growth, (2) the possibility that local keystone plankton and nekton species may migrate diurnally down to and beyond the depth of deep discharge and hence be subjected to tailings impact at depth, (3) the burrow-up capability of deep benthos and their ability to survive high rates of tailings deposition, and (4) the pattern and rate of dispersion of a tailings density current through the deep water column from discharge point to seabed. Actions to obtain relevant information in general and site-specifically are suggested.     

Increased Particle Fluxes at the INDEX Site Attributable to Simulated Benthic Disturbance

Particle fluxes were measured 7 m above the sea bottom during the predisturbance, disturbance, and postdisturbance periods by using time series sediment traps attached to seven deep-sea moorings deployed in the INDEX experiment site in the Central Indian Basin. The predisturbance particle fluxes varied between 22.3 to 55.1 mg m -2 day -1 . Increased and variable particle fluxes were recorded by the sediment traps during the disturbance period. The increase observed was 0.5 to 4 times more than the background predisturbance fluxes. The increases in particle fluxes (~4 times) recorded by the sediment trap located in the southwestern direction (DMS-1) were the greatest, which could be the result of preferential movement of resuspended particles generated during the deep-sea benthic disturbance along the general current direction prevailing in this area during the experimental period. Also, the traps located closer to the disturbance area recorded greater fluxes than did the traps far away, across the Deep Sea Sediment Resuspension System path. This variability in recorded particle fluxes by the traps around the disturbance area clearly indicates that physical characteristics such as grain size and density of the resuspended particles produced during the disturbance had an important effect on particle movement. The postdisturbance measurements during ~5 days showed a reduction in particle fluxes of ~50%, indicating rapid particle settlement.     

Determination of In Situ Sediment Shear Strength from Advanced Piston Corer Pullout Forces

The advanced piston corer (APC) has been used by the Ocean Drilling Program since 1985 for recovering soft sediments from the ocean floor. The pullout force measured on extracting the core barrel from the sediment is shown to correlate with the average shear strength of the sediment core measured in the ship's laboratory. A simple rule of thumb is derived relating the shear strength of the sediment to the pullout force. Multiple APC holes at individual sites allow the consistency of the pullout measurements to be assessed. The effects of different operational procedures during APC coring are also explored. Although generally applicable, the correlation between pullout force and laboratory measurements of shear strength breaks down for some APC holes, possibly because of the disturbance of some sediment types during the APC coring process. A better understanding of the physical process of APC coring, and its effect on the properties of the sediment both inside and immediately outside the core barrel, would indicate what confidence can be put on the measurement of pullout force as a way of evaluating the in situ shear strength of deep sea sediments.     

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.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations.