两种水体吸收系数测量方法的比较研究

基于2011年7月藻类培养实验期间的实测数据,对高光谱吸收衰减系数测量仪(AC-S)和紫外-可见分光光度计(UV2550)获取的水体吸收系数进行了比较分析.结果表明,短波波段AC-S测得吸收光谱曲线普遍低于UV2550测量结果,而长波波段恰恰相反;两种方法测量结果的相对误差基本可控制在±40％范围内;特征波段处,两种方法测量结果线性拟合的相关性较高,均可这98％以上,412 nm、440 nm、443nm波段斜率小于1,而488 nm、531nm、551 nm、667nm、675nm、678 nm波段斜率大于1.     

硬X射线相位光栅的设计与研制

针对在普通实验室和医院实现40—100 keV X射线相衬成像的需求,考虑到成像系统参数、X射线源空间相干特性及光栅衍射效率,设计出硅基相位光栅结构参数.利用我们已发展的光助电化学刻蚀技术研制出直径为5英寸的相位光栅,其空间周期为5.6 μm,线宽为2.8 μm,深度为40—70 μm.在理论分析的基础上,通过提高硅片两端有效工作电压和修正Lehmann电流密度公式,解决了实际刻蚀过程中出现的钻蚀问题.由实验结果可知,本方案对制作大面积高精度相位光栅十分有效.     

不同光强下小球藻纵向沉降及悬浮特性研究

通过用自制沉降柱研究小球藻(Chlorella vulgaris)在表层不同光强作用下纵向沉降特性以及分布规律, 为进一步了解水库中小球藻的纵向分布提供参考。实验室培养的小球藻按其直径可分为小于4.5 μm、4.5～5.5 μm、大于5.5 μm 3 个等级, 不同粒径的小球藻在不同光强的作用下沉速不同; 实验条件下小球藻的沉速分布在0.1～468.2 μm/s, 均值为32.8 μm/s; 小球藻的沉降速度随沉降柱表层光强增强而降低, 无光状态下时沉速是表层光强为10 000 lx 的2～3 倍; 小球藻直径大小与沉速呈正相关, 直径4.5～5.5 μm 的小球藻沉速是3.5～4.5 μm 的5~6 倍; 沉降稳定后实验柱中小球藻从表层至底层粒径逐渐变大, 除底层外小球藻在纵向峰值随光强增加而向下延伸, 如实验柱表层光强为1 000 lx 和4 000 lx时小球藻峰值出现实验柱表层, 而表层光强为7 000 lx 和10 000 lx 的实验峰值分别出现在水下300 mm和600 mm 处。     

卫星高度计及其应用

传统的遥感技术,都是利用地物的电磁波谱特征来提取物质的分类、数最或状态信息。由于海水的导电性,电磁波在海水中被强烈吸收,除了极狭窄的可见波段能透入表面几米至几十米外,其余的红外、微波段电磁波只能透入极表层、μm—mm深度。同时,由于海洋表层     

第一章 遥感图象信息提取和遥感地质工作程序

一、遥感图象地物信息的提取 地球表面物体对外来的电磁波都有反射、吸收和透射的作用。反射、吸收、透射电磁波能量占入射电磁波能量的百分比,即分别为反射率、吸收率和透射率,它们的差异可作为探测和区别地面目标物的有用信息。另外,不同的地物发射电磁波的能力也各不相同,当地物的温度高于绝对零度时,它就会向外发射电磁波(热辐射)。专题绘图仪的TM—6波段为10.40～12.50μm,属于远红外波段,若以远红外波段扫描成像而获得的遥感信     

东海海域典型赤潮水体反射光谱模拟研究

东海原甲藻(Prorocentrum donghaiense Lu)是我国东海海域的典型赤潮藻种,其在水体中通常呈垂直非均匀分布,并存在季节性和日内的垂直迁移现象。本文通过量化垂直迁移过程中东海原甲藻的分布状态,利用Hydrolight软件数值模拟各状态下的水体反射光谱,研究其光谱特征和变化规律。利用叶绿素浓度高斯垂向模型表征东海原甲藻在水体中的垂直分布,结合东海近岸海域二类水体的生物光学模型,模拟得到垂直迁移过程中东海原甲藻赤潮水体的反射光谱。对比分析叶绿素浓度垂向分布参数(背景叶绿素浓度、甲藻主体水层厚度、水体总生物量和叶绿素浓度峰值深度)对水体反射光谱的影响。研究结果表明,在东海原甲藻从次表层向表层垂直向上迁移过程中,水体反射光谱数值在蓝绿波段(400—570nm)减小,在黄红波段(570—720nm)增大,特别是在叶绿素荧光效应波段(680nm)处的变化尤为明显。     

皱纹盘鲍杂交幼鲍闽东内湾度夏初探

为探讨皱纹盘鲍杂交鲍幼鲍在闽东内湾度夏的生长与存活,以山东荣成两家育苗场培育的皱纹盘鲍Haliotis discus hannai杂交鲍幼鲍(XXK、DY)、福建东山岛培育的盘鲍H.discus discus幼鲍(DS)为材料,分别运输至福建霞浦内湾长腰海区、山东荣成爱连湾进行度夏培育.各幼鲍组XXK、DY、DS均为1龄苗种,起始壳长分别为31.51 mm±2.66 mm、30.76 mm±3.30 mm、30.63 mm±2.57 mm,且无显著性差异(P<0.05).经过6个月的培育,在南方闽东内湾培育条件下,皱纹盘鲍杂交鲍幼鲍组壳长的日增长率达95.34 μm/d±29.14μm/73.81 μm/d±29.37 μm/d,存活率为50.06%±0.25%、49.88%±0.17%;盘鲍组壳长的日增长率则为65.81 μm/d±29.71μm/d,存活率为28.81%±4.87%.作为对照,在北方培育条件下,皱纹盘鲍杂交鲍幼鲍组壳长的日增长率达67.85μm/d±29.01μm/d、63.749 μm/d±22.99 μm/d,存活率为78.90%±2.24%、86.56%±2.98%;盘鲍组壳长的日增长率则为27.87μm/d±29.21μm/d,存活率为43.19%±1.85%.双因素方差分析结果表明养殖环境与幼鲍来源,以及两者的交互作用均显著影响幼鲍度夏的生长发育.本研究结果对皱纹盘鲍杂交幼鲍在南方闽东内湾的养成提供了一定的参考.     

海面溢油无人机高光谱遥感检测与厚度估算方法

海上溢油是海洋国家所面临的共同问题，但至今仍没有一种可靠实用的海上溢油准确识别和油量遥感监测方法。为此，本文以无人机高光谱遥感为手段，开展了海面溢油检测与厚度估算方法研究。实验中，通过搭建室外大型水槽溢油实验装置，获取了模拟真实海洋环境条件下不同溢油量的遥感和现场光谱数据，在此基础上，分析并提取了海上溢油特征光谱波段，给出了海上溢油高光谱检测模型；针对现场实验条件下水面油膜厚度难以测定的问题，设计了3种利用总体溢油量的油膜厚度估算模型。得到如下主要结论:（1）675 nm和699 nm是海上溢油检测的有效特征波段，但对极薄的油膜没有检测能力；（2）提出了归一化溢油指数模型、反比例模型和吸收基线模型等3种海上溢油油膜厚度估算模型，其中对于薄油膜（厚度≤ 5 μm）和厚油膜（厚度>50 μm），反比例模型是溢油厚度反演的首选也是唯一选择。对于中厚度油膜，晴朗天气条件下，归一化溢油指数模型是油膜厚度反演的首选，同时反比例模型和溢油吸收基线模型也都有较好的反演能力，而在多云天气条件下，反比例模型效果最佳。     

高分一号在青岛输油管道海面溢油监测中的应用

针对2013年11月22日青岛黄维输油管道泄漏爆炸事故中造成的胶州湾海面溢油,利用GF-1卫星数据对2013年11月26日胶州湾海面溢油特征进行了提取与分析。结果表明,蓝色波段(0.45~0.52μm)与绿色波段(0.52~0.59μm)油水反差明显,尤其绿色波段油膜特征提取效果较好;反射红外波段(0.77~0.89μm)可用作辅助掩膜;红色波段(0.63~0.69μm)没有区分度;基于绿色波段数据,采取频域方法初步处理,并结合以反射红外波段作出的海区掩膜便可以有效提取海面油膜信息。因此,GF-1卫星数据可对近岸海域、小范围海洋溢油实现有效监测。     

珠江磨刀门河口表层沉积物磁性特征及其动力沉积环境意义

基于2015年3月珠江磨刀门河口表层沉积物磁学和粒度测量结果,研究磨刀门河口磁性特征空间分布规律,分析磁性参数与沉积物粒度的关系,并探讨其对沉积动力环境的响应。磁性参数磁化率（χ）和饱和等温剩磁（SIRM）均在拦门沙处出现低值区,并在10 m等深线外呈现向海递减趋势;频率磁化率（χ_fd%）、非磁滞剩磁磁化率（χ_ARM）以及比值参数χ_ARM/SIRM和χ_ARM/χ在拦门沙处出现低值区,而在拦门沙外呈现高值:表明研究区域磁性特征由亚铁磁性矿物主导,而拦门沙区域存在一定量的不完全反铁磁性矿物。粒度是影响沉积物磁性特征的重要因素,SIRM/χ等参数与粗颗粒组分（大于63 μm）呈显著正相关,χ_fd%等参数与小于16 μm粒级组分高度相关,结果显示χ_fd%、χ_ARM、χ_ARM/SIRM以及χ_ARM/χ等参数可作为本区域沉积物细颗粒组分（小于16 μm）的代用指标,而SIRM/χ则可作为粗颗粒组分（大于63 μm）的代用指标。基于沉积物类型、动力环境等综合考虑,选取SIRM、S_-300、SIRM/χ参数聚类分析,可将磨刀门河口动力沉积环境分为4个区,结果与该区域动力环境及动力地貌格局具有一致性。本研究不仅对了解新动力格局下磨刀门河口演变模式具有重要意义,还可以丰富河口沉积动力学研究方法。     

Assessing the Validity of Seismo-Acoustic Predictor Equations for Obtaining Seabed and Sub-Surface Sediment Physical Properties

The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.     

Interannual Sea Level Variations and Annual Tides in the Northwestern Pacific

Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.     

Flow Cytometric Analysis of Coastal Lagoon Bacterioplankton and Picophytoplankton: Fixation and Storage Effects

The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Net Sand Transport Direction in a Tidal Inlet, using Foraminiferal Tests as Natural Tracers

The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance.     

Sea Levels and Coastal Inundation Due to Tropical Cyclones in Indian Coastal Regions of Andhra and Orissa

Coastal inundation associated with extreme sea levels is the main factor which leads to the loss of life and property whenever a severe tropical cyclonic storm hits the Indian coasts. The Andhra and Orissa coasts are most vulnerable for coastal inundation due to extreme rise in sea levels associated with tropical cyclones. Loss of life may be minimized if extreme sea levels and associated coastal flooding is predicted well in advance. Keeping this in view, location specific coastal inundation models are developed and applied for the Andhra and Orissa coasts of India. Several numerical experiments are carried out using the data of past severe cyclones that struck these regions. The simulated inland inundation distances are found to be in general agreement with the reported flooding.     

Role of Siliceous Fossil Dissolution in Downcore Variations of Grain Size and Water Content: Western Margin of Clarion-Clipperton Fracture Zone, NE Equatorial Pacific

Grain size and water content in box-core sediments from the Clarion-Clipperton fracture zone (C-C zone) in the northeast equatorial Pacific were analyzed in detail to understand the downcore variations across a hiatus between Quaternary and Tertiary layers. Grain-size distributions in the topmost core sediments show two modes: a coarse mode (peaked at 50 μm) and a fine mode (at 2-25 μm). The coarse mode disappears gradually with depth accompanied by the dissolution of siliceous fossil tests, whereas the fine mode coarsens due to the formation of authigenic minerals. Water content increases abruptly across a color boundary between an upper pale brown layer and a lower dark brown layer that is the hiatus between Quaternary and Tertiary layers. Abundant smectites and microvoid molds, which are created by the prolonged fossil dissolution in the underlying sediment, are attributed for the abrupt downcore variation of water content. Overall variations in grain size and water content in the topmost core sediments in the western C-C zone are possibly constrained by the dissolution of biogenic siliceous fossils. Variations in geotechnical properties related to these changes must be considered in the design of nodule collectors.     

Sea Levels and Western Boundary Flow Near a Tectonic Zone in the Northern Pacific

This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake.