悬浮沙激光散斑图像处理的研究     

杜军兰  陈靖齐  于连生  刘海坤  徐雷 《海洋技术学报》2001,20(1):107-111

本文以统计模式识别为基础，阐述了图像处理在悬浮沙粒粒径流量中的实际应用，提出了用图像层析来确定放大系数的方法，提出了测量的准确度。  相似文献   

海水中液-固界面的台阶型动力学曲线 Ⅰ.动力学曲线之台阶的消长和变化规律          下载免费PDF全文

刘莲生  张正斌  蔡卫君  潘纲  杜恒清 《海洋与湖沼》1993,(2)

对海水中Zn(Ⅱ),Ca(Ⅱ),Cd(Ⅱ)与高岭石、伊利石和蒙脱石等粘土矿物;无定形水合氧化铁、α-FeOOH等铁的水合氧化物;δ-MaO_2,γ-MnOOH,水锰矿等锰的水合氧化物等30个左右实验体系的液-固界面台阶型动力学曲线进行了系统的实验测定和全面的条件研究。在实验测定上提出两种方法、互为校核。对动力学曲线之台阶的消长和变化规律作了系统研究,确定主要影响因素是:金属离子初始浓度、固体交换剂量、体系的pH值和温度,以及搅拌速度等。  相似文献   

Geochemistry of trace elements and Sr-Nd isotopes of foraminifera shell from the Okinawa Trough   总被引：1，自引：0，他引：1  

Meng Xianwei  Du Dewen  Cheng Zhenbo 《海洋学报(英文版)》2001,20(1):95-103

ＩＮＴＲＯＤＵＣＴＩＯＮＰｒｏｖｅｎａｎｃｅｏｆｍａｒｉｎｅｓｅｄｉｍｅｎｔｓｈａｓａｌｗａｙｓｂｅｅｎａｆｏｃｕｓｅｄｐｒｏｂｌｅｍｉｎｍａｒｉｎｅｓｅｄｉｍｅｎｔｇｅ ｏｌｏｇｙ.Ｒｅｃｏｇｎｉｔｉｏｎｏｆｅｎｄｍｅｍｂｅｒｓａｎｄｅｓｔｉｍａｔｉｏｎｏｆｔｈｅｉｒｒｅｌａｔｉｖｅｐｒｏｐｏｒｔｉｏｎｓｆｒｏｍｍｉｘｅｄｓｅｄｉｍｅｎｔｓｈａｖｅｂｅｅｎａｋｅｙｃｏｎｔｅｎｔｉｎｔｈｅｓｔｕｄｙｏｆｐｒｏｖｅｎａｎｃｅ .Ｆｏｒｔｈｉｓａｉｍ ,ｉｔｉｓｎｅｃｅｓｓａｒｙｔｏｓｅｌｅｃｔｅｎｄｍｅ…  相似文献   

Short-Term Benthic Recolonization after Dredging in the Harbour of Ceuta, North Africa   总被引：2，自引：0，他引：2  

José M. Guerra-García  Juan Corzo  & J. Carlos García-Gómez 《Marine Ecology》2003,24(3):217-229

Abstract. The benthic recovery after dredging (area: 2625 m²) was studied in a polluted and enclosed area of the harbour of Ceuta, in which the recolonization through the water column (larvae and adult bedload transport) could be limited by the lack of renewal. The benthos was sampled at two sites (control and dredged) using a van Veen grab and adopting a BACI (Before, After, Control, Impacted) approach. Five samplings were conducted after dredging (3, 15, 30, 90, 180 days). The proportion of gravel in the sediment of the dredged site increased after dredging, while the organic matter decreased. The impact on the community was estimated at species level, using both univariate and multivariate analyses. The maximum negative effect on benthic macrofauna was a reduction by 65% for species richness (15 days after dredging) and by 75% for abundance (3 days after dredging). Between 15 and 30 days after dredging, the abundance of some species such as the molluscs Parvicardium exiguum and Retusa obtusa and the polychaete Pseudomalacoceros tridentata increased considerably in the dredged site, while typical ‘opportunistic’ species such as Capitella capitata were disfavoured by the disturbance. For this small‐scale dredging, about 6 months are required for the disturbed area to re‐establish a sediment structure and a macrobenthic community similar to the undisturbed area. Small‐patch dredging operations are proposed in harbour management whenever possible, since they allow a quick re‐adjustment of the initial sediment structure and benthic communities.  相似文献   

Gas hydrate disturbance fabrics of southern Hydrate Ridge sediments (ODP Leg 204): Relationship with texture and physical properties   总被引：1，自引：0，他引：1  

Elena Piñero  Eulàlia Gràcia  Francisca Martínez-Ruiz  Juan Cruz Larrasoaña  Alexis Vizcaino  Gemma Ercilla 《Geo-Marine Letters》2007,27(2-4):279-288

Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing sediments due to changes in pressure and temperature conditions. Therefore, the identification of soupy and mousse-like fabrics can be used as a proxy for the presence of gas hydrate in addition to other evidence, such as pore water freshening or anomalously cool temperature. We present here grain-size results, mineralogical composition and magnetic susceptibility data of soupy and mousse-like samples from the southern Hydrate Ridge (Cascadia accretionary complex) acquired during Leg 204 of the Ocean Drilling Program. In order to study the relationship between sedimentary texture and the presence of gas hydrates, we have compared these results with the main textural and compositional data available from the same area. Most of the disturbed analyzed samples from the summit and the western flank of southern Hydrate Ridge show a mean grain size coarser than the average mean grain size of the hemipelagic samples from the same area. The depositional features of the sediments are not recognised due to disturbance. However, their granulometric statistical parameters and distribution curves, and magnetic susceptibility logs indicate that they correspond to a turbidite facies. These results suggest that gas hydrates in the southern Hydrate Ridge could form preferentially in coarser grain-size layers that could act as conduits feeding gas from below the BSR. Two samples from the uppermost metres near the seafloor at the summit of the southern Hydrate Ridge show a finer mean grain-size value than the average of hemipelagic samples. They were located where the highest amount of gas hydrates was detected, suggesting that in this area the availability of methane gas was high enough to generate gas hydrates, even within low-permeability layers. The mineralogical composition of the soupy and mousse-like sediments does not show any specific characteristic with respect to the other samples from the southern Hydrate Ridge.  相似文献   

低硼氢氧化镁的制备及热分解动力学参数     

高荣杰  冯丽娟  杜敏  宁滨  梁丽 《中国海洋大学学报(自然科学版)》2002,32(5):789-794

本文以水合氯化镁、工业氨水为原料制备出了低硼含量的纯度 >99%的氢氧化镁和氧化镁。利用差热 -热重 (DTA- TG)、X-射线衍射 (XRD)、透射电子显微镜 (TEM)等手段 ,对氢氧化镁的热稳定性、相结构、表观状态以及脱水动力学参数进行了分析。结果为 :氢氧化镁以束状纤维和片状粉末共存 ,在 6 2 3K基本完成脱水反应生成氧化镁 ,其脱水反应的表观活化能 E为135 .4 k J· mol-1,指前因子 A为 5 .15× 10 10 ,反应级数 n为 1.10  相似文献   

河口变形效应与涌潮的形成     

杜勇 《中国海洋大学学报(自然科学版)》1989,(3)

作者采用非线性潮波方程,假定河口的宽度B(x)和深度h(x)是任意可微函数,导出了涌潮发生的条件,并讨论了各种变形情况下涌潮的形成。得出结论是,在涌潮形成过程中起决定作用的是浅水非线性效应,而河口变形效应则是起促进作用的。  相似文献   

南日岛周围海域浮游植物的分布   总被引：1，自引：0，他引：1  

杜庆红  冯季芳 《台湾海峡》1996,15(3):280-285

南日岛1990～1991年4个季度月共鉴定浮游植物200种（包括变种、变型），隶属5门64属，硅藻种类最多，其次是甲藻；暖水性种65种，广温性种120种，温带种15种；年平均数量为263．15×104个／m3，5月最多为869．61×104个／m3，8、10月及1月依次减少。主要优势种有细齿角利藻、奇异菱形藻、中肋骨条藻、佛氏海毛藻等。文章初步分析了浮游植物与环境因子的关系。  相似文献   

Distribution of dissolved species and suspended particulate copper in an intertidal ecosystem affected by copper mine tailings in Northern Chile   总被引：1，自引：0，他引：1  

Santiago Andrade  James Moffett  Juan A. Correa   《Marine Chemistry》2006,101(3-4):203-212

The coastline near Chañaral in Northern Chile is one of the most highly Cu-contaminated zones in the world due to discharges from mining activities for more than 60 years. The speciation of Cu has been studied to determine the importance of organic complexation in highly contaminated areas, and to assess the likely physiological impacts of Cu on marine organisms. Dissolved Cu concentrations of up to 500 nM were measured, completely saturating organic ligands and leading to free Cu²⁺ concentrations in excess of 10^− 8 M. These values are higher than those reported in any other marine environment, and because they occur over an extensive area, provide a unique opportunity to study the effects of Cu on marine ecosystems and to see how Cu behaves when its speciation is predominantly inorganic. We found strong gradients in free Cu²⁺ between Chañaral and adjacent areas with lower Cu, where speciation is dominated by organic complexation. There is also a significant increase in the partitioning of Cu onto suspended particles in the contaminated areas, consistent with previous studies that showed that organic ligands stabilize Cu in the dissolved phase, whilst “excess” Cu is rapidly scavenged. Those high dissolved Cu concentrations persist in spite of solid phase partitioning and advective processes along this open-ocean coastline, suggesting that Cu inputs into the system are still very large. Measurements were made using anodic stripping voltammetry with a thin mercury film coated with Nafion, which previous workers have shown can mitigate ambiguity in the data arising from inadvertent reduction of organic complexes. Our findings suggest that this is a useful methodology for contaminated systems.  相似文献   

两项新技术及其在海水苗种生产中的应用   总被引：4，自引：0，他引：4  

杜守恩 《海洋湖沼通报》1995,(3):59-62

本文介绍了两项新技术，用泡沫净化空气、海水和生物效应灯，及其在海水苗种生产中的应用。文中分别讨论了它们的原理、设计安装及使用效果。希望这两项新技术能够得到推广，以提高出苗率，增加海水苗种生产的经济效益。  相似文献