基于.Net框架的网络地理信息系统模型研究

网络地理信息系统(WebGIS)的开发方法众多,传统的WebGIS开发方法已不能满足目前的开发需要。在分析了传统的WebGIS开发方法的基础上,指出了.Net框架下开发WebGIS的优势,以此为基础阐述了一个适合．Net框架的WebGIS模型,并详析了实现该模型的相关技术。     

网络地理信息系统的关键技术及开发应用

网络地理信息系统（WebGIS)是GIS技术和互联网（Interner/Intraner)技术相结合的产物。本文论述了实现网络地理信息系统的关键技术，分析了CGI技术、Plug-in技术及ObjectWeb技术的发展，并给出了一个长江口历年海图查询的具体实例。可以按照年份、地域查询海图，并可以在客户机上实现一般的GIS所需的人机交互功能，如放大缩小移动剖面等。对本实例稍加扩充，可以实现发布任一点的水位变化、与陆图的无缝合成查询以及海域导航等多种实用功能，可以在各种开发项目中得到应用。     

海洋动力环境立体监测数据共享服务系统的设计及实现

以福建省海洋动力环境立体监测数据为例,在分析监测数据来源形成特点的基础上,基于分布式数据库、网络地理信息系统(WebGIS)等技术设计了一个海洋立体监测数据的共享服务系统,并详细介绍了共享服务系统采用的数据组织结构、总体框架、业务功能模块以及空间数据发布与服务的实现方法,最后给出典型应用例子的用户界面。     

基于ArcIMS的影像地图发布

介绍了应用ArcIMS地理信息系统和数据库管理技术,运用Java和XML开发工具,构建影像地图管理和信息发布平台,实现影像信息平台与WebGIS的有机结合,达到影像地图网络发布目的。     

用Java/XML实现WebGIS的问题探讨

Java与XML是两门目前最为流行的网络编程技术,Java语言功能强大,XML在数据转换与传输、内容的表达与搜索等方面有广泛的应用。所以,用Java和XML来实现WebGIS不失为一种理想的方案,并结合当前主要的WebGIS平台进行了论述。     

WebGIS技术在海洋地质领域中的应用

WebGIS是指利用World Wide Web向各种类型的用户提供地理空间信息服务的地理信息系统,是Internet与GIS结合的产物,通过向用户提供多样化的、直观易懂的图形用户界面,来动态地客户化地表现数据。在海洋地质领域中WebGIS主要应用于海洋地质图件的管理、发布以及海洋地质调查船的实时动态监控。随着全国海洋地质资源信息化的发展,WebGIS在海洋地质领域将拥有良好的应用前景。     

水声通信中的鲁棒图像编码研究

由于受各种因素的影响，水下声信道是一种传输差错率较高的信道。标准化的图像编码系统(例如JPEC；H．263，MPEG等)使用了相似的压缩技术，它们往往存在严重的错误扩散，甚至单个错误比特就可能破坏整幅图像，所以一般不适合作为水下声信道图像传输的编码方案。文章针对常用的图像编码的缺点，利用定长编码技术，提出了一种高鲁棒性的图像压缩方案。实验表明在压缩率1．25比特／象素时，压缩后的图像仍然保持了较好的质量，并且能够较好地抵抗信道误码，提高了水下声信道图像传输的质量。     

天津滨海新区风暴潮监测预报预警数据通讯网络设计与实现

首先概述了"天津滨海新区风暴潮监测预报预警技术与示范"项目的背景,然后介绍使用GPRS-APN数据传输网络和3G网络通讯技术实现测站观测数据和视频图像传输、控制功能,最后介绍了项目数据通讯网络的运行情况。     

WebGIS技术在海洋信息共享中的应用

开展海洋信息共享，是我国实现海洋可持续发展的重要基础。海洋基础地理信息以及与空间位置有关的海洋属性信息是海洋信息共享的重要内容，而WebGIS技术可以把这些地理信息及属性信息可以用矢量化图形的方式为社会各界提供网络GIS服务，把枯燥的海洋信息数据以生动直观的方式反映海洋各种现象以及属性。文章就海洋信息共享的海洋基础地理底图研制以及海洋信息WebGIS系统实现等关键技术展开讨论，探索实现海洋信息共享服务的技术路径以及WebGIS在海洋信息共享中的重要作用和发展前景。     

海洋地理信息系统

地理信息系统(GIS)是海岸带资源和环境综合管理的强有力的技术手段。但它应用于海洋必须在数据结构、系统组成、软件功能等方面进行一系列改造,使之适应海洋的特点。经改造而适用于海洋的GIS,被称之为海洋地理信息系统(MGIS)或海岸带地理信息系统(CGIS),它具有许多不同于常规GIS的特点。     

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.     

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.     

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,     

Evaluation of the Risk of Marine Slope Instability: A Pseudo-3D Approach for Application to Large Areas

This article presents a methodology developed to evaluate the instability of submarine slopes that extend over a large area. Special attention was paid to (1) the complex geometry (bathymetry) and the expanse of the slope, (2) the heterogeneity of the sediment, and (3) the distribution of the pore pressure. The safety factor was considered as a spatially varying quantity. The General Formulation (GLE, Fredlund and Krahn 1977), which fully satisfies equilibrium conditions, was used for evaluating the stability of the marine slope. The submarine slope failure, which occurred on 16 October 1979 during the construction of the new Nice airport, was studied in order to test the developed model. Geotechnical parameters were taken from experimental tests carried out by IFREMER on 19 cores extracted at different depths (from 27 m to 1300 m) (Cochonat, Bourillet, and Savoye, 1993; Mulder et al., 1994). Many scenarios were proposed in order to explain the cause of the Nice slope failure (Habib, 1994). In this article, two of those scenarios were tested. Simulation results are presented and discussed.