黑潮锋区的水温分形特征研究

借助GIS ArcView软件分析提取黑潮锋区域,将一定间隔的经纬度点的温度值生成等值线以此为研究对象,应用网格法计算了20°～30°N,120°～130°E范围内黑潮锋区50m和100m深处水温的分维值,100m深处的分维值波动较50m深处小,但整体上分维值较50m深处大。计算结果符合黑潮锋区强度的实际分布情况,初步认为分形维数能够表征黑潮锋强度,分维值随黑潮锋强度的增大而增大。     

哈尔滨市大地水准面精化的思路

详细介绍了哈尔滨市大地水准面精化所采用的基础资料、精化思路以及精度检验方法.     

DZJ2激光垂准仪使用方法及指标的校正

介绍了DZJ2激光垂准仪的性能及基本指标的校正方法,为用户在使用DZJ2激光垂准仪过程中几种基本指标参数的校正提供参考.     

基于苏一光RTS 600全站仪倾斜观测的方法

介绍在工业厂房倾斜观测中运用全站仪观测柱倾斜观测的详细步骤和实现方法,工作实践表明可简化外业工作,提高工作效率。     

测绘成果保密管理工作的途径与思考

测绘科技不断发展、创新,测绘成果越来越丰富、实用和多样化,随着多种数字产品的完成,作为基底支撑和保障的基础地理信息不断应用于各管理系统之中,不仅为政府、行业提供各种服务,而且为社会公众提供直接服务。由于测绘成果绝大部分属于国家秘密,每年大量提供用户使用,保密工作关乎国家的安全和利益,如何做好保密工作,是我们各级管理部门不断适应新形势所必须着力解决的新课题。本文试图通过对测绘成果保密管理工作现状的分析与思考,以一管之见提出测绘保密管理工作的一些思路和途径。     

船只衰落尾迹的小波多尺度广义分形特征分析

船只衰落尾迹遥感图像是弱反差纹理图像,检测强尾迹的方法不具有适用性.基于区域特征统计比较的思想,构建了一种会聚衰落尾迹异常的小波多尺度广义分形特征提取方法.该方法由小波多尺度分解、细节图像融合、多尺度基本特征计算、多尺度分形特征计算和广义分形特征计算等5步骤组成.仿真实验表明,该特征能完整表达尾迹并体现强弱差别,是一种有效的船只衰落尾迹检测技术,具有广泛的应用前景.     

Sediment texture and grain-size implications: the Changjiang subaqueous delta

Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In addition, the environmental sensitive populations of grain size have been extracted. The sediment cores can be divided into two parts, according to the sedimentary structures present. The upper part (0-12 cm) is interpreted as being the active layer, which is influenced frequently by changes i...     

The mapping methods and division of tectonic units of the regional tectonic map in the eastern China seas and adjacent regions

The geological-geophysical map series of the eastern China seas and adjacent region (1:1 000 000) will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The Mapping methods, the division method of geological tectonic units and the main geological tectonic units are mainly discussed. The strata from Pliocene to Holocene are peeled off so as to display the Pre-Pliocene structures. In basins, isopaches are drawn for the Cenozoic deposits. The plate tectonic theory and present tectonic pattern are adopted as the priorities in tectonic division. As to the division of intraplate tectonic units, it is a revision, complement and improvement of previous dividing systems, and the nomenclature for each tectonic unit follows the current system in China. The first-order tectonic unit is plate (Pacific Plate, Eurasian Plate and Philippine Sea Plate). The second-order tectonic unit is tectonic domain (East Asian continental tectonic domain,East Asian continental margin tectonic domain and west Pacific tectonic domain). The Philippine Sea Plate and the west part of the Pacific Plate are called the West Pacific tectonic domain. The part of the Eurasian Plate involved in this study area can be further divided into East Asian continental tectonic domain and East Asian continental margin tectonic domain. The East Asian continental margin domain is composed of the Ryukyu island arc, the Okinawa Trough back-arc basin and the back-arc basin of Sea of Japan. The East Asian continental tectonic domain in this study area is composed of the Sino-Korea Massif, the Changjiang River (Yangtze) Massif and South China Massif. In turn, these massifs consist of basins, folded belts or uplift zones. The basins,the folded belts or the uplift zones are further divided into uplifts and depressions made up of sags and swells.     

A Global Reliability Assessment Method on Aging Offshore Platforms with Corrosion and Cracks

Corrosion and fatigue cracks are major threats to the structural integrity of aging offshore platforms. For the rational estimation of the safety levels of aging platforms, a global reliability assessment approach for aging offshore platforms with corrosion and fatigue cracks is presented in this paper. The base shear capacity is taken as the global ultimate strength of the offshore platforms. It is modeled as a random process that decreases with time in the presence of corrosion and fatigue crack propagati...     

Numerical Prediction of Induced Pressure and Lift of the Planing Surfaces

This paper discusses the numerical prediction of the induced pressure and lift of the planing surfaces in a steady motion based on the potential flow solver as well as the spray drag by use of the practical method.The numerical method for computation of the induced pressure and lift is potential-based boundary element method.Special technique is identified to present upwash geometry and to determine the spray drag.Numerical results of a planing flat plate and planing craft model 4666 are presented.It is shown that the method is robust and efficient and the results agree well with the experimental measurements with various Froude humors.