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991.
992.
F. G. ONeill 《Ocean Engineering》2003,30(16):2053-2063
A theoretical investigation is carried out of the mesh size measurement of an idealized fishing netting mesh. It is assumed that the bending moment of the netting twine is proportional to curvature and that there is no twine extension and no cross-sectional deformation of the twine. The corresponding momentum and force balance equations are analyzed. The measurement method our analysis most approximates is that of the ICES gauge. The effect on mesh measurement of twine bending stiffness, frictional resistance, boundary slope, gauge force and gauge thickness are all examined. 相似文献
993.
994.
Generalization is a comprehensive process. It is not simply a question of an algorithm, such as simplification, selection, displacement, and so on. Only after geometric shapes and topological properties have been understood fully, can a sound and automated generalization process be possible. This article proposes a new theoretical model for sounding generalization in digital nautical charts. First, with the aid of Delaunay triangulation, a tree structure is introduced for a hierarchical representation of the marine topography. Then, an analytical algorithm for the recognition and the measurement of the marine topography is developed through the use of the tree structure. Finally, all of the techniques mentioned above are integrated into a model for sounding generalization, of which results are illustrated with the aid of several examples. 相似文献
995.
Yoshiyuki Nakano Hideshi Kimoto Shuichi Watanabe Koh Harada Yutaka W. Watanabe 《Journal of Oceanography》2006,62(1):71-81
We have developed new systems capable of profiling to >1000 m for measuring in situ pH and fugacity of CO2 (fCO2) in the ocean using spectrophotometric analysis (pH and CO2 profilers). The in situ pH is determined by detecting the color change of the pH indicator (m-cresol purple). It can withstand ambient pressure to 1000 m depth. The CO2 profiler analyzed in situ fCO2 by detecting the change of pH in an inner solution, equilibrated with the seawater through a gas permeable membrane. It can
be operated to 2500 m depth. We used an amorphous fluoropolymer tubing form of AF-2400 for the gas permeable membrane due
to its high gas permeability coefficients. The inner solution was a mixture of 2 μM bromocresol purple (BCP) and 5 μM sodium
hydroxide. This system gave us a response time of 1 minute, which is twice as fast as previous systems. The precisions of
pH and CO2 profilers were within 0.002 and 2.5% respectively. We have used these profilers to study the North Pacific, obtaining good
agreement with the difference between the data from profilers and a discrete bottle of 0.002 ± 0.005 pH (SE, n = 25) and −0.4
± 3 μatm (SE, n = 31). 相似文献
996.
997.
998.
999.
CTD测量技术的现状与发展 总被引:2,自引:0,他引:2
CTD测量技术是海洋研究开发的关键技术之一。本文简述了CTD测量技术基本原理,介绍了国内外CTD技术的现状和动向,同时还探讨了CTD技术的发展趋势和关注的几点看法。 相似文献
1000.
要实现利用微波辐射计对海面溢油的厚度等参数进行遥感监测,必须先对水面油膜的微波辐射特性进行研究,以便为传感器的设计和遥感资料的解译提供依据。在实验室条件下,利用“灰体室”的环境条件及测量方法,测试了原油、燃料油和食用植物油膜的微波发射率与油膜厚度之间的关系,并对测量结果进行分析和讨论。为实际应用提供技术资料。 相似文献