Potential acoustic discrimination within boreal fish assemblages     

Gauthier  Stephane; Horne  John K. 《ICES Journal of Marine Science》2004,61(5):836-845

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Strength Characteristics of the Cement-Stabilized Surface Layer in Dredged and Reclaimed Marine Clay, Korea     

Jung-Mann Yun  Young-Suk Song  Jae-Ho Lee  Tae-Hyung Kim 《Marine Georesources & Geotechnology》2006,24(1):29-45

A series of tests in both laboratory and field were performed to investigate the engineering and mechanical properties, especially flexural strength, of cement-stabilized soils. The strength of cement-stabilized soils mainly depends on water-to-cement ratio and curing temperature. The higher curing temperature and the longer curing time, the higher strength in cement-stabilized soils generates. The high ratio of water-to-cement results in lower strength. The compressive strength observed in the field is similar to the strength in the laboratory. Field tests on a cement-stabilized soil layer indicate that the strength is significantly affected by the thickness of the improved layer, which is directly related to the moment of inertia. In addition, the failure shape observed in a cement-stabilized layer in the field looks likes a bending failure type, because the flexural tensile strength, rather than the compressive strength, mainly dominates the failure of cement-stabilized layer. The flexural tensile strength is closely related to the moment of inertia. Therefore, the flexural tensile strength should be considered for determining the thickness and strength in improvement of soft clay.  相似文献   

烟单14号玉米产量构成模型及提高产量途径分析     

李淑霞  冯瑞龙  赵继业  刘绍棣  程绍义 《中国海洋大学学报(自然科学版)》1988,(Z2)

根据1984—1986年烟单14号玉米田间试验的大量数据,作者在引进弹性系数概念后,建立了烟单14号夏玉米产量的非线性模型: Q=Ay~α_1y~β_2y~γ_3e~ε通过对模型中弹性系数的统计分析,提出大面积烟单14号玉米不同产量水平增产的途径,低产水平区(<250公斤/亩),着重提高亩穗数:中产水平区(250—400公斤/亩),在一定亩穗数的基础上,着重提高穗粒数;高产水平区(>400公斤/亩),提高粒重对产量的增产效益较大。  相似文献   

The influence of ontogeny, physiology, and behaviour on the target strength of walleye pollock (Theragra chalcogramma)     

Horne  John K 《ICES Journal of Marine Science》2003,60(5):1063-1074

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Analysis of Wave Loads on A Semi-Submersible Platform   总被引：10，自引：0，他引：10  

QIAN  Kun 《中国海洋工程》2002,16(3):395-406

For the global and structural fatigue strength analysis of a semi-submersible platform, wave loads under design conditions are calculated by use of the three-dimensional boundary element method. Methods for calculating the forward-speed free-surface Green function are discussed and a computer program with this Green function is developed. According to the special rules, the wave loads under several typical design conditions of the platform are calculated. The maximum vertical bending moment, torsion moment and horizontal split force are determined from a series of contour maps of wave loads for the wave period of 5 to 18 seconds at a certain interval and the wave phase of 0°to 360°at a certain interval. The wave height is determined by the function of wave period with a given exceedance probability. The maximum wave loads under the combination of wave parameters are used as the input of hydrodynamic pressure in the three-dimensional finite element analysis process. The transfer functions of wave loads  相似文献   

Target Strength of encaged Atlantic redfish (Sebastes spp.)     

Gauthier  Stephane; Rose  George A. 《ICES Journal of Marine Science》2001,58(3):562-568

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Processing Multibeam Backscatter Data   总被引：1，自引：0，他引：1  

Qiu-hua Tang  Xing-hua Zhou  Zhong-chen Liu  De-wen DU 《Marine Geodesy》2005,28(3):251-258

A new highly precise source of data has recently become available using multibeam sonar systems in hydrography. Multibeam sonar systems can provide hydrographic quality depth data as well as high-resolution seafloor sonar images. We utilize the seafloor backscatter strength data of each beam from multibeam sonar and the automatic classification technology so that we can get the seafloor type identification maps. In this article, analyzing all kinds of error effects in backscatter strength, data are based on the relationship between backscatter strength and seafloor types. We emphasize particularly analyzing the influences of local bottom slope and near nadir reflection in backscatter strength data. We also give the correction algorithms and results of these two influent factors. After processing the raw backscatter strength data and correcting error effects, we can get processed backscatter strength data which reflect the features of seafloor types only. Applying the processed backscatter strength data and mosaicked seafloor sonar images, we engage in seafloor classification and geomorphy interpretation in future research.  相似文献   

Strength Sensitivity of Marine Ariake Clays     

Zhenshun Hong  Songyu Liu  Takehito Negami 《Marine Georesources & Geotechnology》2005,23(3):221-233

Natural Ariake clays are characterized by high sensitivity. In this study, the mechanism and the factors controlling undrained shear strengths of both undisturbed and remolded Ariake clays are discussed. A series of unconfined compressive tests were performed on undisturbed samples of natural Ariake clays. The remolded undrained shear strength is predicted using a quantitative expression derived from extensive data of remolded undrained shear strength for a number of soils compiled from resources in the literature. The sensitivity of natural Ariake clays derived from the ratio of half of unconfined compressive strength for undisturbed samples to remolded undrained shear strength is found to be affected by both natural water content and normalized water content that is defined as the ratio of natural water content to liquid limit. The smaller the natural water content, the higher the sensitivity is at the same normalized water content. At the same natural water content, the larger the normalized water content, the higher the sensitivity is.  相似文献   

基于剩余强度衰减的混凝土疲劳寿命估算方法   总被引：4，自引：0，他引：4  

朱劲松  宋玉普 《海洋工程》2003,21(3):78-82

从疲劳过程中材料静载强度不断退化的本质出发，提出一个混凝土剩余强度衰减模型，模型的参数可简单地由试验S—N曲线确定。将模型应用于复杂多级疲劳荷载作用下的混凝土剩余疲劳寿命估算时，可以得到令人满意的结果。  相似文献   

A Review of Studies on the Interaction Between Waves and Muddy Bottom     

Zhao Zidan Professor  Doctoral Supervisor  Tianjin University  Tianjin 《中国海洋工程》1992,(2)

This paper presents a brief review of the results on the interaction between waves and muddy bottom obtained during the last decade including the results obtained by the author at the Coastal Engineering Laboratory of Tianjin University.  相似文献