Experimental investigation on a two-part underwater towed system     

Jiaming Wu  Allen T. Chwang 《Ocean Engineering》2001,28(6)

An experimental set-up is developed and proved to be effective for laboratory study of an underwater towed system. The experimental technique gives a practical method for monitoring the kinematic and dynamic performance of an underwater towed system in a ship towing tank. Both the theoretical and experimental results in the investigation indicate that the hydrodynamic response of a towed vehicle to the wave induced motion of a towing ship can be significantly reduced by applying a two-part tow method. A comparison of the numerical and experimental results in the investigation demonstrates that the numerical simulation results are close to the experimental data, overall agreement between experimental and theoretical results is satisfactory. The results qualitatively verify the mathematical model of a two-part underwater towed system proposed by Wu and Chwang [Wu, J., Chwang, A.T., 2000. A hydrodynamic model of a two-part underwater towed system. Ocean Engineering 27 (5), 455–472].  相似文献   

利玛原甲藻腹泻性毒素的生物学测定   总被引：1，自引：0，他引：1  

邱德全  林永水  周近明  熊仕林 《热带海洋学报》1996,(4)

１９９４年和１９９５年分季度从海南省三亚海区采集附生于褐藻上的利玛原甲藻Ｐｒｏｒｏｃｅｎｔｒｕｍｌｉｍａ（Ｅｈｒｅｎｂｅｒｇ）Ｄｏｄｇｅ，经丙酮提取。提取液用ｐＨ＝３的水除去麻痹性贝毒（ＰＳＰ），取残留液注入小白鼠（ＢａＢ／Ｃ纯系），有腹泻性贝毒（ＤｉａｒｒｈｅｔｉｃＳｈｅｌｌｆｉｓｈＰｏｉｓｏｎｉｎｇ即ＤＳＰ）中毒的症状出现。初步确定此种藻中提取的毒素为ＤＳＰ。  相似文献   

A moving PIV system for ship model test in a towing tank     

Jeng-Horng Chen  Che-Chun Chang 《Ocean Engineering》2006,33(14-15):2025-2046

A moving particle image velocimetry (PIV) system was successfully developed and used in a large towing tank for ship model tests to observe velocity fields near ship models. The experimental method involved adjustable optical devices for various test conditions and a special particle-seeding device. The streamwise and cross-streamwise flow fields of a yacht model and a tanker model were measured. Ship type, bottom shape, and towing speed were found to be the causes of problems affecting optical access and image quality. Possible solutions, deeper optical ducts, dark painting color, and pre-processed analysis method, were proposed and discussed.  相似文献   

An experimental study on non-linear progressive wave-induced dynamic stresses in seabed     

S.C. Chang  J.G. Lin  L.K. Chien  Y.F. Chiu   《Ocean Engineering》2007,34(17-18):2311-2329

In this study, the dynamic stresses within the seabed induced by non-linear progressive waves were explored through a series of hydraulic model tests on a movable bed within a wave flume. By comparing Stokes’ 2nd-order wave theory with the theory of wave-induced dynamic stresses within the seabed as proposed by Yamamoto et al. [1978. On the response of a poro-elastic bed to water waves. Journal of Fluid Mechanics 87 (1), 193–206.] and Hsu and Jeng [1994. Wane-induced soil response in an unsaturated anisotropic seabed of finite thickness. International Journal for Numerical and Analytical Methods in Geomechanics 18, 785–807], the experimental results show that the pressure on the seabed surface, the pore water pressure within the seabed as well as the vertical and the horizontal stresses are all smaller than their theoretical values. If we were to obtain the characteristics of seabed soil, the analytical solution of Hsu and Jeng [1994. Wane-induced soil response in an unsaturated anisotropic seabed of finite thickness. International Journal for Numerical and Analytical Methods in Geomechanics 18, 785–807] might agree to the simulation of the wave-induced effective stresses and shear stress in the sandy seabed. A different phase shift exists among all the three soil stresses. Their influences on the three dynamic stresses within seabed soil are important for seabed stability, and can be used in the verification of numerical models. In the whole, the non-linear progressive waves and the naturally deposited seabed are found to have a strong interaction, and the behavior of the induced dynamic stresses within the seabed is very complicated, and should be investigated integrally.  相似文献   

重金属锌,铅对菲律宾蛤仔的急性毒性试验   总被引：14，自引：1，他引：14  

刘琼玉  洪华生 《台湾海峡》1997,16(1):50-54

本文研究了必需元素Ｚｎ及非必需元素Ｐｂ对菲律宾蛤仔的急性毒性作用，得到Ｚｎ对其的４８ｈＬＤ５０和９６ｈＬＤ５０分别为１４７．９１、１６．４０ｍｇ／ｄｍ＾３；Ｐｂ对其的４８ｈＬＤ５０和９６ｈＬＤ５０分别为３１．６２、１４．２８ｍｇ／ｄｍ＾３。估算得到Ｚｎ、Ｐｂ对菲律宾蛤仔的安全浓度分别为０．８２、０．７１ｍｇ／ｄｍ＾３。  相似文献   

模型沙干重度的变化规律及其在泥沙模型试验中的作用     

韩玉芳  陈志昌 《海岸工程》2003,22(1):1-7

模型沙干重度在动床模型试验中是影响起动流速比尺和冲淤时间比尺的重要参数，其随淤积历时、粒径变化、埋置深浅和加工方法的不同有着不同的变化规律。通过试验，结合已有的成果，对模型沙干重度受以上几种因素的影响进行了研究，并进一步分析了其变化规律在动床模型试验中的作用。  相似文献   

Experimental Study on Stability of Breakwaters with Penetrating Box Foundations     

别社安  李伟  李增志  任增金  及春宁 《中国海洋工程》2003,17(1)

1 .ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｐｅｎｅｔｒａｔｉｎｇｂｕｃｋｅｔａｎｄｂｏｘｆｏｕｎｄａｔｉｏｎｉｓａｎｅｗｔｙｐｅｏｆｓｔｒｕｃｔｕｒｅ ,ｗｈｉｃｈｈａｓｂｅｅｎａｐｐｌｉｅｄｉｎｍａｎｙｅｎｇｉｎｅｅｒｉｎｇｆｉｅｌｄｓ .Ｉｎｖｉｅｗｏｆｔｈｅｈｉｇｈｃｏｎｓｔｒｕｃｔｉｏｎｃｏｓｔａｎｄｔｈｅｆｏｒｍｉｄａｂｌｅｃｏｎｓｔｒｕｃｔｉｂｉｌｉｔｙｏｆｏｆｆ ｓｈｏｒｅｐｌａｔｆｏｒｍｓｗｉｔｈｐｉｌｅｄｆｏｕｎｄａｔｉｏｎｓ ,Ｂａｅｒｈｅｉｍｅｔａｌ.(1 990 )ｐｒｏｐｏｓｅｄｔｈｅｃｏｎｃ…  相似文献   

An Experi mental Study on Wave-Induced Dynamic Stresses in Seabed     

S.C.Chang  L.K.Chien  J .G.Lin  Y.F.Chiu 《中国海洋工程》2006,20(1)

1 .IntroductionEvery year ,Taiwanis subjectedtotwo or three typhoonintrusions in average which always causedisasters . Most of the disasters which occur around the coastal zone are due to seabed instability andcoastal structure destruction caused bytyphoo…  相似文献   

水平井含水率上升影响因素   总被引：1，自引：1，他引：0  

凌宗发  王丽娟  李保柱  夏静  朱玉新 《现代地质》2008,22(1):86-90

利用塔里木油田塔中4油田(TZ4)底水油藏相关的地质、流体数据建立数值模型。在所建模型的基础上,应用数值模拟计算的累积产油、产水和产液量回归俞启泰水驱特征曲线,以反映水平井见水特征的参数b。以参数b为研究对象,采用正交试验的方法研究不同因素对b值的影响,筛选影响水平井见水特征的主要因素,认为原油粘度、油层厚度、非均质性及水平井水平段在油藏中的位置是影响水平井含水上升趋势的主要指标。最后建立主要因素与b值的关系式,结合俞启泰曲线b值图版,提出预测水平井见水规律的公式——图版法(F-b法)。应用F-b法对塔里木水平井含水率进行预测,并与其他相关方法及实际生产数据对比,认为F-b法可作为预测塔里木油田水平井含水率、估算可采储量的一种有效方法。  相似文献   

GPS接收机测试评估系统数据库的建立     

陈雷  孙付平  海靖 《测绘工程》2008,17(2):66-69

为评定GPS接收机的性能,建立的接收机测试评估系统在对接收机进行测试的过程中将涉及到大量的测试相关数据。为了对这些数据进行科学、安全的存储管理,文中通过分析数据的来源、数据的存储类型以及数据的相互关系等,在考虑了数据库运行的安全性和稳定性的基础上,详细地介绍了GPS接收机测试评估系统数据库的建立。  相似文献