Calculating Method and Verification of Wave Pressure Distribution on the Breast Wall of Mound Breakwater

In this paper, the calculating charts and formulae about wave pressure on the breast wall are derived with seven parameters on the basis of physical model study. The verification shows that the charts agree with the example, and are adopted in the Specifications of Fishery Harbours Breakwater by the Ministry of Agricultures.     

Elasto-Plastic Analysis of Tubular Joints of Offshore Platforms by Finite Element Method

The plastic node method is reformulated by the variational principle and is applied to elasto-plastic finite element analysis of tubular joints, eventually including the effect of internal and external gussets, stiffener rings, etc., if necessary. Four different joints are studied here in detail for the elasto-plastic behavior, the strain at the hot spot, the strain concentration factor around the intersection line, and the propagation of the plastic region with loading up to collapse in order to determine the ultimate strength, safety factor, and development of the plastic field. The present results are in good agreement with the experimental results.     

三传感器波浪水槽二次反射主动吸收方法

三传感器波浪水槽二次反射主动吸收方法是加拿大科学院水力中心最近开发的一种水槽反射波控制技术。该法在造波板前 1～ 2倍波长处布置 3个传感器 ,通过入反射波分离方法得到准确的入反射波参数 ,以此调整造波信号 ,有效地吸收由建筑物反射回到造波板的二次反射波。文中在分析波浪水槽二次反射吸收方法研究现状的基础上 ,介绍了加拿大水力中心对现有方法的改进及其效果     

唐山市滨海湿地动态演变特征及其机制分析

利用历史资料和Landsat TM卫星遥感图像,研究了唐山市滨海湿地自建国以来的演变特征,着重对1987~2004年陡河———滦河之间的滨海平原湿地类型进行了识别,绘制了不同时期的景观面解译图。利用Mapinfo制图软件计算出两个时期的面积(比例)转化矩阵,显示该区滨海湿地破碎化加重,其动态演变特征呈明显退化趋势,进而提出引起其退化的原因和发展趋势预测。     

Depth- and current-induced effects on wave propagation into the Altamaha River Estuary, Georgia

A study of sea surface wave propagation and its energy deformation was carried out using field observations and numerical experiments over a region spanning the midshelf of the South Atlantic Bight (SAB) to the Altamaha River Estuary, GA. Wave heights on the shelf region correlate with the wind observations and directional observations show that most of the wave energy is incident from the easterly direction. Comparing midshelf and inner shelf wave heights during a time when there was no wind and hence no wave development led to an estimation of wave energy dissipation due to bottom friction with corresponding wave dissipation factor of 0.07 for the gently sloping continental shelf of the SAB. After interacting with the shoaling region of the Altamaha River, the wave energy within the estuary becomes periodic in time showing wave energy during flood to high water phase of the tide and very little wave energy during ebb to low water. This periodic modulation inside the estuary is a direct result of enhanced depth and current-induced wave breaking that occurs at the ebb shoaling region surrounding the Altamaha River mouth at longitude 81.23°W. Modelling results with STWAVE showed that depth-induced wave breaking is more important during the low water phase of the tide than current-induced wave breaking during the ebb phase of the tide. During the flood to high water phase of the tide, wave energy propagates into the estuary. Measurements of the significant wave height within the estuary showed a maximum wave height difference of 0.4 m between the slack high water (SHW) and slack low water (SLW). In this shallow environment these wave–current interactions lead to an apparent bottom roughness that is increased from typical hydraulic roughness values, leading to an enhanced bottom friction coefficient.     

Sediment Transport in Rivers and Coastal Waters

Following Bagnold's approach, a relationship between sediment transport and energy dissipation is developed. The major assumption made in the study is that the near bed velocity plays a dominant role in the process of sediment transport. A general relationship between energy dissipation and sediment transport is first proposed. Then the equations for total sediment transport are derived by introducing the appropriate expression of energy dissipation rate under different conditions, such as open channel flows, combination of wave and current, as well as longshore sediment transport. Within the flows investigated, the derived relationships are fairly consistent with the available data over a wide range of conditions.     

口服免疫药物后中国对虾某些血淋巴因子的测定及方法研究

于１９９１年４－９月，以海捕中国对虾亲虾及养殖中国对虾为材料，运用单向免疫扩散（ＳＲＩＤ）方法测定对虾血淋巴免疫因子，并采用经改进后的Ｈｏｒｏｗｉｔｚ等人的方法测定对虾体内的酚氧化酶（ＰＯ）活性，目的在于运用该两种方法对口服不同免疫药物的养殖对虾的血淋巴免疫因子及ＰＯ活力进行测定。对亲虾和养殖对虾口服不同免疫药物前后的测定结果表明，几种情况下的对虾血淋巴中均存在类似ＩｇＭ的因子，血细胞中存在酚氧化     

大窑湾疏浚物倾倒区环境调查研究

本文以1989年8月调查资料为基础,论述了大窑湾疏浚物倾倒区的水化学要素(pH、盐度、DO、COD、浊度)、营养盐(NO_2-N、NO_3-N、NH_4-N、PO_4-P、SiO_3-Si)和重金属(Cu、Zn、Pb、Cd)等污染物分布特征;分析了水质、底质的环境状况及潮流的影响。从环境地球化学观点探讨了该疏浚物倾倒区选择的科学性。     

近海工程环境应用中各种风资料的平均时间分析

本文从近海工程设计应用的需要出发，对于通常使用的不同来源的测风资料平均时间进行了分析，这些资料来源包括：岸边及近海探查与生产设施上的气象台站、天气观测船、浮标、商船气象报、从受灾情况估计出的极大风速以及动力诊断模型估计出的海面风速。     

耿贝尔逻辑模型在极值风速和有效波高联合概率分布中的应用

首先介绍了耿贝尔逻辑模型，采用该模型对南海海域的涠州岛海洋站的风速和有效波高实测数据进行了分析，结果表明耿贝尔逻辑模型较好地描述了年极值风速和有效波高两随机变量的联合分布；采用得到的极值风浪联合概率分布推算了不同重现期的极值风速和波高，表明考虑风速和波高相关性对设计荷载的确定有显著影响。由于耿贝尔逻辑模型具有函数结构简单，参数估计方便，因此有望成为极值风速和波高联合分布的较理想概率模型。