东海原甲藻的分子鉴定

采用nrDNAITS序列及18S序列两种分子标记,对东海原甲藻和美国国家海洋藻种保藏中心(CCMP)的具齿原甲藻进行分子鉴定,结果表明,两者之间序列非常相似,两者的nrDNAITS序列碱基差异值仅为0.002,nrDNA18S序列的碱基差异值为0.000,根据分子数据,东海原甲藻和美国国家海洋藻种保藏中心的具齿原甲藻应为同一个种.从基因库获取原甲藻的另外3个种nrD-NAITS序列和8个种的18S序列,用计算机软件进行分析和构建分子系统树,结果显示18S序列用于原甲藻的分子鉴定过于保守,而nrDNAITS更适合于该种属界定的分子标准.     

利用消去刚度法进行剪切型系统物理参数识别

提出了 1种能够比较准确地识别剪切型体系的结构参数 (各层质量和层间刚度 )的方法———消去刚度法。该方法从剪切型结构体系的特征值问题出发 ,利用剪切型结构系统质量矩阵和刚度矩阵的特殊形式 ,通过消去各层的刚度系数 ,得到了结构系统的各层质量比表达式。在结构总质量已知的情况下 ,仅利用系统的任意两阶模态信息就可以确定出各层质量 ,并进而计算出层间刚度 ,实现了结构物理参数的递推识别。数值模拟结果表明 ,该方法识别精度较高 ,便于工程应用 ,可以用于类似结构体系的物理参数的初步估计。     

Experimental study of strong reflection of regular water waves over submerged breakwaters in tandem

A series of laboratory experiments was carried out to investigate the strong reflection of regular water waves over a train of submerged breakwaters. Rectangular and trapezoidal shapes of submerged breakwaters are employed and compared for reflecting capability of incident waves. Measured reflection coefficients of regular waves over impermeable submerged breakwaters are verified by comparing with those of the eigenfunction expansion method. A very good agreement is observed. Reflection coefficients of permeable submerged breakwaters are less than those of impermeable breakwaters. The trapezoidal shape is recommended for a submerged breakwater in terms of reflecting capability and practical application.     

Separation of Waves by Interpolation Method

1 .ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｍｅａｓｕｒｅｔｈｅｒｅｆｌｅｃｔｉｏｎｏｆｉｎｃｉｄｅｎｔｗａｖｅｓｐｒｏｄｕｃｅｄｂｙａｐｈｙｓｉｃａｌｍｏｄｅｌｉｎａｗａｖｅｆｌｕｍｅｉｓａｃｏｍｍｏｎｐｒｏｂｌｅｍｗｉｔｈｐｈｙｓｉｃａｌｔｅｓｔｓｏｆｗａｖｅａｃｔｉｏｎｏｎｃｏａｓｔａｌｓｔｒｕｃｔｕｒｅｓ .Ｗａｖｅｓｇｅｎｅｒａｔｅｄｂｙｔｈｅｗａｖｅ ｍａｋｅｒｐｒｏｐａｇａｔｅｆｏｒｗａｒｄｉｎｔｈｅｗａｖｅｆｌｕｍｅａｎｄａｒｅｒｅｆｌｅｃｔｅｄｂｙｔｈｅｐｈｙｓｉｃａｌｍｏｄｅｌ,ａｎｄｔｈｅ…     

Identification of Epinephelus malabaricus and Epinephelus coioides using DNA markers

1 IntroductionBothEpinephelus malabaricusandE. coioidesbelong to the genusEpinephelus(Perciformes: Ser-ranidae: Epinephelinae).They are warm water reeffishes that have similar distribution ranges as well assimilar morphological characteristics, which have…     

Wave interaction with a perforated wall breakwater with a submerged horizontal porous plate

This study examines the hydrodynamic performance of a new perforated-wall breakwater. The breakwater consists of a perforated front wall, a solid back wall and a submerged horizontal porous plate installed between them. The horizontal porous plate enhances the stability and wave-absorbing capacity of the structure. An analytical solution based on linear potential theory is developed for the interaction of water waves with the new proposed breakwater. According to the division of the structure, the whole fluid domain is divided into three sub-domains, and the velocity potential in each domain is obtained using the matched eigenfunction method. Then the reflection coefficient and the wave forces and moments on the perforated front wall and the submerged horizontal porous plate are calculated. The numerical results obtained for limiting cases are exactly the same as previous predictions for a perforated-wall breakwater with a submerged horizontal solid plate [Yip, T.L., Chwang, A.T., 2000. Perforated wall breakwater with internal horiontal plate. Journal of Engineering Mechanics ASCE 126 (5), 533–538] and a vertical wall with a submerged horizontal porous plate [Wu, J.H., Wan, Z.P., Fang, Y., 1998. Wave reflection by a vertical wall with a horizontal submerged porous plate. Ocean Engineering 25 (9), 767–779]. Numerical results show that with suitable geometric porosity of the front wall and horizontal plate, the reflection coefficient will be always rather small if the relative wave absorbing chamber width (distance between the front and back walls versus incident wavelength) exceeds a certain small value. In addition, the wave force and moment on the horizontal plate decrease significantly with the increase of the plate porosity.     

双层局部开孔板沉箱对波浪反射的理论研究

提出了一种用于研究由双层开孔板和一个不透水后板的开孔结构对斜向波反射率的理论分析方法。整个流域被分成三个子域，在每个子域内应用特征函数展开法以得到该域内包含未知展开系数的势函数的表达式，在速度势的展开中，考虑了非传播模态波浪的影响。通过匹配开孔板处的边界条件可以求解待定的展开系数，继而求解双层开孔板防波堤结构对斜向波的反射率。数值计算结果与试验结果进行了比较，符合较好。并进一步讨论了几个重要因素对反射系数的影响。     

分离入射波与反射波的解析方法

提出了一种新的分离入射波和反射波的解析方法（AM）。利用两点处的 波高信息，运用Hilbert变换得到波浪信号在复域内的解析表达式，不需要计算合成波高和相位差即可实现信号的分离。根据分离结果，可以精确地估计入射波与反射波的幅值以及反射系数等参数，能够获得入射波与反射波之间的相位信息，并且可方便地用于不规则波的分离。文中通过数值模拟与物理模型实验对AM法进行了检验，所得的结果与实际值非常吻合。     

Parameter identification of a compliant nonlinear SDOF system in random ocean waves by reverse MISO method

The determination of the drag and inertia coefficients, which enter into the wave force model given by Morison's equation, is particularly uncertain and difficult when a linear spectral model is used for ocean waves, and the structure is compliant and has nonlinear dynamic response. In this paper, a nonlinear System Identification method, called Reverse Multiple Inputs–Single Output (R–MISO) is applied to identify the hydrodynamic coefficients as well as the nonlinear stiffness parameter for a compliant single-degree-of-freedom system. Four different types of problems have been identified for use in various situations and the R–MISO has been applied to all of them. One of the problems requires iterative solution strategy to identify the parameters. The method has been found to be efficient in predicting the parameters with reasonable accuracy and has the potential for use in the laboratory experiments on compliant nonlinear offshore systems.     

Crustal Structures of the Northernmost South China Sea: Seismic Reflection and Gravity Modeling

The South China Sea (SCS) is a marginal sea off shore Southeast Asia. Based on magnetic study, oceanic crust has been suggested in the northernmost SCS. However, the crustal structure of the northernmost SCS was poorly known. To elaborate the crustal structures in the northernmost SCS and off southwest Taiwan, we have analyzed 20 multi-channel seismic profiles of the region. We have also performed gravity modeling to understand the Moho depth variation. The volcanic basement deepens southeastwards while the Moho depth shoals southeastwards. Except for the continental margin, the northernmost SCS can be divided into three tectonic regions: the disturbed and undisturbed oceanic crust (8–12 km thick) in the southwest, a trapped oceanic crust (8 km thick) between the Luzon-Ryukyu Transform Plate Boundary (LRTPB) and Formosa Canyon, and the area to the north of the Formosa Canyon which has the thickest sediments. Instead of faulting, the sediments across the LRTPB have only displayed differential subsidence offset of about 0.5–1 s in the northeast side, indicating that the LRTPB is no longer active. The gravity modeling has shown a relatively thin crust beneath the LRTPB, demonstrating the sheared zone character along the LRTPB. However, probably because of post-spreading volcanism, only the transtension-shearing phenomenon of volcanic basement in the northwest and southeast ends of the LRTPB can be observed. These two basement-fractured sites coincide with low gravity anomalies. Intensive erosion has prevailed over the whole channel of the Formosa Canyon.