Fluctuations of peak energy and peak frequency of local wavelet energy spectrum for wind waves

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减少航道外波浪集聚对策研究

进港航道开挖引起波能重新分布 ,导致航道外近区域波能聚集 ,波高增大 ,从而影响防波堤稳定及港内泊稳条件。文章介绍了 Boussinesq方程的推导过程和发展过程 ,基于深水和缓变地形的色散关系 ,建立了波浪数学模型。该模型可用于研究深水和浅水地区波浪的浅水变形、折射、绕射和反射。并提出了减少波能聚集、降低堤前波高的多种措施。结合大窑湾港实际工程 ,经过多方面的数物模比选 ,利用数学模型优化出一种可行的喇叭口航道开挖方案并付诸实施 ,降低了防波堤的堤前波高 ,满足了预期的设计要求。     

Fully nonlinear numerical wave tank (NWT) simulations and wave run-up prediction around 3-D structures

A finite-difference scheme and a modified marker-and-cell (MAC) algorithm have been developed to investigate the interactions of fully nonlinear waves with two- or three-dimensional structures of arbitrary shape. The Navier–Stokes (NS) and continuity equations are solved in the computational domain and the boundary values are updated at each time step by the finite-difference time-marching scheme in the framework of a rectangular coordinate system. The fully nonlinear kinematic free-surface condition is implemented by the marker-density function (MDF) technique developed for two fluid layers.To demonstrate the capability and accuracy of the present method, the numerical simulation of backstep flows with free-surface, and the numerical tests of the MDF technique with limit functions are conducted. The 3D program was then applied to nonlinear wave interactions with conical gravity platforms of circular and octagonal cross-sections. The numerical prediction of maximum wave run-up on arctic structures is compared with the prediction of the Shore Protection Manual (SPM) method and those of linear and second-order diffraction analyses based on potential theory and boundary element method (BEM). Through this comparison, the effects of non-linearity and viscosity on wave loading and run-up are discussed.     

Seasonal Changes in Soluble Carbohydrates, Starch, and Energy Content in Mediterranean Seagrasses

Abstract. In all scagrass species investigated, rhizomes were the main storage organs for soluble carbohydrate reserves, and the highest levels were found in Cymodocea nodosa (U cria ) A scherson . Sucrose was the primary soluble carbohydrate identified in Posidonia oceanica (L.) D elile , and Zostera noltii H ornem . This disaccharide was dominant in Cymodocea nodosa roots, as well as in its rhizome in winter. Myo-inositol was the main cyclitol in Zostera noltii. In Cymodocea nodosa leaves 1-chiro-inositol was the main sugar component; it was also present to a lesser extent in the roots and rhizomes. The amounts of glucose and fructose were correlated with growth to a certain extent in all species. Higher amounts of starch were stored in the rhizomes of Posidonia oceanica and Zostera noltii. The energy content of Mediterranean scagrasses was significantly higher than in tropical species. No distinct seasonal trend in energy content could be observed.     

Study on the characteristics of the marine boundary layer in the Equatorial Pacific

ＳｔｕｄｙｏｎｔｈｅｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｔｈｅｍａｒｉｎｅｂｏｕｎｄａｒｙｌａｙｅｒｉｎｔｈｅＥｑｕａｔｏｒｉａｌＰａｃｉｆｉｃ￥ＺｈａｎｇＺｉｙｕａｎｄＺｈｏｕＭｉｎｇｙｕ（ＲｅｃｅｉｖｅｄＡｕｇｕｓｔ２１，１９９３；ａｃｃｅｐｔｅｄ...     

北黄海长山群岛海域沉积环境初步研究

本文在获取１９８９－１９９３年黄海北部长山群岛海域沉积物大量数据基础上，借助沉积物粒度分析（Ｑ型），揭示出该海域具有在“岛屿效应”影响下的４种环境能量类型，分析了与其适应的环岛沉积环境及其分布特征。     

“暖池”表层对大气局地强迫的响应特征

利用湍流动能垂直混合模式和ＴＯＧＡ－ＣＯＡＲＥ加强观测期的观测资料,对“暖池”上混合层的垂直混合过程进行数值试验和数值模拟,分析表层温度、盐度的变化特征。结果表明：ＴＫＥ模式可以较好地模拟混层,尤其是表层温度、盐度对大气局地强迫的响应;太阳辐射是热源,感热、潜热通量等会造成“暖池”上混合层的温度降低,“暖池”对大气释放热量;降水有利于“淡水盖”形成和维持,从则使层结稳定,ＳＳＴ升高。但在气温低于海     

Harmonic generation past a submerged porous step

Experiments were conducted in a wave flume to study the differences between harmonic evolution of monochromatic waves as they propagate over a submerged impermeable or porous step under non-breaking conditions. Results are used as a preliminary analysis to establish some engineering design criteria on harmonic generation on submerged porous structures. The root-mean-squared wave height evolution is also studied and compared to linear models as a first approximation. It is shown that porous structure increases the effective relative depth and decreases the relative wave height, resulting in a lower Ursell number and a lower chance to generate harmonics. The effective water depth over a step as defined in the paper, provides information to evaluate the potential harmonic generation.     

近海污损生物的调查方法

近海海区污损生物调查有浮标挂板法和海上设施（浮标及其锚碇系统，Ｍａｒｅｘ水文浮标，移动式钻井平台和固定式生产平台）采样法。由于近海海区污损生物调查工作的特殊性和艰难性，笔者提出了利用已有的海上设施，尤其是固定式平台来积累近海污损生物资料，以便进行生态学研究。