非线性效应对浅水水波变形的影响

本文采用波数矢量无旋和波能守恒方程建立了一个考虑非线性作用的浅水水波变形数值模型,模型中采用Ｂａｔｔｊｅｓ关系与波数矢量无旋,波能守恒方程一起来求解波浪在浅水中变形的波浪要素,在波能守恒方程中考虑了底摩擦的影响。利用本文提出的数值模型对一个斜坡浅滩水域波浪折射绕射现象进行了验证,验证计算中用一个非线性经验弥散关系近似浅水水波变形的非线性效应并与用线性弥散关系的计算结果进行了比较,结果说明使用非线性     

A Modified Form of Mild-Slope Equation with Weakly Nonlinear Effect

Nonlinear effect is of importance to waves propagating from deep water to shallow water.Thenon-linearity of waves is widely discussed due to its high precision in application.But there are still someproblems in dealing with the nonlinear waves in practice.In this paper,a modified form of mild-slope equa-tion with weakly nonlinear effect is derived by use of the nonlinear dispersion relation and the steady mild-slope equation containing energy dissipation.The modified form of mild-slope equation is convenient to solvenonlinear effect of waves.The model is tested against the laboratory measurement for the case of a submergedelliptical shoal on a slope beach given by Berkhoff et al,The present numerical results are also comparedwith those obtained through linear wave theory.Better agreement is obtained as the modified mild-slope e-quation is employed.And the modified mild-slope equation can reasonably simulate the weakly nonlinear ef-fect of wave propagation from deep water to coast.     

滤食性贝类在对虾综合养殖生态系统中的作用

就混养虾池中滤食性贝类如何影响虾池整个生态系统这个问题，综合了国内外这方面的文献，从滤食性贝类对混养虾池的水质、底质和其中的浮游植物、浮游动物的影响，以及混养对养殖效益的影响这几个方面作了探讨。     

蒽胁迫对2种海洋微藻的毒性效应

采用水生毒理学方法以及通过分析蒽对 2种海洋微藻的几种生理生化指标的影响 ,初步研究了蒽胁迫对 2种海洋微藻的毒性效应。结果表明 :随着蒽浓度的不断增大 ,1 2种海洋微藻的相对增长率逐渐降低 ,叶绿素 a和类胡萝卜素含量稍有下降 ,蒽对小新月菱形藻生长的 72 h· EC50为 2 51μg· L-1 ,蒽对亚心形扁藻生长的 72 h· EC50 为 387μg· L-1 ;2还原型谷胱甘肽 (GSH)含量逐渐降低 ;3加入外源性抗氧化剂 (GSH和甘露醇 )可缓解蒽胁迫所造成的 2种海洋微藻的细胞密度的降低 ,即可缓解蒽胁迫对微藻的毒害作用     

考虑发电机尾流作用的潮流能理论可开发量的评估

In this study, we construct one 2–dimensional tidal simulation, using an unstructured Finite Volume Coastal Ocean Model(FVCOM). In the 2–D model, we simulated the tidal turbines through adding additional bottom drag in the element where the tidal turbines reside. The additional bottom drag was calculated from the relationship of the bottom friction dissipation and the rated rotor efficiency of the tidal energy turbine. This study analyzed the effect of the tidal energy turbine to the hydrodynamic environment, and calculated the amount of the extractable tidal energy resource at the Guishan Hangmen Channel, considering the rotor wake effect.     

Direct CPT and CPTu methods for determining bearing capacity of helical piles

Helical piles are structural deep foundation elements, which can be categorized as torque-driven piles without any limitations to implement in marine situations. Different methods are used to predict the axial capacity of helical piles, such as static analysis, but have some limitation for this type of piles on marine conditions. In situ testing methods as supplement of static analysis have been rarely used for helical piles. In geotechnical engineering practice, the most common in situ tests particularly applicable for coastal or offshore site investigation are cone penetration test (CPT) and piezocone penetration test (CPTu). The CPT is simple, repeatable, and prepares the continuous records of soil layers. In this paper, a data bank has been compiled by collecting the results of static pile load tests on thirty-seven helical piles in ten different sites including CPT or CPTu data. Axial capacities of thirty-seven helical piles in different sites were predicted by direct CPT methods and static analysis. Accuracy estimation of ten direct CPT methods to predict the axial capacity of helical piles was investigated in this study. Comparisons have been made among predicted values and measured capacity from the pile load tests. Results indicated that the recently developed methods such as NGI-05 (2005), ICP-05 (2005), and UWA-05 (2005) predicted axial capacity of helical piles more accurately than the other methods such as Meyerhof (1983), Schmertmann (1978), Dutch (1979), LCPC (1982), or Unicone (1997). However, more investigations are required to establish better correlation between CPT data and axial capacity of helical piles.     

利用AMSR-E对台风"泰利"的初步分析

基于洋面上的微波辐射传输模型,采用多元线性回归算法,建立了海洋-大气参数的反演算式,并对其进行了验证。在此基础上,根据AMSR-E的反演结果,对台风“泰利”的发生发展过程进行了初步分析。结果表明,反演算式的精度接近于网上公布的业务产品,反演结果比较符合实际情况;但是由于受到所采用物理模型的限制,反演结果对于强降水区不敏感。     

长江河口横沙东滩自然演变及工程影响

横沙东滩(含横沙浅滩)是长江河口主要浅滩之一,在浅滩两侧(北港和北槽主槽)水流控制下,受浅滩横比降形成的过滩水流和较强的风浪作用影响,滩面长期以来少有淤涨。通过对1995～2002年的地形资料(吴淞基面)进行研究分析表明:从总体上看随着北港主槽向南岸进逼,造成横沙东滩窜沟西部到白条子沙之间的滩区北沿明显内凹;随着长江口深水航道治理双导堤工程的实施,在北导堤产生的堵汊、导流和拦沙的作用下,白条子沙至横沙东滩沟滩面出现微淤;而横沙东滩窜沟以东滩面难以淤高。采用促淤工程和就近吹泥上滩方式,增加横沙东滩的滩面高程以加快造地,从而达到既疏浚航道又增加湿地面积的双赢效果。     

螺旋藻多糖对小鼠S-180肉瘤的免疫抑制作用

研究了螺旋藻多糖对小鼠S-180肉瘤的抑制作用。结果显示：螺旋藻多糖在50—200μg／g的剂量范围对小鼠S-180肉瘤均有一定的抑制作用，具有明显升高小鼠外周血白细胞的功能，促进荷瘤小鼠脾淋巴细胞转化作用，并有较好的剂量—效应关系，促进荷瘤小鼠脾NK细胞对靶细胞的细胞毒作用。提示螺旋藻多糖可通过全面调节机体的免疫功能，刺激T细胞、NK细胞等功能来达到控制和杀灭肿瘤细胞的目的。     

长江河口潮波传播机制及阈值效应分析

河口潮波传播过程受沿程地形(如河宽辐聚、水深变化)及上游径流等诸多因素影响,时空变化复杂。径潮动力非线性相互作用研究有利于揭示河口潮波传播的动力学机制,对河口区水资源高效开发利用具有重要指导意义。本文基于2007—2009年长江河口沿程天生港、江阴、镇江、南京、马鞍山、芜湖的逐日高、低潮位数据及大通站日均流量数据,统计分析不同河段潮波衰减率与余水位坡度随流量的变化特征,结果表明潮波衰减率绝对值与余水位坡度随流量增大并不是单调递增,而是存在一个阈值流量和区域,对应潮波衰减效应的极大值。为揭示这一阈值现象,采用一维水动力解析模型对研究河段的潮波传播过程进行模拟。结果表明,潮波传播的阈值现象主要是由于洪季上游回水作用随流量加强,余水位及水深增大,导致河口辐聚程度减小,而余水位坡度为适应河口形状变化亦有所减小,从而形成相对应的阈值流量和区域。