Influence of processes of nonlinear transformations of waves in the coastal zone on the height of breaking waves

Using data from laboratory, field, and numerical experiments, we investigated regularities in changes in the relative limit height of breaking waves (the breaking index) from peculiarities of nonlinear wave transformations and type of wave breaking. It is shown that the value of the breaking index depends on the relative part of the wave energy in the frequency range of the second nonlinear harmonic. If this part is more than 35%, then the breaking index can be taken as a constant equal to 0.6. These waves are spilling breaking waves, asymmetric on the horizontal axis, and are almost symmetric on the vertical axis. If this part of the energy is less than 35%, then the breaking index increases with increasing energy in the frequency range of the second harmonic. These waves are plunging breaking waves, asymmetric on the vertical axis, and are almost symmetric on the horizontal axis. It is revealed that the breaking index depends on the asymmetry of waves on the vertical axis, determined by the phase shift between the first and second nonlinear harmonic (biphase). It is shown that the relation between the amplitudes of the second and first nonlinear harmonics for an Ursell number less than 1 corresponds to Stokes’ second-order wave theory. The empirical dependences of the breaking index on the parameters of nonlinear transformation of waves are proposed.     

Comparison of Drags on Fish Cages of Different Shapes

1 .Introduction Commercial fishfarming in net cages is becoming widespread around the world as an importantsource of food.In PRChina ,mostfishfarmingtakes placeincalmcoastal areas .Fishcages work wellat these sites becausethe environmental forces are usua…     

我国领海基线向陆一侧“内水”的涵义

我国的《领海及毗连区法》第2条规定:"领海基线向陆地一侧的水域为中华人民共和国的内水"。我国的《海域使用管理法》第2条规定:"本法所称内水,是指中华人民共和国领海基线向陆地一侧至海岸线的海域"。"两法"对"内水"的定义有水域和海域之分,因此容易引起解读上的分歧或执法上的模糊。分歧之一是,根据《海域使用管理法》,从领海基线向陆地一侧至海岸线部分,是否包括河口、海湾、滩涂等"内水";分歧之二是,根据《领海及毗连区法》,是否认定一部分"内水"即内海是由直线基线法所致。为什么"两法"对"内水"有水域和海域两种不同的定义?其一,"两法"针对的客体不同,《领海及毗连区法》针对的客体是国际或国外,该法的主体是国家主权;《海域使用管理法》针对的客体是国内海域,该法的主体是国内海域的使用管理。《联合国海洋法公约》(以下称《公约》)规定"领海基线向陆一面的水域构成国家‘内水’的一部分",那么另一部分"内水"就是正常基线向陆一侧的水域,包括江、河、海湾等,它完全置于国家领土主权之下。其二,用专业术语上的海岸线替代《海域使用管理法》中的海岸线会出现矛盾。专业术语上同指水陆分界线的有海岸线和"干出线"两种。前者是涨潮时离岸最近的线,后者是退潮时离岸最远的线,依据《公约》规定:"测算领海宽度的正常基线是沿海国官方承认的大比例尺海图所标明的沿岸低潮线,即退潮时海水离岸最远的那条线",所以低潮线更加符合《公约》和《海域使用管理法》中海岸线的定义,怎样理解海岸线才不会出现矛盾呢?本文认为,完全意义上的海岸线是大潮高潮线与低潮线之间的一条带状面,这个面有时被水淹没,有时出露,且宽窄不等,陡缓不一。当解读了《公约》的有关条款后,就不难理解领海基线向陆地一侧至海岸线的水域中有盐度为0.05~30和30~36范围的"内水"存在,盐度范围为0.05~30的"内水"是指按正常基线法划定领海基线而出现的"内水",包括水域和海域;盐度范围为30~36的"内水"是指按正常基线与按直线基线法划定的领海基线之间出现的"内水",即内海。它们在法律层面上有主从之分,不能混淆。     

浅析我国海上工程大气污染的监测与监管现状

目前我国对海洋污染的研究主要集中在海水污染和海洋固废污染等方面,对海上大气污染研究较少。相对于陆地企业造成的大气污染,海上油气田、港口、码头等海上工程产生的大气污染的关注程度较弱,相应的监测标准和监督监管措施缺失。文章通过对比陆地企业的大气污染监测与监管,指出我国海上工程大气污染在监测、监管等方面存在的不足,提出研究海上大气污染防治的重要性,对保护海洋环境,促进海洋生态环境改善具有重要意义。     

Effect of shallow and narrow water on added mass of cylinders with various cross-sectional shapes

The sway, heave and roll added masses of three uniform cylinders with semi-circular, rectangular and triangular cross-sectional shapes in shallow and narrow water are numerically analysed. The method is based on simulation of the potential flow induced by the cylinder's mode of motion. The effects of shallow and narrow water on added mass are analysed and presented. It is concluded that the shallow and narrow water effects on added mass depend on the different cross-section shapes of the cylinders. In particular, the water depth effect on sway added mass is stronger than that on heave added mass while the narrow water effect on sway is weaker than that on heave. The shallow water effect on added mass tends to weaken the narrow water effect. Lastly the effect of shallow and narrow water on added mass on a rectangular cylinder is the strongest while that on a triangular cylinder is the weakest.     

国外深水钢悬链线立管研究发展现状

介绍国外在新型深水立管系统--钢悬链线立管关键技术方面的研究发展现状,论述浮体一、二阶运动对钢悬链线立管疲劳寿命的影响、浮体升沉运动对钢悬链线立管触地点疲劳寿命的影响;钢悬链线立管与海底相互作用机制的实验研究及结果;钢悬链线立管涡致振动与疲劳的研究现状.并简要论述钢悬链线立管触地点问题的研究结论.     

Incidence of flexural gravitational waves on the line of contact of two floating ice plates of different thickness

We analyze the influence of a rift in an ice field on the propagation of flexural gravitational waves in a basin of finite constant depth. The ice cover is simulated by two floating semiinfinite elastic plates of different thickness. We studied the dependence of the amplitude coefficients of reflection and transmission of waves incident on the rift on the frequency of running waves, the thickness of ice on both sides of the rift, and the type of contact boundary conditions at the rift. Translated by Peter V. Malyshev and Dmitry, V. Malyshev     

Numerical simulation of oblique water entry of an asymmetrical wedge

The hydrodynamic problem of a two-dimensional asymmetrical wedge entering calm water obliquely at constant speed is analyzed based on the velocity potential theory. The gravity effect on the flow is ignored based on the assumption that the ratio of the entry speed to the acceleration due to gravity is much larger than the time scale of interest. The problem of this similarity flow is solved by a boundary element method together with an analytical solution for the jet based on the shallow water approximation. Various results are provided for the wave elevation, pressure distribution and force at different deadrise angles and at different oblique entry. The effects of asymmetry and horizontal speed on these results are investigated.     

Experimental evaluation of early patterns of colonisation of space on rocky shores and seawalls

The introduction of artificial structures in coastal areas can cause fragmentation and loss of natural habitats. Previous studies found that variation in colonisation of space at mid-shore levels could account for differences in mature assemblages between seawalls and vertical surfaces on adjacent rocky shores in Sydney Harbour (Australia). This study tests the model that the nature of the substratum is responsible for different patterns of early colonisation between vertical ledges of rocky shores and seawalls. According to this model, patterns in early colonisation would differ between cleared areas created on vertical surfaces on rocky shores and seawalls, but not between standard surfaces (panels) installed on each structure. Early colonisation of space differed between seawalls and rocky shores, regardless of the type of substratum (clearings versus panels). Differences in relative abundances between structures were evident on both types of substrata for some taxa, while they varied between substrata for others. No taxa, however, showed consistent differences between structures in only the clearings. In addition, the abundance of some taxa differed between panels on the different structures, suggesting that the effects of the substratum were modulated by factors operating differentially between rocky shores and seawalls.     

Contemporary state of the investigation of the influence of the discharge of rivers on the hydrologic structure of the Black Sea

We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic regime of the sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

波束角效应对航道测宽的影响

从回声测深原理出发,讨论了波束角效应对航道测宽的影响,并根据天津港的航道情况进行了计算,分析了在实际测量中,不同情况下波束角效应影响航道测宽的具体因素。     

长江冲淡水与邻近海域生态环境的关系

基于实测资料和已有的理论结果,我们首先讨论了不同季节长江淡水的路径,还涉及了长江冲淡水对生态环境,特别对生物赖以生存的有机盐分布的影响。     

Research of Influence of Aniline on the Growth of Ocean Algae

This article discusses the interaction of aniline and ocean algae based on the standard appraisal method of chemical medicine for algae toxicity. It is showed by experimental results that aniline has pretty toxic effects on algae. Suspended substances in water can offset some effects of aniline. It also discusses the dynamic constant of first order degradation reaction rate of algae on aniline from the point of view of chemical dynamics.     

Analysis of optical method of determining wave slopes from photographs of glitter zone

We analyze the optical method of determining wave slopes on the sea surface from measurements of the characteristics of the glitter zone on photographs. Two approaches to the implementing this are explored. Their merits and drawbacks are noted. Low-altitude (H = 5–20 m) photographs of the sea surface are used to acquire new diverse information on the fine structure of the glitter zone and its relation to the sea roughness. We present a number of new experimental data on the glitter features and structure that were omitted in the Cox-Munk method. The applicability range for this optical method is estimated.     

低分子量琼胶的抗氧化活性研究

采用化学发光法研究了低分子量琼胶清除羟基自由基(·OH)和超氧阴离子(O2·-)的活性。结果表明,4个组均有清除自由基的作用,其中A3的清除羟基自由基(·OH)的能力比阳性对照硫脲的效果好得多。S2-2,S2-3,S2-4,A3对超氧阴离子(O2·-)和羟基自由基的IC50值分别为:3.7,1.3,0.96,0.83g/L和1.94,1.28,0.85,0.26g/L。     

斜向不规则波对直墙作用的实验研究

通过长峰不规则波和方向波谱对直墙作用的实验研究 ,分别给出了每延米斜向不规则波波浪力与正向力之比 ,方向波谱波浪力与斜向长峰不规则波波浪力之间的关系 ,通过与规则波实验结果的比较给出了斜向规则波与不规则波波浪力之间的相对关系 ;并对斜向不规则波的反射系数与正向波时的变化作出了分析     

海鸟系列CTD数据预处理分析

介绍了海鸟系列温盐深测量仪(CTD)原始数据预处理的方法和步骤,解释各个过程中的原理,根据规范和工作实际对处理过程中存在的问题进行分析,提出解决方案,针对资料的标准化提出建议和意见。     

Spoiler自埋技术特点及其在杭州湾海底管道运行情况分析

海底管道阻流板(Spoiler)自沉埋技术是一种新型管道自埋技术,为深入了解其作用机制及其效果,本文通过分析安装有阻流板的杭州湾海底管道历年检测资料,结合管道附近海域海床、潮流动力特性,深入探讨了阻流板装置在实际工程中的运行效果,分析了其作用机制及其适用条件。研究发现安装阻流板装置的杭州湾海底管道在往复潮流作用下逐渐埋入海床,其埋入段长度由2005年的50%增加到2013年的80%以上,而且平均埋入深度超过2.6 m,自埋效果较好;而在管道路由与海流平行段或管道敷设于抗冲刷强海床上时,阻流板作用不能有效发挥,管道仍然呈现裸露状态。     

压力公式的修正及其在波浪荷载计算中的应用

计入前进速度流动与非定常流动之间的干扰,修正了切片法中计算压力的公式,从而建立了计算波浪荷载的方法,开发了相应的计算机程序。计算实例同国内外有关资料的比较表明结果吻合良好,为船舶与海洋结构物结构有限元分析程序提供了有效的前处理模块     

Study of Adsorption Isotherm Curves of Amino Acids on the Kaolinite

This paper studies the adsorption isotherm curves of four amino acids (glyucine,aspartic acid,glutamic acid and lysine)and the effects of existences of different concentrations of Cu(Ⅱ) on them.Both the adsorption isotherm of the amino acids on the kaolinite and that when the copper ion Cu(Ⅱ） exists belong to the Langmuir type.The slopes of these adsorption isotherm increase with the increasing concentrations of Cu(Ⅱ） added.It can be explained in terms of formation of the type(Ⅰ） ternary surface complexes in these systems.The regular pattern of the effects of copper ion Cu(Ⅱ) on the adsorption isotherm of amino acids on the kaolinite is identical with that of its effects on the exchange and adsorption percentage E(%)-pH on the kaolinite in the same system.