Seasonal variability of the hydrologic-and-acoustic parameters on the Black Sea shelf off the South Crimea coast

Usingin situ temperature and salinity observations from the Marine Hydrophysical Institute's oceanographic data set, regularities of the formation of structure and seasonal variability of the calculated sound speed field, as well as elements of the latter's vertical stratification in the South Crimea shelf area, have been studied. The ray approximation is applied to consider the influence of seasonal variations of the vertical hydrologic-and-acoustic structure on the propagation of sound in the sea. Translated by Vladimir A. Puchkin.     

The delineation of dyanmical characteristics of circulations and their changes in the surface,subsurface, mid-depth and deep layers of the westernmost part of the North Pacific

Configurational structure of ocean circulation in the westernmost part of the North Pacific and its time-vayring processes are revealted through the combination of various means of measurements, that is, the measurements of cross-channel voltage, velocity profile, deep-water velocity, water characteristics together with hydrographic observations. The layered structure of circulation and current bursts of 10 to 20 days are clearly shown as well as the departure of the Kuroshio velocity-field from geostrophy. As a major process which modify the density structure of circulation, an intensified generation of internal tides over the Izu Ridge is also treated.Special lecture presented by the recipient of the prize of the Ocenographic Society of Japan for 7 April 1995.     

海洋岛附近海域春季海洋水文测量结果分析

利用2006年4月在海洋岛附近海域的CTD测量资料,系统分析了该海域温度、盐度、密度和声速的平面分布和垂直分布特征,并探讨了其形成机理。分析指出:4月份是海洋岛附近海域季节性跃层的生成期,海区会产生正跃层、逆跃层、冷中间层、暖中间层等复杂的垂直结构;中间层和底层水文要素受海流的影响较大,而表层水文要素主要受海面风场和气温的影响。     

Approximation to the hydrodynamics of floating pontoons under oblique waves

The hydrodynamic properties of long rigid floating pontoon interacting with linear oblique waves in water of finite arbitrary depth are examined theoretically. The flow is idealized as linearized, velocity potentials are expressed in the form of eigen-function expansions with unknown coefficients. The fluid domain is split into three regions, region (1) wave-ward of the structure, region (2) in the lee of the structure, and region (3) beneath the structure. The different hydrodynamic quantities of interest such as the exciting forces, added mass and damping coefficients, reflection and transmission coefficients were studied for an applicable range of wave/structure parameters. Assuming rigid body motions, dynamic responses of the moored structure is approximately calculated through three equations of motion. Floating pontoons proved to be a convenient alternative for protection from waves in shallow water. The present method of solution was found to be computationally efficient, and results are comparable to those obtained through other techniques.     

东部海洋经济圈海洋产业竞争力实证研究

文章运用偏离份额分析法对东部海洋经济圈所辖3省1市的海洋产业结构和竞争力进行实证研究,进一步将海洋产业生产总值整体作为研究对象进行分析,并根据评价结果将地区分类。结果表明:从海洋产业结构看,研究区域在区域增长效应、产业结构效应和竞争力效应3个方面各有侧重;从整体看,研究区域产业结构较好,上海的产业竞争力相对较差。在此基础上提出相关对策建议,主要包括科学规划海洋产业、加强海洋经济统计、充分利用海洋资源和优化海洋产业结构。     

Horizontal and Vertical Structure of Geostrophic Currents in the Black Sea According to the Data of the Summer Survey Performed as a Part of the ComSBlack-92 Program

We describe the methodology and software developed for the numerical analysis of the characteristics of the horizontal and vertical structure of geostrophic currents. We present the results of computation of these characteristics according to the data of the summer survey of the Black Sea carried out as a part of the ComSBlack-92 program. The distinctive features of the space structure of geostrophic currents discovered as a result and the established parameters of their variability may supplement the existing data on the current field in the Black Sea.     

Comparative study on the seismic performance of two types of quay wall structures

A new type of quay wall structure has been proposed to improve the seismic resistance capability of existing sheet pile quay wall structures. The new structure adopts a combination of stabilized soil and geogrid, and this structure is referred to simply as “SG-WALL”. This paper presents a numerical comparative study on the seismic performances of quay wall structures between the newly developed SG-WALL and the traditional anchor pile-reinforced structure. The calculated results, including displacement of sheet pile, ground settlement, bending moment and stress of sheet pile, and excess pore water pressure, were analyzed and discussed. It was shown that both types of improvement methods can effectively reduce the residual displacements of sheet piles after earthquakes. The residual displacements at the top of the sheet piles in SG-WALL structure and the anchor pile-reinforced structure decreased by 35.6 and 38.2%, respectively. In addition, the SG-WALL structure can more significantly reduce the ground settlement due to earthquakes. The maximum ground settlement in SG-WALL structure and the anchor pile-reinforced structure decreased by 67.3 and 58.9%, respectively.     

海洋产业结构升级对海洋全要素生产率影响的实证研究

文章基于2000—2019年中国11个沿海省(自治区、直辖市)的面板数据,实证分析了海洋产业结构升级对海洋全要素生产率的影响,并以海洋产业结构升级作为门槛变量,进一步研究海洋产业结构升级对海洋全要素生产率的非线性影响。结果说明,海洋产业结构升级对海洋全要素生产率有显著的正向作用;海洋产业结构升级在推动海洋全要素生产率提高的过程中存在一重门槛,随着海洋产业结构升级越过一重门槛,海洋产业结构升级对海洋全要素生产率的推动作用逐渐增大。根据研究结论,未来应加速推进涉海产业转型,鼓励海洋新兴产业发展,同时结合我国海洋产业发展现状,针对不同产业制定具体的对策。     

楚科奇海附近表层沉积物中类脂生物标志物的分布特征和意义

多参数生物标记物法已被广泛用于重建浮游植物生产力和种群结构,研究了2003年夏季我国二次北极考察时采集的楚科奇海表层沉积物样品中浮游植物生物标志物的比例变化及其作为浮游植物种群结构替代指标的潜力。观测海区表层沉积物中菜子甾醇、甲藻甾醇、长链烯酮的总含量为20~3149 ng/g,平均值为1 010 ng/g,生物标志物总量分布表明南部的楚科奇陆架海域生产力明显高于北部海台区,不同站位的菜子甾醇和甲藻甾醇相对比例有明显变化,但都显示菜子甾醇占优势,楚科奇海陆架的站位中都是硅藻为主,菜子甾醇占生物标志物总量的比例为42%~74%,甲藻甾醇占生物标志物总量的比例为17%~37%,在海台区仍然是硅藻占优势,但是甲藻和颗石藻的比例有了很大的提高,加拿大海盆的4个站位中以甲藻和颗石藻为主,硅藻并非加拿大海盆的优势种群。这与用显微镜下鉴定得到的硅藻和甲藻分布趋势相似。研究结果为生物标志物作为浮游植物种群结果替代指标并为利用柱状样中的生物标志物研究古生态提供现代依据。     

Structure of the subsurface counter current beneath the Tsushima warm current simulated by an ocean general circulation model

The subsurface counter current beneath the Tsushima Warm Current is simulated using a three-dimensional circulation model. The model well reproduces the counter current beneath the Tsushima Warm Current on the shelf break. The counter current appears as nearshore parts of the subsurface clockwise circulations from spring to early winter. The clockwise circulations are separated by developed shelves such as the Oki Spur and the Noto Peninsula, thus the counter current is not a continuous flow along the Japanese coast in this model. The vertical structure of the counter current can be explained by a density structure with the thermal wind relationship. The permanent and seasonal pycnoclines form mutually opposite horizontal density gradients near the Japanese coast in summer. Such a density structure results in a speed maximum of the counter current away from the bottom. It is remarkable that the second baroclinic mode is dominant in nearshore parts of the subsurface clockwise circulations in summer, which are attributed to the density structure. Similar density structures are also found in some coastal regions of the world oceans where subsurface counter currents are expected.     

基于熵权的海岛地区城市生态系统健康动态评价研究——以舟山群岛新区为例

文章将舟山群岛新区作为研究对象,以结构、功能、协调这3个基准点为视角,构建舟山群岛新区城市生态系统健康的评价指标体系;运用熵权法进行客观赋权,探讨海岛地区城市生态系统健康的主要影响因素;分析系统各主要因素间彼此的联系和相互关系,评价舟山城市生态系统健康动态,以便进一步提高舟山群岛新区城市生态系统健康水平,优化经济结构,为加强海岛地区生态与环境管理,促进海岛地区经济发展提供决策依据。研究结果表明:近年来,舟山群岛新区城市生态系统健康程度以稳中有升的趋势在不断提高;结构指数有小幅波动,功能指数波动显著,改善明显,其中,城市环境是造成结构指数波动的主要原因。城市文明率较低和可持续性持续走低是城市协调度的主要限制因素。由此,优化资源配置、改善经济结构、持续减排、提升城市环境是确保舟山群岛新区城市生态系统健康水平的关键。     

0903号台风“莲花”的风结构分析

通过对0903号台风“莲花”在登陆福建晋江并沿着海岸线北上过程中的沿海自动站逐时实况风场资料的分析,研究了该台风的风结构状况,得到以下结论：（1）台风近中心最大风速预报值比实测风速偏小,台风7级风半径则比实际的偏大．（2）实测2min平均风速最大值（Vmax）总体上呈减弱趋势,与时间（t）的回归方程式为：Vmax=28．9—0．61t（n=16,r=0．78,r005=0．50）．（3）台风最大风速半径（R）呈逐渐扩大的趋势,与时间（t）的回归方程式为：R=28．28—4．98t＋0．67t。（n=16,r=0．95,r0.05=0．50）．（4）台风最大风速区位于台风后部．认识台风风结构,有助于不断地提高预报的准确性．     

北太平洋中尺度涡时空特征分析

利用1993~2011年19 a的AVISO卫星高度计资料研究了北太平洋(10°~60°N,120°E~100°W)中尺度涡的时空分布特征,结果表明:北太平洋每年约产生1 800余个涡旋,其中气旋涡稍多。北太平洋东部沿岸、西北沿岸、黑潮延伸体北侧、副热带逆流区是中尺度涡的高发区,春、冬季是涡旋的高发季节。涡极性分布以35°N为界,北部多反气旋涡,南部多气旋涡。涡旋半径以100 km左右为主,并且基本随纬度升高而减小,涡旋数量随着周期增长而急剧下降。反气旋涡的平均半径和周期均大于气旋涡。利用Argo浮标剖面资料分析的6个个例涡旋的垂直结构显示,每个涡旋都有其独特的冷暖核结构,深度不同。研究结果对于分析北太平洋涡动能分布及传输具有一定的参考价值。     

Genetic connectivity of the coral‐eating sea star Acanthaster planci during the severe outbreak of 2006–2009 in the Society Islands,French Polynesia

Occasional population outbreaks of the crown‐of‐thorns sea star, Acanthaster planci, are a major threat to coral reefs across the Indo‐Pacific. The presumed association between the serial nature of these outbreaks and the long larval dispersal phase makes it important to estimate larval dispersal; many studies have examined the population genetic structure of A. planci for this purpose using different genetic markers. However, only a few have focused on reef‐scale as well as archipelago‐scale genetic structure and none has used a combination of different genetic markers with different effective population sizes. In our study, we used both mtDNA and microsatellite loci to examine A. planci population genetic structure at multiple spatial scales (from <2 km to almost 300 km) within and among four islands of the Society Archipelago, French Polynesia. Our analysis detected no significant genetic structure based on mtDNA (global F_ST = ?0.007, P = 0.997) and low levels of genetic structure using microsatellite loci (global F_ST = 0.006, P = 0.005). We found no significant isolation by distance patterns within the study area for either genetic marker. The overall genetically homogenized pattern found in both the mitochondrial and nuclear loci of A. planci in the Society Archipelago underscores the significant role of larval dispersal that may cause secondary outbreaks, as well as possible recent colonization in this area.     

细胞结构对浮游植物光学特性的影响

藻细胞抽象为细胞质和叶绿体构成的两层球体结构, 结合Aden-Kerker散射理论, 分析了藻细胞各物理属性对其光学特性的影响, 同时也与均匀球体藻细胞的光学特性进行了对比分析。分析结果表明, 与均匀球体结构相比, 叶绿体为外裹层的细胞结构将显著增强其后向散射效率及后向散射比率, 而叶绿体为内核层的细胞结构因打包效应将削弱藻细胞的吸收效率; 当叶绿体为外裹层时, 细胞粒径大小、叶绿体相对体积、叶绿体复折射率的虚部都对藻细胞的吸收效率会产生显著影响; 同时, 细胞粒径大小和叶绿体复折射率实部是决定细胞后向散射效率和后向散射比率的两个重要指标。     

Geophysical Studies of the Seymour Sewell Seamount on the Flank of the Central Indian Ridge

Oceanology - The volcanic structure of the Seymour Sewell seamount appears to have formed over a relatively long time in at least two stages. Its main massif was formed as a result of volcanic...     

长山群岛海区春季水温垂直结构分析

利用海军大连舰艇学院2006年4月长山群岛海区的CTD调查资料,系统分析了该季节长山群岛海区的温度垂直结构,并探讨了其形成机理。分析指出:4月上、中旬是长山群岛海区季节性温跃层的生成期,群岛东侧和南侧边缘受黄海冷水团形成过程的影响,温跃层的出现概率和跃层强度都远远高于群岛内部;在生成时机上,群岛东侧和南侧边缘海域早于群岛内部水域。中间层和底层海水温度的垂直结构与海流有着很好的相关性,在海洋平流的作用下,海区会产生正跃层、逆跃层、冷中间层、暖中间层等复杂的温度垂直结构。上层海水温度结构主要受海面风场和气温的影响,较强的热辐射和充分的风力搅拌能够加速温跃层的生成。     

深海立柱式平台概念设计研究

以上海交通大学海洋工程国家重点实验室提出的多柱桁架式立柱平台(Cell-Truss Spar)概念为例,对Spar平台的概念设计方法和过程进行了初步的研究,并对其水动力性能进行理论和数值计算,分析一些影响Spar平台运动性能的参数。设计涉及到两方面的问题:一是设计方法、流程以及结构物的形式;二是水动力性能。整个设计流程是一个不断循环的交互式的过程,需要考虑很多方面因素的影响。     

渤海、黄海热结构分析

在多年观测资料基础上,以月平均风应力和周平均海表水温(SST)作为外强迫,对黄海、渤海热结构进行了数值模拟.模拟结果显示渤海的热结构特征自10月至翌年3月为水温垂直均一的冬季型;5～8月为分层结构(由上混合层、跃层、潮混合层组成)的夏季型.4月和9月为两型的过渡期,最低水温出现在2月,最高水温表层出现在8月,底层则在9～10月.黄海沿岸浅水区与渤海有相似的热结构,黄海冷水团和黄海暖流对其中央槽深水区的热结构有重要影响.对底层水的影响而言,前者夏季显著而后者冬季显著,从而导致黄海(槽)的底层水与环境相比呈现夏季冷而冬季暖的特征,底层水温基本上与表面水温的年变化反相;深水区的热结构与渤海相比,均一型结构(1～3月)变短,分层型结构(5～11月)变长,底温年变幅(5℃以内)变小,跃层强度增强.模拟结果还表明,黄海暖流的动力仍然是季风环流,而对黄海冷水团的形成和发展有无动力影响提出质疑.