Assimilation of the Data of Satellite Altimetry in an Eddy-Resolving Model of Circulation of the Black Sea

The data of satellite altimetry are used to simulate the Black-Sea circulation. The altimetry data of the TOPEX/Poseidon and ERS satellites are prepared within the framework of the NASA Ocean Altimeter Pathfinder project. The additional data processing is performed to compute the dynamic level reflecting the circulation of the Black Sea. The altimetry sea-level is assimilated in an eddy-resolving model of circulation of the Black Sea based on primitive equations. The accuracy of the obtained fields of temperature and salinity is estimated by comparing with the data of large-scale hydrographic surveys according to the ComSBlack program. The prognostic capabilities of the proposed model are estimated by comparing the obtained results with the fields computed with the help of assimilation of the altimetry data.     

Radar studies of the distribution of the formation zones of the first radar echo of hail clouds

The results of studying the regions of hail-cell formation in the North Caucasus are considered. The optimal range of the underlying surface heights for their generation is determined based on an analysis of 392 hail cells. It is shown that the majority of hail cells are formed in the zone where the heights of the underlying surface vary from 900 to 2400 m. The most favorable conditions for the formation of hail clouds are recorded in the northern slopes of the Skalistyi (Rocky) ridge. This region accumulates the main maxima of the frequency of first radar echo recording. The second group of the frequency maxima is located over the Pastbishchnyi (Pasturable) and the Lesistyi (Woody) ridges. The generalized scheme for the region under study is constructed of three zones of generation of the first radar echo of the hail cells. It is shown that approximately 70% of hail clouds are formed over submontane and mountainous regions in the central North Caucasus (zones 2 and 3). The directions of motion of hail cells are quantified for each identified zone.     

Solution of the problem of propagation of water waves over a pair of asymmetrical rectangular trenches

The problem of propagation of obliquely incident surface water waves over a pair of asymmetrical rectangular trenches in a channel of finite depth is examined for its solution. The mathematical problem is handled for its numerical solution with the aid of a system of singular integral equations of first kind. The resulting integral equations are solved numerically by using suitably designed polynomial approximations of the unknown functions. System of linear algebraic equations is obtained by utilizing the zeros of Chebyshev polynomial of first kind as collocation points and hence the occurrence of ill-conditioned matrix is avoided. The effectiveness of the pair of trenches is studied by analyzing the physical quantities namely the reflection and transmission coefficients. As a special limiting case, the results for a single trench problem are derived and are found to be in excellent agreement with the results available in the literature. The effect of various parameters are analyzed through different graphs for a pair of asymmetrical trenches. The energy balance relation is derived and used to check the accuracy of numerical results.     

Nonlinear effects of the distribution of amplitudes of sea waves

The effect of nonlinearities, such as wave-breaking and vertical asymmetry associated with sea waves, on the distribution of wave amplitudes is explored. Semiclosed theoretical expressions are derived to describe the distributions of breaking-limited crest and trough amplitudes for Stokes-type nonlinear sea waves. These are compared with the conventional Rayleigh distribution appropriate to linear wave amplitudes. The construction of nonlinear wave envelopes with the fast Fourier transform technique is described. The technique can be utilized to enlarge the data base in empirical analyses of field records which typically contain limited information on amplitude characteristics. The theoretical distributions and the proposed data enlargement technique are demonstrated with the analysis of a nonlinear wave record.     

AUV定位信号检测延时的蒙特卡洛模拟分析

在简要介绍AUV声学定位声纳接收机原理基础上,分析了CW脉冲信号在极性相关检测电路中的传输过程,建立了极性相关积分检测延时仿真分析模型。提出采用蒙特卡洛模拟方法获取检测延时的分布特征和统计参数的观点。实验结果表明蒙特卡洛模拟实验与硬件电路实验结果一致,对于解决随机性检测延时问题具有很强的能力。获得的结果可为AUV定位声纳检测门限的设定、声学测距和定位精度分析以及水声通信延时分析提供参考。     

亚洲沙尘对三种海洋微藻生长的影响

实验研究了采自亚洲沙尘暴源地的4种沙尘及1种采自青岛的沙尘对不同海洋微藻生长的影响,结果表明在营养盐贫乏的条件下,沙尘的添加对旋链角毛藻(Chaetoceros curvisetus),小角毛藻(Chaetoceros minutissimus)和东海原甲藻(Prorocendrum donghaiense)的生长具有明显的促进作用.与不加沙尘的对照组相比,指数生长期的比生长速率明显升高;其中取自青岛的沙尘对3种藻类的影响最明显;内蒙古锡林郭勒盟正蓝旗的沙尘营养盐含量最低,但是由于其可溶性Fe的溶出量最高,其促进作用也比较显著.在营养盐充足的条件下,沙尘的添加对3种微藻生长的影响均不显著.因此亚洲沙尘输送到西北太平洋海域可能对该海域的初级生产力具有显著的影响.     

尼罗罗非鱼对两种网目定置网片反应特性的比较

本文就尼罗罗非鱼对两种网目(12.6和8.4cm)定置网片的反应特性进行了比较研究。结果表明:在两网片邻近区域内的分布尾次数较中间区域为少;随着时间推移,其分布重心有移向大网目网片一侧的倾向。此外,罗非鱼对两种网目网片的趋网、碰网、穿网尾次数及趋网、碰网、穿网时刻也有一定的差异。     

Study of effects of environmental factors on biochemical compositions of four species of marine single-celled algae

INTRODUCTIONThecontentsandtheirvariationofcellularbiochemicalcomponentsinnormallygrowingmarinealgaereflectthedifferenceinecologicalenvironments,reportedbymanyresearchers(MomsandSkea,1978;SmithandMoms,1980;LiandHarrison,1982;SmithandGeider,1985;Yangetal.,1991,1992).Lightintensity,temperatureandnutrientsaremostimPOrtantenvironmentalfactorsintheocean.ThispaperemphasizestheeffectsofenvironmentalfactorsonthecompositionofPhaendactylumtricornutum,Dunaliellaspp.,SkeletonemacostatumandIsOChr…     

栉孔扇贝成熟卵形态与超微结构的研究

实验研究栉孔扇贝成熟卵的形态与超微结构。观察表明卵子表面呈蜂窝状,无卵极标志。受精前质膜形态模糊,属非典型单位膜。卵质内含有线粒体、内质网、高尔基体等细胞器,但缺乏中心粒复合体。皮层内含有皮层颗粒。卵黄形态不同,来源于多种细胞器。卵子的成熟核相为第一次成熟分裂中期。     

波浪计算可视化的研究

文章讨论了波浪场可视化实现过程中的一些关键的算法。文中针对表示波浪面的数据集的特性,采用了一种简单的节点法矢量算法。绘制结果表明,用这种简单算法取代二维和三维的数据场节点法矢量的常用算法,能够保持波浪场三维图形的光照效果。利用层次模型算法进行波浪的动态演示,比较了相同面积的波浪场在不同网格密度情况下图形的显示质量,提出波浪场图形质量有与特征波长相匹配的最佳经验网格密度。     

Analysis of coastal damage of a beach profile under the protection of emergent vegetation

The primary objective of the study was to experimentally explore the protection performance of the emergent vegetation on the morphological changes of a coastal zone. The experiments were conducted under both regular and irregular waves in two different wave flumes. A dimensionless number was derived to characterize the beach profile response under the protection of emergent vegetation. Accordingly, empirical relations were derived that explained the pattern exhibited by the experimental data. The list of wave parameters and beach erosion related functions were incorporated in relation to vegetation intensity in order to define coastal zone response. The relationships of these functions followed good trends with the derived dimensionless number. The findings showed that fall speed parameter is not necessarily involved whereas depth parameter is an important factor while defining the damage. The damage parameter is also considered to formulate the limits of dynamic and static stability of beach profiles under the protection of emergent vegetation.     

4种海洋单胞藻生化组成的环境因子效应研究

在实验室模拟条件下,应用14C示踪法测定4种海洋单胞藻的光合作用速率,研究光、温度和营养盐等环境因子对藻类细胞生化组成的影响.结果表明,三角褐指藻、盐藻、中肋骨条藻和等鞭金藻适宜生长的光强范围为5.8×103～15×103lx.4种单胞藻光合作用速率随光强增加而增大,其中盐藻和等鞭金藻的光响应比较明显.随光强增加,4种单胞藻细胞的碳水化合物含量及其变化量呈增加趋势,而蛋白质含量及其变化量则减少,脂类含量变化很小.三角褐指藻、盐藻、中肋骨条藻和等鞭金藻最适生长温度分别为:14、26、21、26℃左右.在上述4个实验温度时,4种单胞藻光合作用速率最高,细胞内的碳水化合物、蛋白质、脂类含量及其变化量也达到最大值.三角褐指藻、盐藻、中肋骨条藻和等鞭金藻光合作用过程的表观活化能(E)分别为:23.2、38.5、22.4和61.7KJ/mol,温度系数(Q10)分别为:1.74、1.74.1.38和1.69.三角褐指藻和中肋骨条藻在氮磷比(N/P)为16时,盐藻和等鞭金藻在氮磷比为28时,光合作用速率最大.在N/P为16时,4种单胞藻细胞内的碳水化合物、蛋白质、脂类含量和变化量均达到最大值.     

Mechanism of the formation of volcanic chains of French Polynesia

A possible mechanism of the formation of chains of intraplate seamounts and islands alternative to the “hot spot” hypothesis is considered. It is related to the appearance of additional stresses in the lithospheric plate when it ascends over a mantle inhomogeneity and descends from it. The magnitude of these stresses (～600 bar) is sufficient for formation of deep fracture zones. In the paper, schemes of formation of volcanic chains are described. The formation of the “faults-volcanoes-volcanic chains” sequence may follow two different ways. The first is controlled by the fracture zones formed along the direction of the plate movement. In this case, feeding channels are localized along the boundary of the rise. If the chain is gradually formed simultaneously with the plate motion, the age of the volcanoes along the chain may change in a more or less regular way. The second type is formed by fractures orthogonal to the movement direction. They may be formed when the plate ascends over a mantle inhomogeneity and/or descends from it. In this case, adjacent volcanoes may have similar ages. A combination of these two variants may also be encountered. The mechanism posed allowed us to explain selected facts referring to the volcanic chains of French Polynesia and may be applied to other regions of the Pacific Ocean.     

三种贝类的核型分析

采用体内注射PHA和秋水仙素的方法,利用成体的鳃组织,对毛蚶(Scapharca subcrenata)、长竹蛏(Solen strictus)和菲律宾蛤仔(Ruditapes philippinarus)的核型进行了研究.结果表明毛蚶的2倍体数目为2n=38,核型为18m+16sm+2st+2t,NF=72.长竹蛏的2倍体数目为2n=38,核型为30m+6sm+2t,NF=74.菲律宾蛤仔的2倍体数目为2n=38,核型为28m+10sm,NF=76.     

Effect of River Discharge on Bay of Bengal Circulation

The seasonal circulation and mixed layer depths in Bay of Bengal is modeled using the three-dimensional Princeton Ocean Model (POM). Along the coastal boundaries a higher resolution is accomplished using the curvilinear orthogonal grid. Model uses a free-surface and terrain following sigma coordinates. The initial climatological salinity and temperature fields for the model are derived from the World Ocean Atlas-2001(WOA01). The Model is forced with wind stress derived from COADS wind climatology. Bilinear interpolation is used to obtain the initial fields and wind stress to the required model specification. Using the seasonal fields and wind stress the model is integrated for simulating Bay of Bengal circulation. The numerical simulations on climatological scale for monsoon months were conducted to study the evolution of dynamics. The simulations bring out not only the typical characteristic features of fresh water plume along the coast but also intensification of the flow over the monsoon period. The increase in the fresh water flow found to affect only the western parts of the BoB. The opposing currents due to monsoon winds and southward flowing fresh water discharge (FWD) were also delineated. The model results show that the wind stress induced turbulence process is subdued in the presence of strong vertical salinity stratification due to the influence of FWD. The simulated mixed layer depths are in agreement with the reported analytical energy required for mixing values.     

Influence of the discharge of rivers on the formation of level of a closed sea

Within the framework of a two-layer model, we consider the process of, formation of livel in a closed basin under the action of a source with constant flow rate located on its boundary in the upper layer. The response of the level of the basin to the inflow of liquid is observed in the form of the baroclinic and barotropic modes. The baroclinic mode, has the form of an edge wave for which the deviation of level is positive for the upper layer and negative for the lower layer. The barotropic component of the level is almost spatially homogeneous and its intensity increases with time. The increase in the volume of the upper layer caused by the inflow of liquid on the boundary is almost completely attained in the barotropic mode. In the lower layer, the increase in the volume attained in the barotropic mode is completely compensated by the baroclinic edge wave. Translated by Peter V. Malyshev and Dmitry V. Malyshev     

防振锤对深水导管架圆管风致涡激振动抑制研究

研究了阻尼防振锤对深水导管架圆管风致涡激振动的抑制。建立了防振锤动力学模型,分析了防振锤的动力学特性;将在建深水导管架圆管简化为固支梁,建立了结构有限元模型,通过瞬态分析计算了圆管的振动幅值;在圆管中部添加防振锤,分析了防振锤对圆管振动的抑制效果;进行了现场测试,对比了数值模拟和实际测试管道的振动响应。研究表明,文中设计的防振锤可以有效地抑制圆管的涡激共振;数值模拟结果与测试结果非常接近,验证了数值分析方法的有效性。     

Modeling of the propagation of transient waves of moderate steepness

A theoretical approach is applied to predict the propagation and transformation of nonlinear water waves. A semi-analytical solution was derived by applying an eigenfunction expansion method. The solution is applied to analyze the effect of wave frequencies and wave steepness on the propagation of nonlinear waves. The main attention is paid to the wave profile, the wave energy spectrum, and the changes of wave profile and energy spectrum due to the interaction of wave components in a wave train. The results show that for waves of low steepness the nonlinear wave effects and effects associated with the interaction of water waves in a wave train are of secondary importance. For waves of moderate steepness and steep waves the effects associated with the interactions between waves in a wave train are becoming significant and a train of initially sinusoidal waves may drastically change its form within a short distance from its original position. The evolution of wave components has substantial effects on the wave spectrum. A train of initially very narrow-banded waves changes its one-peak spectrum to a multi-peak one in a fairly short period of time. Laboratory experiments were conducted in a wave flume to verify theoretical approaches. The free-surface elevation recorded by a system of wave gauges was compared with the results provided by the semi-analytical solution. Theoretical results are in a fairly good agreement with experimental data. A reasonable agreement between theoretical results and experimental data is observed often even for relatively steep waves.     

刺巨藤壶精子的发生及其超微结构

采用扫描和透射电镜技术, 观察刺巨藤壶(Megabalanus volcano)精子发生和精子的超微结构特征。结果显示, 刺巨藤壶精子发生经历精原细胞、初级精母细胞、次级精母细胞、精细胞和精子等5个阶段。在精子形成期间, 圆形或椭圆形的细胞核在微管的作用下沿轴丝延长并在胞质内弯曲, 核和轴丝随着精细胞的纵向伸长而延长, 细胞核最终成为线状; 斑块状的染色质逐渐解体, 呈细小颗粒状和粗颗粒状, 最后浓缩成高密度的均质物; 高尔基体分泌的囊泡不断融合, 形成大小不一的附属小滴前体, 最后融合并延伸成一个纺锤形的附属小滴; 许多小的线粒体不断融合成一个细长的线粒体, 移至核的后端。精子为前部带有附属小滴的长线状, 全长约58.39μm, 可分为顶体、颈部、中段和尾部四部分。长锥形的顶体位于精子最前端, 其后为基体; 颈部由基体产生的“9+2”型轴丝和与之并行的线状核组成; 顶体和颈部两者长共约6.65μm。中部长约42.95μm, 纺锤形的附属小滴(长约9.33μm, 最宽处约2.13μm)紧靠核和轴丝, 其后为颗粒状糖原及一个细长的线粒体; 尾部长约8.79μm, 只有轴丝贯穿。     

Estimation of the transports through the Strait of Gibraltar

An acoustic doppler current profiler (ADCP) is used to measure the currents and estimate the transports over the Camarinal Sill at the Strait of Gibraltar. The deepest measurements of the ADCP compare well with an underlying conventional current meter. The exchange interface between the Atlantic and the Mediterranean water is defined as the depth of the maximum vertical shear. The mean depth of the shear interface is 147 m. The time series of the depth of the interface and the currents are used to estimate the transports across the Strait. The resulting values are 0.78 Sv for the Atlantic inflow and −0.67 Sv for the Mediterranean outflow. The time series of the shear interface include fortnightly oscillations of 19 m. The time series of the transports are compared with the pressure and sea level difference records across the Strait. Linear multiple regression is used to estimate the (statistical) contribution of each parameter on the variation of transports. The cross strait sea level difference is well correlated with the Atlantic inflow and accounts for 57% of the variability of the transport records which improves to 78% when the fortnightly and monthly cycles are included in the linear regression. The Mediterranean outflow is best correlated with the along strait sea level difference which accounts for only 10% of the variability of the transport record. Again the addition of the M_sf and the MM cycles improves the percentage of the variance accounted for to 37%. The local, along strait wind component is significantly correlated with, both the Atlantic inflow and the across strait sea level difference.