长江口洪水期潮波变形数值模拟研究

由长江口现场水文测验资料分析知,洪水期潮波上溯过程中,潮波变形具有先加剧后趋缓的特点。基于非结构网格FVM方法建立大通至外海的大范围数学模型,复演长江口潮波传播过程,以此为基础,研究长江口洪水期潮波变形特征的形成原因。研究认为:洪水期长江口潮波变形转折点位于潮流界上游;转折点下游潮波变形逐渐加剧是由于高低潮位潮波传播速度差异造成的;转折点上游潮波变形趋缓是由于高潮位重力引起的潮波传播阻力对潮波传播影响大于高低潮位潮波传播速度差异造成的。     

0917号台风“芭玛”折向东南向移动原因分析

利用NCEP全球数据同化系统(GDAS)1°×1°分析资料,对0917号台风"芭玛"折向东南向移动原因进行了分析。结果表明,中高纬度环流调整是"芭玛"折向东南向移动的根本原因;0918号台风"茉莉"通过改变外围环境场的强度、形状对"芭玛"台风产生间接影响,而两台风之间逆时针互旋以及台风"茉莉"外围强大的环流对台风"芭玛"的直接作用是台风"芭玛"折向东南向移动的关键。对台风"芭玛"经纬向UV最大风速变化诊断分析表明,"芭玛"经纬向UV最大风速中心的转移对"芭玛"折向东南向移动有重要影响,经纬向UV最大风速差的变化对"芭玛"转向具有预示作用,经纬向最大风速差的合成风方向与台风中心未来移动方向有一定的关系。     

Biodegradation Studies on Acid Violet 19, a Triphenylmethane Dye,by Pseudomonas aeruginosa BCH

Acid violet 19 (AV) belongs to the triphenylmethane (TPM) class of dyes which are potentially mutagenic or carcinogenic. However, very little studies on biodegradation of AV were reported as compared to other TPM dyes such as malachite green and crystal violet. In this study, AV was decolorized up to 98% within 30 min by Pseudomonas aeruginosa BCH. The decolorization depends on the initial dye concentration, pH, and temperature. However, the dye was decolorized under wide pH and temperature ranges with an optimum of pH 7 and 30°C. Up to 250 mg L^?1 of dye was found to be tolerated and decolorized by this strain. It showed decolorization ability for seven repeated dye addition cycles. The effect of additional carbon sources on dye decolorization was studied in which mannitol containing medium showed decolorization in 15 min. Induction in the enzyme activities of laccase, NADH‐DCIP reductase, and veratryl alcohol oxidase (VAO) indicates their involvement in AV degradation. Various analytical studies viz. UV–VIS, HPTLC, HPLC, and FTIR confirmed the biodegradation of AV by the bacterium. Based on GC‐MS analysis, a possible degradation pathway for AV was proposed. The phytotoxicity studies using Phaseolus mungo and Sorghum vulgare revealed the less toxic nature of metabolites formed after AV degradation.     

关于来流对槽道推进器流体动力性能影响的研究

作为主动操纵装置的船艏侧推器，其侧推效率受船速的影响会有很大的变化。为能有效地进行操纵控制，本文从理论和实验两方面人手，研究了艏侧推器受船速影响的流体动力性能，并在一定的速度范围内，获得了一种理论估算方法。     

Nature of the connection between the Northern and Southern Zechstein Basins across the Mid North Sea High

The seismic expression of a salt-filled channel which cuts across the Mid North Sea High in Quadrant 37 is described, with features interpreted as being produced by salt-edge dissolution forming both eastern and western margins of the channel. The apparent half-graben nature of the channel is shown to be only superficial, and due to complex faulting associated with, but not defining, its western margin. The shallower faulting here is a Mesozoic to early Tertiary growth fault related to local dissolution of Zechstein salt. The dissolution effect appears in turn to have been localized by the presence of a deeper fault that was already downthrown to the east in Zechstein times, when it seems to have limited the eastward progradation of Zechstein shelf carbonates and anhydrites, and had probably ceased to move significantly before the onset of the Late Cimmerian erosional phase. The origin of this arcuate fault is tentatively ascribed to subsidence around a granite batholith. Zechstein salt originally spread some distance to the east and west of the channel; it was dissolved from the edges inwards, mainly before the Late Cretaceous, giving rise to a thicker Mesozoic sequence on parts of the flanks of the channel than in the middle. Besides providing an interesting structural case history, the features described have implications regarding Zechstein sedimentation, reservoir potential, the tectonic history of the North Sea, and the nature of the Mid North Sea High itself.     

NNFFC-adaptive output feedback trajectory tracking control for a surface ship at high speed

An adaptive output feedback controller based on neural network feedback-feedforward compensator (NNFFC) which drives a surface ship at high speed to track a desired trajectory is designed. The tracking problem of the surface ship at low speed has been widely investigated. However, the coupling interactions among the forces from each degree of freedom (DOF) have not been considered in general. Furthermore, the influence of the hydrodynamic damping is also simplified into a linear form or neglected. On the contrary, coupling interactions and the nonlinear characteristics of the hydrodynamic damping can never be neglected in high speed maneuvering situation. For these reasons, the influence of the nonlinear hydrodynamic damping on the tracking precision is considered in this paper. Since the hydrodynamic coefficients of the surface ship at high speed are very difficult to be accurately estimated as a prior, it will be compensated by NNFFC as an unknown part of the tracking dynamics system. The stability analysis will be given by the Lyapunov theory. It indicates that the proposed control scheme can guarantee that all the signals in the closed-loop system are uniformly ultimately bounded (UUB), and numerical simulations can illustrate the excellent tracking performance of the surface ship at high speed under the proposed control scheme.     

青岛地区的台风暴潮与潮灾

本文分析了青岛沿海地区的台风暴潮灾害状况，给出了潮位与海浪的联合作用对灾的影响关系式，提出了今后风暴潮预报的思路。     

Growth of Five Species of Gorgonians (Sub-Class Octocorallia) in the Sedimented Waters of Singapore

Abstract. Annual growth rates of gorgonians in the Indo-Pacific region are reported ror the first tinie. A method of measuring gorgonian growth using periodic photographic monitoring that is sensitive to horizontal growth and changes in growth foci but that does not require tedious underwater measurements is applied. Growth parameters of five species of gorgonians from three Families ( Plexauridae. Melithaeidae . and Subergorgiidae ) were monitored over a period of 18 months using this method. Growth rates ranged from 2.30 cm a^-1 to 7.88 cm. a ^-1 in the highly sedimented waters of Singapore. The maximum number of branches added per year ranged from 1.7 to 14.5.     

Tracking the last sea-level cycle: seafloor morphology and shallow stratigraphy of the latest Quaternary New Jersey middle continental shelf

Seafloor geomorphology and surficial stratigraphy of the New Jersey middle continental shelf provide a detailed record of sea-level change during the last advance and retreat of the Laurentide ice sheet (120 kyr B.P. to Present). A NW–SE-oriented corridor on the middle shelf between water depths of 40 m (the mid-shelf “paleo-shore”) and 100 m (the Franklin “paleo-shore”) encompasses 500 line-km of 2D Huntec boomer profiles (500–3500 Hz), an embedded 4.6 km² 3D volume, and a 490 km² swath bathymetry map. We use these data to develop a relative stratigraphy. Core samples from published studies also provide some chronological and sedimentological constraints on the upper <5 m of the stratigraphic succession.The following stratigraphic units and surfaces occur (from bottom to top): (1) “R”, a high-amplitude reflection that separates sediment >46.5 kyr old (by AMS ¹⁴C dating) from overlying sediment wedges; (2) the outer shelf wedge, a marine unit up to 50 m thick that onlaps “R”; (3) “Channels”, a reflection sub-parallel to the seafloor that incises “R”, and appears as a dendritic system of channels in map view; (4) “Channels” fill, the upper portion of which is sampled and known to represent deepening-upward marine sediments 12.3 kyr in age; (5) the “T” horizon, a seismically discontinuous surface that caps “Channels” fill; (6) oblique ridge deposits, coarse-grained shelly units comprised of km-scale, shallow shelf bedforms; and (7) ribbon-floored swales, bathymetric depressions parallel to modern shelf currents that truncate the oblique ridges and cut into surficial deposits.We interpret this succession of features in light of a global eustatic sea-level curve and the consequent migration of the coastline across the middle shelf during the last 120 kyr. The morphology of the New Jersey middle shelf shows a discrete sequence of stratigraphic elements, and reflects the pulsed episodicity of the last sea-level cycle. “R” is a complicated marine/non-marine erosional surface formed during the last regression, while the outer shelf wedge represents a shelf wedge emplaced during a minor glacial retreat before maximum Wisconsin lowstand (i.e., marine oxygen isotope stage 3.1). “Channels” is a widespread fluvial subarial erosion surface formed at the late Wisconsin glacial maximum 22 kyr B.P. The shoreline migrated back across the mid-shelf corridor non-uniformly during the period represented by “Channels” fill. Oblique ridges are relict features on the New Jersey middle shelf, while the ribbon-floored swales represent modern shelf erosion. There is no systematic relationship between modern seafloor morphology and the very shallowly buried stratigraphic succession.