毛细管气相色谱法在河口气溶胶中脂肪烃分析的应用

国内用气相色谱法分析河口以及海洋环境气溶胶中脂肪烃尚未见详细报道。本文用化学键合玻璃毛细管气相色谱法分析测定长江口海域气溶胶中的正构烷烃和异构烷烃,获得了较满意的结果。     

Flow-Induced Vibration of A Nonlinearly Restrained Curved Pipe Conveying Fluid

Investigated in this study is the flow-induced vibration of a nonlinearly restrained curved pipe conveying fluid. The nonlinear equation of motion is derived by equilibrium of forces on microelement of the system under consideration. The spatial coordinate of the system is discretized by DQM (differential quadrature method). On the basis of the boundary conditions, the dynamic equation is solved by the Newton-Raphson iteration method. The numerical solutions reveal several complex dynamic motions for the variation of the fluid velocity parameter, such as limit cycle motion, buckling and so on. The result obtained also shows that the sub parameter regions corresponding to the several motions may change with the variation of some parameters of the curved pipe. The present study supplies a new reference for investigating the nonlinear dynamic response of some other structures.     

海洋工程中极值水位估计的一种条件分部联合概率方法

在海洋工程建设(如港口建设、沿岸工程和海上平台建筑等)中,必须对正常条件(即作业条件)和极端条件(即恶劣环境条件)下的海洋环境参数作出估计。对于海洋水位而言,如《港口工程规范》(以下简称《规范》)中的设计水位和乘潮水位等即属于前者,校核水位即属于后者。正常条件下的水位参数比较容易确定,因为这种条件下的观测数据比较容易获得,有比较丰富的已知资料。极值水位是指若干年内オ有可能出现的高水位或低水位,例如在《规范》中要求50年一遇的水位作为校核水位。所以如依靠直接观测,必须具备至少几十年的观测资料,这一要求只有在有长期验潮站的港口オ能达到。如资料系列不够长,则必须采用一定的方法对它们的数值作出估计。 在有相当长期观测资料的情况下,常常采用极值分布的方法,即每年取一个最高(或最低)水位,然后拟合某种理论或经验的分布曲线,从而得出不同重现期的极高(或极低)水位。这种方法所得结果比较可靠(但也不是没有问题,详见第五节),但对资料要求高，特别在新建港口或海上工程,常常不能采用。 在有数年观测资料的情况下,可以采用同步差比法(见《规范》)。当拟建港和主港潮汐性质和风暴潮特性相近,特别是两地距离较近时,这种方法常常能给出良好的结果,不失为一种有效的方法,但其应用受到一定的条件限制 近年来,国外提出了一种“联合概率法”(Pugh and Vassie,1978,1980)。这种方法把水位中的潮汐水位(这里指的是可用调和方法预报的潮位,其中也包括周期性的气象潮)和余水位(即实测水位减去预报水位)分开,分别求其分布,然后再用联合概率法回过来求合成水位的分布,从而得出极值水位高度。这种方法的优点是能够充分利用水位观测资料,因而可以在观测时间较短的情况下得出比传统方法更稳定的结果。在Pugh和Vassie所提出的方法中,潮汐和余水位被看作是互相独立的。这一假定在深水海区较接 近实际,但在某些浅海区则与实际有较大出入。例如Pugh和Vassie发现,对位于泰晤士河的绍森德港,由联合概率法按上述假定得出的百年一遇的高水位比由传统极值分布方法得出的数值大约高60cm;而传统方法的结果与49年期间观测到的最高水位较接近。Pugh和Vassie在后来的文章中对绍森徳港的问题作了专门处理,得出较合理的结果,但基本上是采用经验的方法,在一般实际中使用是困难的。 为了考虑潮汐和余水位的这种相关性,我们曾将联合概率法予以推广,提出了条件分布联合概率法(方国洪、王骥,1987)。这种方法不论潮汐和余水位是否相互独立均可应用,具有更强的适应性。本文根据该文的基本想法,选择了我国沿海资料较长,并具有较好代表性的10个长期验潮站共286年的潮汐逐时记录,进行了分析研究,对该文提出的方法作了修改和补充。     

毛细管气相色谱法测定海洋沉积物中饱和烷烃

一、前言 海洋沉积物中饱和烃来源于人为石油烃污染、海洋生物和陆源高等植物。因此海洋沉积物中的饱和烃组成较复杂,含有n-C_(14)—n-C_(36)的正构烷烃和异构烷烃等,沸点范围很宽。用常规填充柱气相色谱难于分离这样复杂的饱和烃。毛细管气相色谱与之相比,具有较高的分离效能,比较适用于测定海洋沉积物中的饱和烃。通过饱和烃含量的测定,可鉴别其是人为     

HOLOCENE SEA LEVEL CHANGES AND CRUSTAL MOVEMENTS ALONG THE NORTHERN COASTS OF THE SOUTH CHINA SEA

This paper discusses level changes of the sea in the last 6000 years and the recent crustal movements of the coasts of the South China Sea. There was one transgression in the middle Holocene (about 6000-3000 years ago); the sea level might not be higher than the actual one. Many terraces and coral reef platforms above the sea level can be explained by recent crustal movements.As far as the intensity of the crustal movements are concerned, the NE faults are the strongest, the NW next, and the WE are the weakest. They intersect ia block-faulting, differing in seismic activity, crustal movement rate and amplitude. On the whole, they gradually become stronger from west to east in accordance with the increasing tendency of stress field.The land is tilting toward the sea, especially ia western Guangxi Province.     

浅水分潮流引起的流矢量分布不对称性及其对泥沙运动的影响

Tidal current asymmetry due to existence of shallow water constituent current is studied. It is found that there is a relationship between the asymmetry and the reversion of tidal current rotating.The influence function for determining when the reversion occurs can be used for finding characteristics of tidal current asymmetry.For a shallow water area where semidiurnal current dominates, the current characteristic at extremum moment ~↑t of the influence function is discovered:if both M2 and M4 constituent currents are in the same direction at the moment ~↑t, then at t=~↑t TM2/2 their directions are opposite. It is convenient to discuss the asymmetry by the use of a parameter α which is defined as a ratio:-WM4 (~↑t)/WM2 (~↑t).In most cases,if α is larger than zero，the reversion of tidal current rotating will be occurring about the moment ~↑t, and current magnitude be adifference of Mz and M4 current magnitudes at ~↑t. If α is smaller than zero,the reversion will not happen,and current magnitude is a sum of both constituent current magnitudes at ~↑t. For the case that|α| is larger than 1,the current directions at ~↑t and ~↑t TM2/2 are the same, as to |α| which is smaller than 1,two directions at two moments are opposite. Especially when ~↑t happens to be close to moments of both M2 and M4 current maximums, influence of the asymmetry will be significant, the larger theM4 current maximum, the more asymmetric the current.The influence of the asymmetry on sand movement is also dealt with,such an asymmetry will lead to the transportation of sand towards certain direction.     

Vibration and Acoustic Radiation from Orthogonally Stiffened Infinite Circular Cylindrical Shells in Water

Based on the motion differential equations of vibration and acoustic coupling system for thin elastic shells with ribs, by means of the Fourier integral transformation and the Fourier inverse transformation, as well as the stationary phase method, an analytic solution, which has satisfying computational effectiveness and precision, is derived for the solution to the vibration and acouslic radiation from a submerged stiffened infinite circular cylinder with both ring and axial ribs. It is easy to analyze the effect of stiffening supports in the acoustic radiation field by use of the formulas obtained by the pre-sented method and corresponding numerical computation. It is shown that the axial-stiffeners can improve the mechanical and acoustical characteristics. Moreover, the present method can be used to study the acoustic radiation mechanism of the type of structure.     

海洋内波对水声场的扰动

针对海洋内波对水声传播影响的问题，在简要引出内波方程，水声方程和内波解，射线理论之后，以水深2100m等Vaisala频率的全板造波内波解对双线性水声剖面情况计算了内波和内波对声场及声线传播的影响，结果表明，内波对声线传播的路径和时间的影响是不可忽略的。     

我国沿海风暴潮的监测及其预报

本文介绍了我国现行的风暴潮监测预报系统以及目前在预报中心风暴潮业务预报中所采用的方法,重点叙述了近几年发展起来的数值预报技术并展望了未来的发展。     

Cu^2＋,Zn^2＋对罗非鱼鳃盖运动的影响

本文研究结果表明：（1）水体中含Cu2+和Zn2+的浓度越高，鱼中毒越深，鳃盖运动振幅的增大和频率的减小就越显著。（2）Cu2+／Zn2+混合液对鳃盖运动的影响具明显的协同作用，它的致毒效应分别为单一因子的3～5倍。（3）毒性次序：5×10－6Cu2+／50×10－6Zn2+＞2．5×10－6Cu2+／25×10－6Zn2+＞5×10－6Cu2+＞50×10－6Zn2+（V／V）。（4）频繁的咳嗽反应是Zn2+中毒的主要症状，驱逐反射是Cu2+中毒的主要症状，两者均可作为单一和混合重金属离子污染的敏感生物学监测指标。