鱼类消化道细菌及其作用研究Ⅱ.鲻鱼

本文报道了从鲻鱼消化道分离的好气性异养细菌数量为（1．5×108±0．4×108～6.4×108±2.0×108）个／g，共分离220株细菌。其种群组成为弧菌、气单胞菌、不动细菌、假单胞菌、微球菌、黄杆菌、葡萄糖细菌、纤维单胞菌、节细菌和棒状杆菌。测定其生化特性，表明该类菌对有机质的分解能力比较强，这些特性有利于鱼类对营养物质的消化和吸收，并进一步促进其生长和发育。     

海洋生物-光学算法研究──南黄海叶绿素浓度的估算

根据１９９５年９月中日合作南黄海现场观测资料，对南黄海生物－光学算法进行研究。首先对南黄海现场多光谱反射比数据进行因子分析，解反射比协方差矩阵的特征问题；解出特征值和对应的特征向量，求出主因子，然后建立叶绿素α对主因子的多元线性回归方程，并对算法进行回报和预报检验。计算结果表明，该算法具有较高精度，同时也显示出天气条件对估算精度产生较大影响。     

Comparison of methods for computing hydrodynamic characteristics of arrays of wave power devices

A comparison of methods for the calculation of the hydrodynamic characteristics of arrays of wave power devices is presented. In particular, the plane-wave approximation and an exact multiple scattering formulation have been used to compute exciting wave forces, hydrodynamic coefficients and q factors for arrays of interacting wave power devices. The results obtained are compared with each other, and accuracy aspects of the computations are stressed and critically assessed.     

CASE ANALYSIS OF SEA LEVEL CIRCULATION FOR THE ATMOSPHERE OF LOW LATITUDES IN MID-SUMMER

In the light of the sea level synoptic charts from July to August for 1975-1978, we obtained more observed records of low latitudes by using the analysed stream and temperature-moisture field (or so called energy field θe field and θse field), the main characteristics of these fields in the period of multi-typhoon genesis and of typhoon interval in the mid-summer are studied.Finally, it should be pointed out that the position of the typhoon genesis and the typhoon track are generally consistent with the low temperature-moisture region of the sea surface as well as with its tendency, so that a valuable information is obtained for the forecast of the typhoon track.     

THE VERTICAL MIGRATION OF DIATOM IN LITTORAL OF XIBIAN AND XIAO''AO

The vertical migration of diatoms in mud-flats was studied in littoral of Xibian, Longhai County and Xiao'ao, Lianjiang County, the dominant species being Gyrosigma spencerii and Hantzschia virgata respectively. Both light and tide are important factors affecting the vertical migration of diatoms. With the advent of tide, the diatom community disappears from the surface. It reappears gradually when exposed to light. In the dark, the diatoms never appear in great quantity on the surface in laboratory or in littoral. Whether in the light or in the dark, the diatoms aggregate in maximum numbers in the upper 2 mm of the sediment. But when the tide has covered the sediments for 4 hr, Hantz. virgata penetrates the mud down to a depth of 14 mm, Gy. spencerii, 12 mm. We have found that Gy. spencerii posseses phototaxis, but no tide rhythm and no day-night rhythm in our laboratory.     

DIATOMS FROM THE SURFACE SEDIMENTS OFF THE SOUTHERN HUANGHAI SEA AND EAST CHINA SEA

Two new species (Nitzschia sinensis Liu, sp. nov. and Podosira granulata Liu, sp. nov.) and one new variety (Xanthiopyxis microspinosa var. ellipticus Liu, var. nov.) collected from the urface sediments off the southern Huanghai Sea and the East China Sea are described and a list of diatoms from the surface sediments in the survey area and some new records in China are attached.     

DIRECT DETERMINATION OF STRONTIUM IN SEAWATER BY FLAME EMISSION SPECTROPHOTOMETRY

A procedure is suggested for direct determination of Sr in seawater using diluted seawater sample and background emission correction by FES. The standard deviation for 8 ppm Sr is better then 2 %, and the recovery of the added Sr is 97-105 %.     

PREDICTION OF MOTION OF SEMI-SUBMERSIBLE DRILLING PLATFORM IN MAVES

Starting from potential theory, this paper presents a new procedure for computing the hydrodynamic forces and six-degrees-of-freedom motion for a semi-submersible platform at an arbitrary heading in waves by using strip theory and linearized viscous damping hypothesis, taking the effects of the free surface and the interaction between main hulls into account. The differential equations of motion for the floating platform are formulated in a new way and the associated computer programs are developed. Comparisons between the theoretical computing results and the full-scale and model-scale experiments show that the present method gives more accurate results than those by previous methods.     

PROBABILITY CHARACTERISTICS OF WAVE AND WAVE PRESSURES IN FRONT OF VERTICAL BREAKWATER

The distribution of wave height in front of a vertical breakwater, the range of wave pressure fluctuation at different subsurface levels, and the wave periods have shown that they are practically invariable with depth and can be determined theoretically. The distribution of crest and trough of total pressures is the same as that of wave height. As far as different subsurface levels are concerned, the spectral constitution of wave pressure field and the regularity of attenuation of spectral components are analyzed at the vertical breakwater, and a new expression describing the equilibrium range of wave pressure spectrum obtained.     

DYNAMIC ANALYSIS OF TYPHOON SURGES ALONG THE COASTS OF ZHEJIANG AND JIANGSU PROVINCES

Based on the numerical model shown in Ref. [1], a dynamic analysis is given for the storm surges caused by the four typhoons (i. e. typhoons Nos. 5310, 5612, 6126 and 6207) on the east coast of Zhejiang and Jiangsu Provinces, in which the contributions of various dynamic factors to local surge elevation are calculated numerically, including the Coriolis force, the atmospheric pressure force, the bottom friction, the local topography and the couple nonlinear interactions between surge current and elevation as well as between surge currents themselves. Moreover, the responses of these factors to different kinds of typhoon tracks and water depths are discussed in more detail, and the effects of grid size on the computed results demonstrated.