On a new species of deep-water Siphonophora, Lensia multicristoides sp. nov. from middle South China Sea

-In this paper, a new species of deep-water Siphonophora, Lensia multicristoides sp. nov., collected from the middle South China Sea is described and compared with some similar species in the genus.     

Fibrous adsorbent containing amidoxime and carboxyl groups and adsorption of uranium

Through introducing amidoxime and carboxyl groups into polyacrylonitrile fiber, a fibrous adsorbent with high capacity and fast adsorption rate was obtained, which could adsorb 4.6 mg uranium/g in 10 days from natural seawater. The influence of the functional group content on equilibrium adsorption capacity Xm and adsorption rate constant K of the adsorbent was studied, thus indicating that the contents of amidoxime and carboxyl groups correlated with Xm and K respectively. It is concluded that the amidoxime group is of reactive adsorption, while the carboxyl group is of promotion in the adsorption of uranium. In this paper, the mechanism of uranium adsorption on the fibrous adsorbent is deduced and the chelating structure of adsorption species is discussed with molecule orbit theory.     

ON A NEW GENUS OF MYSIDACEA, PARALEPTOMYSIS GEN. NOV. FROM THE SOUTH CHINA SEA

Among the specimens of Leptomysim (Crustacea, Mysidacea) collected from the northern part of the South China Sea by the Institute of Oceanology, Academia Siniea, Leptomysis xenops Tattersall and a closely related form were found by the authors. While studying on the morphological characteristics of these two species and their allies in the Tribe Leptomysini, we found that there are two natural groups of species previously ascribed to the genus Leptomysis G. O. Sars. The first group includes the type species of the genus and other 8 known species, viz. Leptomysis gracilis (G. O. Sars. 1864), L. lingvura (G. O. Sars, 1866), L. sardica G. O. Sars, 1877, L. mediterranea G O. Sars, 1877, L. capensis Illig, 1906. L. megalops Zimmer, 1915, L. australiensis Tattersall, 1927. L. peresi Bacescu, 1966, and L. burgii Bacescu, 1966, of which the cornea of the compound eye is normal——with numerous small facelets of equal size, the telson is usually armed with 2 or 3 pairs of larger apical spines; while in species of the second group, in which L. apiops apgops G. O. Sars, 1877, L. apiops banyulensis Bacescu, 1966, L. xenops Tattersall. 1922 and the new species described in this paper are included, the cornea consists of two parts, the anterior part with small and normal faeelets, but of the posterior part, the facelets are very unique, being larger and much elong ted to form a "bauquet"-shaped process. These differences showed that the two groups are heterogenous and belongs actually to two distinct genera. In order to receive the last 4 forms, a new genus, Paraleptomysis gen. nov. is established, and an account of the new genus and Chinese species is given in this paper. The type materials of the new species, P. sinensis sp. nov. are kept in the Institute of Oceanology, Academia Sinica (Qingdao).     

东海春季赤潮过程中优势种的演替:生物-物理耦合数值模拟

In the East China Sea(ECS), the succession of causative species responsible for blooms is a recurrent phenomenon during the spring, which changes from diatoms to dinoflagellates. Observations from space and in situ cruises captured this pattern of succession during spring of 2005. In this study, we coupled two biological models, which were developed previously for Skeletonema costatum and Prorocentrum donghaiense,into a circulation model tailored for the ECS. The coupled biophysical model was used to hindcast the blooms and to test the hypothesis proposed in earlier studies that phosphate(PO4 3–) is the first-order decider of the succession. The coupled model successfully reproduced the hydrodynamics(as described in a companion paper by Sun et al.(1), the spatiotemporal distribution of the chlorophyll a(Chl a) concentration, and the species succession reasonably well. By analyzing the effects of different factors on the surface Chl a distribution, we confirmed that the offshore boundaries of the blooms were confined by PO4 3–. In addition, we suggest that surface wind fields may modulate the horizontal distribution of blooms. Thus, during the dispersal of blooms, surface winds coupled with PO4 3– may control the succession of blooms in the ECS. The proposed coupled model provides a benchmark to facilitate future improvements by including more size classes for organisms, multiple nutrient schemes, and additional processes.     

STUDY ON TIDAL WAVES OF THE QIANTANGJIANG RIVER

In this paper, the characteristic difference schemes are adopted and the proof calculation of actual measurement data of the Qiantangjiang River is made. The calculating result is in agreement with actual measurement data and conforms with the requirements of the engineering (see Table 1, Table 2 and Fig. 2).In the end, the hydraulics model Eq. (16) is discussed and the discussion shows that the characteristic difference schemes (21) can be used to calculate the tidal bore (discontinuity solutions) because the schemes have a pesudo-viscous term (see Theorem I.)     

Study and application of Toxicity Test Method Using Neomysis awatschensis in Toxicity Evaluation of Drilling Fluid

Neomysis awatschensis was collected on the west coast of Jiaozhou Bay,Qingdao in 1992 and acclimated in the laboratory conditions.The acute toxicity method using 4 ～6 day juvenile mysid of this species is studied.The species is compared with M.bahia in taxonomy,geographic distribution,morphology,as well as the sensitivity to reference toxins,Based on the results,we recommend N.awatschensis to be a standard marine organism for toxicity test in China and the method to be applied in toxicity evaluation of drilling fluids.In this paper,we report the results of the above studies and the application of the method in the evaluation of several drilling fluid products.     

Attitude Coordination of Multi-HUG Formation Based on Multibody System Theory

Application of multiple hybrid underwater gliders (HUGs) is a promising method for large scale, long-term ocean survey. Attitude coordination has become a requisite for task execution of multi-HUG formation. In this paper, a multibody model is presented for attitude coordination among agents in the HUG formation. The HUG formation is regarded as a multi-rigid body system. The interaction between agents in the formation is described by artificial potential field (APF) approach. Attitude control torque is composed of a conservative torque generated by orientation potential field and a dissipative term related with angular velocity. Dynamic modeling of the multibody system is presented to analyze the dynamic process of the HUG formation. Numerical calculation is carried out to simulate attitude synchronization with two kinds of formation topologies. Results show that attitude synchronization can be fulfilled based on the multibody method described in this paper. It is also indicated that different topologies affect attitude control quality with respect to energy consumption and adjusting time. Low level topology should be adopted during formation control scheme design to achieve a better control effect.     

GROUP REPRESENTATION AND ITS APPLICATION TO THE ANALYSIS OF OFFSHORE CONCRETE PLATFORMS

- The analysis of concrete gravity offshore platform with oil storages is one of the topics most concerned by the structural designers. In this paper, the group theoretical formulation of offshore structures with a variety of symmetry and in substructuring assembly is presented. In addition, the soil foundation can be also represented by springs and the interaction between structure and soil can be solved through a global model of the whole system. Numerical example is presented for illustration.     

WAVE ATTENUATION BY BOTTOM FRICTION IN CURRENTS

In nature, wave attenuation always occurs with propagation. In some case, it is significant and can not be neglected. In this paper, the attenuation of wave spectra in current by bottom friction is studied. To simplify the calculation, a linearized bottom friction stress formula is introduced, which gives an equivalent energy loss due to bottom friction. Model test data indicate that the authors' method for the calculation of wave attenuation in this paper agrees well with the experimental result.     

Preliminary Approach to the Development of Benthos Survey Implements——Ⅰ. Stone-Mill-Shaped Sieves and Elutriation Separator

In the present paper,the construction and working principle of stone-mill-shaped sievesand elutriation separator for benthos survey are introduced. The stone-mill-shaped sieves are composed of three round screens and a mildde frame.The lowest screen is the biggest in diameter.Compared with the existing square sieves,thestone-mill-shaped sieves have the advantages of preventing losing organisms when sample     

Nonlinear Effect of Wave Propagation in Shallow Water

—In this paper,a nonlinear model is presented to describe wave transformation in shallow wat-er with the zero-vorticity equation of wave-number vector and energy conservation equation.Thenonlinear effect due to an empirical dispersion relation(by Hedges)is compared with that of Dalrymple＇sdispersion relation.The model is tested against the laboratory measurements for the case of a submergedelliptical shoal on a slope beach,where both refraction and diffraction are significant.The computation re-sults,compared with those obtained through linear dispersion relation.show that the nonlinear effect ofwave transformation in shallow water is important.And the empirical dispersion relation is suitable for re-searching the nonlinearity of wave in shallow water.     

WAVE FORCE ON PIER GROUP

In the case of pier-group structures in offshore engineering construction, the calculation of wave forces on piers is quite complicated due to the wave scattering effect on the piers in group. In this paper, the diffraction problem of two piers with unequal diameters is studied and formulas for calculating wave forces on piers are given on the basis of MacCamy-Fuchs linear wave diffraction theory with a strict consideration on the phase difference between the piers in a pier-group.     

Modal Identification of Offshore Platforms Using Statistical Method Based on ERA

Identification of modal parameters of a linear structure with output-only measurements has received much attention over the past decodes. In the paper, the Natural Excitation Technique (NEXT) is used for acquisition of the impulse signals from the structural responses. Then Eigensystem Realization Algorithm (ERA) is utilized for modal identification.For disregarding the fictitious ‘computational modes’, a procedure, Statistically Averaging Modal Frequency Method (SAMFM), is developed to distinguish the true modes from noise modes, and to improve the precision of the identified modal frequencies of the structure. An offshore platform is modeled with the finite element method. The theoretical modal parameters are obtained for a comparison with the identified values. The dynamic responses of the platform under random wave loading are computed for providing the output signals used for identification with ERA. Results of simulation demonstrate that the proposed method can determine the system modal frequency with high precision.     

Comparison of linear and nonlinear extreme wave statistics

An extremely large (“freak”) wave is a typical though rare phenomenon observed in the sea. Special theories (for example, the modulation instability theory) were developed to explain mechanics and appearance of freak waves as a result of nonlinear wave-wave interactions. In this paper, it is demonstrated that the freak wave appearance can be also explained by superposition of linear modes with the realistic spectrum. The integral probability of trough-to-crest waves is calculated by two methods: the first one is based on the results of the numerical simulation of a wave field evolution performed with one-dimensional and two-dimensional nonlinear models. The second method is based on calculation of the same probability over the ensembles of wave fields constructed as a superposition of linear waves with random phases and the spectrum similar to that used in the nonlinear simulations. It is shown that the integral probabilities for nonlinear and linear cases are of the same order of values     

ANALYSIS OF DYNAMIC STABILITY OF SUBMERGED STRUCTURE

The submerged structure is basically a large three-dimensional structure of few statically redundant members. The structure is subjected to vertical dead and live loads in addition to the wave forces. An analysis of dynamic stability of the submerged structure without damping has been made by J. Thomas and Abbas (1980). In this paper the analyses of dynamic stability of the sumberged structure with damping are conducted. The case structure with damping is more complicated 'than the case without it. According to the principle of perturbation, a new model for dynamic stability calculation in consideration of damping effect is developed. In this paper, the formulas are deduced, the computational program is compiled, the practical examples are analysed, and this problem is solved very satisfactorily. The computational results show that the shape and value of the regions of dynamic instability can be changed significantly by damping. So only by considering damping can the property of dynamic stability of the submerged structure be reflected correctly.     

THE “ION EXCHANGE-PRECIPITATION” ISOTHERM OF HEAVY METAL PARTITIONING BETWEEN LIQUID AND SOLID IN SEAWATER——DE BOER-ZWIKKER EQUATION TREATMENT

Determinded in this paper are 18 isotherms of Cu2 and Pb2 partitioning between liquid and solid (kaolinite, illite and montmorillonite), all proved to be "ion exchange-precipitation" isotherms. This is a new type of isotherms in marine chemistry. We have used the modified BET and T6th equations to describe them. In this paper, we proposed the third expression, i. e. de Boer-Zwikker equation. Theoretically, this method has a proper chemical model. Practically, it is simple and easy to compare with experimental data.     

Dynamic Responses of Mobile Offshore Base Connectors

A Mobile Offshore Base (MOB) is a multi-purpose logistics base, which can be stationed in coastal or international waters. In the conceptual design of the MOB, attention should be paid to the dynamic responses of the inter-module connectors because tremendous loads occur in the connectors. In this paper, a study on dynamic responses of the MOB connectors is carried out by use of the Rigid Module Flexible Connector (RMFC) model which assumes that the module stiffness is significantly larger than that of the connector. In the analysis, the connector is modeled as a linear spring, which restricts relative translations but allows for relative rotations of modules. The 3-D source distribution method is adopted to determine the hydrodynamic forces of the modules, and the hydrodynamic interaction between modules is taken into account. The module motions and connector loads for 12 connector stiffness cases in regular and irregular waves are calculated with the multi-rigid-body motion equations. And the calculat     

APPLICATION OF ELECTRONIC COMPUTERTECHNIQUES TO TAXONOMY OFMARINE ORGANISMS

For the identification of Milleporidae in this paper four designs are given as follows:(1) According to the morphological characters of the studied materials, the computer can present a rapid way to help in identifying specimens and to answer the tpecies name at well at its synonyms.(2) The user can take the second design, if asking for synonyms, numbers and a check of the synonyms are shown on the Video Display of the micromputer.(3) If you want to know the morphological characters of a certain specics, you can take the third design, that is, input a valid species name and its morphological characters will be output automatically.(4) When asking for a valid or an invalid species of Millepora, you caa sclect the fourth design, i.e. input its Latin name and the computer will answer "it is a valid species" or "it is an invalid species and the synonym of a certain valid species".