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Acta Geologica Sinica(English Edition) 2011年第6期85卷 1478-1494页

作者： CAI Xiyuan ZHU Rong China Petroleum and Chemical Corporation Beijing 100029 China department of ocean science andengineering Zhejiang University Hangzhou 310028 China

Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level＇s fluctuation on the sandbodies at shallow-water delta front are systematically summarized and the sedimentary dynamic processes are analyzed. The interwell communication among the sandbodies and their planar distribution revealed from the hydrodynamic features of the development wells are integrated during the analysis. The fundamental requirements for the development of the shallow-water delta included flat topography and uniform subsiding rate. The delta plain was connected smoothly with the wide delta front and predelta, without the three-fold structure of topset, foreset, and bottomset as defined in the Gilbert Delta Model. Because of the weak fluvial effect and the lake energy is strong, the small and scattered shallow-water delta is destroyed by the scouring-backwashing, coastal current, and lake wave, resulting in the coastal sheet deposition. As the fluvial effect became stronger and the lake energy became weaker, the shape of the shallow-water deltas transferred from sheets to lumps and then branches.

关键词： lake-level fluctuation shallow-water delta sedimentary dynamics,Songliao Basin China

Elastic Behavior of Polymer Chains

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Chinese Journal of Chemical Physics 2008年第5期21卷 463-468页

作者： Teng Lu Tao Chen Hao-jun Liang Hefei National Laboratory for Physical sciences at Microscale Department of Polymer Science andEngineering University of Science and Technology of China Hefei 230025 China

The elastic behavior of the polymer chain was investigated in a three-dimensional off-lattice model. We sample more than 109 conformations of each kind of polymer chain by using a Monte Carlo algorithm, then analyze them with the non-Gaussian theory of rubberlike elasticity, and end with a statistical study. Through observing the effect of the chain flexibility and the stretching ratio on the mean-square end-to-end distance, the average energy, the average Helmholtz free energy, the elastic force, the contribution of energy to the elastic force, and the entropy contribution to elastic force of the polymer chain, we find that a rigid polymer chain is much easier to stretch than a flexible polymer chain. Also, a rigid polymer chain will become difficult to stretch only at a quite high stretching ratio because of the effect of the entropy contribution. These results of our simulation calculation may explain some of the macroscopic phenomena of polymer and biomacromolecular elasticity.

关键词： Monte Carlo algorithm Three-dimensional off-lattice model Elastic behavior Polymer

Synthesis and Characterization of Cobalt-Carbon Core-Shell Microspheres in Supercritical Carbon Dioxide System

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Chinese Journal of Chemical Physics 2008年第1期21卷 76-80页

作者： Jun-song Yang Qian-wang Chen Hefei National Laboratory for Physical sciences at Microscale Department of Materiab Science andEngineering Department of Chemisto4 University of Science and Technology of China Hefei 230025China

The synthesis of cobalt-carbon core-shell microspheres in supercritical carbon dioxide system was investi- gated. Cobalt-carbon core-shell microspheres with diameter of about 1μm were prepared at 350 ℃ for 12 h in a closed vessel containing an appropriate amount of bis（cyclopentadienyl）cobalt powder and dry ice. Characterization by a variety of techniques, including X-ray powder diffraction, X-ray photoelectron spectroscopy, TransmissiOn electron microscope, Fourier transform infrared spectrum and Raman spectroscopy analysis reveals that each cobalt-carbon core-shell microsphere is made up of an amorphous cobalt core with diameter less than 1 μm and an amorphous carbon shell with thickness of about 200 nm. The possible growth mechanism of cobalt-carbon core-shell microspheres is discussed, based on the pyrolysis of bis（cyclopentadienyl）cobalt in supercritical carbon dioxide and the deposition of carbon or carbon clusters with odd electrons on the surface of magnetic cobalt cores due to magnetic attraction. Magnetic measurements show 141.41 emu/g of saturation magnetization of a typical sample, which is lower than the 168 emu/g of the corresponding metal cobalt bulk material. This is attributed to the considerable mass of the carbon shell and amorphous nature of the magnetic core. Control of magnetism in the cobalt-carbon core-shell microspheres was achieved by annealing treatments.

关键词： Cobalt-carbon core-shell microspheres Supercritical carbon dioxide system

Fully Nonlinear Simulations of Wave Resonance by An Array of Cylinders in Vertical Motions

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China ocean Engineering 2013年第1期27卷 87-98页

作者：黄豪彩王赤忠冷建兴 department of ocean science and Engineering Zhejiang University

The finite element method （FEM） is employed to analyze the resonant oscillations of the liquid confined within multiple or an array of floating bodies with fully nonlinear boundary conditions on the free surface and the body surface in two dimensions. The velocity potentials at each time step are obtained through the FEM with 8-node quadratic shape functions. The finite element linear system is solved by the conjugate gradient （CG） method with a symmetric successive overelaxlation （SSOR） preconditioner. The waves at the open boundary are absorbed by the combination of the damping zone method and the Sommerfeld-Orlanski equation. Numerical examples are given by an array of floating wedge- shaped cylinders and rectangular cylinders. Results are provided for heave motions including wave elevations, profiles and hydrodynamic forces. Comparisons are made in several cases with the results obtained from the second order solution in the time domain. It is found that the wave amplitude in the middle region of the array is larger than those in other places, and the hydrodynamic force on a cylinder increases with the cylinder closing to the middle of the array.

关键词： resonance an array of cylinders fully nonlinear wave high order finite element method

Probabilistic Distribution of the Maximum Wave Heigh

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China ocean Engineering 2014年第5期28卷 579-586页

作者： Dong Hyawn KIM Taerim KIM department of ocean science and Engineering Kunsan National University

A new method of treating maximum wave height as a random variable in reliability analysis of breakwater caissons isproposed. The maximum wave height is expressed as the significant wave height multiplied by the so-called wave height *** proposed wave height ratio is a type of transfer function from the significant wave height to the maximum wave *** the condition of a breaking wave, the ratio is intrinsically nonlinear. Therefore, the probability density function for thevariable cannot be easily defined. In this study, however, it can be derived from the relationship between the maximum andsignificant waves in a nonbreaking environment. Some examples are shown to validate the derived probability density functionfor the wave ratio parameter. By introducing the wave height ratio into reliability analysis of caisson breakwater, the maximumwave height can be used as an independent and primary random variable, which means that the risk of caisson failure during itslifetime can be evaluated realistically.

关键词： maximum wave height wave height ratio reliability caisson breakwater wave breaking

Risk Analysis of Breakwater Caisson Under Wave Attack Using Load Surface Approximation

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China ocean Engineering 2014年第6期28卷 739-748页

作者： Dong Hyawn KIM department of ocean science and Engineering Kunsan National University

A new load surface based approach to the reliability analysis of caisson-type breakwater is proposed. Uncertainties of the horizontal and vertical wave loads acting on breakwater are considered by using the so-called load surfaces, which can be estimated as functions of wave height, water level, and so on. Then, the first-order reliability method（FORM） can be applied to determine the probability of failure under the wave action. In this way, the reliability analysis of breakwaters with uncertainties both in wave height and in water level is possible. Moreover, the uncertainty in wave breaking can be taken into account by considering a random variable for wave height ratio which relates the significant wave height to the maximum wave height. The proposed approach is applied numerically to the reliability analysis of caisson breakwater under wave attack that may undergo partial or full wave breaking.

关键词： failure probability load surface reliability caisson breakwater wave breaking FORM

Micro-phytoplankton distribution and biomass in and around a channel-based fish farm: implications for sustainable aquaculture

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Acta oceanologica Sinica 2014年第12期33卷 180-191页

作者： SADALLY S. B NAZURALLY N TALEB-HOSSENKHAN N BHAGOOLI R department of Biosciences Faculty of Science University of Mauritius department of Marine and ocean science Fisheries and Mariculture Faculty of Ocean Studies

Micro-phytoplankton density, genera composition, chlorophyllaconcentration, and physico-chemical pa-rameters were investigated at five stations （S1-near the coast; S2 and S4-at the edges of the aquaculture set-up; S3-in the center of the set-up; and S5-nearby patch of corals） in and around a coastal channel-based fish farm. The highest total micro-phytoplankton density （TPD）, including diatoms, dinoflagellates and cyanobacteria, was recorded at S3 （（6.28±2.00）×10^6 cells/L） followed by S4 （（5.87±2.81）×10^5 cells/L）, S1 （（4.92×10^5±8.70×10^4） cells/L）, S5 （（3.54×10^5±5.33×10^4） cells/L） and S2 （（2.60±1.14）×10^5cells/L）. Chlorophyll a and nutrient concentrations were highest at S3 and were positively correlated with TPD. Among the 35 genera documented in this study,Chaetoceros spp. was the dominant diatom whilePeridinium spp. was the most dominant dinoflagellate. Very low densities of toxic bloom-forming dinoflagellates were encountered during this study. These results suggest that occurrence of non-bloom densities of micro-phytoplankton, possibly due to the natural flushing of the existing lagoonal channel at the aquaculture site, yielded in little environmental impact and can represent an appropriate sustainable approach for future aquaculture de-velopment.

关键词： chlorophyll a micro-phytoplankton physico-chemical parameters sustainable aquaculture

Characterization of the Elastic-plastic Region Based on Magnetic Memory Effect

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Chinese Journal of Mechanical Engineering 2010年第4期23卷 532-536页

作者： LENG Jiancheng XU Minqiang LI Jianwei ZHANG Jiazhong School of Astronautics Harbin Institute of Technology Harbin 150001 China department of Mechanical science andengineering Daqing Petroleum Institute Daqing 163318 China

Detecting stress concentration, especially critical stress state leading to structure damage or failure, is one of the most important tasks of equipment diagnosis. Metal magnetic memory technique needs further research to evaluate stress concentration quantitatively due to ambiguous physical mechanism, though it has potential to detect early defects in ferromagnetic materials. Mild Q235 steel defective specimens in demagnetization state were loaded in tension up to visible necking, with magnetic memory signals measurement made at increasing stress levels. Magnetic signals varied greatly under first several loadings and subsequently tended to stability in the elastic region, which showed that the magnetization always approaches the anhysteretic magnetization curve and was explained by the theory of magnetomechanical effect. In the plastic stage, an abnormal wave occurred in the stress concentration zone and its height value was sensitive to plastic deformation levels and dependent on the distance between the probe and defect, in accordance with the simulation results based on the magnetic dipole model. Different magnetic signal characteristics in the elastic-plastic region indicate that the magnetic memory technique can identify macroyielding and early damage, which is of profound significance for ensuring safe operation of equipment in service.

关键词： metal magnetic memory plastic deformation magnetomechanical effect magnetic dipole model abnormal wave

Solution of scattering from rough surface with a 2D target above it by a hybrid method based on the reciprocity theorem and the forward-backward method

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Chinese Physics B 2008年第10期17卷 3696-3703页

作者：王运华张彦敏贺明霞郭立新 ocean Remote Sensing Institute Ocean University of China department of Physics Ocean University of China School of science Xidian University

This paper proposes a hybrid method based on the forward-backward method （FBM） and the reciprocity theorem （RT） for evaluating the scattering field from dielectric rough surface with a 2D target above it. Here, the equivalent electric/magnetic current densities on the rough surface as well as the scattering field from it are numerically calculated by FBM, and the scattered field from the isolated target is obtained utilizing the method of moments （MOM）. Meanwhile, the rescattered coupling interactions between the target and the surface are evaluated employing the combination of FBM and RT. Our hybrid method is first validated by available MOM results. Then, the functional dependences of bistatic and monostatic scattering from the target above rough surface upon the target altitude, incident and scattering angles are numerically simulated and discussed. This study presents a numerical description for the scattering mechanism associated with rescattered coupling interactions between a target and an underlying randomly rough surface.

关键词： forward-backward method reciprocity theorem 2D target rough surface scattering

Investigation on the Doppler shifts induced by 1-D ocean surface wave displacements by the first order small slope approximation theory:comparison of hydrodynamic models

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Chinese Physics B 2010年第7期19卷 230-237页

作者：王运华张彦敏郭立新 ocean Remote Sensing Institute Ocean University of China department of Physics Ocean University of China School of science Xidian University

Based on the first order small slope approximation theory （SSA-I） for oceanic surface electromagnetic scattering, this paper predicts the Doppler shifts induced by wave displacements. Theoretical results from three distinct hydrody- namic models are compared： a linear model, the nonlinear Barrick model, and the nonlinear Creamer model. Meanwhile, the predicted Doppler shifts are also compared with the results associated to the resonant Bragg waves and the so-called long waves in the framework of the two-scale model. The dependences of the predicted Doppler shifts on the incident angle, the radar frequency, and the wind speed are discussed. At large incident angles, the predicted Doppler shifts for the linear and nonlinear Barrick models are found to be insensitive to the wind speed and this phenomenon is not coincident with the experimental data. The conclusions obtained in this paper are promising for better understanding the properties of time dependent radar echoes from oceanic surfaces.

关键词： Doppler shifts sea surface model SSA-I electromagnetic scattering