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Biological exposure models for oil spill impact analysis

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Journal of Environmental Sciences 2000年第4期12卷 482-485页

作者： XIONG De qi 1, Mark Reed 2. Narve Ekrol 2.(1. department of Marine Environmental engineering, Dalian Maritime {2., Dalian 11602., china E mail: deqi@*** 2. department of Environmental engineering, SINTEF Applied Chemistry Institut 大连海事大学辽宁大连 1 1 6 0 2 SINTEF Applied Chemistry Institute 挪威 Trondheim 70 3 4

The oil spill impact analysis (OSIA) software system has been developed to supply a tool for comprehensive, quantitative environmental impact assessments resulting from oil spills. In the system, a biological component evaluates potential effects on exposed organisms based on results from a physico chemical fates component, including the extent and characteristics of the surface slick, and dissolved and total concentrations of hydrocarbons in the water column. The component includes a particle based exposure model for migratory adult fish populations, a particle based exposure model for spawning planktonic organisms (eggs and larvae), and an exposure model for wildlife species (sea birds or marine mammals). The exposure model for migratory adult fish populations simulates the migration behaviors of fish populations migrating to or staying in their feeding areas, over wintering areas or spawning areas, and determines the acute effects (mortality) and chronic accumulation (body burdens) from the dissolved contaminant. The exposure model for spawning planktonic organisms simulates the release of eggs and larvae, also as particles, from specific spawning areas during the spawning period, and determines their potential exposure to contaminants in the water or sediment. The exposure model for wild species calculates the exposure to surface oil of wildlife (bird and marine mammal) categories inhabiting the contaminated area. Compared with the earlier models in which all kinds of organisms are assumed evenly and randomly distributed, the updated biological exposure models can more realistically estimate potential effects on marine ecological system from oil spill pollution events.

关键词： oil spill biological exposure acute effects chronic accumulation migration of fish spawning of eggs and larvae habitat

Dynamic behavior of polymer surface and the time dependence of contact angle

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Science china Chemistry 2005年第6期48卷 553-559页

作者： WANG Xinping1, CHEN Zhifang1 & SHEN Zhiquan2.1. Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, department of Applied Chemistry, Zhejiang Institute of Science and Technology, Hangzhou 310033, china 2. department of Polymer Science and engineering, Zhejiang university, Hangzhou 31002., china department of Applied Chemistry Zhejiang Institute of Science and Technology Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry Hangzhou China department of Polymer Science and engineering Zhejiang University Hangzhou China

Time-dependent contact angles were measured by depositing sessile drops of wa-ter on the polymer surfaces and monitoring the drop shape as a function of time. It was found that contact angles decreased sharply with contact time and the equilibrium contact angle was finally attained after a certain time. Values of starting (θ s) and equilibrium contact angles (θ e) obtained by the sessile drop method depend on polymer properties. The Wilhelmy plate technique was used to measure advancing and receding contact angles. The variations of starting (θ s) and equilibrium contact angles (θ e), advancing (θ a) and receding contact angles (θ r) have been studied on the oxidized surface of polymers containing polybutadiene block to explore the cause of time-dependence in contact angle measurement and the meaning of θ s and θ e. The results showed the linear relationships between starting (θ s) and advancing contact angles (θ a), the equilibrium (θ e) and receding contact angles (θ r). The similar relationship was also established between the contact angle hysteresis (θ a?θ r) and differences (θ s ?θ e) in starting contact angles and equilibrium contact angles. Therefore, time-dependence in contact angle measurement was mainly attributed to the surface reconstruction when water drops were deposited on polymer surfaces. The starting contact angle was contributed by the hydrophobic component on polymer surface and the equilibrium contact angle mainly by the hydrophilic component of polymer. These results not only demonstrated the interdependency between two contact angle measurements, the sessile drop method and the Wilhelmy plate technique, but also provided the experimental evidence to explain the cause of time-dependent contact angle. This may also provide a new method to study dynamic behavior of polymer surface.

关键词： contact angle, surface dynamic behavior, polymer surface, dynamic contact angle, time-dependence.

MESHLESS METHOD FOR 2. MIXED-MODE CRACK PROPAGATION BASED ON VORONOI CELL

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Acta Mechanica Solida Sinica 2003年第3期16卷 231-239页

作者： Lou Luliang Zeng Pan (department of mechanical {2.,Tsinghua university,Beijing 100084,china) department of mechanical {2. Tsinghua University Beijing 100084 China

A meshless method integrated with linear elastic fracture mechanics(LEFM)is presented for 2. mixed-mode crack propagation *** domain is divided automatically into sub-domains based on Voronoi cells,which are used for quadrature for the potential energy. The continuous crack propagation is simulated with an incremental crack-extension method which assumes a piecewise linear discretization of the unknown crack *** each increment of the crack extension,the meshless method is applied to carry out a stress analysis of the cracked *** J-integral,which can be decomposed into mode Ⅰ and mode Ⅱ for mixed-mode crack,is used for the evaluation of the stress intensity factors(SIFs).The crack-propagation direction,predicted on an incremental basis, is computed by a criterion defined in terms of the SIFs. The flowchart of the proposed procedure is presented and two numerical problems are analyzed with this *** meshless results agree well with the experimental ones,which validates the accuracy and efficiency of the method.

关键词： meshless method crack propagation mixed-mode crack Voronoi cell

INFLUENCES OF MODIFIERS ON SURFACE PROPERTIES OF WHITE CARBON BLACK AND mechanical PROPERTIES OF SILICONE RUBBER

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 1090-1093页

作者： D.M. Zheng, J. Yan and B.Q. Jiang Chemical engineering department of{2., nanchang 3.0029, china

Various of modifiers were used to modify the surface activity of white carbon black. The oil absorption, viscosity, hydrophobic rate and burning loss of white carbon black and the mechanical propertiess of silicone rubber were measured. The influences of the modifiers on the properties of white carbon black and the mechanical properties of silicone rubber were discussed.

关键词： white carbon black modifier silicone rubber

Tribological Properties of Dimpled Surface Alloying Layer on Carbon Steel

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Journal of Wuhan university of Technology(Materials Science) 2009年第2期24卷 218-222页

作者：万轶 department of Materials Science & engineering Nanjing University of Science and Technology department of mechanical and Electrical {2. Yingtian College

The effect of surface structure and coating on tribological properties of 45^# carbon steel disc was analyzed. A Nd：YAG laser was used to generate rnicrodirnples on steel surfaces. Dimples with diameter of 150 rn and depth of 50 rn were distributed in an orbicular array on disc surface. Then the alloying element Mo was sputtered to 45# carbon steel disc surface by means of double glow plasma technology. Diffusion Mo alloying layer with 30min thickness and high hardness up to 0.02. was formed on the disc surface. Tribological experiments of three types samples （smooth, texturing and texturing＋alloying） were conducted with a pin-on-disc tribometer. It is found that the dimpled-samples are most effective for reducing friction in comparison with smooth steel surthces, improving the lubricating state from boundary to hydrodynamic region.

关键词： laser surface texturing double glow plasma surface alloying technology carbon steel tribological performance lubricating state

The numerical method for three-dimensional impact with friction of multi-rigid-body system

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 102-118页

作者： ZHAO Zhen1,2. LIU Caishan2.& CHEN Bin2.1. Beijing Institute of Graphic Communication, Beijing 102.00, china 2. department of Mechanics & {2. Science, Peking university, Beijing 100871, china Beijing Institute of Graphic Communication Beijing China department of Mechanics & engineering Science Peking University Beijing China

The differential equations for planar impacts reduce to an algebraic form, and can be easily solved. For three dimensional impacts with friction, there is no closed-form solution, and numerical integration is required due to the swerve behavior of tangential impulse during collisions. The dynamic governing equations in the impact process are built up in impulse space based on the Lagrangian equation in this paper. The coefficient of restitution defined by Poisson is used as the condition of impact termination. A valid nu- merical method for solving three-dimensional frictional impact of multi-rigid body system is established. The singular cases of tangential movement in sticking point are especially noticed and analyzed. Several examples are present to reveal the different kinds of tan- gential movement modes varied with the normal impulse during collision.

关键词： multi-rigid body, impact, friction.

STRESS-STRAIN FINITE ELEMENT ANALYSIS AND FATIGUE LIFE PREDICTION FOR BOLTED CONNECTIONS

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Chinese Journal of mechanical engineering 2002年第1期15卷 75-78页

作者： Wang Ziqin Xie Qingsheng mechanical engineering {2.，Guizhou university of Technology，Guiyang 550003，china mechanical engineering {2. Guizhou University of Technology Guiyang 550003

A cyclic plasticity model is used into finite element (FE) method to obtainthe details of elastic-plastic stress-strain in the bolts under cyclic axial loading. Two criteriain multiaxial fatigue are employed to predict fatigue lives of bolts. The predicted fatigue livesare in favorable agreement with the experimental results for machined bolts.

关键词： Finite element Fatigue Bolted connection

Experimental study on bed-load sediment transport under irregular wave and current combined flow

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Acta Oceanologica Sinica 2001年第2期20卷 271-280页

作者： Wu Yongsheng,Qin Chongren (1. department of Hydraulic engineering, Tsinghua {2., Beijing 100084, china 2. School of Civil engineering, Tianjin {2., Tianjin 300072. china) department of Hydraulic engineering Tsinghua University Beijing 100084 China

Using an irregularly oscillating tray and flume, a series of experiments are completed to evaluate bed-load sediment transport rate under irregular wave -current coexistent field. Testing conditions include three interaction angles 0', 45', 90' and two kinds of median sizes (0.38 and 1.10 mm). The results of transport rate show that the net sediment transport rate can be expressed approximately as the function of the maximum bottom shear stress of waves, mean shear stress of current and the grain size.

关键词： Irregular wave-current bed-load transport rate

Numerical Simulation of Shrinkage Cavity Formation in Spheroidal Graphite Iron Castings Based on Micro Modeling

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International Journal of Minerals,Metallurgy and Materials 1998年第1期12卷 9-12页

作者： Wenzhen Li Baicheng Liu Shantong Jin (Metallurgy engineering School, university of Science and Technology Beijing, Beijing 100083,{2.)(department of mechanical engineering, Tsinghua university, Beijing 100084,{2.) Metallurgy engineering School University of Science and Technology Beijing Beijing 100083 China department of mechanical {2. Tsinghua University Beijing 100084 China

A micro-modeling method (MM) for the quantitative prediction of the shrinkage cavity formation in SGiron castings is proposed. The mathematical models describing the volume changes during the solidification ofspheroidal graphite cast iron are established based on the models of solidification kinetics. The shrinkage cavityformation of T-shaped SG iron castings is calculated with MM method. The calculated results are compared with theexperimental results. It is shown that the predicted size, shape and distribution of shrinkage cavity by MM methodare in good agreement with the measured results.

关键词： solidification shrinkage numerical simulation micro modeling spheroidal graphite cast iron