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Transport of bicomponent contaminant in free-surface wetland flow

Transport of bicomponent contaminant in free-surface wetland...

第十一届全国水动力学学术会议暨第二十四届全国水动力学研讨会并周培源诞辰110周年纪念大会

作者： CHEN Bin ZENG Li CHEN Guo-qian WU Yi-hong JI Ping ZHAO Yi-jun WU Zi FENG Le State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal University State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower Research State Key Laboratory of Turbulence and Complex Systems College of EngineeringPeking University

Presented in this paper is a theoretical analysis for a pulsed bicomponent contaminant emission into a free-surface wetland *** equations are introduced for bicomponent contaminant transport in wetland flow under the combined action of advection,mass dispersion, and ecological reaction at phase average *** effect of ecological reaction is separated from hydrodynamic effect via a set of widely used *** solution for evolution of depth-averaged concentration is rigorously derived and illustrated,with a limiting case covering the known solution for single component contaminant *** is found that the depth-averaged species concentration of bicomponent contaminant can approach an equlibrium status which is determined by distribution coefficient.

关键词： Contaminant dispersion Bicomponent contaminant Wetland hydrodynamics Envrionmental risk assessment

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Visualization of signalized intersections in driving simulator and validity of driving behaviors in virtual environments

Advances in Transportation Studies

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Advances in Transportation Studies 2012年第26期 17-28页

作者： Yan, X. Abdel-Aty, M. Guo, D. Radwan, E. MOE Key Laboratory for Transportation Complex Systems Theory and Technology Beijing Jiaotong University Beijing 100044 China Department of Civil and Environmental Engineering University of Central Florida Orlando FL 32816-2450 United States Computer Science Program College of Business Florida Gulf Coast University 10501 FGCU Boulevard South Fort Myers FL 33965-6565 United States Center for Advanced Transportation Systems Simulation University of Central Florida Orlando FL 32816-2450 United States

Visualization of highway traffic environments in virtual reality plays a key role on fidelity of simulation and validity of driving behaviors in driving simulator studies. This paper describes a procedure to replicate a signalized intersection with many complex features into a driving simulator's 3-D databases through building a graphical visual database, constructing a road motion database, and creating simulated traffic. The validity of the visualization was assessed via the comparison of the drivers' speeds in the simulator and the speed data at the real intersection. It was found that both speed data follow normal distributions and have equal means for each intersection approach;however, that the speeds measured in the driving simulator have a larger variability than those measured in the field. The users' subjective evaluation results indicated that 92% subjects could recognize the simulated intersection in the driving simulator experiment. Therefore, the strategy of geo-specific environment modeling would be useful for studying driving behaviors in virtual environments.

关键词： Visualization

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Foreword

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Particuology 2011年第4期9卷 319-319页

作者： Ning Yang Wei Ge Jinghai Li State key laboratory of Multiphase complex systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China Aibing Yu laboratory for simulation and modeling of Particulate systems, School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Laboratory for Simulation and Modeling of Particulate Systems School of Materials Science and Engineering The University of New South Wales Sydney NSW 2052 Australia

Granular materials are ubiquitous in nature and engineering. They display both fluid- and solid-like behavior with fascinating complexity and remarkable uniqueness. Their behavior at different scales is strongly coupl... 详细信息

关键词： materials different Understanding size effects structures complexity challenge products display nature high

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An estimation of ecological risk after dam construction in LRGR, China: Changes on heavy metal pollution and plant distribution

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Procedia Environmental Sciences 2011年 5卷 153-159页

作者： Shaoqing Chen Bin Chen Meirong Su State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

Dam construction has become one of the most controversial and wide-debated issues these days, mainly due to the unanticipated ecological risk it brings to river basin. Though the environmental impact caused by dam project has been reported in considerable literatures, most of them were concerned with the condition of aquatic ecosystem (e.g., hydrology, water quality, sediment, and aquatic fauna) with the potential risk of terrestrial ecosystem remaining unsettled. This study estimated the ecological risk on terrestrial ecosystem after dam construction by focusing on the heavy metal pollution and distribution of plant community in Lancang River of LRGR. The heavy metals were determined, and the plants were investigated in the reservoir and downstream of three dams built on the river. The results showed that notable changes had taken place in both objects, which indicated the existence of ecological risk on river ecosystem. This study might serve as the first step of computing dam-induced risk in wholeecosystem scale.

关键词： River ecosystem Ecological risk Heavy metal pollution Plant distribution LRGR

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Erratum: Chiral phase and quantum phase transitions of anisotropic XY chains with three-site interactions

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Journal of Statistical Mechanics: Theory and Experiment 2012年第11期2012卷

作者： Xiaoxian Liu Ming Zhong Hui Xu Peiqing Tong Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210046 People's Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210046 People's Republic of China

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A new way to quantify ecological and economic interactions between two cities using emergy analysis

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Procedia Environmental Sciences 2011年 5卷 60-64页

City interaction, though of great importance in the context of market-oriented economy, has rarely been studied quantitatively compared to structure and function inside the city due to the tribulation when acquiring and disposing the relational data between cities. Herein, we quantified city-to-city relations in ecological and economic contexts with the application of emergy analysis, which proved to be a promising approach to evaluating various city flows on a common basis. Emergy diagram of urban system was constructed, and the related relational data were chosen from the ecological and economic aspects respectively to form two integrated indicator systems incorporating the transfer of labor, material and currency, etc. Based on the ecological and economic emergy of urban system, the city-to-city sustainability index was established to identify the sustainable conditions of the two cities, and hopefully, it could reveal potential complementarity or competition between these cities over time. With the introduction of emergy analysis, this study provided a new way to quantify city interaction; it might also shed light on how an enhancement and amelioration of inter-city cooperation could substantially contribute to the sustainable development on a regional scale.

关键词： City interaction Emergy analysis Ecological distance Sustainable development

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How to guide a sustainable industrial economy: Emergy account for resources input of Chinese industry

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Procedia Environmental Sciences 2011年 5卷 51-59页

作者： B. Zhang G.Q. Chen Q. Yang Z.M. Chen B. Chen Z. Li State Key Laboratory of Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China

Emergy analysis provides a feasible approach to evaluate the status and position of different energy carriers in the universal energy hierarchy. In this paper, an emergy-based method is conducted to measure the resources input of Chinese industry from 1997 to 2006. Resources inflows including fossil fuels, mineral resources, agricultural products, and other imported materials are accounted, based on which related indicators including resources intensity, industrial output, and environmental emissions are investigated. Results show a steady upward trend for the total resources input of Chinese industry during the past decade. The total resources input amounted to 1.53×1025 sej in 2006, of which non-renewable one accounted for 70.65% owing to the dominating input of fossil fuels and nonmetal minerals. Resources intensity measured by the ratio of resources input to industrial value added declined gradually during 1997–2002, but the rapid expansion of resource–intensive sub–sectors resulted in a reverse trend since 2003. The current resources use pattern of Chinese industry is characterized by increasing input of non-renewable resources, excessive expansion of resource–intensive production, and tremendous challenge from environmental pressure.

关键词： Emergy Resources input Chinese industry

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Evaluation of the changed properties of aquatic animals after dam construction using ecological network analysis

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Procedia Environmental Sciences 2011年 5卷 114-119页

作者： Shaoqing Chen Brian Fath Bin Chen Meirong Su State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China Department of Biological Sciences Towson University Towson MD 21252 USA Dynamic Systems International Institute for Applied Systems Analysis Laxenburg Austria State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

Dam construction results in variations of hydrology, river morphology and habitat and the biota associated with the reservoir change significantly compared to the assemblage before dam construction in order to match these changed environmental conditions. Some attempts so far have been made to ascertain the changed properties of aquatilia due to dam construction. Most of them, however, were focused on perturbances to single factors, such as rearing habitats, reproduction and migration routes, etc. Few have been done on the performance of aquatilia from the whole-ecosystem perspective. Herein, we evaluate the structural properties of aquatic animals and their complex ecological relationships within the ecosystem before and after dam construction based on ecological network analysis. This study provides a feasible way for integral ecosystem evaluation with the application of ecological network analysis to river ecosystem subjected to human disturbance.

关键词： Aquatic Animals Dam Construction Ecological Network Analysis

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Cosmic exergy based ecological assessment for a wetland in Beijing

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Ecological Modelling 2011年第2期222卷 322-329页

作者： Z.M. Chen B. Chen G.Q. Chen State Key Laboratory of Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment No. 19 Xinjiekouwai Street Beijing Normal University Beijing 100875 China

Wetlands research and restoration has become one of the critical concern due to their importance in providing ecosystem services. This study proposes a holistic methodology to assess the wetland ecosystem based on cosmic exergy as a thermodynamic orientor. This new approach is applied to two typical wastewater treatment facilities (an activated sludge system and a cyclic activated sludge system) and to a constructed wetland ecosystem in Beijing for comparison. Results show that the Beijing wetland ecosystem gains positive net present ecological value of 3.08E+14 J c regarding its total life cycle. Comparison with the activated sludge system and cyclic activated sludge system, shows that the wetland ecosystem has greater dependencies on local resources (22% vs. 0% vs. 0%) and renewable resources (67% vs. 38% vs. 31%) as well as a larger ecological sustainability index (0.64157 vs. 0.00005 vs. 0.00008). This implies that the wetland ecosystem is more environmentally friendly and sustainable method for water treatment .

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Heat conduction in one-dimensional aperiodic quantum Ising chains

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Physical Review E 2011年第3期83卷 031128-031128页

作者： Wenjuan Li Peiqing Tong Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210046 People’s Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210046 People’s Republic of China

The heat conductivity of nonperiodic quantum Ising chains whose ends are connected with heat baths at different temperatures are studied numerically by solving the Lindblad master equation. The chains are subjected to a uniform transverse field h, while the exchange coupling Jm between the nearest-neighbor spins takes the two values JA and JB arranged in Fibonacci, generalized Fibonacci, Thue-Morse, and period-doubling sequences. We calculate the energy-density profile and energy current of the resulting nonequilibrium steady states to study the heat-conducting behavior of finite but large systems. Although these nonperiodic quantum Ising chains are integrable, it is clearly found that energy gradients exist in all chains and the energy currents appear to scale as the system size 〈Q〉~Nα. By increasing the ratio of couplings, the exponent α can be modulated from α>−1 to α<−1 corresponding to the nontrivial transition from the abnormal heat transport to the heat insulator. The influences of the temperature gradient and the magnetic field to heat conduction have also been discussed.

关键词： HEAT conduction ISING model EQUATIONS FIBONACCI sequence THERMAL conductivity

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