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Cosmic exergy based ecological assessment for a wetland in Beijing

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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Embodied Energy Account of Chinese Economy 2002

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Procedia environmental Sciences 2011年 5卷 184-198页

作者： M.M. Jiang B. Chen S.Y. Zhou State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China Beijing Development Area Corporate Ltd. Low-carbon Center Beijing 100176 China

In this research, input-output (I-O) model was used to calculate the embodied (direct plus indirect) energy consumption of the Chinese 42 major sectors based on the estimation of the direct energy inputs to the Chinese economy in 2002. Several indicators, involving the embodied energy intensity, imported energy dependent index, and energy balance of trade, were provided to analyze the energy basement of the current Chinese industry. This study also explored the Chinese energy use structure for the added value and final use in 2002, and investigated the disparity in energy use between the rural consumption and the urban consumption. The cluster analysis was employed to group these sectors according to their similarities in embodied energy intensity, imported energy dependency, and energy use structure of final use. Conclusion shows that the energy industries held the highest energy intensities in China while most light industrial sectors, hi-tech sectors and various service sectors enjoyed the lowest energy intensities. And the petroleum associated sectors are most in degree for the imported-energy dependency in 2002, as a great contrast to the coal-associated industries. This was further explored through the Chinese energy balance of trade in 2002, which reveals that the oil consumed sectors encountered serious embodied energy deficits, but the sectors with coal as major fuel held embodied energy surplus.

关键词： Embodied energy Chinese economy I-O analysis 42 sectors Introduction

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Energy cost and greenhouse gas emissions of a Chinese wind farm

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Procedia environmental Sciences 2011年 5卷 25-28页

作者： Q. Yang G.Q. Chen Y.H. Zhao B. Chen Z. Li B. Zhang Z.M. Chen H. Chen State Key Laboratory of Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China China Hua Dian Corporation Beijing 100035 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China

Wind power is considered as one of the most promising renewable energy sources in China. Presented in this study is a life cycle analysis of energy performance and greenhouse gas emission for a typical wind farm in Guangxi, with different stages of manufacturing, transportation, and installation of mechanical components, operation and maintenance, and disassemble and disposal taken into account. Results show that the nonrenewable energy cost and greenhouse gas emission to generate 1 MJ of electricity for the grid are 0.046 MJ and 0.002 kg CO2 equivalent, respectively. In consideration of the dominant power generation technology of coal combustion in China, the nonrenewable energy saving brought about by the concerned wind farm is estimated at 1.22E+7GJ during its twenty year operating period, while the reduced greenhouse gas emissions are as much as 1.03E+06 ton CO2 equivalent. It is believed that this successful example can lend solid support to a future wide use of wind power in China.

关键词： Embodied energy analysis Greenhouse gas emission Wind farm China

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Dual enzymatic saccharification of food waste for ethanol fermentation

Dual enzymatic saccharification of food waste for ethanol fe...

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International Conference on Electrical and control Engineering (ICECE)

作者： Xiangfeng Zhang Tom Richard State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing China Department of Agricultural and Biological Engineering Pennsylvania State University University Park PA USA

Lower efficiency serves as limiting factor in the enzymatic saccharification of food waste (FW) for ethanol fermentation. We investigated the effects of temperature, tetracycline; the optimization of dual enzymatic inoculation using simplex lattice design; as well as batch ethanol fermentation based on optimized FW saccharification The moderate temperature (50°C) was proper to balance the saccharification efficiency and reducing sugar loss. The tetracycline inoculation (80 mg/L) dramatically prevented the reducing sugar loss of saccharification by inhibiting the microbial contaminants. The optimized ratio of α-amylase and amyloglucosidase was 0.5:0.5, which indicated that the experimental results under the optimum conditions agreed well with the model predictions. The ethanol yield reached 0.25 g/g dry FW under optimum conditions of saccharification indicating this strategy could be promising to utilize FW.

关键词： Sugar Ethanol Educational institutions Microorganisms Biochemistry Optimization

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Analysis of an urban energy metabolic system: Comparison of simple and complex model results

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Ecological Modelling 2011年第1期223卷 14-19页

作者： Yan Zhang Shengsheng Li Brian D. Fath Zhifeng Yang Naijin Yang State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Beijing Normal University Xinjiekouwai Street No. 19 Beijing 100875 China Biology Department Towson University Towson MD 21252 USA Advanced Systems Analysis Program International Institute for Applied Systems Analysis Laxenburg Austria

A fundamental difference between simple and complex systems is how the research objects are subdivided to support different study purposes. Based on a comparison between two urban energy system models – one with 5 and the other with 17 sectors – we concluded that the two models were most similar in terms of their description of the overall system structure and most different in terms of their description of specific intra-system relationships. The smaller number of system components and relationships in the 5-sector model facilitated judgments of the system's overall situation, thereby revealing where the key problems were found. In contrast, the 17-sector model provided enough details about the system to assist in the formulation of concrete operational measures to solve specific problems. Our results indicate that the division of a model into sectors should depend on the explicit problem to be solved and the context for that problem; different goals will require different numbers of system components. The results also demonstrate how simple and complex models can be used in tandem to examine a system from different perspectives.

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Notice of Retraction: Growth, Nitrogen and Phosphorous Accumulation of Two Species of Plants in Constructed Wetlands

Notice of Retraction: Growth, Nitrogen and Phosphorous Accum...

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International Conference on Bioinformatics and Biomedical Engineering (ICBBE)

作者： Xiao Liu Tingfangzi Tang Suiliang Huang Yang Luo Numerical Simulation Group for Water Environment Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and En Nankai University Tianjin China Haihe Water Resources Protection Bureau Haihe River Water Conservancy Commission Tianjin China

This article has been retracted by the publisher.

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Image Processing Based Non-Destructive Method for Measuring Growth of Constructed Wetland Plants

Image Processing Based Non-Destructive Method for Measuring ...

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International Conference on Bioinformatics and Biomedical Engineering (ICBBE)

作者： Xiao Liu Tingfangzi Tang Suiliang Huang Yang Luo Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education Numerical Simulation Group for Water Environment Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and En Nankai University Tianjin China Haihe Water Resources Protection Bureau Haihe River Water Conservancy Commission Tianjin China

This paper developed a non-destructive method for measuring growth of constructed wetland plants, and it can be outlined as follow: doing image acquisitions of constructed wetland plants regularly with the help of digital camera; introducing image files to a computer through the developed interface, displaying them on the screen. Under Visual C++ compiling integrated environment, users can use the developed "constructed wetland plant image and growth information extraction software" to acquire plant contours (realized by image edge recognition) and plant sizes (characterized by top projected leaf area). The biomass and manually-measured individual plant heights in the experimental wetlands had good correlations, which indicate that the developed non-destructive method based on computer image processing can provide reliable of plant growing.

关键词： Computers Image color analysis Data mining Image edge detection Biomass Software

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Land use and landscape pattern changes in Nenjiang River basin during 1988-2002

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中国高等学校学术文摘·地球科学 2010年第1期4卷 33-41页

作者： Sihui WANG Yanwei ZHAO Xinan YIN Lei YU Fei XU State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentBeijing Normal University Beijing 100875 China

Based on the Landsat TM data in 1988 and 2002, the GIS technique and Fragstats software were used to calculate the land use conversion matrix and eight landscape metrics at landscape and patch class levels in upstream, midstream, and downstream regions of Nenjiang River basin. The characteristics of land use and landscape pattern changes in each region during 1988-2002 were analyzed. The results show the followings: 1) During the period from 1988 to 2002, farmland and construction land area increased, while the areas of forestland, grassland, and unutilized land decreased in all three regions. The conversion trends from forestland and grassland to farmland were obvious. The conversion from forestland to farmland mainly occurred in the upstream region, whereas the conversion from grassland to farmland primarily occurred in the midstream and downstream regions. 2) The water area in the upstream and midstream regions enlarged, mainly due to the increase of water impounded area as a result of the construction of reservoirs. Comparatively, the water area in the downstream region decreased, and it mainly occurred in the east part of downstream region with concentrated lakes and swamps. 3) The degree of landscape fragmentation increased in each region. The controlling ability of forestland was weakened, and its patch shape became more complicated. In contrast, the controlling ability of farmland was reinforced, and the connectivity among patches increased. 4) The landscape pattern shows some gradient features. From the upstream to downstream regions, the disturbance of human activities on dominant patches was intensified, and consequently, the landscape fragmentation extent and heterogeneity were enhanced.[PUBLICATION ABSTRACT]

关键词： land use landscape pattern Nenjiang River basin

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Integrated water resource security evaluation of Beijing based on GRA and TOPSIS

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中国高等学校学术文摘·地球科学 2010年第3期4卷 357-362页

作者： Jing DAI Jing QI Jingjing CHI Shaoqing CHEN Jin YANG Liping JU Bin CHEN State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

Security evaluation has become a hot topic in the research field of water resource management. In this paper, we established a novel water resource security indicator system based on the Pressure-Status-Response (PSR) framework using gray relation analysis (GRA) and technique for order preference by similarity to ideal solution (TOPSIS). A case study of Beijing from 1996 to 2007 was conducted to verify the evaluation system. Results showed that the gray relative closeness degrees of water resource security to the positive ideal solution were low, with the least one of 0.360 in 1999 and the largest one of 0.527 in 2007, implying that Beijing was facing severer challenges with water resources during the concerned time. Also, the analysis of water resource security indicated that the pressure of water resource was constantly increasing. Finally, factor analysis was employed to calculate the gray relation degrees of evaluating indices with the ideal solutions so as to reveal the relativity of water resource security of Beijing, which may contribute to a better understanding of the urban water resource management and regulation.

关键词： water resource security grey relation analysis (GRA) technique for order preference by similarity to ideal solution (TOPSIS) factor analysis

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Energy cost and greenhouse gas emissions of a Chinese solar tower power plant

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Procedia environmental Sciences 2011年 5卷 77-80页

作者： Q. Yang G.Q. Chen Y.H. Zhao B. Chen Z. Li Z.F. Wang State Key Laboratory of Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China China Hua Dian Corporation Beijing 100035 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China Key Laboratory of Solar Thermal Energy and Photovoltaic System of Chinese Academy of Sciences Institute of Electrical Engineering P.O. Box 2703 Beijing 100190 China

It is commonly assumed that the application of solar power system can save energy and relief global climate change. Presented in this study is the account of energy performance and greenhouse gas emissions of a planned solar tower power plant in China based on the life cycle analysis method. The conservative estimation of energy cost for the concerned plant is 1.21 times of the electricity output, which is a relatively decent performance amongst power generation technologies. In order to analyze the greenhouse gas performance, a comparison is carried out between the solar tower power plant and conventional coal-fired power plant in China. Results show the application of this solar system obtains a net greenhouse gas emission reduction of 0.31E+06 ton CO2 equivalent, during its operating period of twenty years. It is believed that this successful example can lend solid support to a future wide use of solar power in China.

关键词： Solar tower power plant Electricity generation Energy analysis Greenhouse gas emission

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