Unified process assessment for resources use and waste emissions by coal-fired power generation

A unified process assessment is carried out to integrate various resources and emissions associated with the life cycle of typical coal-fired power generation systems, based on the thermodynamic concept of exergy as a common objective measure. For a comprehensive assessment of industrial production systems, three indicators termed as ecological efficiency, resources use efficiency and environmental emission intensity are devised to evaluate the overall efficacy. Concretely assessed in the present work are three typical modes of coal-fired power generation systems, i.e., the Average mode that represents the average emissions and efficiency of coal-fired power plants operating in the US in 1999, the New Source Performance Standards (NSPS) mode that meets the New Source Performance Standards, and the low emission boiler system (LEBS) mode as a kind of highly advanced coal-fired power plant utilizing a low emission boiler, as benchmark cases in related NREL (National Renewable Energy Laboratory) report.     

Ecological accounting and evaluation of urban economy: Taking Beijing city as the case

Urban economy is confronted with increasing biophysical limitations derived from the exhaustion of natural resources and the depletion of environmental capacity, and human cultural diversity has been declining during the fast urbanization. The conventional anthropocentric economics, regarding the natural environment as the ‘exterior’ of human economy, is invalid in the scientific evaluation on the contribution of natural resources and environment as well as human culture when facing the current urban crises. The theory of embodied cosmic exergy, as the latest development of ecological economics and ecological thermodynamics, is introduced in this study to construct an ecological evaluation framework of urban economy. The advantage of embodied cosmic exergy dedicated to ecological economics has been discussed in comparison with other ecological evaluation alternatives. Transformities describing hierarchies and manifesting quality are systematically calculated and tabulated. A new framework of embodied cosmic exergy based on network accounting (EmexNA) is sketched out in this study, taking not only diversity flows but also ecological stocks into consideration. The stock based concept of ‘ecological wealth’ and the flow based concept of ‘ecological cost’ as well as related evaluation indicators are developed based on EmexNA. Taking Beijing city as the case, the network accounting and related ecological evaluation of a practical urban economy are carried out in this study in the light of the basic social, economic and environmental data available from 1990 to 2005 of Beijing. The system construction and the ecological mechanism of the development of Beijing economy are correspondingly illuminated and discussed.     

Cosmic emergy based ecological systems modelling

Ecological systems modelling based on the unified biophysical measure of cosmic emergy in terms of embodied cosmic exergy is illustrated in this paper with ecological accounting, simulation and scenario analysis, by a case study for the regional socio-economic ecosystem associated with the municipality of Beijing. An urbanized regional ecosystem model with eight subsystems of natural support, agriculture, urban production, population, finance, land area, potential environmental impact, and culture is representatively presented in exergy circuit language with 12 state variables governing by corresponding ecodynamic equations, and 60 flows and auxiliary variables. To characterize the regional socio-economy as an ecosystem, a series of ecological indicators based on cosmic emergy are devised. For a systematic ecological account, cosmic exergy transformities are provided for various dimensions including climate flows, natural resources, industrial products, cultural products, population with educational hierarchy, and environmental emissions. For the urban ecosystem of Beijing in the period from 1990 to 2005, ecological accounting is carried out and characterized in full details. Taking 2000 as the starting point, systems modelling is realized to predict the urban evolution in a one hundred time horizon. For systems regulation, scenario analyses with essential policy-making implications are made to illustrate the long term systems effects of the expected water diversion and rise in energy price.     

The water resources assessment based on resource exergy for the mainstream Yellow River

Based on the resource exergy theory, a unified exergetic index is proposed to assess both the quantity and quality of the water of the mainstream Yellow River, thus verifying the real available quantity of the river water in an ecological thermodynamics view. The chemical exergy, thermal exergy, potential exergy and sediment exergy of the river water as partial exergies are, respectively, calculated with the field river water intake data of the mainstream Yellow River. Exergetic potential is also defined to describe different working capacities of the river water along the mainstream. Finally, the temporal and spatial variation of the water resources of the mainstream Yellow River is illuminated with the proposed exergetic measure.     

Scarcity of exergy and ecological evaluation based on embodied exergy

The driving force of the earth system is shown to be the cosmic exergy due to radiational difference between the sun and the cosmic background, instead of the solar energy. The scarcity of cosmic exergy availability as the fundamental natural resource for the ecosphere and the human society is revealed by a systematic study on the global consumption of the cosmic exergy in the earth and a budget of the exergy consumption with respect to main terrestrial processes. A conceptual framework or ecological evaluation is developed on the basis of a new concept referred to as embodied exergy in terms of the cosmic exergy consumed directly or indirectly in making or sustaining a general commodity as a product, service or an emission. As a generalization of Szargut’s cumulative exergy consumption in resource analysis, embodied exergy is chosen, in place of embodied energy, to define Odum’s emergy. Concrete calculation schemes for embodied exergy accounting are provided as a systematic revision and rephrasing of existing embodied emergy analysis.     

Water resources in unified accounting for natural resources

The aim of this paper is to incorporate the water resources into the unified resources accounting based on scientific objectivity so as to present a brief portrait of the significance of water for the resource conversion and management of the national-scale society in a systems ecological perspective. The water resources in sustaining the human society are incorporated into the total exergy budget and national-scale social exergy accounting framework, not only by accounting the conventionally usable water flowing through society regarding seawater as reference environment, but also by introducing the evaporation exergy of freshwater as essential investment from the hydrological cycle. A case study of the Chinese society 2001–2005 is conducted, with the societal system broken down into seven sectors, i.e., extraction, conversion, agriculture, industry, transportation, tertiary and households sectors, to explore the resource utilization structure based on the proposed accounting method. Typical results for China 2005 showed that the total net input of the societal conventional resource exergy was 87.9 EJ, of which 75.4 EJ was from mineral resources and 22.6 EJ from other resources, while the water resource exergy input amounted to 105.1 EJ, which contributed 54.5% of the total resources exergy investment to the total society. Finally, the exergetic resource use intensities (RUIs) for six sectors were calculated, with the results that RUIs of agriculture and conversion sectors are much higher than those derived from conventional resource accounting.     

Exergy-based water resource allocation of the mainstream Yellow River

Based on the water resource exergy including chemical exergy, thermal exergy, potential exergy and sediment exergy, the allocation of water resource exergy along the mainstream Yellow River is illuminated. The water resource exergy for different anthropocentric water uses is also classified as agricultural irrigation exergy, industrial exergy, urban domestic exergy and rural domestic exergy. Aquatic exergetic ecotope (AEE) index is proposed as an indicator of the river ecosystem status in view of resource characteristic of exergetic assessment. Finally, the influences of the intake water on the AEE indices are well illustrated to reveal the possible impacts of water allocation on the river ecosystem status.     

再生水补给河流水质风险评价体系研究

对再生水补给河流后水质的风险状况进行分析,参考土壤的生态风险评价体系,构建新的水质风险等级制度,对由再生水补给的河流的水质进行风险管理.仿真结果验证了评价体系的有效性和可信性.新构建的风险评价体系不但反映了某一特定环境下各种污染物对水环境的影响,也反映了水环境中多种污染物的综合效应,并能运用定量方法划分出潜在生态风险程度,可为水质管理提供更好的参考和依据.     

基于主成分分析的水质评价方法

主成分分析法能够在保证原始数据信息损失最小的情况下,以少数的综合变量取代原有的多维变量,使数据结构大为简化,并且客观地确定变量权数,避免了主观随意性.应用主成分分析法对长春市地面水环境进行评价,且与其它评价方法相比较,结果显示主成分分析法更客观且指导性较强,是一种行之有效的水质评价方法.通过主成分分析进行水质评价,可为水资源规划、利用、开发和环境系统优化提供更为客观的参考依据.     

基于Logistic回归的水质预测研究

在环境系统评价中,水环境质量等级评价是其中十分重要的工作.鉴于对水环境研究中,水质级别为分类变量不能利用传统回归方法分析的特征,基于logistic回归方法建立了一种水质级别预测模型.利用长江流域的水质监测数据,将logistic回归应用于水质数据分析,进行水质建模,对水质级别做出预测.研究结果表明利用logistic回归进行水质分析,具有良好的拟合和预测效果.     

基于学习向量量化神经网络的水环境质量综合评价

针对水环境质量综合评价中指标权重确定方法的不足,利用学习向量量化(LVQ)神经网络具有的强大的非线性运算和相似特征聚类功能,提出一种基于学习向量量化(LVQ)神经网络的水质综合评价决策方法.将它应用于水质综合指标评价,为改进水质综合评价提供了一种简捷的分类评价方法.     

基于未确知测度理论的工业企业经济效益评价

介绍了工业企业经济效益评价的经济指标,建立了基于未确知测度理论的多属性综合评价方法.在确定各评价对象的属性权重时,采用熵值法这一客观性方法来确定.通过实例,将这种方法应用于具体的工业企业经济效益的评价,为评价企业经济效益提供了一种量化处理的方法,从而能够更直观、更合理地分析评价企业的经济效益状况.     

主成分分析在环境质量评价中的失效问题

在环境质量评价中,主成分分析被认为是一种客观而实用的评价方法.但大量的数据分析表明,主成分分析的评价结果并不一定符合实际情况,有时甚至完全失效,存在着一系列问题,而这些问题是由主成分分析本身的性质所决定的.     

Combining principal component analysis and the evidential reasoning approach for healthcare quality assessment

Patient experience and satisfaction surveys have been adopted worldwide to evaluate healthcare quality. Nevertheless, national governments and the general public continue to search for optimal methods to assess healthcare quality from the patient’s perspective. This study proposes a new hybrid method, which combines principal component analysis (PCA) and the evidential reasoning (ER) approach, for assessing patient satisfaction. PCA is utilized to transform correlated items into a few uncorrelated principal components (PCs). Then, the ER approach is employed to aggregate extracted PCs, which are considered as multiple attributes or criteria within the ER framework. To compare the performance of the proposed method with that of another assessment method, analytic hierarchy process (AHP) is employed to acquire the weight of each assessment item in the hierarchical assessment framework, and the ER approach is used to aggregate patient evaluation for each item. Compared with the combined AHP and ER approach, which relies on the respondents’ subjective judgments to calculate criterion and subcriterion weights in the assessment framework, the proposed method is highly objective and completely based on survey data. This study contributes a novel and innovative hybrid method that can help hospital administrators obtain an objective and aggregated healthcare quality assessment based on patient experience.     

基于最优组合赋权的城市生态评价模型及应用

以联合国可持续发展委员会、世界银行等权威机构的典型、高频率的指标为基础,并根据中国统计数据不全的现状,根据可观测性原则,根据"坚持以人为本,全面、协调、可持续的发展观"的科学发展观的内涵构建了适用于地级市行政区的生态评价指标体系。基于最优组合赋权建立了生态评价模型,并对辽宁省14个城市的生态进行实证分析。本文的创新与特色一是通过把人均绿色GDP、单位水资源工业废水负荷等指标纳入"驱动力-压力-状态-影响-响应"框架来构建适用于地级市行政区的生态评价指标体系。二是通过最优组合赋权,实现了各评价对象加权得分与理想点广义距离最小,体现了距理想点越近、得分越高的原理。三是引入Jaynes最大熵原理,基于各评价结果一致性最大的思路确定最优组合权系数,避免了不合理的个别单一赋权方法对组合赋权结果贡献太小的问题。四是实证研究表明,影响辽宁省生态发展最主要的指标是人口增长率、单位水资源工业废水负荷、人均水资源量和人均绿色GDP。     

关于城市生态安全的模式评价原理及模型

根据自然进化原理,用模式评价理论对城市生态安全进行评价,提出评价系统和系统环境的概念,把城市视为评价系统,把建设生态安全城市所需满足的各种要求视为系统环境,并通过评价系统与系统环境的适应程度,建立了关于城市生态安全的模式评价原理及模型,达到了对城市生态安全进行客观评价的目的.     

基于端点白化权函数聚类的水环境质量等级评价分析

为更准确地评价水环境质量,将端点三角白化权函数灰色评估引入到水质综合评价中.针对以往灰色白化权函数评估主要通过测定指标灰聚类系数判定被评价对象的优劣强弱等级进行等级识别评价,对三角白化权函数计算方法进一步扩展,完成多评价对象的准确等级定位及比较排序.将这种方法应用于山东省聊城市东昌湖水水质评价中,经实例计算证明基于三角白化权函数灰色评估评价模型的稳定性、合理性和实用性为水质评价研究方法提供了新的思路和借鉴.     

煤炭资源型城市生态环境状况评价与调控

目前,煤炭在我国的能源生产与消费结构中占有相当大的比重,将来一段时间也将占据主导地位.然而,在煤炭的生产、运输与消费过程中对环境造成了很大影响与破坏,首先就煤炭开发利用对所在区域生态环境的影响进行了系统分析,提出了煤炭资源型城市生态环境评价的概念、评价原则,建立了评价指标体系,应用模糊综合评价的方法建立了煤炭资源型城市生态环境评价模型,提出了煤炭资源型城市生态环境调控的具体措施.     

Unified account of gas pollutants and greenhouse gas emissions: Chinese transportation 1978–2004

To facilitate the aggregation of both quantity and quality of waste emissions, the concept of chemical exergy combining the first and second laws of thermodynamics is introduced for a unified account of gas pollutants and greenhouse gases, by a case study for the Chinese transportation system 1978–2004 with main gas pollutants of NO, SO₂, CO and main greenhouse gases of CO₂ and CH₄. With chemical exergy emission factors concretely estimated, the total emission as well as emission intensity by exergy of the overall transportation system and of its four modes of highways, railways, waterways and civil aviation are accounted in full detail and compared with those by the conventionally prevailing metrics of mass, with essential implications for environmental policy making.     

Dual role of price and myopia in a marketing channel

In this paper we study a dynamic two-player channel where the manufacturer controls the wholesale price and the investment in quality and the retailer chooses the retail price. We consider that the retail price affects both the demand and the perceived quality of the brand and that its variations contribute to the building of an internal reference price. One of the model’s distinctive features is that it accounts for the two meanings of price, i.e., its classical objective measure of the cost of acquiring a particular quantity of the product, and its subjective roles as an assessment of the quality of the product and an evaluation of gains or losses (deal vs. sacrifice) resulting from buying a “cheap” or an “expensive” product. This dual computation is done with respect to the internal reference price.