美国颗粒物污染防治政策对中国的启示

大气颗粒物污染可对公众健康和区域环境造成严重的不良影响,有效控制颗粒物排放是我国当前亟待突破的环境问题。美国颗粒物污染防治工作起步较早;联邦政府以推动空气质量达标为核心目标,分别针对电力、工业、机动车等不同排放源开展了一系列技术改造和总量控制的环境管制措施,目前颗粒物减排已取得了显著成效。回顾分析美国的颗粒物治理历程和相关经验,有助于探索和制定针对我国国情的颗粒物污染控制路线和措施,促进我国颗粒物有效减排、空气质量逐步改善。     

生态市建设的战略环境影响评价初探——以淮南市为例

生态市建设是一项系统工程，是实现可持续发展的必然途径。通过对战略环境影响评价理论、方法的探讨，开发出了针对生态市建设的战略环境影响评价技术框架，并以淮南市为例，构建了一套完整的战略环境影响评价指标体系。最后分析了淮南生态市建设SEIA的主要内容：土地利用规划、产业政策结构调整以及各项战略的环境影响评价，为生态市建设SEIA提供方法和技术支持。     

基于AHP-PSO的滇池流域生态补偿标准评估

通过AHP（层次分析法）在决策目标、影响指标及评估方案3层要素之间,选取湖泊环境、社会因素及经济因素3个维度的25个基层指标,建立了湖泊生态补偿标准评估指标体系。采用MATLAB软件编写了2个程序,分别用于求解初始评分矩阵、计算评估方案权重和辅助PSO（粒子群优化算法）修正指标体系中不满足一致性要求的初始评分矩阵、优化层次分析结果。经计算,生态系统服务价值理论与污染治理费用法的权重分别为38.16%、61.84%。选用生态系统服务价值理论与污染治理费用法两种评估方案,并结合市场价值法、成果参照法、影子工程法、Vollenweider模型及完全混合模型,通过实证研究检验评估标准的合理性。计算得出滇池流域的生态补偿标准总额为32.630 2亿元/a,流域内单位面积的生态补偿标准为5 207元/（a·hm²）。     

三元空间融合视阈下的安全态势感知模型研究*

为全面辨识系统风险并准确评估系统安全状况,从3元空间（信息-物理-社会）融合视角出发,界定安全态势感知概念并解读其内涵,提出安全态势感知概念模型和理论模型,并解析安全态势数据采集层、觉察层、理解层、投射层和预警层的具体内涵和功能。研究结果表明:3元空间融合视阈下的安全态势感知,能够通过物联网和互联网同步采集安全态势数据,在现有安全态势感知（安全态势信息输入、处理、输出）基础上,实现对人、机、物及其相互关系的整体感知,有效应对当前复杂多变的安全态势,为安全态势感知体系优化提供理论指导。     

Control system approaches to ecological systems analysis: Invariants and frequency response

The steady-state assumption is a mainstay for the analysis of ecological systems with more than three or four states. However, it is well accepted in ecology that inputs to large systems come in pulses assumed to have a reasonably constant magnitude and frequency. Steady pulse inputs and the use of electro-chemical–mechanical control systems methodology enables limited short term dynamic responses of ecological systems of a scale often occurring in systems of potential engineering importance to be analyzed. This paper explores and presents a survey of multi-input–multi-output (MIMO) control systems analysis of ecosystem network models to better understand pulse frequency issues and further develop experimentally verifiable approaches to testing the MIMO concept. The analysis process is demonstrated using two network model exemplars. Two aspects of MIMO analyses appear relevant to understanding ecological systems: (1) Eigenvalue invariant analyses and singular value decomposition (SVD) analyses enable assessment of stability and relative strength of states. Eigenvalues reflect time constants and provide a check on experimentally determined system matrices. (2) Analysis of SVD versus frequency for each output indicates maximum pulse frequencies that allow system components to benefit from pulsing. As a group, MIMO analyses complement other analytical methods and provide a theoretical systems focus convenient for analyzing ecosystems from an engineering perspective.     

The Reynolds transport theorem: Application to ecological compartment modeling and case study of ecosystem energetics

The Reynolds transport theorem (RTT) from mathematics and engineering has a rich history of success in mass transport dynamics and traditional thermodynamics. This paper introduces RTT as a complementary approach to traditional compartmental methods used in ecological modeling and network analysis. A universal system equation for a generic flow quantity is developed into a generic open-system differential expression for conservation of energy. Nonadiabatic systems are defined and incorporated into control volume (CV) and control surface (CS) perspectives of RTT where reductive assumptions in empirical data are then formally introduced, reviewed, and appropriately implemented. Compartment models are abstract, time-dependent systems of simultaneous differential equations describing storage and flow of conservative quantities between interconnected entities (the compartments). As such, they represent a set of flexible and somewhat informal, assumptions, definitions, algebraic manipulations, and graphical depictions subject to influence and selectively parsed expression by the modeler. In comparison, RTT compartment models are more rigorous and formal integro-differential equations and graphics initiated by the RTT universal system equation, forcing an ordered identification of simplifying assumptions, ending with clearly identified depictions of the transfer and transport of conservative substances in physical space and time. They are less abstract in the rigor of their equation development leaving less ambiguity to modeler discretion. They achieve greater consistency with other RTT compartment style models while possibly generating greater conformity with physical reality. Characteristics of the RTT approach are compared with those of a traditional compartment model of energy flow in an intertidal oyster-reef community.     

Studying ecological communities from a neutral standpoint: A review of models’ structure and parameter estimation

Neutral models provide an alternative to niche-based assembly rules of ecological communities by assuming that communities’ properties are shaped by the stochastic interplay between ecological drift, migration and speciation. The recent and ongoing interest about neutral assumptions has produced many developments on the theoretical side, with nevertheless limited echoes in terms of analyses of real-world data. The present review paper aims to help bridge the widening gap between modellers and field ecologists through two objectives. First, to provide a multi-criteria typology of the main neutral models, including those from population genetics that have not yet been transposed to ecology, by considering how the fundamental processes of ecological drift, speciation and migration are modelled and, specifically, how space is taken into account. Second, to review methods recently proposed to estimate models parameters from field data, a point that should be mastered to allow for broader applications.     

Incentive compatibility tests of choice experiment value elicitation questions

This paper uses laboratory experiments with induced values to address fundamental issues related to the incentive compatibility of choice experiment value elicitation questions. In particular, we compare two- versus three-option choice sets and the effect of using alternative provision rules, including one where the outcome is influenced by both participant and “regulator” votes. We find the overall proportion of choices that are inconsistent with induced preferences is rather low. However, there are more deviations from induced preferences for two-option choice sets, and for alternatives to a simple plurality vote implementation rule. A multinomial probit analysis of choices in tandem with a mixed logit welfare analysis suggests there is a statistically significant but modest degree of bias towards selecting the status quo option.     

Proposing an information criterion for individual-based models developed in a pattern-oriented modelling framework

Individual-based models (IBMs) have been improved in quality and reliability in recent years with an approach called pattern-oriented modelling (POM). POM proposes guidelines to develop models reproducing multiple patterns observed on the field and to test systematically how well the IBMs reproduce them. POM studies used generally traditional methods of goodness of fit such as the sum of squares evaluation or ad hoc comparisons of fitting errors and variations. Model selection, however, can be a rigorous statistical approach based on information theory and information criteria such as the Akaike's information criterion (AIC) or the deviance information criterion (DIC). So far, it has not been tried to link POM to these rigorous techniques. The main problems to achieve that are: (a) the difficulty to have likelihood functions for IBMs’ parameters and (b) the possibility to obtain posterior distributions of IBMs’ parameters given the patterns to reproduce. In a first part, this paper answers problem (a) by proposing and explaining how to calculate a deviance measure (POMDEV) for models developed in a context of POM. And while answering the second problem, a second part of the paper proposes an information criterion for model selection in a POM context (the pattern-oriented modelling information criterion: POMIC). This criterion does not yet have the same theoretical foundation as, e.g., AIC, but uses formal analogies to the DIC. In a third part POMIC is tested with a modelling exercise. This exercise shows the potential of POMIC to use multiple patterns for selecting among multiple potential submodels and eventually select the most parsimonious and well fitting model version. We conclude that POMIC, although being a heuristically derived approach, can greatly improve the POM framework.     

Transport of volatile compounds in porous media in the presence of a trapped gas phase

The presence of an immobile gaseous phase in an otherwise-saturated porous medium affects the transport of volatile compounds. The linear theory of partitioning tracers suggests that a volatile tracer introduced into such a system should be retarded with a constant retardation factor. Using high concentrations, however, the saturation of the gaseous phase will change as an effect of the tracer test itself. Competitive gas transfer among all volatile compounds and the change of saturation may lead to tracer concentrations that are temporarily higher than those injected. We analyze the system in the framework of the coherence theory by Helfferich [Soc. Pet. Eng. J. 21 (1) (1981) 51]. The governing equations are formulated as functions of total concentration, i.e., the mass of solutes in all phases per pore volume. Neglecting dispersion and mass-transfer kinetics, we derive the characteristic form of the resulting system of hyperbolic equations. In a system with N volatile compounds, a variation of the concentrations splits up into N waves, each traveling with its own characteristic velocity. If the presence of a gaseous phase is sustained, one wave will be a standing one. We perform numerical model calculations for tracers with various Henry's law coefficients and show that the results agree with the semi-analytical solution obtained by coherence theory.