生物干化传质传热数值模拟

基于质量、动量和能量守恒定律理论,建立好氧生物干化的数学模型,探索生物干化过程随时间和空间的变化机理。以污泥为研究对象,数值模拟污泥生物干化过程中堆体内部水分浓度与温度空间的分布形态,分析不同通风方式对水分浓度与温度的影响,模拟得到通风20 min停20 min是最佳的运行方式,同时结合实验研究,模型的水分变化值与实验值的平均绝对误差为1.04%,模型与实验值具有较高的一致性。     

Evaluation of the Fire Simulation Processes of the National Fire Management System's Initial Attack Analysis Processor

The fire simulation processes of the National Fire Management System's (NFMAS) Initial Attack Analysis (IAA) processor were evaluated by conducting two types of sensitivity analysis: one based on a hypothetical set of data to assess IAA's outputs under a wide range of fire input values, and the other using an actual Stanislaus National Forest database to test IAA's validity with a real set of data. The results revealed that IAA's outputs (projected annual number of fires and area burned) were most sensitive, in descending order, to the input values of the fire spread rate, the productivity rates of the suppression forces, and the initial attack time, for all fuel models tested. In contrast, IAA's outputs were extremely insensitive to variations in the fire size at discovery. Changes are necessary in the ways IAA incorporates the fire size at discovery to facilitate the comparison among various fire detection options. The program's “escaped fire situation” analysis was found inadequate, because the projected annual frequencies and final sizes of the simulated escaped fire events produced unacceptable results with the Stanislaus National Forest database. Assigning final sizes to simulated escaped fires according to the fire intensity level in which they are historically expected to occur provides a consistent way of calculation of the projected annual area burned and the consequent cost plus net value change (C + NVC).     

一种选择城市垃圾处理方式的新方法--模糊数学决策法

对模糊数学决策法的基本原理、方法和步骤作了简要介绍,并将其应用到成都市区生活垃圾处理方式的选择中,其决策结果与成都市区目前采用的生活垃圾处理方式相符,表明了该方法的实用性。本研究为合理选择城市垃圾处理方式提供了一种量化方法。     

Understanding Managers’ Views of Global Environmental Risk

This research investigated managers’ views of two global environmental risks: climate change and loss of biodiversity. The intent was to understand why different managers place varying levels of attention and priority on these issues. The data came from in-depth interviews with 28 senior corporate managers across Canada and a range of sectors, although most were employed in the energy sector. Approximately half had direct environmental responsibilities and half had other management duties. Grounded theory was used to collect and analyze the data. From the results, a theoretical framework was constructed to explain important factors that can influence managers’ mental models of environmental risk. Four factors relevant to managers’ appraisal of the threat of environmental risk include: (1) salience, (2) intrinsic value of nature, (3) knowledge, and (4) perceived resilience of nature. In addition, four factors relevant to managers’ view of the appeal of a particular response strategy were: (1) avoidability, (2) perceived costs and benefits, (3) fairness and equity, and (4) effectiveness. The time horizon for decision making was seen as being important in both portions of the mental model.     

Darcian preferential water flow and solute transport through bimodal porous systems: Experiments and modelling

Soils often exhibit a variety of small-scale heterogeneities such as inter-aggregate pores and voids which partition flow into separate regions. In this paper a methodological approach is discussed for characterizing the hydrological behaviour of a heterogeneous clayey–sandy soil in the presence of structural inter-aggregate pores. For the clay soil examined, it was demonstrated that, coupling the transfer function approach for analyzing BTCs and water retention data obtained with different methods from laboratory studies captures the bimodal geometry of the porous system along with the related existence of fast and slow flow paths. To be effectively and reliably applied this approach requires that the predominant effects of the soil hydrological behaviour near saturation be supported by accurate experimental data of both breakthrough curves (BTCs) and hydraulic functions for high water content values. This would allow the separation of flow phases and hence accurate identification of the processes and related parameters.     

生物膜反应器中生物膜脱落的机理及数学模型

生物膜法是一种高效的废水处理方法。对生物膜反应器中的生物膜形成、流体力学、传质以及反应动力学特性都做了较深入的研究。目前，在反应机理研究方面，生物膜的脱落是了解最少的，而反应器中生物膜的脱落对生物膜的形态、稳定性以及转化效率都有直接的影响，因此，生物膜脱落的研究具有十分重要的意义。介绍了生物膜反应器中生物膜脱落的过程及其机理，讨论了影响生物膜脱落的种种因素，并对有关研究生物膜脱落的数学模型作了总结和分析，最后提出了今后生物膜脱落研究的重点。     

A tool to aid emergency managers and communities in appraising private dam safety and policy

Issues concerning dam safety and equitable sharing of catchment run-off are receiving more attention throughout the world. This paper assesses these matters in the context of Australia, and the need for policy responses. Landholders often overlook the common law obligation to review/design dams to current standards because of high costs, leaving them vulnerable to litigation if their dam fails. The paper reports on an innovative spillway design/review procedure, applicable to southeast Australia, but transferable to any region worldwide. Dam safety policy models and guidelines derived from international best practice are linked to the procedure and intended to aid government decision-making. The procedure minimises costs to landholders and provides an acceptable level of safety assurance to downstream communities. Also discussed are recent surveys testing community attitudes to the procedure and implemented dam safety and water allocation policies. These further guide any government wanting to implement this'integrated engineering and community partnerships'approach to preventing potential disasters due to private dam failure and achieving sustainable and safe water storage and use.     

餐厨垃圾生化产甲烷潜力的数学模拟

为资源化回收利用餐厨垃圾,采用BMP实验对其产甲烷潜力进行了研究,测定了不同厌氧消化时间内的沼气产量及COD、VFA浓度,并在此基础上对餐厨垃圾产甲烷潜力进行了数学模拟。结果表明,混合液COD浓度变化曲线呈逐渐下降的趋势,VFA出现短暂积累,应调控厌氧消化系统的碱度。餐厨垃圾经40 d厌氧消化后,实际生物化学产沼气及产甲烷潜力分别可达559.1、349.7 mL·g-1 VS,第20天后累积产气量增加不显著。数学模拟结果表明,餐厨垃圾最初7 d的平均水解常数为0.244 d-1,模拟产沼气及甲烷潜力分别可达578.36和363.72 mL·g-1 VS,实际产沼气及甲烷潜力分别占模拟产沼气及甲烷潜力的96.7%、96.1%,采用固体停留时间为25~30 d进行厌氧消化较为合理。     

三种生产论：可持续发展的基本理论

本文通过研究人与环境的辩证关系，提出了物质生产、人的生产和环境生产是可持续发展系统的基本模型，分析了三种生产之间的和谐关系，并对深化环境影响评价、开展环境建设、建立新伙伴关系等问题进行了探讨。     

基于空间面板模型的碳排放影响因素分析——以长江经济带为例

随着全球变暖问题的日益严峻,气候问题引起了国际社会的广泛关注。长江经济带作为中国区域发展"三大战略"之一,面临着严峻的碳减排压力。为此,以二氧化碳排放为测度指标,定量分析了1998~2012年长江经济带二氧化碳的时空格局特征,并构建碳排放影响因素的空间面板模型,分析了产业结构、人口总量、经济水平、技术水平与城市化水平对长江经济带碳排放的影响。研究结果表明:1碳排放的绝对差异呈增大趋势,相对差异呈波动变化趋势;碳排放与人均GDP(1997年不变价)的相关性较弱;2碳排放空间格局相对稳定,高碳排放区域以江苏为中心,逐渐向四周扩散;3空间面板模型结果表明:人口总量是影响长江经济带碳排放时空格局演化的决定性因素,其次依次为经济水平、技术水平和城市化水平。