基于地表沉陷控制的膏体充填材料的性能优化研究

充填材料性能是充填开采控制地表沉陷的一个重要因素,为克服传统充填材料性能优化试验耗时长、成本高、人为误差较大的缺点,探索将传统正交试验与模糊决策相结合进行充填材料性能优化。基于L9(33)正交试验,确定了S1~S55组充填材料性能优选方案。在综合分析充填材料性能影响因素的基础上,建立充填材料性能优化指标体系,构建AHP-FUZZY模糊综合优选模型对方案进行比选,并分析了正交试验中各因素水平变化对最优方案的敏感性。结果表明:膏体充填材料性能最优方案为“S4”即水泥含量15%,灰矸比1∶2,质量浓度75%,决策结果与试验结果相符,且“灰矸比”对充填材料性能优化的敏感性程度最高,在实际膏体充填开采中要严格控制粉煤灰和煤矸石掺量。     

环洞庭湖区水资源供需系统仿真及优化决策研究

论文运用系统分析的理论与方法,分析环洞庭湖区水资源供需系统的特征和各要素之间的相互作用,建立水资源供需系统模型,仿真模拟传统发展模式、发展经济型模式、节水型模式和协调型模式等四种不同情景下,2010-2030年环洞庭湖区水资源供需变化趋势.结果表明:①随着经济的发展和人口的增长,环洞庭湖区水资源供需矛盾十分突出;②在协调型模式下,模拟期末环洞庭湖区总需水量达到159.1×10⁸ m³,供需缺口最大值出现在2020年,为1.9×10⁸ m³,到2030年水资源供给能力约有3.6×10⁸ m³富余,模拟期内水资源供给基本能够满足社会经济发展的需求,且能够获得最大的综合效益,是环洞庭湖区水资源开发利用的最佳方案;③为了达到预期目标,还需增强节水意识、完善用水管理、优化经济结构,加大水利投入和环境整治,提高节水技术水平和水利保障水平.     

应急物流研究现状及发展动态分析

从应急物流的定义与特征、系统体系构建、保障机制、风险评估以及定量模型等方面对国内外近10年来的应急物流相关成果进行系统分析,指出当前应急物流存在的问题与不足,探讨应急物流发展趋势。分析表明,国内外对应急物流定量模型的研究主要是选址和调度问题分开进行的,对选址调度问题的集成研究还较少,也没有将应急物流的风险识别与选址调度问题结合起来进行研究。另外,应急物流的开展需要多个部门协同决策,开发应急物流协同决策系统也将是未来的研究方向。     

基于案例推理的突发环境事件应急决策模型

突发环境事件不确定性高、演化过程复杂,给企业及政府的应急工作带来很大的困难,故如何提高应急决策的质量,是相关应急工作的重点之一。为了增强以往经验的可用性,利用本体模型进行案例的存储,根据情景构成要素提取方法对情景进行多维的空间表达,在此基础上优化情景匹配算法,实现基于情景的应急决策。最后,通过突发环境事件实例应用,验证该方法能够快速建立实例与本体模型之间的关系,提高知识的可用性和共享性,实现情景的多维表达,进而满足“情景-应对”的应急决策要求。     

Predicting functional response and size selectivity of juvenile Notonecta maculata foraging on Daphnia magna

A mechanistic model was developed to assess the impact of predation of juvenile Notonecta maculata on size structured Daphnia magna populations and to provide a framework for quantifying the backswimmers uptake of food. Results of experiments and model predictions clearly demonstrate selective predation of backswimmers when fed with a choice of daphnid size classes, with patterns of selectivity differing across N. maculata instars. The model describes the foraging process empirically on the base of a general predation cycle including four conditional events instead of using classic functional response curves. For model parameterisation components of predation, namely probability of encounter, attack and success as well as time spent on handling prey was directly observed by means of video tracking experiments. Since attack rate, capture success and handling time appeared to be a function of prey size differing between Notonecta instars, the model takes into account ontogenic changes in both predator and prey characteristics. Independent data of functional response and size selectivity experiments were used for model validation and proved the model outcome to be consistent with observations.     

Resolving future fire management conflicts using multicriteria decision making

Management strategies to reduce the risks to human life and property from wildfire commonly involve burning native vegetation. However, planned burning can conflict with other societal objectives such as human health and biodiversity conservation. These conflicts are likely to intensify as fire regimes change under future climates and as growing human populations encroach farther into fire‐prone ecosystems. Decisions about managing fire risks are therefore complex and warrant more sophisticated approaches than are typically used. We applied a multicriteria decision making approach (MCDA) with the potential to improve fire management outcomes to the case of a highly populated, biodiverse, and flammable wildland–urban interface. We considered the effects of 22 planned burning options on 8 objectives: house protection, maximizing water quality, minimizing carbon emissions and impacts on human health, and minimizing declines of 5 distinct species types. The MCDA identified a small number of management options (burning forest adjacent to houses) that performed well for most objectives, but not for one species type (arboreal mammal) or for water quality. Although MCDA made the conflict between objectives explicit, resolution of the problem depended on the weighting assigned to each objective. Additive weighting of criteria traded off the arboreal mammal and water quality objectives for other objectives. Multiplicative weighting identified scenarios that avoided poor outcomes for any objective, which is important for avoiding potentially irreversible biodiversity losses. To distinguish reliably among management options, future work should focus on reducing uncertainty in outcomes across a range of objectives. Considering management actions that have more predictable outcomes than landscape fuel management will be important. We found that, where data were adequate, an MCDA can support decision making in the complex and often conflicted area of fire management.     

Making Collaborative Watershed Management Work: The Confluence of State and Regional Initiatives

Initiatives in the Neponset, Ipswich, and Sudbury-Assabet-Concord watersheds highlight how watershed-scale innovation in engaging nongovernment participants is influenced, but not dominated, by the statewide program, the Massachusetts Watershed Initiative. The presence or absence of three elements—external support, process, and issue—and the order in which they occur, shape the viability of collaborative watershed-scale management initiatives. External support includes providing personnel or funding from outside an initiative. Process is the interaction among individuals undertaking watershed-wide policy development and/or implementation. An issue is an attention-requiring concern, vital to a watershed, that can most effectively be addressed by a coordinated strategy among different parties. A process generated by an issue is sustainable and amenable to enhancement through external support. The contribution of external support is most apparent when outside assistance is provided after an issue has crystallized into clear problem needs that can be addressed through specific research projects or implementation activities. Process is central in shaping issues, utilizing external support, and generating management results. The outcomes of voluntary processes in the three watershed initiatives highlight how the evolution of the Massachusetts Watershed Initiative leads to, and depends upon, the development of watershed-scale initiatives.