废水处理最佳实用技术的评价模型及其应用

采用层次分析法,以环境、经济和技术综合目标为统一的标准,建立了废水处理最佳实用技术评价模型,并应用于镀铬废水处理技术的优选,以说明该模型的合理性和可信性。     

评定环境工程中标方案的AHP模型及应用

建立了评定环境工程中标方案的层次分析模型（以下简称ＡＨＰ）。对定性因素按１￣９标度构造判断矩阵；对定量因素则采用一定的数学变换，将量化值转化为判断矩阵。ＡＨＰ方法已成功地应用于某废水治理工程项目的评标工作。     

生物-生态组合工艺处理城市污水的启动研究

生物-生态优化组合工艺试验规模为100 m3/d,通过探索自然启动阶段生物-生态的优化组合模式,提高了启动中组合工艺的处理效能、缩短了处理效能波动时段,实现了向运行阶段的平稳过渡,为工程规模的启动提供了系统依据.研究表明,在启动阶段通过生物-生态优化工况组合,可达到组合工艺COD去除率90%、TN去除率40%～70%、TP去除率90%的去除效果.     

A model for the evolution of communal foraging in hierarchically structured populations

A kin selection model is described for populations in which groups of interacting individuals (trait groups, sensu Wilson 1975) are spatially situated within larger aggregations. The model predicts the optimal foraging strategy when resources are shared with other trait group members and there is an individual risk in foraging. The ecological mechanism of variation in group fitness, differential resource accumulation, is explicitly incorporated into the model. The optimal foraging rate obtained from this model depends on the product of a benefit-to-cost ratio and a relatedness parameter. The appropriate definition of relatedness for the evolution of communal foraging is determined by the details of the ecological interaction between consumers and resources. When competition is purely intra-specific, the genetic correlation among interactants relative to other members of the local aggregation defines the relatedness parameter applicable to selection on foraging propensity. When competition is primarily inter-specific, the genetic correlation among trait group members relative to the entire population defines relatedness.     

Differential timing of spring migration in northern wheatears Oenanthe oenanthe: hurried males or weak females?

In a field experiment on the island of Helgoland (southeast North Sea), we investigated whether migration strategy or competition between the sexes cause the differential timing of spring migration of male and female northern wheatears (Oenanthe oenanthe) (males migrating earlier). The study included two subspecies, heading towards Greenland/Iceland and Scandinavia, respectively, and is based on colour-ringing and remote weighing of individuals. Despite food offered ad libitum, most Scandinavian birds left the island on the day of arrival or stayed only 1–3 days, whereas more than half of Greenlandic/Icelandic birds stayed for up to 12 days and refuelled rapidly. In the latter subspecies, males showed a positive correlation of departure fuel load and fuel deposition rate, resembling time-minimizers in optimal migration theory. In contrast, females departed irrespective of fuel deposition rate, with an approximately constant level of fuel stores. This level was lower than in males, but sufficient to enable by-passing of stopover sites en route, allowing us to regard females as time-minimizers also. Since females are not able to reach Greenland without additional refuelling elsewhere and males appeared to have a larger potential for by-passing stopover sites, time-selection seems to be more pronounced in males and may be the reason for earlier migration of males. Intraspecific aggressive interactions between colour-ringed birds were predominantly won by the initiator, by males and by larger birds, whereas fuel load and subspecies did not affect the outcome. Although compared to females, males were more often dominant at the feeding stations or held territories, refuelling patterns could not be explained by dominance. Subordinate or non-territorial birds did not refuel at a lower rate or depart with lower fuel loads than dominant or territorial birds. In non-territorial birds, the restricted access to feeding stations was made up with larger doses of food taken per visit, leading to the same energy intake as that of dominant and territorial birds. Therefore, competition during stopover could be eliminated as the reason for differential timing of migration of male and female wheatears, but this result may be species-specific.Communicated by W. Wiltschko     

Time allocation strategies in insect parasitoids: from ultimate predictions to proximate behavioral mechanisms

As most parasitoids are time limited, they usually die before they have laid all their eggs. In such cases, optimal foraging theory predicts that female parasitoids will adopt behavioral reproductive strategies enabling them to maximize progeny production per unit of time. One key situation in which parasitoid females must optimize their time budget is related to the fact that most of their hosts are distributed in discrete patches in the environment. In this review, I first present the results of basic theoretical models predicting female wasp search duration on a patch of hosts. I then compile and analyze all studies investigating the effect of different factors on parasitoid patch time allocation and patch-leaving decision rules. Different patch-leaving mechanisms that were proposed to explain the results obtained are discussed, along with statistical methods that should be used to estimate them from experimental data. Finally, ideas for future research are presented.     

Multicriteria decision-making for efficient water and land resources allocation in irrigated agriculture

The irrational use of water in agriculture is often responsible for several problems concerning the depletion and/or the pollution of water resources. In these cases specific policy measures should be taken to protect water resources from harmful agricultural activities, mitigating at the same time their potential impact on farmers’ welfare. To this end, a multicriteria decision-making model is formulated that aims at allocating efficiently water and land resources in a rural area of Greece, by optimizing a set of important socio-economic and environmental objectives. According to the model’s output, past and current decisions on irrigated agriculture turned out to be oriented towards meeting exclusively the socio-economic objectives. Yet, there are several other possible allocations schemes that could be applied in order to improve the performance of environmental indicators and to contribute to a more sustainable use of natural resources. Moreover, the decision-making model can be further employed to assess a number of additional policy measures in irrigated agriculture. In this framework, the outcome of imposing various water pricing policies was evaluated. The efficiency of these policies was found tightly connected to the elasticity of water demand. Namely, higher elasticity seems to enhance the flexibility in resource allocation and the movement towards environmental objectives. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

环境监测中最优化抽样策略

本文分析了基本抽样程序,并用来解决环境监测的抽样优化问题。抽样过程形成马尔可夫链,通过划分接收水平和抽样区间建立抽样策略。计算每一组策略的目标函数的取值,找到备选策略中最小成本抽样策略即最优抽样策略。     

城市火灾扑救调度最佳路径分析

针对城市火灾扑救中的资源调度问题，综合考虑道路交通的各种迟滞因素，对通用的Dijkstra法进行修正，通过对两种方法计算结果对比表明，修正算法更为合理。在此基础上，结合受灾建筑本身的情况和消防力量分布状况，运用地理信息系统、图论、网络拓扑分析等领域的理论和方法，建立了优化调度的模型，实现调度优化决策模块。     

一个防灾工程投入优化配置的数学模式

本文建立了一个能反映防灾工程的特征,并将防灾总投入最优地分配到防灾工程的各个部分和各部分的各类投入上,同时又能被整合到防灾工程评价体系中的数学模式。模式的解产生了总投入在减灾工程不同部位、不同种类投入之间优化配置的平衡条件。