面向城市水系环境需水的再生水空间配置——以深圳市宝安区为例

以深圳市宝安区为例,探讨以再生水满足城市水系环境需水的方法.应用一维恒定与非恒定水质模型计算了4种补水水质方案下该区10条主要河流的环境需水量,从水量平衡角度提出全区再生水BOD5的平均值,并进一步分析了补水水质与河流环境需水量的关系.结合该区水系与污水处理系统空间位置,提出3种再生水的空间配置方法.结果表明:茅洲河和...     

多维公平测度下考虑灾民心理痛苦效应的应急资源调配

为有效降低灾后初期应急资源短缺情况下灾民生理和心理受到的伤害,提出等待效应和短缺效应衡量救援过程中的灾民心理痛苦效应,同时耦合时间和供需情况2个维度测度救援过程中的公平性指标,构建调度总时间最短、时间攀比最小和灾民心理痛苦效应最低的多目标应急资源调配模型,研究多灾点、多配送中心、多种类物资救援场景下的应急资源分配和路径...     

农地非农化代际配置与农地资源损失

合理的资源利用要求资源配置在代际上是有效率的。在资源代际最优配置原理的基础上,建立了一个衡量农地非农化是否符合代际配置效率的宏观决策模型,对我国20世纪90年代以来的农地非农化进行了检验。结果显示,若以1989-2003年为研究区间,1989-1996年阶段东、中、西部地区的过度非农化比例分别占各自实际非农化数量的6.58%、6.84%和7.85%,反映出1989-1996年期间的农地非农化存在一定的短期行为,造成农地的过度非农化。因此,未来一段时间的农地非农化政策应该进一步控制农地非农化的速度,来保证农地资源能够在未来得到更优的利用。     

基于链路预测的安全隐患管理研究*

为探寻安全隐患的发生规律，揭示安全隐患的演化特点，为管理人员提供建议和参考。以潞安集团司马煤业有限公司2009—2015年安全隐患记录为数据源，建立无向加权安全隐患共词网络，利用链路预测技术，寻找安全隐患的内在联系及发展趋势。结果表明:相比于共同邻居、资源分配等基于局部信息的相似性指标，资源分配指标能够更好地预测安全隐患各个关键词之间的变化联系；通过分析关键词共现关系，证实预测的准确性，预测出部分未来存在但当前未产生的节点关系。安全管理人员可基于此方法采取有针对性的预防措施，减少相关隐患的发生。     

有关全球气候变化问题上的公平性分析

从《联合国气候变化》了发，对人类社会应对气候变化中的“公平”性问题，从不同角度进行了系统讨论。对发展中国家和发达国家在公平原则下责任、义务及优先事项的差别进行了分析，提出并分析了以人均碳排放权相等为标准，到目标年（例2100年）各国人均碳排放量及过渡期内（例1990-2100）人均累积碳排放量两个趋同的碳排放权分配原则。     

新疆塔里木河沿岸地区2000年水资源优化分配

本文首先建立塔里木河上、中、下游各用水户水资源利用综合效益评价模型,确定了上、中、下游各用水户的优先次序;在此基础上,用分解协调法建立起以取得最佳的综合效益为目标的水资源优化分配两层模型,计算出2000年塔里木河沿岸地区在不同年型下的水资源优化分配方案,取得了较好的效果,有助于今后塔里木河沿岸地区水资源开发利用的科学管理。     

Yolk androgen deposition as a compensatory strategy

The deposition of androgens into the yolks of eggs can have long-lasting effects on the growth and development of young birds. It has been proposed that female birds and reptiles deposit yolk androgens according to the differential allocation hypothesis (DAH), which posits the allocation of more resources to offspring sired by more attractive, higher-quality males. We examined deposition patterns of yolk androgens in relation to mate attractiveness in the house finch Carpodacus mexicanus. Contrary to the predictions of the DAH, female house finches deposited significantly more androgens into eggs sired by less attractive males. We propose that, rather than serving as resources, androgens are used as mediators in a compensatory distribution strategy, enabling females to improve the quality of young produced with less attractive males.     

The effects on welfare of the imposition of individual transferable quotas on a heterogeneous fishing fleet

This paper examines the determination of effort levels, the rental price of quotas and the number of participants in a fishery managed with a total allowable catch and individual transferable quotas. How these variables change is determined for three phases of the management process. Potential participants in the fishery are assumed to be heterogeneous in their catching capabilities so that almost all active fishers earn positive net profits from fishing activities. It is shown that these quasirents are reduced during any of the management phases considered here. The impact of free allocations of permanent quota rights on fishers’ welfare is also considered. This may increase the welfare of all fishers if the allocation is based on catch history. However, an example is provided where the welfare of some highliners is reduced when the allocation is based on effort history.     

Fitness consequences of body-size-dependent host species selection in a generalist ectoparasitoid

In insect parasitoids, offspring fitness is strongly influenced by the adult females choice of host, particularly in ectoparasitoids that attack non-growing host stages. We quantified the fitness consequences of size-dependent host species selection in Dirhinus giffardii, a solitary ectoparasitoid of tephritid fruit fly pupae. We first showed a positive correlation between the size of emerged D. giffardii wasps and the size of their host fruit fly species (in order of decreasing size): Bactrocera latifrons, B. cucurbitae, B. dorsalis or Ceratitis capitata. We then manipulated individual wasps to show that the parasitoid preferred to attack the largest (B. latifrons) to the smallest (C. capitata) host species when provided with a choice, and laid a greater proportion of female eggs in B. latifrons than in C. capitata. There were no differences in developmental time or offspring survival between individuals reared from these two host species. Finally, we compared the foraging efficiency of large versus small wasps (reared from B. latifrons vs C. capitata) under two different laboratory conditions: high versus low host habitat quality, given that realized fecundity in parasitoids may be influenced by either egg-limited or time-limited factors. Under both conditions, large wasps parasitized more hosts than did small ones as a consequence of high searching efficiency in the host-poor habitat, and high capacity for adjusting egg maturation in response to host availability in the host-rich habitat. Considering the flexibility of body growth, the apparent lack of cost of achieving large body size in either development or survival, and the strong dependence of realized reproductive success on a females size, we argue that body size may be a key to understanding evolution of host species selection in ectoparasitoids. We also discuss constraints upon the evolution of size-dependent host species selection in parasitoids.Communicated by D. Gwynne     

Within-brood patterns of paternity and paternal behavior in red-winged blackbirds

We video-taped male and female red-winged blackbirds (Agelaius phoeniceus) feeding individual chicks in order to test the hypothesis that food might be differently allocated to within-pair offspring and extra-pair young. We found no evidence that paternity influenced the allocation of food by either males or females. Both males and females fed male offspring significantly more, but there was no tendency for paternity to be skewed by gender. Females fed older offspring significantly more, whereas males did not; extra-pair fertilizations, however, were not associated with lay or hatch order of the chicks. Given that males do not appear to discriminate within-pair from extra-pair offspring directly, these results are consistent with current theory on the effect of paternity on paternal behavior. We discuss briefly some of the possible reasons why discrimination might be lacking in red-winged blackbirds and in other species in which the possibility of discrimination of paternity and allocation of paternal behavior has been studied.