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131.
132.
In this study, an interactive two-stage stochastic fuzzy programming (ITSFP) approach has been developed through incorporating an interactive fuzzy resolution (IFR) method within an inexact two-stage stochastic programming (ITSP) framework. ITSFP can not only tackle dual uncertainties presented as fuzzy boundary intervals that exist in the objective function and the left- and right-hand sides of constraints, but also permit in-depth analyses of various policy scenarios that are associated with different levels of economic penalties when the promised policy targets are violated. A management problem in terms of water resources allocation has been studied to illustrate applicability of the proposed approach. The results indicate that a set of solutions under different feasibility degrees has been generated for planning the water resources allocation. They can help the decision makers (DMs) to conduct in-depth analyses of tradeoffs between economic efficiency and constraint-violation risk, as well as enable them to identify, in an interactive way, a desired compromise between satisfaction degree of the goal and feasibility of the constraints (i.e., risk of constraint violation). 相似文献
133.
Thomas K. Gottschalk Birgit AueStefan Hotes Klemens Ekschmitt 《Ecological modelling》2011,222(18):3403-3412
High resolution remote sensing data facilitate the use of small-scale habitat features such as trees or hedges in the analysis of species-habitat relationships. Such data potentially enable more accurate species-habitat mapping than lower resolution data. Here, for the first time, we systematically investigated this hypothesis by altering the spatial resolution from 1 m up to 1000 m grain size in species-habitat models of 13 bird species. The study area covered the Nidda river catchment in central Germany, a large heterogeneous landscape of 1620 km2. A high resolution habitat map of the area was converted to coarser spatial and thematic resolutions in seven steps. We investigated how model performance responded to grain size, and we compared the differential effects of spatial resolution and thematic resolution on model performance. Explained deviance (D2) of the bird models generally decreased with coarser spatial resolution of the data, although it did not decrease monotonically in all species. On average across all species, model D2 decreased from 41.5 at 1 m grain size to 15.9 at 1000 m grain size. Ten species were best modelled at 1 m, two species at 3 m and one species at 32 m grain size. Model performance degraded continuously with increasing grain size, both in habitat generalist and habitat specialist bird species, and was systematically lower in habitat generalists. The higher model performance observed at finer grain sizes was most likely caused by the combination of three factors: (1) high spatial accuracy of bird records and (2) a more precise location and delineation of habitat features and, (3) to a lesser degree, by more habitat types differentiated in maps of finer resolution. We conclude that higher spatial and thematic resolution data can be essential for deriving accurate predictions on bird distribution patterns from species-habitat models. Especially for bird species that are sensitive to specific land-use types or to small-scaled habitat features, a grain size of 1-3 m seems most promising. 相似文献
134.
Peter Schippers Eric W.M. StienenAlex G.M. Schotman Robbert P.H. SnepPieter A. Slim 《Ecological modelling》2011,222(17):3061-3070
Most seabirds live in large colonies. This fact signifies that there is an advantage in living and breeding together. Four explanations are put fore ward for this colonial behaviour, more birds have: (1) a reduced per capita predation of chicks in colonies, (2) a better anti-predator defence, (3) a more efficient foraging in temporally patchy environments and (4) sex ratios that are more likely to be close to one. These factors induce a strong Allee-type density-dependent relation, a positive relation between density and population growth rate at low density. Nevertheless, these Allee effects are generally ignored in seabird population studies. Therefore we study the consequences of introducing Allee-type density-dependent relations in a spatially explicit metapopulation model for the Common Tern (Sterna hirundo). Simulations show that Allee effects might be responsible for a 20-fold decline in the recolonization distances, causing patches and parts of metapopulations to effectively become more isolated. This leads to long recolonization times of empty breeding patches which consequently cause slower metapopulation expansion and recovery. Additionally, we show that the typical early warning signals, that show that a population is near its critical threshold induce by Allee effects, is less pronounced in colonies that are part of a metapopulation. Hence, we offer some simple equations to estimate critical densities and thresholds in a colony. 相似文献
135.
/ The role of the public in resource management has undergone aprofound transformation over the past two decades. Public input has evolvedfrom the enthusiasm for the widespread emergence public participation in theearly 1970s, through the realization of the relative effectiveness and costsof lobbying activities in the 1980s, to the emergence of environmentaldispute resolution (EDR) as a promising new alternative for the 1990s.Throughout this changing dynamic, there has been little attention tofundamental conception. This paper addresses this lack of conceptualization.A model of convergence is proposed to explain this transformation and as thebasis for an improved understanding of effective interest representationstrategies. The defining characteristics of lobbying, public participation,and environmental dispute resolution in resources management are outlinedrelative to the publics they involve, interest activity, organization,influence on policy, participatory features, and empowerment. Knowledge ofthese aspects will further aid in the identification and implementation ofeffective strategies to interest representation on a context-specific basis.KEY WORDS: Interest representation; Public participation; Disputeresolution; Lobbying; Resource management 相似文献
136.
鄂州市大气VOCs污染特征及来源解析 总被引:5,自引:4,他引:1
2018年3月~2019年2月,在鄂州市主城区采用在线气相色谱仪对102种大气挥发性有机物(VOCs)定量检测,对比分析了VOCs组成、季节变化特征和日变化规律,并利用最大增量反应活性(MIR)估算了VOCs的臭氧生成潜势(OFP).结果表明,鄂州大气VOCs年均体积分数为(30.78±15.89)×10~(-9),总体表现为冬季高夏季低,具体表现为烷烃含氧化合物卤代烃烯烃芳香烃炔烃.日变化规律表现为夜晚体积分数高于白天,且总体上呈"双峰"分布,芳香烃、卤代烃和OVOCs在00:00至02:00出现"第三峰".对VOCs臭氧生成潜势(OFP)贡献较大的是芳香烃和烯烃,贡献率分别为35.45%和29.5%,其中对OFP贡献率最高的物种为乙烯,达到24.217%.分析VOCs特征物种,发现机动车尾气和溶剂使用是鄂州VOCs的主要来源,其中机动车排放是最主要来源,控制鄂州机动车排放有助于削减大气VOCs活性较大的组分,从而减少臭氧的生成. 相似文献
137.
通过对廊坊市2016年5~9月的空气污染指标进行连续观测,分析了PM2.5污染特征、消光特性,并进行来源解析及潜在污染区域分析.观测期间PM2.5浓度为(43.82±28.68)μg/m,PM2.5中SO42-,NO3-,NH4+,OC和EC分别占PM2.5总质量的24.74%,22.98%,20.54%,8.79%和5.50%,各组分随着PM2.5浓度增加而增加;气溶胶散射系数(Bsp)和吸收系数(Bap)分别为(294.54±257.35),(16.05±9.14)Mm-1,粗粒子(CM)对消光系数的贡献为11.12%,细颗粒子PM2.5在大气消光中起主要作用,其中硝酸盐(32.23%),硫酸盐(27.28%)和OM (20.56%)为最主要消光成分;PM2.5主要来自工业(14.14%)、机动车(15.15%)、二次无机气溶胶(38.38%)、燃煤(22.22%)及扬尘和生物质燃烧(10.10%),对消光系数的贡献分别为工业(1.32%)、机动车(17.25%)、二次气溶胶(55.57%)、燃煤(18.56%),扬尘和生物质燃烧(7.32%).后轨迹分析表明廊坊市以来自山东、河南的小尺度,短距离和来自内蒙古东北部、中部的中短距离传输为主,占比接近80%,污染源的潜在分布区域主要是山东东北部、河南东部、山西东部、辽宁西南等地. 相似文献
138.
建立了利用固相萃取-高分离度快速液相色谱-串联质谱(SPE-RRLC-MS/MS)测定制药废水中青霉素G残留的方法。水样以30%硫酸锌+20%亚铁氰化钾作为沉淀剂沉淀蛋白质后,上清液采用Oasis HLB固相萃取柱富集和净化,以0.01 mol/L乙酸铵溶液(加0.1%甲酸)+乙腈作为流动相进行等度洗脱,经Agilent Plus C18柱分离后,在串联质谱ESI(+)源下进行MRM检测。该方法的青霉素G检出限(S/N=3)为0.02μg/L,目标物在0.0020~1.0 mg/L范围内线性关系良好,线性相关系数为0.9997。在0.20,1.0,2.0μg/L添加水平平均回收率为74.6%~101.4%,相对标准偏差为4.49%~8.17%。该方法灵敏度高、重现性好、定性定量准确,可满足制药废水中青霉素G残留检测的要求。 相似文献
139.
魏玉金 《中国环境管理干部学院学报》2005,15(3):48-51
在环境纠纷的非诉讼解决方面,我国虽然已有运用各种非诉讼纠纷解决方式来处理环境纠纷的实践,但在立法方面以及运作方式上仍然不完善,通过对该机制的各种程序进行分析和阐述,提出我国在环境纠纷解决中运用非诉讼解决机制进行重构. 相似文献
140.
I. F. Salkin 《Journal of Material Cycles and Waste Management》2003,5(1):0009-0012
The limited scientific information about infectious waste, and the heightened public awareness of this special component
of the waste stream, have contributed to the implementation or strengthening of the regulations in this area. This paper proposes
a general working definition of infectious waste, and describes the systems used to limit its potential occupational and public
health impacts. Although incineration and autoclaving are the most widely used methods of treating infectious waste, the introduction
of more stringent air-quality standards for incinerators, and the inherent limitations to the application of autoclaves, have
created a demand for other methods of processing this segment of the solid and liquid waste streams. These alternative technologies
use one or more of the following methods: (1) heating the waste to a minimum of 90–95°C; (2) exposing the waste to suitable
chemicals; (3) subjecting the waste to heated chemicals; (4) irradiating the infectious waste with ionizing sources. The advantages
and disadvantages of each of these alternative forms of treatment are discussed in this paper.
Received: April 22, 2002 / Accepted: October 14, 2002 相似文献