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701.
702.
物元分析法是处理不相容问题的一种有效方法。以竺山湾2010年7月水质监测数据为例,利用物元分析法分析太湖竺山湾水质监测点位分布情况,并将分析结果与系统聚类法的分析结果相比较,发现物元分析法的分析结果是准确、可信的。综合使用物元分析法和系统聚类法,最终确定水质监测点位可由14个优化至11个。 相似文献
703.
金融危机后,西部地区存在大量返乡农民工和就地转移的农村富余劳动力,农民工亟待"就业"与企业亟待"用工"凸显西部地区劳动力市场矛盾和产业结构偏差。西部地区调整产业偏差,进行慎密的产业选择,成为必然。通过构建农民工产业供求模型,对农民工产业流向进行理论分析,表明在区域工业化初期向工业化中期的过渡期以及在工业化中期,重化工业和高端技术产业对资本和技术的偏好,限制了劳动力从农业向非农产业的转移;通过运用比较分析法,考察西部产业选择的宏观与微观条件,透析出西部的资源特点、产业发展现状、城镇化水平、非农产业收入状况、非农产业就业吸纳能力。在理论模型推导和现实社会经济状况分析基础上,提出了产业选择思路和选择结果,即西部地区应重点发展技术—劳动密集型制造业、技术—劳动密集型农产品加工业、技术—劳动密集型服务业、旅游和旅游服务业和公益事业。 相似文献
704.
低碳城市是当今世界城市发展的大趋势,国内外一些城市已经开始践行低碳理念并形成了各具特色的发展模式,较为成熟的可归纳为"哥本哈根模式"、"伦敦模式"、"伯明翰模式"、"东京模式""保定模式"、"上海模式"等。中国低碳城市的建设和发展目前正处于起步阶段,存在一定的盲目性。中国城市的多样性、差异性和复杂性决定了其低碳发展不能千篇一律的复制和模仿,而必须在工业化和城市化进程中探索适合自身的发展模式。本文将中国城市的类型和特征与其低碳发展模式的选择相结合,从人口规模、区位、资源禀赋及工业化阶段等角度对我国城市进行类型划分,并认为任何一类城市的低碳发展都必须依据自身特征选择适宜的发展模式。同时,对武汉市的案例研究表明,因地制宜的选择一条重化工集聚、中部特大型城市的综合低碳发展模式是武汉市实现低碳转型的必然选择。 相似文献
705.
焦化废水生物处理尾水的活性炭吸附及条件优化研究 总被引:6,自引:0,他引:6
国内焦化企业废水生物处理尾水中COD、色度等指标超标的现象大多是由残留的难降解有机物造成的。针对这种现象,通过采用不同种类和孔结构的活性炭、改变炭表面化学性质、优化吸附环境3种方式对生物处理尾水中的COD成分进行强化吸附,考察炭型、表面化学性质及pH值等因素的影响,以明确焦化废水吸附法深度处理的合理炭型及其优化的条件。把已稳定运行的1 320 m3/d处理规模焦化废水A/O/H/O工艺实际工程生物处理尾水作为研究对象,试验了13种活性炭品种的吸附去除COD及色度的效果,发现甲基蓝值和丹宁酸值大的炭型其吸附容量高;而某一种炭样的吸附特性实验中,不同化学改性时表面酸性官能团含量少的活性炭有利于提高其吸附容量,低pH值条件的吸附能力高于碱性条件,曝气混合方式能够缩短吸附平衡时间。经过优选的活性炭在适宜的反应条件下能够将焦化废水生物处理尾水中的COD值及色度值分别降低至60 mg/L及20倍以下,在较低的运行费用条件下使出水达到工业循环冷却水的水质要求。 相似文献
706.
Approach of technical decision-making by element flow analysis and
Monte-Carlo simulation of municipal solid waste stream 总被引:2,自引:0,他引:2
This paper deals with the procedure and methodology which can be used to select the optimal treatment and disposal technology of municipal solid waste (MSW), and to provide practical and effective technical support to policy-making, on the basis of study on solid waste management status and development trend in China and abroad. Focusing on various treatment and disposal technologies and processes of MSW, this study established a Monte-Carlo mathematical model of cost minimization for MSW handling subjected to environmental constraints. A new method of element stream (such as C, H, O, N, S) analysis in combination with economic stream analysis of MSW was developed. By following the streams of different treatment processes consisting of various techniques from generation, separation, transfer, transport, treatment, recycling and disposal of the wastes, the element constitution as well as its economic distribution in terms of possibility functions was identified. Every technique step was evaluated economically. The Mont-Carlo method was then conducted for model calibration. Sensitivity analysis was also carried out to identify the most sensitive factors. Model calibration indicated that landfill with power generation of landfill gas was economically the optimal technology at the present stage under the condition of more than 58% of C, H, O, N, S going to landfill. Whether or not to generate electricity was the most sensitive factor. If landfilling cost increases, MSW separation treatment was recommended by screening first followed with incinerating partially and composting partially with residue landfilling. The possibility of incineration model selection as the optimal technology was affected by the city scale. For big cities and metropolitans with large MSW generation, possibility for constructing large-scale incineration facilities increases, whereas, for middle and small cities, the effectiveness of incinerating waste decreases. 相似文献
707.
新型水处理活性炭选型技术 总被引:8,自引:5,他引:3
活性炭依其原料不同、生产工艺不同,而有不同的吸附性能.使用简易的活性炭选型方法,可以减少应用测试时的备选炭型,从而大大降低活性炭水处理技术的运行成本.以碘值、甲基蓝值、苯酚值和丹宁酸值4种吸附容量性能指标为依据的活性炭选型技术,可以有效地预测活性炭对于水中各种大小不同污染物的去除能力.BET测试结果证明了这4项指标数据对于活性炭孔径分布预测的准确性.2,4-二氯苯酚和腐殖酸等目标化合物的吸附容量实验结果也都验证了这4项指标的预测功用,说明这种简便的活性炭选型技术有着广泛的应用价值. 相似文献
708.
Li Chen 《Journal of the American Water Resources Association》2003,39(5):1157-1165
ABSTRACT: An optimization and simulation model holds promise as an efficient and robust method for long term reservoir operation, an increasingly important facet of managing water resources. Recently, genetic algorithms have been demonstrated to be highly effective optimization methods. According to previous studies, a real coded genetic algorithm (RGA) has many advantages over a binary coded genetic algorithm. Accordingly, this work applies an RGA to obtain the 10‐day (the traditional period of reservoir operation in Taiwan) operating rule curves for the proposed reservoir system. The RGA is combined with an effective and flexible scheme for coding the reservoir rule curves and applied to an important reservoir in Taiwan, considering a water reservoir development scenario to the year 2021. Each rule curve is evaluated using a complex simulation model to determine a performance index for a given flow series. The process of generating and evaluating decision parameters is repeated until no further improvement in performance is obtained. Many experiments were performed to determine the suitable RGA components, including macro evolutionary (ME) selection and blend‐α crossover. Macro evolution (ME) can be applied to prevent the premature problem of the conventional selection scheme of genetic algorithm. The purpose of adjusting a of a crossover scheme is to determine the exploratory or exploitative degree of various subpopulations. The appropriate rule curve searched by an RGA can minimize the water deficit and maintain the high water level of the reservoir. The results also show that the most promising RGA for this problem consists of these revised operators significantly improves the performance of a system. It is also very efficient for optimizing other highly nonlinear systems. 相似文献
709.
定量风险评价(QRA)中的危险辨识方法 总被引:2,自引:1,他引:1
危险辨识是进行定量风险评价(QRA)的关键步骤,QRA分析区域内的危险设备设施可能很多,但并不是每台设备设施都一定要包含并进行定量风险计算,这不仅涉及到QRA的效率和成本问题,也涉及到评价结论准确性、安全投入有效性等问题。本文简要介绍并比较了欧盟ARAMIS和挪威Purple book中推介的2种危险辨识方法,有助于国内QRA分析人员参照比较及提升QRA分析的一致性。 相似文献
710.
Kari E. Gunson Anthony P. Clevenger Adam T. Ford John A. Bissonette Amanda Hardy 《Environmental management》2009,44(2):268-277
Wildlife-vehicle collisions (WVCs) pose a significant safety and conservation concern in areas where high-traffic roads are
situated adjacent to wildlife habitat. Improving transportation safety, accurately planning highway mitigation, and identifying
key habitat linkage areas may all depend on the quality of WVC data collection. Two common approaches to describe the location
of WVCs are spatially accurate data derived from global positioning systems (GPS) or vehicle odometer measurements and less
accurate road-marker data derived from reference points (e.g., mile-markers or landmarks) along the roadside. In addition,
there are two common variable types used to predict WVC locations: (1) field-derived, site-specific measurements and (2) geographic
information system (GIS)-derived information. It is unclear whether these different approaches produce similar results when
attempting to identify and explain the location of WVCs. Our first objective was to determine and compare the spatial error
found in road-marker data (in our case the closest mile-marker) and landmark-referenced data. Our second objective was to
evaluate the performance of models explaining high- and low-probability WVC locations, using congruent, spatially accurate
(<3-m) and road-marker (<800-m) response variables in combination with field- and GIS-derived explanatory variables. Our WVC
data sets were comprised of ungulate collisions and were located along five major roads in the central Canadian Rocky Mountains.
We found that spatial error (mean ± SD) was higher for WVC data referenced to nearby landmarks (516 ± 808 m) than for data
referenced to the closest mile-marker data (401 ± 219 m). The top-performing model using the spatially accurate WVC locations
contained all explanatory variable types, whereas GIS-derived variables were only influential in the best road-marker model
and the spatially accurate reduced model. Our study showed that spatial error and sample size, using road-marker data for
ungulate species, are important to consider for model output interpretation, which will impact the appropriate scale on which
to apply modeling results. Using road-marker references <1.6 km or GPS-derived data locations may represent an optimal compromise
between data acquisition costs and analytical performance.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献