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501.
作为机场与城市间的过渡区,空港区域具有经济-社会-环境发展影响因素众多、变化快的特征.针对此,本文基于空港区域系统动力学模拟模型,结合类比法和情景分析法,用于空港区域不同发展方案的经济、社会、环境影响预测和评价.具体步骤包括:发展分析-影响识别-模型构建-零方案/规划方案模拟-替代方案设计-减缓措施,各步骤间动态反馈.对郑州航空港区进行案例研究,结果表明,相较于零方案,规划方案具有经济社会发展优、污染排放少的优点,但仍无法满足环境容量要求;设计了3种替代情景方案,据此提出产业结构优化、能源结构调整等减缓措施.  相似文献   
502.
A sediment microbial fuel cell (SMFC) with three dimensional floating biocathode (FBC) was developed for the electricity generation and biodegradation of sediment organic matter in order to avoid negative effect of dissolved oxygen (DO) depletion in aqueous environments on cathode performance and search cost-effective cathode materials. The biocathode was made from graphite granules with microbial attachment to replace platinum (Pt)-coated carbon paper cathode in a laboratory-scale SMFC (3 L in volume) filled with river sediment (organic content 49±4 g·kg-1 dry weight). After start-up of 10 days, the maximum power density of 1.00W·m-3 (based on anode volume) was achieved. The biocathode was better than carbon paper cathode catalyzed by Pt. The attached biofilm on cathode enhanced power generation significantly. The FBC enhanced SMFC performance further in the presence aeration. The SMFC was continuously operated for an over 120-day period. Power generation peaked within 24 days, declined gradually and stabilized at a level of 1/6 peak power output. At the end, the sediment organic matter content near the anode was removed by 29% and the total electricity generated was equal to 0.251 g of chemical oxygen demand (COD) removed.  相似文献   
503.
按照1:1尺度设计了实验平台,包括模拟隧道、模拟列车、排烟系统、火灾监控系统、火灾扑救系统以及火灾参数测量系统,是国内第一个专门对铁路隧道救援站的火灾安全性进行系统研究的全尺寸实验平台。实验平台可实现温度场、燃烧成分、火源热辐射等关键参数的测量;可研究不同工况条件下,火灾监控、火灾扑救技术和烟气控制技术的有效性,为发现火灾特征参数的演变规律和掌握有效的火灾控制技术提供了一整套解决方案,具有广阔的应用前景和重要的实际指导意义。本文建立并利用这样一个全尺寸实验平台进行了细水雾灭火系统抑制车厢火灾的模拟实验研究,获取温度、有毒有害气体浓度、热辐射等火场重要参数,发现细水雾灭火系统可有效的抑制车厢火灾,并验证了此实验平台用于铁路隧道内列车火灾实验研究的可行性和有效性。  相似文献   
504.
There has been a growing interest on using local modelling techniques for the analysis of spatio-temporal data because of their powerfulness in extracting the underlying local patterns in the data. In this study, we propose a two-step local smoothing approach to explore spatial patterns and temporal trends of spatio-temporal data via combining the geographically weighted regression and the local polynomial smoothing procedure. The proposed method incorporates both spatial and temporal information into the calibration process and makes it easier to implement visualization of the results. A simulation experiment is conducted to assess the performance of the proposed method and the results show that the method works satisfactorily. A real-world spatio-temporal data set is analyzed to demonstrate the practical usefulness of the method.  相似文献   
505.
The effect of Zr on the catalytic performance of Pd/y-A1203 for the methane combustion was investigated. The results show that the addition of Zr can improve the activity and stability of Pd/γ-Al2O3 catalyst, which, based on the catalyst characterization (N2 adsorption, XRD, CO- Chemisorption, XPS, CHa-TPR and O2-TPO), is ascribed to the interaction between Pd and Zr. The active phase of methane combustion over supported palladium catalyst is the Pd^0/Pd^2+ mixture. Zr addition inhibits Pd aggregation and enhances the redox properties of active phase Pd^0/ Pd^2+. H2 reduction could effectively reduce the oxidation degree of Pd species and regenerate the active sites (Pd^0/ pd^2+).  相似文献   
506.
辽宁省近地层风切变特征研究   总被引:23,自引:20,他引:3  
利用辽宁省风能资源专业观测网26座测风塔2009年6月至2010年5月10~70 m(100 m)的逐时梯度风观测数据,研究了辽宁省近地层风切变特征,结果表明:近地层风速随高度变化基本遵循幂指数规律;各塔年风切变指数为0.024 4~0.405 0,没有明显的空间分布规律,主要受局地地形、地貌环境影响,个体差异较大;有11座测风塔年平均风切变指数大于B类风切变指数,26座测风塔空间平均年风切变指数为0.155 1,也略大于B类风切变指数;风切变指数呈现明显的白天小、夜间大的日变化特征,与气温的日变化呈反位相;春季风切变指数明显偏小;大气中性条件下的风切变指数与年平均风切变指数基本相当,稳定状态下风切变指数明显偏大,不稳定状态下最小;风切变指数具有随风速增大而减小的特点,大风条件下的平均风切变指数小于年平均风切变指数,多数测风塔风速≥15 m/s时风切变指数下降至0.1以下。  相似文献   
507.
Nanoscale zerovalent iron (nZVI) synthesized using sepiolite as a supporter was used to investigate the removal kinetics and mechanisms of decabromodiphenyl ether (BDE-209). BDE-209 was rapidly removed by the prepared sepiolite-supported nZVI with a reaction rate that was 5 times greater than that of the conventionally prepared nZVI because of its high surface area and reactivity. The degradation of BDE-209 occurred in a stepwise debromination manner, which followed pseudo-first-order kinetics. The removal efficiency of BDE-209 increased with increasing dosage of sepiolite-supported nZVI particles and decreasing pH, and the efficiency decreased with increasing initial BDE-209 concentrations. The presence of tetrahydrofuran (THF) as a cosolvent at certain volume fractions in water influenced the degradation rate of sepiolite-supported nZVI. Debromination pathways of BDE-209 with sepiolite-supported nZVI were proposed based on the identified reaction intermediates, which ranged from nona- to mono-brominated diphenylethers (BDEs) under acidic conditions and nona- to penta-BDEs under alkaline conditions. Adsorption on sepiolite-supported nZVI particles also played a role in the removal of BDE-209. Our findings indicate that the particles have potential applications in removing environmental pollutants, such as halogenated organic contaminants.  相似文献   
508.
丰娇  吴耀国  张娜 《化工环保》2012,32(5):413-418
零价铁-Fenton试剂体系在对许多有机污染物有着较好的处理效果的同时,有效地克服了单独零价铁还原与传统Fenton反应的缺点.本文分析了零价铁-Fenton试剂体系的作用机理,总结了零价铁-Fenton试剂体系在处理有机污染物中的新进展,介绍了零价铁-Fenton试剂体系与其他技术联用降解有机污染物的研究成果.并讨论了对该反应有较大影响的几种因素.针对目前的研究中出现的一些问题,结合实际的需要,提出了今后需关注的研究方向.  相似文献   
509.
This study was carried out to evaluate water quality, sediment and plant vegetation in eight tributaries of the Mankyeong River for enhancement of natural purification. Among the tributaries, the Iksancheon water had the highest concentration of BOD, T-N and NH4-N due to inflow of swine wastes from the livestock district. The Yucheon water had the highest level of electrical conductivity and SO4(2-) due to inflow of mis-treated wastewater from industrial districts. The Tabcheon had generally similar concentrations of nitrogen and phosphate to that of the upstream of the Mankyeong River: agricultural activity along the Tabcheon appeared to have little negative influence to the water quality. Among various sediments, concentration of organic matter, nitrogen and phosphate were high in the Iksancheon and the Yucheon due to the livestock wastes and industrial wastes. There were 282 species of plants during summer with 43 aquatic plants, 57 hydrophytes, 178 waterside plants and 4 terrestrial plants. Some plant resources were recommended due to much absorption of nitrogen and phosphate for enhancement of natural purification. C. demersum and H. verticillata were recommended in the submerged aquatic plants, H. dubia, N. indica and N. subinteperrimum in the floating leaf aquatic plants, P. communis, Z. latifolia and T. orientalis in the emerged aquatic plants, C. scutata and P. distichum in the waterside plants.  相似文献   
510.
道路交通危机事件具有意外性、紧急性和危险性等特征,人们在处理过程中往往面临着各种信息不完全、信息不准确或信息反馈不及时等情况,因此,在对整个危机事件的处理过程中都充满了复杂性、快速性等特点。笔者从危机管理角度,提出了道路交通危机和道路交通危机管理的概念;分析了道路交通危机管理的特点以及国内外目前的现状;探讨了在我国建立道路交通危机管理体系的必要性;从道路交通危机管理制度、管理机构、运行机制等方面讨论了构建道路交通危机管理体系的整体框架;从宏观角度重点研究了道路交通危机管理运行机制的预警机制、快速反应机制、信息发布机制、协调机制、评价机制等方面问题。  相似文献   
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