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331.
天津市纪庄子污水处理厂恶臭气体排放研究 总被引:3,自引:0,他引:3
2011年,在天津市纪庄子污水处理厂内采集空气样品,并对其中恶臭气体的浓度、扩散模式、影响范围及污水厂内各主要构筑物间相关系数进行了分析研究。结果表明,污水处理厂格栅处恶臭气体浓度最高,为4.31 ng/mL,其中95.61%为H2S气体,其他构筑物恶臭气体浓度范围为0.09~0.32 ng/mL,恶臭气体浓度较前处理工艺相比有大幅度减少;各主要构筑物排放的恶臭气体符合高斯气体扩散模式,恶臭影响范围为厂界外100 m以内;格栅处恶臭气体的排放对于厂界处恶臭气体浓度的贡献度最大,为42.68%;格栅、初沉池、脱水机房、二沉池之间的相关度在90%以上。 相似文献
332.
稠油热采系统综合能耗监测方法及评价 总被引:1,自引:1,他引:0
针对目前稠油热采系统节能措施和节能产品对某一环节单个节能产品的节能效果进行检测、评价的现状,提出了将稠油热采系统作为一个整体,采取组合节能措施及产品,给出了稠油热采系统的能耗监测流程、监测要求、程序与方法、数据分析评价方法等。形成了稠油热采系统综合能耗监测数据分析及效果评价方法。 相似文献
333.
334.
热真空设备中与温度相关的试验技术探讨 总被引:1,自引:0,他引:1
以RZHM-1400-AB型热真空试验箱为实例,简述设备主要工作原理。强调其温度传递方式及航天产品在热真空试验中温度参数的重要性。以无数试验数据为依据,着重论证何种类型测温传感器与实际设备相匹配,同时论证选取何种外形的测温传感器为最佳温度测量工具。同时,进一步介绍几种在热真空试验中使用这些测温传感器的方法,以减少不必要的人为测量误差。 相似文献
335.
PM2.5在线监测技术概述 总被引:4,自引:0,他引:4
针对PM2.5颗粒物监测技术和PM2.5的监测网络的建设,重点介绍了美国多年来对PM2.5的监测状况,以及采用的Beta射线法、Beta射线光浊度法、微量振荡天平法等监测技术的方法和原理;指出综合国内外多年的监测经验,PM2.5的在线监测需要经过大量手工经典方法数据作为比对和校验,才能给出有效而高质量的PM2.5监测数据。 相似文献
336.
引入投影降维的思想,将遗传投影寻踪与回归分析技术运用到城市环境质量评价中。将此技术与神经网络方法进行实例比较,投影寻踪回归方法不但可以合理地作出环境质量的综合评价,而且消除了神经网络方法中类别判断不够精确的影响。 相似文献
337.
Melissa A. Kenney Peter R. Wilcock Benjamin F. Hobbs Nicholas E. Flores Daniela C. Martínez 《Journal of the American Water Resources Association》2012,48(3):603-615
Kenney, Melissa A., Peter R. Wilcock, Benjamin F. Hobbs, Nicholas E. Flores, and Daniela C. Martínez, 2012. Is Urban Stream Restoration Worth It? Journal of the American Water Resources Association (JAWRA) 48(3): 603-615. DOI: 10.1111/j.1752-1688.2011.00635.x Abstract: Public investment in urban stream restoration is growing, yet little has been done to quantify whether its benefits outweigh its cost. The most common drivers of urban stream projects are water quality improvement and infrastructure protection, although recreational and aesthetic benefits are often important community goals. We use standard economic methods to show that these contributions of restoration can be quantified and compared to costs. The approach is demonstrated with a case study in Baltimore, Maryland, a city with a legal mandate to reduce its pollutant load. Typical urban stream restoration costs of US$500-1,200 per foot are larger than the cost of the least expensive alternatives for management of nitrogen loads from stormwater (here, detention ponds, equivalent to $30-120 per foot of restored stream) and for protecting infrastructure (rip-rap armoring of streambanks, at $0-120 per foot). However, the higher costs of stream restoration can in some cases be justified by its aesthetic and recreational benefits, valued using a contingent valuation survey at $560-1,100 per foot. We do not intend to provide a definitive answer regarding the worth of stream restoration, but demonstrate that questions of worth can be asked and answered. Broader application of economic analysis would provide a defensible basis for understanding restoration benefits and for making restoration decisions. 相似文献
338.
《Journal of Environmental Policy & Planning》2012,14(4):289-302
The concept of sustainable development has become very much in vogue in the past decade. We have also observed a shift in the interpretation of this concept from a global perspective to a meso perspective—that is, at a local, regional or sectoral level. This paper aims at highlighting the urban dimension of environmental issues. After a sketch of urban pollution problems and of tools for economic analysis, the notion of urban sustainability will be advocated as a meaningful analytical and policy concept. Next, the main focus of this paper will be on a typological approach to urban sustainability issues on the basis of three characteristic angles, viz. strong and weak sustainability, absolute and relative decoupling and the spatial ecological footprint. Various methodological issues will also be discussed, while the paper will conclude with some perspectives on policy issues. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
339.
340.
Mohsen Mohammadi Mogharreb Morteza Goldani Bagher Emadi 《International Journal of Sustainable Engineering》2014,7(3):245-252
The underground temperature at a depth of about 3–4 m is almost constant all the year round. In summer, the underground temperature is lower than the ambient temperature, but in winter it is vice versa. This potentiality is considered for greenhouse cooling and heating by using an earth-to-air heat exchanger (EAHE). This paper considers the effects of two parameters as independent variables including the area of greenhouse and the percentage of vegetation coverage inside the greenhouse on the performance of an EAHE system during both cooling and heating modes. The inside temperature, the thermal energy exchange and the coefficient of performance (COP) of the system were considered as dependent variables. The results showed that both greenhouse area and the percentage of vegetation coverage inside the greenhouse had significant effects on the performance of the EAHE system during both cooling and heating modes. However, the COP of the EAHE system was higher in the cooling mode (4.32) than during the heating mode (1.01). The percentage of vegetation coverage negatively affected the performance of the EAHE system in the cooling mode. However, the performance of the EAHE system improved with the increase in the percentage of vegetation coverage during the heating mode. 相似文献