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51.
• The Large scale Urban Consumption of energY model was updated and coupled with WRF. • Anthropogenic heat emissions altered the precipitation and its spatial distribution. • A reasonable AHE scheme could improve the performance of simulated PM2.5. • AHE aggravated the O3 pollution in urban areas. Anthropogenic heat emissions (AHE) play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer, particularly in densely populated megacities like Beijing. In this study, we estimate the AHE by using a Large-scale Urban Consumption of energY (LUCY) model and further couple LUCY with a high-resolution regional chemical transport model to evaluate the impact of AHE on atmospheric environment in Beijing. In areas with high AHE, the 2-m temperature (T2) increased to varying degrees and showed distinct diurnal and seasonal variations with maxima in night and winter. The increase in 10-m wind speed (WS10) and planetary boundary layer height (PBLH) exhibited slight diurnal variations but showed significant seasonal variations. Further, the systematic continuous precipitation increased by 2.1 mm due to the increase in PBLH and water vapor in upper air. In contrast, the precipitation in local thermal convective showers increased little because of the limited water vapor. Meanwhile, the PM2.5 reduced in areas with high AHE because of the increase in WS10 and PBLH and continued to reduce as the pollution levels increased. In contrast, in areas where prevailing wind direction was opposite to that of thermal circulation caused by AHE, the WS10 reduced, leading to increased PM2.5. The changes of PM2.5 illustrated that a reasonable AHE scheme might be an effective means to improve the performance of PM2.5 simulation. Besides, high AHE aggravated the O3 pollution in urban areas due to the reduction in NOx.  相似文献   
52.
A polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE) method was employed to estimate the contamination sources of human enteroviruses and understand how their dominant strains vary in a wastewater treatment and reclamation system consisting of sewage collection, wastewater treatment with membrane bioreactor and open lakes for reclaimed water storage and reuse. After PCR–DGGE using a selected primer set targeting enteroviruses, phylogenetic analysis of acquired enterovirus gene sequences was performed. Enteroviruses identified from the septic tank were much more diverse than those from grey water and kitchen wastewater. Several unique types of enterovirus different from those in wastewater samples were dominant in a biological wastewater treatment unit. Membrane filtration followed by chlorination was proved effective for physically eliminating enteroviruses; however, secondary contamination likely occurred as the reclaimed water was stored in artificial lakes. Enterovirus 71 (EV71), a hand-foot-and-mouth disease (HFMD) viral pathogen, was detected mainly from the artificial lakes, implying that wastewater effluent was not the contamination source of EV71 and that there were unidentified non-point sources of the contamination with the HFMD viral pathogen in the reclaimed water stored in the artificial lakes. The PCR–DGGE targeting enteroviruses provided robust evidence about viral contamination sources in the wastewater treatment and reclamation system.  相似文献   
53.
Environmental Science and Pollution Research - Co3O4 is a promising Hg0 removal catalyst for industrial application. Operating temperature and low sulfur resistance are two of the main problems...  相似文献   
54.
大气污染的危害及防治措施   总被引:1,自引:0,他引:1  
人类将大量的废气、烟尘等排人大气,严重影响了大气环境质量。大气污染对人类及动植物的健康状况、肌体的免疫功能有明显的不良影响,同时引起地球气候异常,给人类生活带来了各种危害,迫使人类必须采取各种防治措施。  相似文献   
55.
新型高效H2-SCR尖晶石型NiFe2O4催化还原NO   总被引:1,自引:0,他引:1  
采用柠檬酸配位溶胶-凝胶法制备尖晶石型复合金属氧化物NiFe2O4,以H2为还原剂,在固定床反应器中考察了该催化剂催化还原NO的性能,并借助X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、比表面积测定(BET)、程序升温还原(TPR)和程序升温脱附(TPD)等方法对样品的晶体结构、形貌等特性进行了表征.结果表明.在空速4500 h-1,H2/NO浓度比为1,温度为400℃下,H2催化还原NO的效率可达97.8%,高H2/NO浓度比对NO转化率提升不大,高空速对其催化活性无明显影响.所制备的NiFe2O4催化剂具有典型的尖晶石结构,颗粒不规则,粒径大约为30—150 nm,并且具有良好的双官能团氧化还原性质.  相似文献   
56.
长三角城郊樟溪流域水体氮磷分布特征及其影响因素   总被引:1,自引:0,他引:1  
快速城镇化和人类活动导致城郊流域水体营养盐污染和富营养化问题加重,识别氮、磷污染对流域水质的管控具有重要的意义。本研究选取长三角典型城郊地区宁波樟溪流域,在流域内根据土地利用类型、地形特征等布设样点,于2016年连续4个季度进行水样采集,研究樟溪流域河流水体氮、磷的含量及形态,及氮、磷在该流域的时空分布特征,并对其来源和影响因素进行分析。研究结果表明,流域内氮、磷分布具有较大的空间差异性,其中NH+4-N(n.d.~1.375 mg·L~(-1))、TN-N(0.570~11.363 mg·L~(-1))、DIP(n.d.~0.169 mg·L~(-1))、TP(0.010~1.908 mg·L~(-1))。在子流域空间分布上,人类活动频度越高的区域氮、磷的浓度越高,各采样点水体不同形态氮含量和磷含量具有明显的季节变化规律:春季和秋季的含量要高于夏季和冬季。本研究选取采样点距城镇距离、距源头距离以及土地利用类型所占采样点缓冲区的比例来表征人类活动的影响,结果表明,TN和TP含量与距城镇距离呈显著负相关关系,表明城镇化水平对流域氮、磷污染的重要影响。另外,典型城郊流域河流水体氮、磷污染主要受土地利用类型的影响,其含量与农业和城镇用地呈显著正相关关系(P0.01),其含量随人类活动频度的增加而升高。  相似文献   
57.
采用C/PTFE气体扩散电极在无隔膜体系中进行H2O2发生工艺研究,探讨了石墨和Vulcan XC-72碳黑两种碳材料以及电解电压、p H值对该反应过程的影响.结果表明,在较低的空气流量(1.41 cm3·min-1·cm-2)下,以Vulcan XC-72碳黑为表面的气体扩散电极相比石墨电极有较高的H2O2产率和电流效率,碱性条件比酸性条件下H2O2产率和电流效率更好;在2.6 V恒定电压下,2 h后,H2O2浓度达到了250 mg·L-1,电流效率从69.8%降到44.7%,单位产量能耗从5.87 k Wh·kg-1升高到9.16 k Wh·kg-1.  相似文献   
58.
开展生态保护红线与各类保护地重叠特征分析及政策法规梳理研究,对推进生态环境治理体系建设具有重要实践意义.以2018年浙江省生态保护红线划定成果为典型案例,采用定量与定性结合的分析方法,分析了生态保护红线与保护地重叠特征,归纳整理了国家及浙江省出台的政策法规文件,分类梳理了各部门监管职能分工.结果表明:(1)浙江省各类保...  相似文献   
59.
针对特种设备数量高速增长与质量管理服务供给不足等日益复杂的形势,研究基于物联网、大数据、云计算等新一代信息技术的特种设备智能检测监测架构与支撑要素,提出面向设备安全管控的检测监测技术应用模式、面向生命周期环节的集成应用模式、基于动静态数据的云服务应用模式等多种云服务模式,集成技术、平台、数据等多种手段探索特种设备行业检测监测应用与服务创新,满足特种设备生产、使用、检验、检测、监管等多方需求,推动特种设备质量提升、技术优化和风险防范能力升级.  相似文献   
60.
The purpose of this study is to investigate the land use intensity and land use change type at the basin scale in the middle and lower reaches of the Hanjiang River Basin (in Hubei Province, China) by combining the Landsat TM images in 1995 and 2000 with the land use database (in scale 1:10,000) and relative data. In this study, the basic data is acquired from the interpretation of remote sensing (RS) images. The intensity of land use and the rate of change in double-directions of land use dynamics are calculated with the support of software ARC/INFO. The intensity of land use is indicated by the intensity coefficient of land use, and the transition of land use types is quantified as the rate of change in double-direction of land use types and also expressed as the transition matrix of land use types. The results are expressed in space by Geographic Information System (GIS) software. Results of this study show that (1) the intensity of land use is high in the study region, the intensity coefficients of land use in 1995 and 2000 are 260.025 and 290.526, respectively, and the intensity of development and utilization of land is trend to increscent; and (2) the rate of land use change in double directions in the whole study region is 0.52 with great spatial variation and the differentiation of land use types. In the differentiation of land use types, the unutilized land (with the rate to 4.391) is developed fast, the grassland (with 2.836) and water area (with 1.664) are disturbed severely, and these changes will influence the eco-environment in the Hanjiang River Basin and all the Yangtze Basin. The rates of the farmland and the woodland are 0.424 and 0.344, respectively, meaning that the fundamentals of regional human-environmental system are relative stable. With this study, we can conclude that (1) the patterns of land use are increasingly changing in the study region, the environmental impacts are escalated on this stage, and the further outcomes are destined to change the stability of the regional human–environmental system; and (2) the most useful method to study the present land use and its change is through the use of the RS/GIS with the land use database (in scale 1:10,000).  相似文献   
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