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1.
选取北京市环境电磁辐射自动监测站点2年多的数据,利用SPSS统计软件,对各站点数据进行了主要电磁辐射源、长期数据趋势、各站点时间代表性分析;并结合网格法监测数据,对自动站点空间代表性进行分析。结果表明,5个环境电磁辐射自动站周围主要电磁辐射源均为移动通信基站;其总体电磁辐射水平为0.69~0.97 V/m,低于北京市1 V/m的电磁辐射环境本底水平,且单站点连续12个月的监测数据可以描述该点位电磁辐射平均水平和变化趋势;经分析,连续5年全市网格法电磁辐射射频电场的监测数据总体具有较好的一致性,但单站点的电磁辐射水平不能代表所在行政区的电磁辐射总体水平。提出了电磁辐射自动监测网络建设建议。  相似文献   

2.
以某中波电台为例,对多个不同频率的中波发射台同时运行时复合场强进行理论估算,对电磁辐射叠加影响进行分析,并将理论估算值与该台电磁辐射环境现状监测数据进行比对,得出距离发射塔近,复合场强理论估算值高于实测值,距离较远理论估算值与实测值较接近等结论。  相似文献   

3.
GSM移动通信基站电磁辐射污染状况研究   总被引:1,自引:0,他引:1       下载免费PDF全文
介绍了GSM移动通信基站系统,指出,在进行GSM移动通信基站环境影响分析时,要注意采样点位的设置和测量要求.现场监测结果表明,GSM移动通信基站对环境电磁辐射水平有一定的影响,特别是对50 m内建筑物影响显著,但绝大多数基站基本符合国家有关电磁辐射环境影响标准的要求,在设备正常运行情况下,不会对周围环境造成电磁辐射污染.  相似文献   

4.
轿车内空气污染监测研究   总被引:5,自引:0,他引:5  
通过实际监测研究,对轿车内空气污染水平、车内外空气污染的相关性、车内空气污染与汽车工况、通风状况的关系进行了评估,分析污染来源并提出了控制对策。  相似文献   

5.
电磁辐射对环境的影响主要包括工频电场、工频磁场、无线电干扰以及对环境产生的噪声。根据《辐射环境保护管理导则电磁辐射监测仪器和方法》(HJ/T10.2—1996),对宜宾110kV吊黄楼变电站进行电磁环境监测,将监测所得结果对照国家规定的限值,对电磁污染水平进行评价。通过仪器的选择,监测点位的确定以及执行标准等方面的内容,比较系统的介绍了现行电磁辐射的环境监测方法。  相似文献   

6.
对连云港移动通信基站电磁辐射环境进行现状调查与评价,将3个时段内移动基站电磁辐射监测数据进行统计分析和分区评价。结果表明,监测数据均能符合相应的环境标准,县域电磁环境辐射水平整体略低于城市区域,基站周边整体受电磁辐射影响程度随高度上升呈增加趋势,10 m~15 m高度处的综合场强平均峰值最高。  相似文献   

7.
对泉州市移动通信GSM基站和TD—SCDMA基站电磁辐射状况进行监测与分析。通过理论计算预测基站电磁辐射安全距离,对典型敏感目标、典型基站进行电磁辐射的监测,结果与理论预测情况相符。选取302个GSM基站和306个TD—SCDMA基站进行电磁辐射的监测,结果表明,各基站电磁辐射满足单个项目管理低于目标限值0.08W/m2的标准。分析表明,基站在正常运行时,对周围的电磁辐射环境影响能满足国家相应标准的要求。  相似文献   

8.
为了解南通市移动通信基站电磁辐射时空分布特征,随机实测504座典型基站,着重从水平和垂直方向50 m范围内开展监测,并选取典型基站开展24 h连续监测。结果表明,南通市移动通信基站电磁辐射水平满足《电磁环境控制限值》(GB 8702—2014)中公众曝露控制限值要求;基站电磁辐射水平分布随距离增大呈现先增加后逐渐减小的趋势,地面最大投射点的距离基本为20~30 m;垂直方向最大监测值出现在与天线高度相近的楼层;24 h基站电场强度随时间呈明显变化,与话务量和数据流量分别进行相关性分析,相关系数为0.968 3和0.709 8,说明目前话务量仍是电磁辐射强度的重要影响因素。  相似文献   

9.
北京市某高层建筑高空电磁辐射环境影响分析   总被引:1,自引:0,他引:1  
选取北京市某代表性高层居民楼顶平台作为高空电磁辐射环境水平监测点进行综合场强和选频监测,评价总体电磁辐射环境水平,并分析监测区域电磁辐射能量的来源。结果表明:该高空监测区域的电磁辐射环境总体水平低于国家规定的公众照射导出限值,但高于地面水平。监测区域主要受30 km 外的中波台影响,其次是9 km 外的中央电视塔。影响最大的是639 kHz频率的中波信号,占100 kHz~300 MHz总场强的95%以上,其次是1.28 MHz频率的中波信号。提出,开展敏感建筑物规划建设时,应考虑中波的传播特性和对环境的影响。  相似文献   

10.
董铮  王琳  田芳 《中国环境监测》2014,30(2):125-128
环境监测任务可信度评估体系能够考评监测任务的全过程,改变以往人们对环境监测数据是否可信的是否判断,对监测计划、现场监测、样品管理、实验室分析、分包、监测数据、质量体系运行、重大不符合工作等8个环节的各个分量进行识别和量化考评,并根据最终得分对监测数据给出一个量化的信用数据。  相似文献   

11.
采用上海市车辆数据和机动车年检站实地调查方式获取车辆技术及分布,用GPS设备采集机动车行驶工况,通过交通流量录像的现场计数的方法获得道路车流分布。调查结果显示,在用汽车排放水平85%以上都达到或超过国Ⅱ标准;在低速、怠速工况区间内,社会车辆的比功率比例最低;道路轻型客车(含出租车)日平均车流量占总车流量的80%以上。机动车活动水平的详细调查将有助于上海实际道路机动车排放清单的精确计算,并获取主要的排放源及其影响因素。  相似文献   

12.
利用真空瓶现场采样并结合单颗粒气溶胶质谱(SPAMS)技术,对主流品牌汽油车和柴油车排放细颗粒物进行组分分析和源谱构建。结果表明:汽、柴油车尾气源谱特征整体较为相似,相似度均值达到0.88,均以碳和钙为主要特征组分;部分柴油车特征源谱中硫酸盐特征较为明显,碳组分中OC特征突出;汽油车源谱特征中磷酸盐特征相对突出,且碳组分中短链元素碳占比较高。根据建立的源谱进行实际道路观测,结合风速、风向等气象要素分析,2021年2月1日—24日观测点位对应的移动源占比为33.5%,其中汽油车贡献21.0%,柴油车贡献12.5%。  相似文献   

13.
In the latest years the effect of powered two-wheelers on air polluting emissions is generally noteworthy all over the world, notwithstanding advances in internal combustion engines allowed to reduce considerably both fuel consumption and exhaust emissions of SI engines. Nowadays, in fact, these vehicles represent common means of quotidian moving, serving to meet daily urban transport necessities with a significant environmental impact on air quality. Besides, the emissive behavior of the two-wheelers measured under fixed legislative driving standards (and not on the local driving conditions) might not be sufficiently representative of real world motorcycle riding.The purpose of this investigation is a deeper research on emissive levels of in-use motorcycles equipped with last generation SI engines under real world driving behavior. In order to analyze the effect of vehicle instantaneous speed and acceleration on emissive behavior, instantaneous emissions of CO, HC and NOX were measured in the exhaust of a four-stroke motorcycle, equipped with a three-way catalyst and belonging to the Euro-3 legislative category. Experimental tests were executed on a chassis dynamometer bench in the laboratories of the National Research Council (Italy), during the Type Approval test cycle, at constant speed and under real-world driving cycles. This analytical-experimental investigation was executed with a methodology that improves vehicles emission assessment in comparison with the modeling approaches that are based on fixed legislative driving standards. The statistical processing results so obtained are very useful also in order to improve the database of emission models commonly used for estimating emissions from road transport sector, then they can be used to evaluate the environmental impact of last generation medium-size motorcycles under real driving behaviors.  相似文献   

14.
This investigation adopts vehicle tracking manner to establish real-world driving patterns and estimates emission factors with dynamometers with 23 traffic-driving variables for 384 in-use light-duty passenger vehicles during non-rush hour. Adequate numbers of driving variables were decided with factor analysis and cluster analysis. The dynamometer tests were performed on FTP75 cycle and five local driving cycles derived from real-world speed profiles. Results presented that local driving cycles and FTP75 cycle were completely different in driving characteristic parameters of typical driving cycles and emission factors. The highest values of emission factor ratios of local driving cycle and FTP75 cycle for CO, NMHC, NO x , CH4, and CO2 were 1.38, 1.65, 1.58, 1.39, and 1.14, respectively.  相似文献   

15.
A preliminary study to determine the profile of PAHs in the exhaust of gasoline vehicles in Delhi was conducted. Three different types of vehicles (cars, autorickshaws and scooters) were selected with different age groups for sampling purpose. The concentration of Total PAHs (Σ12PAHs) was found to be 27.27 ± 2.27, 28.61 ± 3.70 and 29.81 ± 3.57 mg/g in the exhaust of cars, auto- rickshaws (three wheelers) and two wheelers, respectively. The levels of PAHs were found to be high in scooter exhaust as compared to that of cars and autorickshaws. The total PAHs concentration in the present study was found to be higher as compared to other studies. Such a high concentration could be attributed to different parameters like the age of the vehicles, driving conditions, the fuel quality and the emission standards.  相似文献   

16.
A preliminary study to determine the profile of PAHs in the exhaust of diesel vehicles plying on Delhi roads was conducted. Two different types of diesel vehicles (buses and trucks) with different age groups were selected for sampling purpose. The concentration of Total PAHs (12PAHs) was found to be 50.76 ± 6.62 and 57.72 ± 4.15 mg/g in the exhaust of buses and trucks, respectively. The levels of PAHs were found to be high in trucks as compared to that of buses. The total PAHs concentration in the present study was found to be higher as compared to other studies. Such a high concentration could be attributed to different parameters like the age of the vehicles, driving conditions, the fuel quality and the emission standards.  相似文献   

17.
Platinum and Rh content in the atmosphere of Rome as released by car catalytic converters was monitored from 1998 to 2000 in six urban sites with different traffic intensities and in one rural area. Samples collected with medium-volume PM10 samplers were analyzed by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS). The Pt content varied from 2.4 to 60.1 pg m(-3) (mean value 17.8 pg m(-3)) at the urban locations whilst that of Rh spanned the range 0.8-9.4 pg m(-3) (average value 4.0 pg m(-3)). The rural area showed metal levels mostly below the limits of detection, pointing to automobile traffic as the main source of those elements in the urban atmosphere. The highest mean concentrations of Pt and Rh, ie. 22.2 and 5.0 pg m(-3), were detected along the ring road where the traffic density is high (>100,000 vehicles per day) and the driving speed between 100 and 120 km h(-1). The lowest Pt and Rh mean concentrations, i.e. 11.4 and 3.4 pg m(-3), were measured downtown, where traffic density is lower (20,000 vehicles per day) and the driving speed is limited (50 km h(-1)). Significant concentrations of Pt and Rh were found in the vicinity of traffic signals, indicating that the "stop-and-go" conditions might also affect their release. The measured Pt/Rh ratio spanned the range 3.3-5.9 in accordance with that present in the more commonly used gasoline car catalytic converters. Seasonal variations between wintertime (with Pt and Rh mean concentrations of 23.8 and 5.1 pg m(-3), respectively) and summertime (with Pt and Rh mean concentrations of 14.1 and 3.3 pg m(-3), respectively) were also observed.  相似文献   

18.
This paper presents emission factors of a class of passenger cars obtained by applying a statistical model developed to evaluate average emission factors based on driving cycle emission measurements. A multivariate regression method based on principal components, namely, the partial least squares (PLS) method, is applied to calculate the model. The method was applied to emission data from a sample of petrol Euro III 1,200- to 1,400-cc passenger cars taken from the ARTEMIS database. A vehicle effect analysis showed that vehicle effect is considerable, in some cases comparable to or greater than the driving cycle effect. Determination of emission factors is obviously affected by these aspects. Thus, the CO2 PLS model fit results are good, CO, HC and NOX more or less sufficient. PLS-predicted quantities were compared with corresponding quantities estimated by a multiple regression model (GLM) based on a quadratic polynomial equation of sub-cycle overall mean speed. GLM goodness of fit was poorer than PLS ones. A validation effort of models is in progress, which is considering the ARTEMIS database extended with tests performed within other national or international projects. In this way, an extended population of combinations of vehicles and driving cycles will provide a better calculation of models and emission factors.  相似文献   

19.
Methods have been developed to measure in situ the dynamic impact of both road and rail vehicles on the infrastructure and the environment. The resulting data sets have been analysed to quantify the environmental impacts in a transparent manner across both modes. A primary concern is that a small number of vehicles are being operated outside safe or regulatory limits which can have a disproportionate large impact. The analysis enables the various impacts to be ranked across both modes so enabling one to discern the benefits of intermodal transport. The impact of various policy options is considered and how to identify vehicles which can be classified as environmentally friendly. This would require European agreement as many heavy goods vehicle operate across country borders.  相似文献   

20.
系统测量了5辆小型载客汽车分别以20~100 km/h匀速行驶时的车外噪声频谱,得到了低、中、高各频段声压级随车速的变化关系,进一步与城市道路交通噪声频谱相比较,为从声源上控制城市道路交通噪声提供有力的参考依据。  相似文献   

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