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51.
This paper presents a novel approach of measuring radon in-water in the field by inserting a MEDUSA gamma-ray detector into a 210 L or 1000 L container. The experimental measurements include investigating the effect of ambient background gamma-rays on in-field radon measurement, calibrating the detector efficiency using several amounts of KCl salt dissolved in tap water, and measuring radon in borehole water. The results showed that there is fairly good agreement between the field and laboratory measurements of radon in water, based on measurements with Marinelli beakers on a HPGe detector. The MDA of the method is 0.5 Bq L−1 radon in-water.  相似文献   
52.
总结了近年来不同地区对不同环境下大气超细颗粒物的观测和扩散模拟研究进展。大量的观测研究结果表明,大气超细颗粒物的时空分布、组成特征、形成和成长的特性因观测地区的不同而存在很大差异,受气象因素和局部污染源的影响很大;其来源主要包括固定、移动燃烧源的直接排放和大气中颗粒成核现象,前一种来源一般是局部的,而后一种来源则是区域性的。目前,大多数关于大气超细颗粒物扩散的模拟研究都是针对其质量浓度的,对其数浓度扩散的模拟研究主要集中在小范围(机动车排放烟云的研究方面),在城市区域范围上的研究和应用还很少。最后,探讨和展望了大气超细颗粒物今后的主要研究方向和研究中面临的挑战。  相似文献   
53.
The wind potential around an intensely mountainous area has been studied and an experimental analysis is presented the output of which could be used in the wind farm planning procedure aiming at maximization of the wind power production output of an area. The wind speed of a chosen site of Central Greece was studied based on field measurements around a large mountainous area of Central Greece. Understanding flow in the foothills and the wider area of the mountains is of great importance for estimating wind resource in rough terrain. In this article, special focus was given to the speed-up effect and forced air flow around mountainous masses.  相似文献   
54.
Beijing is one of the most polluted cities in the world. In this study, the long-term and continuous measurements of volatile organic compounds (VOCs) in the urban area of Beijing, specifically at Beijing 325 m Meteorological Tower, were conducted from 2000 to 2007. The annual record of VOC trends exhibited in two different phases was separated in 2003. Records show that VOC concentrations increased from 2000 to 2003 due to the abrupt increase in vehicle number. Contrarily, since 2003, there had been a decrease in VOCs concentrations as the policy on gasoline and air pollution was implemented. Toluene, benzene, and i-pentane are the chemicals that abound in and are directly related to vehicle activity, such as in vehicle exhaust and gasoline evaporation. Furthermore, records indicate that there had been seasonal variation in VOCs levels in that VOCs level in summer is higher than that in winter. As such, temperature is considered to significantly contribute to VOCs in Beijing. Records also show that VOCs level was high in the morning and during rush hours in the evening. In contrast, VOCs level was low during midday due to photochemical destruction with OH radical and dilution effect. In this study, a particular benzene to toluene ratio range (0.4-1.0) was used as the indicator of air propelled by vehicular exhaust. We also applied the correlation coefficients between BTEX and i-pentane to evaluate evaporation influence to ambient BTEX in the Beijing urban area.  相似文献   
55.
简要介绍了德国、荷兰和美国等工业化国家的有害废物管理的新动向,以及由工业化国家在有害废物管理中取得的成功经验中,适用于发展中国家的有害废物的基本管理方法和可以作为借鉴的实用措施的指南性环境管理框架。  相似文献   
56.
室内空气污染物的种类及控制措施   总被引:12,自引:0,他引:12  
室内空气污染物包括悬浮固体污染物和气体污染物。其中可吸入颗粒物对人体呼吸系统有极大危害,引起肺炎、肺癌等疾病,主要来源于燃料的燃烧、吸烟以及由室外进入室内的颗粒物。气体污染物主要包括有机气体污染物(挥发性有机物、甲烷等)和无机气体污染物(SO2、NOx、CO等),它们可引起病态建筑综合症、化学物质过敏症(MCS)等相关病症。本文分析了室内空气污染的影响因素,并据此提出了控制室内空气污染以及提高室内空气质量的方法与措施。  相似文献   
57.
In the summer of 1998, the air quality (indicators: CO, NO, NO2, O3) above the water surface of the Lake Balderey (Essen, Ruhr area, North Rhine-Westphalia, Germany), an artificial lake used for recreation purposes, was measured using the Fourier transform infrared spectroscopy (FTIR) and differential optical absorption spectroscopy (DOAS) remote measurement methods. The lake, with an area of 3 km2 was created by damming the Ruhr and is surrounded by higher ground. In calm, bright weather conditions, this location results in a low-exchange situation (formation of temperature inversions, cold air dynamics) with a sustained impact on pollutant concentrations over the lake. The results of trace substance measurements (1/2 h mean values) were compared with values from comparison stations (suburban, high traffic and forest) located outside the area of the lake. In general, it was found that mean CO and NO concentrations over the lake were very low (0.3 ppm and 7.5 ppb, respectively). NO2 values (15 ppb) were some 3.5 times higher than those recorded at the forest station and O3 values, at 27 ppb, almost reached the same level as at the forest station (30 ppb). Mass flow densities as a function of wind direction, diurnal courses, differences between weekdays and weekends and comparisons with air quality standards are presented for the lake station.  相似文献   
58.
Examining the contribution of fossil fuel CO2to the total CO2changes in the atmosphere is of primary concern due to its alarming levels of fossil fuel emissions over the globe,specifi cally developing countries.Atmospheric radiocarbon represents an important observationa constraint and utilized to trace fossil fuel derived CO2(CO2ff) in the atmosphere.For the firs time,we have presented a detailed analysis on the spatial distribution of fossil fuel der...  相似文献   
59.
The expansion of the industrial economy and the increase of population in Northeast Asian countries have caused much interestin climate monitoring related to global warming. However, new techniques and better platforms for the measurement of globalwarming and regional databases are still old-fashioned and arenot being developed sufficiently. With respect to this agenda,since 1993, at the request of the World Meteorological Organization (WMO), to monitor functions of global warming, theKorea Meteorological Administration (KMA) has set up a Global Atmospheric Watch (GAW) Station on the western coast of Korea(Anmyun-do) and has been actively monitoring global warming overNortheast Asia. In addition, atmospheric carbon dioxide (CO2) has been measured for a similar KMA global warmingprogram at Kosan, Cheju Island since 1990. Aerosol and radiationhave also been measured at both sites as well as in Seoul. Theobservations have been analyzed using diagnostics of climate change in Northeast Asia and also have been internationally compared. Results indicate that greenhouse gases are in good statistic agreement with the NOAA/Climate Monitoring and Diagnostics Laboratory (CMDL) long-term trends of monthly meanconcentrations and seasonal cycles. Atmospheric particulatematter has also been analyzed for particular Asian types interms of optical depth, number concentration and size distribution.  相似文献   
60.
Fluctuating asymmetry (FA) in eight cranial measurements was studied in Microtus rossiaemeridionalis voles from two sites of the zone affected by the Totsk Radioactive Trace (TRT) and in the control population. In the affected populations, generalized mean population parameters of FA were significantly higher than in the control and tended to increase in relatively larger animals. The disturbance of ontogenetic homeostasis in voles from the TRT zone probably resulted from environmental stress caused by contamination with radionuclides (primarily plutonium), which entailed irradiation of many vole generations over more than 40 years.  相似文献   
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