Simultaneous occupational exposure to FM and UHF transmitters

Occupational exposure caused by large broadcasting transmitters exceeds current reference levels. As it is common for different radio and TV transmitters to share the location, we analysed combined exposure on a 40-m high mast. The frequency modulation (FM) transmitter, located between the 10th and 30th metre, had the power of 25 kW, whereas an ultra-high frequency (UHF) transmitter of 5 kW occupied the top 8 m of the mast. Measured and calculated values of the electric field strength exceeded the reference levels up to 10 times; however, the results for the specific absorption rate (SAR) values show that the reference levels are very conservative for FM exposure, i.e., basic restrictions are not exceeded even when the reference levels are exceeded 10 times. However, for UHF exposure the reference levels are not conservative; they give a good prediction of real exposure.     

The influence of fatigue on muscle temperature

The aim of the study was to investigate the possibility of using infrared (IR) thermography for assessing muscle fatigue during low effort. Three tests at constant levels of load 5, 15 and 30% of maximum voluntary contraction (MVC) lasting 5 min each were performed on a group of 10 men. Temperature and electromyographic (EMG) signal were registered from biceps brachii (BB). Analysis focused on the influence of load on the values and changes in time of muscle temperature. Correlations between temperature and EMG parameters (RMS, MPF and MF) were also analysed. Constant load sustained during the tests resulted in an increase in the temperature of BB. There were statistically significant correlations between temperature and EMG parameters for most subjects. Results of the study suggest that IR thermography can be an alternative or supplementary method for assessing muscle fatigue at low levels of contraction.     

中国大陆省级无意产生的五氯苯和六氯苯多源大气排放清单

基于技术分类方法构建了动态排放因子数据库,再采用排放因子法,自下而上构建了1960～2019年中国大陆省级无意产生的五氯苯和六氯苯的多源大气排放清单,并探究其时空分布特征.研究结果显示,五氯苯的最大排放源是含氯化学品生产,而六氯苯的最大排放源则是金属冶炼;五氯苯和六氯苯的排放密度均表现为东部地区高于西部地区的特征.从1960～2019年,五氯苯和六氯苯的排放量从1277.9,81.2kg分别上升至11862.3,439.7kg,但排放强度(单位GDP的排放量)却从869.3,55.2g/亿元分别下降至12.0,0.4g/亿元.     

ICP-AES法同时测定新疆石灰性土壤中多种有效元素含量

报道了用全谱直读等离子发射光谱法（ICP-AES）同时测定新疆石灰性土壤中有效元素Cu、Fe、Zn、Mn的分析方法.选择合适的分析线,采用基体匹配法与背景扣除法进行校正.该方法与国家标准方法相比较,结果均十分符合,并具有准确、灵敏度高、操作简便快速等优点.     

The relationship between the black carbon and bisphenol A in sea and river sediments (Southern Baltic)

This study was derived from field investigations to assess bisphenol A (BPA) concentrations in the sea and river sediments of the Gulf of Gdansk. Black carbon (BC) and total organic carbon (TOC) were identified as influencing factors on the accumulation. As a result of the transportation of BC with organic matter via rivers into the Gulf of Gdansk, the highest mean concentrations (11.26 ng BPA/(g dry weight (dw))), were determined in the sediments of river estuaries. Sediments in coastal stations were characterized by the lowest mean concentrations (5.73 ng BPA/(g dw)). TOC content below 0.1% determined the sorption of BPA on BC particles in sediments, and statistically significant correlation between the concentration of BPA and the BC/TOC ratio was found in these cases. In addition, dependency between the concentration of BPA and the content of BC was discovered in sediments where the BC/TOC ratio was > 0.33.     

2005年-2014年新疆生态足迹的计算及分析

随着社会经济的发展和人口密度不断增加的双重压力下,新疆维吾尔自治区的生态环境质量问题也日益突出,这就妨碍了区域经济的可持续发展.生态足迹是评估生态环境质量的重要指标,文章根据新疆维吾尔自治区2005年-2014年自然资源、能源消费、人口等数据,计算得出的生态足迹、生态环境承载能力和生态赤字结果显示,新疆维吾尔自治区自然资源供应和需求之间的关系不均衡,新疆生态足迹和生态承载力并不是处于最佳可持续性状态.     

天津快速的经济发展造成的环境问题及其对策

直面冷峻的环境现状,每一个有理性与责任感的公民无不忧心如焚。蔽日的烟云、腥臭的污河、毒化的农田和振聋发聩的噪音一刻不歇地疯狂考验和鞭笞着人们从心灵到生理的忍耐极限。本文使用大量详实的数据还原出天津环保的真相,社会各界的高度关注、积极参与和成效卓著的努力让我们对天津山清水秀的明日充满了期待。     

博斯腾湖流域浅层地下水重金属分布特征

从新疆博斯腾湖流域采集67个浅层地下水样品,测定其中Cu、Cd、Cr、Mn、Ni和Zn 6种重金属元素的含量,采用Nemerow综合污染指数对地下水中重金属污染程度进行评价,借助GIS技术与地统计法分析地下水中重金属含量与污染水平空间分布格局。结果表明:①博斯腾湖流域地下水6种重金属元素平均含量均未超出《国家地下水质量标准》(GB/T14848—2017)中Ⅲ类标准的限值;②研究区地下水重金属Cd、Cu、Ni与Zn的最佳变异函数理论模型为指数模型,Mn为球状模型,Cr为高斯模型。地下水中6种重金属元素空间分布格局各不相同,均出现含量高值区;③研究区地下水中Cd呈现中度污染,Ni存在点源污染,其它4种元素均呈现无污染。地下水中重金属元素综合污染指数介于0. 23～2. 22之间,平均值为0. 73,呈现轻微污染。Cd与Ni是研究区地下水中污染最高的元素,研究区地下水Cd与Ni污染值得关注。     

爱尔兰防火安全管理简介

本文简明介绍了爱尔兰的建筑物防火安全管理措施,希望对我国的火灾安全防护工作有借鉴意义。 1 简介 一座建筑物的防火安全措施包括以下三个部分: (1)被动火灾安全措施 (2)主动火灾安全措施 (3)火灾安全措施的管理 一座建筑物的安全保卫工作有赖于上述三项的充分实施。首先,被动安