放射源在线监控系统设计与应用

为了防止在用放射源发生脱落、丢失、超标使用、私自转移等情况,最大限度避免辐射安全事故。有必要设计建立放射源在线监控系统,对放射源放射性指标(辐射剂量率)及所处位置(经纬度)实行连续的自动监测。并通过各级监管平台设置放射源超标、异动等报警程序,全面提升放射源科学监管水平。     

重庆市碳排放现状及低碳经济发展战略研究

低碳经济以低能耗、低污染、低排放为基础,是当今世界减缓温室气体排放、应对气候变化的最佳经济发展模式。本文初步估算了重庆市包括二氧化碳排放总量、人均排放量、万元GDP排放强度等碳排放现状,分析了近年来全市碳排放减缓的趋势以及二氧化碳排放来源解析的结果,探讨了重庆市低碳发展的良好基础,提出了重庆市发展低碳经济的战略取向、战略目标、战略重点和战略措施建议,描绘了重庆市低碳发展的行动路线图,认为低碳经济是重庆市转变经济发展方式、实现可持续发展的必然选择。     

220千伏高压输电线路对电磁环境的影响分析及防治对策

通过对220kV输电线路电磁辐射的实际测量和理论计算,研究和讨论了220kV单回路和双回路输电线产生的电磁辐射对环境的影响,并提出降低电磁辐射水平的对策与建议。     

论辐射事故发生原因和预防、解决措施

随着科学技术和社会经济的高速发展,核技术在工业、农业、医疗等领域得到了越来越广泛的应用,但其在带给人类巨大经济效益的同时,也给社会安全带来了潜在的威协,辐射事故时有发生,不仅污染环境,甚至危及人们的身体健康和生命。文中对辐射事故发生的类型、级别以及发生的原因进行了分析,提出了预防和解决的措施。     

徐州市电磁辐射环境的污染现状调查及评价

调查了徐州市电磁辐射污染源的状况,分析了其电磁辐射环境质量的现状,并对全市电磁辐射环境质量进行了评价,指出了分析工作中存在的问题,提出了防治对策。     

High background radiation investigated by gamma spectrometry of the soil in the southwestern region of Cameroon

The aim of this work is to determine the radioactivity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K in sub-surface (0-5 cm) soil samples collected from Awanda, Bikoué, Ngombas in the southwestern region of Cameroon, to assess their contribution to the external dose exposure relative to the United Nation Scientific Committee on Effects of Atomic Radiation (UNSCEAR) data. An HPGe p-type detector coupled to a multichannel analyzer was used to perform measurements and data processing. The activity concentrations of ²²⁶Ra varied from 0.06 ± 0.01 to 0.27 ± 0.02 kBq kg⁻¹ with a mean value of 0.13 ± 0.01 kBq kg⁻¹ wet weight. The activity concentrations of ²³²Th varied from 0.10 ± 0.01 to 0.70 ± 0.05 kBq kg⁻¹ with a mean value of 0.39 ± 0.03 kBq kg⁻¹ wet weight, and ⁴⁰K concentrations varied from 0.37 ± 0.02 to 1.53 ± 0.11 kBq kg⁻¹ with a mean value of 0.85 ± 0.07 kBq kg⁻¹ wet weight, respectively. The mean value of outdoor annual effective doses were estimated to be 0.48 mSv y⁻¹, 0.39 mSv y⁻¹ and 0.38 mSv y⁻¹ from Ngombas, Awanda and Bikoué, respectively. The studied areas can be said to have a high background radiation level.     

An approach to improve the Austrian Radon Potential Map by Bayesian statistics

A Radon Potential Map as well as a mean indoor Radon Concentration Map is available from the Austrian National Radon Project (1992-2002). These maps are based on the average Radon Potential/Concentration within every municipality and they sort municipalities into three radon ‘risk’ classes. This is a convenient way for the administration, but it does not describe the real radon risk distribution within a municipality because of the often inhomogeneous geological situation. Therefore, a combination of indoor radon data with all relevant parameters such as house type, storey and ventilation rates along with geological information should be used to improve the existing radon maps. The method, described here, uses Bayes' theory to combine the Radon Potential derived from indoor radon measurements with information from geology. The existing Radon Potential Map was improved by using available soil gas radon data at certain geological units and extrapolated transfer factors. The modifications of the map are shown and several problems arising with the application of this technique are discussed.     

套管喷旋流技术在热交换器中的应用

套管式空气预热器的传热元件是由两根不同直径的管子套在一起组成,外管由高温烟气获取热量,充分利用排烟余热,内管中通入冷空气,内外管通过对流和辐射的传热方式实现热量传递,是一种结构简单、换热效率高的新型空气换热器。     

SMX degradation by ozonation and UV radiation: a kinetic study

The rate constants of sulfamethoxazole (SMX) degradation by ozonation and UV₂₅₄ radiation were investigated under various parameters including influent ozone gas concentration, initial SMX concentration, UV light intensity, ionic strength, water quality in terms of varying anions (bicarbonate, sulfate and nitrate), humic acid (HA) and pH. The results indicated that the removal of SMX by ozonation and UV₂₅₄ radiation fitted well to a pseudo first-order kinetic model and the rate constants were in the range of (0.9-9.8) × 10⁻³ and (1.7-18.9) × 10⁻³ s⁻¹, respectively. The second-order rate constants of SMX with ozone (k_O3), under varying operational parameters, were also determined and varied in the range of (0.60-3.38) ± 0.13 × 10⁵ M⁻¹ s⁻¹. In addition, SMX degradation through UV pretreatment followed by ozonation in the presence of HA was proved to be an effective method which can remove SMX with a low ozone dose. The results suggested that ozonation of SMX was more affected by concentration of influent ozone gas, alkalinity, and HA, while incident UV light intensity, pH, and HA were the dominant factors influencing UV degradation of SMX.     

Heat map visualization of complex environmental and biomarker measurements

Over the past decade, the assessment of human systems interactions with the environment has permeated all phases of environmental and public health research. We are invoking lessons learned from the broad discipline of Systems Biology research that focuses primarily on molecular and cellular networks and adapting these concepts to Systems Exposure Science which focuses on interpreting the linkage from environmental measurements and biomonitoring to the expression of biological parameters. A primary tool of systems biology is the visualization of complex genomic and proteomic data using “heat maps” which are rectangular color coded arrays indicating the intensity (or amount) of the dependent variable. Heat maps are flexible in that both the x-axis and y-axis can be arranged to explore a particular hypothesis and allow a fast overview of data with a third quantitative dimension captured as different colors. We are now adapting these tools for interpreting cumulative and aggregate environmental exposure measurements as well as the results from human biomonitoring of biological media including blood, breath and urine. This article uses existing EPA measurements of environmental and biomarker concentrations of polycyclic aromatic hydrocarbons (PAHs) to demonstrate the value of the heat map approach for hypothesis development and to link back to stochastic and mixed effects models that were originally used to assess study results.