Characteristics and formation mechanism of regional haze episodes in the Pearl River Delta of China

To investigate the characteristics and the specific mechanism of continuous haze,comprehensive measurements were conducted from 15 October to 19 November in the Atmospheric Environment Monitoring Super-Station in Heshan of Guangdong province.Five haze episodes occurred in October and November 2014 in the Pearl River Delta(PRD)region. The meteorological parameters, gas data, chemical compositions, and optical parameters of the aerosols were obtained. Among these events, the second haze episode,with the highest concentration of PM2.5 of 187.51 μg/m~3, was the most severe. NO~3-was always higher than SO_4~(2-), which indicated that motor vehicles played an important role in the haze, even though the oxidation rate from SO_2 to SO_4~(2-)was faster than that of NOXto NO_3~-. The difference between the hourly averages of Na+and K+during the haze episode and clean days was small, implying that straw combustion and sea salt had no significant effect on the occurrence of haze, and the backward trajectories of the air masses also conformed with this result. The air pollutants were difficult to disperse because of the significant decrease in the planetary boundary layer(PBL) height. Relative humidity played a crucial role in the formation of haze by leading to hygroscopic growth of the diameter of aerosols.     

Distribution of rare earth elements in PM10 emitted from burning coals and soil-mixed coal briquettes

Emission from burning coals is one of the major sources of the airborne particles in China. We carried out a study on the rare earth elements (REEs) in the inhalable particulate matter (PM₁₀) emitted from burning coals and soil-coal honeycomb briquettes with different volatile contents and ash yields in a combustion-dilution system. Gravimetric analysis indicates that the equivalent mass concentration of the PM₁₀ emitted from burning the coals is higher than that emitted from burning the briquettes. The ICP-MS analysis indicates that the contents of total REEs in the coal-burning PM₁₀ are lower than those in the briquette-burning PM₁₀. In addition, the contents of the light rare earth elements (LREEs) are higher than those of the heavy rare earth elements (HREEs) in the PM₁₀ emitted from burning the coals and briquettes, demonstrating that the REEs in both the coal-burning and briquette-burning PM₁₀ are dominated by LREEs. The higher contents of total REEs and LREEs in the coal-burning PM₁₀ are associated with the higher ash yields and lower volatile contents in the raw coals. A comparative analysis indicates that the La/Sm ratios in the PM₁₀ emitted from burning the coals and briquettes, being lower than 2, are lower than those in the particles from gasoline-powered vehicle emission.     

混沌理论在事故分析及预测中的应用

在对江苏常州市某公司安全事故资料进行大量调查与统计的基础上,应用混沌理论分析了该公司安全事故的混沌特征,指出了事故对初始条件的敏感依赖性和事故的长期不可预测性。应用重构相空间理论对安全事故次数的时间序列进行了分析和预测。同时,还对安全事故统计资料进行了R/S分析,得出该时间序列以2 0 0 1年6月为界限,存在两个Hurst指数,H1=1.6 82 8和H2 =0 .2 936 ,表明在以3个月为时间统计尺度的条件下,事故发生次数在前一时间段整体表现为持久相关性,而在后一时间段表现为反持久相关性。预测与分析结果与实际情况符合较好,表明应用混沌理论进行事故分析与预测是可行的,反映了事故的发展趋势。     

铁屑微电解法处理光致抗蚀剂废水的初步研究

初步研究了铁屑微电解法处理先致抗蚀剂废水；对废水pH值、曝气、铁屑和活性炭的用量等作了单因素影响试验。正交试验结果表明：当铁屑投加量50．0g／L，活性碳投加量5．0g／L，废水pH值2．0，反应时间60min时，CODCr去除率达42％。     

压缩空气泡沫系统(CAFS)产生泡沫屈服应力的试验研究

压缩空气泡沫系统(CAFS)是一种高效泡沫灭火手段.泡沫的流变学性能是森林火灾扑救中泡沫发挥直接和间接灭火能力的一个决定因素.本文用专门设计的钟摆式屈服应力测定装置测定了泡沫屈服应力,验证了泡沫屈服应力假设.泡沫屈服应力与泡沫气体百分比、析液时间和泡沫平均直径有关,试验得到了屈服应力与其影响因素的关系曲线和数学表达式模型.部分描述了泡沫这种特殊流体的流变学性质,对应用CAFS系统泡沫扑救森林火灾有重要指导意义,可用于预测外力作用下灭火泡沫的流动行为.     

油田冲砂清洁生产工艺的研究应用

针对传统的油井清砂方法易产生环境污染的现状,胜利采油厂对油田修井冲砂工艺进行了改进,通过改装设备;改进捞砂工艺等措施,自2000年1月至2001年11月,已经实施捞砂作业井417口,一次成功井373口,一次成功率为89.45%。工艺改进实施后,还节省了化学堵剂的使用;杜绝了油层污染;减轻了现场操作人员的劳动强度和冲砂事故发生率,初步实现了油田修井冲砂施工的清洁生产。     

环境监测中氯化氢测定的分析方法试验

针对国家标准《HJ/T27-1999》与《空气和废气监测分析方法》的2种氯化氢测定方法中氢化钾用不同介质进行稀释，和显色时间及试剂加入量的区别进行正交试验，得出结果。     

《海洋的变化:来自大海的呼唤》

艾莉博士的大作《海洋的变化：来自大海的呼唤》是一本伟大的书,它揭示了人类与海洋的关系,对人类与海洋的命运进行了探讨.     

Evaluating the practices of climate-smart agriculture sustainability in Ethiopia using geocybernetic assessment matrix

Environment, Development and Sustainability - The geocybernetic assessment matrix (GAM) evaluation of climate-smart agriculture (CSA) practices in Ethiopia is carried out in this paper. With regard...     

高强度开发下的上海农业环境问题与对策

文章指出高强度开发下上海市郊主要的农业污染问题，并分析了污染形成的原因，提出了符合可持续发展战略的污染探讨对策。