Acute toxicity of benzene derivatives to the tadpoles (Rana japonica) and QSAR analyses

Acute lethal toxicity (the negative logarithm of molar concentrations of 12 h acute median lethal, expressed as 12 h-log1/LC50) of 46 benzene derivatives to Rana japonica tadpoles was determined. 1-octanol/water partition coefficient (logKow)-dependent models were developed to study the toxicity of different categories chemicals. In an effort to model all chemicals, response surface analyses and stepwise multiple regression analyses were performed and successful models were obtained. A general and robust QSAR model was achieved with the combined application of variables reflecting hydrophobicity, electric property, and molecular size respectively (12h-log1/LC50 = 0.393logKow - 0.428Elumo + 0.0110Vol. + 1.362 n = 51, r2 = 0.834) using stepwise multiple regression analyses. Because of strong dissociation of carboxyl group greatly decreasing their observed toxicity, using logDow in instead of logKow the quality of the models is greatly improved. The conventional r2 and cross-validation r2(CV) were 0.914 and 0.785, respectively, indicating that QSAR was both internally consistent and highly predictive.     

砂对海水中溶解油的吸附及影响因素研究

以柴油污染的海水为对象，研究了砂对海水中溶解油的吸附作用及吸附的影响因素。结果表明，砂对溶解油的吸附符合Henry型吸附等温式，其吸附量随着砂粒粒径的减小、温度的降低和盐度的增加而增大。在影响吸附的3种因素中，粒径对吸附的影响最大。通过吸附热力学分析，推断砂对溶解油的吸附属于物理吸附。     

Statistical visualization for data exploration: a case study on Sydney Olympic Park

Due to the powerful graphic interface in modern computers, visualization techniques have become more and more popular for data exploration. As a preliminary investigation, visualization is a greatly useful tool to lead to further statistical analysis and modelling. It is likely that historical environmental data from a range of different studies may contain useful information that should be assessed for determining management actions. However, these historical data are collected from many different studies, which have different space and/or time scales making the visualization process complicated. In this paper we present several ways of visualizing historical data based on a study at Sydney Olympic Park. The tools include spatial coverage and variation for different spatial resolutions, temporal coverage and time series plots for different time scales, multi-panel scatterplots for a small number of variables and "one-to-all" scatterplots for a large number of variables.     

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.     

《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.     

一种从有机废水中获取甲酸的方法

探讨了从环己醇/环己酮生产装置产生的酸性有机废水中获取甲酸的方法.在实验基础上,确定了共沸-分馏组合法回收甲酸的工艺过程、适宜挟带剂及工艺条件.采用共沸-分馏组合法处理该有机废水,可获取质量分数为80%以上的甲酸水溶液,甲酸回收率可达70%以上.同时,经本法处理后,该有机废水的COD由1.0×105～1.6×105 mg/L降至5× 102 mg/L以下,COD去除率达98%以上.     

易腐性有机垃圾的产生与处理技术途径比较

我国城市垃圾以易腐性有机垃圾为主.目前有关管理部门提出逐步减少进入填埋场的易腐性有机垃圾量,因此,必须寻求其他填埋替代技术消纳易腐性有机垃圾物流.本文对几种常规技术方案进行了比较.认为应该根据非餐饮业和餐饮业易腐性有机垃圾各自的产生源特点,采取不同的处理方案;但目前这些替代技术用于处理易腐垃圾时均存在各自的缺陷.本文据此提出了相应的技术完善要求和配套管理政策建议.     

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.