Sorption of the natural endocrine disruptors,oestrone and 17 beta-oestradiol in the aquatic environment

Adsorption of hydrophobic contaminants at the particle/water interface is one of the key processes controlling their fate in the aquatic environment. The sorption of the natural female hormones oestrone and 17-oestradiol has been studied under simulated riverine conditions. Both the kinetics and the effects of varying fundamental environmental parameters (e.g. sediment properties) on the thermodynamic equilibrium partition coefficient (K _p) have been studied in continuous and batch sorption experiments, respectively. Results showed that the sorption of oestrone and 17-oestradiol by sediment was relatively slow, reaching equilibrium in 50 days. In addition, relatively small adsorption of both oestrone and 17-oestradiol onto the sediment was observed, with K _p values between 200 and 250 mL g^–1. The comparable K _p values of the two compounds reflect their structural similarity. It can be concluded that the two endocrine disruptors, oestrone and 17-oestradiol remain primarily in association with the aqueous phase.     

蔬菜对土壤镉铜锌富集能力的研究

调查了福建部分污染严重地区不同蔬菜对镉、锌、铜的富集能力。结果表明蔬菜对镉的平均富集系数为0.017,锌的平均富集系数为0.116.铜的平均富集系数为0.014。蔬菜对镉的富集系数的品种间差异最大,达315倍,远高于锌和铜的富集系数的品种间差异。茭白、豇豆和莲藕对镉的富集能力较低,可作为镉污染土壤优先选种的蔬菜品种,而青包菜、白包菜、芥菜、空心菜、芋头等对镉的富集系数较高,不宜在镉污染土壤上栽培。     

The Surface Roughness of a Rubber Soling Material Determines the Coefficient of Friction on Water-Lubricated Surfaces

For more than a decade, evidence has been accumulating that points to the fact that the microscopic roughness of the footwear soling surface is a major determinant of slip-resistance on lubricated surfaces, but conclusive experimental proof has been lacking. This article describes an experiment in which five pairs of shoes were soled with the same rubber compound. Four of the pairs were abraded by different grades of grit to produce a range of roughness values. The coefficient of friction (CoF) of the five solings was then measured repeatedly by the walking traction method on wet surfaces including glazed wall tiles, vinyl asbestos coated with the wax floor polish, and both sides of a sheet of float glass. The Kruskal-Wallis statistical test proved beyond doubt that the soling roughness is a major factor in determining the CoF of this rubber soling material; p < 10⁻⁵. Nearly all of the grip was due to surface roughness of the soling material on these atypically smooth floors, although the surface roughness of the floors also had a significant effect on CoF; p < 0.003. Float glass is shown to be a promising reference floor material for the measurement of CoF of footwear; there was no statistical difference between results for the two sides of the glass sheet. Float glass could be used in the development of a standard CoF test method because new sheets of glass from the same manufacturer are identical and extremely smooth. The specification of CoF values for solings/floors combinations in lubricated conditions is of little value unless associated with roughness measurements and knowledge of how wear will affect the surface roughness of the sole. This article reports the first evidence that any specification of flooring by measuring CoF based on dry surfaces could lead to an increase in the number of injuries caused by slipping on the wet surfaces. Published by Elsevier Science Ltd     

多环芳烃的零阶价分子连接性指数与正-辛醇/水分配系数

本文建立了准确预测多环芳烃(PAHs)及其烷基衍生物的正-辛醇/水分配系数(Kow)模型。模型表明PAHs的分配性质可用零阶价分子连接性指数(~°x~v)描述,~°x~v数值与PAHs的logKow成正比。应用本模型可以预测大范围PAHs的logKow值。     

宁波-舟山海域入海污染物环境容量研究

在宁波-舟山海域数值模拟潮流场的基础上,建立了该海域各污染源的响应系数场,计算了主要污染源COD、无机氮和活性磷酸盐的分担率场,及各污染源和控制单元的环境容量.研究结果将为该海域入海污染物总量控制提供科学依据.     

锶—89在珍珠岩中吸附的研究

研究了不同粒径的珍珠岩对＾８９Ｓｒ的吸附。结果表明，珍珠岩对＾８９Ｓｒ具有较强的吸附能力，饱和吸附率大于９５％；通过振荡能加速珍珠岩对＾８９Ｓｒ的吸附；珍珠岩对＾８９Ｓｒ的吸附率与时间关系由多项指数描述；不同粒径的珍珠岩对＾８９Ｓｒ的吸附率没有明显差异。     

南京地区相对湿度对气溶胶含量的影响

为了研究南京地区相对湿度对气溶胶的影响,利用位于南京信息工程大学的拉曼-瑞利-米氏激光雷达,分析湿度廓线对消光系数的影响;利用2014年3月~2015年2月国控点环境监测数据对可吸入颗粒物浓度特征进行统计,并与相对湿度进行逐月和四季对比分析,并计算各参数之间的相关系数,以期为南京市的城市布局与规划、大气污染治理等提供更多参考.结果表明,低空气溶胶的消光系数廓线与相对湿度廓线变化趋势高度一致,地面相对湿度与可吸入颗粒物浓度在一定湿度范围（以不发生重力沉降为界限）内,相对湿度越大越有利于颗粒物的形成,超过这个范围,相对湿度越大,颗粒物浓度越低,在南京地区,对于PM₁₀来说,这个界限在40%~49%,对于PM_2.5来说,这个界限在50%~59%.     

成都冬季一次持续污染过程气象成因及气溶胶垂直结构和演变特征

基于气溶胶激光雷达观测和环境监测站污染物浓度数据、气象观测资料及HYSPLIT后向轨迹模式,分析了2017年12月中下旬,成都市一次本地积累和沙尘输送影响的持续污染过程中污染物浓度、污染物来源、天气系统和气溶胶消光系数的垂直分布及演变.结果表明:①此次污染过程持续时间长,根据气象条件和主要污染物种类,分为本地污染累积、北方沙尘输送和混合影响3个阶段.②本地污染积累阶段,消光系数垂直分布不均匀,受湿度、太阳辐照与逆温层等气象因子的影响,垂直结构变化较大.消光系数最大值多出现在250 m附近,此阶段退偏比数值很小.③沙尘影响阶段,消光系数较前期明显下降,高值区位于250 m及2 km处.退偏比显示沙尘粒子于29日午后开始逐渐抵达成都市2 km高空,并于夜间达到峰值.退偏比相较本地污染累积阶段明显增大,各时段退偏比结构类似,近地面数值略低于高空.④混合影响阶段,消光系数强度小幅回升,退偏比显示有部分沙尘粒子漂浮在1～2 km高度上.     

中国水土资源本底匹配状况研究

论文以中国水资源二级区为基本单元,利用单位面积水资源量法和基尼系数法,以二级区水资源总量和潜在可开垦耕地面积为数据基础,评价中国水土资源本底匹配状况,为中国水土资源优化配置提供科学依据。首先根据适宜农作物耕种的高程、坡度和土壤类型条件,得到中国潜在可开垦耕地分布;然后,计算单位潜在可开垦耕地面积水资源量,评价中国水土资源本底匹配分布状况;最后,绘制水土资源洛伦兹曲线,计算基尼系数,对中国水土资源本底匹配总体状况进行评价。研究结果表明： 1）中国北部区域潜在可开垦耕地较多,西南部和南部沿海区域分布较少,未来具有较大耕地开发潜力的区域主要分布在北方; 2）中国本底水资源和潜在可开垦耕地资源空间分布存在严重错位; 3）较之已有研究成果中依据水资源量和耕地面积计算的基尼系数0.566,论文以本底水资源和潜在耕地为基础数据计算的基尼系数0.712要大很多,表征中国本底水土资源不匹配程度要严重得多,中国80%的水资源服务不到23%的潜在可开垦耕地。     

不同侧压力系数下圆形巷道变形破裂规律分析

为研究侧压力系数对巷道周边岩体稳定性的影响,以一条深埋圆形巷道工程为背景,采用离散颗粒元软件PFC3D分析了5种侧压力系数下巷道周边岩体的应力差、位移、破裂分布模式和微裂纹数等,得到了圆形巷道周边岩体应力、变形和破裂随侧压力系数的变化规律。结果表明,1)随侧压力系数增大,巷道顶底部浅部岩体主应力差先增大后减小,深部岩体主应力差逐渐增大;而巷道两帮浅部岩体主应力差变化较小,深部岩体主应力差先减小后增大。这表明在相同埋深情况下,高侧压力系数不一定会对帮部岩体造成更大的破坏,但更容易使顶板产生高剪应力,不利于顶板岩体的稳定。2)侧压力系数越大,巷道顶板岩体竖向位移就越小,且其由拱顶往外平滑递减的规律性也越不明显,而帮部岩体水平位移变化规律与顶板岩体相反。3)巷道顶底部围岩在侧压力系数较大的情况下较易发生破裂,并随侧压力系数增大,其破裂范围越来越大;巷道两帮岩体则在不同侧压力系数下均会发生破裂,且其破裂范围随侧压力系数增大而略减小。4)不同侧压力系数下,巷道岩体总裂纹数都随开挖时间呈指数增长;且当巷道开挖完成后,岩体总裂纹数与侧压力系数呈抛物线关系。