北京市大气污染物浓度空间分布与优化布点研究

基于地统计学方法对北京市2012年11—12月的大气污染物SO2、NO2、PM10和PM2.5浓度数据进行了空间分析。结果表明,4种污染物浓度数据均符合正态分布,满足地统计学分析的使用条件且均呈现中等强度的变异性。4种污染物半变异函数的块金效应值分别是29%、24%、7%、4%,表现出很强的空间相关性。4种污染物长轴变程分别是63、58、62、90 km,短轴变程分别是31、37、48、50 km,空间分布呈现出各向异性,变程范围与中尺度天气系统相当。研究大气污染物的空间分布特性对于整体把握区域环境空气质量和监测点位优化十分重要,以北京市区域空气质量中PM2.5监测站点设置为例,其监测站点在长轴方向上的间隔设置应取20~25 km,短轴方向上布点间隔应为8~12 km。     

巴基斯坦恰希玛核电站安全壳整体密封性试验

介绍了巴基斯坦恰希玛核电站安全壳整体密封性试验的理论方法和试验系统及第一次换料停堆期间进行的整体密封性试验,并对结果进行试验分析。     

用废橡胶制备沥青再生剂的实验

为了实现废物资源综合利用,以橡胶对沥青的性能改善为基础,以废橡胶为原料,在轻组分助剂介质中采用微波降解和助溶处理技术制备沥青再生剂.通过正交实验设计,以再生沥青的针入度、延度、旋转薄膜烘箱老化(RTFOT)后的针入度比及残留延度为评价指标确定了再生剂原材料的合理配比及工艺条件,并进行了再生剂的效果试验.研究表明,最佳配比及条件为增塑剂DOP 40%,芳香油分糠醛抽出油40%,废橡胶粉20%,抗老剂添加量为以上总量的0.5%,微波功率为900 W,处理时间为10 min.再生效果试验表明,10%的再生剂用量可以有效补充老化沥青缺失的组分,恢复其胶体结构及流变性能.     

采用氢氧化钠溶液循环浸出法脱除高砷阳极泥中的砷

采用氢氧化钠溶液循环浸出法处理高砷阳极泥（简称阳极泥）,考察了氢氧化钠溶液与阳极泥质量比（简称液固比）等因素对限极泥中砷、锑、铅浸出率的影响。在液固比为5、氢氧化钠浓度为2．0moL／L、反应温度为70～85℃、反应时间为8h的条件下,砷浸出率可达95％以上;含砷浸出液经硫化钠沉砷后可返回浸出工序重复使用,在硫化钠与砷质量比大于3时,浸出液沉砷率维持在80％以上,同时回用浸出工序后,砷浸出率达95％以上,且铅、锑流失率较低。     

灾害风险理论与风险管理方法研究

灾害风险与风险管理理论是当前学术研究的热点问题,但是对灾害风险内涵的认识还没有统一.在综述国内外灾害风险理论成果的基础上,通过对当前研究现状的综合分析,提出了灾害风险的定义和理论模型.依据对灾害风险理论的界定和认识,从风险辨识、风险分析、风险评估和风险减缓4个方面构建了灾害风险管理理论框架.最后,针对当前灾害风险管理的研究现状明确了未来研究的方向和建议.     

Analytical solution of two-dimensional solute transport in an aquifer–aquitard system

This study deals with two-dimensional solute transport in an aquifer–aquitard system by maintaining rigorous mass conservation at the aquifer–aquitard interface. Advection, longitudinal dispersion, and transverse vertical dispersion are considered in the aquifer. Vertical advection and diffusion are considered in the aquitards. The first-type and the third-type boundary conditions are considered in the aquifer. This study differs from the commonly used averaged approximation (AA) method that treats the mass flux between the aquifer and aquitard as an averaged volumetric source/sink term in the governing equation of transport in the aquifer. Analytical solutions of concentrations in the aquitards and aquifer and mass transported between the aquifer and upper or lower aquitard are obtained in the Laplace domain, and are subsequently inverted numerically to yield results in the real time domain (the Zhan method). The breakthrough curves (BTCs) and distribution profiles in the aquifer obtained in this study are drastically different from those obtained using the AA method. Comparison of the numerical simulation using the model MT3DMS and the Zhan method indicates that the numerical result differs from that of the Zhan method for an asymmetric case when aquitard advections are at the same direction. The AA method overestimates the mass transported into the upper aquitard when an upward advection exists in the upper aquitard. The mass transported between the aquifer and the aquitard is sensitive to the aquitard Peclet number, but less sensitive to the aquitard diffusion coefficient.     

Assessing the impact of ambient ozone on growth and yield of a rice (Oryza sativa L.) and a wheat (Triticum aestivum L.) cultivar grown in the Yangtze Delta, China, using three rates of application of ethylenediurea (EDU)

Foliar applications of ethylenediurea (abbreviated as EDU) were made at 0, 150, 300 or 450 ppm to field-grown rice and wheat in the Yangtze Delta in China. Rice and wheat responded differently to ambient ozone and EDU applications. For wheat, some growth characteristics, such as yield, seed number per plant, seed set rate and harvest index, increased significantly at 300 ppm EDU treatment, while for rice no parameters measured were statistically different regarding EDU application. The reason may be that the wheat cultivar used may be more sensitive to ozone than the rice cultivar. EDU was effective in demonstrating ozone effects on the wheat cultivar, but not on the rice cultivar. Cultivar sensitivity might be an important consideration when assessing the effects of ambient ozone on plants.     

中国水土流失的基本概况及其综合治理

水土流失是一个全球性的环境问题,给人类的生命和物质财产造成极大的危害与破坏。在现代社会,由于人口的持续增长、社会经济生产规模的不断扩大、植被破坏的急剧发展,对国家经济的发展构成了威胁。在上述背景下,本文在对以往研究结果进行综合分析的基础上,根据“再造一个山川秀美的西北地区”之要求,因地制宜地提出了我国水土流失的防治途径。     

土壤镉污染防治对策的研究

本文概述了国内外土壤镉污染治理技术成果,比较了各种不同技术的使用条件及特点,并简要说明了其原理。针对天津市镉污染现状,对一些镉污染防治对策进行了研究,并提出可行性建议和措施。     

CODCr测定方法探讨

对经典测定水样ＣＯＤＣｒ的方法进行了改进,以硫酸银－硫酸铜作催化剂代替单独作用硫酸银,用适量硝酸银、硝酸铋代替硫酸汞消除氯离子的干扰,适当提高了消解用硫酸浓度,缩短回流时间。