An in-situ method of identifying ingredients of zeotropic refrigerants by inversion problem technique

An inversion method is applied to identify ingredients of zeotropic refrigerants in a circular duct. In the case of low Reynolds number and constant fluid pressure, the temperature distribution of direct heat transfer problem can be solved numerically. The thermophysical parameters of zeotropic refrigerants are determined by using inversion problem technique, the ingredients of refrigerants can be identified eventually. An in-situ experimental apparatus was proposed and three test samples with different composition refrigerants were conducted in this study. The experiment results show that the relative error of ingredients identification can be limited within 8.33%.     

Education campaigns to reduce stormwater pollution in commercial areas: Do they work?

A monitoring and evaluation program was undertaken, involving six different styles of evaluation to determine whether a low-cost, eight month education campaign that operated within a small commercial district was successful at changing people's behavior and reducing stormwater litter loads. This project also tested newly developed guidelines for monitoring and evaluating all types of non-structural stormwater quality best management practices (BMPs). The project evaluated: the extent and quality of the campaign's implementation; the degree to which it changed the awareness, attitudes, self-reported behavior and actual behavior of merchants and the public; and the nature of changes in stormwater litter loads. Overall, the education campaign produced mixed results, with the net result being modestly positive. Specifically, it was: unsuccessful at significantly influencing the knowledge or attitudes of merchants or the public; modestly successful at influencing the behavior of merchants and the public; and modestly successful at reducing litter loads in stormwater. At a theoretical level, the project highlights how using different 'styles' of BMP evaluation can help to build a more complete picture of a BMP's performance. At a practical level, the project helped to improve the monitoring and evaluation guidelines and produced evidence-based design guidelines for future campaigns that aim to reduce littering in commercial areas.     

海河干流、大沽排污河沉积物中重金属污染及潜在生态风险评价

采用单因子指数法和Hakanson生态风险指数法,分析了海河干流、大沽排污河沉积物中典型重金属污染物的质量比,评估了沉积物中重金属的污染程度,定量确定了其潜在生态风险程度.结果表明,综合污染程度海河干流比大沽排污河严重.海河干流、大沽排污河沉积物当中的典型重金属污染物的平均综合污染指数 C d分别达到20.89和12.47.海河沉积物中重金属的污染程度依次为Zn、Cu、Pb、Cr、Cd,其中Zn的污染最为严重,平均污染指数 Ci f达到11.24.而大沽排污河中重金属的污染程度依次为Zn、Cr、Cu、Cd、Pb,其中Zn污染较高,Cu、Cr、Cd均为中等污染.大沽排污河比海河潜在生态风险严重,除Cd在两条河流中均具有中等潜在生态风险,其他重金属均具有低等潜在生态风险.     

柴油车尾气处理液应用展望

尾气处理液是柴油车尾气处理SCR技术中所必需的还原剂。本文通过分析柴油车尾气的排放情况及SCR技术应用发展趋势,着重介绍了柴油车尾气处理液的研究现状及应用情况,总结了尾气处理液应用中存在的问题并阐明了后续的发展方向。     

南京市人防工程环境放射性调查

在冬季、春季和夏季分别对南京市人防工程内空气中氡浓度进行了测量.结果显示,对应于不通风、半自然通风、自然通风三种方式,夏季氡浓度最高,为904.2 Bq/m3,是南京市室内平均值的50倍,冬季次之,春季最低,分别为12倍和7.9倍.γ射线空气吸收剂量率和土壤及建筑材料中放射性核素γ能谱分析结果表明,前者为正常本底水平,而后者与全国及南京平均值处于同一水平.根据测量数据,计算了工作人员受到的年有效剂量,为4.29 mSv,是全国平均值(2.30mSv)的1.9倍,且吸入氡及氡子体所致内照射剂量所占比重较大,为84.1%,危害更大.建议采用加强通风的措施降低空气中的氡浓度,以减轻危害.     

深埋突出煤层深孔控制爆破致裂机理和防突效果研究

基于理论分析和数值模拟,探究深孔控制爆破技术在深埋低透高瓦斯煤层防突方面的适用性。考虑爆炸波、爆生气体、煤层原始瓦斯压力、煤层地应力对裂隙的作用。研究深埋低透高瓦斯煤层深孔控制爆破裂隙的扩展的过程、机理及防突效果。对比了理论分析结果和典型的现场试验结果。得出的结论是,煤层深孔控制爆破致裂,是在爆炸波的动态冲击震裂和爆生气体及煤层瓦斯压力的尖劈压裂作用下共同完成的;深埋高应力煤层深孔控制爆破机理与常规浅孔采掘爆破机理不同;控制孔在高应力煤层中的导裂作用并不显著,其主要起到卸压孔和抽放孔的作用。几个典型的高应力低透突出煤层的工程实践表明,采用深孔控制爆破技术后,均获得良好的增透效果,且均未发生煤与瓦斯突出事故。     

生态环境监测及其发展的研究

本文以生态环境监测工作为研究对象,以其在现阶段的应用开发状态为基础,分析未来科技成长中的发展趋势。在论述中,将生态环境监测的目标与特征内容作为理论基础,引出当前生态环境监测工作发展的现状问题,并针对管理体系、技术手段、"3S"开发这三个方面,为相关研究提供例证。     

桂牧1号杂交象草研究进展

系统综述了桂牧1号杂交象草(Pennisetum purpureumcv.Guimu-1)生物学特性、丰产栽培技术、营养品质、饲喂效果等方面的研究状况,并针对生产实际中存在的问题,提出了桂牧1号杂交象草今后生产和研究的主要方向.     

美国温室气体强制报告制度综述

2009年12月美国环境保护署出台了《温室气体强制报告制度》,要求上报温室气体排放量的排放源涉及31个工业部门和种类,对全国约85%的温室气体排放源的排放数据进行监测、统计,以便更加全面、准确地掌握美国温室气体排放状况。文章从《温室气体强制报告制度》建立的背景、制度的主要内容、运行方式和作用四个方面进行了介绍。     

从污染源普查看污染源监测工作有待改进的一些问题

以江阴市为例,简要分析了第一次全国污染源普查中污染源监测数据的应用情况,指出了实际监测法在普查中未能得到广泛采用的原因,并就污染源监测工作的改进作了初步探讨。