Urinary mercury in people living near point sources of mercury emissions

As part of the European Mercury Emissions from Chlor Alkali Plants (EMECAP) project, we tested the hypothesis that contamination of ambient air with mercury around chlor alkali plants using mercury cells would increase the internal dose of mercury in people living close to the plants. Mercury in urine (U-Hg) was determined in 225 individuals living near a Swedish or an Italian chlor alkali plant, and in 256 age- and sex-matched individuals from two reference areas. Other factors possibly affecting mercury exposure were examined. Emissions and concentrations of total gaseous mercury (TGM) around the plants were measured and modeled. No increase in U-Hg could be demonstrated in the populations living close to the plants. This was the case also when the comparison was restricted to subjects with no dental amalgam and low fish consumption. The emissions of mercury to air doubled the background level, but contributed only about 2 ng/m(3) to long-term averages in the residential areas. The median U-Hg levels in subjects with dental amalgam were 1.2 microg/g creatinine (micro/gC) in Italy and 0.6 microg/gC in Sweden. In individuals without dental amalgam, the medians were 0.9 microg/gC and 0.2 microg/gC, respectively. The number of amalgam fillings, as well as chewing, fish consumption, and female sex were associated with higher U-Hg. The difference between the countries is probably due to higher fish consumption in Italy, demethylated methyl mercury (MeHg) being partly excreted in urine. Post hoc power calculations showed that if the background mercury exposure is low it may be possible to demonstrate an increase in U-Hg of as little as about 10 ng/m(3) as a contribution to ambient mercury from a point source.     

大型仓储式超市的安全疏散设计与管理

提出了在大型仓储式超市的安全疏散设计中 ,如何确定安全疏散时间、疏散总人数、安全出口数量及宽度等参数 ,并对此类超市的安全疏散管理提出了要求     

全厚度车辙试验中对试件压实度的控制研究

分析了影响全厚度车辙试验结果的外因,从温度、压实功两方面对全厚度车辙试件各层的压实度进行控制。分析了压实度与动稳定度的关系等,这对完善全厚度车辙试验方法的技术要点、提高全厚度车辙试验结果的科学性有一定的参考意义。     

《预应力筋用锚具、夹具和连接器》GB/T14370-2000修订介绍

就《预应力筋用锚具、夹具和连接器》GB/T14370-2000的修订任务、拟修订的主要内容及国内外20年来锚具性能标准三部分作了简要介绍。同时,对现实中存在的问题进行了讨论。     

带热回收的新风空调系统在医院建筑中的应用分析

针对一个独立新风、集中排风并带全热交换器能量回收的医院输液室空调系统,实验测试了空调系统的能耗,计算了全年节能潜力,并通过测量室内CO2浓度,研究了通风对室内空气质量的改善程度。结果表明,该空调系统在改善室内空气质量的同时可以节约能量,是医院建筑的理想空调系统。     

Microscale fluctuation assay coupled with Sep-PakR concentration as a rapid and sensitive method for screening mutagens in drinking water

A sensitive short-term mutagenicity test, the microscale fluctuation test has been coupled with a concentration method based on adsorption on Sep-Pak^R C₁₈ cartridges as a method for screening drinking water mutagens. Comparison with XAD-2 concentration method showed that Sep-Pak adsorbed 5 times higher quantity of organics but was slightly less efficient for adsorbing TOX.Microscale fluctuation test was found to be more sensitive than Ames test by testing known direct-acting mutagens and concentrates of drinking water. Samples derived from conventional treatment including chlorination from eight surface water supplies in Norway were concentrated at pH 2 by adsorption on the disposable columns. The adsorbates were tested at different doses by the microscale fluctuation assay. The mutagenic properties of drinking water samples were also related to total organic carbon (TOC), total organic halogen (TOX) and trihalomethanes (THM) concentrations. Dose-related mutagenic responses were found for all the samples with S. typhimurium TA 100 and TA98 strains without metabolic activation. Good relationship was found between mutagenicity data and TOX and THM results. The method showed to be simple, rapid and suitable for routine screening of mutagens in drinking water.     

浅论项目全额承包中的成本管理

针对项目法施工中的全额承包活动，及对项目经理部如何搞好全额承包中的成本管理进行了简要的分析和论述。提出了在新的建安工程费用项目划分规定下，全额承包基数的确定原则和方法；对于项目施工过程中的成本管理，进一步分析了完善企业施工定额的意义，提出了成本计划的编制原则及方法，以及施工中成本的控制原则。这些方法和原则对完善施工企业内部承包责任制，提高企业法人及项目承包两个方面的积极性以及增进企业全员的经济效益观念均具有重要的作用。     

工字形截面圆弧曲梁的非线性理论

从任意开口薄壁截面圆弧曲梁精确的翘曲位移出发 ,针对常见的单轴对称工字形、槽形和无对称轴的H形截面曲梁 ,通过参数分析找到一个统一的数学表达式 ,给出相应的应力、应变计算式。在这个基础上 ,依据大变形理论 ,建立了工字形截面圆弧曲梁非线性分析的基本理论 ,并考虑了横向正应力的影响。推导过程中未就材料性质做任何假定 ,所以该理论同样可以应用于曲梁弹塑性阶段的分析。最后给出单轴对称工字形截面两种常见放置条件下曲梁的总势能表达式。     

焓轮式全热回收器的节能分析及其应用

基于目前病态建筑综合症和节约能源日益受到社会各界的关注，提出了一种有效的解决方法一利用全热回收器对空调的排风进行能源回收，分析了全热回收器的工作原理及其构成，并以广州某四星级酒店的空调能耗为例，应用标准年的全年逐时气象数据，计算出在安装全热回收器前后的具体的能耗量，通过比较显示了全热回收器巨大的节能潜力。     

全站仪竖直高程传递技术及其在苏通大桥测控中的应用

高程基准传递是高大建筑物施工测控中重要项目之一,不同的工程因用途不同对高程控制提出不同的精度要求。针对苏通大桥高索塔施工中高程测控的要求,分析水准测量、钢尺高程传递、三角高程测量等常用高程传递技术的适用范围与缺点,它们均不适用于大高差的高精度传递。为此,提出全站仪竖直高程传递技术。详细论述其基本原理,对误差来源、大小进行分析,对所达到的精度进行评估,并研制传递高程的实用装置,经现场试验对比分析,验证该技术方法的可行性与有效性。理论分析与试验验证显示该技术方法对于数百米的高程传递,可以达到国家二等水准精度水平,完全满足建筑物高程测控的需要。最后将该技术成功应用在苏通大桥300m高索塔的高程测控中。