最低价中标势在必行

建设工程最低价中标,是国际通行、成熟的做法,符合市场经济的要求,具有科学性、先进性和旺盛的生命力。我国市场经济的加速深入发展,需要市场经济体制进一步完善,全面推行最低价中标法,对于整顿规范建筑市场具有治本的意义,也是我国融入全球经济一体化与国际市场尽快接轨的需要。 一、最低价中标法势在必行 目前,我国很多地方仍在使用有     

Effect of chlorine content in feeding wastes of incineration on the emission of polychlorinated dibenzo-p-dioxins/dibenzofurans

This study attempts to clarify the effects of chlorine content in waste on the formation mechanisms of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in full scale incinerators by proposing and using the principal component analysis (PCA) to compare the congener profiles of PCDD/Fs in the stack flue gases of 17 emission sources, including incinerators and vehicles. Four incinerators, among these 17 emission sources, were sampled and analyzed in this study, and the data for the other 13 emission sources were selected from previous studies. These 17 emission sources can be classified into four categories, including medical waste incinerators (MWIs, H1-H5), municipal solid waste incinerators (MSWIs, M1-M8), vehicle fuel combustion (unleaded gas-fueled vehicles, UGFV; diesel-fueled vehicles, DFV, n = 2) and polyvinylchloride (PVC) facility vent combustors (PVC1 and PVC2, n = 2). PCA was conducted for these emission sources with the fractions of 17 2,3,7,8-congeners in the stack flue gases as variables to clarify the effect of chlorine content in feeding wastes on the emission of PCDD/Fs. From the results of PCA, we extrapolated that the threshold value of the chlorine content was at 0.8-1.1%, and the formation mechanisms of PCDD/Fs are influenced first by whether the chlorine content in the feeding waste is over or below the threshold value then by other factors, which furnaces or APCDs represent. When the chlorine level in the waste is below the threshold value at 0.8-1.1%, the formation of PCDDs dominates, probably because the chlorine is used to chlorinate the non-substituted phenol to produce chlorophenols, which are important precursors for PCDDs. rather than chlorinate the dibenzofuran. While the chlorine level in the waste exceeds this threshold (0.8-1.1%), the rates of formation of PCDFs increase faster than those of PCDDs, probably because the chlorine content in the waste contributes to the deterioration of combustion conditions, and many products of incomplete combustion (PICs) like PAHs, will grow to a substantial level. When PCDD/Fs are formed from PAHs, the formation rates of PCDFs are higher than those of PCDDs.     

我国最大的悬臂结构机库设计与竖向地震力的试验研究

阐明如何在学习国外先进经验基础上,结合我国国情,设计出这个中国最大也是亚洲最大的悬臂结构机库。在许多关键性技术上,做出了较好的尝试。实践证明,完全可靠,为今后设计同类结构提供了宝贵经验,尤其是对长悬臂结构竖向地震力,做了较系统的试验研究,提出了一批有价值的科学数据。这对今后悬臂结构竖向地震力的计算和规范修订都有参考依据。     

中国尾矿坝地震安全度（5）──大石河尾矿坝现场测试成果及各测试方法间的相关研究

本文基于对中国大石河尾矿坝所完成的现场勘察，给出了三种原位测试数据（ＳＰＴ，ＣＰＲ和ＳＷＶ）的分析结果及其相关性研究成果。     

发展社区家庭养老

本文以翔实的材料来阐述人口老龄化的现象及养老的方向 ,通过对老年人的心理及生理特征的分析 ,对老龄化活动空间的设计提出了具体的实施细则 ,并提出了完善社区养老服务的内容及全社会关心重视和发展社区老年保障事业的迫切性。     

澜沧江流域传统民居研究

通过思考传统民居和其生存环境的现状,本文引入生 态建筑的理念,系统分析了云南澜沧江流域民居的环境协调性 和其生命周期环境影响评价,从而肯定了传统民居的生态精神。     

框架结构层间相对位移变化量在结构损伤检测中的应用

以平面框架为例,通过分析结构的横向柔度,深入研究了局部构件损伤对框架水平位移变化的影响机理特征。基于上述工作,利用框架的层间相对水平位移变化量(RDCSF)作为损伤特征参数,结合神经网络设计,对结构进行损伤检测分析。     

利用高碱原料在回转窑工厂生产高标号(R型)水泥的研究

本文论述了碱对水泥生产和质量影响的机理,探讨了各种措施对缓解碱的有害影响的作用,介绍了克服碱的有害影响的方法。     

Technique for measuring metallic salt effects upon the indigenous heterotrophic microflora of a natural water

The effects of several concentrations of the metallic salts Ag₂SO₄, NaAsO₃, BaCl₂2H₂O, CdCl₂2.5 H₂O, CrCl₂6H₂O, CuCl₂, HgCl₂, NaCl, NiCl₂6H₂O, PbCl₂ and ZnCl₂ upon the indigenous heterotrophic microflora of a natural water were studied. Effects of these salts upon the heterotrophic activity of the microbes were assayed using the heterotrophic technique whereas lethal effects upon the heterotrophic bacteria were determined using nutrient agar plate counts. The heterotrophic activity method is based upon the uptake and mineralization of a radioactively labeled metabolite (in these experiments ¹⁴C-glucose) by the indigenous aquatic microbes and data analysis is by Michaelis—Menten enzyme kinetics equations. Concentrations of metallic salts which resulted in bacterial death also caused erratic uptake and mineralization rates of ¹⁴C-glucose whereas sub-lethal concentrations, as determined by nutrient agar plate counts, caused a non-competitive inhibition of maximum heterotrophic activity and markedly increased the turnover time of the glucose substrate.     

住宅的通风问题及其对策

文章通过对国内几个大城市民用住宅的测试调查,揭示了国内住宅存在的问题,并指出自然通风已经无法满足住宅的基本新风需求。最后通过总结国内外住宅通风的系统型式,提出了机械通风在解决中国室内住宅通风问题时应该采取的原则。