小城镇规划中的“四个结合”———以重庆市酉阳县北部新区修建性详细规划为例

当前,小城镇的规划建设是个热点,也是一个难点,面临很多复杂的问题。本文通过对酉阳县北部新区详规的实践,总结了“四结合”的规划理念,有一定的实际价值。     

电梯减速距离-速度转换器的一种分析设计方法

分析了电梯理想减速特性，针对其在按距离制动时需要兼顾运行效率和舒适感的问题，提出了按理想减速特性设计用于模拟控制的距离-速度转换环节的基本思想，并给出了电路原理及元件选择方法．     

济南市集中供热蒸汽管网热损失的调查及分析

本文调查了济南市蒸汽管网的情况,分析了集中供热蒸汽管道热损失的组成,通过采集济南市具有代表性的三个蒸汽管网的运行数据,计算了其热损失,绘制了蒸汽管网的热损失率曲线图并对其进行了分析,对济南市的蒸汽管网提出了整改建议可供参考。     

摩尔-库仑强度准则计算冻结壁应力场和位移场

将冻结壁视为无限长轴对称厚壁圆筒,利用摩尔-库仑强度准则对冻结壁进行弹塑性分析,得到了平面应变状态下应力场和位移场分布特征,对充分发挥冻结壁承载力和深井冻结壁设计具有一定的参考意义。     

生态山水城——铜都

铜陵市地处安徽南部,位于长江下游南岸,北倚长江,南连黄山、九华山,总面积1113平方公里(其中市区面积280平方公里),是安徽省重要的工贸港口城市,辖一县三区,全市总人口70余万人。     

巴西视点

在有关城市迅速发展的辩论中存在许多说法，特别是对于发展中国家和转型中的国家而言。在这些说法中，有两个在很大程度上是公认的。     

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。