本土营造——西北地区低碳生态乡镇的低技术策略

针对当前我国低碳生态城镇实践过分依赖“高技术、高投入”而难以实施的问题,结合西北地区乡镇发展的现实困境,本文提出西北地区乡镇低碳生态的理想路径为：探索一条具有地域适宜性的”低技术”策略,进而通过对西北地区乡镇碳排放特征的分析,提出加强对乡镇建设性碳排放的控制是西北地区乡镇实现低碳生态目标的关键。最后结合西北地区乡镇的地域特质,依托西安建筑科技大学在地域生态建筑与现代生土材料科学等领域的研究基础,提出：本土营造是降低乡镇建设性碳排放的有效途径,并提出其在规划与管理中的推广、应用策略。     

水泥基材料瞬时高温作用下的爆裂与力学性能

水泥基材料经瞬时高温作用后,随受火温度不同,表现出不同的爆裂与力学性能。研究了掺加不同矿物掺和料的水泥基材料在不同的瞬时高温作用后爆裂与力学性能的影响。结果表明：在100 ℃和300 ℃瞬时高温作用下,所有试样外观完整,未发生爆裂;600 ℃时,所有试件发生粉碎性爆裂。与室温下水泥基材料的物理力学性能相比,在经历瞬时100 ℃作用后,试样的抗压、抗折强度损失率分别达到15%和30%以上;经受300 ℃作用后,强度恢复至室温时强度水平;温度高于300 ℃时,随温度的升高,强度逐渐降低;当温度高于600 ℃时,强度急剧衰减。其中,复掺20%矿粉和10%硅灰的试样经历的低温(≤300 ℃)作用后,抗压、抗折强度均随温度的增加而提高。SEM分析表明,经600 ℃高温作用2 h后,硬化水泥浆体C-S-H整体结构疏松,水化产物连续相被分割为非连续相。     

天然气在线密度补偿

天然气压缩因子和密度的在线补偿是工程中需要解决的问题,为此提供了一种用PLC实现的有效在线实施方案,用于天然气压缩因子和密度的计算。     

Reductive electrochemical remediation of emerging and regulated disinfection byproducts

Long-term exposure to low concentrations of disinfection byproducts (DBPs) in drinking water has been associated with increased human-health risks of bladder cancer and adverse reproductive outcomes. In this study, we investigated electrochemical reduction utilizing a resin-impregnated graphite cathode for the degradation of 17 DBPs (i.e. halomethanes, haloacetonitriles, halopropanones, chloral hydrate and trichloronitromethane) at low μg L⁻¹ concentration levels. The reduction experiments were potentiostatically controlled at cathode potentials −700, −800 and −900 mV vs Standard Hydrogen Electrode (SHE) during 24 h. At the lowest potential applied (i.e. −900 mV vs SHE), the disappearance of DBPs from the solution after 24 h of reduction was >70%, except for chloroform (32%), 1,1-dichloropropanone (48%), and chloral hydrate (31%). Due to the participation of several removal mechanisms (e.g. electrochemical reduction, adsorption, volatilization and/or hydrolysis) it was not possible to distinguish the removal efficiencies of electrochemical reduction of individual compounds. Adsorption of the more hydrophilic DBPs (i.e. haloacetonitriles, chloral hydrate, and 1,1-dichloropropanone) onto the electrode seems to be affected by the cathode polarization, as the removals observed in the open circuit experiments were significantly higher than the ones obtained in electrochemical reduction under the same conditions. The overall efficiency of reduction was estimated based on the analyses of the released Cl⁻, Br⁻ and I⁻ ions. Nearly complete C-I bond cleavage was achieved at all three potentials applied, and from the theoretically predicted release of I⁻ ions, calculated based on the removed DBPs, 86 ± 9 to 92 ± 1% was measured in the catholyte solution at −700 to −900 mV vs SHE. Debromination efficiencies obtained were 74 ± 3, 79 ± 6 and 68 ± 4% at −700, −800 and −900 mV vs SHE, while for C-Cl bond cleavage the obtained values were 69 ± 1, 72 ± 1 and 76 ± 4%, respectively. Nevertheless, dechlorination efficiencies are to be considered as approximate, since an increase in Cl⁻ concentration was observed in the open circuit experiments due to the hydrolysis of some of the chlorine-containing DBPs. Although the Coulombic efficiencies for DPBs dehalogenation were only 1.9 ± 0.3 (−900 mV vs SHE) -4.1 ± 0.2% (−700 mV vs SHE), relatively low energy consumption of the process was observed, estimated at 72 ± 2 Wh m⁻³ at −900 mV vs SHE for the concentration range of DBPs in this study (i.e. 65.3-129.7 μg L⁻¹). The study demonstrated that reductive electrochemical treatment has the potential to be a modern remediation technology for the removal of low concentrations of halogenated DBPs in water.     

中小城市居住区环境质量综合评价初探

分析了当前国内外影响较大的评估体系,结合中小城市的发展现状,以及对新乡市近10年来建设的居住区调研,利用数学方法,建立中小城市居住区全寿命期环境质量综合评价体系,并对所调研的新乡市居住区物理环境进行了评价,指出了优化中小城市居住区环境应该努力的方向。     

外墙保温工程施工技术

在工程实际应用的基础上,对挤塑板外墙保温施工技术进行了总结,并对外墙保温体系的材料性质、施工流程、节点做法、施工要点等进行了详细的论述,指出这种外墙保温系统是一种简单、可靠、耐久性强的保温做法。     

异形索桁架结构浮动式连接可行性研究

针对异形索桁架特殊的结构形式,从拉索结构适应温度变化、对主体结构产生影响、应力及挠度控制和造价几个方面出发,提出异形索桁架通常的硬性连接和新型的两种浮动式连接方式,并对这3种方案形式的构造和受力分别做了分析,利用通用的有限元程序,对3种方案的结构形式在各种工况条件下分别进行静力计算和对主体结构产生影响的分析,同时对3种结构形式的动力响应进行分析,系统地对3种连接方案的异形索桁架从温度变化、对结构产生的影响、挠度控制和工程造价方面分别做了对比性说明,对3种索桁架的动力特性做了具体对比,提出合理的建议,可作为今后索桁架节点设计的参考。     

海南省政府高层办公楼超限抗震性能分析

海南省政府办公楼工程平面选型复杂,楼层平面刚度变化急剧,各层楼板开洞面积和有效楼板宽度指标均超出现行规范规定值较多,属于典型的平面特别不规则的超限高层建筑结构.对该工程结构设计、结构体系及抗震计算分析等做了介绍;结合国家抗震规范的要求,采用三水准、两阶段对主体结构进行抗震分析计算.分析结果表明:结构能满足多遇地震作用下结构强度和变形的要求;在罕遇地震作用下结构具有较好的承载和抗倒塌能力,能够满足大震不倒的性能指标.着重对Push-over的分析方法、模型及计算结果等进行了深入分析和阐述,并对工程进行了结构整体抗震性能和局部性能评价;通过弹塑性静力分析计算,找出结构潜在的抗震薄弱部位和薄弱构件,并提出相应抗震加强措施.     

从上海世博看城市建设的创新及其相关启示

本文综合介绍了上海世博会在规划设计理念上、建筑创作理念上和运营管理方式上的创新等方面的相关情况及对我国城市建设的相关启示,为读者提供可借鉴的资料,以期促进祖国现代化的进程。     

用广义协调Coons混合曲面元分析中厚板的振动

利用文献[1]的厚薄板通用广义协调元Coons混合曲面法分析了中厚板的振动,其优点是自由度少、精度高、程序简便、收敛快。算例计算出了四边简支方板的前几阶频率,其结果与文献[2]的结果符合良好。