基于热气机分布式冷热电三联供效益分析

以上海地区一幢典型五层住宅建筑热、电、冷负荷需求为计算基础,分别计算了基于热气机的冷热电三联供系统和传统冷热电分供系统的一次能耗率、全年净收益以及投资回收期,验证了三联供系统的节能性和经济性。分析表明热气机余热利用率和能源价格是影响该三联供系统节能效益和经济效益的主要因素。     

经济发展分析在小城镇总体规划中的运用 --以丽水市东西岩镇总体规划为例

城市规划是一门交叉性综合学科,在城市规划工作中经济学的应用是必不可少的。该文以一个小城镇总体规划为例,阐述经济发展分析在小城镇总体规划中的性质定位、规划结构和用地布局中的作用。     

国产天然岩沥青微观结构分析及性能研究

对国产天然岩沥青进行实验研究,通过凝胶渗透色谱法分析国产天然岩沥青的元素组成。以90#沥青为基质沥青,采用国产天然岩沥青与特立尼达湖沥青对其改性,对比测试了改性沥青的性能,对国产天然岩沥青在基质沥青中所起到的作用从机理方面进行研究。     

民用建筑走道设置排烟设施限定条件的探讨

基于工程实践,对相关规范和设计手册中涉及的民用建筑走道设置排烟设施的限定条件的内容进行了对比,详细分析了各个文献中表述的涵义及优缺点,并在此基础上给出了作者的阐述。     

超高层建筑结构施工模拟技术最新进展与实践

施工顺序对结构的内力有明显影响,超高层建筑应采用结构逐层或分区激活的方式模拟实际施工过程。对于特殊的结构形式,需要正确选择各阶段激活的范围。通过合理调整施工顺序,得到更为合理的受力形态,减小结构用钢量。框架-延性墙板体系具有较大的侧向刚度与优良的抗震性能,严格控制其墙板的安装顺序对其实现抗震性能非常关键。收缩徐变对超高层建筑混凝土构件的竖向压缩变形量影响显著,各竖向构件的变形差异将引起水平构件附加内力,影响结构的安全性与正常使用,需要采取相应的设计与施工措施。温度作用对超高层建筑结构变形与内力的影响不能忽略。提出最大正、负温差的确定方法。应采取措施减小温度作用的不利影响,严格控制重要的温度敏感构件的合龙温度。基础不均匀沉降与超高层建筑的安全性关系密切,现阶段通过上部结构与地基基础共同工作模型准确预计基础沉降值尚难以实现,还需要通过设置施工后浇带、敏感构件滞后安装等方式尽量减小差异沉降的影响。     

聚环氧琥珀酸(PESA)对高硬度废水生物处理系统的作用

通过在活性污泥法处理高硬度废水的实验过程中加入绿色安全型阻垢剂聚环氧琥珀酸(PESA),对于COD在100～300 mg/L,Ca 2+浓度在110～280 mg/L的高硬度废水,研究活性污泥系统的沉降性能、COD去除率、Ca 2+保留率、生物相变化规律以及污泥减量化效果。结果表明,加入PESA的活性污泥反应器MLSS值低于普通活性污泥反应器,明显减少了污泥中无机组分的含量、钙泥的产出量,减量化程度达到41.33%,从而达到钙质废水处理中污泥减量化的目的;COD去除率能够达到90%以上,Ca 2+保留率达到80%以上;PESA的加入抑制了部分钙盐在活性污泥表面的沉积,保持了活性污泥的良好生物活性;系统耐高硬度水冲击负荷能力增强;     

Deformation analysis of geosynthetic-encased stone column using cavity expansion models with emphasis on boundary condition

This paper presents a modified theoretical model to predict the deformation of geosynthetic-encased stone column (GESC) and surrounding soil, using cylindrical cavity expansion model (CEM). The model was distinguished for single GESC and GESC in groups with emphasis on the different boundary conditions. The displacement boundary of CEM was used for GESC in groups, and the stress boundary of CEM was adopted for single GESC. The plasticity development of the soil obeying the Mohr-Coulomb yielding criterion was considered. The stress and settlement of the GESC were analyzed by radial stress and vertical stress equilibrium. This method has been verified via comparison with test data and numerical simulation results. The influences of applied loading, geosynthetic encasement stiffness, and soil stiffness on the mechanical performance of the GESC and the surrounding soil have also been investigated. The proposed theoretical approaches are suitable for predicting the deformation of the GESC, and the surrounding soil. The proposed method in unit cell analysis was more reasonable for GESC in groups.     

Renewable energy harvesting from water flow

The hydrokinetic energy of flowing water is plentiful, environment-friendly, renewable and can be harvested. This paper reports a new energy harvesting system using vortex-induced vibration (VIV). The proposed convertor harvests vibrations of a bluff body resulting from interaction of the alternating vortices created by the unsteady separation. These vortices are shed from the sides of the bluff body and form a pattern in the wake known as the von Kármán vortex street. The vortices create unsteady loading and induce vibrations with a predictable frequency and amplitude. Assisted by the bluff body with specific geometry and piezoelectric generators, the kinetic energy of the water flow can be converted into mechanical vibrations and electrical energy. In order to maximise the output energy of the harvester, the natural frequency of the mechanical system needs to lock into the frequency of the VIVs. Thus, the geometry of the bluff body has to be optimised to match the natural frequency of the convertor. This study examines the conceptual design of the physical model. The fluid–structure interaction model is applied to study the preliminary design. The maximum energy density that can be extracted by the proposed convertor from the water flow with velocities from 0.2 to 1 m/s is also estimated.Abbreviations: 1.CFD Computational Fluid Dynamics; 2.DC Direct Current (electricity); 3.FIM Fluid Induced Motion; 4.ODE Ordinary Differential Equation; 5.PTC Passive Turbulence Control; 6.VIV Vortex Induced Vibration; 7.VIVACE Vortex Induced Vibration Aquatic Clean Energy; 8.2D Two Dimensional     

基于Matlab的BP神经网络在泥石流危险性评价中的应用

由于泥石流孕育环境、成灾条件及其诱发因素等的随机性、不确定性和模糊性,决定了泥石流是一种非常复杂的非线性系统。人工神经网络因其具有较强的自组织性、自适应性和自学习能力等优势,更适合于解决非线性问题。本文基于Matlab程序建立了区域泥石流危险性评价的BP神经网络模型,并将该模型应用于凉山州德昌县22个乡镇的区域泥石流危险性评价中,取得了良好的应用效果,评价预测的准确率高达95%。该方法不仅解决了泥石流危险度评价因子和评价等级之间的复杂非线性关系,而且过程简单,结果不受人为因素的影响,是一种具有应用价值、有效的泥石流危险性评价方法。     

基于BIM技术的体育馆钢结构智慧化施工管理

本文对基于BIM技术的体育馆钢结构智慧化施工管理进行了研究。通过三维精细化模型创建、模型链接整合、漫游检测、施工模拟、数值模拟、项目协同管理、VR+质量信息追溯和三维可视化技术交底指导现场施工等应用点,说明BIM技术能够有效指导钢结构现场施工,提高施工效率和施工安全,避免浪费和返工,节约成本,有着十分重要的意义。