某铁路π形梁桥的荷载试验研究

以某铁路桥为工程背景,通过结构计算、现场检测、荷载试验等工作,对铁路桥梁的荷载试验过程进行详细阐述,评估受检π形梁的工作性能和承载能力。结果表明,受检π形梁的承载能力能够满足设计荷载等级的要求。工程为π形梁的后期养护及维修提供了基础依据,对同类型铁路桥梁的检测及其承载能力评价有一定的参考价值。     

Dynamic analysis of functionally graded nanocomposite cylinders reinforced by carbon nanotube by a mesh-free method

In this paper, dynamic analysis of nanocomposite cylinders reinforced by single-walled carbon nanotubes (SWCNTs) subjected to an impact load was carried out by a mesh-free method. Free vibration and stress wave propagation analysis of carbon nanotube reinforced composite (CNTRC) cylinders are presented. In this simulation, an axisymmetric model is used. Four types of distributions of the aligned carbon nanotubes (CNTs) are considered; uniform and three kinds of functionally graded (FG) distributions along the radial direction of cylinder. Material properties are estimated by a micro mechanical model. In the mesh-free analysis, moving least squares (MLSs) shape functions are used for approximation of displacement field in the weak form of motion equation and the transformation method was used for the imposition of essential boundary conditions. Effects of the kind of distribution and volume fractions of carbon nanotubes and cylinder thickness on the natural frequencies and stress wave propagation of CNTRC cylinders are investigated. Results obtained for this analysis were compared with FEM and previous published work and good agreement was seen between them.     

绿色生态城区中绿色建筑星级比例研究

绿色生态城区全面发展绿色建筑已经成为共识,针对各星级绿色建筑的比例配置未有研究,提出单位减碳量的增量成本来衡量各星级绿色建筑比例合理性的研究方法,并通过某绿色生态城区案例分析,得出了经济型绿色生态城区和单位减碳量增量成本最低的绿色生态城区的一、二、三星级绿色建筑比例,分别为63%,23.5%,13.5%和16.5%,63%,20.5%。     

地表水水源热泵系统计算机辅助优化设计研究综述

首先阐述了系统优化设计的类型和步骤,在此基础上介绍了国内外对水源热泵作为一个整体研究的情况和系统优化过程中的计算机应用情况;分析了系统各个部件的优化与建模现状;对目前常用的优化算法—遗传算法的概念及在热泵领域的应用进行了介绍。     

水源热泵机组在制取和供应生活热水方面的节能应用

以一项节能改造工程的管理、设计、改造及测评为例,从技术应用的可行性及经济性数据分析出发,总结出在医院、宾馆、高校等一些公共建筑推广这种废热回收技术的应用价值.     

High temperature corrosion studies on friction welded low alloy steel and stainless steel in air and molten salt environment at 650 °C

The investigation on high-temperature corrosion resistance of the weldments is necessary for prolonged service lifetime of the components used in corrosive environments. This paper reports on the performance of friction welded low alloy steel AISI 4140 and stainless steel AISI 304 in air as well as molten salt environment of Na₂SO₄–60%V₂O₅ and NaCl–50%Na₂SO₄ at 650 °C. This paper reports several studies carried out for characterizing the weldments corrosion behavior. Initially thermogravimetric technique was used to establish the kinetics of corrosion. For analyzing the corrosion products, X-ray diffraction, scanning electron microscopy/energy-dispersive analysis and electron probe micro analysis techniques were used. From the results of the experiments, it is observed that the weldments suffered accelerated corrosion in NaCl–Na₂SO₄ environment and showed spalling/sputtering of the oxide scale. Furthermore, corrosion resistance of weld interface was found to be lower than that of parent metals in molten salt environment. Weight gain kinetics in air oxidation studies reveals a steady-state parabolic rate law while the kinetics with salt deposits displays multi-stage growth rates. Moreover NaCl is the main corrosive species in high temperature corrosion, involving mixtures of NaCl and Na₂SO₄ which is responsible for formation of internal attack.     

绿色建筑技术在黄山南大门多层停车库工程中的应用

黄山南大门多层停车场是黄山风景区标志性基础工程,项目占地面积约4.3万m2,总建筑面积10万m2。项目根据所处的山地自然条件和风景区绿色环保的要求,在建筑空间布置、从基础到上部的结构形式、自然通风设计、垂直绿化等方面采用了多项绿色建筑技术,在讲求实效的同时,体现了节能、节地、节水、节材和环保的要求。由于预应力技术的应用,在有限的建筑总高度和层高下,不仅实现了较大的柱距和不同车辆的灵活布置功能,而且确保了结构净空,可同时适应当前一般停车与将来增设机械车位的多种要求。2010年12月完成首期工程并部分投入使用后,大大缓解了黄山风景区旅游车辆停放的压力,同时在投资和使用效果上切实感受到绿色建筑技术所带来的优越性。     

上海市张江高科技园区生态大楼的实时监测报告

分析了张江生态大楼所采用的节能技术,确定了监测该生态大楼所需的建筑热工参数以及环境参数.对建筑物监测点位置以及传感器布置所需注意的细节作了说明.监测数据的实时采集,为实时反映建筑物的实际运行状况、评估节能技术的实际效果以及管理建筑物能源系统提供了可靠的数据来源.     

绿色建筑运行实效问题与碳减排研究分析

重点剖析总结了绿色建筑的运行实效问题,部分项目关键系统设备的运行使用效果不佳,物业管理团队对绿色建筑的高效运行至关重要。同时分析了绿色建筑在全生命周期的碳减排指标,从全生命周期的角度来衡量绿色建筑,突显了绿色建筑的运行使用阶段节能减排的重要性。     

大空间空调中射流理论的适用性问题研究

以大空间空调设计中广泛采用的圆形喷口为例,对比分析了传统半经验射流理论计算结果与CFD模拟结果。研究结果表明,模拟得到的多喷口水平并排射流的射流轴心弯曲及轴心风速衰减均较快;实际建筑空间结构、内部发热条件及喷口布置形式对射流的流场有较大影响;空间温度场分布并非仅与射流的射程有关,还受空间整体气流状况影响。