中空窗玻璃贴低辐射膜的性能研究

热阻和太阳能透过率是分别反映窗玻璃热工性能和光学性能的参数.在不贴膜和室内贴低辐射膜2种情况下,对中空窗玻璃的热阻和太阳能透过率进行实验研究,分析和比较2种情况下的窗玻璃性能及其对节能性的影响.结果表明,实验所用中空窗的固定窗和推拉窗2部分,贴膜后传热阻分别增大31.1%和40.7%,传热系数分别降低23.7%和28.8%.对于玻璃的太阳能透过率,贴膜后从40%减少到28.6%,透过玻璃的辐射热减少28.5%.     

The effect of Urban Heat Island mitigation strategies on outdoor human thermal comfort in the city of Baghdad

Todays, most Iraqi cities suffer from extremely hot-dry climate for long periods throughout the year. However, most urban patterns that exist inside these cities are not suitable for this harsh conditions and lead to an increase in the value of the Urban Heat Island (UHI) index. Consequently, this will increase outdoor human thermal discomfort as well as energy consumption and air pollution in cities. This study attempts to evaluate the effect of UHI mitigation strategies on outdoor human thermal comfort in three different common types of urban patterns in the biggest and most populated city in Iraq, Baghdad. Three different mitigation strategies are used here – vegetation, cool materials, and urban geometry – to build 18 different scenarios. Three-dimensional numerical software ENVI-met 4.2 is utilised to analyse and assess the studied parameters. The input data for simulations process are based on two meteorological stations in Baghdad: Iraqi Meteorological Organization & Seismology, and Iraqi Agrometeorological Network. All measurements are taken in a pedestrian walkway. The results of different scenarios are compared based on their effect on human thermal comfort. Outdoor thermal comfort is assessed according to Predicted Mean Vote index, as mentioned in ISO 7730 standard. This study provides a better understanding of the role of UHI mitigation strategies on human thermal comfort in the outdoor spaces of Baghdad's residential neighbourhoods. This can help generate guidelines of urban design and planning practices for better thermal performance in hot and dry cities.     

温州地区现用外窗节能性能及分析

摘．要：针对温州地区现用外窗节能性能进行了试验研究,分别检测了该地区现用外窗的玻璃露点,气密性能,可见光透射比,传热系数等几项指标,提出了相应的建议,以指导当地居民正确应用节能外窗。     

气泡混凝土降温性能的试验研究及数值模拟

在解决夏季城市热岛效应和楼顶层高温的方法中,屋顶绿化和含水砂层等都有较好的降温效果,但是分别存在着价格昂贵、维护不便等缺点,因此在工程推广中受到限制.气泡混凝土具有价格便宜且维护简单的优点,并且之前的研究已经体现出了它具有良好蒸发降温性能的潜质.通过对不同吸水性能的气泡混凝土降温性能的试验研究,找出气泡混凝土降温与吸水性能之间的关系,为不同的工程需求提供一定的参考建议;并运用多孔介质热湿迁移模型对其蒸发降温过程进行数值模拟,在用部分试验数据验证数值模型的正确性后,使用此模型对剩余试验数据进行预测,并达到了良好的预测效果.     

基于三阶段DEA-Malmquist的华东地区建筑业效率研究

利用增加值法筛选华东地区7省市2007~2014的建筑业效率评价指标,运用三阶段DEA模型对效率的静态水平进行比较研究,弥补了传统DEA模型忽略环境变量和随机误差的缺陷。在此基础上运用Malmquist指数模型分析建筑业效率的动态变化及原因。结果表明,近7年华东地区建筑业效率呈上升趋势,主要归功于技术进步效率指数。在2008~2009年出现下降情况,归结于建筑业未来形势不明朗,规模效应不稳定;管理粗放体系不完善,纯技术效率负增长。     

Experimental and numerical studies on the lateral performance of concrete sandwich walls

A series of quasi‐static tests was presented to study the lateral behavior of concrete sandwich walls and the precast concrete sandwich walls; the finite element analysis (FEA) models were built for numerical simulation of the specimens, and the parameters affecting the seismic performance of sandwich walls, and the precast sandwich walls were also analyzed based on the FEA models. The results show that the shear failure occurs in regular squat shear wall; the setting of the foam plate effectively reduces the stiffness and load capacity, and the reasonable design of sandwich region is conducive to the seismic performance. The responses obtained by the FEA models match well with the experimental results. The stiffness and load capacity of sandwich wall are increased, but the ductility is reduced when the axial load is increased; the deformation capacity can be greatly improved by increasing the aspect ratio but at the cost of load capacity and stiffness; the reasonable match of load capacity, stiffness, and ductility can be achieved by maintaining the appropriate length and thickness of the foam plate. The greater the friction force of CAF in the vertical seam of precast sandwich wall, the greater the load capacity and initial stiffness and the stronger the integrity of the jointed wall. When the strength of SRS in the horizontal seam is small, the concrete sandwich wall basically maintains elasticity; the deformation is mainly concentrated on SRS; when the strength of SRS is too large, SRS do not yield or the yield displacement is large, and the load capacity is mainly affected by the concrete sandwich wall.     

CFRP筋复合式锚具锚固性能的试验研究

当复合材料FRP(Fiber Reinforced Polymer/Plastics)筋或拉索应用到斜拉桥的拉索体系时,黏结式锚具和夹片式锚具均有其自身的局限性。对此,根据普通拉索锚固体系的特点,并结合CFRP筋夹片式锚具和黏结式锚具的研究成果,提出了锚固CFRP筋的复合式锚具。复合式锚具由楔紧锚固端和黏结锚固端组成,其中楔紧锚固端包括锚杯、带有凹齿的夹片、铝套管以及塑料薄膜,黏结锚固端包括钢套筒和黏结介质活性粉末混凝土RPC(Reactive Power Concrete)。静载试验研究了锚杯长度、钢套筒长度、夹片预紧力、筋材预张拉力等试验参数对复合式锚具锚固性能的影响。试验结果表明,复合式锚具的试件极限荷载最大为208kN,相应的锚固效率系数为104%,大于95%,满足规范要求。复合式锚具两种锚固形式的锚固长度较合理组合为:对不预张拉锚具,锚杯长度40mm,黏结锚固长度100mm;对预张拉锚具,锚杯长度60mm,黏结锚固长度60mm。提出的复合式锚具极限荷载计算式具有较好的适用性。     

现浇组合梁抗火性能试验研究与数值模拟

为了对刚接约束下现浇组合梁的抗火性能进行研究,现对刚接约束下的现浇组合梁进行了恒载升温试验研究和数值模拟。在试验过程中,对试验现象进行了详细的观察记录,对现浇组合梁的温度分布和位移变化进行了测量。通过分析试验数据发现,现浇板的温度分布沿板厚方向逐渐降低,板底温度最高,40mm以下区域受火影响最为明显。现浇板会延缓钢梁上翼缘温度的升高,由于温度梯度的影响,现浇板会约束钢梁的变形;现浇板由于温度应力和荷载弯矩的影响,在板顶沿中轴线方向出现贯穿板面的裂缝,冷却后现浇组合梁有较强的变形恢复能力。刚接约束下现浇组合梁的模拟结果与试验结果符合较好,验证了数值模拟的正确性与可行性。     

Experimental investigation of performance and emissions characteristics on single-cylinder direct-injection diesel engine with PSZ coating using radish biodiesel

ABSTRACT

It has been determined that world oil production is likely to level off very shortly and that alternative fuels will have to meet the demands of an increasing energy crisis. The crude oil price is continuing to increase; at the same time the need of energy is also increasing rapidly. So there is an urgent need to switch to some other fuels which could replace petrol and diesel in order to produce energy. An eco-friendly alternative is required to fulfil the growing demand. This project highlights our work on alternate fuels and the importance of choosing radish seed as one such alternative. The aim of this study is the experimental investigation of performance and emissions on a single-cylinder direct-injection diesel engine with a coating. Diesel, B25, B50, B75 and B100 are used as fuels. The engine cylinder head, valves and piston crown are coated with 100 micron of nickel-chrome-aluminium bond coat and 450 micron of partially stabilised zirconia by the atmospheric plasma spray method [Ravikumar and Senthilkumar (2013). “Reduction of NOx Emission on NiCrAl-Titanium Oxide Coated Direct Injection Diesel Engine Fuelled with Radish (Raphanus sativus) Biodiesel.” Journal of Renewable and Sustainable Energy 5 (6): 063121]. Further, by using radish biodiesel and its blends, the emission and performance characteristics are checked and a suitable blend is selected.     

The influence of the envelope on the thermal performance of ventilated and occupied houses

The main objective of this article is to investigate the influence of the thermal properties of the envelope on the thermal performance of occupied and naturally ventilated houses. A naturally ventilated house built in Southern Brazil was modelled and calibrated in the EnergyPlus computer programme. Based on this calibrated model, a reference model for computer simulations was defined, and variations in the materials of the envelope, occupation patterns and ventilation were carried out. Hourly air temperature and relative air humidity were the output data for the thermal zones of each model. By inputting such data in the Analysis Bio computer programme, the percentage of discomfort hours in the models was obtained. Correlations between the percentage of discomfort hours and the equivalent thermal transmittance, thermal capacity and thermal delay values of the components of the envelope were investigated. Such analysis made clear that there is an influence of the envelope on the thermal performance of the occupied and ventilated house, and that the number of discomfort hours is lower in the models with higher thermal capacity and thermal delay envelope values. It was also observed that thermal capacity was the thermal property with the best correlation to discomfort hours.     

胶合木网壳半刚性节点受力性能试验研究

针对凯威特六型胶合木网壳节点,设计并制作了12个足尺节点试件。进行了在胶合木构件轴压力为0、100、200 kN和300 kN共4种工况下节点的受弯承载性能试验,对节点抗弯刚度和受力性能进行分析,研究节点的弯矩-转角关系、节点域破坏模式及其与构件轴压力的关系。结果表明：节点域破坏模式可分为胶合木构件受压破坏、受拉破坏和界限破坏。节点域胶合木构件受拉破坏的节点受弯承载力随木构件轴压力的增大而增加。随着胶合木构件轴压力的增加,节点的初始抗弯刚度增大。发生节点域胶合木构件受压破坏的节点,其刚度较木构件受拉破坏的节点有较大提高。试验测得了节点的荷载-位移曲线和弯矩 转角曲线,并拟合得到了弯矩-转角关系方程,结果表明适度的木构件轴压力有助于提高节点连接的延性。     

Field investigation on consumer behavior and hydraulic performance of a district heating system in Tianjin,China

With the implementation of heat reforms in China, the application of thermostatic radiator valves (TRVs) has been gaining popularity in the new-style district heating systems (DHSs). The objective of this study was to investigate consumer behavior (including regulation of TRVs and opening of windows) and its influences on the hydraulic performance and energy consumption of individuals and the whole system. The concurrence rate of individual behaviors and hydraulic interactions between individuals were analyzed. This study should be helpful to gain a comprehensive understanding of the new DHSs in China and consider a proper design/control strategy for these systems.     

一般大气环境锈蚀钢柱抗震性能试验与数值分析

为研究锈蚀对钢柱抗震性能的影响,对20个钢板试件和7个H型钢柱试件进行一般大气环境加速腐蚀试验。通过锈蚀钢板单调拉伸与低周往复加载试验研究锈蚀钢板单调与循环加载性能的差异性,揭示锈蚀钢材强度、延性退化规律,建立锈蚀钢材循环本构模型;通过锈蚀H型钢柱拟静力试验,研究锈蚀钢柱在地震作用下的损伤过程、破坏形态及性能退化规律,结果表明:锈蚀导致柱脚塑性范围更加集中,并加快屈曲发展,从而引起承载力、刚度、延性和耗能能力显著退化,且较大的轴压比将进一步加快钢柱破坏过程。最后,提出考虑锈蚀程度的损伤钢柱抗震性能数值模拟方法,并进行参数化扩展分析,研究均匀/非均匀锈蚀程度、锈蚀分布范围等影响因素对H型钢柱抗震性能的影响规律,结果表明:非均匀锈蚀导致钢柱抗震性能退化更加严重,且当钢柱翼缘或柱脚发生锈蚀时,抗震性能退化更为显著。     

Thermal comfort and indoor air quality in the lecture room with 4-way cassette air-conditioner and mixing ventilation system

We performed the experimental and the numerical studies on thermal comfort (TC) and indoor air quality (IAQ) in the lecture room with cooling loads when the operating conditions are changed. Predicted mean vote (PMV) value and CO₂ concentration of the lecture room were measured and compared to the numerical results. Both of them showed a reasonable agreement with each other and then we applied the numerical model to analyze TC and IAQ for a couple of different operating conditions. From the results we found that the increment of the discharge angle of 4-way cassette air-conditioner makes uniformity of TC worse, but rarely affects IAQ. It turned out that TC and IAQ are hardly affected by the variation of the discharge airflow. Finally TC was merely affected by the increment of the ventilation rate, but when the ventilation rate is more than 800 m³/h, the average CO₂ concentration can be satisfied with the standard limits of Japanese in our case studies.     

受压焊接空心球节点高温试验研究

为研究受压焊接空心球节点火灾下的性能,利用高温试验炉,对不同空心球外径和壁厚、钢管外径和壁厚、钢材屈服强度和荷载比的6种受压焊接空心球节点试件进行了高温作用下的试验研究,得到了其在高温下的温度分布、位移特征和破坏形式,并研究了对其极限耐火时间的影响因素;根据欧洲规范,对受压焊接空心球节点高温作用下的性能进行了非线性有限元数值模拟,分析了节点的温度场分布规律和影响因素。通过分析高温作用下节点的位移变化特征,确定了其破坏模式;试验结果和有限元分析结果进行了对比,二者吻合较好。研究结果表明：增大焊接钢管壁厚和降低焊接空心球节点实际承受的荷载可以有效地延长受压焊接空心球节点的极限耐火时间;钢管根部是高温作用下受压焊接空心球节点的薄弱部位。图13表2参9     

Nutrient characteristics in the Yangtze River Estuary and the adjacent East China Sea before and after impoundment of the Three Gorges Dam

From November 2002 to 2006, five cruises were undertaken in the Yangtze River Estuary and the adjacent East China Sea to compare the nutrient concentrations, ratios and potential nutrient limitation of phytoplankton growth before and after impoundment (June 2003) of the Three Gorges Dam (TGD). Concentrations of dissolved inorganic nitrogen (DIN), soluble reactive phosphorus (SRP) and total nitrogen (TN) exhibited an increasing trend from 2002 to 2006. In contrast, total phosphorus (TP) concentration exhibited a decreasing trend. The mean concentrations of DIN, SRP, and TN in the total study area increased from 21.4 µM, 0.9 µM, and 41.8 µM in 2002 to 37.5 µM, 1.3 µM, and 82.2 µM in 2006, respectively, while TP decreased from 2.1 µM to 1.7 µM. The concentration of dissolved reactive silica (DRSi) had no major fluctuations and the differences were not significant. The mean concentration of DRSi in the total study area ranged from 52.5 to 92.3 µM. The Si:N ratio decreased significantly from 2.7 in 2002 to 1.3 in 2006, while TN:TP ratio increased from 22.1 to 80.3. The area of potential P limitation of phytoplankton growth expanded after 2003 and potential Si limitation appeared in 2005 and 2006. Potential P limitation mainly occurred in an area of salinity less than 30 after 2003, while potential Si limitation occurred where the salinity was greater than 30. By comparison with historical data, the concentrations of nitrate and SRP in this upper estuary during November 1980-2006 increased obviously after impoundment of TGD but DRSi decreased. Meanwhile, the ratios of N:P, Si:N and Si:P decreased obviously.     

华东地区水湿生木本植物综合评价与 筛选

随着海绵城市建设的推进,水湿生木本植物的应用受到越来越多的关注和重视。运用层次分析法从观赏性、新优性、生物学特性、生态性和经济性5个方面,筛选评价指标,确定各指标的权重,建立综合评价体系,并对124种水湿生木本植物(含少量品种)进行评价,根据综合得分将其分为4个等级：其中评分为Ⅰ级的树种26种,Ⅱ级的树种38种,这2级可以作为华东地区水湿生植物群落营造的推荐树种,Ⅲ级和Ⅳ级树种共60种,这2级适宜作为群落多样性的备选或补充树种。研究结果可为华东地区营造水湿生植物景观、湿地造林、生态修复以及海绵城市建设提供科学依据。     

Experimental and numerical investigation on thermal and electrical performance of a building integrated photovoltaic-thermal collector system

An experimentally validated computational fluid dynamics (CFD) model of a novel building integrated photovoltaic-thermal (BIPV/T) collector is studied to determine the effect of active heat recovery on cell efficiency and to determine the effectiveness of the device as a solar hot water heater. Parametric analysis indicates that cell efficiency can be raised by 5.3% and that water temperatures suitable for domestic hot water use are possible. Thermal and combined (thermal plus electrical) efficiencies reach 19% and 34.9%, respectively. A new correlation is developed relating electrical efficiency to collector inlet water temperature, ambient air temperature and insolation that allows cell efficiency to be calculated directly.     

闽南地区住宅外窗节能设计方法研究

指出闽南地区隶属全国建筑热工设计分区的夏热冬暖地区南区,其住宅外窗节能率仅与遮阳性能密切相关,而与传热性能关系甚小,由此本文提出了适合于该地区住宅外窗节能设计的七种方法,从而促进建筑节能的发展。     

浅谈东西方古典园林的差异

针对古典园林在东西方各自文化艺术中的重要地位,通过苏州园林与凡尔赛宫花园中山水建筑的体验,比较了东西方园林在对自然艺术的表现、园林与建筑的关系和园林表达思想上的不同,从而分析了东西方文化上的差异。