Detection of ventilation paths using high-resolution roughness parameter mapping in a large urban area

In this study, an urban roughness mapping method is presented on the example of a large study area in Szeged, Hungary, as an example. With this roughness mapping procedure, the potential ventilation paths of the city can be located. Our calculations of the roughness parameters are based on a 3D building database; however, this new approach using the lot area polygons provides more detailed results than other recent studies. The detected ventilation paths could play a significant role in the development of the urban heat island circulation and result in the reduction of air pollution in the central parts of the city. Based on our results, we can mark out the areas where the city government should keep the advantages of the ventilation paths considering the human comfort aspects of the urban climate, thus providing important input data for urban planning procedures.     

Width effect on upward flame spread

One previous experimental study has reported a width effect for upward flame spread rate on thermally thin fuels. A similar effect is expected for thermally thick fuels. This study revisited this topic by developing a hypothesis and performing experiments with sidewalls using 18 mm thick, 1000 mm tall PMMA slabs of widths 100, 200, 300, 500 and 700 mm. In the hypothesis, a lateral diffusion throughout the flame width was proposed to cause thicker flame along its centerline for wider flames and enhance combustion efficiency. Higher heat release rate per unit width, larger flame height, higher flame temperature and more heat feedback to the surface were consequently present. The corresponding flame spread rate was also increased and a power value of 0.35 existed between the flame spread rate and width in this study. All the experimental results clearly supported the hypothesis.     

GPS高程转换的新方法研究

提出了一种在“移去-恢复”思路的基础上,综合利用EIGEN—GL04C地球重力场模型、局部地形改正以及几何拟合法进行GPS高程转换的方法。验证了EIGEN-GL04C模型的精度,比较了现有的几种局部地形改正公式,并通过某隧道实例验证了该方法的有效性和严密性,证明该方法在地形起伏较大的重山区同样能够达到较好的精度要求。     

基于GIS与虚拟现实技术的三维地层可视化系统设计与实现

本文在对比多种三维可视化建模方法的优劣后,提出了一种在VRML环境下结合GIS技术实现三维地层可视化的方法,并以某大桥为例,将理论的虚拟现实技术推广到实际应用中,克服了依靠传统钻孔柱状图来反映真实地层分布的弊端,大大提升了勘察结果表达的直观性,给工程勘察信息的整理发布提供了一个有效、科学的技术手段。     

适用于分户热计量的管道暗埋供暖系统

介绍了适用于分户热计量的4种管道暗埋供暖系统的形式,对管道暗埋供暖系统的管材、安装方法及施工要点进行了分析。     

坦桑尼亚议会大厦大型斜跨放射梁圆台形屋盖结构施工技术

坦桑尼亚围家议会大厦工程的斜跨放射状梁板圆台型屋盖,因楼层标高不一,模板、钢筋安装和混凝土浇筑等都存在一定难度,技术要求高,本工程精心计算和设计模板及支撑系统,控制钢筋加工和混凝土浇筑施工工序,合理安排下斜屋面施工获得了圆满成功。     

财富中心二期公寓楼工程超高层建筑施工临时用水设置

财富中心二期公寓楼工程为超高层建筑,施工临时用水的设置采用分阶段、分层次的设置方法,即在工程施工初期设置室外临时用水给水系统,在结构施工阶段设置楼内生产及消防用水系统,在装饰阶段采用正式的消火栓给水系统先行完善、启用的方法;水源选择充分利用施工期间施工降水,并将楼内的施工废水循环利用。与传统作法比较,水资源更节约,消防更安全,操作更简单,运行与维护成本显著降低,具有良好的综合效益。     

新型井下固化下沉式缝高控制剂的研制

以有机硅、松香树脂、石英粉和陶粒等为原料,研制出一种新型双组分井下固化下沉式缝高控制剂。其中A组分为固体颗粒,B组分为液态固化剂;施工时将双组分混合均匀后,随携砂液注入井中,然后在井温条件下沉降固化。重点讨论了体系的初凝时间与温度的关系,以及B组分含量、井温和反应时间等因素对最终隔层强度的影响;利用显微镜技术观察了体系固化前后的微观结构变化,采用热重分析(TGA)法计算了液态B组分固化剂的利用率。结果表明:该缝高控制体系适用于井温为50～70℃的油井,得到的隔层可增加地层应力5～7 MPa,B组分的利用率为71.78%;该产品控缝效果良好,是一种应用前景较好的石油开采用缝高控制剂。     

Deposition and characterisation of TiO2 coatings on various supports for structured (photo)catalytic reactors

Different types of aqueous TiO₂–P25 suspensions were prepared and their properties, including rheological behaviour and zeta potential, were studied. Then, TiO₂ suspensions were used to elaborate TiO₂ coatings on various substrates (cordierite monolith, stainless steel plates and -SiC foam) using a dip-coating method. The relationship between the suspension stability and the coating adhesion has been considered. The structural and morphological characterisation of TiO₂ coatings has been performed using scanning electron microscopy, X-ray diffraction and other methods. Finally, the photocatalytic properties of the materials have been determined by studying the photooxidation of aqueous ammonia.