户外广告如何提升城市形象——以澧县县城户外广告专项规划为例

在高楼迭起的同时,户外广告也依附着建筑与道路蓬勃发展起来。但其中存在着户外广告管理缺失问题,一些无序设置、违法设置、残旧破损的户外广告设施长期占用城市道路,影响市容市貌和道路交通安全。本文以澧县县城户外广告专项规划为例,分析户外广告如何提升城市形象。     

Multiple lines of evidence to identify the sources of fecal pollution at a freshwater beach in Hamilton Harbour, Lake Ontario

Multiple microbial source-tracking methods were investigated to determine the source of elevated Escherichia coli levels at Bayfront Park Beach in Hamilton Harbour, Lake Ontario. E. coli concentrations were highest in wet foreshore sand (114,000 CFU/g dry sand) and ankle-depth water (177,000 CFU/100mL), declining rapidly in deeper waters. Many gull and geese droppings were enumerated each week on the foreshore sand within 2m of the waterline. Both antimicrobial resistance analysis and rep-PCR DNA fingerprinting of E. coli collected at the beach and nearby fecal pollution sources indicated that E. coli in sand and water samples were predominantly from bird droppings rather than from pet droppings or municipal wastewater. Both methods indicated a trend of decreasing bird contamination, and increasing wastewater contamination, moving offshore from the beach. When foreshore sand was treated as a reservoir and secondary source of E. coli, waterborne E. coli were found to be more similar to sand isolates than bird or wastewater isolates out to 150 m offshore. Multiple lines of evidence indicated the importance of bird droppings and foreshore sand as primary and secondary sources of E. coli contamination in beach water at Bayfront Park.     

Numerical study of the effects of trees on outdoor particle concentration distributions

Outdoor particles are a major contributor to indoor particles which influence the indoor air quality. The outdoor particle concentration also affects the outdoor air quality but the real outdoor particle concentration around buildings may differ from monitored concentrations at monitoring sites. One main factor is the effect of vegetation, especially trees. Numerical simulations were used to investigate the effects of trees on particle concentration distributions around target buildings. The drift flux model was combined with the Reynolds-Averaged Navier-Stokes (RANS) model to model the particle distribution and the airflow. Thirteen cases were analyzed to compare the effects of tree type, tree-building distance and tree canopy-canopy distance on the outdoor particle concentration distribution. The results show that cypress trees reduce the outdoor particle concentration more than pine trees, that shorter tree-building distances (TBD) reduce the particle concentration more than longer tree-building distances, and that a zero tree canopy-canopy distance (CCD) reduces the particle concentration more than CCD=2 m. These results provide guidelines for determining the most effective configuration for trees to reduce outdoor particle concentrations near buildings.     

Estimating long-term time-resolved indoor PM2.5 of outdoor and indoor origin using easily obtainable inputs

To evaluate the separate impacts on human health and establish effective control strategies, it is crucial to estimate the contribution of outdoor infiltration and indoor emission to indoor PM_2.5 in buildings. This study used an algorithm to automatically estimate the long-term time-resolved indoor PM_2.5 of outdoor and indoor origin in real apartments with natural ventilation. The inputs for the algorithm were only the time-resolved indoor/outdoor PM_2.5 concentrations and occupants’ window actions, which were easily obtained from the low-cost sensors. This study first applied the algorithm in an apartment in Tianjin, China. The indoor/outdoor contribution to the gross indoor exposure and time-resolved infiltration factor were automatically estimated using the algorithm. The influence of outdoor PM_2.5 data source and algorithm parameters on the estimated results was analyzed. The algorithm was then applied in four other apartments located in Chongqing, Shenyang, Xi'an, and Urumqi to further demonstrate its feasibility. The results provided indirect evidence, such as the plausible explanations for seasonal and spatial variation, to partially support the success of the algorithm used in real apartments. Through the analysis, this study also identified several further development directions to facilitate the practical applications of the algorithm, such as robust long-term outdoor PM_2.5 monitoring using low-cost light-scattering sensors.     

Fracture properties of marble–mortar compounds

Marble panels for outdoor cladding of buildings are generally fastened with mortar and/or anchors. Due to environmental influences (e.g. solar heat, rain and snow), such panels can start to bow and crack, such that eventually they may detach from the wall, possibly causing damage to humans and the environment. Different marble–mortar compounds have been tested for their mechanical and fracture-mechanical characteristics (adhesive strength, notch tensile strength, specific fracture energy, crack growth resistance and characteristic length) by means of the pull-out test and the wedge-splitting method. The propagation of a crack in the marble–mortar compound is characterized on the basis of fracture-mechanics and by use of the load displacement curve. The advantages of using a mortar bed rather than anchors are considered.      

超高层建筑智能化设计要点

结合超高层建筑功能特点和智能化技术应用现状,提出超高层智能化设计要点,旨在探讨和提供适宜此类建筑特点的技术措施。     

Outdoor Air Contaminants and Indoor Air Quality under Transient Conditions

The indoor concentrations of contaminants originating from outdoor sources have been measured and calculated under transient conditions. The results show that contaminants that are supplied to an office building via the ventilation system can reach considerably high concentration levels. The indoor/outdoor concentration ratio and time lag are dependent on the air change rate. In buildings with low air change rates the indoor concentration variations are smoothed out compared to buildings with high air change rates. The results from the theoretical model are compared to the results from both laboratory and field measurements and the model is verified for well mixed conditions in a 20 m³ test chamber. The model can be used to simulate different control strategies for reduction of indoor contaminant concentrations related to outdoor sources. One such control strategy is based on reduction of the outdoor air change rate during periods with peak outdoor contaminant concentrations.     

燃气管道入户处的绝缘作法

根据有关规范对民用建筑做总等电位的要求，分析了燃气管入户的几种做法，得出燃气入户管必须做绝缘的结论给出了合适的绝缘方法。     

Class separation of buildings with high and low prevalence of SBS by principal component analysis

In this study, we were able to separate buildings with high and low prevalence of sick building syndrome (SBS) using principal component analysis. The prevalence of SBS was defined by the presence of at least one typical skin, mucosal and general (headache and fatigue) symptom. Data from the Swedish Office Illness Study describing the presence and level of chemical compounds in outdoor, supply, and room air, respectively, were evaluated together with information about the buildings in six models. When all data were included the most complex model was able to separate 71% of the high prevalence buildings from the low prevalence buildings. The most important variable that separates the high prevalence buildings from the low prevalence buildings was a more frequent occurrence or a higher concentration of compounds with shorter retention time in the high prevalence buildings. Elevated relative humidity in supply and room air and higher levels of total volatile organic compounds in outdoor and supply air were more common in high prevalence buildings. Ten building variables also contributed to the separation of the two classes of low and high prevalence buildings.     

Comfort in urban spaces: defining the boundaries of outdoor thermal comfort for the tropical urban environments

With rapid urbanisation, often without climate responsive guidelines, cities in the Tropics are progressively falling short of sustaining outdoor life. While at the building level such inadvertent climatic modifications have lead to a remarkable demand on the urban energy resources. The rationale for developing a thermally desirable outdoor ambience in such a context has implications that go beyond the requisites of urban design and well into the design of buildings. In order to re-establish and sustain life outdoors it is important that we try to make urban spaces comfortable as far as the ambient climate permits. In order to ascertain conditions of comfort for outdoor spaces we need to define comfort for outdoors. This paper presents findings on outdoor comfort based on field investigations conducted in Dhaka, a city in the wet-Tropics. Findings from a survey conducted on a large number of randomly selected people from urban spaces are presented. The findings include factors affecting comfort outdoors for Dhaka and a comfort regime based on environmental parameters for urban outdoors is presented. Interestingly, comfortable ambient climate leads to comfortable indoor environment particularly with regard to free running buildings. With regard to mechanically controlled indoor environments a comfortable outdoor produces lesser strain on energy environment relationship. By defining conditions of comfort for outdoor environments an important step towards achieving sustainability of our urban environments can be made.     

Outdoor ventilation performance of various configurations of a layout of two adjacent buildings under isothermal conditions

This paper explores the pedestrian-level wind environment around two buildings of unequal heights for the effects of ratio of height of upwind building to that of downwind building, referred to as buildings height ratio, spacing distance between the buildings, and direction of ambient wind, on the outdoor air ventilation. The objective is to propose appropriate spacing distances for various configurations of this type of buildings layout in a suburban area of Kuala Lumpur, which would enable harnessing the full ventilation potential of the local wind conditions. A three-dimensional numerical technique employing computational fluid dynamics simulation of continuity and Reynolds-Averaged Navier-Stokes equations was used to study the turbulent flow field around the full-scale sizes of the buildings. Results indicate the influence of spacing distance between buildings, relative heights of the buildings and direction of ambient wind on outdoor ventilation. Results also show that 3-D turbulent flow processes such as lateral and secondary flows play significant roles in defining the wind flow pattern and ventilation availability. The perpendicular wind direction presents remarkable adverse effects compared to the inclined direction, while a higher upwind building height which would ordinarily be expected to proportionally obstruct wind flow could be of advantage, at low values of building height ratios, in enhancing outdoor ventilation. The findings established the need to give consideration to climatic factors such as wind flow and direction in planning urban cities, as it affects buildings to be situated in close proximity, especially when there is height difference.     

Mass balance modeling of building recirculation rates and filtration efficiencies effects on secondary organic aerosols derived from ozone-initiated chemistry

Recirculation of conditioned air is a common practice in regions with hot and humid climate. This is due to the need to reduce sensible and latent cooling loads in buildings. However, recirculating used indoor air may influence indoor air chemical reactions and products derived from the chemistry. Example of such products is secondary organic aerosols (SOA) derived from ozone initiated indoor chemistry. This present study was conducted using mass balance model to examine the impacts of four recirculation rates on ozone (of outdoor origin) and SOA derived from the ozone initiated indoor chemistry. At steady-states, it was observed that the higher the recirculation rate, the lower the ozone and SOA concentration for all modeled scenarios. At steady-state, outdoor to indoor transport of ozone, indoor ozone and SOA concentrations were found to increase with increasing outdoor ozone levels. Increase in ventilation rate was found to increase outdoor to indoor transport of ozone and steady-state indoor ozone concentration. However, higher ventilation rate resulted in lower SOA concentration at steady-state. Increasing ozone filtration efficiency of activated carbon (AC) filter was found to be effective in reducing indoor ozone and SOA concentrations. This study is relevant to building sustainability in terms of health and comfort of building occupants.     

谈用强化的设计和完善的设施提升建筑品质

从设计方面入手,对住宅的通用设计作了概述,就如何强化建筑功能进行了探讨,从无障碍通道、安全保障设施、室外配套设施等方面阐述了建筑功能的完善程度,并指出加强房屋设施建设,有效地从“量”到“质”的方面提升建筑品质是新时期建筑可持续发展的目标。     

Evaluation of cooling effects: outdoor water mist fan

Evaporative spray cooling systems can be used to provide thermal relief on hot days, even in a subtropical climate such as in Japan. An experiment combining a water mist spray with a fan was conducted to cool an outdoor space and ascertain the comfort of 141 participants on hot summer days. Each participant was surveyed for ‘thermal sensation', ‘general comfort' and ‘feeling of wettedness' and skin temperature was measured before and after entering a mist. To characterize more directly the cooling effect of this particular mist system, a dry silicone rubber skin analogue including embedded heat flux sensors was heated to near-body temperature to measure the near-surface heat flux due to natural convection, forced convection by the fan alone, and the fan and mist together. It was found that the cooling effect of the mist and fan combination is highly efficient and easily exceeds the thermal load of pedestrians, yielding nearly instant decreases in skin temperature. Such outdoor technology has potential to reduce heat stress and discomfort, particularly at large outdoor events and festivals. It could also reduce the required cooling loads within individual buildings by providing inhabitants with thermal relief outdoors.     

On the flight paths of metal particles and embers generated by power lines in high winds-a potential source of wildland fires

In dry grasslands, dangerous wildfires are of particular concern during hot, dry seasons in regions encountering high winds. It is possible that such winds can cause power cables to come close enough together to arc or collide with trees, and produce metal sparks or burning embers which can be carried by the wind and land in adjacent areas of dry vegetation. A major issue is whether or not such possibly generated particles can initiate a brush or grass fire. In this work, a predictive, numerical model is used to calculate trajectories, combustion rates, and lifetimes of metal particles and burning embers of different sizes for various wind conditions and terrain. Three distinct cases are studied: (1) hot particles produced by arcing copper power lines; (2) burning sparks produced by arcing aluminum power lines; and (3) burning embers produced by the collision of high voltage power lines with surrounding trees. The results show that for the same wind conditions, the distances reached by firebrands are the greatest, followed by aluminum and copper. Large aluminum sparks (e.g. 1·5 mm diameter) that do not burn up in flight travel farther than copper particles of the same size. Since copper particles do not emerge burning, they immediately cool down in flight, as they are carried away by the wind. Nonetheless, with a slightly larger heat capacity than that of aluminum (and non-regressing size), a copper particle can bring with it a significant amount of heat into its area of impact. Although smaller aluminum particles can burn out while in flight, larger aluminum particles can land while still burning. Burning embers or firebrands burn heterogeneously and are not susceptible to high Re extinction due to flame blow-off. Larger embers can land still burning; however, they may carry less heat than their metal counterparts.     

Optimizing energy efficiency and occupant comfort with climate specific design of the building

Designing energy efficient and comfortable buildings requires harmonizing the complex interactions of architecture, construction and building service engineering. The building envelope has a particular importance, since it integrates many functions and has direct influence on indoor climate. Focusing on satisfaction of the user means that the indoor climate is a key for a holistic design approach. Only a satisfied user will not intervene with the designed energy concept or the indoor climate control; dissatisfaction results in multiple system interventions which may cause waste of energy and sometimes even damage to building envelope components. Satisfaction with the indoor environment also increases working productivity or enables effective recreation of residents.The paper deals with international research activities in the field of climate specific building design. Various comfort and energy monitoring surveys of office buildings as well as residential buildings provide substantial information about the occupants' behavior and their needs during specific situations under different outdoor climates. This information allows summarizing basic climate dependent design principles which architects should keep in mind during the early stages of the design process. It also helps to develop strategies aiming at reducing building energy demand and at the same time consider comfort aspects. The second part of this paper demonstrates application of the climate dependent design principles in a housing project in Dubai.     

Large scale studies of development of snowdrifts around buildings

Snowdrift formation around buildings should be considered in snowy and windy areas to ensure proper accessibility and safety of buildings. Tools to model snow accumulation include wind tunnels and numerical simulation. These tools need to be carefully validated before they can be used for planning purposes. Important understanding for use in such validation is gathered in outdoor full-scale experiments. This study presents snowdrift accumulation data for two building geometries in two wind episodes. The effect of different wind velocities and snowdrifting intensities is documented. The rate of deposition of a leeward snowdrift was sensitive to the vertical snow concentration profile in that considerably more snow was deposited in such snowdrifts during wind episodes with higher transport rate from suspension mode. The deposition rate of lateral and upwind snowdrifts seems to be dependent on the presence of already deposited snowdrifts. Existing snowdrifts seem to smoothen the wind pattern around a building increasing the shear stress on the ground and decreasing the deposition rate.     

A new damage index for RC buildings based on variations of nonlinear fundamental period

Many vital reinforced concrete (RC) buildings experience moderate or severe earthquakes in their lifetime because they are located in hazardous areas. However, their importance cause to be evaluated by different types of damage functions. In these procedures, structures are usually modelled. These models neither correctly display the effects of the cracks that emerge and plastic hinges nor precisely consider the effects of asymmetric configuration and infill panels. Furthermore, the actual nonlinear dynamic behaviour of existing buildings could be evaluated by assessing nonlinear dynamic characteristics such as the fundamental period. These dynamic characteristics, which are obtained by some field tests such as forced and/or ambient vibration methods, comprise the aforementioned effects. This paper offers a damage index (pattern) for seismic damage assessment of RC buildings based on the variation of the nonlinear fundamental period, which is obtained by field tests. Finally, the seismic situation of existing RC buildings that have experienced an earthquake is precisely and expeditiously assessed by this new damage index. Copyright © 2010 John Wiley & Sons, Ltd.     

基于室外热舒适的寒地教学组团形态设计策略

立足寒地城乡地域特征,修正室外热舒适预测指标,分析寒地高校教学楼组团形态对室外热舒适的影响并提出 优化设计策略,改善寒地室外热舒适性能。基于寒地校园热环境实测数据修正室外热舒适预测指标,通过模拟实验提 出基于室外热舒适的组团形态设计策略。当D/H=2.50 时,教学楼组团室外热舒适和空间感受较好;L 型围合式和三 面围合式是兼顾室外热舒适、节能和空间需求的较优组团形式。室外热舒适评价指标需结合地域特征进行修正,设计 者可通过优化教学楼组团形态改善寒地高校室外热舒适水平。     

Sick Building Syndrome (SBS) in Office Workers and Facial Skin Symptoms among VDT-Workers in Relation to Building and Room Characteristics: Two Case-Referent Studies

In two case-referent studies the associations between questionnaire symptom reports, expressed as SBS (Sick Building Syndrome) in office workers or facial skin symptoms among VDT-workers, and physical data from offices in 160 buildings were investigated. The results show that low outdoor airflow rate and presence of certain pollution sources, such as copying machines, tended to be associated with an elevated prevalence of SBS. Buildings built or remodeled between 1977 and 1986, low-rise buildings with a horizontal roof and a foundation of the type “concrete slab on the ground”, as well as rooms with flourescent tube lighting with metal shields were also associated with higher SBS risks. A number of factors were associated with an overrepresentation of skin symptoms among VDT-workers such as type of foundation (concrete slab on the ground and crawlspace), the frequency of floor cleaning and type of lighting (fluorescent tubes with glass/plastic shields). It has not been possible to establish conclusive explanations for these associations. The difference in associations between building factors and S B S, and between building factors and skin symptoms among VD Tworkers points to different etiologies.