幽默小故事

<正>The Swimmer The teacher told the class the story of a man who swam a river three times before breakfast.Johnny laughed."Do you doubt1that a good swimmer could do that?"asked the teacher."No,sir,"answered Johnny,"but I wonder why he did not swim it four times and get back to the side where his clothes were."     

Spatial practice,conceived space and lived space: Hong Kong’s ‘Piers saga’ through the Lefebvrian lens

By applying the Lefebvrian lens, this paper tries to understand why unlike previous similar cases, the latest removal of the Star Ferry and Queen’s Pier was so controversial. To Lefebvre, embedded in ‘spatial practices’ that ‘secrete’ a place are two contradicting spaces: ‘conceived spaces’ produced by planners to create exchange values and ‘lived spaces’ appropriated by citizens for use values. Applying Lefebvre’s framework to examine the ‘Piers saga’, it is found that the pre‐Second World War (WWII) piers were ‘conceived’ by spatial practices of a colonial and racially segregated trading enclave. The public space in the commercial heart that housed the previous generations of piers was not accessible to the Chinese community, thus denying them opportunities to appropriate them and turn them into ‘lived’ spaces. It was only after WWII when the Government carried out further reclamation to meet the needs of an industrializing economy that inclusive public spaces were conceived in the commercial heart, enabling the general public to ‘appropriate’ them as ‘lived’ space. When the Government planned to remove this very first ‘lived’ space in the political and economic heart of the city to conceive further reclamation for the restructuring economy, the more enlightened citizens were determined to defend it.     

A comparative performance analysis of solar heat exchangers for solar hot water application under controlled laboratory conditions

The paper presents the experimental performance evaluation of a novel retrofit heat exchanger (‘SolaPlug’) developed for solar hot water storage applications. The performance of this system was compared with a traditional dual-coil (‘Coil’) solar cylinder under controlled operating conditions. The tests were conducted under different solar-simulated conditions with a 30 and 20 evacuated tube collector. The results showed that after a 6-h test period, the average water temperatures within the store for the ‘SolaPlug’ system were 58.8°C and 40.5°C at 860 and 459?W?m^?2, respectively, and for the ‘Coil’ system were 60.5°C and 40.6°C when a 30 tube collector was used. The performance of the ‘SolaPlug’ system was marginally better than the ‘Coil’ system under the low solar input condition. Under high insolation condition, the overall ‘SolaPlug’ system efficiency was found to be 4.3% lower than that of the ‘Coil’ system. The ‘SolaPlug’ heat exchanger rating was 222?W?K^?1.     

盾构隧道下穿既有桥桩工程的保护方案研究

郑州市轨道交通1号线某盾构区间下穿某人行天桥桩基础,人行天桥为桩柱式基础,工程场区地质为富水砂层。受周边环境限制,人行天桥桩基础无进行桩基托换的条件,本文针对本工程的特点提出了"顶托+加固"法对人行天桥进行保护,以保证盾构隧道施工期间人行天桥的营运安全及盾构隧道的施工安全。为检校保护方案的加固效果,本文对加固方案进行了数值模拟分析。模拟结果显示,盾构隧道近距离下穿桥梁桩基础将使桥梁桩产生较大变形,严重影响桥梁的使用安全;在无条件进行桥梁桩基托换作业的情况下,对桥梁采取上部结构顶托+桩基础周围注浆的保护方案可显著改善盾构隧道的施工条件。     

Ian McHarg’s Ecological Planning in The Woodlands,Texas: Lessons Learned after Four Decades

The Woodlands, Texas, is well known as a new town development (29,000 acres) that followed Ian McHarg’s ecological planning approach. Primarily by literature review, this paper indicated that early development that followed McHarg’s approach has met the original planning goals to preserve the forest environment and to minimize the development impacts on watershed hydrology. McHarg’s approach was largely abandoned after the ownership change in 1997. Barriers came from each side of the development: homeowner (demand), developer (provider), designer (professional service) and government (policy-maker). The Woodlands’ environmental planning success in early development was also attributed to developer George Mitchell’s personal commitment and financial support, the US Housing and Urban Development’s $50 million loan, and the relatively flexible planning system in the 1970s. However, in the current planning and economic systems, it would be a hard undertaking to replicate McHarg’s ecological planning approach at this scale.     

Lifeworld strategies of women who find themselves homeless in South Africa

This article explores some of the connections and tensions between central and local government as exhibited in the British plan-making process. Research into this topic draws on case studies of the plan-writing process in two locales and analyses these from an actor-network perspective. In particular, the processes of constituting both ‘central government’ and more ‘local’ networks are explored through comparing the two cases. Whilst it was found that a ‘central government’ network ordered much of the plan-writing activities in both cases, significant room for manoeuvre was created for ‘councils’ and ‘planning officers’ in particular. It is concluded, however, that this room for manoeuvre was not fully explored by these groups, and instead established procedures were replicated.     

A New Interpretation in Urban Form of the Wards of Tang Chang’an

By comparing the gridiron plans of ancient western cities with that of Tang Chang’an in the same scale,the authors find that a residential ward of Tang Chang’an was about the same size as an ancient western city.Thus the paper puts forward a hypothesis that Tang Chang’an was not a single city,but a cluster of hundreds of small towns with rigid layout.This theory is then proved by comparing a ward of Tang Chang’an with a typical small town in China from the perspectives of town scale,spatial layout,residential density,and land-use.The authors further explain the main cause for this unique urban form of Tang Chang’an,which was the compulsory migration policy.     

深基坑开挖与邻近隧道相互影响的分析

采用三维快速拉格朗日方法(FLAC3D)模拟软土地区深基坑的分步开挖和支护过程。根据隧道与基坑不同位置关系,分为"紧贴型"和"浅埋型"两类、共7种工况,分析基坑分步开挖对邻近地铁隧道变形的影响以及隧道对基坑连续墙变形和墙后地表位移的影响。数值分析土体采用修正剑桥模型,考虑了连续墙和土体的接触滑移作用。数值分析结果发现隧道变形大小与基坑距离关系并不完全单调,隧道的存在对基坑墙后土体有明显的"加筋效应"。     

Mastering the urbanization process. The urban questions of engineer August Mennes in the Antwerp agglomeration

Processes of urban expansion at the turn of the twentieth century have generally been described in terms of ‘regional planning’. However, in the Belgian context, and in Antwerp more specifically, the concept of the ‘agglomeration’ was put to the fore rather than the ‘region’, and ‘urbanization’ was a more common practice than ‘planning’. This paper shows how a ‘programme of urbanization’ centred on pertinent ‘urban questions’ shaped the contours of the Antwerp Agglomeration. In adopting this perspective of ‘programmatic urbanization’, the paper seeks to place the development of Antwerp extra muros within a different lineage, outside of the quest for comprehensive planning. Recomposing an eclectic catalogue of five pertinent ‘urban questions’, this paper investigates how and to which extent the Study Committee for the development of the Antwerp Agglomeration and its prominent engineer August Mennes, tried to master the urbanization process as it unfolded. Urbanization, then, is framed as a collective practice that generates positive agglomeration effects and surplus values that could not have been produced by individual actors. As such, the paper expands the understanding of urbanization from a random process of capital accumulation to a project that includes the building of social and cultural capital.