改革开放后广州市居住区演进特征分析

改革开放后,广州市居住区建设布局在各方面呈现出新的特点:居住区的分布由中心城区向边缘郊区转移;居住区规模扩大,容积率下降;居住区布局形态从“邻里街坊”型趋于自然流线型;公共设施布局由计划配置到需求调控,由以商业为主到商业、娱乐、教育、康体并重;交通系统由以车为主到以人为本,由单一自行车停放处到多层次、多分工停车场;绿地景观由人工点缀型到自然镶嵌型。     

Determination of nitrite ion in waste and treated waters by resonance Raman spectrometry

The determination of NO₂⁻ ion in aqueous solutions by resonance Raman spectrometry has been examined in view of the application of the method to an optimum control of waste water treatment. In order to induce the resonance Raman effect, NO₂⁻ has been transformed into a colored product (azo dye) by a chemical reaction. From the resonance Raman spectra of the resultant colored product, it has been clarified that the detection limit of NO₂⁻ by this method is about 0.5 ppb, an order of magnitude lower than that of usual colorimetry, and that the analytical curve can be fitted well enough to a straight line in the concentration range below 140 ppb. The sensitivity of this method is regulated by the background intensities of sample solutions, and it has been shown that in the present case, the addition of sodium thiocyanate brings about a marked decrease of background intensities. Moreover, it has been proved that the application of the method developed here to practical waste and treated water samples produces appropriate results. Finally, the excellent selectivity of this method has been demonstrated, and the process of simultaneous determination of NO₂⁻ and NO₃⁻ has been proposed.     

The Unfulfilled Wider Implications of Vernacular Architecture Studies

Abstract

It will be generally agreed that in the last forty years the study of vernacular architecture, largely by members of this Group, has produced a vast amount of information, both regional and national, on all aspects of the subject. House-types have been classified, methods of construction analysed, and the usage of rooms in a house identified. In short, the subject has been brought under control. So much so that one distinguished scholar has doubted whether there is much more to be discovered, and another has told me that the seam is worked out and all that remains is to seal off the pit-head. I disagree with that view and I don't go all the way with the other, for I think that the recent discovery of long-houses in the Vale of York shows that there is still a lot of good coal down the mine.

Nevertheless, a point is being made, for it has to be recognised that despite all the accumulation of knowledge the relationship between our interests and wider themes has made little progress. The time has come to remedy this separation and I want to try to dispel some of the mists which, in my opinion, have obscured the wider implications of our results.     

The residual shear strength of Neogene marly soils in the Granada and Guadix basins, southeastern Spain

The analysis of samples taken from the Neogene and Cretaceous marly series of the Granada and Guadix basins (south east Spain) shows an inverse correlation between the clay content and the residual friction angle. It has been verified that the carbonate fraction of the soil has a significant influence on the residual friction angle; there is a threshold of 25% carbonates, above which the value of φ′_r increases from 20 to 30°. It has been proved that the presence of smectitic clay as the dominant constituent produces a low value of residual shear strength, associated with high fragility in unconsolidated undrained tests. It has been proved that the degree of compaction of the soil and therefore the initial porosity, has a direct influence on the effective residual friction angle (φ′_r). Received: 2 February 1999 · Accepted: 31 March 1999     

A safety factor for LC50 values allowing for differences in sensitivity among species

A safety factor has been derived that can be applied to the mean LC₅₀ value of several test species for a particular toxic compound, for the purpose of arriving at what has been called a hazardous concentration for sensitive species. The application of this factor should provide limited protection to a certain number of species in a relevant community. The derivation is based on the assumption that the LC₅₀ values for both the test species and for the community species can be conceived of as independent random trials from a log-logistic distribution.The proposed hazardous concentration for sensitive species has been chosen such that the LC₅₀ value of the most sensitive species in a community of a certain number of species exceeds that concentration by a specified probability. It allows for the uncertainty in the mean and variance of the LC₅₀ values for the test species that is due to the number of test species being limited. It is possible to calculate the optimum number of species to be tested on basis of a cost-benefit analysis. Examples of the application are given.     

Are telecommuting and personal travel complements or substitutes?

Whether telecommuting and personal travel are complements or substitutes is a key question in urban policy analysis. Urban planners and policy makers have been proposing telecommuting as part of travel demand management (TDM) programs to reduce congestion. Based on small samples, several empirical studies have found that telecommuting has a substitution effect (although small) on commute travel, and have thus argued that policies promoting telecommuting might be promising in reducing travel. Using data from the 2001 and 2009 National Household Travel Surveys (NHTS), this study involves two large national samples to try to more accurately identify the impact of telecommuting on workers’ travel patterns. Through a series of empirical tests, this research investigates how telecommuting influences workers’ one-way commute trips, daily total work trips, and daily non-work trips, and tries to provide some answers to a question that has been discussed for some years—namely, whether telecommuting and personal travel are complements or substitutes. The results of these tests suggest that telecommuting has been an important factor in shaping personal travel patterns over the 2001–2009 period, and that telecommuting indeed has a complementary effect on not just workers’ one-way commute trips, but also their daily total work trips, and total non-work trips.     

Partnerships and networks: The governance of urban regeneration in Britain

Urban regeneration in Britain has often been described as being ‘market-led’. However, such a characterisation does justice neither to the complexity of urban policy over the past 25 years, nor to the changes that have taken place in the same period. Nevertheless, since the beginning of the 1980s partnership with the private sector – however the concept has been understood – has been a vital ingredient of the regeneration process. What is striking is the way that the will to involve the private sector has had a profound impact on local governance. This paper outlines the evolution of urban regeneration in the context of evolving urban policy since 1979. It traces the approach adopted by the Conservative government in the 1980s, specifically through the use of Urban Development Corporations; it examines the change of heart in the early 1990s that preceded the coming into power of a Labour administration; and it looks at the experience of urban regeneration under the leadership of Tony Blair. It explores the changing role of key actors within the process, and the way in which urban local government has responded to the evolution of national policy. The case of Sheffield is used to illustrate the general theme of changing national policy.     

People''s clothing behaviour according to external weather and indoor environment

In prehistoric times man wore furs of animals to protect himself from the cold. Successively over the centuries clothing has become also a tool to distinguish ourselves in society. Clothing has in addition an important impact on people's perception of the indoor environment.

Clothing behaviour has been analysed by investigating the external and indoor parameters that motivate people's choice of clothing. Based on two existing databases, two types of buildings have been investigated: air-conditioned and naturally ventilated (NV) buildings. The impact of outdoor temperature on people's clothing selection has been considered. The outdoor temperature at 6 a.m. seems to affect people's choice of clothes the most. Gender does not significantly affect the selection of clothing insulation.

Latitude has also been investigated and a good correlation has been found between clothing insulation and external temperature in the ranges 20°–40° and −20° to −40° for NV buildings.

Indoor air temperature does not seem to influence the clothing choice early in the morning but it does seem to influence the change of clothing during the day, if this is authorized, in workplaces in NV buildings. Such action can be termed “clothing adjustment” during the day.

Some computer simulations on a test reference year have been carried out for a typical air-conditioned office to analyse a person's comfort when wearing different clothes. It is possible to see that in air-conditioned buildings a variation of 0.1 clo is sufficient to change totally the comfort evaluation. It is evident that further studies are needed in this field.     

Both Rationed and Subsidised: Jersey's Command Economy in Housing

The bailiwick of Jersey's special constitutional position has given it the opportunity to develop its own economic, cultural and policy strategies. Becoming an off-shore tax haven, with a flat rate income tax of 20 per cent, no VAT, no inheritance tax and no capital gains tax, has brought with it the need to strictly limit residency. A key instrument in this has been housing policy and draconian measures have been introduced by the States of Jersey to ration access to housing through a complex series of stacked housing rights directly linked to residency rights. At the same time, the high cost of housing on Jersey that has resulted from economic pressures has forced the States to subsidise housing to certain categories of those who fulfil the residency requirements. This paper describes Jersey's unique and little known housing system. It is suggested that Jersey's housing policy strategy can be fruitfully understood in a broader international comparative context and in relation to other tax-havens and 'micro-states'.     

Turning brownfields into green space in the City of Toronto

Since the mid-1980s, policy makers and planners in North America and Europe have been paying significantly more attention to measures designed to foster sustainable development and improve the quality of life in urban areas. One issue that has received widespread political support has been the cleanup and redevelopment of under-utilized brownfield sites in urban areas. In Canada and the US, the focus of policy-making and redevelopment efforts has been on redeveloping brownfield sites for industrial, commercial, or residential uses that provide economic benefits through tax revenues and/or jobs. However, there has been a growing recognition among community groups and environmental organizations that brownfields hold enormous potential for “greening” city environments, through the implementation of parks, playgrounds, trails, greenways, and other open spaces. The objectives of the current research are to examine the issues, obstacles and processes involved in remediating potentially contaminated urban brownfield sites and converting them into green spaces, to identify the benefits that these green spaces can bring to the community and culture, and to understand the specific planning processes that it involves. Data for this study were collected through a review of 10 pertinent “greening” case studies and personal interviews with relevant stakeholders. Toronto’s brownfield-to-green space redevelopment experience has implications for cities across North America undergoing brownfield planning and seeking to enhance urban quality of life.     

Derivation of the exact stiffness matrix for a two-layer Timoshenko beam element with partial interaction

This paper presents the full closed-form solution of the governing equations describing the behaviour of a shear-deformable two-layer beam with partial interaction. Timoshenko’s kinematic assumptions are considered for both layers, and the shear connection is modelled through a continuous relationship between the interface shear flow and the corresponding slip. The limiting cases of perfect bond and no bond are also considered. The effect of possible transversal separation of the two members has been neglected. With the above assumptions, the present work can be considered as a significant development beyond that available from Newmark et al.’s paper [4]. The differential equations derived considering the above key assumptions have been solved in closed form, and the corresponding “exact” stiffness matrix has been derived using the standard procedure basically inspired by the well-known direct stiffness method. This “exact” stiffness matrix has been implemented in a general displacement-based finite element code, and has been used to investigate the behaviour of shear-deformable composite beams. Both a simply supported and a continuous beam are considered in order to validate the proposed model, at least within the linear range. A parametric analysis has been carried out to study the influence of both shear flexibility and partial interaction on the global behaviour of composite beams. It has been found that the effect of shear flexibility on the deflection is generally more important for composite beams characterized by substantial shear interaction.     

The ultra-modulating gas boiler as an opportunity for domestic energy saving

ABSTRACT

Domestic gas boilers on the market are able to modulate up to a modulation ratio equal to 10; in the present work the convenience of adopting modulation ratios up to 40 has been assessed. A methane condensing domestic boiler has been set up to work over the nominal modulation range up to 15, so that a consumption and efficiency experimental characterisation has been carried out and numerically extended to 40. A bin-method-based model has been implemented in order to estimate the modified boiler consumption for different scenarios. An increasing in the modulation ratio improves the overall boiler efficiency by reducing cycling losses yet rises the operating time and the electrical consumption; accordingly, in the present work a comprehensive analysis has been performed to identify optimal ‘ultra-modulating’ ratios for different climates and buildings.     

The ‘entrepreneurial turn’ and regional economic development mission of universities

In the last 20 years many research universities in the US have added regional business and economic development as a core mission to the traditional ones of instruction and scholarly research. It has been claimed by many critics, however, that this ‘entrepreneurial turn’ presents conflicts with long established academic norms, procedures, and reward systems. This paper utilizes a national survey of faculty attitudes towards academic entrepreneurship to investigate the extent to which the ‘entrepreneurial turn’ has become accepted and taken-for-granted, to identify which academic entrepreneurial activities are deemed appropriate, or legitimate, and those that are widely regarded as inappropriate, and to identify the most salient dimensions by which faculty attitudes vary. The results provide evidence that the entrepreneurial turn within research universities in the US has not yet become ‘taken-for-granted’, that the norm of open science is still widely accepted and conflicts with some academic entrepreneurship activities. There seems to be a broad—though not consensual—agreement on the boundaries of what are deemed appropriate and legitimate entrepreneurial activities that spans disciplines and across prior levels of faculty experience in academic entrepreneurship.     

The Big Society and the Conjunction of Crises: Justifying Welfare Reform and Undermining Social Housing

Abstract

The idea of the “Big Society” can be seen as culmination of a long-standing debate about the regulation of welfare. Situating the concept within governance theory, the article considers how the UK coalition government has justified a radical restructuring of welfare provision, and considers its implications for housing provision. Although drawing on earlier modernization processes, the article contends that the genesis for welfare reform was based on an analysis that the government was forced to respond to a unique conjunction of crises: in morality, the state, ideology and economics. The government has therefore embarked upon a programme, which has served to undermine the legitimacy of the social housing sector (most notably in England), with detrimental consequences for residents and raising significant dilemmas for those working in the housing sector.     

Overcladding with brickwork

Denmark has found that overcladding existing high‐rise buildings in brickwork behind new insulation has practical advantages. It has led to the development of a special wall tie for the purpose and a recommended ‘staggered’ method of working, completing one storey height at a time; this gives better control and minimises mortar droppings fouling the insulation. The technique is described here by a member of the Danish Building Research Institute.     

Questioning the “prototype dwellings” in the framework of Cyprus traditional architecture

As one of the basic narratives of culture, traditional residential architecture is an important value, indicating its relationship with its environment. Due to this, the continuity of culture in rural areas is closely related with the sustainability of traditional residential architecture. Cyprus is a Mediterranean island, which has managed to sustain her rich cultural heritage against the many economical, socio-cultural and political changes she has gone through. There is a need for new dwellings in rural areas and this demand is increasing rapidly. In these areas which are physical environments where sustainability can be maintained easily, the Social Housing Department of the North Cyprus Government has made several studies for the proposal of prototype house plans’ as a solution to the above mentioned problem of a need for housing and the prevention of migration to cities. However, upon analysing the architecture of traditional dwellings; and the life-styles of the people who live in these rural areas, it has been observed that these projects, with incomprehensible, strict and totalitarian design principles, are incompatible with local culture and conditions. It is suggested that there is a need for an appropriate environment for the continuation of the life-style that is natural to the people that live within them. On the contrary, these projects form the basis of a step towards a monotonous settlement development which does not respect either the values of traditional architecture or local identities. It is extremely important that the correct steps are taken for both the conservation of the existing physical environment and for handling the issues of new settlement developments in relation to production relationships and cultural sustainability. The main aim of this paper is to draw attention to the traditional design principles that can be re-interpreted in the proposed ‘prototyped dwellings’ in North Cyprus. In order to achieve this aim, a case study, based on observations, literature survey and site survey techniques has been carried out.     

Raines Court

Much of what has been written about the Raines Court housing project in Hackney, East London, has focused on the logistical challenges of prefabrication. Here, Jeremy Melvin also acknowledges the contribution that Allford Hall Monaghan Morris (AHMM) has made at Raines Court with a high-density scheme that makes a conscious effort to address the public realm, but also uses modular units to advance internal planning. Copyright © 2005 John Wiley & Sons, Ltd.     

Space of Risk: The Contribution of Planning Policies to Conflicts in Cities,Lessons from Nazareth

This article defines a new concept, ‘Space of risk’, as a lived space that has low levels of trust among different urban groups; where people feel vulnerable and defenseless against terrorizing, urban clashes and riots. Based on a qualitative study, the article examines this concept in the city of Nazareth, which has been in turmoil since the introduction of a plan for a plaza. The article concludes that the reasons that may strongly contribute to the production of spaces of risk are: lack of the right to the city for urban inhabitants; the hegemony of the state over the city through ‘ethnocratic’ urban policies; the hegemony of global forces and neo-liberal agendas over the locale; deficient local politics; absence of communicative planning procedures; and contradictions between planners conception of the place and the way inhabitants conceive and experience it in their daily life practices. As planning has the power of creating and triggering risks in cities, the article suggests some practical ways for planners to avoid the production of spaces of risk through new techniques of collaborative planning.     

Harakeke reinforcement of soil–cement building materials: Manufacturability and properties

Fibre from the New Zealand flax plant, Phormium tenax, or Harakeke as it is otherwise known in Maori, has been used to reinforce soil–cement composites in an attempt to improve the strength and ductility of the composite material. Previous investigations have found the interfacial bond strength between the harakeke fibre and the soil–cement matrix to be an important factor for the strength of the composite. In an effort to improve the interfacial bond strength, an enamel paint coating has been applied to the fibre surface. Fibre lengths of 70 and 85 mm have been investigated along with fibre content levels of 0.6% and 0.8% measured as a percentage of the dry mass of the soil in the composite. Significant improvement in the ductility of the soil–cement composite has been realised with the addition of the harakeke fibre-reinforcement. It has been found that the specific make-up of the composite with regard to fibre length and content is not critical for the achievement of ductility improvement. Instead, these parameters were found to be controlled more by manufacturing issues such as the workability of the composite. It was found that 85 mm represented an upper limit on fibre length for the manual mixing technique adopted, while a maximum fibre content level of 0.8% was achieved. In order to reduce manufacturing difficulties, different mixing techniques were studied. A successful tumble mixing technique has been identified which is able to improve composite uniformity and the ease of manufacture. Based on the similarity of results for the two fibre content levels investigated, it is recommended that a level of 0.6% be adopted as this both improves the ease of manufacture and minimises the amount of fibre required. When the fibre content level was dropped below 0.6%, it was found that the material exhibited a more brittle failure behaviour.