一种适用于小城镇住区开发的模式——俄勒冈试验的借鉴

由于中国的经济飞速发展,小城镇的建造速度也快得惊人,发展的现状总是带给我们千镇一面的印象。本文主要是通过对全国各气候分区的小城镇住宅现状进行大量的实态调研和分析,以《俄勒冈试验》为引导,探讨一种适用于小城镇的公众参与的住区开发模式,希望引起设计者们对城镇化住区开发过程中的小城镇特色发展的重视,并努力创造出适合于小城镇住区发展的“有机秩序”。     

Selecting optimal monitoring site locations for peak ambient particulate material concentrations using the MM5-CAMx4 numerical modelling system

Installation of temporary or long term monitoring sites is expensive, so it is important to rationally identify potential locations that will achieve the requirements of regional air quality management strategies. A simple, but effective, numerical approach to selecting ambient particulate matter (PM) monitoring site locations has therefore been developed using the MM5-CAMx4 air pollution dispersion modelling system. A new method, ‘site efficiency,’ was developed to assess the ability of any monitoring site to provide peak ambient air pollution concentrations that are representative of the urban area. ‘Site efficiency’ varies from 0 to 100%, with the latter representing the most representative site location for monitoring peak PM concentrations. Four heavy pollution episodes in Christchurch (New Zealand) during winter 2005, representing 4 different aerosol dispersion patterns, were used to develop and test this site assessment technique. Evaluation of the efficiency of monitoring sites was undertaken for night and morning aerosol peaks for 4 different particulate material (PM) spatial patterns. The results demonstrate that the existing long term monitoring site at Coles Place is quite well located, with a site efficiency value of 57.8%. A temporary ambient PM monitoring site (operating during winter 2006) showed a lower ability to capture night and morning peak aerosol concentrations. Evaluation of multiple site locations used during an extensive field campaign in Christchurch (New Zealand) in 2000 indicated that the maximum efficiency achieved by any site in the city would be 60-65%, while the efficiency of a virtual background site is calculated to be about 7%. This method of assessing the appropriateness of any potential monitoring site can be used to optimize monitoring site locations for any air pollution measurement programme.     

藏区中心城市的演变及格局研究

以山南诸城与拉萨、日喀则、江孜为对象,分析藏区历史上中心城市演变的过程及规律;从藏区自然条件、统治制度、宗教制度和政教合一制度等方面剖析藏区中心城市格局形成与发展的内在原因,揭示出藏区中心城市以宗山和寺庙为中心发展的特征;结合当前快速城市化背景下的城市发展,针对历史格局的保护提出针对性意见。     

政府投资项目管理模式发展研究

结合我国政府投资项目管理模式的改革实践，介绍了我国目前政府投资项目管理模式的试行——代建制，比较了代建制与传统管理模式，借鉴了国外先进的政府投资项目管理经验，对我国的政府投资项目管理模式进行了展望。     

新型住区规划理念探索——以常熟市新市区滨江花园规划为例

传统的行列式及围合式的建筑布局模式已不再适应住区的发展及人的行为模式的需求.常熟市新市区滨江花园规划采用自由式住宅布局,形成带状公共空间,利用建筑与太阳方位角、风向夹角的关系改善住区微气候,并结合住区规划结构,形成多功能、人性化的网状交通结构.     

螺旋升流式反应器的流态特性及流动模型研究

通过示踪试验以及计算流体力学软件Phoenics3．6对SUFR系统单元反应器的流态特性以及流动模型进行了研究。结果表明，SUFR反应器兼有推流与全混流的特点；SUFR单元反应器内的水流以螺旋方式行进，有助于反应器形成推流特征；SUFR单元反应器内的流动模型可以看作8个单元反应器串联而成，其中推流单元反应器与全混流反应器间隔排列，推流流态的容积占有率约为63％，其推流特征较为明显。     

东天山赤湖地区原生晕异常结构特征对寻找斑岩型铜钼矿床的指示意义

赤湖铜钼矿是东天山地区典型的斑岩型铜钼矿床,赤湖地区地表原生晕异常规律的研究表明赤湖及赤湖东地区地表原生晕异常分布特征符合斑岩型铜钼矿的矿致异常结构,即由矿体(矿化体)引起的成矿元素Cu、Mo异常出现在As、Sb、Au、Ag、Pb、Bi等元素异常中相对弱异常部位,从而构成内部为Cu、Mo,外部为As、Sb、Au、Ag、Pb、Bi等的"致矿异常结构"。这一异常结构特征实际上是斑岩型矿床"原生晕"在元素分带上的反映,该原生晕异常特征显示赤湖东地区同样具有较好的斑岩型铜钼矿找矿前景。     

改革城乡行政管理体制促进城镇化的健康发展

中国的城乡管理体制经历了城乡不分、城乡分离、城乡合一三个发展阶段。为了克服长期以来形成的条块分割的弊端,1980年代初开始实行城乡合一体制。20多年的实践证明,城乡合一体制是计划经济体制下思维模式的产物,相应的市领导县体制、整县改市模式已不适应市场经济发展的需要。借鉴国际上通行的城乡分治的成功经验,全面改革行政区划,理顺城乡管理体制,构建跨行政区协调合作机制,是促进城镇化健康发展的迫切要求。     

Effect of feeding pattern and storage on the sludge settleability under aerobic conditions

The selection of filamentous bacteria is often assumed to be associated with specific microbial properties such as growth rate, substrate uptake rate, substrate affinity and potential for substrate storage. In this study we aimed to verify some of these factors. Sequencing batch reactor (SBR) systems were used to scale-down aerobic activated sludge systems with an aerobic selector. Adding acetate in different aerobic feeding periods allowed us to simulate a variable relative size of aerobic selector with different bulk liquid substrate concentrations. The experiments showed that as expected, the aerobic fill time ratio (FTR(ox)) and the corresponding feast period, which can be assumed similar to contact time in an aerobic selector, had a strong effect on the sludge settleability. Promoting a strong substrate gradient in the SBR (FTR(ox)<5.4%) resulted in good sludge settleability (SVI<120mLg(-1)). Whenever acetate was added in a limiting rate (FTR(ox)>6.2%), a condition in which the acetate concentration in the reactor was always very low, the sludge settleability decreased (SVI>150mLg(-1)). Sludge settleability could be improved by changing the feeding strategy to a pulse feed. The maximum specific acetate uptake rate and poly beta-hydroxybutyrate (PHB) production rate of bad settling sludge, including bulking sludge, was similar to well-settling sludge, which is not in accordance with the general assumptions that well settling sludge have a higher maximal substrate uptake rate and better storage capacities. An alternative hypothesis for the development of filamentous structures in biological flocs has been formulated. It is hypothesized that bulking sludge originates from the presence of substrate gradients in sludge aggregates. Whereas at low bulk liquid substrate concentration filamentous bacteria give easier access to the substrate at the outside of the flocs and thereby proliferate, at high bulk liquid substrate concentration there is no substrate advantage for filamentous organisms and smooth bacterial structures predominate. In this hypothesis there is no need for an intrinsic difference in kinetic parameters between floc and filamentous bacteria. Where presence of filamentous bacteria is related to process conditions, the presence of a specific filament is likely due to presence of a specific limiting substrate.     

圩-垛田景观格局下的“水-田-村”布局模式

江苏省兴化地区位于里下河平原腹部的低洼地带,为万水交汇之地,其极具浓郁地域色彩的圩–垛田景观近年来受到众多学者的广泛关注。在区域尺度下,从水文环境变迁和人居环境建设两方面,归纳兴化地区圩–垛田景观发展的演变动力;在市域尺度下,分析兴化地区水利系统、农业开垦及聚落布局的地带特征。从形态学角度,研究兴化地区由东至西,自然地势不断降低、水网逐渐稠密、土地肌理愈发破碎,农田形态发育与聚落形态发展之间的内在关系,以及圩–垛田景观格局下,兴化地区独有的“水–田–村”布局模式。圩–垛田景观的形成是千百年来水与土地不断分解与整合后的结果,圩–垛田景观格局的发展和演变展示了兴化地区传统人居环境营建与自然系统之间相互选择、相互适应的过程,显示了劳动人民治水、农耕和营居的古老智慧。