现代城市设计研究的历史进程及其特征

本文根据当前国内城市发展的客观现实,从城市设计研究的核心问题出发,以城市设计研究近60年来的发展历程为框架,对当代城市设计的内涵、外延、研究目标、研究手段和实施机制等进行了概要性的论述。     

油炸过程中淀粉的颗粒形貌、结晶度与热力学特性变化

采用深层油炸模型,利用扫描电镜分析、差示扫描量热分析和x-射线衍射分析等现代仪器分析方法,研究了油炸过程中淀粉的颗粒形貌、结晶结构和热力学性质的变化规律。SEM分析表明,随着油炸温度的增加和时间的延长,淀粉颗粒形态发生了明显变化。在初炸时,淀粉颗粒逐渐膨胀;随着复炸的进行,淀粉颗粒崩解,相互靠近,融合形成大块的团聚体。同时,也导致了淀粉的碘蓝值逐渐减少。DSC测定结果表明,当初炸25 s和50 s时,淀粉分子发生了一定程度的糊化作用;当初炸75 s和100 s时,淀粉完全糊化;当复炸超过20 s时,淀粉在油炸过程中形成了淀粉-脂质复合物。X-射线衍射分析显示,当初炸超过75 s后,淀粉的结晶度均高于初炸25 s淀粉的结晶度;复炸40 s后淀粉的结晶度随油炸时间的延长而降低。     

黄河下游游荡性河段清水下泄期河道断面形态的调整过程

为预测小浪底水库运用后下游河道断面形态调整趋势，以1960～1964年三门峡水库清水下泄期定位观测资料为基础，结合物理模型试验，研究了清水下泄过程中黄河下游游荡性典型河段河势变化趋势、河道横断面形态的调整过程及其模式。研究表明，若缺乏较完善的整治工程体系的约束，尽管在上游水库建成运用后的清水下泄初期，河势会趋于相对归顺，但冲刷后期将会出现明显的坐湾摆动现象，游荡性并不能改变；横断面调整过程的模式基本上为“下切+展宽—下切—下切+局部河段展宽”；为利于河槽形成窄深断面，上游水库下泄流量不宜过小且历时不能过长，同时，流量变幅不宜过大。     

An analysis of the influence of urban form on energy consumption by individual consumption behaviors from a microeconomic viewpoint

Using 1997 personal trip survey (PTS) data in the Kumamoto metropolitan area, this paper examined the influence of urban form on energy consumption through an energy estimation model from a microeconomic perspective. As all goods and service are assumed to satisfy the need of people, we estimated the individual energy consumption based on the demand of goods, which is explained by a utility maximization problem constrained by income. 52.84 GJ of energy is estimated for one person one year in Kumamoto metropolitan area. 19.57% of energy is used for mobility goods. A spatial regression was performed to analyze the relationship between energy efficiency and urban form characteristics in terms of density, diversity, and accessibility. The results of regression analysis show that employment density, ratio of employee in retail department, transit fare, and distance to city center are the most influential factors of energy efficiency. Findings suggest compact development and integrated policies for increasing employment density, especially, employment proportion of local residents are suggested. Moreover, measures to improve the attractiveness of mass transit should be encouraged to increase energy efficiency in Kumamoto.     

Energy requirements of consumption: Urban form,climatic and socio-economic factors,rebounds and their policy implications

Household consumption requires energy to be used at all stages of the economic process, thereby directly and indirectly leading to environmental impacts across the entire production chain. The levels, structure and determinants of energy requirements of household consumption therefore constitute an important avenue of research. Incorporating the full upstream requirements into the analysis helps to avoid simplistic conclusions which would actually only imply shifts between consumption categories without taking the economy wide effects into account. This paper presents the investigation of the direct and indirect primary energy requirements of Australian households, contrasting urban, suburban and rural consumption patterns as well as inter- and intra-regional levels of inequality in energy requirements. Furthermore the spatial and socio-economic drivers of energy consumption for different categories of energy requirements are identified and quantified. Conclusions regarding the relationships between energy requirements, household characteristics, urban form and urbanization processes are drawn and the respective policy implications are explored.     

城市排水系统集成模拟研究进展

在回顾城市排水系统集成模拟研究发展和现状的基础上,结合可持续性城市排水系统理论,分析了现阶段城市排水系统集成模拟研究的局限和面临的问题。为了适应城市排水系统结构和功能的演变,实现系统的可持续性,今后城市排水系统集成模拟的研究应当完善对系统结构的描述,在集成模拟的过程中考虑不确定性因素对系统的影响,并构建高效能计算平台,解决城市排水系统大规模计算问题。     

燕麦β-葡聚糖的分子链高级结构及溶液行为研究

采用聚酰胺柱层析和乙醇多次沉淀的方法分离纯化,获得燕麦β-葡聚糖主要组分Oglu-1,经HPLC、UV、IR、1HNMR和13CNMR证实Oglu-1为β-D-均聚线型葡聚糖,糖基之间通过β-D-(1→4)和(1→3)糖苷键连接,二者之比为2.1:1,激光光散射测定多糖的相对分子质量为4.49 × 105.通过测定特性黏度和激光光散射分析建立了Oglu-1水溶液中的Mark-Houwink方程([η]=0.161Mw0.585)和均方根旋转半径-相对分子质量关系模型,证实了Oglu-1分子在溶液中的形态为柔顺性线型高分子链;利用AFM直接观测到Oglu-1是分子链长度约250nm,宽度约为5～10nm,高2～3nm的无支链线型柔顺高分子; CD分析表明,多糖分子量、多糖浓度及pH值、温度等环境因素的改变均可导致溶液中燕麦β-葡聚糖立体构象和非对称性的变化.     

河流地貌特征多样性的保护

河流作为一个有机的生态整体与生物多样性共存,构成了一种相互耦合的生态系统.河流丰富的地貌形态为流域生物多样性创造了很好的条件,是生物群落多样性的基础.现代水利工程应该克服对河流形态的多样化重视不足和忽略生态环境的缺陷,在治河过程中,尊重河流流域的自然状况,尊重各类生物的生存权利;认识并遵循河流地貌演变的客观规律,逐步完善河流生态工程建设措施;保护河流地貌形态特征多样性,为生物的生长、繁殖、栖息提供条件,达到保护河流生态系统多样性,维持河流系统健康的目的.     

典型河网形态特征与分布

河流网络系统是地表流水地貌的重要组成部分,具有开放性、随机性、自相似性等特点。不同地区具有其独特的自然环境条件,从而形成了各种外观上迥然不同的河网形态。本文以卫星地图上的平面拓扑结构为依据,划分了3种典型河网形态:羽状河网、叶状河网和枝状河网,并在Horton定律的基础上对这3种典型河网形态的平均Horton比和流域外型参数进行了定量统计分析。此外,进行了中国大陆范围内各种典型河网形态的分布研究,从而探讨了影响河网形态产生的环境条件。     

城市小区雨洪利用系统降雨产流规律研究

以北京市某建有雨洪利用系统的楼房小区为例,基于实测数据,对研究区内的降雨量、产流量、回灌量及相应过程进行统计与回归分析,得出老旧居民区雨洪利用系统建成后的降雨-产流、降雨-回灌之间的规律.研究结果可为类似小区雨洪利用系统建设提供技术支持和关键参数.