亚特兰大塔尔普蕾斯绿地，乔治亚州，美国

介绍一例面积仅0.4hm^2的城市空间绿地的设计,如何以其植物种植设计,材料选择及喷泉布局等手法应用,成功地象征着“城市绿洲”生存于现代城市大环境之中。     

边缘城市:美国城市发展的新趋势

边缘城市(edge city)是在美国郊区化过程中出现的新名词.文章表述了Garreau对边缘城市这一概念所下的定义,分析了边缘城市的产生背景和动因及其空间和产业结构.     

大高宽比方形截面高层建筑的横风向风荷载及风致响应研究

基于一栋高层建筑的刚性模型表面压力测量风洞试验数据,分析了高宽比较大且截面为方形的高层建筑横风向风效应的共同特征。得到如下结论:高层建筑横截面为方形时,其横风向风荷载主要由规则性旋涡脱落导致的尾流激励构成,为窄带随机激励;当高层建筑的高宽比较大时,基阶固有频率相对较低;当高层建筑兼具方形截面和大高宽比这两个特征时,其基阶固有频率可能接近其尾流的旋涡脱落频率,从而发生剧烈的横风向涡激共振。建筑结构截面的小幅增大可使这种剧烈的横风向涡激共振得到有效控制。上部外形的适当处理,也可能有效降低高层建筑的横风向等效风荷载。低矮群楼的出现将在一定程度上影响高层建筑的风荷载。     

城市规划管理的司法监督——基于美英日三国的制度比较

在西方民主国家制度的基本建构中,司法作为保障公民基本权利、维护社会公正公平的最后屏障,发挥着监督和制约立法与行政两大公权机构的重要作用。本文从司法与立法、司法与行政的关系的角度,对美英日三国城市规划管理的司法监督机制及其运行特征进行分析．总结其成功的经验及失败的教训。     

Validating verdancy or vacancy? The relationship of community gardens and vacant lands in the U.S.

Community gardens have gained attention and support in recent years because of a range of expected benefits and outcomes, and they are one of many examples of transformations of vacant land into green space. While the improvements to vacant or underutilized land are lauded, the practice of community gardening is underpinned by the assumption that it is a temporary practice on temporarily-available land. This assumption, which is at times implicit and at others explicit, maintains that support for community gardens—technical assistance and especially access to land—can be temporary. Through a genealogy of community garden advocacy in the U.S., we find that a dominant narrative of community gardening as a means to an end has been continuously reproduced for more than a century in large part by government agencies and philanthropic organizations. In recent decades, community gardeners have become key actors in advocacy, and although they portray gardening as a meaningful part of everyday city life, they also reproduce that narrative of temporariness by promoting it as a means to address various issues. We argue that this tension between means and ends—especially coming from community gardeners—is problematic. It is a challenge for community gardeners and the many other producers of green space on supposedly vacant land because their means-oriented discourse takes precedence in the public imagination; it perpetuates the notion that the land is ultimately still vacant.     

美国绿色建筑评价标准LEED简介

本文通过对美国绿色建筑评价标准——能源及环境设计先导(LEED)的讨论,详细介绍了其发展过程、评价体系和评价过程。     

Determinants of atmospheric mercury concentrations in Reno, Nevada, U.S.A.

Concentrations of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate-bound mercury (PBM) were measured along with ancillary variables 9 km east of downtown Reno, Nevada, U.S.A. from November 2006 through March 2009. Mean two-year (February 2007 through January 2009) GEM, GOM, and PBM concentrations were 2.0 ± 0.7 ng m^− 3 (± standard deviation), 18 ± 22 pg m^− 3, and 7 ± 7 pg m^− 3, respectively. Data collected were compared with observations made at another location just north of the city at 169 m higher elevation. At both locations higher concentrations of GEM and PBM occurred in periods with little atmospheric mixing, indicating that local sources were important for enhancing GEM and PBM concentrations in Reno above that considered continental background. Concentrations of GOM were higher (maximum of 177 pg m^− 3) during periods with higher temperature and lower dew point. Higher GOM concentrations at the higher elevation site with less urban impact relative to the valley site, along with other data trends, support the hypothesis that in northern Nevada subsiding dry air from the free troposphere is a source of GOM to the surface.     

BS5400规范中的荷载及荷载组合

结合对英国规范BS5400中有关荷载规定的理解，就对国内桥梁设计具有重大参考价值的内容，从恒载、二期恒载、活荷载、荷载组合等方面进行了介绍，对于大跨度桥梁横向的动力分析有很好的帮助。     

温州东海广场风荷载数值模拟与风洞试验研究

对温州东海广场工程这一具有较大截面长宽比的复杂高层建筑进行了风荷载数值模拟和风洞试验研究。首先,在工程预研阶段用数值模拟方法计算得到了主要风向角工况下结构表面的平均风荷载分布。然后,参考数值模拟计算结果,引导进行风荷载风洞试验的测点布置方案,进行风洞模拟试验研究。最后,将数值计算结果和风洞试验数据进行了对比,显示数值模拟计算和风洞试验结果两者吻合较好。研究表明,综合采用数值模拟和风洞试验研究,可以较为准确地把握复杂建筑结构的风荷载分布,这种方法有助于提高结构抗风研究的水平。     

Uncertainties in critical loads and target loads of sulphur and nitrogen for European forests: Analysis and quantification

An analysis of the uncertainties in critical loads and target loads of sulphur (S) and nitrogen (N) for 182 European forest soils was carried out using the Very Simple Dynamic (VSD) model. The VSD model was calibrated with a Bayesian approach using prior probability functions for model parameters based on literature data, data from 200 Dutch forest sites and from simulated denitrification rates from a detailed ecosystem model. The calibration strongly improved the fit of the model to observed soil and soil solution concentrations, especially for pH and base saturation. Calibration also narrowed down the ranges in input parameters. The uncertainty analysis showed which parameters contribute most to the uncertainty in the critical loads and target loads. Base cation weathering and deposition and the parameters describing the H-Al equilibrium in the soil solution determine the uncertainty in the maximum critical loads for S, CL_max(S), when based on the aluminium to base cation (Al/Bc) criterion. Uncertainty in CL_max(S) based on an acid neutralizing capacity (ANC) criterion is completely determined by base cation inputs alone. The denitrification fraction is the most important source of uncertainty for the maximum critical loads of N, CL_max(N). N uptake and N immobilisation determine the uncertainties in the critical load for N as a nutrient, CL_nut(N). Calibration of VSD reduced the uncertainty: the coefficient of variation (CV) was reduced for all critical loads and criteria. After calibration, the CV for CL_max(S) was below 0.4 for almost all plots; however for CL_max(N) high values occurred for plots with high denitrification rates. Model calibration also improved the robustness of target load estimates: after calibration, no target loads were needed in any of the simulations for 40% of the plots, with the uncalibrated model there was a positive probability for the need of a target load for almost all plots.     

广州西塔风荷载研究

广州西塔是广州双塔的西塔楼,目前为华南地区第一高楼,高宽比超过6.5,主塔楼结构采用钢管混凝土斜交网格外筒+钢筋混凝土内筒的筒中筒体系。由于广州为台风多发地区,风荷载为其结构设计的控制荷载,故对其抗风设计进行了详尽的介绍。通过风气候分析确定了区域风况和设计风参数,以及与风响应有关的结构参数,并通过模型风洞试验确定了大楼的等效风荷载取值,并对大楼舒适度进行了判别。     

中国城市居住密度特征

在我国城市化以及城市住宅建设大发展的背景下,研究城市居住密度特征有助于规划部门对住宅建设进行宏观控制和微观管理。该文以统计年鉴的数据整理为基础,从人口密度和建筑密度两个方面多个指标对我国城市居住密度的特征进行分析。结果表明我国城市人均住宅面积呈增长趋势;居住人口密度呈下降趋势;住宅建筑毛密度呈上升的趋势。城市建成区面积处于非理性的快速增长状态;居住用地在城市建成区中的比重比较稳定;不同城市住宅面积的增长速度与居住用地的增长速度相比具有不同的特点。     

美国地下防水材料综述(续)

续篇总结了美国液体施工膜、膨润土防水、胶凝和结晶涂料、止水带、防潮材料的发展历程,材料性能,适用范围及施工方法等。     

The Rise of Advanced Services: Some Implications for Economic Development in U.S. Cities

The rise of services characterizing the recent transformation of the U.S. economy remains widely misunderstood. The postwar economy has been marked not only by shifts in final output but also by the growing importance of both services to producers and service-like activities performed within large corporations. Reporting on recent research, the author suggests that the rise of these advanced services has affected cities unevenly. The result is a four-tier urban system comprised of diversified advanced service centers, specialized advanced service centers, production centers, and consumer oriented centers. A review of principle characteristics of economic structure and recent experiences of transformation of these four urban types indicates that new intermetropolitan linkages are developing within the urban system. These linkages are based on the increasingly place specific trading of manufactured goods or consumer services as well as on advanced services. A major conclusion from this analysis is that lower ranking centers—primarily the production and the consumer oriented centers (which are very weak in the advanced service areas)—face enormous developmental problems that only a new urban policy may help alleviate.     

浅析德国经济萎缩地区的城市更新

两德统一后原东德地区的经济与人口结构的巨大变化,导致了当地城市功能的明显萎缩。本文通过介绍近年来德国规划领域针对这一问题进行的相关更新改造实践,总结出对我国城市衰落地区规划方法的若干启示。     

建筑门窗节能体系中美对比研究

中美两国同为能源消耗大国。为应对能源危机问题,中美纷纷出台建筑节能减排相关法规和政策。本文对中美两国建筑节能政策及法律法规、门窗节能标准体系,以及标准中对门窗传热系数、遮阳系数、气密性能等参数的规定进行了对比,最后对中美两国门窗节能标识制度进行了对比研究。通过对中美两国门窗节能体系的对比,有利于制定适合我国国情的门窗节能政策,完善我国节能标准体系与标识系统,进一步开展我国门窗节能工作。     

砌块砌体结构温度作用与荷载效应组合研究

针对现有的砌体结构设计规范未涉及温度作用效应的计算与组合问题,通过实测温差与气象资料计算温差的对比,给出了一种通过气象参数计算设计基准期内结构温差的方法。在此基础上结合一小砌块试点建筑给出了设计基准期内的年温差、日温差和组合温差统计参数。考虑了温度作用对承载能力的影响及荷载对顶层层间相对位移的影响:温度作用对砌体结构的抗压承载能力没有影响,但对顶层山墙的弯曲抗拉承载能力起控制作用,需要考虑温度作用与荷载的组合;常见荷载对顶层相对位移的影响可以忽略。提出了按承载能力设计时的温度作用分项系数取值,给出了考虑温度作用和荷载组合的顶层墙体弯曲拉应力计算公式。     

城市阁楼文化--浅谈LOFTS改造与城市居住的更新

本文对城市阁楼的定义及存在形式进行归纳,描述了世界阁楼式住宅的发展过程。对中国的城市阁楼文化的代表“北京大山子798艺术工厂”和“八号桥”时尚生活中心两个案例进行分析,以及“阁楼的遗风”在城市住宅设计中的反映,希望通过这样的分析与归纳对我们的建筑实践有一定的参考价值。     

美国金融机构的红线政策与中心城市的衰落

20世纪50年代以后,随着郊区化的发展,美国的中心城市开始走向衰落,尤其是东北部和中西部的城市更是出现了严重衰败的局面。城市衰败的原因虽然是多方面的,但金融机构的红线政策无疑发挥了极其恶劣的影响。由于住房保险机构、住房贷款机构对中心城市社区实行的红线政策,使中心城市的储蓄资金流失到郊区、其他地区甚至国外,从而导致了中心城市严重的资金流失和衰落。