城市轨道交通运营规模与经济发展的耦合协调性分析

城市轨道交通运营规模与经济协调发展是城市轨道交通健康发展的基础.为研究城市轨道交通运营规模与经济发展的耦合协调性,采用了物理学的耦合模型对2007-2019年城市轨道交通和经济发展数据进行了实证分析,对城市轨道交通运营规模和经济发展的综合水平、耦合度、耦合协调度进行了测算.研究表明:城市轨道交通运营规模和经济发展综合水平持续上升,城市轨道交通运营规模滞后于经济发展水平;城市轨道交通运营规模与经济发展两者具有较高的耦合度;城市轨道交通运营规模—经济发展耦合协调度是逐年提高的,2016年以后城市轨道交通运营规模和经济发展进入一个较好互动影响阶段.     

Modelling of sound propagation to three-dimensional urban courtyards using the extended fourier PSTD method

Noise from road traffic propagates to acoustically shielded areas as roadside courtyard by multiple reflection and diffraction paths in a complex three-dimensional (3D) environment. The computation of noise levels and assessment of candidate noise mitigation measures for these areas has up to now been based upon two-dimensional (2D) geometrical assumptions. Here, a recently developed efficient wave-based method, the extended Fourier pseudospectral time-domain (PSTD) method, is used to investigate the necessity of a 3D model. For frequencies up to 500 Hz and low traffic velocities of 30 km/h and 50 km/h, a road traffic noise configuration of an urban street canyon with or without cross streets and a closed roadside courtyard is compared to the 2D configuration as studied previously. It can be concluded that the contribution of distant sources is overpredicted by the 2D configuration. As noise mitigation measures, additional façade absorption, façade screens and roof screens have been studied. Results show that the 2D configuration underpredicts the effect of façade mitigation measures, by maximum 1.5 dB(A) for the absorption case and 4.4 dB(A) for the screens case. The effect of roof screens is overpredicted up to 1.7 dB(A). Given these deviations and the found deviations between the 3D configurations of street canyon with and without cross streets, the need for a 3D model can be concluded to be strongly configuration dependent. The 3D model is finally used to investigate the effect of a façade opening to the courtyard, which could lead to up to 10 dB(A) higher noise levels as compared to the noise propagating over the roof level and may prohibit the use of these courtyards as quiet areas. Absorption in the façade opening can significantly limit this negative effect.     

影响城市地价最优因素组合的选择及权重确定

笔者在城市土地定级估价综合模型[1] 的基础上 ,应用最优回归自变量集的选择方法[2 ] ,得到了影响城市地价最优因素组合的选择方法及权重的确定方法 ,并将其实际应用于山西省古交市的地产评估 ,结果表明 ,该方法比现行方法节省经费且使评估结果更符合实际。     

基于GIS空间分析的宁波周边城市群研究

城市作为大规模集中的人类非农性社会经济活动在二维平面上投影点．相互之间存在着空间作用，并在整体同构、功能耦合过程中形成城市群，因此，作为系统的城市群的变动不仅仅是城市单体内在体量影响的结果，还是城市单体空间分布作为位置变量综合作用的结果．文章通过基于GIS的空间分析，对宁波周边城市群形成的机制进行实证性研究．     

基于主成分-灰色关联度的城市暴雨灾害应对能力评价:以江苏省13个地级城市为例

对城市暴雨灾害应对能力进行评价是城市暴雨灾害管理的重要手段.以江苏省13个地级城市为研究对象,基于2010-2013年的面板数据,综合运用主成分与灰色关联度相结合的分析方法,从日常防御、灾前预警、灾中应急和灾后恢复4个方面评价江苏省城市暴雨灾害应对能力.研究发现,江苏省城市暴雨灾害应对能力整体水平逐年提升,但是扬州和泰州小幅波动并略有下降;全省城市暴雨灾害应对能力具有明显的空间分布特征,呈现出由南向北能力递减的演变趋势.研究表明,该方法切实有效地解决了城市暴雨灾害应对能力的评估问题.     

经济结构变化对商品房价格的影响:来自1999-2011年省际面板数据的实证分析

本文以经济结构变化作为切入点对中国住房价格持续高涨现象进行分析,在构建理论分析模型的基础上,运用我国1999年至2011年省际面板数据进行了实证分析。研究结果表明:经济结构对商品房价格具有决定性的影响,长期来看,城乡收入分配结构、城镇化水平、工业化水平、以及财政分权水平决定了房价水平;短期来看,除了经济结构外,房价偏离长期均衡价格的水平决定了房价水平。     

可持续的中国城乡居民养老保险体系数学模型

本文从我国现行养老金政策出发,利用灰关联分析得到养老金收支的影响因素的排序,建立中国城乡居民养老金收支模型.然后利用Logistic人口预测模型估计出不同替代率下2013-2035未来23年我国养老金缺口,并利用仿真方法算出保证我国养老保险体系的可持续性的替代率的合理区间为50%-70%.进一步分析影响替代率各因素的灵敏性,并考虑延迟退休、做实个人账户以及市场化投资等因素对模型进行改进.最后以养老金替代率为切入点,对退休年龄等模型参数的调整和有关措施进行了分析与评价.     

基于GIS的高密度城市声景质量及其影响因素研究 ——以广州天河区为例*

密度城市空间背景下,声景质量对居住舒适度及居民身心健康的影响显著。已有声景研究中鲜有针对街区尺度的声景时空特征及其与居民交互关系的探究,不利于高质量宜居城市空间构建。本文基于地理学视角,通过声景漫步与问卷调查对广州市天河区的声源类型、声环境特征、心理声学感知进行调查研究,旨在阐述城市街区尺度声景质量的空间特征及其影响因素。研究认为：1）声压级低、主观响度低、柔和、舒适、安静、自然的声环境有利于提升声景总体满意度,同时声景感知结构的空间性在总体满意度上存在性别差异;2）城市声景特征的空间结构与道路功能和土地利用功能等要素密切相关,其中建筑密度、道路等级、城市综合密度的提升均不利于声景总体满意度的提升,城市生活活力的提升有助于声景总体满意度的提升。基于此,本文认为应通过城市声景空间规划优化高密度城市声环境质量并提升声景满意度,通过合理规划道路、用地功能、与建筑密度等手段,促进积极声景空间营造,促进并实现健康人居环境。     

University−Urban High School Partnership: Math and Science Professional Learning Communities

This study focused on science and math professional learning communities (PLCs) that were implemented through a university‐urban high school partnership. These PLCs were part of mandated school‐wide, content‐based PLCs implemented as part of the reform efforts initiated in an urban school to address the school's failure to meet Adequate Yearly Progress (AYP) for four years consecutively and low graduation rate (less than 25%) for male students. The key issues were (a) students had continually earned low test scores; (b) there was continuous principal turnover; (c) faculty morale was at an all‐time low, and the quality of teaching was very poor; and (d) the students were not effectively disciplined. The study examined the impact that university faculty‐led mandated PLCs have on teachers' practices and students' learning and achievement. Analysis of data revealed practices that were effective in developing and implementing these successful math and science PLCs. Three themes emerged: ethics of care, teacher agency, and aesthetics of professional interactions. Each theme contained key features that appeared to contribute to the implementation of a successful PLC.     

广州市花都区城镇生活饮用水安全的现状与对策研究

生活饮用水安全关系到大众的生命健康和安全的各个方面,加强对居民生活供水的管理是关乎民生的重要课题。简述了广州市花都区城镇饮用水安全的现状,总结了现阶段饮用水安全保护工作中的不足和困难,并提出了相应的具有可操作性的建议。