上海嘉定区农民新村污水收集处理调查

在对上海嘉定区农民新村污水纳管,污水处理及污水最终排放去向作全面调查的基础上,分析了农民新村污水排放现状.存在的主要问题和发展趋势,并从排水管网基础建设、污水就地处理技术应用、环保部门执法监督和农民环境意识提高等方面,剖析了问题的根源,阐述了解决问题的思路,并得出相应的对策和建议。     

Evaluation of Public Housing Lead Risk Assessment Data

A unique data set from lead risk assessments performed on 67 public housing developments from across the United States was made available for analyzes. The data set includes results of lead analysis from 5906 dust wipes and from 1222 soil samples. A total of 487 dwelling units in these developments, as well as associated common areas, were sampled, all by the same team of inspectors. The number of dwelling units within a development that were sampled reflected the guidelines then in force, the 1990 Interim HUD Guidelines, rather than those specified in the 1995 Guidelines. Median dust lead loadings for floors, 151gm^–2 (14gft^–2), and window sills, 936gm^–2 (87gft^–2), were much less than former HUD limits of 1076gm^–2 (100gft^–2) and 5380gm^–2 (500gft^–2), respectively and are only about one-third of the recently established limits of 431gm^–2 (40gft^–2) and 2690gm^–2 (250gft^–2). In contrast, the median lead loading for window troughs, 8560gm^–2 (795gft^–2), was almost identical to the HUD clearance limit of 8610gm^–2 (800gft^–2). There was a strong positive correlation between floor and window trough lead loading values for samples from the same dwelling units and those from common areas of the housing developments. Door threshold samples, which may reflect conditions exterior to the dwelling unit, were collected from 53 dwelling units. Median lead loading levels of these samples were more than ten times higher than those in floor samples from the same dwelling units, were about the same as window sill samples and about one-half of levels in window trough samples. Composite sample results, simulated by averaging results from four samples within a dwelling unit, revealed that in order to have the same rate of excedence of standards, the composite standards would have to be reduced, for example, from the single sample value of 1076gm^–2 (100gft^–2) to 527gm^–2 (49gft^–2) for floor samples and from the single sample value of 8610gm^–2 (800gft^–2) to 5160gm^–2 (479gft^–2) for window troughs. For this public housing data set, the portion of the units in developments containing more than 225 units which exceeded the established limit for window samples was the same when using either the full data set or a random one-half of the data set. This suggests that, for this data set, the number of dwelling units sampled was excessive . Thus, the required increase in the number of dwelling units to be sampled specified in the 1995 Guidelines for developments with more than 225 dwelling units, may not have been necessary if this data set is representative of public housing developments in the United States.     

Rural and Suburban Sprawl in the U.S. Midwest from 1940 to 2000 and Its Relation to Forest Fragmentation

Abstract:  Housing growth and its environmental effects pose major conservation challenges. We sought to (1) quantify spatial and temporal patterns of housing growth across the U.S. Midwest from 1940–2000, (2) identify ecoregions strongly affected by housing growth, (3) assess the extent to which forests occur near housing, and (4) relate housing to forest fragmentation. We used data from the 2000 U.S. Census to derive fine-scale backcasts of decadal housing density. Housing data were integrated with a 30-m resolution U.S. Geological Survey land cover classification. The number of housing units in the Midwest grew by 146% between 1940 and 2000. Spatially, housing growth was particularly strong at the fringe of metropolitan areas (suburban sprawl) and in nonmetropolitan areas (rural sprawl) that are rich in natural amenities such as lakes and forests. The medium-density housing (4–32 housing units/km²) category increased most in area. Temporally, suburban housing growth was especially high in the post-World War II decades. Rural sprawl was highest in the 1970s and 1990s. The majority of midwestern forests either contained or were near housing. Only 14.8% of the region's forests were in partial block groups with no housing. Housing density was negatively correlated with the amount of interior forest. The widespread and pervasive nature of sprawl shown by our data is cause for conservation concern. Suburban sprawl has major environmental impacts on comparatively small areas because of the high number of housing units involved. In contrast, rural sprawl affects larger areas but with less intensity because associated housing densities are lower. The environmental effects per house, however, are likely higher in the case of rural sprawl because it occurs in less-altered areas. Conservation efforts will need to address both types of sprawl to be successful.     

土地供应计划对房价的传导机制研究

论文在借鉴四象限模型的基础上从理论上剖析了土地供应计划对房价的传导机制,并通过构建住房市场的存量-流量模型,利用湖南省2010-2013年14个市（州）的市本级面板数据,实证检验了土地供应计划对房价的传导机制。研究结果表明：土地供应计划的实施影响开发商预期,预期效应引致开发商的投机行为,进而对房价产生显著负影响,保障性住房用地占住宅用地的比例及供地计划实施率对房价产生显著负影响且影响强度不同,土地供应计划供地结构对房价的贡献大于计划实施率,该结论可为相关部门制定科学可行的供地计划提供重要决策参考。从单个因素分析,开发商的预期效应对房价波动的影响大于消费者预期效应对房价的影响;综合各需求面和供给面的因素分析,需求面因素对房价的影响程度大于供给面因素对房价的影响程度;上一期住房存量的增加进一步推动了房价的上涨。     

Shelter recovery in urban Haiti after the earthquake: the dual role of social capital

This paper documents the culture‐specific understanding of social capital among Haitians and examines its benefits and downsides in post‐disaster shelter recovery following the 12 January 2010 earthquake. The case study of shelter recovery processes in three socioeconomically diverse communities (Pétion‐Ville, Delmas and Canapé Vert) in Port‐au‐Prince suggests that social capital plays dual roles in post‐disaster shelter recovery of the displaced population in Haiti. On the one hand, it provides enhanced access to shelter‐related resources for those with connections. On the other hand, it accentuates pre‐existing inequalities or creates new inequalities among displaced Haitians. In some cases, such inequalities lead to tensions between the have and have‐nots and instigate violence among the displaced.     

Public intervention in rural housing markets

This paper is a revised version of one presented to the Regional Science Association Conference, University of Leeds, September 1983.

The extent of rural poverty is largely hidden, yet mean rural incomes are lower than in urban areas. Equally, the differential between low incomes and high minimum house prices in rural areas not always acknowledged. This paper looks at the planning response to these problems against alternative approaches including discriminatory policies against second home owners in rural areas. The paper concludes by identifying a solution restricting private development and augmenting public‐sector provision in rural areas.     

遥感图像自动识别监测平原地区农村居民点用地变化

以安徽淮北平原地区为研究区,充分利用1993年时相1∶5万土地利用背景空间数据库信息和地理信息系统（GIS）技术,对2003年遥感图像研究采用基于主分量和形态学分析的区域聚类分类方法,自动识别提取农村居民点用地,对安徽淮北平原地区及各市1993和2003年农村居民点用地面积及其变化进行监测, 分析了动态度和相对变化率。方法利用了土地利用背景空间数据的先验知识,将形态学和传统的分类手段相结合,使识别结果更加可靠和准确,经检验精度达到90%以上,基本满足农村居民点用地变化监测需求。1993~2003年,安徽淮北平原地区农村居民点用地面积呈现增加趋势,共增加面积33 17995 hm2,年均动态度为083%,扩展速度较快,各市农村居民点用地扩展程度不一,区域差异明显.     

BP神经网络与Sugeno模糊积分融合 的转子系统故障诊断

目的针对BP神经网络对转子故障诊断方法存在的局限性,提出一种融合Sugeno模糊积分和BP神经网络的转子故障轴心轨迹识别诊断方法。方法首先利用轴心轨迹图像的不变矩为特征向量,提取常见旋转机械转子故障特征,随后利用多个BP神经网络对故障类型进行识别,最终采用Sugeno模糊积分对BP神经网络识别结果进行决策,从而构建转子故障诊断模型,并应用于转子系统故障的诊断。结果通过机械故障仿真模拟实验平台采集了6种常见转子系统故障信号,利用matlab2012a软件编程建模仿真处理,试验表明,该模型有效地提高了转子系统多类别故障的识别正确率。同时,该方法对同一故障类型识别所需样本少,大大节省了数据获取和处理的时间。结论该方法提出并用于转子系统故障诊断中,诊断准确性高,可靠性强,利用样本数据量少,节约时间,对小样本数据的故障诊断有着良好的效果。     

人口迁移视角下城镇化对典型领域碳排放驱动效应研究——以辽宁省为例

城镇化的快速发展为我国带来了日新月异的变化,但城镇化进程中伴随着能源消费快速增长,使我国面临能源供应、节能减排等方面更加严峻的挑战.现有研究主要是从宏观角度研究城镇化对能源消费及碳排放的影响,较少探究人口从农村向城镇迁移过程中对典型领域产生的驱动效应.基于此,本研究以辽宁省为例,应用弹性系数模型,选取居民消费、住宅建筑、道路交通3个典型领域探讨城镇化对碳排放的驱动效应,并提出针对性的碳减排政策.结果表明,2006—2015年,城镇化对居民生活直接消费碳排放的驱动效应最为显著,弹性系数为9.91;对居民生活间接消费碳排放和道路交通领域的驱动效应次之,弹性系数分别为6.94和5.38;对住宅建筑等驱动效应最弱,弹性系数为2.71.研究表明,城乡生活方式差异导致居民直接生活消费碳排放显著增加,相较而言,城乡产品市场差异较小;辽宁省现阶段城镇住宅建筑存量与城镇新增人口的需求基本匹配,但人口城镇化带来的城市边界外扩、人口密度提高,导致道路交通碳排放增长.