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北京郊区居民日常生活方式的行为测度与空间—行为互动 总被引：7，自引：2，他引：5
郊区化及其对居民日常生活的影响成为近年来城市研究的重要议题。时空行为研究认为推动日常生活方式的郊区化是解决郊区化过程中出现的社会与空间问题的根本措施。从日常生活方式的角度出发,需要利用多维度时空行为指标刻画群体的生活方式类型以分析郊区居民的空间—行为互动机制。本文采用活动空间和出行频率指标构建个体日常生活方式的行为测度方法,并基于2012年在北京上地—清河地区进行的GPS调查数据将郊区居民划分为“空间排斥”、“本地化”、“郊区性”、“两极化”、“城市依赖”五种日常生活方式类型。研究发现不同日常生活方式群体在活动分布、活动频率和交通方式上存在差异;并通过多项logistic模型分析郊区化对于个体日常生活方式的影响,发现工作日居民的日常生活方式受到性别、收入、年龄和工作时长等社会经济属性的影响。同时郊区设施配置直接影响着居民对郊区空间的利用程度,土地混合利用、商业设施密度提高更有可能实现日常生活的郊区化。日常生活方式的行为测度方法有助于分析郊区居民日常行为的复杂性,为理解郊区化提供了独特的视角,为构建城市研究的空间—行为互动理论提供了有力的支持。 相似文献
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Sources of sedimentary PAHs in tropical Asian waters: Differentiation between pyrogenic and petrogenic sources by alkyl homolog abundance 总被引：2，自引：0，他引：2
Mahua Saha Kaoruko Mizukawa Hideshige Takada Mohamad P. Zakaria Bui Cach Tuyen Ruchaya Boonyatumanond Badal Bhattacharya Touch Seang Tana 《Marine pollution bulletin》2009,58(2):189-200
We collected surface sediment samples from 174 locations in India, Indonesia, Malaysia, Thailand, Vietnam, Cambodia, Laos, and the Philippines and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. PAHs were widely distributed in the sediments, with comparatively higher concentrations in urban areas (∑PAHs: ∼1000 to ∼100 000 ng/g-dry) than in rural areas (∼10 to ∼100 g-dry), indicating large sources of PAHs in urban areas. To distinguish petrogenic and pyrogenic sources of PAHs, we calculated the ratios of alkyl PAHs to parent PAHs: methylphenanthrenes to phenanthrene (MP/P), methylpyrenes + methylfluoranthenes to pyrene + fluoranthene (MPy/Py), and methylchrysenes + methylbenz[a]anthracenes to chrysene + benz[a]anthracene (MC/C). Analysis of source materials (crude oil, automobile exhaust, and coal and wood combustion products) gave thresholds of MP/P = 0.4, MPy/Py = 0.5, and MC/C = 1.0 for exclusive combustion origin. All the combustion product samples had the ratios of alkyl PAHs to parent PAHs below these threshold values. Contributions of petrogenic and pyrogenic sources to the sedimentary PAHs were uneven among the homologs: the phenanthrene series had a greater petrogenic contribution, whereas the chrysene series had a greater pyrogenic contribution. All the Indian sediments showed a strong pyrogenic signature with MP/P ≈ 0.5, MPy/Py ≈ 0.1, and MC/C ≈ 0.2, together with depletion of hopanes indicating intensive inputs of combustion products of coal and/or wood, probably due to the heavy dependence on these fuels as sources of energy. In contrast, sedimentary PAHs from all other tropical Asian cities were abundant in alkylated PAHs with MP/P ≈ 1-4, MPy/Py ≈ 0.3-1, and MC/C ≈ 0.2-1.0, suggesting a ubiquitous input of petrogenic PAHs. Petrogenic contributions to PAH homologs varied among the countries: largest in Malaysia whereas inferior in Laos. The higher abundance of alkylated PAHs together with constant hopane profiles suggests widespread inputs of automobile-derived petrogenic PAHs to Asian waters. 相似文献
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Landslide susceptibility mapping in the Damrei Romel area, Cambodia using frequency ratio and logistic regression models 总被引：24，自引：0，他引：24
This study applied, tested and compared a probability model, a frequency ratio and statistical model, a logistic regression to Damre Romel area, Cambodia, using a geographic information system. For landslide susceptibility mapping, landslide locations were identified in the study area from interpretation of aerial photographs and field surveys, and a spatial database was constructed from topographic maps, geology and land cover. The factors that influence landslide occurrence, such as slope, aspect, curvature and distance from drainage were calculated from the topographic database. Lithology and distance from lineament were extracted and calculated from the geology database. Land cover was classified from Landsat TM satellite imagery. The relationship between the factors and the landslides was calculated using frequency ratio and logistic regression models. The relationships, frequency ratio and logistic regression coefficient were overlaid to make landslide susceptibility map. Then the landslide susceptibility map was compared with known landslide locations and tested. As the result, the frequency ratio model (86.97%) and the logistic regression (86.37%) had high and similar prediction accuracy. The landslide susceptibility map can be used to reduce hazards associated with landslides and to land cover planning. 相似文献
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N. Touch T. Hibino N. Kinjo Y. Morimoto 《International Journal of Environmental Science and Technology》2018,15(3):507-512
Benthos cannot survive in strongly reduced sediments, in which the redox potential is around ?400 mV. Such sediments are typically found in inner harbors that are exposed to wastewater discharges. Field experiments were conducted to investigate the potential of sediment microbial fuel cells (SMFCs) for improving the benthic environment in such sediments. To the best of our knowledge, this has not been reported in any previous literature. Bottom sediment was collected and used to fuel an SMFC suspended 500 mm below the water surface. The sediments then were collected one year after installation, and their benthos environment was investigated. The most remarkable results are that the diversity and growth of benthos were higher in the SMFC-applied sediment than in a control sediment. The results have further strengthened that the sediment remediation was enhanced, in which the oxygen consumption rate of the sediment was reduced, and the mineralization of the organic matter was increased. Our findings suggest that SMFCs are a promising technology for the remediation of strongly reduced sediment and for the improvement of the benthic environment. 相似文献
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基于多源大数据的城市体征诊断指数构建与计算——以上海市为例 总被引：2，自引：2，他引：0
基于多源大数据,构建了整合城市活动-移动系统、城市人口系统、城市运行系统、城市环境系统4个系统的城市体征诊断指数体系。该指数体系分解为底力、动力、压力、活力4个维度,具有4个层次和12个时空间尺度。底力指数表征土地、人口等空间单元基本属性,用以把握区域总体特征;动力指数通过企业发展状况、环境质量等反映了空间单元的发展状态;压力指数用以监测城市系统运行状况,起到风险评判与预警的作用;活力指数以活动和流的时空特征进行活动动态展现,反映空间单元的真实活力。最后以2016年4月6日为例,计算和展示了上海各街道的综合和各维度体征诊断指数,说明了体征诊断指数的可应用性和指数计算结果的稳健性。城市体征诊断指数可以辅助于城市网格化管理、压力预警等治理需求。 相似文献
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北京市郊区居民汽车拥有和使用状况与活动空间的关系 总被引：2，自引：0，他引：2
机动化与郊区化对城市空间结构与社会生活产生了深远的影响,私人汽车已日渐成为中国城市居民日常出行的重要交通工具。汽车所有权与汽车出行快速上升及其所带来的日常行为变化已经成为中西方学者共同关注的话题。西方学者对机动化与居民活动空间的关系进行了深入的探讨,但是国内这一方面的研究刚刚起步。基于GPS与活动日志相结合的居民一周活动与出行数据,采用GIS空间分析,从非汇总角度对郊区居民的整日活动空间进行测度,分析汽车拥有量与汽车使用对居民整日活动空间的影响。结果表明：机动化对居民活动空间产生深刻影响,家庭汽车所有状况与家庭汽车分配影响个体日常活动空间的分布,活动空间与是否使用小汽车出行具有显著的相关关系。 相似文献
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Asia-Pacific mussel watch: monitoring contamination of persistent organochlorine compounds in coastal waters of Asian countries 总被引：27，自引：0，他引：27
Monirith I Ueno D Takahashi S Nakata H Sudaryanto A Subramanian A Karuppiah S Ismail A Muchtar M Zheng J Richardson BJ Prudente M Hue ND Tana TS Tkalin AV Tanabe S 《Marine pollution bulletin》2003,46(3):281-300
Contamination of persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDT and its metabolites (DDTs), HCH (hexachlorocyclohexane) isomers (HCHs), chlordane compounds (CHLs), and HCB (hexachlorobenzene) were examined in mussels collected from coastal waters of Asian countries such as Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Far East Russia, Singapore, and Vietnam in 1994, 1997, 1998, 1999, and 2001 to elucidate the contamination status, distribution and possible pollution sources and to assess the risks on aquatic organisms and human. OCs were detected in all mussels collected from all the sampling sites investigated. Considerable residue levels of p,p(')-DDT and alpha-HCH were found in mussels and the concentrations of DDTs and HCHs found in mussels from Asian developing countries were higher than those in developed nations suggesting present usage of DDTs and HCHs along the coastal waters of Asian developing countries. On the other hand, lower concentrations of PCBs detected in mussels from Asian developing countries than those in developed countries indicate that PCBs contamination in mussels is strongly related to industrial and activities. To our knowledge, this is a first comprehensive report on monitoring OCs pollution in the Asia-Pacific region. 相似文献
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