Travel From Home: An Economic Geography of Commuting Distances in Montreal

The question of how home and workplace are linked through commuting is at the heart of much recent work on metropolitan areas. However, the emphasis tends to be either on spatial-economic models or on the impact of empirically measured individual, household, neighborhood, and transport mode characteristics; relatively little work has focused on job characteristics and place of employment as they relate to travel to work. In this article, I investigate whether people travel different distances to access different types of job location, with particular attention to the different distances traveled by men and women. My points of reference are the major employment centers (poles) in the Montreal region. After controlling for a wide range of explanations that may account for different travel distances, I conclude that differences in commuting length between different places of work are, by and large, independent of possible explanatory factors such as residential location, economic sector, occupation, income, and participation in household earnings—some places of work generate longer commutes than others. Men and women behave differently in relation to these places: women will travel farther to access jobs in centers whereas men will not; and despite their shorter average overall commutes, women travel farther than men to reach jobs in the CBD. This suggests, at the metropolitan scale, that each job location may have its own local culture or "milieu," and that men and women react differently to them.     

Women in the Field: Critical Feminist Methodologies and Theoretical Perspectives*

Feminist scholars have traditionally emphasized the importance of incorporating “the everyday” worlds of women into the historically masculinist theoretical and empirical foundations of the social sciences. Such emphases have commonly resulted in smaller-scale research projects and more interactive kinds of research methods and methodologies. Feminist geographers have uniquely contributed to the body of feminist scholarship through drawing out the importance of place in everyday constructions of gender and, more recently, sexuality. Critical field-based research has therefore from the beginning been the mainstay of subdisciplinary research. Like the discipline as a whole, however, little explicit attention has been given in publications or pedagogically to the politics of fieldwork (including how a “field” is defined and the politics involved in choosing and working in a particular “field”) or the politics of representation (which includes considerations of the partiality of knowledge and how and to whom we represent our work, ourselves and others in various kinds of texts). These “Opening Remarks” show how these issues are addressed in the papers that follow and how feminist geography has much to contribute to critical analyses of global and multinational processes, including patriarchy, capitalism, and racism.     

香港土壤中的重金属含量及其污染现状

通过详细的土壤调查分析，探讨了香港表层土壤中重金属的含量及其污染现状。５８个代表性样品的分析结果表明，香港土壤的Ａｓ、Ｃｄ、Ｃｕ、Ｐｂ和Ｚｎ分别为１３、１、１７、５７和５５／；用ＮａＨＣＯ３／ＤＴＰＡ浸提的有效态Ｃｄ、Ｃｕ、Ｐｂ和Ｚｎ分别为０．１、０．０３、０．７和１．１ｍｇ／ｋｇ。     

Geochemical and geochronological constraints on Late Jurassic volcanic rocks at Tuen Mun,Hong Kong,with implications for the Palaeo-Pacific subduction

Widespread Mesozoic igneous rocks in Hong Kong form part of the giant Mesozoic igneous province in Southeastern China. The Tuen Mun Formation in the Northwestern New Territories is the oldest volcanic unit known in Hong Kong. This formation contains a lower unit composed of dominantly volcanic breccia, minor dacite, rhyolite, and tuff, and an upper unit of basaltic andesitic to andesitic lava. The volcanic rocks from the lower unit contain zircon grains with a mean U–Pb age of 163.4 ± 0.9 Ma, synchronous with the adjacent Tsuen Wan Volcanic Group in the region. Good inter-correlations between different elements in the Harker diagrams indicate that the volcanic rocks with high SiO₂ (e.g. >65 wt.%) are essentially physical mixtures of intermediate magmas and various xenoliths of country rocks, characterizing the palaeo-volcanic plug facies. Preservation of large amounts of xenoliths of sandstone and marble in the volcanic rocks, which is revealed both in field and under microscopic observation, further supports this hypothesis. The original andesitic magma, represented by the intermediate volcanic rocks with SiO₂ <65 wt.%, exhibit enrichments of LILEs and LREEs compared with N-MORB, but have negative Nb–Ta–Ti anomalies in the primitive-mantle normalized diagram, similar to those derived from metasomatized mantle wedge in an arc environment. Large ranges of SiO₂, MgO, and CaO contents, and negative Eu and Ce anomalies are consistent with significant fractional crystallization of likely olivine/pyroxene and plagioclase. We propose that during the Late Jurassic subduction of the Palaeo-Pacific Plate underneath the coastal continental arc in Southeast China generated prolonged and cyclic volcanism in the northern part of Hong Kong.     

街景影像——基于人工智能的方法与应用

街景影像是感知城市物质环境的一种新型地理大数据.这种数据以人的视角详尽描绘了城市的可视环境,同时也隐性地表达了可视环境背后有关城市功能、社会经济和人类活动的信息.然而,传统的数字图像处理技术对街景影像的处理能力有限,不能高效地理解其中的语义信息.近年来,随着人工智能领域的不断发展,图像分析和机器学习方法取得了突破性的进...     

港珠澳大桥人工岛越浪量试验

港珠澳大桥人工岛位于伶仃洋海域,台风期较大的越浪量可能危及人工岛和隧道的运营安全,越浪量是人工岛护岸设计的重要参数。通过波浪断面物理模型,研究人工岛护岸护面块体型式、消浪平台尺度、挡浪墙前护肩宽度等结构参数对越浪量的影响,试验结果表明,坡肩宽度对越浪量的影响非常大,并且越浪量较小时,试验值明显小于当前广泛采用的van der Meer公式计算值,由此针对人工岛护岸结构特点,提出考虑了坡肩折减系数K_c的越浪量计算方法。计算结果与试验数据吻合良好,为人工岛越浪控制措施的采用及后期越浪量预警提供技术支撑。     

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sediments from Hong Kong

Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in 14 sediment samples collected from four sites in the Mai Po Marshes Nature Reserve (within a RAMSAR Site) and from another six sites in Victoria Harbour and along the Hong Kong coastline. Elevated levels of PCDDs, and particularly OCDD, were detectable in all samples collected from the Mai Po Marshes and five of the six sites. In contrast to PCDDs, PCDFs were mainly found in sediment samples collected from industrial areas (Kwun Tong and To Kwa Wan) in Victoria Harbour. PCDD/F levels and congener profiles in the samples from the Mai Po Marshes Nature Reserve in particular show strong similarities to those reported in studies which have attributed similar elevated PCDD concentrations to nonanthropogenic PCDD sources.     

香港九龙复活破火山的鉴别及其地质意义

香港主城区座落在香港岛一九龙地区的九龙花岗岩体上,该花岗岩体平面形态呈直径约11km的圆形,周边火山岩群山环绕,构成特殊的圆形盆地地貌,以往曾有人认为是陨石坑。笔者根据前人地质资料分析并经实地考察,认为该地貌形态实为大致以尖沙咀为中心的一个大型晚中生代复活破火山机构,九龙花岗岩体为破火口塌陷后侵位的中央侵入体,周围火山地层产状围斜内倾,发育环形断裂（主要为高角度正断层）和放射状断裂,具典型复活破火山特征,可称之为“九龙复活破火山”。     

城市居民休闲的地方依恋研究——以广州荔枝湾为例

以广州荔枝湾为例,城市居民对休闲空间的地方依恋可分为地方依赖和地方认同两个维度,其中,地方认同即情感性依恋强于地方依赖即功能性依恋。城市居民对休闲空间的地方依恋及地方认同、地方依赖的程度随休闲距离的增加而衰减,随年龄的增长而增强,随教育程度的提高而减弱,同时,还受到闲暇时间的影响,但并不受收入水平的影响。依据休闲活动的地方依赖度和地方认同度差异,可将城市居民划分为功能需求型、地方冷淡型、地方依恋型和情感认同型4类休闲群体。     

综合电法在温州市蒲州新闸消力池上的应用

在蒲州新闸消力池综合电法勘查中，使用高密度电阻率法圈定了消力地域内砂体的分布位置；用自然电场法查明了地下水的渗流方向，解释了该区内桩体离折、缩颈的原因，并提出了处理意见。