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许博 《中国历史地理论丛》2013,28(1):117-126
河西地区主要水系之一石羊河及其支流,在历史上曾使用"谷水"、"马城河"、"五涧谷(水)"、"三岔河"等名称,沿用至今的"石羊河"一名迟至清代前中期方才出现。"石羊河"之名,首先出现在流域下游镇番县的地方志中,命名的初衷则是为处于上游武威县境内的河流定名,其指代对象存在逐步明确的过程。上游武威县对"石羊河"名及其指向,经历了从不在意到接受、并有所延展的演变历程。"石羊河"名的出现,与下游镇番县河源水权观念的兴起存在密切关联。塑造河名是上、下游水资源权利关系生成中,下游构建自身水权的策略之一。 相似文献
3.
基于北京市六环内住房租赁样本的交易数据,本文以北京地铁为例,采用空间回归模型实证探讨轨道交通对合租和整租这两种不同方式下的住房租赁价格的影响。结果表明:①基于轨道交通的就业可达性对于租赁价格会产生显著的增值效应,租客愿意为就业可达性较好的住房支付溢价租金。②地铁站点密度对整租的租赁价格具有正向影响,对合租无显著影响,而地铁换乘线路变量未对租赁价格产生显著影响。③轨道交通对合租和整租住房租赁价格的影响随着距离增加呈现差异化的演变规律。合租方式的租赁价格的影响随着实际路网距离的增加呈现单调递减,距站点500m范围内影响最大;而整租方式呈现倒“U”形变化,在500-1500m范围内增值效应最大。针对研究结果,建议政府加大租赁住房供给的同时要充分考虑轨道交通要素,精准施策以实现公共资源的空间高效配置。 相似文献
4.
Hydrothermal water–(pyroclastic) rock interactions were examined using flow-through experiments to deduce the effect of mass transport phenomena on the reaction process. A series of experiments were conducted over the temperature range 75–250°C, with a constant temperature for each experiment, and at saturated vapour pressure, to estimate the apparent rate constants as a function of temperature.
Based on the chemistry of analysed solutions, the water–rock interaction in the experiments was controlled by diffusion from the reaction surface and by the existence of a surface layer at the rock–fluid interface, which regulated the chemical reaction rate. The reaction progress depended to a high degree on flow velocity and temperature conditions, with element abundances in the fluid significantly affected by these factors. Mass transport coefficients for diffusion from the rock surface to the bulk solution have been estimated. Ca is selectively depleted under lower temperature conditions ( T < 150°C), whereas Na is greatly depleted under higher temperature conditions ( T > 150°C), and K reaction rates are increased when flow velocity increases. Using these conditions, specific alkali and alkali earth cations were selectively leached from mineral surfaces. The 'surface layer' comprised a 0.5–1.8 mm boundary film on the solution side (the thickness of this layer has no dependence on chemical character) and a reaction layer. The reaction layer was composed of a Si, Al-rich cation-leached layer, whose thickness was dependent on temperature, flow velocity and reaction length. The reaction layer varied in thickness from about 10−4 to 10−7 mm under high temperature/low fluid velocity and low temperature/high fluid velocity conditions, respectively. 相似文献
Based on the chemistry of analysed solutions, the water–rock interaction in the experiments was controlled by diffusion from the reaction surface and by the existence of a surface layer at the rock–fluid interface, which regulated the chemical reaction rate. The reaction progress depended to a high degree on flow velocity and temperature conditions, with element abundances in the fluid significantly affected by these factors. Mass transport coefficients for diffusion from the rock surface to the bulk solution have been estimated. Ca is selectively depleted under lower temperature conditions ( T < 150°C), whereas Na is greatly depleted under higher temperature conditions ( T > 150°C), and K reaction rates are increased when flow velocity increases. Using these conditions, specific alkali and alkali earth cations were selectively leached from mineral surfaces. The 'surface layer' comprised a 0.5–1.8 mm boundary film on the solution side (the thickness of this layer has no dependence on chemical character) and a reaction layer. The reaction layer was composed of a Si, Al-rich cation-leached layer, whose thickness was dependent on temperature, flow velocity and reaction length. The reaction layer varied in thickness from about 10
5.
Matthew Gandy 《Transactions (Institute of British Geographers : 1965)》1997,22(3):338-358
Much practically orientated environmental research is marked by a polarity between functionalist abstraction and ahistorical normative discourse. This paper seeks to bridge the divide between theoretical and empirical research through a case study of New York City's water supply. Current processes of socio-economic restructuring are leading to negative environmental consequences obscured by a failure to extend analysis beyond limited temporal, spatial or sectoral scales. Insights from regulationist theory show that a combination of fiscal, political and other developments are bringing about a wide-ranging reformulation of existing patterns of environmental regulation and service provision in the city. The power of the state is being radically diminished in relation to the power of capital and a plethora of different interest groups. A relatively simple centralized model of environmental regulation is being transformed into a complex decentralized pattern involving the emergence of new approaches to urban governance. Further research is needed on the contradictions between capitalist accumulation and environmental regulation at different spatial scales in order to link New York's changing role within the global economy to the declining political legitimacy and fiscal capability of the state to play an extensive role in environmental management. 相似文献
6.
R. Lee Lyman 《Journal of archaeological science》1985,12(3):221-236
Human transport of bones with high food values, and destruction of bones with low density values are the traditionally invoked explanations of the frequencies of bones in archeological contexts. The manner in which these two explanations have been used suggests archaeologists assume the explanations to be independent of one another. The transport explanation is operationalized as the modified general utility index (MGUI) of Binford, and the destruction explanation is operationalized with measures of bone density. Statistical correlation of the MGUI with bone density, while weak, indicates that many high utility bones have low density values while many low utility bones have high density values. Because low density bones tend to be destroyed more readily than high density bones, inferences of human utility strategies derived from bone frequencies and based on the MGUI may be inaccurate. The utility strategies suggested by three archaeofaunas are compared to bone density, and two of these faunas are shown to potentially be the result of differential destruction and not human transport as measured by the MGUI. 相似文献
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Abbas Ziafati Bafarasat 《European Planning Studies》2016,24(11):2057-2075
This paper discusses three normative standpoints on conflict in strategic spatial planning: no conflict, conflict for consensus and conflict for meta-consensus on the validity of dispute. These views apply to the questions of whether and why projects, as a major source of conflict, should be identified in the process of strategic planning. In their approaches to these questions, the performance school advocates the production of general guidelines to avoid conflict, the collaborative perspective supports the identification of projects in strategic planning in order to utilize their potential in a conflict-to-consensus journey and the conflict-oriented perspective favours the identification of projects in strategic planning in order to arrive at meta-consensus on the immediate disputability of robust agreements. Reflecting on the collaborative perspective, this paper tests a hypothetical model of how conflicts created in the face of project identification can feed in making consensual strategies. Findings in the North West region of England support the model and suggest some difficulties with reviewing such consensus around which a resistance network forms. The paper puts forward some recommendations for overcoming the review challenge. 相似文献
9.
Carme Miralles-Guasch Montserrat Martínez Melo Oriol Marquet 《Gender, place and culture : a journal of feminist geography》2016,23(3):398-417
Gender differences in mobility patterns between women and men have long been acknowledged. This study analyses how these differences are reproduced in different urban and rural contexts. Using mobility data from a large travel survey taken in 2006 in Spain, we examine the differences between gender mobility through age, modal split and trip purposes. Special attention is paid to how territory shapes mobility and how these territorial settings differently affect gendered mobilities. The use of this data source allows the comparison of all trips made by the total population, including all means of transport. By taking a global view on mobility, the uneven relationships that men and women have with different means of transport become more visible. After disaggregating data by age and territorial settings, results show that women are using sustainable transport modes more often than men, and travelling for more diverse reasons. Gender is thus a fundamental variable in understanding modal split and, by extension, transport sustainability, in terms of energy consumption and the emission of greenhouse gases. From this point of view, we consider women's mobility knowledge and practices – typically related to the most sustainable means of transport – as factors with rising value that could effectively guide public policy in its way to promote more sustainable mobility patterns. 相似文献
10.
The Krafla geothermal system is located in Iceland's northeastern neovolcanic zone, within the Krafla central volcanic complex. Geothermal fluids are superheated steam closest to the magma heat source, two‐phase at higher depths, and sub‐boiling at the shallowest depths. Hydrogen isotope ratios of geothermal fluids range from ?87‰, equivalent to local meteoric water, to ?94‰. These fluids are enriched in 18O relative to the global meteoric line by +0.5–3.2‰. Calculated vapor fractions of the fluids are 0.0–0.5 wt% (~0–16% by volume) in the northwestern portion of the geothermal system and increase towards the southeast, up to 5.4 wt% (~57% by volume). Hydrothermal epidote sampled from 900 to 2500 m depth has δD values from ?127 to ?108‰, and δ18O from ?13.0 to ?9.6‰. Fluids in equilibrium with epidote have isotope compositions similar to those calculated for the vapor phase of two‐phase aquifer fluids. We interpret the large range in δDEPIDOTE and δ18OEPIDOTE across the system and within individual wells (up to 7‰ and 3.3‰, respectively) to result from variable mixing of shallow sub‐boiling groundwater with condensates of vapor rising from a deeper two‐phase reservoir. The data suggest that meteoric waters derived from a single source in the northwest are separated into the shallow sub‐boiling reservoir, and deeper two‐phase reservoir. Interaction between these reservoirs occurs by channelized vertical flow of vapor along fractures, and input of magmatic volatiles further alters fluid chemistry in some wells. Isotopic compositions of hydrothermal epidote reflect local equilibrium with fluids formed by mixtures of shallow water, deep vapor condensates, and magmatic volatiles, whose ionic strength is subsequently derived from dissolution of basalt host rock. This study illustrates the benefits of combining phase segregation effects in two‐phase systems during analysis of wellhead fluid data with stable isotope values of hydrous alteration minerals when evaluating the complex hydrogeology of volcano‐hosted geothermal systems. 相似文献