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1.
Margaret Desmond 《Area》2004,36(3):262-269
This paper engages with recent debates in geography and associated disciplines that are concerned with the wider analytic issues to be confronted in researching an elite. Drawing on a case study of the construction of a policy position on GMOs and the Environment in Ireland, the methodological challenges encountered researching up the hybrid elite central to this development are interrogated. In particular, emphasis is placed on the politics of time, which becomes central when a new sector is emerging, and meanings and definitions are being constructed.  相似文献   

2.
中国城市网络的凝聚子群及影响因素研究   总被引:2,自引:1,他引:1  
盛科荣  杨雨  张红霞 《地理研究》2019,38(11):2639-2652
凝聚子群特征及形成机理的研究是理解城市网络发育规律及其动力机制的重要切入点。利用2016年中国上市公司500强企业总部-分支机构数据,研究了中国城市网络凝聚子群的多维度特征,定量测度了城市间链接关系的影响因素,探索性的分析了凝聚子群的形成机理。结果发现:派系、k-核、lambda集合、核心-边缘方法都表明中国城市网络存在凝聚子群现象,揭示了城市网络链接强度的层级特征;经济规模、政治资源、知识资本是凝聚子群发育的重要影响因素,网络邻近性、地理区位和历史基础也深刻的影响着凝聚子群的空间格局;择优链接和路径依赖是凝聚子群发育的动力机制,城市关键资源和区位优势将进一步转化为城市网络竞争优势。在网络发展环境下,中国政府需要在更大空间尺度上推动城市间合作,并积极应对城市间发展差距趋于扩大的问题。  相似文献   

3.
The goal of this study is to provide information on the process of pothole growth on a gorge streambed. Pothole geometries were measured in a reach of the Dabu river bed at the head of a gorge more than 200 m deeply incising into a 650–750 m high planation surface formed in the middle Miocene in northern Guangdong, China. Geometric and derivative data of the potholes obtained from fieldwork were interpreted using standard statistical methodologies. Our study shows that the formation and development of a stream pothole were only related to local conditions of a stream reach where the pothole occurs; the weaknesses, which are usually intersect fractures, typically interconnected vertical joints, or triangular pits generated by hitting of rock fragments during floods, initiate the pothole development on a streambed; the geometrical dimensions of the potholes are controlled by tectonic joints developed in bedrock of the stream reach; the radius and the depth of potholes are strongly (log) positive correlated; the pothole shapes and the flow patterns are inconstant during pothole growth; a pothole can be formed within a short period, but cannot be fully developed and maintained for a long time in a strong incision streambed. The finding in our study can improve the understanding of Quaternary environment in Guangdong.  相似文献   

4.
Forest commons in Slovenia are a poorly known indigenous institution for common resource management. They are a functional entity linked to a specific community that establishes interpersonal and intergenerational ties, as well as a link to the resource. We refer to shared ownership of resource, once made of pastures; today forests prevail. Collective property management remained despite community changes and legislation development. Today registered forest commons represent approximately one-third of those that existed before 1945. We highlight seven developmental turns to explain their revival. Six indicators are used in the analysis of current conditions. Forest commons are a potentially effective response to forest management challenges in Slovenia but also a potential model of social cohesion, rational resource use, and a balance between forest use and conservation. However, they are plagued by state ignorance, which hinders statistically sound analyses.  相似文献   

5.
陈霄 《地理研究》2014,33(7):1217-1229
酒吧作为城市休闲空间的代表,近年来迅速地在中国城市中扩散。欧美世界的酒吧与地方秩序、社会问题联系紧密,第三世界的酒吧经常被西方学者作为西方的文化飞地,地方权力集中的代表。运用克里斯威尔的“不得其所”为概念框架,以中国沿海城市宁波的一条酒吧街老外滩为案例地,通过问卷调查与访谈观察中外消费者的不同消费行为及空间选择,探讨中国酒吧街的权力结构,试图找出一条不同于西方语境的地方权力建构路径。所得结论如下:① 宁波老外滩酒吧街的“不得其所”现象表现为:中外消费者在选择酒吧上是空间分离的,而且在中国消费者存在的酒吧并不欢迎外国消费者,这一现象建构了酒吧街的地方性;② 参与老外滩地方性建构的主要力量是中外消费者,其中中国消费者在建构地方性中占据主导地位,他们不仅不再将酒吧街作为外国人消费的场所,也排斥不属于自己群体的其他人;③ 与西方研究多认为第三世界酒吧是西方的“文化飞地”,消费者通常是西方人或接受过西方教育的本地精英,其他本地人被隔绝在外不同,宁波老外滩的酒吧呈现出一种中国消费者“反隔离”西方消费者的现象。  相似文献   

6.
J.M. Hooke   《Geomorphology》2007,91(3-4):236
River meanders are natural features on the surface of Earth that present some degree of regularity of form. They range from being highly dynamic to being stable under present conditions. Conventional theory is that meanders develop to an equilibrium form which is related to discharge and sediment load. Other research has demonstrated that many highly active meanders exhibit a continuous evolution over time and a non-linearity in rate of development. Ideas of autogenesis and of self-organised criticality as being an explanation of some meander changes have been proposed. In this paper data from rivers around the world are examined for further evidence of autogenic, self-organised or non-linear behaviour through analysis of change in sinuosity over time for reaches and change in individual bend form, particularly bend curvature and bend elongation. Some examples do exhibit trends of increasing sinuosity over time and a few show limits from which large decreases occur. Several case studies show non-linearity of behaviour and increasing complexity of form. Other case studies, however, do not exhibit such trends. Phase space plots are used to help uncover emergent behaviour but show a variety of patterns. The example of a reach in which multiple cut-offs occurred is analysed for mechanisms of self-organisation of the planform and in the pool-riffle pattern. Riffles are more closely spaced and also more transient in the more rapidly changing and higher sinuosity parts of the channel. Hypothetical trajectories of different meander behaviour, including for bedrock meanders, are plotted but the challenge remains to uncover the conditions for occurrence and for divergence of tendencies to stability and instability. Identification of attractors and phase space of behaviour of different meandering systems offer the potential for application to sustainable channel management.  相似文献   

7.
Pore-water conditions are not well known in road cut slopes in the tropics, despite the particularly acute stability problems in many areas in that climatic zone. Two prediction models are formulated from a study of conditions in road cut slopes in the Caribbean island of St Lucia. These are shown to be capable of predicting pore-water pressures to an acceptable level of accuracy from knowledge of only storm precipitation, material permeability and topography. More generally, such procedures are seen as potentially helpful in the context of cut slope design in tropical areas.  相似文献   

8.
高阳  冯喆  娄峰  李双成 《地理研究》2013,32(7):1345-1355
地理学研究以综合性和区域性为特色。提高地表过程研究中人文与自然要素综合分析的深度与广度,寻找学科交叉的综合途径是地理学中具有挑战性的课题。可计算一般均衡模型(Computable General Equilibrium,CGE) 是环境与经济系统之间互动影响关系模拟的有力工具,在地理学综合研究中得到广泛应用。本文概括了CGE模型在资源环境的可持续性、气候变化与资源税、灾害与综合风险管理、污染物的区域环境过程等多个方面的应用,从模拟主体、模型约束、模拟方法以及过程与结果表达4 个角度,总结了CGE模型与地理学综合研究之间的契合点,并指出与地理学其他模型的耦合以及情景模拟的地理学依据是CGE模型下一步的发展方向。  相似文献   

9.
This paper takes a new approach to investigating people who age in place. It provides an explanation for why people age in a place that can be useful in government and corporate planning. Our research investigates the principal factors that drive the decision of a rising number of older Australians to age in place. Many older people wish to age in place rather than move in with their children or be institutionalised. They wish to continue to be active in their local communities and maintain their existing social ties. The concept of ageing in place covers two distinct groups: those who are able to stay in their current dwellings and age in home and those who move house but remain in their local community and age in neighbourhood. Age-friendly home modification is a response to ageing in home, whereas the provision of institutional healthcare and the provision of age-suitable housing to facilitate downsizing are associated with ageing in neighbourhood. Using Household, Income and Labour Dynamics in Australia (HILDA) survey data, this research examines the mobility decisions of older Australians and identifies the major determinants of a decision to age in place. This research argues for a better understanding of ageing in place, differentiating between those ageing in home and those ageing in neighbourhood.  相似文献   

10.
There are a number of serious problems connected with building and repairing water-retaining elements in embankment dams in cold regions. One of them is the difficulty in finding inexpensive clay materials with the necessary structural properties and using them in the winter. Another is the cracks that appear in the upper part of a dam when the core freezes to the banks, and leakage along the cracks threatens to destroy the dam. Still another is the process of erosion at the bottom of the core which may occur through fissures in the rock foundation of a dam and in transport constructions. Also, the behaviour of water-retaining elements during earthquakes is unreliable. All of these problems can be solved by using ice- and cryogel-soil composites created by cryotropic gel formation (CGF). Our laboratory investigations demonstrate that the materials proposed for water-retaining elements have the necessary permeable, plastic, thermophysical, and strength properties to solve all of these problems. Certain constructions of water-retaining elements which may prove to be both safe and cost-effective are proposed. However, these ice- and cryogel-soil composites need to be field-validated before they are used in dams and transport structures in cold regions.  相似文献   

11.
采用总人口和劳动力等直接指标单独测度,结合出生率、死亡率、少年系数和老年系数等指标进行综合测度,分析1996—2015年非洲51个国家(地区)人口扩张区的数量变化、空间分布及演化特征,并对比了不同测度指标和方法之间的差异。发现:①总人口扩张区的比重虽高,但扩张程度有所放缓,地域分布整体呈现“南北弱、中部强”的特征,其在东非地区缩减明显;②劳动力扩张区较总人口扩张区扩张程度更为明显,两者在北非和南非部分地区差异较大,其地域分布整体呈现“北退南进”的变化过程;③“劳动力增长率大于总人口增长率”地区比重高于“总人口增长率大于劳动力增长率”,且差距有不断拉大的趋势,前者以北非地区西北部、西非地区几内亚湾沿岸较为集中,后者主要集中分布在中非、东非与西非部分地区;④基于综合指标结果显示,重度扩张型占有较高的比重,中度扩张型增速较快,轻度扩张型占比呈波动下降;⑤综合指标与单一指标结果有一定的趋同性,但区别也比较明显,综合指标在综合性、前瞻性方面有一定优势。  相似文献   

12.
The article gives an overview of the work pursued by the medical geography research group in Trondheim. Activities are centred on a mortality data base containing more than 800,000 individual records for 1966–1985, with very flexible options for geographical manipulation. In addition, several other data bases are being used. References are made to research on regional variations and trends in cardiovascular disease and some cancers, and their potential causes, to comparisons between mortality patterns in Iceland and Norway, and to a thesis on aspects of the health and health care system in Poland.  相似文献   

13.
荒漠土壤微生物群落结构特征研究进展   总被引:3,自引:2,他引:1  
李婷  张威  刘光琇  陈拓 《中国沙漠》2018,38(2):329-338
荒漠生态系统占地球陆地面积三分之一,是地球化学循环中的重要部分。荒漠干旱高温、缺乏植被、UV辐射强,曾被认为是没有生命的地方。然而在这恶劣环境中却蕴含有大量的微生物资源,尤其是荒漠土壤富集了大量微生物。微生物参与和主导整个荒漠生态系统地球生物化学循环,对于调节重要生态过程、修复和稳定荒漠生态系统起到重要作用,对其的研究生态学意义突出。本文综述了国内外对荒漠土壤微生物群落结构特征、群落功能多样性以及微生物群落、微生物与植物、微生物与环境之间相互关系的研究现状,旨在充分了解荒漠土壤微生物多样性研究,总结对荒漠微生物生态认识的不足,为荒漠微生物生态研究方向提供参考。  相似文献   

14.
Candidates for possible Precambrian proto-basement throughout Svalbard are considered and evaluated. The paper provides a tectono-stratigraphic framework for consideration of new data. Proto-basement, in the sense of basement in Proterozoic time, implies the occurrence of a Precambrian tectonic event. Vendian rocks are widespread in Svalbard and, because there is no known Vendian major tectonic event, the search is narrowed to pre-Vendian rocks. The approach is primarily tectono-stratigraphic, to identify a significant break by unconformity, contrast in metamorphic facies and isotopic age determinations.
The paper concludes that the following rock units are proto-basement: Isbjømhamna and (newly defined) Eimfjellet groups, Nordbukta Group, Magnethøgda Group, the Richarddalen Complex; the Atomfjella Complex, the Brennevinsfjorden Group and the granitoids related to the Kapp Hansteen Group and the Duvefjorden Complex. While considered unlikely to be proto-basement the following cannot be ruled out: the Mefonntoppane and Kistefjellet rocks and the Sigfredbogen unit, the blue-schist Vestgötabreen rocks, the Pinkie Formation and parts of the Kongsvegen Group.
Terrane implications are consistent with the three terrane model of Harland & Wright (1979), modified by Harland et al. (1993); but the data presented here hardly constrain such a model. In so far as the conclusions here are valid the effect is to subtract from, rather than add to, the outcrops commonly mapped as likely proto-basement.  相似文献   

15.
我国半干旱地区现代沙漠化驱动因素的定量辩识   总被引:28,自引:9,他引:19  
董玉祥 《中国沙漠》2001,21(4):412-417
现代沙漠化的成因是目前沙漠化研究中争论较大的问题之一,其根源在于对现代沙漠化驱动因素的辨识不清,难以确定现代沙漠化过程中的主要驱动因素。本文对位于我国半干旱地区的主要沙漠化地区科尔沁、浑善达克、乌盟后山、共和盆地、藏北高原和藏南河谷地区内各选择一个典型区,分别是白音他拉、那日图、西井子、共和盆地、那曲地区和扎囊县,利用主成分分析和相关分析等定量方法,分析了6个典型区现代沙漠化过程中多种影响因素的作用,找出了现代沙漠化过程中的主要驱动因素。研究结果,6个典型研究区现代沙漠化的驱动因素具有综合性、地域性和主导因素的差异性,说明在我国半干旱地区的现代沙漠化是一个自然与人为因素共同作用的综合过程,其驱动因素有着较大的地域性和差异性。推广之,对我国沙漠化驱动力或成因的认识也不能一概而论,现代沙漠化的成因应具有一定的地域性。  相似文献   

16.
广东大峡谷河床壶穴形态的形成与发育   总被引:1,自引:0,他引:1  
The goal of this study is to provide information on the process of pothole growth on a gorge streambed. Pothole geometries were measured in a reach of the Dabu river bed at the head of a gorge more than 200 m deeply incising into a 650–750 m high planation surface formed in the middle Miocene in northern Guangdong, China. Geometric and derivative data of the potholes obtained from fieldwork were interpreted using standard statistical methodologies. Our study shows that the formation and development of a stream pothole were only related to local conditions of a stream reach where the pothole occurs; the weaknesses, which are usually intersect fractures, typically interconnected vertical joints, or triangular pits generated by hitting of rock fragments during floods, initiate the pothole development on a streambed; the geometrical dimensions of the potholes are controlled by tectonic joints developed in bedrock of the stream reach; the radius and the depth of potholes are strongly (log) positive correlated; the pothole shapes and the flow patterns are inconstant during pothole growth; a pothole can be formed within a short period, but cannot be fully developed and maintained for a long time in a strong incision streambed. The finding in our study can improve the understanding of Quaternary environment in Guangdong. Foundation: National Natural Science Foundation of China, No.40871020; Guangdong Natural Science Foundation, No.7005836 Author: Wang Wei (1956–), Ph.D and Professor, specialized in Quaternary geology and geomorphology.  相似文献   

17.
Mike Coombes  Simon Raybould 《Area》2004,36(2):202-222
Early results from the 2001 census of England allow a preliminary analysis of joblessness. People in the prime working ages (25–49) are more likely to be in work than those in their 50s, but the differences are quite subtle: in particular, men without qualifications are not much more likely to be in work when they are younger, despite the suggestions that too many men cease working in their 50s. The evidence supports the view that there is a national shortfall of demand for labour, that the low-skilled are the least able to compete for scarce jobs, and older people are the most likely to be unqualified. Moreover there is a strong spatial clustering of areas where job availability has declined or grown least, undermining the government's claim that there were often available jobs near to concentrations of people without work.  相似文献   

18.
我国生物地理学研究进展   总被引:6,自引:1,他引:5  
生物地理学研究是生物学和地理学交叉非常明显的部门自然地理学学科,它具有很强的基础研究特点,同时研究成果也具有很大的应用潜力。近年来,我国生物地理学基础研究在国家自然科学基金委等部门的支持下,在山地植被与地理环境、干旱半干旱区植被与地理环境、植物区系、植物物候、土壤动物与土壤生态功能、土壤生物结皮等方面开展了全面而深入的研究。同时拓展了传统生物地理学的研究方向,在植物地理学与全球变化、植物地理学与生物多样性保护、植物地理学与生态系统管理等方面也开展了大量研究。尤为可贵的是干旱半干旱区土壤生物结皮研究、典型温带荒漠区原生荒漠植被对水分改变的响应与适应研究取得了令国内外关注的高水平研究成果。  相似文献   

19.
Urbanization trends in Botswana are reviewed. The colonial origins of urbanization are first outlined. The author then focuses on the period since independence and finds that urbanization is a recent phenomenon. Although the rate of urbanization is high, the country as a whole remains relatively unurbanized.  相似文献   

20.
In the current climate of economic restructuring, technological change and demographic transition, cities such as Melbourne are experiencing new and different pressures. That these pressures are exerted upon an already developed urban structure, and within a particular planning and administrative structure, means that outcomes vary from city to city. However, Melbourne, in common with a number of cities, is facing substantial changes in many aspects including the nature and location of economic enterprise, the structure and composition of the population, and the relative competitive strength of the region. The result is that Melbourne has experienced problems both in its ability to hold and continue to attract activities which provide a basis for further growth and development, and in the exacerbation of internal variations in the level of opportunity and quality of life available to different groups in the population.

The role of government has traditionally been relatively minor in guiding the process of urban development in Australia. However, since 1982 the state government in Victoria has made a concerted effort to reorganise and coordinate urban management and planning, integrating these with other strategic initiatives relating to economic development and social justice. While there is evidence that many of the initiatives are proving effective, there are still a number of problem areas. Some of these, such as global economic trends, are beyond the scope of government to control. Others, such as measures to facilitate the development of new economic activities, are within the power of government, but require careful formulation and management. The extent to which such measures are successful depends upon both the correct identification of problems and solutions, and the ability of government to gain a wide degree of acceptance of its goals. It is these that will prove the most difficult to achieve in the long run.  相似文献   


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