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1.
The concept of space is fundamental to various theories on the organization of intraurban economic activities. This concept has evolved from the totalitarian perspective of Greek philosophers into the contemporary space–time dichotomy. Through examining the historical concepts of space, the most significant limits of organizational theories regarding economic activity may be identified. Therefore, the aim of this paper is to analyze the evolution of the concept of space in addition to the relationship of this concept with different theories on the organization of intraurban economic activities. New reflections on the concept of space are presented in order to provide insight into future directions and perspectives in the analysis of urban space. Finally, this article explores the contemporary space–time dichotomy as applied to the organization of economic activities in the city and reflects upon space as an active, dynamic, and biased factor in such organization.  相似文献   

2.
A new and simple concept based on the idea of correcting for non-associative characteristics of (geologic) media is presented. A special form of the concept is adopted and introduced in a critical state plasticity model. An example problem of behaviour of a soil tested under triaxial conditions is included. The concept can permit a simplified treatment of non-associativeness and under certain assumptions can allow use of existing formulations of plasticity by maintaining symmetry of the associated matrices.  相似文献   

3.
痕迹组构的概念、型式与分析   总被引:1,自引:0,他引:1  
扼要介绍和论述了痕迹组构的概念、复合型式、痕迹分层、梯阶类型或结构模式以及痕迹组构的一般描述方法等内容。  相似文献   

4.
纳米结构矿物的特殊结构和表-界面反应性   总被引:1,自引:0,他引:1       下载免费PDF全文
袁鹏 《地球科学》2018,43(5):1384-1407
纳米矿物是纳米地球科学(Nanogeoscience)的核心研究对象之一.鉴于"纳米矿物"的概念在实际运用时较宽泛,有时与经典定义不符,建议用"纳米结构矿物"代替"纳米矿物",并简析了纳米结构矿物(Nanostructured Minerals)的概念.以管状纳米结构矿物(埃洛石和伊毛缟石)、球状纳米结构矿物(水铝英石)、层间纳米结构矿物(蒙脱石和伊/蒙混层矿物)和多孔纳米结构矿物(硅藻质蛋白石)为例,分析了纳米结构矿物的结构、表面基团的特殊性及其所衍生的特殊界面反应性,讨论了它们对矿物资源利用和油气生成等地球物质循环过程的重要意义.   相似文献   

5.
Astronomy Reports - The concept of a multi-functional astronomical complex as applied to robotic astronomy networks and systems is formulated. The practical realization of this concept in the...  相似文献   

6.
松权衡  于城  李军  秦洪莲 《吉林地质》2006,25(2):28-35,47
本文的主要目的是把地球化学块体概念、地球化学场概念及地球化学异常概念的异同性及空间关系进行比较,供读者加以参考。并从它们的基本概念开始论述,然后自内涵的相同与不同、以及在生产实践中的意义方面总结了3个勘查地球化学模式的区别与内在的联系;最后总结它们在地质找矿中的意义。  相似文献   

7.
首次讨论了第三环境工程地质问题,举出了在大型环境工程地质勘查中应用第三环境工程地质问题这一观点的成功实例。指出在进行第三环境工程地质问题的勘查与研究人员必须具有更加丰富的经验和广泛的知识,方能取得良好效果。  相似文献   

8.
土壤生态地球化学基准值及其确定方法   总被引:1,自引:0,他引:1  
从科研工作的实际需要出发,引入了"生态地球化学基准场"这一概念,并以此为基础探讨了土壤生态地球化学基准值的涵义及其概念。以漳州研究区试验结果为例,应用相关关系法有效地确定了土壤生态地球化学基准值,为相关研究提供了思路和参考案例。  相似文献   

9.
Fully softened shear strength is an important empirical engineering concept for slope stability analyses of cuts in stiff clays and compacted embankments constructed of high-plasticity clays. This concept has been used to explain many first-time failures for which the back calculated shear strength is below the peak strength measured in the laboratory. A comprehensive review of case histories and laboratory studies related to fully softened shear strength was used to assess the application of this concept. The case history data were also used to provide guidelines on the soil types for which fully softened shear strength is appropriate, how and when this shear strength should be used in slope stability analysis, and how the fully softened failure envelope should be characterized. This paper contains specific guidelines on when and how the fully softened shear strength concept should be used in slope stability analyses.  相似文献   

10.
This paper considers the results of development of the bilayer hydrosphere concept of the Earth offered by the author in 2000. The bilayering concept is logically based on the classical works in the field of geochemistry and is in the context of mid-twentieth century studies on the structure of the biosphere. The research methods based on this concept are interdisciplinary in nature and make it possible to unify and thereby to facilitate the solution of many problems in the field of oceanology, hydrology and other geographic sciences related to geochemistry.  相似文献   

11.
经验勘查与理论勘查的发展趋势   总被引:2,自引:1,他引:2  
施俊法  肖庆辉 《地质通报》2004,23(8):809-815
经验勘查与理论勘查相互依存,互为补充,二者都会促进实际观测和资料收集,促进矿产勘查。建立模型是这2种勘查战略固有的工作,是指导资料收集和资料解释的手段,而不是目的,或者说建模是勘查工作中深化资料收集和认识的运行过程,而不是终结。理论勘查与经验勘查的交叉与融合,是通向矿产勘查的成功之路。成矿理论研究正步入第三个里程碑阶段,形成了以地球动力学为核心的众多生长点,如岩石圈构造不连续面、流体作用、超大陆旋回、地幔柱与成矿作用等,它们都处于快速发展时期,不断产生新的成矿理论和认识。新方法和新技术的不断出现和发展为经验勘查注入了活力,极大地促进了找矿工程学的发展。  相似文献   

12.
Storm water control in urban areas helps to conserve the natural water balance and to protect soil and groundwater from hazardous substances. This paper introduces the concept for a near-natural storm water control system, including an associated decision-making chart. In this concept, the quantitative aspects of storm water infiltration are checked first. All important factors and their parameters, which enable a judgement on the tolerance of rising groundwater levels, are identified and evaluated. If the predicted rise in groundwater level is considered tolerable, the qualitative aspects of storm water infiltration are then checked. Again, all important factors and their parameters, which enable a judgement on the hazards to the soil and groundwater, are identified and evaluated. The presented concept also includes recommendations and demonstrates alternative control systems. Urban planners and public authorities are regarded as potential users of this concept.  相似文献   

13.
本文首次讨论了第三环境工程地质问题。根据多年工程地质勘查中所积累的经验教训,作者深感有单独提出第三环境工程地质问题这一概念的必要。与之同时,文中也举出了大大型环境工程地质勘查中应用这一观点的成功实例。此外,作者认为,进行第三环境工程地质问题的勘查与研究的人员必须具有更中丰富的经验和广泛的知识,方能取得良好效果。  相似文献   

14.
岩质边坡稳定性的工程地质研究   总被引:14,自引:0,他引:14       下载免费PDF全文
孙玉科  李建国 《地质科学》1965,6(4):330-352
岩质边坡稳定问题是工程地质学的一个重要研究課题,也是工程实践中迫切要求解决的问题。但是,对这个问题的研究,无论是国內国外都在进行探讨,还沒有形成一套完整的理论体系。为了推动这一方面的研究工作和解决生产实践中所提出的问题,本文试图从工程地质观点,并结合力学概念作一初步探讨,不妥和错误之处,希读者批评指正。  相似文献   

15.
The ‘poly morphological (PM) concept’ is used to assess geological heterogeneity in glacial sediments and to evaluate groundwater recharge to aquifers, especially those underlying clay till. The novelty of the PM concept is that it enhances the knowledge of, especially, heterogeneity of till units in geological models by using superimposed geomorphological units with typical sediment types related to the individual landforms. The PM concept is demonstrated through the construction of a poly morphological map for Zealand in Denmark and an aggregated map comparing clay-till-thickness distribution within individual PM types. The hydrogeological applicability of the PM concept was tested with a physical-based distributed 3D hydrological model. The aggregated PM map was compared with fracture and redox conditions at 21 field sites to evaluate the PM-type correlation to: (1) till thickness, (2) thickness of the reduced-till zone, and (3) depth to the zone with fracture spacing >1 m The results show that the till thickness is a critical parameter for the formation of fracture networks in clay till, and that fracture density decreases in till thicker than 8–10 m. However, the amount of data is still inadequate for statistically proving the PM concept.  相似文献   

16.
在分析和总结前人对红藻石和蓝藻石研究成果基础上,结合岩石薄片显微镜下观察实例,发现在以往碳酸盐岩颗粒分类中没有红藻石和蓝藻石的合适位置。鉴于红藻石重要的成因意义和造礁作用,有必要明确红藻石的概念和归属。珊瑚藻本身极易钙化,经生物矿化作用最终保存下来的珊瑚藻屑一直放在生物碎屑中,而红藻石是由非固着的珊瑚藻构成的钙质独立结核,因此也可以被划分到生物碎屑中。蓝藻石作为蓝细菌钙化作用的产物,同时鉴于蓝藻石的广泛存在,把钙化蓝细菌形成的核形石命名为蓝藻石,这一重要概念从提出到现在一直被使用。然而蓝绿藻概念已变更为蓝细菌,蓝藻石的形成与藻类无关,显然将其称作蓝菌石更加确切。因此,应将红藻石和蓝藻石分别归为生物碎屑和核形石当中,并用新的术语蓝菌石替代蓝藻石。其意义在于使红藻石和蓝藻石的概念及归属更为规范,并为碳酸盐岩颗粒的深入研究提供有益线索。  相似文献   

17.
根据产业发展规划的编制要求,结合实际案例,探讨了规划的总体编制理念和分析方法,即科学发展观、系统观念、综合集成法,并对产业生命周期、SWOT分析等进行了探讨。  相似文献   

18.
The purpose of this paper is to visualize atmospheric ozone data using a new knowledge representation method called Formal Concept Analysis. This method is based on the concept of concept and represents data in hierarchical line diagrams combining the logic of implications with statistical frequency analysis and hierarchical search methods.  相似文献   

19.
Nancy Worth 《Geoforum》2009,40(6):1050-1060
Drawing on recent work in psychology, philosophy, and youth geographies, this article responds to calls for theoretical rigour in children’s geographies by developing the concept of becoming for youth transitions research. Becoming has been used by psychologist Gordon Allport (1955) in his work on the processual nature of personal identity, while Elizabeth Grosz (1999) has used the concept of becoming to explore conceptions of time as a lived experience, focusing on the dynamics of time as duration. This article uses the unifying concept of futurity to tie together the works of Allport and Grosz, exploring how the concept of becoming can be used to consider the inherent complexities of contemporary youth transitions. To demonstrate the value of working with these reconceptualizations, examples of becoming will be explored through research with visually impaired young people. This research productively uses narrative and a life mapping technique to capture the messiness of becoming, seeing transition through the scale of a life and important life events.  相似文献   

20.
复合地基变形控制设计新思想   总被引:3,自引:1,他引:3  
变形控制设计一直是复合地基设计中的难点,现今提出了“变参数、变刚度、整体调平”的设计思想,同时指出了实现此设计思想的复合地基变形控制设计系统(DCDS)的开发流程。鉴于复合地基实践超前于理论的现实,为了完善“变参数、变刚度、整体调平”复合地基变形控制设计,最后指出了围绕这一设计思想需要进一步研究的重要问题。  相似文献   

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