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51.
试论我国城市发展方针 总被引:6,自引:0,他引:6
在执行重重工业的发展战略和城乡分割体制的计划经济背景下,我国制定了“控制大城市规模,合理发展中等城市,积极发展小城市”的城市建设方针。但是分析表明,这一方针不能适应市场经济和对外开放形势的需要,也不符合我国人多地少、农村剩余劳动力多的国情,必须调整现有的城市发展方针,选择适宜的城市化发展道路。因此,本文就适度发展大中城市,提高城市现代化水平;加速乡村城市化,积极合理发展小城镇;以及根据不同地区的具体情况,因地制宜地指定城市化途径等方面作了探讨。 相似文献
52.
本文以山东省日照市蓝色经济区为研究区, 通过野外地质调查和室内综合分析, 选取场地稳定性、工程地质条件、地下水条件, 地形排水条件、地质灾害及其他因素6个一级评价因子, 构造活动、场地土类型、建筑场地类别等13个二级评价因子, 利用专家-层次分析定权法进行区内工程建设适宜性评价, 得到了相应工程建设评价分区图。评价结果表明, 日照市场地工程建设适宜性总体较好, 大部分地区适宜进行高层建筑工程建设, 占84.50%; 地下空间开发利用条件优越, 全区多数地区属于城市地下空间建设适宜区, 适宜性差及不适宜区主要分布在付疃河两岸附近和海岸附近、大型高速公路和铁路沿线一带区域及城区; 轨道交通建设适宜性良好, 小部分不适宜区主要集中在付疃河下游夹仓和小古镇一带及其沿海地区。评价结果可有效地服务于该地区规划布局、建设发展和工程选址, 具有重要的理论和实践指导意义。 相似文献
53.
本文介绍了全球稀土资源供需历史、现状和对未来的展望。从矿床成因视角切入,将稀土矿床分为内生和外生两大类型,其中内生稀土矿床包括碳酸岩型、碱性岩型、碱性岩型- 碳酸岩型、氧化铁铜金型、热液脉型,外生稀土矿床包括风化壳离子吸附型、沉积岩型、沉积矿产(煤矿、铝土矿和沉积磷矿)伴生型、砂矿和现代海洋底部含稀土的锰结核、结壳和软泥型。归纳总结了主要类型矿床的基本特点和时空分布;认为内生稀土矿床产出于四类构造环境,包括裂谷环境、碰撞后伸展环境、大陆碰撞环境和后俯冲伸展环境;从构造演化入手,探讨了在外生与内生地质过程中稀土元素的迁移和富集规律,建立了涵盖主要矿床类型的构造- 成矿模型。 相似文献
54.
P. D. Katsabanis A. Tawadrous C. Braun C. Kennedy 《Fragblast: International Journal for Blasting and Fragmentation》2006,10(1):83-93
A series of small scale tests, simulating multi-hole blasts have been performed to establish the effect of delays on blast fragmentation. The blasts were performed in high quality granodiorite blocks, which were cut from stone prepared by dimensional stone quarry operations. The pattern used was equilateral triangular, with a distance of 10.2 cm between boreholes, which had a diameter of 11 mm, were loaded with detonating cord and the coupling medium was water. The delays used were achieved using different lengths of detonating cord for the cases of delays between 0 and 100 μs between holes and a sequential blasting machine firing seismic detonators for larger delays up to 4 ms. All fragments were collected and screened. The experiments showed that the worst fragmentation was achieved with simultaneous initiation of all charges. Fragmentation improved with the delay time between holes up to 1 ms between holes. If the experiments are scaled up, the results show that in granodiorite, fragmentation optimization requires delays of few milliseconds per metre of burden. The findings, agree with previously published work, involving larger scale experiments and other rock types. 相似文献
55.
Within the framework of recent research projects, basic tools for GIS-based seismic risk assessment technologies were developed and applied to the building stock and regional particularities of German earthquake regions. Two study areas are investigated, being comparable by the level of seismic hazard and the hazard-consistent scenario events (related to mean return periods of 475, 2475 and 10000 years). Significant differences exist with respect to the number of inhabitants, the grade and extent of urbanisation, the quality and quantity of building inventory: the case study of Schmölln in Eastern Thuringia seems to be representative for the majority of smaller towns in Germany, the case study of Cologne (Köln) stands for larger cities. Due to the similarities of hazard and scenario intensities, the considerable differences do not only require proper decisions concerning the appropriate methods and acceptable efforts, they enable conclusions about future research strategies and needs for disaster reduction management. Not least important, results can sharpen the focus of public interest. Seismic risk maps are prepared for different scenario intensities recognising the scatter and uncertainties of site-dependent ground motion and also of the applied vulnerability functions. The paper illustrates the impact of model assumptions and the step-wise refinements of input variables like site conditions, building stock or vulnerability functions on the distribution of expected building damage within the study areas. Furthermore, and in contrast to common research strategies, results support the conclusion that in the case of stronger earthquakes the damage will be of higher concentration within smaller cities like Schmölln due to the site-amplification potential and/or the increased vulnerability of the building stock. The extent of damage will be pronounced by the large number of masonry buildings for which lower vulnerability classes have to be assigned. Due to the effect of deep sedimentary layers and the composition of building types, the urban centre of Cologne will be less affected by an earthquake of comparable intensity. 相似文献
56.
Landscapes change in complex ways, creating surface patterns reminiscent of forms seen through a kaleidoscope. On the Earth's surface, those forms are linked to, and caused by, processes that originate with bedrock‐soil‐vegetation‐atmosphere interactions. Human‐caused alterations to landscapes are additionally tied to socioeconomic processes. Evaluation of landscape‐level processes can benefit from examining (1) the influence of disturbance regimes in altering landscape patterns, (2) the importance of considering surficial processes, (3) the subtle and cryptic spatial relations that may be present, (4) the reciprocal relationships among local processes and regional consequences, (5) the increased likelihood of some land cover transitions compared to others, and (6) the special case of landscapes with long histories of human use. These are all examples of potential fruitful arenas for interactions and represent a path for expansion of landscape ecology through accommodation of a broad range of content covered by the international GIScience community. 相似文献
57.
The place of individuals in the politics of scale 总被引:1,自引:0,他引:1
Julie Cidell 《Area》2006,38(2):196-203
Conceptualizations and re-conceptualizations of scale have been powerful tools for explaining spatial processes that transcend traditionally-bounded territories. Examining the role of individuals within a politics of scale can do even more to explain multi-scalar conflicts. This paper does so by examining struggles over airport expansion in the US, showing how an understanding of the various roles of individuals in the politics of scale – as sites of multiple scales, as actors constituting other scales, and as scales in and of themselves – better explains multi-scalar conflicts and offers more opportunities for resolving them. 相似文献
58.
'Dad says I'm tied to a shooting star!' Grounding (research on) British expatriate belonging 总被引:1,自引:0,他引:1
Katie Walsh 《Area》2006,38(3):268-278
This paper analyses one British woman's everyday practices of belonging as she negotiates expatriate life in Dubai, United Arab Emirates. In doing so, it responds to widespread calls to ground research on processes of transnationalism and diaspora by drawing on 18 months of ethnographic research and adopting a three-stranded analytical framework to reflect on the significance of domesticity, intimacy and foreignness in expatriate belonging. The author focuses on a single research subject to draw attention to a particular British expatriate experience otherwise neglected in migration research and the paper resonates with theoretical literatures aiming to challenge the binary divisions of geographies of belonging, including attachment/detachment. 相似文献
59.
60.
In their comment, Park & Ree have raised several points against the interpretation by Park et al. , and argued that the remagnetization in the Jeongseon area was caused by the thermal effects of a Late Cretaceous pluton and/or associated short-range hydrothermal fluids, rather than by long-range fluids advocated by us.
We disagree with most points raised by Park & Ree and we make a case that these are invalid because of what we believe is incorrect geologic evidence. Hence, our model—that the fluids causing the chemical remagnetization might migrate through the fault system within the Ogcheon Fold Belt—is the most plausible scenario. We recognize that our model needs to be tested in a future study and we welcome new interpretations for or against our model based on reliable geologic or geophysical data. 相似文献
We disagree with most points raised by Park & Ree and we make a case that these are invalid because of what we believe is incorrect geologic evidence. Hence, our model—that the fluids causing the chemical remagnetization might migrate through the fault system within the Ogcheon Fold Belt—is the most plausible scenario. We recognize that our model needs to be tested in a future study and we welcome new interpretations for or against our model based on reliable geologic or geophysical data. 相似文献