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11.
Traditional models of urban development are no longer adequate to describe current metropolitan transformations. These are now at the centre of a debate concerning management and administration. In Italy, delays in resolving problems of urban and metropolitan government, despite the legal framework provided by Law 142/90, have weighed heavily on the larger urban areas of the country: Rome, Naples, Milan, which have not been able to tackle the issue of metropolitan government. Recent legislation, while not providing a pre-defined institutional solution, allows separate administrative districts to collectively establish metropolitan institutions of `variable geometry'. The Milan urban area is not one city, but a system of mutually-dependent cities, linked to each other and the rest of the world by a transport network still requiring much investment. The vitality of its economic structure (especially its small firms) is held back by seriously inadequate infrastructure and low external economic efficiency. The provincial capital may boast `historic centrality' but the most interesting potential for development is to be found on the periphery and in the administrative districts immediately surrounding it, in the recovery of derelict industrial areas and dormitory towns established in the 1950s and 1960s, especially to the north. Recovery of derelict areas, green areas, and better transport links within the urban area and with the outside world are the key elements in the reorganization of `Greater Milan'. In this situation of rapid transformation the most appropriate political strategies involve negotiated planning. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
12.
西南地区铀资源现状与找矿前景展望   总被引:9,自引:2,他引:9  
陈友良 《铀矿地质》2004,20(1):1-3,15
本文概述了西南地区铀资源现状,简要介绍了滇西、川西高原、川北、黔中4个铀成矿区的基本特征,并对西南地区的找铀前景进行了展望。  相似文献   
13.
Solutions to the problem of discarding in fisheries have been debated for decades. Despite this attention, measures to ameliorate discarding have had limited success. Regulators, researchers, and industry continue to struggle with fisheries management and foregone yield in the face of the continued wastage of valuable resources due to discarding.Waste minimization and by-product utilization are powerful imperatives in other sectors that are also reliant on the harvest of natural resources. This paper considers the performance of these sectors in waste minimization and by-product utilization, with the aim of identifying practices and processes that may be applied to ameliorate discarding in fisheries.This paper describes the handling, utilization, and mitigation of discards and waste in the livestock farming, agriculture, mining, and waste management industries, and in particular, in forestry. In terms of biological impact, economic objectives, and management approaches the harvesting of trees has substantial similarities to industrialized fishing. However, the forestry sector has found ways to utilize almost 100% of the natural product harvest by establishing markets and new products. Analogous developments within the fishing industry could substantially improve sustainability through reduced levels of discarding and wastage. Based on the experiences of these sectors it is suggested that evaluations of potential Management Strategies are developed to specifically examine discard mitigation approaches on a broader scale than previously conducted.  相似文献   
14.
李家振  张爱民 《现代地质》1997,11(2):253-260
摘 要  北淮阳金寨—苏仙石地区中生代侵入岩出露面积约150km 2 ‚按岩石谱系单位的划 分原则‚可分为3个超单元(包括10个单元)和3个独立单元。根据主要造岩矿物及副矿物组 合、岩石化学和地球化学特征判别结果‚岩体成因类型以 I 型为主‚少数为 A 型和 S 型。岩 浆来源约30km 深处‚相当于下地壳或壳幔过渡部位。岩体形成深度约3~4km‚压力约0∙1 ~0∙2GPa。形成温度约866~1150℃‚氧逸度 log f O 2 平均为—10∙97。进一步讨论了岩浆的 水逸度、水压及岩浆密度、岩浆演化和侵入岩与火山岩的成因关系。  相似文献   
15.
Considering the fact that there is only one pair of fixed potential poles in one direction used to monitor the resistivity changes under the observatory station which may indicate process of earthquake preparation, based on the precondition that the resistivity structure is 1-dimensional under the observatory station, and by way of equivalent model put forward by the authors, this paper suggests a kind of method trying to separate the resistivity changes in deep layers from that of the shallow layer. Analysis shows that, to obtain the same measured data with the same array, any a multi-layered geo-electrical structure can be equivalently taken as a two-layered one, we call it equivalent model. In this paper, the resistivity and thickness of the upper layer of the equivalent model are equal to that of the first layer of the original one, the resistivity of the lower layer of the equivalent model is obtained with calculation according to the requirement of equivalence, its value is relevant with the resistivities and thicknesses of all layer of the original model except for the first one, so the resistivity change of the equivalent layer can indicate the synthetic effect of variation of all layers of the original model except for the first one. The primary research results show that this method can work well. Foundation item: Chinese Joint Seismological Science Foundation (100146).  相似文献   
16.
空间信息技术是防洪减灾现代化的基础   总被引:2,自引:5,他引:2  
我国洪涝灾害频繁,洪灾损失严重,防洪减灾将是一项长期而艰巨的任务。在防洪减灾研究中,必须积极引进当今最新科学技术成果,以高新技术改造水利这一传统产业,以水利信息化推动水利现代化。以遥感、地理信息系统和全球导航定位系统为支撑的空间信息技术可以广泛地应用于防洪减灾中,是防洪减灾现代化的基础。本文分析了空间信息技术在防洪减灾中的作用,并对空间信息技术在防洪减灾中的应用趋势作出展望。  相似文献   
17.
1 Introduction The mean meridional circulation plays an important role in the transportation and balance of heat, momen- tum, vortex and vapor between different latitudes. According to the data analysis, there are three circula- tions from the equator to the polar area: the Hadley circulation, a heat-driven circulation which rises around the equator and sinks at a certain latitude; the subpolar circulation, another heat-driven circulation around the polar area; and the Ferrel circulation, an i…  相似文献   
18.
19.
东昆仑野马泉地区矽卡岩矿床地质特征及控矿条件   总被引:16,自引:1,他引:16  
野马泉地区蕴藏有丰富的矽卡岩型铁、铜、铅、锌、银矿床等,是东昆仑地区重要的多金属矿产地之一。对野马泉多金属矿床的产状、矿物共生组合、矿石结构构造、围岩蚀变类型等进行了研究,查明矿床主要产于花岗岩与围岩的接触面及其附近的断裂带中,其形成与区域晚古生代-早中生代构造岩浆旋回末期的岩浆活动关系密切,属岩浆矽卡岩型矿床。  相似文献   
20.
周莉蓉 《四川测绘》2001,24(3):122-124
在目前流行的计算机制图中,必须面对如何解决使用不同投影的地图资料的问题,本文从实际应用的角度出发,介绍并讨论解决方法及应用手段。  相似文献   
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