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491.
South Africa has developed niche competencies around the extraction and processing of mineral resources. Firms involved in the manufacture and supply of inputs to mining and mineral processing represent a key source of competitive advantage upon which future growth and development in the country can be planned. Drawing on a qualitative and quantitative study of 678 supplier firms conducted in 2004, this paper presents an assessment of the state of the South African minerals inputs cluster. The various demand and supply relationships, dynamics, and growth opportunities within the cluster are highlighted and the threats affecting the cluster's future competitiveness reviewed. The interventions needed to overcome and/or enhance them are also identified.  相似文献   
492.
The steadily increasing world market prices for fossil fuels in the past years have significantly increased interest in the development of indigenous sources of energy in the Pacific islands. As an import substitution strategy, many Pacific island Governments are looking into the use of local biomass resources to replace traditionally imported fuels such as petrol and diesel by biofuels. An overview of biofuel activities is given, with experiences and key achievements in Fiji, Samoa, Vanuatu, Solomon Islands, Papua New Guinea, Kiribati and Marshall Islands with regard to efforts to develop alternative fuels. There are strong linkages between developments in the various Pacific island countries and lessons to be learned from experiences and policies implemented among Governments in the Pacific region. The paper concludes that there is a need for standardization, quality control and testing facilities for biofuels in the region. Governments need to investigate further the level of support that is required to make biofuel operations viable and maximize macroeconomic and environmental benefits.  相似文献   
493.
The extent and causes of changes in the fresh-water wetlands of South Kingstown, Rhode Island were determined through field work and through the analysis of panchromatic aerial photographs taken in 1939 and 1972. During this period, there was a net loss of 0.9 percent of the total area (2345.2 ha) of wetland present in 1939. Highway construction and residential development accounted for most of this loss. Approximately 17 percent of the wetland present in 1939 had changed sufficiently by 1972 to warrant reclassification. Plant succession alone accounted for 57 percent of the changes in wetland types, while man's activities were influential in 41 percent of the cases. Ninety-two percent of the natural changes in wetland types was progressive, while 58 percent of the changes induced by man and undetermined causes was retrogressive. Man's major role was to alter the water regimes and vegetation of wetlands. There was a decrease in wetland diversity as the most abundant type, wooded swamp, grew in area while the abundance of shallow marshes, meadows, and shrub swamps declined. A knowledge of wetland dynamics is essential in the management of wetlands for a diversity of wildlife and other natural values.  相似文献   
494.
南海渔业资源具有"公共池塘资源"的基本属性是导致其面临地缘政治紧张局势的内生困境,为此有必要从南海渔业在低敏度领域的现实表征为立足点,与南海领土主权与海域划界争端等高敏度领域相互结合的角度考察与评判南海渔业资源环境保护的主权变动动向:应该注重传统捕鱼权在南海周边国家的海洋管辖权边界的应用.以东南亚渔业管理组织和新建立南海渔业管理组织联合协同组织新的东南亚渔业管理组织必定有助于南海渔业资源纠纷的解决.  相似文献   
495.
长江口南北支水沙特性观测研究   总被引:1,自引:0,他引:1  
利用2009和2010年洪枯季、大小潮长江口南北支长时间序列的水沙盐观测资料,系统分析了近期南北支的水沙盐时空分布特征及南北支之间的关系,探讨了北支水沙盐倒灌,特别是泥沙倒灌对南支水域悬沙浓度的影响。分析结果表明:北支盐度和悬沙浓度年际、季节性及大小潮差异明显,一般大潮大于小潮,枯季大于洪季,平水年大于丰水年;南支受径流影响大,悬沙浓度均值在0.2kg/m3左右,盐度在0.25‰左右,南支悬沙浓度和盐度的大小均较北支小一个量级,其变化较北支复杂,尤其是在落潮时段盐度和悬沙浓度短时间内明显增加。北支作为河口唯一受潮汐控制的分支,水沙盐倒灌南支,倒灌期间南支悬沙浓度增加,洪季大潮有微弱沙量倒灌,悬沙浓度有0.05kg/m3的增幅,枯季大潮泥沙倒灌尤甚,南支悬沙浓度长时间维持在0.25kg/m3左右,最高可达0.62kg/m3。如上游径流量减小显著,则北支泥沙和盐水倒灌对南支的影响会增大。  相似文献   
496.
分析了珠江口和邻近海域沉积有机质(OM)的总有机碳(TOC)、总氮(TN)及稳定碳同位素组成〔δ(13C)〕等地球化学参数,并对有机质的来源和沉积通量进行了研究. 结果表明,珠江口沉积有机质来自大陆(52%)和水生(48%)混合来源;而邻近海域沉积有机质主要为水生来源(93%). 珠江口陆源有机质含量〔w(T-OC)为5.4  mg/g〕远远高于邻近海域(0.49  mg/g),近年来珠江口TOC和陆源有机质(T-OC)的平均沉积通量分别为5.57和2.2~3.6 mg/(cm2·a),说明珠江河口接受了大量的陆源有机物的输入,这是由于自20世纪后期的几十年以来,华南地区经济快速增长造成大量土地开垦,以及工农业生产和生活污水的排放所致. 珠江口和邻近海域的水生有机质沉积通量在近年均呈增加趋势,在珠江口达到最大值3.6 mg/(cm2·a),说明大量的营养物质导致水体的富营养化,从而促使水域初级生产力的增长.   相似文献   
497.
自珠江三角洲和南海北部海域采集了66个表层沉积物样品,以研究该区域中PBDEs的含量、分布、来源和在环境中的迁移.研究结果表明,东江和珠江是PBDEs的高污染区,含量为12.7~7361ng·g-1,其中BDE209平均含量为1199ng·g-1,是目前世界上已报道沉积物中含量最高的区域之一.在几乎所有被分析的样品中BDE209都是最主要的同系物.东江和珠江的PBDEs主要来自东莞和广州的本地排放,而西江的PBDEs主要通过大气的传播输入.另一个高污染区澳门水域被验证是珠江三角洲水体环境中有机污染物的“汇”.  相似文献   
498.
In recent years, the debate on corporate responsibility has shifted from a focus on environmental management towards a broader concept of corporate social responsibility (CSR). This article examines the chemical industry's approach to CSR from the perspective of two emerging economies: Mexico and South Africa. The global chemical industry was one of the first to respond to public concerns about environmental pollution, toxic waste and human health by adopting an industry‐wide code of practice, known as Responsible Care. This article examines the extent to which the chemical industry has responded to the broader debate on CSR. On the basis of a comparative case study, this article argues that the response to social issues by Mexican and South African chemical companies has tended to be limited to the ‘community awareness and emergency response’ (CAER) or community dialogue component of the international voluntary management framework, Responsible Care. Similarities and differences in regulatory and institutional conditions, as well as different levels of civil society engagement, reveal additional limitations for CSR, beyond that of the Responsible Care framework. This article argues that the socio‐political context influences the extent to which companies embrace CSR, especially in emerging economies, and highlights several challenges for the chemical industry in moving forward on CSR: credibility, stakeholder engagement, value‐chain accountability, disclosure and transparency. Reflecting on these challenges, the authors conclude by recommending a renewed focus on: (1) developing a broader set of CSR management practices beyond Responsible Care; (2) institutionalizing stronger accountability measures, such as reporting and verification; and (3) developing multi‐stakeholder partnerships that complement regulation and build public sector regulatory and guidance capacity.  相似文献   
499.
This article deals with the use of the procurement or purchasing power of governments to protect the environment. The focus is on South Africa and the aim is to show that South African organs of state can use procurement as an environmental policy tool to contribute to sustainable development as they have commendably done so to address past discriminatory policies and practices. It is argued that such use does not fall outside the current legislative framework governing procurement and suggestions are made as to how environmental considerations could be incorporated throughout the procurement process, namely the preparatory stage; the drawing up of tender or technical specifications; ensuring the capability or responsibility of contractors; the use of criteria to compare different tenders; and ensuring that eventual performance under a contract is environmentally sound.  相似文献   
500.
节能环保产业作为战略性新兴产业的七大重点领域之一,新形势下发展具备有利条件,特别是十二五以来我国环保产业得到了飞速发展,但是由于体制机制、技术、市场等多方面原因环保产业发展也面临诸多挑战和障碍。日本与韩国,环保产业已进入技术成熟期,逐渐成为本国国民经济的支柱产业和世界环保市场的主力,借鉴日韩环保产业的发展经验,提出中国推动环保产业发展的对策建议。  相似文献   
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