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1.
The paper first provides, for Latin America and the Caribbean, country-specific synthetic quantitative measures of the degree of adoption of governance reforms in the electricity sector, focusing on four key dimensions (market structure, private sector participation (PSP), regulatory autonomy and operational organization). These measures are then correlated with standard policy performance outcomes measures. The findings suggest that, the reforms, considered jointly, were statistically significantly associated with higher technical and process quality but not with social or service improvements. Considered individually, increased regulatory autonomy enjoyed the highest positive correlation with desirable outcomes, but PSP has no significant correlation with any of the outcomes. In sum, as of 2018, governance reforms, considered jointly, had still not delivered on some promised payoffs, notably in addressing energy poverty, although the sensitivity analysis suggests that, for some indicators, the relationships are stronger for larger than for smaller countries. 相似文献
2.
本文选取高度城市化国家美国为研究对象,对美国及其国内49个州的经济及城市化发展过程以及两者在发展过程中的相关关系进行分析,发现地区城市化发展特征差异明显,经济发展影响着城市化发展,相对的经济位置决定城市化水平的高低;但经济水平不是决定城市化发展的唯一因素,且经济发展对城市化的影响存在不同的阶段,传统的城市化理论已经在局部地区城市化发展中不再适用。 相似文献
3.
Incidence of adenoviruses in raw and treated water 总被引:6,自引:0,他引:6
Adenoviruses are of major public health importance and are associated with a variety of clinical manifestations, i.e. gastroenteritis, eye infections and respiratory infections. The importance of water in the epidemiology of adenoviruses and the potential health risks constituted by adenoviruses in water sources and supplies are widely recognised. This study was conducted to assess the incidence of human adenoviruses in raw and treated water systems. Various raw and treated water were routinely monitored for the presence of adenoviruses, over a 1-year period (July 2000-June 2001). The supplies were derived from acceptable quality surface water sources using treatment processes, which conform to international standards for the production of safe drinking water. Adenoviruses were detected by firstly amplifying the viruses in cell cultures and then amplifying the extracted nucleic acids of these viruses using molecular techniques (nested PCR). The results indicated human adenoviruses present in 13 (12.75%) of the raw and 9 (4.41%) of the treated water samples tested. The combination of cell culture and nested PCR has proved to be a quick and reliable method for the detection of adenoviruses in water environments. 相似文献
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5.
南美Llanos盆地中部地区为盆地内的重要产油区,对其烃源岩及原油的地球化学特征分析,能揭示出盆地内的排烃和运聚过程及原油的生物降解特征。通过岩石热解、原油组分分析等方法和手段,结合多种生标参数,对这一地区的烃源岩及原油的地球化学特征进行了系统和全面的分析,结果表明:Gacheta组烃源岩沉积在较少的陆源有机质、咸水和弱氧化—弱还原环境,为腐泥—腐殖混合型干酪根;Los Cuervos组烃源岩沉积在较多的陆源有机质、半咸水和氧化环境,为腐泥—腐殖混合型和腐殖型干酪根,2套烃源岩都处于低—中等的成熟程度,均具有较强的生烃潜力;盆地中部地区存在A、B、C三类原油,其中A类为白垩系烃源岩油;B类为古近系烃源岩油;C类系前两者的混合;在大部分的油样中含有丰富的重排甾烷,二苯并噻吩/菲含量低,而Pr/Ph值较高,这说明原油对应的烃源岩为海相页岩而非碳酸盐岩;原油组分受生物降解及二次充注过程的控制,从Santiago油田沿北东方向到La Gloria等油田生物降解作用呈减弱的趋势,而Cupiagua和Buenos Aires油田的样品受二次充注的轻质油的影响,其API远远超过La Gloria等油田。 相似文献
6.
美国Haynesville高压页岩气气藏与中国长宁—威远国家级页岩气示范区下志留统龙马溪组高压页岩气藏的地质、钻井条件最为类似,前者的钻井提速技术思路对于我国页岩气快速钻井也具有重要的参考借鉴意义。为了实现我国页岩气藏的钻井提速,通过对比中国和美国典型高压页岩气藏钻井提速技术,分析探讨了上述两个气藏在钻井提速技术方面的异同点。研究结果表明:①目前美国Haynesville等页岩气藏已将水平段井眼尺寸从215.9 mm缩小到171.5 mm或161.1 mm,单井钻井投资降低超过25%,节能减排优势明显;②美国同行采用的"高效钻头+配套井下提速工具+钻井参数优化软件/装备"的硬研磨性难钻地层系统化钻井提速技术,值得国内重视、借鉴、攻关、应用;③"控压钻井+降密度"钻井技术能够在高压页岩层段钻井提速中起到至关重要的提速应用效果。结论认为,应积极在国内国家级页岩气示范区开展缩小井身结构尺寸及其相关的钻井配套装备、工具、软件的应用探索试验;在目的层段值得持续探索、优化、应用控压钻井技术。 相似文献
7.
为找出中美煤矿事故调查报告的异同,给我国事故调查报告的编写提供具体建议,以中美两国正式发布的事故调查报告为研究基础,系统调研事故调查相关文献,对事故调查报告编写依据进行分析,并以中国金山沟煤矿"10·30"特别重大瓦斯爆炸事故和美国Upper Big Branch煤矿事故调查报告为例,从报告的结构内容和原因2方面进行具体分析。结果表明,中国应该出台统一的煤矿事故调查报告编写标准,实现事故调查报告标准化;美国事故调查报告不包含责任追究部分,原因分析部分所占篇幅多;美国事故调查进行原因分析时与中国所站角度不同,美国仅对事故单位进行分析,中国除此外还分析相关单位问题。 相似文献
8.
The southern region of South America, a subtropical and temperate zone, is an important region for the production of beef and lamb meat, which is mainly produced in extensive pasture-based systems. Because of its content in highly valuable nutrients such as iron, zinc, selenium, fatty acids, and vitamins, meat is a unique and necessary food for the human diet in order to secure a long and healthy life, without nutritional deficiencies. Beef and lamb production systems based on temperate or tropical grasslands show interesting and, in some cases, a differential content in minerals, fatty acids and vitamins. This review deals with the distinctive aspects of the nutritional quality of beef and lamb meat produced in this region in terms of nutritional composition and the bioavailability of key nutrients related to its contribution for a healthy diet for all ages. 相似文献
9.
After decades of reduced need for investment, transmission regulation is increasingly gaining relevance and complexity in liberalised power sectors, mainly due to the need to integrate sometimes distant and large-scale renewable energy sources. We identify the key principles that should be considered at three levels: transmission expansion, remuneration, and cost allocation.The proposals we develop are built upon a review of the noteworthy experiences matured in South America, a region which, besides leading restructuring in the 1980s and 1990s, has with different levels of success always relied on innovative solutions to deal with this crucial regulatory challenge. 相似文献
10.
Sylvain LefebvreRomain Roult 《Cities》2011,28(4):330-339
The Formula One (F1) industry has become a true microcosm of the world economy, as new business opportunities surface in emerging countries. Until the beginning of the twenty-first century, this sport was mostly relevant to traditional western urban elites, but since then, the F1 calendar has been largely altered to the benefit of ‘dominant-emerging cities’ and to the detriment of more traditional destinations. This article focuses on this urban question through a historical analysis of the F1 circuit’s expansion phases as well as through a study of the current Grand Prix’s estimate sanction fee. 相似文献