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891.
中国已经在7个省市进行了碳排放权交易市场的试点,并拟于2017年建立全国碳排放权交易市场。随着碳市场政策的逐步完善,碳排放将成为企业的总量控制目标之一。在全国碳市场即将建立的背景下,研究企业对于全国碳市场政策的预期,分析企业的响应规律,估算企业对于碳信用的支付意愿,对于保障全国碳市场的顺利建立和有效运行具有重要的意义。基于此,本研究利用多边界离散选择的方式,调查了全国范围内29个省市的555家企业,对于由于全国碳市场建立而导致的能源价格提高的接受程度,并利用多元线性回归模型分析影响企业接受程度的因素,最后估算企业对于碳市场中碳信用的支付意愿。结果显示:(1)企业可接受的能源价格提高比例的平均值为8.3%,其中碳试点企业可接受的提高比例最高,达到10.2%,非碳试点企业可接受的提高比例最低,为7.5%;(2)对企业接受程度的影响因素分析显示,企业的能源价格压力,以及企业对于全国碳市场到来的时间预期与接受程度显著负相关;企业对于碳减排技术的了解程度,以及企业对于全国碳市场控制程度的预期与接受程度显著正相关;(3)对于全国碳市场中的碳信用,企业平均愿意支付的价格为79.6元/t CO_2,其中碳试点企业的支付意愿最高,为95.9元/t CO_2,非碳试点企业的支付意愿最低,为72.6元/t CO_2。据此,为保障全国碳排放权交易市场的顺利建立,实现对企业碳排放的有效控制,政府应该注重降低企业的用能成本,引导与支持企业进行技术创新与升级,提高企业对于碳市场政策的认识和了解,并充分考虑不同地区的差异和不同企业的支付能力差别,合理设定碳价。  相似文献   
892.
The ability for the water accommodated fraction (WAF) of oil-dispersant mixtures to become aerosolized following natural sea surface activity markedly increases the probability of inhalation exposure to this aerosolized mixture and subsequent adverse respiratory health effects. Thus, the purpose of this study was to elucidate the chemical composition of WAF of these mixtures as well as determine how this relates to lung epithelial cell cytotoxicity. WAF was prepared by mixing each dispersant (Corexit 9500/9527/9580) with crude oil. For “chemical constituent fingerprinting,” these prepared WAF were extracted prior with dichloromethane, analyzed by Gas chromatography/mass spectrometry, and qualitatively evaluated using the NIST08 database. Results from chemical analysis revealed an increase in structure complexity of the WAF oil-dispersant mixtures when compared to WAF of crude oil only. This complexity was characterized by high molecular weight compounds such as alkyl derivatives, esters, and polycyclic aromatic hydrocarbons. Previously a concentration-dependent reduction in cultured A549 cells was noted at 2 or 24?h time points following exposure to either the WAF-oil/9500 or WAF-oil/9527. Thus, a possible correlation exists between the chemical complexity of these mixtures and the ability to induce lung epithelial cell death in potentially exposed individuals.  相似文献   
893.
The pyrolysis and chlorination of petroleum coke in a NaCl‐KCl melt results in the production of CCl4 and C6Cl6. Polychlorinated dibenzo‐p‐dioxins (PCDDs) are produced from the air oxidation and chlorination of coal using HCl or Cl2. Smoking of tobacco containing 36Cle provides CH3 36Cl.

At 350°C, the rateof aromatization of 1,3‐cyclohexadiene is negligible as compared to that of 1,4‐cyclohexadiene. The aromatization of the latter diene proceeds through the molecular elimination of hydrogen; while that of 1,3‐cyclohexadiene expecially at higher pressure (10–90 Torr) and at 362–421 °C involves free radical chain mechanism.  相似文献   
894.
根据技术效率、经济效率、自然效率、社会效率之间的关系,探讨了四个效率背离所导致的资源配置效率丧失以及由此引发的社会福利损失问题。在分析价格信号在资源配置过程中的作用的基础上,探讨了市场失效和价格背离现象。进一步指出了中国经济转型时期存在着自然资本富聚现象,并进一步分析其根源。包括:政府有效干预不足、现行经济增长方式和经济效率实现以对自然资本的低成本占用、机会导向型的资源配置方式、资本的价值取向、对经济财富以及单一行为人的效率追逐、产权缺位等。强调需要强化环境管理的公共管理属性,并对环境资源的权益主体的权利、责任和利益进行有效的界定和实施,通过制度和政策变革,干预和规范市场运作,促进资源的高效和公平配置。  相似文献   
895.
三峡水域氮磷污染对水华暴发/消涨行为的协同影响   总被引:3,自引:0,他引:3  
刘信安  湛敏  罗彦凤  郭圣文 《环境科学》2006,27(8):1554-1559
藻类生长/消退与藻类对氮、磷的吸收比率ω1ω2相关,ωi正/负增长分别对应藻类生长时从水体中吸收氮磷的加速阶段和藻类分解时向水体释放氮磷的消退阶段,在特定磷氮比(P/N)范围出现ω1ω2同时突变有可能从理论上解释水华的暴发/消退.根据三峡流域实测数据和藻类吸收氮磷的关联函数,在三维空间表征了随氮磷浓度协同作用导致的ω1ω2在特定P/N区域同时突变所揭示出的水华暴发/消退现象,从而直观、合理地解释了:①适当的P/N范围才可能暴发水华;②如果P/N区间同时满足ω1ω2正向急剧增长的要求,藻类疯长,而ω1ω2同时朝负值方向急剧降低,水华消退;③水华暴发/消退的速率为同一数量级,且水华暴发/消退在氮、磷浓度达到某一敏感范围时将表现出明显的周期性振荡.这些性态可能更真实地反映出水华暴发/消退时藻类对营养盐的吸收/释放机理.  相似文献   
896.
综采工作面安全性评价的逼近理想解(TOPSIS)方法   总被引:8,自引:2,他引:6  
基于熵权的TOPSIS(逼近理想解的排序方法)方法是一种新的安全性评价方法,该方法以灰熵理论确定评价指标的权重———熵权,从而避免低层次多因素权重确定的主观性。以评价对象与理想解和负理想解的距离确定的相对接近度作为评价准则,避免了评价方法的主观性。通过对平顶山煤业集团有限责任公司六矿综采工作面安全性进行的评价,指出综采工作面安全管理中存在的问题,并提出相应的改进措施。理论与实例表明,该方法较其他方法更加客观,更易于操作,结果也更符合生产实际。  相似文献   
897.
Abstract

Increasing populations are causing an increase in food demands, and the area of cultivated land expands every year. Inappropriate land transition from ecology to production results in the constant decline of the ecological security level and influences the regional sustainable development. Adjusting unreasonable land use mode and reconstructing natural land cover are important ways to maintain and improve the ecological environment. Also reclaiming farmland as areas for forests and grasslands (FRFG) is another way. Successful implementation of FRFG in China is the result of comprehensive effect of the multi-scales driving forces. This paper analyses the driving forces of FRFG in China on a national (country)—regional (province)—local (county)—household (farmer) level scale, and the results are: driving forces at the national scale include ecological and food security and the western development of China; at the regional scale, ecological and economic benefits become the main factors to influence the dimension of FRFG under the same policy. The driving forces can be divided into 6 types: industrial structure adjustment, water source protection, flood prevention, the Three-Gorge Project protection, reduction of the amount of sediment flowing into the Yellow River and wind erosion desertification prevention. The driving forces at the local scale can be divided into 12 types with developing leading industries, increasing farmers' income and improving agricultural production conditions as the main types; at the household scale, the national policy meeting farmers' demands and the optimization of individual interests are all driving forces.  相似文献   
898.
In the field of sustainable product development, a new perspective for approaching sustainability has been advocated, challenging designers and engineers to aim beyond ‘reducing unsustainability’. Several design strategies – including Biomimicry and Cradle to Cradle – have been suggested for developing truly sustainable, or ‘beneficial’, products. But do these strategies help in developing such products, and how to assess their ‘sustainability’? Based on a review of the objectives in nature-inspired design, we argue that assessing environmental sustainability is not straightforward. Whereas both Biomimicry and Cradle to Cradle build on the perspective of ‘achieving sustainability’, current life-cycle assessment-based tools are geared towards reducing current impacts. As a consequence, existing tools are insufficiently equipped for the purpose of the assessment: they do not cover some of the main results that nature-inspired design is set out to accomplish. To be able to include these results, we propose two new constituents to current life-cycle-based product assessment: assessing against conditions of sustainability and assessing ‘achievement’, the extent to which these conditions of sustainability have been achieved. Furthermore, the product context needs to be included for assessing beneficial impacts. This article discusses how these constituents can contribute to an assessment tool that enables designers and engineers to assess the development of environmentally sustainable solutions.  相似文献   
899.
The conceptual rubric of ecosystem management has been widely discussed and deliberated in conservation biology, environmental policy, and land/resource management. In this paper, I argue that two critical aspects of the ecosystem management concept require greater attention in policy and practice. First, although emphasis has been placed on the “space” of systems, the “time”—or rates of change—associated with biophysical and social systems has received much less consideration. Second, discussions of ecosystem management have often neglected the temporal disconnects between changes in biophysical systems and the response of social systems to management issues and challenges. The empirical basis of these points is a case study of the “Crown of the Continent Ecosystem,” an international transboundary area of the Rocky Mountains that surrounds Glacier National Park (USA) and Waterton Lakes National Park (Canada). This project assessed the experiences and perspectives of 1) middle- and upper-level government managers responsible for interjurisdictional cooperation, and 2) environmental nongovernment organizations with an international focus. I identify and describe 10 key challenges to increasing the extent and intensity of transboundary cooperation in land/resource management policy and practice. These issues are discussed in terms of their political, institutional, cultural, information-based, and perceptual elements. Analytic techniques include a combination of environmental history, semistructured interviews with 48 actors, and text analysis in a systematic qualitative framework. The central conclusion of this work is that the rates of response of human social systems must be better integrated with the rates of ecological change. This challenge is equal to or greater than the well-recognized need to adapt the spatial scale of human institutions to large-scale ecosystem processes and transboundary wildlife.  相似文献   
900.
Recycled water use in urban areas is viewed as one part of the solution to Australia's water shortage. The effectiveness of policies designed to promote recycled water systems depends on the acceptance by the community of the price, colour, odour and salt content of the recycled water. In Australia and other countries, limited research has been conducted that investigates community attitudes to and willingness to pay for recycled water, especially in urban settings. Community acceptance of recycled water and the economic feasibility of such projects have not been widely evaluated, even though the long-term feasibility of many projects is dependent on such information. This paper examines the attitudes of an urban Australian community living at Mawson Lakes in South Australia, to using recycled water for non-potable domestic purposes. Conjoint analysis (CA) was used to evaluate participant's (n=136) preferences for various attributes of recycled water (colour, odour, salt content and price) for various uses (garden watering, toilet flushing and clothes washing). The analysis was used to estimate the respondent's willingness to pay (WTP) for quality increases for each of the attributes. Differences in WTP were investigated according to various demographic variables including income and education. Results indicate that for garden watering having 'low salt levels' is the most important attribute of recycled water, for clothes washing 'colourless' is the most important attribute, and for toilet flushing a 'low price' was the most important attribute. Respondents were willing to pay for increases in the quality of recycled water. The amount they were willing to pay varied depending on applied use and the attribute in question. Respondents were most willing to pay for an increase in quality of recycled water when used for clothes washing (willing to pay Australian dollars (A$) 0.07/cubic meter (m(3)) for removal of colour, A$0.065 per cubic meter for an increase in quality of recycled water from 'salty' to 'low salt,' and A$ 0.06/m(3) for removal of odour (1A$=0.75 US $ and 0.62 euro, August 24, 2005)). Segmentation of the price attribute by demographic sectors reveals that those in the higher income bracket, higher education sector, middle age group, and who are male, had a higher marginal valuation on price. The results of this study provide important information for recycled water retailers and water policy developers, helping achieve greater economic feasibility for future recycled water projects, to the satisfaction of the communities involved.  相似文献   
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