浅谈我国未来循环经济的发展与战略选择

循环经济是一种新兴的物尽其用的经济发展模式,它强调资源的再使用和再循环。实行循环经济是保障工业企业可持续发展的客观需要,也是实施可持续发展战略的重要途径和实现方式。 更多还原     

城市生态系统能值利用的相图分析——以乌鲁木齐市为例

为促进干旱区城市可持续发展,以乌鲁木齐城市系统为例,基于2004和2010年统计数据,利用相图法分析得出:2003和2009年系统对不可更新自然资源的利用比例极大,对可更新自然资源利用比例最小;6年间系统对自然资源利用比例下降,尤其对可更新资源利用比例下降显著,为33.84%,而社会反馈投入能值比例上升;两年系统虽都处于可持续发展状态,但可持续发展指数有所下降且均接近下限。欲提升系统可持续发展性能,必须合理调整其能值利用结构。     

Chemical equilibria involved in the oxygen-releasing step of manganese ferrite water-splitting thermochemical cycle

Sodium ferrimanganite carbonatation reaction was investigated at different temperatures/carbon dioxide partial pressures to evaluate the feasibility of the thermochemical water-splitting cycle based on the MnFe₂O₄/Na₂CO₃/Na(Mn_1/3Fe_2/3)O₂ system.After thermal treatments in selected experimental conditions, the obtained powder samples were investigated by using the X-ray diffraction (XRD) technique and Rietveld analysis.Two different lamellar Na_1−xMn_1/3Fe_2/3O_2−δ phases were observed together with the expected MnFe₂O₄/Na₂CO₃ mixture. Different equilibrium regions among sodium-depleted lamellar phases, manganese ferrite and sodium carbonate were found as a function of the different reaction conditions. A hypothesis concerning the regeneration mechanism of the initial compounds is proposed. Chemical equilibrium between stoichiometric and sub-stoichiometric forms of sodium ferrimanganite and sodium carbonate formation/dissociation appears to be essential factors governing the oxygen-releasing step of the manganese ferrite thermochemical cycle.     

Sustainability in bankruptcy problems

This paper focuses on a new property for bankruptcy rules, calledsustainability, which requires that the agents with small enough claims be fully reimbursed. We show that the constrained equal-awards rule is the only rule that satisfies path independence and sustainability. Exploiting duality relations, we also provide a characterization of the constrained equal-losses rule, as the only one that satisfies composition and independence of residual claims (the dual property of sustainability).     

Castanea sativa by-products: a review on added value and sustainable application

Castanea sativa Mill. is a species of the family Fagaceae abundant in south Europe and Asia. The fruits (chestnut) are an added value resource in producing countries. Chestnut economic value is increasing not only for nutritional qualities but also for the beneficial health effects related with its consumption. During chestnut processing, a large amount of waste material is generated namely inner shell, outer shell and leaves. Studies on chestnut by-products revealed a good profile of bioactive compounds with antioxidant, anticarcinogenic and cardioprotective properties. These agro-industrial wastes, after valorisation, can be used by other industries, such as pharmaceutical, food or cosmetics, generating more profits, reducing pollution costs and improving social, economic and environmental sustainability.

The purpose of this review is to provide knowledge about the type of chestnut by-products produced, the studies concerning its chemical composition and biological activity, and also to discuss other possible applications of these materials.