基于“能源碳足迹”的纯电动汽车的技术经济研究

该文从“能源碳足迹”的角度,追踪纯电动汽车与一般燃油汽车的碳排放足迹,结合碳平衡的观点,对纯电动汽车与一般燃油汽车进行了技术经济分析,直观地反应纯电动汽车的优势与不足,并基于电动汽车产业当前的实际情况,给出合理建议。     

Assessment of CO2 emissions reduction in a distribution warehouse

Building energy use accounts for almost 50% of the total CO₂ emissions in the UK. Most of the research has focused on reducing the operational impact of buildings, however in recent years many studies have indicated the significance of embodied energy in different building types. This paper primarily focuses on illustrating the relative importance of operational and embodied energy in a flexible use light distribution warehouse. The building is chosen for the study as it is relatively easy to model and represents many distribution centres and industrial warehouses in Europe.A carbon footprinting study was carried out by conducting an inventory of the major installed materials with potentially significant carbon impact and material substitutions covering the building structure. Ecotect computer simulation program was used to determine the energy consumption for the 25 years design life of the building. This paper evaluates alternative design strategies for the envelope of the building and their effects on the whole life emissions by investigating both embodied and operational implications of changing the envelope characteristics. The results provide an insight to quantify the total amount of CO₂ emissions saved through design optimisation by modeling embodied and operational energy.     

北京市旅游餐饮生态足迹实证分析

研究北京旅游生态环境保护和建设的有效途径对北京的旅游业可持续发展及整个北京生态环境的治理与管理具有重要意义。基于旅游生态足迹模型和来京旅游者的生物、能源消费及结构特征,文章通过计算分析2004-2006年北京市外来旅游者旅游餐饮生态足迹认为：北京市外来旅游者人均餐饮生态足迹特别是对能源的需求呈增加趋势,平均增长率为4.41%;北京的生物资源及能源供给大部分来自外部,生态负担转嫁范围大,旅游生态环境处在不可持续状态。建议北京市提高能源利用率,高效利用现有旅游设施,大力发展生态旅游等旅游模式,减少旅游带来的环境冲击,促进旅游业可持续发展。     

建筑工程物化环境影响的生态足迹评价

生态足迹方法可以将建设项目的资源和能源消费量转化为所必需的各种生态生产性土地的面积,用以客观反映建筑工程的环境影响,国外已有研究将生态足迹方法应用于建筑工程、产品或活动的环境影响评价。文章基于生态足迹的基本理论,建立了建筑工程物化阶段环境影响的一种定量评价模型,并用该模型对北京“未来之家”的示范建筑进行测算,分析了生态足迹方法评价建筑工程环境影响的适用性和应用条件。     

Atomic force microscopy of the morphology and mechanical behaviour of barnacle cyprid footprint proteins at the nanoscale

Barnacles are a major biofouler of man-made underwater structures. Prior to settlement, cypris larvae explore surfaces by reversible attachment effected by a ‘temporary adhesive’. During this exploratory behaviour, cyprids deposit proteinaceous ‘footprints’ of a putatively adhesive material. In this study, footprints deposited by Balanus amphitrite cyprids were probed by atomic force microscopy (AFM) in artificial sea water (ASW) on silane-modified glass surfaces. AFM images obtained in air yielded better resolution than in ASW and revealed the fibrillar nature of the secretion, suggesting that the deposits were composed of single proteinaceous nanofibrils, or bundles of fibrils. The force curves generated in pull-off force experiments in sea water consisted of regions of gradually increasing force, separated by sharp drops in extension force manifesting a characteristic saw-tooth appearance. Following the relaxation of fibrils stretched to high strains, force–distance curves in reverse stretching experiments could be described by the entropic elasticity model of a polymer chain. When subjected to relaxation exceeding 500 ms, extended footprint proteins refolded, and again showed saw-tooth unfolding peaks in subsequent force cycles. Observed rupture and hysteresis behaviour were explained by the ‘sacrificial bond’ model. Longer durations of relaxation (>5 s) allowed more sacrificial bond reformation and contributed to enhanced energy dissipation (higher toughness). The persistence length for the protein chains (L_P) was obtained. At high elongation, following repeated stretching up to increasing upper strain limits, footprint proteins detached at total stretched length of 10 µm.     

Life cycle assessment of the transmission network in Great Britain

Analysis of lower carbon power systems has tended to focus on the operational carbon dioxide (CO₂) emissions from power stations. However, to achieve the large cuts required it is necessary to understand the whole-life contribution of all sectors of the electricity industry. Here, a preliminary assessment of the life cycle carbon emissions of the transmission network in Great Britain is presented. Using a 40-year period and assuming a static generation mix it shows that the carbon equivalent emissions (or global warming potential) of the transmission network are around 11 gCO_2-eq/kWh of electricity transmitted and that almost 19 times more energy is transmitted by the network than is used in its construction and operation. Operational emissions account for 96% of this with transmission losses alone totalling 85% and sulphur hexafluoride (SF₆) emissions featuring significantly. However, the CO₂ embodied within the raw materials of the network infrastructure itself represents a modest 3%. Transmission investment decisions informed by whole-life cycle carbon assessments of network design could balance higher financial and carbon ‘capital’ costs of larger conductors with lower transmission losses and CO₂ emissions over the network lifetime. This will, however, necessitate new regulatory approaches to properly incentivise transmission companies.     

基于生态足迹法的天水市土地整治效果研究

土地整治是盘活存量土地、强化节约集约用地、适时补充耕地和提升土地产量的重要手段,分析土地整治效果对土地整治项目的评价具有重要意义。本文运用生态足迹模型对2007-2012年间土地整治项目中的新增耕地的生态足迹及生态承载力进行了测算与评价。结果表明：1）2007年天水市土地整治后的新增耕地人均生态承载力为0.000 6 hm^2,占当年总的人均生态承载力0.648 4 hm^2的0.09%,占当年人均生态赤字1.074 4 hm^2 的0.05%。2011年新增耕地的人均生态承载力为0.001 2 hm^2,占当年总的人均生态承载力0.734 7 hm^2中的0.16%,占当年人均生态赤字1.118 4 hm^2的0.10%,若没有进行土地整治,天水市2011年生态赤字会增加0.10%。2）通过2007-2011年天水市人均新增耕地面积与其生态承载力的动态变化,可以发现,随着新增耕地面积的增多,人均生态承载力也相应变化,两者的关系呈现为正相关,一定程度上缓解了天水市的生态环境压力。      

基于生态足迹的建设项目生态效益评价研究

目前建设项目已对生态环境造成了前所未有的负面影响,迫切需要降低建设项目的生态环境影响,提高其生态效益。构建了全寿命周期生态足迹测算模型体系,基于建设项目提供容纳人数和活动空间两方面功能价值的考虑,提出了全寿命周期生态足迹人年均效益和空间效益指标,用于测算建设项目全寿命周期的生态效益,以反映实现以上两方面功能价值所消耗的生态足迹是否满足生态可持续性发展要求。并研究了武汉展馆项目全寿命周期的生态效益,结果表明,与传统项目相比,该展馆项目绿色设计方案的生态效益呈现出很大程度的提高,但仍有提升空间。     

Carbon footprint as an instrument for enhancing food quality: overview of the wine,olive oil and cereals sectors

The quantification of greenhouse gases (GHG) emissions represents a critical issue for the future development of agro‐food produces. Consumers' behaviour could play an important role in requiring environmental performance as an essential element for food quality. Nowadays, the carbon footprint (CFP) is a tool used worldwide by agro‐food industries to communicate environmental information. This paper aims to investigate the role that CFP could have in consumers' choices in three significant agro‐food sectors in the Mediterranean area: wine, olive oil and cereals. A critical review about the use of CFP was carried out along the supply chain of these three sectors, in order to identify opportunities for enhancing food quality and environmental sustainability and highlighting how environmental information could influence consumers' preferences. The analysis of the state of the art shows a great variability of the results about GHG emissions referred to agricultural and industrial processes. In many cases, the main environmental criticisms are linked to the agricultural phase, but the other phases of the supply chain could also contribute to the increased CFP. However, despite the wide use of CFP by companies as a communication tool to help consumers' choices in agro‐food products, some improvements are needed in order to provide clearer and more understandable information. © 2016 Society of Chemical Industry     

Effect of feeding strategies and cropping systems on greenhouse gas emission from Wisconsin certified organic dairy farms

Organic agriculture continues to expand in the United States, both in total hectares and market share. However, management practices used by dairy organic producers, and their resulting environmental impacts, vary across farms. This study used a partial life cycle assessment approach to estimate the effect of different feeding strategies and associated crop production on greenhouse gas emissions (GHG) from Wisconsin certified organic dairy farms. Field and livestock-driven emissions were calculated using 2 data sets. One was a 20-yr data set from the Wisconsin Integrated Cropping System Trial documenting management inputs, crop and pasture yields, and soil characteristics, used to estimate field-level emissions from land associated with feed production (row crop and pasture), including N₂O and soil carbon sequestration. The other was a data set summarizing organic farm management in Wisconsin, which was used to estimate replacement heifer emission (CO₂ equivalents), enteric methane (CH₄), and manure management (N₂O and CH₄). Three combinations of corn grain (CG) and soybean (SB) as concentrate (all corn = 100% CG; baseline = 75% CG + 25% SB; half corn = 50% CG + 50% SB) were assigned to each of 4 representative management strategies as determined by survey data. Overall, GHG emissions associated with crop production was 1,297 ± 136 kg of CO₂ equivalents/t of ECM without accounting for soil carbon changes (ΔSC), and GHG emission with ΔSC was 1,457 ± 111 kg of CO₂ equivalents/t of ECM, with greater reliance on pasture resulting in less ΔSC. Higher levels of milk production were a major driver associated with reduction in GHG emission per metric tonne of ECM. Emissions per metric tonne of ECM increased with increasing proportion of SB in the ration; however, including SB in the crop rotation decreased N₂O emission per metric tonne of ECM from cropland due to lower applications of organically approved N fertility inputs. More SB at the expense of CG in the ration reduced enteric CH₄ emission per metric tonne of ECM (because of greater dietary fat content) but increased N₂O emission per metric tonne of ECM from manure (because of greater N content). An increased reliance on pasture for feed at the expense of grain resulted in decreased in milk production, subsequently leading to substantially higher emissions per metric tonne of ECM.