基于粒子群优化的再入可达区计算方法研究

针对升力式高超声速飞行器再入可达区计算问题,提出了一种粒子群优化（PSO）和倾侧角反转相结合的混合求解方案。为了减小待优化变量的搜寻空间,设计了一种参数化的倾侧角剖面,利用约束PSO算法求解满足再入过程约束和末端约束的最优滑翔轨迹。通过倾侧角正向和逆向反转逻辑直接生成倾侧角指令集合,进而实现高超声速飞行器再入可达区的快速估算。高升阻比再入滑翔飞行器CAV-H仿真实例表明,该混合优化求解方案易于实现且无需预估参数初值,具有良好的可操作性。     

重庆种植业灰水足迹核算及空间差异分析

用灰水足迹方法评价水环境变化,逐渐成为水环境及相关研究的热点之一。为了掌握重庆农业水环境状况,把灰水足迹与农业面源污染联系起来,首先核算重庆2007年种植业灰水足迹,然后对其空间差异进行分析。结果表明①重庆2007年的种植业灰水足迹为22.088 8亿m³;②重庆多数区县种植业灰水足迹密度差异不大;③重庆2007年的种植业灰水足迹强度东部高、西部低;④种植业水环境压力指数西部高、东部低,城市发展新区的13个区县种植业已对水环境造成污染。研究表明,重庆水环境保护要重视种植业产生的污染。     

产品制造过程碳足迹核算及其优化问题

为了减少各产品在制造过程中的碳足迹,并为未来产品碳标签核算提供较为准确的计算方法,提出了一种基于制造过程碳排放与被加工产品之间对应关系的产品制造过程碳足迹计算方法;针对柔性作业车间,为减少产品制造过程碳足迹,并保证完工时间以及车间设备利用率,提出了一种以所有产品制造过程碳足迹总和最短、最长完工时间最短、车间设备利用率最大的多目标优化调度模型;设计了第二代非支配解遗传算法进行求解,与传统调度模型的对比说明,所提出的优化调度模型在完工时间损失不大并保证车间设备利用率有改善时,可以使所有产品制造过程碳足迹有较大的改善,从而验证了研究的有效性。     

基于生命周期理论的建筑卫生陶瓷碳足迹研究

应用生命周期理论,以华东地区生产的建筑卫生陶瓷为研究对象,对建筑卫生陶瓷原材料开采、原材料运输、产品生产、产品运输等4个子过程进行了清单分析,并分别计算了各阶段向环境排放的CO2量.结果表明,生命周期内建筑陶瓷的CO2排放量为9.59 kg/m2,卫生陶瓷为776.75 kg/t.其中,产品生产过程的碳排放所占比例最高,建筑陶瓷为72.8％,卫生陶瓷为70.7％,具有决定性影响.原材料开采、运输及产品运输阶段碳排放所占比例不到30％.     

沼气发酵猪粪管理系统对温室气体排放的影响

基于生命周期清单分析以及清洁发展机制,引入"碳足迹"概念,对我国散养猪以及规模化养猪场引入沼气发酵系统后猪粪管理系统温室气体排放及减排进行了估算。农户散养猪粪处理系统中,12 m3沼气池厌氧发酵过程碳足迹为223.40 kg CO2e/a,沼气代替原煤燃烧减少444.33 kg CO2e/a温室气体,沼气发酵净减少220.93 kg CO2e/a温室气体,我国散养生猪产生的猪粪以此沼气池发酵可减少温室气体20 984.62 Gg CO2e/a;分析运行规模约1 000 m3大型沼气工程的碳足迹,保守估计为2 835.32 t CO2e/a,运行沼气工程替代煤炭以及减少猪粪排放的温室气体共约2 914.23 t CO2e/a,故沼气工程年减少温室气体78.91 t CO2e,该项目共可减排1 578.20 t CO2e。在猪粪管理系统中采用沼气发酵系统可以更好地促进温室气体减排的进行。     

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.