建筑是温室气体(GHG)排放的主要来源,也是造成气候危机的原因之一。为了满足缓解气候变化的需要,不仅要关注建筑运行的能耗及其对应的温室气体排放,更要关注建筑的整个生命周期。本研究通过系统编制和分析650多个生命周期评估(LCA)案例...建筑是温室气体(GHG)排放的主要来源,也是造成气候危机的原因之一。为了满足缓解气候变化的需要,不仅要关注建筑运行的能耗及其对应的温室气体排放,更要关注建筑的整个生命周期。本研究通过系统编制和分析650多个生命周期评估(LCA)案例,分析了全球建筑生命周期中温室气体排放的趋势。基于一个由238个案例组成的最终样本,对不同的能效等级进行了分析,结果显示,当运营能效提高时,生命周期内温室气体排放有明显的下降趋势。然而,分析显示,所谓的"体现"温室气体排放的相对贡献和绝对贡献均有所增加,如,制造和加工建筑材料所产生的废气。虽然按照现行的能效法规,建筑物的实际温室气体排放量约占整个生命周期温室气体排放量的20%~25%,但在极端情况下,这一数字将上升至45%~50%,并超过90%。此外,本研究分析了温室气体排放的发生时间,突出了建筑生产的"碳峰值"。将结果与瑞士新亚能源效率路径中现有的建筑物温室气体排放基准相比较,结果显示大多数案例超出了11.0 kg CO2eq/m^2·a的目标。考虑到全球温室气体减排目标,研究结果表明迫切需要通过优化运行和具体影响来减少建筑物的温室气体排放。展开更多
The CS radical was generated by discharging the mixture gas of CS2 and Helium. The Doppler limited spectra of CS were recorded in the region of 12350-12950 cm^-1 using optical heterodyne concentration modulation absor...The CS radical was generated by discharging the mixture gas of CS2 and Helium. The Doppler limited spectra of CS were recorded in the region of 12350-12950 cm^-1 using optical heterodyne concentration modulation absorption spectroscopy. Three hundred and twenty-six lines were recorded and assigned to the d^3△-a^3П （8,1） band, in which eighty-three transitions were first observed. A set of improved molecular constants for the d^3△（v=8） and a^3П（v=1） levels were determined by a non-linear least-squares fitting of all the lines to the effective Hamiltonian.展开更多
A flux equation of diffusion for bi-disperse porous catalyst pellets was proposed by modifying the previously developed model equation over fractal trajectories. The proposed fractal model equation considered the same...A flux equation of diffusion for bi-disperse porous catalyst pellets was proposed by modifying the previously developed model equation over fractal trajectories. The proposed fractal model equation considered the same tortuous degree for both micro-and macro-pores. The experimental data of diffusion over a bi-disperse Ni/gamma-alumina pellet were obtained with a standard Wicke-Kallenbach diffusion cell for both carbon monoxide- ethylene and carbon dioxide-ethylene binary mixtures. The fitting between experimental results and the fractal model equation leads to a fractal dimension of 1.11. The prediction of diffusion flux over the bi-disperse Ni/gamma- alumina pellet by the proposed fractal model equation is much better than the traditional tortuosity-based model equation by comparison with the measured flux through the pellet.展开更多
文摘建筑是温室气体(GHG)排放的主要来源,也是造成气候危机的原因之一。为了满足缓解气候变化的需要,不仅要关注建筑运行的能耗及其对应的温室气体排放,更要关注建筑的整个生命周期。本研究通过系统编制和分析650多个生命周期评估(LCA)案例,分析了全球建筑生命周期中温室气体排放的趋势。基于一个由238个案例组成的最终样本,对不同的能效等级进行了分析,结果显示,当运营能效提高时,生命周期内温室气体排放有明显的下降趋势。然而,分析显示,所谓的"体现"温室气体排放的相对贡献和绝对贡献均有所增加,如,制造和加工建筑材料所产生的废气。虽然按照现行的能效法规,建筑物的实际温室气体排放量约占整个生命周期温室气体排放量的20%~25%,但在极端情况下,这一数字将上升至45%~50%,并超过90%。此外,本研究分析了温室气体排放的发生时间,突出了建筑生产的"碳峰值"。将结果与瑞士新亚能源效率路径中现有的建筑物温室气体排放基准相比较,结果显示大多数案例超出了11.0 kg CO2eq/m^2·a的目标。考虑到全球温室气体减排目标,研究结果表明迫切需要通过优化运行和具体影响来减少建筑物的温室气体排放。
文摘The CS radical was generated by discharging the mixture gas of CS2 and Helium. The Doppler limited spectra of CS were recorded in the region of 12350-12950 cm^-1 using optical heterodyne concentration modulation absorption spectroscopy. Three hundred and twenty-six lines were recorded and assigned to the d^3△-a^3П （8,1） band, in which eighty-three transitions were first observed. A set of improved molecular constants for the d^3△（v=8） and a^3П（v=1） levels were determined by a non-linear least-squares fitting of all the lines to the effective Hamiltonian.
基金Supported by the National Natural Science Foundation of China (No. 50228203 and No. 20476076)
文摘A flux equation of diffusion for bi-disperse porous catalyst pellets was proposed by modifying the previously developed model equation over fractal trajectories. The proposed fractal model equation considered the same tortuous degree for both micro-and macro-pores. The experimental data of diffusion over a bi-disperse Ni/gamma-alumina pellet were obtained with a standard Wicke-Kallenbach diffusion cell for both carbon monoxide- ethylene and carbon dioxide-ethylene binary mixtures. The fitting between experimental results and the fractal model equation leads to a fractal dimension of 1.11. The prediction of diffusion flux over the bi-disperse Ni/gamma- alumina pellet by the proposed fractal model equation is much better than the traditional tortuosity-based model equation by comparison with the measured flux through the pellet.
