太阳系中,以木卫二和土卫二为代表的冰天体具有突出的生命潜力,可能在21世纪解答人类关于地外生命的终极问题.Exo-AUV能在冰壳中、冰水交界和海底等潜力区域执行生命探测任务,被NASA等机构寄予厚望.然而,具体在哪、基于何方法、开发何种...太阳系中,以木卫二和土卫二为代表的冰天体具有突出的生命潜力,可能在21世纪解答人类关于地外生命的终极问题.Exo-AUV能在冰壳中、冰水交界和海底等潜力区域执行生命探测任务,被NASA等机构寄予厚望.然而,具体在哪、基于何方法、开发何种Exo-AUV和技术、达到什么目标,是未来冰天体生命探测任务重要议题.本研究以木卫二为假想目标,探讨了冰天体生命探测任务的科学目标、可探测对象、潜力区域和生源性分析,提出了一种基于Exo-AUV的冰天体生命探测方法;解析了Exo-AUV在不同作业场景下的关键条件,提出了艇体、载荷和自主三方面基本技术要求;介绍了Exo-AUV的研究背景、研究现状和存在问题,提出了一套Exo-AUV概念开发技术路线和一种多Exo-AUV系统作业概念(ConOps for MEAS).该系统将帮助行星科学家和天体生物学家探索冰天体、寻找强生源信号,甚至活体生命和前生命化学系统.展开更多
Assessing and accounting for material consumption and environmental impact are necessary to measure environmental externalities of the aluminum industry and to construct an ecological civilization.In this research,lif...Assessing and accounting for material consumption and environmental impact are necessary to measure environmental externalities of the aluminum industry and to construct an ecological civilization.In this research,life cycle assessment(LCA)theory was used to assess the environmental impact of primary aluminum based on the lime soda Bayer process and different power generation modes,and the sources and distributions of the four selected impact categories were analyzed.The results show that,(1)Negative environmental impact of aluminum industry generally occurs from alumina extraction,carbon anode fabrication and electrolysis,particularly electrolysis and alumina extraction.Primary energy demand(PED),water use(WU),global warming potential(GWP)and freshwater eutrophication potential(FEP)are main environmental impact categories.(2)The environmental load with thermal power is higher than that with hydropower,e.g.,for the former,the greenhouse gas emission coefficient of 21800 kg CO2 eq/t(Al)will be generated,while for the latter,4910 kg CO2 eq/t(Al)will be generated.(3)Both power mode methods reflect the energy structure,whereas direct emissions reflect the technical level,indicating the potential for large energy savings and emission reductions,and some policies,related to clean power,energy efficiency and technological progress,should be made for emission reduction.展开更多
文摘太阳系中,以木卫二和土卫二为代表的冰天体具有突出的生命潜力,可能在21世纪解答人类关于地外生命的终极问题.Exo-AUV能在冰壳中、冰水交界和海底等潜力区域执行生命探测任务,被NASA等机构寄予厚望.然而,具体在哪、基于何方法、开发何种Exo-AUV和技术、达到什么目标,是未来冰天体生命探测任务重要议题.本研究以木卫二为假想目标,探讨了冰天体生命探测任务的科学目标、可探测对象、潜力区域和生源性分析,提出了一种基于Exo-AUV的冰天体生命探测方法;解析了Exo-AUV在不同作业场景下的关键条件,提出了艇体、载荷和自主三方面基本技术要求;介绍了Exo-AUV的研究背景、研究现状和存在问题,提出了一套Exo-AUV概念开发技术路线和一种多Exo-AUV系统作业概念(ConOps for MEAS).该系统将帮助行星科学家和天体生物学家探索冰天体、寻找强生源信号,甚至活体生命和前生命化学系统.
基金Projects(71633006,71403298) supported by the National Natural Science Foundation of ChinaProjects(14YJCZH045,15YJCZH019) supported by the Ministry of Education of Humanities and Social Science,China
文摘Assessing and accounting for material consumption and environmental impact are necessary to measure environmental externalities of the aluminum industry and to construct an ecological civilization.In this research,life cycle assessment(LCA)theory was used to assess the environmental impact of primary aluminum based on the lime soda Bayer process and different power generation modes,and the sources and distributions of the four selected impact categories were analyzed.The results show that,(1)Negative environmental impact of aluminum industry generally occurs from alumina extraction,carbon anode fabrication and electrolysis,particularly electrolysis and alumina extraction.Primary energy demand(PED),water use(WU),global warming potential(GWP)and freshwater eutrophication potential(FEP)are main environmental impact categories.(2)The environmental load with thermal power is higher than that with hydropower,e.g.,for the former,the greenhouse gas emission coefficient of 21800 kg CO2 eq/t(Al)will be generated,while for the latter,4910 kg CO2 eq/t(Al)will be generated.(3)Both power mode methods reflect the energy structure,whereas direct emissions reflect the technical level,indicating the potential for large energy savings and emission reductions,and some policies,related to clean power,energy efficiency and technological progress,should be made for emission reduction.
