Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail med...Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.展开更多
Although the carbon pricing policy is a critical driving factor that will help China achieve economic growth,energy transition,and dual climate change mitigation goals,the kind of carbon pricing policy that will compl...Although the carbon pricing policy is a critical driving factor that will help China achieve economic growth,energy transition,and dual climate change mitigation goals,the kind of carbon pricing policy that will complement the country's current development situation remains controversial.We apply the World Induced Technical Change Hybrid(WITCH)model to explore the heterogeneity and synergy of different carbon pricing policies,and the results indicate that it will be challenging to achieve carbon neutrality before 2060.The study find that the combined policy-a mix of carbon tax and carbon market policies--has the optimal emission reduction effect but comes with the highest economic cost,proving to be unsuitable in the long run.The carbon tax policy is an important transitional means to assist in emission reduction,which can serve as an important supplement to carbon market policy and be phased out after the market mechanism matures.展开更多
CO_(2)捕集、利用与封存(CO_(2)Capture, Utilization and Storage, CCUS)技术是减少碳排放的有效手段之一,是实现中国“双碳”目标的重要技术保障,其中CO_(2)管道输送是最重要的一环。从CCUS技术和CO_(2)管道设计两个维度综述了国内外C...CO_(2)捕集、利用与封存(CO_(2)Capture, Utilization and Storage, CCUS)技术是减少碳排放的有效手段之一,是实现中国“双碳”目标的重要技术保障,其中CO_(2)管道输送是最重要的一环。从CCUS技术和CO_(2)管道设计两个维度综述了国内外CO_(2)捕集、CO_(2)运输、CO_(2)封存和CO_(2)利用的研究进展,针对运输过程,着重从工艺设计、杂质、含水量、止裂控制和风险评估等方面梳理了CO_(2)管道设计的研究成果。中国目前正在大力推进CCUS技术,中国石油、中国石化和中国海洋石油等机构分别成立了相关的研究机构,聚焦CCUS发展的各个环节。虽然中国尚处于技术发展的初级阶段,但相信随着科研人员的努力会很快赶超发达国家,跻身第一方阵。研究结果旨在为中国的CCUS技术发展提供参考,促进中国CCUS技术的推广实施和CO_(2)管道的合理设计。展开更多
Climate change is a global challenge that threatens global ecological security and sustainable development.Find-ing ways to mitigate their impacts is paramount through engineering carbon storage,low-carbon energy tran...Climate change is a global challenge that threatens global ecological security and sustainable development.Find-ing ways to mitigate their impacts is paramount through engineering carbon storage,low-carbon energy tran-sition,or natural climate solutions(NCS).NCS involve a set of measures(e.g.,afforestation,land restoration,biochar reuse or sustainable land use practices).Implementing NCS increases carbon sequestration and mitigates climate change at the lowest costs and greenest ways.In addition,NCS practices can improve multiple ecosystem services(ES)such as air quality,flood and erosion regulation,pest control,water purification,wild food biomass,recreation or landscape aesthetics.However,unsustainable implementation of NCS,such as over-afforestation of dense mono-forest,can lead to tradeoffs with water supply,wildfire risk,and decreased grasslands and crop-lands.Therefore,to optimise the NCS implementation,reducing the tradeoffs associated and transforming the“expand ecosystem area”to“improve ecosystem management efficiency”is vital.Although NCS can contribute significantly to mitigating climate change,systematic climate actions must be accompanied by a transformation in the global society and investment in new technologies.This will be key to addressing global challenges such as the achievement of Sustainable Development Goals(SDGs),such as SDG 13(Climate Action),SDG 15(Life on Land),SDG 2(Zero Hunger),SDG 3(Good Health and Wellbeing),SDG 6(Clean Water and Sanitation),and SDG 14(Life Bellow Water).展开更多
Local actors appear as inseparable components of the integrated flood risk mitigation strategy in Vietnam.Recognizing this fact,this study examined the long-term improvement in precautions taken by commune authorities...Local actors appear as inseparable components of the integrated flood risk mitigation strategy in Vietnam.Recognizing this fact,this study examined the long-term improvement in precautions taken by commune authorities and households between two major floods in 1999 and 2017 by applying both quantitative and qualitative methods.Two flood-prone villages were selected for a survey;one in a rural area and the other in a suburban area of Thua Thien Hue Province,central Vietnam.The findings indicate that most villagers doubted the structural works’efficacy and were dissatisfied with the current efforts of local authorities.Households’self-preparation thus became the decisive factor in mitigating risk.While most households have paid greater attention to flood precautions in 2017,others seem to be lagging.Poverty-related barriers were the root causes restraining households in both rural and suburban villages.The suburban riverine residents were further identified as vulnerable by their limitations in upgrading structural measures,which was ascribed to the inconsistency in the ancient town’s preservation policy.This multidimensional comparison,in terms of vulnerability,emphasized the importance of space-function links in the suburb and the contradictions of different policy initiatives,such as landscape rehabilitation,disaster prevention,and livelihood maintenance.展开更多
This paper uses Lorenz curve and Gini index with adjustment to per capita historical cumulative emission to construct carbon Gini index to measure inequality in climate change area. The analysis shows that 70% of carb...This paper uses Lorenz curve and Gini index with adjustment to per capita historical cumulative emission to construct carbon Gini index to measure inequality in climate change area. The analysis shows that 70% of carbon space in the atmosphere has been used for unequal distribution, which is almost the same as that of incomes in a country with the biggest gap between the rich and the poor in the world. The carbon equity should be an urgency and priority in the climate agenda. Carbon Gini index established in this paper can be used to measure inequality in the distribution of carbon space and provide a quantified indicator for measurement of carbon equity among different proposals.展开更多
气候智慧型农业(climate-smart agriculture,CSA)已成为全球可持续发展目标(Sustainable Development Goals,SDGs)下应对气候变化和粮食安全双挑战的农业系统解决方案。通过全面梳理CSA的概念内涵,评估其与可持续发展目标的关联,进一步...气候智慧型农业(climate-smart agriculture,CSA)已成为全球可持续发展目标(Sustainable Development Goals,SDGs)下应对气候变化和粮食安全双挑战的农业系统解决方案。通过全面梳理CSA的概念内涵,评估其与可持续发展目标的关联,进一步归纳其基本议题和未来发展趋势。研究发现:①CSA不仅可直接促进SDG13-气候行动,而且与其他SDGs有紧密的内在联系,有利于实现消除贫困、饥饿、促进公平的SDG目标。②结合中国语境,CSA可界定为一项基于系统思维,能在多目标、多尺度下平衡粮食可持续增产(粮食安全)、提高农业对气候的适应能力(适应)、减缓温室气体排放(减缓)3个目标之间的优先事项,增强农业系统弹性的土地利用工程。③CSA研究可从理论探讨、水平测度、实践举措、优化调控4个方面深入探索,掌握概念标准、公平正义、多目标协同权衡、促进实践采纳等研究的关键节点,布局未来研究蓝图。本文期待为CSA发展成多学科交融和多系统互动的综合研究奠定基础,最终促使中国CSA研究走向国际理论关联和本土实践创新。展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.U2268210,52302474,52072249).
文摘Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.
基金supported by the National Natural Science Foundation of China(71874133)the Youth Innovation Team of Shaanxi Universities,and the Annual Basic Scientific Research Project of Xidian University(2019).
文摘Although the carbon pricing policy is a critical driving factor that will help China achieve economic growth,energy transition,and dual climate change mitigation goals,the kind of carbon pricing policy that will complement the country's current development situation remains controversial.We apply the World Induced Technical Change Hybrid(WITCH)model to explore the heterogeneity and synergy of different carbon pricing policies,and the results indicate that it will be challenging to achieve carbon neutrality before 2060.The study find that the combined policy-a mix of carbon tax and carbon market policies--has the optimal emission reduction effect but comes with the highest economic cost,proving to be unsuitable in the long run.The carbon tax policy is an important transitional means to assist in emission reduction,which can serve as an important supplement to carbon market policy and be phased out after the market mechanism matures.
文摘CO_(2)捕集、利用与封存(CO_(2)Capture, Utilization and Storage, CCUS)技术是减少碳排放的有效手段之一,是实现中国“双碳”目标的重要技术保障,其中CO_(2)管道输送是最重要的一环。从CCUS技术和CO_(2)管道设计两个维度综述了国内外CO_(2)捕集、CO_(2)运输、CO_(2)封存和CO_(2)利用的研究进展,针对运输过程,着重从工艺设计、杂质、含水量、止裂控制和风险评估等方面梳理了CO_(2)管道设计的研究成果。中国目前正在大力推进CCUS技术,中国石油、中国石化和中国海洋石油等机构分别成立了相关的研究机构,聚焦CCUS发展的各个环节。虽然中国尚处于技术发展的初级阶段,但相信随着科研人员的努力会很快赶超发达国家,跻身第一方阵。研究结果旨在为中国的CCUS技术发展提供参考,促进中国CCUS技术的推广实施和CO_(2)管道的合理设计。
基金C.Y.and W.Z.were supported by National Natural Science Founda-tion of China(Grant No.42271292)State Key Laboratory of Earth Sur-face Processes and Resource Ecology(Grant No.2022-ZD-08)+1 种基金the Fundamental Research Funds for the Central Universities of ChinaP.P.was supported by the project MApping and Forecasting Ecosystem Ser-vices in URban areas(MAFESUR),financed by the Lithuanian Research Council.Nr.P-MIP-23-426.
文摘Climate change is a global challenge that threatens global ecological security and sustainable development.Find-ing ways to mitigate their impacts is paramount through engineering carbon storage,low-carbon energy tran-sition,or natural climate solutions(NCS).NCS involve a set of measures(e.g.,afforestation,land restoration,biochar reuse or sustainable land use practices).Implementing NCS increases carbon sequestration and mitigates climate change at the lowest costs and greenest ways.In addition,NCS practices can improve multiple ecosystem services(ES)such as air quality,flood and erosion regulation,pest control,water purification,wild food biomass,recreation or landscape aesthetics.However,unsustainable implementation of NCS,such as over-afforestation of dense mono-forest,can lead to tradeoffs with water supply,wildfire risk,and decreased grasslands and crop-lands.Therefore,to optimise the NCS implementation,reducing the tradeoffs associated and transforming the“expand ecosystem area”to“improve ecosystem management efficiency”is vital.Although NCS can contribute significantly to mitigating climate change,systematic climate actions must be accompanied by a transformation in the global society and investment in new technologies.This will be key to addressing global challenges such as the achievement of Sustainable Development Goals(SDGs),such as SDG 13(Climate Action),SDG 15(Life on Land),SDG 2(Zero Hunger),SDG 3(Good Health and Wellbeing),SDG 6(Clean Water and Sanitation),and SDG 14(Life Bellow Water).
基金This study was financially supported by the Vietnamese government and Okayama University,Japan.Besides
文摘Local actors appear as inseparable components of the integrated flood risk mitigation strategy in Vietnam.Recognizing this fact,this study examined the long-term improvement in precautions taken by commune authorities and households between two major floods in 1999 and 2017 by applying both quantitative and qualitative methods.Two flood-prone villages were selected for a survey;one in a rural area and the other in a suburban area of Thua Thien Hue Province,central Vietnam.The findings indicate that most villagers doubted the structural works’efficacy and were dissatisfied with the current efforts of local authorities.Households’self-preparation thus became the decisive factor in mitigating risk.While most households have paid greater attention to flood precautions in 2017,others seem to be lagging.Poverty-related barriers were the root causes restraining households in both rural and suburban villages.The suburban riverine residents were further identified as vulnerable by their limitations in upgrading structural measures,which was ascribed to the inconsistency in the ancient town’s preservation policy.This multidimensional comparison,in terms of vulnerability,emphasized the importance of space-function links in the suburb and the contradictions of different policy initiatives,such as landscape rehabilitation,disaster prevention,and livelihood maintenance.
基金National Basic Research Programme(No.2010CB955303)
文摘This paper uses Lorenz curve and Gini index with adjustment to per capita historical cumulative emission to construct carbon Gini index to measure inequality in climate change area. The analysis shows that 70% of carbon space in the atmosphere has been used for unequal distribution, which is almost the same as that of incomes in a country with the biggest gap between the rich and the poor in the world. The carbon equity should be an urgency and priority in the climate agenda. Carbon Gini index established in this paper can be used to measure inequality in the distribution of carbon space and provide a quantified indicator for measurement of carbon equity among different proposals.
文摘气候智慧型农业(climate-smart agriculture,CSA)已成为全球可持续发展目标(Sustainable Development Goals,SDGs)下应对气候变化和粮食安全双挑战的农业系统解决方案。通过全面梳理CSA的概念内涵,评估其与可持续发展目标的关联,进一步归纳其基本议题和未来发展趋势。研究发现:①CSA不仅可直接促进SDG13-气候行动,而且与其他SDGs有紧密的内在联系,有利于实现消除贫困、饥饿、促进公平的SDG目标。②结合中国语境,CSA可界定为一项基于系统思维,能在多目标、多尺度下平衡粮食可持续增产(粮食安全)、提高农业对气候的适应能力(适应)、减缓温室气体排放(减缓)3个目标之间的优先事项,增强农业系统弹性的土地利用工程。③CSA研究可从理论探讨、水平测度、实践举措、优化调控4个方面深入探索,掌握概念标准、公平正义、多目标协同权衡、促进实践采纳等研究的关键节点,布局未来研究蓝图。本文期待为CSA发展成多学科交融和多系统互动的综合研究奠定基础,最终促使中国CSA研究走向国际理论关联和本土实践创新。
