With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have i...With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have increased dramatically,especially for providing airborne Internet services.However,due to dynamic service demands and onboard LEO resources over time and space,it poses huge challenges in satellite-aircraft access and service management in ultra-dense LEO satellite networks(UDLSN).In this paper,we propose a deep reinforcement learning-based approach for ultra-dense LEO satellite-aircraft access and service management.Firstly,we develop an airborne Internet architecture based on UDLSN and design a management mechanism including medium earth orbit satellites to guarantee lightweight management.Secondly,considering latency-sensitive and latency-tolerant services,we formulate the problem of satellite-aircraft access and service management for civil aviation to ensure service continuity.Finally,we propose a proximal policy optimization-based access and service management algorithm to solve the formulated problem.Simulation results demonstrate the convergence and effectiveness of the proposed algorithm with satisfying the service continuity when applying to the UDLSN.展开更多
Transactions of Nanjing University of Acronautics&Astronautics(TNUAA)is a bimonthly joumnal facing intermational academic community.Emphasizing prompt and efective dissemination of key data and new scientific insi...Transactions of Nanjing University of Acronautics&Astronautics(TNUAA)is a bimonthly joumnal facing intermational academic community.Emphasizing prompt and efective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civill aviation.展开更多
As African economies continue to expand their trade networks,digital transformation and e-commerce have emerged as key drivers of economic development.Ethiopia has embraced this trend,aiming to modernise its logistics...As African economies continue to expand their trade networks,digital transformation and e-commerce have emerged as key drivers of economic development.Ethiopia has embraced this trend,aiming to modernise its logistics and aviation infrastructure to meet the growing demand.展开更多
1.Opportunities for electric motor drives in the low-altitude economy The implementation plan for the innovative application of general aviation equipment(2024–2030)outlines that by 2027,new general aviation equipmen...1.Opportunities for electric motor drives in the low-altitude economy The implementation plan for the innovative application of general aviation equipment(2024–2030)outlines that by 2027,new general aviation equipment will achieve commercial applications in urban air transport,logistics distribution and emergency rescue.展开更多
The increasing use of robotic surgery has seen a wave of technology ripple through global healthcare.Similar changes occurred in aviation several decades ago.New robot types have increased access for both patients and...The increasing use of robotic surgery has seen a wave of technology ripple through global healthcare.Similar changes occurred in aviation several decades ago.New robot types have increased access for both patients and surgeons.The modern robotic curriculum therefore needs to train surgeons of varying experience,gaining access to several robot types,and based in centres around the world.Drawing on this analogy with aviation helps to derive principles for curriculum design,and considers humanemachine interface,non-technical skills,team training,and simulation.The components of the curriculum could be core(cross-platform),platform-specific,specialty-specific,and platform-transitional.Analogous concepts also emerge,including type rating,control as surgery-by-wire,spatio-haptic envelope,and virtual operations.The fourth industrial revolution sets anticipation for progress.展开更多
Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific ins...Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.展开更多
Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific ins...Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.展开更多
Transactions of Nanjing University of Aeronautics & Astronautics(TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific ...Transactions of Nanjing University of Aeronautics & Astronautics(TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.展开更多
African Aviation continues to fall short of serving the demands of the fast-growing African population. For major air transport in and out of the African continent, African travellers rely mainly on non-African Airlin...African Aviation continues to fall short of serving the demands of the fast-growing African population. For major air transport in and out of the African continent, African travellers rely mainly on non-African Airlines. There is, however, one successful airline on the continent at the writing of this paper: Ethiopian Airlines and the Ethiopian Aviation Group. Why are no further successful airlines possible on a continent of 1.4 billion people (25% of the world’s population) and only a 2%-share of global air transport? At the introduction of SAATM, which is anticipated as the start of the domestic African aviation boom, most African countries seem unprepared to build a success story like Ethiopia. Transportation infrastructure in sub-Saharan Africa does not start with roads and rail but with runways and airlines. This research investigates the basic requirements needed to equip Africa with a competitive aviation industry that would contribute some 5% to the continent’s GDP and create hundreds of thousands of workplaces. Interviews with African SAATM leaders signal a slowdown in the effort to succeed. The research is also concerned about the lack of inclusion in the implementation of a NetZero CO2 emission scheme in Africa.展开更多
Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst an...Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst and the number of acceptable H*receptors.This study prepares highly dispersed Ni nanoparticles(NPs)catalysts on a Beta substrate via precursor structure topology transformation.In contrast to traditional support materials,the coordination and electronic structure changes between the Ni NPs and the support were achieved,further optimizing the active interface sites and enhancing hydrogen activation and hydrogenation performance.Additionally,the-OH groups at the strong acid sites in zeolite effectively intensified the hydrogen spillover effect as receptors for H^(*)migration and anchoring,accelerating the hydrogenation rate of aromatic rings.Under solvent-free conditions,this catalyst was used for the hydrogenation reaction of aromatic-rich oils,directly producing a C_(8)-C_(14)branched cycloalkanes mixture with an aromatic conversion rate of>99%.The cycloalkanes mixture produced by this method features high density(0.92 g/mL)and a low freezing point(<-60℃),making it suitable for use as high-density aviation fuel or as an additive to enhance the volumetric heat value of conventional aviation fuels in practical applications.展开更多
With the rapid development of aviation industry and its increasing impact on the global climate change,the contributions of carbon emissions frominternational flights are attracting more and more attention worldwide.T...With the rapid development of aviation industry and its increasing impact on the global climate change,the contributions of carbon emissions frominternational flights are attracting more and more attention worldwide.This study,taking Macao as the aviation hub,established the cross-border aviation carbon emission evaluation model to explore dynamic carbon emissions and net-zero path of international flights.The aviation hubmainly covers 58 routes and five types of civil aircraft from 12 countries or regions during 2000-2022.The results show that the aviation transportation in Macao emitted about 1.44 million tons CO_(2)eq in 2019,which is high 3.6 times that of 2000.The COVID-19 has led to a rapid decline in aviation carbon emissions in a short period of time,carbon emissions in 2020 decreased by 80%compared to 2019.In terms of cumulative carbon emissions from 2000 to 2019,the A321 and A320 Airbus contribute to 80%of carbon emissions.And the Chinese mainland(37%)and Taiwan(29%)are the main sources of emissions.In 2000-2019,the proportion of carbon emissions from China(including Taiwan and Hong Kong)decrease from 91%to 53%,while the contribution from Southeast Asia(from 5% to 26%),Japan and South Korea(from 2% to 19%)keep the growth trends.In the optimal scenario(B3C3),net zero emissions of cross-border aviation in Macao can be not achieved,and there is still only by removing 0.3 million tons CO_(2)eq.Emission reduction technology and new energy usage are priorities for the aviation emission reduction.展开更多
Please feel free to contact us with your personal stories or vivid pictures!Address:24 Baiwanzhuang St.,Xicheng Dist.,Beijing,100037 E-mail:chinatodaynews@aliyun.com I am an architect,urbanist,and airport planner.I wo...Please feel free to contact us with your personal stories or vivid pictures!Address:24 Baiwanzhuang St.,Xicheng Dist.,Beijing,100037 E-mail:chinatodaynews@aliyun.com I am an architect,urbanist,and airport planner.I worked on diverse projects in Russia and Germany.I have recently started to work for aviation startups.Now,I am a senior counselor of Frankfurt Airport.展开更多
With the development of civil aviation industry,the number of retired aircraft is increasing year by year.How to deal with retired aircraft,build aviation,avoid damage to the ecological environment,and develop their r...With the development of civil aviation industry,the number of retired aircraft is increasing year by year.How to deal with retired aircraft,build aviation,avoid damage to the ecological environment,and develop their residual value has attracted widespread attention internationally,and gradually formed dismantling industry for the commercial and reuse of retired aircraft.From the perspective of the industrial chain,the essence of aircraft dismantling is how to maximize the value of highvalue assets at the of their life cycle,that is,to balance the value of aircraft parts and the value of the whole aircraft,which is the last chain in the complete industrial of civil aircraft from design,manufacturing to usage and retirement.The paper studied the dismantling industrial modes of civil aircraft,analyzed the problems and challenges faced by aircraft dismantling,and put forward relevant measures and suggestions,which point out the direction for the development of domestic civil aircraft dismantling industry.展开更多
The aerospace and aviation industry has long been at the forefront of materials and processing technologies,driven by its ongoing demand for lightweight,highly reliable,and durable components.Precision manufacturing i...The aerospace and aviation industry has long been at the forefront of materials and processing technologies,driven by its ongoing demand for lightweight,highly reliable,and durable components.Precision manufacturing is a critical discipline that directly affects the performance,functionality,and safety of aircraft and aerospace vehicles.To meet the above-mentioned stringent requirements,advanced materials and cutting-edge processing technologies have evolved alongside aerospace innovations.展开更多
The aerospace and aviation industries have consistently led advancements in materials and processing technologies due to their ongoing demand for lightweight,highly reliable,and durable components.Precision manufactur...The aerospace and aviation industries have consistently led advancements in materials and processing technologies due to their ongoing demand for lightweight,highly reliable,and durable components.Precision manufacturing of components is critical to ensuring the performance,functionality,and safety of aircraft and aerospace vehicles.展开更多
Sustainable aviation fuel(SAF)production from biomass and biowaste streams is an attractive option for decarbonizing the aviation sector,one of the most-difficult-to-electrify transportation sectors.Despite ongoing co...Sustainable aviation fuel(SAF)production from biomass and biowaste streams is an attractive option for decarbonizing the aviation sector,one of the most-difficult-to-electrify transportation sectors.Despite ongoing commercialization efforts using ASTM-certified pathways(e.g.,lipid conversion,Fischer-Tropsch synthesis),production capacities are still inadequate due to limited feedstock supply and high production costs.New conversion technologies that utilize lignocellulosic feedstocks are needed to meet these challenges and satisfy the rapidly growing market.Combining bio-and chemo-catalytic approaches can leverage advantages from both methods,i.e.,high product selectivity via biological conversion,and the capability to build C-C chains more efficiently via chemical catalysis.Herein,conversion routes,catalysis,and processes for such pathways are discussed,while key challenges and meaningful R&D opportunities are identified to guide future research activities in the space.Bio-and chemo-catalytic conversion primarily utilize the carbohydrate fraction of lignocellulose,leaving lignin as a waste product.This makes lignin conversion to SAF critical in order to utilize whole biomass,thereby lowering overall production costs while maximizing carbon efficiencies.Thus,lignin valorization strategies are also reviewed herein with vital research areas identified,such as facile lignin depolymerization approaches,highly integrated conversion systems,novel process configurations,and catalysts for the selective cleavage of aryl C-O bonds.The potential efficiency improvements available via integrated conversion steps,such as combined biological and chemo-catalytic routes,along with the use of different parallel pathways,are identified as key to producing all components of a cost-effective,100%SAF.展开更多
Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The...Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The methodology utilizes circular tubes with two different diameters.The density of aviation kerosene RP-3 was experimentally measured for the first time within a pressure range from 6 MPa to 8 MPa and a temperature range from 323 K to 783 K,with a maximum relative uncertainty of 0.35%.The experimental setup used n-decane for calibration,achieving an average calibration error of 0.91%.The data indicate that the density of RP-3 ranges from 764 kg/m^(3)to 247 kg/m^(3)under the tested conditions.The results show that the density of kerosene RP-3 decreases with an increase in temperature at a constant pressure,and at a given temperature,a higher pressure results in a higher density.Polynomial fitting was applied to the data,resulting in the average absolute deviation of 1.09%,0.80%,and 0.76%at different pressures of 6,7,and 8 MPa,respectively.展开更多
As an economic concept,the low-altitude economy aims to utilise the unique resources of low-altitude airspace in a bid to develop general aviation or civilian non-airline flight,and energise the related industries fro...As an economic concept,the low-altitude economy aims to utilise the unique resources of low-altitude airspace in a bid to develop general aviation or civilian non-airline flight,and energise the related industries from the sky to the ground.展开更多
Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific i...Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.展开更多
By analyzing the successful case of meteorological support services for the navigation ceremony of Langzhong Airport,the practice experience,existing problems and future improvement directions of aviation meteorologic...By analyzing the successful case of meteorological support services for the navigation ceremony of Langzhong Airport,the practice experience,existing problems and future improvement directions of aviation meteorological support services were analyzed and summarized to provide reference for the airport and its subsequent aviation meteorological support services in the future.展开更多
基金supported in part by the National Key R&D Program of China under Grant 2020YFB1806104in part by Innovation and Entrepreneurship of Jiangsu Province High-level Talent Program+1 种基金in part by Natural Sciences and Engineering Research Council of Canada (NSERC)the support from Huawei
文摘With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have increased dramatically,especially for providing airborne Internet services.However,due to dynamic service demands and onboard LEO resources over time and space,it poses huge challenges in satellite-aircraft access and service management in ultra-dense LEO satellite networks(UDLSN).In this paper,we propose a deep reinforcement learning-based approach for ultra-dense LEO satellite-aircraft access and service management.Firstly,we develop an airborne Internet architecture based on UDLSN and design a management mechanism including medium earth orbit satellites to guarantee lightweight management.Secondly,considering latency-sensitive and latency-tolerant services,we formulate the problem of satellite-aircraft access and service management for civil aviation to ensure service continuity.Finally,we propose a proximal policy optimization-based access and service management algorithm to solve the formulated problem.Simulation results demonstrate the convergence and effectiveness of the proposed algorithm with satisfying the service continuity when applying to the UDLSN.
文摘Transactions of Nanjing University of Acronautics&Astronautics(TNUAA)is a bimonthly joumnal facing intermational academic community.Emphasizing prompt and efective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civill aviation.
文摘As African economies continue to expand their trade networks,digital transformation and e-commerce have emerged as key drivers of economic development.Ethiopia has embraced this trend,aiming to modernise its logistics and aviation infrastructure to meet the growing demand.
基金supported by the National Natural Science Foundation of China(No.52407064)。
文摘1.Opportunities for electric motor drives in the low-altitude economy The implementation plan for the innovative application of general aviation equipment(2024–2030)outlines that by 2027,new general aviation equipment will achieve commercial applications in urban air transport,logistics distribution and emergency rescue.
文摘The increasing use of robotic surgery has seen a wave of technology ripple through global healthcare.Similar changes occurred in aviation several decades ago.New robot types have increased access for both patients and surgeons.The modern robotic curriculum therefore needs to train surgeons of varying experience,gaining access to several robot types,and based in centres around the world.Drawing on this analogy with aviation helps to derive principles for curriculum design,and considers humanemachine interface,non-technical skills,team training,and simulation.The components of the curriculum could be core(cross-platform),platform-specific,specialty-specific,and platform-transitional.Analogous concepts also emerge,including type rating,control as surgery-by-wire,spatio-haptic envelope,and virtual operations.The fourth industrial revolution sets anticipation for progress.
文摘Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.
文摘Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.
文摘Transactions of Nanjing University of Aeronautics & Astronautics(TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.
文摘African Aviation continues to fall short of serving the demands of the fast-growing African population. For major air transport in and out of the African continent, African travellers rely mainly on non-African Airlines. There is, however, one successful airline on the continent at the writing of this paper: Ethiopian Airlines and the Ethiopian Aviation Group. Why are no further successful airlines possible on a continent of 1.4 billion people (25% of the world’s population) and only a 2%-share of global air transport? At the introduction of SAATM, which is anticipated as the start of the domestic African aviation boom, most African countries seem unprepared to build a success story like Ethiopia. Transportation infrastructure in sub-Saharan Africa does not start with roads and rail but with runways and airlines. This research investigates the basic requirements needed to equip Africa with a competitive aviation industry that would contribute some 5% to the continent’s GDP and create hundreds of thousands of workplaces. Interviews with African SAATM leaders signal a slowdown in the effort to succeed. The research is also concerned about the lack of inclusion in the implementation of a NetZero CO2 emission scheme in Africa.
基金financially supported by the National Natural Science Foundation of China(Grant 22278439,21776313)the Shandong Province Higher Education Youth Innovation Technology Support Program(Grant 2022KJ074)。
文摘Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst and the number of acceptable H*receptors.This study prepares highly dispersed Ni nanoparticles(NPs)catalysts on a Beta substrate via precursor structure topology transformation.In contrast to traditional support materials,the coordination and electronic structure changes between the Ni NPs and the support were achieved,further optimizing the active interface sites and enhancing hydrogen activation and hydrogenation performance.Additionally,the-OH groups at the strong acid sites in zeolite effectively intensified the hydrogen spillover effect as receptors for H^(*)migration and anchoring,accelerating the hydrogenation rate of aromatic rings.Under solvent-free conditions,this catalyst was used for the hydrogenation reaction of aromatic-rich oils,directly producing a C_(8)-C_(14)branched cycloalkanes mixture with an aromatic conversion rate of>99%.The cycloalkanes mixture produced by this method features high density(0.92 g/mL)and a low freezing point(<-60℃),making it suitable for use as high-density aviation fuel or as an additive to enhance the volumetric heat value of conventional aviation fuels in practical applications.
基金supported by the Science and Technology Development Fund,Macao SAR,China(Nos.0033/2022/AFJ and 0011/2023/AMJ)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012017).
文摘With the rapid development of aviation industry and its increasing impact on the global climate change,the contributions of carbon emissions frominternational flights are attracting more and more attention worldwide.This study,taking Macao as the aviation hub,established the cross-border aviation carbon emission evaluation model to explore dynamic carbon emissions and net-zero path of international flights.The aviation hubmainly covers 58 routes and five types of civil aircraft from 12 countries or regions during 2000-2022.The results show that the aviation transportation in Macao emitted about 1.44 million tons CO_(2)eq in 2019,which is high 3.6 times that of 2000.The COVID-19 has led to a rapid decline in aviation carbon emissions in a short period of time,carbon emissions in 2020 decreased by 80%compared to 2019.In terms of cumulative carbon emissions from 2000 to 2019,the A321 and A320 Airbus contribute to 80%of carbon emissions.And the Chinese mainland(37%)and Taiwan(29%)are the main sources of emissions.In 2000-2019,the proportion of carbon emissions from China(including Taiwan and Hong Kong)decrease from 91%to 53%,while the contribution from Southeast Asia(from 5% to 26%),Japan and South Korea(from 2% to 19%)keep the growth trends.In the optimal scenario(B3C3),net zero emissions of cross-border aviation in Macao can be not achieved,and there is still only by removing 0.3 million tons CO_(2)eq.Emission reduction technology and new energy usage are priorities for the aviation emission reduction.
文摘Please feel free to contact us with your personal stories or vivid pictures!Address:24 Baiwanzhuang St.,Xicheng Dist.,Beijing,100037 E-mail:chinatodaynews@aliyun.com I am an architect,urbanist,and airport planner.I worked on diverse projects in Russia and Germany.I have recently started to work for aviation startups.Now,I am a senior counselor of Frankfurt Airport.
文摘With the development of civil aviation industry,the number of retired aircraft is increasing year by year.How to deal with retired aircraft,build aviation,avoid damage to the ecological environment,and develop their residual value has attracted widespread attention internationally,and gradually formed dismantling industry for the commercial and reuse of retired aircraft.From the perspective of the industrial chain,the essence of aircraft dismantling is how to maximize the value of highvalue assets at the of their life cycle,that is,to balance the value of aircraft parts and the value of the whole aircraft,which is the last chain in the complete industrial of civil aircraft from design,manufacturing to usage and retirement.The paper studied the dismantling industrial modes of civil aircraft,analyzed the problems and challenges faced by aircraft dismantling,and put forward relevant measures and suggestions,which point out the direction for the development of domestic civil aircraft dismantling industry.
文摘The aerospace and aviation industry has long been at the forefront of materials and processing technologies,driven by its ongoing demand for lightweight,highly reliable,and durable components.Precision manufacturing is a critical discipline that directly affects the performance,functionality,and safety of aircraft and aerospace vehicles.To meet the above-mentioned stringent requirements,advanced materials and cutting-edge processing technologies have evolved alongside aerospace innovations.
文摘The aerospace and aviation industries have consistently led advancements in materials and processing technologies due to their ongoing demand for lightweight,highly reliable,and durable components.Precision manufacturing of components is critical to ensuring the performance,functionality,and safety of aircraft and aerospace vehicles.
基金supported by the Center for Bioenergy Innovation(CBI)supported by the Office of Biological and Environmental Research in the DOE Office of Science and led by Oak Ridge National Laboratory.Oak Ridge National Laboratory is managed by UT-Battelle,LLC for the US DOE under Contract Number DE-AC05-00OR22725+2 种基金authored in part by the Na-tional Renewable Energy Laboratory,operated by Alliance for Sustainable Energy,LLC,for the U.S.Department of Energy(DOE)under Contract No.DE-LC-000L054provided by the U.S.Department of Energy(DOE),Office of Energy Efficiency and Renewable Energy(EERE),and Bioenergy Technologies Office(BETO)at the Pacific Northwest National Laboratory(PNNL)under Contract No.DE-AC05-76RL01830supported by Laboratory Directed Research and Development(LDRD)funding from Argonne National Laboratory,provided by the Director,Office of Science,of the U.S.Department of Energy under Contract No.DE-AC02-06CH11357。
文摘Sustainable aviation fuel(SAF)production from biomass and biowaste streams is an attractive option for decarbonizing the aviation sector,one of the most-difficult-to-electrify transportation sectors.Despite ongoing commercialization efforts using ASTM-certified pathways(e.g.,lipid conversion,Fischer-Tropsch synthesis),production capacities are still inadequate due to limited feedstock supply and high production costs.New conversion technologies that utilize lignocellulosic feedstocks are needed to meet these challenges and satisfy the rapidly growing market.Combining bio-and chemo-catalytic approaches can leverage advantages from both methods,i.e.,high product selectivity via biological conversion,and the capability to build C-C chains more efficiently via chemical catalysis.Herein,conversion routes,catalysis,and processes for such pathways are discussed,while key challenges and meaningful R&D opportunities are identified to guide future research activities in the space.Bio-and chemo-catalytic conversion primarily utilize the carbohydrate fraction of lignocellulose,leaving lignin as a waste product.This makes lignin conversion to SAF critical in order to utilize whole biomass,thereby lowering overall production costs while maximizing carbon efficiencies.Thus,lignin valorization strategies are also reviewed herein with vital research areas identified,such as facile lignin depolymerization approaches,highly integrated conversion systems,novel process configurations,and catalysts for the selective cleavage of aryl C-O bonds.The potential efficiency improvements available via integrated conversion steps,such as combined biological and chemo-catalytic routes,along with the use of different parallel pathways,are identified as key to producing all components of a cost-effective,100%SAF.
基金supported by the Science Center for Gas Turbine Project,China(No.P2022-C-II-005-001)。
文摘Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The methodology utilizes circular tubes with two different diameters.The density of aviation kerosene RP-3 was experimentally measured for the first time within a pressure range from 6 MPa to 8 MPa and a temperature range from 323 K to 783 K,with a maximum relative uncertainty of 0.35%.The experimental setup used n-decane for calibration,achieving an average calibration error of 0.91%.The data indicate that the density of RP-3 ranges from 764 kg/m^(3)to 247 kg/m^(3)under the tested conditions.The results show that the density of kerosene RP-3 decreases with an increase in temperature at a constant pressure,and at a given temperature,a higher pressure results in a higher density.Polynomial fitting was applied to the data,resulting in the average absolute deviation of 1.09%,0.80%,and 0.76%at different pressures of 6,7,and 8 MPa,respectively.
文摘As an economic concept,the low-altitude economy aims to utilise the unique resources of low-altitude airspace in a bid to develop general aviation or civilian non-airline flight,and energise the related industries from the sky to the ground.
文摘Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.
文摘By analyzing the successful case of meteorological support services for the navigation ceremony of Langzhong Airport,the practice experience,existing problems and future improvement directions of aviation meteorological support services were analyzed and summarized to provide reference for the airport and its subsequent aviation meteorological support services in the future.
