Metok,located in Nyingchi,the Xizang Autonomous Region,is known as the last county in China to be connected by road.Poor transportation and limited access to petroleum were two obstacles to its development.As soon as ...Metok,located in Nyingchi,the Xizang Autonomous Region,is known as the last county in China to be connected by road.Poor transportation and limited access to petroleum were two obstacles to its development.As soon as the highway connecting Metok and the outside world was completed in 2014,China National Petroleum Corporation’s(CNPC)first gas station in the county was put into operation,providing the momentum for this"secret land of Lotus"and helping it embark on a journey toward openness and prosperity.展开更多
The compact torus injector(CTI)for the central fueling of the EAST tokamak has undergone significant upgrades to enhance its injection capability.During the initial phase of the platform testing phase,EAST-CTI demonst...The compact torus injector(CTI)for the central fueling of the EAST tokamak has undergone significant upgrades to enhance its injection capability.During the initial phase of the platform testing phase,EAST-CTI demonstrated relatively low performance,with a maximum velocity of 150 km s^(−1) and a single compact torus(CT)plasma mass of 90μg[Kong D et al 2023 Plasma Sci.Technol.25065601].These parameters were insufficient for conducting central fueling experiments on the EAST tokamak.Consequently,extensive upgrades were carried out to improve the performance of the EAST-CTI system.The compression region was extended from 280 mm to 700 mm to prevent rapid compression and deceleration of the CT plasma,along with an extension of the acceleration region to further increase the plasma acceleration.The power supply system has also been upgraded.These improvements elevated the operating voltage from 8 kV to 15 kV,increased the discharge current from 120 kA to 300 kA and enabled repetitive operation at a maximum rate of 2 Hz.As a result,significant advances in EAST-CTI performance were achieved,with the maximum velocity increasing to 330 km s^(−1) and the CT plasma density reaching 1.5×10^(22) m^(−3),thereby enhancing the system capability for future fueling experiments on EAST.This study offers valuable insights into CTI modification and the improvement of central fueling systems for prospective fusion reactors.展开更多
Driven by the global“dual-carbon”goals,hydrogen fuel cell electric vehicles(FCEVs)are being rapidly promoted as a zero-emission transportation solution.However,their large-scale application is constrained by issues ...Driven by the global“dual-carbon”goals,hydrogen fuel cell electric vehicles(FCEVs)are being rapidly promoted as a zero-emission transportation solution.However,their large-scale application is constrained by issues such as inefficient operation,poor information flow between vehicles and stations,and potential safety hazards,which are caused by insufficient intelligence of hydrogen refueling stations.This study aims to address these problems by deeply integrating Cellular Vehicle-to-Everything(C-V2X)technology with hydrogen refueling stations,thereby building a safe,efficient,and low-carbon hydrogen energy application ecosystem to promote the global transition to zero-carbon transportation.Firstly,through literature review and technical analysis,this study expounds on the core technologies and process flows of current hydrogen refueling stations,aswell as the technical architecture and development evolution of C-V2X technology.Then,based on the analysis of relevant literature,it proposes a“vehicle-road-station-cloud”collaborative architecture that integrates C-V2X with hydrogen refueling stations.Combined with 5G communication and big data technologies,it elaborates on the implementation path for achieving real-time data interaction among hydrogen refueling stations,hydrogen-powered vehicles,and road infrastructure.This interconnection mode enables hydrogen refueling stations to obtain real-time information of surrounding vehicles,which plays an important role in building a safe,efficient,and low-carbon hydrogen energy application ecosystem and promoting the global transition to zero-carbon transportation.Finally,the future development prospects and potential of this scheme are put forward.展开更多
Compact torus(CT)injection is a highly promising technique for the central fueling of future reactor-grade fusion devices since it features extremely high injection velocity and relatively high plasma mass.Recently,a ...Compact torus(CT)injection is a highly promising technique for the central fueling of future reactor-grade fusion devices since it features extremely high injection velocity and relatively high plasma mass.Recently,a CT injector for the EAST tokamak,EAST-CTI,was developed and platform-tested.In the first round of experiments conducted with low parameter settings,the maximum velocity and mass of the CT plasma were 150 km·s^(-1)and 90μg,respectively.However,the parameters obtained by EAST-CTI were still very low and were far from the requirements of a device such as EAST that has a strong magnetic field.In future,we plan to solve the spark problem that EAST-CTI currently encounters(that mainly hinders the further development of experiments)through engineering methods,and use greater power to obtain a more stable and suitable CT plasma for EAST.展开更多
Migratory birds rely on fueling prior to migratory flights. Fueling in migrants is controlled by intrinsic as well as ex- trinsic factors. From captive studies we have started understanding the internal mechanisms con...Migratory birds rely on fueling prior to migratory flights. Fueling in migrants is controlled by intrinsic as well as ex- trinsic factors. From captive studies we have started understanding the internal mechanisms controlling bird migration. Field studies have demonstrated the effects of external factors, such as food availability, weather, competitors, parasites or diseases, on the stopover behavior of migrants. However, an integrated approach is still missing to study coherently how the innate migration program interacts with the varying environmental cues and to estimate the contribution of the innate migration program and the environment to realized migration. The northern wheatear Oenanthe oenanthe offers a unique opportunity for integrated studies. It breeds across almost the whole Holarctic with just a ＂gap＂ between eastern Canada and Alaska. All breeding populations over- winter in sub-Saharan Africa which makes the northern wheatear one of the most long-distant migratory songbirds with extraor- dinary long non-stop flights across oceans. It is a nocturnal migrant which travels without parental or social aid/guidance. Thus, young birds rely entirely on endogenous mechanisms of timing, route selection and fueling on their first outbound migration. By establishing indoor housing under controlled conditions the endogenous control mechanisms of northern wheatear migration could be revealed. At the same time, environmental factors controlling fueling could be investigated in the field. On migration wheatears occur in a variety of habitats with sparse vegetation where their stopover behavior could be quantitatively studied in the light of ＂optimal migration＂ theory by the use of remote balances, radio-tagging and even experimentally manipulated food availability. The present paper summarizes our approach to understand the control of migration in northern wheatears by combin- ing field and laboratory studies at various spatial and temporal scales, and linking various sub-disciplines .展开更多
To understand the effect of injected deuterium(D)pellets on background plasma,the ablation of D pellets and the transport of D species in both atomic and ionic states in the EAST device are simulated using a modified ...To understand the effect of injected deuterium(D)pellets on background plasma,the ablation of D pellets and the transport of D species in both atomic and ionic states in the EAST device are simulated using a modified dynamic neutral gas shield model combined with the edge plasma code SOLPS-ITER.The simulation results show that there is a phenomenon of obvious atomic deposition in the scrape-off layer(SOL)after pellet injection,which depends strongly on the injection velocity.With increasing injection velocity,the atomic density in the SOL decreases evidently and the deposition time is relatively shortened.Possible effects for triggering of edge localized modes(ELMs)by D and Li pellets are also discussed.With the same pellet size and injection velocity,the maximum perturbation pressure caused by D pellets is obviously higher.It is found that the resulting maximum perturbed pressure is remarkably enhanced when the injection velocity is reduced from 300 m/s to 100 m/s for a pellet with a cross section of 1.6 mm,which indicates that the injection velocity is important for ELM pacing.This work can provide reasonable guidance for choosing pellet parameters for fueling and ELM triggering.展开更多
High-pressure gas injection has proved to be an effective disruption mitigation tech- nique in DIII-D tokamak experiments. If the method can be applied in future tokamak reactors not only for disruption mitigation but...High-pressure gas injection has proved to be an effective disruption mitigation tech- nique in DIII-D tokamak experiments. If the method can be applied in future tokamak reactors not only for disruption mitigation but also for plasma termination and fueling, it will have an attractive advantage over the pellet and liquid injection from the viewpoint of economy and engineering design. In order to investigate the feasibility of this option, a study has been carried out with relevant parameters for conveying tubes of different geometrical sizes and for different gases. These parameters include pressure drop, lagger time after the valve＇s opening, gas diffusion in an ultra-high vacuum condition, and particle number contour.展开更多
The supersonic molecular beam (SMB) ablation and penetration processes in the HL-1M tokamak experiments are studied. The cluster formation and dissolution, SMB adiabatic expansion, shielding and cooling effect are all...The supersonic molecular beam (SMB) ablation and penetration processes in the HL-1M tokamak experiments are studied. The cluster formation and dissolution, SMB adiabatic expansion, shielding and cooling effect are all taken into account. An optimized numerical model is applied in the analysis and shown to be in good agreement with the experimental observations. The possibility of fueling large tokamak plasmas with SMB injection is explored.展开更多
Tritium self-sufficiency in future deuterium–tritium fusion reactors is a crucial challenge.As an engineering test reactor,the China Fusion Engineering Test Reactor requires a burning fraction of 3%for the goal to te...Tritium self-sufficiency in future deuterium–tritium fusion reactors is a crucial challenge.As an engineering test reactor,the China Fusion Engineering Test Reactor requires a burning fraction of 3%for the goal to test the accessibility to the future fusion plant.To self-consistently simulate burning plasmas with profile changes in pellet injection scenarios and to estimate the corresponding burning fraction,a one-dimensional multi-species radial transport model is developed in the BOUT++framework.Several pellet-fueling scenarios are then tested in the model.The results show that the increased fueling depth improves the burning fraction by particle confinement improvement and fusion power increase.Nevertheless,by increasing the depth,the pellet cooling-down may significantly lower the temperature in the core region.Taking the density perturbation into consideration,the reasonable parameters of the fueling scenario in these simulations are estimated as pellet radius r_(p)=3 mm,injection rate=4 Hz,and pellet injection velocity=1000–2000 m s^(-1) without drift or 450 m s^(-1) with high-field-side drift.展开更多
Several high performance tokamak operation regimes have been achieved experimentally in the experiments with the peaked density profiles. The regimes include the improved Ohmic confinement in ASDEX, the pellet enhance...Several high performance tokamak operation regimes have been achieved experimentally in the experiments with the peaked density profiles. The regimes include the improved Ohmic confinement in ASDEX, the pellet enhanced performance mode in Alcator-C, and the super-shot mode in TFTR. In these regimes, peaked core density profiles are always existent, and almost always go with the internal transport barriers, these barriers generally produced by sheared radial electric field. In addition to enhance confinement, the peaked density profile is also needed for the optimized fusion reaction rate and alpha heating power in tokamak plasma, and combined peaked density profile and peaked temperature profile, would make the ignition condition easy obtained. It is desirable to seek and analyze the density profile control schemes that effectively lead to density profile peaking in particle transports experimental investigation.展开更多
In the ever fusion experiments in SWIP, pellet forming process was carried out through adjusting relative devices by staff member in site, which will make every pellet-forming process slight distinction and will resul...In the ever fusion experiments in SWIP, pellet forming process was carried out through adjusting relative devices by staff member in site, which will make every pellet-forming process slight distinction and will result in pellet difference in shape, size and intensity. In the intervals of HL-2A discharges, staff member have to go site to accomplish the pellet-forming process, this wastes human power and increase the potential danger. So it is necessary to develop a remote control system to perform the pellet-forming process. The control system needs have the features of real-time, reliability and be easy to operate and maintain.展开更多
FOR Nigerians who have long enjoyed having their fuel prices subsidized, events in early January pulled the rug out from under them. The Nigerian Government removed its oil subsidy from January 1 this year, an action ...FOR Nigerians who have long enjoyed having their fuel prices subsidized, events in early January pulled the rug out from under them. The Nigerian Government removed its oil subsidy from January 1 this year, an action it said has become necessary to provide money for the improvement of the country＇s inadequate infrastructure and complete the deregulation of the downstream sector of the oil industry.展开更多
The discovery of oil and gas in Uganda has attracted many investors, leading to increase in fuel/gas distributing companies and fueling stations creating rapid demand for land to locate the stations compared to availa...The discovery of oil and gas in Uganda has attracted many investors, leading to increase in fuel/gas distributing companies and fueling stations creating rapid demand for land to locate the stations compared to available open urban land. Because of the explosive and combustion characteristics of fuel stored and dispensed at stations, several studies have been conducted on different fires at fueling stations such as static fire, jet fire, vapor cloud explosions, open fires, etc. but there was need to assess spatially the risk of fire from stations, its consequences and sovereignty on buildings surrounding them. This was done basing on seven parameters—proximity of buildings to stations, building materials, distance between buildings, wind speed, temperature, slope and vegetation. Analytical hierarchy process and pairwise comparison were used to weight the parameters based on their relative importance. Weighted sum tool was applied to generate the fire risk maps for the quarters—December to February, March to May, June to August, and September to November from 2008 to 2013. The parameters were overlaid with the buildings in each risk zone for all the four quarters and their influences determined. The highest contributors were proximity of the buildings to stations, building materials and separation between buildings. Most of the affected buildings were made of rusted corrugated iron sheets and wood;the separation distance from one building to another ranged from 0 - 4 m. Most of buildings located within 100 m from stations were at moderate risk level and within 50 m were at highest risk level. The period of December to February and June to August had the highest risk. The findings can be used to guide planners and policy makers on building location vs. material vs. separation. It can also guide developers on where, when and how to carry out their developments.展开更多
Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand fr...Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand from solar or wind power. Gasification, however, can be energy self-sufficient using a recently-patented thermochemical conversion technology known as I-HPG （indirectly-heated pyrolytic gasification）. I-HPG produces a tar-free syngas from non-food woody biomass. This means the balance of plant can be small, so the overall system is economical at modest sizes. This makes it possible to produce renewable hydrogen from local agricultural residues; sufficient to create distributed refueling stations wherever there is feedstock. This work describes the specifics of a novel bio-hydrogen refueling station whereby the syngas produced has much of the hydrogen extracted with the remainder powering a generator to provide the electric power to the I-HPG system. Thus the system runs continuously. When paired with another new technology, moderate-pressure storage of hydrogen in porous silicon, there is the potential to also power the refueling operation. Such systems can be operated independently. It is even possible to design an energy self-sufficient farm where all electric power, heat, and hydrogen fuel is produced from the non-food residues of agricultural operations. No water is required, and the carbon footprint is negative, or at least neutral.展开更多
With the development of fuel cell electric vehicle industry in China,the 70-MPa hydrogen storage cylinders have been widely applied on vehicles in recent years.The revised standard,GB/T 26779-2021,Hydrogen fuel cell e...With the development of fuel cell electric vehicle industry in China,the 70-MPa hydrogen storage cylinders have been widely applied on vehicles in recent years.The revised standard,GB/T 26779-2021,Hydrogen fuel cell electric vehicle refueling receptacle,was released on March 9,2021 with added stipulations for the 70-MPa hydrogen refuelling receptacle.The main technical contents of GB/T 26779-2021 and its similarities and differences with GB/T 26779-2011 are discussed in this paper.展开更多
Efficient and secure refueling within the vehicle refueling systems exhibits a close correlation with the issues concerning fuel backflow and gasoline evaporation.This paper investigates the transient flow behavior in...Efficient and secure refueling within the vehicle refueling systems exhibits a close correlation with the issues concerning fuel backflow and gasoline evaporation.This paper investigates the transient flow behavior in fuel hose refilling and simplified tank fuel replenishment using the volume of fluid method.The numerical simulation is validated with the simplified hose refilling experiment and the evaporation simulation of Stefan tube.The effects of injection flow rate and injection directions have been discussed in the fuel hose refilling part.For both the experiment and simulation,the pressure at the end of the refueling pipe in the lower located nozzle case is 30%higher than that in the upper located nozzle case at a high flow rate,and the backflow phenomenon occurs at the lower filling mode.The fluid will directly flush into the first pipe elbow,changing the flow pattern from bubble flow to slug flow,which results in low-frequency and high-amplitude flowpressure fluctuations.Ahexane refueling system,consisting of a refueling pipe,fuel tank and a vapor return line,is analyzed,in which hexane evaporation is considered.At the early refueling period,a higher refueling rate will lead to more obvious splashing,which leads to a higher average mass of hexane vapor and pressure in the tank.Two optimized fuel tank designs are examined.The lower fuel tank filling port exhibits significantly lower vapor hexane in the fuel tank compared to the other design,resulting in a reduction of 200 Pa in the peak pressure in the tank,which contributes to a substantial reduction of gasoline loss during tank filling.展开更多
Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including p...Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including poor spectral absorption,inefficient charge separation,and structural instability under operational stress,which demand innovative durable materials with tailored electronic properties.Nanodiamond(ND)has recently been recognized as a suitable material because of its exceptional chemical stability,superior charge carrier mobility,and possible surface functionalization.While its intrinsic wide bandgap limits its response to visible-light,different methods have been demonstrated to activate its catalytic potential.Here,several emerging strategies for improving the catalytic performance of ND-based photocatalytic systems are summarized,including surface functionalization,plasmonic hybridization,heteroatom doping,and heterostructure design.And the structure-activity relationship and design principle are proposed to improve the light harvesting,charge transport,and redox kinetics for constructing high efficiency ND-based photocatalysts used in the renewable energy and environmental industries.展开更多
Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provid...Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.展开更多
Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylat...Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylation-hydrogenation processes.This study systematically evaluates the catalytic performance of various zeolites(Hβ,HZSM-5,MCM-41 and HUSY)in the alkylation reaction of phenol with cyclohexanol.Characterization results demonstrate that HUSY zeolite showed superior catalytic activity compared to other zeolites,attributable to its favorable pore architecture and well-balanced acid site distribution that synergistically facilitate molecular diffusion and catalytic transformations.To further enhance the catalytic properties,HUSY zeolite was modified with citric acid at various concentrations and compared with those treated with NaOH and oxalic acid.The results revealed that citric acid treatment preserved the crystallinity of the zeolite while modulating its acid distribution and pore structure.All modified zeolites enhanced phenol alkylation activity.Notably,the HUSY-0.5M catalyst,which exhibited the highest medium-strong acid to total acid ratio,achieved superior catalytic performance,80.4%conversion of phenol and 99.6%selectivity for alkylation products.The catalyst also exhibited high activity in the alkylation of various lignin-derived compounds,demonstrating its broad applicability.This work provides a new strategy for the valorization of lignin-derived phenols into high-value fuel precursors through alkylation.展开更多
Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied p...Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.展开更多
文摘Metok,located in Nyingchi,the Xizang Autonomous Region,is known as the last county in China to be connected by road.Poor transportation and limited access to petroleum were two obstacles to its development.As soon as the highway connecting Metok and the outside world was completed in 2014,China National Petroleum Corporation’s(CNPC)first gas station in the county was put into operation,providing the momentum for this"secret land of Lotus"and helping it embark on a journey toward openness and prosperity.
基金supported by the National MCF Energy R&D Program of China(Nos.2024YFE03130001 and 2024YFE03130002)the Institute of Energy,Hefei Comprehensive National Science Center(Anhui Energy Laboratory)(Nos.21KZS202 and 23KHH140)+3 种基金the University Synergy Innovation Program of Anhui Province(Nos.GXXT-2021-014 and GXXT-2021-029)National Natural Science Foundation of China(Nos.12105088 and 12305247)the Fundamental Research Funds for the Central Universities of China(No.PA2024GDSK0097)the Anhui Province Key Research and Development Plan Program(Nos.202304a05020006 and 2021006).
文摘The compact torus injector(CTI)for the central fueling of the EAST tokamak has undergone significant upgrades to enhance its injection capability.During the initial phase of the platform testing phase,EAST-CTI demonstrated relatively low performance,with a maximum velocity of 150 km s^(−1) and a single compact torus(CT)plasma mass of 90μg[Kong D et al 2023 Plasma Sci.Technol.25065601].These parameters were insufficient for conducting central fueling experiments on the EAST tokamak.Consequently,extensive upgrades were carried out to improve the performance of the EAST-CTI system.The compression region was extended from 280 mm to 700 mm to prevent rapid compression and deceleration of the CT plasma,along with an extension of the acceleration region to further increase the plasma acceleration.The power supply system has also been upgraded.These improvements elevated the operating voltage from 8 kV to 15 kV,increased the discharge current from 120 kA to 300 kA and enabled repetitive operation at a maximum rate of 2 Hz.As a result,significant advances in EAST-CTI performance were achieved,with the maximum velocity increasing to 330 km s^(−1) and the CT plasma density reaching 1.5×10^(22) m^(−3),thereby enhancing the system capability for future fueling experiments on EAST.This study offers valuable insights into CTI modification and the improvement of central fueling systems for prospective fusion reactors.
基金supported in part by the Key Research and Development Program of Shandong Province under Grant 2022KJHZ002.
文摘Driven by the global“dual-carbon”goals,hydrogen fuel cell electric vehicles(FCEVs)are being rapidly promoted as a zero-emission transportation solution.However,their large-scale application is constrained by issues such as inefficient operation,poor information flow between vehicles and stations,and potential safety hazards,which are caused by insufficient intelligence of hydrogen refueling stations.This study aims to address these problems by deeply integrating Cellular Vehicle-to-Everything(C-V2X)technology with hydrogen refueling stations,thereby building a safe,efficient,and low-carbon hydrogen energy application ecosystem to promote the global transition to zero-carbon transportation.Firstly,through literature review and technical analysis,this study expounds on the core technologies and process flows of current hydrogen refueling stations,aswell as the technical architecture and development evolution of C-V2X technology.Then,based on the analysis of relevant literature,it proposes a“vehicle-road-station-cloud”collaborative architecture that integrates C-V2X with hydrogen refueling stations.Combined with 5G communication and big data technologies,it elaborates on the implementation path for achieving real-time data interaction among hydrogen refueling stations,hydrogen-powered vehicles,and road infrastructure.This interconnection mode enables hydrogen refueling stations to obtain real-time information of surrounding vehicles,which plays an important role in building a safe,efficient,and low-carbon hydrogen energy application ecosystem and promoting the global transition to zero-carbon transportation.Finally,the future development prospects and potential of this scheme are put forward.
基金support of the National Key Research and Development Program of China(Nos.2017YFE0300501,2017YFE0300500)Institute of Energy,Hefei Comprehensive National Science Center(Nos.21KZS202,19KZS205)+3 种基金University Synergy Innovation Program of Anhui Province(Nos.GXXT-2021-014,GXXT-2021-029)National Natural Science Foundation of China(No.11905143)the Fundamental Research Funds for the Central Universities of China(No.JZ2022HGTB0302)supported in part by the Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE008)。
文摘Compact torus(CT)injection is a highly promising technique for the central fueling of future reactor-grade fusion devices since it features extremely high injection velocity and relatively high plasma mass.Recently,a CT injector for the EAST tokamak,EAST-CTI,was developed and platform-tested.In the first round of experiments conducted with low parameter settings,the maximum velocity and mass of the CT plasma were 150 km·s^(-1)and 90μg,respectively.However,the parameters obtained by EAST-CTI were still very low and were far from the requirements of a device such as EAST that has a strong magnetic field.In future,we plan to solve the spark problem that EAST-CTI currently encounters(that mainly hinders the further development of experiments)through engineering methods,and use greater power to obtain a more stable and suitable CT plasma for EAST.
文摘Migratory birds rely on fueling prior to migratory flights. Fueling in migrants is controlled by intrinsic as well as ex- trinsic factors. From captive studies we have started understanding the internal mechanisms controlling bird migration. Field studies have demonstrated the effects of external factors, such as food availability, weather, competitors, parasites or diseases, on the stopover behavior of migrants. However, an integrated approach is still missing to study coherently how the innate migration program interacts with the varying environmental cues and to estimate the contribution of the innate migration program and the environment to realized migration. The northern wheatear Oenanthe oenanthe offers a unique opportunity for integrated studies. It breeds across almost the whole Holarctic with just a ＂gap＂ between eastern Canada and Alaska. All breeding populations over- winter in sub-Saharan Africa which makes the northern wheatear one of the most long-distant migratory songbirds with extraor- dinary long non-stop flights across oceans. It is a nocturnal migrant which travels without parental or social aid/guidance. Thus, young birds rely entirely on endogenous mechanisms of timing, route selection and fueling on their first outbound migration. By establishing indoor housing under controlled conditions the endogenous control mechanisms of northern wheatear migration could be revealed. At the same time, environmental factors controlling fueling could be investigated in the field. On migration wheatears occur in a variety of habitats with sparse vegetation where their stopover behavior could be quantitatively studied in the light of ＂optimal migration＂ theory by the use of remote balances, radio-tagging and even experimentally manipulated food availability. The present paper summarizes our approach to understand the control of migration in northern wheatears by combin- ing field and laboratory studies at various spatial and temporal scales, and linking various sub-disciplines .
基金the National Key R&D Program of China under Grant Nos.2017YFE0301100 and 2019YFE03030004the National Natural Science Foundation of China under Grant No.11575039Users with Excellence Program of Hefei Science Center CAS(2020HSCUE010)。
文摘To understand the effect of injected deuterium(D)pellets on background plasma,the ablation of D pellets and the transport of D species in both atomic and ionic states in the EAST device are simulated using a modified dynamic neutral gas shield model combined with the edge plasma code SOLPS-ITER.The simulation results show that there is a phenomenon of obvious atomic deposition in the scrape-off layer(SOL)after pellet injection,which depends strongly on the injection velocity.With increasing injection velocity,the atomic density in the SOL decreases evidently and the deposition time is relatively shortened.Possible effects for triggering of edge localized modes(ELMs)by D and Li pellets are also discussed.With the same pellet size and injection velocity,the maximum perturbation pressure caused by D pellets is obviously higher.It is found that the resulting maximum perturbed pressure is remarkably enhanced when the injection velocity is reduced from 300 m/s to 100 m/s for a pellet with a cross section of 1.6 mm,which indicates that the injection velocity is important for ELM pacing.This work can provide reasonable guidance for choosing pellet parameters for fueling and ELM triggering.
基金The project supported by the Nuclear Researchers Exchange Program of Japan Society for the Promotion of Science
文摘High-pressure gas injection has proved to be an effective disruption mitigation tech- nique in DIII-D tokamak experiments. If the method can be applied in future tokamak reactors not only for disruption mitigation but also for plasma termination and fueling, it will have an attractive advantage over the pellet and liquid injection from the viewpoint of economy and engineering design. In order to investigate the feasibility of this option, a study has been carried out with relevant parameters for conveying tubes of different geometrical sizes and for different gases. These parameters include pressure drop, lagger time after the valve＇s opening, gas diffusion in an ultra-high vacuum condition, and particle number contour.
文摘The supersonic molecular beam (SMB) ablation and penetration processes in the HL-1M tokamak experiments are studied. The cluster formation and dissolution, SMB adiabatic expansion, shielding and cooling effect are all taken into account. An optimized numerical model is applied in the analysis and shown to be in good agreement with the experimental observations. The possibility of fueling large tokamak plasmas with SMB injection is explored.
基金supported by National Natural Science Foundation of China(Nos.11975087 and 41674165)the National Key Research and Development Program of China(Nos.2017YFE0300501 and 2018YFE030310)。
文摘Tritium self-sufficiency in future deuterium–tritium fusion reactors is a crucial challenge.As an engineering test reactor,the China Fusion Engineering Test Reactor requires a burning fraction of 3%for the goal to test the accessibility to the future fusion plant.To self-consistently simulate burning plasmas with profile changes in pellet injection scenarios and to estimate the corresponding burning fraction,a one-dimensional multi-species radial transport model is developed in the BOUT++framework.Several pellet-fueling scenarios are then tested in the model.The results show that the increased fueling depth improves the burning fraction by particle confinement improvement and fusion power increase.Nevertheless,by increasing the depth,the pellet cooling-down may significantly lower the temperature in the core region.Taking the density perturbation into consideration,the reasonable parameters of the fueling scenario in these simulations are estimated as pellet radius r_(p)=3 mm,injection rate=4 Hz,and pellet injection velocity=1000–2000 m s^(-1) without drift or 450 m s^(-1) with high-field-side drift.
文摘Several high performance tokamak operation regimes have been achieved experimentally in the experiments with the peaked density profiles. The regimes include the improved Ohmic confinement in ASDEX, the pellet enhanced performance mode in Alcator-C, and the super-shot mode in TFTR. In these regimes, peaked core density profiles are always existent, and almost always go with the internal transport barriers, these barriers generally produced by sheared radial electric field. In addition to enhance confinement, the peaked density profile is also needed for the optimized fusion reaction rate and alpha heating power in tokamak plasma, and combined peaked density profile and peaked temperature profile, would make the ignition condition easy obtained. It is desirable to seek and analyze the density profile control schemes that effectively lead to density profile peaking in particle transports experimental investigation.
文摘In the ever fusion experiments in SWIP, pellet forming process was carried out through adjusting relative devices by staff member in site, which will make every pellet-forming process slight distinction and will result in pellet difference in shape, size and intensity. In the intervals of HL-2A discharges, staff member have to go site to accomplish the pellet-forming process, this wastes human power and increase the potential danger. So it is necessary to develop a remote control system to perform the pellet-forming process. The control system needs have the features of real-time, reliability and be easy to operate and maintain.
文摘FOR Nigerians who have long enjoyed having their fuel prices subsidized, events in early January pulled the rug out from under them. The Nigerian Government removed its oil subsidy from January 1 this year, an action it said has become necessary to provide money for the improvement of the country＇s inadequate infrastructure and complete the deregulation of the downstream sector of the oil industry.
文摘The discovery of oil and gas in Uganda has attracted many investors, leading to increase in fuel/gas distributing companies and fueling stations creating rapid demand for land to locate the stations compared to available open urban land. Because of the explosive and combustion characteristics of fuel stored and dispensed at stations, several studies have been conducted on different fires at fueling stations such as static fire, jet fire, vapor cloud explosions, open fires, etc. but there was need to assess spatially the risk of fire from stations, its consequences and sovereignty on buildings surrounding them. This was done basing on seven parameters—proximity of buildings to stations, building materials, distance between buildings, wind speed, temperature, slope and vegetation. Analytical hierarchy process and pairwise comparison were used to weight the parameters based on their relative importance. Weighted sum tool was applied to generate the fire risk maps for the quarters—December to February, March to May, June to August, and September to November from 2008 to 2013. The parameters were overlaid with the buildings in each risk zone for all the four quarters and their influences determined. The highest contributors were proximity of the buildings to stations, building materials and separation between buildings. Most of the affected buildings were made of rusted corrugated iron sheets and wood;the separation distance from one building to another ranged from 0 - 4 m. Most of buildings located within 100 m from stations were at moderate risk level and within 50 m were at highest risk level. The period of December to February and June to August had the highest risk. The findings can be used to guide planners and policy makers on building location vs. material vs. separation. It can also guide developers on where, when and how to carry out their developments.
文摘Hydrogen fuel cell cars are now available for lease and for sale. Renewable hydrogen fuel can be produced from water via electrolysis, or from biomass via gasification. Electrolysis is power-hungry with high demand from solar or wind power. Gasification, however, can be energy self-sufficient using a recently-patented thermochemical conversion technology known as I-HPG （indirectly-heated pyrolytic gasification）. I-HPG produces a tar-free syngas from non-food woody biomass. This means the balance of plant can be small, so the overall system is economical at modest sizes. This makes it possible to produce renewable hydrogen from local agricultural residues; sufficient to create distributed refueling stations wherever there is feedstock. This work describes the specifics of a novel bio-hydrogen refueling station whereby the syngas produced has much of the hydrogen extracted with the remainder powering a generator to provide the electric power to the I-HPG system. Thus the system runs continuously. When paired with another new technology, moderate-pressure storage of hydrogen in porous silicon, there is the potential to also power the refueling operation. Such systems can be operated independently. It is even possible to design an energy self-sufficient farm where all electric power, heat, and hydrogen fuel is produced from the non-food residues of agricultural operations. No water is required, and the carbon footprint is negative, or at least neutral.
基金supported by the National Key Research and Development Program of China with the project number of 2021YFB2501500
文摘With the development of fuel cell electric vehicle industry in China,the 70-MPa hydrogen storage cylinders have been widely applied on vehicles in recent years.The revised standard,GB/T 26779-2021,Hydrogen fuel cell electric vehicle refueling receptacle,was released on March 9,2021 with added stipulations for the 70-MPa hydrogen refuelling receptacle.The main technical contents of GB/T 26779-2021 and its similarities and differences with GB/T 26779-2011 are discussed in this paper.
基金supported by the National Natural Science Foundation of China with Grant No.12002334 for C.Z.,Zhejiang Provincial Natural Science Foundation(Grant No.LQ21A020004 for C.Z.)the Excellent Youth Natural Science Foundation of Zhejiang Province,National Science Foundation of Anhui Province(2108085QE226)+1 种基金China(No.LR21E060001 for L.Q.and C.Z.)C.Z.acknowledges the China Scholarship Council(No.202108330166)for providing him with a visiting scholarship at NUS,Singapore.
文摘Efficient and secure refueling within the vehicle refueling systems exhibits a close correlation with the issues concerning fuel backflow and gasoline evaporation.This paper investigates the transient flow behavior in fuel hose refilling and simplified tank fuel replenishment using the volume of fluid method.The numerical simulation is validated with the simplified hose refilling experiment and the evaporation simulation of Stefan tube.The effects of injection flow rate and injection directions have been discussed in the fuel hose refilling part.For both the experiment and simulation,the pressure at the end of the refueling pipe in the lower located nozzle case is 30%higher than that in the upper located nozzle case at a high flow rate,and the backflow phenomenon occurs at the lower filling mode.The fluid will directly flush into the first pipe elbow,changing the flow pattern from bubble flow to slug flow,which results in low-frequency and high-amplitude flowpressure fluctuations.Ahexane refueling system,consisting of a refueling pipe,fuel tank and a vapor return line,is analyzed,in which hexane evaporation is considered.At the early refueling period,a higher refueling rate will lead to more obvious splashing,which leads to a higher average mass of hexane vapor and pressure in the tank.Two optimized fuel tank designs are examined.The lower fuel tank filling port exhibits significantly lower vapor hexane in the fuel tank compared to the other design,resulting in a reduction of 200 Pa in the peak pressure in the tank,which contributes to a substantial reduction of gasoline loss during tank filling.
文摘Photocatalysis is an important technology for using solar energy to produce hydrogen,convert CO_(2) to synthetic fuels,and decrease persistent pollutant.However,conventional photocatalysts have limitations,including poor spectral absorption,inefficient charge separation,and structural instability under operational stress,which demand innovative durable materials with tailored electronic properties.Nanodiamond(ND)has recently been recognized as a suitable material because of its exceptional chemical stability,superior charge carrier mobility,and possible surface functionalization.While its intrinsic wide bandgap limits its response to visible-light,different methods have been demonstrated to activate its catalytic potential.Here,several emerging strategies for improving the catalytic performance of ND-based photocatalytic systems are summarized,including surface functionalization,plasmonic hybridization,heteroatom doping,and heterostructure design.And the structure-activity relationship and design principle are proposed to improve the light harvesting,charge transport,and redox kinetics for constructing high efficiency ND-based photocatalysts used in the renewable energy and environmental industries.
基金Support by National Natural Science Foundation of China(22127802,22573091)the HY Action(62402010305)。
文摘Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.
基金Supported by National Key Research&Development Program of China (2022YFB4201800)Key Program of National Natural Science Foundation of China (52130610)。
文摘Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylation-hydrogenation processes.This study systematically evaluates the catalytic performance of various zeolites(Hβ,HZSM-5,MCM-41 and HUSY)in the alkylation reaction of phenol with cyclohexanol.Characterization results demonstrate that HUSY zeolite showed superior catalytic activity compared to other zeolites,attributable to its favorable pore architecture and well-balanced acid site distribution that synergistically facilitate molecular diffusion and catalytic transformations.To further enhance the catalytic properties,HUSY zeolite was modified with citric acid at various concentrations and compared with those treated with NaOH and oxalic acid.The results revealed that citric acid treatment preserved the crystallinity of the zeolite while modulating its acid distribution and pore structure.All modified zeolites enhanced phenol alkylation activity.Notably,the HUSY-0.5M catalyst,which exhibited the highest medium-strong acid to total acid ratio,achieved superior catalytic performance,80.4%conversion of phenol and 99.6%selectivity for alkylation products.The catalyst also exhibited high activity in the alkylation of various lignin-derived compounds,demonstrating its broad applicability.This work provides a new strategy for the valorization of lignin-derived phenols into high-value fuel precursors through alkylation.
基金supported by grants from the Natural Science Foundation of China(22362031 and 21805121)the Science and Technology Project of Yunnan Province(2019FD137)。
文摘Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.
