reactors may be subjected to dynamic loads, and in order to ensure that Leak-Before-Break (LBB) technology is safely and reliably applied to the primary piping of reactor coolant system, dynamic load impact analysis o...
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Helical coil once-through tube steam generator (HCOTSG) has the advantages of compact structure and higher heat transfer efficiency due to its special structure. In order to study the flow boiling heat transfer charac...
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Aqueous zinc-ion batteries are highly favored for their enhanced safety and reduced ***,there exist challenges including zinc dendrite,hydrogen evolution,and surface corrosion to be *** electrolyte additives is a high...
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Aqueous zinc-ion batteries are highly favored for their enhanced safety and reduced ***,there exist challenges including zinc dendrite,hydrogen evolution,and surface corrosion to be *** electrolyte additives is a highly convenient approach to solving zinc anode-related *** by industrial corrosion protection,a trace amount of the corrosion inhibitor urotropine(URT)is used as an electrolyte additive to protect the zinc *** calculation and experimental analysis confirm the adsorption of URT molecules onto the surface of Zn,which inhibits hydrogen *** adsorption further leads to the formation of an inorganic-organic bilayer solid electrolyte interface(SEI)on the surface of the zinc anode,effectively protecting the Zn anode from corrosion,hydrogen evolution and zinc *** presence of SEI enables symmetrical Zn//Zn cells to exhibit a long cycling performance of 1750 h at 1mA/cm^(2)and an average coulombic efficiency of 99.0%at 1mA/cm^(2)in Zn//Cu *** being coupled with polyaniline(PANI),the Zn//PANI full battery displays excellent cycle stability and specific capacity.
A comparative computational fluid dynamics(CFD)study was conducted on the three different types of pressurized water reactor(PWR)upper plenum,named TYPE 1(support columns(SCs)and control rod guide tubes(CRGTs)with two...
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A comparative computational fluid dynamics(CFD)study was conducted on the three different types of pressurized water reactor(PWR)upper plenum,named TYPE 1(support columns(SCs)and control rod guide tubes(CRGTs)with two large windows),TYPE 2(SCs and CRGTs without windows),and TYPE 3(two parallel perforated barrel shells and CRGTs).First,three types of upper plenum geometry information were collected,simplified,and adopted into the BORA facility,which is a 1/5 scale system of the four-loop PWR ***,the geometry,including the upper half core,upper plenum region,and hot legs,was built using the Salome *** that,an unsteady calculation to simulate the reactor balance operation at hot full power scenario was ***,the differences of flowrate distribution at the core outlet and temperature distribution and transverse velocity inside the hot legs with different upper plenum internals were *** results suggest that TYPE 1 upper plenum internals cause the largest flowrate difference at the core outlet while TYPE 3 leads to the most even distributed *** distribution and evolution pattern of the tangential velocity inside hot legs is highly dependent on the upper plenum *** counter-rotating swirls exist inside the TYPE 1 hot leg and only one swirl revolving around the hog leg axis exist inside the TYPE 2 hot *** TYPE 3,two swirls like that of TYPE 1 rotating around the hot leg axis significantly increase the temperature homogenization *** research provides meaningful guidelines for the future optimization and design of advanced PWR upper plenum internal structures.
TRISO coated fuel particle has been adopted in the design of various reactors and Accident Tolerant Fuel (ATF) due to its excellent accident tolerant performance under high temperatures and other severe conditions. Ac...
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The oxide dispersion strengthening(ODS)high entropy alloy(HEA)exhibits the high elevated temperature performance and radiation resistance due to severe atomic lattice distortion and oxide particles dispersed in matrix...
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The oxide dispersion strengthening(ODS)high entropy alloy(HEA)exhibits the high elevated temperature performance and radiation resistance due to severe atomic lattice distortion and oxide particles dispersed in matrix,which is expected to become the most promising structural material in the next generation of nuclear energy ***,microstructure and damage evolution of irradiated ODS HEA under loading remain elusive at submicron scale using the existing simulations owing to a lack of atomic-lattice-distortion information from a micromechanics ***,the random field theory informed discrete dislocation dynamics simulations based on the results of high-resolution transmission electron microscopy are developed to study the dislocation behavior and damage evolution in ODS HEA considering the influence of severe lattice distortion and nanoscale oxide ***,the damage behavior shows an unusual trend of the decreasing-to-increasing transition with the continuous loading *** are two main types of damage micromechanics generated in irradiated ODS HEA:the dislocation loop damage in which the damage is controlled by irradiation-induced dislocation loops and their evolution,the strain localization damage in which the damage comes from the dislocation multiplication in the local plastic *** oxide particle hinders the dislocation movement in the main slip plane,and the lattice distortion induces the dislocation sliding to the secondary slip plane,which promotes the dislocation cross-slip and dislocation loop annihilation,and thus reduces the material damage in the elastic damage *** findings can deeply understand atomic-scale damage mechanism and guide the design of ODS HEA with high radiation resistance.
The reactor Operation Digital Twin (RODT) is a numerical representation method designed for the operational phase of nuclear reactors, aiming to solve forward problems (such as state prediction) based on input paramet...
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Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metavers...
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Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metaverses. However, avatar tasks include a multitude of human-to-avatar and avatar-to-avatar interactive applications, e.g., augmented reality navigation,which consumes intensive computing resources. It is inefficient and impractical for vehicles to process avatar tasks locally. Fortunately, migrating avatar tasks to the nearest roadside units(RSU)or unmanned aerial vehicles(UAV) for execution is a promising solution to decrease computation overhead and reduce task processing latency, while the high mobility of vehicles brings challenges for vehicles to independently perform avatar migration decisions depending on current and future vehicle status. To address these challenges, in this paper, we propose a novel avatar task migration system based on multi-agent deep reinforcement learning(MADRL) to execute immersive vehicular avatar tasks dynamically. Specifically, we first formulate the problem of avatar task migration from vehicles to RSUs/UAVs as a partially observable Markov decision process that can be solved by MADRL algorithms. We then design the multi-agent proximal policy optimization(MAPPO) approach as the MADRL algorithm for the avatar task migration problem. To overcome slow convergence resulting from the curse of dimensionality and non-stationary issues caused by shared parameters in MAPPO, we further propose a transformer-based MAPPO approach via sequential decision-making models for the efficient representation of relationships among agents. Finally, to motivate terrestrial or non-terrestrial edge servers(e.g., RSUs or UAVs) to share computation resources and ensure traceability of the sharing records, we apply smart contracts and blockchain technologies to achieve secure sharing management. Numerical results demonstrate that the proposed approach
The equivalent effect relationship formula of LOCA hydraulic load in the bend section of the heat transfer tube of the steam generator is deduced. The hydraulic load factors affecting the stress of the heat transfer t...
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The curvature effect and bubbles are the key factors that affect the gas-liquid two-phase flow and turbulent characteristics in the 180-degree elbow. Limited by the difficulty of experimental measurement and numerical...
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