0 INTRODUCTION The lunar surface lacks an atmosphere and is continuously subjected to a combination of space weathering factors such as cosmic rays,solar wind,and micrometeorite impacts,forming a several-meter-thick l...0 INTRODUCTION The lunar surface lacks an atmosphere and is continuously subjected to a combination of space weathering factors such as cosmic rays,solar wind,and micrometeorite impacts,forming a several-meter-thick lunar regolith(Sorokin et al.,2020).展开更多
The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by deposit...The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight.展开更多
On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil ...On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil particles.However,soil particles on the Earth with the similar composition lack such structures and properties.This discrepancy raises a key question whether there is a direct relationship between solar wind irradiation and the alterations in the structure and chemical performance of extraterrestrial materials.To address this question,this work investigates the effects of proton irradiation,simulating solar wind radiation,on the structure and photothermal catalytic properties of the classic catalyst In_(2)O_(3).It reveals that proton irradiation induces structural features in In_(2)O_(3) analogous to those characteristics of solar wind weathering observed in extraterrestrial materials.Furthermore,after proton beam irradiation with an energy of 30 keV and a dose of 3×10^(17) protons·cm^(-2),the methanol production yield of the In_(2)O_(3) catalyst increased to 2.6 times of its preirradiation level,and the methanol selectivity improved to 2.1 times of the original value.This work provides both theoretical and experimental support for the development of high-efficiency,radiation-resistant photothermal catalysts.展开更多
High-entropy alloys(HEAs)exhibit the excellent elevated-temperature performance and irradiation resistance due to the important core effect of serious lattice distortion for impeding dislocation motion,as candidate ma...High-entropy alloys(HEAs)exhibit the excellent elevated-temperature performance and irradiation resistance due to the important core effect of serious lattice distortion for impeding dislocation motion,as candidate materials for nuclear applications.Despite the growth of the nuclear power sector,the effects of high-temperature and high-dose irradiation-induced voids on the mechanical properties of HEA in higher power nuclear reactors remain insufficiently researched,hindering its industrial application.In this study,we establish a consistent parameterization crystal plastic constitutive model for the hardening and creep behaviors of HEA,incorporating the spatial distribution of void size and shape effects,in contrast to traditional creep models that rely on temperature-related fitting parameters of the phenomenological power law equation.The model matches well with experimental data at different temperatures and irradiation doses,demonstrating its robustness.The effects of irradiation dose,temperature,and degree of lattice distortion on irradiation hardening and creep behavior of void-containing HEA are investigated.The results indicate that HEA with high lattice distortion exhibits better creep resistance under higher stress loads.The yield stress of irradiated HEA increases with increasing irradiation dose and temperature.The creep resistance increases with increasing irradiation dose and decreases with increasing irradiation temperature.The increase in irradiation dose causes a specific morphological transformation from spherical to cubic voids.The modeling and results could provide an effective theoretical way for tuning the yield strength and alloy design in advanced HEAs to meet irradiation properties.展开更多
To elucidate the fracturing mechanism of deep hard rock under complex disturbance environments,this study investigates the dynamic failure behavior of pre-damaged granite subjected to multi-source dynamic disturbances...To elucidate the fracturing mechanism of deep hard rock under complex disturbance environments,this study investigates the dynamic failure behavior of pre-damaged granite subjected to multi-source dynamic disturbances.Blasting vibration monitoring was conducted in a deep-buried drill-and-blast tunnel to characterize in-situ dynamic loading conditions.Subsequently,true triaxial compression tests incorporating multi-source disturbances were performed using a self-developed wide-low-frequency true triaxial system to simulate disturbance accumulation and damage evolution in granite.The results demonstrate that combined dynamic disturbances and unloading damage significantly accelerate strength degradation and trigger shear-slip failure along preferentially oriented blast-induced fractures,with strength reductions up to 16.7%.Layered failure was observed on the free surface of pre-damaged granite under biaxial loading,indicating a disturbance-induced fracture localization mechanism.Time-stress-fracture-energy coupling fields were constructed to reveal the spatiotemporal characteristics of fracture evolution.Critical precursor frequency bands(105-150,185-225,and 300-325 kHz)were identified,which serve as diagnostic signatures of impending failure.A dynamic instability mechanism driven by multi-source disturbance superposition and pre-damage evolution was established.Furthermore,a grouting-based wave-absorption control strategy was proposed to mitigate deep dynamic disasters by attenuating disturbance amplitude and reducing excitation frequency.展开更多
The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the safe operation of molten salt reactors(MSRs).Raman spectroscopy and a slow positron beam were employed to inv...The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the safe operation of molten salt reactors(MSRs).Raman spectroscopy and a slow positron beam were employed to investigate the effects of He ion irradiation fluences and subsequent annealing on the microstructure and defects of the matrix graphite.He ions with 500 keV energy and fluences ranging from 1.1×10^(15)ions∕cm^(2)to 3.5×10^(17)ions∕cm^(2)were used to simulate neutron irradiation at 300 K.The samples with an irradiation fluence of 3.5×10^(16)ions∕cm^(2)were subjected to isochronal annealing at different temperatures(573 K,873 K and 1173 K)for 3 h.The Raman results revealed that the D peak gradually increased,whereas the intrinsic G peak decreased with increasing irradiation fluence.At the same irradiation fluence,the D peak gradually decreased,whereas the intrinsic G peak increased with increasing annealing temperature.Slow positron beam analysis demonstrated that the density or size of irradiation defects(vacancy type)increased with higher irradiation fluence,but decreased rapidly with increasing annealing temperature.The Raman spectral analysis of sample cross sections subjected to high irradiation fluences revealed the emergence of amorphization precisely at the depth where ion damage was most pronounced,whereas the surface retained its crystalline structure.Raman and positron annihilation analyses indicated that the matrix graphite exhibited good irradiation resistance to He ions at 300 K.However,vacancy-type defects induced by He ion irradiation exhibit poor thermal stability and can be easily removed during annealing.展开更多
The SiO_(2) inverse opal photonic crystals(PC)with a three-dimensional macroporous structure were fabricated by the sacrificial template method,followed by infiltration of a pyrene derivative,1-(pyren-8-yl)but-3-en-1-...The SiO_(2) inverse opal photonic crystals(PC)with a three-dimensional macroporous structure were fabricated by the sacrificial template method,followed by infiltration of a pyrene derivative,1-(pyren-8-yl)but-3-en-1-amine(PEA),to achieve a formaldehyde(FA)-sensitive and fluorescence-enhanced sensing film.Utilizing the specific Aza-Cope rearrangement reaction of allylamine of PEA and FA to generate a strong fluorescent product emitted at approximately 480 nm,we chose a PC whose blue band edge of stopband overlapped with the fluorescence emission wavelength.In virtue of the fluorescence enhancement property derived from slow photon effect of PC,FA was detected highly selectively and sensitively.The limit of detection(LoD)was calculated to be 1.38 nmol/L.Furthermore,the fast detection of FA(within 1 min)is realized due to the interconnected three-dimensional macroporous structure of the inverse opal PC and its high specific surface area.The prepared sensing film can be used for the detection of FA in air,aquatic products and living cells.The very close FA content in indoor air to the result from FA detector,the recovery rate of 101.5%for detecting FA in aquatic products and fast fluorescence imaging in 2 min for living cells demonstrate the reliability and accuracy of our method in practical applications.展开更多
In the heterogeneous power internet of things(IoT)environment,data signals are acquired to support different business systems to realize advanced intelligent applications,with massive,multi-source,heterogeneous and ot...In the heterogeneous power internet of things(IoT)environment,data signals are acquired to support different business systems to realize advanced intelligent applications,with massive,multi-source,heterogeneous and other characteristics.Reliable perception of information and efficient transmission of energy in multi-source heterogeneous environments are crucial issues.Compressive sensing(CS),as an effective method of signal compression and transmission,can accurately recover the original signal only by very few sampling.In this paper,we study a new method of multi-source heterogeneous data signal reconstruction of power IoT based on compressive sensing technology.Based on the traditional compressive sensing technology to directly recover multi-source heterogeneous signals,we fully use the interference subspace information to design the measurement matrix,which directly and effectively eliminates the interference while making the measurement.The measure matrix is optimized by minimizing the average cross-coherence of the matrix,and the reconstruction performance of the new method is further improved.Finally,the effectiveness of the new method with different parameter settings under different multi-source heterogeneous data signal cases is verified by using orthogonal matching pursuit(OMP)and sparsity adaptive matching pursuit(SAMP)for considering the actual environment with prior information utilization of signal sparsity and no prior information utilization of signal sparsity.展开更多
Due to the development of cloud computing and machine learning,users can upload their data to the cloud for machine learning model training.However,dishonest clouds may infer user data,resulting in user data leakage.P...Due to the development of cloud computing and machine learning,users can upload their data to the cloud for machine learning model training.However,dishonest clouds may infer user data,resulting in user data leakage.Previous schemes have achieved secure outsourced computing,but they suffer from low computational accuracy,difficult-to-handle heterogeneous distribution of data from multiple sources,and high computational cost,which result in extremely poor user experience and expensive cloud computing costs.To address the above problems,we propose amulti-precision,multi-sourced,andmulti-key outsourcing neural network training scheme.Firstly,we design a multi-precision functional encryption computation based on Euclidean division.Second,we design the outsourcing model training algorithm based on a multi-precision functional encryption with multi-sourced heterogeneity.Finally,we conduct experiments on three datasets.The results indicate that our framework achieves an accuracy improvement of 6%to 30%.Additionally,it offers a memory space optimization of 1.0×2^(24) times compared to the previous best approach.展开更多
Accurate monitoring of track irregularities is very helpful to improving the vehicle operation quality and to formulating appropriate track maintenance strategies.Existing methods have the problem that they rely on co...Accurate monitoring of track irregularities is very helpful to improving the vehicle operation quality and to formulating appropriate track maintenance strategies.Existing methods have the problem that they rely on complex signal processing algorithms and lack multi-source data analysis.Driven by multi-source measurement data,including the axle box,the bogie frame and the carbody accelerations,this paper proposes a track irregularities monitoring network(TIMNet)based on deep learning methods.TIMNet uses the feature extraction capability of convolutional neural networks and the sequence map-ping capability of the long short-term memory model to explore the mapping relationship between vehicle accelerations and track irregularities.The particle swarm optimization algorithm is used to optimize the network parameters,so that both the vertical and lateral track irregularities can be accurately identified in the time and spatial domains.The effectiveness and superiority of the proposed TIMNet is analyzed under different simulation conditions using a vehicle dynamics model.Field tests are conducted to prove the availability of the proposed TIMNet in quantitatively monitoring vertical and lateral track irregularities.Furthermore,comparative tests show that the TIMNet has a better fitting degree and timeliness in monitoring track irregularities(vertical R2 of 0.91,lateral R2 of 0.84 and time cost of 10 ms),compared to other classical regression.The test also proves that the TIMNet has a better anti-interference ability than other regression models.展开更多
This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimiz...This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimization effect,etc.,aiming to better provide a certain guideline and reference for relevant researchers.展开更多
As a multipurpose research reactor,fission molybdenum-technetium irradiation production is one of the wide applications of China Advanced Research Reactor CARR.The goal of this study is to achieve“online loading and ...As a multipurpose research reactor,fission molybdenum-technetium irradiation production is one of the wide applications of China Advanced Research Reactor CARR.The goal of this study is to achieve“online loading and unloading”of the target during fission molybdenum-99(99Mo)to technetium-99m(99mTc)irradiation production without affecting the normal reactor operation and other irradiation channels,which will make CARR more efficient in performing irradiation tasks.This paper introduces the design principles,requirements and concept structural design of the irradiation device of fission 99Mo-99mTc.展开更多
Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been...Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been proved that laser irradiation can improve drilling and blasting efficiency when combined with mechanical rock fracturing methods,which are irrelevant for borehole stabilization.To improve the latter,this study used laser ablation for borehole reinforcement.The high-power laser was applied to typical rock samples(sandstone,mudstone and coal)in both dry and saturated conditions.Multi-technique observations and measurements were used to fully understand the peculiar modifications of the specimens under laser treatment,i.e.mechanical loading,acoustic emission(AE)monitoring,digital image correlation(DIC)strain field evaluation,infrared thermography(IRT)monitoring and X-ray computed tomography(CT)scanning.The results showed that,in addition to the effects already demonstrated,laser irradiation can improve the strength of the soft rock,especially in the saturated state.The process involved a complicated phase change including melting and evaporation of the matrix under high-temperature and high-pressure to form a glassy high strength silicate material.This process is similar to the reaction between molten lava and water,or the impact of an asteroid on the earth.Inspired by the results,a conceptual path for a new borehole stabilization technology using laser ablation was outlined.展开更多
With the acceleration of intelligent transformation of energy system,the monitoring of equipment operation status and optimization of production process in thermal power plants face the challenge of multi-source heter...With the acceleration of intelligent transformation of energy system,the monitoring of equipment operation status and optimization of production process in thermal power plants face the challenge of multi-source heterogeneous data integration.In view of the heterogeneous characteristics of physical sensor data,including temperature,vibration and pressure that generated by boilers,steam turbines and other key equipment and real-time working condition data of SCADA system,this paper proposes a multi-source heterogeneous data fusion and analysis platform for thermal power plants based on edge computing and deep learning.By constructing a multi-level fusion architecture,the platform adopts dynamic weight allocation strategy and 5D digital twin model to realize the collaborative analysis of physical sensor data,simulation calculation results and expert knowledge.The data fusion module combines Kalman filter,wavelet transform and Bayesian estimation method to solve the problem of data time series alignment and dimension difference.Simulation results show that the data fusion accuracy can be improved to more than 98%,and the calculation delay can be controlled within 500 ms.The data analysis module integrates Dymola simulation model and AERMOD pollutant diffusion model,supports the cascade analysis of boiler combustion efficiency prediction and flue gas emission monitoring,system response time is less than 2 seconds,and data consistency verification accuracy reaches 99.5%.展开更多
Multi-source data fusion provides high-precision spatial situational awareness essential for analyzing granular urban social activities.This study used Shanghai’s catering industry as a case study,leveraging electron...Multi-source data fusion provides high-precision spatial situational awareness essential for analyzing granular urban social activities.This study used Shanghai’s catering industry as a case study,leveraging electronic reviews and consumer data sourced from third-party restaurant platforms collected in 2021.By performing weighted processing on two-dimensional point-of-interest(POI)data,clustering hotspots of high-dimensional restaurant data were identified.A hierarchical network of restaurant hotspots was constructed following the Central Place Theory(CPT)framework,while the Geo-Informatic Tupu method was employed to resolve the challenges posed by network deformation in multi-scale processes.These findings suggest the necessity of enhancing the spatial balance of Shanghai’s urban centers by moderately increasing the number and service capacity of suburban centers at the urban periphery.Such measures would contribute to a more optimized urban structure and facilitate the outward dispersion of comfort-oriented facilities such as the restaurant industry.At a finer spatial scale,the distribution of restaurant hotspots demonstrates a polycentric and symmetric spatial pattern,with a developmental trend radiating outward along the city’s ring roads.This trend can be attributed to the efforts of restaurants to establish connections with other urban functional spaces,leading to the reconfiguration of urban spaces,expansion of restaurant-dedicated land use,and the reorganization of associated commercial activities.The results validate the existence of a polycentric urban structure in Shanghai but also highlight the instability of the restaurant hotspot network during cross-scale transitions.展开更多
Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from...Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from the Global Biodiversity Information Facility(GBIF),population distribution data from the Oak Ridge National Laboratory(ORNL)in the United States,as well as information on the composition of tree species in suitable forest areas for birds and the forest geographical information of the Ming Tombs Forest Farm,which is based on literature research and field investigations.By using GIS technology,spatial processing was carried out on bird observation points and population distribution data to identify suitable bird-watching areas in different seasons.Then,according to the suitability value range,these areas were classified into different grades(from unsuitable to highly suitable).The research findings indicated that there was significant spatial heterogeneity in the bird-watching suitability of the Ming Tombs Forest Farm.The north side of the reservoir was generally a core area with high suitability in all seasons.The deep-aged broad-leaved mixed forests supported the overlapping co-existence of the ecological niches of various bird species,such as the Zosterops simplex and Urocissa erythrorhyncha.In contrast,the shallow forest-edge coniferous pure forests and mixed forests were more suitable for specialized species like Carduelis sinica.The southern urban area and the core area of the mausoleums had relatively low suitability due to ecological fragmentation or human interference.Based on these results,this paper proposed a three-level protection framework of“core area conservation—buffer zone management—isolation zone construction”and a spatio-temporal coordinated human-bird co-existence strategy.It was also suggested that the human-bird co-existence space could be optimized through measures such as constructing sound and light buffer interfaces,restoring ecological corridors,and integrating cultural heritage elements.This research provided an operational technical approach and decision-making support for the scientific planning of bird-watching sites and the coordination of ecological protection and tourism development.展开更多
The operational lifespan of nuclear graphite is significantly affected by irradiation creep,yet the microstructural mechanism underlying this creep phenomenon remains unclear.Some theories attempt to link microstructu...The operational lifespan of nuclear graphite is significantly affected by irradiation creep,yet the microstructural mechanism underlying this creep phenomenon remains unclear.Some theories attempt to link microstructural evolution with creep behavior,but the rapid migration rate of defects under irradiation and loading makes it difficult to capture the specific evolution process experimentally,resulting in a lack of direct structural evidence.Therefore,in this study,molecular dynamics simulations are employed to investigate the irradiation behavior and microstructural migration under external loading.The aim is to provide microstructural evidence for theories such as the dislocation pinning-unpinning and crystal yielding.The results demonstrate that high tensile loads can increase the potential energy and reduce threshold displacement energy of graphite crystals.Consequently,displacement damage probability and creep rate increase,which is not considered in previous theories.Meanwhile,different creep mechanisms are observed at different damage states and applied loads.In low-dose damage states dominated by interstitials and vacancies,the pinning-unpinning process at basal plane may be caused by a defect diffusion mode.Under high stress levels,direct breaking of pinning structures occurs,leading to rapid migration of basal planes,demonstrating the microstructural evolution process of irradiated crystal yielding and plastic flow.In high-dose damage states characterized significantly by amorphous components,short-range atomic diffusion can become the dominant creep mechanism,and diffusion along the c-axis of graphite crystals is no longer constrained.These findings provide a crucial reference for understanding the irradiation and creep behavior of nuclear graphite in reactors.展开更多
This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-bas...This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-based elastomer(PBE)at concentrations ranging from 0 to 50 wt%,underwent a melt blending process and subsequent cobalt-60 gamma-ray irradiation with doses ranging from 0 to 250 kGy.Electrical conductivity,trap distribution,and alternating(AC)breakdown strength were chosen to assess the insulation performance.These results indicate that the addition of PBE significantly improves the electrical properties of PP under irradiation.For PP,the electrical conductivity increased with irradiation,whereas the trap depth and breakdown strength decreased sharply.Conversely,for the blend,these changes initially exhibit opposite trends.When the irradiation was increased to 250 kGy,the AC breakdown strength of the blend improved by more than 21%compared to that of PP.The physical and chemical structures of the samples were investigated to explore the improvement mechanisms.The results offer insights into the design of new cable-insulation materials suitable for NPPs.展开更多
Evaluation of damage evolution effects in biodegradable pure Mg was carried out,using transmission electron microscope as surrogate irradiation for high-energy radionuclide β decay in Brachytherapy.Time-dependent qua...Evaluation of damage evolution effects in biodegradable pure Mg was carried out,using transmission electron microscope as surrogate irradiation for high-energy radionuclide β decay in Brachytherapy.Time-dependent quantitative defect production,evolution dynamics,and evolution statistics were revealed in-situ for two prism foils(z=[1.210],[10.10]),in as-received and heat-treated pure Mg,after 300 keV electron irradiation up to 0.468 dpa at R.T.Preferred nucleation of basal-plane interstitial-type 1/6<20.23>loops was confirmed,in addition to a small portion of prism-plane 1/3<11.20>loops.No cavities were found.A higher yield of point defect concentration and a more evident trend of defect coarsening were identified in[1.210]than in[10.10].Pre-existing dislocations(on the orders of 10^(13)−10^(14) m^(−2))in pure Mg resulted in a delay of the first occurrence of visible defects.Defect migration and elastic interactions governed the microstructural evolution of electron irradiation damage in pure Mg,giving rise to events of loop coalescence,growth,and sometimes rotation of habit plane.The influence of incident electron energy can be correlated to the rates of point defect production,and is quantifiable;however,interfered by defect cluster stability,defect mobility,and defect interactions.This forms an important theoretical basis for the application of Mg subjected to MeV-level β-decay radiation in Brachytherapy.The paper concludes with a brief comparison between Mg and conventional Ti casing,outlines the advantages and challenges,and provides reference points for the validation of Mg/Mg-alloys in Brachytherapy seed application.展开更多
Volumetric additive manufacturing(VAM) transforms traditional 2D light pattern projection into spatial light field energy superposition,maximizing the utilization of radiated light and allowing for ultra-fast,support-...Volumetric additive manufacturing(VAM) transforms traditional 2D light pattern projection into spatial light field energy superposition,maximizing the utilization of radiated light and allowing for ultra-fast,support-free printing,which has specific applications in fields such as life sciences and optics.However,traditional VAM processes require numerous projections and extensive computational preparation,limiting practical applications due to low projection efficiency and prolonged calculation times.In this study,we developed sparse-view irradiation processing VAM(SVIP-VAM),employing an optimized odd-even(OE) irradiation strategy inspired by sparse-view computed tomography.Theoretically,we demonstrated structural contour reconstruction feasibility with as few as 8 projections.Using this sparse-view approach,we achieved high-quality fabrication with only 15 projections,enhancing each projection efficiency by over 60 times and reducing projection set computational time by nearly 10-fold.Ultimately,this efficient sparse-view method significantly expands VAM applications into fields requiring rapid manufacturing,such as tissue engineering,medical implants,and aerospace manufacturing.展开更多
基金supported by the National Major Scientific and Technological Infrastructure Project“Space Environment Simulation and Research Infrastructure”financially supported in part by the National Natural Science Foundation of China(No.52275241)the Fund for National Key Laboratory of Space Environment and Matter Behaviors(No.2023059)。
文摘0 INTRODUCTION The lunar surface lacks an atmosphere and is continuously subjected to a combination of space weathering factors such as cosmic rays,solar wind,and micrometeorite impacts,forming a several-meter-thick lunar regolith(Sorokin et al.,2020).
基金supported by the Science and Technology Planning Project of Fujian Province(No.2023Y4015)the Marine and Fishery Development Special Fund of Xiamen(No.23YYST064QCB36)the Natural Science Foundation of Fujian Province(No.2021J011210).
文摘The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight.
基金National Key Research and Development Program of China(2020YFA0710302)The Major Research Plan of the National Natural Science Foundation of China(91963206)+2 种基金The National Natural Science Foundation of China(52072169,51972164,51972167,22279053)The Fundamental Research Funds for the Central Universities(14380193)The Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2019ZT08L101).
文摘On the surfaces of celestial bodies with no or thin atmospheres,such as the Moon and Mars,the solar wind irradiation process leads to the formation of hydrogen and helium enriched regions in the extraterrestrial soil particles.However,soil particles on the Earth with the similar composition lack such structures and properties.This discrepancy raises a key question whether there is a direct relationship between solar wind irradiation and the alterations in the structure and chemical performance of extraterrestrial materials.To address this question,this work investigates the effects of proton irradiation,simulating solar wind radiation,on the structure and photothermal catalytic properties of the classic catalyst In_(2)O_(3).It reveals that proton irradiation induces structural features in In_(2)O_(3) analogous to those characteristics of solar wind weathering observed in extraterrestrial materials.Furthermore,after proton beam irradiation with an energy of 30 keV and a dose of 3×10^(17) protons·cm^(-2),the methanol production yield of the In_(2)O_(3) catalyst increased to 2.6 times of its preirradiation level,and the methanol selectivity improved to 2.1 times of the original value.This work provides both theoretical and experimental support for the development of high-efficiency,radiation-resistant photothermal catalysts.
基金support from the National Natural Science Foundation of China(Nos.12302083,U2267252,12372069,and 12172123)the China Postdoctoral Science Foundation(Nos.2023M731061 and BX20230109)+1 种基金the Natural Science Foundation of Hunan Province(No.2022JJ20001)the Hunan Provincial Innovation Foundation for Postgraduate(No.CX20230420).
文摘High-entropy alloys(HEAs)exhibit the excellent elevated-temperature performance and irradiation resistance due to the important core effect of serious lattice distortion for impeding dislocation motion,as candidate materials for nuclear applications.Despite the growth of the nuclear power sector,the effects of high-temperature and high-dose irradiation-induced voids on the mechanical properties of HEA in higher power nuclear reactors remain insufficiently researched,hindering its industrial application.In this study,we establish a consistent parameterization crystal plastic constitutive model for the hardening and creep behaviors of HEA,incorporating the spatial distribution of void size and shape effects,in contrast to traditional creep models that rely on temperature-related fitting parameters of the phenomenological power law equation.The model matches well with experimental data at different temperatures and irradiation doses,demonstrating its robustness.The effects of irradiation dose,temperature,and degree of lattice distortion on irradiation hardening and creep behavior of void-containing HEA are investigated.The results indicate that HEA with high lattice distortion exhibits better creep resistance under higher stress loads.The yield stress of irradiated HEA increases with increasing irradiation dose and temperature.The creep resistance increases with increasing irradiation dose and decreases with increasing irradiation temperature.The increase in irradiation dose causes a specific morphological transformation from spherical to cubic voids.The modeling and results could provide an effective theoretical way for tuning the yield strength and alloy design in advanced HEAs to meet irradiation properties.
基金supported by the National Key R&D Program of China(No.2023YFB2603602)the National Natural Science Foundation of China(Nos.52222810 and 52178383).
文摘To elucidate the fracturing mechanism of deep hard rock under complex disturbance environments,this study investigates the dynamic failure behavior of pre-damaged granite subjected to multi-source dynamic disturbances.Blasting vibration monitoring was conducted in a deep-buried drill-and-blast tunnel to characterize in-situ dynamic loading conditions.Subsequently,true triaxial compression tests incorporating multi-source disturbances were performed using a self-developed wide-low-frequency true triaxial system to simulate disturbance accumulation and damage evolution in granite.The results demonstrate that combined dynamic disturbances and unloading damage significantly accelerate strength degradation and trigger shear-slip failure along preferentially oriented blast-induced fractures,with strength reductions up to 16.7%.Layered failure was observed on the free surface of pre-damaged granite under biaxial loading,indicating a disturbance-induced fracture localization mechanism.Time-stress-fracture-energy coupling fields were constructed to reveal the spatiotemporal characteristics of fracture evolution.Critical precursor frequency bands(105-150,185-225,and 300-325 kHz)were identified,which serve as diagnostic signatures of impending failure.A dynamic instability mechanism driven by multi-source disturbance superposition and pre-damage evolution was established.Furthermore,a grouting-based wave-absorption control strategy was proposed to mitigate deep dynamic disasters by attenuating disturbance amplitude and reducing excitation frequency.
基金supported by the National Natural Science Foundation of China(Nos.12005289,52072397)State Key Laboratory of Nuclear Detection and Electronics,University of Science and Technology of China(SKLPDE-KF-202316).
文摘The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the safe operation of molten salt reactors(MSRs).Raman spectroscopy and a slow positron beam were employed to investigate the effects of He ion irradiation fluences and subsequent annealing on the microstructure and defects of the matrix graphite.He ions with 500 keV energy and fluences ranging from 1.1×10^(15)ions∕cm^(2)to 3.5×10^(17)ions∕cm^(2)were used to simulate neutron irradiation at 300 K.The samples with an irradiation fluence of 3.5×10^(16)ions∕cm^(2)were subjected to isochronal annealing at different temperatures(573 K,873 K and 1173 K)for 3 h.The Raman results revealed that the D peak gradually increased,whereas the intrinsic G peak decreased with increasing irradiation fluence.At the same irradiation fluence,the D peak gradually decreased,whereas the intrinsic G peak increased with increasing annealing temperature.Slow positron beam analysis demonstrated that the density or size of irradiation defects(vacancy type)increased with higher irradiation fluence,but decreased rapidly with increasing annealing temperature.The Raman spectral analysis of sample cross sections subjected to high irradiation fluences revealed the emergence of amorphization precisely at the depth where ion damage was most pronounced,whereas the surface retained its crystalline structure.Raman and positron annihilation analyses indicated that the matrix graphite exhibited good irradiation resistance to He ions at 300 K.However,vacancy-type defects induced by He ion irradiation exhibit poor thermal stability and can be easily removed during annealing.
基金supported by the National Natural Science Foundation of China(21663032 and 22061041)the Open Sharing Platform for Scientific and Technological Resources of Shaanxi Province(2021PT-004)the National Innovation and Entrepreneurship Training Program for College Students of China(S202110719044)。
文摘The SiO_(2) inverse opal photonic crystals(PC)with a three-dimensional macroporous structure were fabricated by the sacrificial template method,followed by infiltration of a pyrene derivative,1-(pyren-8-yl)but-3-en-1-amine(PEA),to achieve a formaldehyde(FA)-sensitive and fluorescence-enhanced sensing film.Utilizing the specific Aza-Cope rearrangement reaction of allylamine of PEA and FA to generate a strong fluorescent product emitted at approximately 480 nm,we chose a PC whose blue band edge of stopband overlapped with the fluorescence emission wavelength.In virtue of the fluorescence enhancement property derived from slow photon effect of PC,FA was detected highly selectively and sensitively.The limit of detection(LoD)was calculated to be 1.38 nmol/L.Furthermore,the fast detection of FA(within 1 min)is realized due to the interconnected three-dimensional macroporous structure of the inverse opal PC and its high specific surface area.The prepared sensing film can be used for the detection of FA in air,aquatic products and living cells.The very close FA content in indoor air to the result from FA detector,the recovery rate of 101.5%for detecting FA in aquatic products and fast fluorescence imaging in 2 min for living cells demonstrate the reliability and accuracy of our method in practical applications.
基金supported by National Natural Science Foundation of China(12174350)Science and Technology Project of State Grid Henan Electric Power Company(5217Q0240008).
文摘In the heterogeneous power internet of things(IoT)environment,data signals are acquired to support different business systems to realize advanced intelligent applications,with massive,multi-source,heterogeneous and other characteristics.Reliable perception of information and efficient transmission of energy in multi-source heterogeneous environments are crucial issues.Compressive sensing(CS),as an effective method of signal compression and transmission,can accurately recover the original signal only by very few sampling.In this paper,we study a new method of multi-source heterogeneous data signal reconstruction of power IoT based on compressive sensing technology.Based on the traditional compressive sensing technology to directly recover multi-source heterogeneous signals,we fully use the interference subspace information to design the measurement matrix,which directly and effectively eliminates the interference while making the measurement.The measure matrix is optimized by minimizing the average cross-coherence of the matrix,and the reconstruction performance of the new method is further improved.Finally,the effectiveness of the new method with different parameter settings under different multi-source heterogeneous data signal cases is verified by using orthogonal matching pursuit(OMP)and sparsity adaptive matching pursuit(SAMP)for considering the actual environment with prior information utilization of signal sparsity and no prior information utilization of signal sparsity.
基金supported by Natural Science Foundation of China(Nos.62303126,62362008,author Z.Z,https://www.nsfc.gov.cn/,accessed on 20 December 2024)Major Scientific and Technological Special Project of Guizhou Province([2024]014)+2 种基金Guizhou Provincial Science and Technology Projects(No.ZK[2022]General149) ,author Z.Z,https://kjt.guizhou.gov.cn/,accessed on 20 December 2024)The Open Project of the Key Laboratory of Computing Power Network and Information Security,Ministry of Education under Grant 2023ZD037,author Z.Z,https://www.gzu.edu.cn/,accessed on 20 December 2024)Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China(No.ICT2024B25),author Z.Z,https://www.gzu.edu.cn/,accessed on 20 December 2024).
文摘Due to the development of cloud computing and machine learning,users can upload their data to the cloud for machine learning model training.However,dishonest clouds may infer user data,resulting in user data leakage.Previous schemes have achieved secure outsourced computing,but they suffer from low computational accuracy,difficult-to-handle heterogeneous distribution of data from multiple sources,and high computational cost,which result in extremely poor user experience and expensive cloud computing costs.To address the above problems,we propose amulti-precision,multi-sourced,andmulti-key outsourcing neural network training scheme.Firstly,we design a multi-precision functional encryption computation based on Euclidean division.Second,we design the outsourcing model training algorithm based on a multi-precision functional encryption with multi-sourced heterogeneity.Finally,we conduct experiments on three datasets.The results indicate that our framework achieves an accuracy improvement of 6%to 30%.Additionally,it offers a memory space optimization of 1.0×2^(24) times compared to the previous best approach.
基金supported by the Sichuan Science and Technology Program(Nos.2024JDRC0100 and 2023YFQ0091)the National Natural Science Foundation of China(Nos.U21A20167 and 52475138)the Scientific Research Foundation of the State Key Laboratory of Rail Transit Vehicle System(No.2024RVL-T08).
文摘Accurate monitoring of track irregularities is very helpful to improving the vehicle operation quality and to formulating appropriate track maintenance strategies.Existing methods have the problem that they rely on complex signal processing algorithms and lack multi-source data analysis.Driven by multi-source measurement data,including the axle box,the bogie frame and the carbody accelerations,this paper proposes a track irregularities monitoring network(TIMNet)based on deep learning methods.TIMNet uses the feature extraction capability of convolutional neural networks and the sequence map-ping capability of the long short-term memory model to explore the mapping relationship between vehicle accelerations and track irregularities.The particle swarm optimization algorithm is used to optimize the network parameters,so that both the vertical and lateral track irregularities can be accurately identified in the time and spatial domains.The effectiveness and superiority of the proposed TIMNet is analyzed under different simulation conditions using a vehicle dynamics model.Field tests are conducted to prove the availability of the proposed TIMNet in quantitatively monitoring vertical and lateral track irregularities.Furthermore,comparative tests show that the TIMNet has a better fitting degree and timeliness in monitoring track irregularities(vertical R2 of 0.91,lateral R2 of 0.84 and time cost of 10 ms),compared to other classical regression.The test also proves that the TIMNet has a better anti-interference ability than other regression models.
文摘This paper deeply discusses the causes of gear howling noise,the identification and analysis of multi-source excitation,the transmission path of dynamic noise,simulation and experimental research,case analysis,optimization effect,etc.,aiming to better provide a certain guideline and reference for relevant researchers.
文摘As a multipurpose research reactor,fission molybdenum-technetium irradiation production is one of the wide applications of China Advanced Research Reactor CARR.The goal of this study is to achieve“online loading and unloading”of the target during fission molybdenum-99(99Mo)to technetium-99m(99mTc)irradiation production without affecting the normal reactor operation and other irradiation channels,which will make CARR more efficient in performing irradiation tasks.This paper introduces the design principles,requirements and concept structural design of the irradiation device of fission 99Mo-99mTc.
基金supported by the National Natural Science Foundation of China(Grant No.51804296)China Scholarship Council Grant(Grant No.CSC#202006425019).
文摘Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been proved that laser irradiation can improve drilling and blasting efficiency when combined with mechanical rock fracturing methods,which are irrelevant for borehole stabilization.To improve the latter,this study used laser ablation for borehole reinforcement.The high-power laser was applied to typical rock samples(sandstone,mudstone and coal)in both dry and saturated conditions.Multi-technique observations and measurements were used to fully understand the peculiar modifications of the specimens under laser treatment,i.e.mechanical loading,acoustic emission(AE)monitoring,digital image correlation(DIC)strain field evaluation,infrared thermography(IRT)monitoring and X-ray computed tomography(CT)scanning.The results showed that,in addition to the effects already demonstrated,laser irradiation can improve the strength of the soft rock,especially in the saturated state.The process involved a complicated phase change including melting and evaporation of the matrix under high-temperature and high-pressure to form a glassy high strength silicate material.This process is similar to the reaction between molten lava and water,or the impact of an asteroid on the earth.Inspired by the results,a conceptual path for a new borehole stabilization technology using laser ablation was outlined.
文摘With the acceleration of intelligent transformation of energy system,the monitoring of equipment operation status and optimization of production process in thermal power plants face the challenge of multi-source heterogeneous data integration.In view of the heterogeneous characteristics of physical sensor data,including temperature,vibration and pressure that generated by boilers,steam turbines and other key equipment and real-time working condition data of SCADA system,this paper proposes a multi-source heterogeneous data fusion and analysis platform for thermal power plants based on edge computing and deep learning.By constructing a multi-level fusion architecture,the platform adopts dynamic weight allocation strategy and 5D digital twin model to realize the collaborative analysis of physical sensor data,simulation calculation results and expert knowledge.The data fusion module combines Kalman filter,wavelet transform and Bayesian estimation method to solve the problem of data time series alignment and dimension difference.Simulation results show that the data fusion accuracy can be improved to more than 98%,and the calculation delay can be controlled within 500 ms.The data analysis module integrates Dymola simulation model and AERMOD pollutant diffusion model,supports the cascade analysis of boiler combustion efficiency prediction and flue gas emission monitoring,system response time is less than 2 seconds,and data consistency verification accuracy reaches 99.5%.
基金Under the auspices of the Key Program of National Natural Science Foundation of China(No.42030409)。
文摘Multi-source data fusion provides high-precision spatial situational awareness essential for analyzing granular urban social activities.This study used Shanghai’s catering industry as a case study,leveraging electronic reviews and consumer data sourced from third-party restaurant platforms collected in 2021.By performing weighted processing on two-dimensional point-of-interest(POI)data,clustering hotspots of high-dimensional restaurant data were identified.A hierarchical network of restaurant hotspots was constructed following the Central Place Theory(CPT)framework,while the Geo-Informatic Tupu method was employed to resolve the challenges posed by network deformation in multi-scale processes.These findings suggest the necessity of enhancing the spatial balance of Shanghai’s urban centers by moderately increasing the number and service capacity of suburban centers at the urban periphery.Such measures would contribute to a more optimized urban structure and facilitate the outward dispersion of comfort-oriented facilities such as the restaurant industry.At a finer spatial scale,the distribution of restaurant hotspots demonstrates a polycentric and symmetric spatial pattern,with a developmental trend radiating outward along the city’s ring roads.This trend can be attributed to the efforts of restaurants to establish connections with other urban functional spaces,leading to the reconfiguration of urban spaces,expansion of restaurant-dedicated land use,and the reorganization of associated commercial activities.The results validate the existence of a polycentric urban structure in Shanghai but also highlight the instability of the restaurant hotspot network during cross-scale transitions.
基金Sponsored by Beijing Youth Innovation Talent Support Program for Urban Greening and Landscaping——The 2024 Special Project for Promoting High-Quality Development of Beijing’s Landscaping through Scientific and Technological Innovation(KJCXQT202410).
文摘Taking the Ming Tombs Forest Farm in Beijing as the research object,this research applied multi-source data fusion and GIS heat-map overlay analysis techniques,systematically collected bird observation point data from the Global Biodiversity Information Facility(GBIF),population distribution data from the Oak Ridge National Laboratory(ORNL)in the United States,as well as information on the composition of tree species in suitable forest areas for birds and the forest geographical information of the Ming Tombs Forest Farm,which is based on literature research and field investigations.By using GIS technology,spatial processing was carried out on bird observation points and population distribution data to identify suitable bird-watching areas in different seasons.Then,according to the suitability value range,these areas were classified into different grades(from unsuitable to highly suitable).The research findings indicated that there was significant spatial heterogeneity in the bird-watching suitability of the Ming Tombs Forest Farm.The north side of the reservoir was generally a core area with high suitability in all seasons.The deep-aged broad-leaved mixed forests supported the overlapping co-existence of the ecological niches of various bird species,such as the Zosterops simplex and Urocissa erythrorhyncha.In contrast,the shallow forest-edge coniferous pure forests and mixed forests were more suitable for specialized species like Carduelis sinica.The southern urban area and the core area of the mausoleums had relatively low suitability due to ecological fragmentation or human interference.Based on these results,this paper proposed a three-level protection framework of“core area conservation—buffer zone management—isolation zone construction”and a spatio-temporal coordinated human-bird co-existence strategy.It was also suggested that the human-bird co-existence space could be optimized through measures such as constructing sound and light buffer interfaces,restoring ecological corridors,and integrating cultural heritage elements.This research provided an operational technical approach and decision-making support for the scientific planning of bird-watching sites and the coordination of ecological protection and tourism development.
基金supported the Science and Technology Commission of Shanghai Municipality(No.21DZ2206900)。
文摘The operational lifespan of nuclear graphite is significantly affected by irradiation creep,yet the microstructural mechanism underlying this creep phenomenon remains unclear.Some theories attempt to link microstructural evolution with creep behavior,but the rapid migration rate of defects under irradiation and loading makes it difficult to capture the specific evolution process experimentally,resulting in a lack of direct structural evidence.Therefore,in this study,molecular dynamics simulations are employed to investigate the irradiation behavior and microstructural migration under external loading.The aim is to provide microstructural evidence for theories such as the dislocation pinning-unpinning and crystal yielding.The results demonstrate that high tensile loads can increase the potential energy and reduce threshold displacement energy of graphite crystals.Consequently,displacement damage probability and creep rate increase,which is not considered in previous theories.Meanwhile,different creep mechanisms are observed at different damage states and applied loads.In low-dose damage states dominated by interstitials and vacancies,the pinning-unpinning process at basal plane may be caused by a defect diffusion mode.Under high stress levels,direct breaking of pinning structures occurs,leading to rapid migration of basal planes,demonstrating the microstructural evolution process of irradiated crystal yielding and plastic flow.In high-dose damage states characterized significantly by amorphous components,short-range atomic diffusion can become the dominant creep mechanism,and diffusion along the c-axis of graphite crystals is no longer constrained.These findings provide a crucial reference for understanding the irradiation and creep behavior of nuclear graphite in reactors.
基金supported by the National Natural Science Foundation of China(No.52077151)the State Key Laboratory of Electrical Insulation and Power Equipment(No.EIPE23208)the Key Laboratory of Engineering Dielectrics and Its Application,Ministry of Education(No.KFM202203).
文摘This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-based elastomer(PBE)at concentrations ranging from 0 to 50 wt%,underwent a melt blending process and subsequent cobalt-60 gamma-ray irradiation with doses ranging from 0 to 250 kGy.Electrical conductivity,trap distribution,and alternating(AC)breakdown strength were chosen to assess the insulation performance.These results indicate that the addition of PBE significantly improves the electrical properties of PP under irradiation.For PP,the electrical conductivity increased with irradiation,whereas the trap depth and breakdown strength decreased sharply.Conversely,for the blend,these changes initially exhibit opposite trends.When the irradiation was increased to 250 kGy,the AC breakdown strength of the blend improved by more than 21%compared to that of PP.The physical and chemical structures of the samples were investigated to explore the improvement mechanisms.The results offer insights into the design of new cable-insulation materials suitable for NPPs.
基金National Natural Science Foundation of China for funding support via grant No 12175013the Interdisciplinary Research Project for Young Researchers of USTB and the Youth Teacher International Exchange&Growth Program of USTB(Fundamental Research Funds for the Central Universities,China)for funding support via grant No FRF-IDRY-21–018 and QNXM20250033,respectively.
文摘Evaluation of damage evolution effects in biodegradable pure Mg was carried out,using transmission electron microscope as surrogate irradiation for high-energy radionuclide β decay in Brachytherapy.Time-dependent quantitative defect production,evolution dynamics,and evolution statistics were revealed in-situ for two prism foils(z=[1.210],[10.10]),in as-received and heat-treated pure Mg,after 300 keV electron irradiation up to 0.468 dpa at R.T.Preferred nucleation of basal-plane interstitial-type 1/6<20.23>loops was confirmed,in addition to a small portion of prism-plane 1/3<11.20>loops.No cavities were found.A higher yield of point defect concentration and a more evident trend of defect coarsening were identified in[1.210]than in[10.10].Pre-existing dislocations(on the orders of 10^(13)−10^(14) m^(−2))in pure Mg resulted in a delay of the first occurrence of visible defects.Defect migration and elastic interactions governed the microstructural evolution of electron irradiation damage in pure Mg,giving rise to events of loop coalescence,growth,and sometimes rotation of habit plane.The influence of incident electron energy can be correlated to the rates of point defect production,and is quantifiable;however,interfered by defect cluster stability,defect mobility,and defect interactions.This forms an important theoretical basis for the application of Mg subjected to MeV-level β-decay radiation in Brachytherapy.The paper concludes with a brief comparison between Mg and conventional Ti casing,outlines the advantages and challenges,and provides reference points for the validation of Mg/Mg-alloys in Brachytherapy seed application.
基金supported financially by the Beijing Municipal Natural Science Foundation (L232109)National Natural Science Foundation of China (22073003)Fundamental Research Funds for the Central Universities (YWF-22-K-101)。
文摘Volumetric additive manufacturing(VAM) transforms traditional 2D light pattern projection into spatial light field energy superposition,maximizing the utilization of radiated light and allowing for ultra-fast,support-free printing,which has specific applications in fields such as life sciences and optics.However,traditional VAM processes require numerous projections and extensive computational preparation,limiting practical applications due to low projection efficiency and prolonged calculation times.In this study,we developed sparse-view irradiation processing VAM(SVIP-VAM),employing an optimized odd-even(OE) irradiation strategy inspired by sparse-view computed tomography.Theoretically,we demonstrated structural contour reconstruction feasibility with as few as 8 projections.Using this sparse-view approach,we achieved high-quality fabrication with only 15 projections,enhancing each projection efficiency by over 60 times and reducing projection set computational time by nearly 10-fold.Ultimately,this efficient sparse-view method significantly expands VAM applications into fields requiring rapid manufacturing,such as tissue engineering,medical implants,and aerospace manufacturing.
