In order to study the mechanical properties of damaged reinforced concrete(RC)beams reinforced with ultra-high-performance concrete(UHPC),a four-point bending test was conducted to systematically investigate the influ...In order to study the mechanical properties of damaged reinforced concrete(RC)beams reinforced with ultra-high-performance concrete(UHPC),a four-point bending test was conducted to systematically investigate the influence of factors such as the number of reinforcement surfaces and the degree of damage.The results indicate that single-sided repaired beams have certain advantages in crack resistance performance,but are more disadvantageous in ultimate bearing capacity,with obvious debonding phenomenon before the end of loading.Compared with single-sided reinforcement,the cracking load of the three-sided reinforced beam increased by an average of 1.85 times,the ultimate bearing capacity increased by an average of 177.5%,and a good UHPC-RC combination effect could be formed,which could work synergistically until the end of loading.The degree of pre damage has a significant impact on the crack resistance performance of reinforced beams,while its impact on the ultimate bearing capacity is relatively limited.When the pre splitting width of the RC beam increases from 0.2 mm to 0.4 mm,the ultimate bearing capacity decreases by 28.33%.展开更多
Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects ...Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects of different types of cementitious materials,chemical shrinkage-reducing agents(SRA)and steel fiber(SF)were assessed.Compared with M2-UHPC and M3-UHPC,M1-UHPC was found to have better fluidity and shrinkage cracking performance.Moreover,different SRA incorporation methods,dosage and different SF types and aspect ratios were implemented.The incorporation of SRA and SF led to a decrease in the fluidity of UHPC.SRA internal content of 1%(NSRA-1%),SRA external content of 1%(WSRA-1%),STS-0.22 and STE-0.7 decreased the fluidity of UHPC by 3.3%,8.3%,9.2%and 25%,respectively.However,SRA and SF improved the UHPC shrinkage cracking performance.NSRA-1%and STE-0.7 reduced the shrinkage value of UHPC by 40%and 60%,respectively,and increased the crack resistance by 338%and 175%,respectively.In addition,the addition of SF was observed to make the microstructure of UHPC more compact,and the compressive strength and flexural strength of 28 d were increased by 26.9%and 19.9%,respectively.展开更多
Catalytic cracking oil slurry is a by-product of catalytic cracking projects,and the efficient conversion and sustainable utilization of this material are issues of continuous concern in the petroleum refining industr...Catalytic cracking oil slurry is a by-product of catalytic cracking projects,and the efficient conversion and sustainable utilization of this material are issues of continuous concern in the petroleum refining industry.In this study,oxygen-enriched activated carbon is prepared using a one-step KOH activation method with catalytic cracking oil slurry as the raw material.The as-prepared oil slurry-based activated carbon exhibits a high specific surface area of 2102 m^(2)/g,welldefined micropores with an average diameter of 2 nm,and a rich oxygen doping content of 32.97%.The electrochemical performance of the nitrogen-doped porous carbon is tested in a three-electrode system using a 6 mol/L KOH solution as the electrolyte.It achieves a specific capacitance of up to 230 F/g at a current density of 1 A/g.Moreover,the capacitance retention rate exceeds 89%after 10000 charge and discharge cycles,demonstrating excellent cycle stability.This method not only improves the utilization efficiency of industrial fuel waste but also reduces the production cost of supercapacitor electrode materials,thereby providing a simple and effective strategy for the resource utilization of catalytic cracking oil slurries.展开更多
A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first t...A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first time in the world. The porestructure characteristics of the NSZ zeolite prepared for industrial use were analyzed and characterized using BET. The resultsindicate a significant increase in the secondary pore volume of NSZ zeolite compared to the existing ultra-stable zeolite HSZ-5, which is produced through a conventional gas-phase method. The average secondary pore volume to total pore volume ratioin NSZ zeolite was found to be 58.96% higher. The catalytic cracking performance of NSZ zeolite was evaluated. The resultsshowed that the NSC-LTA catalyst, with NSZ as the active component, outperformed the HSC-LTA catalyst with HSZ-5 zeolitein terms of obtaining more high-value products (gasoline and liquefied petroleum gas) during the hydrogenated light cycle oilprocessing. Additionally, the NSC-LTA catalyst showed a significant improvement in coke selectivity.展开更多
Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hin...Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.展开更多
The growing demands for energy storage systems,electric vehicles,and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries.It is essential to design functional separat...The growing demands for energy storage systems,electric vehicles,and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries.It is essential to design functional separators with improved mechanical and electrochemical characteristics.This review covers the improved mechanical and electrochemical performances as well as the advancements made in the design of separators utilizing a variety of techniques.In terms of electrolyte wettability and adhesion of the coating materials,we provide an overview of the current status of research on coated separators,in situ modified separators,and grafting modified separators,and elaborate additional performance parameters of interest.The characteristics of inorganics coated separators,organic framework coated separators and inorganic-organic coated separators from different fabrication methods are compared.Future directions regarding new modified materials,manufacturing process,quantitative analysis of adhesion and so on are proposed toward next-generation advanced lithium batteries.展开更多
The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this work.Some test improvements were...The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this work.Some test improvements were suggested to improve test control of the CRM road performance based on the discovered flaws.Besides,the properties of reclaimed asphalt pavement(RAP),including the content of old asphalt,penetration index,passing rate of 4.75 mm sieve,and gradation change rate after extraction,were examined.The effects of RAP characteristics on splitting tensile strength,water stability,the high-and low-temperature performance of emulsified asphalt CRM were studied.The results show that the optimum moisture content of CRM should be determined when the compaction work matches the specimen’s molding work.Among the analyzed methods of bulk specific gravity assessment,the dry-surface and CoreLok methods provide more robust and accurate results than the wax-sealing method,while the dry-surface method is the most cost-efficient.The modified theoretical maximum relative density test method is proposed,which can reduce the systematic error of the vacuum test method.The following RAP-CRM trends can be observed.The lower the content of old asphalt and the smaller the change rate of gradation,the smaller the voids and the better the water stability of CRM.The greater the penetration of old asphalt,the higher the fracture work and low-temperature splitting strength.The greater the penetration,the higher the passing rate of 4.75 mm sieve after extraction,and the worse the high-temperature performance of CRM.展开更多
In recent decades,control performance monitoring(CPM)has experienced remarkable progress in research and industrial applications.While CPM research has been investigated using various benchmarks,the historical data be...In recent decades,control performance monitoring(CPM)has experienced remarkable progress in research and industrial applications.While CPM research has been investigated using various benchmarks,the historical data benchmark(HIS)has garnered the most attention due to its practicality and effectiveness.However,existing CPM reviews usually focus on the theoretical benchmark,and there is a lack of an in-depth review that thoroughly explores HIS-based methods.In this article,a comprehensive overview of HIS-based CPM is provided.First,we provide a novel static-dynamic perspective on data-level manifestations of control performance underlying typical controller capacities including regulation and servo:static and dynamic properties.The static property portrays time-independent variability in system output,and the dynamic property describes temporal behavior driven by closed-loop feedback.Accordingly,existing HIS-based CPM approaches and their intrinsic motivations are classified and analyzed from these two perspectives.Specifically,two mainstream solutions for CPM methods are summarized,including static analysis and dynamic analysis,which match data-driven techniques with actual controlling behavior.Furthermore,this paper also points out various opportunities and challenges faced in CPM for modern industry and provides promising directions in the context of artificial intelligence for inspiring future research.展开更多
Excellent detonation performances and low sensitivity are prerequisites for the deployment of energetic materials.Exploring the underlying factors that affect impact sensitivity and detonation performances as well as ...Excellent detonation performances and low sensitivity are prerequisites for the deployment of energetic materials.Exploring the underlying factors that affect impact sensitivity and detonation performances as well as exploring how to obtain materials with desired properties remains a long-term challenge.Machine learning with its ability to solve complex tasks and perform robust data processing can reveal the relationship between performance and descriptive indicators,potentially accelerating the development process of energetic materials.In this background,impact sensitivity,detonation performances,and 28 physicochemical parameters for 222 energetic materials from density functional theory calculations and published literature were sorted out.Four machine learning algorithms were employed to predict various properties of energetic materials,including impact sensitivity,detonation velocity,detonation pressure,and Gurney energy.Analysis of Pearson coefficients and feature importance showed that the heat of explosion,oxygen balance,decomposition products,and HOMO energy levels have a strong correlation with the impact sensitivity of energetic materials.Oxygen balance,decomposition products,and density have a strong correlation with detonation performances.Utilizing impact sensitivity of 2,3,4-trinitrotoluene and the detonation performances of 2,4,6-trinitrobenzene-1,3,5-triamine as the benchmark,the analysis of feature importance rankings and statistical data revealed the optimal range of key features balancing impact sensitivity and detonation performances:oxygen balance values should be between-40%and-30%,density should range from 1.66 to 1.72 g/cm^(3),HOMO energy levels should be between-6.34 and-6.31 eV,and lipophilicity should be between-1.0 and 0.1,4.49 and 5.59.These findings not only offer important insights into the impact sensitivity and detonation performances of energetic materials,but also provide a theoretical guidance paradigm for the design and development of new energetic materials with optimal detonation performances and reduced sensitivity.展开更多
Background Sow longevity and reproductivity are essential in the modern swine industry.Although many studies have focused on the genetic and genomic factors for selection,little is known about the associations between...Background Sow longevity and reproductivity are essential in the modern swine industry.Although many studies have focused on the genetic and genomic factors for selection,little is known about the associations between the microbiome and sows with longevity in reproduction.Results In this study,we collected and sequenced rectal and vaginal swabs from 48 sows,nine of which completed up to four parities(U4P group),exhibiting reproductive longevity.We first identified predictors of sow longevity in the rectum(e.g.,Akkermansia)and vagina(e.g.,Lactobacillus)of the U4P group using RandomForest in the early breeding stage of the first parity.Interestingly,these bacteria in the U4P group showed decreased predicted KEGG gene abundance involved in the biosynthesis of amino acids.Then,we tracked the longitudinal changes of the micro-biome over four parities in the U4P sows.LEfSe analysis revealed parity-associated bacteria that existed in both the rectum and vagina(e.g.,Streptococcus in Parity 1,Lactobacillus in Parity 2,Veillonella in Parity 4).We also identi-fied patterns of bacterial change between the early breeding stage(d 0)and d 110,such as Streptococcus,which was decreased in all four parties.Furthermore,sows in the U4P group with longevity potential also showed better reproductive performance.Finally,we discovered bacterial predictors(e.g.,Prevotellaceae NK3B31 group)for the total number of piglets born throughout the four parities in both the rectum and vagina.Conclusions This study highlights how the rectal and vaginal microbiome in sows with longevity in reproduc-tion changes within four parities.The identification of parity-associated,pregnancy-related,and reproductive performance-correlated bacteria provides the foundation for targeted microbiome modulation to improve animal production.展开更多
This study investigates the flexural performance of ultra-high performance concrete(UHPC)in reinforced concrete T-beams,focusing on the effects of interfacial treatments.Three concrete T-beam specimens were fabricated...This study investigates the flexural performance of ultra-high performance concrete(UHPC)in reinforced concrete T-beams,focusing on the effects of interfacial treatments.Three concrete T-beam specimens were fabricated and tested:a control beam(RC-T),a UHPC-reinforced beam with a chiseled interface(UN-C-50F),and a UHPC-reinforced beam featuring both a chiseled interface and anchored steel rebars(UN-CS-50F).The test results indicated that both chiseling and the incorporation of anchored rebars effectively created a synergistic combination between the concrete T-beam and the UHPC reinforcement layer,with the UN-CS-50F exhibiting the highest flexural resistance.The cracking load and ultimate load of UN-CS-50F were 221.5%and 40.8%,respectively,higher than those of the RC-T.Finite element(FE)models were developed to provide further insights into the behavior of the UHPCreinforced T-beams,showing a maximumdeviation of just 8%when validated against experimental data.A parametric analysis varied the height,thickness,andmaterial strength of the UHPC reinforcement layer based on the validated FE model,revealing that increasing the UHPC layer thickness from 30 to 50 mm improved the ultimate resistance by 20%while reducing the UHPC reinforcement height from 440 to 300 mm led to a 10%decrease in bending resistance.The interfacial anchoring rebars significantly reduced crack propagation and enhanced stress redistribution,highlighting the importance of strengthening interfacial bonds and optimizing geometric parameters ofUHPCfor improved T-beam performance.These findings offer valuable insights for the design and retrofitting of UHPC-reinforced bridge girders.展开更多
Solid-state batteries are widely recognized as the next-generation energy storage devices with high specific energy,high safety,and high environmental adaptability.However,the research and development of solid-state b...Solid-state batteries are widely recognized as the next-generation energy storage devices with high specific energy,high safety,and high environmental adaptability.However,the research and development of solid-state batteries are resource-intensive and time-consuming due to their complex chemical environment,rendering performance prediction arduous and delaying large-scale industrialization.Artificial intelligence serves as an accelerator for solid-state battery development by enabling efficient material screening and performance prediction.This review will systematically examine how the latest progress in using machine learning(ML)algorithms can be used to mine extensive material databases and accelerate the discovery of high-performance cathode,anode,and electrolyte materials suitable for solid-state batteries.Furthermore,the use of ML technology to accurately estimate and predict key performance indicators in the solid-state battery management system will be discussed,among which are state of charge,state of health,remaining useful life,and battery capacity.Finally,we will summarize the main challenges encountered in the current research,such as data quality issues and poor code portability,and propose possible solutions and development paths.These will provide clear guidance for future research and technological reiteration.展开更多
Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In ...Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In order to obtain high-quality HMX@PDA-based PBX explosives with high sphericity and a narrow particle size distribution,composite microspheres were prepared using co-axial droplet microfluidic technology.The formation mechanism,thermal behavior,mechanical sensitivity,electrostatic spark sensitivity,compressive strength,and combustion performance of the microspheres were investigated.The results show that PDA can effectively enhance the interfacial interaction between the explosive particles and the binder under the synergistic effect of chemical bonds and the physical"mechanical interlocking"structure.Interface reinforcement causes the thermal decomposition temperature of the sample microspheres to move to a higher temperature,with the sensitivity to impact,friction,and electrostatic sparks(for S-1)increasing by 12.5%,31.3%,and 81.5%respectively,and the compressive strength also increased by 30.7%,effectively enhancing the safety performance of the microspheres.Therefore,this study provides an effective and universal strategy for preparing high-quality functional explosives,and also provides some reference for the safe use of energetic materials in practical applications.展开更多
Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bott...Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.展开更多
The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experim...The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experiments,this study used inert materials with similar physical properties to partially substitute for the actual energetic components in the preparation of simulant materials.By thoroughly analyzing slurry physical properties,a simulation framework and an extensive performance evaluation method were developed.Such tools guide the design of the structure and configuration of process parameters.Results demonstrate that employing the Pin element significantly enhances radial mixing within the screw,minimizes temperature variations in the slurry,and improves both efficiency and safety in the mixing process.Further,adjustments such as widening the cone angle of the barrel,modifying the solid content of the slurry,and varying the speed of the screw can optimize the mechanical and thermal coupling in the flow field.These adjustments promote higher-quality slurry and create a safer production environment for the extrusion process.展开更多
To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying ...To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying method.The morphology,structure and thermal decomposition properties of the samples were analyzed using scanning electron microscopy(SEM),X-ray energy spectroscopy(EDS),infrared spectroscopy(FT-IR),and simultaneous thermal analyzer(TG-DSC).Additionally,the combustion process of the samples was tested using a high-speed camera.The results show that the addition of nano-Si contributes to the formation of composite explosives with regular morphology and smaller particle size.The Si/NC/CL-20 composite explosive has better and more uniform sphericity,with an average particle size of 73.4 nm,compared to the NC/CL-20 composite explosive.The Si/NC/CL-20 composite explosive which produced by the electrostatic spraying method,achieves physically uniform distribution of the components including NC,CL-20,Si.The addition of Si promotes the thermal decomposition of CL-20.In comparison to the NC/CL-20 composite explosive,the activation energy of the Si/NC/CL-20 composite explosive decreases by 16.78 kJ/mol,and the self-accelerated decomposition temperature and the critical temperature of thermal explosion decreases by 3.12 K and 2.61 K,respectively.Furthermore,Si/NC/CL-20 composite explosive has shorter ignition delay time and faster combustion rate compared to the NC/CL-20 composite explosive,which shows that Si can improve the combustion performance of CL-20.展开更多
Lithium ion batteries are important for new energy technologies and manufacturing systems.However,enhancing their capacity and cycling stability poses a significant challenge.This study proposes a novel method,i.e.,mo...Lithium ion batteries are important for new energy technologies and manufacturing systems.However,enhancing their capacity and cycling stability poses a significant challenge.This study proposes a novel method,i.e.,modifying current collectors with perforations,to address these issues.Lithium ion batteries with mechanically perforated current collectors are prepared and tested with charge/discharge cycles,revealing superior capacity as well as enhanced electrochemical stability over cycles.Impedance spectroscopy,scanning electron microscopy,and peeling tests are conducted to investigate the underlying mechanisms.Higher peel resistance,minimized interface cracking,and reduced electrical impedance are found in the perforated electrodes after cycles.Investigations indicate that the perforation holes on current collectors allow the active materials coating on the two sides of the current collector to bind together and,thus,lead to enhanced adhesion between the current collector and active layer.Mechanical simulation illustrates the role of perforated current collectors in curbing interface cracking during lithiation,while electrochemical simulation shows that the interfacial cracking hinders the diffusion of lithium ions,thereby increasing battery impedance and reducing the cyclic performance.This investigation reveals the potential of designing non-active battery components to enhance battery performance,advocating a nuanced approach to battery design emphasizing structural integrity and interface optimization.展开更多
This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ra...This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.展开更多
To investigate the effects of the spraying process and different fibers on the mechanical properties and failure patterns of ultrahigh performance concrete(UHPC),three types of fibers were used.These fibers were forme...To investigate the effects of the spraying process and different fibers on the mechanical properties and failure patterns of ultrahigh performance concrete(UHPC),three types of fibers were used.These fibers were formed using both spraying and molding methods.Uniaxial compression tests were conducted,and two nondestructive monitoring techniques,acoustic emission(AE)and digital image correlation,were employed to monitor the uniaxial compression tests.The results indicated that the compressive strength of UHPC with single steel fibers and hybrid fibers increased by about 19%and 14%compared with those of UHPC with polyoxymethylene fibers.In comparison with molded UHPC,sprayed UHPC showed a slight improvement in compressive strength.Specimens containing steel fibers exhibited better post-cracking ductility,whereas those with only polyoxymethylene fibers displayed a certain degree of brittle failure.In sprayed UHPC,the onset of significant internal damage was delayed,which was related to the redistribution of internal fibers.The failure of UHPC was characterized by primary tensile cracks,supplemented by shear cracks.The spraying process can better restrict the development of tensile cracks in UHPC.Sprayed UHPC typically exhibited multiple crack developments leading to failure,whereas molded UHPC generally failed in the form of a single main crack penetrating the specimen.The addition of steel fibers delayed the occurrence of local stress concentration zones,aligning well with AE monitoring data.展开更多
文摘In order to study the mechanical properties of damaged reinforced concrete(RC)beams reinforced with ultra-high-performance concrete(UHPC),a four-point bending test was conducted to systematically investigate the influence of factors such as the number of reinforcement surfaces and the degree of damage.The results indicate that single-sided repaired beams have certain advantages in crack resistance performance,but are more disadvantageous in ultimate bearing capacity,with obvious debonding phenomenon before the end of loading.Compared with single-sided reinforcement,the cracking load of the three-sided reinforced beam increased by an average of 1.85 times,the ultimate bearing capacity increased by an average of 177.5%,and a good UHPC-RC combination effect could be formed,which could work synergistically until the end of loading.The degree of pre damage has a significant impact on the crack resistance performance of reinforced beams,while its impact on the ultimate bearing capacity is relatively limited.When the pre splitting width of the RC beam increases from 0.2 mm to 0.4 mm,the ultimate bearing capacity decreases by 28.33%.
基金the Key Research and Development Program of Hubei Province(2022BCA082 and 2022BCA077).
文摘Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects of different types of cementitious materials,chemical shrinkage-reducing agents(SRA)and steel fiber(SF)were assessed.Compared with M2-UHPC and M3-UHPC,M1-UHPC was found to have better fluidity and shrinkage cracking performance.Moreover,different SRA incorporation methods,dosage and different SF types and aspect ratios were implemented.The incorporation of SRA and SF led to a decrease in the fluidity of UHPC.SRA internal content of 1%(NSRA-1%),SRA external content of 1%(WSRA-1%),STS-0.22 and STE-0.7 decreased the fluidity of UHPC by 3.3%,8.3%,9.2%and 25%,respectively.However,SRA and SF improved the UHPC shrinkage cracking performance.NSRA-1%and STE-0.7 reduced the shrinkage value of UHPC by 40%and 60%,respectively,and increased the crack resistance by 338%and 175%,respectively.In addition,the addition of SF was observed to make the microstructure of UHPC more compact,and the compressive strength and flexural strength of 28 d were increased by 26.9%and 19.9%,respectively.
基金the National Natural Science Foundation of China(52206262)Small and Medium-sized Sci-tech Enterprises Innovation Capability Improvement Project of Shandong Province,China(2022TSGC2248,2023TSGC0579)+1 种基金Talent Research Project of Qilu University of Technology(Shandong Academy of Sciences)(2023RCKY170)Natural Science Foundation of Shandong Province,China(ZR2020ME191).
文摘Catalytic cracking oil slurry is a by-product of catalytic cracking projects,and the efficient conversion and sustainable utilization of this material are issues of continuous concern in the petroleum refining industry.In this study,oxygen-enriched activated carbon is prepared using a one-step KOH activation method with catalytic cracking oil slurry as the raw material.The as-prepared oil slurry-based activated carbon exhibits a high specific surface area of 2102 m^(2)/g,welldefined micropores with an average diameter of 2 nm,and a rich oxygen doping content of 32.97%.The electrochemical performance of the nitrogen-doped porous carbon is tested in a three-electrode system using a 6 mol/L KOH solution as the electrolyte.It achieves a specific capacitance of up to 230 F/g at a current density of 1 A/g.Moreover,the capacitance retention rate exceeds 89%after 10000 charge and discharge cycles,demonstrating excellent cycle stability.This method not only improves the utilization efficiency of industrial fuel waste but also reduces the production cost of supercapacitor electrode materials,thereby providing a simple and effective strategy for the resource utilization of catalytic cracking oil slurries.
基金the National Key R&D Program of China(2022YFA1504404)the SINOPEC Research Program(121036-5).
文摘A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first time in the world. The porestructure characteristics of the NSZ zeolite prepared for industrial use were analyzed and characterized using BET. The resultsindicate a significant increase in the secondary pore volume of NSZ zeolite compared to the existing ultra-stable zeolite HSZ-5, which is produced through a conventional gas-phase method. The average secondary pore volume to total pore volume ratioin NSZ zeolite was found to be 58.96% higher. The catalytic cracking performance of NSZ zeolite was evaluated. The resultsshowed that the NSC-LTA catalyst, with NSZ as the active component, outperformed the HSC-LTA catalyst with HSZ-5 zeolitein terms of obtaining more high-value products (gasoline and liquefied petroleum gas) during the hydrogenated light cycle oilprocessing. Additionally, the NSC-LTA catalyst showed a significant improvement in coke selectivity.
文摘Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.
基金the Center of Lithium Battery Membrane Materials jointly established by School of Chemistry and Chemical Engineering of Huazhong University of Science and Technology and Shenzhen Senior Technology Material Co.Ltd.,the National Natural Science Foundation of China(52020105012,52303084)the Young Scientists Fund of Natural Science Foundation of Hubei Province(2023AFB220)for the support of this work.
文摘The growing demands for energy storage systems,electric vehicles,and portable electronics have significantly pushed forward the need for safe and reliable lithium batteries.It is essential to design functional separators with improved mechanical and electrochemical characteristics.This review covers the improved mechanical and electrochemical performances as well as the advancements made in the design of separators utilizing a variety of techniques.In terms of electrolyte wettability and adhesion of the coating materials,we provide an overview of the current status of research on coated separators,in situ modified separators,and grafting modified separators,and elaborate additional performance parameters of interest.The characteristics of inorganics coated separators,organic framework coated separators and inorganic-organic coated separators from different fabrication methods are compared.Future directions regarding new modified materials,manufacturing process,quantitative analysis of adhesion and so on are proposed toward next-generation advanced lithium batteries.
文摘The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this work.Some test improvements were suggested to improve test control of the CRM road performance based on the discovered flaws.Besides,the properties of reclaimed asphalt pavement(RAP),including the content of old asphalt,penetration index,passing rate of 4.75 mm sieve,and gradation change rate after extraction,were examined.The effects of RAP characteristics on splitting tensile strength,water stability,the high-and low-temperature performance of emulsified asphalt CRM were studied.The results show that the optimum moisture content of CRM should be determined when the compaction work matches the specimen’s molding work.Among the analyzed methods of bulk specific gravity assessment,the dry-surface and CoreLok methods provide more robust and accurate results than the wax-sealing method,while the dry-surface method is the most cost-efficient.The modified theoretical maximum relative density test method is proposed,which can reduce the systematic error of the vacuum test method.The following RAP-CRM trends can be observed.The lower the content of old asphalt and the smaller the change rate of gradation,the smaller the voids and the better the water stability of CRM.The greater the penetration of old asphalt,the higher the fracture work and low-temperature splitting strength.The greater the penetration,the higher the passing rate of 4.75 mm sieve after extraction,and the worse the high-temperature performance of CRM.
基金supported in part by the National Natural Science Foundation of China(62125306)Zhejiang Key Research and Development Project(2024C01163)the State Key Laboratory of Industrial Control Technology,China(ICT2024A06)
文摘In recent decades,control performance monitoring(CPM)has experienced remarkable progress in research and industrial applications.While CPM research has been investigated using various benchmarks,the historical data benchmark(HIS)has garnered the most attention due to its practicality and effectiveness.However,existing CPM reviews usually focus on the theoretical benchmark,and there is a lack of an in-depth review that thoroughly explores HIS-based methods.In this article,a comprehensive overview of HIS-based CPM is provided.First,we provide a novel static-dynamic perspective on data-level manifestations of control performance underlying typical controller capacities including regulation and servo:static and dynamic properties.The static property portrays time-independent variability in system output,and the dynamic property describes temporal behavior driven by closed-loop feedback.Accordingly,existing HIS-based CPM approaches and their intrinsic motivations are classified and analyzed from these two perspectives.Specifically,two mainstream solutions for CPM methods are summarized,including static analysis and dynamic analysis,which match data-driven techniques with actual controlling behavior.Furthermore,this paper also points out various opportunities and challenges faced in CPM for modern industry and provides promising directions in the context of artificial intelligence for inspiring future research.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2682024GF019)。
文摘Excellent detonation performances and low sensitivity are prerequisites for the deployment of energetic materials.Exploring the underlying factors that affect impact sensitivity and detonation performances as well as exploring how to obtain materials with desired properties remains a long-term challenge.Machine learning with its ability to solve complex tasks and perform robust data processing can reveal the relationship between performance and descriptive indicators,potentially accelerating the development process of energetic materials.In this background,impact sensitivity,detonation performances,and 28 physicochemical parameters for 222 energetic materials from density functional theory calculations and published literature were sorted out.Four machine learning algorithms were employed to predict various properties of energetic materials,including impact sensitivity,detonation velocity,detonation pressure,and Gurney energy.Analysis of Pearson coefficients and feature importance showed that the heat of explosion,oxygen balance,decomposition products,and HOMO energy levels have a strong correlation with the impact sensitivity of energetic materials.Oxygen balance,decomposition products,and density have a strong correlation with detonation performances.Utilizing impact sensitivity of 2,3,4-trinitrotoluene and the detonation performances of 2,4,6-trinitrobenzene-1,3,5-triamine as the benchmark,the analysis of feature importance rankings and statistical data revealed the optimal range of key features balancing impact sensitivity and detonation performances:oxygen balance values should be between-40%and-30%,density should range from 1.66 to 1.72 g/cm^(3),HOMO energy levels should be between-6.34 and-6.31 eV,and lipophilicity should be between-1.0 and 0.1,4.49 and 5.59.These findings not only offer important insights into the impact sensitivity and detonation performances of energetic materials,but also provide a theoretical guidance paradigm for the design and development of new energetic materials with optimal detonation performances and reduced sensitivity.
基金funded by the National Key Research and Development Program of China (2023YFE0124400)the Specific university discipline construction project (2023B10564001)+1 种基金grants administered by the Arkansas Biosciences Institute and the USDAa core grant (P20GM121293, proteogenomics core)。
文摘Background Sow longevity and reproductivity are essential in the modern swine industry.Although many studies have focused on the genetic and genomic factors for selection,little is known about the associations between the microbiome and sows with longevity in reproduction.Results In this study,we collected and sequenced rectal and vaginal swabs from 48 sows,nine of which completed up to four parities(U4P group),exhibiting reproductive longevity.We first identified predictors of sow longevity in the rectum(e.g.,Akkermansia)and vagina(e.g.,Lactobacillus)of the U4P group using RandomForest in the early breeding stage of the first parity.Interestingly,these bacteria in the U4P group showed decreased predicted KEGG gene abundance involved in the biosynthesis of amino acids.Then,we tracked the longitudinal changes of the micro-biome over four parities in the U4P sows.LEfSe analysis revealed parity-associated bacteria that existed in both the rectum and vagina(e.g.,Streptococcus in Parity 1,Lactobacillus in Parity 2,Veillonella in Parity 4).We also identi-fied patterns of bacterial change between the early breeding stage(d 0)and d 110,such as Streptococcus,which was decreased in all four parties.Furthermore,sows in the U4P group with longevity potential also showed better reproductive performance.Finally,we discovered bacterial predictors(e.g.,Prevotellaceae NK3B31 group)for the total number of piglets born throughout the four parities in both the rectum and vagina.Conclusions This study highlights how the rectal and vaginal microbiome in sows with longevity in reproduc-tion changes within four parities.The identification of parity-associated,pregnancy-related,and reproductive performance-correlated bacteria provides the foundation for targeted microbiome modulation to improve animal production.
基金The National Natural Science Foundation of China(Grant#52278161)the Science and Technology Project of Guangzhou(Grant#2024A04J9888)the Guangdong Basic and Applied Basic Research Foundation(Grant#2023A1515010535).
文摘This study investigates the flexural performance of ultra-high performance concrete(UHPC)in reinforced concrete T-beams,focusing on the effects of interfacial treatments.Three concrete T-beam specimens were fabricated and tested:a control beam(RC-T),a UHPC-reinforced beam with a chiseled interface(UN-C-50F),and a UHPC-reinforced beam featuring both a chiseled interface and anchored steel rebars(UN-CS-50F).The test results indicated that both chiseling and the incorporation of anchored rebars effectively created a synergistic combination between the concrete T-beam and the UHPC reinforcement layer,with the UN-CS-50F exhibiting the highest flexural resistance.The cracking load and ultimate load of UN-CS-50F were 221.5%and 40.8%,respectively,higher than those of the RC-T.Finite element(FE)models were developed to provide further insights into the behavior of the UHPCreinforced T-beams,showing a maximumdeviation of just 8%when validated against experimental data.A parametric analysis varied the height,thickness,andmaterial strength of the UHPC reinforcement layer based on the validated FE model,revealing that increasing the UHPC layer thickness from 30 to 50 mm improved the ultimate resistance by 20%while reducing the UHPC reinforcement height from 440 to 300 mm led to a 10%decrease in bending resistance.The interfacial anchoring rebars significantly reduced crack propagation and enhanced stress redistribution,highlighting the importance of strengthening interfacial bonds and optimizing geometric parameters ofUHPCfor improved T-beam performance.These findings offer valuable insights for the design and retrofitting of UHPC-reinforced bridge girders.
基金the National Key Research Program of China under granted No.92164201National Natural Science Foundation of China for Distinguished Young Scholars No.62325403+2 种基金Natural Science Foundation of Jiangsu Province(BK20230498)Jiangsu Funding Program for Excellent Postdoctoral Talent(2024ZB427)the National Natural Science Foundation of China(62304147).
文摘Solid-state batteries are widely recognized as the next-generation energy storage devices with high specific energy,high safety,and high environmental adaptability.However,the research and development of solid-state batteries are resource-intensive and time-consuming due to their complex chemical environment,rendering performance prediction arduous and delaying large-scale industrialization.Artificial intelligence serves as an accelerator for solid-state battery development by enabling efficient material screening and performance prediction.This review will systematically examine how the latest progress in using machine learning(ML)algorithms can be used to mine extensive material databases and accelerate the discovery of high-performance cathode,anode,and electrolyte materials suitable for solid-state batteries.Furthermore,the use of ML technology to accurately estimate and predict key performance indicators in the solid-state battery management system will be discussed,among which are state of charge,state of health,remaining useful life,and battery capacity.Finally,we will summarize the main challenges encountered in the current research,such as data quality issues and poor code portability,and propose possible solutions and development paths.These will provide clear guidance for future research and technological reiteration.
基金supported by the National Natural Science Foundation of China(Grant No.22005275).
文摘Surface engineering plays a crucial role in improving the performance of high energy materials,and polydopamine(PDA)is widely used in the field of energetic materials for surface modification and functionalization.In order to obtain high-quality HMX@PDA-based PBX explosives with high sphericity and a narrow particle size distribution,composite microspheres were prepared using co-axial droplet microfluidic technology.The formation mechanism,thermal behavior,mechanical sensitivity,electrostatic spark sensitivity,compressive strength,and combustion performance of the microspheres were investigated.The results show that PDA can effectively enhance the interfacial interaction between the explosive particles and the binder under the synergistic effect of chemical bonds and the physical"mechanical interlocking"structure.Interface reinforcement causes the thermal decomposition temperature of the sample microspheres to move to a higher temperature,with the sensitivity to impact,friction,and electrostatic sparks(for S-1)increasing by 12.5%,31.3%,and 81.5%respectively,and the compressive strength also increased by 30.7%,effectively enhancing the safety performance of the microspheres.Therefore,this study provides an effective and universal strategy for preparing high-quality functional explosives,and also provides some reference for the safe use of energetic materials in practical applications.
基金supported by the National Natural Science Foundation of China(Nos.52371128,52304378,52101031 and 92163107).
文摘Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.
基金financially supported by the Fundamental Research Funds for the Central Universities(Grant No.30923011018)。
文摘The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experiments,this study used inert materials with similar physical properties to partially substitute for the actual energetic components in the preparation of simulant materials.By thoroughly analyzing slurry physical properties,a simulation framework and an extensive performance evaluation method were developed.Such tools guide the design of the structure and configuration of process parameters.Results demonstrate that employing the Pin element significantly enhances radial mixing within the screw,minimizes temperature variations in the slurry,and improves both efficiency and safety in the mixing process.Further,adjustments such as widening the cone angle of the barrel,modifying the solid content of the slurry,and varying the speed of the screw can optimize the mechanical and thermal coupling in the flow field.These adjustments promote higher-quality slurry and create a safer production environment for the extrusion process.
基金National Natural Science Foundation of China(No.22275150)。
文摘To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying method.The morphology,structure and thermal decomposition properties of the samples were analyzed using scanning electron microscopy(SEM),X-ray energy spectroscopy(EDS),infrared spectroscopy(FT-IR),and simultaneous thermal analyzer(TG-DSC).Additionally,the combustion process of the samples was tested using a high-speed camera.The results show that the addition of nano-Si contributes to the formation of composite explosives with regular morphology and smaller particle size.The Si/NC/CL-20 composite explosive has better and more uniform sphericity,with an average particle size of 73.4 nm,compared to the NC/CL-20 composite explosive.The Si/NC/CL-20 composite explosive which produced by the electrostatic spraying method,achieves physically uniform distribution of the components including NC,CL-20,Si.The addition of Si promotes the thermal decomposition of CL-20.In comparison to the NC/CL-20 composite explosive,the activation energy of the Si/NC/CL-20 composite explosive decreases by 16.78 kJ/mol,and the self-accelerated decomposition temperature and the critical temperature of thermal explosion decreases by 3.12 K and 2.61 K,respectively.Furthermore,Si/NC/CL-20 composite explosive has shorter ignition delay time and faster combustion rate compared to the NC/CL-20 composite explosive,which shows that Si can improve the combustion performance of CL-20.
基金supported by the National Natural Science Foundation of China under Grant Nos.12172205,11872236,and 12072183.
文摘Lithium ion batteries are important for new energy technologies and manufacturing systems.However,enhancing their capacity and cycling stability poses a significant challenge.This study proposes a novel method,i.e.,modifying current collectors with perforations,to address these issues.Lithium ion batteries with mechanically perforated current collectors are prepared and tested with charge/discharge cycles,revealing superior capacity as well as enhanced electrochemical stability over cycles.Impedance spectroscopy,scanning electron microscopy,and peeling tests are conducted to investigate the underlying mechanisms.Higher peel resistance,minimized interface cracking,and reduced electrical impedance are found in the perforated electrodes after cycles.Investigations indicate that the perforation holes on current collectors allow the active materials coating on the two sides of the current collector to bind together and,thus,lead to enhanced adhesion between the current collector and active layer.Mechanical simulation illustrates the role of perforated current collectors in curbing interface cracking during lithiation,while electrochemical simulation shows that the interfacial cracking hinders the diffusion of lithium ions,thereby increasing battery impedance and reducing the cyclic performance.This investigation reveals the potential of designing non-active battery components to enhance battery performance,advocating a nuanced approach to battery design emphasizing structural integrity and interface optimization.
基金supported by grants from the Natural Science Foundation of Fujian Province(2021J011062)Minjiang Scholars Funding(GY-633Z21067).
文摘This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.
基金The National Natural Science Foundation of China(No.52379124)the National Key Research and Development Program of China(No.2021YFB2600200).
文摘To investigate the effects of the spraying process and different fibers on the mechanical properties and failure patterns of ultrahigh performance concrete(UHPC),three types of fibers were used.These fibers were formed using both spraying and molding methods.Uniaxial compression tests were conducted,and two nondestructive monitoring techniques,acoustic emission(AE)and digital image correlation,were employed to monitor the uniaxial compression tests.The results indicated that the compressive strength of UHPC with single steel fibers and hybrid fibers increased by about 19%and 14%compared with those of UHPC with polyoxymethylene fibers.In comparison with molded UHPC,sprayed UHPC showed a slight improvement in compressive strength.Specimens containing steel fibers exhibited better post-cracking ductility,whereas those with only polyoxymethylene fibers displayed a certain degree of brittle failure.In sprayed UHPC,the onset of significant internal damage was delayed,which was related to the redistribution of internal fibers.The failure of UHPC was characterized by primary tensile cracks,supplemented by shear cracks.The spraying process can better restrict the development of tensile cracks in UHPC.Sprayed UHPC typically exhibited multiple crack developments leading to failure,whereas molded UHPC generally failed in the form of a single main crack penetrating the specimen.The addition of steel fibers delayed the occurrence of local stress concentration zones,aligning well with AE monitoring data.
