Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently wor...Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.展开更多
The pre-weld heat treatment was carried out to obtain different initial microstructures of the GH4169 superalloy,and then Linear Friction Welding(LFW)was performed.The effect of the pre-weld heat treatment on the micr...The pre-weld heat treatment was carried out to obtain different initial microstructures of the GH4169 superalloy,and then Linear Friction Welding(LFW)was performed.The effect of the pre-weld heat treatment on the microstructure evolution and mechanical properties of the joint was analyzed,and the joint electrochemical corrosion behavior as well as the hot corrosion behavior was studied.The results show that the joint hardness of Base Metal(BM)increases after pre-weld heat treatment,and the strengthening phasesγ′andγ″further precipitate.However,the precipitation phases dissolve significantly in the Weld Zone(WZ)due to the thermal process of LFW.The corrosion resistance in BM is reduced after the pre-weld heat treatment,while it is similar in WZ with a slight decrease.The surface morphology of the BM and WZ can be generally divided into a loose and porous matrix and a scattered oxide particle layer after hot corrosion.The joint cross section exhibits a Cr-depleted zone with the diffusion of Cr to form an oxide film.The corrosion product mainly consists of Fe_(2)O_(3)/Fe_(3)O_(4) as the outer layer and Cr_(2)O_(3) as the inner layer.展开更多
In recent years,the study of Majorana signatures in quantum transport has become a central focus in condensed matter physics.Here,we present a rigorous and systematic derivation of the fermionic superoperator describi...In recent years,the study of Majorana signatures in quantum transport has become a central focus in condensed matter physics.Here,we present a rigorous and systematic derivation of the fermionic superoperator describing the open quantum dynamics of electron transport through Majorana zero modes,building on the techniques introduced in Phys.Rev.B 105,035121(2022).The numerical implementation of this superoperator is to construct its differential equivalence,the hierarchical equations of motion(HEOM).The HEOM approach describes the system-bath correlated dynamics.Furthermore,we also develop a functional derivative scheme that provides exact expressions for the transport observables in terms of the auxiliary density operators introduced in the HEOM formulation.The superoperator formalism establishes a solid theoretical foundation for analyzing key transport signatures that may uncover the unique characteristics of Majorana physics in mesoscopic systems.展开更多
As a renewable energy source,the thermal conversion of poultry manure,is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions.Currently,pr...As a renewable energy source,the thermal conversion of poultry manure,is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions.Currently,pressurized gasification of poultry manure is still a novel research field,especially when combined with a novel technological route of oxy-fuel gasification.Oxy-fuel gasification is a newly proposed and promising gasification technology for power generation that facilitates future carbon capture and storage.In this work,based on a commercially operated industrial-scale chicken manure gasification power plant in Singapore,we presented an interesting first exploration of the coupled pressurization technology for oxy-fuel gasification of poultry manure using CFD numerical simulation,analyzed the effects of pressure and oxygen enrichment concentration as well as the coupling mechanism between them,and discussed the conversion and emission of nitrogen-and sulfur-containing pollutants.The results indicate that under oxy-fuel gasification condition(Oxy-30,i.e.,30%O_(2)/70%CO_(2)),as the pressure increases from 0.1 to 0.5 MPa,the CO concentration in the syngas increases slightly,the H_(2)concentration increases to approximately 25%,and the CH4 concentration(less than 1%)decreases,resulting in an increase in the calorific value of syngas from 5.2 to 5.6 MJ·m^(-3).Compared to atmospheric pressure conditions,a relatively higher oxygen-enriched concentration interval(Oxy-40 to Oxy-50)under pressurized conditions is advantageous for autothermal gasification.Pressurization increases NO precursors production and also promotes homogeneous and heterogeneous reduction of NO,and provides favorable conditions for self-desulfurization.This work offers reference for the realization of a highly efficient and low-energy-consumption thermochemical treatment of livestock manure coupled with negative carbon emission technology.展开更多
Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential.This work presents an innovative research exploration-coupling coal pressurized fluidiz...Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential.This work presents an innovative research exploration-coupling coal pressurized fluidized bed oxy-fuel combustion technology with energy utilization of poultry manure as a renewable and carbon-neutral fuel,in order to capture CO_(2)and solve the problem of poultry manure treatment simultaneously.In this study,a stable co-combustion of coal and chicken manure in a laboratory-scale pressurized fluidized bed under typical oxy-fuel condition(30%O_(2)/70%CO_(2),i.e.,Oxy-30)is achieved.The key parameters including the combustion pressure(0.1-0.5 MPa)and chicken-manure proportion(0%to 100%)and their impacts on fundamental combustion efficiency,carbon conversion,nitrogen and sulfur pollutant emissions,and residue ash characteristics have been investigated.The result show that pressurization favors an increase in the CO_(2)enrichment concentration and fluidized bed combustion efficiency.During co-combustion under 0.1 and 0.3 MPa,the CO_(2)concentration in the flue gas is the highest when the chicken manure blending ratio(M_(pm))is 25%.Although the NO emissions fluctuate and even increase as Mpm increases,the co-combustion of coal and chicken manure exhibits a synergistic effect in reducing NO conversion rate(XNO).The effect of pressurization on reducing NO emission is significant,XNO at M_(pm)=25%decreasing from 15%to 5%as the pressure(P)increases from 0.1 to 0.5 MPa.As P increases from 0.1 to 0.5 MPa and Mpm increases from 0%to 50%,the SO_(2) emissions and conversion rates decrease.The self-desulfurization process plays an important role in the reduction of SO_(2) emissions during pressurized oxy-fuel co-combustion.The aim of this work is to advance the development and application of pressurized fluidized bed oxy-fuel co-combustion technology and promote a circular bioeconomy and carbon-free waste management for biomass derived from livestock manure.展开更多
In this work,we develop an extended dissipaton theory that generalizes the environmental couplings beyond the conventional linear and quadratic forms,enabling the treatment of ar-bitrary order of bath couplings.Ap-ply...In this work,we develop an extended dissipaton theory that generalizes the environmental couplings beyond the conventional linear and quadratic forms,enabling the treatment of ar-bitrary order of bath couplings.Ap-plying this theoretical framework to the condensed-phase non-Condon spectroscopy,we demonstrate the in-terplay of anharmonicity,non-Con-don and solvent effects on optical spectra,where the higher-order cou-plings arise from the anharmonicity of nuclear potential surface of the excited state.Precise simulations are carried out with high efficiency on linear absorption spectra involving the above mentioned correlated effects.We exhibit how an anharmonic potential modulates the vibronic feature,offering insights into the role of nonlinear environmental couplings in spectroscopic signatures and exemplifying the success of the extended dissipaton formalism as an exact and efficient method for higher-or-der bath couplings.展开更多
Ni-based superalloys are one of the most important materials employed in high-temperature applications within the aerospace and nuclear energy industries and in gas turbines due to their excellent corrosion,radiation,...Ni-based superalloys are one of the most important materials employed in high-temperature applications within the aerospace and nuclear energy industries and in gas turbines due to their excellent corrosion,radiation,fatigue resistance,and high-temperature strength.Linear friction welding(LFW)is a new joining technology with near-net-forming characteristics that can be used for the manu-facture and repair of a wide range of aerospace components.This paper reviews published works on LFW of Ni-based superalloys with the aim of understanding the characteristics of frictional heat generation and extrusion deformation,microstructures,mechanical proper-ties,flash morphology,residual stresses,creep,and fatigue of Ni-based superalloy weldments produced with LFW to enable future optim-um utilization of the LFW process.展开更多
AIM:To explore the effect of visual perception learning software training(VPT)on binocular visual function reconstruction in children with intermittent exotropia after strabismus surgery.METHODS:Ninety children with i...AIM:To explore the effect of visual perception learning software training(VPT)on binocular visual function reconstruction in children with intermittent exotropia after strabismus surgery.METHODS:Ninety children with intermittent exotropia admitted to our hospital from June 2018 to December 2018 were included,and randomly divided into VPT and control groups.Children in the control group received basic binocular vision training,while those in the VPT group received VPT after strabismus surgery.Tertiary visual function,visual perception function,Newcastle Control Score(NCS),and ocular position retraction rate were compared at 3 and 12mo after the surgery.RESULTS:At 3 and 12mo after the surgery,the proportion of simultaneous perception,binocular fusion version and binocular stereo vision in the VPT group was conspicuously higher than that in the control group(P<0.05).After the vision training,the binocular visual perception functions of children in both groups were significantly improved compared with that before training(P<0.05).Interestingly,the grating sharpness,texture perception and texture motion perception in the VPT group were dramatically better than control group(P<0.01).The NCS in the VPT group was significantly lower than that in the control group(P<0.05).The ocular position retraction rate in the VPT group was significantly lower than that in the control group at 12mo(8.89%vs 26.67%,P=0.03).CONCLUSION:VPT effectively promotes binocular visual function reconstruction in intermittent exotropia children after strabismus surgery and reduces the strabismus severity and ocular position retraction rate.展开更多
Linear Friction Welding(LFW)technology was used to realize the welding of GH4169 superalloy,and the effect of welding parameters on the microstructure,mechanical properties and corrosion behavior of the joint was anal...Linear Friction Welding(LFW)technology was used to realize the welding of GH4169 superalloy,and the effect of welding parameters on the microstructure,mechanical properties and corrosion behavior of the joint was analyzed.The results show that there is a positive correlation between the weld hardness and the tensile strength.With the gradual increase of heat input and welding pressure,the joint quality is gradually improved,but the heat affected zone is not significantly increased.The smaller the grain size of the weld,the higher the strength and plasticity of the joint.With the increase of the joint shortening amount,the corrosion resistance of the weld first gradually increases.However,when the shortening reaches a certain level,the corrosion resistance of the joint becomes little changed.With the increase of solution temperature,the corrosion current density increases and the polarization impedance decreases.The higher the corrosion temperature,the worse the corrosion resistance of the joint.There is no significant correlation between the joint strength and the corrosion resistance.The corrosion resistance of the joint can be enhanced without changing the joint mechanical properties by reducing the welding frequency and amplitude or increasing the welding pressure.展开更多
Hard carbon stands out as the most promising candidate for anodes in sodium-ion battery.Nevertheless,addressing the challenges of low initial Coulombic efficiency and rate performance is crucial for practical applicat...Hard carbon stands out as the most promising candidate for anodes in sodium-ion battery.Nevertheless,addressing the challenges of low initial Coulombic efficiency and rate performance is crucial for practical applications.In this study,we employed a dimensionally designed approach,using six different biomass precursors,to preserve their inherent fine hierarchical morphological structures and appearances during the synthesis of selfsupporting carbon materials.Benefiting from its low-tortuosity structure that facilitates electron and ion transport,as well as its surface-enriched C=O functional groups and significant closed micropore areas,the obtained carbon material exhibits excellent electrochemical performance in sodium-ion storage,demonstrated by finite element simulation.Notably,the carbonized basswood exhibited a remarkable initial Coulombic efficiency of up to 92.4%and demonstrated outstanding rate performance,achieving a capacity of 223.3 mAh·g^(-1)at a high current density of2 A·g^(-1).In addition,thorough investigation was conducted on the influence of microstructure on the sodium storage behavior of hard carbon.Ex situ X-ray diffraction(XRD)was used to confirm that the capacity in the plateau region originates from interlayer insertion and closed-pore filling,which is consistent with the results obtained from smallangle X-ray scattering.These findings underscore the immense potential of leveraging surface functionalization and structural design to bolster the performance of hard carbon,paving the way for promising future advancements in this field.展开更多
Mobile location-based services(MLBS)refer to services around geographic location data.Mobile terminals use wireless communication networks(or satellite positioning systems)to obtain users’geographic location coordina...Mobile location-based services(MLBS)refer to services around geographic location data.Mobile terminals use wireless communication networks(or satellite positioning systems)to obtain users’geographic location coordinate information based on spatial databases and integrate with other information to provide users with required location-related services.The development of systems based on MLBS has significance and practical value.In this paper a visualization management information system for personnel in major events based on microservices,namely MEPMIS,is designed and implemented by using MLBS.The system consists of a server and a client app,and it has some functions including map search and query,personnel positioning and scheduling,location management,messaging,and location service.Managers of the events can quickly search and locate the staff on the specific area of the map in real-time,and make broadcasting messages to the staff,and manage the staff.The client app is developed on the Android system,by which staff users can send the positions information to the server timely.The client users can search fuzzily near their peers and list their locations,and also call near peers through sending messages or query the history record of staff locations.In the design of the system,several new proposed techniques,including visual annotation method for overlapping locations,correcting trajectory drift algorithm,microservices-based overall system architecture methodology and other new techniques,which are applied to the implementation of the system.Also,HTML5,JQuery,MLBS APIs(Application Program Interfaces)related programming techniques have been used and combined with loading Ajax asynchronously and Json data encapsulation,map marker optimization techniques,that can improve the positioning accuracy and the performance of the system.The developed system with practical functions can enhance the efficiencies of the organization and management of major events.展开更多
GH4169 joints manufactured by Linear Friction Welding(LFW)are subjected to tensile test and stair-case method to evaluate the High Cycle Fatigue(HCF)performance at 650℃.The yield and ultimate tensile strengths are 58...GH4169 joints manufactured by Linear Friction Welding(LFW)are subjected to tensile test and stair-case method to evaluate the High Cycle Fatigue(HCF)performance at 650℃.The yield and ultimate tensile strengths are 582 MPa and 820 MPa,respectively.The HCF strength of joint reaches 400 MPa,which is slightly lower than that of Base Metal(BM),indicating reliable quality of this type of joint.The microstructure observation results show that all cracks initiate at the inside of specimens and transfer into deeper region with decrease of external stress,and the crack initiation site is related with microhardness of matrix.The Electron Backscattered Diffraction(EBSD)results of the observed regions with different distances to fracture show that plastic deformation plays a key role in HCF,and the Schmid factor of most grains near fracture exceeds 0.4.In addition,the generation of twins plays a vital role in strain concentration release and coordinating plastic deformation among grains.展开更多
Lung cancer, the leading cause of cancer deaths worldwide and in China, has a 19.7% five-year survival rate due to terminal-stage diagnosis^([1-3]).Although low-dose computed tomography(CT) screening can reduce mortal...Lung cancer, the leading cause of cancer deaths worldwide and in China, has a 19.7% five-year survival rate due to terminal-stage diagnosis^([1-3]).Although low-dose computed tomography(CT) screening can reduce mortality, high false positive rates can create economic and psychological burdens.展开更多
Rate of penetration(ROP)is the key factor affecting the drilling cycle and cost,and it directly reflects the drilling efficiency.With the increasingly complex field data,the original drilling parameter optimization me...Rate of penetration(ROP)is the key factor affecting the drilling cycle and cost,and it directly reflects the drilling efficiency.With the increasingly complex field data,the original drilling parameter optimization method can't meet the needs of drilling parameter optimization in the era of big data and artificial intelligence.This paper presents a drilling parameter optimization method based on big data of drilling,which takes machine learning algorithms as a tool.First,field data is pre-processed according to the characteristics of big data of drilling.Then a formation clustering model based on unsupervised learning is established,which takes sonic logging,gamma logging,and density logging data as input.Formation clusters with similar stratum characteristics are decided.Aiming at improving ROP,the formation clusters are input into the ROP model,and the mechanical parameters(weight on bit,revolution per minute)and hydraulic parameters(standpipe pressure,flow rate)are optimized.Taking the Southern Margin block of Xinjiang as an example,the MAPE of prediction of ROP after clustering is decreased from 18.72%to 10.56%.The results of this paper provide a new method to improve drilling efficiency based on big data of drilling.展开更多
In recent years,various highly pathogenic viruses have spread worldwide,posing serious threats to human life and property,thus creating an urgent demand for antibacterial structural materials.In this study,we develope...In recent years,various highly pathogenic viruses have spread worldwide,posing serious threats to human life and property,thus creating an urgent demand for antibacterial structural materials.In this study,we developed two types of antibacterial medium-entropy alloys (MEAs):as-cast (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(88-x)Cu_(12)Ag_(x)(x=2,4 at%)(which do not require antibacterial aging heat treatment) and heat-treated (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(99.5-x)Cu_(x)Ag_(0.5)(x=2,4 at%)(abbreviated as CuxAg0.5 and Cu12Agx).Both MEA s exhibit in transformation-induced plasticity (TRIP) and twinning-induced plasticity effects,demonstrating outstanding mechanical properties.Compared to 304 stainless steels,these ME As exhibit superior corrosion resistance,with the Cu2Ag0.5alloy performing the best,exhibiting a corrosion current density of 1.022 A·cm^(-2)and a corrosion potential of-0.297 VSCE.The antibacterial rate of the MEAs reached99.9%after 24 h of interaction with Escherichia coli and Staphylococcus aureus,with Cu 12Ag2 achieving 99.9%antimicrobial activity within 6 h,indicating a shorter activation time for antibacterial activity.According to firstprinciples calculations of state density,work function,and surface energy,Cu12Ag2 demonstrated the highest ion release capability,with a work function of 3.7 eV and surface energy of 1.9 J·m^(-2).The electrostatic adsorption of the Xanthium sibiricum bionic structure,characterized by a nanoscale spherical phase within the antibacterial phase with a size less than 350 nm,promotes ion penetration into bacterial cells,enhancing the synergistic effects of ionic,electronic,and catalytic antibacterial mechanisms.This study provides a new approach for designing high-performance alloys that integrate functional and structural properties,offering broad-spectrum,efficient antibacterial applications under load-bearing conditions.展开更多
基金supported by National Natural Science Foundation of China(Nos.32271791,32171709 and 22475053)Hunan Provincial Natural Science Foundation of China(No.2024JJ7643)Natural Science Foundation of Shanghai(No.22ZR1404100).
文摘Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.
基金supported by the National Natural Science Foundation of China(Nos.52074228,52305420 and 51875470)the Practice and Innovation Funds for Graduate Students of Northwestern Polytechnical University,China(No.PF2024053)the Xi’an Beilin District Science and Technology Planning Project,China(No.GX2349).
文摘The pre-weld heat treatment was carried out to obtain different initial microstructures of the GH4169 superalloy,and then Linear Friction Welding(LFW)was performed.The effect of the pre-weld heat treatment on the microstructure evolution and mechanical properties of the joint was analyzed,and the joint electrochemical corrosion behavior as well as the hot corrosion behavior was studied.The results show that the joint hardness of Base Metal(BM)increases after pre-weld heat treatment,and the strengthening phasesγ′andγ″further precipitate.However,the precipitation phases dissolve significantly in the Weld Zone(WZ)due to the thermal process of LFW.The corrosion resistance in BM is reduced after the pre-weld heat treatment,while it is similar in WZ with a slight decrease.The surface morphology of the BM and WZ can be generally divided into a loose and porous matrix and a scattered oxide particle layer after hot corrosion.The joint cross section exhibits a Cr-depleted zone with the diffusion of Cr to form an oxide film.The corrosion product mainly consists of Fe_(2)O_(3)/Fe_(3)O_(4) as the outer layer and Cr_(2)O_(3) as the inner layer.
基金supported by the National Natural Science Foundation of China(Nos.224B2305,22373091)the Innovation Program for Quantum Science and Technology(No.2021ZD0303301)。
文摘In recent years,the study of Majorana signatures in quantum transport has become a central focus in condensed matter physics.Here,we present a rigorous and systematic derivation of the fermionic superoperator describing the open quantum dynamics of electron transport through Majorana zero modes,building on the techniques introduced in Phys.Rev.B 105,035121(2022).The numerical implementation of this superoperator is to construct its differential equivalence,the hierarchical equations of motion(HEOM).The HEOM approach describes the system-bath correlated dynamics.Furthermore,we also develop a functional derivative scheme that provides exact expressions for the transport observables in terms of the auxiliary density operators introduced in the HEOM formulation.The superoperator formalism establishes a solid theoretical foundation for analyzing key transport signatures that may uncover the unique characteristics of Majorana physics in mesoscopic systems.
基金supported by the National Natural Science Foundation of China(52306131)the Natural Science Foundation of Jiangsu Province(BK20230847)+2 种基金the Key Project of the National Natural Science Foundation of China(52336005)the Fundamental Research Funds for the Central Universities(2242024RCB0036)the Open Project Program of State Key Laboratory of Low-carbon Smart Coal-fired Power Generation and Ultra-clean Emission(D2024FK156).
文摘As a renewable energy source,the thermal conversion of poultry manure,is a promising waste treatment solution that can generate circular economic outputs such as energy and reduce greenhouse gas emissions.Currently,pressurized gasification of poultry manure is still a novel research field,especially when combined with a novel technological route of oxy-fuel gasification.Oxy-fuel gasification is a newly proposed and promising gasification technology for power generation that facilitates future carbon capture and storage.In this work,based on a commercially operated industrial-scale chicken manure gasification power plant in Singapore,we presented an interesting first exploration of the coupled pressurization technology for oxy-fuel gasification of poultry manure using CFD numerical simulation,analyzed the effects of pressure and oxygen enrichment concentration as well as the coupling mechanism between them,and discussed the conversion and emission of nitrogen-and sulfur-containing pollutants.The results indicate that under oxy-fuel gasification condition(Oxy-30,i.e.,30%O_(2)/70%CO_(2)),as the pressure increases from 0.1 to 0.5 MPa,the CO concentration in the syngas increases slightly,the H_(2)concentration increases to approximately 25%,and the CH4 concentration(less than 1%)decreases,resulting in an increase in the calorific value of syngas from 5.2 to 5.6 MJ·m^(-3).Compared to atmospheric pressure conditions,a relatively higher oxygen-enriched concentration interval(Oxy-40 to Oxy-50)under pressurized conditions is advantageous for autothermal gasification.Pressurization increases NO precursors production and also promotes homogeneous and heterogeneous reduction of NO,and provides favorable conditions for self-desulfurization.This work offers reference for the realization of a highly efficient and low-energy-consumption thermochemical treatment of livestock manure coupled with negative carbon emission technology.
基金supported by the National Natural Science Foundation of China(52306131)the Natural Science Foundation of Jiangsu Province(BK20230847)+1 种基金the Key Project of the National Natural Science Foundation of China(52336005)the Open Project Program of State Key Laboratory of Low-carbon Smart Coalfired Power Generation and Ultra-clean Emission(D2024FK156).
文摘Pressurized oxy-fuel combustion is a next-generation and low-cost carbon capture technology with industrial application potential.This work presents an innovative research exploration-coupling coal pressurized fluidized bed oxy-fuel combustion technology with energy utilization of poultry manure as a renewable and carbon-neutral fuel,in order to capture CO_(2)and solve the problem of poultry manure treatment simultaneously.In this study,a stable co-combustion of coal and chicken manure in a laboratory-scale pressurized fluidized bed under typical oxy-fuel condition(30%O_(2)/70%CO_(2),i.e.,Oxy-30)is achieved.The key parameters including the combustion pressure(0.1-0.5 MPa)and chicken-manure proportion(0%to 100%)and their impacts on fundamental combustion efficiency,carbon conversion,nitrogen and sulfur pollutant emissions,and residue ash characteristics have been investigated.The result show that pressurization favors an increase in the CO_(2)enrichment concentration and fluidized bed combustion efficiency.During co-combustion under 0.1 and 0.3 MPa,the CO_(2)concentration in the flue gas is the highest when the chicken manure blending ratio(M_(pm))is 25%.Although the NO emissions fluctuate and even increase as Mpm increases,the co-combustion of coal and chicken manure exhibits a synergistic effect in reducing NO conversion rate(XNO).The effect of pressurization on reducing NO emission is significant,XNO at M_(pm)=25%decreasing from 15%to 5%as the pressure(P)increases from 0.1 to 0.5 MPa.As P increases from 0.1 to 0.5 MPa and Mpm increases from 0%to 50%,the SO_(2) emissions and conversion rates decrease.The self-desulfurization process plays an important role in the reduction of SO_(2) emissions during pressurized oxy-fuel co-combustion.The aim of this work is to advance the development and application of pressurized fluidized bed oxy-fuel co-combustion technology and promote a circular bioeconomy and carbon-free waste management for biomass derived from livestock manure.
基金supported by the National Natural Sci-ence Foundation of China(Nos.22373091,224B2305,and 22573099).
文摘In this work,we develop an extended dissipaton theory that generalizes the environmental couplings beyond the conventional linear and quadratic forms,enabling the treatment of ar-bitrary order of bath couplings.Ap-plying this theoretical framework to the condensed-phase non-Condon spectroscopy,we demonstrate the in-terplay of anharmonicity,non-Con-don and solvent effects on optical spectra,where the higher-order cou-plings arise from the anharmonicity of nuclear potential surface of the excited state.Precise simulations are carried out with high efficiency on linear absorption spectra involving the above mentioned correlated effects.We exhibit how an anharmonic potential modulates the vibronic feature,offering insights into the role of nonlinear environmental couplings in spectroscopic signatures and exemplifying the success of the extended dissipaton formalism as an exact and efficient method for higher-or-der bath couplings.
基金supported by the National Natural Science Foundation of China(Nos.52074228,52305420,and 51875470)the China Postdoctoral Science Foundation(No.2023M742830)the Xi’an Beilin District Science and Technology Planning Project,China(No.GX2349).
文摘Ni-based superalloys are one of the most important materials employed in high-temperature applications within the aerospace and nuclear energy industries and in gas turbines due to their excellent corrosion,radiation,fatigue resistance,and high-temperature strength.Linear friction welding(LFW)is a new joining technology with near-net-forming characteristics that can be used for the manu-facture and repair of a wide range of aerospace components.This paper reviews published works on LFW of Ni-based superalloys with the aim of understanding the characteristics of frictional heat generation and extrusion deformation,microstructures,mechanical proper-ties,flash morphology,residual stresses,creep,and fatigue of Ni-based superalloy weldments produced with LFW to enable future optim-um utilization of the LFW process.
文摘AIM:To explore the effect of visual perception learning software training(VPT)on binocular visual function reconstruction in children with intermittent exotropia after strabismus surgery.METHODS:Ninety children with intermittent exotropia admitted to our hospital from June 2018 to December 2018 were included,and randomly divided into VPT and control groups.Children in the control group received basic binocular vision training,while those in the VPT group received VPT after strabismus surgery.Tertiary visual function,visual perception function,Newcastle Control Score(NCS),and ocular position retraction rate were compared at 3 and 12mo after the surgery.RESULTS:At 3 and 12mo after the surgery,the proportion of simultaneous perception,binocular fusion version and binocular stereo vision in the VPT group was conspicuously higher than that in the control group(P<0.05).After the vision training,the binocular visual perception functions of children in both groups were significantly improved compared with that before training(P<0.05).Interestingly,the grating sharpness,texture perception and texture motion perception in the VPT group were dramatically better than control group(P<0.01).The NCS in the VPT group was significantly lower than that in the control group(P<0.05).The ocular position retraction rate in the VPT group was significantly lower than that in the control group at 12mo(8.89%vs 26.67%,P=0.03).CONCLUSION:VPT effectively promotes binocular visual function reconstruction in intermittent exotropia children after strabismus surgery and reduces the strabismus severity and ocular position retraction rate.
基金supported by the research fund of the National Natural Science Foundation of China(Nos.52305420,52074228,51875470)the China Postdoctoral Science Foundation(No.2023M742830)the Xi’an Beilin District Science and Technology Planning Project,China(No.GX2349).
文摘Linear Friction Welding(LFW)technology was used to realize the welding of GH4169 superalloy,and the effect of welding parameters on the microstructure,mechanical properties and corrosion behavior of the joint was analyzed.The results show that there is a positive correlation between the weld hardness and the tensile strength.With the gradual increase of heat input and welding pressure,the joint quality is gradually improved,but the heat affected zone is not significantly increased.The smaller the grain size of the weld,the higher the strength and plasticity of the joint.With the increase of the joint shortening amount,the corrosion resistance of the weld first gradually increases.However,when the shortening reaches a certain level,the corrosion resistance of the joint becomes little changed.With the increase of solution temperature,the corrosion current density increases and the polarization impedance decreases.The higher the corrosion temperature,the worse the corrosion resistance of the joint.There is no significant correlation between the joint strength and the corrosion resistance.The corrosion resistance of the joint can be enhanced without changing the joint mechanical properties by reducing the welding frequency and amplitude or increasing the welding pressure.
基金financially supported by the National Natural Science Foundation of China(Nos.32171709 and 32271791)China Postdoctoral Science Foundation(No.2023M743972)。
文摘Hard carbon stands out as the most promising candidate for anodes in sodium-ion battery.Nevertheless,addressing the challenges of low initial Coulombic efficiency and rate performance is crucial for practical applications.In this study,we employed a dimensionally designed approach,using six different biomass precursors,to preserve their inherent fine hierarchical morphological structures and appearances during the synthesis of selfsupporting carbon materials.Benefiting from its low-tortuosity structure that facilitates electron and ion transport,as well as its surface-enriched C=O functional groups and significant closed micropore areas,the obtained carbon material exhibits excellent electrochemical performance in sodium-ion storage,demonstrated by finite element simulation.Notably,the carbonized basswood exhibited a remarkable initial Coulombic efficiency of up to 92.4%and demonstrated outstanding rate performance,achieving a capacity of 223.3 mAh·g^(-1)at a high current density of2 A·g^(-1).In addition,thorough investigation was conducted on the influence of microstructure on the sodium storage behavior of hard carbon.Ex situ X-ray diffraction(XRD)was used to confirm that the capacity in the plateau region originates from interlayer insertion and closed-pore filling,which is consistent with the results obtained from smallangle X-ray scattering.These findings underscore the immense potential of leveraging surface functionalization and structural design to bolster the performance of hard carbon,paving the way for promising future advancements in this field.
基金The work is supported by the Tianjin Planning Project of Philosophy and Social Science under Grant No.TJGL20-018 for Dr.L.J.Hou of Tianjin Normal University,China。
文摘Mobile location-based services(MLBS)refer to services around geographic location data.Mobile terminals use wireless communication networks(or satellite positioning systems)to obtain users’geographic location coordinate information based on spatial databases and integrate with other information to provide users with required location-related services.The development of systems based on MLBS has significance and practical value.In this paper a visualization management information system for personnel in major events based on microservices,namely MEPMIS,is designed and implemented by using MLBS.The system consists of a server and a client app,and it has some functions including map search and query,personnel positioning and scheduling,location management,messaging,and location service.Managers of the events can quickly search and locate the staff on the specific area of the map in real-time,and make broadcasting messages to the staff,and manage the staff.The client app is developed on the Android system,by which staff users can send the positions information to the server timely.The client users can search fuzzily near their peers and list their locations,and also call near peers through sending messages or query the history record of staff locations.In the design of the system,several new proposed techniques,including visual annotation method for overlapping locations,correcting trajectory drift algorithm,microservices-based overall system architecture methodology and other new techniques,which are applied to the implementation of the system.Also,HTML5,JQuery,MLBS APIs(Application Program Interfaces)related programming techniques have been used and combined with loading Ajax asynchronously and Json data encapsulation,map marker optimization techniques,that can improve the positioning accuracy and the performance of the system.The developed system with practical functions can enhance the efficiencies of the organization and management of major events.
基金supported by the National Natural Science Foundation of China(Nos.52074228,52305420,and 51875470)the China Postdoctoral Science Foundation(No.2023M742830)。
文摘GH4169 joints manufactured by Linear Friction Welding(LFW)are subjected to tensile test and stair-case method to evaluate the High Cycle Fatigue(HCF)performance at 650℃.The yield and ultimate tensile strengths are 582 MPa and 820 MPa,respectively.The HCF strength of joint reaches 400 MPa,which is slightly lower than that of Base Metal(BM),indicating reliable quality of this type of joint.The microstructure observation results show that all cracks initiate at the inside of specimens and transfer into deeper region with decrease of external stress,and the crack initiation site is related with microhardness of matrix.The Electron Backscattered Diffraction(EBSD)results of the observed regions with different distances to fracture show that plastic deformation plays a key role in HCF,and the Schmid factor of most grains near fracture exceeds 0.4.In addition,the generation of twins plays a vital role in strain concentration release and coordinating plastic deformation among grains.
基金supported by the National Natural Science Foundation of China(grant numbers 82204127 and 72204172)。
文摘Lung cancer, the leading cause of cancer deaths worldwide and in China, has a 19.7% five-year survival rate due to terminal-stage diagnosis^([1-3]).Although low-dose computed tomography(CT) screening can reduce mortality, high false positive rates can create economic and psychological burdens.
基金financially supported by Sichuan Science and Technology Program(No.2025ZNSFSC0373)National Natural Science foundation of China(Grant No.52104006)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(Grant No.2020CX040202)。
文摘Rate of penetration(ROP)is the key factor affecting the drilling cycle and cost,and it directly reflects the drilling efficiency.With the increasingly complex field data,the original drilling parameter optimization method can't meet the needs of drilling parameter optimization in the era of big data and artificial intelligence.This paper presents a drilling parameter optimization method based on big data of drilling,which takes machine learning algorithms as a tool.First,field data is pre-processed according to the characteristics of big data of drilling.Then a formation clustering model based on unsupervised learning is established,which takes sonic logging,gamma logging,and density logging data as input.Formation clusters with similar stratum characteristics are decided.Aiming at improving ROP,the formation clusters are input into the ROP model,and the mechanical parameters(weight on bit,revolution per minute)and hydraulic parameters(standpipe pressure,flow rate)are optimized.Taking the Southern Margin block of Xinjiang as an example,the MAPE of prediction of ROP after clustering is decreased from 18.72%to 10.56%.The results of this paper provide a new method to improve drilling efficiency based on big data of drilling.
基金financially supported by the National Natural Science Foundation of China(Nos.12404230 and 52061027)Zhejiang Provincial Natural Science Foundation of China(No.LY23E010002)+2 种基金the Science and Technology Program Project of Gansu Province(Nos.22YF7GA155 and 22ZD6GA008)Lanzhou Youth Science and Technology Talent Innovation Project(No.2023-QN-91)the support from Gansu Provincial Computing Center
文摘In recent years,various highly pathogenic viruses have spread worldwide,posing serious threats to human life and property,thus creating an urgent demand for antibacterial structural materials.In this study,we developed two types of antibacterial medium-entropy alloys (MEAs):as-cast (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(88-x)Cu_(12)Ag_(x)(x=2,4 at%)(which do not require antibacterial aging heat treatment) and heat-treated (Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(99.5-x)Cu_(x)Ag_(0.5)(x=2,4 at%)(abbreviated as CuxAg0.5 and Cu12Agx).Both MEA s exhibit in transformation-induced plasticity (TRIP) and twinning-induced plasticity effects,demonstrating outstanding mechanical properties.Compared to 304 stainless steels,these ME As exhibit superior corrosion resistance,with the Cu2Ag0.5alloy performing the best,exhibiting a corrosion current density of 1.022 A·cm^(-2)and a corrosion potential of-0.297 VSCE.The antibacterial rate of the MEAs reached99.9%after 24 h of interaction with Escherichia coli and Staphylococcus aureus,with Cu 12Ag2 achieving 99.9%antimicrobial activity within 6 h,indicating a shorter activation time for antibacterial activity.According to firstprinciples calculations of state density,work function,and surface energy,Cu12Ag2 demonstrated the highest ion release capability,with a work function of 3.7 eV and surface energy of 1.9 J·m^(-2).The electrostatic adsorption of the Xanthium sibiricum bionic structure,characterized by a nanoscale spherical phase within the antibacterial phase with a size less than 350 nm,promotes ion penetration into bacterial cells,enhancing the synergistic effects of ionic,electronic,and catalytic antibacterial mechanisms.This study provides a new approach for designing high-performance alloys that integrate functional and structural properties,offering broad-spectrum,efficient antibacterial applications under load-bearing conditions.
