Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without ...Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without the dependence of antibiotic.Methods:Herein,we prepared ultrasound/magnetic field-responsive ferroferric oxide nanoparticles(Fe_(3)O_(4))/glucose oxidase microbubbles(FGMB)to form a cascade catalytic system for effective removing methicillin-resistant Staphylococcus aureus biofilms.FGMB were prepared through interfacial self-assembly of Fe_(3)O_(4) nanoparticles(NPs)and glucose oxidase(GOx)at the gas-liquid interface stabilized by surfactants.Under ultrasound/magnetic field stimulation,FGMB disrupted biofilm architecture through microbubble collapse-induced microjets and magnetically driven displacement.Simultaneously,ultrasound-triggered rupture of FGMB released GOx and Fe_(3)O_(4) NPs.Glucose can be oxidized by GOx to generate gluconic acid and hydrogen peroxide which was subsequently catalyzed into hydroxyl radicals by Fe_(3)O_(4) NPs,enabling chemical eradication of biofilm-embedded bacteria.Results:Optical microscopy images demonstrated that FGMB have spherical structure with average size of approximately 17μm.FGMB showed a 65.4%decrease in methicillin-resistant Staphylococcus aureus biofilm biomass and 1.1 log bacterial inactivation efficiency(91.2%),suggesting effective biofilm elimination.In vitro experimental results also indicate that FGMB have good biocompatibility.Conclusion:This antibiofilm strategy integrated dual modes of physical biofilm disruption with chemical bacteria-killing shows great potential as a versatile,non-resistant strategy for bacterial biofilm elimination.展开更多
Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is p...Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is proposed.The electric field applied between the template and the substrate drives the contact,tilting,filling,and holding processes.By accurately controlling the introduced included angle between the flexible template and the substrate,tilted nanostructures with a controllable angle are imprinted onto the substrate,although they are vertical on the template.By flexibly adjusting the electric field intensity and the included angle,large-area uniform-tilted,gradient-tilted,and high-angle-tilted nanostructures are fabricated.In contrast to traditional replication,the morphology of the nanoimprinting structure is extended to customized control.This work provides a cost-effective,efficient,and versatile technology for the fabrication of various large-area tilted metasurface structures.As an illustration,a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays,demonstrating superior imaging quality.展开更多
Peroxymonosulfate(PMS)-based advanced oxidation processes(AOPs)are an effective way to remove emerging contaminants(ECs)from water.The catalytic process involving PMS is hindered by the suboptimal electron trans-fer e...Peroxymonosulfate(PMS)-based advanced oxidation processes(AOPs)are an effective way to remove emerging contaminants(ECs)from water.The catalytic process involving PMS is hindered by the suboptimal electron trans-fer efficiency of current catalysts,the further application of AOPs technology is limited.Here,it is proposed that the interfacial electric field can be controlled by bor(B)-doped FeNC catalysts,which shows significant advantages in the efficient generation,release and participation of reactive oxygen species(ROS)in the reaction.The super exchange interaction between Fe sites and N and B sites is realized through the directional transfer of electrons in the interfacial electric field,which ensures the high efficiency and stability of the PMS catalytic process.B doping increases the d orbitals distribution at Fermi level,which facilitates enhanced electron transition activity,thereby promoting the effective generation of (1)^O_(2).At the same time,orbital hybridization causes the center of the d band to move to a lower energy level,which not only contributes to the desorption process of (1)^O_(2),but also accelerates its release.In addition,B-doping also improved the adsorption capacity of organic pollutants and shortened the migration distance of ROS,thereby significantly improving the degradation efficiency of ECs.The B-doping strategy outlined offers a novel approach to the development of FeNC catalysts,it lays a theoretical foundation and offers technical insights for the integration of PMS/AOPs technology in the ECs management.展开更多
A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible...A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore,and then uses the hydraulic jet technology to induce multiple fractures to fracture.Finally,the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string,to realize the efficient development of the remaining reserves among the wells.The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing.The flexible sidetracking horizontal well drilling includes three aspects:flexible drill pipe structure and material optimization,drilling technology,and sealed coring tool.The sidetracking horizontal well fracturing includes two aspects:fracturing scheme optimization,fracturing tools and implementation process optimization.The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing,China.The results show that by changing well type and reducing row spacing of oil and water wells,the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells.It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.展开更多
Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these i...Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these internal magnetic fields accurately,data selection based on specific criteria is often employed to minimize the influence of rapidly changing current systems in the ionosphere and magnetosphere.However,the quantitative impact of various data selection criteria on internal geomagnetic field modeling is not well understood.This study aims to address this issue and provide a reference for constructing and applying geomagnetic field models.First,we collect the latest MSS-1 and Swarm satellite magnetic data and summarize widely used data selection criteria in geomagnetic field modeling.Second,we briefly describe the method to co-estimate the core,crustal,and large-scale magnetospheric fields using satellite magnetic data.Finally,we conduct a series of field modeling experiments with different data selection criteria to quantitatively estimate their influence.Our numerical experiments confirm that without selecting data from dark regions and geomagnetically quiet times,the resulting internal field differences at the Earth’s surface can range from tens to hundreds of nanotesla(nT).Additionally,we find that the uncertainties introduced into field models by different data selection criteria are significantly larger than the measurement accuracy of modern geomagnetic satellites.These uncertainties should be considered when utilizing constructed magnetic field models for scientific research and applications.展开更多
Many planets,including the Earth,possess a global dipolar magnetic field.To diagnose the interior source of the dipolar field,researchers usually adopt a dipole model consisting of six parameters to fit the observed d...Many planets,including the Earth,possess a global dipolar magnetic field.To diagnose the interior source of the dipolar field,researchers usually adopt a dipole model consisting of six parameters to fit the observed dataset of the magnetic field.However,the simultaneous fitting of these parameters often leads to multiple local optimal parameter sets.To address this fitting dilemma,Rong ZJ et al.(2021)recently developed a current loop model.This technique can successively separate and invert the loop parameters.Here,we further show how this technique can be reduced and modified to fit a dipole model.Applications of this reduced technique to the International Geomagnetic Reference Field model and the Martian crustal field model highlight its unique ability to diagnose both the planetary global dipolar field and the local crustal field anomaly,a capability that sets it apart from existing methods.The potential impact of this technique on geomagnetism and planetary magnetism is significant,given its unique ability to diagnose both the planetary global dipolar field and the local crustal field anomaly.展开更多
A robust spontaneous exchange bias effect after zero-field cooling was observed in Co_(2)Sn_(1-x)Cr_(x)O_(4)system,which was driven by the transition from superspin-glass to superferromagnetic domain embedded in the f...A robust spontaneous exchange bias effect after zero-field cooling was observed in Co_(2)Sn_(1-x)Cr_(x)O_(4)system,which was driven by the transition from superspin-glass to superferromagnetic domain embedded in the ferrimagnetic matrix.Additionally,the exchange bias effect is gradually pronounced with the positive increase in the cooling field,known as the conventional exchange bias effect.However,as the cooling field gradually decreases and transits from positive to negative,the exchange bias effect can robustly remain positive in the low-negative-field region until the cooling field increases to be sufficiently large in the negative direction.展开更多
Earthquakes are caused directly by the motion of the stress field,therefore,observing the stress field is significant.Experiments on the relationships among wave velocity,stress factors,and faults show that the wave v...Earthquakes are caused directly by the motion of the stress field,therefore,observing the stress field is significant.Experiments on the relationships among wave velocity,stress factors,and faults show that the wave velocity of rock media under stable stress fields corresponds one-to-one with stress factors.Therefore,the wave velocity gradient can indicate the direction of stress vector,and the gradient divergence can indicate the strength of the stress field.To verify the results,considering the limitations of wave velocity measurement in solid crustal media,two quantities,namely the apparent wave velocity and Poisson ratios relating to wave velocity,were used to refl ect the stress field state.The seismic data of the Tangshan and Luzhou regions were studied separately.The calculated apparent wave velocity and Poisson ratios were interpolated to achieve regional data gridding.The gradients and the gradient divergences of the apparent wave velocity and Poisson ratio fields in the two regions were analyzed,and it was found that their spatial distribution in the same region was the same.They are believed to refl ect the vertical projection of the stress direction vector and strength on the surface in the stress field,consistent with the experimental results.Whether it can eff ectively refl ect the stress field requires further analysis of the specific situation of the local medium and the movement mode of the stress field.展开更多
Typhoon Chaba was the most intense typhoon to strike western Guangdong since Typhoon Mujigae in 2015.According to the National Disaster Reduction Center of China,in the morning of July 7,2022,over 1.5 million people i...Typhoon Chaba was the most intense typhoon to strike western Guangdong since Typhoon Mujigae in 2015.According to the National Disaster Reduction Center of China,in the morning of July 7,2022,over 1.5 million people in Guangdong,Guangxi,and Hainan were affected by Typhoon Chaba.The typhoon also caused the“Fukui 001”ship to be in distress in the waters near Yangjiang,Guangdong,on July 2,resulting in big casualties.Studies have indicated that wind field forecast for Typhoon Chaba was not accurate.To better simulate typhoon events and assess their impacts,we proposed the use of a model wind field(Fujita-Takahashi)integrated with the Copernicus Marine and Environmental Monitoring Service(CMEMS)data to reconstruct effectively the overall wind field of Typhoon Chaba.The simulation result aligns well with the observations,particularly at the Dashu Island Station,showing consistent trends in wind speed changes.However,certain limitations were noted.The model shows that the attenuation of wind speed is slower when typhoon neared land than that observed,indicating that the model has a high simulation accuracy for the ocean wind field,but may have deviations near coastal areas.The result is accurate for open sea but deviated for near land due to the land friction effect.Therefore,we recommend to adjust the model to improve the accuracy for near coasts.展开更多
The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan h...The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan highsulfidation Cu-Au deposit,the Luoboling porphyry Cu-Mo deposit,the transitional style Cu deposit(Longjiangting and Wuziqilong)and the Yueyang low-sulfidation Agpolymetallic deposit(Zhang,2013;Zhang et al.,2003)展开更多
By combining data from the Challenging Minisatellite Payload(CHAMP),Swarm-A,and newest Macao Science Satellite-1(MSS-1) missions,we constructed a lithospheric magnetic field model up to spherical harmonic degree N = 1...By combining data from the Challenging Minisatellite Payload(CHAMP),Swarm-A,and newest Macao Science Satellite-1(MSS-1) missions,we constructed a lithospheric magnetic field model up to spherical harmonic degree N = 100.To isolate the lithospheric magnetic field signals,we utilized the latest CHAOS-8(CHAMP,Φrsted,and SAC-C 8) model and MGFM(Multisource Geomagnetic Field Model) to remove nonlithospheric sources,including the core field,magnetospheric field,ocean tidal field,and ocean circulation field.Subsequently,orbit-by-orbit processing was applied to both scalar and vector data,such as spherical harmonic high-pass filtering,singular spectrum analysis,and line leveling,to suppress noise and residual signals along the satellite tracks.With an orbital inclination of only 41°,MSS-1 effectively captures fine-scale lithospheric magnetic field signals in mid-to low-latitude regions.Its data exhibit a root mean square error of only 0.77 nT relative to the final model,confirming the high quality and utility of lithospheric field modeling.The resulting model exhibits excellent consistency with the MF7(Magnetic Field Model 7),maintaining a high correlation up to N = 90 and still exceeding 0.65 at N = 100.These results demonstrate the reliability and value of MSS-1 data in global lithospheric magnetic field modeling.展开更多
The field-reversed configuration(FRC)plasma thruster driven by rotating magnetic field(RMF),abbreviated as the RMF-FRC thruster,is a new type of electric propulsion technology that is expected to accelerate the deep s...The field-reversed configuration(FRC)plasma thruster driven by rotating magnetic field(RMF),abbreviated as the RMF-FRC thruster,is a new type of electric propulsion technology that is expected to accelerate the deep space exploration.An experimental prototype,including diagnostic devices,was designed and constructed based on the principles of the RMF-FRC thruster,with an RMF frequency of 210 kHz and a maximum peak current of 2 kA.Under the rated operating conditions,the initial plasma density was measured to be 5×10^(17)m^(-3),and increased to 2.2×10^(19)m^(-3)after the action of RMF.The coupling efficiency of RMF was about 53%,and the plasma current reached 1.9 kA.The axial magnetic field changed in reverse by 155 Gauss,successfully reversing the bias magnetic field of 60 Gauss,which verifies the formation of FRC plasma.After optimization research,it was found that when the bias magnetic field is 100 Gauss,the axial magnetic field reverse variation caused by FRC is the highest at 164 Gauss.The experimental results are discussed and strategies are proposed to improve the performance of the prototype.展开更多
The results of the study of the effect of partial substitution of Fe by Mn in the La Fe_(11.2-x)Mn_(x)Co_(0.7)Si_(1.1)system on magnetization,specific heat,magnetostriction and magnetocaloric effect are presented.Dire...The results of the study of the effect of partial substitution of Fe by Mn in the La Fe_(11.2-x)Mn_(x)Co_(0.7)Si_(1.1)system on magnetization,specific heat,magnetostriction and magnetocaloric effect are presented.Direct measurements of the adiabatic temperature change(ΔT_(ad))were carried out in alternating magnetic fields(AMF)using the magnetic field modulation method.Partial substitution of Fe atoms by Mn atoms leads to a shift in the Curie temperature(T_(C))towards lower temperatures without a noticeable deterioration in magnetic properties.A correlation was found between the structural component of the magnetocaloric effect and the stability of the frequency of theΔT_(ad)in the AMFs—an increase in the manganese concentration leads to a decrease in magnetostriction and to a lower dependence ofΔT_(ad)on the frequency of the magnetic field.Estimates of the specific cooling power Q_(C)as a function of the frequency of the AMF showed that the highest value of Q_(C)at f=20 Hz in a magnetic field of 12k Oe is 26.3 W g^(-1)and is observed for the composition with x=0.1.This value is higher than that of Gd,for which,under the same conditions,Q_(C)=21.6 W g^(-1).All the samples studied show stability of the value ofΔT_(ad)without any sign of deterioration of the effect up to 60,000cycles of switching on/off of the magnetic field of 12 k Oe.The discovered frequency and cyclic stability ofΔT_(ad)of the studied samples increase their prospects for application in magnetic cooling technology.展开更多
Seepage refers to the flow of water through porous materials.This phenomenon has a crucial role in dam,slope,excavation,tunnel,and well design.Performing seepage analysis usually is a challenging task,as one must cope...Seepage refers to the flow of water through porous materials.This phenomenon has a crucial role in dam,slope,excavation,tunnel,and well design.Performing seepage analysis usually is a challenging task,as one must cope with the uncertainty associated with the parameters such as the hydraulic conductivity in the horizontal and vertical directions that drive this phenomenon.However,at the same time,the data on horizontal and vertical hydraulic conductivities are typically scarce in spatial resolution.In this context,so-called non-traditional approaches for uncertainty quantification(such as intervals and fuzzy variables)offer an interesting alternative to classical probabilistic methods,since they have been shown to be quite effective when limited information on the governing parameters of a phenomenon is available.Therefore,the main contribution of this study is the development of a framework for conducting seepage analysis in saturated soils,where uncertainty associated with hydraulic conductivity is characterized using fuzzy fields.This method to characterize uncertainty extends interval fields towards the domain of fuzzy numbers.In fact,it is illustrated that fuzzy fields are an effective tool for capturing uncertainties with a spatial component,since they allow one to account for available physical measurements.A case study in confined saturated soil shows that with the proposed framework,it is possible to quantify the uncertainty associated with seepage flow,exit gradient,and uplift force effectively.展开更多
The angular dependence of magnetoresistance(MR)in antiferromagnetic half-Heusler HoAuSn single crystals has been systematically studied.Negative MR,as large as~99%,is observed at 9 T,is not restricted to the specific ...The angular dependence of magnetoresistance(MR)in antiferromagnetic half-Heusler HoAuSn single crystals has been systematically studied.Negative MR,as large as~99%,is observed at 9 T,is not restricted to the specific configuration of applied magnetics fields and current and can persist up to 20 K,much higher than the Ne'el temperature(T_(N)≈1.9 K).Experiments and first-principles calculations suggest that the observed large negative MR is derived from a magnetic field that reconstructs the band structure and induces a Weyl point,which changes the carrier concentration.展开更多
We investigate the energy bands,magnetism,and superconductivity of bilayer octagraphene with A-A stackingunder a perpendicular electric field.A tight-binding model is used to analyze the band structure of the system.T...We investigate the energy bands,magnetism,and superconductivity of bilayer octagraphene with A-A stackingunder a perpendicular electric field.A tight-binding model is used to analyze the band structure of the system.The doubling of the unit cell results in each band of the single layer splitting into two.We find that applyinga perpendicular electric field increases the band splitting.As the electric field strength increases,the nestingof the Fermi surface(FS)weakens,eventually disrupting the antiferromagnetic order,and bilayer octagrapheneexhibits superconductivity.Spin fluctuations can induce unconventional superconductivity with s±-wave pairing.Applying a perpendicular electric field to bilayer octagraphene parent weakens the nesting of the FS,ultimatelykilling the spin-density-wave(SDW)ordered state and transitioning it into the superconducting state,whichworks as a doping effect.We use the random-phase approximation approach to obtain the pairing eigenvaluesand pairing symmetries of the perpendicular electric field-tuned bilayer octagraphene in the weak coupling limit.By tuning the strength of the perpendicular electric field,the critical interaction strength for SDW order can bemodified,which in turn may promote the emergence of unconventional superconductivity.展开更多
As the plasma current power in tokamak devices increases,a significant number of stray magnetic fields are generated around the equipment.These stray magnetic fields can disrupt the operation of electronic power devic...As the plasma current power in tokamak devices increases,a significant number of stray magnetic fields are generated around the equipment.These stray magnetic fields can disrupt the operation of electronic power devices,particularly transformers in switched-mode power supplies.Testing flyback converters with transformers under strong background magnetic fields highlights electromagnetic compatibility(EMC)issues for such switched-mode power supplies.This study utilizes finite element analysis software to simulate the electromagnetic environment of switched-mode power supply transformers and investigates the impact of variations in different magnetic field parameters on the performance of switched-mode power supplies under strong stray magnetic fields.The findings indicate that EMC issues are associated with transformer core saturation and can be alleviated through appropriate configurations of the core size,air gap,fillet radius,and installation direction.This study offers novel solutions for addressing EMC issues in high magnetic field environments.展开更多
Nitrate(NO_(3)^(-))accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO_(3)^(-)content in intensive agricultural regions.Agricultural land-use change(ALUC),typically...Nitrate(NO_(3)^(-))accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO_(3)^(-)content in intensive agricultural regions.Agricultural land-use change(ALUC),typically accompanied by substantial alterations in nitrogen fertilizer application and irrigation practices,is an important influencing factor.This study evaluated the changes in NO_(3)^(-)accumulation and transport in the deep vadose zone(DVZ,below the root zone),and the groundwater NO_(3)^(-)content associated with ALUC from grain to vegetable fields in the North China Plain(NCP).The ALUC from grain to vegetable resulted in nitrate–nitrogen(NO_(3)^(-)-N)accumulation in DVZ increased by 235.5 kg ha^(-1)m^(-1)(163.2%)in the piedmont plain and 224.9 kg ha^(-1)m^(-1)(102.7%)in the central plain,respectively.This change accelerated downward transport velocity in the DVZ(from 0.81±0.47 to 0.89±0.55 m yr^(-1)in the piedmont plain,and from 0.24±0.12 to 0.92±0.12 m yr^(-1)in the central plain)and increased NO_(3)^(-)leaching fluxes.High transport velocity and leaching fluxes resulted in chemical N-fertilizer entering the aquifer in several areas in the piedmont plain.The impact of the agricultural activity intensity changes,accompanied by the ALUC,on groundwater quantity and quality should be considered in similar regions.展开更多
In the electroslag remelting(ESR)process,it mainly relies on thermal experiments or analysis via mechanistic models to realize the physical fields simulation of the electromagnetic field and temperature field coupled ...In the electroslag remelting(ESR)process,it mainly relies on thermal experiments or analysis via mechanistic models to realize the physical fields simulation of the electromagnetic field and temperature field coupled transfer,which has the limitations of high cost,a large amount of calculating data and high computing power requirements.A novel network based on physics-informed neural network(PINN)was designed to realize the fast and high-fidelity prediction of the distribution of electromagnetic field and temperature field in ESR process.The physical laws were combined with the deep learning network through PINN,and physical constraints were embedded to achieve effective solution of partial differential equations(PDEs).PINN was used to minimize the loss function consisting of data error,physical information error and boundary condition error.The physical laws and boundary condition constraints in the ESR process were considered to maintain high PDE solution accuracy under different spatial and temporal resolutions.Automatic differentiation(Autodiff)technique and gradient descent algorithm were used to optimize the network parameters.The experimental results show that compared with the mechanistic models,PINN can effectively replace thermal experiments to realize the physical field simulation of ESR process with only a few experimental data,which can avoid the disadvantages of pure data-driven network simulation that requires a large amount of training data.Moreover,the solution of PINN has good physical interpretability and reliability of simulation results.For simulating electromagnetic field and temperature field distribution,the training time of the network is only 140 and 203 s,and the regression indicators of root mean square error can reach 12.65 and 13.76,respectively.展开更多
Einstein aimed to find a unified theoretical model to explain various interactions in nature,and the relationship between gravitational and electric fields was particularly important.For the first time,this paper prov...Einstein aimed to find a unified theoretical model to explain various interactions in nature,and the relationship between gravitational and electric fields was particularly important.For the first time,this paper provides the internal relationship equations of the electric and magnetic fields.Further,the relationship between the magnetic and gravity fields is analyzed,and the relationship equations of the electric,magnetic,and gravity fields are established.On this basis,a general formula for calculating the radius of charged particles is derived.Simultaneously,we also discussed and made predictions on black holes,providing convenience for future research and experimental detection.展开更多
基金supported by the National Natural Science Foundation of China(22375101)the Natural Science of Colleges and Universities in Jiangsu Province(24KJB430027).
文摘Background:The bacterial biofilm poses a significant challenge to traditional antibiotic therapy.There is a great need to develop novel antibiofilm agents combined with biofilm disrupting and bacteria-killing without the dependence of antibiotic.Methods:Herein,we prepared ultrasound/magnetic field-responsive ferroferric oxide nanoparticles(Fe_(3)O_(4))/glucose oxidase microbubbles(FGMB)to form a cascade catalytic system for effective removing methicillin-resistant Staphylococcus aureus biofilms.FGMB were prepared through interfacial self-assembly of Fe_(3)O_(4) nanoparticles(NPs)and glucose oxidase(GOx)at the gas-liquid interface stabilized by surfactants.Under ultrasound/magnetic field stimulation,FGMB disrupted biofilm architecture through microbubble collapse-induced microjets and magnetically driven displacement.Simultaneously,ultrasound-triggered rupture of FGMB released GOx and Fe_(3)O_(4) NPs.Glucose can be oxidized by GOx to generate gluconic acid and hydrogen peroxide which was subsequently catalyzed into hydroxyl radicals by Fe_(3)O_(4) NPs,enabling chemical eradication of biofilm-embedded bacteria.Results:Optical microscopy images demonstrated that FGMB have spherical structure with average size of approximately 17μm.FGMB showed a 65.4%decrease in methicillin-resistant Staphylococcus aureus biofilm biomass and 1.1 log bacterial inactivation efficiency(91.2%),suggesting effective biofilm elimination.In vitro experimental results also indicate that FGMB have good biocompatibility.Conclusion:This antibiofilm strategy integrated dual modes of physical biofilm disruption with chemical bacteria-killing shows great potential as a versatile,non-resistant strategy for bacterial biofilm elimination.
基金supported by National Natural Science Foundation of China(No.52025055 and 52275571)Basic Research Operation Fund of China(No.xzy012024024).
文摘Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is proposed.The electric field applied between the template and the substrate drives the contact,tilting,filling,and holding processes.By accurately controlling the introduced included angle between the flexible template and the substrate,tilted nanostructures with a controllable angle are imprinted onto the substrate,although they are vertical on the template.By flexibly adjusting the electric field intensity and the included angle,large-area uniform-tilted,gradient-tilted,and high-angle-tilted nanostructures are fabricated.In contrast to traditional replication,the morphology of the nanoimprinting structure is extended to customized control.This work provides a cost-effective,efficient,and versatile technology for the fabrication of various large-area tilted metasurface structures.As an illustration,a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays,demonstrating superior imaging quality.
基金supported by the National Natural Science Foundation of China(No.22278156)the Guangdong Special Support Program Project(No.2021JC060580)+1 种基金the Young Elite Scientists Sponsorship Program by CAST-Doctoral Student Special Plan,the China Scholarship Council Program(No.202406150148)the Natural Science Foundation of Guangdong Province(No.2023A1515011186).
文摘Peroxymonosulfate(PMS)-based advanced oxidation processes(AOPs)are an effective way to remove emerging contaminants(ECs)from water.The catalytic process involving PMS is hindered by the suboptimal electron trans-fer efficiency of current catalysts,the further application of AOPs technology is limited.Here,it is proposed that the interfacial electric field can be controlled by bor(B)-doped FeNC catalysts,which shows significant advantages in the efficient generation,release and participation of reactive oxygen species(ROS)in the reaction.The super exchange interaction between Fe sites and N and B sites is realized through the directional transfer of electrons in the interfacial electric field,which ensures the high efficiency and stability of the PMS catalytic process.B doping increases the d orbitals distribution at Fermi level,which facilitates enhanced electron transition activity,thereby promoting the effective generation of (1)^O_(2).At the same time,orbital hybridization causes the center of the d band to move to a lower energy level,which not only contributes to the desorption process of (1)^O_(2),but also accelerates its release.In addition,B-doping also improved the adsorption capacity of organic pollutants and shortened the migration distance of ROS,thereby significantly improving the degradation efficiency of ECs.The B-doping strategy outlined offers a novel approach to the development of FeNC catalysts,it lays a theoretical foundation and offers technical insights for the integration of PMS/AOPs technology in the ECs management.
基金Supported by the National Key Research and Development Program of China(2023YFF0615403)CNPC Science and Technology Project(2023ZZ0803).
文摘A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore,and then uses the hydraulic jet technology to induce multiple fractures to fracture.Finally,the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string,to realize the efficient development of the remaining reserves among the wells.The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing.The flexible sidetracking horizontal well drilling includes three aspects:flexible drill pipe structure and material optimization,drilling technology,and sealed coring tool.The sidetracking horizontal well fracturing includes two aspects:fracturing scheme optimization,fracturing tools and implementation process optimization.The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing,China.The results show that by changing well type and reducing row spacing of oil and water wells,the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells.It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.
基金supported by the National Natural Science Foundation of China(42250101)the Macao Foundation。
文摘Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these internal magnetic fields accurately,data selection based on specific criteria is often employed to minimize the influence of rapidly changing current systems in the ionosphere and magnetosphere.However,the quantitative impact of various data selection criteria on internal geomagnetic field modeling is not well understood.This study aims to address this issue and provide a reference for constructing and applying geomagnetic field models.First,we collect the latest MSS-1 and Swarm satellite magnetic data and summarize widely used data selection criteria in geomagnetic field modeling.Second,we briefly describe the method to co-estimate the core,crustal,and large-scale magnetospheric fields using satellite magnetic data.Finally,we conduct a series of field modeling experiments with different data selection criteria to quantitatively estimate their influence.Our numerical experiments confirm that without selecting data from dark regions and geomagnetically quiet times,the resulting internal field differences at the Earth’s surface can range from tens to hundreds of nanotesla(nT).Additionally,we find that the uncertainties introduced into field models by different data selection criteria are significantly larger than the measurement accuracy of modern geomagnetic satellites.These uncertainties should be considered when utilizing constructed magnetic field models for scientific research and applications.
基金supported by the National Natural Science Foundation of China(Grant No.42388101)the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-SSW-TLC00103)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS-202102).
文摘Many planets,including the Earth,possess a global dipolar magnetic field.To diagnose the interior source of the dipolar field,researchers usually adopt a dipole model consisting of six parameters to fit the observed dataset of the magnetic field.However,the simultaneous fitting of these parameters often leads to multiple local optimal parameter sets.To address this fitting dilemma,Rong ZJ et al.(2021)recently developed a current loop model.This technique can successively separate and invert the loop parameters.Here,we further show how this technique can be reduced and modified to fit a dipole model.Applications of this reduced technique to the International Geomagnetic Reference Field model and the Martian crustal field model highlight its unique ability to diagnose both the planetary global dipolar field and the local crustal field anomaly,a capability that sets it apart from existing methods.The potential impact of this technique on geomagnetism and planetary magnetism is significant,given its unique ability to diagnose both the planetary global dipolar field and the local crustal field anomaly.
基金financially supported by the National Natural Science Foundation of China(Nos.11474111 and 11604281)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20220618)the Hundreds of Talents program of Sun Yat-sen University(No.210192)
文摘A robust spontaneous exchange bias effect after zero-field cooling was observed in Co_(2)Sn_(1-x)Cr_(x)O_(4)system,which was driven by the transition from superspin-glass to superferromagnetic domain embedded in the ferrimagnetic matrix.Additionally,the exchange bias effect is gradually pronounced with the positive increase in the cooling field,known as the conventional exchange bias effect.However,as the cooling field gradually decreases and transits from positive to negative,the exchange bias effect can robustly remain positive in the low-negative-field region until the cooling field increases to be sufficiently large in the negative direction.
文摘Earthquakes are caused directly by the motion of the stress field,therefore,observing the stress field is significant.Experiments on the relationships among wave velocity,stress factors,and faults show that the wave velocity of rock media under stable stress fields corresponds one-to-one with stress factors.Therefore,the wave velocity gradient can indicate the direction of stress vector,and the gradient divergence can indicate the strength of the stress field.To verify the results,considering the limitations of wave velocity measurement in solid crustal media,two quantities,namely the apparent wave velocity and Poisson ratios relating to wave velocity,were used to refl ect the stress field state.The seismic data of the Tangshan and Luzhou regions were studied separately.The calculated apparent wave velocity and Poisson ratios were interpolated to achieve regional data gridding.The gradients and the gradient divergences of the apparent wave velocity and Poisson ratio fields in the two regions were analyzed,and it was found that their spatial distribution in the same region was the same.They are believed to refl ect the vertical projection of the stress direction vector and strength on the surface in the stress field,consistent with the experimental results.Whether it can eff ectively refl ect the stress field requires further analysis of the specific situation of the local medium and the movement mode of the stress field.
基金Supported by the National Key Research and Development Program of China(Nos.2021YFC3101801,2023YFC3008200)the National Natural Science Foundation of China(Nos.42476219,41976200)+6 种基金the National Foreign Experts Program(No.S20240134)the Innovative Team Plan of the Department of Education of Guangdong Province(No.2023KCXTD015)the Tropical Ocean Environment in Western Coastal Waters Observation and Research Station of Guangdong Province(No.2024B1212040008)the Independent Research Project of the Southern Ocean Laboratory(No.SML2022SP301)the Shandong Innovation and Development Research Institute Think Tank Projectthe Guangdong Ocean University Scientific Research Program(No.060302032106)the Start-up Fund for Ph D Researchers(No.060302032104)。
文摘Typhoon Chaba was the most intense typhoon to strike western Guangdong since Typhoon Mujigae in 2015.According to the National Disaster Reduction Center of China,in the morning of July 7,2022,over 1.5 million people in Guangdong,Guangxi,and Hainan were affected by Typhoon Chaba.The typhoon also caused the“Fukui 001”ship to be in distress in the waters near Yangjiang,Guangdong,on July 2,resulting in big casualties.Studies have indicated that wind field forecast for Typhoon Chaba was not accurate.To better simulate typhoon events and assess their impacts,we proposed the use of a model wind field(Fujita-Takahashi)integrated with the Copernicus Marine and Environmental Monitoring Service(CMEMS)data to reconstruct effectively the overall wind field of Typhoon Chaba.The simulation result aligns well with the observations,particularly at the Dashu Island Station,showing consistent trends in wind speed changes.However,certain limitations were noted.The model shows that the attenuation of wind speed is slower when typhoon neared land than that observed,indicating that the model has a high simulation accuracy for the ocean wind field,but may have deviations near coastal areas.The result is accurate for open sea but deviated for near land due to the land friction effect.Therefore,we recommend to adjust the model to improve the accuracy for near coasts.
基金financially supported by Zijin Mining Group(No.01612216)the Ministry of Natural Resources,China(No.ZKKJ202426)。
文摘The Zijinshan ore field located in southwestern Fujian Province,China,is a representative porphyry-epithermal ore system hosting diverse mineralization types(Mao et al.,2013).The ore field comprises of the Zijinshan highsulfidation Cu-Au deposit,the Luoboling porphyry Cu-Mo deposit,the transitional style Cu deposit(Longjiangting and Wuziqilong)and the Yueyang low-sulfidation Agpolymetallic deposit(Zhang,2013;Zhang et al.,2003)
基金the support of the National Natural Science Foundation of China (Nos. 42250103, 41974073, and 41404053)the Macao Foundation and the preresearch project of Civil Aerospace Technologies (Nos. D020308 and D020303)funded by China’s National Space Administration, and the Specialized Research Fund for State Key Laboratories。
文摘By combining data from the Challenging Minisatellite Payload(CHAMP),Swarm-A,and newest Macao Science Satellite-1(MSS-1) missions,we constructed a lithospheric magnetic field model up to spherical harmonic degree N = 100.To isolate the lithospheric magnetic field signals,we utilized the latest CHAOS-8(CHAMP,Φrsted,and SAC-C 8) model and MGFM(Multisource Geomagnetic Field Model) to remove nonlithospheric sources,including the core field,magnetospheric field,ocean tidal field,and ocean circulation field.Subsequently,orbit-by-orbit processing was applied to both scalar and vector data,such as spherical harmonic high-pass filtering,singular spectrum analysis,and line leveling,to suppress noise and residual signals along the satellite tracks.With an orbital inclination of only 41°,MSS-1 effectively captures fine-scale lithospheric magnetic field signals in mid-to low-latitude regions.Its data exhibit a root mean square error of only 0.77 nT relative to the final model,confirming the high quality and utility of lithospheric field modeling.The resulting model exhibits excellent consistency with the MF7(Magnetic Field Model 7),maintaining a high correlation up to N = 90 and still exceeding 0.65 at N = 100.These results demonstrate the reliability and value of MSS-1 data in global lithospheric magnetic field modeling.
基金supported by National Natural Science Foundation of China (NSFC) (Nos.62201217 and 51821005)。
文摘The field-reversed configuration(FRC)plasma thruster driven by rotating magnetic field(RMF),abbreviated as the RMF-FRC thruster,is a new type of electric propulsion technology that is expected to accelerate the deep space exploration.An experimental prototype,including diagnostic devices,was designed and constructed based on the principles of the RMF-FRC thruster,with an RMF frequency of 210 kHz and a maximum peak current of 2 kA.Under the rated operating conditions,the initial plasma density was measured to be 5×10^(17)m^(-3),and increased to 2.2×10^(19)m^(-3)after the action of RMF.The coupling efficiency of RMF was about 53%,and the plasma current reached 1.9 kA.The axial magnetic field changed in reverse by 155 Gauss,successfully reversing the bias magnetic field of 60 Gauss,which verifies the formation of FRC plasma.After optimization research,it was found that when the bias magnetic field is 100 Gauss,the axial magnetic field reverse variation caused by FRC is the highest at 164 Gauss.The experimental results are discussed and strategies are proposed to improve the performance of the prototype.
基金financially supported by Russian Science Foundation(No.24-43-00156,https://rscf.ru/en/project/24-43-00156/)the National Natural Science Foundation of China(No.52171169)the State Key Laboratory for Advanced Metals and Materials(No.2023-ZD01)。
文摘The results of the study of the effect of partial substitution of Fe by Mn in the La Fe_(11.2-x)Mn_(x)Co_(0.7)Si_(1.1)system on magnetization,specific heat,magnetostriction and magnetocaloric effect are presented.Direct measurements of the adiabatic temperature change(ΔT_(ad))were carried out in alternating magnetic fields(AMF)using the magnetic field modulation method.Partial substitution of Fe atoms by Mn atoms leads to a shift in the Curie temperature(T_(C))towards lower temperatures without a noticeable deterioration in magnetic properties.A correlation was found between the structural component of the magnetocaloric effect and the stability of the frequency of theΔT_(ad)in the AMFs—an increase in the manganese concentration leads to a decrease in magnetostriction and to a lower dependence ofΔT_(ad)on the frequency of the magnetic field.Estimates of the specific cooling power Q_(C)as a function of the frequency of the AMF showed that the highest value of Q_(C)at f=20 Hz in a magnetic field of 12k Oe is 26.3 W g^(-1)and is observed for the composition with x=0.1.This value is higher than that of Gd,for which,under the same conditions,Q_(C)=21.6 W g^(-1).All the samples studied show stability of the value ofΔT_(ad)without any sign of deterioration of the effect up to 60,000cycles of switching on/off of the magnetic field of 12 k Oe.The discovered frequency and cyclic stability ofΔT_(ad)of the studied samples increase their prospects for application in magnetic cooling technology.
文摘Seepage refers to the flow of water through porous materials.This phenomenon has a crucial role in dam,slope,excavation,tunnel,and well design.Performing seepage analysis usually is a challenging task,as one must cope with the uncertainty associated with the parameters such as the hydraulic conductivity in the horizontal and vertical directions that drive this phenomenon.However,at the same time,the data on horizontal and vertical hydraulic conductivities are typically scarce in spatial resolution.In this context,so-called non-traditional approaches for uncertainty quantification(such as intervals and fuzzy variables)offer an interesting alternative to classical probabilistic methods,since they have been shown to be quite effective when limited information on the governing parameters of a phenomenon is available.Therefore,the main contribution of this study is the development of a framework for conducting seepage analysis in saturated soils,where uncertainty associated with hydraulic conductivity is characterized using fuzzy fields.This method to characterize uncertainty extends interval fields towards the domain of fuzzy numbers.In fact,it is illustrated that fuzzy fields are an effective tool for capturing uncertainties with a spatial component,since they allow one to account for available physical measurements.A case study in confined saturated soil shows that with the proposed framework,it is possible to quantify the uncertainty associated with seepage flow,exit gradient,and uplift force effectively.
基金financially supported by the National Key R&D Program of China(No.2022YFA1402600)the National Natural Science Foundation of China(Nos.12304150 and 52161135108)support by the National Science Centre(Poland)(No.2021/40/Q/ST5/00066)。
文摘The angular dependence of magnetoresistance(MR)in antiferromagnetic half-Heusler HoAuSn single crystals has been systematically studied.Negative MR,as large as~99%,is observed at 9 T,is not restricted to the specific configuration of applied magnetics fields and current and can persist up to 20 K,much higher than the Ne'el temperature(T_(N)≈1.9 K).Experiments and first-principles calculations suggest that the observed large negative MR is derived from a magnetic field that reconstructs the band structure and induces a Weyl point,which changes the carrier concentration.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402802)the National Natural Science Foundation of China(Grant Nos.12494591 and 92165204)+4 种基金the Leading Talent Program of Guangdong Special Projects(Grant No.201626003)the Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)the Research Center for Magnetoelectric Physics of Guangdong Province(Grant No.2024B0303390001)the Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401010)supported by the National Natural Science Foundation of China(Grant Nos.12234016 and 12074031)。
文摘We investigate the energy bands,magnetism,and superconductivity of bilayer octagraphene with A-A stackingunder a perpendicular electric field.A tight-binding model is used to analyze the band structure of the system.The doubling of the unit cell results in each band of the single layer splitting into two.We find that applyinga perpendicular electric field increases the band splitting.As the electric field strength increases,the nestingof the Fermi surface(FS)weakens,eventually disrupting the antiferromagnetic order,and bilayer octagrapheneexhibits superconductivity.Spin fluctuations can induce unconventional superconductivity with s±-wave pairing.Applying a perpendicular electric field to bilayer octagraphene parent weakens the nesting of the FS,ultimatelykilling the spin-density-wave(SDW)ordered state and transitioning it into the superconducting state,whichworks as a doping effect.We use the random-phase approximation approach to obtain the pairing eigenvaluesand pairing symmetries of the perpendicular electric field-tuned bilayer octagraphene in the weak coupling limit.By tuning the strength of the perpendicular electric field,the critical interaction strength for SDW order can bemodified,which in turn may promote the emergence of unconventional superconductivity.
基金supported by the Natural Science Foundation of Anhui Province(No.228085ME142)the Comprehensive Research Facility for the Fusion Technology Program of China(No.20180000527301001228)the Open Fund of the Magnetic Confinement Fusion Laboratory of Anhui Province(No.2024AMF04003)。
文摘As the plasma current power in tokamak devices increases,a significant number of stray magnetic fields are generated around the equipment.These stray magnetic fields can disrupt the operation of electronic power devices,particularly transformers in switched-mode power supplies.Testing flyback converters with transformers under strong background magnetic fields highlights electromagnetic compatibility(EMC)issues for such switched-mode power supplies.This study utilizes finite element analysis software to simulate the electromagnetic environment of switched-mode power supply transformers and investigates the impact of variations in different magnetic field parameters on the performance of switched-mode power supplies under strong stray magnetic fields.The findings indicate that EMC issues are associated with transformer core saturation and can be alleviated through appropriate configurations of the core size,air gap,fillet radius,and installation direction.This study offers novel solutions for addressing EMC issues in high magnetic field environments.
基金National Natural Science Foundation of China,No.41930865Project for Innovative Capacity Improvement in Hebei Province,No.225A4201D。
文摘Nitrate(NO_(3)^(-))accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO_(3)^(-)content in intensive agricultural regions.Agricultural land-use change(ALUC),typically accompanied by substantial alterations in nitrogen fertilizer application and irrigation practices,is an important influencing factor.This study evaluated the changes in NO_(3)^(-)accumulation and transport in the deep vadose zone(DVZ,below the root zone),and the groundwater NO_(3)^(-)content associated with ALUC from grain to vegetable fields in the North China Plain(NCP).The ALUC from grain to vegetable resulted in nitrate–nitrogen(NO_(3)^(-)-N)accumulation in DVZ increased by 235.5 kg ha^(-1)m^(-1)(163.2%)in the piedmont plain and 224.9 kg ha^(-1)m^(-1)(102.7%)in the central plain,respectively.This change accelerated downward transport velocity in the DVZ(from 0.81±0.47 to 0.89±0.55 m yr^(-1)in the piedmont plain,and from 0.24±0.12 to 0.92±0.12 m yr^(-1)in the central plain)and increased NO_(3)^(-)leaching fluxes.High transport velocity and leaching fluxes resulted in chemical N-fertilizer entering the aquifer in several areas in the piedmont plain.The impact of the agricultural activity intensity changes,accompanied by the ALUC,on groundwater quantity and quality should be considered in similar regions.
基金supported by National Natural Science Foundation of China(52274323 and 524743495)the Postdoctoral Fellowship Program of CPSF under Grant Number GZC20240231.
文摘In the electroslag remelting(ESR)process,it mainly relies on thermal experiments or analysis via mechanistic models to realize the physical fields simulation of the electromagnetic field and temperature field coupled transfer,which has the limitations of high cost,a large amount of calculating data and high computing power requirements.A novel network based on physics-informed neural network(PINN)was designed to realize the fast and high-fidelity prediction of the distribution of electromagnetic field and temperature field in ESR process.The physical laws were combined with the deep learning network through PINN,and physical constraints were embedded to achieve effective solution of partial differential equations(PDEs).PINN was used to minimize the loss function consisting of data error,physical information error and boundary condition error.The physical laws and boundary condition constraints in the ESR process were considered to maintain high PDE solution accuracy under different spatial and temporal resolutions.Automatic differentiation(Autodiff)technique and gradient descent algorithm were used to optimize the network parameters.The experimental results show that compared with the mechanistic models,PINN can effectively replace thermal experiments to realize the physical field simulation of ESR process with only a few experimental data,which can avoid the disadvantages of pure data-driven network simulation that requires a large amount of training data.Moreover,the solution of PINN has good physical interpretability and reliability of simulation results.For simulating electromagnetic field and temperature field distribution,the training time of the network is only 140 and 203 s,and the regression indicators of root mean square error can reach 12.65 and 13.76,respectively.
基金supported by the Hunan Provincial Natural Science Foundation(No.2016JJ3034).
文摘Einstein aimed to find a unified theoretical model to explain various interactions in nature,and the relationship between gravitational and electric fields was particularly important.For the first time,this paper provides the internal relationship equations of the electric and magnetic fields.Further,the relationship between the magnetic and gravity fields is analyzed,and the relationship equations of the electric,magnetic,and gravity fields are established.On this basis,a general formula for calculating the radius of charged particles is derived.Simultaneously,we also discussed and made predictions on black holes,providing convenience for future research and experimental detection.
