The doubled haploid(DH)technique accelerates homozygosity by inducing chromosome doubling in haploid embryos derived from hybrid plants.This approach offers significant advantages over conventional rice breeding metho...The doubled haploid(DH)technique accelerates homozygosity by inducing chromosome doubling in haploid embryos derived from hybrid plants.This approach offers significant advantages over conventional rice breeding methods by shortening the breeding cycle and enabling rapid development of pure homozygous lines.Anther culture(AC)has been established as an efficient and successful method for producing DH plants via androgenesis in rice.However,despite its success in japonica rice.展开更多
The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
Wing design is a critical factor in the aerodynamic performance of flapping-wing(FW)robots.Inspired by the natural wing structures of insects,bats,and birds,we explored how bio-mimetic wing vein morphologies,combined ...Wing design is a critical factor in the aerodynamic performance of flapping-wing(FW)robots.Inspired by the natural wing structures of insects,bats,and birds,we explored how bio-mimetic wing vein morphologies,combined with a bio-inspired double wing clap-and-fling mechanism,affect thrust generation.This study focused on increasing vertical force and payload capacity.Through systematic experimentation with various vein configurations and structural designs,we developed innovative wings optimized for thrust production.Comprehensive tests were conducted to measure aerodynamic forces,power consumption,and wing kinematics across a range of flapping frequencies.Additionally,wings with different aspect ratios,a key factor in wing design,were fabricated and extensively evaluated.The study also examined the role of bio-inspired vein layouts on wing flexibility,a critical component in improving flight efficiency.Our findings demonstrate that the newly developed wing design led to a 20%increase in thrust,achieving up to 30 g-force(gf).This research sheds light on the clap-and-fling effect and establishes a promising framework for bio-inspired wing design,offering significant improvements in both performance and payload capacity for FW robots.展开更多
Layered double hydroxides(LDHs)are promising electrocatalysts for the oxygen evolution reaction(OER),yet their practical application remains limited by poor electrical conductivity and sluggish reaction kinetics.In th...Layered double hydroxides(LDHs)are promising electrocatalysts for the oxygen evolution reaction(OER),yet their practical application remains limited by poor electrical conductivity and sluggish reaction kinetics.In this work,we synthesize three high-entropy LDHs(HELDHs)featuring a hierarchical architecture of microspheres assembled from ultrathin nanosheets,via a simple hydrothermal method using a combination of low-cost,catalytically active transition metals(Fe,Co,Ni,Mn,Zn,Cu,and Cr).Among them,the FeCoNiMnZn HELDH exhibits outstanding OER performance,requiring an overpotential of only 306 mV to reach a current density of 100 mA cm^(-2).Notably,during 200 h of continuous operation,the device exhibits a stable and,in some cases,increasing current output.This exceptional activity is attributed to the formation of abundant cation vacancies,induced by Zn leaching,which enhance the intrinsic catalytic properties by optimizing the adsorption energies of key OER intermediates.Density functional theory calculations further validate that these vacancies modulate the electronic structure and lower reaction barriers,underscoring the effectiveness of cation-vacancy engineering in high-entropy systems for efficient and durable water oxidation catalysis.The optimized catalyst was further evaluated as the air cathode in a zinc-air battery,demonstrating practical electrochemical performance.展开更多
Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while...Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.展开更多
The present study investigates the flow,heat,and mass transfer analysis in the bioconvection of nanofluid containing motile gyrotactic microorganisms through a semi-porous curved oscillatory channel with a magnetic fi...The present study investigates the flow,heat,and mass transfer analysis in the bioconvection of nanofluid containing motile gyrotactic microorganisms through a semi-porous curved oscillatory channel with a magnetic field.These microorganisms produce density gradients by swimming,which induces macroscopic convection flows in the fluid.This procedure improves the mass and heat transfer,illustrating the interaction between biological activity and fluid dynamics.Furthermore,instead of considering traditional Fourier's and Fick's law the energy and concentration equations are developed by incorporating Cattaneo-Christov double diffusion theory.Moreover,to examine the influence of thermophoresis and Brownian diffusions in the fluid we have adopted the Buongiorno nanofluid model.Due to the oscillation of the surface of the channel,the mathematical development of the considered flow problem is obtained in the form of partial differential equations via the curvilinear coordinate system.The convergent series solution of the governing flow equations is obtained after applying the homotopy analysis method(HAM).The effects of different pertinent flow parameters on velocity,motile microorganism density distribution,concentration,pressure,temperature,and skin friction coefficient are examined and discussed in detail with the help of graphs and tables.It is observed during the current study that the density of microorganisms is enhanced for higher values of Reynolds number,Peclet number,radius of curvature variable,and Lewis number.展开更多
Soft X-ray detectors play a vital role in materials science,high-energy physics and medical imaging.Cs_(2)AgBiBr_(6),a lead-free double perovskite,has gained attention for its excellent optoelectronic properties,stabi...Soft X-ray detectors play a vital role in materials science,high-energy physics and medical imaging.Cs_(2)AgBiBr_(6),a lead-free double perovskite,has gained attention for its excellent optoelectronic properties,stability,and nontoxicity.However,its fast crystallization and requirement for high-temperature annealing(>250℃)often lead to inferior film quality,limiting its application in flexible devices.This study introduces an alloying strategy that significantly improves the quality of Cs_(2)AgBiBr_(6)thin films annealed at a reduced temperature of 150℃.Devices based on the alloyed thin films exhibit an ultra-low dark current of 0.32 nA·cm^(-2)and a quantum efficiency of 725%.Furthermore,the first successful integration of Cs_(2)AgBiBr_(6)with a thinfilm transistor backplane demonstrates its superior imaging performance,indicating that Cs_(2)AgBiBr_(6)is a promising material for next-generation soft X-ray sensors.展开更多
Objective:To explore the therapeutic effect of double-puncture tympanic membrane puncture and tympanic cavity drug injection in patients with acute secretory otitis media.Methods:A total of 84 patients with acute secr...Objective:To explore the therapeutic effect of double-puncture tympanic membrane puncture and tympanic cavity drug injection in patients with acute secretory otitis media.Methods:A total of 84 patients with acute secretory otitis media admitted to our hospital from June 2024 to June 2025 were selected and randomly divided into two groups by drawing lots.The control group(42 cases)was treated with the traditional single-puncture tympanic membrane puncture and tympanic cavity drug injection method,while the observation group(42 cases)was treated with the double-puncture tympanic membrane puncture and tympanic cavity drug injection method.The therapeutic effects of the two groups were compared.Results:The overall treatment response rate,overall complication rate,time to symptom relief,and improvement in hearing threshold in the observation group were all superior to those in the control group,with statistically significant differences(P<0.05).Conclusion:For acute secretory otitis media,the treatment method of double-puncture tympanic membrane puncture and tympanic cavity drug injection demonstrates definite efficacy,significantly reducing the incidence of complications,accelerating symptom relief,and improving hearing function,making it worthy of promotion.展开更多
Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen ba...Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs.展开更多
Background:Double blind-ending ureter(DBU)is an extremely rare congenital anomaly involving a duplicated ureter with no connection to the renal pelvis or bladder,making diagnosis difficult.Case Description:A 10-year-o...Background:Double blind-ending ureter(DBU)is an extremely rare congenital anomaly involving a duplicated ureter with no connection to the renal pelvis or bladder,making diagnosis difficult.Case Description:A 10-year-old girl presented with recurrent abdominal pain and ultrasound evidence of left hydroureteronephrosis.Magnetic resonance imaging(MRI)and three-dimensional(3D)reconstruction revealed a 30 cm blind-ending ureter.Robotic-assisted excision(Da Vinci Xi)was performed safely,preserving adjacent structures.Histology confirmed a nonfunctional ureteral remnant.Conclusions:DBU is a rare duplication variant.Advanced imaging and robotic surgery are essential for accurate diagnosis and effective,minimally invasive treatment.展开更多
Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon ...Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon dioxide upon electron-impact.Through fragment ions and electron coincidence momentum imaging,we unambiguously determine the ionization mechanism by measuring the projectile energy loss in association with the C^(+) +O_(2)^(+) channel.Further potential energy and trajectory calculations enable us to elucidate the dynamical details of this fragmentation process,in which a bond rearrangement pathway is found to proceed via the structural deformation to a triangular intermediate.Moreover,we demonstrate a further roaming pathway for the formation of O_(2)^(+) from CO_(2)^(+) 2,in which a frustrated C-O bond cleavage leaves the O atom without sufficient energy to escape.The O atom then wanders around varied configuration spaces of the flat potential energy regions and forms a C-O-O_(2)^(+) intermediate prior to the final products C^(+) +O_(2)^(+).Considering the large quantities of free electrons in interstellar space,the processes revealed here are expected to be significant and should be incorporated into atmospheric evolution models.展开更多
Lanthanide ions(Ln^(3+))doping provides a potential strategy to control over the luminescent properties of lead-free halide double perovskite nanocrystals(DP NCs).However,due to the low energy transfer efficiency betw...Lanthanide ions(Ln^(3+))doping provides a potential strategy to control over the luminescent properties of lead-free halide double perovskite nanocrystals(DP NCs).However,due to the low energy transfer efficiency between self-trapped exciton(STE)and Ln^(3+)ions,the characteristic emissions of Ln^(3+)ions are not prominent.Furthermore,the energy transfer mechanism between STE and Ln^(3+)ions is also elusive and requires in-depth study.We chose trace Bi^(3+)-doped Cs_(2)Ag_(0.6)Na_(0.4)InCl_(6-x)Br_(x) as a representative DP matrix to demonstrate that by tuning the bromide concentration,the Ln^(3+)emission can be greatly enhanced.Such enhanced STE and Ln^(3+)ions energy transfer originates from the high covalency of Ln-Br bond,which contributes to improve ment of the characteristic emission of Ln^(3+)ions.Furthermo re,optical spectroscopy reveals that the energy transfer mechanism from DP to Eu^(3+)ions is different from all the other doped Ln^(3+)ions.The energy transfer from DP to Eu^(3+)ions is mostly through Eu-Br charge transfer while the other Ln^(3+)ions are excited by energy transfer from STE.The distinct energy transfer mechanism has resulted from the energy separation between the excited energy level of Ln^(3+)ions and the bottom of conduction band of DP.With increasing the energy separation,the energy transfer from STE to Ln^(3+)ions is less efficient because of the generation of a larger number of phonons and finally becomes impossible for Eu^(3+)ions.Our results provide new insight into tuning the energy transfer of Ln^(3+)-doped DP NCs.展开更多
Lead-free hybrid double perovskites(LFHDPs) have received a lot of attention due to their environmental friendliness and promising attributes. However, studying the effect of film thickness on LFHDPs optoelectronic pr...Lead-free hybrid double perovskites(LFHDPs) have received a lot of attention due to their environmental friendliness and promising attributes. However, studying the effect of film thickness on LFHDPs optoelectronic properties has not yet been investigated. Herein, we synthesized two new Ruddlesden–Popper LFHDPs, namely(C_(5)H_(12)N)_(4)AgBiI_(8)(CAB-1) and(C_(6)H_(14)N)_(4)Ag Bi I8(CAB-2) using cyclopentylamine and cyclohexylamine as monoamine ligands. Indeed, these two Ag(Ⅰ)-Bi(Ⅲ) LFHDPs form smooth and uniform films ranging in thickness from 250 nm to 1 μm, with preferred orientations. Notably, the studies on the optical properties showed that the direct band gap value decreased from 2.17 e V to 1.91 e V for CAB-1 and from 2.05 e V to 1.86 e V for CAB-2 with increasing thickness. Accordingly, photo-current response using a xenon lamp revealed a significant difference of over 1000 n A between light and dark conditions for1 μm-thickness films, suggesting potential for light harvesting. Other than that, thicker films of CAB-1and CAB-2 exhibit high stability for 90 days in a relatively humid environment(RH of 55%), paving the way for promising optoelectronic applications.展开更多
The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits ...The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth.In this study,a double gyroid(DG)Ti6Al4V scaffold based on a triply periodic minimal surface(TPMS)structure was devised,and the osseointegration performance of DG structural scaffolds with varying porosities was investigated.Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants.In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation,vascularization,and osteogenic differentiation compared to the cubic structure.The DG structure with 55%porosity exhibited the most favorable outcomes.In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation;those with 55%porosity performed best.Comparing the surface area,specific surface area per unit volume,and internal flow distribution characteristics of gyroid and DG structure scaffolds,the latter are more conducive to cell adhesion and growth within scaffolds.This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds,inducing angiogenesis,and advancing the clinical application of titanium scaffolds for repairing bone defects.展开更多
The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a block...The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises.展开更多
Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the...Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.展开更多
基金supported by the Science and Technology Innovation Program of Fujian Agriculture and Forestry University,China(Grant No.KFB22045)the General Program of Natural Science Foundation Fujian,China(Grant No.2023J01460).
文摘The doubled haploid(DH)technique accelerates homozygosity by inducing chromosome doubling in haploid embryos derived from hybrid plants.This approach offers significant advantages over conventional rice breeding methods by shortening the breeding cycle and enabling rapid development of pure homozygous lines.Anther culture(AC)has been established as an efficient and successful method for producing DH plants via androgenesis in rice.However,despite its success in japonica rice.
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
基金Nguyen Tat Thanh University,Ho Chi Minh City,Vietnam for supporting this study。
文摘Wing design is a critical factor in the aerodynamic performance of flapping-wing(FW)robots.Inspired by the natural wing structures of insects,bats,and birds,we explored how bio-mimetic wing vein morphologies,combined with a bio-inspired double wing clap-and-fling mechanism,affect thrust generation.This study focused on increasing vertical force and payload capacity.Through systematic experimentation with various vein configurations and structural designs,we developed innovative wings optimized for thrust production.Comprehensive tests were conducted to measure aerodynamic forces,power consumption,and wing kinematics across a range of flapping frequencies.Additionally,wings with different aspect ratios,a key factor in wing design,were fabricated and extensively evaluated.The study also examined the role of bio-inspired vein layouts on wing flexibility,a critical component in improving flight efficiency.Our findings demonstrate that the newly developed wing design led to a 20%increase in thrust,achieving up to 30 g-force(gf).This research sheds light on the clap-and-fling effect and establishes a promising framework for bio-inspired wing design,offering significant improvements in both performance and payload capacity for FW robots.
基金supported by the National Natural Science Foundation of China(NSFC)(22302151,52502312)Natural Science Foundation of Hubei Province(2024AFB755,2024AFB267)+1 种基金Key Project of Hubei Provincial Department of Education Scientific Research Plan(F2023007)Wuhan Institute of Technology Graduate Education Innovation Fund(CX2024285)。
文摘Layered double hydroxides(LDHs)are promising electrocatalysts for the oxygen evolution reaction(OER),yet their practical application remains limited by poor electrical conductivity and sluggish reaction kinetics.In this work,we synthesize three high-entropy LDHs(HELDHs)featuring a hierarchical architecture of microspheres assembled from ultrathin nanosheets,via a simple hydrothermal method using a combination of low-cost,catalytically active transition metals(Fe,Co,Ni,Mn,Zn,Cu,and Cr).Among them,the FeCoNiMnZn HELDH exhibits outstanding OER performance,requiring an overpotential of only 306 mV to reach a current density of 100 mA cm^(-2).Notably,during 200 h of continuous operation,the device exhibits a stable and,in some cases,increasing current output.This exceptional activity is attributed to the formation of abundant cation vacancies,induced by Zn leaching,which enhance the intrinsic catalytic properties by optimizing the adsorption energies of key OER intermediates.Density functional theory calculations further validate that these vacancies modulate the electronic structure and lower reaction barriers,underscoring the effectiveness of cation-vacancy engineering in high-entropy systems for efficient and durable water oxidation catalysis.The optimized catalyst was further evaluated as the air cathode in a zinc-air battery,demonstrating practical electrochemical performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.42407267 and 52374152)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20220975).
文摘Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.
文摘The present study investigates the flow,heat,and mass transfer analysis in the bioconvection of nanofluid containing motile gyrotactic microorganisms through a semi-porous curved oscillatory channel with a magnetic field.These microorganisms produce density gradients by swimming,which induces macroscopic convection flows in the fluid.This procedure improves the mass and heat transfer,illustrating the interaction between biological activity and fluid dynamics.Furthermore,instead of considering traditional Fourier's and Fick's law the energy and concentration equations are developed by incorporating Cattaneo-Christov double diffusion theory.Moreover,to examine the influence of thermophoresis and Brownian diffusions in the fluid we have adopted the Buongiorno nanofluid model.Due to the oscillation of the surface of the channel,the mathematical development of the considered flow problem is obtained in the form of partial differential equations via the curvilinear coordinate system.The convergent series solution of the governing flow equations is obtained after applying the homotopy analysis method(HAM).The effects of different pertinent flow parameters on velocity,motile microorganism density distribution,concentration,pressure,temperature,and skin friction coefficient are examined and discussed in detail with the help of graphs and tables.It is observed during the current study that the density of microorganisms is enhanced for higher values of Reynolds number,Peclet number,radius of curvature variable,and Lewis number.
基金supported by the NSFC under Grant No.62474169the National Key Research and Development Program of China under Grant No.2024YFB3212200the funding from USTC under Grant Nos.WK2100000025,KY2190000003,and KY2190000006。
文摘Soft X-ray detectors play a vital role in materials science,high-energy physics and medical imaging.Cs_(2)AgBiBr_(6),a lead-free double perovskite,has gained attention for its excellent optoelectronic properties,stability,and nontoxicity.However,its fast crystallization and requirement for high-temperature annealing(>250℃)often lead to inferior film quality,limiting its application in flexible devices.This study introduces an alloying strategy that significantly improves the quality of Cs_(2)AgBiBr_(6)thin films annealed at a reduced temperature of 150℃.Devices based on the alloyed thin films exhibit an ultra-low dark current of 0.32 nA·cm^(-2)and a quantum efficiency of 725%.Furthermore,the first successful integration of Cs_(2)AgBiBr_(6)with a thinfilm transistor backplane demonstrates its superior imaging performance,indicating that Cs_(2)AgBiBr_(6)is a promising material for next-generation soft X-ray sensors.
文摘Objective:To explore the therapeutic effect of double-puncture tympanic membrane puncture and tympanic cavity drug injection in patients with acute secretory otitis media.Methods:A total of 84 patients with acute secretory otitis media admitted to our hospital from June 2024 to June 2025 were selected and randomly divided into two groups by drawing lots.The control group(42 cases)was treated with the traditional single-puncture tympanic membrane puncture and tympanic cavity drug injection method,while the observation group(42 cases)was treated with the double-puncture tympanic membrane puncture and tympanic cavity drug injection method.The therapeutic effects of the two groups were compared.Results:The overall treatment response rate,overall complication rate,time to symptom relief,and improvement in hearing threshold in the observation group were all superior to those in the control group,with statistically significant differences(P<0.05).Conclusion:For acute secretory otitis media,the treatment method of double-puncture tympanic membrane puncture and tympanic cavity drug injection demonstrates definite efficacy,significantly reducing the incidence of complications,accelerating symptom relief,and improving hearing function,making it worthy of promotion.
基金financially supported by the National Natural Science Foundation of China(U21A20311,U24A2040,52171141,52272117)the Natural Science Foundation of Shandong Province(ZR2022JQ19)+3 种基金the Key Technology Research Project of Shandong Province(2023CXGC010202)the Taishan Industrial Experts Program(TSCX202306142)the Core Facility Sharing Platform of Shandong Universitythe Foundation of Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University。
文摘Co_(3)S_(4)electrocatalysts with mixed valences of Co ions and excellent structural stability possess favorable oxygen evolution reaction(OER)activity,yet challenges remain in fabricating rechargeable lithiumoxygen batteries(LOBs)due to their poor OER performance,resulting from poor electrical conductivity and overly strong intermediate adsorption.In this work,fancy double heterojunctions on 1T/2H-MoS_(2)@Co_(3)S_(4)(1T/2H-MCS)were constructed derived from the charge donation from Co to Mo ions,thus inducing the phase transformation of Mo S_(2)from 2H to 1T.The unique features of these double heterojunctions endow the1T/2H-MCS with complementary catalysis during charging and discharging processes.It is worth noting that 1T-Mo S2@Co3S4could provide fast Co-S-Mo electron transport channels to promote ORR/OER kinetics,and 2H-MoS_(2)@Co_(3)S_(4)contributed to enabling moderate egorbital occupancy when adsorbed with oxygen-containing intermediates.On the basis,the Li_(2)O_(2)nucleation route was changed to solution and surface dual pathways,improving reversible deposition and decomposition kinetics.As a result,1T/2H-MCS cathodes exhibit an improved electrocatalytic performance compared with those of Co_(3)S_(4)and Mo S2cathodes.This innovative heterostructure design provides a reliable strategy to construct efficient transition metal sulfide catalysts by improving electrical conductivity and modulating adsorption toward oxygenated intermediates for LOBs.
文摘Background:Double blind-ending ureter(DBU)is an extremely rare congenital anomaly involving a duplicated ureter with no connection to the renal pelvis or bladder,making diagnosis difficult.Case Description:A 10-year-old girl presented with recurrent abdominal pain and ultrasound evidence of left hydroureteronephrosis.Magnetic resonance imaging(MRI)and three-dimensional(3D)reconstruction revealed a 30 cm blind-ending ureter.Robotic-assisted excision(Da Vinci Xi)was performed safely,preserving adjacent structures.Histology confirmed a nonfunctional ureteral remnant.Conclusions:DBU is a rare duplication variant.Advanced imaging and robotic surgery are essential for accurate diagnosis and effective,minimally invasive treatment.
基金supported by the National Natural Science Foundation of China (Grant Nos.12325406,92261201,12404305,and W2512072)the Shaanxi Province Natural Science Fundamental Research Project (Grant Nos.2023JC-XJ-03 and23JSQ013)the China Postdoctoral Science Foundation (Grant Nos.BX20240286 and 2024M7625)。
文摘Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon dioxide upon electron-impact.Through fragment ions and electron coincidence momentum imaging,we unambiguously determine the ionization mechanism by measuring the projectile energy loss in association with the C^(+) +O_(2)^(+) channel.Further potential energy and trajectory calculations enable us to elucidate the dynamical details of this fragmentation process,in which a bond rearrangement pathway is found to proceed via the structural deformation to a triangular intermediate.Moreover,we demonstrate a further roaming pathway for the formation of O_(2)^(+) from CO_(2)^(+) 2,in which a frustrated C-O bond cleavage leaves the O atom without sufficient energy to escape.The O atom then wanders around varied configuration spaces of the flat potential energy regions and forms a C-O-O_(2)^(+) intermediate prior to the final products C^(+) +O_(2)^(+).Considering the large quantities of free electrons in interstellar space,the processes revealed here are expected to be significant and should be incorporated into atmospheric evolution models.
基金Project supported by the Research Project of Mindu Innovation Laboratory(2021ZZ114)Natural Science Foundation of Xiamen(3502Z20227255)+1 种基金Major Research Project of Xiamen(3502Z20191015)the Science and Technology Major Project of Fujian Province(2021HZ021013)。
文摘Lanthanide ions(Ln^(3+))doping provides a potential strategy to control over the luminescent properties of lead-free halide double perovskite nanocrystals(DP NCs).However,due to the low energy transfer efficiency between self-trapped exciton(STE)and Ln^(3+)ions,the characteristic emissions of Ln^(3+)ions are not prominent.Furthermore,the energy transfer mechanism between STE and Ln^(3+)ions is also elusive and requires in-depth study.We chose trace Bi^(3+)-doped Cs_(2)Ag_(0.6)Na_(0.4)InCl_(6-x)Br_(x) as a representative DP matrix to demonstrate that by tuning the bromide concentration,the Ln^(3+)emission can be greatly enhanced.Such enhanced STE and Ln^(3+)ions energy transfer originates from the high covalency of Ln-Br bond,which contributes to improve ment of the characteristic emission of Ln^(3+)ions.Furthermo re,optical spectroscopy reveals that the energy transfer mechanism from DP to Eu^(3+)ions is different from all the other doped Ln^(3+)ions.The energy transfer from DP to Eu^(3+)ions is mostly through Eu-Br charge transfer while the other Ln^(3+)ions are excited by energy transfer from STE.The distinct energy transfer mechanism has resulted from the energy separation between the excited energy level of Ln^(3+)ions and the bottom of conduction band of DP.With increasing the energy separation,the energy transfer from STE to Ln^(3+)ions is less efficient because of the generation of a larger number of phonons and finally becomes impossible for Eu^(3+)ions.Our results provide new insight into tuning the energy transfer of Ln^(3+)-doped DP NCs.
基金supported by the National Natural Science Foundation of China (Nos. 22375157 and W2433042)the Key Scientific and Technological Innovation Team of Shaanxi Province(No. 2020TD-001)+1 种基金the Fundamental Research Funds for Central Universities, State Key Laboratory of Electrical Insulation and Power Equipment (No. EIPE23409)the Instrument Analysis Center of Xi’an Jiaotong University for assistance。
文摘Lead-free hybrid double perovskites(LFHDPs) have received a lot of attention due to their environmental friendliness and promising attributes. However, studying the effect of film thickness on LFHDPs optoelectronic properties has not yet been investigated. Herein, we synthesized two new Ruddlesden–Popper LFHDPs, namely(C_(5)H_(12)N)_(4)AgBiI_(8)(CAB-1) and(C_(6)H_(14)N)_(4)Ag Bi I8(CAB-2) using cyclopentylamine and cyclohexylamine as monoamine ligands. Indeed, these two Ag(Ⅰ)-Bi(Ⅲ) LFHDPs form smooth and uniform films ranging in thickness from 250 nm to 1 μm, with preferred orientations. Notably, the studies on the optical properties showed that the direct band gap value decreased from 2.17 e V to 1.91 e V for CAB-1 and from 2.05 e V to 1.86 e V for CAB-2 with increasing thickness. Accordingly, photo-current response using a xenon lamp revealed a significant difference of over 1000 n A between light and dark conditions for1 μm-thickness films, suggesting potential for light harvesting. Other than that, thicker films of CAB-1and CAB-2 exhibit high stability for 90 days in a relatively humid environment(RH of 55%), paving the way for promising optoelectronic applications.
基金supported bythe National Natural Science Foundation of China(Nos.U23A20523,82272504,and 82072456)the Department of Science and Technology of Jilin Province,China(Nos.20210101439JC,20210101321JC,20220204119YY,202201ZYTS131,202201ZYTS129,20230204114YY,YDZJ202201ZYTS505,and YDZJ202301ZYTS076)+4 种基金the Special Program for Science and Technology Personnel of Changchun(No.ZKICKJJ2023015)the Key Training Plan for Outstanding Youth of Jilin University(No.419070623036)the Research Fund of the First Hospital of Jilin University(No.2021-zl-01)the Graduate Innovation Fund of Jilin University(No.2024CX125)the Foun-dation of National Center for Translational Medicine(Shanghai)SHU Branch,China(No.SUITM-202405).
文摘The pore structure of porous scaffolds plays a crucial role in bone repair.The prevalent bone implant structure in clinical practice is the traditional cubic structure.However,the traditional cubic structure exhibits sharp edges and junctions that are not conducive to cell adhesion or growth.In this study,a double gyroid(DG)Ti6Al4V scaffold based on a triply periodic minimal surface(TPMS)structure was devised,and the osseointegration performance of DG structural scaffolds with varying porosities was investigated.Compression tests revealed that the elastic modulus and compressive strength of DG structural scaffolds were sufficient for orthopedic implants.In vitro cellular experiments demonstrated that the DG structure significantly enhanced cell proliferation,vascularization,and osteogenic differentiation compared to the cubic structure.The DG structure with 55%porosity exhibited the most favorable outcomes.In vivo experiments in rabbits further demonstrated that DG scaffolds could promote neovascularization and bone regeneration and maturation;those with 55%porosity performed best.Comparing the surface area,specific surface area per unit volume,and internal flow distribution characteristics of gyroid and DG structure scaffolds,the latter are more conducive to cell adhesion and growth within scaffolds.This study underscored the potential of DG scaffolds based on the TPMS structure in optimizing the pore structure design of titanium scaffolds,inducing angiogenesis,and advancing the clinical application of titanium scaffolds for repairing bone defects.
基金supported in part by the National Natural Science Foundation of China(62273310)the Natural Science Foundation of Zhejiang Province of China(LY22F030006,LZ24F030009)
文摘The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises.
基金supported in part by the Xi’an Jiaotong-Liverpool University(XJTLU)Research Development Fund(2024–2027)under Grant RDF-23-02-010supported in part by the Guangdong Basic and Applied Basic Research Foundation under Grant 2023A1515110732+5 种基金supported in part by the National Natural Science Foundation of China(NSFC)under Grant 62071247supported in part by the Science and Technology Development Fund,Macao,China SAR under Grants 0087/2022/AFJ and 001/2024/SKLin part by the National Natural Science Foundation of China under Grant 62261160650in part by the Research Committee of University of Macao,Macao SAR,China under Grants MYRG-GRG2023-00116-FST-UMDF and MYRG2020-00095-FSTsupported in part by the NSFC under Grant 62261160576 and 62301148in part by the Fundamental Research Funds for the Central Universities under Grant 2242023K5003.
文摘Reconfigurable intelligent surface(RIS)is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves.In the prior literature,the inter-RIS links which also contribute to the performance of the whole system are usually neglected when multiple RISs are deployed.In this paper we investigate a general double-RIS assisted multiple-input multiple-output(MIMO)wireless communication system under spatially correlated non line-of-sight propagation channels,where the cooperation of the double RISs is also considered.The design objective is to maximize the achievable ergodic rate based on full statistical channel state information(CSI).Specifically,we firstly present a closedform asymptotic expression for the achievable ergodic rate by utilizing replica method from statistical physics.Then a full statistical CSI-enabled optimal design is proposed which avoids high pilot training overhead compared to instantaneous CSI-enabled design.To further reduce the signal processing overhead and lower the complexity for practical realization,a common-phase scheme is proposed to design the double RISs.Simulation results show that the derived asymptotic ergodic rate is quite accurate even for small-sized antenna arrays.And the proposed optimization algorithm can achieve substantial gain at the expense of a low overhead and complexity.Furthermore,the cooperative double-RIS assisted MIMO framework is proven to achieve superior ergodic rate performance and high communication reliability under harsh propagation environment.
