Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field c...Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field coupled with chloride ions(Cl-)fixation strategy in dual single-atom catalysts(DSACs)was proposed,and the resultant catalyst delivered considerable ORR performance in a seawater electrolyte,with a high half-wave potential(E_(1/2))of 0.868 V and a good maximum power density(Pmax)of 182 mW·cm^(−2)in the assembled SZABs,much higher than those of the Pt/C catalyst(E_(1/2):0.846 V;Pmax:150 mW·cm^(−2)).The in-situ characterization and theoretical calculations revealed that the Fe sites have a higher Cl^(−)adsorption affinity than the Co sites,and preferentially adsorbs Cl^(−)in a seawater electrolyte during the ORR process,and thus constructs a low-concentration Cl^(−)local microenvironment through the common-ion exclusion effect,which prevents Cl^(−)adsorption and corrosion in the Co active centers,achieving impressive catalytic stability.In addition,the directional charge movement between Fe and Co atomic pairs establishes a local electric field,optimizing the adsorption energy of Co sites for oxygen-containing intermediates,and further improving the ORR activity.展开更多
Batteries play a critical role in electric vehicles and distributed energy generation.With the growing demand for energy storage solutions,new battery materials and systems are continually being developed.In this proc...Batteries play a critical role in electric vehicles and distributed energy generation.With the growing demand for energy storage solutions,new battery materials and systems are continually being developed.In this process,molecular dynamics(MD)simulations can reveal the microscopic mechanisms of battery processes,thereby boosting the design of batteries.Compared to other MD simulation techniques,the machine learning force field(MLFF)holds the advantages of first-principles accuracy along with large spatial and temporal scale,offering opportunities to uncover new mechanisms in battery systems.This review presents a detailed overview of the fundamental principles and model types of MLFFs,as well as their applications in simulating the structure,transport properties,and chemical reaction properties of bulk battery materials and interfaces.Notably,we emphasize the long-range interaction corrections and constant-potential methods in the model design of MLFFs.Finally,we discuss the challenges and prospects of applying MLFF models in the research of batteries.展开更多
Rational design of hierarchical structures and a dual-interface built-in electric field(BIEF)are vital for enhancing dielectric loss and directional charge transport in microwave absorption materials(MAMs).Herein,we p...Rational design of hierarchical structures and a dual-interface built-in electric field(BIEF)are vital for enhancing dielectric loss and directional charge transport in microwave absorption materials(MAMs).Herein,we propose a dual-interface BIEF engineering strategy to construct a multifunctional MoS_(2)@C/CoS_(x)composites.Inspired by the spiderweb hunting mechanism,magnetic Co-based Prussian blue(PB)is electro spun with polyacrylonitrile to form Co@CoO/C nanofibers,followed by sulfidation to induce ordered array architectures.The structural evolution enables the formation of heterogeneous MoS_(2)-CoSx-C interfaces and modulates the interfacial electric field intensity to enhance dielectric polarization.Density functional theory(DFT)calculations confirm that the work function difference(ΔΦ)of C/CoS_(2)/MoS_(2) is 6.179 eV,which indicates that the differencesΔΦamong MoS_(2),CoS_(x)and C components drive the spontaneous formation of dual-interface BIEF.This facilitates directional charge migration and strong dipolar/interface polarization,significantly improving the microwave attenuation capability.Benefiting from this design,the composite achieves a minimum reflection loss(RL_(min))of-63.83 dB and a maximum effective absorption bandwidth(EAB_(max))of 6.96 GHz,covering both C and Ku bands.In addition,the material reveals excellent infrared stealth performance due to its unique spiderweb-inspired ordered array structure.This study provides new insights into interfacial electric field modulation and a generalizable approach for designing multi-band and tunable microwave absorbers with synergistic electromagnetic and thermal stealth functions.展开更多
数据清洗、特征选择和预测模型建立是基于数据采集与监视控制系统(supervisory control and data acquisition,SCADA)数据,实现风电机组异常状态预警不可缺少的重要环节。先结合孤立森林(isolation forest,iForest)和基于密度的空间聚类...数据清洗、特征选择和预测模型建立是基于数据采集与监视控制系统(supervisory control and data acquisition,SCADA)数据,实现风电机组异常状态预警不可缺少的重要环节。先结合孤立森林(isolation forest,iForest)和基于密度的空间聚类(density-based spatial clustering of applications with noise,DBSCAN)算法对SCADA数据异常点进行有效清洗,并采用随机森林算法(random forests,RF)与Person相关系数法优选模型输入参数;再进而基于Optuna优化的类别提升树(categorical boosting,CATBoost)算法,建立风电机组正常工况齿轮箱油池温度的预测模型;然后采用滑动窗方法,构建状态评价指标,并使用区间估计理论确定油温异常状态判别的临界阈值;实现油温异常预警;最后,采用某风电机组SCADA系统油温异常的真实历史故障数据进行检验,验证了该方法的有效性。展开更多
针对串行抵消列表(Successive Cancellation List,SCL)译码框架下基于搜索集的路径分裂选择策略的缺陷,提出两种改进策略:基于可靠性函数的路径分裂策略和依靠辅助路径度量值(Auxiliary Path Metric,APM)的剪枝策略。在此基础上,提出一...针对串行抵消列表(Successive Cancellation List,SCL)译码框架下基于搜索集的路径分裂选择策略的缺陷,提出两种改进策略:基于可靠性函数的路径分裂策略和依靠辅助路径度量值(Auxiliary Path Metric,APM)的剪枝策略。在此基础上,提出一种新的译码算法——基于可靠性函数的路径分裂选择策略辅助串行抵消列表(Path Splitting Selecting Strategy Based on Reliability Function under the Successive Cancellation List,PSS-RF-SCL)译码算法。该算法在译码阶段,每个信息比特在进行路径分裂前,会计算所有路径的路径度量(Path Metric,PM)值。利用这些PM值,进一步计算该比特的可靠性函数值。算法将可靠性函数值低于其平均值(即阈值α)的信息比特视为需要进行路径分裂的比特,从而减少了多余的路径分裂次数。此外,算法计算每条路径的APM值,并将APM值高于正确译码路径的APM平均值(即阈值β)的路径视为不可靠路径,对不可靠路径进行剪枝,有效控制了译码列表总数。仿真结果表明,相较于传统的基于搜索集的路径分裂策略辅助的SCL译码算法,所提出的PSS-RF-SCL译码算法在保持相同译码性能的前提条件下,显著降低了译码复杂度。展开更多
Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in...Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical resonance.Here,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere monolayer.The form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,respectively.The strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell geometry.The chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically investigated.The DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.展开更多
基金supported by the National Natural Science Foundation of China(52164028,52274297)the Start-up Research Foundation of Hainan University(KYQD(ZR)20008,KYQD(ZR)21125,KYQD(ZR)23169))+1 种基金Collaborative Innovation Center of Marine Science and Technology of Hainan University(XTCX2022HYC14)Innovative Research Project for Postgraduate Students in Hainan Province(Qhyb2024-95).
文摘Development of robust electrocatalyst for oxygen reduction reaction(ORR)in a seawater electrolyte is the key to realize seawater electrolyte-based zinc-air batteries(SZABs).Herein,constructing a local electric field coupled with chloride ions(Cl-)fixation strategy in dual single-atom catalysts(DSACs)was proposed,and the resultant catalyst delivered considerable ORR performance in a seawater electrolyte,with a high half-wave potential(E_(1/2))of 0.868 V and a good maximum power density(Pmax)of 182 mW·cm^(−2)in the assembled SZABs,much higher than those of the Pt/C catalyst(E_(1/2):0.846 V;Pmax:150 mW·cm^(−2)).The in-situ characterization and theoretical calculations revealed that the Fe sites have a higher Cl^(−)adsorption affinity than the Co sites,and preferentially adsorbs Cl^(−)in a seawater electrolyte during the ORR process,and thus constructs a low-concentration Cl^(−)local microenvironment through the common-ion exclusion effect,which prevents Cl^(−)adsorption and corrosion in the Co active centers,achieving impressive catalytic stability.In addition,the directional charge movement between Fe and Co atomic pairs establishes a local electric field,optimizing the adsorption energy of Co sites for oxygen-containing intermediates,and further improving the ORR activity.
基金funding support from the National Natural Science Foundation of China(92472109,T2325012)the Program for HUST Academic Frontier Youth Team+1 种基金support from the Fundamental Research Funds for the Central Universities(HUST,5003120083)supported by the Postdoctoral Fellowship Program of CPSF(GZC20240532)。
文摘Batteries play a critical role in electric vehicles and distributed energy generation.With the growing demand for energy storage solutions,new battery materials and systems are continually being developed.In this process,molecular dynamics(MD)simulations can reveal the microscopic mechanisms of battery processes,thereby boosting the design of batteries.Compared to other MD simulation techniques,the machine learning force field(MLFF)holds the advantages of first-principles accuracy along with large spatial and temporal scale,offering opportunities to uncover new mechanisms in battery systems.This review presents a detailed overview of the fundamental principles and model types of MLFFs,as well as their applications in simulating the structure,transport properties,and chemical reaction properties of bulk battery materials and interfaces.Notably,we emphasize the long-range interaction corrections and constant-potential methods in the model design of MLFFs.Finally,we discuss the challenges and prospects of applying MLFF models in the research of batteries.
基金supported by the National Natural Science Foundation of China(No.52462026)Postdoctoral Research Foundation of China(No.2018M643699)Shaanxi Province Postdoctoral Science Foundation(No.2018BSHEDZZ 101).
文摘Rational design of hierarchical structures and a dual-interface built-in electric field(BIEF)are vital for enhancing dielectric loss and directional charge transport in microwave absorption materials(MAMs).Herein,we propose a dual-interface BIEF engineering strategy to construct a multifunctional MoS_(2)@C/CoS_(x)composites.Inspired by the spiderweb hunting mechanism,magnetic Co-based Prussian blue(PB)is electro spun with polyacrylonitrile to form Co@CoO/C nanofibers,followed by sulfidation to induce ordered array architectures.The structural evolution enables the formation of heterogeneous MoS_(2)-CoSx-C interfaces and modulates the interfacial electric field intensity to enhance dielectric polarization.Density functional theory(DFT)calculations confirm that the work function difference(ΔΦ)of C/CoS_(2)/MoS_(2) is 6.179 eV,which indicates that the differencesΔΦamong MoS_(2),CoS_(x)and C components drive the spontaneous formation of dual-interface BIEF.This facilitates directional charge migration and strong dipolar/interface polarization,significantly improving the microwave attenuation capability.Benefiting from this design,the composite achieves a minimum reflection loss(RL_(min))of-63.83 dB and a maximum effective absorption bandwidth(EAB_(max))of 6.96 GHz,covering both C and Ku bands.In addition,the material reveals excellent infrared stealth performance due to its unique spiderweb-inspired ordered array structure.This study provides new insights into interfacial electric field modulation and a generalizable approach for designing multi-band and tunable microwave absorbers with synergistic electromagnetic and thermal stealth functions.
文摘数据清洗、特征选择和预测模型建立是基于数据采集与监视控制系统(supervisory control and data acquisition,SCADA)数据,实现风电机组异常状态预警不可缺少的重要环节。先结合孤立森林(isolation forest,iForest)和基于密度的空间聚类(density-based spatial clustering of applications with noise,DBSCAN)算法对SCADA数据异常点进行有效清洗,并采用随机森林算法(random forests,RF)与Person相关系数法优选模型输入参数;再进而基于Optuna优化的类别提升树(categorical boosting,CATBoost)算法,建立风电机组正常工况齿轮箱油池温度的预测模型;然后采用滑动窗方法,构建状态评价指标,并使用区间估计理论确定油温异常状态判别的临界阈值;实现油温异常预警;最后,采用某风电机组SCADA系统油温异常的真实历史故障数据进行检验,验证了该方法的有效性。
文摘针对串行抵消列表(Successive Cancellation List,SCL)译码框架下基于搜索集的路径分裂选择策略的缺陷,提出两种改进策略:基于可靠性函数的路径分裂策略和依靠辅助路径度量值(Auxiliary Path Metric,APM)的剪枝策略。在此基础上,提出一种新的译码算法——基于可靠性函数的路径分裂选择策略辅助串行抵消列表(Path Splitting Selecting Strategy Based on Reliability Function under the Successive Cancellation List,PSS-RF-SCL)译码算法。该算法在译码阶段,每个信息比特在进行路径分裂前,会计算所有路径的路径度量(Path Metric,PM)值。利用这些PM值,进一步计算该比特的可靠性函数值。算法将可靠性函数值低于其平均值(即阈值α)的信息比特视为需要进行路径分裂的比特,从而减少了多余的路径分裂次数。此外,算法计算每条路径的APM值,并将APM值高于正确译码路径的APM平均值(即阈值β)的路径视为不可靠路径,对不可靠路径进行剪枝,有效控制了译码列表总数。仿真结果表明,相较于传统的基于搜索集的路径分裂策略辅助的SCL译码算法,所提出的PSS-RF-SCL译码算法在保持相同译码性能的前提条件下,显著降低了译码复杂度。
基金financially supported by the National Natural Science Foundation of China(No.11604227)International Visiting Program for Excellent Young Scholars of SCU(No.20181504)International Science and Technology Innovation Cooperation of Sichuan Province(No.21GJHZ0230)。
文摘Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical resonance.Here,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere monolayer.The form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,respectively.The strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell geometry.The chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically investigated.The DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.
