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Nano high-entropy oxide cathode with enhanced stability for direct borohydride fuel cells

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Journal of Energy Chemistry 2025年第1期100卷 309-316页

作者： Lei Zhang Lingfeng Kuang Lianke Zhang wen Chu Haiying Qin Jing Zhang Junjing He Hualiang Ni Hongzhong chi New Energy Materials Research Center College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhou 310018ZhejiangChina School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027ZhejiangChina Key Laboratory of MEMS of Ministry of Education School of Integrated CircuitsSoutheast UniversityNanjing 210096JiangsuChina

High-entropy materials have become high-activity electrocatalysis owing to their high-entropy effect and multiple active ***,we synthesize a series of carbon-supported nano high-entropy oxides(HEOs/C),specifically (PtFeCoNiCu)O/C,using a carbothermal shock (CTS) method for application as a cathode catalyst in direct borohydride fuel cells (DBFCs).The microstructure of the prepared catalysts was characterized by X-ray photoelectron spectroscopy,X-ray absorption fine structure,and transmission electron *** prepared (PtFeCoNiCu)O/C,with particle sizes ranging from 2 to 4 nm,demonstrates 3.94 transferred electrons towards the oxygen reduction reaction in an alkaline environment,resulting in a minimal H_(2)O_(2)yield of 2.6%.Additionally,it exhibits a Tafel slope of 61 mV dec-1,surpassing that of commercial Pt/C (82 mV dec-1).Furthermore,after 40,000 cycles of cyclic voltammetry(CV) testing,the half-wave potential of (PtFeCoNiCu)O/C shows a positive shift of 3 mV,with no notable decline in the limiting current *** (PtFeCoNiCu)O/C is used as a cathode catalyst in DBFCs,the DBFC achieves a maximum power density of 441 mW cm^(-2)at 60°C and sustains a cell voltage of approximately 0.73 V after 52 h at 30°*** findings confirm that HEO/C is a promising cathode catalyst for DBFCs.

关键词： High-entropy oxides Oxygen reduction reaction Carbothermal shock Stability Direct borohydride fuel cells

Relativistic two-fluid hydrodynamics with quantized vorticity from the nonlinear Klein–Gordon equation

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Communications in Theoretical Physics 2025年第2期77卷 161-171页

作者： chi Xiong Kerson Huang Minjiang Collaborative Center for Theoretical Physics Minjiang University Institute of Advanced Studies & School of Physical and Mathematical Science Nanyang Technological University Physics Department Massachusetts Institute of Technology Cambridge

We consider a relativistic two-fluid model of superfluidity, in which the superfluid is described by an order parameter that is a complex scalar field satisfying the nonlinear Klein–Gordon equation(NLKG). The coupling to the normal fluid is introduced via a covariant current–current interaction, which results in the addition of an effective potential, whose imaginary part describes particle transfer between superfluid and normal fluid. Quantized vorticity arises in a class of singular solutions and the related vortex dynamics is incorporated in the modified NLKG,facilitating numerical analysis which is usually very complicated in the phenomenology of vortex filaments. The dual transformation to a string theory description(Kalb–Ramond) of quantum vorticity, the Magnus force, and the mutual friction between quantized vortices and normal fluid are also studied.

关键词： relativistic superfluidity nonlinear Klein-Gordon field theory quantized vortices two-fluid model Kalb-Ramond field global string

Molecular dynamics simulations of helium transport through inorganic mineral nanopores

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Science china Earth Sciences 2025年第1期68卷 237-252页

作者： Dandan SONG Ping GUAN chi ZHANG Jiahao REN School of Earth and Space Sciences Peking UniversityBeijing100871China

Helium transport through nanoscale inorganic mineral pores and pore throats is essential for its overall *** elucidate helium's transport dynamics within nanopores,we employed equilibrium and non-equilibrium molecular dynamics simulations to investigate helium's static self-diffusion and pressure-driven flow in quartz slit-shaped *** also introduced water and various gases,including hydrogen,methane,ethane,nitrogen,and carbon dioxide,into the nanopores to assess their influence on helium *** findings indicate minimal helium adsorption on quartz pore *** conditions where the pore size is less than 5 nm and the pressure under 10 MPa,environmental factors markedly influence helium *** pore sizes,high temperatures,and low gas pressures enhance helium desorption and facilitate faster *** observed a positive correlation between helium flow velocity and factors such as pore size,pressure gradient,and surface smoothness of the ***,the presence of pore water and carrier gases in quartz nanopores,which diffuse more slowly than helium,tends to reduce helium surface adsorption and slow its *** the carrier gases studied,nitrogen showed similar adsorption capacity,diffusivity,and stability to helium,while carbon dioxide displayed the highest adsorption capacity and the slowest diffusion rate,markedly differing from *** on the simulation results,we concluded that water and carrier gases primarily function as transport mediums in helium migration,moving together with ***,which shares similar properties with helium,effectively assists in this co-migration ***,carbon dioxide,due to its high adsorption capacity and slow diffusion,tends to be lost during *** a result,gas reservoirs with high nitrogen levels and low carbon dioxide levels are more likely to have higher helium ***,the smaller pore sizes and higher gas pressures in caproc

关键词： Helium transport Slit nanopores Molecular dynamics simulations Diffusion Flow carriers

Prompt fission neutron uranium logging(Ⅱ):dead-time effect of the neutron time spectrum

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Nuclear Science and Techniques 2025年第2期36卷 82-94页

作者： Yan Zhang chi Liu Shi-Liang Liu Hao-Ran Zhang Hai-Tao Wang Jin-Hui Qu wen-Xing Hu Ren-Bo Wang Bin Tang National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing East China University of TechnologyNanchang 330013China Fundamental Science on Radioactive Geology and Exploration Technology Laboratory East China University of TechnologyNanchang 330013China

The acquisition of neutron time spectrum data plays a pivotal role in the precise quantification of uranium via prompt fission neutron uranium logging(PFNUL).However,the impact of the detector dead-time effect remains paramount in the accurate acquisition of the neutron time ***,it is imperative for neutron logging instruments to establish a dead-time correction method that is not only uncomplicated but also practical and caters to various logging *** study has formulated an innovative equation for determining dead time and introduced a dead-time correction method for the neutron time spectrum,called the“dual flux method.”Using this approach,a logging instrument captures two neutron time spectra under disparate neutron *** carefully selecting specific“windows”on the neutron time spectrum,the dead time can be accurately *** substantiate its efficacy and discern the influencing factors,experiments were conducted utilizing a deuterium-tritium(D-T)neutron source,a Helium-3(3He)detector,and polyethylene shielding to collate and analyze the neutron time spectrum under varying neutron fluxes(at high voltages).The findings underscore that the“height”and“spacing”of the two windows are the most pivotal influencing ***,the“height”(fd)should surpass 2,and the“spacing”twd should exceed 200μ*** dead time of the 3 He detector determined in the experiment was 7.35μ*** the dead-time correction,the deviation of the decay coefficients from the theoretical values for the neutron time spectrum under varying neutron fluxes decreased from 12.4%to within 5%.Similarly,for the PFNUL instrument,the deviation in the decay coefficients decreased from 22.94 to 0.49%after correcting for the dead-time *** results demonstrate the exceptional efficacy of the proposed method in ensuring precise uranium *** dual flux method was experimentally validated as a universal approach applicable to pulsed neutron logging instrumen

关键词： PFNUL Neutron time spectrum Dead time Pulsed source Correction method

Sporadic E responds to the 2022 Tonga volcano eruptions recorded by the Meridian Project

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Earth and Planetary Physics 2025年第1期9卷 20-28页

作者： YangYi Sun Tao Yu Jin Wang chi Long School of Geophysics and Geomatics China University of Geosciences(Wuhan)Wuhan 430047China School of Physics and Electronic Science Guizhou Normal UniversityGuizhou 550001China

In this study,ionosonde observations over Fuke(19.5°N,109.1°E),Wuhan(30.5°N,114.4°E),and Mohe(53.5°N,122.3°E)were analyzed to demonstrate the responses of the sporadic E()to the severe atmospheric disturbances caused by the Tonga volcanic eruptions on January 15,*** most prominent signature was the disappearance of the layer after~10:00 UT over Wuhan and Fuke,which was attributed to the vertical drift caused by the *** occurred intermittently after 13:00 UT following the arrival of the tropospheric Lamb *** examine the causal mechanism for the intermittence,we also included data of horizontal winds in the mesosphere and lower thermosphere region recorded by the meteor radars at Wuhan and Mohe in this *** wind disturbances with periods of~20 hours contributed to the formation of the layer in the nighttime on January 15.

关键词： sporadic E Tonga eruptions neutral wind disturbances

Adaptive optimal control system design for semi-active suspension system by supposing variable parameters under exogenous road disturbance

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Control Theory and Technology 2025年第1期23卷 64-73页

作者： Viet Nguyen Hoang Feiqi Deng chi Nguyen Van School of Automation Science and Engineering South China University of TechnologyGuangzhou510640GuangdongChina Thai Nguyen University of Technology Thai Nguyen CityVietnam

This article presents an adaptive optimal control method for a semi-active suspension *** model of the suspension system is built,in which the components of uncertain parameters and exogenous disturbance are *** adaptive optimal control law consists of the sum of the optimal control component and the adaptive control ***,the optimal control law is designed for the model of the suspension system after ignoring the components of uncertain parameters and exogenous disturbance caused by the road *** optimal control law expresses the desired dynamic characteristics of the suspension ***,the adaptive component is designed with the purpose of compensating for the effects caused by uncertain parameters and exogenous disturbance caused by the road surface;the adaptive component has adaptive parameter rules to estimate uncertain parameters and exogenous *** exogenous disturbances are eliminated,the system responds with an optimal controller *** separating theoretically the dynamic of a semi-active suspension system,this solution allows the design of two separate controllers easily and has reduced the computational burden and the use of too many tools,thus allowing for more convenient hardware *** simulation results also show the effectiveness of damping oscillations of the proposed solution in this article.

关键词： Quarter car suspension system Semi-active suspension Adaptive control Optimal control Linear-quadratic regulator Exogenous disturbance

Extraordinary synergy on 3D hierarchical porous Co-Cu nanocomposite for catalytic elimination of VOCs at low temperature and high space velocity

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Journal of Environmental Sciences 2025年第5期151卷 714-732页

作者： Jinyan Xiao chi Zhang Lei Yang Shengwei Tang wenxiang Tang School of Chemical Engineering Sichuan UniversityChengdu 610065China

It is still a challenge to develop hierarchically nanostructured catalysts with simple approaches to enhance the low-temperature catalytic ***,a set of mesoporous Co-Cu binary metal oxides with different morphologies were successfully prepared via a facile ammonium bicarbonate precipitation method without any templates or surfactants,which were further applied for catalytic removal of carcinogenic *** the catalysts with different ratios,the CoCu_(0.2)composite oxide presented the best performance,where the temperature required for 90%conversion of toluene was only 237°C at the high weight hour space velocity(WHSV)of 240,000 mL/(gcat·hr).Meanwhile,compared to the related Co-Cu composite oxides prepared by using different precipitants(NaOH and H_(2)C_(2)O_(4)),the NH_(4)HCO_(3)-derived CoCu_(0.2)sample exhibited better catalytic efficiency in toluene oxidation,while the T90 were 22 and 28°C lower than those samples prepared by NaOH andH_(2)C_(2)O_(4)routes,*** on various characterizations,it could be deduced that the excellent performance was related to the small crystal size(6.7 nm),large specific surface area(77.0 m2/g),hollow hierarchical nanostructure with abundant high valence Co ions and adsorbed oxygen *** situ DRIFTS further revealed that the possible reaction pathway for the toluene oxidation over CoCu_(0.2)catalyst followed the route of absorbed toluene→benzyl alcohol→benzaldehyde→benzoic acid→carbonate→CO_(2)and H_(2)*** addition,CoCu_(0.2)sample could keep stable with long-time operation and occur little inactivation under humid condition(5 vol.%water),which revealed that the NH_(4)HCO_(3)-derived CoCu_(0.2)nanocatalyst possessed great potential in industrial applications for VOCs abatement.

关键词： Toluene oxidation Co-Cu composite Synergistic effect Hollow hierarchical nanostructure Precipitation method

Using fracture mechanics method to analyze the failure mechanism and equilibrium equation of interfacial loess-mudstone landslides

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Journal of Mountain Science 2025年第1期22卷 156-166页

作者： LI Shuanhu LI chi GAO Yu Key Laboratory of Geological Hazards and Geotechnical Engineering Defense in Sandy and Drought Regions at Universities of Inner Mongolia Autonomous Region Inner Mongolia University of TechnologyHohhot 010051China Inner Mongolia Engineering Research Center of Geological Technology and Geotechnical Engineering Inner Mongolia University of TechnologyHohhot 010051China College of Resource and Environmental Engineering Inner Mongolia University of TechnologyHohhot 010051China

Loess-mudstone landslides are common in the Loess *** into the mechanical theory of loess-mudstone landslides have become a challenging undertaking due to the distinctive interfacial properties of loess-mudstone and the unique water sensitivity characteristics of ***,it is imperative to develop innovative mechanical models and mathematical equations specifically tailored to loess-mudstone *** this study,we analyze the fracture mechanism of the loess-mudstone sliding zone using plastic fracture mechanics and develop a unique fracture yield *** calculate the energy release rate during the expansion of the loess-mudstone interface tip region,the shear fracture energy G is applied,which reflects both the yield failure criterion and the fracture failure *** better understand the instability mechanism of loess-mudstone landslides,equilibrium equations based on G are established for tractive,compressive,and tensile loess-mudstone *** on the equilibrium equation,the critical length Lc of the sliding zone can be used for the safety evaluation of loess-mudstone *** this way,this study proposes a new method for determining the failure mechanism and equilibrium equation of loessmudstone landslides,which resolves their starting mechanism,mechanical equilibrium equations,and safety evaluation indicators,thus justifying the scientific significance and practical value of this research.

关键词： Loess-mudstone landslide Failure mechanism Shear fracture energy Equilibrium equation Safety factor

Enhanced battery life prediction with reduced data demand via semi-supervised representation learning

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Journal of Energy Chemistry 2025年第2期101卷 524-534页

作者： Liang Ma Jinpeng Tian Tieling Zhang Qinghua Guo chi Yung Chung School of Mechanical Materials Mechatronic and Biomedical Engineering University of Wollongong Department of Electrical and Electronic Engineering and Research Centre for Grid Modernisation The Hong Kong Polytechnic University Photonics Research Institute The Hong Kong Polytechnic University School of Electrical Computer and Telecommunications Engineering University of Wollongong

Accurate prediction of the remaining useful life(RUL) is crucial for the design and management of lithium-ion *** various machine learning models offer promising predictions,one critical but often overlooked challenge is their demand for considerable run-to-failure data for *** of such training data leads to prohibitive testing efforts as the run-to-failure tests can last for ***,we propose a semi-supervised representation learning method to enhance prediction accuracy by learning from data without RUL *** approach builds on a sophisticated deep neural network that comprises an encoder and three decoder heads to extract time-dependent representation features from short-term battery operating data regardless of the existence of RUL *** approach is validated using three datasets collected from 34 batteries operating under various conditions,encompassing over 19,900 charge and discharge *** method achieves a root mean squared error(RMSE)within 25 cycles,even when only 1/50 of the training dataset is labelled,representing a reduction of 48%compared to the conventional *** also demonstrate the method's robustness with varying numbers of labelled data and different weights assigned to the three decoder *** projection of extracted features in low space reveals that our method effectively learns degradation features from unlabelled *** approach highlights the promise of utilising semi-supervised learning to reduce the data demand for reliability monitoring of energy devices.

关键词： Lithium-ion batteries Battery degradation Remaining useful life Semi-supervised learning