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Enhanced cycling stability and rate performance of Co-doped and La_(2)O_(3)-coated LiNi_(0.9)Mn_(0.1)O_(2) toward power battery

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Rare Metals 2024年第2期43卷 658-670页

作者： Jia-Qi Peng yuan-yuan wei Dong-Ming Liu Yun Li Bin Hu Bin Huang Jian-Wen Yang Shun-Hua Xiao Ren-Heng Wang Guangxi Key Laboratory of Electrochemical and Magneto-Chemical Functional Materials College of Chemistry and BioengineeringGuilin University of TechnologyGuilin541004China Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China

Ultra-high nickel layered oxide cathode material with high energy density is the most promising material to improve the electrochemical performance of lithium-ion batteries(LIBs).However,the poor structural stability and severe surface/interface side reactions of the material lead to poor rate performance and cyclic stability,which limits its application in *** this paper,the dual-modification strategy of Co doping and La_(2)O_(3) coating is used to meet the above *** doping can effectively widen layer spacing and reduce Li^(+)/Ni^(2+) mixing,and La_(2)O_(3) coating can effectively eliminate the residual alkali on the surface of active material,inhibit the thickening of cathode electrolyte interphase(CEI)film and reduce surface/interface side ***,the modified material(NM90-CL)with excellent electrochemical properties is achieved through the synergistic enhancement of Co doping and La_(2)O_(3) *** capacity retention rate can reach 77.9%after 200 cycles at 1.0℃ and 75.7%after 200 cycles at 5.0℃.Its reversible capacity can up to 153.5 mAh·g^(–1) at 10.0℃.This dual-modification strategy will provide theoretical guidance and technical support for the synthesis of other high-performance electrode materials.

关键词： High nickel cathode material Co doping La_(2)O_(3) coating Electrochemical performance Electrochemical mechanism

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Adaptive beam forming for time-variant channels with a multi-beam antenna

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 37-40页

作者： JIANG Ze MEI yuan-yuan RUAN wei College of Electronic Engineering Chongqing University of Posts and Telecommunications Chongqing 400065 China

A multi-beam adaptive antenna is investigated by considering the adaptive beam forming performance for time-variant channels on the focus of mobile to base station or reverse link. This antenna is constructed by Fresnel zone phase-correcting plane （FZP） focusing element and uniformly spaced feeds array. An estimator for the beamforming weight vector in the presence of angle spreads is derived using a code filtering approach. Owing to the time-varying nature of the channels, a recursive method for computing and tracking the above optimal weight vector solution that is easy to implement is applied. The effects of angle spread, maximum Doppler frequency, and forgetting factor are studied. Simulation results showed that this type of adaptive antenna is capable of performing adaptive beam forming for time-variant channels effectively.

关键词： adaptive antenna adaptive beam forming FZP mismatch loss

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Effects of chest compressions on cardiorespiratory function in a non-arrested porcine model

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Chinese Medical Journal 2013年第12期126卷 2348-2353页

作者： CONG Lu-hong LI Chun-sheng GUO Zhi-jun WANG Shuo WU Jun-yuan yuan wei Department of Emergency Medicine Beijing Chaoyang Hospital Capital Medical University Beijing 100020 China

Background The effects of chest compressions to hemodynamic and respiratory parameters during hands-only cardiopulmonary resuscitation （CPR） in a non-arrested patient who suddenly collapses are *** this research,we investigated the effects of chest compressions in a non-arrested porcine *** Fourteen male domestic pigs were randomized into sham control group （SHAM group,only anesthetized and instrumented without chest compression,n=6） or chest compression group （CC group,2 minutes of chest compressions,n=8）.Continuous hemodynamic parameters,dynamic lung compliance （Cdyn）,and blood gas analysis outcomes were *** levels of catecholamine were measured at baseline and 2 minutes,30 minutes,4 hours,and 24 hours after chest *** computed tomography （CT） was performed at 30 minutes and 24 *** histopathology evaluation was *** After two minutes of chest compressions in the CC group,heart rate and extravascular lung water increased significantly; mean arterial pressure,stroke volume,and global ejection fraction significantly *** significantly decreased to valley levels at 30 minutes and slowly *** with the baseline,serum levels of catecholamine significantly increased at 2 minutes and rapidly decreased 24 hours *** 30 minutes after chest compressions,chest CT showed local exudation,which was absorbed 24 hours *** This research showed that 2 minutes of chest compressions causes various heart and lung tissue damage in the normal a normal porcine *** also impacts the hemodynamic and Cdyn.

关键词： chest compression lung contusion cardiopulmonary function non-arrested

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Brugada syndrome associated with out-of-hospital cardiac arrest: A case report

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World Journal of Clinical Cases 2021年第19期9卷 5345-5351页

作者： Guo-Hua Ni Hua Jiang Li Men yuan-yuan wei Dila A Xiang Ma Sichuan Academy of Medical Sciences&Sichuan Provincial People's Hospital(Chengdu Jinjiang Sohome Comprehensive Outpatient Clinic) Chengdu 610072Sichuan ProvinceChina Department of Geriatrics Affiliated Hospital of Chengdu UniversityChengdu 610081Sichuan ProvinceChina Department of Cardiology First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830000Xinjiang Uygur Autonomous RegionChina Department of Physiology Basic Medicine CollegeChengdu UniversityChengdu 610106Sichuan ProvinceChina

BACKGROUND Brugada syndrome(BrS)is an inherited disease characterized by an electrocardiogram(ECG)with a coved-type ST-segment elevation in the right precordial leads(V1-V3),which predisposes to sudden cardiac death(SCD)due to polymorphic ventricular tachycardia or ventricular fibrillation in the absence of structural heart *** report the case of a 29-year-old man with out-ofhospital cardiac *** is associated with a high incidence of SCD in adults,and increasing the awareness of BrS and prompt recognition of the Brugada ECG pattern can be *** SUMMARY A 29-year-old man suffered from out-of-hospital cardiac arrest,and after defibrillation,his ECG demonstrated a coved-type elevated ST segment in V1 and *** findings were compatible with type 1 Brugada pattern,and ECG of his brother showed a type 2 Brugada *** diagnosis was BrS,NYHF IV,multiple organ dysfunction syndrome,sepsis,and hypoxic ischemic *** patient had no arrhythmia episodes after discharge throughout a follow-up period of 36 *** Increasing awareness of BrS and prompt recognition of the Brugada ECG pattern can be lifesaving.

关键词： Brugada syndrome Out-of-hospital cardiac arrest Electrocardiogram Ventricular fibrillation Family history Case report

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Pyrolysis Empirical Modeling of Polyester Glass Fiber Reinforced Plastics Using Sestak-Berggren Model Method

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Journal of Thermal Science 2024年第2期33卷 725-738页

作者： NAN wei JI Wenhui yuan Yanping yuan Zhongyuan SUN Yong School of Mechanical Engineering Southwest Jiaotong UniversityChengdu610031China CRRC Changchun Railway Vehicles Co. LtdChangchun130062China

Polyester Glass Fiber Reinforced Plastic(Polyester GFRP),a thermosetting plastic comprised of glass fiber and polyester polymer compounds,is extensively utilized in high-speed *** its pyrolysis mechanism is crucial as it significantly influences the combustion characteristics and fire safety ***,kinetic research on polyester GFRP primarily focuses on employing the Coats-Redfern method to derive a theoretical kinetic ***,the pyrolysis process of polyester GFRP is complex and the aforementioned theoretical model fails to accurately describe the pyrolysis ***,this study seeks to utilize the Sestak and Berggren(SB) model as a methodological approach to reveal the complex reaction mechanism during the pyrolysis *** on thermogravimetric analysis,the entire pyrolysis process of polyester GFRP is divided into two primary ***,model-free methods are employed to ascertain the activation energy and pre-exponential *** results show that the fitted empirical models of the two main pyrolysis stages are f(α)=(1-α)^(1.47)[-ln(1-α)]^(1.50) and f(α)=(1-α)^(1.77)[-ln(1-α)]^(1.72),*** predicted results are in good agreement with experimental data under different heating rates,which indicates that the empirical model can sufficiently describe the pyrolysis process of polyester GFRP.

关键词： polyester GFRP model-fitting methods empirical models pyrolysis

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Development of component stiffness equations for thread-fixed one-side bolt connections to an enclosed rectangular hollow section column under tension

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 568-586页

作者： Fu-wei WU yuan-Qi LI Department of Structural Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this *** unknown stiffness components are considered:the TOBs connection and the enclosed RHS ***,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated *** on the findings,the thread-shank serial-parallel stiffness model of TOB connection is *** analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate *** to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load *** to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,***,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub *** proposed component stiffness equations are an effective supplement to the component-based method.

关键词： initial stiffness component based method thread-fixed one-side bolt rectangular hollow sections analytical equation

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Single-atom Ag-loaded carbon nitride photocatalysts for efficient degradation of acetaminophen:The role of Ag-atom and O_(2)

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Journal of Environmental Sciences 2024年第5期139卷 12-22页

作者： Yi yuan Wen-Long Wang Zhi-wei Wang Jin Wang Qian-yuan Wu Key Laboratory of Microorganism Application and Risk Control of Shenzhen Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental SafetyInstitute of Environment and EcologyShenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China College of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China

Carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light *** this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTCN)via thermal polymerization,the catalyst obtained is called *** Ag hardly changed the carbon nitride's layered and porous physical *** exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for *** with Ag improved the photocatalytic performance of UTCN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair *** addition,Ag doping facilitated O_(2) adsorption on UTCN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).

关键词： Ag single atom Carbon nitride Photocatalysis Visible light Adsorption energy Reactive species

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Analysis and Modeling of Calendar Aging and Cycle Aging of LiCoO_(2)/Graphite Cells

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Journal of Thermal Science 2024年第3期33卷 1109-1118页

作者： WANG wei yuan Baoqiang SUN Qie WENNERSTEN Ronald Institute of Thermal Science and Technology Shandong UniversityJi’nan250061China School of Energy and Power Engineering Shandong UniversityJi’nan250061China Institute for Advanced Science and Technology Shandong UniversityJi’nan250061China

Lithium-ion batteries are used in a wide range of ***,their cycle life suffers from the problem of capacity fade,which includes calendar and cycle *** effects of storage time,temperature and partial charge-discharge cycling on the capacity fade of Li-ion batteries are investigated in this *** calendar aging and cycle aging are presented based on the storage and cycling experiment on LiCoO_(2)/graphite cells under different storage temperature and different ranges of state of charge(SOC).Based on the measurement data,a one-component and a double-component aging model are presented to respectively describe the capacity fade caused by calendar and cycle *** calendar aging of LiCoO_(2)/graphite batteries is mainly affected by temperature and SOC during the *** SOC and change in SOC(ΔSOC)are the main factors affecting battery degradation during cycling operation.

关键词： Lithium-ion battery LiCoO_(2)(LCO)/graphite calendar aging cycle aging lifetime model

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Numerical Analysis of Heat Transfer Characteristics to Supercritical CO_(2) in a Vertical Mini-Channel:Transition and Pseudo-Boiling

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Journal of Thermal Science 2024年第1期33卷 101-113页

作者： yuan Baoqiang WANG wei XIN Gongming DU Wenjing School of Energy and Power Engineering Shandong UniversityJi'nan 250061China

Large eddy simulations have been conducted to study upward transitional flows and heat transfer characteristics of supercritical CO_(2) in a vertical *** numerical simulation was carried out on a modified buoyantPimpleFOAM solver in OpenFOAM 7,and was verified using experiment *** results indicate that increasing the Grashof numbers can reduce the flow stability and make the flow transition *** are four stages of heat transfer in the transition process,i.e.,weakened,improved,recovered and normal heat *** heat transfer phenomena in the transition process were explained from three perspectives:thermal boundary layer theory,turbulent transport and pseudo-boiling *** transfer enhancement during transition is related to the transport of supercritical molecular clusters,and these molecular clusters are regarded as pseudo-bubbles in pseudo-boiling *** flow pattern of the pseudo-phases in the dia-Widom process contains single-phase flow,steady pseudo-film flow,unsteady pseudo-film flow,partial pseudo-bubbles flow and flocculent pseudo-film ***-bubbles have similar behaviors to subcritical bubbles,i.e.,break-up,deformation,condensation and *** researches in this work are favorable for understanding the heat transfer mechanism of supercritical fluids during flow transition.

关键词： supercritical heat transfer large eddy simulation transition pseudo-boiling

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Micro-flow structure at regime transition from bubbling to turbulent fluidization in a fluidized bed

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Particuology 2024年第6期89卷 117-130页

作者： Chaoyu Yan Yue yuan Xiaoyang wei Jesse Zhu State Key Laboratory of Heavy Oil Processing Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of PetroleumBeijing 102249China China Beacons Institute The University of NottinghamNingbo315100China Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioN6A 5B9Canada

Gas-solid fluidized beds have found extensive utilization in frontline manufacturing,in particular as low-velocity *** fluidization status,the bubbling or turbulent flow regime and the transition in between,determine the system performance in practical *** the convoluted hydrodynamics are quantitively evaluated through numerous data-processing methodologies,none of them alone can reflect all the critical information to identify the transition from the bubbling to the turbulent ***,this study was to exploit a coupling data processing methodology,in the combination of standard deviation,power spectrum density,probability density function,wavelet transform,and wavelet multiresolution method,to jointly explain the micro-flow structure at the regime transition from bubbling to turbulent *** transient differential pressure fluctuation was measured for the evaluation in a fluidized bed(0.267 m i.d.×2.5 m height)with FCC catalysts(d_(p)=65μm,ρ_(p)=1780kg/m^(3))at different superficial gas velocities(0.02–1.4 m/s).The results show that the onset of turbulent fluidization starts earlier in the top section of the bed than in the bottom *** wavelet decomposition displays that the fluctuation of differential pressure mainly concentrates on the sub-signals with an intermediate frequency *** sub-signals could be synthesized into three types of scales(micro-scale,meso-scale,and macro-scale),representing the multi-scale hydrodynamics in the fluidized *** micro-scale signal has the characteristic information of bubbling fluidization,and the characteristic information of turbulent fluidization is mainly represented by the meso-scale *** work provides a systematic comprehension of fluidization status assessment and serves as an impetus for more coupling analysis in this sector.

关键词： Flow regime transition Bubbling fluidization Turbulent fluidization Micro-flow structure Differential pressure fluctuation

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