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Flexible mille-feuille structure electromagnetic interference shielding film with excellent thermal conductivity and Joule heating

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Nano Research 2024年第5期17卷 4544-4554页

作者： Dingwen Yin Huijuan Xiu Simin Wang Yanfei Pan Na Li Rui Cheng shaoyan Huang sha.fan Jinbao Li College of Bioresources Chemical&Materials Engineering Shaanxi University of Science&TechnologyXi'an 710021China National Demonstration Center for Experimental Light Chemistry Engineering Education Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper DevelopmentXi'an 710021China College of Material Science and Art Design Inner Mongolia Agricultural UniversityHohhot 010018China

The intelligent electronic devices have urgent demands for electromagnetic interference(EMI)shielding films with excellent heat dissipation ***,it is challenging to obtain excellent EMI shielding and thermal conductivity performances ***,inspired by mille-feuille structure,the multifunctional EMI shielding films developed by a layer-by-layer self-assembly and hot-pressing *** ingenious introduction of silver nanoparticles(AgNPs)with large specific surface area and highly conductive into the network formed by TEMPO-oxidized cellulose nanofibrils(TOCNFs)with large aspect ratio to form the TOCNFs/*** the graphene nanoplates(GNPs)with high conductivity loss distributed alternately with TOCNFs/AgNPs to construct mille-feuille structure,which had highly efficient conductive network,complete thermally conduction pathway and rich heterogeneous ***,the designed films presented high electrical conductivity of 8520 S/cm,superb EMI effectiveness(SE)of 98.05 dB,and excellent thermal conductivity of 18.82 W/(m·K).Furthermore,the films possessed outstanding Joule heating performances with low voltages,including high heating temperature(100℃),fast response time(<20 s),and impressive heating stability and ***,such high-performance EMI shielding films with fascinating thermal conductivity and Joule heating performances have substantial application in flexible electronics,electromagnetic waves shielding and thermal management.

关键词： TEMPO-oxidized cellulose nanofibrils/silver nanoparticles(TOCNFs/AgNPs) mille-feuille structure electromagnetic interference shielding thermal conductivity Joule heating

Nonlinear Extrapolation Estimates of π

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 91-108页

作者： Wen-qing Xu sha-sha Wang Da-chuan Xu Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing100124China Department of Mathematics and Statistics California State UniversityLong BeachCalifornia90840USA Department of Mathematics and Physics Shijiazhuang Tiedao UniversityShijiazhuang050043China

The classical Archimedean approximation of π uses the semiperimeter or area of regular polygons inscribed in or circumscribed about a unit circle in R~2 and it is well-known that by using linear combinations of these basic estimates,modern extrapolation techniques can greatly speed up the approximation ***,when n vertices are randomly selected on the circle,the semiperimeter and area of the corresponding random inscribed and circumscribing polygons are known to converge to π almost surely as n→∞,and by further applying extrapolation processes,faster convergence rates can also be achieved through similar linear combinations of the semiperimeter and area of these random *** this paper,we further develop nonlinear extrapolation methods for approximating π through certain nonlinear functions of the semiperimeter and area of such *** focus on two types of extrapolation estimates of the forms χ_n=S_n~αA_n~β and Y_n(p)=(αS_n~p+βA_n~p)~(1/p) where α+β=1,p≠0,and Sn and An respectively represents the semiperimeter and area of a random n-gon inscribed in the unit circle in R~2,and Xn may be viewed as the limit of Y_n(p) when p→*** deriving probabilistic asymptotic expansions with carefully controlled error estimates for Xn and Y_n(p),we show that the choice α=4/3,β=-1/3 minimizes the approximation error in both cases,and their distributions are also asymptotically normal.

关键词： Archimedean polygons random polygons approximations ofπ extrapolation processes asymptotic convergence

Insight into the development of electrolytes for aqueous zinc metal batteries from alkaline to neutral

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Chinese Chemical Letters 2024年第2期35卷 232-241页

作者： An Duan sha Luo Wei Sun School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Aqueous zinc metal batteries are considered as promising candidates for next-generation electrochemical energy storage devices,especially for large-scale energy storage,due to the advantages of high-safety,high energy density and low *** the bridge connecting cathode and anode,electrolyte provides a realistic operating *** alkaline and neutral aqueous zinc metal batteries,issues associated with electrolyte and anode are still *** this review,we reveal the development and evolution of electrolytes for aqueous zinc metal batteries from alkaline to neutral via the description of fundamentals and challenges in terms of comparison and *** also elaborate the strategies in electrolytes regulation and highlight the basic roles and progresses in additives engineering.

关键词： Aqueous electrolytes Zinc metal batteries pH-dependent chemistry Electrolyte regulation Additives engineering

The Extended Hybrid Carrier-Based Multiple Access Technology for High Mobility Scenarios

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China Communications 2024年第1期21卷 53-68页

作者： Ge Song Xiaojie fang Xuejun sha School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China

The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering *** this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless *** employing the EHC modulation,a power layered multiplexing framework is realized,which exhibits enhanced interference suppression capability owing to the more uniform energy distribution *** implementation method and advantage mechanism are explicated respectively for the uplink and downlink,and the performance analysis under varying channel conditions is *** addition,considering the connectivity demand,we explore the non-orthogonal multiple access(NOMA)method of the EHC system and develop the EHC sparse code multiple access *** proposed scheme melds the energy spread superiority of EHC with the access capacity of NOMA,facilitating superior support for massive connectivity in high mobility *** results have verified the feasibility and advantages of the proposed *** with existing HC multiple access schemes,the proposed scheme exhibits robust bit error rate performance and can better guarantee multiple access performance in complex scenarios of nextgeneration communications.

关键词： extended hybrid carrier system high mo-Received:Jun.09,2023 Revised:Nov.20,2023 Editor:Yuanwei Liu bility communications multiple access

Establishment of a three-dimensional particle library for graded crushed stone based on a new aggregate morphology characterization method

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第1期11卷 117-130页

作者： Haitao Ge Aimin sha Zhenqiang Han School of Future Transportation Chang'an UniversityXi'an 710064China University of Strasbourg INSA StrasbourgCNRSICubeUMR 7357Strasbourg F-67000France School of Highway Chang'an UniversityXi'an 710064China Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang'an UniversityXi'an 710064China

The morphology of graded crushed stone(GCS)particles has an essential influence on the performance of aggregate *** impact of particle shape is a comprehensive effect that cannot be considered separately,leading to difficulties in establishing the relationship between the mixture properties and the aggregate morphology by using laboratory *** discrete element method(DEM)is an effective way widely adopted to reconstruct the morphology of particles and simulate performance tests of granular ***,selecting limited particles characterizing a real particle-assembly for simulation is still a challenge in current research due to the inherent rich variability of particle *** this study,based on the acquisition of three-dimensional(3D)aggregate shapes by using laser scanning,ellipsoid index(EDI)translating the particle shape as a function of surface area,volume,and contour length is proposed to comprehensively evaluate aggregate ***,a particle library capable of characterizing aggregate morphology distribution is established based on the statistics of the corresponding morphological characteristics of particle *** model reliability is validated by carrying out a series of experimental and numerical penetration tests with nine different *** established particle library can be used to model aggregate mixtures and the proposed simulation framework is promising for optimizing the mixture gradation design numerically.

关键词： Particle library Discrete element method 3D laser scanning Coarse aggregate Morphology characterization Gradation design

An improved interval model updating method via adaptive Kriging models

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 497-514页

作者： sha WEI Yifeng CHEN Hu DING Liqun CHEN shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China shanghai Institute of Aircraft Mechanics and Control Shanghai 200092China

Interval model updating(IMU)methods have been widely used in uncertain model updating due to their low requirements for sample ***,the surrogate model in IMU methods mostly adopts the one-time construction *** makes the accuracy of the surrogate model highly dependent on the experience of users and affects the accuracy of IMU ***,an improved IMU method via the adaptive Kriging models is *** method transforms the objective function of the IMU problem into two deterministic global optimization problems about the upper bound and the interval diameter through universal grey *** optimization problems are addressed through the adaptive Kriging models and the particle swarm optimization(PSO)method to quantify the uncertain parameters,and the IMU is *** the construction of these adaptive Kriging models,the sample space is gridded according to sensitivity *** sampling is then performed in key subspaces based on the maximum mean square error(MMSE)*** interval division coefficient and random sampling coefficient are adaptively adjusted without human interference until the model meets accuracy *** effectiveness of the proposed method is demonstrated by a numerical example of a three-degree-of-freedom mass-spring system and an experimental example of a butted cylindrical *** results show that the updated results of the interval model are in good agreement with the experimental results.

关键词： interval model updating(IMU) non-probabilistic uncertainty adaptive Kriging model surrogate model grey number

Early screening for post-stroke depression and its effect on functional outcomes, quality of life, and mortality: A meta-analysis

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World Journal of Psychiatry 2024年第9期14卷 1397-1403页

作者： Jie Dai sha-sha Zhao Su-Xiang Zhang Department of Neurology 6 Cangzhou Central HospitalCangzhou 061001Hebei ProvinceChina

BACKGROUND Post-stroke depression(PSD)is a common and debilitating condition affecting stroke survivors,significantly impacting their recovery and overall quality of *** To assess the effects of early PSD screening on functional outcomes,quality of life,and *** From an initial pool of 1065 articles,6 studies met the inclusion criteria and were selected for *** outcomes were measured using the functional independence measure(FIM).RESULTS The analysis revealed a significant improvement in FIM scores for a PSD scree-ning group compared to controls[standardized mean difference(SMD)=8.90,95%confidence interval(CI):4.65-13.15,P<0.01].Quality of life was assessed using the Stroke-Specific Quality of Life Scale,with the screening group showing significantly higher scores(SMD=20.83,95%CI:15.27-26.38,P<0.01).Mortality analysis indicated a reduction in five-year mortality rates for the PSD screening *** Early PSD screening enhances functional recovery,improves quality of life,and reduces mortality rates in stroke ***,integrating PSD screening into routine stroke care improves long-term outcomes for patients.

关键词： Post-stroke depression Early screening Functional outcomes Quality of life Mortality

Microstructure and Mechanical Property of Mg‑13Gd‑0.2Ni Alloy Processed by Extrusion and Aging

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1367-1376页

作者： Hang Zhang Jiaying Zhao Rongguang Li Boshu Liu shanshan Li sha sha Yuehong Zhang Man Xu Yan Tang School of Mechanical and Power Engineering Shenyang University of Chemical TechnologyShenyang 110142China Instrumental Analysis Center Shenyang University of Chemical TechnologyShenyang 110142China

In this work,a good combination of strength and ductility is achieved in a Mg-13Gd-0.2Ni alloy by conventional extrusion and following aging *** aged Mg-13Gd-0.2Ni alloy exhibits a yield strength(YS)of 363 MPa,an ultimate tensile strength(UTS)of 433 MPa,and an elongation of 11.9%.The aged Mg-13Gd-0.2Ni alloy contains a microstructure with a 95%proportion of dynamically recrystallized(DRXed)grains with a micron size,weak texture,and a high number density of prismaticβ′precipitates within *** bulk compounds enriched with Ni element which are mainly formed during casting and stable in the extruded and aged *** dynamic compounds are formed during extrusion,and a high density of prismaticβ′precipitates are formed during *** high density of prismaticβ′precipitates results in a significant increase in the strength of the Mg-13Gd-0.2Ni alloy,and the YS and UTS are increased by 153 and 136 MPa,*** high proportion of DRXed grains with a weak texture contributes mainly to the high ductility and the fine compounds with a low density at grain boundaries formed during aging have no significant adverse effect on ductility of the aged Mg-13Gd-0.2Ni *** findings for the novel Mg-Gd-Ni alloy can provide guidance for the design of wrought Mg alloys with superior mechanical properties.

关键词： Mg-Gd-Ni alloy Extrusion Aging Strength Ductility

Stochastic uncertain lubrication in gear transmission subjected to tribodynamic loading

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Friction 2024年第8期12卷 1741-1756页

作者： Zhou CHEN Haiming sha Sheng LI Zheming TONG Shuiguang TONG State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Mechanical Engineering Zhejiang UniversityHangzhou 310027China Wright State University 3640 Colonel Glenn HighwayDaytonOH 45435USA

A stochastic uncertain tribodynamic model is established for a spur gear pair for the first *** stochastic uncertainty of pinion rotation speed propagated to lubrication performance is *** probability density function of the minimum lubricant film thickness hmin evolves over time periodically at interval of an engagement *** between abrupt increase in meshing force and amplification of hmin uncertainty is *** and reliable lubrication performance can be achieved by suppressing the hmin uncertainty and decreasing the lubrication failure *** can be done by increasing lubricant viscosity,and decreasing input torque and uncertainty level of input rotation *** work lays a solid foundation for robust and reliability based optimization for tribodynamic gear system.

关键词： stochastic uncertainty gears elastohydrodynamic lubrication(EHL) tribodynamics