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Rheological Behaviors of Polymers with Nanoparticles Tethered at Each End

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Chinese Journal of Polymer Science 2024年第3期42卷 400-406,I0009页

作者： Song-Qi Zhang Wen-Qing Wang Jia-Ping Lin Li-Quan Wang Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

The polymer with nanoparticles tethered at each end is a unique model for unraveling the effect of chain ends on the polymer dynamics. We investigated the rheological behavior of this kind of polymer by using nonequilibrium molecular dynamics simulation. The effect of polymer lengths and nanoparticle radii on the complex moduli and viscosity was examined. The dependence of complex moduli on the frequency becomes less pronounced as the polymer is short or the nanoparticle is large. The shear thinning behavior was revealed for these systems, and the scaling exponent of complex viscosity with respect to the frequency was found to change from-1/2 to-3/4 as the polymer shortens or the nanoparticle enlarges. The rheological behavior was further explained by analyzing the mean square distance of nanoparticles. The simulation results were compared with the existing experimental finding, showing an agreement. The work provides information for understanding the chain end effect on polymer rheology.

关键词： Polymer rheology Modulus Viscosity Molecular dynamics

Impact response and energy absorption of metallic buffer with entangled wire mesh damper

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Defence Technology（防务技术） 2024年第5期35卷 137-150页

作者： Chao Zheng Jun Wu Mangong Zhang Xin Xue Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Wuhan Second Ship Design and Research Institute Wuhan 430205China

An innovative metallic buffer consisting of series-connected hat-shaped entangled wire mesh damper(EWMD)and parallel springs are proposed in this work to enhance the reliability of engineering *** impact response and the energy dissipation mechanism of hat-shaped EWMD under different quasi-static compression deformations(2-7 mm)and impact heights(100-200 mm)are investigated using experimental and numerical *** results demonstrate distinct stages in the quasi-static mechanical characteristics of hat-shaped EWMD,including stiffness softening,negative stiffness,and stiffness *** loss factor gradually increases with increasing compression deformation before entering the stiffness hardening *** impact loads,the hat-shaped EWMD exhibits optimal impact energy absorption when it enters the negative stiffness stage(150 mm),resulting in the best impact isolation effect of metallic ***,the impact energy absorption significantly decreases when hat-shaped EWMD enters the stiffness hardening ***,quasi-static compression analysis after experiencing different impact loads reveals the disappearance of the negative stiffness ***,with increasing impact loads,the stiffness hardening point progressively shifts to an earlier stage.

关键词： Metallic buffer Hat-shaped EWMD Drop impact Energy absorption characteristics Mechanical behavior

One-step construction of strongly coupled Co_(3)V_(2)O_(8)/Co_(3)O_(4)/MXene heterostructure via in-situ Co-F bonds for high performance all-solid-state asymmetric supercapacitors

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Rare Metals 2024年第2期43卷 682-691页

作者： Ji Zhou Bin-Bin Liu Hu Zheng Wen-Qing Ma Qian Li Cai-Xia Xu Institute for Advanced Interdisciplinary Research(iAIR) Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of ShandongSchool of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China

Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) composite was easily synthesized via one-step succinct-operated hydrothermal *** interconnected Co_(3)V_(2)O_(8)/Co_(3)O_(4) nanowires network can in-situ grow and anchor on the surface of Ti_(3)C_(2)T_(x) via the strong Co-F bonds and contribute tremendously to depress Ti_(3)C_(2)T_(x) *** from the synergistically interplayed effect among the multiple interfaces and high conductivity of Ti_(3)C_(2)T_(x) as well as outstanding stability of the as-designed nanostructure,the optimum Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x)electrode reaches a commendable specific capacitance(up to 3800 mF·cm^(−2)),great rate capability(80%capacitance retention after 20-times current increasing),and preeminent cycling stability(95.4%/85.5%retention at 7000th/20,000th cycle).Moreover,the all-solid-state asymmetric supercapacitor based on Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) and active carbon can deliver a high energy density of 84.0μWh·cm^(−2) at the power energy of 3.2 mW·cm^(−2),and excellent cycling durability with 87.0%of initial capacitance retention upon 20,000 *** work provides a practicable pathway to tailor MXene-based composites for high-performance supercapacitor.

关键词： Ti_(3)C_(2)T_(x) Co_(3)V_(2)O_(8)/Co_(3)O_(4) Heterostructure Cathode Supercapacitor

Boosting charge transfer via interface charge reconstruction between amorphous NiFe-LDH and crystalline NiCo_(2)O_(4)for efficient alkaline water/seawater oxidation

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Nano Research 2024年第6期17卷 4856-4863页

作者： Zhonghang Xing Yi Zhao Yunhai Wang Xiaohe Liu Zhiqiang Guo Qingyun Chen International Research Center for Renewable Energy and State Key Laboratory of Multiphase Flow in Power engineering Xi’an Jiaotong UniversityXi’an 710049China Department of Environmental Science and engineering Xi’an Jiaotong UniversityXi’an 710049China China school of Geology and Environment Xi’an University of Science and TechnologyXi’an 710049China Changqing engineering Design Co. Ltd.Xi’an 710018China

Electrocatalysts with optimal efficiency and durability for the oxygen evolution reaction(OER)are becoming increasingly important as the demand for alkaline water/seawater electrolysis technology ***,a novel rose-shaped NiFe-layered double hydroxide(LDH)/NiCo_(2)O_(4)composed of amorphous wrinkled NiFe-LDH and highly crystalline NiCo_(2)O_(4)was synthesized with rich *** unsaturated metal sites are generated due to significant charge reconstruction at the heterointerface between the crystalline and amorphous *** metal sites could trigger and provide more active *** density functional theory(DFT)reveals that a new charge transfer channel(Co-Fe)was formed at the heterointerface between NiFe-LDH as electron acceptor and NiCo_(2)O_(4)as electron *** new charge transfer channel boosts interfacial charge transfer and enhances catalytic *** NiFe-LDH/NiCo_(2)O_(4)/nickel foam(NF)drives current densities of 10 and 100 mA·cm−2 with overpotentials of 193 and 236 mV,*** composite electrode demonstrates a fast turnover frequency(0.0143 s−1)at 1.45 V ***(RHE=reversible hydrogen electrode),which is 5.5 times greater than pure NiCo_(2)O_(4),suggesting its superior intrinsic ***,NiFe-LDH/NiCo_(2)O_(4)/NF electrode exhibited negligible degradation after 150 h of uninterrupted running in alkaline seawater *** study introduces a method for preparing high-efficiency electrocatalysts utilized in alkaline water/seawater electrolysis.

关键词： NiFe-layered double hydroxide(LDH)/NiCo_(2)O_(4)/nickel foam(NF) heterogeneous interfaces charge reconstruction water/seawater electrolysis

Cage-confinement synthesis of MoC nanoclusers as efficient sulfiphilic and lithiophilic regulator for superior Li–S batteries

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Rare Metals 2024年第2期43卷 624-634页

作者： Xing-Yuan Zhang Mei-Na Lei Shan Tian Jian-Gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi’an710072China

High-energy-density Li-S batteries are subjected to serious sulfur deactivation and short cycle lifetime caused by undesirable polysulfide shuttle effect and frantic lithium dendrite *** this work,a controllable cage-confinement strategy to fabricate molybdenum carbide(MoC)nanoclusters as a high-efficient sulfiphilic and lithiophilic regulator to mitigate the formidable issues of Li-S batteries is *** sub-2 nm MoC nanoclusters not only guarantee robust chemisorption and fast electrocatalytic conversion of polysulfides to enhance the sulfur electrochemistry,but also homogenize Li^(+) flux to suppress the lithium dendrite *** a consequence,the MoC-modified separator endows the batteries with boosted reaction kinetics,promoted sulfur utilization,and improved cycling stability.A reversible capacity of 701 mAh·g^(−1) at a high rate of 5.0C and a small decay rate of 0.076%per cycle at 1.0C over 600 cycles are *** study offers a rational route for design and synthesis of bifunctional nanoclusers with both sulfiphilicity and lithiophilicity for high-performance Li-S batteries.

关键词： Li-S batteries Nanocluster Electrocatalyst Polysulfide shuttle Li dendrites

Janus Quasi‑Solid Electrolyte Membranes with Asymmetric Porous Structure for High‑Performance Lithium‑Metal Batteries

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Nano-Micro Letters 2024年第6期16卷 221-232页

作者： Zerui Chen Wei Zhao Qian Liu Yifei Xu Qinghe Wang Jinmin Lin Hao Bin Wu Institute for Composites Science Innovation(InCSI)and State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China

Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains ***,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous *** Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD ***,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 *** results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.

关键词： Metal-organic frameworks Mesoporous silicas Quasi-solid electrolytes Janus structure Lithium-metal battery

Machine learning of element geochemical anomalies for adverse geology identification in tunnels

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Journal of Earth Science 2024年

作者： Ruiqi Shao Peng Lin Zhenhao Xu Fumin Liu Yilong Liu school of Qilu Transportation， Shandong University State Key Laboratory for Tunnel engineering Jinan Institute of Geotechnical and Underground engineering， Shandong University

Geological analysis， despite being a long-term method for identifying adverse geology in tunnels， has significant limitations due to its reliance on empirical analysis. The quantitative aspects of geochemical anomalies associated with adverse geology provide a novel strategy for addressing these limitations. However， statistical methods for identifying geochemical anomalies are insufficient for tunnel engineering. In contrast， data mining techniques such as machine learning have demonstrated greater efficacy when applied to geological data. Herein， a method for identifying adverse geology using machine learning of geochemical anomalies is proposed. The method was identified geochemical anomalies in tunnel that were not identified by statistical methods. We by employing robust factor analysis and self-organizing maps to reduce the dimensionality of geochemical data and extract the anomaly elements combination (AEC). Using the AEC sample data， we trained an isolation forest model to identify the multi-element anomalies， successfully. We analyzed the adverse geological features based the multi-element anomalies. This study， therefore， extends the traditional approach of geological analysis in tunnels and demonstrates that machine learning is an effective tool for intelligent geological analysis. Correspondingly， the research offers new insights regarding the adverse geology and the prevention of hazards during the construction of tunnels and underground engineering projects.

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The governance technology for blockchain systems:a survey

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Frontiers of Computer Science 2024年第2期18卷 181-197页

作者： Guocheng ZHU Debiao HE Haoyang AN Min LUO Cong PENG school of Cyber Science and engineering Wuhan UniversityWuhan 430072China Shandong Provincial Key Laboratory of Computer Networks Qilu University of Technology(Shandong Academy of Sciences)Jinan 250014China

After the Ethereum DAO attack in 2016,which resulted in significant economic losses,blockchain governance has become a prominent research ***,there is a lack of comprehensive and systematic literature review on blockchain *** deeply understand the process of blockchain governance and provide guidance for the future design of the blockchain governance model,we provide an in-depth review of blockchain *** this paper,first we introduce the consensus algorithms currently used in blockchain and relate them to governance ***,we present the main content of off-chain governance and investigate two well-known off-chain governance ***,we investigate four common on-chain governance voting techniques,then summarize the seven attributes that the on-chain governance voting process should meet,and finally analyze four well-known on-chain governance blockchain projects based on the previous *** hope this survey will provide an in-depth insight into the potential development direction of blockchain governance and device future research agenda.

关键词： blockchain governance off-chain governance on-chain governance voting

Analytical model for predicting folding stable state of bistable deployable composite boom

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Chinese Journal of Aeronautics 2024年第8期37卷 460-469页

作者： Tianwei LIU Jiangbo BAI Nicholas FANTUZZI school of Transportation Science and engineering Beihang UniversityBeijing 100191China Jingdezhen Research Institute of Beihang University Jingdezhen 333000China DICAM Department University of BolognaBologna 40136Italy

Bistable Deployable Composite Boom(Bi-DCB)can achieve bistable function by storing and releasing strain energy,which has a good application prospect in space *** example,it serves as the main support section of deployable structures(e.g.,solar arrays and antennas).This paper investigates folding stable state of Bi-DCB through the analytical *** on Archimedes’helix and energy principle,an analytical model for predicting folding stable state of Bi-DCB was *** failure index of Bi-DCB in folding stable state were analyzed using the Tsai-Hill criterion and the maximum stress ***,a 2400 mm long Bi-DCB was fabricated using autoclave *** prediction results of the proposed model were compared with experiments and results of two other analytical *** is shown that the proposed model shows good prediction ***,the effect of geometric parameters on folding stable state of Bi-DCB was further investigated with the aid of the proposed model.

关键词： Bistable Deployable composite boom Solar arrays Antennas Archimedes’helix Folding Failure analysis