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Rare Metals 2024年第3期43卷 1048-1061页

作者： zheng-Hua He jian-Fei Gao Ling-Bin Kong State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of TechnologyLanzhou730050China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou730050China

Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical ***,there are few reports about the wide potential window materials except Bi_(2)O_(3)and VO_(2).Therefore,the MnF_(2)synthesized by solvothermal reaction was served as the electrode for *** MnF_(2)exhibited electrochemical activity in alkaline solution in three-electrode system,especially with a wide potential window from-0.8 to+0.5 V in 2 mol·L^(-1)***,the assembled MnF_(2)//MnF_(2)symmetrical HSC had a potential window of 1.5 V,and it exhibited outstanding long-cycle ***,when MnF_(2)was taken as the negative and positive respectively,the potential windows of asymmetric devices CoMoO_(4)//MnF_(2)and MnF_(2)//Activated Carbon(AC)could reach 1.3 and 1.45 V,respectively,showing excellent cycle *** work shows that MnF_(2)material has great research value in HSC,and provides a new research direction for developing high-performance devices.

关键词： Manganese fluoride Potential window Hybrid supercapacitors Electrochemical performance

Molecular Chain Flexibility and Dielectric Loss at High-Frequency:Impact of Ester Bond Arrangement in Poly(ester imide)s

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Chinese Journal of Polymer Science 2024年第8期42卷 1122-1133页

作者： Ya-Dong Li Hong Li Lu-Kun Feng Feng bao Ming-Liang Wang Cai-Zhen Zhu Zhao-Hui zheng Xiao-Bin Ding jian Xu Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100081China Institute of Low-Dimensional Materials Genome Initiative College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China

The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer ***,it has been theorized that rigid molecular chains lead to lower dielectric ***,the validity of this proposition at high frequencies remains *** scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic *** introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry *** dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)***,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic *** simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water *** sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality *** research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.

关键词： 5G communications Poly(ester imide)s Molecular chain flexibility Dielectric properties Humidity absorption

O_(2) adsorption on Fe_(3)O_(4) (110) surface and effect of gangue element Al doping: combined study of binding experiment and ab initio molecular dynamics

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Journal of Iron and Steel Research International 2024年第4期31卷 810-827页

作者： zheng-jian Liu Hui-qing jiang Yao-zu Wang jian-liang Zhang Hong-mei Qiao An-yang zheng Fang-yu Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 100083China Beijing Shougang Co. Ltd.Qian'an 064404HebeiChina Department of Physics National University of Defense TechnologyChangsha 410128HunanChina

At high temperature,the chemical reaction mechanism at the interface of magnetite and the influence mechanism of gangue element Al on the oxidation performance of magnetite are not *** addition,due to the limitation of existing experimental equipment,it is difficult to clarify the interface reaction mechanism in the oxidation process and the influence mechanism of Al on the surface oxidation reaction of Fe_(3)O_(4) at an atomic scale at high *** surface oxidation reaction mechanism of magnetite and the influence mechanism of Al on the oxidation of magnetite were studied by experiments and AIMD(ab initio molecular dynamics).The experimental results show that the existence of Al_(2)O_(3) will reduce the initial oxidation temperature and comprehensive oxidation performance of *** AIMD results show that aluminum can accelerate the interface reaction rate of Fe_(3)O_(4) in the high-temperature oxidation atmosphere,but the strong Al-O binding ability is not conducive to the transfer of O atoms in the oxidation process.

关键词： Ironmaking Magnetite oxidation Interface reaction Adsorption-Gangue aluminum AIMD

Preliminary discussion on the ignition mechanism of exploding foil initiators igniting boron potassium nitrate

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Defence Technology（防务技术） 2024年第2期32卷 222-231页

作者： Haotian jian Guoqiang zheng Lejian Chen zheng Ning Guofu Yin Peng Zhu Ruiqi Shen School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Micro-Nano Energetic Devices Key Laboratory of MIIT Nanjing University of Science and TechnologyNanjing 210094China Anhui Province Key Laboratory of Microsystem the 43rd Research Institute of CETCHefei 230088China Science and Technology on Applied Physical and Chemistry Laboratory Shanxi Applied Physics and Chemistry Research Institute Xi'an 710061China

Exploding foil initiator(EFI)is a kind of advanced device for initiating explosives,but its function is unstable when it comes to directly igniting *** solve the problem,this research aims to reveal the ignition mechanism of EFIs directly igniting *** oscilloscope,a photon Doppler velocimetry,and a plasma spectrum measurement system were employed to obtain information of electric characteristics,impact pressure,and plasma *** results of the electric characteristics and the impact pressure were inconsistent with ignition *** only thing that the ignition success tests had in common was that their plasma all had a relatively long period of high-temperature duration(HTD).It eventually concludes that the ignition mechanism in this research is the microconvection heat transfer rather than the shock initiation,which differs from that of exploding foil initiators detonating ***,the methods for evaluating the ignition success of semiconductor bridge initiators are not entirely applicable to the tests mentioned in this *** HTD is the critical parameter for judging the ignition success,and it is influenced by two factors:the late time discharge and the energy of the electric *** longer time of the late time discharge and the more energy of the electric explosion,the easier it is to expand the HTD,which improves the probability of the ignition success.

关键词： Exploding foil initiator PDV Plasma spectrum Ignition mechanism Boron potassium nitrate

Utility and Application of a Versatile Analytical Method for MMF Calculation in AC Machines

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 22-31页

作者： Ze-zheng Wu Robert Nilssen jian-Xin Shen IEEE the College of Electrical Engineering Zhejiang UniversityHangzhou 310027China the Department of Electric Energy Norwegian University of Science and TechnologyTrondheimNorwayand also affiliated with the College of Electrical EngineeringZhejiang UniversityHangzhou 310027China

A versatile analytical method(VAM) for calculating the harmonic components of the magnetomotive force(MMF) generated by diverse armature windings in AC machines has been proposed, and the versatility of this method has been established in early literature. However, its practical applications and significance in advancing the analysis of AC machines need further elaboration. This paper aims to complement VAM by augmenting its theory, offering additional insights into its conclusions, as well as demonstrating its utility in assessing armature windings and its application of calculating torque for permanent magnet synchronous machines(PMSM). This work contributes to advancing the analysis of AC machines and underscores the potential for improved design and performance optimization.

关键词： AC machine Analytical method Harmonic analysis MMF Magnetic field Torque calculation

Spherical Confinement Generates Entropic Force to Accelerate Polymer Chain Detachment

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Chinese Journal of Polymer Science 2024年第3期42卷 407-416,I0010页

作者： Yu-Shan zheng jian-Ping Zhou Yan Xu Kai Li Mechanical Engineering Xinjiang UniversityUrumqi 830002China

To understand the dynamic process of polymer detachment, it is necessary to determine the mean detachment time of a single breakable link, which is modeled as a spring. Normally, this time can be viewed as the escape of a Brownian particle from the potential well of the spring. However, as the free dangling length of the polymer chain increases, the conformational entropy of the chain is affected by geometric confinement. It means that the wall exerts a repulsive force on the chain, resulting in accelerated link detachment from a macroscopic perspective. In this work, we investigate the effect of entropy on the detachment rate in the case where the substrate is spherical. We demonstrate that spherical confinement accelerates chain detachment both inside and outside the sphere. An analytical expression for the mean detachment time of breakable links is given, which includes an additional pre-factor that is related to the partition function. Additionally, we analyze the expressions for entropic forces inside the sphere, outside the sphere, and on a flat wall, comparing their magnitudes to explain the difference in mean detachment time.

关键词： Polymer detachment Breakable link Entropic force Mean first passage time

New model of linkage evolution for the transtensional fault systems in the Nanpu Sag of Bohai Bay Basin: Insight from seismic interpretation and analogue modelling

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Petroleum Science 2024年第4期21卷 2287-2310页

作者： Yu-Heng Wang Fu-Sheng Yu bao-Yin Zhao Ling-jian Meng College of Geosciences China University of Petroleum (Beijing) State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Jidong Oilfield Company PetroChina Limited Company

The evolution of faults within the same stress field is frequently influenced by numerous factors,involving the reactivation of pre-existing structures, stress transmission through ductile detachment layers, and the growth, interaction, as well as linkage of new fault segments. This study analyses a complex multi-phase oblique extension fault system in the Nanpu Sag(NPS) of the Bohai Bay Basin(BBB),China. High-resolution three-dimensional(3D) seismic data and analogue modelling indicate that the oblique extensional reactivation of pre-existing structures governs the sequential arrangement of fault segments in the caprock, and they dip synthetically to the reactivated fault at depth. During the NW-SE extension in the Eocene, the predominant movement of the pre-existing fault is strike-slip. Subsequently,during the N-S extension since the Oligocene, inclined at *** the pre-existing fault, forming splay fault segments and ultimately creating large en-echelon arcuate faults linked by relay ramps. Using fault throw-distance(T-D) and laser scanning, we reconstructed the fault evolution model of oblique extension reactivation in the presence of a ductile detachment basement. Our study illustrates that the arcuate faults can be categorized into linear master fault segments controlled by pre-existing structures, bending splay faults in the termination zone, and normal fault segments responding to the regional stress *** interaction between faults occurs among normal faults and strike-slip faults, and the kinematic unification of the two fault systems is accomplished in the intersection zone. As the faults continue to evolve, the new fault segments tend to relinquish the control of pre-existing structures and concentrate more on the development of planar and continuous major faults. The ductile detachment layer significantly contributes to the uniform distribution of strain, resulting in narrow shear zones and discontinuous normal faults in its absence.

关键词： Analogue modelling Transtensional deformation Fault linkage Fault intersection zone Nanpu Sag of Bohai Bay basin

Attaining synergetic equilibrium of electrical conductivity and tensile strength in GQDs@GN/Cu composites through multi-scale intragranular and intergranular reinforcements

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Rare Metals 2024年第1期43卷 366-379页

作者： Shuang-Yin Zhang Liang Liu Rui bao jian-Hong Yi Sheng-Da Guo Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Advanced Materials of Yunnan Province Kunming University of Science and TechnologyKunming 650093China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China

The configuration and quality of reinforcements, as well as the robustness of interfacial bonding,holding a critical significance in determining the concurrence between electrical conductivity and mechanical strength in metal matrix composites. In this study, citric acid was employed as the precursor for synthesizing multiscale carbon nanomaterials(graphene quantum dots and graphene, abbreviated as GQDs and GN). The GQDs@GN/Cu composites were fabricated through a segmented ball milling process in conjunction with subsequent spark plasma sintering(SPS). The intragranular GQDs and intergranular GQDs@GN had synergistically reinforced Cu composites through Orowan strengthening, load transfer strengthening and refinement strengthening. Furthermore,the robust interface bonding between GQDs@GN and Cu effectively mitigated interfacial impedance stemming from electron-boundary scattering. The yield strength and ultimate tensile strength of the GQDs@GN/Cu composites were recorded as 270 and 314 MPa, respectively, representing an improvement of 92 and 28% over pure Cu, while maintaining electrical conductivity at a level comparable to that of pure Cu. This study advances the understanding of the possibility of realizing a synergistic compatibility between electrical conductivity and mechanical strength in Cu composites.

关键词： Cu matrix composites Interface bonding Mechanical property Graphene quantum dots(GQDs) Electrical conductivity

A reputation-based blockchain scheme for sustained carbon emission reduction

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Science China(Information Sciences) 2024年第5期67卷 329-330页

作者： Lixiao ZHOU Changbing TANG zheng bao Yang LIU Xinghuo YU College of Physics and Electronics Information Engineering Zhejiang Normal University School of Computer Science and Technology Zhejiang Normal University School of Mathematical Sciences Zhejiang Normal University School of Engineering RMIT University

Climate change is a global issue that necessitates collective responsibility from all nations. Recently, a blockchainenabled emission trading scheme(ETS) has been proposed for reducing carbon emissions to overcome the drawbacks of centralized methods [1, 2]. However, existing consensus protocols in blockchain have not been well prepared for low energy consumption and high incentive compatibility [3],which is contrary to the low carbon goal of ETS.

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Permanent lining castable with low bulk density and thermal conductivity:bauxite castable for tundish obtained by adding pearlescent sand

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Journal of Iron and Steel Research International 2024年第3期31卷 634-646页

作者： Yi Wang jian Yang bao Wang Hai-jun Zhang Juan Han Pei-yan Pei Wen-long Lv jian-an Zhou The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Wuhan Research Institute of Metallurgical Construction MCCWuhan 430081HubeiChina

The low thermal conductivity and light mass of castables for tundish permanent linings are crucial for minimizing the heat loss of molten *** consideration of the low bulk density and thermal conductivity of pearlescent sand,the thermal insulation performance of castables was attempted to be improved by adding pearlescent *** sand was modified to prevent the strength of its porous structure from *** modification mechanism of pearlescent sand and the effect of pearlescent sand on the performance of bauxite castables were *** results suggested that the addition of the modified pearlescent sand significantly raised the apparent porosity and decreased the bulk density of bauxite *** 1000℃,the bulk density of more than 60%of the modified pearlescent sand-bauxite castable was only 2.03 g/cm^(3).The mechanical properties and thermal shock resistance of the modified pearlescent sand-bauxite castable were inferior to those of conventional bauxite castable but were adequate to meet the use conditions of casta-bles for tundish permanent *** high temperatures of 200-800℃,the thermal conductivity of more than 60%of the modified pearlescent sand-bauxite castable was smaller than that of conventional bauxite *** addition of the modified pearlescent sand can greatly reduce the thermal conductivity and bulk density of bauxite castable.

关键词： Pearlescent sand-Hydrophobic modification Bauxite castable Thermal insulation performance Mechanical property