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On-surface synthesis and characterization of polyynic carbon chains

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National Science Review 2024年第3期11卷 192-199页

作者： Wenze Gao Wei Zheng Luye Sun Faming Kang Zheng Zhou Wei Xu Interdisciplinary materials research center School of Materials Science and Engineering Tongji University

Carbyne, an elusive sp-hybridized linear carbon allotrope, has fascinated chemists and physicists for decades. Due to its high chemical reactivity and extreme instability, carbyne was much less explored in contrast to the sp2-hybridized carbon allotropes such as graphene. Herein, we report the on-surface synthesis of polyynic carbon chains by demetallization of organometallic polyynes on the Au（111） surface;the longest one observed consists of ～60 alkyne units（120 carbon atoms）. The polyynic structure of carbon chains with alternating triple and single bonds was unambiguously revealed by bond-resolved atomic force microscopy. Moreover, an atomically precise polyyne, C14, was successfully produced via tip-induced dehalogenation and ring-opening of the decachloroanthracene molecule(C14Cl10) on a bilayer NaCl/Au（111） surface at 4.7 K, and a band gap of 5.8 eV was measured by scanning tunnelling spectroscopy,in a good agreement with the theoretical HOMO–LUMO gap（5.48 eV）.

关键词： polyyne scanning probe microscopy carbon allotrope on-surface synthesis organometallic polyyne

Simultaneously enhanced energy storage performance and luminance resistance in (K_(0.5)Na_(0.5))NbO_(3) -based ceramics via synergistic optimization strategy

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Journal of Advanced Ceramics 2024年第1期13卷 34-43页

作者： Yu Huan Diyu Gui Changxiao Li Tao Wei Lingzhi Wu Xinjian Wang Xiaozhi Wang Zhenxiang Cheng School of materials Science and Engineering University of JinanJinan 250022China Yangtze Delta Region Transformation center for Advanced Technological Achievements Suzhou 215000China Electronic materials research Laboratory Key Laboratory of the Ministry of Education and International Center for Dielectric ResearchXi’an Jiaotong UniversityXi’an 710032China Institute for superconducting and Electronic materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation CampusNorth Wollongong 2500Australia

The rapidly advancing energy storage performance of dielectric ceramics capacitors has garnered significant interest for applications in fast charge/discharge and high-power electronic *** the exceptional electrical properties in harsh environments can further promote their practical *** carriers can be excited under luminance irradiation,thereby leading to degradation of energy storage ***,a synergic optimization strategy is proposed to enhance energy storage properties and luminance resistance of(K_(0.5)Na_(0.5))NbO_(3)-base(KNN)***,the introduction of Bi(Zn0.5Ti0.5)O_(3) solid solution and La3+ions disrupts the long-range polar orders and enhances super paraelectric relaxation ***,doping La3+ions can increase the band gap and reduce oxygen vacancy concentration,resulting in excellent luminance ***,the viscous polymer process is employed to suppress the grain growth and promote chemical *** a result,ultrahigh recoverable energy storage density(Wrec)of 8.11 J/cm3 and high efficiency(η)of 80.98%are achieved under an electric field of 568 kV/***,the variations in Wrec andηare only 12.45%and 1.75%,respectively,under 500 W xenon lamp irradiation compared to the performance under a dark *** findings hold great potential in facilitating the practical application of dielectric ceramic capacitors in luminance irradiation environments.

关键词： potassium-sodium niobate energy storage performance illumination resistance oxygen vacancy viscous polymer processing

Oscillating paramagnetic Meissner effect and Berezinskii-Kosterlitz-Thouless transition in underdoped Bi2Sr2CaCu2O8+δ

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National Science Review 2024年第5期11卷 142-152页

作者： Shiyuan Wang Yijun Yu Jinxiang Hao Keyi Liang Bingke Xiang Jinjiang Zhu Yishi Lin Yinping Pan Genda Gu Kenji Watanabe Takashi Taniguchi Yang Qi Yuanbo Zhang Yihua Wang State Key Laboratory of Surface Physics and Department of Physics Fudan University Condensed Matter Physics and materials Science Department Brookhaven National Laboratory research center for Functional materials National Institute for Materials Science International center for materials Nanoarchitectonics National Institute for Materials Science Shanghai research center for Quantum Sciences

superconducting phase transitions in two dimensions lie beyond the description of the Ginzburg-Landau symmetry-breaking paradigm for three-dimensional *** are Berezinskii-KosterlitzThouless（BKT） transitions of paired-electron condensate driven by the unbinding of topological excitations,*** recently discovered monolayers of layered high-transition-temperature（TC）cuprate superconductor Bi2Sr2CaCu2O8+δ（Bi2212） meant that this 2D superconductor promised to be ideal for the study of unconventional *** inhomogeneity posed challenges for distinguishing BKT physics from charge correlations in this ***,we utilize the phase sensitivity of scanning superconducting quantum interference device microscopy susceptometry to image the local magnetic response of underdoped Bi2212 from the monolayer to the bulk throughout its phase *** monolayer segregates into domains with independent phases at elevated temperatures below *** a single domain,we find that the susceptibility oscillates with flux between diamagnetism and paramagnetism in a Fraunhofer-like pattern up to *** finite modulation period,as well as the broadening of the peaks when approaching Tc from below,suggests well-defined vortices that are increasingly screened by the dissociation of vortex-antivortex plasma through a BKT *** the multilayers,the susceptibility oscillation differs in a small temperature regime below TC,consistent with a dimensional crossover led by interlayer *** as strong evidence for BKT transition in the bulk,we observe a sharp jump in phase stiffness and paramagnetism at small fields just below *** results unify the superconducting phase transitions from the monolayer to the bulk underdoped Bi2212,and can be collectively referred to as the BKT transition with interlayer coupling.

关键词： cuprate superconductor monolayer Berezinskii-Kosterlitz-Thouless transition scanning SQUID paramagnetic Meissner effect

Design of efficient thermoelectric generators

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Science China materials 2024年第1期67卷 377-378页

作者： Min Liu Yanzhong Pei Interdisciplinary materials research center School of Materials Science and EngineeringTongji UniversityShanghai 201804China

Thermoelectricity,which enables direct conversion between heat and electricity,undergoes impressive developments in recent decades,and is particularly promising for recovering low-grade heat of<600 K[1,2].Currently,only Bi2Te3-based thermoelectric devices are commercialized[3].However,the scarcity of tellurium(Te)(Fig.1a)is the main *** leads to numerous recent efforts on the development of efficient nonBi2Te3 thermoelectrics as potential alternatives,and successful examples(Fig.1b)include Mg3Sb2-alloys[2,3]and MgAgSb[1,2].

关键词： enable efficient electricity

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Correlation between platinum–aluminide coating features and tensile behavior of nickel-based superalloy Rene?80

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Rare Metals 2024年第10期43卷 5391-5402页

作者： Mohammad Mehdi Barjesteh Seyed Mehdi Abbasi Karim Zangeneh Madar Kourosh Shirvani Metallic materials research center Malek Ashtar University of Technology (MUT) Department of Advanced materials and New Energies Iranian Research Organization for Science and Technology (IROST)

The effect of platinum （a rare metal）–aluminide coating parameters on the tensile properties of nickel-based superalloy Rene?80 was evaluated at 871。*** this purpose,initial layers of platinum with different thicknesses （2,4,6 and 8μm） were coated on tensile samples Then,low-temperature high-activity （LTHA） and hightemperature low-activity （HTLA） processes were used for *** of microstructural evaluations using scanning electron microscope （SEM） and phase analysis by X-ray diffraction （XRD） showed a three-layer structure coating for different platinum layer thicknesses and both aluminizing *** the thickness of the platinum layer from 2 to 8μm led to the improvement in the final coating thickness from 91.6 to 102.1μm in *** increase was from 128.1 to 148.6 μm in *** results of hot tensile tests at 871℃ showed a decrease in strength properties of the coated samples compared to the uncoated ***,HTLA and high thicknesses of the initial platinum layer showed an intense *** results of fractographic evaluations abou uncoated samples showed a ductile *** the other hand,coated samples showed a simultaneous ductile and brittle fracture failure *** the main fracture morphology was brittle cleavage fracture which was for the HTLA.

关键词： Aluminizing Fractography Platinum–aluminide Rene®80 Tensile properties

Progress and challenges for replacing n-methyl-2-pyrrolidone/polyvinylidene fluoride slurry formulations in lithium-ion battery cathodes

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Progress in Natural Science:materials International 2024年第01期34卷 194-206页

作者： Sung Cik Mun Yeong Hoon Jeon Jong Ho Won Battery materials research center LG Chem Department of Energy Engineering Dankook University

With electric vehicles, energy storage systems, and portable electronic devices becoming increasingly popular, the demand for lithium-ion batteries has surged considerably. In the lithium-ion battery industry, n-methyl-2-pyrrolidone(NMP) is widely used as the solvent for cathode slurry, and polyvinylidene fluoride(PVDF) is used as the cathode binder. However, because of the harmful effect of NMP on the environment and human health, the use of NMP and PVDF for lithium-ion batteries will be highly regulated in the future. Therefore, developing eco-friendly alternatives is crucial for formulating systems using new solvents and binders. Despite numerous efforts, these alternatives have not been widely adopted across the lithium-ion battery industry. It is due to their limited ability to compete on price or performance to replace the traditional NMP/PVDF slurry formulations. This review investigates developments in the search for new solvents and binders that can be used in cathode slurry compositions. The new systems can potentially decrease energy consumption and manufacturing costs associated with NMP recovery, energy-intensive drying processes, and material expenses. We discuss key factors and technical challenges from earlier studies and compare them with the current, optimized formulations based on NMP and PVDF.

关键词： Lithium-ion battery Eco-friendly alternative Slurry formulation Chemical regulation Binder performance

Ant-nest-inspired porous structure for MXene composites with high-performance energy-storage and actuating multifunctions

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Nano research 2024年第7期17卷 6673-6685页

作者： Yi Wang Guanfeng Xue Zhiling Luo Wei Zhang Luzhuo Chen Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy materials College of Physics and EnergyFujian Normal UniversityFuzhou 350117China Fujian Provincial Collaborative Innovation center for Advanced High-Field superconducting materials and Engineering Fuzhou 350117China

Integrating energy-storage devices(supercapacitors)and shape-deformation devices(actuators)advances the miniaturization and multifunctional development of soft ***,soft robots necessitate supercapacitors with high energy-storage performance and actuators with excellent actuation ***,inspired by ant nests,we present a porous structure fabricated by MXene-graphene-methylcellulose(M-GMC)composite,which overcomes the self-stacking of MXene nanosheets and offers a larger specific surface *** porous structure provides more channels and active sites for electrolyte ions,resulting in high energy storage *** areal capacitance of the M-GMC electrode reaches up to 787.9 mF·cm^(−2),significantly superior to that of the pristine MXene electrode(449.1 mF·cm^(−2)).Moreover,the M-GMC/polyethylene bilayer composites with energy storage and multi-responsive actuation functions are *** M-GMC is used as the electrode and the polyethylene is used as the encapsulation layer of the quasi-solid-state ***,the actuators fabricated by the bilayer composites can be driven by light or low voltage(≤9 V).The maximum bending curvature is up to 5.11 cm^(−1).Finally,a smart gripper and a fully encapsulated smart integrated circuit based on the M-GMC/polyethylene are *** smart gripper enables programmable control with multi-stage *** applications realize the intelligence and miniaturization of soft *** ant-nest-inspired M-GMC composites would provide a promising development strategy for soft robots and smart integrated devices.

关键词： MXene graphene ant nest supercapacitor actuator multi-functional

Close-packed layer spacing as a practical guideline for structure symmetry manipulation of IV-VI/I-V-VI_(2) thermoelectrics

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InfoMat 2024年第2期6卷 99-106页

作者： Tao Jin Long Yang Xinyue Zhang Wen Li Yanzhong Pei Interdisciplinary materials research center School of Materials Science and EngineeringTongji UniversityShanghaithe People's Republic of China

The crystal-structure symmetry in real space can be inherited in the reciprocal space,making high-symmetry materials the top candidates for thermoelectrics due to their potential for significant electronic band degeneracy.A practical indicator that can quantitatively describe structural changes would help facilitate the advanced thermoelectric material *** face-centered cubic structures,the spatial environment of the same crystallographic plane family is isotropic,such that the distances between the close-packed layers can be derived from the atomic distances within the *** by this,the relationship between inter-and intra-layer geometric information can be used to compare crystal structures with their desired cubic *** close-packed layer spacing was found to be a practical guideline of crystal structure symmetry in IV-VI chalcogenides and I-V-VI_(2) ternary semiconductors,both of which are historically important *** continuous structural evolution toward high symmetry can be described by the layer spacing when temperature or/and composition change,which is demonstrated by a series of pristine and alloyed thermoelectric materials in this *** layerspacing-based guideline provides a quantitative pathway for manipulating crystal structures to improve the electrical and thermal properties of thermoelectric materials.

关键词： phase transition structure manipulation thermoelectric materials x-ray diffraction

Recent Advances in Asymmetric Structural Composites for Excellent Electromagnetic Interference Shielding: A Review

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Chinese Journal of Polymer Science 2024年第6期42卷 693-710页

作者： Ying Zhou Bai Xue Lan Xie Chang-Mei Wu Qiang Zheng Department of Polymer materials and Engineering College of Materials and Metallurgy Guizhou University National Engineering research center for Compounding and Modification of Polymer materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane Processes State Key Laboratory of Public Big Data Guizhou University Department of Polymer Science and Engineering Zhejiang University

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness(EMI SE) via designing the hierarchical structures for electromagnetic interference(EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the “absorption-reflection-reabsorption” shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation(5G) technology.

关键词： Asymmetric structure Micro/nano functional filler Polymer composite Electromagnetic interference shielding