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Antiferromagnetic second-order topological insulator with fractional mass-kink

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npj Computational Materials 2022年第1期8卷 788-794页

作者： Haimen Mu Gan Zhao Huimin Zhang zhengfei wang Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Strongly-Coupled Quantum Matter PhysicsDepartment of PhysicsUniversity of Science and Technology of ChinaHefeiAnhui230026China Key Laboratory of Material Modification by Laser Ion and Electron BeamsDalian University of TechnologyMinistry of EducationDalian116024China

Generally,the topological corner state in two-dimensional(2D)second-order topological insulator(SOTI)is equivalent to the well-known domain wall state,which is originated from the mass-inversion between two adjacent edges with phase shift ofπ.In this work,go beyond this conventional physical picture,we report a fractional mass-kink induced 2D SOTI in monolayer FeSe with canted checkerboard antiferromagnetic(AFM)order by analytic model and first-principles *** canted spin associated in-plane Zeeman field can gap out the quantum spin Hall edge state of FeSe,forming a fractional mass-kink with phase shift ofπ/2 at the rectangular corner,and generating an in-gap topological corner state with fractional charge of e/***,the topological corner state is robust to a finite perturbation,existing in both naturally and non-naturally cleaved corners,regardless of the edge *** results not only demonstrate a material system to realize the unique 2D AFM SOTI,but also pave a way to design the higher-order topological states from fractional mass-kink with arbitrary phase shift.

关键词： topological fractional insulator

Application of Blockchain Sharding Technology in Chinese Medicine Traceability System

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Computers, Materials & Continua 2023年第7期76卷 35-48页

作者： Fuan Xiao Tong Lai Yutong Guan Jiaming Hong Honglai Zhang Guoyu Yang zhengfei wang School of Medical Information Engineering Guangzhou University of Chinese MedicineGuangzhou510006China Institute of Artificial Intelligence and Blockchain Guangzhou UniversityGuangzhou510006China

Traditional Chinese Medicine(TCM)is one of the most promising programs for disease prevention and ***,the quality of TCM has garnered much *** ensure the quality of TCM,many works are based on the blockchain scheme to design the traceability scheme of TCM to trace its *** these schemes can ensure the integrity,sharability,credibility,and immutability of TCM more effectively,many problems are exposed with the rapid growth of TCM data in blockchains,such as expensive overhead,performance bottlenecks,and the traditional blockchain architecture is unsuitable for TCM data with dynamic *** by the aforementioned problems,we propose a novel and lightweight TCM traceability architecture based on the blockchain using sharding(LBS-TCM).Compared to the existing blockchain-based TCM traceability system,our architecture utilizes sharding to develop a novel traceability mechanism that supports more convenient traceability operations for TCM requirements such as uploading,querying,and ***,our architecture consists of a leader shard blockchain layer as its main component,which employs a sharding mechanism to conveniently TCM *** evaluations demonstrated that our architecture showed better performance in many aspects compared to traditional blockchain architectures,such as TCM transaction processing,TCM transaction querying,TCM uploading,*** our architecture,tracing TCM has become a very efficient operation,which ensures the quality of TCM and provides great convenience for subsequent TCM analysis and retrospective research.

关键词： Blockchain sharding traceability traditional chinese medicine

Magnetic-field enhanced high-thermoelectric performance in topological Dirac semimetal Cd3As2 crystal

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Science Bulletin 2018年第7期63卷 411-418页

作者： Honghui wang Xigang Luo Weiwei Chen Naizhou wang Bin Lei Fanbao Meng Chao Shang Likuan Ma Tao Wu Xi Dai zhengfei wang Xianhui Chen Hefei National Laboratory for Physical Science at Microscale and Department of Physics University of Science and Technology of China and Key Laboratory of Strongly-coupled Quantum Matter Physics. Chinese Academy of Sciences Hefei 230026 China Physics Department Hong Kong University of Science and Technology Hang Kong China High Magnetic Field Laboratory of the Chinese Academy of Sciences Hefei 230031 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China

Thermoelectric materials can be used to convert heat to electric power through the Seebeck effect. We study magneto-thermoelectric figure of merit （ZT） in three-dimensional Dirac semimetal Cd3A 5 2 crystal. It is found that enhancement of power factor and reduction of thermal conductivity can be realized at the same time through magnetic field although magnetoresistivity is greatly increased. ZT can be highly enhanced from 0.17 to 1.1 by more than six times around 350 K under a perpendicular magnetic field of 7 T. The huge enhancement of ZT by magnetic field arises from the linear Dirac band with large Fermi velocity and the large electric thermal conductivity in CdsA 5 2. Our work paves a new way to greatly enhance the thermoelectric performance in the quantum topological materials.

关键词： Dirac semimetal Thermoelectric material Magnetic field Enhancement of figure of merit

Evolutionary changes of Hox genes and relevant regulatory factors provide novel insights into mammalian morphological modifications

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Integrative Zoology 2018年第1期13卷 21-35页

作者： Kui LI Xiaohui SUN Meixiu CHEN Yingying SUN Ran TIAN zhengfei wang Shixia XU Guang YANG Jiangsu Key Laboratory for Biodiversity and Biotechnology College of Life SciencesNanjing Normal UniversityNanjing 210023China

The diversity of body plans of mammals accelerates the innovation of lifestyles and the extensive adaptation to different habitats,including terrestrial,aerial and aquatic ***,the genetic basis of those phenotypic modifications,which have occurred during mammalian evolution,remains poorly *** the present study,we synthetically surveyed the evolutionary pattern of Hox clusters that played a powerful role in the morphogenesis along the head-tail axis of animal embryos and the main regulatory factors(Mll,Bmi1 and E2f6)that control the expression of Hox genes.A deflected density of repetitive elements and lineage-specific radical mutations of Mll have been determined in marine mammals with morphological changes,suggesting that evolutionary changes may alter Hox gene expression in these lineages,leading to the morphological modification of these *** no positive selection was detected at certain ancestor nodes of lineages,the increasedωvalues of Hox genes implied the relaxation of functional constraints of these genes during the mammalian evolutionary *** importantly,49 positively-selected sites were identified in mammalian lineages with phenotypic modifications,indicating adaptive evolution acting on Hox genes and regulatory *** addition,3 parallel amino acid substitutions in some Hox genes were examined in marine mammals,which might be responsible for their streamlined body.

关键词： evolutionary changes Hox genes mammals morphological modifications

A functional cathode sodium compensation agent for stable sodium-ion batteries

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Green Energy & Environment 2025年第1期10卷 173-182页

作者： Wei Wu Zhenglin Hu zhengfei Zhao Aoxuan wang Jiayan Luo Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering Shaoxing312000China

Hard carbon(HC)is widely used in sodium-ion batteries(SIBs),but its performance has always been limited by lowinitial Coulombic efficiency(ICE)and cycling *** compensation agent is a favorable strategy to make up for the loss of active sodium ions consumed *** it lacks agent that effectively decomposes to increase the active sodium ions as well as regulate carbon defects for decreasing the irreversible sodium ions ***,we propose 1,2-dihydroxybenzene Na salt(NaDB)as a cathode compensation agent with high specific capacity(347.9 mAh g^(-1)),lower desodiation potential(2.4–2.8 V)and high utilization(99%).Meanwhile,its byproduct could functionalize HC with more C]O groups and promote its reversible ***,the presodiation hard carbon(pHC)anode exhibits highly reversible capacity of 204.7 mAh g^(-1) with 98%retention at 5 C rate over 1000 ***,with 5 wt%NaDB initially coated on the Na3V2(PO4)3(NVP)cathode,the capacity retention of NVP t NaDBjHC cell could increase from 22%to 89%after 1000 cycles at 1 C *** work provides a new avenue to improve reversible capacity and cycling performance of SIBs through designing functional cathode compensation agent.

关键词： Hard carbon ICE Cathode compensation agent Reversible capacity Stability

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基于推理的安全数据库审计框架

计算机研究与发展 2006年第9期43卷 1630-1638页

作者：严和平王正飞汪卫施伯乐复旦大学计算机与信息技术系上海200433 湖南商学院计算机与电子工程系长沙410205

信息技术的发展给安全数据库带来了新的挑战,各种安全策略明确以法律条文形式颁布,这要求采用有效的手段证实,对数据库的访问与安全策略的一致性,审计访问数据库的各种查询正好能实现这一目标,但常规的审计方法只能对单个查询的查询结... 详细信息

信息技术的发展给安全数据库带来了新的挑战,各种安全策略明确以法律条文形式颁布,这要求采用有效的手段证实,对数据库的访问与安全策略的一致性,审计访问数据库的各种查询正好能实现这一目标,但常规的审计方法只能对单个查询的查询结果进行审计,而蓄意破坏的用户可能利用多个查询的查询结果进行推理来访问敏感信息,这就要求审计的同时也应具备基本的推理能力,提出了切实可行的安全数据库推理审计框架,该框架具有①MVD推理审计能力;②FFD推理审计能力;③FD推理审计能力,而且具有审计方法快速、准确、细粒度等特点.

关键词：安全数据库推理审计

碳纳米管增强Nb-Si基复合材料界面应力传递的研究

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应用力学学报 2020年第2期37卷 793-800,I0023,I0024页

作者：龙文元汪正飞颜燕华南昌航空大学航空制造工程学院南昌330063

基于均匀化理论,建立了碳纳米管增强Nb-Si基复合材料的代表体积元模型,并采用剪切滞后模型对碳纳米管增强Nb-Si基复合材料界面上的应力分布和传递机制进行了研究,探讨了分子间作用力、杨氏模量比β、长径比α、体积分数?等对其应力分布... 详细信息

基于均匀化理论,建立了碳纳米管增强Nb-Si基复合材料的代表体积元模型,并采用剪切滞后模型对碳纳米管增强Nb-Si基复合材料界面上的应力分布和传递机制进行了研究,探讨了分子间作用力、杨氏模量比β、长径比α、体积分数?等对其应力分布和传递机制的影响。结果表明,复合材料界面应力分布的变化主要集中在碳纳米管的两端,最大的应力都是分布在加载端或拔出端,然后向另一端传递;分子间作用力、杨氏模量比、长径比、体积分数等参数对界面应力的传递均有一定的影响,其中长径比和体积分数的影响最明显,体积分数为0.02时拔出端的界面剪切应力值相对于体积分数为0.0025时增大幅度达到近7倍,而长径比从200减小到50时,其应力传递距离增大了近8倍。

关键词： Nb-Si基复合材料碳纳米管界面应力范德华力