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Two-Dimensional Node-Line Semimetals in a Honeycomb-Kagome Lattice

Chinese Physics Letters 2017年第5期34卷 106-110页

作者：卢金炼罗伟李雪阳杨晟祺曹觉先龚新高向红军 Department of Physics Xiangtan University Xiangtan 411105 key laboratory of computational physical sciences (Ministry of Education) State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 Collaborative Innovation Center of Advanced Microstructures Nanjing 210093

Recently, the concept of topological insulators has been generalized to topological semimetals, including three-dimensional （3D） Weyl semimetals, 3D Dirac semimetMs, and 3D node-line semimetals （NLSs）. In particular, several compounds （e.g., certain 3D graphene networks, Cu3PdN, Ca3P2 ） were discovered to be 3D NLSs, in which the conduction and valence bands cross at closed lines in the Brillouin zone. Except for the two-dimensional （2D） Dirac semimetal （e.g., graphene）, 2D topological semimetals are much less investigated. Here we propose a new concept of a 2D NLS and suggest that this state could be realized in a new mixed lattice （named as HK lattice） composed by Kagome and honeycomb lattices. It is found that A3B2 （A is a group-liB cation and B is a group-VA anion） compounds （such as Hg3As2） with the HK lattice are 2D NLSs due to the band inversion between the cation Hg-s orbital and the anion As-pz orbital with respect to the mirror symmetry. Since the band inversion occurs between two bands with the same parity, this peculiar 2D NLS could be used as transparent conductors. In the presence of buckling or spin-orbit coupling, the 2D NLS state may turn into a 2D Dirac semimetal state or a 2D topological crystalline insulating state. Since the band gap opening due to buckling or spin-orbit coupling is small, Hg3As3 with the HK lattice can still be regarded as a 2D NLS at room temperature. Our work suggests a new route to design topological materials without involving states with opposite parities.

关键词： As Hg NLS Two-Dimensional Node-Line Semimetals in a Honeycomb-Kagome Lattice

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PLK1 phosphorylation of ZW10 guides accurate chromosome segregation in mitosis

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Journal of Molecular Cell Biology 2024年第2期16卷 47-62页

作者： Sm Faysal Bellah Fangyuan Xiong Zhen Dou Fengrui Yang Xing Liu Xuebiao Yao Xinjiao Gao Liangyu Zhang moe key laboratory for Membraneless Organelles and Cellular Dynamics Hefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of China School of Life SciencesHefei 230027China Anhui key laboratory for Cellular Dynamics and Chemical Biology Hefei 230027China

Stable transmission of genetic information during cell division requires faithful chromosome *** evidence has demonstrated that polo-like kinase 1(PLK1)dynamics at kinetochores control correct kinetochore–microtubule attachments and subsequent silencing of the spindle assembly ***,the mechanisms underlying PLK1-mediated silencing of the spindle checkpoint remain ***,we identified a regulatory mechanism by which PLK1-elicited zeste white 10(ZW10)phosphorylation regulates spindle checkpoint silencing in ***10 is a cognate substrate of PLK1,and the phosphorylation of ZW10 at Ser12 enables dynamic ZW10–Zwint1 *** of ZW10 phosphorylation resulted in misaligned chromosomes,while persistent expression of phospho-mimicking ZW10 mutant caused premature anaphase,in which sister chromatids entangled as cells entered *** findings reveal the previously uncharacterized PLK1–ZW10 interaction through which dynamic phosphorylation of ZW10 fine-tunes accurate chromosome segregation in mitosis.

关键词： ZW10 PLK1 kinetochore mitosis phosphorylation

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Survey on performance optimization for database systems

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Science China(Information sciences) 2023年第2期66卷 24-46页

作者： Shiyue HUANG Yanzhao QIN Xinyi ZHANG Yaofeng TU Zhongliang LI Bin CUI key laboratory of High Confidence Software Technologies (moe) School of Computer Science Peking University ZTE Corporation Institute of computational Social Science Peking University (Qingdao)

The performance optimization of database systems has been widely studied for years. From the perspective of the operation and maintenance personnel, it mainly includes three topics: prediction, diagnosis,and tuning. The prediction of future performance can guide the adjustment of configurations and *** diagnosis of anomalies can determine the root cause of performance regression. Tuning operations improve performance by adjusting influencing factors, e.g., knobs, indexes, views, resources, and structured query language(SQL) design. In this review, we focus on the performance optimization of database systems and review notable research work on the topics of prediction, diagnosis, and tuning. For prediction, we summarize the techniques, strengths, and limitations of several proposed systems for single and concurrent queries. For diagnosis, we categorize the techniques by the input data, i.e., monitoring metrics, logs, or time metrics, and analyze their abilities. For tuning, we focus on the approaches commonly adopted by the operation and maintenance personnel, i.e., knob tuning, index selection, view materialization, elastic resource, storage management, and SQL antipattern detection. Finally, we discuss some challenges and future work.

关键词： database management system performance optimization performance prediction anomaly diagnosis database tuning

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A Simulation Study of the Mesoscale Convective Systems Associated with a Meiyu Frontal Heavy Rain Event

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Acta meteorologica Sinica 2009年第4期23卷 438-454页

作者：张进谈哲敏 key laboratory of Mesoscale Severe Weather/moe and School of Atmospheric Sciences Nanjing University

In this study, evolution of the mesoscale convective systems （MCSs） within a Meiyu front during a particularly heavy rainfall event on 22 June 1999 in East China was simulated by using a nonhydrostatic numerical model ARPS （Advanced Regional Prediction System）. Investigations were conducted with emphasis on the impact of the interaction among multi-scale weather systems （MWSs） on the development of MCSs in the Meiyu frontal environment. For this case, the development of MCSs experienced three different stages. （1） The convections associated with MCSs were firstly triggered by the eastward-moving Southwest Vortex （SWV） from the Sichuan Basin, accompanying the intensification of the upper-level jet （ULJ） and the low-level jet （LLJ） that were approaching the Meiyu front. （2） Next, a low-level shear line （LSL） formed, which strengthened and organized the MCSs after the SWV decayed. Meanwhile, the ULJ and LLJ enhanced and produced favorable conditions for the MCSs development. （3） Finally, as the MCSs got intensified, a mesoscale convective vortex （MCV）, a mesoscale LLJ and a mesoscale ULJ were established. Then a coupled-development of MWSs was achieved through the vertical frontal circulations, which further enhanced the MCV and resulted in the heavy rainfall. This is a new physical mechanism for the formation of Meiyu heavy rainfall related to the SWV during the warm season in East China. In the three stages of the heavy rainfall, the vertical frontal circulations exhibited distinguished structures and played a dynamic role, and they enhanced the interaction among the MWSs. A further examination on the formation and evolution of the MCV showed that the MCV was mainly caused by the latent heat release of the MCSs, and the positive feedback between the MCSs and MCV was a key characteristic of the scale interaction in this case.

关键词： mesoscale convective systems (MCSs) Meiyu front mesoscale convective vortex (MCV) scale interaction

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Short exposure to paclitaxel induces multipolar spindle formation and aneuploidy through promotion of acentrosomal pole assembly

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Science China(Life sciences) 2010年第11期53卷 1322-1329页

作者： BIAN MingLei1, FU JingYan1, YAN Yan1, CHEN Qiang1, YANG Chao2, SHI QingHua2,JIANG Qing1 & ZHANG ChuanMao1 1moe key laboratory of Cell Proliferation and Differentiation and the State key laboratory of Bio-membrane and Membrane Bio-engineering, College of Life sciences, Peking University, Beijing 100871, China 2Hefei National laboratory for physical sciences at Microscale and School of Life sciences, University of Science and Technology of China, Hefei 230026, China moe key laboratory of Cell Proliferation and Differentiation and the State key laboratory of Bio-membrane and Membrane Bio-engineering College of Life Sciences Peking University Beijing China Hefei National laboratory for physical sciences at Microscale and School of Life sciences University of Science and Technology of China Hefei China

Paclitaxel is a widely used microtubule drug and cancer medicine. Here we report that by short exposure to paclitaxel at a low dose, multipolar spindles were induced in mitotic cells without centrosome amplification. Both TPX2 depletion and Aurora-A overexpression antagonized the multipolarity. Live cell imaging showed that some paclitaxel-treated cells accomplished multipolar cell division and a portion of the daughter cells went on to the next round of mitosis. The surviving cells grew into clones with varied genome content. The results indicated that an aneuploidy population could be induced by short exposure to paclitaxel at a low dose, implicating potential side effects of paclitaxel.

关键词： paclitaxel tpx2 Aurora-A multipolar cell division aneuploidy

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Polar Coordinate Lattice Boltzmann Kinetic Modeling of Detonation Phenomena

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Communications in Theoretical Physics 2014年第11期61卷 737-748页

作者：林传栋许爱国张广财李英俊 State key laboratory for GeoM echanics and Deep Underground Engineering China University of Mining and Technology National key laboratory of computational Physics Institute of Applied Physics and Computational Mathematics Center for Applied Physics and Technology MOE Key Center for High Energy Density Physics Simulations College of Engineering Peking University State key laboratory of Explosion Science and Technology Beijing Institute of Technology State key laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences

A novel polar coordinate lattice Boltzmann kinetic model for detonation phenomena is presented and applied to investigate typical implosion and explosion processes. In this model, the change of discrete distribution function due to local chemical reaction is dynamically coupled into the modified lattice Boltzmann equation which could recover the Navier–Stokes equations, including contribution of chemical reaction, via the Chapman–Enskog *** the numerical investigations, the main focuses are the nonequilibrium behaviors in these processes. The system at the disc center is always in its thermodynamic equilibrium in the highly symmetric case. The internal kinetic energies in different degrees of freedom around the detonation front do not coincide. The dependence of the reaction rate on the pressure, influences of the shock strength and reaction rate on the departure amplitude of the system from its local thermodynamic equilibrium are probed.

关键词： lattice Boltzmann method detonation wave nonequilibrium behavior polar coordinate

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Anisotropic phonon thermal transport in two-dimensional layered materials

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Frontiers of physics 2023年第4期18卷 217-225页

作者： Yuxin Cai Muhammad Faizan Huimin Mu Yilin Zhang Hongshuai Zou Hong Jian Zhao Yuhao Fu Lijun Zhang State key laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOEInternational Center of Computational Method and SoftwareSchool of Materials Science and EngineeringJilin UniversityChangchun 130012China State key laboratory of Superhard Materials International Center of Computational Method and SoftwareCollege of PhysicsJilin UniversityChangchun 130012China

Two-dimensional layered materials(2DLMs)have attracted growing attention in optoelectronic devices due to their intriguing anisotropic physical *** members of 2DLMs exhibit unique anisotropic electrical,optical,and thermal properties,fundamentally related to their crystal *** them,directional heat transfer plays a vital role in the thermal management of electronic ***,we use density functional theory calculations to investigate the thermal transport properties of representative layered materials:β-InSe,γ-InSe,MoS2,and *** found that the lattice thermal conductivities ofβ-InSe,γ-InSe,MoS_(2),and h-BN display diverse anisotropic behaviors with anisotropy ratios of 10.4,9.4,64.9,and 107.7,*** analysis of the phonon modes further indicates that the phonon group velocity is responsible for the anisotropy of thermal ***,the low lattice thermal conductivity of the layered InSe mainly comes from low phonon group velocity and atomic *** findings provide a fundamental physical understanding of the anisotropic thermal transport in layered *** hope this study could inspire the advancement of 2DLMs thermal management applications in next-generation integrated electronic and optoelectronic devices.

关键词： thermal conductivity two-dimensional layered materials firstprinciples calculation Boltzmann transport theory

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Magnetoelectricity in multiferroics: a theoretical perspective

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National Science Review 2019年第4期6卷 629-641页

作者： Shuai Dong Hongjun Xiang Elbio Dagotto School of Physics Southeast University key laboratory of computational physical sciences (Ministry of Education) State Key Laboratory of Surface Physics and Department of Physics Fudan University Collaborative Innovation Center of Advanced Microstructures Department of Physics and Astronomy University of Tennessee Materials Science and Technology Division Oak Ridge National Laboratory

The key physical property of multiferroic materials is the existence of coupling between magnetism and polarization, i.e. magnetoelectricity. The origin and manifestations of magnetoelectricity can be very different in the available plethora of multiferroic systems, with multiple possible mechanisms hidden behind the phenomena. In this review, we describe the fundamental physics that causes magnetoelectricity from a theoretical viewpoint. The present review will focus on mainstream physical mechanisms in both single-phase multiferroics and magnetoelectric heterostructures. The most recent tendencies addressing possible new magnetoelectric mechanisms will also be briefly outlined.

关键词： multiferroics magnetoelectricity spin–orbit coupling spin–lattice coupling spin–charge coupling

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Identification of the Most Stable Sc2C80 Isomers： Structure, Electronic Property, and Molecular Spectra Investigations

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Chinese Journal of Chemistry 2012年第4期30卷 765-770页

作者：吴静怡王太山舒春英吕鑫王春儒 key laboratory of Molecular Nanostructure and Nanotechnology Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China State key laboratory of physical Chemistry of Solid Surfaces&Fujian Provincial key laboratory of Theoretical and computational Chemistry College of Chemistry&Chemical EngineeringXiamen UniversityXiamenFujian 361005China

A systematic density functional theory investigation has been carried out to explore the possible structures of Sc2C80 at the BMK/6-31 G（d） level. The results clearly show that Sc2@C80-Ih, Sc2@Cso-Dsh, and Sc2C2@C78-C2v can be identified as three isomers of Sc2C80 metallofullerene with the lowest energy. Frontier molecular orbital analysis indicates that the two Sc2@C80 isomers have a charge state as （Sc〉）2@ C60 and the Sc2C2@C78 has a charge state of （Sc3＋）2 C22- @ C784-. Moreover, the metal-cage covalent interactions have been studied to reveal the dynamics of endohedral moiety. The vertical electron affinity, vertical ionization potential, infrared spectra and 13C nuclear mag- netic resonance spectra have been also computed to further disclose the molecular structures and properties.

关键词： metallofullerenes density functional theory relative energy HOMO-LUMO gap

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Exploration of B-site alloying in partially reducing Pb toxicity and regulating thermodynamic stability and electronic properties of halide perovskites

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Science China(Physics,Mechanics & Astronomy) 2023年第3期66卷 130-138页

作者： Xinjiang Wang Muhammad Faizan Kun Zhou Hongshuai Zou Qiaoling Xu Yuhao Fu Lijun Zhang State key laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China State key laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOECollege of Materials Science and EngineeringJilin UniversityChangchun 130012China College of Physics and Electronic Engineering Center for Computational SciencesSichuan Normal UniversityChengdu 610068China International Center of computational Method and Software Jilin UniversityChangchun 130012China

Alloying strategies provide a high degree of freedom for reducing lead toxicity,improving thermodynamic stability, tuning the optoelectronic properties of ABX3 halide perovskites by varying the alloying element species and their *** the key role of B-site cations in contributing band edge states and modulating structure factors in halide perovskites,the partial replacement of Pb2+with different B-site metal ions has been *** several experimental attempts have been made to date,the effect of B-site alloying on the stability and electronic properties of halide perovskites has not been fully ***,we take cubic CsPbBr3 perovskite as the prototype material and systematically explore the effects of B-site alloying on Pb-containing *** to the presence or absence of the corresponding perovskite phase,the ten alloying elements investigated are classified into three types(i.e.,Type Ⅰ:Sn Ge,Ca,Sr;Type Ⅱ:Cd,Mg,Mn;Type Ⅲ:Ba,Zn,Cu).Based on the first-principles calculations,we obtain the following ***,these B-site alloys will exist as disordered solid solutions rather than ordered structures at room temperature throughout the composition ***,the alloying of Sn and Ge enhances the thermodynamic stability of the cubic perovskite host,whereas the alloying of the other elements has no remarkable effect on the thermodynamic stability of the cubic perovskite ***,the underlying physical mechanism for bandgap tuning can be attributed to the atomic orbital energy mismatch or quantum confinement ***,the alloying of different elements demonstrates the diversity in the regulation of crystal structure and electronic properties,indicating potential applications in photovoltaic s and self-trapped exciton-based light-emitting *** work provides theoretical guidance for using alloying strategies to reduce lead toxicity,enhance stability,and optimize the electronic properties of halide perovsk

关键词： lead-based halide perovskites alloying thermodynamic stability first-principles calculations optoelectronic applications

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