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Topological hinge modes in Dirac semimetals

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Frontiers of physics 2023年第1期18卷 85-95页

作者： xu-tao zeng Ziyu Chen Cong Chen Bin-Bin Liu Xian-Lei Sheng Shengyuan A.Yang School of Physics Beihang UniversityBeijing 100191China Department of Physics The University of Hong KongHong KongChina Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China Research Laboratory for Quantum Materials Singapore University of Technology and DesignSingapore 487372Singapore Center for Quantum Transport and Thermal Energy Science School of Physics and TechnologyNanjing Normal UniversityNanjing 210023China

Dirac semimetals(DSMs)are an important class of topological states of ***,focusing on DSMs of band inversion type,we investigate their boundary modes from the effective model *** show that in order to properly capture the boundary modes,k-cubic terms must be included in the effective model,which would drive an evolution of surface degeneracy manifold from a nodal line to a nodal *** k-cubic terms are also needed for better exposing the topological hinge modes in the *** first-principles calculations,we demonstrate that this feature and the topological hinge modes can be clearly exhibited inβ-*** extend the discussion to magnetic DSMs and show that the time-reversal symmetry breaking can gap out the surface bands and hence is beneficial for the experimental detection of hinge ***,we show that magnetic DSMs serve as a parent state for realizing multiple other higher-order topological phases,including higher-order Weyl-point/nodal-line semimetals and higher-order topological insulators.

关键词： topological hinge Dirac semimetals

Achieving full mutualism with massive passive devices for multiuser MIMO symbiotic radio

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Science China(Information Sciences) 2024年第9期67卷 196-212页

作者： Jingran xu Zhuoyin DAI Yong zeng Shi JIN tao JIANG National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories Research Center of 6G Mobile Communications School of Cyber Science and Engineering and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

Symbiotic radio(SR) is one of the attractive communication technologies to facilitate largescale Internet of Things(IoT) connections with enhanced energy and spectrum efficiency, where passive backscatter devices(BDs) modulate their information over the radio frequency(RF) signals emitted by the active primary transmitters(PTs). Meanwhile, the primary transmission can be strengthened with the additional multipaths created by BDs. To capitalize to a greater extent on the mutualism relationship between the two types of communication, this paper studies multiple-input multiple-output(MIMO) SR communication systems including multiple PTs and massive BDs. We derive the achievable rate expressions of each PT and BD, as well as the sum rate expressions of primary and secondary communication, *** asymptotic analysis is given to derive the active and passive communication rates with a large number of BDs. Furthermore, for the general case with a finite number of BDs, we study the precoding optimization problem to maximize the sum rate of primary communication, while ensuring that the sum rate of secondary communication and the individual rate for each PT and BD in the prescribed active and passive user sets satisfy the specified thresholds. Simulation results are presented to verify the analytical studies.

关键词： multiuser MIMO SR backscattering massive backscatter devices asymptotic analysis active and passive communication

Transparent micropatterned conductive films based on highlyordered nanowire network

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Nano Research 2024年第5期17卷 4288-4297页

作者： Xin-Ran Zhang Hai-tao Deng xu zeng Yi-Lin Wang Peng Huang Xiao-Sheng Zhang School of Integrated Circuit Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Transparent conductive films that are based on nanowire networks are essential to construct flexible,wearable,and even stretchable ***,large-scale precise micropatterning,especially with regard to the controllability of the organizing orientation of nanowires,is a critical ***,we proposed a liquid film rupture self-assembly approach for manufacturing transparent conductive films with microstructure arrays based on a highly ordered nanowire *** large-scale microstructure conductive films were fabricated through air-liquid interface self-assembly and liquid film rupture *** typical micropattern morphologies,including square,hexagon,circle,serpentine,etc.,were prepared to reveal the universal applicability of the proposed *** homogeneity and controllability of this approach were verified for multiple *** the assembly cycles increasing,the optical transmittance decreases *** addition,theoretical model analysis is carried out,and the analytical formula of the speed of the film moving with the surface tension and the density of the liquid film is ***,the feasibility of this approach for piezoresistive strain sensors is *** fabrication approach demonstrated a cost-effective and efficient method for precisely arranging nanowires,which is useful in transparent and wearable applications.

关键词： flexible electronics transparent conductive network micropatterning nanowires micro electromechanical systems(MEMS)

Systematic review and network meta-analysis of different nonsteroidal anti-inflammatory drugs for juvenile idiopathic arthritis

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World Journal of Clinical Cases 2024年第12期12卷 2056-2064页

作者： tao zeng Jian-Zhong Ye Hui Qin Qian-Qian xu College of Medicine Jingchu University of Technology JingmenJingmen 448000Hubei ProvinceChina

BACKGROUND Various non-steroidal anti-inflammatory drugs(NSAIDs)have been used for juvenile idiopathic arthritis(JIA).However,the optimal method for JIA has not yet been *** To perform a systematic review and network meta-analysis to determine the optimal *** We searched for randomized controlled trials(RCTs)from PubMed,EMBASE,Google Scholar,CNKI,and Wanfang without restriction for publication date or language at August,*** RCTs that comparing the effectiveness of NSAIDs with each other or placebo for JIA were included in this network *** surface under the cumulative ranking curve(SUCRA)analysis was used to rank the treatments.P value less than 0.05 was identified as statistically *** We included 8 RCTs(1127 patients)comparing 8 different instructions including meloxicam(0.125 qd and 0.250 qd),Celecoxib(3 mg/kg bid and 6 mg/kg bid),piroxicam,Naproxen(5.0 mg/kg/d,7.5 mg/kg/d and 12.5 mg/kg/d),inuprofen(30-40 mg/kg/d),Aspirin(60-80 mg/kg/d,75 mg/kg/d,and 55 mg/kg/d),Tolmetin(15 mg/kg/d),Rofecoxib,and *** were no significant differences between any two NSAIDs regarding ACR Pedi 30 *** SUCRA shows that celecoxib(6 mg/kg bid)ranked first(SUCRA,88.9%),rofecoxib ranked second(SUCRA,68.1%),Celecoxib(3 mg/kg bid)ranked third(SUCRA,51.0%).There were no significant differences between any two NSAIDs regarding adverse *** SUCRA shows that placebo ranked first(SUCRA,88.2%),piroxicam ranked second(SUCRA,60.5%),rofecoxib(0.6 mg/kg qd)ranked third(SUCRA,56.1%),meloxicam(0.125 mg/kg qd)ranked fourth(SUCRA,56.1%),and rofecoxib(0.3 mg/kg qd)ranked fifth(SUCRA,56.1%).CONCLUSION In summary,celecoxib(6 mg/kg bid)was found to be the most effective NSAID for treating ***,piroxicam,and meloxicam may be safer options,but further research is needed to confirm these findings in larger trials with higher quality studies.

关键词： Non-steroidal anti-inflammatory drugs Juvenile idiopathic arthritis Network meta-analysis Systematic review

Zigzag magnetic order in a novel tellurate compound Na_(4-δ)NiTeO_6 with S=1 chains

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Science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 128-137页

作者： Cheng Su xu-tao zeng Yi Li Nvsen Ma Zhengwang Lin Chuandi Zhang Chin-Wei Wang Ziyu Chen Xingye Lu Wei Li Xian-Lei Sheng Wentao Jin School of Physics Beihang UniversityBeijing 100191China Center for Advanced Quantum Studies and Department of Physics Beijing Normal UniversityBeijing 100875China Australian Nuclear Science and Technology Organisation Lucas Heights NSW 2234Australia CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

Na_(4-δ)Ni Te O_(6) is a rare example in the transition-metal tellurate family of realizing an S=1 spin-chain *** performing neutron powder diffraction measurements,the ground-state magnetic structure of Na_(4-δ)Ni Te O_(6) is *** measurements reveal that below T_N~6.8(2)K,the Ni^(2+) moments form a screwed ferromagnetic(FM)spin-chain structure running along the crystallographic a axis but these FM spin chains are coupled antiferromagnetically along the b and c directions,giving rise to a magnetic propagation vector of k=(0,1/2,1/2).This zigzag magnetic order is well supported by first-principles *** moment size of Ni^(2+) spins is determined to be 2.1(1) μ_(B) at 3 K,suggesting a significant quenching of the orbital moment due to the crystalline electric field(CEF)*** previously reported metamagnetic transition near H_(c)~0.1 T can be understood as a field-induced spin-flip *** relatively easy tunability of the dimensionality of its magnetism by external parameters makes Na_(4-δ)Ni Te O_(6)a promising candidate for further exploring various types of novel spin-chain physics.

关键词： zigzag magnetic order spin chain neutron diffraction first-principles calculations

Discovery of Partial Differential Equations from Highly Noisy and Sparse Data with Physics-Informed Information Criterion

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Research 2024年第1期2023卷 247-259页

作者： Hao xu Junsheng zeng Dongxiao Zhang BIC-ESAT EREand SKLTCSCollege of EngineeringPeking UniversityBeijing 100871P.R.China Institute of Applied Physics and Computational Mathematics Beijing 100088P.R.China Eastern Institute for Advanced Study Eastern Institute of TechnologyNingbo 315200ZhejiangP.R.China National Center for Applied Mathematics Shenzhen(NCAMS) Southern University of Science and TechnologyShenzhen 518055GuangdongP.R.China Department of Mathematics and Theories Peng Cheng LaboratoryShenzhen 518000GuangdongP.R.China

Data-driven discovery of partial differential equations(PDEs)has recently made tremendous progress,and many canonical PDEs have been discovered successfully for proof of ***,determining the most proper PDE without prior references remains challenging in terms of practical *** this work,a physics-informed information criterion(PIC)is proposed to measure the parsimony and precision of the discovered PDE *** proposed PIC achieves satisfactory robustness to highly noisy and sparse data on 7 canonical PDEs from different physical scenes,which confirms its ability to handle difficult *** PIC is also employed to discover unrevealed macroscale governing equations from microscopic simulation data in an actual physical *** results show that the discovered macroscale PDE is precise and parsimonious and satisfies underlying symmetries,which facilitates understanding and simulation of the physical *** proposition of the PIC enables practical applications of PDE discovery in discovering unrevealed governing equations in broader physical scenes.

关键词： process canonical proof

An accurate and efficient space-time Galerkin spectral method for the subdiffusion equation

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Science China Mathematics 2024年第10期67卷 2387-2408页

作者： Wei zeng Chuanju xu School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling and High Performance Scientific Computing Xiamen UniversityXiamen 361005China

In this paper, we design and analyze a space-time spectral method for the subdiffusion ***, we are facing two difficulties. The first is that the solutions of this equation are usually singular near the initial time. Consequently, traditional high-order numerical methods in time are inefficient. The second obstacle is that the resulting system of the space-time spectral approach is usually large and time-consuming to solve. We aim at overcoming the first difficulty by proposing a novel approach in time, which is based on variable transformation techniques. Suitable ψ-fractional Sobolev spaces and a new variational framework are introduced to establish the well-posedness of the associated variational problem. This allows us to construct our space-time spectral method using a combination of temporal generalized Jacobi polynomials(GJPs) and spatial Legendre polynomials. For the second difficulty, we propose a fast algorithm to effectively solve the resulting linear system. The fast algorithm makes use of a matrix diagonalization in space and QZ decomposition in time. Our analysis and numerical experiments show that the proposed method is exponentially convergent with respect to the polynomial degrees in both space and time directions, even though the exact solution has very limited regularity.

关键词： subdiffusion equations variable transformation Ψ-Sobolev spaces well-posedness space-time Galerkin spectral method error estimate fast algorithm

Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

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Petroleum Science 2024年第2期21卷 791-805页

作者： xu zeng tao Yang Jian-Wei Feng Cong-Sheng Bian Ming Guan Wei Liu Bing-Cheng Guo Jin Dong Research Institute of Petroleum Exploration and Development China National Petroleum CorporationBeijing100083China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China School of Earth Sciences China University of PetroleumQingdao266400ShandongChina

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in th

关键词： Fractures Development characteristics Controlling factors Shale oil Sweet spot

Two H3K36 methyltransferases differentially associate with transcriptional activity and enrichment of facultative heterochromatin in rice blast fungus

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aBIOTECH 2024年第1期5卷 1-16页

作者： Mengting xu Ziyue Sun Huanbin Shi Jiangnan Yue Xiaohui Xiong Zhongling Wu Yanjun Kou zeng tao Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects Institute of BiotechnologyZhejiang UniversityHangzhou 310058China State Key Lab of Rice Biology and Breeding China National Rice Research InstituteHangzhou 310021China

Di-and tri-methylation of lysine 36 on histone H3(H3K36me2/3)is catalysed by histone methyltransferase Set2,which plays an essential role in transcriptional *** there is a single H3K36 methyltransferase in yeast and higher eukaryotes,two H3K36 methyltransferases,Ash1 and Set2,were present in many filamentous ***,their roles in H3K36 methylation and transcriptional regulation remained *** with methods of RNA-seq and ChIP-seq,we revealed that both Ash1 and Set2 are redundantly required for the full H3K36me2/3 activity in Magnaporthe oryzae,which causes the devastating worldwide rice blast ***1 and Set2 distinguish genomic H3K36me2/3-marked regions and are differentially associated with repressed and activated transcription,***,Ash1-catalysed H3K36me2 was co-localized with H3K27me3 at the chromatin,and Ash1 was required for the enrichment and transcriptional silencing of H3K27me3-occupied *** the different roles of Ash1 and Set2,in H3K36me2/3 enrichment and transcriptional regulation on the stress-responsive genes,they differentially respond to various stresses in ***,we reveal a novel mechanism by which two H3K36 methyltransferases catalyze H3K36me2/3 that differentially associate with transcriptional activities and contribute to enrichment of facultative heterochromatin in eukaryotes.

关键词： Ash1 Facultative heterochromatin H3K36me2/3 Magnaporthe oryzae Set2 Transcriptional regulation