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Conductivity of carbon-based molecular junctions from ab-initio methods

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Frontiers of physics 2014年第6期9卷 748-759页

作者： xiao-fei li Yi Luo School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu 610054 China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei 230026 China KTH Royal Institute of Technology School of Biotechnology Division of Theoretical Chemistry and Biology S-106 91 Stockholm Sweden

Carbon nanomaterials （CNMs） are prompting candidates tor next generational electronics. In this review we provide a mini overview of recent results on the conductivity of carbon-based molecular junctions obtained from ab-mitio methods. CNMs used as nanoelectrodes and molecular materials in molecular junctions are discussed. The flmctionalities that include the nanomechanically controlled molecular conductance switches, negative differential resistance devices, and electronic rectifiers realized by using CNMs have been demonstrated.

关键词： carbon nanotubes graphene all-carbon nanodevice quantum transport ab-initio molecular dynamics simulations

Interior non-uniformity of acoustically excited oscillating gas bubbles

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Journal of Hydrodynamics 2019年第4期31卷 725-732页

作者： Yu-ning Zhang xiao-fei li Zhong-yu Guo Key Laboratory of Condition Monitoring and Control for Power Plant Equipment (Ministry of Education) School of Energy Power and Mechanical Engineering North China Electric Power University Beijing 102206 China Key Labor at oiy of Fluid and Power Machinery Ministry of Education Xihua IJnivarsily Chengdu 610039 China College of Mechanical and Transportation Engineering China University of Petroleum-Beijing Beijing 102249 China Beijing Key Laboratory of Process Fluid Filtration and Separation China University of Petroleum-Beijing Beijing 102249 China

In the present paper, the interior non-uniformity of oscillating gas bubbles in liquids under an acoustic field is theoretically investigated, as well as the temperature non-uniformity in the surrounding liquid. The pressure, the density and the temperature inside the gas bubbles are quantitatively predicted for a wide range of bubble Mach numbers. It is shown that the bubble interior non-uniformity increases significantly with the increase of the bubble Mach number. In the case of a large Mach number, the values of aforementioned paramount parameters at the bubble center are significantly larger than those at the bubble interface. Except for a very thin layer close to the bubble interface, the effects of the temperature non-uniformity in the bulk liquid could be safely ignored.

关键词： Cavitation gas bubbles acoustic field radial oscillation non-uniformity Mach number

Mechanical behavior of concrete filled glass fiber reinforced polymer-steel tube under cyclic loading

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第11期14卷 778-788页

作者： Chun-yang ZHU Ying-hua ZHAO Shuang GAO xiao-fei li Institute of Road and Bridge Engineering Dalian Maritime University

The mechanical behavior of concrete-filled glass fiber reinforced polymer(GFRP)-steel tube structures under combined seismic loading is investigated in this study. Four same-sized specimens with different GFRP layout modes were tested by a quasi-static test system. Finite element analysis(FEA) was also undertaken and the results were presented. Results of the numerical simulation compared well with those from experimental tests. Parametric analysis was conducted by using the FE models to evaluate the effects of GFRP thickness, axial compression rate, and cross sectional steel ratio. The experimental and numerical results show that the technique of GFRP strengthening is effective in improving the seismic performance of traditional concrete-filled steel tubes, with variations related to different GFRP layout modes.

关键词： Concrete-filled glass fiber reinforced polymer(GFRP)-steel tube Seismic Energy dissipation Stiffness degradation

NUMERICAL SIMULATION OF IRREGULAR WAVE-SIMULATING IRREGULAR WAVE TRAIN

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Journal of Hydrodynamics 2010年第4期22卷 537-545页

作者： liANG Xiu-feng YANG Jian-min li Jun xiao Long-fei li Xin State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200030 China

In real sea states,damage incidents on offshore floating structures are not due to the whole time series of wave elevation characterized as statistical one but due to few extreme waves or wave groups in irregular wave ***,using CFD tools to precisely simulate predetermined irregular wave train will lay sound basis for understanding the local characteristic of the flow field and impact loads on offshore floating structures when damage incidents *** this article,the generation of single extreme wave is investigated in a numerical wave ***,experimental irregular wave train is decomposed into certain number of small-amplitude *** Fourier series expansion is performed to determine the amplitude and initial phase angle of each wave component.A hydrodynamic transfer function is used to calculate the amplitude of wave-maker motion associated with each wave *** superposition is carried out on all of the wave-maker motion components to get the final wave-maker *** the wave-maker motion as input,simulation of the single extreme irregular wave train is modeled *** the method is applied to simulating a much more complicated irregular wave *** again main features of the complicated irregular wave train are reproduced compared with experiment carried out in the new deepwater experimental basin at Shanghai Jiao Tong *** the simulation,dynamic mesh method is enabled to model the piston-type wave-maker,the Volume Of Fluid（VOF） method is employed to capture the free surface and a dissipation zone is introduced to deal with wave reflection.

关键词： numerical wave tank irregular wave train Volume of Fluid (VOF) dynamic mesh

Connecting the Dots in Self-Supervised Learning:A Brief Survey for Beginners

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Journal of Computer Science & Technology 2022年第3期37卷 507-526页

作者： Peng-fei Fang Xian li Yang Yan Shuai Zhang Qi-Yue Kang xiao-fei li Zhen-Zhong Lan School of Engineering WestLake UniversityHangzhou 310030China College of Engineering and Computer Science Australian National UniversityCanberraACT 2601Australia College of Computer Science and Technology Zhejiang UniversityHangzhou 310027China

The artificial intelligence(AI)community has recently made tremendous progress in developing self-supervised learning(SSL)algorithms that can learn high-quality data representations from massive amounts of unlabeled *** methods brought great results even to the fields outside of *** to the joint efforts of researchers in various areas,new SSL methods come out ***,such a sheer number of publications make it difficult for beginners to see clearly how the subject *** survey bridges this gap by carefully selecting a small portion of papers that we believe are milestones or essential *** see these researches as the"dots"of SSL and connect them through how they ***,by viewing the connections of these dots,readers will have a high-level picture of the development of SSL across multiple disciplines including natural language processing,computer vision,graph learning,audio processing,and protein learning.

关键词： artificial intelligence(AI) dot self-supervised learning(SSL) survey

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丙型肝炎的诊疗进展

世界华人消化杂志 2024年第7期32卷 484-489页

作者：张红吉刁婷婷刘超李晓非昆明市第三人民医院(云南省传染性疾病临床医学中心) 云南省昆明市650041

丙型肝炎(丙肝)是由丙型肝炎病毒(hepatitis C virus,HCV)引起的一种常见传染病,2019年全球有慢性HCV感染者5800万人,29万人死于HCV感染引起的肝硬化,2019年全球新发感染者约150万人.丙肝危害严重,早发现、早诊断、早治疗在其中起到重... 详细信息

丙型肝炎(丙肝)是由丙型肝炎病毒(hepatitis C virus,HCV)引起的一种常见传染病,2019年全球有慢性HCV感染者5800万人,29万人死于HCV感染引起的肝硬化,2019年全球新发感染者约150万人.丙肝危害严重,早发现、早诊断、早治疗在其中起到重要意义.因此,本文作者总结了丙肝的诊断、治疗方法.丙肝的诊断需结合流行病学史、临床表现和实验室检查等进行.应根据基因型、肝脏损伤严重程度、适应症和禁忌症等选择合适的方案.

关键词：丙型肝炎丙型肝炎病毒诊断治疗综述

Signifying quantum uncertainty relations by optimal observable sets and the tightest uncertainty constants

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 43-50页

作者： xiao-Bin liang Bo li Shao-Ming fei School of Mathematics and Computer Science Shangrao Normal UniversityShangrao 334001China Quantum Information Research Center Shangrao Normal UniversityShangrao 334001China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

Quantum uncertainty relations constrain the precision of measurements across multiple non-commuting quantum mechanical ***,we introduce the concept of optimal observable sets and define the tightest uncertainty constants to accurately describe these measurement *** any quantum state,we establish optimal sets of three observables for both product and summation forms of uncertainty relations,and analytically derive the corresponding tightest uncertainty *** demonstrate that the optimality of these sets remains consistent regardless of the uncertainty relation ***,the existence of the tightest constants excludes the validity of standard real quantum mechanics,underscoring the essential role of complex numbers in this ***,our findings resolve the conjecture posed in[***.118,180402(2017)],offering novel insights and potential applications in understanding preparation uncertainties.

关键词： uncertainty relation the tightest uncertainty constants optimal observable sets

Evolutionary timescale of chalcidoid wasps inferred from over one hundred mitochondrial genomes

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Zoological Research 2023年第3期44卷 467-482页

作者： Jia-Chen Zhu Hui xiao Pu Tang xiao-fei li Xuan-Kun li Chao-Dong Zhu Qiong Wu Jin-Hua xiao Cornelis van Achterberg Da-Wei Huang Xue-Xin Chen State Key Laboratory of Rice Biology Ministry of Agriculture and Rural Affairs Key Lab of Molecular Biology of Crop Pathogens and Insect PestsProvincial Key Lab of Biology of Crop Pathogens and Insect Pests of ZhejiangInstitute of Insect SciencesZhejiang UniversityHangzhouZhejiang 310058China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Florida Museum of Natural History University of FloridaGainesvilleFL 32611 USA College of life Sciences Nankai UniversityTianjin 300071China

Chalcidoidea is one of the most biologically diverse groups among *** are characterized by extraordinary parasitic lifestyles and extensive host ranges,among which several species attack plants or serve as ***,higher-level chalcidoid relationships remain ***,we performed mitochondrial phylogenomic analyses for major clades(18out of 25 families)of Chalcidoidea based on 139 mitochondrial *** compositional heterogeneity and conflicting backbone relationships in Chalcidoidea were assessed using various datasets and tree *** phylogenetic results supported the monophyly of 16families and polyphyly of Aphelinidae and *** preferred topology recovered the relationship(Mymaridae+(Signiphoridae+Leucospidae)+(Chalcididae+((Perilampidae+Eucharitidae)+remaining Chalcidoidea))).The monophyly of Agaonidae and Sycophaginae was rejected,while the gall-associated((Megastigmidae+Ormyridae)+(Ormocerinae+Eurytomidae))relationship was supported in most results.A six-gene inversion may be a synapomorphy for most families,whereas other derived gene orders may introduce confusion in phylogenetic signals at deeper *** estimates suggested that Chalcidoidea arose near the Jurassic/Cretaceous boundary and that two dynamic shifts in diversification occurred during the evolution of *** hypothesized that the potential codiversification between chalcidoids and their hosts may be crucial for accelerating the diversification of *** state reconstruction analyses supported the hypothesis that gallinducers were mainly derived from parasitoids of gallinducers,while other gall-inducers were derived from phytophagous *** together,these findings advance our understanding of mitochondrial genome evolution in the major interfamilial phylogeny of Chalcidoidea.

关键词： Mitochondrial genome Chalcidoidea Compositional heterogeneity Divergence time Evolution of host and gall associations

Surface Polarization Effects on Collapse Transition of Polyelectrolyte Brushes

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Chinese Journal of Polymer Science 2024年第9期42卷 1313-1320,I0006页

作者： xiao-fei Xu State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai200237China

Polyelectrolyte brushes(PEBs)are commonly used to modify surface that have attracted great research *** dielectric permittivity of the grafted surface is typically significantly different from that of solution,which results in surface polarization(SP)effect with a jump of electric *** is thus important to study how SP alters the PEB’s structure and *** this work,the SP effects on PEB structure was studied using a statistical thermodynamic *** free energy functional to describe SP effect was constructed by using the image-charge ***,the electrostatic potential was solved from a modified Poisson-Boltzmann equation taking the ion solvation effect into *** the absence of SP,the thickness of PEB exhibited a continuous collapse transition when decreasing the solvent *** the presence of SP,the collapse became a jump-like *** energy analysis showed that the long-range Coulombic interaction dominated the transition because of the enhanced counterion condensation in the presence of *** theory provides an effective tool to study SP effect on PEBs,and the results explain the underlying physics in PEB collapse transition.

关键词： Surface polarization Polyelectrolyte brush Image charge Ion solvation Polyelectrolyte collapse transition