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Triboelectric nanogenerators with a constant inherent capacitance design

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Nano Research 2023年第3期16卷 4077-4084页

作者： Lanyue Gan Fan Xia Panpan Zhang Xijun Jiang Yuxuan Liu Simiao Niu Youfan Hu Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411102China Key Laboratory for the Physics and Chemistry of Nanodevices Center for Carbon-Based ElectronicsAcademy for Advanced Interdisciplinary StudiesSchool of ElectronicsPeking UniversityBeijing 100871China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Biomedical Engineering Rutgers UniversityPiscatawayNJ 08854USA

Triboelectric nanogenerators(TENGs)utilize the phenomena of contact electrification and electrostatic induction to harvest mechanical energy from the environment.A good match between the motion frequency and the circuit characteristic frequency is critical for the effective power generation of a ***,most TENGs have a time-dependent inherent capacitance(TICTENG),which hinders an optimal design for efficient energy ***,we propose a novel structure of a TENG with a constant inherent capacitance(CIC-TENG)and a mathematical model is established to provide analytical expressions of key output parameters of the device,which gives numerical simulation results that are in good agreement with the experimentally obtained *** of merit and an optimization strategy are also given as guidelines for the optimization of material selection,geometry design,***,a disk-formed CIC-TENG(DCIC-TENG)with polarity-switched triboelectric pairs is constructed to harvest unidirectional mechanical energy continuously,achieving an output power density of 55 mW/m^(2).The effects of the motion frequency,the number of electrodes and triboelectric pairs on the charge transfer efficiency of the DCICTENG are assessed and a preferred design strategy is ***,the CIC-TENG demonstrates approximately two-fold advantages in power transfer efficiency over the TIC-TENG,and a DCIC-TENG-based self-powered anemometer was fabricated to measure wind speed in real time.

关键词： triboelectric nanogenerator inherent capacitance output power linearity

Phosphafluorenyl lithiums:direct synthesis from white phosphorus,structure and diversified synthons

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Science China Chemistry 2022年第2期65卷 322-327页

作者： Jingyuan Hu Zhengqi Chai Wei Liu Zhe Huang Junnian Wei Wen-Xiong Zhang Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory of Rare Earth Materials Chemistry and Applications&Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationCollege of ChemistryPeking UniversityBeijing 100871China

While rich chemistry of phospholyl anions is discovered,phosphafluorenyl anions are only proposed as the critical intermediates for the synthesis of *** this article,we reported the direct synthesis of phosphafluorenyl lithiums from white phosphorus(P_(4))through direct P-C bond *** reaction between P4 and biphenyl dilithio reagents efficiently afforded phosphafluorenyl lithiums,which were further used to synthesize different kinds of organophosphorus *** aggregation states of phosphafluorenyl lithiums were investigated for the first *** studies by DFT calculations revealed a cooperative nucleophilic attack of two C−Li bonds on P_(4)molecule.

关键词： white phosphorus organophosphorus compounds P–C bond formation P_(4)functionalization phosphafluorenyl lithium

Metagenomic insights into the profile of antibiotic resistomes in sediments of aquaculture wastewater treatment system

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Journal of Environmental Sciences 2022年第3期34卷 345-355页

作者： Jianfei Chen Yuyin Yang Xinshu Jiang Yanchu Ke Tao He Shuguang Xie State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China State Key Joint Laboratory of Environment Simulation and Pollution Control(SKJLESPC) Beijing Key Laboratory for Emerging Organic Contaminants Control(BKLEOC)School of EnvironmentPOPs Research CenterTsinghua UniversityBeijing 100084China South China Institute of Environmental Sciences(SCIES) Ministry of Ecology and Environment(MEE)Guangzhou 510655China

To meet the rapidly growing global demand for aquaculture products,large amounts of antibiotics were used in aquaculture,which might accelerate the evolution of antibiotic-resistant bacteria(ARB)and the propagation of antibiotic genes(ARGs).In our research,we revealed the ARGs profiles,their co-occurrence with mobile genetic elements(MGEs),and potential hosts in sediments of a crab pond wastewater purification system based on metagenomic *** residual antibiotic seems to increase the propagation of ARGs in the crab pond,but there was no clear relationship between a given antibiotic type and the corresponding resistance *** effect of aquaculture on sediment was not as profound as that of other anthropogentic activities,but increased the relative abundance of sulfon-amide resistance gene.A higher abundance of MGEs,especially plasmid,increased the po-tential ARGs dissemination risk in crab and purification *** and sulfonamide resistance genes had greater potential to transfer because they were more frequently carried by *** horizontal gene transfer was likely to occur among a variety of microorgan-isms,and various ARGs hosts including Pseudomonas,Acinetobacter,Escherichia,and Klebsiella were *** community influenced the composition of ARG hosts,and Pro-teobacteria was the predominant ***,our study provides novel insights into the environmental risk of ARGs in sediments of aquaculture wastewater treatment system.

关键词： Metagenomic sequencing Aquaculture Antibiotic resistome Antibiotic resistance genes(ARGs) Mobile genetic elements(MGEs) ARG hosts

Calculation of Feynman loop integration and phase-space integration via auxiliary mass flow

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Chinese Physics C 2021年第1期45卷 162-174页

作者： Xiao Liu Yan-Qing Ma Wei Tao Peng Zhang School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for high Energy Physics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We extend the auxiliary-mass-flow(AMF) method originally developed for Feynman loop integration to calculate integrals which also involve phase-space *** flow of the auxiliary mass from the boundary(∞) to the physical point(0+) is obtained by numerically solving differential equations with respective to the auxiliary *** problems with two or more kinematical invariants,the AMF method can be combined with the traditional differential-equation method,providing systematic boundary conditions and a highly nontrivial self-consistency *** method is described in detail using a pedagogical example of e+e-→γ*→tt+X at *** show that the AMF method can systematically and efficiently calculate integrals to high precision.

关键词： phase-space integration perturbation theory multi-loop

Nonlinear phase dynamics of ideal kink mode in the presence of shear flow

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Plasma Science and Technology 2021年第4期23卷 9-14页

作者： Yi ZHANG Zhibin GUO State Key Laboratory of Nuclear Physics and Technology Fusion Simulation CenterSchool of PhysicsPeking UniversityBeijing 100871People’s Republic of China

We investigate nonlinear phase dynamics of an ideal kink mode,induced by E×B *** the phase is the cross phase(θ_(c))between perturbed stream function of velocity(f)and magnetic field(y),i.e.θ_(c)=θf−θψ.A dimensionless parameter,analogous to the R_(i)chardson number,R_(i)=16gkink w^(2)E^(2)(γkink:the normalized growth rate of the pure kink mode;wE:normalized E×B shearing rate)is defined to measure the competition between phase pinning by the current density and phase detuning by the flow *** R_(i)>1,θ_(c) is locked to a fixed value,corresponding to the conventional eigenmode *** R_(i).1,θ_(c) enters a phase slipping or oscillating state,corresponding to a nonmodal *** nonlinear phase dynamics method provides a more intuitive explanation of the complex dynamical behavior of the kink mode in the presence of E×B shear flow.

关键词： kink mode E×B flow nonlinear phase dynamics Richardson number

Complete reduction of integrals in two-loop five-light-parton scattering amplitudes

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Chinese Physics C 2020年第9期44卷 62-68页

作者： Xin Guan Xiao Liu Yan-Qing Ma School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for high Energy Physics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We reduce all the most complicated Feynman integrals in two-loop five-light-parton scattering amplitudes to basic master integrals,while other integrals can be reduced even *** results are expressed as systems of linear relations in the block-triangular form,very efficient for numerical *** results are crucial for complete next-to-next-to-leading order quantum chromodynamics calculations for three-jet,photon,and/or hadron production at hadron *** determine the block-triangular relations,we develop an efficient and general method,which may provide a practical solution to the bottleneck problem of reducing multiloop multiscale integrals.

关键词： Feynman integrals reduction five-light-parton scattering

HⅠVertical Structure of Nearby Edge-on Galaxies from CHANG-ES

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Research in Astronomy and Astrophysics 2022年第8期22卷 49-62页

作者： Yun Zheng Jing Wang Judith Irwin QDaniel Wang Jiangtao Li Jayanne English Qingchuan Ma Ran Wang Ke Wang Marita Krause Toky H.Randriamampandry Rainer Beck Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Department of Physics Engineering Physics&AstronomyQueen’s UniversityKingstonONK7L 3N6Canada Astronomy Department University of MassachusettsAmherstMA 01003USA Department of Astronomy University of MichiganAnn ArborMI48109-1107USA Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China Department of Physics and Astronomy University of ManitobaWinnipegManitobaR3T 2N2Canada Max-Planck-Institut für Radioastronomie Auf dem Hügel D-6953121 BonnGermany

We study the vertical distribution of the highly inclined galaxies from the Continuum Halos in Nearby Galaxies—an EVLA Survey(CHANG-ES).We explore the feasibility of photometrically deriving the HⅠdisk scale heights from the moment-0 images of the relatively edge-on galaxies with inclination>80°,by quantifying the systematic broadening effects and thus deriving correction equations for direct *** corrected HⅠdisk scale heights of the relatively edge-on galaxies from the CHANG-ES sample show trends consistent with the quasiequilibrium model of the vertical structure of gas *** procedure provides a convenient way to derive the scale heights and can easily be applied to statistical samples in the future.

关键词： galaxies:ISM galaxies:spiral galaxies:structure

Analysis of the role of branching angle in the dynamic rupture process on a 3-D branching fault system

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Earth and Planetary Physics 2020年第5期4卷 523-531页

作者： JingXing Fang Feng Qian HaiMing Zhang School of Earth and Space Sciences Peking UniversityBeijing 100871China

The fault branching phenomenon,which may heavily influence the patterns of rupture propagation in fault systems,is one of the geometric complexities of fault systems that is widely observed in *** this study,we investigate the effect of the branching angle on the rupture inclination and the interaction between branch planes in two-fork branching fault systems by numerical simulation and theoretical analysis based on Mohr’s circle.A friction law dependent on normal stress is used,and special attention is paid to studying how ruptures on the upper and lower branch planes affect the stress and rupture on each other *** results show that the two branch planes affect each other in different patterns and that the intensity of the effect changes with the branching *** rupture of the lower branch plane has a negative effect on the rupture of the upper branch plane in the case of a small branching angle but has almost no negative effect in the case of a large branching *** rupture of the upper branch plane,however,suppresses the rupture of the lower branch plane regardless of whether the branching angle is large or small.

关键词： branching faults Mohr–Coulomb diagram boundary integral equation method earthquake source dynamics rupture selectivity

Implementing fractional Fourier transform and solving partial differential equations using acoustic computational metamaterials in space domain

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Acta Mechanica Sinica 2021年第9期37卷 1371-1377,I0001页

作者： Zengyao Lv Peng Liu Yuanshuai Ding Hangyu Li Yongmao Pei Department of Engineering Mechanics Center for Flexible Electronics TechnologyApplied Mechanics LaboratoryTsinghua UniversityBeijing100084China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of EngineeringPeking UniversityBeijing100871China Locomotive and Car Research Institute China Academy of Railway Sciences Corporation LimitedBeijing100081China

Metamaterials can control incident waves in the sub-wavelength range through the design of artificial structures, and realize the functions that natural materials cannot achieve. The study of metamaterials has important theoretical value and application prospects. In recent years, the proposal of computational metamaterials has opened up a brand-new direction for analog computing, providing high-throughput, energy-free computing methods for special computing tasks. However, the development of acoustic computing metamaterials is relatively preliminary, and it is necessary to develop design theories. There is no work to solve partial differential equations and realize fractional Fourier transform in spatial domain acoustic computing metamaterials. In this paper, the acoustic wave computational metamaterial is designed, and the simulation realizes the spatial domain fractional Fourier transform and partial differential equation calculation. It is expected that acoustic computational metamaterials will enable new capabilities in signal acquisition and processing, network computing, and drive new applications of sound wave.

关键词： Fractional Fourier transform Partial differential equations Acoustic computational metamaterials