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Actively Reconfigurable Valley Topological Edge and Corner States in Photonic Crystals Based on Phase Change Material Ge2Sb2Te5

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激光与光电子学进展 2024年第5期61卷 557-571页

作者： li Wei Peng Yuxiang Su Peihao li jianbo Wang Kaijun liu Exian liu Jianqiang He Mengdong College of Science Hunan Province Key Laboratory of Materials Surface&Interface Science and TechnologyCentral South University of Forestry and TechnologyChangsha 410004HunanChina College of Science Jiujiang UniversityJiujiang 332005JiangxiChina

The immunity of topological states against backscattering and structural defects provides them with a unique advantage in the exploration and design of high-precision low-loss optical devices.However,the operating bandwidth of the topological states in certain photonic structures is difficult to actively tune and flexibly reconfigure.In this study,we propose a valley topological photonic crystal(TPC)comprising two inverse honeycomb photonic crystals,consisting of hexagonal silicon and Ge2Sb2Te5(GST)rods.When GST transitions from the amorphous phase to the crystalline phase,the edge band of the TPC appears as a significant redshift and is inversed from a“∪”to an“∩”shape with topological phase transition,which enables active tuning of the operating bandwidth and propagation direction of topological edge states.Both the topological edge and corner states in a triangular structure constructed using TPCs can be simultaneously adjusted and reconfigured via GST phase transition,along with a change in the group number of corner states.Using the adjustability of topological edge states and electromagnetic coupling between two different topological bearded interfaces,we develop a multichannel optical router with a high tuning degree of freedom,where channels can be actively reconfigured and their on/off states can be freely switched.Our study provides a strategy for the active regulation of topological states and may be beneficial for the development of reconfigurable topological optical devices.

关键词： topological edge states topological corner states phase change material active reconfiguration topological photonic crystal

Flight dynamics modeling and analysis for a Mars helicopter

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中国航空学报:英文版 2023年第9期36卷 221-230页

作者： Hong ZHAO Zhiwei DING Gen LENG jianbo li National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Helicopter Research&Development Institute Jingdezhen 33300China

Flight dynamics modeling for the Mars helicopter faces great challenges.Aerodynamic modeling of coaxial rotor with high confidence and high computational efficiency is a major difficulty for the field.This paper builds an aerodynamic model of coaxial rotor in the extremely thin Martian atmosphere using the viscous vortex particle method.The aerodynamic forces and flow characteristics of rigid coaxial rotor are computed and analyzed.Meanwhile,a high fidelity aerodynamic surrogate model is built to improve the computational efficiency of the flight dynamics model.Results in this paper reveal that rigid coaxial rotor can bring the Mars helicopter sufficient controllability but result in obvious instability and control couplings in forward flight.This highlights the great differences in flight dynamics characteristics compared with conventional helicopters on Earth.

关键词： Aerodynamic modeling Coaxial rotor Flight dynamics Mars helicopter Viscous Vortex Particle Method(VVPM)

Load distribution strategy for multi-lift system with helicopters based on power consumption and robust adaptive game control

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Chinese Journal of Aeronautics 2023年第4期36卷 268-285页

作者： Dengyan DUAN Gen LENG Jie GAO Xinming FENG jianbo li National Key Laboratory of Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

It is of great significance to reasonably distribute the slung load to each helicopter while considering difference in power consumption,relative position and interaction comprehensively.Therefore,the load distribution strategy based on power consumption and robust adaptive game control is proposed in this paper.The study is on a"2-lead"multi-lift system of four tandem heli-copters carrying a load cooperatively.First,based on the hierarchical control,the load distribution problem is divided into two parts:the calculation of expected cable force and the calculation of the anti-disturbance cable force.Then,aimed at minimizing the maximum equivalent power of heli-copter,an optimization problem is set up to calculate the expected cable force.Specially,the agent power model is trained by BP neural network,the safe distance constraint between helicopters is set to 2.5 rotor diameters to reduce aerodynamic interference,and the helicopters with different perfor-mance can be considered by introducing the equivalent power factor into the objective function.Next,considering the difference and interaction between helicopters,the robust adaptive differen-tial game control is proposed to calculate the anti-disturbance cable force.Particularly,to solve the coupled Hamiltonian equations,an adaptive solving method for value function is proposed,and its stability is proved in the sense of Lyapunov.The simulation results indicate that the proposed load distribution method based on power consumption is applicable to the entire flight trajectory even there are differences between helicopters.The game control can consider interaction between heli-copters,can deal with different objective functions,and has strong robustness and small steady-state error.Based on the entire strategy,the cable force can be reasonably allocated so as to resist disturbance and improve the flight performance of the whole system.

关键词： Differential game Helicopter Load distribution Multi-lift system Power consumption Tracking control

The m6A methylation regulates gonadal sex differentiation in chicken embryo

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Journal of Animal Science and Biotechnology 2022年第6期13卷 1657-1670页

作者： jianbo li Xiuan Zhang Xiqiong Wang Congjiao Sun Jiangxia Zheng Junying li Guoqiang Yi Ning Yang National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics Breeding and ReproductionMinistry of Agriculture and Rural AffairsChina Agricultural UniversityBeijingChina Shenzhen Branch Guangdong Laboratory of Lingnan Modern AgricultureGenome Analysis Laboratory of the Ministry of Agriculture and Rural AffairsAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina

Background:As a ubiquitous reversible epigenetic RNA modification,N6-methyladenosine(m6A)plays crucial regulatory roles in multiple biological pathways.However,its functional mechanisms in sex determination and differentiation during gonadal development of chicken embryos are not clear.Therefore,we established a transcriptome-wide m6A map in the female and male chicken left gonads of embryonic day 7(E7)by methylated RNA immunoprecipitation sequencing(MeRIP-seq)to offer insight into the landscape of m6A methylation and investigate the post-transcriptional modification underlying gonadal differentiation.Results:The chicken embryonic gonadal transcriptome was extensively methylated.We found 15,191 and 16,111 m6A peaks in the female and male left gonads,respectively,which were mainly enriched in the coding sequence(CDS)and stop codon.Among these m6A peaks,we identified that 1013 and 751 were hypermethylated in females and males,respectively.These differential peaks covered 281 and 327 genes,such as BMP2,SMAD2,SOX9 and CYP19A1,which were primarily associated with development,morphogenesis and sex differentiation by functional enrichment.Further analysis revealed that the m6A methylation level was positively correlated with gene expression abundance.Furthermore,we found that YTHDC2 could regulate the expression of sex-related genes,especially HEMGN and SOX9,in male mesonephros/gonad mingle cells,which was verified by in vitro experiments,suggesting a regulatory role of m6A methylation in chicken gonad differentiation.Conclusions:This work provided a comprehensive m6A methylation profile of chicken embryonic gonads and revealed YTHDC2 as a key regulator responsible for sex differentiation.Our results contribute to a better understanding of epigenetic factors involved in chicken sex determination and differentiation and to promoting the future development of sex manipulation in poultry industry.

关键词： Chicken Embryo Gonads m6A YTHDC2

Facile synthesis of KVPO_(4)F/reduced graphene oxide hybrid as a high-performance cathode material for potassium-ion batteries

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Journal of Energy Chemistry 2022年第5期31卷 284-292页

作者： Jianzhi Xu Jiaying liao Yifan Xu jianbo li Chuannan Zhu Jun lin Xiaosi Zhou Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborative Innovation Center of Biomedical Functional MaterialsSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023JiangsuChina

Potassium-ion batteries(PIBs) as a substitute for lithium-ion batteries have aroused widespread attention and have been rapidly developed. In the positive electrode materials, polyanionic compound has a high working voltage and large reversible capacity on account of its distinct framework and the strong inducing effect of the anionic group. Herein, a KVPO_(4)F/reduced graphene oxide(KVPF/r GO) hybrid was fabricated via a simple multi-step approach as the polyanionic cathode material for PIBs. Profiting from the small size of KVPF nanoparticles and their uniform distribution in the r GO framework, the assynthesized KVPF/r GO hybrid manifests a large discharge capacity of 103.2 mAh g^(-1) with an outstanding energy density of 436.5 Wh kg^(-1). Through r GO decoration, the hybrid also demonstrates remarkable rate and cycling properties. By employing ex-situ X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) techniques, the potassium storage mechanism of KVPF was clearly revealed. The facile preparation procedure and superior properties endow it great application prospects in large-scale energy storage.

关键词： KVPO_(4)F Potassium-ion battery Cathode Reduced graphene oxide Ex-situ XRD

Tailoring MgH_(2) for hydrogen storage through nanoengineering and catalysis

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Journal of Magnesium and Alloys 2022年第11期10卷 2946-2967页

作者： Zhao Ding Yuting li Hang Yang Yangfan Lu Jun Tan jianbo li Qian li Yu'an Chen Leon L.Shaw Fusheng Pan College of Materials Science and Engineering National Engineering Research Center for Magnesium AlloysChongqing UniversityChongqing 400044China The State Key Laboratory of Refractories and Metallurgy Institute of Advanced Materials and NanotechnologyWuhan University of Science and TechnologyWuhan 430081China Department of Mechanical Materials and Aerospace EngineeringIllinois Institute of TechnologyChicago 60616United States

Hydrogen energy has been recognized as “Ultimate Power Source” in the 21st century, which could be the best solution to the looming energy crisis and climate degeneration in the near future. Due to its high safety, low price, abundant resources and decent hydrogen storage density, magnesium based solid-state hydrogen storage materials are becoming the leading candidate for onboard hydrogen storage. However,the high operation temperature and slow reaction rate of MgH_(2), as a result of the large formation enthalpy and high reaction activation energy,respectively, are the first and most difficult problems we need to face and overcome to realize its industrialization. Herein, a state-of-the-art review on tailoring the stable thermodynamics and sluggish kinetics of hydrogen storage in MgH_(2), particularly through nanoengnieering and catalysis is presented, aiming to provide references and solutions for its promotion and application. Promising methods to overcome the challenges faced by MgH_(2)/Mg, such as bidirectional catalysts and nanoconfinement with in-situ catalysis are compared and the required improvements are discussed to stimulate further discussions and ideas in the rational design of MgH_(2)/Mg systems with ability for hydrogen release/uptake at lower temperatures and cycle stability in the near future.

关键词： Hydrogen storage materials MgH_(2) Nanoengineering Catalysis Hydrogen release Hydrogen uptake

Demonstration of fully-connected quantum communication network exploiting entangled sideband modes

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Frontiers of physics 2023年第4期18卷 277-282页

作者： Fan li Xiaoli Zhang jianbo li Jiawei Wang Shaoping Shi Long Tian Yajun Wang lirong Chen Yaohui Zheng State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-ElectronicsShanxi UniversityTaiyuan 030006China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Quantum communication network scales point-to-point quantum communication protocols to more than two detached parties,which would permit a wide variety of quantum communication applications.Here,we demonstrate a fully-connected quantum communication network,exploiting three pairs of Einstein–Podolsky–Rosen(EPR)entangled sideband modes,with high degree entanglement of 8.0 dB,7.6 dB,and 7.2 dB.Each sideband modes from a squeezed field are spatially separated by demultiplexing operation,then recombining into new group according to network requirement.Each group of sideband modes are distributed to one of the parties via a single physical path,making sure each pair of parties build their own private communication links with high channel capacity better than any classical scheme.

关键词： quantum network quantum communication entangled sideband modes quantum dense coding

Investigation on lateral dispersion characteristics of fuel particles in dense phase zone of a large-scale circulating fluidized bed boiler under combustion conditions

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Particuology 2023年第7期78卷 62-72页

作者： Zhongzhi Yang Xiaofeng Lu Zhonghao Dong Rongdi Zhang Jiayi Lu Jiayi Jue Baosheng Meng Quanhai Wang Yinhu Kang jianbo li Key Laboratory of Low-grade Energy Utilization Technologies and Systems(Chongqing University) Ministry of EducationChongqing400044China Dongfang Boiler Group Co LtdChengdu611731.China Geely Baikuang Group Co. LtdGuangxi533000China

The dispersion characteristics of fuel particles in the dense phase zone in circulating fluidized bed(CFB)boilers have an important influence on bed temperature distribution and pollutant emissions.However,previous research in literature was mostly on small-scale apparatus,whose results could not be applied directly to large-scale CFB with multiple dispersion sources.To help solve this problem,we proposed a novel method to estimate the lateral dispersion coefficient(Dx)of fuel particles under partial coal cut-off condition in a 35o MW supercritical CFB boiler based on combustion and dispersion models.Meanwhile,we carried out experiments to obtain the Dx in the range of 0.1218-0.1406 m2/s.Numerical simulations were performed and the influence of operating conditions and furnace structure on fuel dispersion characteristics was investigated,the simulation value of Dx was validated against experimental data.Results revealed that the distribution of bed temperature caused by the fuel dispersion was mainly formed by char combustion.Because of the presence of intermediate water-cooled partition wall,the mixing and dispersion of fuel and bed material particles between the left and right sides of the furnace were hindered,increasing the non-uniformity of the bed temperature near furnace front wall.

关键词： Dispersion Large-scale CFB Fuel particles Combustion Dense phase zone

Hierarchical carbon nanosheet confined defective MoS_(x) cathode towards long-cycling zinc-ion-battery

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Nano Research 2023年第7期16卷 9364-9370页

作者： Xiaoqi Wang Shimeng Zhang Rui Yang Shengchi Bai jianbo li Yu Wu Bowen Jin Xu Jin Mingfei Shao Bo Wang School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Research Center of New Energy PetroChina Research Institute of Petroleum Exploration&DevelopmentBeijing 100083China

Aqueous zinc-ion batteries(ZIBs)have attracted increasing attention due to their low cost and high safety.MoS_(2) is a promising cathode material for aqueous ZIBs due to its favorable Zn^(2+)accommodation ability.However,the structural strain and large volume changes during intercalation/deintercalation lead to exfoliation of active materials from substrate and cause irreversible capacity fading.In this work,a highly stable cathode was developed by designing a hierarchical carbon nanosheet-confined defective MoS_(x)material(CNS@MoS_(x)).This cathode material exhibits an excellent cycling stability with high capacity retention of 88.3%and~100%Coulombic efficiency after 400 cycles at 1.2 A·g^(-1),much superior compared to bare MoS_(2).Density functional theory(DFT)calculations combined with experiments illustrate that the promising electrochemical properties of CNS@MoS_(x)are due to the unique porous conductive structure of CNS with abundant active sites to anchor MoS_(x)via strong chemical bonding,enabling MoS_(x)to be firmly confined on the substrate.Moreover,this unique hierarchical complex structure ensures the fast migration of Zn^(2+)within MoS_(x)interlayer.

关键词： aqueous zinc-ion batteries MoS_(x)cathode porous carbon nanosheets long-cycling hierarchical structure