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Visible-light-induced,autopromoted nickel-catalyzed threecomponent arylsulfonation of 1,3-enynes and mechanistic insights

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Science China Chemistry 2022年第4期65卷 753-761页

作者： duo-duo hu Qian Gao Jing-Cheng Dai Ru Cui Yuan-Bo Li Yuan-Ming Li Xiao-Guo Zhou Kang-Jie Bian Bing-Bing Wu Kai-Fan Zhang Xi-Sheng Wang Yan Li Hefei National Laboratory for Physical Sciences at the Microscale Department of ChemistryCenter for Excellence in Molecular Synthesis of CASUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China

A light-induced,nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is *** methodology exhibited mild conditions,broad scope and high efficiency,and its synthetic utility has been demonstrated by a concise total synthesis of sulfone-containing drug *** mechanistic studies indicated that this light induced nickel catalysis is autopromoted by in situ produced allene,which plays a key role as co-ligand in the photoactive excited state Ni(Ⅰ)species for the LMCT *** detailed elucidation of this light-induced nickel catalytic cycle may shed some lights on the exploitation of new catalytic activity and establishment of novel methods.

关键词： light-induced autopromoted ligand to metal charge transfer nickel allene

Averaging analyses for spacecraft orbital motions around asteroids

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Acta Mechanica Sinica 2014年第3期30卷 294-300页

作者： Wei-duo hu D.J.Scheeres School of Astronautics Beihang University Department of Aerospace Engineering Science The University of Colorado

This paper summarizes a few cases of spacecraft orbital motion around asteroid for which averaging method can be applied, i.e., when central body rotates slowly, fast, and when a spacecraft is near to the resonant orbits between the spacecraft mean motion and the central body＇s rotation. Averaging conditions for these cases are given. As a major extension, a few classes of near resonant orbits are analyzed by the averaging method. Then some resulted conclusions of these averaging analyses are applied to understand the stabil- ity regions in a numerical experiment. Some stability conclu- sions are obtained. As a typical example, it is shown in detail that near circular 1 ： 2 resonant orbit is always unstable.

关键词： Orbital mechanics Asteroid Secular motion Resonant orbit Averaging theory

Flow-pattern-altered syntheses of core–shell and hole–shell microparticles in an axisymmetric microfluidic device

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Acta Mechanica Sinica 2021年第9期37卷 1378-1386,I0001页

作者： duo Wang Xu Zheng Xiaodong Chen Guoqing hu State Key Laboratory of Fluid Power and Mechatronic Systems Department of Engineering MechanicsZhejiang UniversityHangzhou310027China State Key Laboratory of Nonlinear Mechanics(LNM) Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Aerospace Engineering Beijing Institute of TechnologyBeijing100081China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China

Droplet-based microfluidics offers unique advantages to create platforms that fabricate functionalized particles with increased accessibility,robustness,and *** we present a three-phase microfluidic device that can control the flow pattern to directly generate either core–shell or hole–shell *** major benefits of this device are the ease of controlling the morphology of the compound droplets by the flow rates and thus the microstructure of the synthesized *** transition between flow patterns enables the generation of either core–shell particles or Janus particles in a single *** further show the versatility of the proposed device in fabrication of functionalized particles:the hole size of the hole–shell microparticle can be fine-tuned while its outer diameter is kept constant,and by adding Fe_(3)O_(4) nanoparticles into the photocurable phase,the obtained magnetoresponsive microparticle can move rotationally or translationally under an external magnetic *** anticipate that the present method could facilitate the fabrication of the functional microparticles for diverse applications.

关键词： Microfluidics Droplet Microparticle Janus particle

Periodic Orbits in Rotating Second Degree and Order Gravity Fields

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Chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 108-118页

作者： Wei-duo hu Daniel J. Scheeres School of Astronautics BeiHang University Beijing 100083 Department of Aerospace Engineering The University of Michigan Ann Arbor MI48109 USA

Periodic orbits in an arbitrary 2nd degree and order uniformly rotating gravity field are studied. We investigate the four equilibrium points in this gravity field. We see that close relation exists between the stability of these equilibria and the existence and stability of their nearby periodic orbits. We check the periodic orbits with non-zero periods. In our searching procedure for these periodic orbits, we remove the two unity eigenvalues from the state transition matrix to find a robust, non-singular linear map to solve for the periodic orbits. The algorithm converges well, especially for stable periodic orbits. Using the searching procedure, which is relatively automatic, we find five basic families of periodic orbits in the rotating second degree and order gravity field for planar motion, and discuss their existence and stability at different central body rotation rates.

关键词： celestial / orbital mechanics - asteroid - periodic orbit - resonance

Sediment settlement rate and consolidation time of flling reclamation in coal mining subsidence land

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International Journal of Coal Science & Technology 2022年第3期9卷 232-246页

作者： Linghua duo Zhenqi hu Kun Yang Yanan Li Faculty of Geomatics East China University of TechnologyNanchang 30013China School of Environment and Spatial Informatics China University of Mining and TechnologyXuzhou 221116China Institute of Land Reclamation and Ecological Restoration China University of Mining and Technology(Beijing)D11 Xueyuan RoadHaidian DistrictBeijing 100083China

With the continuous growth of the population and the continuous reduction of cultivated land,China’s food security is greatly *** addition,China’s coal mining has been mainly underground mining,causing land subsidence and damaging existing cultivated *** efect intensifes the contradiction between the growth of the risk population and the reduction of cultivated *** reclamation of mining subsidence land with Yellow River sediment is often used as an efective way to improve the recovery rate of cultivated *** the reclamation time and realizing continuous flling are signifcant *** work presented in this paper studied the sediment settlement rate and consolidation time by combining theory,feld flling and reclamation tests and numerical simulations.A feld flling test study was carried out in the lowlands of Jibeiwang Village,Qihe County,Shandong Province,*** calculating the drainage consolidation time,the consolidation factor of 0.015656 m^(2)/d,and the time factor for sediment consolidation of 0.575 were *** sediment consolidation time for this test was 9.18 *** calculation of sediment deposition rate and consolidation time is of great practical signifcance to guide the Yellow River sediment flling,realize continuous flling,and save reclamation time and cost.

关键词： Yellow River sediment Mining subsidence land Filling reclamation Consolidation time

Research on consensus of multi-agent systems with and without input saturation constraints

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Journal of Systems Engineering and Electronics 2021年第4期32卷 947-955页

作者： QI duo hu Junhua LIANG Xiaolong ZHANG Jiaqiang ZHANG Zhihao Air Traffic Control and Navigation College Air Force Engineering UniversityXi’an 710051China Shaanxi Province Lab.of Meta-Synthesis for Electronic&Information System Xi’an 710051China Aeronautical Engineering College Air Force Engineering UniversityXi’an 710038China

In recent years,with the continuous development of multi-agent technology represented by unmanned aerial vehicle(UAV)swarm,consensus control has become a hot spot in academic *** this paper,we put forward a discrete-time consensus protocol and obtain the necessary and sufficient conditions for the second-order consensus of the second-order multi-agent system with a fixed structure under the condition of no saturation *** theoretical derivation verifies that the two eigenvalues of the Laplacian of the communication network matrix and the sampling period have an important effect on achieving *** we construct and verify sufficient conditions to achieve consensus under the condition of input saturation *** results show that consensus can be achieved if velocity,position gain,and sampling period satisfy a set of inequalities related to the eigenvalues of the Laplacian ***,the accuracy and validity of the theoretical results are proved by numerical simulations.

关键词： multi-agent system consensus control input constraint distributed control

Joint Trajectory and Power Optimization for Securing UAV Communications Against Active Eavesdropping

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China Communications 2021年第1期18卷 88-99页

作者： Bin duo Junsong Luo Yilian Li Hao hu Zibin Wang College of Information Science and Technology Chengdu University of TechnologyChengdu 610059China National Key Laboratory of Science and Technology on Information System Security Beijing 100093China

Due to both of jamming and eavesdropping,active eavesdroppers can induce more serious security threats to unmanned aerial vehicle(UAV)-enabled *** paper considers a secure UAV communication system including both the downlink(DL)and uplink(UL)transmissions,where the confidential information is transmitted between a UAV and a ground node in the presence of an active *** aim to maximize the average secrecy rates of the DL and UL communications,respectively,by jointly optimizing the UAV trajectory and the UAV/ground node’s transmit power control over a given flight *** to the non-convexity of the formulated problems,it is difficult to obtain globally optimal ***,we propose efficient iterative algorithms to obtain high-quality suboptimal solutions by applying the block coordinate descent and successive convex optimization *** results show that the joint optimization algorithms can effectively improve the secrecy rate performance for both the DL and UL communications,as compared with other baseline *** proposed schemes can be considered as special cases of UAV-assisted non-orthogonal multiple access(NOMA)networks.

关键词： UAV communications active eavesdropping physical-layer security secrecy rate maximization power control trajectory design

Effect of Nb-V microalloying on the hot deformation behavior of medium Mn steels

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 360-368页

作者： Yumeng Wang Qinyi Guo Bin hu Haiwen Luo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The influence of Nb-V microalloying on the hot deformation behavior and microstructures of medium Mn steel(MMS)was investigated by uniaxial hot compression *** establishing the constitutive equations for simulating the measured flow curves,we successfully constructed deformation activation energy(Q)maps and processing maps for identifying the region of flow *** concluded the following consequences of Nb-V alloying for MMS.(i)The critical strain increases and the increment diminishes with the increasing deformation temperature,suggesting that NbC precipitates more efficiently retard dynamic recrystallization(DRX)in MMS compared with solute Nb.(ii)The deformation activation energy of MMS is significantly increased and even higher than that of some reported high Mn steels,suggesting that its ability to retard DRX is greater than that of the high Mn content.(iii)The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress,in which fine recrystallized and coarse unrecrystallized grains are present.

关键词： medium manganese steel niobium-vanadium microalloying flow behavior dynamic recrystallization hot workability

Research progress in rare earths and their composites based electrode materials for supercapacitors

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Green Energy & Environment 2020年第3期5卷 259-273页

作者： Subasri Arunachalam Balakrishnan Kirubasankar duo Pan hu Liu Chao Yan Zhanhu Guo Subramania Angaiah Electro-Materials Research Laboratory Centre for Nanoscience and TechnologyPondicherry UniversityPondicherry605014India School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003China Key Laboratory of Materials Processing and Mold(Zhengzhou University) National Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China Integrated Composites Laboratory(ICL) Department of Chemical and Biomolecular EngineeringUniversity of TennesseeKnoxvilleUSA

Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power *** the last decade,carbon and carbonaceous materials,conducting polymers and transition metal oxide/hydroxide based electrode materials have been made to show a remarkable electrochemical ***-earth materials have attracted significant research attention as an electrode material for supercapacitor applications based on their physicochemical *** this review,rare earth metals,rare earth metal oxides/hydroxides,rare-earth metal chalcogenides,rare-earth metal/carbon composites and rare-earth metal/metal oxide composites based electrode materials are discussed for *** also discuss the energy chemistry of rare-earth metal-based *** the factors that affect the performance of the electrode materials,their evaluation methods and supercapacitor performances are discussed in ***,the future outlook in rare-earth-based electrode materials is revealed towards its current developments for supercapacitor applications.

关键词： Rare-earth metals Rare-earth metal oxides Rare earth metal hydroxides Supercapacitor Electrode materials