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Chinese Journal of Aeronautics 2020年第11期33卷 2877-2897页

作者： Yingxun WANG Tian ZHANG Zhihao CAI Jiang zhao kun WU School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100083China Flying College Beihang UniversityBeijing 100083China

The paper proposes a new swarm intelligence-based distributed Model Predictive Control(MPC)approach for coordination control of multiple Unmanned Aerial Vehicles(UAVs).First,a distributed MPC framework is designed and each member only shares the information with *** Chaotic Grey Wolf Optimization(CGWO)method is developed on the basis of chaotic initialization and chaotic search to solve the local Finite Horizon Optimal Control Problem(FHOCP).Then,the distributed cost function is designed and integrated into each FHOCP to achieve multi-UAV formation control and trajectory tracking with no-fly zone ***,an event-triggered strategy is proposed to reduce the computational burden for the distributed MPC approach,which considers the predicted state errors and the convergence of cost *** results show that the CGWO-based distributed MPC approach is more computationally efficient to achieve multi-UAV coordination control than traditional method.

关键词： Chaotic Grey Wolf Optimization(CGWO) Coordination control Distributed Model Predictive Control(MPC) Event-triggered strategy Multi-UAV

Determining the key conditions for the formation of metamorphic core complexes by geodynamic modeling and insights into the destruction of North China Craton

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Science China Earth Sciences 2016年第9期59卷 1873-1884页

作者： LU Gang zhao Liang ZHENG TianYu WANG kun yaNG JianFeng State Key Laboratory of Lithospheric Evolution of Geology and Geophysics Chinese Academy of Sciences

Metamorphic core complex(MCC) is characterized by the exhumation of lower crust over a large-scale detachment fault, providing natural records for tectonic extension. MCCs are widely identified in the North China Craton(NCC), which have been intensively studied on their structural and geological characteristics. Yet, the condition for the formation of MCCs and their link with NCC destruction are still in debate. In this study, we perform numerical simulations to investigate MCC formation under extension, with a focus on the effect of crustal rheologies. Results indicate that three end-member modes of deformation may occur: the metamorphic core complex mode, the detachment fault-uplifting mode and the pure shear mode. Weaker lower crust and stronger upper crust may promote the formation of MCC. In contrast, stronger lower crust(>1.3×1021 Pa s) may prohibit the exhumation of lower crust(detachment fault-uplifting mode), while weaker upper crust(<7.8×1021 Pa s) may fail to develop detachment faults(pure shear mode). Given that cratons typically have a strong crust, we suggest that the lower crust of NCC was weakened prior to extension, which promoted the formation of MCC in a later stage under the back-arc extension.

关键词： Metamorphic core complex Numerical modeling North China Craton Extension

Ca_(2)MnO_(4)-layered perovskite modified by NaNO_(3)for chemical-looping oxidative dehydrogenation of ethane to ethylene

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Chinese Journal of Chemical Engineering 2024年第4期68卷 53-64页

作者： Weixiao Ding kun zhao Shican Jiang Zhen Huang Fang He College of Chemistry and Bioengineering Guilin University of TechnologyGuilin 541006China Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Chemical-looping oxidative dehydrogenation(CL-ODH)is a process designed for the conversion of alkanes into olefins through cyclic redox reactions,eliminating the need for gaseous O_(2).In this work,we investigated the use of Ca_(2)MnO_(4)-layered perovskites modified with NaNO_(3) dopants,serving as redox catalysts(also known as oxygen carriers),for the CL-ODH of ethane within a temperature range of 700-780℃.Our findings revealed that the incorporation of NaNO_(3) as a modifier significantly-nhanced the selectivity for-thylene generation from Ca_(2)MnO_(4).At 750℃and a gas hourly space velocity of 1300 h^(-1),we achieved an-thane conversion up to 68.17%,accompanied by a corresponding-thylene yield of 57.39%.X-ray photoelectron spectroscopy analysis unveiled that the doping NaNO_(3) onto Ca_(2)MnO_(4) not only played a role in reducing the oxidation state of Mn ions but also increased the lattice oxygen content of the redox ***,formation of NaNO_(3) shell on the surface of Ca_(2)MnO_(4) led to a reduction in the concentration of manganese sites and modulated the oxygen-releasing behavior in a step-wise *** modulation contributed significantly to the enhanced selectivity for ethylene of the NaNO_(3)-doped Ca_(2)MnO_(4) *** findings provide compelling evidence for the potential of Ca_(2)MnO_(4)-layered perovskites as promising redox catalysts in the context of CL-ODH reactions.

关键词： Chemical-looping oxidative dehydrogenation Ethane Ethylene NaNO_(3)-doped Ca_(2)MnO_(4)redox catalyst Layered perovskites

Demonstration of eight-partite two-diamond shape cluster state for continuous variables

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Frontiers of physics 2013年第1期8卷 20-26页

作者： Xiao-Long Su Shu-Hong Hao ya-Ping zhao Xiao-Wei Deng Xiao-Jun Jia Chang-De Xie kun-Chi Peng State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Opto-Electronics Shanxi University Taiyuan 030006 China

Multipartite entangled state is the basic resource for implementing quantum information networks and quantum computation. In this paper, we present the experimental demonstration of the eight-partite two-diamond shape cluster states for continuous variables, which consist of eight spatially separated and entangled optical modes. Eight resource squeezed states of light with classical coherence are produced by four nondegenerate optical parametric amplifiers and then they are transformed to the eight-partite two-diamond shape cluster states by a specially designed linear optical network. Since the spatially separated multipartite entangled state can be prepared off-line, it can be conveniently applied in the future quantum technology.

关键词： quantum computation continuous variable cluster state squeezed state

Distributed coordinated control scheme of UAV swarm based on heterogeneous roles

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Chinese Journal of Aeronautics 2022年第1期35卷 81-97页

作者： Jiang zhao Jiaming SUN Zhihao CAI Yingxun WANG kun WU School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100083China Flying College Beihang UniversityBeijing 100083China

This paper proposes a new distributed coordinated control scheme based on heterogeneous roles for Unmanned Aerial Vehicle(UAV)swarm to achieve formation ***,the framework of the distributed coordinated control scheme is designed on the basis of Distributed Model Predictive Control(DMPC).Then,the effect of heterogeneous roles including leader,coordinator and follower is discussed,and the role-based cost functions are developed to improve the performance of coordinated control for UAV ***,a group of coordination strategies are proposed for UAVs with different roles to achieve swarm conflict *** simulations demonstrate that the presented distributed coordinated control scheme is effective to formulate and maintain the desired formation for the UAV swarm.

关键词： Coordination strategy Distributed control Heterogeneous roles Swarm intelligence Unmanned Aerial Vehicles(UAV)

Symmetric alteration of four knots of B-spline and NURBS surfaces

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第6期7卷 1084-1087页

作者： LI ya-juan WANG Guo-zhao Institute of Computer Graphics and Image Processing Department of Mathematics Zhejiang University Hangzhou 310027 China

Modifying the knots of a B-spline curve, the shape of the curve will be changed. In this paper, we present the effect of the symmetric alteration of four knots of the B-spline and the NURBS surfaces, i.e., symmetrical alteration of the knots of surface, the extended paths of points of the surface will converge to a point which should be expressed with several control points. This theory can be used in the constrained shape modification of B-spline and NURBS surfaces.

关键词： B-spline surface NURBS surface Knot modification Path

A review on the critical challenges and progress of SiO_(x)-based anodes for lithium-ion batteries

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International Journal of Minerals,Metallurgy and Materials 2022年第4期29卷 876-895页

作者： Nana yao Yu Zhang Xianhui Rao zhao yang kun Zheng KonradŚwierczek Hailei zhao School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Faculty of Energy and Fuels AGH University of Science and Technologyal.A.Mickiewicza 30Krakow30-059Poland Beijing Key Lab of New Energy Materials and Technology Beijing 100083China

With the advantages of abundant resources,high specific capacity,and relatively stable cycling performance,silicon suboxides(SiO_(x) ,x<2)have been recently suggested as promising anodes for next-generation lithium-ion batteries(LIBs).SiO_(x) exhibits superior storage capability because of the presence of silicon and smaller volume change upon charge/discharge than Si owing to the buffering effect of the initial lithiation products of inert lithium oxide and lithium silicates,enabling a stable cycle life of ***,significant improvements such as overcoming issues related to volume changes in cycling and initial irreversible capacity loss and enhancing the ionic and electronic charge transport in poorly conducting SiO_(x) electrodes,are still needed to achieve the satisfactory performance required for commercial *** review summarizes recent progress on the cycling performance and initial coulombic efficiency of SiO_(x) .Advances in the design of particle morphology and composite composition,prelithiation and prereduction methods,and usage of electrolyte additives and optimized electrode binders are *** on the promising research directions that might lead to further improvement of the electrochemical properties of SiO_(x) -based anodes are *** paper can serve as a basis for the research and development of high-energy-density LIBs.

关键词： silicon suboxides preparation structural optimization anode lithium-ion batteries

Full-scale site evaluation of ventilation expressway embankments underlain by warm permafrost along the Gonghe−Yushu Expressway

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Frontiers of Structural and Civil Engineering 2023年第7期17卷 1047-1059页

作者： Shuangjie WANG Qi ZHANG Yuanhong DONG kun YUAN Binhua HU Huilong zhao Nanlu zhao CCCC First Highway Consultants Co. Ltd.Xi’an 710065China State Key Laboratory of Road Engineering Safety and Health in Cold and High-Altitude Regions Xi’an 710065China Qinghai Huashixia Permafrost Highway Engineering Safety National Observation and Research Station Xi’an 710065China

Ventilation embankments,including those with forced ventilation,natural ventilation,and combination of these,were adopted for the construction of the Gonghe−Yushu Expressway in warm permafrost *** evaluate the actual thermal performance of ventilation embankment in the Qinghai−Tibet Plateau,four types of ventilation embankments were selected as objects,and their long-term thermal characteristics were analyzed based on monitoring *** was found that:1)under the strong scale effect of a wide embankment,the crushed-rock embankment(CRE)was warming up and the permafrost table was declining year by ***,the combined ventilated slab and CRE and ventilated ducts embankment can effectively decrease the ground temperature and raise permafrost table in the year with a colder winter;2)transverse temperature difference caused by the shady–sunny slope effect existed in all the four ***,it was weakened by the combined ventilated slab and CRE and the ventilated ducts embankment due to their stronger cooling effect;and 3)the pre-existing embankment had a remarkable thermal disturbance to the adjacent newly-built embankment,so a reasonable embankment spacing should be considered in practical *** findings would provide a reference for construction of expressway embankments in permafrost regions.

关键词： warm permafrost expressway ventilation embankments temperature field

Molecular Chain Flexibility and Dielectric Loss at High-Frequency:Impact of Ester Bond Arrangement in Poly(ester imide)s

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Chinese Journal of Polymer Science 2024年第8期42卷 1122-1133页

作者： ya-Dong Li Hong Li Lu-kun Feng Feng Bao Ming-Liang Wang Cai-Zhen Zhu zhao-Hui Zheng Xiao-Bin Ding Jian Xu Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100081China Institute of Low-Dimensional Materials Genome Initiative College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China

The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer ***,it has been theorized that rigid molecular chains lead to lower dielectric ***,the validity of this proposition at high frequencies remains *** scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic *** introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry *** dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)***,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic *** simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water *** sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality *** research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.

关键词： 5G communications Poly(ester imide)s Molecular chain flexibility Dielectric properties Humidity absorption

Revolutionizing photothermal CO_(2)hydrogenation with ceria-based catalysts

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Nano Research 2025年第1期18卷 30-49页

作者： zhaorui Zhang Xiao Han Junhong Zhang Yunyun Dong Jinsheng zhao Qian Xu ingqiang Zhang School of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China Institute for Catalysis Hokkaido UniversityN-21W-10Sapporo 001-0021Japan National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

In the context of achieving carbon neutrality,CO_(2)catalytic conversion technologies are effective in reducing atmospheric CO_(2)concentrations while simultaneously producing renewable *** approach is seen as a viable method for constructing a new carbon cycle,thereby effectively addressing the issue of global *** CO_(2)conversion has recently emerged as a promising research focus due to its high energy utilization efficiency,superior CO_(2)conversion,excellent product selectivity,mild operating conditions,low energy consumption and minimal operating *** oxide(CeO_(2))has been widely used in photothermal catalysis due to its unique chemical properties,particularly when used as a support material with supported metals,creating distinctive interfacial sites for catalytic *** an emerging star support in photothermal CO_(2)conversion,its contributions are equally significant and should not be ***,to our knowledge,there has been no comprehensive review of CeO_(2)applications in catalytic hydrogenation of CO_(2).In this paper,we summarize and discuss CeO_(2)-based materials for photothermal CO_(2)conversion to value-added *** research particularly focuses on the synthesis methods of CeO_(2)-supported catalysts,the history of CeO_(2)in photothermal catalysis,types of photothermal catalytic reactors,unique characterization methods for the photothermal catalysts and the photothermal CO_(2)hydrogenation reactions by CeO_(2)-based *** related to further challenges and future directions for photothermal CO_(2)hydrogenation are also provided.

关键词： CO_(2)neutrality hydrogenation photothermal catalysis ceria C1 chemistry