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Trajectory tracking anti-disturbance control for unmanned aerial helicopter based on disturbance characterization index

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Control Theory and Technology 2023年第2期21卷 233-245页

作者： Linbo Chen Tao Li lijun liu Zehui Mao College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106JiangsuChina

This work studies the trajectory tracking control for unmanned aerial helicopter(UAH)system under both matched disturbance and mismatched ***,to tackle the strong coupling,an input-output feedback linearization method is utilized to simplify the nonlinear UAH ***,a set of finite-time disturbance observers(FTDOs)are proposed to estimate mismatched disturbances with their successive derivatives,which are utilized to design the feedforward controller via ***,as for matched disturbance,by defining the disturbance characterization index(DCI)to determine whether the disturbance is harmful or not for the UAH system,a feedback controller is proposed and a sufficient condition is established to ensure the convergence of the tracking ***,some numerical simulations and comparisons illustrate the validity and advantages of our control scheme.

关键词： Unmanned aerial helicopter(UAH) Trajectory tracking control Finite-time disturbance observer(FTDO) Backstepping control Disturbance characterization index(DCI)

Drain-engineered carbon-nanotube-film field-effect transistors with high performance and ultra-low current leakage

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Nano Research 2020年第7期13卷 1875-1881页

作者： lijun liu Chenyi Zhao Li Ding Lianmao Peng Zhiyong Zhang Key Laboratory far the Physics and Chemistry of Nanodevices and Department of Electronics Peking UniversityBeijing 100871China

A small bandgap and light carrier effective mass(mo)lead to obv ous ambipolar transport behavior in carbon nanotube(CNT)fild-effect transistors(FE Ts),including a high off-state current and severe degradation of the subthreshold swing(SS)with increasing drain bias *** demonstrate a drain-engineered method to cope with this common problem in CNT-film FETs with a sub-μum channel length,i.e.,suppressing the ambipolar behavion while maintaining high on-state performance by adopting a feedback gate(FBG)structure to extend the drain region from the CNT/metal contact to the proximate CNT channels to suppress the tunneling ***-400-nm-channel-length FETs with a FBG structure statistially present a high on/off ratio of up to 10*and a sub-200 mV/dec SS under a high drain bias of up to-2 V whle maintaining a high on-state current of 0.2 mA/μm or a peak transconductance of 0.2 mS/*** lowering the supply voltage to 1.5 V,FBG CNT-fim FETs can meet the requirement of standard-pertormance ultra large scale integrated circuits(ULSICs).Therefore,the introduction of the drain engineering structure enables applications of CNT-film-based FETs in ULSICs and could also be widely extended to other small-bandgap semiconductor-based FETs for an improvement in their off-state property.

关键词： carbon nanotube field-effect transistor current leakage subthreshold swing small bandgap semiconductor

Subduction tectonics *** tectonics——Discussion on driving forces for plate motion

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Science China Earth Sciences 2020年第3期63卷 315-328页

作者： Ling CHEN Xu WANG Xiaofeng LIANG Bo WAN lijun liu State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China Innova tion Academy for Earth Science Chinese Academy of SciencesBeijing 100029China Department of Geology University of Illinois at Urbana-ChampaignChampaign 61820USA

Plate tectonics describes the horizontal motions of lithospheric plates,the Earths outer shell,and interactions among them across the Earths *** the establishment of the theory of plate tectonics about half a century ago,considerable debates have remained regarding the driving forces for plate *** early"Bottom up"view,i.e.,the convecting mantledriven mechanism,states that mantle plumes originating from the core-mantle boundary act at the base of plates,accelerating continental breakup and driving plate *** the present,however,the"Top down"idea is more widely accepted,according to which the negative buoyancy of oceanic plates is the dominant driving force for plate motion,and the subducting slabs control surface tectonics and mantle *** this regard,plate tectonics is also known as subduction tectonics."Top down"tectonics has received wide supports from numerous geological and geophysical *** the other hand,recent studies indicate that the acceleration/deceleration of individual plates over the million-year timescale may reflect the effects of mantle *** is also suggested that surface uplift and subsidence within stable cratonic areas are correlated with plumerelated magmatic activities over the hundred-million-year *** the global scale,the cyclical supercontinent assembly and breakup seem to be coupled with superplume activities during the past two billion *** correlations over various spatial and temporal scales indicate the close relationship and intensive interactions between plate tectonics and plume tectonics throughout the history of the Earth and the considerable influence of plumes on plate ***,we can acquire a comprehensive understanding of the driving forces for plate motion and operation mechanism of the Earth's dynamic system only through joint analyses and integrated studies on plate tectonics and plume tectonics.

关键词： Driving forces for plate motion,Negative buoyancy of plates Subduction tectonics Plume tectonics

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Invertebrate community characteristics in biologically active carbon filter

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Journal of Environmental Sciences 2010年第5期22卷 648-655页

作者： Xiaowei Li Yufeng Yang lijun liu Jinsong Zhang Qing Wang Institute of Hydrobiology Jinan University Guangzhou 510632 China School of Environmental Science and Engineering Tongji University Shanghai 200092 China Shenzhen Water Group Shenzhen 518032 China School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

Biologically active carbon （BAC） system was set up in a water plant of South China during January to December 2007,to study the invertebrate community characteristics of BAC ***-seven invertebrate species were found,of which 28 belonging to *** operation could lead to an output of invertebrates in high abundances with the filtrate,and the maximum density could reach 5608 individuals/m *** abundances in the effluent water increased in 27-33 folds in comparison to the influent water during the sampling *** community succession had the following trend：filter-feeding animals → small benthic invertebrates → large benthic and resistant *** of large-sized invertebrates （copepod adult and oligochaete） at bigger-media column were significantly higher than that at small-media *** results implied the abundant species diversity of invertebrate in BAC *** relationship between invertebrate and biofilm still remain to be studied in detail.

关键词： biologically active carbon filter invertebrate community characteristics filter media

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Hierarchical In_(2)S_(3)microflowers decorated with WO_(3)quantum dots:Sculpting S-scheme heterostructure for enhanced photocatalytic H_(2)evolution and nitrobenzene hydrogenation

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Journal of Materials Science & Technology 2024年第7期174卷 218-225页

作者： Yuan Lin Lv Chen Jianhua Zhang Yunyun Gui lijun liu Hubei Key Laboratory of Biomass Fibers and Eco-dyeing&Finishing College of Chemistry and Chemical EngineeringWuhan Textile UniversityWuhan 430200China

Solar energy conversion and high-value chemical production are of utmost ***,the de-velopment of efficient photocatalysts with strong redox ability remains *** we report a unique 3D/0D In_(2)S_(3)/WO_(3)S-scheme heterojunction photocatalyst obtained by depositing WO_(3)quantum dots(QDs)onto hierarchical In_(2)S_(3)*** In_(2)S_(3)/WO_(3)composite exhibits outstanding visible light absorption,with a maximum optical response of up to 600 *** electronic interaction and charge separation at interfaces are explored by in situ X-ray photoelectron spectroscopy(XPS)and density func-tional theory(DFT)*** difference in work function causes In_(2)S_(3)to donate electrons to WO_(3)upon combination,leading to the formation of an internal electric field(IEF)at the *** to the IEF and bent energy bands,the transfer and separation of photogenerated charge carriers follow an S-scheme pathway within In_(2)S_(3)/WO_(3).Owing to the strong redox ability,spatial charge separation and lower H 2-generation barrier of S active sites,the optimized In_(2)S_(3)/WO_(3)heterojunctions show enhanced photocatalytic hydrogen evolution of 0.39 mmol h^(-1)g^(-1),6.7 times that of pristine In_(2)S_(3).In addition,the In_(2)S_(3)/WO_(3)S-scheme heterojunctions afford a remarkable activity for photocatalytic nitrobenzene hydro-genation with nearly 98%conversion and 99%selectivity of aniline within 1 *** work might present new insights into developing efficient S-scheme heterojunctions for various photocatalytic applications.

关键词： S-scheme heterojunctions In_(2)S_(3)microflowers WO_(3)quantum dots H_(2)production Electron transfer

A Fault-tolerant Controller Selection Strategy for the F-16 Fighter with Fault Misdiagnosis 36

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A Fault-tolerant Controller Selection Strategy for the F-16 ...

A Preliminary Review of Metallogenic Regularity of Gold Deposits in China

第36届中国控制会议

作者： Zhen Yu Chuan Guo lijun liu Department of Automation Xiamen University

ISBN: (纸本)9781538629185

In this paper,a fault-tolerant controller selection strategy for the F-16 fighter with fault misdiagnosis is ***,a multiplicative fault model for its actuator is built,and a design method of H fault-tolerant controller for the F-16 fighter model is ***,according to the severity of system faults,a cost function of the selection strategy is designed for selecting a pre-computed controller in the presence of fault *** proposed selection strategy can optimize the balance between the stability and the control performance of faulty ***,the effectiveness of the proposed strategy is verified by simulations.

关键词： fault misdiagnosis F-16 fighter fault-tolerant controller selection strategy

来源： cnki会议评论

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Acta Geologica Sinica(English Edition) 2015年第2期89卷 632-651页

作者： WANG Chenghui WANG Denghong XU Jue YING Lijuan liu lijun liu Shanbao MLR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological Sciences The School of Earth Science and Resources Chang'an University China University of Geosciences

Gold is one of the most important mineral resources in China with its rich mineral resources. In recent years, significant progress has been made on the process of gold resource exploration. Some large and giant gold deposits were newly found and some important expansions in the main mining regions were also been completed. Studies on metailogenic regularity of gold deposits in China also have made achievements with a long-term work. This review aims to conclude the achievements of research on gold metallogenic regularity in China. Based on the data of about 2000 gold deposits and other ore （mineralized） occurrences, gold deposits in China were classified into five prediction types： gold deposits genetically related to granite-greenstone formation, gold deposits related to sedimentary formation （including the Carlin type and the metamorphosed clastic rock related vein gold deposit）, gold deposits genetically related to volcanic rocks （including the continental and marine types）, gold deposits genetically related to intrusions （including the porphyry type and the inner intrusion and contact zone related gold deposit）, gold deposits of supergenesis （including fracture zone-altered rock gold deposit, placer gold deposit, gossan type gold precise chronology data of gold deposits indicate deposit and soil type gold deposit）. Statistics on that there occurred 5 main periods of gold- mineralization in geological history of China. They were Neoarchean to Paleoproterozoic, Meso- Neoproterozoic, Paleozoic, Mesozoic, and Cenozoic. Gold deposits in China mainly formed in the Mesozoic and the Cenozoic. On the studies of the spatial-temporal distribution characteristics of gold deposits, 53 gold-forming belts were delineated in China. The metallogenic regularity of gold deposits was preliminarily summarized and 71 gold metallogenic series were proposed in China. This suggests that it is necceary to deepen the study on metallogenic regularity of gold deposits and to provide the t

关键词： gold prediction types mineralization epoch gold-forming belt metallogenic regularity,metallogenic series of gold deposits

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Iterative hybrid decoding algorithm for LDPC codes based on attenuation factor

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Frontiers of Electrical and Electronic Engineering in China 2012年第3期7卷 279-285页

作者： Minghua liu lijun ZHANG School of Electronic and Information Engineering Beijing JiaotongUniversity Beijing 100044 China

An attenuated iterative reliability-based major- ity-logic （AIML） decoding algorithm for low-density parity-check （LDPC） codes is proposed, which pertains to hybrid decoding schemes. The algorithm is devised based on the orthogonal check-sums of one-step majority- logic （OSMLG） decoding algorithm in conjunction with certain of reliability measures of the received symbols. Computation of reliability measure of the syndrome sum is refined by introducing an attenuation factor. Simulation results show that, in binary-input additive white Gaussian noise （BI-AWGN） channel, the AIML decoding algorithm outperforms other popular iterative reliability-based major- ity-logic （IML） decoding algorithms with a slight increase in computational complexity. Within maximum iteration number of 5, the AIML algorithm can achieve almost identical error performance to sum-product algorithm （SPA）. No error floor effect can be observed for the AIML algorithm down to the bit error rate （BER） of 10- s, while error floor appears for SPA around the BER of 10 7 even with maximum iteration number of 100. Furthermore, the inherent feature of parallel procession for AIML algorithm enforces the decoding speed in contrast to those serial decoding schemes, such as weighted bit-flipping （WBF） algorithm.

关键词： attenuation factor reliability-based iterative,majority-logic low-density parity-check (LDPC) codes

Parallel Sketch Based Super Node Detection with Traceability

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Chinese Journal of Electronics 2018年第6期27卷 1133-1140页

作者： ZHOU Aiping liu lijun ZHU Huisheng ZHU Chen'gang CHEN Lin School of Computer Science and Technology Taizhou UniversityTaizhou 225300 China Key Laboratory of Computer Network and Information Integration (Southeast University) Ministry of Education

Traffic measurement and monitoring is crucial for network applications, such as network security, network management and so on. One central problem is to detect super nodes, which have significant change of connection degree between consecutive measurement *** to weakness in massive network traffic processing for the centralized algorithm and low detection accuracy, space efficiency for super node detection algorithm based on flow sampling, we propose Parallel sketch based super node detection with traceability(PSD). It constructs parallel sketch and estimates connection degree of nodes by probabilistic counting approach, so that super nodes are identified using connection degree change between consecutive measurement periods. Moreover, IP addresses of super nodes are reconstructed by simple computing to trace attacker or victims. The experimental results illustrate that the proposed method outperforms the Compact spread estimator(CSE) and Data streaming and sampling(DSS) in terms of detection accuracy and storage utilization.

关键词： Network measurement Super node detection Parallel sketch Network data stream