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Dynamic impact properties of deep sandstone under thermal-hydraulicmechanical coupling loads

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Journal of Mountain Science 2024年第6期21卷 2113-2129页

作者： CAO Chunhui ding Haonan zou Baoping School of Civil Engineering and Architecture Zhejiang University of Science and TechnologyHangzhou 310023China Zhejiang-Singapore Joint Laboratory for Urban Renewal and Future City Hangzhou 310023China

The deep rock mass within coal mines situated in a challenging environment are characterized by high ground stress,high geotemperature,high osmotic water pressure,and dynamic disturbances from mechanical *** investigate the impact of this complex mechanical environment on the dynamic characteristics of roof sandstone in self-formed roadways without coal pillars,standard specimens of deep sandstone from the 2611 upper tunnel working face of the Yongmei Company within the Henan Coal Chemical Industry Group in Henan,China were prepared,and an orthogonal test was *** a self-developed geotechnical dynamic impact mechanics test system,triaxial dynamic impact tests under thermal-hydraulicmechanical coupling conditions were conducted on deep *** results indicate that under high confining pressure,deep sandstone exhibits pronounced brittle failure at low temperatures,with peak strength gradually decreasing as temperature and osmotic water pressure ***,under low confining pressure and low temperature,the brittleness of deep sandstone weakens gradually,while ductility ***,sandstone demonstrates higher peak strength at low temperatures under high axial pressure conditions,lower peak strength at high temperatures,and greater strain under low axial pressure and high osmotic water *** in impact air pressure and osmotic water pressure have proportionally greater effects on peak stress and peak *** 50%of the input strain energy is utilized as effective energy driving the sandstone fracture *** analysis identifies the optimal combination of factors affecting the peak stress and peak strain of *** the coupling effect,intergranular and transgranular fractures occur within the *** images illustrate that the damage forms range from minor damage with multiple fissures to extensive fractures and severe *** study elucidates the varied dynamic impact me

关键词： Deep sandstone Thermal-hydraulicmechanical coupling Dynamic impact Stress-strain Failure Modes Polar analysis

Ultimately Bounded Output Feedback Control for Networked Nonlinear Systems With Unreliable Communication Channel: A Buffer-Aided Strategy

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1566-1578页

作者： Yuhan Zhang Zidong Wang Lei zou yun Chen Guoping Lu the College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China IEEE the Department of Computer Science Brunel UniversityUB83PHUnited Kingdom the College of Information Science and Technology Donghua UniversityShanghai 201620 the Engineering Research Center of Digitalized Textile and Fashion Technology Ministry of EducationShanghai 201620China the School of Automation Hangzhou Dianzi UniversityHangzhou 310018China the School of Electrical Engineering Nantong UniversityNantong 226019China

This paper concerns ultimately bounded output-feedback control problems for networked systems with unknown nonlinear dynamics. Sensor-to-observer signal transmission is facilitated over networks that has communication *** transmissions are carried out over an unreliable communication channel. In order to enhance the utilization rate of measurement data, a buffer-aided strategy is novelly employed to store historical measurements when communication networks are inaccessible. Using the neural network technique, a novel observer-based controller is introduced to address effects of signal transmission behaviors and unknown nonlinear *** the application of stochastic analysis and Lyapunov stability, a joint framework is constructed for analyzing resultant system performance under the introduced controller. Subsequently, existence conditions for the desired output-feedback controller are delineated. The required parameters for the observerbased controller are then determined by resolving some specific matrix inequalities. Finally, a simulation example is showcased to confirm method efficacy.

关键词： Buffer-aided strategy neural networks nonlinear control output-feedback control unreliable communication channel

The Crested Ibises expanding to plain areas exhibit a higher tolerance of human proximity

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Avian Research 2024年第1期15卷 60-65页

作者： Yuqi zou Yiting Jiang Zitan Song Xiaobin Fang Changqing ding School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing100083China Department of Biology University of KonstanzKonstanz78464Germany Center for the Advanced Study of Collective Behavior University of KonstanzKonstanz78464Germany School of Life Sciences Liaoning UniversityShenyang110036China Comparative Socioecology Group Max Planck Institute for Animal BehaviorKonstanz78467Germany

Animals must strike a balance between anti-predation behavior and other essential behaviors,such as *** the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator *** Crested Ibis(Nipponia nippon)exhibits such *** is an endangered species,once inhabiting exclusively in China’s Qinling *** used to be the sole remaining wild ***,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape *** used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human ***,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human *** findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human *** results showed that FID decreased with distance to the nearest human *** finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two *** results provide insights into the in situ conservation of the threatened species within the context of global urbanization.

关键词： Anti-predation behavior Flight initiation distance Habitat expansion Human activity Nipponia nippon

Insight into demand-driven preparation of single-atomic mediators for lithium–sulfur batteries

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Journal of Energy Chemistry 2024年第3期90卷 205-219,I0007页

作者： Miaoyu Lu Yifan ding Zaikun Xue Ziang Chen Yuhan zou Jingyu Sun College of Energy Soochow Institute for Energy and Materials InnovationsKey Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006JiangsuChina Beijing Graphene Institute Beijing 100095China

Lithium-sulfur(Li-S) batteries have attracted considerable attention as one of the most appealing energy storage *** efforts have been devoted to tackling the tremendous challenges,mainly pertaining to the severe shuttle effect,sluggish redox kinetics and lithium dendritic ***-atomic mediators as promising candidates exhibit impressive performance in addressing these intractable *** research often utilizes a trial-and-error approach,proposing solutions to fabricate single-atomic materials with diversified ***,comprehensive review articles especially targeting demand-driven preparation are still in a nascent *** by these considerations,this review summarizes the design of single-atomic mediators based on the application case-studies in LiS batteries and other metal-sulfur *** preparation routes represented by chemical vapor deposition technology are introduced in a demand-oriented ***,future research directions are proposed to foster the advancement of single-atomic mediators in Li-S realm.

关键词： Single-atom catalyst Lithium–sulfur battery Chemical vapor deposition Demand-driven preparation

Active disturbance rejection distributed secondary control for DC microgrids

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High Voltage 2024年第1期9卷 241-251页

作者： Jianlin Li Honghao You Shuo Liu Xingchen Li Ziyang ding Fei zou National User-Side Energy Storage Innovation Research and Development Center North China University of TechnologyBeijingChina

A novel control scheme is presented to eliminate the negative effects of communication disturbances,which introduces active disturbance rejection control(ADRC)in the control strategy design to achieve the objectives of the restoration of the bus voltage and the sharing of the power even in the presence of disturbances and delays in ***,its dynamic disturbance decoupling feature is used to realise the decoupling between power and voltage,so that the proposed controller only exchanges power information with its neighbours,reducing the communication burden and simplifying control *** control performance of the strategy is verified by employing steady-state *** impact of controller parameters is studied by establishing a small signal ***,both simulation cases and experimental tests prove the feasibility of this scheme.

关键词： Active disturbance establishing

Torque Limit-based Inertial Control Method Based on Delayed Support for Primary Frequency Control of Wind Turbines

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 561-570页

作者： Wei Gu Zaiyu Chen Qun Li Minghui Yin Qiang Li yun zou School of Automation Nanjing University of Science and TechnologyNanjing 210094China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjing 211103China

To avoid the secondary frequency dip caused by the steep drop of the electrical power of wind turbines(WTs)at the end of frequency support stage,the torque limit-based iner-tial control(TLIC)method sets the power reference as a linear function of rotor speed,rather than the step form for the step-wise inertial ***,the compensation effect on the frequency nadir(FN)caused by the load surge is weakened as the TLIC power is no longer in the step ***,the maximum point of the frequency response component(FRC)contributed by TLIC occurs earlier than the minimum point of FRC corresponding to the load surge,so that the FN cannot be adequately ***,this paper first investigates the relation between the peak and nadir times of FRCs stimulated by the TLIC and load *** this basis,with the compensation principle of matching the peak and nadir times of FRCs,the improved TLIC method based on delayed support is ***,the effectiveness of the proposed method is validated via the experiments on the test bench of wind-integrated power system.

关键词： Wind turbine frequency response component torque limit inertial control delayed support

Construction of flower-like MoS_(2)decorated on Cu doped CoZn-ZIF derived N-doped carbon as superior microwave absorber

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Nano Research 2024年第9期17卷 8250-8260页

作者： yun Han Di Lan Mengjun Han Zihao Xia Jiaxiao zou Zirui Jia College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China

The rational design of composition nanostructures and morphologies of the carbon-based composites materials has a significant potential for tuning electromagnetic parameters and thereby improving their performance as electromagnetic wave(EMW)*** this work,the flower-like Cu/Co-NC/MoS_(2)(NC=N-doped carbon skeleton)composites were successfully prepared by employing CuCoZn-ZIF(ZIF=zeolitic imidazolate framework)as precursor with subsequent annealing and hydrothermal *** unique flower-like morphology and electromagnetic synergy strategy between components enable the as-obtained Cu/Co-NC/MoS_(2)composites to exhibit outstanding microwave absorption ***,the minimum reflection loss of Cu/Co-NC/MoS_(2)reaches-54.36 dB at 2.7 *** the thickness reduces to 2.2 mm,the maximum effective absorption bandwidth can be achieved as large as 6.72 *** research develops useful ideas for optimizing multicomponent microwave absorbing materials.

关键词： ternary metal-organic frameworks(MOFs) MoS_(2) flower-like morphology microwave absorption

Boosting Hydrogen Storage Performance of MgH_(2) by Oxygen Vacancy-Rich H-V_(2)O_(5) Nanosheet as an Excited H-Pump

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Nano-Micro Letters 2024年第8期16卷 398-416页

作者： Li Ren Yinghui Li Zi Li Xi Lin Chong Lu Wenjiang ding Jianxin zou National Engineering Research Center of Light Alloys Net Forming&State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Shanghai Engineering Research Center of Mg Materials and Applications&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Center of Hydrogen Science Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Instrumental Analysis Center of SJTU Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

MgH_(2) is a promising high-capacity solid-state hydrogen storage material,while its application is greatly hindered by the high desorption temperature and sluggish ***,intertwined 2D oxygen vacancy-rich V_(2)O_(5) nanosheets(H-V_(2)O_(5))are specifically designed and used as catalysts to improve the hydrogen storage properties of MgH_(2).The as-prepared MgH_(2)-H-V_(2)O_(5) composites exhibit low desorption temperatures(Tonset=185℃)with a hydrogen capacity of 6.54 wt%,fast kinetics(Ea=84.55±1.37 kJ mol^(-1) H_(2) for desorption),and long cycling ***,hydrogen absorption can be achieved at a temperature as low as 30℃ with a capacity of 2.38 wt%within 60 ***,the composites maintain a capacity retention rate of~99%after 100 cycles at 275℃.Experimental studies and theoretical calculations demonstrate that the in-situ formed VH_(2)/V catalysts,unique 2D structure of H-V_(2)O_(5) nanosheets,and abundant oxygen vacancies positively contribute to the improved hydrogen sorption ***,the existence of oxygen vacancies plays a double role,which could not only directly accelerate the hydrogen ab/de-sorption rate of MgH_(2),but also indirectly affect the activity of the catalytic phase VH_(2)/V,thereby further boosting the hydrogen storage performance of MgH_(2).This work highlights an oxygen vacancy excited“hydrogen pump”effect of VH_(2)/V on the hydrogen sorption of Mg/MgH_(2).The strategy developed here may pave a new way toward the development of oxygen vacancy-rich transition metal oxides catalyzed hydride systems.

关键词： Hydrogen storage MgH_(2) V_(2)O_(5)nanosheets Oxygen vacancies VH_(2)

Multiple model PHD filter for tracking sharply maneuvering targets using recursive RANSAC based adaptive birth estimation

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Journal of Systems Engineering and Electronics 2024年第3期35卷 780-792页

作者： ding Changwen ZHOU Di zou Xinguang DU Runle LIU Jiaqi School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing 100076China

An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile *** probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.

关键词： multitarget tracking probability hypothesis density(PHD)filter sharply maneuvering targets multiple model adaptive birth intensity estimation