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| 1 | Thermal annealing synthesis of double-shell truncated octahedral Pt-Ni alloys for oxygen reduction reaction of polymer electrolyte membrane fuel cells显示文摘Shape-controlled Pt-Ni alloys usually offer an exceptional electrocatalytic activity toward the oxygen reduction reaction(ORR)of polymer electrolyte membrane fuel ceils(PEMFCs),whose tricks lie in welldesigned structures and surface morphologies.In this paper,a novel synthesis of truncated octahedral PtNi_(3.5) alloy catalysts that consist of homogeneous Pt-Ni alloy cores enclosed by NiO-Pt double shells through thermally annealing defective heterogeneous PtNi35 alloys is reported.By tracking the evolution of both compositions and morphologies,the outward segregation of both PtOv and NiO are first observed in Pt-Ni alloys.It is speculated that the diffusion of low-coordination atoms results in the formation of an energetically favorable truncated octahedron while the outward segregation of oxides leads to the formation of NiO-Pt double shells.It is very attractive that after gently removing the NiO outer shell,the dealloyed truncated octahedral core-shell structure demonstrates a greatly enhanced ORR activity.The asobtained truncated octahedral Pt_(2.1)Ni core-shell alloy presents a 3.4-folds mass-specific activity of that for unannealed sample,and its activity preserves 45.4%after 30000 potential cycles of accelerated degradation test(ADT).The peak power density of the dealloyed truncated octahedral Pt2jNi core-shell alloy catalyst based membrane electrolyte assembly(MEA)reaches 679.8 mW/cm^(2),increased by 138.4 mW/cm^(2) relative to that based on commercial Pt/C. | Xiashuang LUO Yangge GUO Hongru ZHOU Huan REN Shuiyun SHEN Guanghua WEI Junliang ZHANG | 2020 | Frontiers in Energy2020，14，4： | 2 |
| 2 | Early specializations for mimicry and defense in a Jurassic stick insect显示文摘Mimicry and secondary defense are staples among predator–prey interactions.Among insects,the stick and leaf insects are masters of camouflage.Nonetheless,a meager understanding of their origin and early mimetic evolution persists.Here,we report the earliest mimetic and defensive strategies of a stick insect from the Middle Jurassic of China,Aclistophasma echinulatum gen.et sp.nov.,exquisitely preserving abdominal extensions and femoral spines.The distribution of these characteristics mapped onto the phylogeny of Phasmatodea reveals that abdominal extensions and femoral spines developed multiple times during the evolution of stick insects,and indicates that the origin of abdominal extensions predates other modifications,while tergal extensions predate other expansions of the body,such as those of the sterna and pleura,as well as defensive femoral spines.The new fossil provides clues into early antipredator defensive strategies,allows inferences as to the potential environment and predators,and reveals the mimetic and defensive mechanisms of stick insects from 165 million years ago. | Hongru Yang Chaofan Shi Michael S.Engel Zhipeng Zhao Dong Ren Taiping Gao | 2021 | National Science Review2021，8，1： | 1 |
| 3 | Distributed event triggering control for six-rotor UAV systems with asymmetric time-varying output constraints显示文摘Inspired by the practical operability and safety of unmanned aerial vehicles(UAVs)in confined areas,this paper investigates adaptive trajectory tracking control problems in multiple six-rotor UAV systems with asymmetric time-varying output constraints and input saturation.Under model and disturbance uncertainties,six-rotor UAV systems are modeled as two non-strict-feedback systems,including attitude(inner-loop)and position(outer-loop)regulation systems.For the inner-loop design,the neural-based distributed adaptive attitude consensus control protocol is employed to realize the leader-follower consensus.Adaptive first-order sliding mode differentiators and an auxiliary dynamic system are introduced to address the“explosion of complexity”and saturation nonlinearity issues,respectively.Then,an event-triggered condition is predefined to alleviate the communication loads and reduce the number of messages to be transmitted from the controller to actuator.In addition,a class of asymmetric time-varying barrier Lyapunov functions are constructed for preventing the violation of time-varying output constraints.Accordingly,the proposed double-loop control strategies guarantee that all signals of UAV systems are semi-globally and uniformly bounded.Simulation results demonstrate that the proposed control method is effective. | Liang CAO Hongru REN Wei MENG Hongyi LI Renquan LU | 2021 | Science China(Information Sciences)2021，64，7： | 1 |
| 4 | Event-based performance guaranteed tracking control for constrained nonlinear system via adaptive dynamic programming method显示文摘An optimal tracking control problem for a class of nonlinear systems with guaranteed performance and asymmetric input constraints is discussed in this paper.The control policy is implemented by adaptive dynamic programming(ADP)algorithm under two event-based triggering mechanisms.It is often challenging to design an optimal control law due to the system deviation caused by asymmetric input constraints.First,a prescribed performance control technique is employed to guarantee the tracking errors within predetermined boundaries.Subsequently,considering the asymmetric input constraints,a discounted non-quadratic cost function is introduced.Moreover,in order to reduce controller updates,an event-triggered control law is developed for ADP algorithm.After that,to further simplify the complexity of controller design,this work is extended to a self-triggered case for relaxing the need for continuous signal monitoring by hardware devices.By employing the Lyapunov method,the uniform ultimate boundedness of all signals is proved to be guaranteed.Finally,a simulation example on a mass–spring–damper system subject to asymmetric input constraints is provided to validate the effectiveness of the proposed control scheme. | Xingyi Zhang Zijie Guo Hongru Ren Hongyi Li | 2023 | Journal of Automation and Intelligence2023，2，4： | 0 |
| 5 | A disturbance observer based intelligent control for nonstrict-feedback nonlinear systems显示文摘Focusing on one class of nonlinear systems with input saturation,the adaptive fuzzy dynamic event-triggered control problem is successfully solved.A dynamic event-triggered mechanism is adopted to save the communication burden of the system,and is integrated into the controller design process based on the backstepping technique.For handling the asymmetric input saturation,an auxiliary system with the same order as the considered system is constructed.Analysis problems caused by unknown continuous functions are efficiently tackled by applying the approximation theory of fuzzy logic systems.It is proven that all the signals of the resulting closed-loop system are bounded via Lyapunov stability analysis.Both numerical and practical simulations are presented to demonstrate the effectiveness of the theoretical results. | REN HongRu MA Hui LI HongYi LU RenQuan | 2023 | Science China(Technological Sciences)2023，66，2： | 0 |
| 6 | A method for detecting two-dimensional plane stress distribution in basin-type insulator based on critically refracted longitudinal wave显示文摘Basin-type insulator often has small cracks due to stress concentration.The current method cannot accurately reflect the stress condition of the insulator to find the stress concentration areas.To solve these problems,a method for detecting two-dimensional plane stress(δ_(1) andδ_(2))within different depth ranges in a basin-type insulator is proposed based on critically refracted longitudinal(LCR)wave.First,the acoustoelastic equation characterising the relationship between the variation of LCR wave propagation time and the plane stress was derived.Next,the propagation characteristics of LCR wave in epoxy resin samples were investigated.Then,the stress distribution within different depth ranges of the insulator subjected to hydraulic load was measured using the proposed method,including direction(θ),δ_(1) andδ_(2).The results show that the magnitude of the stress alone cannot accurately characterise the stress state.Points with equal distances to the centre have similar stress magnitudes,but their directions are not the same.With increasing depth,θremains essentially unchanged at the same location,whileδ1 andδ2 decrease,and the rate of decrease varies at different locations.Comparing the measured and simulated data,the results showed that they were in good agreement,and the maximum errors of stress value andθwere 0.69 MPa and 2.97°,respectively,which confirmed the feasibility and accuracy of the stress detection in the proposed method. | Zhaoyang Kang Fuqiang Ren Hongru Zhang Jingjing Yang Kaining Hou Qingquan Li Dongxin He Hongshun Liu Yongzhi Zhao Huaxin Wen | 2024 | High Voltage2024，9，1： | 0 |
| 7 | Multi-fluorous-included Counter Anions-based Ionic Copolymers:Synthesis and Enhanced Hydrophobic Adsorption Films on Copper Surface for Super Protection显示文摘Three multi-fluorous-carried anions-based ionic copolymers(ICs)including(fluorosulfonyl)imide(FSI-),(trifluorometha-nesulfonyl)imide(TFSI-)and hexafluorophosphate anions(PF6-)(IC[FSI-]),poly[1,1'-(butane-1,4-diyl)bis(3-pentyl-1H-imidazol-3-ium)bis(fluorosulfonyl)amide](IC[TFSI-]),poly{1,1'-(butane-1,4-diyl)bis(3-pentyl-1H-imidazol-3-ium)bis[(trifluoromethyl)sulfonyl]-amide}(IC[PF6-]),poly[1,1'-(butane-1,4-diyl)bis(3-pentyl-1H-imidazol-3-ium)bishexafluorophosphate]were synthesized with a simple ionic exchange method by using amphiphilic poly[1,1'-(butane-1,4-diyl)bis(3-pentyl-1H-imidazol-3-ium)bisbromide](IC[Br-])as the intermediate ionic polymer.The chemical srutrcures of the target ICs were characterized by nuclear magnetic resonance(NMR)spectroscopy and Fourier-transform infrared spectroscopy(FTIR).It is shown that the target ICs could be spontaneously adsorbed on copper surface in N,N-dimethflormamide(DMF),and the tight adsorption films were formed on metal surface.The contacting angles suggest that the formed adsorption layers of target ICs on copper surface were characterized with hydrophobic nature.Furthermore,the target ICs-copper chemistry bonding was confirmed by various means.The electrochemistry analysis showed that the target ICs adsorption layers could prevent from copper corrosion in H2SO4solution efficiently,and the maximal anticorrosion efficiency was over 95%at 0.100 g/L.In particular,the target ICs showed 85%or above anticorrosion efficiency for copper at a low concentration of 0.025 g/L,which was greater than the intermediate polymer IC[Br-].In addition,an insight of mixed chemisorption and physisorption of the target ICs on metal surface was analyzed and discussed. | REN Weihua SHI Yueting CHEN Lingli YANG Song ZHANG Shengtao LIU Xiaohong REN Xiaolei LI Hongru | 2023 | Chemical Research in Chinese Universities2023，39，5： | 0 |
| 8 | Partition and planning:A human-like motion decision for UAV in trap environment显示文摘This paper presents a human-like motion decision-making method for unmanned aerial vehicles(UAVs)navigating in trap environments.We proposed a space partitioning method based on sampling and consistency control to conduct a preliminary analysis of the indoor environment based on architectural blueprints.This method reduces the dimensionality of the path planning problem,thereby enhancing the efficiency.Then,we designed a target-switching logic for the dynamic window approach.This improvement endows the UAV with the capability of both real-time obstacle avoidance and global navigation,enhancing the efficiency of the UAV in flying to task spots indoors.Additionally,by applying human-like methods of batch distance perception and obstacle perception to this scheme,we have further enhanced the robustness and efficiency of path decisions.Finally,considering the scenario of high-rise fire rescue,we conducted simulation verification.It demonstrates that our scheme enhances the efficiency and robustness of path planning. | CHEN JinTao ZHOU Qi REN HongRu LI HongYi | 2024 | Science China(Technological Sciences)2024，67，4： | 0 |
| 9 | Adaptive Fixed-Time Control of Nonlinear MASs With Actuator Faults显示文摘The adaptive fixed-time consensus problem for a class of nonlinear multi-agent systems(MASs)with actuator faults is considered in this paper.To approximate the unknown nonlinear functions in MASs,radial basis function neural networks are used.In addition,the first order sliding mode differentiator is utilized to solve the“explosion of complexity”problem,and a filter error compensation method is proposed to ensure the convergence of filter error in fixed time.With the help of the Nussbaum function,the actuator failure compensation mechanism is constructed.By designing the adaptive fixed-time controller,all signals in MASs are bounded,and the consensus errors between the leader and all followers converge to a small area of origin.Finally,the effectiveness of the proposed control method is verified by simulation examples. | Hongru Ren Hui Ma Hongyi Li Zhenyou Wang | 2023 | IEEE/CAA Journal of Automatica Sinica2023，10，5： | 0 |
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