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Singularity analysis and avoidance for an SSRMS-type reconfigurable space manipulator with a non-spherical wrist and two lockable passive telescopic links

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Chinese Journal of Aeronautics 2024年第8期37卷 435-459页

作者： Zhiyuan ZHAO Xiaohang YANG Yuntao LI Zichun XU Jingdong ZHAO Hong LIU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This study focuses on addressing kinematic singularity analysis and avoidance issues for a space station remote manipulator system(SSRMS)-type reconfigurable space *** manipulator is equipped with a non-spherical wrist and two lockable passive telescopic links(LPTLs),which enable it to have both active revolute and passive prismatic joints and operate in two distinct *** begin with the kinematic singularity analysis,the study derives the differential kinematic equations for the manipulator and identifies the dominant Jacobian matrix that causes ***,an in-depth analysis of singularities from multiple perspectives is ***,a kinematic singularity map method is proposed to capture the distribution of singularities within the reachable ***,the influence of the two LPTLs on singularities is thoroughly ***,a new method based on the matrix rank equivalence principle is introduced to determine singularity conditions,enabling the identification of all the singular configurations for the SSRMS-type reconfigurable ***,this method significantly reduces computational complexity,and the singularity conditions obtained have more concise *** the singularity avoidance problem,a novel method is developed,which simultaneously addresses the requirements of real-time performance,high precision,and the avoidance of both kinematic singularities and joint limit *** from these excellent properties,the proposed method can effectively resolve the singularity issues encountered separately by the SSRMS-type reconfigurable manipulator in its two operational *** typical simulations validate the utility of all the proposed methods.

关键词： Reconfigurable space manipulator Redundant manipulator Kinematics Singularity analysis Singularity avoidance

Selective oxygen electroreduction to hydrogen peroxide in acidic media:The superiority of single-atom catalysts

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Nano Research 2024年第6期17卷 4668-4681页

作者： Ergui Luo Tongtong Yang Jingyi Liang Yuhong Chang Junming Zhang Tianjun Hu Junjie Ge Jianfeng Jia Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China School of Chemistry and Materials science University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Electroanalytic Chemistry Jilin Province Key Laboratory of Low Carbon Chemistry PowerChangchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Two-electron oxygen reduction reaction(2e-ORR)provides an environmentally friendly direction for the on-site production of hydrogen peroxide(H_(2)O_(2)).Central to this technology is the exploitation of efficient,economical,and safe 2e-ORR *** overview starts with the fundamental chemistry of ORR to highlight the decisive role of adsorbing intermediates on the reaction pathway and activity,followed by a comprehensive survey of the tuning strategies to favor 2e-ORR on traditional precious *** latest achievements in designing efficient and selective precious-metal-based single-atom catalysts(SACs)and metal-nitrogen-carbon(M-Nx/C)catalysts,from the aspects of material synthesis,theoretical calculations,and mass transport promotion,are systematically *** introductions on the evaluation metrics for 2e-ORR catalysts and the primary reactor designs for cathodic H_(2)O_(2)synthesis are also *** conclude this review with an outlook on the challenges and direction of efforts to advance electrocatalytic 2e-ORR into realistic H_(2)O_(2)production.

关键词： oxygen reduction reaction H_(2)O_(2)production single-atom catalysts selectivity

Quantitative phase imaging based on holography:trends and new perspectives

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Light(science & Applications) 2024年第7期13卷 1235-1277页

作者： Zhengzhong Huang Liangcai Cao Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In 1948,Dennis Gabor proposed the concept of holography,providing a pioneering solution to a quantitative description of the optical *** 75 years of development,holographic imaging has become a powerful tool for optical wavefront measurement and quantitative phase *** emergence of this technology has given fresh energy to physics,biology,and materials *** holography(DH)possesses the quantitative advantages of wide-field,non-contact,precise,and dynamic measurement capability for *** has unique capabilities for the propagation of optical fields by measuring light scattering with phase *** offers quantitative visualization of the refractive index and thickness distribution of weak absorption samples,which plays a vital role in the pathophysiology of various diseases and the characterization of various *** provides a possibility to bridge the gap between the imaging and scattering *** propagation of wavefront is described by the complex *** complex-value in the complex-domain is reconstructed from the intensityvalue measurement by camera in the ***,we regard the process of holographic recording and reconstruction as a transformation between complex-domain and real-domain,and discuss the mathematics and physical principles of *** review the DH in underlying principles,technical approaches,and the breadth of *** conclude with emerging challenges and opportunities based on combining holographic imaging with other methodologies that expand the scope and utility of holographic imaging even *** multidisciplinary nature brings technology and application experts together in label-free cell biology,analytical chemistry,clinical sciences,wavefront sensing,and semiconductor production.

关键词： holographic phase precise

A Novel Prescribed-Performance Path-Following Problem for Non-Holonomic Vehicles

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1476-1484页

作者： Zirui Chen Jingchuan Tang Zongyu Zuo Seventh Research Division Beihang University(BUAA)Beijing 100191China IEEE

The issue of achieving prescribed-performance path following in robotics is addressed in this paper,where the aim is to ensure that a desired path within a specified region is accu-rately converged to by the controlled *** this context,a novel form of the prescribed performance guiding vector field is introduced,accompanied by a prescribed-time sliding mode con-trol ***,the interdependence among the pre-scribed parameters is *** validate the effectiveness of the proposed method,numerical simulations are presented to demonstrate the efficacy of the approach.

关键词： Guiding vector field non-holonomic vehicle path following prescribed performance sliding mode control

Two-dimensional C2N-based single-atom catalyst with complex microenvironment for enhanced electrochemical nitrogen reduction:A descriptor-based design

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Journal of Energy Chemistry 2024年第10期97卷 110-119页

作者： Enduo Dai Wei An Ruixian Guo Xugen Shi Yunyi Li Yibo Wang Mingming Liu College of Chemistry and Chemical Engineering Shanghai University of Engineering Science

The catalytic descriptor with operational feasibility is highly desired towards rational design of high-performance catalyst especially the electrode/electrolyte solution interface working under mild ***,we demonstrate that the descriptor Ω parameterized by readily accessible intrinsic properties of metal center and coordination is highly operational and efficient in rational design of single-atom catalyst（SAC） for driving electrochemical nitrogen reduction（NRR）.Using twodimensional metal（M）-BxPySzNm@C2N as prototype SAC models,we reveal that*N2+（H++e-）→*N2H acts predominantly as the potential-limiting step（PLS） of NRR on M-B2P2S2@C2N and M-B1P1S1N3@C2N regardless of the distinction in coordination *** the 28 screened M active sites,with Ω values close to the optimal 4,M-B2P2S2@C2N(M=V（Ω=3.53）,Mo（Ω=5.12）,and W（Ω=3.92）) and M-B1P1S1N3@C2N(M=V（Ω=3.00）,Mo（Ω=4.34）,and W（Ω=3.32）) yield the lowered limiting potential（UL） as-0.45,-0.54.-0.36,-0.58,-0.25,and-0.24 V,respectively,thus making them the promising NRR *** importantly,these SACs are located around the top of volcano-shape plot of ULversus Ω,re-validating Ω as an effective descriptor for accurately predicting the high-activity NRR SACs even with complex *** study unravels the relationship between active-site structure and NRR performance via the descriptor Ω,which can be applied to other important sustainable electrocatalytic reactions involving activation of small molecules via σ-donation and π*-backdonation mechanism.

关键词： Descriptor DFT Electrocatalysis N2 reduction Single-atom catalyst

Probabilistic back-analysis of rainfall-induced landslides for slope reliability prediction with multi-source information

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3575-3594页

作者： Shui-Hua Jiang Hong-Hu Jie Jiawei Xie Jinsong Huang Chuang-Bing Zhou School of Infrastructure Engineering Nanchang UniversityXuefu Road 999Nanchang330031China Discipline of Civil Surveying and Environmental EngineeringFaculty of Engineering and Built EnvironmentThe University of NewcastleCallaghanNSW2308Australia

Probabilistic back-analysis is an important means to infer the statistics of uncertain soil parameters,making the slope reliability assessment closer to the engineering ***,multi-source information(including test data,monitored data,field observation and slope survival records)is rarely used in current probabilistic *** the probabilistic back-analysis of spatially varying soil parameters and slope reliability prediction under rainfalls by integrating multi-source information is a challenging task since thousands of random variables and high-dimensional likelihood function are usually *** this paper,a framework by integrating a modified Bayesian Updating with Subset simulation(mBUS)method with adaptive Conditional Sampling(aCS)algorithm is established for the probabilistic back-analysis of spatially varying soil parameters and slope reliability *** this framework,the high-dimensional probabilistic back-analysis problem can be easily tackled,and the multi-source information(*** pressure heads and slope survival records)can be fully used in the back-analysis.A real Taoyuan landslide case in Taiwan,china is investigated to illustrate the effectiveness and performance of the established *** findings show that the posterior knowledge of soil parameters obtained from the established framework is in good agreement with the field ***,the updated knowledge of soil parameters can be utilized to reliably predict the occurrence probability of a landslide caused by the heavy rainfall event on September 12,2004 or forecast the potential landslides under future rainfalls in the Fuhsing District of Taoyuan City,Taiwan,china.

关键词： Rainfall-induced landslide Spatial variability Probabilistic back-analysis Slope reliability analysis Bayesian updating

Charge-asymmetry Fe_(1)Cu single-atom alloy catalyst for efficient oxygen reduction reaction

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Nano Research 2024年第6期17卷 4702-4710页

作者： Xudong Niu Jian Wei Dongyao Xu Jiajing Pei Rui Sui School of Chemical&Environmental Engineering China University of Mining and TechnologyBeijing 100083China Institute of Water Ecology and Environment Chinese Research Academy of Environmental SciencesBeijing 100083China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084China

The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air *** promising way is to develop Fe single-atom ***,the single active center and inherent electronic structure of Fe single-atom catalysts lead to the undesirable adsorption of multiple ORR ***,a charge-asymmetry single-atom alloy(SAA)catalyst with Fe-Cu dual sites supported on nitrogen-doped carbon nanosheet(Fe_(1)Cu SAA/NC)was *** characterizations manifest the existence of electron interaction between Fe and Cu in Fe_(1)Cu SAA/NC,which facilitates the adsorption of ORR intermediate for fast ***,the charge-asymmetry Fe_(1)Cu SAA/NC exhibits much faster ORR kinetics with a half-wave potential of 0.917 V *** hydrogen electrode(RHE),outperforming its counterparts in the ***,Fe_(1)Cu SAA/NC still maintains a high half-wave potential with only a drop of 5 mV after 5000 cycles,indicating excellent *** work provides a new strategy to design highly active and non-noble metal ORR electrocatalysts,which hold great potential for various catalytic applications.

关键词： Fe_(1)Cu single-atom alloy(SAA) electrocatalysis oxygen reduction reaction charge-asymmetry

Role of Multi-scale Hierarchical Structures in Regulating Wetting State and Wetting Properties of Structured Surfaces

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Journal of Bionic Engineering 2024年第3期21卷 1347-1359页

作者： Yue Jiang Xinyi Li Zhichao Ma Zhihui Zhang Cuie Wen Zhonghao Jiang Nan Lin Luquan Ren Key Laboratory of Bionic Engineering of Ministry of Education College of Biological and Agricultural EngineeringJilin UniversityChangchun130022China Hubei Provincial Engineering Technology Research Center for Microgrid College of Electrical Engineering and New EnergyChina Three Gorges UniversityYichang443002China School of Mechanical and Aerospace Engineering Jilin UniversityChangchun130025China Centre for Additive Manufacturing School of EngineeringRMIT UniversityMelbourneVictoria3001Australia Key Laboratory of Automobile Materials of Ministry of Education College of Materials Science and EngineeringJilin UniversityChangchun130025China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry Jilin UniversityChangchun130012China

Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured *** theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and Wenzel wetting *** wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface *** wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.

关键词： Hierarchical structure Wetting state regulation Wetting transition Superhydrophobicity Superhydrophilicity

A Tri-Salt Composite Electrolyte with Temperature Switch Function for Intelligently Temperature-Controlled Lithium Batteries

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 84-93页

作者： Fu, Ende Wang, Huimin Zhang, Yating Xiao, Zhenxue Zheng, Xiu Hao, Shuai Gao, Xueping Nankai Univ Inst New Energy Mat Chem Sch Mat Sci & Engn Tianjin 300350 Peoples R China

The intense research of lithium-ion batteries has been motivated by their successful applications in mobile devices and electronic vehicles. The emerging of intelligent control in kinds of devices brings new requirements for battery systems. The high-energy lithium batteries are expected to respond or react under different environmental conditions. In this work, a tri-salt composite electrolyte is designed with a temperature switch function for intelligently temperature-controlled lithium batteries. Specifically, the halide Li3YBr6 together with LiTFSI and LiNO3 works as active fillers in a low-melting-point polymer matrix (polyethyleneglycol dimethyl ether (PEGDME) and polyethylene oxide (PEO)), which is further filled into the pre-lithiated alumina fiber skeleton. Above 60 degrees C, the composite electrolyte exists in the liquid state and fully contacts with the working electrodes on the liquid-solid interface, effectively minimizing the interfacial resistance and leading to high discharge capacity in the cell. The electrolyte is changed into a solid state below 30 degrees C so that the ionic conductivity is significantly reduced and the interface resistance is increased dramatically on the solid-solid interface. Therefore, by simply adjusting the temperature, the cell can be turned "ON" or "OFF" intentionally. This novel function of the composite electrolyte has enlightening significance in developing intelligently temperature-controlled lithium batteries. A tri-salt composite electrolyte is developed by adding Li3YBr6, LiTFSI, and LiNO3 into PEGDME/PEO. It reversibly transforms between solid and liquid through adjusting the temperature, with lithium-ion conductivity and interfacial contact dramatically changed. Correspondingly, the cells are blocked or conductive as turning "off" and "on" reversibly and flexibly. This switch function shows great potential for developing intelligently temperature-controlled lithium batteries. image

关键词： composite electrolyte halide electrolyte low melting point solid-state battery temperature switch function SOLID POLYMER ELECTROLYTES IONIC-CONDUCTIVITY RECENT PROGRESS COMPATIBILITY INTERFACE NANOWIRES CATHODE SIO2