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Pd cluster decorated free standing flexible cathode for high performance Li-oxygen batteries

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Nano Research 2024年第4期17卷 2678-2686页

作者： Liang Guo Guoliang Zhang Ruonan Yang Dongmei Zhang Xiuqi Zhang Han Yu Xia Li Feng Dang key laboratory for Liquid-Solid Structure Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

As a promising candidate for the next generation energy storage system,rechargeable lithium-oxygen batteries(LOBs)still face substantial challenges caused by insulating discharge products that preclude their practical *** highly efficient cathode catalysts capable of facilitating formation/decomposition of discharge products is considered as an essential approach towards high performance ***,Pd decorated Te nanowires(Pd@Te NWs)were synthesized as advanced catalyst in LOBs to maximize Pd utilization and achieve synergistic effect,in which Pd clusters were uniformly grown on Te substrate though regulating the Pd:Te ***,Pd@Te nanowires assembled into an interpenetrating network-like structure by vacuum filtration and employed as flexible cathode,enabling LOBs achieved an ultralong 190 cycles stability and a superior specific capacity of 3.35 mAh·cm^(-2).Experimental studies and density functional theory(DFT)calculations reveal the excellent catalytic ability of Pd@Te and synergistic catalytic mechanism of Pd and Te,in which uniform electron distribution,extensive electron exchange,and large adsorption distance between Pd cluster and discharge products promote homogeneous adsorption/desorption of discharge products,while the high adsorption energy of Te substrate for Li species reduces the initial dynamical energy barrier during discharging *** current work provides viable strategy to design composite catalysts for flexible cathode of LOBs with synergistic catalytic effects.

关键词： flexible lithium-oxygen batteries Pd@Te synergistic catalysis cathode catalysts density functional theory(DFT)calculation

Inhibiting shuttle effect of lithium polysulfides by double metal selenides for high-performance lithium-sulfur batteries

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Rare Metals 2024年第6期43卷 2546-2559页

作者： Lei Li Xue-Jing Yang Yi-Yang Li Bo Jin Hui Liu Meng-Yang Cui Dong-Bo Guan Xing-You Lang Qing Jiang key laboratory of Automobile Materials Ministry of Educationand College of Materials Science and EngineeringJilin UniversityChangchun 130022China

Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production ***,the low electronic conductivity of active material and shuttling effect of lithium polysulfides(LiPSs)limit the commercial development of *** solve these problems,we design a core-shell composite with nitrogen-doped carbon(NC)and two types of selenides(FeSe_(2)-NC@ZnSe-NC).The FeSe_(2)-NC@ZnSe-NC has a strong adsorption capacity,and can effectively adsorb *** the same time,it also effectively alleviates the shuttling effect of LiPSs,and improves the utilization of the active substance during the charge/discharge reaction *** mechanism involved in FeSe_(2)-NC@ZnSe-NC is demonstrated by both experiments and density-functional theory(DFT)*** electrochemical test results indicate that LSB with S/FeSe_(2)-NC@ZnSe-NC delivers an initial discharge capacity of 1260 mAh·g^(-1)at *** after 500 cycles at 1C,the capacity decay rate per cycle is 0.031%,and the capacity retention rate is 85%.The FeSe_(2)-NC@ZnSe-NC core-shell structure verifies a rational strategy to construct an electrode material for high-performance LSBs.

关键词： Lithium-sulfur batteries Shuttling effect Metal selenide Nitrogen-doped carbon Lithium polysulfides

Perception field based imitation learning for unlabeled multi-agent pathfinding

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Science China(Information Sciences) 2024年第5期67卷 115-135页

作者： Wenjie CHU Ailun YU Wei ZHANG Haiyan ZHAO Zhi JIN School of Computer Science Peking University key laboratory of High-Confidence Software Technologies (Peking University) Ministry of Education

This paper proposes an imitation learning method to learn a universal agent policy for unlabeled multi-agent pathfinding(unlabeled MAPF) in grid environments. The method transforms the unlabeled MAPF problem into a series of temporal-independent homogeneous classification problems for each *** on this transformation, a neural network is designed to imitate a distance-optimal expert *** neural network consists of two successive modules: perception field learner and field integrating *** former refines and encodes the current system state into a perception field for each agent by combining a set of learnable field-generating functions. The latter takes an agent's perception field as input and decides the agent's next action based on a triplet cross-attention mechanism. We evaluate our method on a diverse set of unlabeled MAPF tasks. Compared with state-of-the-art counterparts, the experimental results manifest the superiority of the proposed method in both generalization ability and scalability.

关键词： unlabeled multi-agent pathfinding perception field triplet cross-attention multi-agent imitation learning learning-based planning

Optimized Mask-RCNN model for particle chain segmentation based on improved online ferrograph sensor

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Friction 2024年第6期12卷 1194-1213页

作者： Shuo WANG Miao WAN Tonghai WU Zichen BAI Kunpeng WANG key laboratory of education ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China

Ferrograph-based wear debris analysis(WDA)provides significant information for wear fault analysis of mechanical *** decades of offline application,this conventional technology is being driven by the online ferrograph sensor for real-time wear state ***,online ferrography has been greatly limited by the low imaging quality and segmentation accuracy of particle chains when analyzing degraded lubricant oils in practical *** address this issue,an integrated optimization method is developed that focuses on two aspects:the structural re-design of the online ferrograph sensor and the intelligent segmentation of particle *** enhancing the imaging quality of wear particles,the magnetic pole of the online ferrograph sensor is optimized to enable the imaging system directly observe wear particles without penetrating ***,a light source simulation model is established based on the light intensity distribution theory,and the LED installation parameters are determined for particle illumination uniformity in the online ferrograph *** this basis,a Mask-RCNN-based segmentation model of particle chains is constructed by specifically establishing the region of interest(ROI)generation layer and the ROI align layer for the irregular particle *** these measures,a new online ferrograph sensor is designed to enhance the image acquisition and information extraction of wear *** verification,the developed sensor is tested to collect particle images from different degraded oils,and the images are further handled with the Mask-RCNN-based model for particle feature *** results reveal that the optimized online ferrography can capture clear particle images even in highly-degraded lubricant oils,and the illumination uniformity reaches 90%in its imaging *** importantly,the statistical accuracy of wear particles has been improved from 67.2%to 94.1%.

关键词： wear particle analysis online ferrography particle image acquisition particle chain segmentation

Regioselective and asymmetric allylic alkylation of vinyl epoxides for the construction of allylic alcohols via synergistic catalysis

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Science China Chemistry 2024年第2期67卷 542-550页

作者： Min Chen Longqing Yang Yuzhen Li Yinhe Qu Guihua Pan Xiaoming Feng Xiaohua Liu key laboratory of Green Chemistry&Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengdu610064China

A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step *** protocol utilizes a strategy of synergistic catalysis with a chiral N,N'-dioxide/Ni~Ⅱ complex and an achiral Pd~0 catalyst,generating a series of multisubstituted allylic alcohols with a quaternary carbon stereocenter in high yield and excellent regio-,Z/E-and enantioselectivity under mild *** transformations of the product demonstrate the potential utility of this protocol in the synthesis of allyl alcohol derivatives and natural product *** studies revealed that the N,N′-dioxide/metal complexes play an important role in controlling the Z/E-and *** density functional theory(DFT) calculations further demonstrated that multiple C–H···π interactions between the aromatic rings of the two substrates and the amide moiety in the ligand stabilized the dominant transition state.

关键词： asymmetric allylic alkylation synergistic catalysis vinyl epoxides allyl alcohol multiple weak interactions

In situ atomic-scale tracking of unusual interface reaction circulation and phase reversibility in(de)potassiated alloy-typed anode

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Journal of Energy Chemistry 2024年第8期95卷 241-249,I0006页

作者： Lin Su Ruining Fu Shuangying Lei Yuchen Pan Chongyang Zhu Pengcheng Liu Feng Xu SEU-FEI Nano-Pico Center Key Laboratory of MEMS of the Ministry of EducationSoutheast UniversityNanjing210096China

Alloy-typed anode materials,endowed innately with high theoretical specific capacity,hold great promise as an alternative to intercalation-typed counterparts for alkali-ion *** tremendous efforts devoted to addressing drastic volume change and severe pulverization issues of such anodes,the underlying mechanisms involving dynamic phase evolutions and reaction kinetics have not yet been fully ***,taking antimony(Sb)anode as a representative paradigm,its microscopic operating mechanisms down to the atomic scale during live(de)potassiation cycling are systematically unraveled using in situ transmission electron *** reversible phase transformations at single-particle level,that are Sb←→KSb_(2)←→KSb←→K_5Sb_(4)←→K_(3)Sb,were revealed during ***,multiple phase interfaces associated with different reaction kinetics coexisted and this phenomenon was properly elucidated in the context of density functional theory ***,previously unexplored unidirectional circulation of reaction interfaces within individual Sb particle is confirmed for both potassiation and *** on the empirical results,the surface diffusion-mediated potassiation-depotassiation pathways at single-particle level are *** work affords new insights into energy storage mechanisms of Sb anode and valuable guidance for targeted optimization of alloy-typed anodes(not limited to Sb)toward advanced potassium-ion batteries.

关键词： Alloy-typed anode Potassium storage mechanism In situ transmission electron microscopy Reaction interface

Multi-locomotion transition of tensegrity mobile robot under different terrains

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Science China(Technological Sciences) 2024年第2期67卷 536-557页

作者： YANG Qi LIU XinYu WANG PanFeng SONG YiMin SUN Tao key laboratory of Mechanism Theory and Equipment Design(Tianjin University) Ministry of EducationTianjin UniversityTianjin 300350China

Knowing how to make a multi-locomotion robot achieve locomotion transition under different terrains is a challenging problem,especially for tensegrity robots with multi-locomotion *** this study,a motion planning method for the transition of a multi-locomotion tensegrity robot(hereafter TJUBot)under different terrains is *** robot can achieve four locomotion modes:earthworm-like,inchworm-like,tumbling,and sliding locomotion with only two *** models of the four locomotion modes under five typical terrains,including flat ground,confined space,obstacle,gap,and descending slope,are established using the energy ***,the kinematic characteristics(driving law and initial position)of the robot under these terrains are *** this basis,motion planning for the locomotion transition of TJUBot is conducted,which includes a perception strategy based on three laser sensors and a transition strategy under different *** driving laws of the two motors that can ensure the effective locomotion transition of TJUBot under different terrains are naturally ***,experiments are *** demonstrate that the robot can achieve effective locomotion transition when the motion planning method is used.

关键词： multi-locomotion robot tensegrity kinematic modeling locomotion transition

Long-term exposure to aryl hydrocarbon receptor agonist neburon induces reproductive toxicity in male zebrafish(Danio rerio)

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Journal of Environmental Sciences 2024年第8期142卷 193-203页

作者： Fucong Zhang Chen Tang Yue Zhu Qian Wang Xin Huang Chunyan Yang Chengyong He Zhenghong Zuo key laboratory of the ministry of education for Coastal and Wetland Ecosystems School of Life SciencesXiamen UniversityXiamen 361102China

Neburon is a phenylurea herbicide that is widely used worldwide,but its toxicity is poorly *** our previous study,we found that neburon has strong aryl hydrocarbon receptor(AhR)agonist activity,but whether it causes reproductive toxicity is not *** the present study,zebrafish were conducted as a model organism to evaluate whether environmental concentrations of neburon(0.1,1 and 10μg/L)induce reproductive disorder in *** exposure to neburon for 150 days from embryo to adult,that the average spawning egg number in high concentration group was 106.40,which was significantly lower than 193.00in control *** result was mainly due to the abnormal male reproductive behavior caused by abnormal transcription of genes associated with reproductive behavior in the brain,such as *** proportions of spermatozoa in the medium and high concentration groups were 82.40%and 83.84%,respectively,which were significantly lower than 89.45%in control *** result was mainly caused by hormonal disturbances and an increased proportion of apoptotic *** hormonal disruption was due to the significant changes in the transcription levels of key genes in the hypothalamus-pituitary-gonadal axis following neburon *** treatment also significantly activated the AhR signaling pathway,causing oxidative stress damage and eventually leading to a significant increase in apoptosis in the exposed ***,these data filled the currently more vacant profile of neburon toxicity and might provide information to assess the ecotoxicity of neburon on male reproduction at environmentally relevant concentrations.

关键词： Zebrafish Neburon Male reproductive toxicity HPG axis AhR agonist

Artificial intelligence-assisted design of new chemical materials: a perspective

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Science China(Information Sciences) 2024年第8期67卷 334-336页

作者： Feng QIAN Wenli DU Weimin ZHONG Yang TANG Jingyi LU key laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and Technology

New chemical materials are a fresh category of substances created through chemical reactions or by refining existing materials through secondary processes. By using creative methods, advanced technologies, innovative techniques, and state-of-the-art equipment, these materials(e.g., high-end polyolefin, nano materials) [1] are carefully designed and developed to showcase outstanding performance and unique capabilities beyond what traditional chemical materials can offer [2].

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