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Science China Chemistry 2024年第5期67卷 1373-1374页

作者： Haoran Wang Ben Zhong Tang hong kong Branch of chinese National engineering Research Center for Tissue Restoration and Reconstruction Department of Chemistry.Institute of Molecular Functional MaterialsState Key Laboratory of NeuroscienceDivision of Biomedical Engineering and Division of Life ScienceThe Hong Kong University of Science and TechnologyHong Kong 999077China School of Science and engineering Shenzhen Institute of Aggregate Science and Technology The Chinese University of Hong KongShenzhen(CUHK-Shenzhen)Shenzhen 518172China

Nanotechnology hailed as a revolutionary new technology of the 21st century, has ignited a wave of innovation across diverse fields spanning chemistry, physics, materials science,medicine, engineering, and electronics. In 2016, Nature published an article titled “The nanolight revolution is coming”, underscoring that “virus-sized particles that emit light in every color could transform applications ranging from television displays to cancer treatment”.

关键词： sized loading treatment

Insight into structural degradation of NCMs under extreme fast charging process

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Rare Metals 2024年第1期43卷 41-50页

作者： Yu Tang Xing-Yu Wang Jin-Can Ren Bo-Wen Chen Zhi-Yong Huang Wei Wang Ya-Lan Huang Bing-Hao Zhang Si Lan Zhang-Long He Qi Liu Hao He department of Physics City University of Hong KongHong Kong 999077China Shenzhen Research Institute City University of Hong KongShenzhen 518057China College of Materials Science and engineering Changsha University of Science&TechnologyChangsha 410114China

Lithium-ion batteries(LIBs)with extreme fast charging(XFC)capability are considered an effective way to alleviate range anxiety for electric vehicle(EV)*** to the high ionic and electronic conductivity of LiNi_(x)Co_(y)Mn_zO_(2)(x+y+z=1,NCM)cathodes,the inevitable Li plating of graphite in NCM|graphite cell is usually identified as a key bottleneck for XFC ***,the capacity decay mechanism of cathode materials under XFC has not been fully *** this work,three typical NCM cathode materials with different Ni fractions were chosen and their electrochemical performances under XFC associated with structural evolution were investigated.A faster capacity decay of NCMs under XFC conditions is observed,especially for Ni-rich ***-situ X-ray diffraction(XRD)reveals that the multiple caxis parameters appear at the high-voltage regions in Nirich NCMs,which is probably triggered by the larger obstruction of Li(de)***,NCMs with moderate Ni fraction also present a similar trend under XFC *** phenomenon is more detrimental to the structural and morphological stability,resulting in a faster capacity decay than that under low current *** work provides new insight into the degradation mechanism of NCMs under XFC conditions,which can promote the development of NCM cathode materials with XFC capability.

关键词： Lithium-ion batteries Ni fraction Extreme fast charging Structural evolution

Finite-size-induced non-Hermitian phase transitions in real space

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 105-111页

作者： hongfei Wang Biye Xie Wei Ren department of Physics International Center for Quantum and Molecular StructuresShanghai UniversityShanghai 200444China School of Science and engineering The Chinese University of Hong KongShenzhen 518172China

While non-Hermiticity provokes intriguing phenomena without Hermitian counterparts, e.g., the skin effect and the breakdown of bulk-boundary correspondence, attracting extensive attention both in fundamental physics and device engineering, the role of finite sizes therein remains elusive. Here, we propose a class of finite-size-induced non-Hermitian phase transitions, relying upon higher-order topological invariants associated with real-space wave functions. The phase diagrams for general non-Hermitian chiral models are further acquired to demonstrate our topological definition. Such phase transitions are elucidated qualitatively by an effective intercell coupling alteration that depends on finite sizes in respective directions. Besides, we mimic these phenomena by analogizing the circuit Laplacian in finite-size electric circuits with nonreciprocal couplings. The resultant admittance spectra agree with our theoretical predictions. Our findings shed light on the finite-size mechanism of non-Hermitian topological phase transitions and pave the way for applications in switching and sensing.

关键词： non-Hermitian phase transitions finite-size effects higher-order topological invariants

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LLM4CP:Adapting Large Language Models for Channel Prediction

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Journal of Communications and Information Networks 2024年第2期9卷 113-125页

作者： Boxun Liu Xuanyu Liu Shijian Gao Xiang Cheng Liuqing Yang State Key Laboratory of Advanced Optical Communication Systems and Networks School of ElectronicsPeking UniversityBeijing 100871China Internet of Things Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China Internet of Things Thrust and Intelligent Transportation Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China department of electronic and Computer engineering and department of Civil and Environmental engineering The Hong Kong University of Science and TechnologyHong KongChina

Channel prediction is an effective approach for reducing the feedback or estimation overhead in massive multi-input multi-output (m-MIMO) systems. However, existing channel prediction methods lack precision due to model mismatch errors or network generalization issues. Large language models (LLMs) have demonstrated powerful modeling and generalization abilities, and have been successfully applied to cross-modal tasks, including the time series analysis. Leveraging the expressive power of LLMs, we propose a pre-trained LLM-empowered channel prediction(LLM4CP)method to predict the future downlink channel state information (CSI) sequence based on the historical uplink CSI sequence. We fine-tune the network while freezing most of the parameters of the pre-trained LLM for better cross-modality knowledge transfer. To bridge the gap between the channel data and the feature space of the LLM,preprocessor, embedding, and output modules are specifically tailored by taking into account unique channel characteristics. Simulations validate that the proposed method achieves state-of-the-art (SOTA) prediction performance on full-sample, few-shot, and generalization tests with low training and inference costs.

关键词： channel prediction massive multi-input multi-output(m-MIMO) large language models(LLMs) fine-tuning time-series

Recent Advances in Aqueous Zn||MnO_(2)Batteries

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Transactions of Tianjin university 2024年第1期30卷 27-39页

作者： Chuan Li Rong Zhang Huilin Cui Yanbo Wang Guojin Liang Chunyi Zhi department of Materials Science and engineering City University of Hong Kong83 Tat Chee AvenueKowloon 999077Hong KongChina Faculty of Materials Science and Energy engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China hong kong Institute for Clean Energy City University of Hong KongKowloon 999077Hong KongChina hong kong Institute for Advanced Study City University of Hong KongKowloon 999077Hong KongChina

Recently,rechargeable aqueous zinc-based batteries using manganese oxide as the cathode(e.g.,MnO_(2))have gained attention due to their inherent safety,environmental friendliness,and low *** their potential,achieving high energy density in Zn||MnO_(2)batteries remains challenging,highlighting the need to understand the electrochemical reaction mechanisms underlying these batteries more deeply and optimize battery components,including electrodes and *** review comprehensively summarizes the latest advancements for understanding the electrochemistry reaction mechanisms and designing electrodes and electrolytes for Zn||MnO_(2)batteries in mildly and strongly acidic ***,we highlight the key challenges hindering the extensive application of Zn||MnO_(2)batteries,including high-voltage requirements and areal capacity,and propose innovative solutions to overcome these *** suggest that MnO_(2)/Mn^(2+)conversion in neutral electrolytes is a crucial aspect that needs to be addressed to achieve high-performance Zn||MnO_(2)*** approaches could lead to breakthroughs in the future development of Zn||MnO_(2)batteries,off ering a more sustainable,costeff ective,and high-performance alternative to traditional batteries.

关键词： Aqueous Zn||MnO_(2)batteries Zinc-ion batteries Zinc batteries MnO_(2)

Examining the characteristics between time and distance gaps of secondary crashes

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Transportation Safety and Environment 2024年第1期6卷 116-131页

作者： Xinyuan Liu Jinjun Tang Chen Yuan Fan Gao Xizhi Ding Smart Transport Key Laboratory of Hunan Province School of Transport and Transportation EngineeringCentral South UniversityChangsha 410075China department of Computer Science City University of Hong Kong999077Kowloon TongHong KongChina department of Geography and Resource Management The Chinese University of Hong KongShatinNT 999077Hong KongChina

Understanding the characteristics of time and distance gaps between the primary(PC)and secondary crashes(SC)is crucial for preventing SC ccurrences and improving road *** previous studies have tried to analyse the variation of gaps,there is limited evidence in quantifying the relationships between different gaps and various influential *** study proposed a two-layer stacking framework to discuss the time and distance ***,the framework took random forests(RF),gradient boosting decision tree(GBDT)and eXtreme gradient boosting as the base classifiers in the first layer and applied logistic regression(LR)as a combiner in the second *** this basis,the local interpretable model-agnostic explanations(LIME)technology was used to interpret the output of the stacking model from both local and global *** SC dentification and feature selection,346 SCs and 22 crash-related factors were collected from California interstate *** results showed that the stacking model outperformed base models evaluated by accuracy,precision,and recall *** explanations based on LIME suggest that collision type,distance,speed and volume are the critical features that affect the time and distance *** volume can prolong queue length and increase the distance gap from the SCs to *** collision types,peak periods,workday,truck involved and tow away likely induce a long-distance ***,there is a shorter distance gap when secondary roads run in the same direction and are close to the primary *** speed is a significant factor resulting in a long-time gap,while the higher speed is correlated with a short-time *** results are expected to provide insights into how contributory features affect the time and distance gaps and help decision-makers develop accurate decisions to prevent SCs.

关键词： secondary crash(SC) time and distance gaps stacking framework local interpretable model-agnostic explanations(LIME)

Resonant Beam Communications:A New Design Paradigm and Challenges

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Journal of Communications and Information Networks 2024年第1期9卷 80-87页

作者： Yuanming Tian Dongxu Li Chuan Huang Qingwen Liu Shengli Zhou Future Network of Intelligence Institute and School of Science and engineering the Chinese University of Hong KongShenzhen 518172China School of Science and engineering and the Future Network of Intelligence Institute the Chinese University of Hong KongShenzhen 518172China College of electronics and Information engineering Tongji UniversityShanghai 201804China department of Electrical and Computer engineering University of ConnecticutStorrsCT 06250USA

Resonant beam communications (RBCom), which adopts oscillating photons between two separate retroreflectors for information transmission, exhibits potential advantages over other types of wireless optical communications (WOC). However, echo interference generated by the modulated beam reflected from the receiver affects the transmission of the desired information. To tackle this challenge, a synchronization-based point-to-point RBCom system is proposed to eliminate the echo interference, and the design for the transmitter and receiver is discussed. Subsequently,the performance of the proposed RBCom is evaluated and compared with that of visible light communications(VLC)and free space optical communications (FOC). Finally, future research directions are outlined and several implementation challenges of RBCom systems are highlighted.

关键词： resonant beam communications(RBCom) wireless optical communications(WOC) echo interference elimination mobility multiple access

Atomscopic of ripple origins for two-dimensional monolayer transition metal dichalcogenides

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Nano Research 2024年第3期17卷 2136-2144页

作者： Haitao Yu Mingzi Sun Xiao Wu Cheuk Hei Chan Bolong Huang Zhong Lin Wang CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina Research Centre for Carbon-Strategic Catalysis The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina School of Materials Science and engineering Georgia Institute of TechnologyAtlantaGeorgia 30332USA

During the development of ultrathin two-dimensional(2D)materials,the appearance of ripples has been widely ***,the formation mechanisms and their influences are still rarely investigated,especially their contributions to the electronic structures and optical *** compensate for the knowledge gap,we have carried out comprehensive theoretical studies on the monolayer WSe_(2) with a series of ripple structures from 0 to 12Åin different lattice *** sensitivity of the formation energy,band structures,electronic structures,and optical properties to the ripple structures have been performed systematically for the first *** formation of ripples in Armchair and zigzag simultaneously are more energetically favorable,leading to more flexible optimizations of the optoelectronic *** improved charge-locking effect and extension of absorption ranges indicate the significant role of ripple *** spontaneous formation of ripples is associated with orbital rearrangements and structural *** leads to the unique charge carrier correlate inversion between W-5d and Se-4p orbitals,resulting in the pinning of the Fermi *** work has supplied significant references to understand ultrathin 2D structures and benefit their future developments and applications in high-performance optoelectronic devices.

关键词： two-dimensional(2D)materials ripples strain effect charge carrier correlation inversion optoelectronic properties

Rotor Angle Stability Prediction Using Temporal and Topological Embedding Deep Neural Network Based on Grid-informed Adjacency Matrix

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 695-706页

作者： Peiyuan Sun Long Huo Xin Chen Siyuan Liang the School of Electrical engineering Xi’an Jiaotong UniversityXi’an 710049China the School of Electrical engineering and the Center of Nanomaterials for Renewable EnergyState Key Laboratory of Electrical Insulation and Power EquipmentXi’an Jiaotong UniversityXi’an 710049China the department of Computer Science and engineering The Chinese University of Hong KongShatin999077Hong KongChina

Rotor angle stability(RAS)prediction is critically essential for maintaining normal operation of the interconnected synchronous machines in power *** wide deployment of phasor measurement units(PMUs)promotes the development of data-driven methods for RAS *** paper proposes a temporal and topological embedding deep neural network(TTEDNN)model to accurately and efficiently predict RAS by extracting the temporal and topological features from the PMU *** grid-informed adjacency matrix incorporates the structural and electrical parameter information of the power *** the small-signal RAS with disturbance under initial operating conditions and the transient RAS with short circuits on transmission lines are *** studies of the IEEE 39-bus and IEEE 300-bus power systems are used to test the performance,scalability,and robustness against measurement uncertainties of the TTEDNN *** show that the TTEDNN model performs best among existing deep learning ***,the superior transfer learning ability from small-signal RAS conditions to transient RAS conditions has been proved.

关键词： Rotor angle stability prediction topological embedding deep learning graph convolution network

engineering the axial coordination of cobalt single atom catalysts for efficient photocatalytic hydrogen evolution

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Nano Research 2024年第6期17卷 5114-5121页

作者： Ning Kang Lingwen Liao Xue Zhang Zhen He Binlu Yu Jiahong Wang Yongquan Qu Paul KChu Seeram Ramakrishna Xue-Feng Yu Xin Wang Licheng Bai Materials Interfaces Center Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences(CAS)Shenzhen 518055China Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsChinese Academy of SciencesHefei 230031China department of Chemistry City University of Hong KongKowloonHong Kong 999077China hong kong Branch of National Precious Metals Material engineering Research Center(NPMM) City University of Hong KongKowloonHong Kong 999077China Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China department of Physics and department of Materials Science and engineering City University of Hong KongKowloonHong Kong 999077China National university of Singapore(NUS)Centre for Nanofibers and Nanotechnology Department of Mechanical EngineeringNational University of SingaporeSingapore 117542Singapore

Improving the catalytic activity of non-noble metal single atom catalysts(SACs)has attracted considerable attention in materials *** optimizing the local electronic structure of single atom can greatly improve their catalytic activity,it often involves in-plane modulation and requires high ***,we report a novel strategy to manipulate the local electronic structure of SACs via the modulation of axial Co-S bond anchored onto graphitic carbon nitride(C_(3)N_(4))at room temperature(RT).Each Co atom is bonded to four N atoms and one S atom(Co-(N,S)/C_(3)N_(4)).Owing to the greater electronegativity of S in the Co-S bond,the local electronic structure of the Co atoms is available to be controlled at a relatively moderate ***,when employed for the photocatalytic hydrogen evolution reaction,the adsorption energy of intermediate hydrogen(H*)on the Co atoms is remarkably *** the presence of the Co-(N,S)/C_(3)N_(4)SACs,the hydrogen evolution rates reach up to 10 mmol/(g·h),which is nearly 10 and 2.5 times greater than the rates in the presence of previously reported transition metal/C_(3)N_(4)and noble platinum nanoparticles(PtNPs)/C_(3)N_(4)catalysts,*** to the tailorable axial Co-S bond in the SAC,the local electronic structure of the Co atoms can be further optimized for other photocatalytic *** axial coordination engineering strategy is universal in catalyst designing and can be used for a variety of photocatalytic applications.

关键词： transition metal single-atom local electronic structure photocatalytic hydrogen evolution graphitic carbon nitride axial coordination environment