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Energy & Environmental Materials 2024年第4期7卷 163-174页

作者： Hao Li Rui Wang Jiangping Song Dan Liu Hongyang Gao Yimin Chao Haolin Tang A State Key laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Department of Chemistry Chemical Engineering and Life Science Wuhan University of Technology Foshan Xianhu laboratory of the Advanced Energy science and Technology Guangdong laboratory school of Chemistry University of East Anglia

As the persistent concerns regarding sluggish reaction kinetics and insufficient conductivities of sulfur cathodes in all-solid-state Li-S batteries(ASSLSBs),numerous carbon additives and solid-state electrolytes (SSEs) have been incorporated into the cathode to facilitate ion/electron pathways around ***,this has resulted in a reduced capacity and decomposition of SSEs.

关键词： all-solid-state lithium–sulfur batteries conversion/intercalation high-loading and long-life low carbon content mixed ionic/electronic conductivities

QAAS:quick accurate auto-scaling for streaming processing

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Frontiers of Computer science 2024年第1期18卷 5-15页

作者： Shiyuan LIU Yunchun LI Hailong YANG Ming DUN Chen CHEN Huaitao ZHANG Wei LI State Key laboratory of Software Development Environment Beijing 100191China school of Computer science and Engineering Beihang UniversityBeijing 100191China school of Cyber science and Technology Beihang UniversityBeijing 100191China school of Computer science and Technology Xi’an Jiaotong UniversityXi’an 710049China

In recent years,the demand for real-time data processing has been increasing,and various stream processing systems have *** the amount of data input to the stream processing system fluctuates,the computing resources required by the stream processing job will also *** resources used by stream processing jobs need to be adjusted according to load changes,avoiding the waste of computing *** present,existing works adjust stream processing jobs based on the assumption that there is a linear relationship between the operator parallelism and operator resource consumption(e.g.,throughput),which makes a significant deviation when the operator parallelism *** paper proposes a nonlinear model to represent operator *** divide the operator performance into three stages,the Non-competition stage,the Non-full competition stage,and the Full competition *** our proposed performance model,given the parallelism of the operator,we can accurately predict the CPU utilization and operator *** with actual experiments,the prediction error of our model is below 5%.We also propose a quick accurate auto-scaling(QAAS)method that uses the operator performance model to implement the auto-scaling of the operator parallelism of the Flink *** to previous work,QAAS is able to maintain stable job performance under load changes,minimizing the number of job adjustments and reducing data backlogs by 50%.

关键词： stream processing performance model auto-scaling

Towards kernelizing the classifier for hyperbolic data

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Frontiers of Computer science 2024年第1期18卷 17-31页

作者： Meimei YANG Qiao LIU Xinkai SUN Na SHI Hui XUE school of Computer science and Engineering Southeast UniversityNanjing 210096China MOE Key laboratory of Computer science and Information Integration(Southeast University) Nanjing 210096China

Data hierarchy,as a hidden property of data structure,exists in a wide range of machine learning applications.A common practice to classify such hierarchical data is first to encode the data in the Euclidean space,and then train a Euclidean ***,such a paradigm leads to a performance drop due to distortion of data embedding in the Euclidean *** relieve this issue,hyperbolic geometry is investigated as an alternative space to encode the hierarchical data for its higher ability to capture the hierarchical *** methods cannot explore the full potential of the hyperbolic geometry,in the sense that such methods define the hyperbolic operations in the tangent plane,causing the distortion of data *** this paper,we develop two novel kernel formulations in the hyperbolic space,with one being positive definite(PD)and another one being indefinite,to solve the classification tasks in hyperbolic *** PD one is defined via mapping the hyperbolic data to the Drury-Arveson(DA)space,which is a special reproducing kernel Hilbert space(RKHS).To further increase the discrimination of the classifier,an indefinite kernel is further defined in the Krein ***,we design a 2-layer nested indefinite kernel which first maps hyperbolic data into the DA spaces,followed by a mapping from the DA spaces to the Krein *** experiments on real-world datasets demonstrate the superiority ofthe proposed kernels.

关键词： data hierarchy hyperbolic cgeometry drury-arveson space krein space

A new quantum key distribution resource allocation and routing optimization scheme

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Chinese Physics B 2024年第3期33卷 244-259页

作者：毕琳袁晓同吴炜杰林升熙 school of Computer science and Technology Changchun University of Science and TechnologyChangchun 130012China Key laboratory of Network and Information Security in Jilin Province Changchun 130012China

Quantum key distribution(QKD)is a technology that can resist the threat of quantum computers to existing conventional cryptographic ***,due to the stringent requirements of the quantum key generation environment,the generated quantum keys are considered valuable,and the slow key generation rate conflicts with the high-speed data transmission in traditional optical *** this paper,for the QKD network with a trusted relay,which is mainly based on point-to-point quantum keys and has complex changes in network resources,we aim to allocate resources reasonably for data packet ***,we formulate a linear programming constraint model for the key resource allocation(KRA)problem based on the time-slot ***,we propose a new scheduling scheme based on the graded key security requirements(GKSR)and a new micro-log key storage algorithm for effective storage and management of key ***,we propose a key resource consumption(KRC)routing optimization algorithm to properly allocate time slots,routes,and key *** results show that the proposed scheme significantly improves the key distribution success rate and key resource utilization rate,among others.

关键词： quantum key distribution(QKD) resource allocation key storage routing algorithm

“Capture-activation-recapture” mechanism-guided design of double-atom catalysts for electrocatalytic nitrogen reduction

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Journal of Energy Chemistry 2024年第9期96卷 437-447页

作者： Cheng He Shiqi Yan Wenxue Zhang State Key laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina school of Materials science and Engineering Chang’an UniversityXi’an 710064ShaanxiChina

Compared with the traditional industrial nitrogen fixation, electrocatalytic methods, especially those utilizing double-atom catalysts containing nonmetals, can give good consideration to the economy and environmental protection. However, the existing “acceptance-donation” mechanism is only applicable to bimetallic catalysts and nonmetallic double-atom catalysts containing boron atoms. Herein, a novel “capture-activation-recapture” mechanism for metal-nonmetal double-atom catalyst is proposed to solve the problem by adjusting the coordination environments of nonmetallic atoms and utilizing the activation effect of metal atoms on nitrogen. Based on this mechanism, the nitrogen reduction reaction (NRR) activity of 48 structures is calculated by density functional theory calculation, and four candidates are selected as outstanding electrocatalytic nitrogen reduction catalysts: Si-Fe@NG (U_(L) = –0.14 V), Si-Co@NG (U_(L)= –0.15 V), Si-Mo@BP1 (U_(L) = 0 V), and Si-Re@BP1 (U_(L) = –0.02 V). The analyses of electronic properties further confirm “capture-activation-recapture” mechanism and suggest that the difference in valence electron distribution between metal and Si atoms triggers the activation of N≡N bonds. In addition, a machine learning approach is utilized to generate an expression and an intrinsic descriptor that considers the coordination environment to predict the limiting potential. This study offers profound insight into the synergistic mechanism of TM and Si for NRR and guidance in the design of novel double-atom nitrogen fixation catalysts.

关键词： "Capture-activation-recapture"mechanism Double-atom catalyst Nitrogen reduction reaction Density functional theory

Tuning the solubility of polysulfides for constructing practical lithium-sulfur battery

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Journal of Energy Chemistry 2024年第8期95卷 611-617,I0013页

作者： Jiapeng Li Jianlong Cong Haijin Ji Ting Shi Lixia Yuan Yunhui Huang State Key laboratory of Material Processing and Die&Mold Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina

Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low ***,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li *** get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_*** introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode *** minor Se substitution compensates the decrease in kinetic due to the decreased solubility of *** this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,***,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode *** makes more sense to guide the electrolyte design for practical Li-S batteries.

关键词： Li-S batteries Lithium polysulfides Solubility Shuttle effect Interface Se doping

Constructing a 3D multichannel structure to enhance performance of Ni–Co–Mn hydroxide electrodes for flexible supercapacitors

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Rare Metals 2024年第1期43卷 148-163页

作者： Zhi-Hui Xu Shi-Shuai Sun Xue-Lei Li Zhi-Hui Zhang Hai-Ying Li Shuang-Ting Ruan Shou-Gen Yin Key laboratory of Display Materials and Photoelectric Devices(Ministry of Education)and Tianjin Key laboratory for Photoelectric Materials and Devices School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China College of science Tianjin University of TechnologyTianjin 300384China school of Materials science and Engineering Inner Mongolia University of TechnologyHohhot 010051China

The balancing of the electrochemical performance,mechanical stability,and processing technology for applying supercapacitors to flexible and wearable electronics continues to encounter severe ***,we prepare Ni-Co-Mn hydroxide electrodes with a threedimensional multichannel structure via a simple hydrothermal *** are constructed using vertically contiguous nano sheets with a uniform thickness and rough *** electrodes can provide numerous electroactive sites and accelerate the transmission of electrolyte *** relationship between the structure and electrochemical performances is verified by experiments and theoretical ***-dimensional(2D)planar and one-dimensional(1D)fiber electrodes are prepared using a flexible carbon cloth(CC)and carbon fiber(CF),respectively,as *** assembled quasi-solid-state flexible asymmetric supercapacitor(FASC)with a twodimensional sandwich structure using NiCoMn-OH/CC as the electrode achieves a remarkable energy density of73.8 Wh·kg^(-1)at a power density of 1.03 kW·kg^(-1).The quasi-solid-state FASC with a 1D linear structure using NiCoMn-OH/CF as the electrode also attains a high energy density(12.9 Wh·kg^(-1)at a power density of0.75 W·kg^(-1)).Moreover,the electrochemical performances of the NiCoMn/CC//AC/CC and NiCoMn/CF//AC/CF FASCs are not disturbed at different bending angles(0°,45°,90°,135°and 180°),This indicates the superior flexibility of the *** also assemble a self-powered energy-harvesting storage system by integrating FASCs and commercial solar cells to verify its *** displays sustainable development potential for energy storage.

关键词： Supercapacitors Flexible Ni–Co–Mn hydroxide 3D multichannel structure High performances

On the low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing

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Journal of Materials science & Technology 2024年第1期168卷 227-238页

作者： Guangyi Guo Guofu Xu Yuan Tang Zhihao Zhao Zhihao Yi Haoran Li Ruohan Wang Xiaoyan Peng school of Materials science and Engineering Central South UniversityChangsha 410083China Key laboratory of Nonferrous Materials science and Engineering of Ministry of Education Changsha 410083China

The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain *** showed that NIA improved the low cycle fatigue life(more than 7000 cycles)by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties(570 MPa for tensile strength)and conductivity(nearly 39%IACS)to conventional isothermal ageing,*** observation combined with molecular dynamic simula-tion revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resis-tance.A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA,responsible for the dramatic displacement steps on the surface and resultant poor fatigue *** the NIA further proceeded,moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density ef-fectively impeded the dislocation movement and weaken the slip localisation to a great extent,improving the fatigue performance within a few hours.

关键词： Non-isothermal ageing Fatigue Al-Zn-Mg-Cu alloy Precipitate manipulation Slip localization

A deep learning model enabled multi-event recognition for distributed optical fiber sensing

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science China(Information sciences) 2024年第3期67卷 291-307页

作者： Yujiao LI Xiaomin CAO Wenhao NI Kuanglu YU Institute of Information science School of Computer and Information TechnologyBeijing Jiaotong University Beijing Key laboratory of Advanced Information science and Network Technology Beijing Jiaotong University

Fiber optic sensors that utilize backscattered light offer distributed real-time measurements and have been seen tremendous improvements in sensing distance and spatial resolution over the last ***, these improvements in sensor capabilities lead to a significant increase in the amount of data that needs to be processed. Traditional processing schemes are no longer adequate, so the development of novel signal processing methods is critical. Phase-sensitive optical time domain reflectometry(Φ-OTDR) is now applied in various applications for multi-event recognition, and it would usually be difficult, sometimes even unrealistic to label all the acquired samples due to its real-time and seamless monitoring nature. To fully take advantage of the information contained within the large number of unlabeled samples, which were formerly not utilized and hence wasted, we propose a semi-supervised model to boost the event classification performance of Φ-OTDR. The model extracts respectively the temporal features and the spatial bidirectional features together with a dual attention mechanism. Its classification accuracy has been improved up to 96.9%with only 1230 labeled samples. In addition, our model shows significant advantages when the number of labeled samples is reduced. Importantly, our method improves the accuracy of multi-event classification without any modification to the optical setup.

关键词： $\Phi$-OTDR event recognition semi-supervised learning mean teacher MT-ACNN-SA-BiLSTM

Multifunctional photothermal hydrogels: Design principles, various functions, and promising biological applications

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Chinese Chemical Letters 2024年第10期35卷 79-88页

作者： Zikang Hu Hengjie Zhang Zhengqiu Li Tianbao Zhao Zhipeng Gu Qijuan Yuan Baoshu Chen school of Materials science and Engineering Xihua University College of Polymer science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University

Photothermal hydrogels with excellent photo responsive and thermal conversion ability had attract a great deal of attention from researchers to explore their biological applications. This review aimed to provide a comprehensive overview of photothermal hydrogels, focusing on their design principles, various functions, and biological applications. Firstly, several classifications of photothermal hydrogels were given according to different photothermal agents(metal, metal sulfide/oxide, MXene, carbon-based, dyes, black phosphorus, and polymer) utilized in hydrogel construction. The photothermal conversion mechanism and hydrogel fabrication were also discussed in detail. Then, the relationship between their photothermal conversion property and functions, together with some indispensable property such as biocompatibility,adhesion, mechanical properties, and self-healing properties was fully introduced. Furthermore, the applications of photothermal hydrogels in the biomedical(i.e., wound healing, antibacterial treatments, controlled drug release, bone repair, and tumor treatment) was summarized. Finally, the future opportunities and challenges of photothermal hydrogels were proposed. We believe that this review could provide a new horizon for further preparation of photothermal hydrogels, and could promote their applications in wider fields.

关键词： Multifunctional hydrogels Photothermal agents Photothermal conversion Tissue repair Wound healing