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Gradient sparsification for efficient wireless federated learning with differential privacy

Science China(Information Sciences) 2024年第4期67卷 272-288页

作者： Kang WEI Jun LI Chuan ma Ming DING feng SHU Haitao ZHAO Wen CHEN Hongbo ZHU School of Electronic and Optical Engineering Nanjing University of Science and Technology Zhejiang Lab Key Laboratory of Computer Network and Information Integration(Southeast University) Ministry of Education Data61 Commonwealth Scientific and Industrial Research Organisation School of Information and Communication Engineering Hainan University School of Communications and Information Engineering Nanjing University of Posts and Telecommunications School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University

Federated learning(FL) enables distributed clients to collaboratively train a machine learning model without sharing raw data with each other. However, it suffers from the leakage of private information from uploading models. In addition, as the model size grows, the training latency increases due to the limited transmission bandwidth and model performance degradation while using differential privacy(DP)protection. In this paper, we propose a gradient sparsification empowered FL framework with DP over wireless channels, to improve training efficiency without sacrificing convergence performance. Specifically, we first design a random sparsification algorithm to retain a fraction of the gradient elements in each client’s local model, thereby mitigating the performance degradation induced by DP and reducing the number of transmission parameters over wireless channels. Then, we analyze the convergence bound of the proposed algorithm, by modeling a non-convex FL problem. Next, we formulate a time-sequential stochastic optimization problem for minimizing the developed convergence bound, under the constraints of transmit power, the average transmitting delay, as well as the client’s DP requirement. Utilizing the Lyapunov drift-plus-penalty framework, we develop an analytical solution to the optimization problem. Extensive experiments have been implemented on three real-life datasets to demonstrate the effectiveness of our proposed algorithm. We show that our proposed algorithms can fully exploit the interworking between communication and computation to outperform the baselines, i.e., random scheduling, round robin, and delay-minimization algorithms.

关键词： federated learning differential privacy gradient sparsification Lyapunov drift convergence analysis

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Insight into the capacity degradation and structural evolution of single-crystal Ni-rich cathodes

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Journal of Energy Chemistry 2024年第8期95卷 68-76,I0003页

作者： Xiaodong Zhang Jiao Lin Ersha Fan Qingrong Huang Su ma Renjie Chen feng Wu Li Li Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Advanced Technology Research Institute Beijing Institute of TechnologyJinan 250300ShandongChina Collaborative Innovation Center of Electric Vehicles in Beijing Beijing 100081China

Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline ***,the phase evolution and capacity degradation of these single-crystal cathodes during continuous lithation/delithation cycling remains *** the mapping relationship between the macroscopic electrochemical properties and the material physicochemical properties is ***,we investigate the correlation between the physical-chemical characteristics,phase transition,and capacity decay using capacity differential curve feature identification and in-situ X-ray spectroscopic *** systematically clarify the dominant mechanism of phase evolution in aging *** high cut-off voltages can mitigate the slow kinetic and electrochemical properties of single-crystal *** also find that second-order differential capacity discharge characteristic curves can be used to identify the crystal structure disorder of Ni-rich *** findings constitute a step forward in elucidating the correlation between the electrochemical extrinsic properties and the physicochemical intrinsic properties and provide new perspectives for failure analysis of layered electrode materials.

关键词： Single-crystal cathodes Capacity decay Phase transition Differential capacity analysis

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The Novel Long QT Syndrome Type 2-associated F129I Mutation in the KCNH2 Gene Significantly Affects IKr Through the hERG1 Homomeric and Heteromeric Potassium Channels

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Cardiology Discovery 2024年第2期4卷 174-182页

作者： Li feng Kejuan ma Xin Li Nian Liu Deyong Long Changsheng ma Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityNational Clinical Research Center for Cardiovascular DiseasesBeijing 100029China Community Health Service Center of Beijing Nomal University Beijing 100875China.

Objective:The long QT syndrome type 2 is caused by the loss-of-function mutations in the KCNH2 gene,which encodes hERG1,the voltage-gated potassium *** hERG1 channels conduct rapid delayed rectifier K^(+)currents(I_(Kr))in the human cardiac ***2 encodes 2 main isoforms-hERG1a and hERG1b,which assemble to form the homomeric or heteromeric hERG1 ***,the functional characteristics of the heteromeric hERG1 channels in long QT syndrome type 2 are not *** this study,a novel mutation in the N-terminus of hERG1a(F129l)was identified in a proband of long QT syndrome type *** purpose of this study was to identify the electrophysiological change of homomeric and heteromeric hERG1 channels with ***:Candidate genes were screened by direct sequencing.F129l-hERG1a was cloned in the pcDNA3.1 vector by site-directed ***,the wild-type(WT)hERG1a and/or F129l-hERG1a were transiently expressed in the HEK293 cells with or without hERG1b *** expression levels of the transgenes,cellular distribution of hERG1a and hERG1b,and the electrophysiological features of the homomeric and the heteromeric hERG1 channels with the WT-hERG1a or F129l-hERG1a were analyzed using whole-cell patch-clamp electrophysiology,western blotting,and immunofluorescence ***:The proband was clinically diagnosed with long QT syndrome type 2 and carried a heterozygous mutation c.385T>A(F1291)in the KCNH2 *** study proved that the F129l substitution in hERG1a significantly decreased I_(Kr) in both the homomeric and heteromeric hERG1channels by 86%and 70%,respectively(WT-hERG1a(54.88±18.74)pA/pF vs.F129l-hERG1a(7.34±1.90)pA/pF,P<0.001;WT-hERG1a/hERG1b(89.92±24.51)pA/pF vs.F129l-hERG1a/hERG1b(26.54±9.83)pA/pF,P<0.001).The voltage dependence of I_(Kr) activation(V_(1/2) and k)was not affected by the mutation in both the homomeric and heteromeric hERG1 *** peak current densities and the kinetic charact

关键词： Long QT syndrome Arrhythmia lon channels hERG

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Microwave-accelerated direct regeneration of LiCoO_(2)cathodes for Li-ion batteries

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Science China Chemistry 2024年第7期67卷 2181-2189页

作者： Xueshan Hu Yun-chao Yin chao Li Lihui Zhou Lin Yang Yitian feng Daxian Zuo Chenhui Ning Das Soham Sheng Dai Longbin Qiu Lin Zeng Haw Jiunn Woo Jiayu Wan Future Battery Research Center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Centre for Ionics University of malaya Department of PhysicsFaculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia Key Laboratory for Advanced materials and Feringa Nobel Prize Scientist Joint Research Center School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Department of Natural and Applied Sciences Duke Kunshan UniversityKunshan 215316China

Recycling spent lithium-ion batteries is integral to today's low-carbon environmental protection *** concept of direct regeneration,acknowledged for its environmental sustainability,economic viability,and consistent performance of recycled materials,is gaining *** study presents an efficient and nondestructive approach by utilizing an ultrafast microwave technology to directly regenerate spent lithium cobaltate(LCO)cathode *** contrast to conventional furnacebased processes,this method significantly reduces the regeneration *** subjecting the spent LCO mixed with lithium sources to three microwave heating cycles(at approximately 1,350 K),LCO regeneration is achieved,yielding a specific capacity of 140.8 mah g^(-1)(0.2 C)with a robust cycle *** further environmental and economic benefits,the ultrafast microwave technology holds scientific promise for directly regenerating cathode materials,while establishing competitiveness for industrial applications.

关键词： battery recycling spent lithium cobaltate microwave directly regeneration cathode materials

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Pathogenic Surveillance of Foodborne Illness-Related Diarrhea—Beijing Municipality,China,2013-2023

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China CDC weekly 2024年第24期6卷 568-573页

作者： chao Wang Tongyu Wang Yanlin Niu Yangbo Wu Jinru Jiang Xiaochen ma Institute for Nutrition and Food Hygiene Beijing Center for Disease Prevention and ControlBeijingChina

Summary What is already known about this topic?Foodborne diseases present a significant public health concern,particularly in China,where they represent a significant food safety ***,there is a need for a thorough and systematic analysis of the extended epidemiological patterns of foodborne diseases in Beijing *** is added by this report?

关键词： Beijing safety borne

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Microstructures and mechanical properties of a commercial Mg-Al-Zn-Mn alloy with various hot-extrusion processes

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Rare Metals 2024年第3期43卷 1329-1336页

作者： He ma Fan-Zhi Meng Qiang Yang Ze-feng Xie Yuan-Ding Huang Xin Qiu State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of materials Science and Engineering Changchun University of Science and TechnologyChangchun130022China magIC-magnesium Innovation Center Helmholtz-Zentrum Geesthacht21502GeesthachtGermany Engineering Research Center of Optoelectronic Functional materials Ministry of EducationChangchun University of Science and TechnologyChangchun130022China

Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg... 详细信息

关键词： alloys alloy corrosion

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MoS_(x)nanowire networks derived from[Mo_(3)S_(13)]^(2−)clusters for efficient electrocatalytic hydrogen evolution

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Nano Research 2024年第8期17卷 6910-6915页

作者： Haoxuan Yu Junan Pan Kang Chen Wang chao Zechao Zhuang Sizhuo feng Jianmei Chen Lingbin Xie Longlu Wang Qiang Zhao College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts and Telecommunications9 Wenyuan RoadNanjing 210023China Department of Chemical Engineering Columbia UniversityNew YorkNY 10027USA Institute of Advanced materials(IAM)&Institute of Flexible Electronics(Future Technology) Nanjing University of Posts and Telecommunications9 Wenyuan RoadNanjing 210023China

Precise design and synthesis of sub-nano scale catalysts with controllable electronic and geometric structures are pivotal for enhancing the hydrogen evolution reaction(HER)performance of molybdenum sulfide(MoS_(2))and unraveling its structure−activity *** leveraging transition molybdenum polysulfide clusters as functional units for multi-level ordering,we successfully designed and synthesized MoS_(x)nanowire networks derived from[Mo_(3)S_(13)]^(2−)clusters via evaporationinduced self-assembly,which exhibit enhanced HER activity attributed to a high density of active sites and dynamic evolution behavior under cathodic ***_(x)nanowire networks electrode yields a current density of 100 ma·cm^(−2)at 142 mV in 0.5 M H_(2)SO_(4).This work provides an attractive prospect for optimizing catalysts at the sub-nano scale and offers insights into a strategy for designing catalysts in various gas evolution reactions.

关键词： MoS_(x)nanowire networks [Mo_(3)S_(13)]^(2−)clusters hydrogen evolution reaction(HER) sub-nano scale

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Nitrogen-doped carbon dots as photocatalysts for organic synthesis:Effect of nitrogen content on catalytic activity

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Nano Research 2024年第6期17卷 4825-4833页

作者： Kai-Kai Niu chao-Qun ma Rui-Zhi Dong Hui Liu Sheng-Sheng Yu Ling-Bao Xing School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000China

Regulating the doping of carbon dots(CDs)and the generation of reactive oxygen species(ROS)is essential to selectively control their application in photocatalytic organic *** study successfully synthesized five newly developed nitrogen-doped carbon dots(CDs 1-5)with varying nitrogen content,which have the ability to generate ROS when exposed to light radiation,specifically superoxide anion radicals(O_(2)•-)and singlet oxygen(^(1)O_(2)).The utilization of the aforementioned nitrogen-doped CDs as photocatalysts enables the realization of their potential in facilitating efficient photocatalytic organic ***,it was observed that the photocatalytic efficiency exhibited a gradual decrease when the nitrogen content in the CDs *** order to provide more evidence for this claim,we employed a set of five CDs in the context of photocatalytic dehalogenation ofα-bromoacetophenone,photocatalytic oxidative coupling reaction of amines to imines,photooxidation reaction of sulfides to sulfoxides,and cross-dehydrogenation coupling(CDC)reaction,in which it was further observed that there was a steady decrease in the yields of photocatalytic organic reactions as the nitrogen content in CDs ***,CDs 1 exhibited the best photocatalytic efficiency,thereby reinforcing the hypothesis that a higher nitrogen content corresponds to a decreased catalytic *** study not only investigates the impact of the nitrogen content on the catalytic performance of CDs,but also offers valuable insights for the future utilization of CDs for photocatalytic organic reactions in water.

关键词： carbon dots nitrogen-doped reactive oxygen species photocatalysis

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Simulation design of thin film lithium niobate electro-optic modulator with bimetallic layer electrodes

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Optoelectronics Letters 2024年第6期20卷 339-345页

作者： WU Qiulin feng Xinkai CHEN Jiaying ma Lei CHEN Huaixi LIANG Wanguo Fujian Institute of Research on the Structure of matter Chinese Academy of SciencesFuzhou 350108China University of Chinese Academy of Sciences Beijing 100059China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China1

Thin-film lithium niobate electro-optical modulator will become the key device in the future optical communication,which has the advantages of high modulation rate,low half-wave voltage,large bandwidth,and easy integration compared with conventional bulk lithium niobate ***,because the electrode gap of the lithium niobate film modulator is very narrow,when the microwave frequency gets higher,it leads to higher microwave loss,and the electro-optical performance of the modulator will be greatly ***,we propose a thin film lithium niobate electro-optic modulator with a bimetallic layer electrode structure to achieve microwave loss less than 8 dB/cm in the range of 200 GHz,exhibiting a voltage-length product of 1.1 V·cm and a 3 dB electro-optic bandwidth greater than 160 ***-speed data transmission test has been performed,showing good performance.

关键词： Simulation design of thin film lithium niobate electro-optic modulator with bimetallic layer electrodes

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Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage

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National Science Review 2024年第4期11卷 195-205页

作者： Yanhua Wan Changyao Wang Xingmiao Zhang Yang Yin Mengmeng Liu Bing ma Linlin Duan Yuzhu ma Wei Zhang Changlin Zheng Dongliang chao Fei Wang Yongyao Xia Wei Li Department of Chemistry Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials State Key Laboratory of Molecular Engineering of Polymers College of Chemistry and Materials ScienceFudan University State Key Laboratory of Surface Physics and Department of Physics Fudan University

Due to their uncontrollable assembly and crystallization process,the synthesis of mesoporous metal oxide single crystals remains a formidable ***,we report the synthesis of single-crystal-like mesoporous Li2TiSiO5by using soft micelles as *** key lies in the atomic-scale self-assembly and step-crystallization processes,which ensure the formation of single-crystal-like mesoporous Li2TiSiO5microparticles via an oriented attachment growth mechanism under the confinement of an in-situ formed carbon *** mesoporous Li2TiSiO5anode achieves a superior rate capability(148 mah g-1at5.0 A g-1) and outstanding long-term cycling stability(138 mah g-1after 3000 cycles at 2.0 A g-1) for lithium storage as a result of the ultrafast Li+diffusion caused by penetrating mesochannels and nanosized crystal frameworks（5-10 nm）.In comparison,bulk Li2TiSiO5exhibits poor rate capability and cycle performance due to micron-scale diffusion *** method is very simple and reproducible,heralding a new way of designing and synthesizing mesoporous single crystals with controllable frameworks and chemical functionalities.

关键词： mesoporous materials micelles single-crystal-like Li2TiSiO5 lithium-ion batteries

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