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Sources appointment and health risks of PM_(2.5)-bound trace elements in a coastal city of southeastern China

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Journal of Environmental Sciences 2024年第4期138卷 561-571页

作者： Ziyi Lin Xiaolong Fan Gaojie chen Youwei hong Mengren Li Lingling Xu Baoye Hu chen Yang Yanting chen Zhiqian Shao Jinsheng chen Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy ofSciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Minnan Normal University Zhangzhou 363000China

To gain a comprehensive understanding of sources and health risks of trace elements in an area of China with high population densities and low PM_(2.5)concentrations,15 trace elements(Al,K,Ca,Ti,V,Cr,Mn,Fe,Ni,Cu,Zn,As,Sn,Ba,Pb)in PM_(2.5)were monitored from December 2020 to November 2021 in a representative city,*** concentrations of trace elements in Xiamen displayed an obvious seasonal variation and were dominated by K,Fe,Al,Ca and *** on Positive Matrix Factorization analysis,source appointment revealed that the major sources of trace elements in Xiamen were traffic,dust,biomass and firework combustion,industrial manufacture and shipping *** to health risk assessment combined with the source appointment results,it indicated that the average noncarcinogenic risk was below the threshold and cancer risk of four hazardous metals(Cr,Ni,As,Pb)exceeded the threshold(10^(-6)).Traffic-related source had almost half amount of contribution to the health risk induced by PM_(2.5)-bound trace *** the dust transport period or Spring Festival period,the health risks exceeded an acceptable threshold even an order of magnitude higher,suggesting that the serious health risks still existed in low PM_(2.5)environment at certain *** risk assessment reminded that the health risk reduction in PM_(2.5)at southeastern China should prioritize traffic-related hazardous trace elements and highlighted the importance of controlling vehicles emissions in the future.

关键词： PM_(2.5)-bound trace elements Seasonal variations Source appointment Health risks Traffic-related source

Harmonic State Space Based Impedance Modeling and Virtual Impedance Based Stability Enhancement Control for LCC-HVDC Systems

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 287-298页

作者： Yifeng Liu Xiaoping Zhou Quan chen Hanhang Yin Lerong hong Hao Tian Ying chen Siyuan Li the College of Electrical and Information Engineering Hunan UniversityChangsha 410082China the Zhejiang Magtron Intelligent Technology Limited Cooperation Jiaxing 314000China the State Grid Qianjiang Electric Power Company Qianjiang 433100China

Line commutated converter based high-voltage direct-current(LCC-HVDC)transmissions are prone to harmonic oscillation under weak *** modeling is an effective method for assessing interaction ***,this paper proposes an improved calculation method for the DC voltage and AC currents of commutation stations to address the complex linearization of the commutation process and constructs an overall harmonic state-space(HSS)model of an *** on the HSS model,the closed-loop AC impedances on the LCC-HVDC sending and receiving ends are then derived and *** impedance characteristics of the LCC-HVDC are then analyzed to provide a physical explanation for the harmonic oscillation of the *** effects of the grid strength and control parameters on system stability are also *** improve the impedance characteristics and operating stability of the LCC-HVDC system,a virtual impedance based stability enhancement control is proposed,and a parameter design method is considered to ensure satisfactory phase margins at both the sending and receiving ***,simulation results are presented to verify the validity of the impedance model and virtual impedance based stability enhancement control.

关键词： Line commutated converter based high-voltage direct-current(LCC-HVDC)transmission harmonic state space stability analysis harmonic oscillation virtual impedance

A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

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Science China Chemistry 2024年第3期67卷 862-868页

作者： Shi-Yi Liu Xue-Xin Li Wei-Chao chen kui-Zhan Shao Xin-Long Wang Chao Qin Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction *** we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton ***,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting *** result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

Enhancing cut selection through reinforcement learning

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Science China Mathematics 2024年第6期67卷 1377-1394页

作者： Shengchao Wang Liang chen Lingfeng Niu Yu-hong Dai Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China Research Center on Fictitious Economy and Data Science Chinese Academy of SciencesBeijing100190China

With the rapid development of artificial intelligence in recent years,applying various learning techniques to solve mixed-integer linear programming(MILP)problems has emerged as a burgeoning research *** from constructing end-to-end models directly,integrating learning approaches with some modules in the traditional methods for solving MILPs is also a promising *** cutting plane method is one of the fundamental algorithms used in modern MILP solvers,and the selection of appropriate cuts from the candidate cuts subset is crucial for enhancing *** to the reliance on expert knowledge and problem-specific heuristics,classical cut selection methods are not always transferable and often limit the scalability and generalizability of the cutting plane *** provide a more efficient and generalizable strategy,we propose a reinforcement learning(RL)framework to enhance cut selection in the solving process of ***,we design feature vectors to incorporate the inherent properties of MILP and computational information from the solver and represent MILP instances as bipartite ***,we choose the weighted metrics to approximate the proximity of feasible solutions to the convex hull and utilize the learning method to determine the weights assigned to each ***,a graph convolutional neural network is adopted with a self-attention mechanism to predict the value of weighting ***,we transform the cut selection process into a Markov decision process and utilize RL method to train the *** experiments are conducted based on a leading open-source MILP solver *** on both general and specific datasets validate the effectiveness and efficiency of our proposed approach.

关键词： reinforcement learning mixed-integer linear programming cutting plane method cut selection

Extreme value theory applied to the auroral electrojet indices

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Earth and Planetary Physics 2024年第2期8卷 375-381页

作者： Si chen hong Yuan Yong Wei Guang Yang FengZheng Yu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The study of extreme weather and space events has gained paramount importance in modern society owing to rapid advances in high *** and describing exceptional occurrences plays a crucial role in making decisive assessments of their potential impact on technical,economic,and social aspects in various *** research focuses on analyzing the hourly values of the auroral electrojet(AE)geomagnetic index from 1957 to 2019 by using the peak over threshold method in extreme value *** fitting the generalized Pareto distribution to extreme AE values,shape parameter indices were derived,revealing negative values that establish an upper bound for this time ***,it became evident that the AE values had reached a plateau,suggesting that extreme events exceeding the established upper limit are *** a result,although the need for diligent precautions to mitigate the consequences of such extreme events persists,surpassing the upper limit of AE values becomes increasingly *** is also possible to observe an aurora in the middle-and low-latitude regions during the maximum period of the AE index.

关键词： auroral electrojet indices extreme value theory extreme events

Unsteady aerodynamic noise prediction of contra-rotating open rotor using meshless method

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Chinese Journal of Aeronautics 2024年第8期37卷 144-165页

作者： Zhiliang hong Meng SU Haitao ZHANG Zerui XU Lin DU Lingfeng chen College of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China Civil Aviation Administration of China Beijing 100710China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

The Contra-Rotating Open Rotor(CROR)design confronts significant noise challenges despite being one of the possible options for future green *** efficiently estimate the noise emitted from a CROR,a three-dimensional unsteady prediction model based on the meshless method is *** unsteady wake flow and the aerodynamic load fluctuations on the blade are solved through the viscous vortex particle method,the blade element momentum theory and vortex lattice ***,the acoustic field is obtained through the Farassat’s formulation *** of this method is conducted on a CROR,and a mesh-based method,e.g.,Nonlinear Harmonic(NLH)method,is also employed for *** is found that the presented method is three times faster than NLH method while maintaining a comparable precision.A thorough parametric analysis is also carried out to illustrate the effects of rotational speed,rotor-rotor spacing and rear rotor diameter on the noise *** rotor speed is found to be the most influencing factor,and by optimizing the speed difference between the front and rear rotors,a notable noise reduction can be *** current findings not only contribute to a deeper comprehension of the CROR’s aeroacoustic properties but also offer an effective tool for engineering applications.

关键词： Contra-Rotating Open Rotor(CROR) Aerodynamic noise Blade element momentum theory Viscosity vortex particle method Farassat’s formulation 1A

Hydrogen-rich water alleviates constipation by attenuating oxidative stress through the sirtuin1/nuclear factor-erythroid-2-related factor 2/heme oxygenase-1 signaling pathway

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World Journal of Gastroenterology 2024年第20期30卷 2709-2725页

作者： Kai-Di chen kui-Ling Wang chen chen Yi-Jia Zhu Wen-Wen Tang Yu-Ji Wang Ze-Peng chen Lin-Hai He Yu-Gen chen Wei Zhang Jiangsu Province Hospital of Chinese Medicine The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina The No.1 Clinical Medical College Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Department of Colorectal Surgery Jiangsu Province Hospital of Chinese MedicineThe Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Jiangsu Province Key Laboratory of Tumor Systems Biology and Chinese Medicine The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Jiangsu Collaborative Innovation Center of Chinese Medicine in Prevention and Treatment of Tumor The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina

BACKGROUND Constipation,a highly prevalent functional gastrointestinal disorder,induces a significant burden on the quality of patients'life and is associated with substantial healthcare ***,identifying efficient therapeutic modalities for constipation is of paramount *** stress is a pivotal contributor to colonic dysmotility and is the underlying pathology responsible for constipation ***,we postulate that hydrogen therapy,an emerging and promising intervention,can serve as a safe and efficacious treatment for *** To determine whether hydrogen-rich water(HRW)alleviates constipation and its potential *** Constipation models were established by orally loperamide to Sprague-Dawley *** freely consumed HRW,and were recorded their 24 h total stool weight,fecal water content,and charcoal propulsion *** samples were subjected to 16S rDNA gene *** non-targeted metabolomic analysis,malondialdehyde,and superoxide dismutase levels were *** tissues were stained with hematoxylin and eosin,Alcian blue-periodic acid-Schiff,reactive oxygen species(ROS)immunofluorescence,and immunohistochemistry for cell growth factor receptor kit(c-kit),PGP 9.5,sirtuin1(SIRT1),nuclear factor-erythroid-2-related factor 2(Nrf2),and heme oxygenase-1(HO-1).Quantitative real-time PCR and western blot analysis were conducted to determine the expression level of SIRT1,Nrf2 and HO-1.A rescue experiment was conducted by intraperitoneally injecting the SIRT1 inhibitor,EX527,into constipated ***460 cells were induced with H2O2 and treated with the metabolites to evaluate ROS and SIRT1 *** HRW alleviated constipation symptoms by improving the total amount of stool over 24 h,fecal water content,charcoal propulsion rate,thickness of the intestinal mucus layer,c-kit expression,and the number of intestinal *** modulated intestinal microbiota imbalance and abnormaliti

关键词： Hydrogen-rich water Constipation Sirtuin1 Oxidative stress Gut microbiota Serum metabolites

PEPFL:A framework for a practical and efficient privacy-preserving federated learning

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Digital Communications and Networks 2024年第2期10卷 355-368页

作者： Yange chen Baocang Wang Hang Jiang Pu Duan Yuan Ping Zhiyong hong State Key Laboratory of Integrated Service Networks Xidian UniversityXi'an710071China School of Information Engineering Xuchang UniversityXuchang461000China School of Telecommunications Engineering Xidian UniversityXi'an710071China Secure Collaborative Intelligence Laboratory Ant GroupHangzhou310000China Facility of Intelligence Manufacture Wuyi UniversityJiangmen529020China

As an emerging joint learning model,federated learning is a promising way to combine model parameters of different users for training and inference without collecting users’original ***,a practical and efficient solution has not been established in previous work due to the absence of efficient matrix computation and cryptography schemes in the privacy-preserving federated learning model,especially in partially homomorphic *** this paper,we propose a Practical and Efficient Privacy-preserving Federated Learning(PEPFL)***,we present a lifted distributed ElGamal cryptosystem for federated learning,which can solve the multi-key problem in federated ***,we develop a Practical Partially Single Instruction Multiple Data(PSIMD)parallelism scheme that can encode a plaintext matrix into single plaintext for encryption,improving the encryption efficiency and reducing the communication cost in partially homomorphic *** addition,based on the Convolutional Neural Network(CNN)and the designed cryptosystem,a novel privacy-preserving federated learning framework is designed by using Momentum Gradient Descent(MGD).Finally,we evaluate the security and performance of *** experiment results demonstrate that the scheme is practicable,effective,and secure with low communication and computation costs.

关键词： Federated learning Partially single instruction multiple data Momentum gradient descent ElGamal Multi-key Homomorphic encryption

Ionically Imprinting-Based Copper(Ⅱ)Label-Free Detection for Preventing Hearing Loss

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Engineering 2024年第2期33卷 276-282页

作者： Huan Wang Hui Zhang Xiaoli Zhang hong chen Ling Lu Renjie Chai The Eighth Affiliated Hospital Sun Yat-Sen UniversityShenzhen 518033China State Key Laboratory of Digital Medical Engineering Department of Otolaryngology Head and Neck SurgeryZhongda Hospital&Advanced Institute for Life and HealthSoutheast UniversityNanjing 210096China Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging Department of Biomedical EngineeringShenzhen UniversityShenzhen 518060China Department of Otolaryngology Head and Neck Surgery Jiangsu Provincial Key Medical DisciplineNanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008China Co-Innovation Center of Neuroregeneration Nantong UniversityNantong 226001China Department of Otolaryngology Head and Neck Surgery Sichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengdu 610072China Institute for Stem Cell and Regeneration Chinese Academy of ScienceBeijing 100101China Beijing Key Laboratory of Neural Regeneration and Repair Capital Medical UniversityBeijing 100069China

Copper is a microelement with important physiological functions in the ***,the excess copper ion(Cu^(2+))may cause severe health problems,such as hair cell apoptosis and the resultant hearing ***,the assay of Cu^(2+)is *** integrate ionic imprinting technology(IIT)and structurally colored hydrogel beads to prepare chitosan-based ionically imprinted hydrogel beads(IIHBs)as a low-cost and high-specificity platform for Cu^(2+)*** IIHBs have a macroporous microstructure,uniform size,vivid structural color,and magnetic *** incubated in solution,IIHBs recognize Cu^(2+)and exhibit a reflective peak change,thereby achieving label-free *** addition,benefiting from the IIT,the IIHBs display good specificity and selectivity and have an imprinting factor of 19.14 at 100μmol·L^(-1).These features indicated that the developed IIHBs are promising candidates for Cu^(2+)detection,particularly for the prevention of hearing loss.

关键词： Structural color Microfluidics Ionic imprinting Label-free detection Hearing loss