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Cascaded ELM-Based Joint Frame Synchronization and Channel Estimation over Rician Fading Channel with Hardware Imperfections

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China Communications 2024年第6期21卷 87-102页

作者： Qing Chaojin Rao Chuangui yang na Tang Shuhai Wang Jiafan School of Electrical Engineering and Electronic Information Xihua UniversityChengdu 610039China

Due to the interdependency of frame synchronization(FS)and channel estimation(CE),joint FS and CE(JFSCE)schemes are proposed to enhance their functionalities and therefore boost the overall performance of wireless communication *** traditional JFSCE schemes alleviate the influence between FS and CE,they show deficiencies in dealing with hardware imperfection(HI)and deterministic line-of-sight(LOS)*** tackle this challenge,we proposed a cascaded ELM-based JFSCE to alleviate the influence of HI in the scenario of the Rician fading ***,the conventional JFSCE method is first employed to extract the initial features,and thus forms the non-Neural Network(NN)solutions for FS and CE,***,the ELMbased networks,named FS-NET and CE-NET,are cascaded to capture the NN solutions of FS and *** and analysis results show that,compared with the conventional JFSCE methods,the proposed cascaded ELM-based JFSCE significantly reduces the error probability of FS and the normalized mean square error(NMSE)of CE,even against the impacts of parameter variations.

关键词： channel estimation extreme learning machine frame synchronization hardware imperfection nonlinear distortion synchronization metric

Identification of in situ Generated Iron-Vacancy Induced Oxygen Evolution Reaction Kinetics on Cobalt Iron Oxyhydroxide

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Chinese Journal of Chemistry 2024年第4期42卷 343-350页

作者： na yao Juan Zhu Hongnan Jia Hengjiang Cong Wei Luo College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei430072 China

Developing highly efficient and low-cost electrocatalysts towards oxygen evolution reaction(OER)is essential for practical application in water electrolyzers and rechargeable metal-air *** Fe-based oxyhydroxides are regarded as state-of-the-art non-noble OER electrocatalysts,the origin of performance enhancement derived from Fe doping remains a hot topic of considerable ***,we demonstrate that in situ generated Fe vacancies in the pristine CoFeOOH catalyst through a pre-conversion process during alkaline OER result from dynamic Fe dissolution,identifying the origin of Fe-vacancy-induced enhanced OER *** functional theory(DFT)calculations and experimental results including X-ray absorption fine-structure spectroscopy,in situ UV-Vis spectroscopy,and in situ Raman spectroscopy reveal that the Fe vacancies could significantly promote the d-band center and valence states of adjacent Co sites,alter the active site from Fe atom to Co atom,accelerate the formation of high-valent active Co^(4+)species,and reduce the energy barrier of the potential-determining step,thereby contribute to the significantly enhanced OER performance.

关键词： CoFe oxyhydroxide Oxygen evolution reaction Fe vacancy Electrocatalysis Kinetics Reaction mechanisms

Unveiling the performance of a novel alkalizing bacterium Enterobacter ***-2 in immobilization of available Cd

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Journal of Environmental Sciences 2024年第3期137卷 245-257页

作者： Yixin Luo Min Liao Xiongxiong Lu na Xu Xiaomei Xie Weiming Gao College of Environmental and Resource Science Zhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Hangzhou 310058China national Demonstration Center for Experimental Environmental and Resources Education Zhejiang UniversityHangzhou 310058China

A novel alkalizing strain Enterobacter ***-2 that could resist 400 mg/L Cd was isolated from Cd-contaminated soil,which immobilized 96.05%Cd^(2+)from *** distribution analysis demonstrated that more than half of the Cd^(2+)was converted into extracellular precipitated Cd through mobilization of the alkali-producing mechanism by the strain LYX-2,achieving the high immobilization efficiency of Cd^(2+).Biosorption experiments revealed that strain LYX-2 had superior biosorption capacity of 48.28 mg/g for *** experiments with Brassica rapa *** performed with and without strain *** to control,15.92%bioavailable Cd was converted to non-bioavailable Cd and Cd content in aboveground vegetables was decreased by 37.10%with addition of strain *** Cd was mainly immobilized through extracellular precipitation,cell-surface biosorption and intracellular accumulation of strain LYX-2,which was investigated through Cd distribution,Scanning Electron Microscope and Energy-Dispersive X-ray Spectroscopy(SEM-EDS),Fourier Transform Infrared Spectroscopy(FT-IR),X-ray Photoelectron Spectroscopy(XPS)and Transmission Electron Microscopy(TEM)*** addition,the application of strain LYX-2 significantly promoted the growth of vegetables about *** results indicated that highly Cd-resistant alkalizing strain LYX-2,as a novel microbial passivator,had excellent ability and reuse value to achieve the remediation of Cd-contaminated soil coupled with safe production of vegetables simultaneously.

关键词： Cadmium Enterobacter sp.LYX-2 Cd Immobilization Microbial passivator

Multimodal Fusion of Brain Imaging Data: Methods and Applications

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Machine Intelligence Research 2024年第1期21卷 136-152页

作者： na Luo Weiyang Shi Zhengyi yang Ming Song Tianzi Jiang Brainnetome Center and national Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Center for Excellence in Brain Science and Intelligence Technology Institute of AutomationChinese Academy of SciencesBeijing 100190China Research Center for Augmented Intelligence Zhejiang LaboratoryHangzhou 311100China

Neuroimaging data typically include multiple modalities,such as structural or functional magnetic resonance imaging,dif-fusion tensor imaging,and positron emission tomography,which provide multiple views for observing and analyzing the *** lever-age the complementary representations of different modalities,multimodal fusion is consequently needed to dig out both inter-modality and intra-modality *** the exploited rich information,it is becoming popular to combine multiple modality data to ex-plore the structural and functional characteristics of the brain in both health and disease *** this paper,we first review a wide spectrum of advanced machine learning methodologies for fusing multimodal brain imaging data,broadly categorized into unsupervised and supervised learning *** by this,some representative applications are discussed,including how they help to under-stand the brain arealization,how they improve the prediction of behavioral phenotypes and brain aging,and how they accelerate the biomarker exploration of brain ***,we discuss some exciting emerging trends and important future ***,we intend to offer a comprehensive overview of brain imaging fusion methods and their successful applications,along with the chal-lenges imposed by multi-scale and big data,which arises an urgent demand on developing new models and platforms.

关键词： Multimodal fusion supervised learning unsupervised learning brain atlas cognition brain disorders

Interfacial growth of N,S-codoped mesoporous carbon onto biomass-derived carbon for superior potassium-ion storage

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nano Research 2024年第4期17卷 2619-2627页

作者： na Huang Cheng Tang Hao Jiang Jie Sun Aijun Du Haijiao Zhang Institute of nanochemistry and nanobiology School of Environmental and Chemical EngineeringShanghai UniversityShanghai 200444China School of Chemistry and Physics and Centre for Materials Science Queensland University of TechnologyBrisbaneQLD 4001Australia Shanghai Engineering Research Center of Hierarchical nanomaterials Frontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

Carbonaceous materials have been recognized as one of the most promising anode materials for potassium-ion batteries(PIBs)due to their abundant raw materials,controllable structure,superior conductivity,and good chemical ***,the large radius of K ions and the low potassium content of intercalation compounds result in the sluggish storage kinetics and low reversible capacity of carbon *** this work,we present a unique heteroatom-doped carbon composite(denoted as NS-MC/SC)through a facile interfacial assembly route and simple heat-treatment process,where NS-MC is well grafted onto the biomass-derived spore carbon(SC).This unique structural design endows it with abundant mesoporous channels,expanded layer spacing,and highly doped N and *** these merits,the NS-MC/SC anode in PIBs exhibits a high reversible capacity of 350.4 mAh·g^(-1) at 100 mA·g^(-1) after 300 cycles,and an outstanding cycling ***,in-situ Raman spectra further verify the high reversibility of K ions insertion/***,theoretical simulations also reveal that the N,S dual-doping is an efficient approach for improving the potassium-ion storage performance of NS-MC/SC.

关键词： mesoporous carbon(MC) biomass-derived carbon(BC) N S co-doping interfacial assembly potassium-ion batteries(PIBs)

Investigation of granite failure precursor under axial load using modified LSTM framework

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Journal of Central South University 2024年第8期31卷 2930-2943页

作者： Wang, ya-lei Xu, Jin-ming Department of Civil Engineering Shanghai University Shanghai China

Granite is usually composed of quartz, biotite, feldspar, and cracks, and the variation characteristics of these components could reflect the deformation and failure process of rock well. Taking granite as an example, the video camera was used to record the deformation and failure process of rock. The distribution of meso-components in video images was then identified. The meso-components of rock failure precursors were also discussed. Moreover, a modified LSTM (long short-term memory method) based on SSA (sparrow search algorithm) was proposed to estimate the change of meso-components of rock failure precursor. It shows that the initiation and expansion of cracks are mainly caused by feldspar and quartz fracture, and when the quartz and feldspar exit the stress framework, rock failure occurs; the second large increase of crack area and the second large decrease of quartz or feldspar area may be used as a precursor of rock failure; the precursor time of rock failure based on meso-scopic components is about 4 s earlier than that observed by the naked eye; the modified LSTM network has the strongest estimation ability for quartz area change, followed by feldspar and biotite, and has the worst estimation ability for cracks; when using the modified LSTM network to predict the precursors of rock instability and failure, quartz and feldspar could be given priority. The results presented herein may provide reference in the investigation of rock failure mechanism.

关键词： axial load failure precursor granite modified long short-term memory method

The Adjustment Analysis Method of the Active Surface Antenna Based on Convolutional Neural Network

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Research in Astronomy and Astrophysics 2024年第6期24卷 294-306页

作者： You Ban Shang Shi na Wang Qian Xu Shufei Feng School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Active surface technique is one of the key technologies to ensure the reflector accuracy of the millimeter/submillimeter wave large reflector *** antenna is complex,large-scale,and high-precision equipment,and its active surfaces are affected by various factors that are difficult to comprehensively deal *** this paper,based on the advantage of the deep learning method that can be improved through data learning,we propose the active adjustment value analysis method of large reflector antenna based on deep *** method constructs a neural network model for antenna active adjustment analysis in view of the fact that a large reflector antenna consists of multiple panels spliced *** on the constraint that a single actuator has to support multiple panels(usually 4),an autonomously learned neural network emphasis layer module is designed to enhance the adaptability of the active adjustment neural network *** classical 8-meter antenna is used as a case study,the actuators have a mean adjustment error of 0.00252 mm,and the corresponding antenna surface error is0.00523 *** active adjustment result shows the effectiveness of the method in this paper.

关键词： techniques:radar astronomy telescopes methods:analytical methods:numerical

Bilayer borophene:an efficient catalyst for hydrogen evolution reaction

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 13-23页

作者： na Xing nan Gao Panbin Ye Xiaowei yang Haifeng Wang Jijun Zhao College of Sciences/Xinjiang Production&Construction Corps Key Laboratory of Advanced Energy Storage Materials and Technologies Shihezi UniversityShihezi832000China Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Ministry of Education)Dalian University of TechnologyDalian116024China School of Materials Science and Engineering Taizhou UniversityTaizhou318000China

The electrocatalytic hydrogen evolution reaction is a crucial technique for green hydrogen ***,finding affordable,stable,and efficient catalyst materials to replace noble metal catalysts remains a significant *** experimental breakthroughs in the synthesis of two-dimensional bilayer borophene provide a theoretical framework for exploring their physical and chemical *** this study,we systematically considered nine types of bilayer borophenes as potential electrocatalysts for the hydrogen evolution *** first-principles calculations revealed that bilayer borophenes exhibit high stability and excellent conductivity,possessing a relatively large specific surface area with abundant active *** surface boron atoms and the bridge sites between two boron atoms can serve as active sites,displaying high activity for the hydrogen evolution ***,the Gibbs free energy change associated with adsorption for these bilayer borophenes can reach as low as−0.002 eV,and the Tafel reaction energy barriers are lower(0.70 eV)than those on ***,the hydrogen evolution reaction activity of these two-dimensional bilayer borophenes can be described by engineering their work ***,we considered the effect of pH on hydrogen evolution reaction activity,with significant activity observed in an acidic *** theoretical results reveal the excellent catalytic performance of two-dimensional bilayer borophenes and provide crucial guidance for the experimental exploration of multilayer boron for various energy applications.

关键词： bilayer borophene hydrogen evolution reaction work function pH effect

Poverty Volatility and Tax Revenue Instability in Developing Countries

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Fudan Journal of the Humanities and Social Sciences 2024年第2期17卷 279-311页

作者： Sèna Kimm Gnangnon World Trade Organization Rue de Lausanne 154CH-1211Geneva 21Switzerland

This paper complements the relatively few existing studies on the macroeconomic effects of poverty in developing countries, by investigating the effect of poverty volatility on tax revenue instability. The empirical analysis has been conducted using an unbalanced panel dataset of 97 developing countries covering the period of 1980–2017 and primarily the two-step system generalized method of moments estimator. Findings have revealed that least developed countries tend to experience a positive tax revenue instability effect of poverty volatility, while poverty volatility results in lower tax revenue instability in relatively advanced countries. Additionally, poverty volatility dampens the instability of tax revenue when poverty rates are low, and enhances it when countries face a greater extent of external shocks. From a policy perspective, this analysis shows that it would be essential for policymakers to dampen the volatility of poverty rates (notably in countries with high poverty rates) if they were to ensure the stability of tax revenue or reduce its instability, given the adverse effect of tax revenue instability on economic growth.

关键词： Poverty volatility Poverty rates External shocks Tax revenue instability