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Construction of Cu-Zn Co-doped layered materials for sodium-ion batteries with high cycle stability

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Chinese Chemical Letters 2024年第5期35卷 441-446页

作者： Xiping Dong Xuan Wang Zhixiu Lu Qinhao Shi Zhengyi Yang Xuan yu Wuliang feng Xingli Zou Yang Liu yufeng zhao Institute for Sustainable Energy&College of Sciences Shanghai UniversityShanghai 200444China Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province Yancheng Institute of TechnologyYancheng 224051China State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

Due to its high operational voltage and energy density,P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) has become a leading cathode material for sodium-ion batteries(SIBs),which is an ideal option for large-scale energy storage.However,the practical application of P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2) is limited by the capacity constraints and unwanted phase transitions,presenting significant challenges to the widespread application of SIBs.To address these challenges and optimize the electrochemical properties of the P2 phase cathode material,this study proposes a Cu and Zn co-doped strategy to improve the electrochemical performance.The incorporation of Cu/Zn can stabilize the P2-phase structure against P2-O2 phase transitions,thus enhancing its electrochemical properties.The as-obtained P2-type Na0.67[Ni_(0.3)Mn_(0.58)Cu_(0.09)Zn_(0.03)]O_(2) cathode material shows an impressive cycling stability,maintaining 80%capacity retention after 1000 cycles at 2 C.The cyclic voltammetry(CV)tests show that the Cu^(2+)/Cu^(3+)redox reaction is also involved in charge compensation during the charge/discharge process.

关键词： Sodium-ion batteries Cathode material Cycle performance Cu/Zn co-doped P2-type Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)

Suppression of multistep phase transitions of O3-type cathode for sodium-ion batteries

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Chinese Chemical Letters 2024年第5期35卷 453-458页

作者： Shengyu zhao Qinhao Shi Wuliang feng Yang Liu Xinxin Yang Xingli Zou Xionggang Lu yufeng zhao Institute for Sustainable Energy&College of Sciences Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

O3-type layered oxide cathodes have been widely investigated due to their high reversible capacities and sufficient Na+reservoirs.However,such materials usually suffer from complex multistep phase transitions along with drastic volume changes,leading to the unsatisfied cycle performance.Herein,we report a Mg/Ti co-doped O3-type NaNi_(0.5)Mn_(0.5)O_(2),which can effectively suppress the complex multistep phase transition and realize a solid-solution reaction within a wide voltage range.It is confirmed that,the Mg/Ti co-doping is beneficial to enhance the structural stability and integrity by absorbing micro-strain and distortions.Thus,the as obtained sample delivers an outstanding cyclic performance(82.3%after 200 cycles at 1 C)in the voltage range of 2.0-4.0 V,and a high discharge capacity of 86.6 mAh/g after 100 cycles within the wide voltage range(2.0-4.5 V),which outperform the existing literatures.This co-doping strategy offers new insights into high performance O3-type cathode for sodium ion batteries.

关键词： Sodium ion batteries Mg/Ti co-doping Phase transition Cyclic performance High voltage performance

Sound event localization and detection based on deep learning

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Journal of Systems Engineering and Electronics 2024年第2期35卷 294-301页

作者： zhao Dada DING Kai QI Xiaogang CHEN yu feng Hailin School of Mathematics and Statistics Xidian UniversityXi’an 710071China Science and Technology on Near-Surface Detection Laboratory Wuxi 214035China

Acoustic source localization(ASL)and sound event detection(SED)are two widely pursued independent research fields.In recent years,in order to achieve a more complete spatial and temporal representation of sound field,sound event localization and detection(SELD)has become a very active research topic.This paper presents a deep learning-based multioverlapping sound event localization and detection algorithm in three-dimensional space.Log-Mel spectrum and generalized cross-correlation spectrum are joined together in channel dimension as input features.These features are classified and regressed in parallel after training by a neural network to obtain sound recognition and localization results respectively.The channel attention mechanism is also introduced in the network to selectively enhance the features containing essential information and suppress the useless features.Finally,a thourough comparison confirms the efficiency and effectiveness of the proposed SELD algorithm.Field experiments show that the proposed algorithm is robust to reverberation and environment and can achieve higher recognition and localization accuracy compared with the baseline method.

关键词： sound event localization and detection(SELD) deep learning convolutional recursive neural network(CRNN) channel attention mechanism

Caseinolytic mitochondrial matrix peptidase X is essential for homologous chromosome synapsis and recombination during meiosis of male mouse germ cells

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Asian Journal of Andrology 2024年第2期26卷 165-174页

作者： Hai-Wei feng yu zhao Yan-Ling Gao Dong-Teng Liu Li-Jun Huo Key Laboratory of Agricultural Animal Genetics Breeding and ReproductionEducation Ministry of ChinaCollege of Animal Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China Shenzhen Key Laboratory of Fertility Regulation Reproductive Medicine CenterThe University of Hong Kong-Shenzhen HospitalShenzhen 518053China Maternal-Fetal Medicine Institute Department of Obstetrics and GynaecologyShenzhen Baoan Women's and Children's HospitalJinan UniversityShenzhen 518100China Department of Obstetrics and Gynaecology Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong SARChina

Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various proteins.The mitochondrial protease complex(ClpXP),which consists of caseinolytic mitochondrial matrix peptidase X(ClpX)and caseinolytic protease P(ClpP)and mediates the degradation of misfolded,damaged,and oxidized proteins,is essential for maintaining mitochondrial homeostasis.ClpXP has been implicated in meiosis regulation,but its precise role is currently unknown.In this study,we engineered an inducible male germ cell-specific knockout caseinolytic mitochondrial matrix peptidase X(Clpx^(cKO))mouse model to investigate the function of ClpX in meiosis.We found that disrupting Clpx in male mice induced germ cell apoptosis and led to an absence of sperm in the epididymis.Specifically,it caused asynapsis of homologous chromosomes and impaired meiotic recombination,resulting in meiotic arrest in the zygotene-to-pachytene transition phase.The loss of ClpX compromised the double-strand break(DSB)repair machinery by markedly reducing the recruitment of DNA repair protein RAD51 homolog 1(RAD51)to DSB sites.This dysfunction may be due to an insufficient supply of energy from the aberrant mitochondria in Clpx^(cKO) spermatocytes,as discerned by electron microscopy.Furthermore,ubiquitination signals on chromosomes and the expression of oxidative phosphorylation subunits were both significantly attenuated in Clpx^(cKO) spermatocytes.Taken together,we propose that ClpX is essential for maintaining mitochondrial protein homeostasis and ensuring homologous chromosome pairing,synapsis,and recombination in spermatocytes during meiotic prophase I.

关键词： ClpX homologous chromosome meiosis mitochondrial recombination synapsis

Parameter optimization and experiment of the negative pressure precision seed-metering device for wheat

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 154-162页

作者： yubo feng Xiaoshun zhao Jincai Li Huali yu Hongpeng zhao Baozhong Yin State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001HebeiChina College of Mechanical and Electrical Engineering Hebei Agricultural UniversityBaoding 071001HebeiChina College of Plant Protection Hebei Agricultural UniversityBaoding 071001HebeiChina

In order to ensure the most reasonable distribution of wheat seeds in the field to improve seeding quality and uniformity,a set of negative pressure precision seed-metering device was designed,which shares a hollow shaft.Every seed-metering device can sow two rows of wheat.By the STAR-CCM+,the analysis of nephogram,vectogram and streamline graph showed that more ideal structural parameters of the seed-metering device are 0.5 mm width of the slit sucking seed(WSS),150-200 mm diameter of the seed-metering disc(DSD),2.0 mm axial depth of air chamber in the seed-metering disc(ADS),and arc-shaped cross-section shape of the ring groove sucking seed(CSGS).Single-factor test on the JPS-12 test-bed analyzed the influence of the CSGS,WSS,DSD,and ADS on the qualified index(Iq),multiple index(Imul),miss index(Imiss)and coefficient of variation of qualified seed spacing(CV).Through the orthogonal on the JPS-12 test-bed,it is found that the influence of vacuum negative pressure and seed-metering device shaft speed is significant on the Iq,Imiss and Imul.Based on these,the structural parameters of the seed-metering device were optimized.The DSD is 180 mm,the WSS is 0.7 mm,the ADS is 2.5 mm,and the CSGS is arc-shaped.The optimization seed-metering device was tested on the JPS-12 test-bed.The Iq is 86.66%,the Imiss is 5.09%,the Imul is 8.25%,and the CV is 24.50%.These testing results fully coincide with the standard JB/T 10293-2013 Specifications of single seed drill(precision drill).The seed-metering device meets fully the requirements for wheat precision seeding.

关键词： wheat seed-metering device negative pressure precision parameter optimization STAR-CCM+ orthogonal test variance analysis

STGNN-LMR:A Spatial–Temporal Graph Neural Network Approach Based on sEMG Lower Limb Motion Recognition

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Journal of Bionic Engineering 2024年第1期21卷 256-269页

作者： Weifan Mao Bin Ma zhao Li Jianxing Zhang Yizhou Lu Zhuting yu feng Zhang Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 101408China University of Science and Technology of China Hefei 230026China Shanghai Zhongyan Jiuyi Technology Co. Ltd.Shanghai 201821China Academy of Military Science Bejing 100091China

Lower limb motion recognition techniques commonly employ Surface Electromyographic Signal(sEMG)as input and apply a machine learning classifier or Back Propagation Neural Network(BPNN)for classification.However,this artificial feature engineering technique is not generalizable to similar tasks and is heavily reliant on the researcher’s subject expertise.In contrast,neural networks such as Convolutional Neural Network(CNN)and Long Short-term Memory Neural Network(LSTM)can automatically extract features,providing a more generalized and adaptable approach to lower limb motion recognition.Although this approach overcomes the limitations of human feature engineering,it may ignore the potential correlation among the sEMG channels.This paper proposes a spatial–temporal graph neural network model,STGNN-LMR,designed to address the problem of recognizing lower limb motion from multi-channel sEMG.STGNN-LMR transforms multi-channel sEMG into a graph structure and uses graph learning to model spatial–temporal features.An 8-channel sEMG dataset is constructed for the experimental stage,and the results show that the STGNN-LMR model achieves a recognition accuracy of 99.71%.Moreover,this paper simulates two unexpected scenarios,including sEMG sensors affected by sweat noise and sudden failure,and evaluates the testing results using hypothesis testing.According to the experimental results,the STGNN-LMR model exhibits a significant advantage over the control models in noise scenarios and failure scenarios.These experimental results confirm the effectiveness of the STGNN-LMR model for addressing the challenges associated with sEMG-based lower limb motion recognition in practical scenarios.

关键词： Lower limb motion recognition Exoskeleton sEMG.Graph neural network Noise Sensor failure

H-and J-aggregation of conjugated small molecules in organic solar cells

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Journal of Energy Chemistry 2024年第6期93卷 174-192,I0005页

作者： Qiaoqiao zhao feng He State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan 250353ShangdongChina Shenzhen Grubbs Institute and Department of Chemistry Southern University of Science and TechnologyShenzhen 518055GuangdongChina Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055GuangdongChina

As H-and J-aggregation receive more and more attention in the research of organic solar cells(OSCs),especially in small molecular systems,deep understanding of aggregation behavior is needed to guide the design of conjugated small molecular structure and the fabrication process of OSC device.For this end,this review is written.Here,the review firstly introduced the basic information about H-and J-aggregation of conjugated small molecules in OSCs.Then,the characteristics of H-and J-aggregation and the methods to identify them were summarized.Next,it reviewed the research progress of H-and J-aggregation of conjugated small molecules in OSCs,including the factors influencing H-and J-aggregation in thin film and the effects of H-and J-aggregation on OPV performance.

关键词： H-aggregation J-aggregation Organic solar cells Small molecules Efficiency Stability

Frequency Domain Fatigue Evaluation on SCR Girth-Weld Based on Structural Stress

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China Ocean Engineering 2024年第2期38卷 255-270页

作者： ZHANG Long zhao Tian-feng College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing 102249China

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating platform.The harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue failure.The structural stress fatigue theory and Master S-N curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue evaluation.Here,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural stress.Besides,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into account.The research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

关键词： SCR girth weld random vibration self(cross)power spectrum structural stress method biaxial fatigue damage

Synergy between CSST galaxy survey and gravitational-wave observation: Inferring the Hubble constant from dark standard sirens

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 7-19页

作者： Ji-yu Song Ling-feng Wang Yichao Li Ze-Wei zhao Jing-Fei Zhang Wen zhao Xin Zhang Key Laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China CAS Key Laboratory for Researches in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaChinese Academy of SciencesHefei 230026China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern Universty Shenyang 110819China

Gravitational waves(GWs) from compact binary coalescences encode the absolute luminosity distances of GW sources. Once the redshifts of GW sources are known, one can use the distance-redshift relation to constrain cosmological parameters. One way to obtain the redshifts is to localize GW sources by GW observations and then use galaxy catalogs to determine redshifts from a statistical analysis of redshift information of the potential host galaxies, commonly referred to as the dark siren method. The third-generation(3G) GW detectors are planned to work in the 2030s and will observe numerous compact binary coalescences.Using these GW events as dark sirens requires high-quality galaxy catalogs from future sky survey projects. The China Space Station Telescope(CSST) will be launched in 2024 and will observe billions of galaxies within a 17500 deg^(2) survey area with redshift up to z ~ 4, providing photometric and spectroscopic galaxy catalogs. In this work, we simulate the CSST galaxy catalogs and the 5-year GW data from the 3G GW detectors and combine them to infer the Hubble constant(H_(0)). Our results show that the measurement precision of H0could reach the sub-percent level, meeting the standard of precision cosmology. We conclude that the synergy between CSST and the 3G GW detectors is of great significance in measuring the Hubble constant.

关键词： CSST galaxy survey galaxy catalogs gravitational waves dark sirens the Hubble constant