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Dynamics of a Reaction-diffusion-ODE System in a Heterogeneous Media

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 275-301页

作者： Cong-hui zhang Hai-feng zhang Mei-rong zhang School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

The existence and stability of stationary solutions for a reaction-diffusion-ODE system are investigated in this *** first show that there exist both continuous and discontinuous stationary *** a good understanding of the stability of discontinuous stationary solutions is gained under an appropriate *** addition,we demonstrate the influences of the diffusion coefficient on stationary *** results we obtained are based on the super-/sub-solution method and the generalized mountain pass ***,some numerical simulations are given to illustrate the theoretical results.

关键词： reaction-diffusion-ODE system discontinuous stationary solutions stability asymptotic behavior monotone solutions

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Recyclable hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) magnetic composites as adsorbents for selective cationic dye adsorption

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Frontiers of Chemical Science and Engineering 2024年第2期18卷 113-125页

作者： feng zhang Shuainan Xu Xiumei Geng Meixia Shan Yatao zhang School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China

Polymers of intrinsic microporosity shows great potential for dye adsorption and magnetic Fe_(3)O_(4) are easy to be *** this work,hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) composite adsorbents were prepared by phase inversion and hydrolysis process for cationic dye *** chemical structure and morphology of the composite adsorbents were systematically characterized by several characterization *** methylene blue as the target dye,the influences of solution pH,contact time,initial dye concentration,and system temperature on the methylene blue adsorption process were *** incorporation of Fe_(3)O_(4) particle into hydrolyzed polymers of intrinsic microporosity-1 endow the adsorbent with high magnetic saturation(20.7 emu·g^(–1))which allows the rapid separation of the ***,the adsorption process was simulated by adsorption kinetics,isotherms and thermodynamics to gain insight onto the intrinsic adsorption *** addition,the composite adsorbents are able to selectively adsorb cationic dyes from mixed dyes *** polymers of intrinsic microporosity/Fe_(3)O_(4) shows only a slight decrease for methylene blue adsorption after 10 adsorption/regeneration cycles,demonstrating the outstanding regeneration *** high adsorption capacity,outstanding regeneration ability,together with simple preparation method,endow the composite adsorbents great potential for selective removal of cationic dyes in wastewater system.

关键词： polymers of intrinsic microporosity magnetic adsorbent cationic dye adsorption

Is appendoscope a new option for the treatment of acute appendicitis?

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World Journal of Gastroenterology 2024年第28期30卷 3386-3392页

作者： Shu-Jiong feng Yi-feng Zhou Jian-feng Yang Hong-zhang Shen Guang-Xing Cui Xiao-feng zhang Department of Gastroenterology Affiliated Hangzhou First People’s HospitalSchool of MedicineWestlake UniversityHangzhou 310000Zhejiang ProvinceChina Department of Gastroenterology Key Laboratory of Integrated Traditional Chinese and Western Medicine for Biliary and Pancreatic Diseases of Zhejiang ProvinceHangzhou 310000Zhejiang ProvinceChina Department of Gastroenterology Hangzhou Institute of Digestive DiseasesHangzhou 310000Zhejiang ProvinceChina

Acute appendicitis is a common surgical *** is commonly caused by obstruction of the appendiceal lumen due to fecaliths,tumors,or lymphoid *** over a century,appendectomy has been the primary treatment for acute *** Groves performed the first open appendectomy in *** 1983,Kurt Semm completed the first laparoscopic appendectomy,heralding a new era in ***,appendectomy is associated with certain complications and a rate of negative *** have suggested controversy over the impact of appendectomy on the development of inflammatory bowel disease and Parkinson’s disease,but an increasing number of studies indicate a possible positive correlation between appendectomy and colorectal cancer,gallstones,and cardiovascular *** the recognition that the appendix is not a vestigial organ and the advancement of endoscopic technology,Liu proposed the endoscopic retrograde appendicitis *** is an effective minimally invasive alternative for treating uncomplicated acute *** team has developed an appendoscope with a disposable digital imaging system operated through the biopsy channel of a colonoscope and successfully applied it in the treatment of *** article provides an overview of the progress in endoscopic treatment for acute appendicitis and offers a new perspective on the future direction of appendiceal disease treatment.

关键词： Acute appendicitis Endoscopic technology Endoscopic retrograde appendicitis therapy Appendoscope Appendiceal disease treatment

The study of lithographic variation in resistive random access memory

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Journal of Semiconductors 2024年第5期45卷 69-79页

作者： Yuhang zhang Guanghui He feng zhang Yongfu Li Guoxing Wang Department of Micro-Nano Electronics Shanghai Jiao Tong UniversityShanghai 200240China MoE Key Lab of Artificial Intelligence Shanghai Jiao Tong UniversityShanghai 200240China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China

Reducing the process variation is a significant concern for resistive random access memory(RRAM).Due to its ultrahigh integration density,RRAM arrays are prone to lithographic variation during the lithography process,introducing electrical variation among different RRAM *** this work,an optical physical verification methodology for the RRAM array is developed,and the effects of different layout parameters on important electrical characteristics are systematically *** results indicate that the RRAM devices can be categorized into three clusters according to their locations and lithography *** read resistance is more sensitive to the locations in the array(~30%)than SET/RESET voltage(<10%).The increase in the RRAM device length and the application of the optical proximity correction technique can help to reduce the variation to less than 10%,whereas it reduces RRAM read resistance by 4×,resulting in a higher power and area *** such,we provide design guidelines to minimize the electrical variation of RRAM arrays due to the lithography process.

关键词： layout lithography process variation resistive random access memory

Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

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Nuclear Science and Techniques 2024年第6期35卷 90-100页

作者： Ming-Hao zhang Yu-Hai zhang Ying Zou Xiu-Xiu Yang Gen zhang feng-Shou zhang The Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China School of Physical Science and Technology Guangxi UniversityNanning 530004China National Laboratory of Heavy Ion Accelerator of Lanzhou Center of Theoretical Nuclear PhysicsLanzhou 730000China

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental *** synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 *** influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in *** reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

关键词： Superheavy nuclei Dinuclear system model Fusion reaction Evaporation residue cross section

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

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Journal of Iron and Steel Research(International) 2024年第5期31卷 1210-1220页

作者： Xiao-yong Gao Hong Wei Li-feng zhang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Materials Science and Engineering Yanshan UniversityQinhuangdao066004HebeiChina School of Mechanical and Materials Engineering North China University of TechnologyBeijing100144China

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was *** field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS *** inclusions play an important role in the shape control of MnS *** oxides fovored to decrease the size and the aspect ratio of MnS *** less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in ***,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in *** of MnS by oxide inclusions improved the strength and inhibited the *** oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

关键词： High-strength low-alloy steel MnS Oxide inclusion Mechanical property Anisotropy

Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of Electronics 2024年第1期33卷 195-203页

作者： Li ZHAO Yi REN Qi WANG Lange DENG feng zhang School of Electronic Information Engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Neural networks Measurement uncertainty Position measurement Harmonic analysis Light emitting diodes Frequency estimation Indoor positioning systems

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 ***,this artificial feature engineering technique is not generalizable to similar tasks and is heavily reliant on the researcher’s subject *** 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 *** this approach overcomes the limitations of human feature engineering,it may ignore the potential correlation among the sEMG *** paper proposes a spatial–temporal graph neural network model,STGNN-LMR,designed to address the problem of recognizing lower limb motion from multi-channel ***-LMR transforms multi-channel sEMG into a graph structure and uses graph learning to model spatial–temporal *** 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 *** to the experimental results,the STGNN-LMR model exhibits a significant advantage over the control models in noise scenarios and failure *** 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

Urea-induced interfacial engineering enabling highly reversible aqueous zinc-ion battery

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Rare Metals 2024年第4期43卷 1599-1609页

作者： Bin-Rui Xu Quan-An Li Yong Liu Guang-Bin Wang Zi-He zhang feng-zhang Ren School of Material Science and Engineering Henan University of Science and TechnologyLuoyang471023China School of Information Engineering Henan University of Science and TechnologyLuoyang471023China Longmen Laboratory Luoyang471023China Provincial and Ministerial Co-Construction of Collaborative Innovation Center for Non-Ferrous Metal New Materials and Advanced Processing Technology Luoyang471023China

Aqueous zinc-ion batteries(AZIBs)have been regarded as prospective rechargeable energy storage devices because of the high theoretical capacity and low redox potential of Zn ***,the uncontrollable formation of dendrites and the water-induced side reactions at the Zn/electrolyte interface,and the poor reversibility under a high current density(>2 mA·cm^(-2))and large area capacity(>2 mAh·cm^(-2))still limit the practical applications of ***,a strategy that can overcome these difficulties is urgently ***,we introduce an environmentally friendly and low-cost additive,namely urea,to the electrolyte of AZIBs to induce uniform Zn deposition and suppress the side *** of the adsorption behavior,electrochemical characterization,and observations of the morphology revealed the interfacial modification induced by urea on the Zn/electrolyte interface,demonstrating its huge potential in ***,the long-term cycling stability(over2100 h)of a Zn/Zn symmetric cell under a high current density of 5 mA·cm^(-2)and a capacity of 5 mAh·cm^(-2)was achieved with a 1 mol·L^(-1)ZnSO_(4)electrolyte with the urea ***,the assembled Zn/NH_4V_4O_(10)full cell with urea exhibited excellent cycling performance and an outstanding average Coulombic efficiency of 99.98%.These results indicate that this is a low-cost and effective additive strategy for realizing highly reversible AZIBs.

关键词： Zn anode Urea additive Interface engineering Dendrite growth Side reaction