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A nonlocal dispersal and time delayed HIV infection model with general incidences

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Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 448-457页

作者： WU peng zhang Yu-huai WANG Ling School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China School of Humanities and Management Zhejiang Chinese Medical UniversityHangzhou 311402China Public Foundational Courses Department Nanjing Vocational University of Industry TechnologyNanjing 210023China

Biologically,because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells,time delay and spatial heterogeneity should be *** this paper,we establish an HIV infection model with nonlocal dispersal and infection ***,applying the theory of Fourier transformation and von Foerster rule,we transform the model to an integrodifferential equation with nonlocal time delay and *** well-posedness,positivity,and boundedness of the solution for the model are studied.

关键词： HIV model nonlocal dispersal time delay general incidences

Class imbalance problem in short-term solar flare prediction

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Research in Astronomy and Astrophysics 2021年第9期21卷 231-236页

作者： Jie Wan Jun-Feng Fu Jin-Fu Liu Jia-Kui Shi Cheng-Gang Jin huai-peng zhang Laboratory for Space Environment and Physical Sciences Harbin Institute of Technology School of Electrical Engineering and Automation Harbin Institute of Technology School of Energy Science and Engineering Harbin Institute of Technology

Using data-driven algorithms to accurately forecast solar flares requires reliable data *** solar flare dataset is composed of many non-flaring samples with a small percentage of flaring *** is called the class imbalance problem in data mining *** prediction model is sensitive to most classes of the original data set during ***,the class imbalance problem for building up the flare prediction model from observational data should be systematically *** at the problem of class imbalance,three strategies are proposed corresponding to the data set,loss function,and training process:TypeⅠresamples the training samples,including oversampling for the minority class,undersampling,or mixed sampling for the majority ***Ⅱusually changes the decision-making boundary,assigning the majority and minority categories of prediction loss to different ***Ⅲassigns different weights to the training samples,the majority categories are assigned smaller weights,and the minority categories are assigned larger weights to improve the training process of the prediction *** main work of this paper compares these imbalance processing methods when building a flare prediction model and tries to find the optimal *** results show that among these strategies,the performance of oversampling and sample weighting is better than other strategies in most parameters,and the generality of resampling and changing the decision boundary is better.

关键词： The Sun Sun:X-rays,gamma rays Sun:sunspots Sun:magnetic fields Sun:flares methods:data analysis

Seismicity changes and numerical simulation of coseismic deformation following the 2022 M_(s)6.8 Luding earthquake in Sichuan,China

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Science China Earth Sciences 2024年第8期67卷 2507-2521页

作者： Qiu MENG Zitao WANG huai zhang Key Laboratory of Computational Geodynamics of Chinese Academy of Sciences College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijing 100049China Institute of Earthquake Forecasting China Earthquake AdministrationBeijing 100036China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Beijing Yanshan Earth Critical Zone National Research Station Beijing 101408China

The Xianshuihe fault is a major tectonic boundary between the Sichuan-Yunnan rhombic and Bayanhar blocks in Southwest *** an average left-lateral strike-slip movement of 10–15 mm/yr,it is a fast-moving strike-slip continental *** September 5,2022,the Ms6.8 Luding earthquake occurred along the Moxi segment of the Xianshuihe fault,reaching a maximum intensity of IX and resulting in a significant number of casualties and severe property *** earthquake broke the long-standing seismic quiescence of the Xianshuihe fault,which lasted for more than 40 years,and was followed by a significant number of *** outstanding question is how the behavior of the Xianshuihe fault and major earthquakes changed following this *** this study,we examined the changes in regional seismicity following the Luding earthquake and identified the potential for future strong earthquakes along the Xianshuihe *** used a finite element numerical method to simulate the environment of the seismogenic fault and its adjacent *** addition,we used the coseismic slip model of the Luding earthquake with the split-node method to calculate how the stress and strain fields in the surrounding area were affected by the2022 *** stress changes were resolved in the main faults,and the seismicity of adjacent faults was analyzed in conjunction with the observed seismic *** results indicate that regional tectonic movement primarily occurred to the southeast along the Moxi *** stress field is approximately north-south in tension and east-west in *** in the stress field in the epicentral region of the Luding earthquake exceeded 1 *** maximum displacement of the coseismic deformation field was concentrated between Moxi town and Tuanjie village,and the Coulomb stress of the fault zone in this region experienced the largest ***,the b-value of the Gutenberg-Richter magnitude-frequency relationship at the epicenter a

关键词： Luding earthquake Seismicity Coulomb failure stress change Finite element numerical simulation

Electronic origin of structural degradation in Li-rich transition metal oxides:The case of Li_(2)MnO_(3)and Li_(2)RuO_(3)

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Journal of Semiconductors 2024年第4期45卷 82-86页

作者： peng zhang Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics andOp toelec-tronic EngineeringShenzhen UniversityShenzhen 518060China

Li_(2)MnO_(3)and Li_(2)RuO_(3)represent two prototype Li-rich transition metal(TM)oxides as high-capacity cathodes for Li-ion batteries,which have similar crystal structures but show quite different cycling ***,based on the first-princi-ples calculations,we systematically studied the electronic structures and defect properties of these two Li-rich cathodes,in order to get more understanding on the structural degradation mechanism in Li-rich TM *** calculations indicated that the structural and cycling stability of Li_(2)MnO_(3)and Li_(2)RuO_(3)depend closely on their electronic structures,especially the energy of their highest occupied electronic states(HOS),as it largely determines the defect properties of these *** Li_(2)MnO_(3)with low-energy HOS,we found that,due to the defect charge transfer mechanism,various defects can form spontaneously in its host structure as Li ions are extracted upon delithiation,which seriously deteriorates its structural and cycling *** for Li_(2)RuO_(3),on the other hand,we identified that the high-energy HOS prevents it from the defect formation upon delithi-ation and thus preserve its cycling *** studies thus illustrated an electronic origin of the structural degradation in Li-rich TM oxides and implied that it is possible to improve their cycling performances by carefully adjusting their TM compo-nents.

关键词： defects Li-ion batteries first-principles calculations

Theoretical understanding of correlation between magnetic phase transition and the superconducting dome in high-Tc cuprates

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 167-173页

作者： Chen zhang Cai-Xin zhang Su-huai Wei Haiqing Lin Hui-Xiong Deng State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Computational Science Research Center Beijing 100193China

Many issues concerning the origin of high-temperature superconductivity(HTS)are still under *** example,how the magnetic order varies with doping and its relationship with the superconducting temperature(Tc);and why Tcalways peaks near the quantum critical *** this paper,taking hole-doped La_(2)CuO_(4)as a classical example,we employ the first-principles band structure and total energy calculations with Monte Carlo simulations to explore how the symmetry-breaking magnetic ground state evolves with hole doping and the origin of a dome-shaped superconductivity region in the phase *** demonstrate that the local antiferromagnetic order and doping play key roles in determining the electron-phonon coupling,thus ***,the La_(2)CuO_(4)possesses a checkerboard local antiferromagnetic ground *** the hole doping increases,Tcincreases with the enhanced electron-phonon coupling *** as the doping increases further,the strength of the antiferromagnetic interaction weakens and spin fluctuation *** the critical doping level,a magnetic phase transition occurs that reduces the local antiferromagnetism-assisted electron-phonon coupling,thus diminishing the *** superconductivity disappears in the heavily overdoped region when the ferromagnetic order *** observations could account for why cuprates have a dome-shaped superconductivity region in the phase *** study,thus,contributes to a fundamental understanding of the correlation between doping,local magnetic order,and superconductivity of HTS.

关键词： high-temperature superconductivity antiferromagnetic order electron-phonon coupling doping effect cuprates

A three-dimensional co-continuous network structure polymer electrolyte with efficient ion transport channels enabling ultralong-life all solid-state lithium metal batteries

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Journal of Energy Chemistry 2024年第7期94卷 635-645页

作者： Meng Wang Hu zhang Yewen Li Ruiping Liu huai Yang School of Chemical&Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering&School of Materials Science and Engineering Peking UniversityBeijing 100871China

Solid polymer electrolytes(SPEs)have emerged as one of the most promising candidates for the construction of solid-state lithium batteries due to their excellent flexibility,scalability,and interface compatibility with ***,a novel all-solid polymer electrolyte(PPLCE)was fabricated by the copolymer network of liquid crystalline monomers and poly(ethylene glycol)dimethacrylate(PEGDMA)acts as a structural frame,combined with poly(ethylene glycol)diglycidyl ether short chain interspersed serving as mobile ion transport *** preparaed PPLCEs exhibit excellent mechanical property and out-standing electrochemical performances,which is attributed to their unique three-dimensional cocontinuous structure,characterized by a cross-linked semi-interpenetrating network and an ionic liquid phase,resulting in a distinctive nanostructure with short-range order and long-range ***,the addition of PEGDMA is proved to be critical to the comprehensive performance of the PPLCEs,which effectively modulates the microscopic morphology of polymer networks and improves the mechanical properties as well as cycling stability of the solid *** used in a lithiumion symmetrical battery configuration,the 6 wt%-PPLCE exhibites super stability,sustaining operation for over 2000 h at 30 C,with minimal and consistent overpotential of 50 *** resulting Li|PPLCE|LFP solid-state battery demonstrates high discharge specific capacities of 160.9 and 120.1 mA h g^(-1)at current densities of 0.2 and 1 C,*** after more than 300 cycles at a current density of 0.2 C,it retaines an impressive 73.5%***,it displayes stable cycling for over 180 cycles at a high current density of *** super cycle stability may promote the application for ultralong-life all solid-state lithium metal batteries.

关键词： Solid-state electrolyte Lithium-metal batteries Liquid crystalline polymer Copolymer 3D co-continuous structure Long cycle stability

Accelerated water harvesting from vapor via a bio-inspired hydrogel pattern

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National Science Review 2024年第3期11卷 48-49页

作者： Lianbin zhang peng Wang State Key Laboratory of Material Processing and Die&Mould Technology Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology(HUST) School of Environmental Science and Engineering Sun Yat-sen University

Water and energy sustainability are integral parts of resource sustainability of the world. Due to water molecules' superior capability of serving as both hydrogenbond donor and acceptor, phase change of water, especially between liquid and vapor, underpins global water cycles,facilitates energy transformation and transfer, and thus helps shape the unique local weather and global climate patterns.

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Heat exposure and hospitalizations for chronic kidney disease in China: a nationwide time series study in 261 major Chinese cities

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Military Medical Research 2024年第4期11卷 469-478页

作者： Fu-Lin Wang Wan-Zhou Wang Fei-Fei zhang Su-Yuan peng huai-Yu Wang Rui Chen Jin-Wei Wang peng-Fei Li Yang Wang Ming-Hui Zhao Chao Yang Lu-Xia zhang Institute of Medical Technology Peking University Health Science CenterBeijing 100191China National Institute of Health Data Science at Peking University Beijing 100191China Department of Occupational and Environmental Health Sciences School of Public HealthPeking UniversityBeijing 100191China Renal Division Department of MedicinePeking University First HospitalPeking University Institute of NephrologyBeijing 100034China Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases Chinese Academy of Medical SciencesBeijing 100034China Advanced Institute of Information Technology Peking UniversityHangzhou 311215China National Climate Center China Meteorological AdministrationBeijing 100081China Peking-Tsinghua Center for Life Sciences Beijing 100034China

Background:Climate change profoundly shapes the population health at the global ***,there was still insufficient and inconsistent evidence for the association between heat exposure and chronic kidney disease(CKD).Methods:In the present study,we studied the association of heat exposure with hospitalizations for cause-specific CKD using a national inpatient database in China during the study period of hot season from 2015 to *** time-series regression models and random-effects Meta-analysis were developed to estimate the city-specific and national averaged associations at a 7 lag-day span,***:A total of 768,129 hospitalizations for CKD was recorded during the study *** results showed that higher temperature was associated with elevated risk of hospitalizations for CKD,especially in sub-tropical *** a 1℃ increase in daily mean temperature,the cumulative relative risks(RR)over lag 0-7 d were 1.008[95% confidence interval(CI)1.003-1.012]for *** attributable fraction of CKD hospitalizations due to high temperatures was 5.50%.Stronger associations were observed among younger patients and those with obstructive *** study also found that exposure to heatwaves was associated with added risk of hospitalizations for CKD compared to non-heatwave days(RR=1.116,95%CI 1.069-1.166)above the effect of daily mean ***:Short-term heat exposure may increase the risk of hospitalization for *** findings provide insights into the health effects of climate change and suggest the necessity of guided protection strategies against the adverse effects of high temperatures.

关键词： Chronic kidney disease Hospitalization Climate change Temperature Time-series study

Stabilization and Blow-up in an Infinite Memory Wave Equation with Logarithmic Nonlinearity and Acoustic Boundary Conditions

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Journal of Systems Science & Complexity 2024年第4期37卷 1368-1391页

作者： peng Qingqing zhang Zhifei School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan 430074China

In this paper,the authors consider the stabilization and blow up of the wave equation with infinite memory,logarithmic nonlinearity and acoustic boundary *** authors discuss the existence of global solutions for the initial energy less than the depth of the potential well and investigate the energy decay estimates by introducing a Lyapunov ***,the authors establish the finite time blow up results of solutions and give the blow up time with upper bounded initial energy.

关键词： Acoustic boundary condition finite time blow-up general decay infinite memory logarithmic nonlinearity