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The dynamics of traveling wavefronts for a model describing host tissue degradation by bacteria

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International Journal of Biomathematics 2024年第3期17卷 265-287页

作者： xing-xing Yang Guo-Bao Zhang Ge tian College of Mathematics and Statistics Northwest Normal University Lanzhou Gansu 730070P.R.China

In this paper,we mainly investigate the dynamics of traveling wavefronts for a model describing host tissue degradation by *** first establish the existence of spreading speed,and show that the spreading speed coincides with the minimal wave speed of traveling ***,a lower bound estimate of the spreading speed is ***,we prove that the traveling wavefronts with large speeds are globally exponentially stable,when the initial perturbation around the traveling wavefronts decays exponentially asχ→-∞,but the initial perturbation can be arbitrarily large in other *** adopted methods are the weighted energy and the squeezing technique.

关键词： Host tissue degradation bacterial infection traveling wavefronts minimal wave speed stability

Impact of Mo/Ni alloying on microstructural modulation and low-temperature toughness of high-strength low-alloy steel

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1746-1762页

作者： Wei Liu Hong-li Zhao Bing-xing Wang Yong tian State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

The high-strength low-alloy steel plates with varying Ni/Mo contents were manufactured using the thermos-mechanical control *** investigation was conducted to explore the effect of Ni/Mo microalloying on microstructure evolution and mechanical properties of the *** results revealed that the increase in Ni content from 1 to 2 wt.%reduced the transition temperature of ferrite and the growth range of ferritic grain was narrowed,which promoted grain *** optimized combination of grain size,high-angle grain boundaries(HAGBs),and martensite-austenite(M-A)islands parameter contributed to the excellent impact toughness of S1 steel at-100℃(impact absorbed energy of 218.2 J at-100℃).As the Mo increases from 0 to 2 wt.%,the matrix structure changes from multiphase structure to granular bainite,which increases the average effective grain size to~4.62 pm and reduces HAGBs proportion to~36.22%.With these changes,the low-temperature impact toughness of S3 steel is *** addition,based on the analysis of the characteristics of crack propagation path,it was found that M-A islands with low content(~2.21%)and small size(~1.76 pm)significantly retarded crack propagation,and the fracture model of M-A islands with different morphologies was further ***,correlation between behaviour of delamination and toughness was further analysed by observing delamination size and impact energy parameters.

关键词： High-strength low-alloy steel Microstructural regulation Ni addition Mo addition Crack propagation Low-temperature toughness

Numerical Study on Reduction in Aerodynamic Drag and Noise of High-Speed Pantograph

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2155-2173页

作者： Deng Qin xing Du tian Li Jiye Zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China School of Electrical Engineering Southwest Jiaotong UniversityChengdu610031China

Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly,energy efficient and rapid advances in train *** computational fluid dynamics theory and the K-FWH acoustic equation,a numerical simulation is conducted to investigate the aerodynamic characteristics of high-speed pantographs.A component optimization method is proposed as a possible solution to the problemof aerodynamic drag and noise in high-speed *** results of the study indicate that the panhead,base and insulator are the main contributors to aerodynamic drag and noise in high-speed ***,a gradual optimization process is implemented to improve the most significant components that cause aerodynamic drag and *** optimizing the cross-sectional shape of the strips and insulators,the drag and noise caused by airflow separation and vortex shedding can be *** aerodynamic drag of insulator with circular cross section and strips with rectangular cross section is the *** insulators and optimizing the chamfer angle and height of the windward surface of the strips can improve the aerodynamic performance of the *** addition,the streamlined fairing attached to the base can eliminate the complex flow and shield the radiated *** contrast to the original pantograph design,the improved pantograph shows a 21.1%reduction in aerodynamic drag and a 1.65 dBA reduction in aerodynamic noise.

关键词： High-speed pantograph aerodynamic drag aerodynamic noise reduction optimizing

Cage-confinement synthesis of MoC nanoclusers as efficient sulfiphilic and lithiophilic regulator for superior Li–S batteries

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Rare Metals 2024年第2期43卷 624-634页

作者： xing-Yuan Zhang Mei-Na Lei Shan tian Jian-Gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi’an710072China

High-energy-density Li-S batteries are subjected to serious sulfur deactivation and short cycle lifetime caused by undesirable polysulfide shuttle effect and frantic lithium dendrite *** this work,a controllable cage-confinement strategy to fabricate molybdenum carbide(MoC)nanoclusters as a high-efficient sulfiphilic and lithiophilic regulator to mitigate the formidable issues of Li-S batteries is *** sub-2 nm MoC nanoclusters not only guarantee robust chemisorption and fast electrocatalytic conversion of polysulfides to enhance the sulfur electrochemistry,but also homogenize Li^(+) flux to suppress the lithium dendrite *** a consequence,the MoC-modified separator endows the batteries with boosted reaction kinetics,promoted sulfur utilization,and improved cycling stability.A reversible capacity of 701 mAh·g^(−1) at a high rate of 5.0C and a small decay rate of 0.076%per cycle at 1.0C over 600 cycles are *** study offers a rational route for design and synthesis of bifunctional nanoclusers with both sulfiphilicity and lithiophilicity for high-performance Li-S batteries.

关键词： Li-S batteries Nanocluster Electrocatalyst Polysulfide shuttle Li dendrites

An estimation model for the fragmentation properties of brittle rock block due to the impacts against an obstruction

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Journal of Mountain Science 2017年第6期14卷 1161-1173页

作者： hou tian-xing XU Qiang XIE Hong-qiang XU Nu-wen Zhou Jia-wen State Key Laboratory of Hydraulics and Mountain River Engineering Siehuan University Chengdu 610065 China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China College of Water Resource and Hydropower Sichuan University Chengdu 610065 China

Mountain hazards with large masses of rock blocks in motion – such as rock falls, avalanches and landslides – threaten human lives and structures. Dynamic fragmentation is a common phenomenon during the movement process of rock blocks in rock avalanche, due to the high velocity and impacts against obstructions. In view of the energy consumption theory for brittle rock fragmentation proposed by Bond, which relates energy to size reduction, a theoretical model is proposed to estimate the average fragment size for a moving rock block when it impacts against an obstruction. Then, different forms of motion are studied, with various drop heights and slope angles for the moving rock block. The calculated results reveal that the average fragment size decreases as the drop height increases, whether for free-fall or for a sliding or rolling rock block, and the decline in size is rapid for low heights and slow for increasing heights in the corresponding curves. Moreover, the average fragment size also decreases as the slope angle increases for a slidingrock block. In addition, a rolling rock block has a higher degree of fragmentation than a sliding rock block, even for the same slope angle and block volume. Finally, to compare with others' results, the approximate number of fragments is estimated for each calculated example, and the results show that the proposed model is applicable to a relatively isotropic moving rock block.

关键词：估算模型脆性岩石障碍物破碎特性石块运动形式计算结果平均粒径

Preparation of Laser Cladding Coating Undercooling Cu-based Alloy and Co on Non-equilibrium Solidification Structure

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 463-472页

作者：田徐铭 CAO Shichao hou Kai hou Xiaopeng WANG Hongfu 张煜 Department of Outpatient Xinzhou People’s HospitalXinzhou 034099China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Department of Neurosurgery Xinzhou People’s HospitalXinzhou 034099China Department of Orthopedics Xinzhou People’s HospitalXinzhou 034099China

The effect of the gradient content of Co element on the solidification process of Cu-based alloy under deep under cooling conditions was *** non-equilibrium solidification structure of the under cooled alloy samples were *** is found that the rapidly solidified alloy has undergone twice grain refinement during the undercooling *** and significance of the maximum undercooling refinement structure of Cu60Ni35Co5 at T=253 K were ***-density defects were observed,such as dislocations,stacking faults networks,and twinning *** standard FCC diffraction pattern represents that it is still a single-phase *** on the metallographic diagram,EBSD and TEM data analysis,it is illustrated that the occurrence of grain refinement under high undercooling is due to stress induced *** addition,the laser cladding technology is used to coat Co-based alloy(Stellite12) coating on 304 stainless steel substrate;the microstructure of the coating cross-section was *** was found that the microstructure of the cross-section is presented as columnar crystals,planar crystals,and disordered growth direction,so that the coating has better hardness and wear *** electrochemical corrosion of the substrate and coating,it can be seen that the Co and Cr elements present in the coating are more likely to form a dense passivation film,which improved the corrosion resistance of the coating.

关键词： non-equilibrium solidification structure undercooling recrystallization laser cladding coating

DMF-scMT-seq linking methylome and transcriptome within single cells with digital microfluidics

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Science China Chemistry 2024年第6期67卷 2070-2078页

作者： xing Xu Xi Zeng Xin Lin Shiyan Lin Shanshan Liang tian tian Rui Su Jia Song Chaoyong Yang Collaborative Innovation Center of Chemistry for Energy Materials The MOE Key Laboratory of Spectrochemical Analysis and InstrumentationState Key Laboratory of Physical Chemistry of Solid SurfacesDepartment of Chemical BiologyCollege of Chemistry and Chemical EngineeringThe First Affiliated Hospital of Xiamen UniversityXiamen UniversityXiamen361005China Institute of Molecular Medicine Renji HospitalShanghai Jiao Tong University School of MedicineShanghai200127China Chemistry and Materials Science College Shanghai Normal UniversityShanghai200234China Chemistry and Biomedicine Innovation Center(ChemBIC) School of Chemistry and Chemical EngineeringNanjing UniversityNanjing210023China

Single-cell joint analysis of methylome and transcriptome reveals how the methylation regulates the transcriptional ***,traditional bench-top protocols for single-cell DNA methylation and RNA transcription co-detection are laborintensive,cost-ineffective and ***,we establish the DMF-sc MT-seq,a highly-efficient and cost-effective method to simultaneously analyze single-cell DNA methylation and transcriptional activity based on digital *** MT-seq automates the workflow of single-cell isolation,cellular hypotonic lysis,nucleic acid separation and methylome/transcriptome library construction in a contactless and addressable *** system ensures high accuracy(R>0.85),high gene detection ability(14,697 genes per cell at 4 million sequencing depth),and high CpG coverage(677,198 CpG sites per cell at 1million sequencing depth).By using DMF-sc MT-seq,the relationship of DNA methylation and RNA transcription under different genomic contexts is *** further apply DMF-sc MT-seq to study the dynamics of transcription regulation with methylation-inhibiting anti-tumor Decitabine,and identify the methylated promoter/gene body driven genes in response to Decitabine ***-sc MT-seq facilitates the construction of the correlation of DNA methylation and transcriptional activity at the single-cell level in a flexible,sensitive and accurate way,which is anticipated to be a powerful tool in studying single-cell biological systems.

关键词： single-cell analysis digital microfluidics methylome sequencing transcriptome sequencing

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Effect of Ca Micro-Alloying on the Microstructure and Anti-Corrosion Property of Mg0.5Zn0.2Ge Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1147-1160页

作者： Bishan Cheng Depeng Li Baikang xing Ruiqing hou Pingli Jiang Shijie Zhu Shaokang Guan School of Materials Science and Engineering and Henan Key Laboratory of Advanced Magnesium Alloys Zhengzhou UniversityZhengzhou450001China Center of Advanced Analysis and Gene Sequencing Zhengzhou UniversityZhengzhou450001China Key Laboratory of Materials Processing and Mold Technology Ministry of EducationZhengzhou450002China

Magnesium and its alloys have attracting rising attention as one of biodegradable metallic ***,the rapid corrosion and severe localized corrosion still hinder their extensive applications in *** this study,micro-alloying of Ca(≤0.1 wt%)into Mg0.5Zn0.2Ge alloy developed in our previous work was explored to further enhance the corrosion resistance and alleviate the localized corrosion of the *** results reveal that the addition of Ca leads to the transformation of the cathodic Mg_(2)Ge phase in Mg0.5Zn0.2Ca alloy into anodic MgCaGe phase in Ca-containing alloys,thereby changing the galvanic couples in alloys during *** preferential dissolution of MgCaGe phase promotes the participation of Ca and Ge into the formation of corrosion products,resulting in the enrichment of Ca and Ge in the outmost of corrosion product layer,which stabilizes and passivates the corrosion product layer on Mg alloy ***,the enrichment of Zn at the corrosion interface seems to further hinder the corrosion of Mg *** of these factors confer a slower and more uniform corrosion on Mg0.5Zn0.2GexCa(x<0.1 wt%)alloy,which provides favorable candidates for the further processing to gain suitable biodegradable Mg alloys.

关键词： Magnesium alloy Micro-alloying Calcium Corrosion resistance

Optimized tillage methods increase mechanically transplanted rice yield and reduce the greenhouse gas emissions

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Journal of Integrative Agriculture 2024年第4期23卷 1150-1163页

作者： Shuang Cheng Zhipeng xing Chao tian Mengzhu Liu Yuan Feng Hongcheng Zhang Jiangsu Key Laboratory of Crop Cultivation and Physiology/Jiangsu Co-innovation Center for Modern Production Technology of Grain Crops/Research Institute of Rice Industrial Engineering Technology Yangzhou UniversityYangzhou 225009China

Biaxia lrotary tillage in dryland(DBRT)can complete biaxial rotary tillage with straw incorporation,secondary suppression,and ditching,and it has been previously studied in direct-seeded rice and ***,the effects of DBRT on the mechanically transplanted rice yield and greenhouse gas emissions remain *** evaluate the effects of DBRT on improving the food security of mechanically transplanted rice and reducing the greenhouse gas emissions,we conducted an experiment for two years with wheat straw *** tillage methods were set up:DBRT,uniaxial rotary tillage in dryland and paddy(DPURT),and uniaxial rotary tillage in paddy(PURT).The results showed that compared with DPURT and PURT,DBRT increased the yield of machine-transplanted rice by 7.5-11.0%and 13.3-26.7%,respectively,while the seasonal cumulative CH_(4) emissions were reduced by 13.9-21.2%and 30.2-37.0%,respectively,and the seasonal cumulative N_(2)O emissions were increased by 13.5-28.6%and 50.0-73.1%,***,DBRT reduced the global warming potential by 10.7-15.5%and 23.7-28.6%,respectively,andtheyield-scaledglobalwarmingpotentialby18.2-21.8%and36.4-39.3%,respectively,compared to DPURT and *** results were mainly related to the fact that DBRT significantly reduced soil bulk density and increased soil redox potential(Eh).Therefore,implementing DBRT in machine-transplanted rice fields is feasible,which cannot only increase the rice yield,but also reduce the greenhouse gas emissions.

关键词： integrated tillage rice grain yield CH_(4) N_(2)O