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Effect of surface tension and viscosity on bubble growth of single mode Rayleigh-Taylor instability

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Applied Mathematics and Mechanics(English Edition) 2016年第12期37卷 1607-1614页

作者： mingjun li Qiaofeng ZHU Guibo li School of Mathematics and System Science Shenyang Normal University School of Mathematics and Computational Science Xiangtan University

Based on the Zufiria theoretical model, a new model regarding the asymptotic bubble velocity for the Rayleigh-Taylor （RT） instability is presented by use of the complex velocity potential proposed by Sohn. The proposed model is an extension of the ordinary Zufiria model and can deal with non-ideal fluids. With the control variable method, the effect of the viscosity and surface tension on the bubble growth rate of the RT instability is studied. The result is consistent with Cao＇s result if we only consider the viscous effect and with Xia＇s result if we only consider the surface tension effect. The asymptotic bubble velocity predicted by the Zufiria model is smaller than that predicted by the Layzer model, and the result from the Zufiria model is much closer to White＇s experimental data.

关键词： viscosity surface tension Rayleigh-Taylor (RT) instability Zufiria model

Antibacterial Performance of a Cu-bearing Stainless Steel against Microorganisms in Tap Water

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Journal of Materials Science & Technology 2015年第3期31卷 243-251页

作者： mingjun li li Nan Dake Xu Guogang Ren Ke Yang Institute of Metal Research Chinese Academy of Sciences School of Engineering and Technology University of Hertfordshire

Tap water is one of the most commonly used water resources in our daily life. However, the increasing water contamination and the health risk caused by pathogenic bacteria, such as Staphylococcus aureus and Escherichia coli have attracted more attention. The mutualism of different pathogenic bacteria may diminish antibacterial effect of antibacterial agents. It was found that materials used for making pipe and tap played one of the most important roles in promoting bacterial growth. This paper is to report the performance of an innovative type 304 Cu-bearing stainless steel(304Cu SS) against microbes in tap water. The investigation methodologies involved were means of heterotrophic plate count, contact angle measurements, scanning electron microscopy for observing the cell and subtract surface morphology,atomic absorption spectrometry for copper ions release study, and confocal laser scanning microscopy used for examining live/dead bacteria on normal 304 stainless steel and 304 Cu SS. It was found that the surface free energy varied after being immersed in tap water with polar component and Cu ions *** results showed 304 Cu SS could effectively kill most of the planktonic bacteria(max 95.9% antibacterial rate), and consequently inhibit bacterial biofilms formation on the surface, contributing to the reduction of pathogenic risk to the surrounding environments.

关键词： Cu-bearing stainless steel Tap water Antibacterial

A conservative local discontinuous Galerkin method for the solution of nonlinear Schrdinger equation in two dimensions

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Science China Mathematics 2017年第12期60卷 2515-2530页

作者： ZHANG RongPei YU XiJun li mingjun li XiangGui School of Mathematics and Systematic Sciences Shenyang Normal University Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics School of Mathematics and Computational Science Xiangtan University School of Applied Science Beijing Information Science and Technology University

In this study, we present a conservative local discontinuous Galerkin(LDG) method for numerically solving the two-dimensional nonlinear Schrdinger(NLS) equation. The NLS equation is rewritten as a firstorder system and then we construct the LDG formulation with appropriate numerical flux. The mass and energy conserving laws for the semi-discrete formulation can be proved based on different choices of numerical fluxes such as the central, alternative and upwind-based flux. We will propose two kinds of time discretization methods for the semi-discrete formulation. One is based on Crank-Nicolson method and can be proved to preserve the discrete mass and energy conservation. The other one is Krylov implicit integration factor(IIF) method which demands much less computational effort. Various numerical experiments are presented to demonstrate the conservation law of mass and energy, the optimal rates of convergence, and the blow-up phenomenon.

关键词： discontinuous Galerkin method nonlinear Schrdinger equation conservation Krylov implicit integration factor method

Antibacterial behavior and related mechanisms of martensitic Cu-bearing stainless steel evaluated by a mixed infection model of Escherichia coli and Staphylococcus aureus in vitro

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Journal of Materials Science & Technology 2021年第3期62卷 139-147页

作者： mingjun li li Nan Chunyong liang Ziqing Sun Lei Yang Ke Yang Center for Health Science and Engineering School of Materials Science and EngineeringHebei University of TechnologyTianjin 300130China Institute of Metal Research University of Chinese Academy of SciencesShenyang 110016China International Research Center for Translational Orthopaedics(IRCTO) China

Escherichia coli(***)and Staphylococcus aureus(***)are the most typical pathogenic bacteria with a significantly high risk of bio-contamination,widely existing in hospital and public *** studies on antibacterial materials and the related mechanisms have attracted more interests of ***,the antibacterial behavior of materials is usually evaluated separately on the single bacterial strain,which is far from the practical ***,the interaction between the polymicrobial communities can promote the growing profile of bacteria,which may weaken the antibacterial effect of *** this work,a 420 copper-bearing martensitic stainless steel(420 CuSS)was studied with respect to its antibacterial activity and the underlying mechanism in a co-culturing infection model using both *** and *** *** via plating and counting colony forming units(CFU),Cu releasing,and material characterization,420 CuSS was proved to present excellent antibacterial performance against the mixed bacteria with an approximately 99.4%of antibacterial *** addition,420 CuSS could effectively inhibit the biofilm formation on its surfaces,resulting from a synergistic antibacterial effect of Cu ions,Fe ions,reactive oxygen species(ROS),and proton consumption of bacteria.

关键词： Mixed bacterial strains E.coli S.aureus 420 Cu-bearing stainless steel Antibacterial mechanism

Acute Effects of Low Temperatures and Cold Waves on Elderly Infectious Pneumonia Mortality—Jinan City,Shandong Province,China,2014-2022

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China CDC weekly 2024年第5期6卷 77-82,I0002-I0005页

作者： Huiyun Chang mingjun li Ying Wang liangliang Cui Tiantian li Jinan Municipal Center for Disease Control and Prevention Jinan Municipal Center for Disease Control and Prevention Affiliated to Shandong UniversityJinan CityShandong ProvinceChina Chinese Filed Epidemiology Training Program Chinese Center for Disease Control and PreventionBeijingChina China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?The mortality rate due to pneumonia varies depending on the infectious agents present in a low-temperature *** is added by this report?This study aimed to examine the relationship between low temperatures and cold waves and the risk of mortality from infectious pneumonia in the *** findings indicate a significant increase in the risk of infectious pneumonia.

关键词： environment Shandong finding

Parameter Effects of the Potential‑Field‑Driven Model Predictive Controller for Shared Control

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Automotive Innovation 2023年第1期6卷 48-61页

作者： mingjun li Chao Jiang Xiaolin Song Haotian Cao State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

Parameter effects of the potential-field-driven model predictive control(PF-MPC)method on performances of shared control systems during obstacles avoidance are *** PF-MPC controllers of autonomous driving and shared control systems are designed based on the constructed potential fields and model predictive control method,and the driver-vehicle dynamics and the driver-related costs are also considered in the design of the shared *** explore a potential approach of alleviating driver-automation conflicts of the shared control systems,different motion planning results generated by the PF-MPC controller are explored by adjusting effects of potential fields’parameters,which provides possibilities to decrease driver-automation conflicts between the planned trajectory and driver’s target ***,two case studies are designed to discuss different frameworks and parameters effects on shared control *** show that the proposed shared control frameworks considering driver-vehicle dynamics and the driver-related cost show better performances regarding driver-automation conflicts management and driving safety than the decentralized control *** the longitudinal normalized constant of potential fields parameters shows influences on the driver-automation conflicts management and driving safety performances of shared control.

关键词： PF-MPC method Potential field Parameter effect Driver-automation conflict

Effects of location within the tree canopy on carbohydrates,organic acids,amino acids and phenolic compounds in the fruit peel and flesh from three apple(Malus×domestica)cultivars

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Horticulture Research 2014年第1期1卷 214-220页

作者： Fengjuan Feng mingjun li Fengwang Ma Lailiang Cheng Department of Horticulture Cornell UniversityIthacaNY 14853USA School of Management Shandong Jiaotong UniversityJinan 250357China State Key Laboratory of Crop Stress Biology for Arid Areas College of HorticultureNorthwest A&F UniversityYangling 712100China

Fruits from three cultivars of apple(Malus × domestica Borkh.)—‘McIntosh’,‘Gala’and‘Mutsu’—were harvested from the exterior and interior of the tree *** and flesh tissues were sampled separately to determine how the position of the fruit on the tree might affect the levels of the primary and secondary metabolites in the *** from the outer-canopy had a higher fresh weight and a higher soluble solids content compared with inner-canopy *** the flesh and peel of the outer-canopy fruit had higher concentrations of soluble sugars and sugar alcohols,but lower starch concentrations than the inner-canopy *** position did not significantly affect malic acid concentrations,except in the peel of‘McIntosh’and the flesh of‘Mutsu’.Although levels of ascorbic and succinic acids were higher in the peel of the outer-canopy fruit,the responses of other organic acids to canopy position depended on tissue type and *** for histidine,lysine,threonine and glycine,most amino acids accumulated at higher concentrations in the inner-canopy *** contrast,levels of phenolic compounds from both the peel and flesh were significantly higher in the outer-canopy *** significant effects of location within the canopy on both primary metabolites and secondary metabolites demonstrate the importance of light exposure on apple fruit quality.

关键词： phenolic outer sugar

Overexpression of MdFRK2 enhances apple drought resistance by promoting carbohydrate metabolism and root growth under drought stress

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Horticultural Plant Journal 2023年第5期9卷 884-897页

作者： Jingjing Yang Ruiling Zhan Lan Wang Junqiao li Baiquan Ma Fengwang Ma mingjun li Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong College of AgricultureLudong UniversityYantaiShandong 264025China State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple College of HorticultureNorthwest A&F UniversityYanglingShaanxi 712100China Key Laboratory of Fruit Tree Research in Ganzi Academy of Agricultural Sciences KangdingSichuan 626000China

Soluble sugars function not only as the energy and structural blocks supporting plants,but also as osmoregulators and signal molecules during plant adaptation to water ***,we investigated drought resistance in transgenic apple(Malus×domestica)overexpressing MdFRK2,a key gene regulating fructose content and sugar *** is no obvious phenotypic difference between MdFRK2-overexpressing transgenic plants and WT plants under the well-watered ***,the transgenic plants and the grafted plants using MdFRK2-overexpressing rootstock exhibited improved tolerance to drought *** of MdFRK2 significantly promoted the growth of root system under drought *** sequencing showed that under drought stress,genes involved in sugar metabolism,transcription regulation,signal transduction or hormone metabolism were differentially expressed in MdFRK2 transgenic *** with the gene expression profile,the activities of enzyme(SDH,FRK and NI)involved in sugar metabolism in the roots of MdFRK2 transgenic plants were significantly higher than those of untransformed control plants after drought *** drought stress,overexpression of MdFRK2 promoted the accumulation of IAA,and decreased the contents of ABA and CK in apple root *** conclusion,these results suggest that MdFRK2 can promote the growth of apple roots under drought stress by regulating sugar metabolism and accumulation,hormone metabolism and signal transduction,and then resist drought stress.

关键词： Malus×domestica MdFRK2 Drought stress Sugar Auxin Signal transduction Transcriptome

Effects of Sampling Conditions on Composition and Emission Characteristics of Volatile Organic Compounds in Process Units from Different Refineries

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China Petroleum Processing & Petrochemical Technology 2020年第3期22卷 65-72页

作者： Feng Yunxia Xiao Anshan li Bo Dong Rui Jia Runzhong li mingjun State Key Laboratory of Safety and Control for Chemicals SINOPEC Research Institute of Safety EngineeringQingdao 266101

This study investigates the effects of sampling conditions on volatile organic compound(VOC)compositions including different flow restrictors,SUMMA volumes,sampling heights,and wind *** show that at the six sampling heights the concentrations of main VOC species were slightly different,while the wind speed had a greater impact on the VOC composition of source *** the increase of wind speed,the weighted percentage of high-carbon aromatic hydrocarbons was ***,there was an extremely different profile between the normal production and shutdown conditions of the delayed coking *** compare the emission characteristics of VOCs in various process units of the S and the C refineries,the samples were collected from the catalytic cracking unit,the continuous catalytic reforming unit,and the delayed coking *** the continuous catalytic reforming unit,C3-C5 alkanes and low-carbon aromatic hydrocarbons were the main components collected from the S and the C refineries,accounting for 67.1%and 34.9%,*** the delayed coking unit,the total weighted percentage of high carbon C6-C12 alkanes was significantly higher than other units in the S and the C refineries,accounting for 30.5%and 24.4%,*** the catalytic cracking unit,the low-carbon C2-C5 alkanes were abundant,and the weighted percentage of propylene was *** emission characteristics obtained were consistent with the processing technology of production *** results indicate that the VOC emission characteristics from the same production unit in different refineries have similarities and significant differences which are related to the technological *** emission characteristics of VOCs could provide the data support for source apportionment work in the production units.

关键词： petrochemical refinery volatile organic compounds inﬂuencing factors emission characteristics