检索结果-南通市图书馆

Diffusion process in enzyme-metal hybrid catalysts

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2022年第6期16卷 921-929页

作者： Shitong cui Jun Ge Key Lab for Industrial Biocatalysis Ministry of EducationDepartment of Chemical EngineeringTsinghua UniversityBeijing 100084China Institute of Biopharmaceutical and Health Engineering Tsinghua Shenzhen International Graduate SchoolShenzhen 518055China

Enzyme-metal hybrid catalysts bridge the gap between enzymatic and heterogeneous catalysis,which is significant for expanding biocatalysis to a broader *** studies have demonstrated that the enzyme-metal hybrid catalysts exhibited considerably higher catalytic efficiency in cascade reactions,compared with that of the combination of separated enzyme and metal ***,the precise mechanism of this phenomenon remains ***,we investigated the diffusion process in enzyme-metal hybrid catalysts using Pd/lipase-Pluronic conjugates and the combination of immobilized lipase(Novozyme 435)and Pd/C as *** reference to experimental data in previous studies,the Weisz-Prater parameter and efficiency factor of internal diffusion were calculated to evaluate the internal diffusion limitations in these ***,a kinetic model was developed and fitted to describe the proximity effect in hybrid *** indicated that the enhanced catalytic efficiency of hybrid catalysts may arise from the decreased internal diffusion limitation,size effect of Pd clusters and proximity of the enzyme and metal active sites,which provides a theoretical foundation for the rational design of enzyme-metal hybrid catalysts.

关键词： enzyme-metal hybrid catalyst internal diffusion proximity effect kinetic model

CEO自恋对高管团队成员工作幸福感的影响:CEO谦卑与领导关系认同的作用

在线全文

学校读者我要写书评

暂无评论

管理工程学报 2025年第2期39卷 206-220页

作者：尹奎赵景宋萌崔国东董念念北京科技大学经济管理学院北京100083 中国人民大学劳动人事学院北京100872 北京工业大学经济管理学院北京100124 山东大学山东省人才发展战略研究院山东济南250100

自恋的CEO在企业中比比皆是,会对员工与组织产生深远影响,而CEO谦卑特质是重要的情境因素。高管团队成员直面CEO并担负着组织内部重要的领导职责,对CEO自恋特质的感知和反应更深刻,其工作幸福感可能也更容易受到影响。基于关系认同理论... 详细信息

自恋的CEO在企业中比比皆是,会对员工与组织产生深远影响,而CEO谦卑特质是重要的情境因素。高管团队成员直面CEO并担负着组织内部重要的领导职责,对CEO自恋特质的感知和反应更深刻,其工作幸福感可能也更容易受到影响。基于关系认同理论,本文构建了一个有中介的调节效应模型,对56位CEO与319位TMT成员的配对数据进行分析,结果表明:CEO自恋对TMT成员工作幸福感产生负向影响;CEO谦卑能够弱化CEO自恋对TMT成员有关领导关系认同的消极影响;TMT成员对领导关系的认同积极影响工作幸福感,中介了CEO谦卑对CEO自恋与TMT成员工作幸福感关系的调节作用。研究拓展了领导自恋影响员工工作幸福感的研究层次与边界情境,揭示了领导关系认同在CEO谦卑弱化CEO自恋消极影响效应中的内在机制,验证了不同领导组合相对于单一领导对领导关系认同与工作幸福感的增强更具有效性,因而丰富了工作幸福感影响因素研究的主体,对CEO的遴选与培训具有潜在的指导意义。

关键词： CEO自恋 CEO谦卑工作幸福感领导关系认同

Propagation of combined longitudinal and torsional stress waves in a functionally graded thin-walled tube

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第12期42卷 1717-1732页

作者： Shitang cui Xiaojun NI CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

An analytical model for the propagation of combined stress waves in a functionally graded thin-walled tube subjected to combined longitudinal and torsional impact loading is *** material properties of the tube are assumed to be continuously graded along the length according to a power law function with respect to the volume fractions of the *** generalized characteristic theory is used to analyze the main features of the characteristic wave speeds and simple wave solutions in the functionally graded thin-walled *** finite difference method is used to discretize the governing *** types of typical solutions are obtained for the functionally graded tube and the homogeneous tube subjected to combined longitudinal and torsional step *** numerical results reveal some abnormal phenomena in the stress path and wave process of the functionally graded thin-walled tube.

关键词： elastoplastic behavior combined stress wave finite difference scheme thinwalled tube

A review on numerical studies of airflow dynamics and particle deposition in human respiratory system Author links open overlay panel

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第8期91卷 351-377页

作者： Hao Jing Xinguang cui School of Aerospace Engineering Huazhong University of Science and TechnologyWuhan430074China

Accurate assessment and prediction of airflow dynamics and particle deposition in the human respiratory tract are essential for human health,involving inhaled drugs for treating various diseases and toxic particles that can cause *** intricate process involves complex multiphase flow with distinct respiratory *** fluid dynamics(CFD)acts as a bridge,overcoming the limitations of in vivo and in vitro experiments and providing a means to fully comprehend and reveal the fundamental mechanisms of respiratory flow and particle behavior on a microscopic *** paper provides a comprehensive overview and concise summary of recent advancements in the numerical simulation of airflow and particle deposition in the human respiratory ***,it summarizes the transition of respiratory tract models from segmented models to emerging physiological characteristic models and whole-lung airway models,and the latest developments on the effects of key factors such as geometric variations,respiratory patterns,and particle physical/chemical properties on respiratory flow and particle deposition.A notable focus of this review is on emerging physiological characteristics models and their associated complex airflow and particle dynamics inside *** paper concludes with recommendations for future research to further advance the development of this field.

关键词： Airflow dynamics Particle deposition Human respiratory system Numerical modeling

Experimental investigation of evolutive mode-I and mode-II fracture behavior of fiber-reinforced cemented paste backfill:Effect of curing temperature and curing time

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2023年第2期17卷 256-270页

作者： Kun FANG Liang cui School of Mines China University of Mining&TechnologyXuzhou 221116China Department of Civil Engineering Lakehead UniversityOntario P7B 5E1Canada

The curing temperature-dependent cement hydration causes the nonlinear evolution of fracture behavior and properties of fiber-reinforced cemented paste backfill(CPB)and thus influences the stability of mine backfill materials in deep ***,the coupled effect of curing temperature(20,35,and 45℃)and cement hydration at different curing times(3,7,and 28 d)on the mode-I and mode-II fracture behavior and properties of fiber-reinforced CPB is investigated.A comprehensive experimental testing program consisting of semicircular bend tests,direct shear tests,measurement of volumetric water content and matric suction,TG/DTG tests,and SEM observation is carried *** results show that the coupled thermochemical effect results in strongly nonlinear development of pre-and post-peak behavior of fiber-reinforced ***,the results discover a positive linear correlation between fracture toughness and shear strength parameters and also reveal the vital role played by matric suction in the formation of fracture ***,predictive functions are developed to estimate the coupled thermochemical effect on the development of KIc and ***,the findings and the developed mathematical tools have the potential to promote the successful application of fiber-reinforced CPB technology in deep underground mines.

关键词： fiber reinforcement cemented paste backfill fracture behavior underground mine cement hydration

Lattice-Boltzmann simulations for analysing the detachment of micron-sized spherical particles from surfaces with large-scale roughness structures

在线全文

学校读者我要写书评

暂无评论

Particuology 2022年第2期20卷 47-59页

作者： Yan cui Martin Sommerfeld School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074HubeiChina Multiphase Flow Systems Institute of Process EngineeringOtto-von-Guericke-University MagdeburgHoher Weg 7bD-06120 Halle(Saale)Germany

Fully resolved numerical simulations of a micron-sized spherical particle residing on a surface with large-scale roughness are performed by using the Lattice-Boltzmann *** aim is to investigate the influence of surface roughness on the detachment of fine drug particles from larger carrier particles for transporting fine drug particles in a DPI(dry powder inhaler).Often the carrier surface is modified by mechanical treatments for modifying the surface roughness in order to reduce the adhesion force of drug ***,drug particle removal from the carrier surface is equivalent to the detachment of a sphere from a rough plane *** a sphere with a diameter of 5μm at a particle Reynolds number of 1.0,3.5 and 10 are *** surface roughness is described as regularly spaced semi-cylindrical asperities(with the axes oriented normal to the flow direction)on a smooth *** influence of asperity distance and size ratio(*** radius of the semi-cylinder to the particle radius,Rc/Rd)on particle adhesion and detachment are *** asperity distance is varied in the range 1.2

关键词： Lattice-Boltzmann method Fully-resolved simulations Particle detachment Surface roughness Semi-cylindrical asperities Particle detachment model

Building three-dimensional pedestrian networks in cities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Underground Space 2021年第2期6卷 217-224页

作者： Jianqiang cui School of Environment and Science Griffith UniversityBrisbaneAustralia

With the rapid growth of automobile transport over the last century,conflicts between automobile and pedestrian transport have been viewed as a major concern in urban and transport *** and underground pedestrian networks,which compensate for sidewalks at the street level and provide alternative options for pedestrians,have been developed in many *** and underground pedestrian networks offer pedestrian–car separation in a vertical dimension and efficient connections between transit services and cities for subway *** study aims to provide a balanced understanding of the development of underground pedestrian networks and propose supportive strategies for decision makers,planners,and designers concerned with the future implementation of underground pedestrian networks and the building of three-dimensional pedestrian networks in *** study applied textual analysis to examine the *** study indicated that three-dimensional pedestrian systems were developed based on historical *** highlighted important considerations(such as dense cities,disaster mitigation and protection,and urban functions)in developing underground pedestrian networks in ***,it discussed significant aspects in planning and designing such networks,including safety,ease of orientation,and *** paper also discussed policy implications in developing underground pedestrian networks and the building of three-dimensional pedestrian networks in cities.

关键词： Pedestrian planning Compact city Underground transport

Topology Optimization of Truss-Like Structure with Stress Constraints Under Multiple-Load Cases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2020年第2期33卷 226-238页

作者： Hao cui Kemin Zhou College of Civil Engineering Huaqiao UniversityNo.668 Jimei AvenueXiamen 361021FujianChina

A new method for topology optimization of truss-like structures with stress constraints under multiple-load cases(MLCs)is presented.A spatial truss-like material model with three families of orthotropic members is adopted,in which the three families of members along three orthotropic directions are embedded continuously in a weak *** densities and directions of the three families of members at the nodes are taken as the design *** optimality criterion is suggested based on the concept of directional ***,under each single-load case(SLC),the truss-like structure is optimized as per the fully stressed ***,the directional stiffness of the optimal structure under an SLC at every node is ***,the directional stiffness of the truss-like structure under MLCs is determined by ensuring that the directional stiffness is as similar as possible to the maximum directional stiffness of the optimal structure under every SLC along all ***,the directions and densities of the members in the optimal truss-like structures under MLCs are obtained by solving the eigenvalue problems of the coefficient matrix of the directional stiffness at every *** examples are presented to demonstrate the effectiveness and efficiency of the method.

关键词： Topology optimization Truss-like structure Stress constraints Multiple-load cases Eigenvalue problem

Molecular Dynamics Simulations of the Effects of Surface Sinusoidal Nanostructures on Nanoscale Liquid Film Phase-Change

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2020年第4期29卷 1076-1084页

作者： CAO Qun cui Zheng Institute of Thermal Science and Technology Shandong UniversityJinan 250061China

Nanostructures on heat transfer surfaces can enhance micro/nanoscale phase-change heat transfer processes. To understand the enhancement mechanisms provided by nanostructures, evaporation processes of nanoscale liquid films on periodic sinusoidal-shaped surfaces were investigated via molecular dynamics simulations. By changing the amplitudes(A) and periods(T) of the curves describing the sinusoidal shapes, which possess shapes similar to f(x)=h0+Asin(2πx/T), sinusoidal surfaces of different sizes were constructed. An unevaporated region always existed on the copper plate for all surfaces during phase-change processes. Moreover, we calculated the interfacial thermal resistances and the mismatches between the vibrational density of states of the solid and liquid for different surfaces. The results show that the argon temperature changes and evaporation rates during the phase-change process on sinusoidal surfaces are higher than those on flat surfaces, and these results increase with the increase in amplitudes and the decrease in periods within certain limits mainly because of the thermal resistance decrease at the solid-liquid interface. Furthermore, the corresponding mismatches between the vibrational density of states of the solid and liquid also decrease, which indicates that the existence of sinusoidal nanostructures enhances the heat transfer of the phase-change process.

关键词： molecular dynamics simulation sinusoidal surface phase-change interfacial thermal resistance nanoscale