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Science China(Technological Sciences) 2024年第9期67卷 2965-2967页

作者： LI Ou lei junbo QIN ChengJin ZHANG ZhiNan TAO JianFeng LIU ChengLiang State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Misfire fault, as a major fault of diesel engines, usually occurs because of low fuel quality, insufficient compression, ignition system failure, *** engines may experience issues such as reduced power, increased fuel consumption, and increased noise when misfire happens. Therefore, timely detection and diagnosis of diesel engine misfire faults are of great significance in the industry [1].

关键词： Diesel diagnosis network

The Application of Analytic Hierarchy Process Method in the Evaluation of Educational Quality in Colleges and Universities

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Journal of Contemporary Educational Research 2024年第7期8卷 335-342页

作者： junbo lei Yanxia Xu Junpeng Wang School of Foreign Languages Heilongjiang University of Business and TechnologyHarbin 150025Heilongjiang ProvinceChina School of Foreign Language Harbin Cambridge UniversityHarbin 150086Heilongjiang ProvinceChina English Department Heilongjiang International UniversityHarbin 150500Heilongjiang ProvinceChina

Talent quality is the lifeline of colleges and *** on employment guidance,this paper establishes a student quality evaluation and control system including knowledge,moral character,and ability,and uses the Analytic Hierarchy Process(AHP)method to analyze the factors affecting the quality of education in colleges and *** addition,some suggestions are provided to improve the quality of students.

关键词： Student quality Knowledge Ability Literacy

Nonlinear Static and Dynamic Stiffness Characteristics of Support Hydraulic System of TBM

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Chinese Journal of Mechanical Engineering 2019年第6期32卷 26-34页

作者： Jianfeng Tao junbo lei Chengliang Liu Wei Yuan School of mechanical engineering Shanghai Jiaotong UniversityShanghai 200240China School of Electronic Information Jiangsu University of Science and TechnologyZhenjiang 212003China

Full-face hard rock tunnel boring machines(TBM)are essential equipment in highway and railway tunnel engineering *** the tunneling process,TBM have serious vibrations,which can damage some of its key *** support system,an important part of TBM,is one path through which vibrational energy from the cutter head is *** reduce the vibration of support systems of TBM during the excavation process,based on the structural features of the support hydraulic system,a nonlinear dynamical model of support hydraulic systems of TBM is *** influences of the component structure parameters and operating conditions parameters on the stiffness characteristics of the support hydraulic system are *** analysis results indicate that the static stiffness of the support hydraulic system consists of an increase stage,stable stage and decrease *** static stiffness value increases with an increase in the *** pre-compression length of the spring in the relief valve a ects the range of the stable stage of the static stiffness,and it does not a ect the static stiffness *** dynamic stiffness of the support hydraulic system consists of a U-shape and reverse *** bottom value of the U-shape increases with the amplitude and frequency of the external force acting on the cylinder body,however,the top value of the reverse U-shape remains *** study instructs how to design the support hydraulic system of TBM.

关键词： Tunnel boring machine Support hydraulic system Nonlinear model Static stiffness characteristics Dynamic stiffness characteristics

COMPUTERIZED PREDICTION SYSTEM FOR THERMOPHYSICAL PROPERTIES

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中国有色金属学会会刊：英文版 1997年第2期7卷 30-34页

作者： Zhang, Jiayun Ma, Yongjian Zhou, Tuping lei, junbo Fang, Xueliang Univ of Science & Technology Beijing Beijing China

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ＣＯＭＰＵＴＥＲＩＺＥＤＰＲＥＤＩＣＴＩＯＮＳＹＳＴＥＭＦＯＲＴＨＥＲＭＯＰＨＹＳＩＣＡＬＰＲＯＰＥＲＴＩＥＳ①ＺｈａｎｇＪｉａｙｕｎ，ＭａＹｏｎｇｊｉａｎ，ＺｈｏｕＴｕｐｉｎｇ，ＬｅｉＪｕｎｂｏ，ＦａｎｇＸｕｅｌｉａｎｇＤｅｐａｒｔｍｅｎｔｏｆＰ...

关键词： prediction of thermophysical property intellectualized data base management system metallic melt ionic melt

Fast scaling approach based on cavitation conditions to estimate the speed limitation for axial piston pump design

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Frontiers of Mechanical Engineering 2021年第1期16卷 176-185页

作者： Qun CHAO Jianfeng TAO junbo lei Xiaoliang WEI Chengliang LIU Yuanhang WANG Linghui MENG State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China China Electronic Product Reliability and Environmental Testing Research Institute Guangzhou 510610China

The power density of axial piston pumps can benefit greatly from increased rotational ***,the maximum rotational speed of axial piston machines is limited by the cavitation phenomenon for a given volumetric *** paper presents a scaling law derived from an analytical cavitation model to estimate the speed limitations for the same series of axial piston *** cavitation model is experimentally verified using a high-speed axial piston pump,and the scaling law is validated with open specification data in product *** show that the speed limitation is approximately proportional to the square root of the inlet pressure and inversely proportional to the cube root of volumetric ***,a characteristic constant is defined based on the presented scaling *** constant can represent the comprehensive capacity of axial piston pumps free from cavitation.

关键词： axial piston pump cavitation speed limitation scaling law

Development and evaluation of an online monitoring single-particle optical particle counter with polarization detection

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Journal of Environmental Sciences 2024年第4期138卷 585-596页

作者： Weijie Yao Xiaole Pan Yu Tian Hang Liu Yuting Zhang Shandong lei junbo Zhang Yinzhou Zhang LinWu Yele Sun Zifa Wang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

We developed a single-particle optical particle counter with polarization detection(SOPC)for the real-time measurement of the optical size and depolarization ratio(defined as the ratio of the vertical component to the parallel component of backward scattering)of atmospheric particles,the polarization ratio(DR)value can reflect the irregularity of the *** SOPC can detect aerosol particles with size larger than 500 nm and the maximum particle count rate reaches~1.8×10^(5)particles per *** SOPC uses a modulated polarization laser to measure the optical size of particles according to forward scattering signal and the DR value of the particles by backward S and P signal *** sampling rate of the SOPC was 106#/(sec·channel),and all the raw data were processed *** calibration curve was obtained by polystyrene latex spheres with sizes of 0.5-10μm,and the average relative deviation of measurement was 3.96% for sub 3μm particles.T-matrix method calculations showed that the DR value of backscatter light at 120°could describe the variations in the aspect ratio of particles in the above size *** performed insitu observations for the evaluation of the SOPC,the mass concentration constructed by the SOPC showed good agreement with the PM_(2.5)measurements in a nearby state-controlled monitoring *** instrument could provide useful data for source appointment and regulations against air pollution.

关键词： Instrument development Single particle detection Measurement uncertainty Optical simulation Mass concentration

Porous silica nano-flowers stabilized Pt-Pd bimetallic nanoparticles as heterogeneous catalyst for efficiently synthesizing guaiacol from 2-methoxycyclohexanol

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Chinese Journal of Chemical Engineering 2024年第6期70卷 222-233页

作者： junbo Feng Junyan Wu Dongdong Yan Yadong Zhang School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Coking Coal Exploitation and Comprehensive Utilization Pingdingshan 467000China Jiyuan Research Institute Zhengzhou UniversityJiyuan 459000China School of Materials and Chemical Engineering Zhongyuan University of TechnologyZhengzhou 450007China

Porous silica nano-flowers(KCC-1)immobilized Pt-Pd alloy NPs(Pt-Pd/KCC-1)with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction,using hydrazinium hydroxide as a reducing *** as-synthesized silica nanospheres possess radial fibers with a distance of 15 nm,exhibiting a high specific surface area(443.56 m^(2)·g^(-1)).Meanwhile,the obtained Pt-Pd alloy NPs are uniformly dispersed on the silica surface with a metallic particle size of 4-6 nm,which exist as metallic Pd and Pt on the surface of monodisperse KCC-1,showing the transfer of electrons from Pd to *** as-synthesized 2.5%Pt-2.5%Pd/KCC-1 exhibited excellent catalytic activity and stability for the continuous dehydrogenation of 2-methoxycyclohexanol to prepare *** with Pt or Pd single metal supported catalysts,the obtained 2.5%Pt-2.5%Pd/KCC-1 shows 97.2%conversion rate of 2-methoxycyclohexanol and 76.8%selectivity for guaiacol,which attributed to the significant synergistic effect of bimetallic Pt-Pd alloy ***,turn over frequency value of the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs achieved 4.36 s^(-1),showing higher catalytic efficiency than other two monometallic *** pathways of dehydro-aromatization of 2-methoxycyclohexanol over the obtained catalyst are ***,the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs prove their potential in the dehydrogenation of 2-methoxycyclohexanol,while the kinetics and mechanistic study of the dehydrogenation reaction over the catalyst in a continuous fixed-bed reactor may provide valuable information for the development of green,outstanding and powerful synthetic pathway of guaiacol.

关键词： Supported catalyst Nanoparticles Dehydrogenation 2-Methoxycyclohexanol Guaiacol

Recent progress in the development of dielectric elastomer materials and their multilayer actuators

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 183-205页

作者： Shengchao JIANG junbo PENG Lvting WANG Hanzhi MA Ye SHI ZJU-UIUC Institute Zhejiang UniversityJiaxing 314400China College of Mechanical Engineering Zhejiang UniversityHangzhou 310058China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310058China

Dielectric elastomers(DEs)have emerged as one of the most promising artificial muscle technologies,due to their exceptional properties such as large actuation strain,fast response,high energy density,and flexible processibility for various *** the past two decades,researchers have been working on developing DE materials with improved properties and exploring innovative applications of dielectric elastomer actuators(DEAs).This review article focuses on two main topics:recent material innovation of DEs and development of multilayer stacking processes for DEAs,which are important to promoting commercialization of *** begins by explaining the working principle of a ***,recently developed strategies for preparing new DE materials are introduced,including reducing mechanical stiffness,increasing dielectric permittivity,suppressing viscoelasticity loss,and mitigating electromechanical instability without *** the next section,different multilayer stacking methods for fabricating multilayer DEAs are discussed,including conventional dry stacking,wet stacking,a novel dry stacking method,and micro-fabrication-enabled stacking *** review provides a comprehensive and up-to-date overview of recent developments in high-performance DE materials and multilayer stacking *** highlights the progress made in the field and also discusses potential future directions for further advancements.

关键词： Dielectric elastomer actuator(DEA) Dielectric elastomer(DE) Material svnthesis Multilaver stacking method

Experimental and numerical analyses of the effect of fibre content on the close-in blast performance of a UHPFRC beam

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Defence Technology（防务技术） 2024年第1期31卷 242-261页

作者： junbo Yan Qiyue Zhang Yan Liu Yingliang Xu Zhenqing Shi Fan Bai Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Limited research has been conducted on the influences of fiber content on close-in blasting characteristics for ultrahigh-performance fiber-reinforced concrete(UHPFRC)*** paper aims to address this knowledge gap through experimental and mesoscale numerical *** were conducted on ten UHPFRC beams built with varying steel fiber volumetric fractions subjected to close-in explosive ***,this study considered other parameters,such as the longitudinal reinforcement type and *** the case of UHPFRC beams featuring normal-strength longitudinal reinforcement of diametersΦ12,Φ16,andΦ20,a reduction in maximum displacement by magnitudes of19.6%,19.5%,and 17.4%was observed,respectively,as the volumetric fractions of fiber increased from1.0%to 2.5%.In addition,increasing the longitudinal reinforcement ratio and using high-strength steel longitudinal reinforcement both significantly reduced the deformation characteristics and increase the blasting resistances of UHPFRC ***,the effects on the local crushing and spalling damage were not significant.A mesoscale finite element model,which considers the impacts of fiber parameters on UHPFRC beam behaviors,was also established and well correlated with the test ***,parametric analyses were further conducted to examine the impacts of the steel fiber content and length and the hybrid effects of various types of microfibers and steel fibers on the blasting performance of UHPFRC beams.

关键词： Blast performance Close-in blast Fiber content Mesoscale approach UHPFRC beams

High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

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Defence Technology（防务技术） 2024年第2期32卷 553-571页

作者： Xu Li Yan Liu junbo Yan Zhenqing Shi Hongfu Wang Yingliang Xu Fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China China Research and Development Academy of Machinery Equipment Beijing100089China

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 *** study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic *** the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/*** erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered *** examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration ***,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation ***,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present *** upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or *** to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

关键词： High-speed penetration Concrete target Erosion Projectile nose evolution model