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Origin and evolution of false brinelling and fretting corrosion under rolling conditions

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Friction 2024年第4期12卷 618-631页

作者： Xin JIA Lu HUANG Miao SUN wenbin li National Institute of Metrology Beijing 100029China Yantai Tiancheng Machinery Co. Ltd.Yantai 264006China

Rolling bearings working in oscillating applications often suffer from false brinelling and fretting corrosion that limit their service *** present,the study of oscillation-induced failures is primarily dominated by a large number of sliding and bench ***,most of the previous work are not able to fully describe the two closely related but different failure *** this study,the origin and evolution of the two failures are thoroughly investigated under strictly controlled oscillating rolling *** results show that failure evolves from false brinelling to fretting corrosion under dry friction conditions regardless of the oscillation *** process is accompanied by a large area peeling and serious oxidation,and the oxygen content increases from 2.50 wt%to 21.22 wt%.Oxidation is a crucial factor in the evolution of false brinelling into fretting ***,the distribution of microwear and oxygen content depend on the oscillation *** lubrication conditions,the friction coefficient(COF)is smaller in the initial stage and led to local slip or transient instability of rolling ***,the size of the wear marks and COF increased and appeared to be larger than those under a dry friction ***,grease can separate the contact surfaces,only surface deformation owing to false brinelling and slight damage at the roughness level *** evolution of false brinelling and fretting corrosion is also closely related to residual *** brinelling often occurrs with residual stress accomulation,meanwhile,the residual stress increases from 120 to 300 *** peeling occurs,residual stress is *** failure pattern transformed from false brinelling to fretting corrosion and is accompanied by *** far,none of investigation is able to show satisfactory evolution of oscillating-induced failures,this study may contribute to more scientific understanding of rolling bearings against long-

关键词： oscillating false brinelling fretting corrosion wear residual stress

Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

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Defence Technology（防务技术） 2024年第3期33卷 295-307页

作者： Dou Hong wenbin li Yu Zheng Yiming li Ning Jiang Kebin Zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjingChina

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation *** study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 *** penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was *** was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear *** the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were ***,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target *** results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter *** equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

关键词： Impact damage Ultimate penetration velocity Bulge height Target penetration energy Failure modes

Jet formation and penetration performance of a double-layer charge liner with chemically-deposited tungsten as the inner liner

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Defence Technology（防务技术） 2024年第3期33卷 374-385页

作者： Bihui Hong wenbin li Yiming li Zhiwei Guo Binyou Yan Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjing 210094China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Xiamen Tungsten Co. Ltd.Xiamen 361004China

This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner *** feasibility of this design was evaluated through penetration ***-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper *** microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration *** shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation *** results showed that the double-layer liners could form well-shaped *** errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated *** with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% *** summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.

关键词： Shaped charge Chemical vapor deposition Tungsten Double-layer charge liner X-ray Penetration

Electrolyte-gated SrCoO_(x) FET sensor for highly sensitive detecting pH in extreme alkalinity solution

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Nano Research 2024年第4期17卷 3079-3086页

作者： Han Zhou Gaocan Qi wenbin li Yuhang Wang Zhihao Yuan School of Materials Science and Engineering Tianjin Key Lab of Photoelectric Materials&Devicesand Key Laboratory of Display Materials and Photoelectric Devices(Ministry of Education)Tianjin University of TechnologyTianjin 300384China

The pH monitoring is significantly important in chemical industry,biological process,and pollution ***,it remains a great challenge to measure pH in extreme alkalinity ***,we employ an electrolyte-gated field-effect-transistor(FET)strategy using non-stoichiometric SrCoO_(x) with rich oxygen-vacancy defects as channel materials for detecting extreme *** corresponding channel can provide effective oxygen-ion-migration sites for reversible transformation of OH-↔O_(2)-+H^(+)driven by electric *** resultant electrolyte-gated FET sensor exhibits a sensitive linear response to high concentrations of alkaline solution,1–20 ***,the sensor has the ability to directly indicate the pH values ranging from 14.0 to 17.0 in consideration of ion-activity coefficient *** work offers a great possibility for directly detecting base concentration as well as pH values in extreme alkaline solutions.

关键词： field-effect-transistor(FET) pH sensor extreme alkaline solution SrCoO_(x) oxygen-ion migration

Research progress on simulation of multiscale mass transfer processes in gas-solid system by computational mass transfer

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Particuology 2024年第7期90卷 478-492页

作者： Xu li Yaohui Wang Leifu li Runye Zhang Hailun Ren wenbin li Zhongli Tang Donghui Zhang The Research Center of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China The Department of Chemical Engineering Tianjin Renai CollegeTianjin 301636China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Particle-fluid system is one of the most popular systems in chemical *** to complex interface structure and high-velocity turbulence,the momentum and mass transfer exhibit nonlinear characteristics,which pose a great challenge for further study and *** solve this problem,computational mass transfer(CMT)emerged and has been proved to be effective in deeply exploring the mass transfer behavior of particle-fluid ***,this paper reviews recent gas-solid numerical studies of turbulence issues from empirical to theoretical,then discusses interphase mass transfer rate models and the interfacial interaction ***,the present study particularly reviews researches on mass transfer process of fixed and fluidized regime by CMT,providing reliable analysis of turbulent anisotropy diffusivity as well as multiscale structure and presenting theoretical instruction for the industrial optimization of mass transfer processes in chemical engineering.

关键词： Fixed bed Fluidized bed Computational mass transfer Turbulent mass diffusion Multiscale Anisotropy

Covalent triazine frameworks materials for photo-and electrocatalysis

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Nano Research 2024年第9期17卷 7830-7839页

作者： Aoji liang wenbin li Anbai li Hui Peng Guofu Ma Lei Zhu Ziqiang Lei Yuxi Xu Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education Key Laboratory of Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou 730070China School of Chemistry and Materials Science Hubei Key Laboratory of Quality Control of Characteristic Fruits and VegetablesHubei Engineering UniversityXiaogan 432000China School of Engineering Westlake UniversityHangzhou 310024China

Covalent triazine frameworks(CTFs)are a class of unique two-dimensional nitrogen-rich triazine framework with adjustable chemical and electronic structures,rich porosity,good stability and excellent semiconductivity,which enable great various applications in efficient gas/molecular adsorption and separation,energy storage and conversion,especially photo-and *** synthesis strategies strongly affect the morphology of CTFs and play an important role in their structure and *** this concept,we provide a comprehensive and systematic review of the synthesis methods such as ionothermal synthesis,phosphorus pentoxide catalytic method,polycondensation and ultra-strong acid catalyzed method,and applications of CTFs in photo-and *** we offer some insights into the future development progress of CTFs materials for catalytic applications.

关键词： covalent triazine frameworks synthetic strategy photocatalysis electrocatalysis

High adsorption selectivity of activated carbon and carbon molecular sieve boosting CO_(2)/N_(2) and CH_(4)/N_(2) separation

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Chinese Journal of Chemical Engineering 2024年第3期67卷 282-297页

作者： Siang Chen Wenling Wu Zhaoyang Niu Deqi Kong wenbin li Zhongli Tang Donghui Zhang The Research Center of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Flue gas and coal bed methane are two important sources of greenhouse *** swing adsorption process has a wide range of application in the field of gas separation,and the selection of adsorbent is *** this regard,in order to assess the better adsorbent for separating CO_(2) from flue gas and CH_(4) from coal bed methane,adsorption isotherms of CO_(2),CH_(4) and N_(2) on activated carbon and carbon molecular sieve are measured at 303.15,318.15 and 333.15 K,and up to 250 *** experimental data fit better with Langmuir 2 compared to Langmuir 3 and Langmuir-Freundlich models,and Clausius-Clapeyron equation was used to calculate the isosteric *** the order of the adsorbed amount and the adsorption heat on the two adsorbents are CO_(2)>CH_(4)>N_(2).The adsorption kinetics are calculated by the pseudo-first kinetic model,and the order of adsorption rates on activated carbon is N_(2)-CH_(4)>CO_(2),while on carbon molecular sieve,it is CO_(2)-N_(2)>CH_(4).It is shown that relative molecular mass and adsorption heat are the primary effect on kinetics for activated carbon,while kinetic diameter is the main resistance factor for carbon molecular ***,the adsorption selectivity of CH_(4)/N_(2) and CO_(2)/N_(2) were estimated with the ideal adsorption solution theory,and carbon molecular sieve performed best at 318.15 K for both CO_(2) and CH_(4) *** study suggested that activated carbon is a better choice for separating flue gas and carbon molecular sieve can be a strong candidate for separating coal bed methane.

关键词： Activated carbon Carbon molecular sieve Adsorbent evaluation Adsorption equilibrium and kinetics Heat of adsorption Selectivity

Design of multi-section luffing apple pruning equipment and cutting test of the key components

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 109-117页

作者： Siyuan Tong wenbin li Yaxiong Wang Lei Zhang Feng Kang School of Technology Beijing Forestry UniversityKey Lab of State Forestry and Grassland Administration for Forestry Equipment and AutomationBeijing 100083China

In order to reduce the labor intensity and improve the efficiency of pruning,this study designed a multi-section luffing apple pruning equipment suitable for apple orchards in hilly and mountainous areas of *** the essay,the structure and working principle of the equipment are expounded,the cutter was analyzed,and the parameters were *** the self-made test bench to simulate the field experiment,this study selected the ratio of cutting speed to feeding speed and feeding speed as the influencing factors and took the cut-off rate,cutting efficiency and cutting power as the objectives to carry out single factor experiment and quadratic regression orthogonal *** test results show that the cutting power increases with the increase of ratio of cutting speed to feeding speed,and the cut-off rate and cutting efficiency first increase and then *** the feeding speed increases,the cutting efficiency and power increase,and the cut-off rate *** the cutoff rate was greater than 80%,the optimal combination of operating parameters was the feeding speed of 0.55 m/s and ratio of cutting speed to feeding speed of *** this combination,the cut-off rate was 84.9%,the cutting efficiency was 13.1,and the cutting power was 175.7 *** error between the predicted target value of the model and the average measured target value was less than 7%,so the test results are *** to the obtained optimal operating parameters,the actual cutting experiment of the pruning equipment in the field was carried out,and the cutting rate was 96.3%,which meet the design *** study can also meet the needs of mechanized pruning of fruit trees with different crown shapes,improve the applicability of pruning equipment,and provide support for the development of mechanized pruning equipment in China.

关键词： apple pruning equipment cutting test optimal parameters regression analysis

Uncertainties of landslide susceptibility prediction:influences of different study area scales and mapping unit scales

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International Journal of Coal Science & Technology 2024年第2期11卷 143-172页

作者： Faming Huang Yu Cao wenbin li Filippo Catani Guquan Song Jinsong Huang Changshi Yu School of Civil Engineering and Architecture Nanchang UniversityNanchang 330031China Hebei International Joint Research Center for Remote Sensing of Agricultural Drought Monitoring/School of Land Science and Space Planning Hebei GEO UniversityShijiazhuang 050031China Department of Geosciences University of PadovaPaduaItaly Discipline of Civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringUniversity of NewcastleCallaghanNSWAustralia School of Information Engineering Nanchang UniversityNanchang 330031China

This study aims to investigate the effects of different mapping unit scales and study area scales on the uncertainty rules of landslide susceptibility prediction(LSP).To illustrate various study area scales,Ganzhou City in China,its eastern region(Ganzhou East),and Ruijin County in Ganzhou East were *** mapping unit scales are represented by grid units with spatial resolution of 30 and 60 m,as well as slope units that were extracted by multi-scale segmentation *** 3855 landslide locations and 21 typical environmental factors in Ganzhou City are first determined to create spatial datasets with ***,landslide susceptibility maps(LSMs)of Ganzhou City,Ganzhou East and Ruijin County are pro-duced using a support vector machine(SVM)and random forest(RF),*** LSMs of the above three regions are then extracted by mask from the LSM of Ganzhou City,along with the LSMs of Ruijin County from Ganzhou ***,LSMs of Ruijin at various mapping unit scales are generated in *** and landslide suscepti-bility indexes(LSIs)distribution are used to express LSP *** LSP uncertainties under grid units significantly decrease as study area scales decrease from Ganzhou City,Ganzhou East to Ruijin County,whereas those under slope units are less affected by study area *** course,attentions should also be paid to the broader representativeness of large study *** LSP accuracy of slope units increases by about 6%–10%compared with those under grid units with 30 m and 60 m resolution in the same study area's *** significance of environmental factors exhibits an averaging trend as study area scale increases from small to *** importance of environmental factors varies greatly with the 60 m grid unit,but it tends to be consistent to some extent in the 30 m grid unit and the slope unit.

关键词： Landslide susceptibility prediction Uncertainty analysis Study areas scales Mapping unit scales Slope units Random forest