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Study of poly-disperse aerosols deposition in turbulent flow with different Reynolds numbers

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Particuology 2024年第6期89卷 32-43页

作者： Zhichao Gao Yongzheng chen Dandi Zhang Peng chen Lili Tong Xuewu Cao School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240China China Nuclear Power Technology Research Institute Co. Ltd.Shenzhen518000China

The turbulent deposition mechanism is one of the main mechanisms of aerosol deposition in nuclear power plant *** experimental study of poly-disperse aerosol deposition in a horizontal tube is conducted,where the nominal Reynolds number(Re)is in a range of 3600–200,*** aerosol deposition velocity first increases and then decreases with the increase of Res,and at high Re,particle rebound occurs during aerosol deposition in the *** the Re is low,the aerosol deposition velocity increases with the increase of aerosol *** the Re is greater than 60,000,the deposition velocity first increases and then decreases with the increase of aerosol diameter due to particle surface rebound.A new aerosol deposition model has been developed by establishing the energy conservation equation of the rebounded particles in the viscous *** calculated results of the new model are in good agreement with these experimental results,and the error between the aerosol deposition velocity calculated by the model and experimental results is between−60%and 150%.

关键词： Aerosol Turbulent deposition Rebound High Reynolds number

Vibration-assisted vat photopolymerization for pixelated-aliasing-free surface fabrication

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International Journal of Extreme Manufacturing 2024年第3期6卷 440-456页

作者： Han Xu Renzhi Hu Shuai chen Junhong Zhu Chi Zhou Yong chen Center for Advanced Manufacturing University of Southern CaliforniaLos AngelesCA 90007United States of America Daniel J.Epstein Department of Industrial and Systems Engineering University of Southern CaliforniaLos AngelesCA 90089United States of America Department of Aerospace and Mechanical Engineering University of Southern CaliforniaLos AngelesCA 90089United States of America Department of Industrial and Systems Engineering University of BuffaloBuffaloNY 14260United States of America

Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and ***,MIP-VPP employing liquid crystal displays(LCDs)has gained traction,increasingly replacing digital micromirror devices,particularly among hobbyists and in educational settings,and is now beginning to be used in industrial ***,LCD-based MIP-VPPsuffers from pronounced pixelated aliasing arising from LCD’s discrete image pixels and itsdirect-contact configuration in MIP-VPP machines,leading to rough surfaces on the 3D-printed ***,we propose a vibration-assisted MIP-VPP method that utilizes a microscalevibration to uniformize the light intensity distribution of the LCD-based mask image on VPP’s building *** maintaining the same fabrication speed,our technique generates asmoother,non-pixelated mask image,reducing the roughness on flat surfaces and boundary segments of 3D-printed *** light intensity modeling and simulation,we derived an optimal vibration pattern for LCD mask images,subsequently validated by *** assessed the surface texture,boundary integrity,and dimensional accuracy of componentsproduced using the vibration-assisted *** notably smoother surfaces and improved boundary roughness enhance the printing quality of MIP-VPP,enabling its promisingapplications in sectors like the production of 3D-printed optical devices and others.

关键词： additive manufacturing vat photopolymerization piezo vibration sub-pixel resolution aliasing

Enhancing the mechanical properties of casting eutectic high -entropy alloys via W addition

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1364-1372页

作者： Xu Yang Dezhi chen Li Feng Gang Qin Shiping Wu Ruirun chen National Key Laboratory for Precision Hot Processing of Metals School of Material Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

The effect of W element on the microstructure evolution and mechanical properties of Al_(1.25)CoCrFeNi3 eutectic high-entropy alloy and Al_(1.25)CoCrFeNi_(3-x)W_(x)(x=0,0.05,0.1,0.3,and 0.5;atomic ratio)high-entropy alloys(HEAs)were *** show that the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs are composed of face-centered cubic and body-centered cubic(BCC)*** W content increases,the microstructure changes from eutectic to *** addition of W lowers the nucleation barrier of the BCC phase,decreases the valence electron concentration of the HEAs,and replaces Al in the BCC phase,thus facilitating the nucleation of the BCC *** results show that the addition of W greatly improves the mechanical properties,and solid-solution,heterogeneous-interface,and second-phase strengthening are the main strengthening *** yield strength,tensile strength,and elongation of the Al_(1.25)CoCrFeNi2.95W0.05 HEA are 601.44 MPa,1132.26 MPa,and 15.94%,respectively,realizing a balance between strength and *** fracture mode of the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs is ductile–brittle mixed fracture,and the crack propagates and initiates in the BCC *** eutectic lamellar structure impedes crack propagation and maintains plasticity.

关键词： high-entropy alloy microstructure mechanical property fracture behavior

Uncertainty quantification of mechanism motion based on coupled mechanism—motor dynamic model for ammunition delivery system

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Defence Technology（防务技术） 2024年第3期33卷 125-133页

作者： Jinsong Tang Linfang Qian Longmiao chen Guangsong chen Mingming Wang Guangzu Zhou Nanjing University of Science and Technology Nanjing 210094China Northwest Institute of Mechanical and Electrical Engineering Xianyang 712099China

In this paper,a dynamic modeling method of motor driven electromechanical system is presented,and the uncertainty quantification of mechanism motion is investigated based on this *** main contribution is to propose a novel mechanism-motor coupling dynamic modeling method,in which the relationship between mechanism motion and motor rotation is established according to the geometric coordination of the *** advantages of this include establishing intuitive coupling between the mechanism and motor,facilitating the discussion for the influence of both mechanical and electrical parameters on the mechanism,and enabling dynamic simulation with controller to take the randomness of the electric load into *** simulation considering feedback control of ammunition delivery system is carried out,and the feasibility of the model is verified *** on probability density evolution theory,we comprehensively discuss the effects of system parameters on mechanism motion from the perspective of uncertainty *** work can not only provide guidance for engineering design of ammunition delivery mechanism,but also provide theoretical support for modeling and uncertainty quantification research of mechatronics system.

关键词： Ammunition delivery system Electromechanical coupling dynamics Uncertainty quantification Generalized probability density evolution

Single-Ni-atoms on nitrogenated humic acid based porous carbon for CO_(2) electroreduction

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 37-47页

作者： Delei Yu Ying chen Yao chen Xiangchun Liu Xianwen Wei Ping Cui Anhui Key Laboratory of Coal Clean Conversion&Utilization School of Chemistry and Chemical EngineeringAnhui University of TechnologyMa’anshan 243002Chin

tWe proposed a facile synthesis of single-Ni-atom catalysts on low-cost porous carbon using a calcina-tion method at the temperatures of 850-1000°C,which were used for CO_(2) electrochemical reduction to *** porous carbon was prepared by carbonizing cheap and abundant humic *** structural characterizations of the as-synthesized catalysts and their electrocatalytic performances were *** results showed that the single-Ni-atom catalyst activated at 950°C showed an optimum catalytic performance,and it reached a CO Faradaic efficiency of 91.9% with a CO partial current density of 6.9 mAcm^(-2)at-0.9 V *** hydrogen electrode(RHE).Additionally,the CO Faradaic efficiency and current density of the optimum catalyst changed slightly after 8 h of continuous operation,suggesting that it possessed an excellent *** structure-activity relations indicate that the variation in the CO_(2) electroche-mical reduction performance for the as-synthesized catalysts is ascribed to the combined effects of the increase in the content of pyrrolic N,the evaporation of Ni and N,the decrease in pore volume,and the change in graphitization degree.

关键词： CO_(2) electroreduction single-Ni-atom cataly-sts humic acid based porous carbon

Rock mass quality prediction on tunnel faces with incomplete multi-source dataset via tree-augmented naive Bayesian network

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International Journal of Mining Science and Technology 2024年第3期34卷 323-337页

作者： Hongwei Huang chen Wu Mingliang Zhou Jiayao chen Tianze Han Le Zhang Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Qingdao Guoxin Second Jiaozhou Bay Subsea Tunnel Co. Ltd.Qingdao 266071China

Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel *** tunneling practice,the rock mass quality is often assessed via a combination of qualitative and quantitative ***,due to the harsh on-site construction conditions,it is rather difficult to obtain some of the evaluation parameters which are essential for the rock mass quality *** this study,a novel improved Swin Transformer is proposed to detect,segment,and quantify rock mass characteristic parameters such as water leakage,fractures,weak *** site experiment results demonstrate that the improved Swin Transformer achieves optimal segmentation results and achieving accuracies of 92%,81%,and 86%for water leakage,fractures,and weak interlayers,respectively.A multisource rock tunnel face characteristic(RTFC)dataset includes 11 parameters for predicting rock mass quality is *** the limitations in predictive performance of incomplete evaluation parameters exist in this dataset,a novel tree-augmented naive Bayesian network(BN)is proposed to address the challenge of the incomplete dataset and achieved a prediction accuracy of 88%.In comparison with other commonly used Machine Learning models the proposed BN-based approach proved an improved performance on predicting the rock mass quality with the incomplete *** utilizing the established BN,a further sensitivity analysis is conducted to quantitatively evaluate the importance of the various parameters,results indicate that the rock strength and fractures parameter exert the most significant influence on rock mass quality.

关键词： Rock mass quality Tunnel faces Incomplete multi-source dataset Improved Swin Transformer Bayesian networks

Chain Dynamics Heterogeneity in Plasticized Poly(vinyl butyral)(PVB) as Elucidated by Solid-State NMR

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Chinese Journal of Polymer Science 2024年第1期42卷 113-124,I0010页

作者： Jing Lv Xu chen Zi-Shuo Wu Ya-Hui Li Wei chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Scienceand Technology of ChinaHefei 230026China

The chain dynamics heterogeneity of the poly(vinyl butyral)(PVB) plasticized by triethylene glycol bis(2-ethylhexa noate)(TEG-EH) was investigated by various solid-state NMR *** plasticized PVB shows two domains in distinct molecular dynamics differences,namely,rigid and soft domains,where the latter is the plasticizer-rich *** time domain low field NMR was first used to investigate the dynamics heterogeneity of the plasticized PVB,and the results show the decreasing activated energy of components in the soft domain of plasticized PVB(E_a=20.2 kJ/mol) as compared with that of the pristine one(E_a=24.3 kJ/mol).Detailed dynamics heterogeneity was obtained by high-field NMR with site-specific *** quadrupole-echo ~2H-NMR was adopted to elucidate the dynamics heterogeneity of the vinyl alcohol(VA) units,where only the hydroxyl group of VA is *** ~1H-^(13)C WISE NMR spectra show that there is not much difference in the mobility of the VB unit in PVB with and without plasticizer,whereas the glass transition temperature differed by approximately 53℃.This is further supported by Torchia's T_1 relaxation *** origin of such an unusual phenomenon is attributed to the critical role of the remaining VA(~22%) in the soft domain,where the VA units locally aggregate through hydrogen ***,the existence of a mobility gradient in the VB unit has been ***,the mobility difference for VB with different stereo-geometry(meso or racemic conformation) is observed for the first *** indicates the importance of modulating the ratio of meso over racemic VB for controlling the macroscopic perfo rmance of PVB.

关键词： Poly(vinyl butyral) Dynamics heterogeneity Plasticizer Solid state NMR

SWIR FluorescenceImaging In Vivo Monitoring and Evaluating Implanted M2 Macrophages in Skeletal Muscle Regeneration

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Engineering 2024年第2期33卷 283-294页

作者： Mo chen Yuzhou chen Sijia Feng Shixian Dong Luyi Sun Huizhu Li Fuchun chen Nguyen Thi Kim Thanh Yunxia Li Shiyi chen You Wang Jun chen Sports Medicine Institute of Fudan University Department of Sports MedicineHuashan HospitalFudan UniversityShanghai 200040China Department of Bone and Joint Surgery Department of OrthopedicsRenji HospitalSchool of MedicineShanghai Jiaotong UniversityShanghai 200127China Department of Anatomy and Physiology School of MedicineShanghai Jiao Tong UniversityShanghai 200025China Key Laboratory of Infrared System Detection&Imaging Technology Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China Biophysics Group Department of Physics and AstronomyUniversity College LondonLondon WC1E 6BTUK Healthcare Biomagnetic and Nanomaterials Laboratories University College LondonLondon W1S 4BSUK

Skeletal muscle has a robust regeneration ability that is impaired by severe injury,disease,and *** in a decline in skeletal muscle ***,improving skeletal muscle regeneration is a key challenge in treating skeletal muscle-related *** to their significant role in tissue regeneration,implantation of M2 macrophages(M2MФ)has great potential for improving skeletal muscle ***,we present a short-wave infrared(SWIR)fluorescence imaging technique to obtain more in vivo information for an in-depth evaluation of the skeletal muscle regeneration effect after M2MФ*** fluorescence imaging was employed to track implanted M2MФin the injured skeletal muscle of mouse *** is found that the implanted M2MФaccumulated at the injury site for two ***,SWIR fluorescence imaging of blood vessels showed that M2MФimplantation could improve the relative perfusion ratio on day 5(1.09±0.09 vs 0.85±0.05;p=0.01)and day 9(1.38±0.16 vs 0.95±0.03;p=0.01)post-injury,as well as augment the degree of skeletal muscle regencration on day 13 ***,multiple linear regression analyses determined that post-injury time and relative perfusion ratio could be used as predictive indicators to evaluate skeletal muscle *** results provide more in vivo details about M2MФin skeletal muscle regeneration and confirm that M2MФcould promote angiogenesis and improve the degree of skeletal muscle repair,which will guide the research and development of M2MФimplantation to improve skeletal muscle regeneration.

关键词： In vivo Short-wave infrared Skeletal muscle Macrophage Regeneration

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可降解共混塑料在海水中的光降解研究

环境科学学报 2023年第7期43卷 81-89页

作者：张静赵艳陈思宝张洪瑜李璇孙翠竹赵莎莎李锋民中国海洋大学环境科学与工程学院近海环境污染控制研究所海洋环境与生态教育部重点实验室青岛266100 威海齐心环保咨询有限公司威海264209 长江设计集团有限公司水利部长江治理与保护重点实验室武汉430010 中国海洋大学三亚海洋研究院三亚572000 青岛海洋科学与技术试点国家实验室海洋生态与环境科学功能实验室青岛266071

可降解共混塑料因价格低廉而得到广泛应用,然而共混塑料在海水中的光降解和微塑料的形成有待深入研究.因此,本文以聚乙烯/碳酸钙(PE/CaCO3)和聚乙烯/热塑性淀粉(PE/TPS)共混塑料为研究对象,聚乙烯(PE)作为对照,通过机械研磨制备微塑料,... 详细信息

可降解共混塑料因价格低廉而得到广泛应用,然而共混塑料在海水中的光降解和微塑料的形成有待深入研究.因此,本文以聚乙烯/碳酸钙(PE/CaCO3)和聚乙烯/热塑性淀粉(PE/TPS)共混塑料为研究对象,聚乙烯(PE)作为对照,通过机械研磨制备微塑料,研究微塑料在天然海水中阳光照射下的光降解.结果表明,相同风化条件下,共混塑料比PE更容易产生小粒径的颗粒.光降解后老化共混塑料表面的碎片、颗粒明显多于PE.光降解后PE的ATR-FTIR和C1s XPS光谱没有明显变化;PE/CaCO3因光氧化形成含氧官能团C—O;PE/TPS的TPS特征峰减弱,表明TPS光降解.结合3种微塑料接触角、表面电势的变化可知,老化共混塑料对亲水性污染物的吸附能力可能比PE更强.综上所述,可降解共混塑料在海洋环境中的光降解程度高于PE,海洋环境风险可能更大,应谨慎推广.

关键词：微塑料可降解塑料共混塑料光降解海洋环境