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Theoretical Modeling and Surface Roughness Prediction of Microtextured Surfaces in Ultrasonic Vibration-Assisted Milling

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 163-183页

作者： Chenbing Ni Junjie Zhu Youqiang Wang Dejian Liu Xuezhao Wang lida Zhu School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266525China School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China

Textured surfaces with certain micro/nano structures have been proven to possess some advanced functions,such as reducing friction,improving wear and increasing *** prediction of micro/nano surface textures is of great significance for the design,fabrication and application of functional textured *** this paper,based on the kinematic analysis of cutter teeth,the discretization of ultrasonic machining process,transformation method of coordinate systems and the cubic spline data interpolation,an integrated theoretical model was established to characterize the distribution and geometric features of micro textures on the surfaces machined by different types of ultrasonic vibration-assisted milling(UVAM).Based on the theoretical model,the effect of key process parameters(vibration directions,vibration dimensions,cutting parameters and vibration parameters)on tool trajectories and microtextured surface morphology in UVAM is ***,the effect of phase difference on the elliptical shape in 2D/3D ultrasonic elliptical vibration-assisted milling(UEVAM)was *** to conventional numerical models,the method of the cubic spline data interpolation is applied to the simulation of microtextured surface morphology in UVAM,which is more suitable for characterizing the morphological features of microtextured surfaces than traditional methods due to the presence of numerous micro *** prediction of surface roughness indicates that the magnitude of ultrasonic amplitude in z-direction should be strictly limited in 1D rotary UVAM,2D and 3D UEVAM due to the unfavorable effect of axial ultrasonic vibration on the surface *** study can provide theoretical guidance for the design and fabrication of microtextured surfaces in UVAM.

关键词： Theoretical modeling Microtextured surface Ultrasonic vibration-assisted milling Cubic spline interpolation Surface roughness

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Flame Retardant Material Based on Cellulose Scaffold Mineralized by Calcium Carbonate

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Journal of Renewable Materials 2024年第1期12卷 89-102页

作者： Jinshuo Wang lida Xing Fulong Zhang Chuanfu Liu State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510640China

Wood-based functional materials have developed *** the flammability significantly limits its further *** improve the flame retardancy,the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold,and then alternately immersed in CaCl_(2) ethanol solution and NaHCO3 aqueous solution under *** high porosity and wettability resulting from delignification benefited the following mineralization process,changing the thermal properties of balsa wood *** organic-inorganic wood composite showed abundant CaCO_(3) spherical particles under scanning electron *** peak of the heat release rate of delignified balsa-CaCO_(3) was reduced by 33%compared to the native balsa,according to the cone calorimetric *** flame test demonstrated that the mineralized wood was flame retardant and ***,the mineralized wood also displayed lower thermal *** study developed a feasible way to fabricate a lightweight,fire-retardant,self-extinguishing,and heat-insulating wood composite,providing a promising route for the valuable application of cellulosic biomass.

关键词： Cellulose scaffold delignification CaCO_(3) mineralization fire retardancy

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Printability disparities in heterogeneous material combinations via laser directed energy deposition:a comparative study

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International Journal of Extreme Manufacturing 2024年第2期6卷 389-405页

作者： Jinsheng Ning lida Zhu Shuhao Wang Zhichao Yang Peihua Xu Pengsheng Xue Hao Lu Miao Yu Yunhang Zhao Jiachen Li Susmita Bose Amit Bandyopadhyay School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819People’s Republic of China School of Machinery and Automation Wuhan University of Science and TechnologyWuhan 430081People’s Republic of China School of Mechanical Engineering Xi’an University of Science and TechnologyXi’an 710054People’s Republic of China Beijing Institute of Space Launch Technology Beijing 100076People’s Republic of China W.M.Keck Biomedical Materials Research Lab School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America

Additive manufacturing provides achievability for the fabrication of bimetallic and multi-material structures;however,the material compatibility and bondability directly affect the parts’formability and final *** is essential to understand the underlying printability of different material combinations based on an adapted ***,the printability disparities of two common and attractive material combinations(nickel-and iron-based alloys)are evaluated at the macro and micro levels via laser directed energy deposition(DED).The deposition processes were captured using in situ high-speed imaging,and the dissimilarities in melt pool features and track morphology were quantitatively investigated within specific process ***,the microstructure diversity of the tracks and blocks processed with varied material pairs was comparatively elaborated and,complemented with the informative multi-physics modeling,the presented non-uniformity in mechanical properties(microhardness)among the heterogeneous material pairs was *** differences in melt flow induced by the unlike thermophysical properties of the material pairs and the resulting element intermixing and localized re-alloying during solidification dominate the presented dissimilarity in printability among the material *** work provides an in-depth understanding of the phenomenological differences in the deposition of dissimilar materials and aims to guide more reliable DED forming of bimetallic parts.

关键词： directed energy deposition printability microstructure microhardness bimetallic parts

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An Aerial–Wall Robotic Insect That Can Land, Climb, and Take Off from Vertical Surfaces

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Research 2024年第1期2023卷 149-163页

作者： Qian Li Haoze Li Huan Shen Yangguang Yu Haoran He Xincheng Feng Yi Sun Zhiyuan Mao Guangming Chen Zongjun Tian lida Shen Xiangming Zheng Aihong Ji College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjingChina College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjingChina State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjingChina

Insects that can perform flapping-wing flight,climb on a wall,and switch smoothly between the 2 locomotion regimes provide us with excellent biomimetic ***,very few biomimetic robots can perform complex locomotion tasks that combine the 2 abilities of climbing and ***,we describe an aerial–wall amphibious robot that is self-contained for flying and climbing,and that can seamlessly move between the air and *** adopts a flapping/rotor hybrid power layout,which realizes not only efficient and controllable flight in the air but also attachment to,and climbing on,the vertical wall through a synergistic combination of the aerodynamic negative pressure adsorption of the rotor power and a climbing mechanism with bionic adhesion *** the basis of the attachment mechanism of insect foot pads,the prepared biomimetic adhesive materials of the robot can be applied to various types of wall surfaces to achieve stable *** longitudinal axis layout design of the rotor dynamics and control strategy realize a unique cross-domain movement during the flying–climbing transition,which has important implications in understanding the takeoff and landing of ***,it enables the robot to cross the air–wall boundary in 0.4 s(landing),and cross the wall–air boundary in 0.7 s(taking off).The aerial–wall amphibious robot expands the working space of traditional flying and climbing robots,which can pave the way for future robots that can perform autonomous visual monitoring,human search and rescue,and tracking tasks in complex air–wall environments.

关键词： robot smoothly Vertical

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阿科松博大坝与加纳国家建构

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西亚非洲 2024年第4期 140-158,164页

作者：冯理达中国社会科学院世界历史研究所

独立初期,加纳的国家建构面临政治和经济上的困境,建设阿科松博大坝为破解这一困境提供了机遇。大坝为该国初兴的工业生产提供了水电能源,同时提高了居民电力覆盖率;部分电力资源还出口到周边国家,使加纳迈出了摆脱单一经济结构和外部... 详细信息

独立初期,加纳的国家建构面临政治和经济上的困境,建设阿科松博大坝为破解这一困境提供了机遇。大坝为该国初兴的工业生产提供了水电能源,同时提高了居民电力覆盖率;部分电力资源还出口到周边国家,使加纳迈出了摆脱单一经济结构和外部依赖的重要一步;大坝本身的形象,经过加纳政府的改造,也从殖民主义项目成为国家的新象征,推动了加纳国民建立起对新生国家的认同。此外,以大坝建设为契机,恩克鲁玛通过官僚机构和专家团队对长期处于边缘地位的沃尔特河盆地区域进行了改造,使该区域被纳入国家行政管理之中,加强了居民对国家的依赖以及区域同国家政治经济的融合,提高了国家治理能力。虽然阿科松博大坝项目在推动国家建构方面的效果受到了国内、国际政治环境以及大坝本身设计、管理等多方因素制约,但大坝对加纳国家建构仍起到了不可替代的作用。

关键词：国家建构加纳阿科松博大坝恩克鲁玛

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Verification and Validation of High-Resolution Inviscid and Viscous Conical Nozzle Flows

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Communications on Applied Mathematics and Computation 2024年第1期6卷 533-549页

作者： Luciano K.Araki Rafael B.de R.borges Nicholas Dicati P.da Silva Chi-Wang Shu Department of Mechanical Engineering Federal University of ParanáCuritiba81531-980ParanáBrazil Mathematics and Statistics Institute Rio de Janeiro State UniversityRio de Janeiro20550-900Rio de JaneiroBrazil Department of Mechanical Engineering State University of MaringáMaringá87020-900ParanáBrazil Division of Applied Mathematics Brown UniversityProvidenceRI02912USA

Capturing elaborated flow structures and phenomena is required for well-solved numerical *** finite difference methods allow simple discretization of mesh and model ***,they need simpler meshes,e.g.,*** inverse Lax-Wendroff(ILW)procedure can handle complex geometries for rectangular ***-resolution and high-order methods can capture elaborated flow structures and *** also have strong mathematical and physical backgrounds,such as positivity-preserving,jump conditions,and wave propagation *** perceive an effort toward direct numerical simulation,for instance,regarding weighted essentially non-oscillatory(WENO)***,we propose to solve a challenging engineering application without turbulence *** aim to verify and validate recent high-resolution and high-order *** check the solver accuracy,we solved vortex and Couette ***,we solved inviscid and viscous nozzle flows for a conical *** employed the finite difference method,positivity-preserving Lax-Friedrichs splitting,high-resolution viscous terms discretization,fifth-order multi-resolution WENO,ILW,and third-order strong stability preserving *** showed the solver is high-order and captured elaborated flow structures and *** can see oblique shocks in both nozzle *** the viscous flow,we also captured a free-shock separation,recirculation,entrainment region,Mach disk,and the diamond-shaped pattern of nozzle flows.

关键词： High-resolution Compressible Navier-Stokes Free-shock separation Nozzle flow

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Novel Brick Technology for Carbon Reduction Footprint in Steel Shop Linings

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China's Refractories 2024年第2期33卷 16-21页

作者： Carlos PAGLIOSA Leandro ROCHA Marcelo borges Celio CAVALCANTE RHI MAGNESITA Contagem32210-000Brazil

Clean steel encompasses a multitude of concepts that are based on fulfilling customer requirements and can be produced in many ways depending on the existing equipment and detailed customer demands.A common feature of all clean steel production is tight process control along with continuous *** meet an increasing demand for cold-rolled(CR)steel sheets of improved mechanical properties,and to cope with the change of the annealing process from a batch-type to a continuous process,it is necessary to establish a technique for making ultralow carbon(ULC)steel with a C-concentration lower than 20 ppm for the steelmaking process associated with a major challenge to guarantee the competitiveness with observance of environmental *** ladle lining plays an important role on the energy consumption during the production and the refractory lining design contributes to minimize thermal bath loss,carbon pick up and shell temperature.A new generation of unfired zero carbon refractories was developed with two specific approaches:(1)replacement of firing bricks reducing CO_(2) footprint and(2)replacement of carbon containing with performance *** can be used in working and safety linings with a unique microstructure with better heat scattering and similar thermomechanical *** work presents customers’performance compared to traditional products highlighting energy savings.

关键词： steel ladle zero carbon energy saving

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Efficacy and safety of bamlanivimab in patients with COVID-19:A systematic review and meta-analysis

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World Journal of Virology 2024年第1期13卷 120-132页

作者： Behnam Amani lida Khodavirdilou Kourosh Rajabkhah Vida Kardan Moghaddam Arash Akbarzadeh Bahman Amani Department of Health Management and Economics School of Public HealthTehran University of Medical SciencesTehran ***Iran Department of Pharmaceutical Sciences Jerry H.Hodge School of PharmacyTexas Tech University Health Sciences CenterAmarilloTX 79106United States Deputy of Research and Technology Tehran University of Medical SciencesTehran ***Iran School of Medicine and Dentistry Griffith UniversityQueenslandBrisbane 4222Australia Department of Epidemiology and Biostatistics School of Public HealthTehran University of Medical SciencesTehran ***Iran

BACKGROUND Monoclonal antibodies(mAbs)have shown clinical benefits against coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Several studies have reported the use of bamlanivimab as a promising treatment option for *** To synthesize the latest evidence for the efficacy and safety of bamlanivimab alone in the treatment of adult patients with *** A literature search was conducted in PubMed,Cochrane Library,Web of Science,medRxiv,and Google Scholar using“SARS-CoV-2”,“COVID-19”,“LY-CoV555”,and“Bamlanivimab”keywords up to January 25,*** quality of included studies was assessed using the Cochrane bias *** Comprehensive Meta-Analysis software version 3.0 was used to analyze the *** A total of 30 studies involving 47368 patients were included.A significant difference was observed between the bamlanivimab and standard of care/placebo groups in terms of mortality rate[risk ratio(RR)=50,95%confidence interval(CI):0.36-0.70],hospitalization rate(RR=0.51;95%CI:0.39-0.68),and emergency department(ED)visits(RR=0.69;95%CI:0.47-0.99);while the two groups exhibited no significant difference in terms of intensive care unit(ICU)admission(P>0.05).Compared to other mAbs,bamlanivimab was associated with a higher rate of hospitalization(RR=1.44;95%CI:1.07-1.94).However,no significant difference was detected between the bamlanivimab and other mAbs groups in terms of mortality rate,ICU admission,and ED(P>0.05).The incidence of any adverse events was similar between the bamlanivimab and control groups(P>0.05).CONCLUSION Although the results suggest the efficacy and safety of bamlanivimab in COVID-19 patients,further research is required to confirm the efficacy of this drug for the current circulating SARS-CoV-2 variants.

关键词： SARS-CoV-2 COVID-19 Bamlanivimab Monoclonal antibody Meta-analysis

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Energy Blockchain in Smart Communities: Towards Affordable Clean Energy Supply for the Built Environment

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Energy Engineering 2024年第8期121卷 2313-2330页

作者： Mingguan Zhao lida Liao Penglong Liang Meng Li Xinsheng Dong Yang Yang Hongxia Wang Zhenhao Zhang Electric Power Research Institute State Grid Xinjiang Electric Power Co.Ltd.Urumqi830013China School of Energy and Power Engineering Changsha University of Science&TechnologyChangsha410114China Kumul Power Supply Company State Grid Xinjiang Electric Power Co.Ltd.Urumqi830013China Xinjiang Key Laboratory of Extreme Environment Operation and Detection Technology of Power Transmission&Transformation Equipment Urumqi830013China

The rapid growth of distributed renewable energy penetration is promoting the evolution of the energy system toward decentralization and decentralized and digitized smart *** study was based on energy blockchain,and developed a dual-biding mechanism based on the real-time energy surplus and demand in the local smart grid,which is expected to enable reliable,affordable,and clean energy supply in smart *** the proposed system,economic benefits could be achieved by replacing fossil-fuel-based electricity with the high penetration of affordable solar PV *** reduction of energy surplus realized by distributed energy production and P2P energy trading,within the smart grid results in less transmission loss and lower requirements for costly upgrading of existing *** adopting energy blockchain and smart contract technologies,energy secure trading with a low risk of privacy leakage could be *** prototype is examined through a case study,and the feasibility and efficiency of the proposed mechanism are further validated by scenario analysis.

关键词： Solar PV smart community energy blockchain P2P energy trading smart grid affordable energy supply

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基于声发射Ib值分析的渗铝321钢损伤特性研究

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仪器仪表学报 2024年第1期45卷 211-220页

作者：廖力达向旭宏舒王咏黄斌罗晓长沙理工大学能源与动力工程学院长沙410114 UniSA STEM University of South AustraliaAdelaideSA 5095Australia

太阳能热发电换热管主要材料渗铝321钢的损伤会导致换热管的寿命缩短甚至断裂,因此必须进行损伤检测。采用声发射方法对渗铝321钢的损伤特性进行分析,实现对换热管性能的在线动态监测。通过采用声发射Ib值特征来表征渗铝321钢的损伤程度... 详细信息

太阳能热发电换热管主要材料渗铝321钢的损伤会导致换热管的寿命缩短甚至断裂,因此必须进行损伤检测。采用声发射方法对渗铝321钢的损伤特性进行分析,实现对换热管性能的在线动态监测。通过采用声发射Ib值特征来表征渗铝321钢的损伤程度,并运用自组织映射(SOM)神经网络算法进行声发射特征参数聚类,以分析材料的损伤模式。结果表明,力学塑性阶段的声发射事件数量剧增,能量和振铃计数的峰值标志着试件的断裂。此外,在试件失效前,Ib值显著降低且密度变密集,表明Ib值的变化特征可以作为材料临界失效的预警信号。通过SOM算法对特征参数进行聚类分析得到4个簇及其对应的特征频率,并使用扫描电子显微镜(SEM)观察试件的断口形貌,得出4个簇分别对应于孔洞生长与汇合、微裂纹成核、宏观裂纹扩展和纤维状断裂4类损伤模式。这项研究旨在探索金属管材的损伤演化行为,并为管材的损伤分析和健康监测提供依据。

关键词：渗铝321钢声发射 Ib值 SOM神经网络损伤演化

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