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Tribological Performance of Different Concentrations of Al_(2)O_(3)Nanofluids on Minimum Quantity Lubrication Milling

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 67-78页

作者： Xiufang Bai Juan jiang Changhe li Lan Dong Hafiz Muhammad Ali Shubham Sharma School of Mechanical and Automotive Engineering Qingdao University of TechnologyQingdao 266520China School of Mechanical and Electrical Engineering Qingdao Binhai UniversityQingdao 266555China Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Department of Mechanical Engineering IK Gujral Punjab Technical UniversityMain Campus-KapurthalaJalandhar 144603India

Nanofluid minimum quantity lubrication(NMQL)is a green processing *** oil is suitable as base oil because of excellent lubrication performance,low freezing temperature,and high ***_(2)O_(3)nanoparticles improve not only the heat transfer capacity but also the lubrication *** physical and chemical proper-ties of nanofluid change when Al_(2)O_(3)nanoparticles are ***,the effects of the concentration of nanofluid on lubrication performance remain ***,the mechanisms of interaction between Al_(2)O_(3)nanoparti-cles and cottonseed oil are *** this research,nanofluid is prepared by adding different mass concentrations of Al_(2)O_(3)nanoparticles(0,0.2%,0.5%,1%,1.5%,and 2%wt)to cottonseed oil during minimum quantity lubrication(MQL)milling 45 *** tribological properties of nanofluid with different concentrations at the tool/workpiece interface are studied through macro-evaluation parameters(milling force,specific energy)and micro-evaluation parameters(surface roughness,micro morphology,contact angle).The result show that the specific energy is at the minimum(114 J/mm^(3)),and the roughness value is the lowest(1.63μm)when the concentration is 0.5 wt%.The surfaces of the chip and workpiece are the smoothest,and the contact angle is the lowest,indicating that the tribological proper-ties are the best under 0.5 wt%.This research investigates the intercoupling mechanisms of Al_(2)O_(3)nanoparticles and cottonseed base oil,and acquires the optimal Al_(2)O_(3)nanofluid concentration to receive satisfactory tribological properties.

关键词： Milling Al_(2)O_(3)nanofluid Minimum quantity lubrication(MQL) Surface micromorphology

Slag Melting Characteristic of Slag Forming and Slag Splashing for BOF Less Slag Smelting

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Journal of Iron and Steel Research International 2012年第7期19卷 20-25,32页

作者： WU Wei MENG hua-dong liU liu YUAN Tian-xiang BAI Yan-jiang YAN Zhan-hui Metallurgical Technology Research Department Central Iron and Steel Research InstituteBeijing 100081China Steelmaking Works Shougang Jingtang Iron and Steel Co LtdTangshan 063200HebeiChina

The slag melting characteristic of slag forming and slag splashing for 300 t BOF less slag process is researched by combining the methods of the slag chemical composition, the melting point determination and the petrographic analysis. The results show that the melting point of final slag for less slag smelting is 20 ~C lower than that for conventional smelting. According to results of the petrographic analysis, the C3S （3CaO ~ SiO2） and C2S （2CaO · SiO2） content for less slag smelting are lower than those for conventional smelting, while the RO （FeO, MgO, MnO, etc） phase and C4AF （4CaO · Al2O3· Fe2O3） phase are higher than those for conventional smelting. According to results of the chemical analysis, the （CaO） content and slag basicity for less slag smelting are higher than those for conventional smelting, while （FeO） and （MgO） content in slag for less slag smelting are almost equal to those for conventional smelting. The reason why slag melting point for less slag smelting is lower than that for con- ventional smelting is that the quantity of added fluorite for less slag smelting is more than that for conventional smel- ting. According tO the analysis results the slag melting point is determined by the C3S, C2S, RO phase and C4AF content. According to the results of slag melting characteristic before and after slag splashing for less slag smelting, the present adjusting slag process has little effect. It is important to adjust the composition of BOF final slag. The （FeO） content in slag is to be reduced at the slag splashing and adjusting slag process for less slag smelting.

关键词： less slag smelting melting point determination petrographic analysis slag forming process slag splashing

Toward understanding the microstructure characteristics,phase selection and magnetic properties of laser additive manufactured Nd-Fe-B permanent magnets

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International Journal of Extreme Manufacturing 2024年第1期6卷 277-294页

作者： Bo Yao Nan Kang Xiangyu li Dou li Mohamed EL Mansori Jing Chen Haiou Yang hua Tan Xin lin State Key Laboratory of Solidiffcation Processing Northwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Arts et Metiers Institute of Technology MSMPHESAM UniversitéF-51006 Chˆalons-en-ChampagneFrance Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843United States of America

Nd-Fe-B permanent magnets play a crucial role in energy conversion and electronic *** essential magnetic properties of Nd-Fe-B magnets,particularly coercivity and remanent magnetization,are significantly infuenced by the phase characteristics and *** this work,Nd-Fe-B magnets were manufactured using vacuum induction melting(VIM),laser directed energy deposition(LDED)and laser powder bed fusion(LPBF)*** evolution and phase selection of Nd-Fe-B magnets were then clarified in *** results indicated that the solidification velocity(V)and cooling rate(R)are key factors in the phase *** terms of the VIM-casting Nd-Fe-B magnet,a large volume fraction of theα-Fe soft magnetic phase(39.7 vol.%)and Nd2Fe17Bxmetastable phase(34.7 vol.%)areformed due to the low R(2.3×10-1?C s-1),whereas only a minor fraction of the Nd2Fe14B hard magnetic phase(5.15 vol.%)is *** the LDED-processed Nd-Fe-B deposit,although the Nd2Fe14B hard magnetic phase also had a low value(3.4 vol.%)as the values of V(10-2m s-1)and R(1.45×106?C s-1)in the LPBF process resulted in the substantial formation of the Nd2Fe14B hard magnetic phase(55.8 vol.%)directly from the liquid,while theα-Fe soft magnetic phase and Nd2Fe17Bxmetastable phase precipitation are suppressed in the LPBF-processed Nd-Fe-B ***,crystallographic texture analysis reveals that the LPBF-processedNd-Fe-B magnets exhibit isotropic magnetic ***,the LPBF-processed Nd-Fe-B deposit,exhibiting a coercivity of 656 k A m-1,remanence of 0.79 T and maximum energy product of 71.5 k J m-3,achieved an acceptable magnetic perfor

关键词： laser additive manufacturing(LAM) Nd-Fe-B permanent magnets numerical simulation microstructure magnetic properties

A Computer-Aided System for Ocular Myasthenia Gravis Diagnosis

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Tsinghua Science and Technology 2021年第5期26卷 749-758页

作者： Guanjie liu Yan Wei Yunshen Xie Jianqiang li liyan Qiao Ji-jiang Yang the Faculty of Information Technology Beijing University of TechnologyBeijing 100124China the Neurology Department The Second Affiliated Hospital of Tsinghua UniversityBeijing 100040China the Department of Automation Tsinghua UniversityBeijing 100084China

The current mode of clinical aided diagnosis of Ocular Myasthenia Gravis(OMG)is time-consuming and laborious,and it lacks quantitative *** aided diagnostic system for OMG is proposed to solve this *** values calculated by the system include three clinical indicators:eyelid distance,sclera distance,and palpebra superior fatigability test *** the first two indicators,the semantic segmentation method was used to extract the pathological features of the patient's eye image and a semantic segmentation model was *** patient eye image was divided into three regions:iris,sclera,and *** indicators were calculated based on the position of the pixels in the segmentation *** the last indicator,a calculation method based on the Eyelid Aspect Ratio(EAR)is proposed;this method can better reflect the change of eyelid distance over *** system was evaluated based on the collected patient *** results show that the segmentation model achieves a mean Intersection-Over-Union(mIoU)value of 86.05%.The paired-sample T-test was used to compare the results obtained by the system and doctors,and the p values were all greater than ***,the system can reduce the cost of clinical diagnosis and has high application value.

关键词： ocular myasthenia gravis computer-aided system semantic segmentation eyelid aspect ratio

Numerical research on airfoil transition delay by alternative current dielectric barrier discharge actuation

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Chinese Journal of Aeronautics 2021年第2期34卷 441-453页

作者： Bei liU hua liANG Zhonghua HAN Yinghong li Fei liU jiangbo CHI Zhiwen DING Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXian 710038China Institute of Aerodynamic and Multidisciplinary Design Optimization National Key Laboratory of Science and Technology on Aerodynamic Design and ResearchSchool of AeronauticsNorthwestern Poly technical UniversityXi'an 710072China

A Dielectric Barrier Discharge(DBD) plasma actuator can create a body force which locally accelerates the base flow leading to an attenuation of broadband disturbance to delay the transition. In this study, numerical simulation on an NLF0416 airfoil is conducted to investigate transition delay and drag reduction by a DBD plasma actuator. To simulate plasma’s effect more accurately, boundary-layer data is acquired from Reynolds Averaged Navier Stocks(RANS) equations instead of laminar boundary layer equations, although RANS equations need a much finer boundary-layer grid, and the linear stability analysis method is used to analyze the boundary layer and get the transition point. In this study, the influences of different actuation intensities and positions are investigated, and results show that if the actuation intensity is stronger and the actuation position is closer to the base transition point, more drag reduction can be obtained. However, the efficiency of plasma transition delay is really low. For example, when the actuation voltage is 16 k V,the actuation frequency is 1 k Hz, and the main Mach number is 0.1, the saved power due to drag reduction is about 5.09 W, but the power consumed is about 32.61 W, and the efficiency is just15.6%.

关键词： Dielectric Barrier Discharge(DBD) Efficiency analysis linear stability analysis Plasma flow control Plasma transition delay

Parameterized Post-Post-Newtonian light Propagation in the Field of One Spherically-Symmetric Body

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Communications in Theoretical Physics 2019年第12期71卷 1455-1460页

作者： Xiao-Yan Zhu Bo Yang Chun-hua jiang Wen-Bin lin School of Mathematics and Physics University of South ChinaHengyang 421001China School of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610031China

We derive a more generally parameterized post-post-Newtonian solution for the light propagation in the gravitational field of one spherically-symmetric *** on the solution for the light velocity,we give the formula of the light deflection when both the emitter and receiver are located in the regions far away from the body,which is the most important scenario in the real *** results can be applied to more metric theories of gravitation.

关键词： PPN spherically-symmetric metric light propagation light deflection

Carrimycin inhibits coronavirus replication by decreasing the efficiency of programmed–1 ribosomal frameshifting through directly binding to the RNA pseudoknot of viral frameshift-stimulatory element

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Acta Pharmaceutica Sinica B 2024年第6期14卷 2567-2580页

作者： Hongying li Jianrui li Jiayu li Hu li Xuekai Wang Jing jiang Lei Lei Han Sun Mei Tang Biao Dong Weiqing He Shuyi Si Bin Hong Yinghong li Danqing Song Zonggen Peng Yongsheng Che Jian-Dong jiang CAMS Key Laboratory of Antiviral Drug Research Institute of Medicinal BiotechnologyChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China Beijing Key Laboratory of Antimicrobial Agents Institute of Medicinal BiotechnologyChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China Key Laboratory of Biotechnology of Antibiotics the National Health and Family Planning Commission(NHFPC)Institute of Medicinal BiotechnologyChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China

The pandemic of SARS-CoV-2 worldwide with successive emerging variants urgently calls for small-molecule oral drugs with broad-spectrum antiviral ***,we show that carrimycin,a new macrolide antibiotic in the clinic and an antiviral candidate for SARS-CoV-2 in phase III trials,decreases the efficiency of programmed–1 ribosomal frameshifting of coronaviruses and thus impedes viral replication in a broad-spectrum *** binds directly to the coronaviral frameshift-stimulatory element(FSE)RNA pseudoknot,interrupting the viral protein translation switch from ORF1a to ORF1b and thereby reducing the level of the core components of the viral replication and transcription *** carrimycin with known viral replicase inhibitors yielded a synergistic inhibitory effect on *** the FSE mechanism is essential in all coronaviruses,carrimycin could be a new broad-spectrum antiviral drug for human coronaviruses by directly targeting the conserved coronaviral FSE *** finding may open a new direction in antiviral drug discovery for coronavirus variants.

关键词： Carrimycin Coronavirus Broad-spectrum antiviral activity Programmed-1 ribosomal frameshifting RNA pseudoknot Antiviral agent RNA target Synergistic inhibitory effect

Cultivation of uncultured marine microorganisms

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Marine life Science & Technology 2021年第2期3卷 117-120页

作者： Fengping Wang Meng li li huang Xiao-hua Zhang State Key Laboratory of Microbial Metabolism School of OceanographySchool of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai200240China Shenzhen Key Laboratory of Marine Microbiome Engineering Institute for Advanced StudyShenzhen UniversityShenzhen518060China Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of SciencesBeijing100101China College of Marine life Sciences and Institute of Evolution and Marine Biodiversity Ocean University of ChinaQingdao266003China

Microorganisms(both pro-and eukaryotes)occur in all marine environments with an estimated abundance of 10^(3)–10^(10)cells/cm^(3)in sediments and 10^(4)–10^(7)cells/ml in seawater;in these habitats they play key roles in marine biogeochemical cycles(Overmann and Lepleux 2016).Surveys employing molecular marker-based high-throughput sequencing and sophisticated metagenomic approaches have revealed the vast diversity of microorganisms in marine environments and have substantially expanded the tree of life(Castelle and Banfield 2018;Hug et al.2016;Nayfach et al.2020).However,many of the novel lineages have no cultured *** fact,most(>99%)of the marine microorganisms have not been cultured under laboratory conditions(Hofer 2018;Jiao et al.2020)and are seen as“microbial dark matter”(Lok 2015).Although culture-independent approaches have enabled elucidation of the marine microbial assemblies and their metabolic potentials,pure cultures remain needed for microbiological *** example,pure cultures are critical for an understanding of the morphology,ecophysiology,and biochemistry of these organisms,which are key to recognizing their functions in complex environmental ***,cultures are needed for discovering new bioactive substances,such as anti-tumor bioactive substances,new antibiotics and other secondary metabolites(Ding et al.2020).

关键词： marine environments expanded

Adsorption of Re(Ⅶ) by coated solvent-impregnated resins containing Alamine 304-1 from sulfuric acid solutions

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Rare Metals 2020年第8期39卷 942-950页

作者： Xue-Yi Guo Zhong-Chen Ma Gao-Wei liu Dong li Qing-hua Tian School of Metallurgy and Environment Central South UniversityChangsha 410083China National and Regional Joint Engineering Research Center of Nonferrous Metal Resource Recycling Changsha 410083China

The recovery of rhenium from waste acid is an urgent issue due to low rhenium concentration and high sulfuric *** solve the problem,novel coated solvent-impregnated resins consisting of inert resins LS-300,Alamine 304-1 and the PVA film(304-CSIRs)were prepared for the separation of Re(Ⅶ)from high sulfuric acid *** was shown that the PVA film coated completely on the surfaces of LS-300 resins with a thickness of 5μm,and Alamine 304-1 distributed completely inside the porous of LS-300 *** adsorption fitted well with Langmuir model and pseudo-second-order model with the saturation adsorption capacity of139.40 mg·*** maximum separation factor of Re(Ⅶ)versus Cu(Ⅱ)was up to 483,and 304-CSIRs had no adsorptions for As(V).The adsorption capacity of Re(Ⅶ)onto 304-CSIRs maintained in 97.79%at the fifth adsorption-desorption cycle.99.87%of rhenium was recovered by 304-CSIRs from waste acid generated from a copper smelter.

关键词： Adsorption Re(Ⅶ) Coated Solvent-impregnated resins Alamine 304-1