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Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.t.Jeong S.W.Lee W.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

the superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 K.the microstructural refinement of this alloy was achieved by employing high-ratio differential speed rolling.the best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were obtained.During the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 K.therefore,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and mechanisms.In the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation mechanism.It was concluded that solute drag creep is unlikely to occur.During the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain hardening.Deformation mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Correlation of work function and stacking fault energy through Kelvin probe force microscopy and nanohardness in diluteα-magnesium

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Journal of Magnesium and Alloys 2024年第1期12卷 237-250页

作者： Yigit türe Ali Arslan Kaya hüseyin Aydin Jiang Peng Servet turan Eskisehir technical University Porsuk Vocational SchoolElectronics and Automation DepartmentProgram of MechatronicsEskisehirTurkey Mugla Sitki Kocman University Engineering FacultyMetallurgy and Materials Engineering DepartmentMuglaTurkey hüseying Aydın TUBITAK MRCTurkey Jiang Peng Chongqing UniversityChina Eskisehir technical University Engineering FacultyMaterials Science and Engineering DepartmentEskisehirTurkey

Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba systems.this investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,i.***.the electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the literature.It was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>Mg-Ba.thus,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'level.Nano-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three alloys.Correlation withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of assumptions.As asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental systems.Our investigation has shown that such a qualitative correlation is possible.After all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density distributions.Our study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPFM and nanoindentation.

关键词： Mg alloys Dilute alloys Work function Stacking fault energy Kelvin probe force microscopy Short range order Miedema Nanoindentation Eutectics

Search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 teV using CMS open data

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Chinese Physics C 2024年第4期48卷 6-13页

作者： Y.Mahmoud h.Abdallah M.t.hussein S.Elgammal Centre for theoretical physics The British University in EgyptEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

In this study,we conducted a search for dark matter using a part of the data recorded by the CMS experiment during run-I of the LhC in 2012 with a center of mass energy of 8 teV and an integrated luminosity of 11.6 fb−1.these data were gathered from the CMS open data.Dark matter,in the framework of the simplified model(mono-Z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,Z′.thus,the search was conducted in the dimuon plus large missing transverse momentum channel.One benchmark scenario of mono-Z′,which is known as light vector,was used for interpreting the CMS open data.No evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and Z′at 95%confidence level.

关键词： dark matter large hadron collider CMS open data search for new physics dark fermion

Photoluminescence and ratiometric thermo-response of Eu2+ and Eu3+ in BaAl2B2O7:Eu2+,Eu3+ phosphor materials

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Journal of Rare Earths 2024年第7期42卷 1240-1249页

作者： Ziyao Wang haitao Fu Xiufeng Zhan Bo tong Guofeng Ma h.t.(Bert) hintzen Institute of Innovative Science and technology Shenyang University College of Mechanical Engineering Shenyang University Faculty of Applied Sciences Delft University of Technology

A novel Eu2+-Eu3+co-activated ratiometric thermo-sensitive phosphor was developed and synthesized by solid-state reaction.the valence state of Eu,photoluminescence and thermo-sensitive performance of the phosphor prepared either in ambient air or carbothermally were investigated and discussed.the phosphor shows high sensitivity(Sa=0.0173 K-1,Sr=0.461%/K) and superior signal discriminability(Δv～10380 cm-1).the thermo-sensitive performance is subject to the dual effects of different thermoresponses by Eu2+versus Eu3+combined with energy transfer from Eu2+to Eu3+,so that the sensitivity of the phosphor in the temperature range presents a non-monotonic trend.the development of the BaAl2B2O7:Eu2+,Eu3+phosphor is not only expected to be relevant for application in the field of temperature sensing,but also of reference significance for improving the sensitivity by means of energy transfer between co-activator ions over a wider temperature range of Eu2+-Eu3+co-activated ratiometric thermo-sensitive phosphors.

关键词： Eu2+/Eu3+ Phosphor Photoluminescence Rare earths Ratiometric thermo-response

Phytoconstituents Profiling of Indigenous herbal Drugs and Its in vitro Microbial,in Silico Biological Examination against Severe Acute Respiratory Syndrome Coronavirus 2

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World Journal of traditional Chinese Medicine 2024年第1期10卷 121-136页

作者： t.h.Mohamed Ahadu Shareef MMohamed Divan Masood Irfan Navabshan MSaiyad Musthafa Department of Chemistry The New College(Autonomous)Affiliated to the University of MadrasChennaiTamil NaduIndia School of Computer Applications B.S.Abdur Rahman Crescent Institute of Science and TechnologyChennaiTamil NaduIndia Crescent School of Pharmacy B.S.Abdur Rahman Crescent Institute of Science and TechnologyChennaiTamil NaduIndia Department of Zoology The New College(Autonomous)Affiliated to the University of MadrasChennaiTamil NaduIndia

Background:habb-E-Shifa,hamdard Sualin,and hamdard Joshanda traditional herbal medicines may promote host resistance against infection by bacteria,viruses,and fungi which are easily accessible at inexpensive with no complexity.these herbal medicines are used to cure sore throat,cough,fever,lung cancer,and asthma patients in developing South Asian countries.these traditional herbal medicines acted a crucial role in the prevention and control of coronavirus disease 2019(COVID-19).Aims and Objectives:this research article aimed at conducting phytochemistry,antimicrobial activity,COVID-19 docking and some spectroscopic(Infrared,Ultraviolet,13C-Nuclear Magnetic Resonance(13C-NMR),1h-NMR,and Mass Spectra)characterizations of the polyherbal drugs were carried out.Additionally,In-vitro and In-silico analyses were performed to measure activity against COVID-19.high Performance-Liquid Chromatography(hPLC),Gas Chromatography-Mass Spectrometry(GC-MS),antimicrobial,and docking studies were carried out.the preliminary phytochemical assay and bioactive compounds were screened using hPLC and GC-MS.the study is an attempt to assess the promising effects of selected polyherbal indigenous drugs such as habb-E-Shifa,hamdard Sualin,and hamdard Joshanda phytoconstituents against the severe acute respiratory syndrome coronavirus-2(SARS-Co V-2).Materials and Methods:the extract of the selected polyherbal formulations showed high-to-moderate preventive effects on the growth inhibition in the pathogenic bacterium,namely Streptococcus oralis,Staphylococcus aureus,Propionibacterium acnes,Pseudomonas aeruginosa,Escherichia coli,and Proteus vulgaris,and three fungal Candida albicans,Aspergillus fumigatus,and Aspergillus niger.Further docking study evaluates the pharmacological activity of bioactive chemical compounds with SARS-Co V-2 NSP5(PDB ID:7nxh)and SARS-Co V-2 Omicron spike protein with human angiotensin-converting enzyme 2(ACE-2)(PDB ID:7wk6).Results:In this study,for the first time,we attempted to examine some spectroscopic characteri

关键词： Antimicrobial herbal drug Omicron and coronavirus disease 2019 phytochemicals spectroscopic

In situ tEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10Gd-3Y-1Zn-0.5Zr alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： M.Lv h.L.Ge Q.Q.Jin X.h.Shao Y.t.Zhou B.Zhang X.L.Ma Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China Materials Science and Engineering Research Center Guangxi University of Science and Technology

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10Gd-3Y-1Zn-0.5Zr(GWZ1031K, wt.%)alloy to improve the hardness. the results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250 ℃ is 1.64 GPa, which is approximately 64% higher than that of the samples before being treated. It is mainly attributed to γ' precipitates on the basal plane after irradiation and the high-density nanoscale β' precipitates on the prismatic plane after aging, which should be closely related to the irradiation-induced homogenous clusters. the latter plays a key role in precipitation hardening. this result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation hardening Precipitates In-situ tEM

Soil nutrient stoichiometric ratios and their influencing factors in mountainous areas of the Ili River Valley

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Rao Algorithms-Based Structure Optimization for heterogeneous Wireless Sensor Networks

Zhongshan Daxue Xuebao/Acta Scientiarum Natralium Universitatis Sunyatseni 2024年第3期63卷 60-70页

作者： Yang h. Sun h. tian Z. Liu t. Wu F. Jin X. School of Geography and tourism Xinjiang Normal University Urumqi 830054 China College of Life Science Xinjiang Normal University Urumqi 830054 China

Studying the soil stoichiometric ratios and the influencing factors of different altitude gradients in mountain ecosystems in arid zones is significant in revealing the soil nutrient status and maintaining the sustainable development of mountain ecosystems. In this paper, 13 sample plots were established along the elevation gradient in the mountains of the southern Ili River Valley, and soil in the depth of 0-20 cm was studied to investigate nutrient stoichiometric ratios and their influencing factors. the results showed that: (1) Soil acidity gradually increased with elevation. Organic carbon and total nitrogen contents are significantly higher in the middle and high mountain belts than in the low mountain belts, while total phosphorus and total potassium contents are opposite. (2) Due to altitudinal differences, the carbon-to-nitrogen ratio is significantly higher in the mid-alpine belt than in the low and alpine belts; carbon and phosphorus ratios are significantly higher in the middle and high mountain belts than in the middle and low mountain belts; carbon and potassium ratios are significantly higher in the middle and high mountain belts than in the low mountain belts; nitrogen-phosphorus ratios are higher in the alpine zone, but there is no major difference between the transition zone and the low mountain zone; nitrogen-potassium ratios are much higher in the alpine zone, whereas there is no significant difference between the mid-alpine zone and the transition zone; the differences of phosphorus/potassium ratios between altitudinal gradients are ignorable. (3) the dominant factors affecting the stoichiometric ratios of soil physicochemical indicators are soil organic carbon (62.4%), total phosphorus (15.9%), and total carbon (13.7%); while the major environmental factors are mean annual soil temperature (27.1%), vegetation index (11.2%), elevation (12.3%), and mean annual atmospheric temperature (3.4%). the study showed that the physicochemical indicators have an important influence on the soil stoichiomet

关键词： Ili River valley mountains impact factor soil nutrients stoichiometric ratio

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Computers, Materials & Continua 2024年第1期78卷 873-897页

作者： Shereen K.Refaay Samia A.Ali Moumen t.El-Melegy Louai A.Maghrabi hamdy h.El-Sayed Faculty of Computers and Artificial Intelligence Sohag UniversitySohag82524Egypt Faculty of Engineering Assiut UniversityAssiut711745Egypt College of Engineering University of Business and TechnologyJeddah23411Saudi Arabia

the structural optimization of wireless sensor networks is a critical issue because it impacts energy consumption and hence the network’s lifetime.Many studies have been conducted for homogeneous networks,but few have been performed for heterogeneouswireless sensor networks.this paper utilizes Rao algorithms to optimize the structure of heterogeneous wireless sensor networks according to node locations and their initial energies.the proposed algorithms lack algorithm-specific parameters and metaphorical connotations.the proposed algorithms examine the search space based on the relations of the population with the best,worst,and randomly assigned solutions.the proposed algorithms can be evaluated using any routing protocol,however,we have chosen the well-known routing protocols in the literature:Low Energy Adaptive Clustering hierarchy(LEACh),Power-Efficient Gathering in Sensor Information Systems(PEAGSIS),Partitioned-based Energy-efficient LEACh(PE-LEACh),and the Power-Efficient Gathering in Sensor Information Systems Neural Network(PEAGSIS-NN)recent routing protocol.We compare our optimized method with the Jaya,the Particle Swarm Optimization-based Energy Efficient Clustering(PSO-EEC)protocol,and the hybrid harmony Search Algorithm and PSO(hSA-PSO)algorithms.the efficiencies of our proposed algorithms are evaluated by conducting experiments in terms of the network lifetime(first dead node,half dead nodes,and last dead node),energy consumption,packets to cluster head,and packets to the base station.the experimental results were compared with those obtained using the Jaya optimization algorithm.the proposed algorithms exhibited the best performance.the proposed approach successfully prolongs the network lifetime by 71% for the PEAGSIS protocol,51% for the LEACh protocol,10% for the PE-LEACh protocol,and 73% for the PEGSIS-NN protocol;Moreover,it enhances other criteria such as energy conservation,fitness convergence,packets to cluster head,and packets to the base station.

关键词： Wireless sensor networks Rao algorithms optimization LEACh PEAGSIS

Advancing Wound Filling Extraction on 3D Faces:An Auto-Segmentation and Wound Face Regeneration Approach

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2197-2214页

作者： Duong Q.Nguyen thinh D.Le Phuong D.Nguyen Nga t.K.Le h.Nguyen-Xuan Department of Mathematics and Statistics Quy Nhon UniversityQuy Nhon City55100Viet Nam Applied Research Institute for Science and technology Quy Nhon UniversityQuy Nhon City55100Viet Nam CIRtECh Institute HUTECH UniversityHo Chi Minh City72308Viet Nam

Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical applications.In this paper,we propose an efficient approach for automating 3D facial wound segmentation using a two-stream graph convolutional network.Our method leverages the Cir3D-FaIR dataset and addresses the challenge of data imbalance through extensive experimentation with different loss functions.to achieve accurate segmentation,we conducted thorough experiments and selected a high-performing model from the trainedmodels.the selectedmodel demonstrates exceptional segmentation performance for complex 3D facial wounds.Furthermore,based on the segmentation model,we propose an improved approach for extracting 3D facial wound fillers and compare it to the results of the previous study.Our method achieved a remarkable accuracy of 0.9999993% on the test suite,surpassing the performance of the previous method.From this result,we use 3D printing technology to illustrate the shape of the wound filling.the outcomes of this study have significant implications for physicians involved in preoperative planning and intervention design.By automating facial wound segmentation and improving the accuracy ofwound-filling extraction,our approach can assist in carefully assessing and optimizing interventions,leading to enhanced patient outcomes.Additionally,it contributes to advancing facial reconstruction techniques by utilizing machine learning and 3D bioprinting for printing skin tissue implants.Our source code is available at https://***/SIMOGroup/WoundFilling3D.

关键词： 3D printing technology face reconstruction 3D segmentation 3D printed model